1 // symtab.cc -- the gold symbol table
3 // Copyright 2006, 2007, 2008, 2009, 2010, 2011 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"
43 #include "incremental.h"
50 // Initialize fields in Symbol. This initializes everything except u_
54 Symbol::init_fields(const char* name, const char* version,
55 elfcpp::STT type, elfcpp::STB binding,
56 elfcpp::STV visibility, unsigned char nonvis)
59 this->version_ = version;
60 this->symtab_index_ = 0;
61 this->dynsym_index_ = 0;
62 this->got_offsets_.init();
63 this->plt_offset_ = -1U;
65 this->binding_ = binding;
66 this->visibility_ = visibility;
67 this->nonvis_ = nonvis;
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_warning_ = false;
75 this->is_copied_from_dynobj_ = false;
76 this->is_forced_local_ = false;
77 this->is_ordinary_shndx_ = false;
78 this->in_real_elf_ = false;
79 this->is_defined_in_discarded_section_ = false;
80 this->undef_binding_set_ = false;
81 this->undef_binding_weak_ = false;
82 this->is_predefined_ = false;
85 // Return the demangled version of the symbol's name, but only
86 // if the --demangle flag was set.
89 demangle(const char* name)
91 if (!parameters->options().do_demangle())
94 // cplus_demangle allocates memory for the result it returns,
95 // and returns NULL if the name is already demangled.
96 char* demangled_name = cplus_demangle(name, DMGL_ANSI | DMGL_PARAMS);
97 if (demangled_name == NULL)
100 std::string retval(demangled_name);
101 free(demangled_name);
106 Symbol::demangled_name() const
108 return demangle(this->name());
111 // Initialize the fields in the base class Symbol for SYM in OBJECT.
113 template<int size, bool big_endian>
115 Symbol::init_base_object(const char* name, const char* version, Object* object,
116 const elfcpp::Sym<size, big_endian>& sym,
117 unsigned int st_shndx, bool is_ordinary)
119 this->init_fields(name, version, sym.get_st_type(), sym.get_st_bind(),
120 sym.get_st_visibility(), sym.get_st_nonvis());
121 this->u_.from_object.object = object;
122 this->u_.from_object.shndx = st_shndx;
123 this->is_ordinary_shndx_ = is_ordinary;
124 this->source_ = FROM_OBJECT;
125 this->in_reg_ = !object->is_dynamic();
126 this->in_dyn_ = object->is_dynamic();
127 this->in_real_elf_ = object->pluginobj() == NULL;
130 // Initialize the fields in the base class Symbol for a symbol defined
131 // in an Output_data.
134 Symbol::init_base_output_data(const char* name, const char* version,
135 Output_data* od, elfcpp::STT type,
136 elfcpp::STB binding, elfcpp::STV visibility,
137 unsigned char nonvis, bool offset_is_from_end,
140 this->init_fields(name, version, type, binding, visibility, nonvis);
141 this->u_.in_output_data.output_data = od;
142 this->u_.in_output_data.offset_is_from_end = offset_is_from_end;
143 this->source_ = IN_OUTPUT_DATA;
144 this->in_reg_ = true;
145 this->in_real_elf_ = true;
146 this->is_predefined_ = is_predefined;
149 // Initialize the fields in the base class Symbol for a symbol defined
150 // in an Output_segment.
153 Symbol::init_base_output_segment(const char* name, const char* version,
154 Output_segment* os, elfcpp::STT type,
155 elfcpp::STB binding, elfcpp::STV visibility,
156 unsigned char nonvis,
157 Segment_offset_base offset_base,
160 this->init_fields(name, version, type, binding, visibility, nonvis);
161 this->u_.in_output_segment.output_segment = os;
162 this->u_.in_output_segment.offset_base = offset_base;
163 this->source_ = IN_OUTPUT_SEGMENT;
164 this->in_reg_ = true;
165 this->in_real_elf_ = true;
166 this->is_predefined_ = is_predefined;
169 // Initialize the fields in the base class Symbol for a symbol defined
173 Symbol::init_base_constant(const char* name, const char* version,
174 elfcpp::STT type, elfcpp::STB binding,
175 elfcpp::STV visibility, unsigned char nonvis,
178 this->init_fields(name, version, type, binding, visibility, nonvis);
179 this->source_ = IS_CONSTANT;
180 this->in_reg_ = true;
181 this->in_real_elf_ = true;
182 this->is_predefined_ = is_predefined;
185 // Initialize the fields in the base class Symbol for an undefined
189 Symbol::init_base_undefined(const char* name, const char* version,
190 elfcpp::STT type, elfcpp::STB binding,
191 elfcpp::STV visibility, unsigned char nonvis)
193 this->init_fields(name, version, type, binding, visibility, nonvis);
194 this->dynsym_index_ = -1U;
195 this->source_ = IS_UNDEFINED;
196 this->in_reg_ = true;
197 this->in_real_elf_ = true;
200 // Allocate a common symbol in the base.
203 Symbol::allocate_base_common(Output_data* od)
205 gold_assert(this->is_common());
206 this->source_ = IN_OUTPUT_DATA;
207 this->u_.in_output_data.output_data = od;
208 this->u_.in_output_data.offset_is_from_end = false;
211 // Initialize the fields in Sized_symbol for SYM in OBJECT.
214 template<bool big_endian>
216 Sized_symbol<size>::init_object(const char* name, const char* version,
218 const elfcpp::Sym<size, big_endian>& sym,
219 unsigned int st_shndx, bool is_ordinary)
221 this->init_base_object(name, version, object, sym, st_shndx, is_ordinary);
222 this->value_ = sym.get_st_value();
223 this->symsize_ = sym.get_st_size();
226 // Initialize the fields in Sized_symbol for a symbol defined in an
231 Sized_symbol<size>::init_output_data(const char* name, const char* version,
232 Output_data* od, Value_type value,
233 Size_type symsize, elfcpp::STT type,
235 elfcpp::STV visibility,
236 unsigned char nonvis,
237 bool offset_is_from_end,
240 this->init_base_output_data(name, version, od, type, binding, visibility,
241 nonvis, offset_is_from_end, is_predefined);
242 this->value_ = value;
243 this->symsize_ = symsize;
246 // Initialize the fields in Sized_symbol for a symbol defined in an
251 Sized_symbol<size>::init_output_segment(const char* name, const char* version,
252 Output_segment* os, Value_type value,
253 Size_type symsize, elfcpp::STT type,
255 elfcpp::STV visibility,
256 unsigned char nonvis,
257 Segment_offset_base offset_base,
260 this->init_base_output_segment(name, version, os, type, binding, visibility,
261 nonvis, offset_base, is_predefined);
262 this->value_ = value;
263 this->symsize_ = symsize;
266 // Initialize the fields in Sized_symbol for a symbol defined as a
271 Sized_symbol<size>::init_constant(const char* name, const char* version,
272 Value_type value, Size_type symsize,
273 elfcpp::STT type, elfcpp::STB binding,
274 elfcpp::STV visibility, unsigned char nonvis,
277 this->init_base_constant(name, version, type, binding, visibility, nonvis,
279 this->value_ = value;
280 this->symsize_ = symsize;
283 // Initialize the fields in Sized_symbol for an undefined symbol.
287 Sized_symbol<size>::init_undefined(const char* name, const char* version,
288 elfcpp::STT type, elfcpp::STB binding,
289 elfcpp::STV visibility, unsigned char nonvis)
291 this->init_base_undefined(name, version, type, binding, visibility, nonvis);
296 // Return true if SHNDX represents a common symbol.
299 Symbol::is_common_shndx(unsigned int shndx)
301 return (shndx == elfcpp::SHN_COMMON
302 || shndx == parameters->target().small_common_shndx()
303 || shndx == parameters->target().large_common_shndx());
306 // Allocate a common symbol.
310 Sized_symbol<size>::allocate_common(Output_data* od, Value_type value)
312 this->allocate_base_common(od);
313 this->value_ = value;
316 // The ""'s around str ensure str is a string literal, so sizeof works.
317 #define strprefix(var, str) (strncmp(var, str, sizeof("" str "") - 1) == 0)
319 // Return true if this symbol should be added to the dynamic symbol
323 Symbol::should_add_dynsym_entry(Symbol_table* symtab) const
325 // If the symbol is only present on plugin files, the plugin decided we
327 if (!this->in_real_elf())
330 // If the symbol is used by a dynamic relocation, we need to add it.
331 if (this->needs_dynsym_entry())
334 // If this symbol's section is not added, the symbol need not be added.
335 // The section may have been GCed. Note that export_dynamic is being
336 // overridden here. This should not be done for shared objects.
337 if (parameters->options().gc_sections()
338 && !parameters->options().shared()
339 && this->source() == Symbol::FROM_OBJECT
340 && !this->object()->is_dynamic())
342 Relobj* relobj = static_cast<Relobj*>(this->object());
344 unsigned int shndx = this->shndx(&is_ordinary);
345 if (is_ordinary && shndx != elfcpp::SHN_UNDEF
346 && !relobj->is_section_included(shndx)
347 && !symtab->is_section_folded(relobj, shndx))
351 // If the symbol was forced local in a version script, do not add it.
352 if (this->is_forced_local())
355 // If the symbol was forced dynamic in a --dynamic-list file, add it.
356 if (parameters->options().in_dynamic_list(this->name()))
359 // If dynamic-list-data was specified, add any STT_OBJECT.
360 if (parameters->options().dynamic_list_data()
361 && !this->is_from_dynobj()
362 && this->type() == elfcpp::STT_OBJECT)
365 // If --dynamic-list-cpp-new was specified, add any new/delete symbol.
366 // If --dynamic-list-cpp-typeinfo was specified, add any typeinfo symbols.
367 if ((parameters->options().dynamic_list_cpp_new()
368 || parameters->options().dynamic_list_cpp_typeinfo())
369 && !this->is_from_dynobj())
371 // TODO(csilvers): We could probably figure out if we're an operator
372 // new/delete or typeinfo without the need to demangle.
373 char* demangled_name = cplus_demangle(this->name(),
374 DMGL_ANSI | DMGL_PARAMS);
375 if (demangled_name == NULL)
377 // Not a C++ symbol, so it can't satisfy these flags
379 else if (parameters->options().dynamic_list_cpp_new()
380 && (strprefix(demangled_name, "operator new")
381 || strprefix(demangled_name, "operator delete")))
383 free(demangled_name);
386 else if (parameters->options().dynamic_list_cpp_typeinfo()
387 && (strprefix(demangled_name, "typeinfo name for")
388 || strprefix(demangled_name, "typeinfo for")))
390 free(demangled_name);
394 free(demangled_name);
397 // If exporting all symbols or building a shared library,
398 // and the symbol is defined in a regular object and is
399 // externally visible, we need to add it.
400 if ((parameters->options().export_dynamic() || parameters->options().shared())
401 && !this->is_from_dynobj()
402 && this->is_externally_visible())
408 // Return true if the final value of this symbol is known at link
412 Symbol::final_value_is_known() const
414 // If we are not generating an executable, then no final values are
415 // known, since they will change at runtime.
416 if (parameters->options().output_is_position_independent()
417 || parameters->options().relocatable())
420 // If the symbol is not from an object file, and is not undefined,
421 // then it is defined, and known.
422 if (this->source_ != FROM_OBJECT)
424 if (this->source_ != IS_UNDEFINED)
429 // If the symbol is from a dynamic object, then the final value
431 if (this->object()->is_dynamic())
434 // If the symbol is not undefined (it is defined or common),
435 // then the final value is known.
436 if (!this->is_undefined())
440 // If the symbol is undefined, then whether the final value is known
441 // depends on whether we are doing a static link. If we are doing a
442 // dynamic link, then the final value could be filled in at runtime.
443 // This could reasonably be the case for a weak undefined symbol.
444 return parameters->doing_static_link();
447 // Return the output section where this symbol is defined.
450 Symbol::output_section() const
452 switch (this->source_)
456 unsigned int shndx = this->u_.from_object.shndx;
457 if (shndx != elfcpp::SHN_UNDEF && this->is_ordinary_shndx_)
459 gold_assert(!this->u_.from_object.object->is_dynamic());
460 gold_assert(this->u_.from_object.object->pluginobj() == NULL);
461 Relobj* relobj = static_cast<Relobj*>(this->u_.from_object.object);
462 return relobj->output_section(shndx);
468 return this->u_.in_output_data.output_data->output_section();
470 case IN_OUTPUT_SEGMENT:
480 // Set the symbol's output section. This is used for symbols defined
481 // in scripts. This should only be called after the symbol table has
485 Symbol::set_output_section(Output_section* os)
487 switch (this->source_)
491 gold_assert(this->output_section() == os);
494 this->source_ = IN_OUTPUT_DATA;
495 this->u_.in_output_data.output_data = os;
496 this->u_.in_output_data.offset_is_from_end = false;
498 case IN_OUTPUT_SEGMENT:
505 // Class Symbol_table.
507 Symbol_table::Symbol_table(unsigned int count,
508 const Version_script_info& version_script)
509 : saw_undefined_(0), offset_(0), table_(count), namepool_(),
510 forwarders_(), commons_(), tls_commons_(), small_commons_(),
511 large_commons_(), forced_locals_(), warnings_(),
512 version_script_(version_script), gc_(NULL), icf_(NULL)
514 namepool_.reserve(count);
517 Symbol_table::~Symbol_table()
521 // The symbol table key equality function. This is called with
525 Symbol_table::Symbol_table_eq::operator()(const Symbol_table_key& k1,
526 const Symbol_table_key& k2) const
528 return k1.first == k2.first && k1.second == k2.second;
532 Symbol_table::is_section_folded(Object* obj, unsigned int shndx) const
534 return (parameters->options().icf_enabled()
535 && this->icf_->is_section_folded(obj, shndx));
538 // For symbols that have been listed with -u option, add them to the
539 // work list to avoid gc'ing them.
542 Symbol_table::gc_mark_undef_symbols(Layout* layout)
544 for (options::String_set::const_iterator p =
545 parameters->options().undefined_begin();
546 p != parameters->options().undefined_end();
549 const char* name = p->c_str();
550 Symbol* sym = this->lookup(name);
551 gold_assert(sym != NULL);
552 if (sym->source() == Symbol::FROM_OBJECT
553 && !sym->object()->is_dynamic())
555 Relobj* obj = static_cast<Relobj*>(sym->object());
557 unsigned int shndx = sym->shndx(&is_ordinary);
560 gold_assert(this->gc_ != NULL);
561 this->gc_->worklist().push(Section_id(obj, shndx));
566 for (Script_options::referenced_const_iterator p =
567 layout->script_options()->referenced_begin();
568 p != layout->script_options()->referenced_end();
571 Symbol* sym = this->lookup(p->c_str());
572 gold_assert(sym != NULL);
573 if (sym->source() == Symbol::FROM_OBJECT
574 && !sym->object()->is_dynamic())
576 Relobj* obj = static_cast<Relobj*>(sym->object());
578 unsigned int shndx = sym->shndx(&is_ordinary);
581 gold_assert(this->gc_ != NULL);
582 this->gc_->worklist().push(Section_id(obj, shndx));
589 Symbol_table::gc_mark_symbol_for_shlib(Symbol* sym)
591 if (!sym->is_from_dynobj()
592 && sym->is_externally_visible())
594 //Add the object and section to the work list.
595 Relobj* obj = static_cast<Relobj*>(sym->object());
597 unsigned int shndx = sym->shndx(&is_ordinary);
598 if (is_ordinary && shndx != elfcpp::SHN_UNDEF)
600 gold_assert(this->gc_!= NULL);
601 this->gc_->worklist().push(Section_id(obj, shndx));
606 // When doing garbage collection, keep symbols that have been seen in
609 Symbol_table::gc_mark_dyn_syms(Symbol* sym)
611 if (sym->in_dyn() && sym->source() == Symbol::FROM_OBJECT
612 && !sym->object()->is_dynamic())
614 Relobj* obj = static_cast<Relobj*>(sym->object());
616 unsigned int shndx = sym->shndx(&is_ordinary);
617 if (is_ordinary && shndx != elfcpp::SHN_UNDEF)
619 gold_assert(this->gc_ != NULL);
620 this->gc_->worklist().push(Section_id(obj, shndx));
625 // Make TO a symbol which forwards to FROM.
628 Symbol_table::make_forwarder(Symbol* from, Symbol* to)
630 gold_assert(from != to);
631 gold_assert(!from->is_forwarder() && !to->is_forwarder());
632 this->forwarders_[from] = to;
633 from->set_forwarder();
636 // Resolve the forwards from FROM, returning the real symbol.
639 Symbol_table::resolve_forwards(const Symbol* from) const
641 gold_assert(from->is_forwarder());
642 Unordered_map<const Symbol*, Symbol*>::const_iterator p =
643 this->forwarders_.find(from);
644 gold_assert(p != this->forwarders_.end());
648 // Look up a symbol by name.
651 Symbol_table::lookup(const char* name, const char* version) const
653 Stringpool::Key name_key;
654 name = this->namepool_.find(name, &name_key);
658 Stringpool::Key version_key = 0;
661 version = this->namepool_.find(version, &version_key);
666 Symbol_table_key key(name_key, version_key);
667 Symbol_table::Symbol_table_type::const_iterator p = this->table_.find(key);
668 if (p == this->table_.end())
673 // Resolve a Symbol with another Symbol. This is only used in the
674 // unusual case where there are references to both an unversioned
675 // symbol and a symbol with a version, and we then discover that that
676 // version is the default version. Because this is unusual, we do
677 // this the slow way, by converting back to an ELF symbol.
679 template<int size, bool big_endian>
681 Symbol_table::resolve(Sized_symbol<size>* to, const Sized_symbol<size>* from)
683 unsigned char buf[elfcpp::Elf_sizes<size>::sym_size];
684 elfcpp::Sym_write<size, big_endian> esym(buf);
685 // We don't bother to set the st_name or the st_shndx field.
686 esym.put_st_value(from->value());
687 esym.put_st_size(from->symsize());
688 esym.put_st_info(from->binding(), from->type());
689 esym.put_st_other(from->visibility(), from->nonvis());
691 unsigned int shndx = from->shndx(&is_ordinary);
692 this->resolve(to, esym.sym(), shndx, is_ordinary, shndx, from->object(),
698 if (parameters->options().gc_sections())
699 this->gc_mark_dyn_syms(to);
702 // Record that a symbol is forced to be local by a version script or
706 Symbol_table::force_local(Symbol* sym)
708 if (!sym->is_defined() && !sym->is_common())
710 if (sym->is_forced_local())
712 // We already got this one.
715 sym->set_is_forced_local();
716 this->forced_locals_.push_back(sym);
719 // Adjust NAME for wrapping, and update *NAME_KEY if necessary. This
720 // is only called for undefined symbols, when at least one --wrap
724 Symbol_table::wrap_symbol(const char* name, Stringpool::Key* name_key)
726 // For some targets, we need to ignore a specific character when
727 // wrapping, and add it back later.
729 if (name[0] == parameters->target().wrap_char())
735 if (parameters->options().is_wrap(name))
737 // Turn NAME into __wrap_NAME.
744 // This will give us both the old and new name in NAMEPOOL_, but
745 // that is OK. Only the versions we need will wind up in the
746 // real string table in the output file.
747 return this->namepool_.add(s.c_str(), true, name_key);
750 const char* const real_prefix = "__real_";
751 const size_t real_prefix_length = strlen(real_prefix);
752 if (strncmp(name, real_prefix, real_prefix_length) == 0
753 && parameters->options().is_wrap(name + real_prefix_length))
755 // Turn __real_NAME into NAME.
759 s += name + real_prefix_length;
760 return this->namepool_.add(s.c_str(), true, name_key);
766 // This is called when we see a symbol NAME/VERSION, and the symbol
767 // already exists in the symbol table, and VERSION is marked as being
768 // the default version. SYM is the NAME/VERSION symbol we just added.
769 // DEFAULT_IS_NEW is true if this is the first time we have seen the
770 // symbol NAME/NULL. PDEF points to the entry for NAME/NULL.
772 template<int size, bool big_endian>
774 Symbol_table::define_default_version(Sized_symbol<size>* sym,
776 Symbol_table_type::iterator pdef)
780 // This is the first time we have seen NAME/NULL. Make
781 // NAME/NULL point to NAME/VERSION, and mark SYM as the default
784 sym->set_is_default();
786 else if (pdef->second == sym)
788 // NAME/NULL already points to NAME/VERSION. Don't mark the
789 // symbol as the default if it is not already the default.
793 // This is the unfortunate case where we already have entries
794 // for both NAME/VERSION and NAME/NULL. We now see a symbol
795 // NAME/VERSION where VERSION is the default version. We have
796 // already resolved this new symbol with the existing
797 // NAME/VERSION symbol.
799 // It's possible that NAME/NULL and NAME/VERSION are both
800 // defined in regular objects. This can only happen if one
801 // object file defines foo and another defines foo@@ver. This
802 // is somewhat obscure, but we call it a multiple definition
805 // It's possible that NAME/NULL actually has a version, in which
806 // case it won't be the same as VERSION. This happens with
807 // ver_test_7.so in the testsuite for the symbol t2_2. We see
808 // t2_2@@VER2, so we define both t2_2/VER2 and t2_2/NULL. We
809 // then see an unadorned t2_2 in an object file and give it
810 // version VER1 from the version script. This looks like a
811 // default definition for VER1, so it looks like we should merge
812 // t2_2/NULL with t2_2/VER1. That doesn't make sense, but it's
813 // not obvious that this is an error, either. So we just punt.
815 // If one of the symbols has non-default visibility, and the
816 // other is defined in a shared object, then they are different
819 // Otherwise, we just resolve the symbols as though they were
822 if (pdef->second->version() != NULL)
823 gold_assert(pdef->second->version() != sym->version());
824 else if (sym->visibility() != elfcpp::STV_DEFAULT
825 && pdef->second->is_from_dynobj())
827 else if (pdef->second->visibility() != elfcpp::STV_DEFAULT
828 && sym->is_from_dynobj())
832 const Sized_symbol<size>* symdef;
833 symdef = this->get_sized_symbol<size>(pdef->second);
834 Symbol_table::resolve<size, big_endian>(sym, symdef);
835 this->make_forwarder(pdef->second, sym);
837 sym->set_is_default();
842 // Add one symbol from OBJECT to the symbol table. NAME is symbol
843 // name and VERSION is the version; both are canonicalized. DEF is
844 // whether this is the default version. ST_SHNDX is the symbol's
845 // section index; IS_ORDINARY is whether this is a normal section
846 // rather than a special code.
848 // If IS_DEFAULT_VERSION is true, then this is the definition of a
849 // default version of a symbol. That means that any lookup of
850 // NAME/NULL and any lookup of NAME/VERSION should always return the
851 // same symbol. This is obvious for references, but in particular we
852 // want to do this for definitions: overriding NAME/NULL should also
853 // override NAME/VERSION. If we don't do that, it would be very hard
854 // to override functions in a shared library which uses versioning.
856 // We implement this by simply making both entries in the hash table
857 // point to the same Symbol structure. That is easy enough if this is
858 // the first time we see NAME/NULL or NAME/VERSION, but it is possible
859 // that we have seen both already, in which case they will both have
860 // independent entries in the symbol table. We can't simply change
861 // the symbol table entry, because we have pointers to the entries
862 // attached to the object files. So we mark the entry attached to the
863 // object file as a forwarder, and record it in the forwarders_ map.
864 // Note that entries in the hash table will never be marked as
867 // ORIG_ST_SHNDX and ST_SHNDX are almost always the same.
868 // ORIG_ST_SHNDX is the section index in the input file, or SHN_UNDEF
869 // for a special section code. ST_SHNDX may be modified if the symbol
870 // is defined in a section being discarded.
872 template<int size, bool big_endian>
874 Symbol_table::add_from_object(Object* object,
876 Stringpool::Key name_key,
878 Stringpool::Key version_key,
879 bool is_default_version,
880 const elfcpp::Sym<size, big_endian>& sym,
881 unsigned int st_shndx,
883 unsigned int orig_st_shndx)
885 // Print a message if this symbol is being traced.
886 if (parameters->options().is_trace_symbol(name))
888 if (orig_st_shndx == elfcpp::SHN_UNDEF)
889 gold_info(_("%s: reference to %s"), object->name().c_str(), name);
891 gold_info(_("%s: definition of %s"), object->name().c_str(), name);
894 // For an undefined symbol, we may need to adjust the name using
896 if (orig_st_shndx == elfcpp::SHN_UNDEF
897 && parameters->options().any_wrap())
899 const char* wrap_name = this->wrap_symbol(name, &name_key);
900 if (wrap_name != name)
902 // If we see a reference to malloc with version GLIBC_2.0,
903 // and we turn it into a reference to __wrap_malloc, then we
904 // discard the version number. Otherwise the user would be
905 // required to specify the correct version for
913 Symbol* const snull = NULL;
914 std::pair<typename Symbol_table_type::iterator, bool> ins =
915 this->table_.insert(std::make_pair(std::make_pair(name_key, version_key),
918 std::pair<typename Symbol_table_type::iterator, bool> insdefault =
919 std::make_pair(this->table_.end(), false);
920 if (is_default_version)
922 const Stringpool::Key vnull_key = 0;
923 insdefault = this->table_.insert(std::make_pair(std::make_pair(name_key,
928 // ins.first: an iterator, which is a pointer to a pair.
929 // ins.first->first: the key (a pair of name and version).
930 // ins.first->second: the value (Symbol*).
931 // ins.second: true if new entry was inserted, false if not.
933 Sized_symbol<size>* ret;
938 // We already have an entry for NAME/VERSION.
939 ret = this->get_sized_symbol<size>(ins.first->second);
940 gold_assert(ret != NULL);
942 was_undefined = ret->is_undefined();
943 was_common = ret->is_common();
945 this->resolve(ret, sym, st_shndx, is_ordinary, orig_st_shndx, object,
947 if (parameters->options().gc_sections())
948 this->gc_mark_dyn_syms(ret);
950 if (is_default_version)
951 this->define_default_version<size, big_endian>(ret, insdefault.second,
956 // This is the first time we have seen NAME/VERSION.
957 gold_assert(ins.first->second == NULL);
959 if (is_default_version && !insdefault.second)
961 // We already have an entry for NAME/NULL. If we override
962 // it, then change it to NAME/VERSION.
963 ret = this->get_sized_symbol<size>(insdefault.first->second);
965 was_undefined = ret->is_undefined();
966 was_common = ret->is_common();
968 this->resolve(ret, sym, st_shndx, is_ordinary, orig_st_shndx, object,
970 if (parameters->options().gc_sections())
971 this->gc_mark_dyn_syms(ret);
972 ins.first->second = ret;
976 was_undefined = false;
979 Sized_target<size, big_endian>* target =
980 parameters->sized_target<size, big_endian>();
981 if (!target->has_make_symbol())
982 ret = new Sized_symbol<size>();
985 ret = target->make_symbol();
988 // This means that we don't want a symbol table
990 if (!is_default_version)
991 this->table_.erase(ins.first);
994 this->table_.erase(insdefault.first);
995 // Inserting INSDEFAULT invalidated INS.
996 this->table_.erase(std::make_pair(name_key,
1003 ret->init_object(name, version, object, sym, st_shndx, is_ordinary);
1005 ins.first->second = ret;
1006 if (is_default_version)
1008 // This is the first time we have seen NAME/NULL. Point
1009 // it at the new entry for NAME/VERSION.
1010 gold_assert(insdefault.second);
1011 insdefault.first->second = ret;
1015 if (is_default_version)
1016 ret->set_is_default();
1019 // Record every time we see a new undefined symbol, to speed up
1021 if (!was_undefined && ret->is_undefined())
1023 ++this->saw_undefined_;
1024 if (parameters->options().has_plugins())
1025 parameters->options().plugins()->new_undefined_symbol(ret);
1028 // Keep track of common symbols, to speed up common symbol
1030 if (!was_common && ret->is_common())
1032 if (ret->type() == elfcpp::STT_TLS)
1033 this->tls_commons_.push_back(ret);
1034 else if (!is_ordinary
1035 && st_shndx == parameters->target().small_common_shndx())
1036 this->small_commons_.push_back(ret);
1037 else if (!is_ordinary
1038 && st_shndx == parameters->target().large_common_shndx())
1039 this->large_commons_.push_back(ret);
1041 this->commons_.push_back(ret);
1044 // If we're not doing a relocatable link, then any symbol with
1045 // hidden or internal visibility is local.
1046 if ((ret->visibility() == elfcpp::STV_HIDDEN
1047 || ret->visibility() == elfcpp::STV_INTERNAL)
1048 && (ret->binding() == elfcpp::STB_GLOBAL
1049 || ret->binding() == elfcpp::STB_GNU_UNIQUE
1050 || ret->binding() == elfcpp::STB_WEAK)
1051 && !parameters->options().relocatable())
1052 this->force_local(ret);
1057 // Add all the symbols in a relocatable object to the hash table.
1059 template<int size, bool big_endian>
1061 Symbol_table::add_from_relobj(
1062 Sized_relobj_file<size, big_endian>* relobj,
1063 const unsigned char* syms,
1065 size_t symndx_offset,
1066 const char* sym_names,
1067 size_t sym_name_size,
1068 typename Sized_relobj_file<size, big_endian>::Symbols* sympointers,
1073 gold_assert(size == parameters->target().get_size());
1075 const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
1077 const bool just_symbols = relobj->just_symbols();
1079 const unsigned char* p = syms;
1080 for (size_t i = 0; i < count; ++i, p += sym_size)
1082 (*sympointers)[i] = NULL;
1084 elfcpp::Sym<size, big_endian> sym(p);
1086 unsigned int st_name = sym.get_st_name();
1087 if (st_name >= sym_name_size)
1089 relobj->error(_("bad global symbol name offset %u at %zu"),
1094 const char* name = sym_names + st_name;
1097 unsigned int st_shndx = relobj->adjust_sym_shndx(i + symndx_offset,
1100 unsigned int orig_st_shndx = st_shndx;
1102 orig_st_shndx = elfcpp::SHN_UNDEF;
1104 if (st_shndx != elfcpp::SHN_UNDEF)
1107 // A symbol defined in a section which we are not including must
1108 // be treated as an undefined symbol.
1109 bool is_defined_in_discarded_section = false;
1110 if (st_shndx != elfcpp::SHN_UNDEF
1112 && !relobj->is_section_included(st_shndx)
1113 && !this->is_section_folded(relobj, st_shndx))
1115 st_shndx = elfcpp::SHN_UNDEF;
1116 is_defined_in_discarded_section = true;
1119 // In an object file, an '@' in the name separates the symbol
1120 // name from the version name. If there are two '@' characters,
1121 // this is the default version.
1122 const char* ver = strchr(name, '@');
1123 Stringpool::Key ver_key = 0;
1125 // IS_DEFAULT_VERSION: is the version default?
1126 // IS_FORCED_LOCAL: is the symbol forced local?
1127 bool is_default_version = false;
1128 bool is_forced_local = false;
1132 // The symbol name is of the form foo@VERSION or foo@@VERSION
1133 namelen = ver - name;
1137 is_default_version = true;
1140 ver = this->namepool_.add(ver, true, &ver_key);
1142 // We don't want to assign a version to an undefined symbol,
1143 // even if it is listed in the version script. FIXME: What
1144 // about a common symbol?
1147 namelen = strlen(name);
1148 if (!this->version_script_.empty()
1149 && st_shndx != elfcpp::SHN_UNDEF)
1151 // The symbol name did not have a version, but the
1152 // version script may assign a version anyway.
1153 std::string version;
1155 if (this->version_script_.get_symbol_version(name, &version,
1159 is_forced_local = true;
1160 else if (!version.empty())
1162 ver = this->namepool_.add_with_length(version.c_str(),
1166 is_default_version = true;
1172 elfcpp::Sym<size, big_endian>* psym = &sym;
1173 unsigned char symbuf[sym_size];
1174 elfcpp::Sym<size, big_endian> sym2(symbuf);
1177 memcpy(symbuf, p, sym_size);
1178 elfcpp::Sym_write<size, big_endian> sw(symbuf);
1179 if (orig_st_shndx != elfcpp::SHN_UNDEF && is_ordinary)
1181 // Symbol values in object files are section relative.
1182 // This is normally what we want, but since here we are
1183 // converting the symbol to absolute we need to add the
1184 // section address. The section address in an object
1185 // file is normally zero, but people can use a linker
1186 // script to change it.
1187 sw.put_st_value(sym.get_st_value()
1188 + relobj->section_address(orig_st_shndx));
1190 st_shndx = elfcpp::SHN_ABS;
1191 is_ordinary = false;
1195 // Fix up visibility if object has no-export set.
1196 if (relobj->no_export()
1197 && (orig_st_shndx != elfcpp::SHN_UNDEF || !is_ordinary))
1199 // We may have copied symbol already above.
1202 memcpy(symbuf, p, sym_size);
1206 elfcpp::STV visibility = sym2.get_st_visibility();
1207 if (visibility == elfcpp::STV_DEFAULT
1208 || visibility == elfcpp::STV_PROTECTED)
1210 elfcpp::Sym_write<size, big_endian> sw(symbuf);
1211 unsigned char nonvis = sym2.get_st_nonvis();
1212 sw.put_st_other(elfcpp::STV_HIDDEN, nonvis);
1216 Stringpool::Key name_key;
1217 name = this->namepool_.add_with_length(name, namelen, true,
1220 Sized_symbol<size>* res;
1221 res = this->add_from_object(relobj, name, name_key, ver, ver_key,
1222 is_default_version, *psym, st_shndx,
1223 is_ordinary, orig_st_shndx);
1225 // If building a shared library using garbage collection, do not
1226 // treat externally visible symbols as garbage.
1227 if (parameters->options().gc_sections()
1228 && parameters->options().shared())
1229 this->gc_mark_symbol_for_shlib(res);
1231 if (is_forced_local)
1232 this->force_local(res);
1234 if (is_defined_in_discarded_section)
1235 res->set_is_defined_in_discarded_section();
1237 (*sympointers)[i] = res;
1241 // Add a symbol from a plugin-claimed file.
1243 template<int size, bool big_endian>
1245 Symbol_table::add_from_pluginobj(
1246 Sized_pluginobj<size, big_endian>* obj,
1249 elfcpp::Sym<size, big_endian>* sym)
1251 unsigned int st_shndx = sym->get_st_shndx();
1252 bool is_ordinary = st_shndx < elfcpp::SHN_LORESERVE;
1254 Stringpool::Key ver_key = 0;
1255 bool is_default_version = false;
1256 bool is_forced_local = false;
1260 ver = this->namepool_.add(ver, true, &ver_key);
1262 // We don't want to assign a version to an undefined symbol,
1263 // even if it is listed in the version script. FIXME: What
1264 // about a common symbol?
1267 if (!this->version_script_.empty()
1268 && st_shndx != elfcpp::SHN_UNDEF)
1270 // The symbol name did not have a version, but the
1271 // version script may assign a version anyway.
1272 std::string version;
1274 if (this->version_script_.get_symbol_version(name, &version,
1278 is_forced_local = true;
1279 else if (!version.empty())
1281 ver = this->namepool_.add_with_length(version.c_str(),
1285 is_default_version = true;
1291 Stringpool::Key name_key;
1292 name = this->namepool_.add(name, true, &name_key);
1294 Sized_symbol<size>* res;
1295 res = this->add_from_object(obj, name, name_key, ver, ver_key,
1296 is_default_version, *sym, st_shndx,
1297 is_ordinary, st_shndx);
1299 if (is_forced_local)
1300 this->force_local(res);
1305 // Add all the symbols in a dynamic object to the hash table.
1307 template<int size, bool big_endian>
1309 Symbol_table::add_from_dynobj(
1310 Sized_dynobj<size, big_endian>* dynobj,
1311 const unsigned char* syms,
1313 const char* sym_names,
1314 size_t sym_name_size,
1315 const unsigned char* versym,
1317 const std::vector<const char*>* version_map,
1318 typename Sized_relobj_file<size, big_endian>::Symbols* sympointers,
1323 gold_assert(size == parameters->target().get_size());
1325 if (dynobj->just_symbols())
1327 gold_error(_("--just-symbols does not make sense with a shared object"));
1331 if (versym != NULL && versym_size / 2 < count)
1333 dynobj->error(_("too few symbol versions"));
1337 const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
1339 // We keep a list of all STT_OBJECT symbols, so that we can resolve
1340 // weak aliases. This is necessary because if the dynamic object
1341 // provides the same variable under two names, one of which is a
1342 // weak definition, and the regular object refers to the weak
1343 // definition, we have to put both the weak definition and the
1344 // strong definition into the dynamic symbol table. Given a weak
1345 // definition, the only way that we can find the corresponding
1346 // strong definition, if any, is to search the symbol table.
1347 std::vector<Sized_symbol<size>*> object_symbols;
1349 const unsigned char* p = syms;
1350 const unsigned char* vs = versym;
1351 for (size_t i = 0; i < count; ++i, p += sym_size, vs += 2)
1353 elfcpp::Sym<size, big_endian> sym(p);
1355 if (sympointers != NULL)
1356 (*sympointers)[i] = NULL;
1358 // Ignore symbols with local binding or that have
1359 // internal or hidden visibility.
1360 if (sym.get_st_bind() == elfcpp::STB_LOCAL
1361 || sym.get_st_visibility() == elfcpp::STV_INTERNAL
1362 || sym.get_st_visibility() == elfcpp::STV_HIDDEN)
1365 // A protected symbol in a shared library must be treated as a
1366 // normal symbol when viewed from outside the shared library.
1367 // Implement this by overriding the visibility here.
1368 elfcpp::Sym<size, big_endian>* psym = &sym;
1369 unsigned char symbuf[sym_size];
1370 elfcpp::Sym<size, big_endian> sym2(symbuf);
1371 if (sym.get_st_visibility() == elfcpp::STV_PROTECTED)
1373 memcpy(symbuf, p, sym_size);
1374 elfcpp::Sym_write<size, big_endian> sw(symbuf);
1375 sw.put_st_other(elfcpp::STV_DEFAULT, sym.get_st_nonvis());
1379 unsigned int st_name = psym->get_st_name();
1380 if (st_name >= sym_name_size)
1382 dynobj->error(_("bad symbol name offset %u at %zu"),
1387 const char* name = sym_names + st_name;
1390 unsigned int st_shndx = dynobj->adjust_sym_shndx(i, psym->get_st_shndx(),
1393 if (st_shndx != elfcpp::SHN_UNDEF)
1396 Sized_symbol<size>* res;
1400 Stringpool::Key name_key;
1401 name = this->namepool_.add(name, true, &name_key);
1402 res = this->add_from_object(dynobj, name, name_key, NULL, 0,
1403 false, *psym, st_shndx, is_ordinary,
1408 // Read the version information.
1410 unsigned int v = elfcpp::Swap<16, big_endian>::readval(vs);
1412 bool hidden = (v & elfcpp::VERSYM_HIDDEN) != 0;
1413 v &= elfcpp::VERSYM_VERSION;
1415 // The Sun documentation says that V can be VER_NDX_LOCAL,
1416 // or VER_NDX_GLOBAL, or a version index. The meaning of
1417 // VER_NDX_LOCAL is defined as "Symbol has local scope."
1418 // The old GNU linker will happily generate VER_NDX_LOCAL
1419 // for an undefined symbol. I don't know what the Sun
1420 // linker will generate.
1422 if (v == static_cast<unsigned int>(elfcpp::VER_NDX_LOCAL)
1423 && st_shndx != elfcpp::SHN_UNDEF)
1425 // This symbol should not be visible outside the object.
1429 // At this point we are definitely going to add this symbol.
1430 Stringpool::Key name_key;
1431 name = this->namepool_.add(name, true, &name_key);
1433 if (v == static_cast<unsigned int>(elfcpp::VER_NDX_LOCAL)
1434 || v == static_cast<unsigned int>(elfcpp::VER_NDX_GLOBAL))
1436 // This symbol does not have a version.
1437 res = this->add_from_object(dynobj, name, name_key, NULL, 0,
1438 false, *psym, st_shndx, is_ordinary,
1443 if (v >= version_map->size())
1445 dynobj->error(_("versym for symbol %zu out of range: %u"),
1450 const char* version = (*version_map)[v];
1451 if (version == NULL)
1453 dynobj->error(_("versym for symbol %zu has no name: %u"),
1458 Stringpool::Key version_key;
1459 version = this->namepool_.add(version, true, &version_key);
1461 // If this is an absolute symbol, and the version name
1462 // and symbol name are the same, then this is the
1463 // version definition symbol. These symbols exist to
1464 // support using -u to pull in particular versions. We
1465 // do not want to record a version for them.
1466 if (st_shndx == elfcpp::SHN_ABS
1468 && name_key == version_key)
1469 res = this->add_from_object(dynobj, name, name_key, NULL, 0,
1470 false, *psym, st_shndx, is_ordinary,
1474 const bool is_default_version =
1475 !hidden && st_shndx != elfcpp::SHN_UNDEF;
1476 res = this->add_from_object(dynobj, name, name_key, version,
1477 version_key, is_default_version,
1479 is_ordinary, st_shndx);
1484 // Note that it is possible that RES was overridden by an
1485 // earlier object, in which case it can't be aliased here.
1486 if (st_shndx != elfcpp::SHN_UNDEF
1488 && psym->get_st_type() == elfcpp::STT_OBJECT
1489 && res->source() == Symbol::FROM_OBJECT
1490 && res->object() == dynobj)
1491 object_symbols.push_back(res);
1493 if (sympointers != NULL)
1494 (*sympointers)[i] = res;
1497 this->record_weak_aliases(&object_symbols);
1500 // Add a symbol from a incremental object file.
1502 template<int size, bool big_endian>
1504 Symbol_table::add_from_incrobj(
1508 elfcpp::Sym<size, big_endian>* sym)
1510 unsigned int st_shndx = sym->get_st_shndx();
1511 bool is_ordinary = st_shndx < elfcpp::SHN_LORESERVE;
1513 Stringpool::Key ver_key = 0;
1514 bool is_default_version = false;
1515 bool is_forced_local = false;
1517 Stringpool::Key name_key;
1518 name = this->namepool_.add(name, true, &name_key);
1520 Sized_symbol<size>* res;
1521 res = this->add_from_object(obj, name, name_key, ver, ver_key,
1522 is_default_version, *sym, st_shndx,
1523 is_ordinary, st_shndx);
1525 if (is_forced_local)
1526 this->force_local(res);
1531 // This is used to sort weak aliases. We sort them first by section
1532 // index, then by offset, then by weak ahead of strong.
1535 class Weak_alias_sorter
1538 bool operator()(const Sized_symbol<size>*, const Sized_symbol<size>*) const;
1543 Weak_alias_sorter<size>::operator()(const Sized_symbol<size>* s1,
1544 const Sized_symbol<size>* s2) const
1547 unsigned int s1_shndx = s1->shndx(&is_ordinary);
1548 gold_assert(is_ordinary);
1549 unsigned int s2_shndx = s2->shndx(&is_ordinary);
1550 gold_assert(is_ordinary);
1551 if (s1_shndx != s2_shndx)
1552 return s1_shndx < s2_shndx;
1554 if (s1->value() != s2->value())
1555 return s1->value() < s2->value();
1556 if (s1->binding() != s2->binding())
1558 if (s1->binding() == elfcpp::STB_WEAK)
1560 if (s2->binding() == elfcpp::STB_WEAK)
1563 return std::string(s1->name()) < std::string(s2->name());
1566 // SYMBOLS is a list of object symbols from a dynamic object. Look
1567 // for any weak aliases, and record them so that if we add the weak
1568 // alias to the dynamic symbol table, we also add the corresponding
1573 Symbol_table::record_weak_aliases(std::vector<Sized_symbol<size>*>* symbols)
1575 // Sort the vector by section index, then by offset, then by weak
1577 std::sort(symbols->begin(), symbols->end(), Weak_alias_sorter<size>());
1579 // Walk through the vector. For each weak definition, record
1581 for (typename std::vector<Sized_symbol<size>*>::const_iterator p =
1583 p != symbols->end();
1586 if ((*p)->binding() != elfcpp::STB_WEAK)
1589 // Build a circular list of weak aliases. Each symbol points to
1590 // the next one in the circular list.
1592 Sized_symbol<size>* from_sym = *p;
1593 typename std::vector<Sized_symbol<size>*>::const_iterator q;
1594 for (q = p + 1; q != symbols->end(); ++q)
1597 if ((*q)->shndx(&dummy) != from_sym->shndx(&dummy)
1598 || (*q)->value() != from_sym->value())
1601 this->weak_aliases_[from_sym] = *q;
1602 from_sym->set_has_alias();
1608 this->weak_aliases_[from_sym] = *p;
1609 from_sym->set_has_alias();
1616 // Create and return a specially defined symbol. If ONLY_IF_REF is
1617 // true, then only create the symbol if there is a reference to it.
1618 // If this does not return NULL, it sets *POLDSYM to the existing
1619 // symbol if there is one. This sets *RESOLVE_OLDSYM if we should
1620 // resolve the newly created symbol to the old one. This
1621 // canonicalizes *PNAME and *PVERSION.
1623 template<int size, bool big_endian>
1625 Symbol_table::define_special_symbol(const char** pname, const char** pversion,
1627 Sized_symbol<size>** poldsym,
1628 bool* resolve_oldsym)
1630 *resolve_oldsym = false;
1632 // If the caller didn't give us a version, see if we get one from
1633 // the version script.
1635 bool is_default_version = false;
1636 if (*pversion == NULL)
1639 if (this->version_script_.get_symbol_version(*pname, &v, &is_global))
1641 if (is_global && !v.empty())
1643 *pversion = v.c_str();
1644 // If we get the version from a version script, then we
1645 // are also the default version.
1646 is_default_version = true;
1652 Sized_symbol<size>* sym;
1654 bool add_to_table = false;
1655 typename Symbol_table_type::iterator add_loc = this->table_.end();
1656 bool add_def_to_table = false;
1657 typename Symbol_table_type::iterator add_def_loc = this->table_.end();
1661 oldsym = this->lookup(*pname, *pversion);
1662 if (oldsym == NULL && is_default_version)
1663 oldsym = this->lookup(*pname, NULL);
1664 if (oldsym == NULL || !oldsym->is_undefined())
1667 *pname = oldsym->name();
1668 if (!is_default_version)
1669 *pversion = oldsym->version();
1673 // Canonicalize NAME and VERSION.
1674 Stringpool::Key name_key;
1675 *pname = this->namepool_.add(*pname, true, &name_key);
1677 Stringpool::Key version_key = 0;
1678 if (*pversion != NULL)
1679 *pversion = this->namepool_.add(*pversion, true, &version_key);
1681 Symbol* const snull = NULL;
1682 std::pair<typename Symbol_table_type::iterator, bool> ins =
1683 this->table_.insert(std::make_pair(std::make_pair(name_key,
1687 std::pair<typename Symbol_table_type::iterator, bool> insdefault =
1688 std::make_pair(this->table_.end(), false);
1689 if (is_default_version)
1691 const Stringpool::Key vnull = 0;
1693 this->table_.insert(std::make_pair(std::make_pair(name_key,
1700 // We already have a symbol table entry for NAME/VERSION.
1701 oldsym = ins.first->second;
1702 gold_assert(oldsym != NULL);
1704 if (is_default_version)
1706 Sized_symbol<size>* soldsym =
1707 this->get_sized_symbol<size>(oldsym);
1708 this->define_default_version<size, big_endian>(soldsym,
1715 // We haven't seen this symbol before.
1716 gold_assert(ins.first->second == NULL);
1718 add_to_table = true;
1719 add_loc = ins.first;
1721 if (is_default_version && !insdefault.second)
1723 // We are adding NAME/VERSION, and it is the default
1724 // version. We already have an entry for NAME/NULL.
1725 oldsym = insdefault.first->second;
1726 *resolve_oldsym = true;
1732 if (is_default_version)
1734 add_def_to_table = true;
1735 add_def_loc = insdefault.first;
1741 const Target& target = parameters->target();
1742 if (!target.has_make_symbol())
1743 sym = new Sized_symbol<size>();
1746 Sized_target<size, big_endian>* sized_target =
1747 parameters->sized_target<size, big_endian>();
1748 sym = sized_target->make_symbol();
1754 add_loc->second = sym;
1756 gold_assert(oldsym != NULL);
1758 if (add_def_to_table)
1759 add_def_loc->second = sym;
1761 *poldsym = this->get_sized_symbol<size>(oldsym);
1766 // Define a symbol based on an Output_data.
1769 Symbol_table::define_in_output_data(const char* name,
1770 const char* version,
1776 elfcpp::STB binding,
1777 elfcpp::STV visibility,
1778 unsigned char nonvis,
1779 bool offset_is_from_end,
1782 if (parameters->target().get_size() == 32)
1784 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
1785 return this->do_define_in_output_data<32>(name, version, defined, od,
1786 value, symsize, type, binding,
1794 else if (parameters->target().get_size() == 64)
1796 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
1797 return this->do_define_in_output_data<64>(name, version, defined, od,
1798 value, symsize, type, binding,
1810 // Define a symbol in an Output_data, sized version.
1814 Symbol_table::do_define_in_output_data(
1816 const char* version,
1819 typename elfcpp::Elf_types<size>::Elf_Addr value,
1820 typename elfcpp::Elf_types<size>::Elf_WXword symsize,
1822 elfcpp::STB binding,
1823 elfcpp::STV visibility,
1824 unsigned char nonvis,
1825 bool offset_is_from_end,
1828 Sized_symbol<size>* sym;
1829 Sized_symbol<size>* oldsym;
1830 bool resolve_oldsym;
1832 if (parameters->target().is_big_endian())
1834 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
1835 sym = this->define_special_symbol<size, true>(&name, &version,
1836 only_if_ref, &oldsym,
1844 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
1845 sym = this->define_special_symbol<size, false>(&name, &version,
1846 only_if_ref, &oldsym,
1856 sym->init_output_data(name, version, od, value, symsize, type, binding,
1857 visibility, nonvis, offset_is_from_end,
1858 defined == PREDEFINED);
1862 if (binding == elfcpp::STB_LOCAL
1863 || this->version_script_.symbol_is_local(name))
1864 this->force_local(sym);
1865 else if (version != NULL)
1866 sym->set_is_default();
1870 if (Symbol_table::should_override_with_special(oldsym, defined))
1871 this->override_with_special(oldsym, sym);
1882 // Define a symbol based on an Output_segment.
1885 Symbol_table::define_in_output_segment(const char* name,
1886 const char* version,
1892 elfcpp::STB binding,
1893 elfcpp::STV visibility,
1894 unsigned char nonvis,
1895 Symbol::Segment_offset_base offset_base,
1898 if (parameters->target().get_size() == 32)
1900 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
1901 return this->do_define_in_output_segment<32>(name, version, defined, os,
1902 value, symsize, type,
1903 binding, visibility, nonvis,
1904 offset_base, only_if_ref);
1909 else if (parameters->target().get_size() == 64)
1911 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
1912 return this->do_define_in_output_segment<64>(name, version, defined, os,
1913 value, symsize, type,
1914 binding, visibility, nonvis,
1915 offset_base, only_if_ref);
1924 // Define a symbol in an Output_segment, sized version.
1928 Symbol_table::do_define_in_output_segment(
1930 const char* version,
1933 typename elfcpp::Elf_types<size>::Elf_Addr value,
1934 typename elfcpp::Elf_types<size>::Elf_WXword symsize,
1936 elfcpp::STB binding,
1937 elfcpp::STV visibility,
1938 unsigned char nonvis,
1939 Symbol::Segment_offset_base offset_base,
1942 Sized_symbol<size>* sym;
1943 Sized_symbol<size>* oldsym;
1944 bool resolve_oldsym;
1946 if (parameters->target().is_big_endian())
1948 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
1949 sym = this->define_special_symbol<size, true>(&name, &version,
1950 only_if_ref, &oldsym,
1958 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
1959 sym = this->define_special_symbol<size, false>(&name, &version,
1960 only_if_ref, &oldsym,
1970 sym->init_output_segment(name, version, os, value, symsize, type, binding,
1971 visibility, nonvis, offset_base,
1972 defined == PREDEFINED);
1976 if (binding == elfcpp::STB_LOCAL
1977 || this->version_script_.symbol_is_local(name))
1978 this->force_local(sym);
1979 else if (version != NULL)
1980 sym->set_is_default();
1984 if (Symbol_table::should_override_with_special(oldsym, defined))
1985 this->override_with_special(oldsym, sym);
1996 // Define a special symbol with a constant value. It is a multiple
1997 // definition error if this symbol is already defined.
2000 Symbol_table::define_as_constant(const char* name,
2001 const char* version,
2006 elfcpp::STB binding,
2007 elfcpp::STV visibility,
2008 unsigned char nonvis,
2010 bool force_override)
2012 if (parameters->target().get_size() == 32)
2014 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
2015 return this->do_define_as_constant<32>(name, version, defined, value,
2016 symsize, type, binding,
2017 visibility, nonvis, only_if_ref,
2023 else if (parameters->target().get_size() == 64)
2025 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
2026 return this->do_define_as_constant<64>(name, version, defined, value,
2027 symsize, type, binding,
2028 visibility, nonvis, only_if_ref,
2038 // Define a symbol as a constant, sized version.
2042 Symbol_table::do_define_as_constant(
2044 const char* version,
2046 typename elfcpp::Elf_types<size>::Elf_Addr value,
2047 typename elfcpp::Elf_types<size>::Elf_WXword symsize,
2049 elfcpp::STB binding,
2050 elfcpp::STV visibility,
2051 unsigned char nonvis,
2053 bool force_override)
2055 Sized_symbol<size>* sym;
2056 Sized_symbol<size>* oldsym;
2057 bool resolve_oldsym;
2059 if (parameters->target().is_big_endian())
2061 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
2062 sym = this->define_special_symbol<size, true>(&name, &version,
2063 only_if_ref, &oldsym,
2071 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
2072 sym = this->define_special_symbol<size, false>(&name, &version,
2073 only_if_ref, &oldsym,
2083 sym->init_constant(name, version, value, symsize, type, binding, visibility,
2084 nonvis, defined == PREDEFINED);
2088 // Version symbols are absolute symbols with name == version.
2089 // We don't want to force them to be local.
2090 if ((version == NULL
2093 && (binding == elfcpp::STB_LOCAL
2094 || this->version_script_.symbol_is_local(name)))
2095 this->force_local(sym);
2096 else if (version != NULL
2097 && (name != version || value != 0))
2098 sym->set_is_default();
2103 || Symbol_table::should_override_with_special(oldsym, defined))
2104 this->override_with_special(oldsym, sym);
2115 // Define a set of symbols in output sections.
2118 Symbol_table::define_symbols(const Layout* layout, int count,
2119 const Define_symbol_in_section* p,
2122 for (int i = 0; i < count; ++i, ++p)
2124 Output_section* os = layout->find_output_section(p->output_section);
2126 this->define_in_output_data(p->name, NULL, PREDEFINED, os, p->value,
2127 p->size, p->type, p->binding,
2128 p->visibility, p->nonvis,
2129 p->offset_is_from_end,
2130 only_if_ref || p->only_if_ref);
2132 this->define_as_constant(p->name, NULL, PREDEFINED, 0, p->size,
2133 p->type, p->binding, p->visibility, p->nonvis,
2134 only_if_ref || p->only_if_ref,
2139 // Define a set of symbols in output segments.
2142 Symbol_table::define_symbols(const Layout* layout, int count,
2143 const Define_symbol_in_segment* p,
2146 for (int i = 0; i < count; ++i, ++p)
2148 Output_segment* os = layout->find_output_segment(p->segment_type,
2149 p->segment_flags_set,
2150 p->segment_flags_clear);
2152 this->define_in_output_segment(p->name, NULL, PREDEFINED, os, p->value,
2153 p->size, p->type, p->binding,
2154 p->visibility, p->nonvis,
2156 only_if_ref || p->only_if_ref);
2158 this->define_as_constant(p->name, NULL, PREDEFINED, 0, p->size,
2159 p->type, p->binding, p->visibility, p->nonvis,
2160 only_if_ref || p->only_if_ref,
2165 // Define CSYM using a COPY reloc. POSD is the Output_data where the
2166 // symbol should be defined--typically a .dyn.bss section. VALUE is
2167 // the offset within POSD.
2171 Symbol_table::define_with_copy_reloc(
2172 Sized_symbol<size>* csym,
2174 typename elfcpp::Elf_types<size>::Elf_Addr value)
2176 gold_assert(csym->is_from_dynobj());
2177 gold_assert(!csym->is_copied_from_dynobj());
2178 Object* object = csym->object();
2179 gold_assert(object->is_dynamic());
2180 Dynobj* dynobj = static_cast<Dynobj*>(object);
2182 // Our copied variable has to override any variable in a shared
2184 elfcpp::STB binding = csym->binding();
2185 if (binding == elfcpp::STB_WEAK)
2186 binding = elfcpp::STB_GLOBAL;
2188 this->define_in_output_data(csym->name(), csym->version(), COPY,
2189 posd, value, csym->symsize(),
2190 csym->type(), binding,
2191 csym->visibility(), csym->nonvis(),
2194 csym->set_is_copied_from_dynobj();
2195 csym->set_needs_dynsym_entry();
2197 this->copied_symbol_dynobjs_[csym] = dynobj;
2199 // We have now defined all aliases, but we have not entered them all
2200 // in the copied_symbol_dynobjs_ map.
2201 if (csym->has_alias())
2206 sym = this->weak_aliases_[sym];
2209 gold_assert(sym->output_data() == posd);
2211 sym->set_is_copied_from_dynobj();
2212 this->copied_symbol_dynobjs_[sym] = dynobj;
2217 // SYM is defined using a COPY reloc. Return the dynamic object where
2218 // the original definition was found.
2221 Symbol_table::get_copy_source(const Symbol* sym) const
2223 gold_assert(sym->is_copied_from_dynobj());
2224 Copied_symbol_dynobjs::const_iterator p =
2225 this->copied_symbol_dynobjs_.find(sym);
2226 gold_assert(p != this->copied_symbol_dynobjs_.end());
2230 // Add any undefined symbols named on the command line.
2233 Symbol_table::add_undefined_symbols_from_command_line(Layout* layout)
2235 if (parameters->options().any_undefined()
2236 || layout->script_options()->any_unreferenced())
2238 if (parameters->target().get_size() == 32)
2240 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
2241 this->do_add_undefined_symbols_from_command_line<32>(layout);
2246 else if (parameters->target().get_size() == 64)
2248 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
2249 this->do_add_undefined_symbols_from_command_line<64>(layout);
2261 Symbol_table::do_add_undefined_symbols_from_command_line(Layout* layout)
2263 for (options::String_set::const_iterator p =
2264 parameters->options().undefined_begin();
2265 p != parameters->options().undefined_end();
2267 this->add_undefined_symbol_from_command_line<size>(p->c_str());
2269 for (Script_options::referenced_const_iterator p =
2270 layout->script_options()->referenced_begin();
2271 p != layout->script_options()->referenced_end();
2273 this->add_undefined_symbol_from_command_line<size>(p->c_str());
2278 Symbol_table::add_undefined_symbol_from_command_line(const char* name)
2280 if (this->lookup(name) != NULL)
2283 const char* version = NULL;
2285 Sized_symbol<size>* sym;
2286 Sized_symbol<size>* oldsym;
2287 bool resolve_oldsym;
2288 if (parameters->target().is_big_endian())
2290 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
2291 sym = this->define_special_symbol<size, true>(&name, &version,
2300 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
2301 sym = this->define_special_symbol<size, false>(&name, &version,
2309 gold_assert(oldsym == NULL);
2311 sym->init_undefined(name, version, elfcpp::STT_NOTYPE, elfcpp::STB_GLOBAL,
2312 elfcpp::STV_DEFAULT, 0);
2313 ++this->saw_undefined_;
2316 // Set the dynamic symbol indexes. INDEX is the index of the first
2317 // global dynamic symbol. Pointers to the symbols are stored into the
2318 // vector SYMS. The names are added to DYNPOOL. This returns an
2319 // updated dynamic symbol index.
2322 Symbol_table::set_dynsym_indexes(unsigned int index,
2323 std::vector<Symbol*>* syms,
2324 Stringpool* dynpool,
2327 for (Symbol_table_type::iterator p = this->table_.begin();
2328 p != this->table_.end();
2331 Symbol* sym = p->second;
2333 // Note that SYM may already have a dynamic symbol index, since
2334 // some symbols appear more than once in the symbol table, with
2335 // and without a version.
2337 if (!sym->should_add_dynsym_entry(this))
2338 sym->set_dynsym_index(-1U);
2339 else if (!sym->has_dynsym_index())
2341 sym->set_dynsym_index(index);
2343 syms->push_back(sym);
2344 dynpool->add(sym->name(), false, NULL);
2346 // Record any version information.
2347 if (sym->version() != NULL)
2348 versions->record_version(this, dynpool, sym);
2350 // If the symbol is defined in a dynamic object and is
2351 // referenced in a regular object, then mark the dynamic
2352 // object as needed. This is used to implement --as-needed.
2353 if (sym->is_from_dynobj() && sym->in_reg())
2354 sym->object()->set_is_needed();
2358 // Finish up the versions. In some cases this may add new dynamic
2360 index = versions->finalize(this, index, syms);
2365 // Set the final values for all the symbols. The index of the first
2366 // global symbol in the output file is *PLOCAL_SYMCOUNT. Record the
2367 // file offset OFF. Add their names to POOL. Return the new file
2368 // offset. Update *PLOCAL_SYMCOUNT if necessary.
2371 Symbol_table::finalize(off_t off, off_t dynoff, size_t dyn_global_index,
2372 size_t dyncount, Stringpool* pool,
2373 unsigned int* plocal_symcount)
2377 gold_assert(*plocal_symcount != 0);
2378 this->first_global_index_ = *plocal_symcount;
2380 this->dynamic_offset_ = dynoff;
2381 this->first_dynamic_global_index_ = dyn_global_index;
2382 this->dynamic_count_ = dyncount;
2384 if (parameters->target().get_size() == 32)
2386 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_32_LITTLE)
2387 ret = this->sized_finalize<32>(off, pool, plocal_symcount);
2392 else if (parameters->target().get_size() == 64)
2394 #if defined(HAVE_TARGET_64_BIG) || defined(HAVE_TARGET_64_LITTLE)
2395 ret = this->sized_finalize<64>(off, pool, plocal_symcount);
2403 // Now that we have the final symbol table, we can reliably note
2404 // which symbols should get warnings.
2405 this->warnings_.note_warnings(this);
2410 // SYM is going into the symbol table at *PINDEX. Add the name to
2411 // POOL, update *PINDEX and *POFF.
2415 Symbol_table::add_to_final_symtab(Symbol* sym, Stringpool* pool,
2416 unsigned int* pindex, off_t* poff)
2418 sym->set_symtab_index(*pindex);
2419 pool->add(sym->name(), false, NULL);
2421 *poff += elfcpp::Elf_sizes<size>::sym_size;
2424 // Set the final value for all the symbols. This is called after
2425 // Layout::finalize, so all the output sections have their final
2430 Symbol_table::sized_finalize(off_t off, Stringpool* pool,
2431 unsigned int* plocal_symcount)
2433 off = align_address(off, size >> 3);
2434 this->offset_ = off;
2436 unsigned int index = *plocal_symcount;
2437 const unsigned int orig_index = index;
2439 // First do all the symbols which have been forced to be local, as
2440 // they must appear before all global symbols.
2441 for (Forced_locals::iterator p = this->forced_locals_.begin();
2442 p != this->forced_locals_.end();
2446 gold_assert(sym->is_forced_local());
2447 if (this->sized_finalize_symbol<size>(sym))
2449 this->add_to_final_symtab<size>(sym, pool, &index, &off);
2454 // Now do all the remaining symbols.
2455 for (Symbol_table_type::iterator p = this->table_.begin();
2456 p != this->table_.end();
2459 Symbol* sym = p->second;
2460 if (this->sized_finalize_symbol<size>(sym))
2461 this->add_to_final_symtab<size>(sym, pool, &index, &off);
2464 this->output_count_ = index - orig_index;
2469 // Compute the final value of SYM and store status in location PSTATUS.
2470 // During relaxation, this may be called multiple times for a symbol to
2471 // compute its would-be final value in each relaxation pass.
2474 typename Sized_symbol<size>::Value_type
2475 Symbol_table::compute_final_value(
2476 const Sized_symbol<size>* sym,
2477 Compute_final_value_status* pstatus) const
2479 typedef typename Sized_symbol<size>::Value_type Value_type;
2482 switch (sym->source())
2484 case Symbol::FROM_OBJECT:
2487 unsigned int shndx = sym->shndx(&is_ordinary);
2490 && shndx != elfcpp::SHN_ABS
2491 && !Symbol::is_common_shndx(shndx))
2493 *pstatus = CFVS_UNSUPPORTED_SYMBOL_SECTION;
2497 Object* symobj = sym->object();
2498 if (symobj->is_dynamic())
2501 shndx = elfcpp::SHN_UNDEF;
2503 else if (symobj->pluginobj() != NULL)
2506 shndx = elfcpp::SHN_UNDEF;
2508 else if (shndx == elfcpp::SHN_UNDEF)
2510 else if (!is_ordinary
2511 && (shndx == elfcpp::SHN_ABS
2512 || Symbol::is_common_shndx(shndx)))
2513 value = sym->value();
2516 Relobj* relobj = static_cast<Relobj*>(symobj);
2517 Output_section* os = relobj->output_section(shndx);
2519 if (this->is_section_folded(relobj, shndx))
2521 gold_assert(os == NULL);
2522 // Get the os of the section it is folded onto.
2523 Section_id folded = this->icf_->get_folded_section(relobj,
2525 gold_assert(folded.first != NULL);
2526 Relobj* folded_obj = reinterpret_cast<Relobj*>(folded.first);
2527 unsigned folded_shndx = folded.second;
2529 os = folded_obj->output_section(folded_shndx);
2530 gold_assert(os != NULL);
2532 // Replace (relobj, shndx) with canonical ICF input section.
2533 shndx = folded_shndx;
2534 relobj = folded_obj;
2537 uint64_t secoff64 = relobj->output_section_offset(shndx);
2540 bool static_or_reloc = (parameters->doing_static_link() ||
2541 parameters->options().relocatable());
2542 gold_assert(static_or_reloc || sym->dynsym_index() == -1U);
2544 *pstatus = CFVS_NO_OUTPUT_SECTION;
2548 if (secoff64 == -1ULL)
2550 // The section needs special handling (e.g., a merge section).
2552 value = os->output_address(relobj, shndx, sym->value());
2557 convert_types<Value_type, uint64_t>(secoff64);
2558 if (sym->type() == elfcpp::STT_TLS)
2559 value = sym->value() + os->tls_offset() + secoff;
2561 value = sym->value() + os->address() + secoff;
2567 case Symbol::IN_OUTPUT_DATA:
2569 Output_data* od = sym->output_data();
2570 value = sym->value();
2571 if (sym->type() != elfcpp::STT_TLS)
2572 value += od->address();
2575 Output_section* os = od->output_section();
2576 gold_assert(os != NULL);
2577 value += os->tls_offset() + (od->address() - os->address());
2579 if (sym->offset_is_from_end())
2580 value += od->data_size();
2584 case Symbol::IN_OUTPUT_SEGMENT:
2586 Output_segment* os = sym->output_segment();
2587 value = sym->value();
2588 if (sym->type() != elfcpp::STT_TLS)
2589 value += os->vaddr();
2590 switch (sym->offset_base())
2592 case Symbol::SEGMENT_START:
2594 case Symbol::SEGMENT_END:
2595 value += os->memsz();
2597 case Symbol::SEGMENT_BSS:
2598 value += os->filesz();
2606 case Symbol::IS_CONSTANT:
2607 value = sym->value();
2610 case Symbol::IS_UNDEFINED:
2622 // Finalize the symbol SYM. This returns true if the symbol should be
2623 // added to the symbol table, false otherwise.
2627 Symbol_table::sized_finalize_symbol(Symbol* unsized_sym)
2629 typedef typename Sized_symbol<size>::Value_type Value_type;
2631 Sized_symbol<size>* sym = static_cast<Sized_symbol<size>*>(unsized_sym);
2633 // The default version of a symbol may appear twice in the symbol
2634 // table. We only need to finalize it once.
2635 if (sym->has_symtab_index())
2640 gold_assert(!sym->has_symtab_index());
2641 sym->set_symtab_index(-1U);
2642 gold_assert(sym->dynsym_index() == -1U);
2646 // If the symbol is only present on plugin files, the plugin decided we
2648 if (!sym->in_real_elf())
2650 gold_assert(!sym->has_symtab_index());
2651 sym->set_symtab_index(-1U);
2655 // Compute final symbol value.
2656 Compute_final_value_status status;
2657 Value_type value = this->compute_final_value(sym, &status);
2663 case CFVS_UNSUPPORTED_SYMBOL_SECTION:
2666 unsigned int shndx = sym->shndx(&is_ordinary);
2667 gold_error(_("%s: unsupported symbol section 0x%x"),
2668 sym->demangled_name().c_str(), shndx);
2671 case CFVS_NO_OUTPUT_SECTION:
2672 sym->set_symtab_index(-1U);
2678 sym->set_value(value);
2680 if (parameters->options().strip_all()
2681 || !parameters->options().should_retain_symbol(sym->name()))
2683 sym->set_symtab_index(-1U);
2690 // Write out the global symbols.
2693 Symbol_table::write_globals(const Stringpool* sympool,
2694 const Stringpool* dynpool,
2695 Output_symtab_xindex* symtab_xindex,
2696 Output_symtab_xindex* dynsym_xindex,
2697 Output_file* of) const
2699 switch (parameters->size_and_endianness())
2701 #ifdef HAVE_TARGET_32_LITTLE
2702 case Parameters::TARGET_32_LITTLE:
2703 this->sized_write_globals<32, false>(sympool, dynpool, symtab_xindex,
2707 #ifdef HAVE_TARGET_32_BIG
2708 case Parameters::TARGET_32_BIG:
2709 this->sized_write_globals<32, true>(sympool, dynpool, symtab_xindex,
2713 #ifdef HAVE_TARGET_64_LITTLE
2714 case Parameters::TARGET_64_LITTLE:
2715 this->sized_write_globals<64, false>(sympool, dynpool, symtab_xindex,
2719 #ifdef HAVE_TARGET_64_BIG
2720 case Parameters::TARGET_64_BIG:
2721 this->sized_write_globals<64, true>(sympool, dynpool, symtab_xindex,
2730 // Write out the global symbols.
2732 template<int size, bool big_endian>
2734 Symbol_table::sized_write_globals(const Stringpool* sympool,
2735 const Stringpool* dynpool,
2736 Output_symtab_xindex* symtab_xindex,
2737 Output_symtab_xindex* dynsym_xindex,
2738 Output_file* of) const
2740 const Target& target = parameters->target();
2742 const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
2744 const unsigned int output_count = this->output_count_;
2745 const section_size_type oview_size = output_count * sym_size;
2746 const unsigned int first_global_index = this->first_global_index_;
2747 unsigned char* psyms;
2748 if (this->offset_ == 0 || output_count == 0)
2751 psyms = of->get_output_view(this->offset_, oview_size);
2753 const unsigned int dynamic_count = this->dynamic_count_;
2754 const section_size_type dynamic_size = dynamic_count * sym_size;
2755 const unsigned int first_dynamic_global_index =
2756 this->first_dynamic_global_index_;
2757 unsigned char* dynamic_view;
2758 if (this->dynamic_offset_ == 0 || dynamic_count == 0)
2759 dynamic_view = NULL;
2761 dynamic_view = of->get_output_view(this->dynamic_offset_, dynamic_size);
2763 for (Symbol_table_type::const_iterator p = this->table_.begin();
2764 p != this->table_.end();
2767 Sized_symbol<size>* sym = static_cast<Sized_symbol<size>*>(p->second);
2769 // Possibly warn about unresolved symbols in shared libraries.
2770 this->warn_about_undefined_dynobj_symbol(sym);
2772 unsigned int sym_index = sym->symtab_index();
2773 unsigned int dynsym_index;
2774 if (dynamic_view == NULL)
2777 dynsym_index = sym->dynsym_index();
2779 if (sym_index == -1U && dynsym_index == -1U)
2781 // This symbol is not included in the output file.
2786 typename elfcpp::Elf_types<size>::Elf_Addr sym_value = sym->value();
2787 typename elfcpp::Elf_types<size>::Elf_Addr dynsym_value = sym_value;
2788 elfcpp::STB binding = sym->binding();
2789 switch (sym->source())
2791 case Symbol::FROM_OBJECT:
2794 unsigned int in_shndx = sym->shndx(&is_ordinary);
2797 && in_shndx != elfcpp::SHN_ABS
2798 && !Symbol::is_common_shndx(in_shndx))
2800 gold_error(_("%s: unsupported symbol section 0x%x"),
2801 sym->demangled_name().c_str(), in_shndx);
2806 Object* symobj = sym->object();
2807 if (symobj->is_dynamic())
2809 if (sym->needs_dynsym_value())
2810 dynsym_value = target.dynsym_value(sym);
2811 shndx = elfcpp::SHN_UNDEF;
2812 if (sym->is_undef_binding_weak())
2813 binding = elfcpp::STB_WEAK;
2815 binding = elfcpp::STB_GLOBAL;
2817 else if (symobj->pluginobj() != NULL)
2818 shndx = elfcpp::SHN_UNDEF;
2819 else if (in_shndx == elfcpp::SHN_UNDEF
2821 && (in_shndx == elfcpp::SHN_ABS
2822 || Symbol::is_common_shndx(in_shndx))))
2826 Relobj* relobj = static_cast<Relobj*>(symobj);
2827 Output_section* os = relobj->output_section(in_shndx);
2828 if (this->is_section_folded(relobj, in_shndx))
2830 // This global symbol must be written out even though
2832 // Get the os of the section it is folded onto.
2834 this->icf_->get_folded_section(relobj, in_shndx);
2835 gold_assert(folded.first !=NULL);
2836 Relobj* folded_obj =
2837 reinterpret_cast<Relobj*>(folded.first);
2838 os = folded_obj->output_section(folded.second);
2839 gold_assert(os != NULL);
2841 gold_assert(os != NULL);
2842 shndx = os->out_shndx();
2844 if (shndx >= elfcpp::SHN_LORESERVE)
2846 if (sym_index != -1U)
2847 symtab_xindex->add(sym_index, shndx);
2848 if (dynsym_index != -1U)
2849 dynsym_xindex->add(dynsym_index, shndx);
2850 shndx = elfcpp::SHN_XINDEX;
2853 // In object files symbol values are section
2855 if (parameters->options().relocatable())
2856 sym_value -= os->address();
2862 case Symbol::IN_OUTPUT_DATA:
2863 shndx = sym->output_data()->out_shndx();
2864 if (shndx >= elfcpp::SHN_LORESERVE)
2866 if (sym_index != -1U)
2867 symtab_xindex->add(sym_index, shndx);
2868 if (dynsym_index != -1U)
2869 dynsym_xindex->add(dynsym_index, shndx);
2870 shndx = elfcpp::SHN_XINDEX;
2874 case Symbol::IN_OUTPUT_SEGMENT:
2875 shndx = elfcpp::SHN_ABS;
2878 case Symbol::IS_CONSTANT:
2879 shndx = elfcpp::SHN_ABS;
2882 case Symbol::IS_UNDEFINED:
2883 shndx = elfcpp::SHN_UNDEF;
2890 if (sym_index != -1U)
2892 sym_index -= first_global_index;
2893 gold_assert(sym_index < output_count);
2894 unsigned char* ps = psyms + (sym_index * sym_size);
2895 this->sized_write_symbol<size, big_endian>(sym, sym_value, shndx,
2896 binding, sympool, ps);
2899 if (dynsym_index != -1U)
2901 dynsym_index -= first_dynamic_global_index;
2902 gold_assert(dynsym_index < dynamic_count);
2903 unsigned char* pd = dynamic_view + (dynsym_index * sym_size);
2904 this->sized_write_symbol<size, big_endian>(sym, dynsym_value, shndx,
2905 binding, dynpool, pd);
2909 of->write_output_view(this->offset_, oview_size, psyms);
2910 if (dynamic_view != NULL)
2911 of->write_output_view(this->dynamic_offset_, dynamic_size, dynamic_view);
2914 // Write out the symbol SYM, in section SHNDX, to P. POOL is the
2915 // strtab holding the name.
2917 template<int size, bool big_endian>
2919 Symbol_table::sized_write_symbol(
2920 Sized_symbol<size>* sym,
2921 typename elfcpp::Elf_types<size>::Elf_Addr value,
2923 elfcpp::STB binding,
2924 const Stringpool* pool,
2925 unsigned char* p) const
2927 elfcpp::Sym_write<size, big_endian> osym(p);
2928 osym.put_st_name(pool->get_offset(sym->name()));
2929 osym.put_st_value(value);
2930 // Use a symbol size of zero for undefined symbols from shared libraries.
2931 if (shndx == elfcpp::SHN_UNDEF && sym->is_from_dynobj())
2932 osym.put_st_size(0);
2934 osym.put_st_size(sym->symsize());
2935 elfcpp::STT type = sym->type();
2936 // Turn IFUNC symbols from shared libraries into normal FUNC symbols.
2937 if (type == elfcpp::STT_GNU_IFUNC
2938 && sym->is_from_dynobj())
2939 type = elfcpp::STT_FUNC;
2940 // A version script may have overridden the default binding.
2941 if (sym->is_forced_local())
2942 osym.put_st_info(elfcpp::elf_st_info(elfcpp::STB_LOCAL, type));
2944 osym.put_st_info(elfcpp::elf_st_info(binding, type));
2945 osym.put_st_other(elfcpp::elf_st_other(sym->visibility(), sym->nonvis()));
2946 osym.put_st_shndx(shndx);
2949 // Check for unresolved symbols in shared libraries. This is
2950 // controlled by the --allow-shlib-undefined option.
2952 // We only warn about libraries for which we have seen all the
2953 // DT_NEEDED entries. We don't try to track down DT_NEEDED entries
2954 // which were not seen in this link. If we didn't see a DT_NEEDED
2955 // entry, we aren't going to be able to reliably report whether the
2956 // symbol is undefined.
2958 // We also don't warn about libraries found in a system library
2959 // directory (e.g., /lib or /usr/lib); we assume that those libraries
2960 // are OK. This heuristic avoids problems on GNU/Linux, in which -ldl
2961 // can have undefined references satisfied by ld-linux.so.
2964 Symbol_table::warn_about_undefined_dynobj_symbol(Symbol* sym) const
2967 if (sym->source() == Symbol::FROM_OBJECT
2968 && sym->object()->is_dynamic()
2969 && sym->shndx(&dummy) == elfcpp::SHN_UNDEF
2970 && sym->binding() != elfcpp::STB_WEAK
2971 && !parameters->options().allow_shlib_undefined()
2972 && !parameters->target().is_defined_by_abi(sym)
2973 && !sym->object()->is_in_system_directory())
2975 // A very ugly cast.
2976 Dynobj* dynobj = static_cast<Dynobj*>(sym->object());
2977 if (!dynobj->has_unknown_needed_entries())
2978 gold_undefined_symbol(sym);
2982 // Write out a section symbol. Return the update offset.
2985 Symbol_table::write_section_symbol(const Output_section* os,
2986 Output_symtab_xindex* symtab_xindex,
2990 switch (parameters->size_and_endianness())
2992 #ifdef HAVE_TARGET_32_LITTLE
2993 case Parameters::TARGET_32_LITTLE:
2994 this->sized_write_section_symbol<32, false>(os, symtab_xindex, of,
2998 #ifdef HAVE_TARGET_32_BIG
2999 case Parameters::TARGET_32_BIG:
3000 this->sized_write_section_symbol<32, true>(os, symtab_xindex, of,
3004 #ifdef HAVE_TARGET_64_LITTLE
3005 case Parameters::TARGET_64_LITTLE:
3006 this->sized_write_section_symbol<64, false>(os, symtab_xindex, of,
3010 #ifdef HAVE_TARGET_64_BIG
3011 case Parameters::TARGET_64_BIG:
3012 this->sized_write_section_symbol<64, true>(os, symtab_xindex, of,
3021 // Write out a section symbol, specialized for size and endianness.
3023 template<int size, bool big_endian>
3025 Symbol_table::sized_write_section_symbol(const Output_section* os,
3026 Output_symtab_xindex* symtab_xindex,
3030 const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
3032 unsigned char* pov = of->get_output_view(offset, sym_size);
3034 elfcpp::Sym_write<size, big_endian> osym(pov);
3035 osym.put_st_name(0);
3036 if (parameters->options().relocatable())
3037 osym.put_st_value(0);
3039 osym.put_st_value(os->address());
3040 osym.put_st_size(0);
3041 osym.put_st_info(elfcpp::elf_st_info(elfcpp::STB_LOCAL,
3042 elfcpp::STT_SECTION));
3043 osym.put_st_other(elfcpp::elf_st_other(elfcpp::STV_DEFAULT, 0));
3045 unsigned int shndx = os->out_shndx();
3046 if (shndx >= elfcpp::SHN_LORESERVE)
3048 symtab_xindex->add(os->symtab_index(), shndx);
3049 shndx = elfcpp::SHN_XINDEX;
3051 osym.put_st_shndx(shndx);
3053 of->write_output_view(offset, sym_size, pov);
3056 // Print statistical information to stderr. This is used for --stats.
3059 Symbol_table::print_stats() const
3061 #if defined(HAVE_TR1_UNORDERED_MAP) || defined(HAVE_EXT_HASH_MAP)
3062 fprintf(stderr, _("%s: symbol table entries: %zu; buckets: %zu\n"),
3063 program_name, this->table_.size(), this->table_.bucket_count());
3065 fprintf(stderr, _("%s: symbol table entries: %zu\n"),
3066 program_name, this->table_.size());
3068 this->namepool_.print_stats("symbol table stringpool");
3071 // We check for ODR violations by looking for symbols with the same
3072 // name for which the debugging information reports that they were
3073 // defined in disjoint source locations. When comparing the source
3074 // location, we consider instances with the same base filename to be
3075 // the same. This is because different object files/shared libraries
3076 // can include the same header file using different paths, and
3077 // different optimization settings can make the line number appear to
3078 // be a couple lines off, and we don't want to report an ODR violation
3081 // This struct is used to compare line information, as returned by
3082 // Dwarf_line_info::one_addr2line. It implements a < comparison
3083 // operator used with std::sort.
3085 struct Odr_violation_compare
3088 operator()(const std::string& s1, const std::string& s2) const
3090 // Inputs should be of the form "dirname/filename:linenum" where
3091 // "dirname/" is optional. We want to compare just the filename:linenum.
3093 // Find the last '/' in each string.
3094 std::string::size_type s1begin = s1.rfind('/');
3095 std::string::size_type s2begin = s2.rfind('/');
3096 // If there was no '/' in a string, start at the beginning.
3097 if (s1begin == std::string::npos)
3099 if (s2begin == std::string::npos)
3101 return s1.compare(s1begin, std::string::npos,
3102 s2, s2begin, std::string::npos) < 0;
3106 // Returns all of the lines attached to LOC, not just the one the
3107 // instruction actually came from.
3108 std::vector<std::string>
3109 Symbol_table::linenos_from_loc(const Task* task,
3110 const Symbol_location& loc)
3112 // We need to lock the object in order to read it. This
3113 // means that we have to run in a singleton Task. If we
3114 // want to run this in a general Task for better
3115 // performance, we will need one Task for object, plus
3116 // appropriate locking to ensure that we don't conflict with
3117 // other uses of the object. Also note, one_addr2line is not
3118 // currently thread-safe.
3119 Task_lock_obj<Object> tl(task, loc.object);
3121 std::vector<std::string> result;
3122 // 16 is the size of the object-cache that one_addr2line should use.
3123 std::string canonical_result = Dwarf_line_info::one_addr2line(
3124 loc.object, loc.shndx, loc.offset, 16, &result);
3125 if (!canonical_result.empty())
3126 result.push_back(canonical_result);
3130 // OutputIterator that records if it was ever assigned to. This
3131 // allows it to be used with std::set_intersection() to check for
3132 // intersection rather than computing the intersection.
3133 struct Check_intersection
3135 Check_intersection()
3139 bool had_intersection() const
3140 { return this->value_; }
3142 Check_intersection& operator++()
3145 Check_intersection& operator*()
3148 template<typename T>
3149 Check_intersection& operator=(const T&)
3151 this->value_ = true;
3159 // Check candidate_odr_violations_ to find symbols with the same name
3160 // but apparently different definitions (different source-file/line-no
3161 // for each line assigned to the first instruction).
3164 Symbol_table::detect_odr_violations(const Task* task,
3165 const char* output_file_name) const
3167 for (Odr_map::const_iterator it = candidate_odr_violations_.begin();
3168 it != candidate_odr_violations_.end();
3171 const char* const symbol_name = it->first;
3173 std::string first_object_name;
3174 std::vector<std::string> first_object_linenos;
3176 Unordered_set<Symbol_location, Symbol_location_hash>::const_iterator
3177 locs = it->second.begin();
3178 const Unordered_set<Symbol_location, Symbol_location_hash>::const_iterator
3179 locs_end = it->second.end();
3180 for (; locs != locs_end && first_object_linenos.empty(); ++locs)
3182 // Save the line numbers from the first definition to
3183 // compare to the other definitions. Ideally, we'd compare
3184 // every definition to every other, but we don't want to
3185 // take O(N^2) time to do this. This shortcut may cause
3186 // false negatives that appear or disappear depending on the
3187 // link order, but it won't cause false positives.
3188 first_object_name = locs->object->name();
3189 first_object_linenos = this->linenos_from_loc(task, *locs);
3192 // Sort by Odr_violation_compare to make std::set_intersection work.
3193 std::sort(first_object_linenos.begin(), first_object_linenos.end(),
3194 Odr_violation_compare());
3196 for (; locs != locs_end; ++locs)
3198 std::vector<std::string> linenos =
3199 this->linenos_from_loc(task, *locs);
3200 // linenos will be empty if we couldn't parse the debug info.
3201 if (linenos.empty())
3203 // Sort by Odr_violation_compare to make std::set_intersection work.
3204 std::sort(linenos.begin(), linenos.end(), Odr_violation_compare());
3206 Check_intersection intersection_result =
3207 std::set_intersection(first_object_linenos.begin(),
3208 first_object_linenos.end(),
3211 Check_intersection(),
3212 Odr_violation_compare());
3213 if (!intersection_result.had_intersection())
3215 gold_warning(_("while linking %s: symbol '%s' defined in "
3216 "multiple places (possible ODR violation):"),
3217 output_file_name, demangle(symbol_name).c_str());
3218 // This only prints one location from each definition,
3219 // which may not be the location we expect to intersect
3220 // with another definition. We could print the whole
3221 // set of locations, but that seems too verbose.
3222 gold_assert(!first_object_linenos.empty());
3223 gold_assert(!linenos.empty());
3224 fprintf(stderr, _(" %s from %s\n"),
3225 first_object_linenos[0].c_str(),
3226 first_object_name.c_str());
3227 fprintf(stderr, _(" %s from %s\n"),
3229 locs->object->name().c_str());
3230 // Only print one broken pair, to avoid needing to
3231 // compare against a list of the disjoint definition
3232 // locations we've found so far. (If we kept comparing
3233 // against just the first one, we'd get a lot of
3234 // redundant complaints about the second definition
3240 // We only call one_addr2line() in this function, so we can clear its cache.
3241 Dwarf_line_info::clear_addr2line_cache();
3244 // Warnings functions.
3246 // Add a new warning.
3249 Warnings::add_warning(Symbol_table* symtab, const char* name, Object* obj,
3250 const std::string& warning)
3252 name = symtab->canonicalize_name(name);
3253 this->warnings_[name].set(obj, warning);
3256 // Look through the warnings and mark the symbols for which we should
3257 // warn. This is called during Layout::finalize when we know the
3258 // sources for all the symbols.
3261 Warnings::note_warnings(Symbol_table* symtab)
3263 for (Warning_table::iterator p = this->warnings_.begin();
3264 p != this->warnings_.end();
3267 Symbol* sym = symtab->lookup(p->first, NULL);
3269 && sym->source() == Symbol::FROM_OBJECT
3270 && sym->object() == p->second.object)
3271 sym->set_has_warning();
3275 // Issue a warning. This is called when we see a relocation against a
3276 // symbol for which has a warning.
3278 template<int size, bool big_endian>
3280 Warnings::issue_warning(const Symbol* sym,
3281 const Relocate_info<size, big_endian>* relinfo,
3282 size_t relnum, off_t reloffset) const
3284 gold_assert(sym->has_warning());
3285 Warning_table::const_iterator p = this->warnings_.find(sym->name());
3286 gold_assert(p != this->warnings_.end());
3287 gold_warning_at_location(relinfo, relnum, reloffset,
3288 "%s", p->second.text.c_str());
3291 // Instantiate the templates we need. We could use the configure
3292 // script to restrict this to only the ones needed for implemented
3295 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
3298 Sized_symbol<32>::allocate_common(Output_data*, Value_type);
3301 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
3304 Sized_symbol<64>::allocate_common(Output_data*, Value_type);
3307 #ifdef HAVE_TARGET_32_LITTLE
3310 Symbol_table::add_from_relobj<32, false>(
3311 Sized_relobj_file<32, false>* relobj,
3312 const unsigned char* syms,
3314 size_t symndx_offset,
3315 const char* sym_names,
3316 size_t sym_name_size,
3317 Sized_relobj_file<32, false>::Symbols* sympointers,
3321 #ifdef HAVE_TARGET_32_BIG
3324 Symbol_table::add_from_relobj<32, true>(
3325 Sized_relobj_file<32, true>* relobj,
3326 const unsigned char* syms,
3328 size_t symndx_offset,
3329 const char* sym_names,
3330 size_t sym_name_size,
3331 Sized_relobj_file<32, true>::Symbols* sympointers,
3335 #ifdef HAVE_TARGET_64_LITTLE
3338 Symbol_table::add_from_relobj<64, false>(
3339 Sized_relobj_file<64, false>* relobj,
3340 const unsigned char* syms,
3342 size_t symndx_offset,
3343 const char* sym_names,
3344 size_t sym_name_size,
3345 Sized_relobj_file<64, false>::Symbols* sympointers,
3349 #ifdef HAVE_TARGET_64_BIG
3352 Symbol_table::add_from_relobj<64, true>(
3353 Sized_relobj_file<64, true>* relobj,
3354 const unsigned char* syms,
3356 size_t symndx_offset,
3357 const char* sym_names,
3358 size_t sym_name_size,
3359 Sized_relobj_file<64, true>::Symbols* sympointers,
3363 #ifdef HAVE_TARGET_32_LITTLE
3366 Symbol_table::add_from_pluginobj<32, false>(
3367 Sized_pluginobj<32, false>* obj,
3370 elfcpp::Sym<32, false>* sym);
3373 #ifdef HAVE_TARGET_32_BIG
3376 Symbol_table::add_from_pluginobj<32, true>(
3377 Sized_pluginobj<32, true>* obj,
3380 elfcpp::Sym<32, true>* sym);
3383 #ifdef HAVE_TARGET_64_LITTLE
3386 Symbol_table::add_from_pluginobj<64, false>(
3387 Sized_pluginobj<64, false>* obj,
3390 elfcpp::Sym<64, false>* sym);
3393 #ifdef HAVE_TARGET_64_BIG
3396 Symbol_table::add_from_pluginobj<64, true>(
3397 Sized_pluginobj<64, true>* obj,
3400 elfcpp::Sym<64, true>* sym);
3403 #ifdef HAVE_TARGET_32_LITTLE
3406 Symbol_table::add_from_dynobj<32, false>(
3407 Sized_dynobj<32, false>* dynobj,
3408 const unsigned char* syms,
3410 const char* sym_names,
3411 size_t sym_name_size,
3412 const unsigned char* versym,
3414 const std::vector<const char*>* version_map,
3415 Sized_relobj_file<32, false>::Symbols* sympointers,
3419 #ifdef HAVE_TARGET_32_BIG
3422 Symbol_table::add_from_dynobj<32, true>(
3423 Sized_dynobj<32, true>* dynobj,
3424 const unsigned char* syms,
3426 const char* sym_names,
3427 size_t sym_name_size,
3428 const unsigned char* versym,
3430 const std::vector<const char*>* version_map,
3431 Sized_relobj_file<32, true>::Symbols* sympointers,
3435 #ifdef HAVE_TARGET_64_LITTLE
3438 Symbol_table::add_from_dynobj<64, false>(
3439 Sized_dynobj<64, false>* dynobj,
3440 const unsigned char* syms,
3442 const char* sym_names,
3443 size_t sym_name_size,
3444 const unsigned char* versym,
3446 const std::vector<const char*>* version_map,
3447 Sized_relobj_file<64, false>::Symbols* sympointers,
3451 #ifdef HAVE_TARGET_64_BIG
3454 Symbol_table::add_from_dynobj<64, true>(
3455 Sized_dynobj<64, true>* dynobj,
3456 const unsigned char* syms,
3458 const char* sym_names,
3459 size_t sym_name_size,
3460 const unsigned char* versym,
3462 const std::vector<const char*>* version_map,
3463 Sized_relobj_file<64, true>::Symbols* sympointers,
3467 #ifdef HAVE_TARGET_32_LITTLE
3470 Symbol_table::add_from_incrobj(
3474 elfcpp::Sym<32, false>* sym);
3477 #ifdef HAVE_TARGET_32_BIG
3480 Symbol_table::add_from_incrobj(
3484 elfcpp::Sym<32, true>* sym);
3487 #ifdef HAVE_TARGET_64_LITTLE
3490 Symbol_table::add_from_incrobj(
3494 elfcpp::Sym<64, false>* sym);
3497 #ifdef HAVE_TARGET_64_BIG
3500 Symbol_table::add_from_incrobj(
3504 elfcpp::Sym<64, true>* sym);
3507 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
3510 Symbol_table::define_with_copy_reloc<32>(
3511 Sized_symbol<32>* sym,
3513 elfcpp::Elf_types<32>::Elf_Addr value);
3516 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
3519 Symbol_table::define_with_copy_reloc<64>(
3520 Sized_symbol<64>* sym,
3522 elfcpp::Elf_types<64>::Elf_Addr value);
3525 #ifdef HAVE_TARGET_32_LITTLE
3528 Warnings::issue_warning<32, false>(const Symbol* sym,
3529 const Relocate_info<32, false>* relinfo,
3530 size_t relnum, off_t reloffset) const;
3533 #ifdef HAVE_TARGET_32_BIG
3536 Warnings::issue_warning<32, true>(const Symbol* sym,
3537 const Relocate_info<32, true>* relinfo,
3538 size_t relnum, off_t reloffset) const;
3541 #ifdef HAVE_TARGET_64_LITTLE
3544 Warnings::issue_warning<64, false>(const Symbol* sym,
3545 const Relocate_info<64, false>* relinfo,
3546 size_t relnum, off_t reloffset) const;
3549 #ifdef HAVE_TARGET_64_BIG
3552 Warnings::issue_warning<64, true>(const Symbol* sym,
3553 const Relocate_info<64, true>* relinfo,
3554 size_t relnum, off_t reloffset) const;
3557 } // End namespace gold.