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 symbol table key equality function. This is called with
508 Symbol_table::Symbol_table_eq::operator()(const Symbol_table_key& k1,
509 const Symbol_table_key& k2) const
511 return k1.first == k2.first && k1.second == k2.second;
515 Symbol_table::is_section_folded(Object* obj, unsigned int shndx) const
517 return (parameters->options().icf_enabled()
518 && this->icf_->is_section_folded(obj, shndx));
521 // For symbols that have been listed with -u option, add them to the
522 // work list to avoid gc'ing them.
525 Symbol_table::gc_mark_undef_symbols(Layout* layout)
527 for (options::String_set::const_iterator p =
528 parameters->options().undefined_begin();
529 p != parameters->options().undefined_end();
532 const char* name = p->c_str();
533 Symbol* sym = this->lookup(name);
534 gold_assert(sym != NULL);
535 if (sym->source() == Symbol::FROM_OBJECT
536 && !sym->object()->is_dynamic())
538 Relobj* obj = static_cast<Relobj*>(sym->object());
540 unsigned int shndx = sym->shndx(&is_ordinary);
543 gold_assert(this->gc_ != NULL);
544 this->gc_->worklist().push(Section_id(obj, shndx));
549 for (Script_options::referenced_const_iterator p =
550 layout->script_options()->referenced_begin();
551 p != layout->script_options()->referenced_end();
554 Symbol* sym = this->lookup(p->c_str());
555 gold_assert(sym != NULL);
556 if (sym->source() == Symbol::FROM_OBJECT
557 && !sym->object()->is_dynamic())
559 Relobj* obj = static_cast<Relobj*>(sym->object());
561 unsigned int shndx = sym->shndx(&is_ordinary);
564 gold_assert(this->gc_ != NULL);
565 this->gc_->worklist().push(Section_id(obj, shndx));
572 Symbol_table::gc_mark_symbol_for_shlib(Symbol* sym)
574 if (!sym->is_from_dynobj()
575 && sym->is_externally_visible())
577 //Add the object and section to the work list.
578 Relobj* obj = static_cast<Relobj*>(sym->object());
580 unsigned int shndx = sym->shndx(&is_ordinary);
581 if (is_ordinary && shndx != elfcpp::SHN_UNDEF)
583 gold_assert(this->gc_!= NULL);
584 this->gc_->worklist().push(Section_id(obj, shndx));
589 // When doing garbage collection, keep symbols that have been seen in
592 Symbol_table::gc_mark_dyn_syms(Symbol* sym)
594 if (sym->in_dyn() && sym->source() == Symbol::FROM_OBJECT
595 && !sym->object()->is_dynamic())
597 Relobj* obj = static_cast<Relobj*>(sym->object());
599 unsigned int shndx = sym->shndx(&is_ordinary);
600 if (is_ordinary && shndx != elfcpp::SHN_UNDEF)
602 gold_assert(this->gc_ != NULL);
603 this->gc_->worklist().push(Section_id(obj, shndx));
608 // Make TO a symbol which forwards to FROM.
611 Symbol_table::make_forwarder(Symbol* from, Symbol* to)
613 gold_assert(from != to);
614 gold_assert(!from->is_forwarder() && !to->is_forwarder());
615 this->forwarders_[from] = to;
616 from->set_forwarder();
619 // Resolve the forwards from FROM, returning the real symbol.
622 Symbol_table::resolve_forwards(const Symbol* from) const
624 gold_assert(from->is_forwarder());
625 Unordered_map<const Symbol*, Symbol*>::const_iterator p =
626 this->forwarders_.find(from);
627 gold_assert(p != this->forwarders_.end());
631 // Look up a symbol by name.
634 Symbol_table::lookup(const char* name, const char* version) const
636 Stringpool::Key name_key;
637 name = this->namepool_.find(name, &name_key);
641 Stringpool::Key version_key = 0;
644 version = this->namepool_.find(version, &version_key);
649 Symbol_table_key key(name_key, version_key);
650 Symbol_table::Symbol_table_type::const_iterator p = this->table_.find(key);
651 if (p == this->table_.end())
656 // Resolve a Symbol with another Symbol. This is only used in the
657 // unusual case where there are references to both an unversioned
658 // symbol and a symbol with a version, and we then discover that that
659 // version is the default version. Because this is unusual, we do
660 // this the slow way, by converting back to an ELF symbol.
662 template<int size, bool big_endian>
664 Symbol_table::resolve(Sized_symbol<size>* to, const Sized_symbol<size>* from)
666 unsigned char buf[elfcpp::Elf_sizes<size>::sym_size];
667 elfcpp::Sym_write<size, big_endian> esym(buf);
668 // We don't bother to set the st_name or the st_shndx field.
669 esym.put_st_value(from->value());
670 esym.put_st_size(from->symsize());
671 esym.put_st_info(from->binding(), from->type());
672 esym.put_st_other(from->visibility(), from->nonvis());
674 unsigned int shndx = from->shndx(&is_ordinary);
675 this->resolve(to, esym.sym(), shndx, is_ordinary, shndx, from->object(),
681 if (parameters->options().gc_sections())
682 this->gc_mark_dyn_syms(to);
685 // Record that a symbol is forced to be local by a version script or
689 Symbol_table::force_local(Symbol* sym)
691 if (!sym->is_defined() && !sym->is_common())
693 if (sym->is_forced_local())
695 // We already got this one.
698 sym->set_is_forced_local();
699 this->forced_locals_.push_back(sym);
702 // Adjust NAME for wrapping, and update *NAME_KEY if necessary. This
703 // is only called for undefined symbols, when at least one --wrap
707 Symbol_table::wrap_symbol(const char* name, Stringpool::Key* name_key)
709 // For some targets, we need to ignore a specific character when
710 // wrapping, and add it back later.
712 if (name[0] == parameters->target().wrap_char())
718 if (parameters->options().is_wrap(name))
720 // Turn NAME into __wrap_NAME.
727 // This will give us both the old and new name in NAMEPOOL_, but
728 // that is OK. Only the versions we need will wind up in the
729 // real string table in the output file.
730 return this->namepool_.add(s.c_str(), true, name_key);
733 const char* const real_prefix = "__real_";
734 const size_t real_prefix_length = strlen(real_prefix);
735 if (strncmp(name, real_prefix, real_prefix_length) == 0
736 && parameters->options().is_wrap(name + real_prefix_length))
738 // Turn __real_NAME into NAME.
742 s += name + real_prefix_length;
743 return this->namepool_.add(s.c_str(), true, name_key);
749 // This is called when we see a symbol NAME/VERSION, and the symbol
750 // already exists in the symbol table, and VERSION is marked as being
751 // the default version. SYM is the NAME/VERSION symbol we just added.
752 // DEFAULT_IS_NEW is true if this is the first time we have seen the
753 // symbol NAME/NULL. PDEF points to the entry for NAME/NULL.
755 template<int size, bool big_endian>
757 Symbol_table::define_default_version(Sized_symbol<size>* sym,
759 Symbol_table_type::iterator pdef)
763 // This is the first time we have seen NAME/NULL. Make
764 // NAME/NULL point to NAME/VERSION, and mark SYM as the default
767 sym->set_is_default();
769 else if (pdef->second == sym)
771 // NAME/NULL already points to NAME/VERSION. Don't mark the
772 // symbol as the default if it is not already the default.
776 // This is the unfortunate case where we already have entries
777 // for both NAME/VERSION and NAME/NULL. We now see a symbol
778 // NAME/VERSION where VERSION is the default version. We have
779 // already resolved this new symbol with the existing
780 // NAME/VERSION symbol.
782 // It's possible that NAME/NULL and NAME/VERSION are both
783 // defined in regular objects. This can only happen if one
784 // object file defines foo and another defines foo@@ver. This
785 // is somewhat obscure, but we call it a multiple definition
788 // It's possible that NAME/NULL actually has a version, in which
789 // case it won't be the same as VERSION. This happens with
790 // ver_test_7.so in the testsuite for the symbol t2_2. We see
791 // t2_2@@VER2, so we define both t2_2/VER2 and t2_2/NULL. We
792 // then see an unadorned t2_2 in an object file and give it
793 // version VER1 from the version script. This looks like a
794 // default definition for VER1, so it looks like we should merge
795 // t2_2/NULL with t2_2/VER1. That doesn't make sense, but it's
796 // not obvious that this is an error, either. So we just punt.
798 // If one of the symbols has non-default visibility, and the
799 // other is defined in a shared object, then they are different
802 // Otherwise, we just resolve the symbols as though they were
805 if (pdef->second->version() != NULL)
806 gold_assert(pdef->second->version() != sym->version());
807 else if (sym->visibility() != elfcpp::STV_DEFAULT
808 && pdef->second->is_from_dynobj())
810 else if (pdef->second->visibility() != elfcpp::STV_DEFAULT
811 && sym->is_from_dynobj())
815 const Sized_symbol<size>* symdef;
816 symdef = this->get_sized_symbol<size>(pdef->second);
817 Symbol_table::resolve<size, big_endian>(sym, symdef);
818 this->make_forwarder(pdef->second, sym);
820 sym->set_is_default();
825 // Add one symbol from OBJECT to the symbol table. NAME is symbol
826 // name and VERSION is the version; both are canonicalized. DEF is
827 // whether this is the default version. ST_SHNDX is the symbol's
828 // section index; IS_ORDINARY is whether this is a normal section
829 // rather than a special code.
831 // If IS_DEFAULT_VERSION is true, then this is the definition of a
832 // default version of a symbol. That means that any lookup of
833 // NAME/NULL and any lookup of NAME/VERSION should always return the
834 // same symbol. This is obvious for references, but in particular we
835 // want to do this for definitions: overriding NAME/NULL should also
836 // override NAME/VERSION. If we don't do that, it would be very hard
837 // to override functions in a shared library which uses versioning.
839 // We implement this by simply making both entries in the hash table
840 // point to the same Symbol structure. That is easy enough if this is
841 // the first time we see NAME/NULL or NAME/VERSION, but it is possible
842 // that we have seen both already, in which case they will both have
843 // independent entries in the symbol table. We can't simply change
844 // the symbol table entry, because we have pointers to the entries
845 // attached to the object files. So we mark the entry attached to the
846 // object file as a forwarder, and record it in the forwarders_ map.
847 // Note that entries in the hash table will never be marked as
850 // ORIG_ST_SHNDX and ST_SHNDX are almost always the same.
851 // ORIG_ST_SHNDX is the section index in the input file, or SHN_UNDEF
852 // for a special section code. ST_SHNDX may be modified if the symbol
853 // is defined in a section being discarded.
855 template<int size, bool big_endian>
857 Symbol_table::add_from_object(Object* object,
859 Stringpool::Key name_key,
861 Stringpool::Key version_key,
862 bool is_default_version,
863 const elfcpp::Sym<size, big_endian>& sym,
864 unsigned int st_shndx,
866 unsigned int orig_st_shndx)
868 // Print a message if this symbol is being traced.
869 if (parameters->options().is_trace_symbol(name))
871 if (orig_st_shndx == elfcpp::SHN_UNDEF)
872 gold_info(_("%s: reference to %s"), object->name().c_str(), name);
874 gold_info(_("%s: definition of %s"), object->name().c_str(), name);
877 // For an undefined symbol, we may need to adjust the name using
879 if (orig_st_shndx == elfcpp::SHN_UNDEF
880 && parameters->options().any_wrap())
882 const char* wrap_name = this->wrap_symbol(name, &name_key);
883 if (wrap_name != name)
885 // If we see a reference to malloc with version GLIBC_2.0,
886 // and we turn it into a reference to __wrap_malloc, then we
887 // discard the version number. Otherwise the user would be
888 // required to specify the correct version for
896 Symbol* const snull = NULL;
897 std::pair<typename Symbol_table_type::iterator, bool> ins =
898 this->table_.insert(std::make_pair(std::make_pair(name_key, version_key),
901 std::pair<typename Symbol_table_type::iterator, bool> insdefault =
902 std::make_pair(this->table_.end(), false);
903 if (is_default_version)
905 const Stringpool::Key vnull_key = 0;
906 insdefault = this->table_.insert(std::make_pair(std::make_pair(name_key,
911 // ins.first: an iterator, which is a pointer to a pair.
912 // ins.first->first: the key (a pair of name and version).
913 // ins.first->second: the value (Symbol*).
914 // ins.second: true if new entry was inserted, false if not.
916 Sized_symbol<size>* ret;
921 // We already have an entry for NAME/VERSION.
922 ret = this->get_sized_symbol<size>(ins.first->second);
923 gold_assert(ret != NULL);
925 was_undefined = ret->is_undefined();
926 was_common = ret->is_common();
928 this->resolve(ret, sym, st_shndx, is_ordinary, orig_st_shndx, object,
930 if (parameters->options().gc_sections())
931 this->gc_mark_dyn_syms(ret);
933 if (is_default_version)
934 this->define_default_version<size, big_endian>(ret, insdefault.second,
939 // This is the first time we have seen NAME/VERSION.
940 gold_assert(ins.first->second == NULL);
942 if (is_default_version && !insdefault.second)
944 // We already have an entry for NAME/NULL. If we override
945 // it, then change it to NAME/VERSION.
946 ret = this->get_sized_symbol<size>(insdefault.first->second);
948 was_undefined = ret->is_undefined();
949 was_common = ret->is_common();
951 this->resolve(ret, sym, st_shndx, is_ordinary, orig_st_shndx, object,
953 if (parameters->options().gc_sections())
954 this->gc_mark_dyn_syms(ret);
955 ins.first->second = ret;
959 was_undefined = false;
962 Sized_target<size, big_endian>* target =
963 parameters->sized_target<size, big_endian>();
964 if (!target->has_make_symbol())
965 ret = new Sized_symbol<size>();
968 ret = target->make_symbol();
971 // This means that we don't want a symbol table
973 if (!is_default_version)
974 this->table_.erase(ins.first);
977 this->table_.erase(insdefault.first);
978 // Inserting INSDEFAULT invalidated INS.
979 this->table_.erase(std::make_pair(name_key,
986 ret->init_object(name, version, object, sym, st_shndx, is_ordinary);
988 ins.first->second = ret;
989 if (is_default_version)
991 // This is the first time we have seen NAME/NULL. Point
992 // it at the new entry for NAME/VERSION.
993 gold_assert(insdefault.second);
994 insdefault.first->second = ret;
998 if (is_default_version)
999 ret->set_is_default();
1002 // Record every time we see a new undefined symbol, to speed up
1004 if (!was_undefined && ret->is_undefined())
1005 ++this->saw_undefined_;
1007 // Keep track of common symbols, to speed up common symbol
1009 if (!was_common && ret->is_common())
1011 if (ret->type() == elfcpp::STT_TLS)
1012 this->tls_commons_.push_back(ret);
1013 else if (!is_ordinary
1014 && st_shndx == parameters->target().small_common_shndx())
1015 this->small_commons_.push_back(ret);
1016 else if (!is_ordinary
1017 && st_shndx == parameters->target().large_common_shndx())
1018 this->large_commons_.push_back(ret);
1020 this->commons_.push_back(ret);
1023 // If we're not doing a relocatable link, then any symbol with
1024 // hidden or internal visibility is local.
1025 if ((ret->visibility() == elfcpp::STV_HIDDEN
1026 || ret->visibility() == elfcpp::STV_INTERNAL)
1027 && (ret->binding() == elfcpp::STB_GLOBAL
1028 || ret->binding() == elfcpp::STB_GNU_UNIQUE
1029 || ret->binding() == elfcpp::STB_WEAK)
1030 && !parameters->options().relocatable())
1031 this->force_local(ret);
1036 // Add all the symbols in a relocatable object to the hash table.
1038 template<int size, bool big_endian>
1040 Symbol_table::add_from_relobj(
1041 Sized_relobj<size, big_endian>* relobj,
1042 const unsigned char* syms,
1044 size_t symndx_offset,
1045 const char* sym_names,
1046 size_t sym_name_size,
1047 typename Sized_relobj<size, big_endian>::Symbols* sympointers,
1052 gold_assert(size == parameters->target().get_size());
1054 const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
1056 const bool just_symbols = relobj->just_symbols();
1058 const unsigned char* p = syms;
1059 for (size_t i = 0; i < count; ++i, p += sym_size)
1061 (*sympointers)[i] = NULL;
1063 elfcpp::Sym<size, big_endian> sym(p);
1065 unsigned int st_name = sym.get_st_name();
1066 if (st_name >= sym_name_size)
1068 relobj->error(_("bad global symbol name offset %u at %zu"),
1073 const char* name = sym_names + st_name;
1076 unsigned int st_shndx = relobj->adjust_sym_shndx(i + symndx_offset,
1079 unsigned int orig_st_shndx = st_shndx;
1081 orig_st_shndx = elfcpp::SHN_UNDEF;
1083 if (st_shndx != elfcpp::SHN_UNDEF)
1086 // A symbol defined in a section which we are not including must
1087 // be treated as an undefined symbol.
1088 bool is_defined_in_discarded_section = false;
1089 if (st_shndx != elfcpp::SHN_UNDEF
1091 && !relobj->is_section_included(st_shndx)
1092 && !this->is_section_folded(relobj, st_shndx))
1094 st_shndx = elfcpp::SHN_UNDEF;
1095 is_defined_in_discarded_section = true;
1098 // In an object file, an '@' in the name separates the symbol
1099 // name from the version name. If there are two '@' characters,
1100 // this is the default version.
1101 const char* ver = strchr(name, '@');
1102 Stringpool::Key ver_key = 0;
1104 // IS_DEFAULT_VERSION: is the version default?
1105 // IS_FORCED_LOCAL: is the symbol forced local?
1106 bool is_default_version = false;
1107 bool is_forced_local = false;
1111 // The symbol name is of the form foo@VERSION or foo@@VERSION
1112 namelen = ver - name;
1116 is_default_version = true;
1119 ver = this->namepool_.add(ver, true, &ver_key);
1121 // We don't want to assign a version to an undefined symbol,
1122 // even if it is listed in the version script. FIXME: What
1123 // about a common symbol?
1126 namelen = strlen(name);
1127 if (!this->version_script_.empty()
1128 && st_shndx != elfcpp::SHN_UNDEF)
1130 // The symbol name did not have a version, but the
1131 // version script may assign a version anyway.
1132 std::string version;
1134 if (this->version_script_.get_symbol_version(name, &version,
1138 is_forced_local = true;
1139 else if (!version.empty())
1141 ver = this->namepool_.add_with_length(version.c_str(),
1145 is_default_version = true;
1151 elfcpp::Sym<size, big_endian>* psym = &sym;
1152 unsigned char symbuf[sym_size];
1153 elfcpp::Sym<size, big_endian> sym2(symbuf);
1156 memcpy(symbuf, p, sym_size);
1157 elfcpp::Sym_write<size, big_endian> sw(symbuf);
1158 if (orig_st_shndx != elfcpp::SHN_UNDEF && is_ordinary)
1160 // Symbol values in object files are section relative.
1161 // This is normally what we want, but since here we are
1162 // converting the symbol to absolute we need to add the
1163 // section address. The section address in an object
1164 // file is normally zero, but people can use a linker
1165 // script to change it.
1166 sw.put_st_value(sym.get_st_value()
1167 + relobj->section_address(orig_st_shndx));
1169 st_shndx = elfcpp::SHN_ABS;
1170 is_ordinary = false;
1174 // Fix up visibility if object has no-export set.
1175 if (relobj->no_export()
1176 && (orig_st_shndx != elfcpp::SHN_UNDEF || !is_ordinary))
1178 // We may have copied symbol already above.
1181 memcpy(symbuf, p, sym_size);
1185 elfcpp::STV visibility = sym2.get_st_visibility();
1186 if (visibility == elfcpp::STV_DEFAULT
1187 || visibility == elfcpp::STV_PROTECTED)
1189 elfcpp::Sym_write<size, big_endian> sw(symbuf);
1190 unsigned char nonvis = sym2.get_st_nonvis();
1191 sw.put_st_other(elfcpp::STV_HIDDEN, nonvis);
1195 Stringpool::Key name_key;
1196 name = this->namepool_.add_with_length(name, namelen, true,
1199 Sized_symbol<size>* res;
1200 res = this->add_from_object(relobj, name, name_key, ver, ver_key,
1201 is_default_version, *psym, st_shndx,
1202 is_ordinary, orig_st_shndx);
1204 // If building a shared library using garbage collection, do not
1205 // treat externally visible symbols as garbage.
1206 if (parameters->options().gc_sections()
1207 && parameters->options().shared())
1208 this->gc_mark_symbol_for_shlib(res);
1210 if (is_forced_local)
1211 this->force_local(res);
1213 if (is_defined_in_discarded_section)
1214 res->set_is_defined_in_discarded_section();
1216 (*sympointers)[i] = res;
1220 // Add a symbol from a plugin-claimed file.
1222 template<int size, bool big_endian>
1224 Symbol_table::add_from_pluginobj(
1225 Sized_pluginobj<size, big_endian>* obj,
1228 elfcpp::Sym<size, big_endian>* sym)
1230 unsigned int st_shndx = sym->get_st_shndx();
1231 bool is_ordinary = st_shndx < elfcpp::SHN_LORESERVE;
1233 Stringpool::Key ver_key = 0;
1234 bool is_default_version = false;
1235 bool is_forced_local = false;
1239 ver = this->namepool_.add(ver, true, &ver_key);
1241 // We don't want to assign a version to an undefined symbol,
1242 // even if it is listed in the version script. FIXME: What
1243 // about a common symbol?
1246 if (!this->version_script_.empty()
1247 && st_shndx != elfcpp::SHN_UNDEF)
1249 // The symbol name did not have a version, but the
1250 // version script may assign a version anyway.
1251 std::string version;
1253 if (this->version_script_.get_symbol_version(name, &version,
1257 is_forced_local = true;
1258 else if (!version.empty())
1260 ver = this->namepool_.add_with_length(version.c_str(),
1264 is_default_version = true;
1270 Stringpool::Key name_key;
1271 name = this->namepool_.add(name, true, &name_key);
1273 Sized_symbol<size>* res;
1274 res = this->add_from_object(obj, name, name_key, ver, ver_key,
1275 is_default_version, *sym, st_shndx,
1276 is_ordinary, st_shndx);
1278 if (is_forced_local)
1279 this->force_local(res);
1284 // Add all the symbols in a dynamic object to the hash table.
1286 template<int size, bool big_endian>
1288 Symbol_table::add_from_dynobj(
1289 Sized_dynobj<size, big_endian>* dynobj,
1290 const unsigned char* syms,
1292 const char* sym_names,
1293 size_t sym_name_size,
1294 const unsigned char* versym,
1296 const std::vector<const char*>* version_map,
1297 typename Sized_relobj<size, big_endian>::Symbols* sympointers,
1302 gold_assert(size == parameters->target().get_size());
1304 if (dynobj->just_symbols())
1306 gold_error(_("--just-symbols does not make sense with a shared object"));
1310 if (versym != NULL && versym_size / 2 < count)
1312 dynobj->error(_("too few symbol versions"));
1316 const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
1318 // We keep a list of all STT_OBJECT symbols, so that we can resolve
1319 // weak aliases. This is necessary because if the dynamic object
1320 // provides the same variable under two names, one of which is a
1321 // weak definition, and the regular object refers to the weak
1322 // definition, we have to put both the weak definition and the
1323 // strong definition into the dynamic symbol table. Given a weak
1324 // definition, the only way that we can find the corresponding
1325 // strong definition, if any, is to search the symbol table.
1326 std::vector<Sized_symbol<size>*> object_symbols;
1328 const unsigned char* p = syms;
1329 const unsigned char* vs = versym;
1330 for (size_t i = 0; i < count; ++i, p += sym_size, vs += 2)
1332 elfcpp::Sym<size, big_endian> sym(p);
1334 if (sympointers != NULL)
1335 (*sympointers)[i] = NULL;
1337 // Ignore symbols with local binding or that have
1338 // internal or hidden visibility.
1339 if (sym.get_st_bind() == elfcpp::STB_LOCAL
1340 || sym.get_st_visibility() == elfcpp::STV_INTERNAL
1341 || sym.get_st_visibility() == elfcpp::STV_HIDDEN)
1344 // A protected symbol in a shared library must be treated as a
1345 // normal symbol when viewed from outside the shared library.
1346 // Implement this by overriding the visibility here.
1347 elfcpp::Sym<size, big_endian>* psym = &sym;
1348 unsigned char symbuf[sym_size];
1349 elfcpp::Sym<size, big_endian> sym2(symbuf);
1350 if (sym.get_st_visibility() == elfcpp::STV_PROTECTED)
1352 memcpy(symbuf, p, sym_size);
1353 elfcpp::Sym_write<size, big_endian> sw(symbuf);
1354 sw.put_st_other(elfcpp::STV_DEFAULT, sym.get_st_nonvis());
1358 unsigned int st_name = psym->get_st_name();
1359 if (st_name >= sym_name_size)
1361 dynobj->error(_("bad symbol name offset %u at %zu"),
1366 const char* name = sym_names + st_name;
1369 unsigned int st_shndx = dynobj->adjust_sym_shndx(i, psym->get_st_shndx(),
1372 if (st_shndx != elfcpp::SHN_UNDEF)
1375 Sized_symbol<size>* res;
1379 Stringpool::Key name_key;
1380 name = this->namepool_.add(name, true, &name_key);
1381 res = this->add_from_object(dynobj, name, name_key, NULL, 0,
1382 false, *psym, st_shndx, is_ordinary,
1387 // Read the version information.
1389 unsigned int v = elfcpp::Swap<16, big_endian>::readval(vs);
1391 bool hidden = (v & elfcpp::VERSYM_HIDDEN) != 0;
1392 v &= elfcpp::VERSYM_VERSION;
1394 // The Sun documentation says that V can be VER_NDX_LOCAL,
1395 // or VER_NDX_GLOBAL, or a version index. The meaning of
1396 // VER_NDX_LOCAL is defined as "Symbol has local scope."
1397 // The old GNU linker will happily generate VER_NDX_LOCAL
1398 // for an undefined symbol. I don't know what the Sun
1399 // linker will generate.
1401 if (v == static_cast<unsigned int>(elfcpp::VER_NDX_LOCAL)
1402 && st_shndx != elfcpp::SHN_UNDEF)
1404 // This symbol should not be visible outside the object.
1408 // At this point we are definitely going to add this symbol.
1409 Stringpool::Key name_key;
1410 name = this->namepool_.add(name, true, &name_key);
1412 if (v == static_cast<unsigned int>(elfcpp::VER_NDX_LOCAL)
1413 || v == static_cast<unsigned int>(elfcpp::VER_NDX_GLOBAL))
1415 // This symbol does not have a version.
1416 res = this->add_from_object(dynobj, name, name_key, NULL, 0,
1417 false, *psym, st_shndx, is_ordinary,
1422 if (v >= version_map->size())
1424 dynobj->error(_("versym for symbol %zu out of range: %u"),
1429 const char* version = (*version_map)[v];
1430 if (version == NULL)
1432 dynobj->error(_("versym for symbol %zu has no name: %u"),
1437 Stringpool::Key version_key;
1438 version = this->namepool_.add(version, true, &version_key);
1440 // If this is an absolute symbol, and the version name
1441 // and symbol name are the same, then this is the
1442 // version definition symbol. These symbols exist to
1443 // support using -u to pull in particular versions. We
1444 // do not want to record a version for them.
1445 if (st_shndx == elfcpp::SHN_ABS
1447 && name_key == version_key)
1448 res = this->add_from_object(dynobj, name, name_key, NULL, 0,
1449 false, *psym, st_shndx, is_ordinary,
1453 const bool is_default_version =
1454 !hidden && st_shndx != elfcpp::SHN_UNDEF;
1455 res = this->add_from_object(dynobj, name, name_key, version,
1456 version_key, is_default_version,
1458 is_ordinary, st_shndx);
1463 // Note that it is possible that RES was overridden by an
1464 // earlier object, in which case it can't be aliased here.
1465 if (st_shndx != elfcpp::SHN_UNDEF
1467 && psym->get_st_type() == elfcpp::STT_OBJECT
1468 && res->source() == Symbol::FROM_OBJECT
1469 && res->object() == dynobj)
1470 object_symbols.push_back(res);
1472 if (sympointers != NULL)
1473 (*sympointers)[i] = res;
1476 this->record_weak_aliases(&object_symbols);
1479 // This is used to sort weak aliases. We sort them first by section
1480 // index, then by offset, then by weak ahead of strong.
1483 class Weak_alias_sorter
1486 bool operator()(const Sized_symbol<size>*, const Sized_symbol<size>*) const;
1491 Weak_alias_sorter<size>::operator()(const Sized_symbol<size>* s1,
1492 const Sized_symbol<size>* s2) const
1495 unsigned int s1_shndx = s1->shndx(&is_ordinary);
1496 gold_assert(is_ordinary);
1497 unsigned int s2_shndx = s2->shndx(&is_ordinary);
1498 gold_assert(is_ordinary);
1499 if (s1_shndx != s2_shndx)
1500 return s1_shndx < s2_shndx;
1502 if (s1->value() != s2->value())
1503 return s1->value() < s2->value();
1504 if (s1->binding() != s2->binding())
1506 if (s1->binding() == elfcpp::STB_WEAK)
1508 if (s2->binding() == elfcpp::STB_WEAK)
1511 return std::string(s1->name()) < std::string(s2->name());
1514 // SYMBOLS is a list of object symbols from a dynamic object. Look
1515 // for any weak aliases, and record them so that if we add the weak
1516 // alias to the dynamic symbol table, we also add the corresponding
1521 Symbol_table::record_weak_aliases(std::vector<Sized_symbol<size>*>* symbols)
1523 // Sort the vector by section index, then by offset, then by weak
1525 std::sort(symbols->begin(), symbols->end(), Weak_alias_sorter<size>());
1527 // Walk through the vector. For each weak definition, record
1529 for (typename std::vector<Sized_symbol<size>*>::const_iterator p =
1531 p != symbols->end();
1534 if ((*p)->binding() != elfcpp::STB_WEAK)
1537 // Build a circular list of weak aliases. Each symbol points to
1538 // the next one in the circular list.
1540 Sized_symbol<size>* from_sym = *p;
1541 typename std::vector<Sized_symbol<size>*>::const_iterator q;
1542 for (q = p + 1; q != symbols->end(); ++q)
1545 if ((*q)->shndx(&dummy) != from_sym->shndx(&dummy)
1546 || (*q)->value() != from_sym->value())
1549 this->weak_aliases_[from_sym] = *q;
1550 from_sym->set_has_alias();
1556 this->weak_aliases_[from_sym] = *p;
1557 from_sym->set_has_alias();
1564 // Create and return a specially defined symbol. If ONLY_IF_REF is
1565 // true, then only create the symbol if there is a reference to it.
1566 // If this does not return NULL, it sets *POLDSYM to the existing
1567 // symbol if there is one. This sets *RESOLVE_OLDSYM if we should
1568 // resolve the newly created symbol to the old one. This
1569 // canonicalizes *PNAME and *PVERSION.
1571 template<int size, bool big_endian>
1573 Symbol_table::define_special_symbol(const char** pname, const char** pversion,
1575 Sized_symbol<size>** poldsym,
1576 bool* resolve_oldsym)
1578 *resolve_oldsym = false;
1580 // If the caller didn't give us a version, see if we get one from
1581 // the version script.
1583 bool is_default_version = false;
1584 if (*pversion == NULL)
1587 if (this->version_script_.get_symbol_version(*pname, &v, &is_global))
1589 if (is_global && !v.empty())
1591 *pversion = v.c_str();
1592 // If we get the version from a version script, then we
1593 // are also the default version.
1594 is_default_version = true;
1600 Sized_symbol<size>* sym;
1602 bool add_to_table = false;
1603 typename Symbol_table_type::iterator add_loc = this->table_.end();
1604 bool add_def_to_table = false;
1605 typename Symbol_table_type::iterator add_def_loc = this->table_.end();
1609 oldsym = this->lookup(*pname, *pversion);
1610 if (oldsym == NULL && is_default_version)
1611 oldsym = this->lookup(*pname, NULL);
1612 if (oldsym == NULL || !oldsym->is_undefined())
1615 *pname = oldsym->name();
1616 if (!is_default_version)
1617 *pversion = oldsym->version();
1621 // Canonicalize NAME and VERSION.
1622 Stringpool::Key name_key;
1623 *pname = this->namepool_.add(*pname, true, &name_key);
1625 Stringpool::Key version_key = 0;
1626 if (*pversion != NULL)
1627 *pversion = this->namepool_.add(*pversion, true, &version_key);
1629 Symbol* const snull = NULL;
1630 std::pair<typename Symbol_table_type::iterator, bool> ins =
1631 this->table_.insert(std::make_pair(std::make_pair(name_key,
1635 std::pair<typename Symbol_table_type::iterator, bool> insdefault =
1636 std::make_pair(this->table_.end(), false);
1637 if (is_default_version)
1639 const Stringpool::Key vnull = 0;
1641 this->table_.insert(std::make_pair(std::make_pair(name_key,
1648 // We already have a symbol table entry for NAME/VERSION.
1649 oldsym = ins.first->second;
1650 gold_assert(oldsym != NULL);
1652 if (is_default_version)
1654 Sized_symbol<size>* soldsym =
1655 this->get_sized_symbol<size>(oldsym);
1656 this->define_default_version<size, big_endian>(soldsym,
1663 // We haven't seen this symbol before.
1664 gold_assert(ins.first->second == NULL);
1666 add_to_table = true;
1667 add_loc = ins.first;
1669 if (is_default_version && !insdefault.second)
1671 // We are adding NAME/VERSION, and it is the default
1672 // version. We already have an entry for NAME/NULL.
1673 oldsym = insdefault.first->second;
1674 *resolve_oldsym = true;
1680 if (is_default_version)
1682 add_def_to_table = true;
1683 add_def_loc = insdefault.first;
1689 const Target& target = parameters->target();
1690 if (!target.has_make_symbol())
1691 sym = new Sized_symbol<size>();
1694 Sized_target<size, big_endian>* sized_target =
1695 parameters->sized_target<size, big_endian>();
1696 sym = sized_target->make_symbol();
1702 add_loc->second = sym;
1704 gold_assert(oldsym != NULL);
1706 if (add_def_to_table)
1707 add_def_loc->second = sym;
1709 *poldsym = this->get_sized_symbol<size>(oldsym);
1714 // Define a symbol based on an Output_data.
1717 Symbol_table::define_in_output_data(const char* name,
1718 const char* version,
1724 elfcpp::STB binding,
1725 elfcpp::STV visibility,
1726 unsigned char nonvis,
1727 bool offset_is_from_end,
1730 if (parameters->target().get_size() == 32)
1732 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
1733 return this->do_define_in_output_data<32>(name, version, defined, od,
1734 value, symsize, type, binding,
1742 else if (parameters->target().get_size() == 64)
1744 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
1745 return this->do_define_in_output_data<64>(name, version, defined, od,
1746 value, symsize, type, binding,
1758 // Define a symbol in an Output_data, sized version.
1762 Symbol_table::do_define_in_output_data(
1764 const char* version,
1767 typename elfcpp::Elf_types<size>::Elf_Addr value,
1768 typename elfcpp::Elf_types<size>::Elf_WXword symsize,
1770 elfcpp::STB binding,
1771 elfcpp::STV visibility,
1772 unsigned char nonvis,
1773 bool offset_is_from_end,
1776 Sized_symbol<size>* sym;
1777 Sized_symbol<size>* oldsym;
1778 bool resolve_oldsym;
1780 if (parameters->target().is_big_endian())
1782 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
1783 sym = this->define_special_symbol<size, true>(&name, &version,
1784 only_if_ref, &oldsym,
1792 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
1793 sym = this->define_special_symbol<size, false>(&name, &version,
1794 only_if_ref, &oldsym,
1804 sym->init_output_data(name, version, od, value, symsize, type, binding,
1805 visibility, nonvis, offset_is_from_end);
1809 if (binding == elfcpp::STB_LOCAL
1810 || this->version_script_.symbol_is_local(name))
1811 this->force_local(sym);
1812 else if (version != NULL)
1813 sym->set_is_default();
1817 if (Symbol_table::should_override_with_special(oldsym, defined))
1818 this->override_with_special(oldsym, sym);
1829 // Define a symbol based on an Output_segment.
1832 Symbol_table::define_in_output_segment(const char* name,
1833 const char* version,
1839 elfcpp::STB binding,
1840 elfcpp::STV visibility,
1841 unsigned char nonvis,
1842 Symbol::Segment_offset_base offset_base,
1845 if (parameters->target().get_size() == 32)
1847 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
1848 return this->do_define_in_output_segment<32>(name, version, defined, os,
1849 value, symsize, type,
1850 binding, visibility, nonvis,
1851 offset_base, only_if_ref);
1856 else if (parameters->target().get_size() == 64)
1858 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
1859 return this->do_define_in_output_segment<64>(name, version, defined, os,
1860 value, symsize, type,
1861 binding, visibility, nonvis,
1862 offset_base, only_if_ref);
1871 // Define a symbol in an Output_segment, sized version.
1875 Symbol_table::do_define_in_output_segment(
1877 const char* version,
1880 typename elfcpp::Elf_types<size>::Elf_Addr value,
1881 typename elfcpp::Elf_types<size>::Elf_WXword symsize,
1883 elfcpp::STB binding,
1884 elfcpp::STV visibility,
1885 unsigned char nonvis,
1886 Symbol::Segment_offset_base offset_base,
1889 Sized_symbol<size>* sym;
1890 Sized_symbol<size>* oldsym;
1891 bool resolve_oldsym;
1893 if (parameters->target().is_big_endian())
1895 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
1896 sym = this->define_special_symbol<size, true>(&name, &version,
1897 only_if_ref, &oldsym,
1905 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
1906 sym = this->define_special_symbol<size, false>(&name, &version,
1907 only_if_ref, &oldsym,
1917 sym->init_output_segment(name, version, os, value, symsize, type, binding,
1918 visibility, nonvis, offset_base);
1922 if (binding == elfcpp::STB_LOCAL
1923 || this->version_script_.symbol_is_local(name))
1924 this->force_local(sym);
1925 else if (version != NULL)
1926 sym->set_is_default();
1930 if (Symbol_table::should_override_with_special(oldsym, defined))
1931 this->override_with_special(oldsym, sym);
1942 // Define a special symbol with a constant value. It is a multiple
1943 // definition error if this symbol is already defined.
1946 Symbol_table::define_as_constant(const char* name,
1947 const char* version,
1952 elfcpp::STB binding,
1953 elfcpp::STV visibility,
1954 unsigned char nonvis,
1956 bool force_override)
1958 if (parameters->target().get_size() == 32)
1960 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
1961 return this->do_define_as_constant<32>(name, version, defined, value,
1962 symsize, type, binding,
1963 visibility, nonvis, only_if_ref,
1969 else if (parameters->target().get_size() == 64)
1971 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
1972 return this->do_define_as_constant<64>(name, version, defined, value,
1973 symsize, type, binding,
1974 visibility, nonvis, only_if_ref,
1984 // Define a symbol as a constant, sized version.
1988 Symbol_table::do_define_as_constant(
1990 const char* version,
1992 typename elfcpp::Elf_types<size>::Elf_Addr value,
1993 typename elfcpp::Elf_types<size>::Elf_WXword symsize,
1995 elfcpp::STB binding,
1996 elfcpp::STV visibility,
1997 unsigned char nonvis,
1999 bool force_override)
2001 Sized_symbol<size>* sym;
2002 Sized_symbol<size>* oldsym;
2003 bool resolve_oldsym;
2005 if (parameters->target().is_big_endian())
2007 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
2008 sym = this->define_special_symbol<size, true>(&name, &version,
2009 only_if_ref, &oldsym,
2017 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
2018 sym = this->define_special_symbol<size, false>(&name, &version,
2019 only_if_ref, &oldsym,
2029 sym->init_constant(name, version, value, symsize, type, binding, visibility,
2034 // Version symbols are absolute symbols with name == version.
2035 // We don't want to force them to be local.
2036 if ((version == NULL
2039 && (binding == elfcpp::STB_LOCAL
2040 || this->version_script_.symbol_is_local(name)))
2041 this->force_local(sym);
2042 else if (version != NULL
2043 && (name != version || value != 0))
2044 sym->set_is_default();
2049 || Symbol_table::should_override_with_special(oldsym, defined))
2050 this->override_with_special(oldsym, sym);
2061 // Define a set of symbols in output sections.
2064 Symbol_table::define_symbols(const Layout* layout, int count,
2065 const Define_symbol_in_section* p,
2068 for (int i = 0; i < count; ++i, ++p)
2070 Output_section* os = layout->find_output_section(p->output_section);
2072 this->define_in_output_data(p->name, NULL, PREDEFINED, os, p->value,
2073 p->size, p->type, p->binding,
2074 p->visibility, p->nonvis,
2075 p->offset_is_from_end,
2076 only_if_ref || p->only_if_ref);
2078 this->define_as_constant(p->name, NULL, PREDEFINED, 0, p->size,
2079 p->type, p->binding, p->visibility, p->nonvis,
2080 only_if_ref || p->only_if_ref,
2085 // Define a set of symbols in output segments.
2088 Symbol_table::define_symbols(const Layout* layout, int count,
2089 const Define_symbol_in_segment* p,
2092 for (int i = 0; i < count; ++i, ++p)
2094 Output_segment* os = layout->find_output_segment(p->segment_type,
2095 p->segment_flags_set,
2096 p->segment_flags_clear);
2098 this->define_in_output_segment(p->name, NULL, PREDEFINED, os, p->value,
2099 p->size, p->type, p->binding,
2100 p->visibility, p->nonvis,
2102 only_if_ref || p->only_if_ref);
2104 this->define_as_constant(p->name, NULL, PREDEFINED, 0, p->size,
2105 p->type, p->binding, p->visibility, p->nonvis,
2106 only_if_ref || p->only_if_ref,
2111 // Define CSYM using a COPY reloc. POSD is the Output_data where the
2112 // symbol should be defined--typically a .dyn.bss section. VALUE is
2113 // the offset within POSD.
2117 Symbol_table::define_with_copy_reloc(
2118 Sized_symbol<size>* csym,
2120 typename elfcpp::Elf_types<size>::Elf_Addr value)
2122 gold_assert(csym->is_from_dynobj());
2123 gold_assert(!csym->is_copied_from_dynobj());
2124 Object* object = csym->object();
2125 gold_assert(object->is_dynamic());
2126 Dynobj* dynobj = static_cast<Dynobj*>(object);
2128 // Our copied variable has to override any variable in a shared
2130 elfcpp::STB binding = csym->binding();
2131 if (binding == elfcpp::STB_WEAK)
2132 binding = elfcpp::STB_GLOBAL;
2134 this->define_in_output_data(csym->name(), csym->version(), COPY,
2135 posd, value, csym->symsize(),
2136 csym->type(), binding,
2137 csym->visibility(), csym->nonvis(),
2140 csym->set_is_copied_from_dynobj();
2141 csym->set_needs_dynsym_entry();
2143 this->copied_symbol_dynobjs_[csym] = dynobj;
2145 // We have now defined all aliases, but we have not entered them all
2146 // in the copied_symbol_dynobjs_ map.
2147 if (csym->has_alias())
2152 sym = this->weak_aliases_[sym];
2155 gold_assert(sym->output_data() == posd);
2157 sym->set_is_copied_from_dynobj();
2158 this->copied_symbol_dynobjs_[sym] = dynobj;
2163 // SYM is defined using a COPY reloc. Return the dynamic object where
2164 // the original definition was found.
2167 Symbol_table::get_copy_source(const Symbol* sym) const
2169 gold_assert(sym->is_copied_from_dynobj());
2170 Copied_symbol_dynobjs::const_iterator p =
2171 this->copied_symbol_dynobjs_.find(sym);
2172 gold_assert(p != this->copied_symbol_dynobjs_.end());
2176 // Add any undefined symbols named on the command line.
2179 Symbol_table::add_undefined_symbols_from_command_line(Layout* layout)
2181 if (parameters->options().any_undefined()
2182 || layout->script_options()->any_unreferenced())
2184 if (parameters->target().get_size() == 32)
2186 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
2187 this->do_add_undefined_symbols_from_command_line<32>(layout);
2192 else if (parameters->target().get_size() == 64)
2194 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
2195 this->do_add_undefined_symbols_from_command_line<64>(layout);
2207 Symbol_table::do_add_undefined_symbols_from_command_line(Layout* layout)
2209 for (options::String_set::const_iterator p =
2210 parameters->options().undefined_begin();
2211 p != parameters->options().undefined_end();
2213 this->add_undefined_symbol_from_command_line<size>(p->c_str());
2215 for (Script_options::referenced_const_iterator p =
2216 layout->script_options()->referenced_begin();
2217 p != layout->script_options()->referenced_end();
2219 this->add_undefined_symbol_from_command_line<size>(p->c_str());
2224 Symbol_table::add_undefined_symbol_from_command_line(const char* name)
2226 if (this->lookup(name) != NULL)
2229 const char* version = NULL;
2231 Sized_symbol<size>* sym;
2232 Sized_symbol<size>* oldsym;
2233 bool resolve_oldsym;
2234 if (parameters->target().is_big_endian())
2236 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
2237 sym = this->define_special_symbol<size, true>(&name, &version,
2246 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
2247 sym = this->define_special_symbol<size, false>(&name, &version,
2255 gold_assert(oldsym == NULL);
2257 sym->init_undefined(name, version, elfcpp::STT_NOTYPE, elfcpp::STB_GLOBAL,
2258 elfcpp::STV_DEFAULT, 0);
2259 ++this->saw_undefined_;
2262 // Set the dynamic symbol indexes. INDEX is the index of the first
2263 // global dynamic symbol. Pointers to the symbols are stored into the
2264 // vector SYMS. The names are added to DYNPOOL. This returns an
2265 // updated dynamic symbol index.
2268 Symbol_table::set_dynsym_indexes(unsigned int index,
2269 std::vector<Symbol*>* syms,
2270 Stringpool* dynpool,
2273 for (Symbol_table_type::iterator p = this->table_.begin();
2274 p != this->table_.end();
2277 Symbol* sym = p->second;
2279 // Note that SYM may already have a dynamic symbol index, since
2280 // some symbols appear more than once in the symbol table, with
2281 // and without a version.
2283 if (!sym->should_add_dynsym_entry(this))
2284 sym->set_dynsym_index(-1U);
2285 else if (!sym->has_dynsym_index())
2287 sym->set_dynsym_index(index);
2289 syms->push_back(sym);
2290 dynpool->add(sym->name(), false, NULL);
2292 // Record any version information.
2293 if (sym->version() != NULL)
2294 versions->record_version(this, dynpool, sym);
2296 // If the symbol is defined in a dynamic object and is
2297 // referenced in a regular object, then mark the dynamic
2298 // object as needed. This is used to implement --as-needed.
2299 if (sym->is_from_dynobj() && sym->in_reg())
2300 sym->object()->set_is_needed();
2304 // Finish up the versions. In some cases this may add new dynamic
2306 index = versions->finalize(this, index, syms);
2311 // Set the final values for all the symbols. The index of the first
2312 // global symbol in the output file is *PLOCAL_SYMCOUNT. Record the
2313 // file offset OFF. Add their names to POOL. Return the new file
2314 // offset. Update *PLOCAL_SYMCOUNT if necessary.
2317 Symbol_table::finalize(off_t off, off_t dynoff, size_t dyn_global_index,
2318 size_t dyncount, Stringpool* pool,
2319 unsigned int* plocal_symcount)
2323 gold_assert(*plocal_symcount != 0);
2324 this->first_global_index_ = *plocal_symcount;
2326 this->dynamic_offset_ = dynoff;
2327 this->first_dynamic_global_index_ = dyn_global_index;
2328 this->dynamic_count_ = dyncount;
2330 if (parameters->target().get_size() == 32)
2332 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_32_LITTLE)
2333 ret = this->sized_finalize<32>(off, pool, plocal_symcount);
2338 else if (parameters->target().get_size() == 64)
2340 #if defined(HAVE_TARGET_64_BIG) || defined(HAVE_TARGET_64_LITTLE)
2341 ret = this->sized_finalize<64>(off, pool, plocal_symcount);
2349 // Now that we have the final symbol table, we can reliably note
2350 // which symbols should get warnings.
2351 this->warnings_.note_warnings(this);
2356 // SYM is going into the symbol table at *PINDEX. Add the name to
2357 // POOL, update *PINDEX and *POFF.
2361 Symbol_table::add_to_final_symtab(Symbol* sym, Stringpool* pool,
2362 unsigned int* pindex, off_t* poff)
2364 sym->set_symtab_index(*pindex);
2365 pool->add(sym->name(), false, NULL);
2367 *poff += elfcpp::Elf_sizes<size>::sym_size;
2370 // Set the final value for all the symbols. This is called after
2371 // Layout::finalize, so all the output sections have their final
2376 Symbol_table::sized_finalize(off_t off, Stringpool* pool,
2377 unsigned int* plocal_symcount)
2379 off = align_address(off, size >> 3);
2380 this->offset_ = off;
2382 unsigned int index = *plocal_symcount;
2383 const unsigned int orig_index = index;
2385 // First do all the symbols which have been forced to be local, as
2386 // they must appear before all global symbols.
2387 for (Forced_locals::iterator p = this->forced_locals_.begin();
2388 p != this->forced_locals_.end();
2392 gold_assert(sym->is_forced_local());
2393 if (this->sized_finalize_symbol<size>(sym))
2395 this->add_to_final_symtab<size>(sym, pool, &index, &off);
2400 // Now do all the remaining symbols.
2401 for (Symbol_table_type::iterator p = this->table_.begin();
2402 p != this->table_.end();
2405 Symbol* sym = p->second;
2406 if (this->sized_finalize_symbol<size>(sym))
2407 this->add_to_final_symtab<size>(sym, pool, &index, &off);
2410 this->output_count_ = index - orig_index;
2415 // Compute the final value of SYM and store status in location PSTATUS.
2416 // During relaxation, this may be called multiple times for a symbol to
2417 // compute its would-be final value in each relaxation pass.
2420 typename Sized_symbol<size>::Value_type
2421 Symbol_table::compute_final_value(
2422 const Sized_symbol<size>* sym,
2423 Compute_final_value_status* pstatus) const
2425 typedef typename Sized_symbol<size>::Value_type Value_type;
2428 switch (sym->source())
2430 case Symbol::FROM_OBJECT:
2433 unsigned int shndx = sym->shndx(&is_ordinary);
2436 && shndx != elfcpp::SHN_ABS
2437 && !Symbol::is_common_shndx(shndx))
2439 *pstatus = CFVS_UNSUPPORTED_SYMBOL_SECTION;
2443 Object* symobj = sym->object();
2444 if (symobj->is_dynamic())
2447 shndx = elfcpp::SHN_UNDEF;
2449 else if (symobj->pluginobj() != NULL)
2452 shndx = elfcpp::SHN_UNDEF;
2454 else if (shndx == elfcpp::SHN_UNDEF)
2456 else if (!is_ordinary
2457 && (shndx == elfcpp::SHN_ABS
2458 || Symbol::is_common_shndx(shndx)))
2459 value = sym->value();
2462 Relobj* relobj = static_cast<Relobj*>(symobj);
2463 Output_section* os = relobj->output_section(shndx);
2465 if (this->is_section_folded(relobj, shndx))
2467 gold_assert(os == NULL);
2468 // Get the os of the section it is folded onto.
2469 Section_id folded = this->icf_->get_folded_section(relobj,
2471 gold_assert(folded.first != NULL);
2472 Relobj* folded_obj = reinterpret_cast<Relobj*>(folded.first);
2473 unsigned folded_shndx = folded.second;
2475 os = folded_obj->output_section(folded_shndx);
2476 gold_assert(os != NULL);
2478 // Replace (relobj, shndx) with canonical ICF input section.
2479 shndx = folded_shndx;
2480 relobj = folded_obj;
2483 uint64_t secoff64 = relobj->output_section_offset(shndx);
2486 bool static_or_reloc = (parameters->doing_static_link() ||
2487 parameters->options().relocatable());
2488 gold_assert(static_or_reloc || sym->dynsym_index() == -1U);
2490 *pstatus = CFVS_NO_OUTPUT_SECTION;
2494 if (secoff64 == -1ULL)
2496 // The section needs special handling (e.g., a merge section).
2498 value = os->output_address(relobj, shndx, sym->value());
2503 convert_types<Value_type, uint64_t>(secoff64);
2504 if (sym->type() == elfcpp::STT_TLS)
2505 value = sym->value() + os->tls_offset() + secoff;
2507 value = sym->value() + os->address() + secoff;
2513 case Symbol::IN_OUTPUT_DATA:
2515 Output_data* od = sym->output_data();
2516 value = sym->value();
2517 if (sym->type() != elfcpp::STT_TLS)
2518 value += od->address();
2521 Output_section* os = od->output_section();
2522 gold_assert(os != NULL);
2523 value += os->tls_offset() + (od->address() - os->address());
2525 if (sym->offset_is_from_end())
2526 value += od->data_size();
2530 case Symbol::IN_OUTPUT_SEGMENT:
2532 Output_segment* os = sym->output_segment();
2533 value = sym->value();
2534 if (sym->type() != elfcpp::STT_TLS)
2535 value += os->vaddr();
2536 switch (sym->offset_base())
2538 case Symbol::SEGMENT_START:
2540 case Symbol::SEGMENT_END:
2541 value += os->memsz();
2543 case Symbol::SEGMENT_BSS:
2544 value += os->filesz();
2552 case Symbol::IS_CONSTANT:
2553 value = sym->value();
2556 case Symbol::IS_UNDEFINED:
2568 // Finalize the symbol SYM. This returns true if the symbol should be
2569 // added to the symbol table, false otherwise.
2573 Symbol_table::sized_finalize_symbol(Symbol* unsized_sym)
2575 typedef typename Sized_symbol<size>::Value_type Value_type;
2577 Sized_symbol<size>* sym = static_cast<Sized_symbol<size>*>(unsized_sym);
2579 // The default version of a symbol may appear twice in the symbol
2580 // table. We only need to finalize it once.
2581 if (sym->has_symtab_index())
2586 gold_assert(!sym->has_symtab_index());
2587 sym->set_symtab_index(-1U);
2588 gold_assert(sym->dynsym_index() == -1U);
2592 // Compute final symbol value.
2593 Compute_final_value_status status;
2594 Value_type value = this->compute_final_value(sym, &status);
2600 case CFVS_UNSUPPORTED_SYMBOL_SECTION:
2603 unsigned int shndx = sym->shndx(&is_ordinary);
2604 gold_error(_("%s: unsupported symbol section 0x%x"),
2605 sym->demangled_name().c_str(), shndx);
2608 case CFVS_NO_OUTPUT_SECTION:
2609 sym->set_symtab_index(-1U);
2615 sym->set_value(value);
2617 if (parameters->options().strip_all()
2618 || !parameters->options().should_retain_symbol(sym->name()))
2620 sym->set_symtab_index(-1U);
2627 // Write out the global symbols.
2630 Symbol_table::write_globals(const Stringpool* sympool,
2631 const Stringpool* dynpool,
2632 Output_symtab_xindex* symtab_xindex,
2633 Output_symtab_xindex* dynsym_xindex,
2634 Output_file* of) const
2636 switch (parameters->size_and_endianness())
2638 #ifdef HAVE_TARGET_32_LITTLE
2639 case Parameters::TARGET_32_LITTLE:
2640 this->sized_write_globals<32, false>(sympool, dynpool, symtab_xindex,
2644 #ifdef HAVE_TARGET_32_BIG
2645 case Parameters::TARGET_32_BIG:
2646 this->sized_write_globals<32, true>(sympool, dynpool, symtab_xindex,
2650 #ifdef HAVE_TARGET_64_LITTLE
2651 case Parameters::TARGET_64_LITTLE:
2652 this->sized_write_globals<64, false>(sympool, dynpool, symtab_xindex,
2656 #ifdef HAVE_TARGET_64_BIG
2657 case Parameters::TARGET_64_BIG:
2658 this->sized_write_globals<64, true>(sympool, dynpool, symtab_xindex,
2667 // Write out the global symbols.
2669 template<int size, bool big_endian>
2671 Symbol_table::sized_write_globals(const Stringpool* sympool,
2672 const Stringpool* dynpool,
2673 Output_symtab_xindex* symtab_xindex,
2674 Output_symtab_xindex* dynsym_xindex,
2675 Output_file* of) const
2677 const Target& target = parameters->target();
2679 const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
2681 const unsigned int output_count = this->output_count_;
2682 const section_size_type oview_size = output_count * sym_size;
2683 const unsigned int first_global_index = this->first_global_index_;
2684 unsigned char* psyms;
2685 if (this->offset_ == 0 || output_count == 0)
2688 psyms = of->get_output_view(this->offset_, oview_size);
2690 const unsigned int dynamic_count = this->dynamic_count_;
2691 const section_size_type dynamic_size = dynamic_count * sym_size;
2692 const unsigned int first_dynamic_global_index =
2693 this->first_dynamic_global_index_;
2694 unsigned char* dynamic_view;
2695 if (this->dynamic_offset_ == 0 || dynamic_count == 0)
2696 dynamic_view = NULL;
2698 dynamic_view = of->get_output_view(this->dynamic_offset_, dynamic_size);
2700 for (Symbol_table_type::const_iterator p = this->table_.begin();
2701 p != this->table_.end();
2704 Sized_symbol<size>* sym = static_cast<Sized_symbol<size>*>(p->second);
2706 // Possibly warn about unresolved symbols in shared libraries.
2707 this->warn_about_undefined_dynobj_symbol(sym);
2709 unsigned int sym_index = sym->symtab_index();
2710 unsigned int dynsym_index;
2711 if (dynamic_view == NULL)
2714 dynsym_index = sym->dynsym_index();
2716 if (sym_index == -1U && dynsym_index == -1U)
2718 // This symbol is not included in the output file.
2723 typename elfcpp::Elf_types<size>::Elf_Addr sym_value = sym->value();
2724 typename elfcpp::Elf_types<size>::Elf_Addr dynsym_value = sym_value;
2725 elfcpp::STB binding = sym->binding();
2726 switch (sym->source())
2728 case Symbol::FROM_OBJECT:
2731 unsigned int in_shndx = sym->shndx(&is_ordinary);
2734 && in_shndx != elfcpp::SHN_ABS
2735 && !Symbol::is_common_shndx(in_shndx))
2737 gold_error(_("%s: unsupported symbol section 0x%x"),
2738 sym->demangled_name().c_str(), in_shndx);
2743 Object* symobj = sym->object();
2744 if (symobj->is_dynamic())
2746 if (sym->needs_dynsym_value())
2747 dynsym_value = target.dynsym_value(sym);
2748 shndx = elfcpp::SHN_UNDEF;
2749 if (sym->is_undef_binding_weak())
2750 binding = elfcpp::STB_WEAK;
2752 binding = elfcpp::STB_GLOBAL;
2754 else if (symobj->pluginobj() != NULL)
2755 shndx = elfcpp::SHN_UNDEF;
2756 else if (in_shndx == elfcpp::SHN_UNDEF
2758 && (in_shndx == elfcpp::SHN_ABS
2759 || Symbol::is_common_shndx(in_shndx))))
2763 Relobj* relobj = static_cast<Relobj*>(symobj);
2764 Output_section* os = relobj->output_section(in_shndx);
2765 if (this->is_section_folded(relobj, in_shndx))
2767 // This global symbol must be written out even though
2769 // Get the os of the section it is folded onto.
2771 this->icf_->get_folded_section(relobj, in_shndx);
2772 gold_assert(folded.first !=NULL);
2773 Relobj* folded_obj =
2774 reinterpret_cast<Relobj*>(folded.first);
2775 os = folded_obj->output_section(folded.second);
2776 gold_assert(os != NULL);
2778 gold_assert(os != NULL);
2779 shndx = os->out_shndx();
2781 if (shndx >= elfcpp::SHN_LORESERVE)
2783 if (sym_index != -1U)
2784 symtab_xindex->add(sym_index, shndx);
2785 if (dynsym_index != -1U)
2786 dynsym_xindex->add(dynsym_index, shndx);
2787 shndx = elfcpp::SHN_XINDEX;
2790 // In object files symbol values are section
2792 if (parameters->options().relocatable())
2793 sym_value -= os->address();
2799 case Symbol::IN_OUTPUT_DATA:
2800 shndx = sym->output_data()->out_shndx();
2801 if (shndx >= elfcpp::SHN_LORESERVE)
2803 if (sym_index != -1U)
2804 symtab_xindex->add(sym_index, shndx);
2805 if (dynsym_index != -1U)
2806 dynsym_xindex->add(dynsym_index, shndx);
2807 shndx = elfcpp::SHN_XINDEX;
2811 case Symbol::IN_OUTPUT_SEGMENT:
2812 shndx = elfcpp::SHN_ABS;
2815 case Symbol::IS_CONSTANT:
2816 shndx = elfcpp::SHN_ABS;
2819 case Symbol::IS_UNDEFINED:
2820 shndx = elfcpp::SHN_UNDEF;
2827 if (sym_index != -1U)
2829 sym_index -= first_global_index;
2830 gold_assert(sym_index < output_count);
2831 unsigned char* ps = psyms + (sym_index * sym_size);
2832 this->sized_write_symbol<size, big_endian>(sym, sym_value, shndx,
2833 binding, sympool, ps);
2836 if (dynsym_index != -1U)
2838 dynsym_index -= first_dynamic_global_index;
2839 gold_assert(dynsym_index < dynamic_count);
2840 unsigned char* pd = dynamic_view + (dynsym_index * sym_size);
2841 this->sized_write_symbol<size, big_endian>(sym, dynsym_value, shndx,
2842 binding, dynpool, pd);
2846 of->write_output_view(this->offset_, oview_size, psyms);
2847 if (dynamic_view != NULL)
2848 of->write_output_view(this->dynamic_offset_, dynamic_size, dynamic_view);
2851 // Write out the symbol SYM, in section SHNDX, to P. POOL is the
2852 // strtab holding the name.
2854 template<int size, bool big_endian>
2856 Symbol_table::sized_write_symbol(
2857 Sized_symbol<size>* sym,
2858 typename elfcpp::Elf_types<size>::Elf_Addr value,
2860 elfcpp::STB binding,
2861 const Stringpool* pool,
2862 unsigned char* p) const
2864 elfcpp::Sym_write<size, big_endian> osym(p);
2865 osym.put_st_name(pool->get_offset(sym->name()));
2866 osym.put_st_value(value);
2867 // Use a symbol size of zero for undefined symbols from shared libraries.
2868 if (shndx == elfcpp::SHN_UNDEF && sym->is_from_dynobj())
2869 osym.put_st_size(0);
2871 osym.put_st_size(sym->symsize());
2872 elfcpp::STT type = sym->type();
2873 // Turn IFUNC symbols from shared libraries into normal FUNC symbols.
2874 if (type == elfcpp::STT_GNU_IFUNC
2875 && sym->is_from_dynobj())
2876 type = elfcpp::STT_FUNC;
2877 // A version script may have overridden the default binding.
2878 if (sym->is_forced_local())
2879 osym.put_st_info(elfcpp::elf_st_info(elfcpp::STB_LOCAL, type));
2881 osym.put_st_info(elfcpp::elf_st_info(binding, type));
2882 osym.put_st_other(elfcpp::elf_st_other(sym->visibility(), sym->nonvis()));
2883 osym.put_st_shndx(shndx);
2886 // Check for unresolved symbols in shared libraries. This is
2887 // controlled by the --allow-shlib-undefined option.
2889 // We only warn about libraries for which we have seen all the
2890 // DT_NEEDED entries. We don't try to track down DT_NEEDED entries
2891 // which were not seen in this link. If we didn't see a DT_NEEDED
2892 // entry, we aren't going to be able to reliably report whether the
2893 // symbol is undefined.
2895 // We also don't warn about libraries found in a system library
2896 // directory (e.g., /lib or /usr/lib); we assume that those libraries
2897 // are OK. This heuristic avoids problems on GNU/Linux, in which -ldl
2898 // can have undefined references satisfied by ld-linux.so.
2901 Symbol_table::warn_about_undefined_dynobj_symbol(Symbol* sym) const
2904 if (sym->source() == Symbol::FROM_OBJECT
2905 && sym->object()->is_dynamic()
2906 && sym->shndx(&dummy) == elfcpp::SHN_UNDEF
2907 && sym->binding() != elfcpp::STB_WEAK
2908 && !parameters->options().allow_shlib_undefined()
2909 && !parameters->target().is_defined_by_abi(sym)
2910 && !sym->object()->is_in_system_directory())
2912 // A very ugly cast.
2913 Dynobj* dynobj = static_cast<Dynobj*>(sym->object());
2914 if (!dynobj->has_unknown_needed_entries())
2915 gold_undefined_symbol(sym);
2919 // Write out a section symbol. Return the update offset.
2922 Symbol_table::write_section_symbol(const Output_section* os,
2923 Output_symtab_xindex* symtab_xindex,
2927 switch (parameters->size_and_endianness())
2929 #ifdef HAVE_TARGET_32_LITTLE
2930 case Parameters::TARGET_32_LITTLE:
2931 this->sized_write_section_symbol<32, false>(os, symtab_xindex, of,
2935 #ifdef HAVE_TARGET_32_BIG
2936 case Parameters::TARGET_32_BIG:
2937 this->sized_write_section_symbol<32, true>(os, symtab_xindex, of,
2941 #ifdef HAVE_TARGET_64_LITTLE
2942 case Parameters::TARGET_64_LITTLE:
2943 this->sized_write_section_symbol<64, false>(os, symtab_xindex, of,
2947 #ifdef HAVE_TARGET_64_BIG
2948 case Parameters::TARGET_64_BIG:
2949 this->sized_write_section_symbol<64, true>(os, symtab_xindex, of,
2958 // Write out a section symbol, specialized for size and endianness.
2960 template<int size, bool big_endian>
2962 Symbol_table::sized_write_section_symbol(const Output_section* os,
2963 Output_symtab_xindex* symtab_xindex,
2967 const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
2969 unsigned char* pov = of->get_output_view(offset, sym_size);
2971 elfcpp::Sym_write<size, big_endian> osym(pov);
2972 osym.put_st_name(0);
2973 if (parameters->options().relocatable())
2974 osym.put_st_value(0);
2976 osym.put_st_value(os->address());
2977 osym.put_st_size(0);
2978 osym.put_st_info(elfcpp::elf_st_info(elfcpp::STB_LOCAL,
2979 elfcpp::STT_SECTION));
2980 osym.put_st_other(elfcpp::elf_st_other(elfcpp::STV_DEFAULT, 0));
2982 unsigned int shndx = os->out_shndx();
2983 if (shndx >= elfcpp::SHN_LORESERVE)
2985 symtab_xindex->add(os->symtab_index(), shndx);
2986 shndx = elfcpp::SHN_XINDEX;
2988 osym.put_st_shndx(shndx);
2990 of->write_output_view(offset, sym_size, pov);
2993 // Print statistical information to stderr. This is used for --stats.
2996 Symbol_table::print_stats() const
2998 #if defined(HAVE_TR1_UNORDERED_MAP) || defined(HAVE_EXT_HASH_MAP)
2999 fprintf(stderr, _("%s: symbol table entries: %zu; buckets: %zu\n"),
3000 program_name, this->table_.size(), this->table_.bucket_count());
3002 fprintf(stderr, _("%s: symbol table entries: %zu\n"),
3003 program_name, this->table_.size());
3005 this->namepool_.print_stats("symbol table stringpool");
3008 // We check for ODR violations by looking for symbols with the same
3009 // name for which the debugging information reports that they were
3010 // defined in different source locations. When comparing the source
3011 // location, we consider instances with the same base filename and
3012 // line number to be the same. This is because different object
3013 // files/shared libraries can include the same header file using
3014 // different paths, and we don't want to report an ODR violation in
3017 // This struct is used to compare line information, as returned by
3018 // Dwarf_line_info::one_addr2line. It implements a < comparison
3019 // operator used with std::set.
3021 struct Odr_violation_compare
3024 operator()(const std::string& s1, const std::string& s2) const
3026 std::string::size_type pos1 = s1.rfind('/');
3027 std::string::size_type pos2 = s2.rfind('/');
3028 if (pos1 == std::string::npos
3029 || pos2 == std::string::npos)
3031 return s1.compare(pos1, std::string::npos,
3032 s2, pos2, std::string::npos) < 0;
3036 // Check candidate_odr_violations_ to find symbols with the same name
3037 // but apparently different definitions (different source-file/line-no).
3040 Symbol_table::detect_odr_violations(const Task* task,
3041 const char* output_file_name) const
3043 for (Odr_map::const_iterator it = candidate_odr_violations_.begin();
3044 it != candidate_odr_violations_.end();
3047 const char* symbol_name = it->first;
3048 // Maps from symbol location to a sample object file we found
3049 // that location in. We use a sorted map so the location order
3050 // is deterministic, but we only store an arbitrary object file
3051 // to avoid copying lots of names.
3052 std::map<std::string, std::string, Odr_violation_compare> line_nums;
3054 for (Unordered_set<Symbol_location, Symbol_location_hash>::const_iterator
3055 locs = it->second.begin();
3056 locs != it->second.end();
3059 // We need to lock the object in order to read it. This
3060 // means that we have to run in a singleton Task. If we
3061 // want to run this in a general Task for better
3062 // performance, we will need one Task for object, plus
3063 // appropriate locking to ensure that we don't conflict with
3064 // other uses of the object. Also note, one_addr2line is not
3065 // currently thread-safe.
3066 Task_lock_obj<Object> tl(task, locs->object);
3067 // 16 is the size of the object-cache that one_addr2line should use.
3068 std::string lineno = Dwarf_line_info::one_addr2line(
3069 locs->object, locs->shndx, locs->offset, 16);
3070 if (!lineno.empty())
3072 std::string& sample_object = line_nums[lineno];
3073 if (sample_object.empty())
3074 sample_object = locs->object->name();
3078 if (line_nums.size() > 1)
3080 gold_warning(_("while linking %s: symbol '%s' defined in multiple "
3081 "places (possible ODR violation):"),
3082 output_file_name, demangle(symbol_name).c_str());
3083 for (std::map<std::string, std::string>::const_iterator it2 =
3085 it2 != line_nums.end();
3087 fprintf(stderr, _(" %s from %s\n"),
3088 it2->first.c_str(), it2->second.c_str());
3091 // We only call one_addr2line() in this function, so we can clear its cache.
3092 Dwarf_line_info::clear_addr2line_cache();
3095 // Warnings functions.
3097 // Add a new warning.
3100 Warnings::add_warning(Symbol_table* symtab, const char* name, Object* obj,
3101 const std::string& warning)
3103 name = symtab->canonicalize_name(name);
3104 this->warnings_[name].set(obj, warning);
3107 // Look through the warnings and mark the symbols for which we should
3108 // warn. This is called during Layout::finalize when we know the
3109 // sources for all the symbols.
3112 Warnings::note_warnings(Symbol_table* symtab)
3114 for (Warning_table::iterator p = this->warnings_.begin();
3115 p != this->warnings_.end();
3118 Symbol* sym = symtab->lookup(p->first, NULL);
3120 && sym->source() == Symbol::FROM_OBJECT
3121 && sym->object() == p->second.object)
3122 sym->set_has_warning();
3126 // Issue a warning. This is called when we see a relocation against a
3127 // symbol for which has a warning.
3129 template<int size, bool big_endian>
3131 Warnings::issue_warning(const Symbol* sym,
3132 const Relocate_info<size, big_endian>* relinfo,
3133 size_t relnum, off_t reloffset) const
3135 gold_assert(sym->has_warning());
3136 Warning_table::const_iterator p = this->warnings_.find(sym->name());
3137 gold_assert(p != this->warnings_.end());
3138 gold_warning_at_location(relinfo, relnum, reloffset,
3139 "%s", p->second.text.c_str());
3142 // Instantiate the templates we need. We could use the configure
3143 // script to restrict this to only the ones needed for implemented
3146 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
3149 Sized_symbol<32>::allocate_common(Output_data*, Value_type);
3152 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
3155 Sized_symbol<64>::allocate_common(Output_data*, Value_type);
3158 #ifdef HAVE_TARGET_32_LITTLE
3161 Symbol_table::add_from_relobj<32, false>(
3162 Sized_relobj<32, false>* relobj,
3163 const unsigned char* syms,
3165 size_t symndx_offset,
3166 const char* sym_names,
3167 size_t sym_name_size,
3168 Sized_relobj<32, false>::Symbols* sympointers,
3172 #ifdef HAVE_TARGET_32_BIG
3175 Symbol_table::add_from_relobj<32, true>(
3176 Sized_relobj<32, true>* relobj,
3177 const unsigned char* syms,
3179 size_t symndx_offset,
3180 const char* sym_names,
3181 size_t sym_name_size,
3182 Sized_relobj<32, true>::Symbols* sympointers,
3186 #ifdef HAVE_TARGET_64_LITTLE
3189 Symbol_table::add_from_relobj<64, false>(
3190 Sized_relobj<64, false>* relobj,
3191 const unsigned char* syms,
3193 size_t symndx_offset,
3194 const char* sym_names,
3195 size_t sym_name_size,
3196 Sized_relobj<64, false>::Symbols* sympointers,
3200 #ifdef HAVE_TARGET_64_BIG
3203 Symbol_table::add_from_relobj<64, true>(
3204 Sized_relobj<64, true>* relobj,
3205 const unsigned char* syms,
3207 size_t symndx_offset,
3208 const char* sym_names,
3209 size_t sym_name_size,
3210 Sized_relobj<64, true>::Symbols* sympointers,
3214 #ifdef HAVE_TARGET_32_LITTLE
3217 Symbol_table::add_from_pluginobj<32, false>(
3218 Sized_pluginobj<32, false>* obj,
3221 elfcpp::Sym<32, false>* sym);
3224 #ifdef HAVE_TARGET_32_BIG
3227 Symbol_table::add_from_pluginobj<32, true>(
3228 Sized_pluginobj<32, true>* obj,
3231 elfcpp::Sym<32, true>* sym);
3234 #ifdef HAVE_TARGET_64_LITTLE
3237 Symbol_table::add_from_pluginobj<64, false>(
3238 Sized_pluginobj<64, false>* obj,
3241 elfcpp::Sym<64, false>* sym);
3244 #ifdef HAVE_TARGET_64_BIG
3247 Symbol_table::add_from_pluginobj<64, true>(
3248 Sized_pluginobj<64, true>* obj,
3251 elfcpp::Sym<64, true>* sym);
3254 #ifdef HAVE_TARGET_32_LITTLE
3257 Symbol_table::add_from_dynobj<32, false>(
3258 Sized_dynobj<32, false>* dynobj,
3259 const unsigned char* syms,
3261 const char* sym_names,
3262 size_t sym_name_size,
3263 const unsigned char* versym,
3265 const std::vector<const char*>* version_map,
3266 Sized_relobj<32, false>::Symbols* sympointers,
3270 #ifdef HAVE_TARGET_32_BIG
3273 Symbol_table::add_from_dynobj<32, true>(
3274 Sized_dynobj<32, true>* dynobj,
3275 const unsigned char* syms,
3277 const char* sym_names,
3278 size_t sym_name_size,
3279 const unsigned char* versym,
3281 const std::vector<const char*>* version_map,
3282 Sized_relobj<32, true>::Symbols* sympointers,
3286 #ifdef HAVE_TARGET_64_LITTLE
3289 Symbol_table::add_from_dynobj<64, false>(
3290 Sized_dynobj<64, false>* dynobj,
3291 const unsigned char* syms,
3293 const char* sym_names,
3294 size_t sym_name_size,
3295 const unsigned char* versym,
3297 const std::vector<const char*>* version_map,
3298 Sized_relobj<64, false>::Symbols* sympointers,
3302 #ifdef HAVE_TARGET_64_BIG
3305 Symbol_table::add_from_dynobj<64, true>(
3306 Sized_dynobj<64, true>* dynobj,
3307 const unsigned char* syms,
3309 const char* sym_names,
3310 size_t sym_name_size,
3311 const unsigned char* versym,
3313 const std::vector<const char*>* version_map,
3314 Sized_relobj<64, true>::Symbols* sympointers,
3318 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
3321 Symbol_table::define_with_copy_reloc<32>(
3322 Sized_symbol<32>* sym,
3324 elfcpp::Elf_types<32>::Elf_Addr value);
3327 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
3330 Symbol_table::define_with_copy_reloc<64>(
3331 Sized_symbol<64>* sym,
3333 elfcpp::Elf_types<64>::Elf_Addr value);
3336 #ifdef HAVE_TARGET_32_LITTLE
3339 Warnings::issue_warning<32, false>(const Symbol* sym,
3340 const Relocate_info<32, false>* relinfo,
3341 size_t relnum, off_t reloffset) const;
3344 #ifdef HAVE_TARGET_32_BIG
3347 Warnings::issue_warning<32, true>(const Symbol* sym,
3348 const Relocate_info<32, true>* relinfo,
3349 size_t relnum, off_t reloffset) const;
3352 #ifdef HAVE_TARGET_64_LITTLE
3355 Warnings::issue_warning<64, false>(const Symbol* sym,
3356 const Relocate_info<64, false>* relinfo,
3357 size_t relnum, off_t reloffset) const;
3360 #ifdef HAVE_TARGET_64_BIG
3363 Warnings::issue_warning<64, true>(const Symbol* sym,
3364 const Relocate_info<64, true>* relinfo,
3365 size_t relnum, off_t reloffset) const;
3368 } // End namespace gold.