| // symtab.cc -- the gold symbol table |
| |
| // Copyright 2006, 2007 Free Software Foundation, Inc. |
| // Written by Ian Lance Taylor <iant@google.com>. |
| |
| // This file is part of gold. |
| |
| // This program is free software; you can redistribute it and/or modify |
| // it under the terms of the GNU General Public License as published by |
| // the Free Software Foundation; either version 3 of the License, or |
| // (at your option) any later version. |
| |
| // This program is distributed in the hope that it will be useful, |
| // but WITHOUT ANY WARRANTY; without even the implied warranty of |
| // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| // GNU General Public License for more details. |
| |
| // You should have received a copy of the GNU General Public License |
| // along with this program; if not, write to the Free Software |
| // Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, |
| // MA 02110-1301, USA. |
| |
| #include "gold.h" |
| |
| #include <stdint.h> |
| #include <set> |
| #include <string> |
| #include <utility> |
| #include "demangle.h" |
| |
| #include "object.h" |
| #include "dwarf_reader.h" |
| #include "dynobj.h" |
| #include "output.h" |
| #include "target.h" |
| #include "workqueue.h" |
| #include "symtab.h" |
| |
| namespace gold |
| { |
| |
| // Class Symbol. |
| |
| // Initialize fields in Symbol. This initializes everything except u_ |
| // and source_. |
| |
| void |
| Symbol::init_fields(const char* name, const char* version, |
| elfcpp::STT type, elfcpp::STB binding, |
| elfcpp::STV visibility, unsigned char nonvis) |
| { |
| this->name_ = name; |
| this->version_ = version; |
| this->symtab_index_ = 0; |
| this->dynsym_index_ = 0; |
| this->got_offset_ = 0; |
| this->plt_offset_ = 0; |
| this->type_ = type; |
| this->binding_ = binding; |
| this->visibility_ = visibility; |
| this->nonvis_ = nonvis; |
| this->is_target_special_ = false; |
| this->is_def_ = false; |
| this->is_forwarder_ = false; |
| this->has_alias_ = false; |
| this->needs_dynsym_entry_ = false; |
| this->in_reg_ = false; |
| this->in_dyn_ = false; |
| this->has_got_offset_ = false; |
| this->has_plt_offset_ = false; |
| this->has_warning_ = false; |
| this->is_copied_from_dynobj_ = false; |
| this->needs_value_in_got_ = false; |
| } |
| |
| // Return the demangled version of the symbol's name, but only |
| // if the --demangle flag was set. |
| |
| static std::string |
| demangle(const char* name) |
| { |
| if (!parameters->demangle()) |
| return name; |
| |
| // cplus_demangle allocates memory for the result it returns, |
| // and returns NULL if the name is already demangled. |
| char* demangled_name = cplus_demangle(name, DMGL_ANSI | DMGL_PARAMS); |
| if (demangled_name == NULL) |
| return name; |
| |
| std::string retval(demangled_name); |
| free(demangled_name); |
| return retval; |
| } |
| |
| std::string |
| Symbol::demangled_name() const |
| { |
| return demangle(this->name()); |
| } |
| |
| // Initialize the fields in the base class Symbol for SYM in OBJECT. |
| |
| template<int size, bool big_endian> |
| void |
| Symbol::init_base(const char* name, const char* version, Object* object, |
| const elfcpp::Sym<size, big_endian>& sym) |
| { |
| this->init_fields(name, version, sym.get_st_type(), sym.get_st_bind(), |
| sym.get_st_visibility(), sym.get_st_nonvis()); |
| this->u_.from_object.object = object; |
| // FIXME: Handle SHN_XINDEX. |
| this->u_.from_object.shndx = sym.get_st_shndx(); |
| this->source_ = FROM_OBJECT; |
| this->in_reg_ = !object->is_dynamic(); |
| this->in_dyn_ = object->is_dynamic(); |
| } |
| |
| // Initialize the fields in the base class Symbol for a symbol defined |
| // in an Output_data. |
| |
| void |
| Symbol::init_base(const char* name, Output_data* od, elfcpp::STT type, |
| elfcpp::STB binding, elfcpp::STV visibility, |
| unsigned char nonvis, bool offset_is_from_end) |
| { |
| this->init_fields(name, NULL, type, binding, visibility, nonvis); |
| this->u_.in_output_data.output_data = od; |
| this->u_.in_output_data.offset_is_from_end = offset_is_from_end; |
| this->source_ = IN_OUTPUT_DATA; |
| this->in_reg_ = true; |
| } |
| |
| // Initialize the fields in the base class Symbol for a symbol defined |
| // in an Output_segment. |
| |
| void |
| Symbol::init_base(const char* name, Output_segment* os, elfcpp::STT type, |
| elfcpp::STB binding, elfcpp::STV visibility, |
| unsigned char nonvis, Segment_offset_base offset_base) |
| { |
| this->init_fields(name, NULL, type, binding, visibility, nonvis); |
| this->u_.in_output_segment.output_segment = os; |
| this->u_.in_output_segment.offset_base = offset_base; |
| this->source_ = IN_OUTPUT_SEGMENT; |
| this->in_reg_ = true; |
| } |
| |
| // Initialize the fields in the base class Symbol for a symbol defined |
| // as a constant. |
| |
| void |
| Symbol::init_base(const char* name, elfcpp::STT type, |
| elfcpp::STB binding, elfcpp::STV visibility, |
| unsigned char nonvis) |
| { |
| this->init_fields(name, NULL, type, binding, visibility, nonvis); |
| this->source_ = CONSTANT; |
| this->in_reg_ = true; |
| } |
| |
| // Allocate a common symbol in the base. |
| |
| void |
| Symbol::allocate_base_common(Output_data* od) |
| { |
| gold_assert(this->is_common()); |
| this->source_ = IN_OUTPUT_DATA; |
| this->u_.in_output_data.output_data = od; |
| this->u_.in_output_data.offset_is_from_end = false; |
| } |
| |
| // Initialize the fields in Sized_symbol for SYM in OBJECT. |
| |
| template<int size> |
| template<bool big_endian> |
| void |
| Sized_symbol<size>::init(const char* name, const char* version, Object* object, |
| const elfcpp::Sym<size, big_endian>& sym) |
| { |
| this->init_base(name, version, object, sym); |
| this->value_ = sym.get_st_value(); |
| this->symsize_ = sym.get_st_size(); |
| } |
| |
| // Initialize the fields in Sized_symbol for a symbol defined in an |
| // Output_data. |
| |
| template<int size> |
| void |
| Sized_symbol<size>::init(const char* name, Output_data* od, |
| Value_type value, Size_type symsize, |
| elfcpp::STT type, elfcpp::STB binding, |
| elfcpp::STV visibility, unsigned char nonvis, |
| bool offset_is_from_end) |
| { |
| this->init_base(name, od, type, binding, visibility, nonvis, |
| offset_is_from_end); |
| this->value_ = value; |
| this->symsize_ = symsize; |
| } |
| |
| // Initialize the fields in Sized_symbol for a symbol defined in an |
| // Output_segment. |
| |
| template<int size> |
| void |
| Sized_symbol<size>::init(const char* name, Output_segment* os, |
| Value_type value, Size_type symsize, |
| elfcpp::STT type, elfcpp::STB binding, |
| elfcpp::STV visibility, unsigned char nonvis, |
| Segment_offset_base offset_base) |
| { |
| this->init_base(name, os, type, binding, visibility, nonvis, offset_base); |
| this->value_ = value; |
| this->symsize_ = symsize; |
| } |
| |
| // Initialize the fields in Sized_symbol for a symbol defined as a |
| // constant. |
| |
| template<int size> |
| void |
| Sized_symbol<size>::init(const char* name, Value_type value, Size_type symsize, |
| elfcpp::STT type, elfcpp::STB binding, |
| elfcpp::STV visibility, unsigned char nonvis) |
| { |
| this->init_base(name, type, binding, visibility, nonvis); |
| this->value_ = value; |
| this->symsize_ = symsize; |
| } |
| |
| // Allocate a common symbol. |
| |
| template<int size> |
| void |
| Sized_symbol<size>::allocate_common(Output_data* od, Value_type value) |
| { |
| this->allocate_base_common(od); |
| this->value_ = value; |
| } |
| |
| // Return true if this symbol should be added to the dynamic symbol |
| // table. |
| |
| inline bool |
| Symbol::should_add_dynsym_entry() const |
| { |
| // If the symbol is used by a dynamic relocation, we need to add it. |
| if (this->needs_dynsym_entry()) |
| return true; |
| |
| // If exporting all symbols or building a shared library, |
| // and the symbol is defined in a regular object and is |
| // externally visible, we need to add it. |
| if ((parameters->export_dynamic() || parameters->output_is_shared()) |
| && !this->is_from_dynobj() |
| && this->is_externally_visible()) |
| return true; |
| |
| return false; |
| } |
| |
| // Return true if the final value of this symbol is known at link |
| // time. |
| |
| bool |
| Symbol::final_value_is_known() const |
| { |
| // If we are not generating an executable, then no final values are |
| // known, since they will change at runtime. |
| if (!parameters->output_is_executable()) |
| return false; |
| |
| // If the symbol is not from an object file, then it is defined, and |
| // known. |
| if (this->source_ != FROM_OBJECT) |
| return true; |
| |
| // If the symbol is from a dynamic object, then the final value is |
| // not known. |
| if (this->object()->is_dynamic()) |
| return false; |
| |
| // If the symbol is not undefined (it is defined or common), then |
| // the final value is known. |
| if (!this->is_undefined()) |
| return true; |
| |
| // If the symbol is undefined, then whether the final value is known |
| // depends on whether we are doing a static link. If we are doing a |
| // dynamic link, then the final value could be filled in at runtime. |
| // This could reasonably be the case for a weak undefined symbol. |
| return parameters->doing_static_link(); |
| } |
| |
| // Class Symbol_table. |
| |
| Symbol_table::Symbol_table() |
| : saw_undefined_(0), offset_(0), table_(), namepool_(), |
| forwarders_(), commons_(), warnings_() |
| { |
| } |
| |
| Symbol_table::~Symbol_table() |
| { |
| } |
| |
| // The hash function. The key is always canonicalized, so we use a |
| // simple combination of the pointers. |
| |
| size_t |
| Symbol_table::Symbol_table_hash::operator()(const Symbol_table_key& key) const |
| { |
| return key.first ^ key.second; |
| } |
| |
| // The symbol table key equality function. This is only called with |
| // canonicalized name and version strings, so we can use pointer |
| // comparison. |
| |
| bool |
| Symbol_table::Symbol_table_eq::operator()(const Symbol_table_key& k1, |
| const Symbol_table_key& k2) const |
| { |
| return k1.first == k2.first && k1.second == k2.second; |
| } |
| |
| // Make TO a symbol which forwards to FROM. |
| |
| void |
| Symbol_table::make_forwarder(Symbol* from, Symbol* to) |
| { |
| gold_assert(from != to); |
| gold_assert(!from->is_forwarder() && !to->is_forwarder()); |
| this->forwarders_[from] = to; |
| from->set_forwarder(); |
| } |
| |
| // Resolve the forwards from FROM, returning the real symbol. |
| |
| Symbol* |
| Symbol_table::resolve_forwards(const Symbol* from) const |
| { |
| gold_assert(from->is_forwarder()); |
| Unordered_map<const Symbol*, Symbol*>::const_iterator p = |
| this->forwarders_.find(from); |
| gold_assert(p != this->forwarders_.end()); |
| return p->second; |
| } |
| |
| // Look up a symbol by name. |
| |
| Symbol* |
| Symbol_table::lookup(const char* name, const char* version) const |
| { |
| Stringpool::Key name_key; |
| name = this->namepool_.find(name, &name_key); |
| if (name == NULL) |
| return NULL; |
| |
| Stringpool::Key version_key = 0; |
| if (version != NULL) |
| { |
| version = this->namepool_.find(version, &version_key); |
| if (version == NULL) |
| return NULL; |
| } |
| |
| Symbol_table_key key(name_key, version_key); |
| Symbol_table::Symbol_table_type::const_iterator p = this->table_.find(key); |
| if (p == this->table_.end()) |
| return NULL; |
| return p->second; |
| } |
| |
| // Resolve a Symbol with another Symbol. This is only used in the |
| // unusual case where there are references to both an unversioned |
| // symbol and a symbol with a version, and we then discover that that |
| // version is the default version. Because this is unusual, we do |
| // this the slow way, by converting back to an ELF symbol. |
| |
| template<int size, bool big_endian> |
| void |
| Symbol_table::resolve(Sized_symbol<size>* to, const Sized_symbol<size>* from, |
| const char* version ACCEPT_SIZE_ENDIAN) |
| { |
| unsigned char buf[elfcpp::Elf_sizes<size>::sym_size]; |
| elfcpp::Sym_write<size, big_endian> esym(buf); |
| // We don't bother to set the st_name field. |
| esym.put_st_value(from->value()); |
| esym.put_st_size(from->symsize()); |
| esym.put_st_info(from->binding(), from->type()); |
| esym.put_st_other(from->visibility(), from->nonvis()); |
| esym.put_st_shndx(from->shndx()); |
| this->resolve(to, esym.sym(), esym.sym(), from->object(), version); |
| if (from->in_reg()) |
| to->set_in_reg(); |
| if (from->in_dyn()) |
| to->set_in_dyn(); |
| } |
| |
| // Add one symbol from OBJECT to the symbol table. NAME is symbol |
| // name and VERSION is the version; both are canonicalized. DEF is |
| // whether this is the default version. |
| |
| // If DEF is true, then this is the definition of a default version of |
| // a symbol. That means that any lookup of NAME/NULL and any lookup |
| // of NAME/VERSION should always return the same symbol. This is |
| // obvious for references, but in particular we want to do this for |
| // definitions: overriding NAME/NULL should also override |
| // NAME/VERSION. If we don't do that, it would be very hard to |
| // override functions in a shared library which uses versioning. |
| |
| // We implement this by simply making both entries in the hash table |
| // point to the same Symbol structure. That is easy enough if this is |
| // the first time we see NAME/NULL or NAME/VERSION, but it is possible |
| // that we have seen both already, in which case they will both have |
| // independent entries in the symbol table. We can't simply change |
| // the symbol table entry, because we have pointers to the entries |
| // attached to the object files. So we mark the entry attached to the |
| // object file as a forwarder, and record it in the forwarders_ map. |
| // Note that entries in the hash table will never be marked as |
| // forwarders. |
| // |
| // SYM and ORIG_SYM are almost always the same. ORIG_SYM is the |
| // symbol exactly as it existed in the input file. SYM is usually |
| // that as well, but can be modified, for instance if we determine |
| // it's in a to-be-discarded section. |
| |
| template<int size, bool big_endian> |
| Sized_symbol<size>* |
| Symbol_table::add_from_object(Object* object, |
| const char *name, |
| Stringpool::Key name_key, |
| const char *version, |
| Stringpool::Key version_key, |
| bool def, |
| const elfcpp::Sym<size, big_endian>& sym, |
| const elfcpp::Sym<size, big_endian>& orig_sym) |
| { |
| Symbol* const snull = NULL; |
| std::pair<typename Symbol_table_type::iterator, bool> ins = |
| this->table_.insert(std::make_pair(std::make_pair(name_key, version_key), |
| snull)); |
| |
| std::pair<typename Symbol_table_type::iterator, bool> insdef = |
| std::make_pair(this->table_.end(), false); |
| if (def) |
| { |
| const Stringpool::Key vnull_key = 0; |
| insdef = this->table_.insert(std::make_pair(std::make_pair(name_key, |
| vnull_key), |
| snull)); |
| } |
| |
| // ins.first: an iterator, which is a pointer to a pair. |
| // ins.first->first: the key (a pair of name and version). |
| // ins.first->second: the value (Symbol*). |
| // ins.second: true if new entry was inserted, false if not. |
| |
| Sized_symbol<size>* ret; |
| bool was_undefined; |
| bool was_common; |
| if (!ins.second) |
| { |
| // We already have an entry for NAME/VERSION. |
| ret = this->get_sized_symbol SELECT_SIZE_NAME(size) (ins.first->second |
| SELECT_SIZE(size)); |
| gold_assert(ret != NULL); |
| |
| was_undefined = ret->is_undefined(); |
| was_common = ret->is_common(); |
| |
| this->resolve(ret, sym, orig_sym, object, version); |
| |
| if (def) |
| { |
| if (insdef.second) |
| { |
| // This is the first time we have seen NAME/NULL. Make |
| // NAME/NULL point to NAME/VERSION. |
| insdef.first->second = ret; |
| } |
| else if (insdef.first->second != ret) |
| { |
| // This is the unfortunate case where we already have |
| // entries for both NAME/VERSION and NAME/NULL. |
| const Sized_symbol<size>* sym2; |
| sym2 = this->get_sized_symbol SELECT_SIZE_NAME(size) ( |
| insdef.first->second |
| SELECT_SIZE(size)); |
| Symbol_table::resolve SELECT_SIZE_ENDIAN_NAME(size, big_endian) ( |
| ret, sym2, version SELECT_SIZE_ENDIAN(size, big_endian)); |
| this->make_forwarder(insdef.first->second, ret); |
| insdef.first->second = ret; |
| } |
| } |
| } |
| else |
| { |
| // This is the first time we have seen NAME/VERSION. |
| gold_assert(ins.first->second == NULL); |
| |
| was_undefined = false; |
| was_common = false; |
| |
| if (def && !insdef.second) |
| { |
| // We already have an entry for NAME/NULL. If we override |
| // it, then change it to NAME/VERSION. |
| ret = this->get_sized_symbol SELECT_SIZE_NAME(size) ( |
| insdef.first->second |
| SELECT_SIZE(size)); |
| this->resolve(ret, sym, orig_sym, object, version); |
| ins.first->second = ret; |
| } |
| else |
| { |
| Sized_target<size, big_endian>* target = |
| object->sized_target SELECT_SIZE_ENDIAN_NAME(size, big_endian) ( |
| SELECT_SIZE_ENDIAN_ONLY(size, big_endian)); |
| if (!target->has_make_symbol()) |
| ret = new Sized_symbol<size>(); |
| else |
| { |
| ret = target->make_symbol(); |
| if (ret == NULL) |
| { |
| // This means that we don't want a symbol table |
| // entry after all. |
| if (!def) |
| this->table_.erase(ins.first); |
| else |
| { |
| this->table_.erase(insdef.first); |
| // Inserting insdef invalidated ins. |
| this->table_.erase(std::make_pair(name_key, |
| version_key)); |
| } |
| return NULL; |
| } |
| } |
| |
| ret->init(name, version, object, sym); |
| |
| ins.first->second = ret; |
| if (def) |
| { |
| // This is the first time we have seen NAME/NULL. Point |
| // it at the new entry for NAME/VERSION. |
| gold_assert(insdef.second); |
| insdef.first->second = ret; |
| } |
| } |
| } |
| |
| // Record every time we see a new undefined symbol, to speed up |
| // archive groups. |
| if (!was_undefined && ret->is_undefined()) |
| ++this->saw_undefined_; |
| |
| // Keep track of common symbols, to speed up common symbol |
| // allocation. |
| if (!was_common && ret->is_common()) |
| this->commons_.push_back(ret); |
| |
| return ret; |
| } |
| |
| // Add all the symbols in a relocatable object to the hash table. |
| |
| template<int size, bool big_endian> |
| void |
| Symbol_table::add_from_relobj( |
| Sized_relobj<size, big_endian>* relobj, |
| const unsigned char* syms, |
| size_t count, |
| const char* sym_names, |
| size_t sym_name_size, |
| typename Sized_relobj<size, big_endian>::Symbols* sympointers) |
| { |
| gold_assert(size == relobj->target()->get_size()); |
| gold_assert(size == parameters->get_size()); |
| |
| const int sym_size = elfcpp::Elf_sizes<size>::sym_size; |
| |
| const unsigned char* p = syms; |
| for (size_t i = 0; i < count; ++i, p += sym_size) |
| { |
| elfcpp::Sym<size, big_endian> sym(p); |
| elfcpp::Sym<size, big_endian>* psym = &sym; |
| |
| unsigned int st_name = psym->get_st_name(); |
| if (st_name >= sym_name_size) |
| { |
| relobj->error(_("bad global symbol name offset %u at %zu"), |
| st_name, i); |
| continue; |
| } |
| |
| const char* name = sym_names + st_name; |
| |
| // A symbol defined in a section which we are not including must |
| // be treated as an undefined symbol. |
| unsigned char symbuf[sym_size]; |
| elfcpp::Sym<size, big_endian> sym2(symbuf); |
| unsigned int st_shndx = psym->get_st_shndx(); |
| if (st_shndx != elfcpp::SHN_UNDEF |
| && st_shndx < elfcpp::SHN_LORESERVE |
| && !relobj->is_section_included(st_shndx)) |
| { |
| memcpy(symbuf, p, sym_size); |
| elfcpp::Sym_write<size, big_endian> sw(symbuf); |
| sw.put_st_shndx(elfcpp::SHN_UNDEF); |
| psym = &sym2; |
| } |
| |
| // In an object file, an '@' in the name separates the symbol |
| // name from the version name. If there are two '@' characters, |
| // this is the default version. |
| const char* ver = strchr(name, '@'); |
| |
| Sized_symbol<size>* res; |
| if (ver == NULL) |
| { |
| Stringpool::Key name_key; |
| name = this->namepool_.add(name, true, &name_key); |
| res = this->add_from_object(relobj, name, name_key, NULL, 0, |
| false, *psym, sym); |
| } |
| else |
| { |
| Stringpool::Key name_key; |
| name = this->namepool_.add_prefix(name, ver - name, &name_key); |
| |
| bool def = false; |
| ++ver; |
| if (*ver == '@') |
| { |
| def = true; |
| ++ver; |
| } |
| |
| Stringpool::Key ver_key; |
| ver = this->namepool_.add(ver, true, &ver_key); |
| |
| res = this->add_from_object(relobj, name, name_key, ver, ver_key, |
| def, *psym, sym); |
| } |
| |
| (*sympointers)[i] = res; |
| } |
| } |
| |
| // Add all the symbols in a dynamic object to the hash table. |
| |
| template<int size, bool big_endian> |
| void |
| Symbol_table::add_from_dynobj( |
| Sized_dynobj<size, big_endian>* dynobj, |
| const unsigned char* syms, |
| size_t count, |
| const char* sym_names, |
| size_t sym_name_size, |
| const unsigned char* versym, |
| size_t versym_size, |
| const std::vector<const char*>* version_map) |
| { |
| gold_assert(size == dynobj->target()->get_size()); |
| gold_assert(size == parameters->get_size()); |
| |
| if (versym != NULL && versym_size / 2 < count) |
| { |
| dynobj->error(_("too few symbol versions")); |
| return; |
| } |
| |
| const int sym_size = elfcpp::Elf_sizes<size>::sym_size; |
| |
| // We keep a list of all STT_OBJECT symbols, so that we can resolve |
| // weak aliases. This is necessary because if the dynamic object |
| // provides the same variable under two names, one of which is a |
| // weak definition, and the regular object refers to the weak |
| // definition, we have to put both the weak definition and the |
| // strong definition into the dynamic symbol table. Given a weak |
| // definition, the only way that we can find the corresponding |
| // strong definition, if any, is to search the symbol table. |
| std::vector<Sized_symbol<size>*> object_symbols; |
| |
| const unsigned char* p = syms; |
| const unsigned char* vs = versym; |
| for (size_t i = 0; i < count; ++i, p += sym_size, vs += 2) |
| { |
| elfcpp::Sym<size, big_endian> sym(p); |
| |
| // Ignore symbols with local binding. |
| if (sym.get_st_bind() == elfcpp::STB_LOCAL) |
| continue; |
| |
| unsigned int st_name = sym.get_st_name(); |
| if (st_name >= sym_name_size) |
| { |
| dynobj->error(_("bad symbol name offset %u at %zu"), |
| st_name, i); |
| continue; |
| } |
| |
| const char* name = sym_names + st_name; |
| |
| Sized_symbol<size>* res; |
| |
| if (versym == NULL) |
| { |
| Stringpool::Key name_key; |
| name = this->namepool_.add(name, true, &name_key); |
| res = this->add_from_object(dynobj, name, name_key, NULL, 0, |
| false, sym, sym); |
| } |
| else |
| { |
| // Read the version information. |
| |
| unsigned int v = elfcpp::Swap<16, big_endian>::readval(vs); |
| |
| bool hidden = (v & elfcpp::VERSYM_HIDDEN) != 0; |
| v &= elfcpp::VERSYM_VERSION; |
| |
| // The Sun documentation says that V can be VER_NDX_LOCAL, |
| // or VER_NDX_GLOBAL, or a version index. The meaning of |
| // VER_NDX_LOCAL is defined as "Symbol has local scope." |
| // The old GNU linker will happily generate VER_NDX_LOCAL |
| // for an undefined symbol. I don't know what the Sun |
| // linker will generate. |
| |
| if (v == static_cast<unsigned int>(elfcpp::VER_NDX_LOCAL) |
| && sym.get_st_shndx() != elfcpp::SHN_UNDEF) |
| { |
| // This symbol should not be visible outside the object. |
| continue; |
| } |
| |
| // At this point we are definitely going to add this symbol. |
| Stringpool::Key name_key; |
| name = this->namepool_.add(name, true, &name_key); |
| |
| if (v == static_cast<unsigned int>(elfcpp::VER_NDX_LOCAL) |
| || v == static_cast<unsigned int>(elfcpp::VER_NDX_GLOBAL)) |
| { |
| // This symbol does not have a version. |
| res = this->add_from_object(dynobj, name, name_key, NULL, 0, |
| false, sym, sym); |
| } |
| else |
| { |
| if (v >= version_map->size()) |
| { |
| dynobj->error(_("versym for symbol %zu out of range: %u"), |
| i, v); |
| continue; |
| } |
| |
| const char* version = (*version_map)[v]; |
| if (version == NULL) |
| { |
| dynobj->error(_("versym for symbol %zu has no name: %u"), |
| i, v); |
| continue; |
| } |
| |
| Stringpool::Key version_key; |
| version = this->namepool_.add(version, true, &version_key); |
| |
| // If this is an absolute symbol, and the version name |
| // and symbol name are the same, then this is the |
| // version definition symbol. These symbols exist to |
| // support using -u to pull in particular versions. We |
| // do not want to record a version for them. |
| if (sym.get_st_shndx() == elfcpp::SHN_ABS |
| && name_key == version_key) |
| res = this->add_from_object(dynobj, name, name_key, NULL, 0, |
| false, sym, sym); |
| else |
| { |
| const bool def = (!hidden |
| && (sym.get_st_shndx() |
| != elfcpp::SHN_UNDEF)); |
| res = this->add_from_object(dynobj, name, name_key, version, |
| version_key, def, sym, sym); |
| } |
| } |
| } |
| |
| if (sym.get_st_shndx() != elfcpp::SHN_UNDEF |
| && sym.get_st_type() == elfcpp::STT_OBJECT) |
| object_symbols.push_back(res); |
| } |
| |
| this->record_weak_aliases(&object_symbols); |
| } |
| |
| // This is used to sort weak aliases. We sort them first by section |
| // index, then by offset, then by weak ahead of strong. |
| |
| template<int size> |
| class Weak_alias_sorter |
| { |
| public: |
| bool operator()(const Sized_symbol<size>*, const Sized_symbol<size>*) const; |
| }; |
| |
| template<int size> |
| bool |
| Weak_alias_sorter<size>::operator()(const Sized_symbol<size>* s1, |
| const Sized_symbol<size>* s2) const |
| { |
| if (s1->shndx() != s2->shndx()) |
| return s1->shndx() < s2->shndx(); |
| if (s1->value() != s2->value()) |
| return s1->value() < s2->value(); |
| if (s1->binding() != s2->binding()) |
| { |
| if (s1->binding() == elfcpp::STB_WEAK) |
| return true; |
| if (s2->binding() == elfcpp::STB_WEAK) |
| return false; |
| } |
| return std::string(s1->name()) < std::string(s2->name()); |
| } |
| |
| // SYMBOLS is a list of object symbols from a dynamic object. Look |
| // for any weak aliases, and record them so that if we add the weak |
| // alias to the dynamic symbol table, we also add the corresponding |
| // strong symbol. |
| |
| template<int size> |
| void |
| Symbol_table::record_weak_aliases(std::vector<Sized_symbol<size>*>* symbols) |
| { |
| // Sort the vector by section index, then by offset, then by weak |
| // ahead of strong. |
| std::sort(symbols->begin(), symbols->end(), Weak_alias_sorter<size>()); |
| |
| // Walk through the vector. For each weak definition, record |
| // aliases. |
| for (typename std::vector<Sized_symbol<size>*>::const_iterator p = |
| symbols->begin(); |
| p != symbols->end(); |
| ++p) |
| { |
| if ((*p)->binding() != elfcpp::STB_WEAK) |
| continue; |
| |
| // Build a circular list of weak aliases. Each symbol points to |
| // the next one in the circular list. |
| |
| Sized_symbol<size>* from_sym = *p; |
| typename std::vector<Sized_symbol<size>*>::const_iterator q; |
| for (q = p + 1; q != symbols->end(); ++q) |
| { |
| if ((*q)->shndx() != from_sym->shndx() |
| || (*q)->value() != from_sym->value()) |
| break; |
| |
| this->weak_aliases_[from_sym] = *q; |
| from_sym->set_has_alias(); |
| from_sym = *q; |
| } |
| |
| if (from_sym != *p) |
| { |
| this->weak_aliases_[from_sym] = *p; |
| from_sym->set_has_alias(); |
| } |
| |
| p = q - 1; |
| } |
| } |
| |
| // Create and return a specially defined symbol. If ONLY_IF_REF is |
| // true, then only create the symbol if there is a reference to it. |
| // If this does not return NULL, it sets *POLDSYM to the existing |
| // symbol if there is one. This canonicalizes *PNAME and *PVERSION. |
| |
| template<int size, bool big_endian> |
| Sized_symbol<size>* |
| Symbol_table::define_special_symbol(const Target* target, const char** pname, |
| const char** pversion, bool only_if_ref, |
| Sized_symbol<size>** poldsym |
| ACCEPT_SIZE_ENDIAN) |
| { |
| Symbol* oldsym; |
| Sized_symbol<size>* sym; |
| bool add_to_table = false; |
| typename Symbol_table_type::iterator add_loc = this->table_.end(); |
| |
| if (only_if_ref) |
| { |
| oldsym = this->lookup(*pname, *pversion); |
| if (oldsym == NULL || !oldsym->is_undefined()) |
| return NULL; |
| |
| *pname = oldsym->name(); |
| *pversion = oldsym->version(); |
| } |
| else |
| { |
| // Canonicalize NAME and VERSION. |
| Stringpool::Key name_key; |
| *pname = this->namepool_.add(*pname, true, &name_key); |
| |
| Stringpool::Key version_key = 0; |
| if (*pversion != NULL) |
| *pversion = this->namepool_.add(*pversion, true, &version_key); |
| |
| Symbol* const snull = NULL; |
| std::pair<typename Symbol_table_type::iterator, bool> ins = |
| this->table_.insert(std::make_pair(std::make_pair(name_key, |
| version_key), |
| snull)); |
| |
| if (!ins.second) |
| { |
| // We already have a symbol table entry for NAME/VERSION. |
| oldsym = ins.first->second; |
| gold_assert(oldsym != NULL); |
| } |
| else |
| { |
| // We haven't seen this symbol before. |
| gold_assert(ins.first->second == NULL); |
| add_to_table = true; |
| add_loc = ins.first; |
| oldsym = NULL; |
| } |
| } |
| |
| if (!target->has_make_symbol()) |
| sym = new Sized_symbol<size>(); |
| else |
| { |
| gold_assert(target->get_size() == size); |
| gold_assert(target->is_big_endian() ? big_endian : !big_endian); |
| typedef Sized_target<size, big_endian> My_target; |
| const My_target* sized_target = |
| static_cast<const My_target*>(target); |
| sym = sized_target->make_symbol(); |
| if (sym == NULL) |
| return NULL; |
| } |
| |
| if (add_to_table) |
| add_loc->second = sym; |
| else |
| gold_assert(oldsym != NULL); |
| |
| *poldsym = this->get_sized_symbol SELECT_SIZE_NAME(size) (oldsym |
| SELECT_SIZE(size)); |
| |
| return sym; |
| } |
| |
| // Define a symbol based on an Output_data. |
| |
| Symbol* |
| Symbol_table::define_in_output_data(const Target* target, const char* name, |
| const char* version, Output_data* od, |
| uint64_t value, uint64_t symsize, |
| elfcpp::STT type, elfcpp::STB binding, |
| elfcpp::STV visibility, |
| unsigned char nonvis, |
| bool offset_is_from_end, |
| bool only_if_ref) |
| { |
| if (parameters->get_size() == 32) |
| { |
| #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG) |
| return this->do_define_in_output_data<32>(target, name, version, od, |
| value, symsize, type, binding, |
| visibility, nonvis, |
| offset_is_from_end, |
| only_if_ref); |
| #else |
| gold_unreachable(); |
| #endif |
| } |
| else if (parameters->get_size() == 64) |
| { |
| #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG) |
| return this->do_define_in_output_data<64>(target, name, version, od, |
| value, symsize, type, binding, |
| visibility, nonvis, |
| offset_is_from_end, |
| only_if_ref); |
| #else |
| gold_unreachable(); |
| #endif |
| } |
| else |
| gold_unreachable(); |
| } |
| |
| // Define a symbol in an Output_data, sized version. |
| |
| template<int size> |
| Sized_symbol<size>* |
| Symbol_table::do_define_in_output_data( |
| const Target* target, |
| const char* name, |
| const char* version, |
| Output_data* od, |
| typename elfcpp::Elf_types<size>::Elf_Addr value, |
| typename elfcpp::Elf_types<size>::Elf_WXword symsize, |
| elfcpp::STT type, |
| elfcpp::STB binding, |
| elfcpp::STV visibility, |
| unsigned char nonvis, |
| bool offset_is_from_end, |
| bool only_if_ref) |
| { |
| Sized_symbol<size>* sym; |
| Sized_symbol<size>* oldsym; |
| |
| if (parameters->is_big_endian()) |
| { |
| #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG) |
| sym = this->define_special_symbol SELECT_SIZE_ENDIAN_NAME(size, true) ( |
| target, &name, &version, only_if_ref, &oldsym |
| SELECT_SIZE_ENDIAN(size, true)); |
| #else |
| gold_unreachable(); |
| #endif |
| } |
| else |
| { |
| #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE) |
| sym = this->define_special_symbol SELECT_SIZE_ENDIAN_NAME(size, false) ( |
| target, &name, &version, only_if_ref, &oldsym |
| SELECT_SIZE_ENDIAN(size, false)); |
| #else |
| gold_unreachable(); |
| #endif |
| } |
| |
| if (sym == NULL) |
| return NULL; |
| |
| gold_assert(version == NULL || oldsym != NULL); |
| sym->init(name, od, value, symsize, type, binding, visibility, nonvis, |
| offset_is_from_end); |
| |
| if (oldsym != NULL |
| && Symbol_table::should_override_with_special(oldsym)) |
| this->override_with_special(oldsym, sym); |
| |
| return sym; |
| } |
| |
| // Define a symbol based on an Output_segment. |
| |
| Symbol* |
| Symbol_table::define_in_output_segment(const Target* target, const char* name, |
| const char* version, Output_segment* os, |
| uint64_t value, uint64_t symsize, |
| elfcpp::STT type, elfcpp::STB binding, |
| elfcpp::STV visibility, |
| unsigned char nonvis, |
| Symbol::Segment_offset_base offset_base, |
| bool only_if_ref) |
| { |
| if (parameters->get_size() == 32) |
| { |
| #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG) |
| return this->do_define_in_output_segment<32>(target, name, version, os, |
| value, symsize, type, |
| binding, visibility, nonvis, |
| offset_base, only_if_ref); |
| #else |
| gold_unreachable(); |
| #endif |
| } |
| else if (parameters->get_size() == 64) |
| { |
| #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG) |
| return this->do_define_in_output_segment<64>(target, name, version, os, |
| value, symsize, type, |
| binding, visibility, nonvis, |
| offset_base, only_if_ref); |
| #else |
| gold_unreachable(); |
| #endif |
| } |
| else |
| gold_unreachable(); |
| } |
| |
| // Define a symbol in an Output_segment, sized version. |
| |
| template<int size> |
| Sized_symbol<size>* |
| Symbol_table::do_define_in_output_segment( |
| const Target* target, |
| const char* name, |
| const char* version, |
| Output_segment* os, |
| typename elfcpp::Elf_types<size>::Elf_Addr value, |
| typename elfcpp::Elf_types<size>::Elf_WXword symsize, |
| elfcpp::STT type, |
| elfcpp::STB binding, |
| elfcpp::STV visibility, |
| unsigned char nonvis, |
| Symbol::Segment_offset_base offset_base, |
| bool only_if_ref) |
| { |
| Sized_symbol<size>* sym; |
| Sized_symbol<size>* oldsym; |
| |
| if (parameters->is_big_endian()) |
| { |
| #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG) |
| sym = this->define_special_symbol SELECT_SIZE_ENDIAN_NAME(size, true) ( |
| target, &name, &version, only_if_ref, &oldsym |
| SELECT_SIZE_ENDIAN(size, true)); |
| #else |
| gold_unreachable(); |
| #endif |
| } |
| else |
| { |
| #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE) |
| sym = this->define_special_symbol SELECT_SIZE_ENDIAN_NAME(size, false) ( |
| target, &name, &version, only_if_ref, &oldsym |
| SELECT_SIZE_ENDIAN(size, false)); |
| #else |
| gold_unreachable(); |
| #endif |
| } |
| |
| if (sym == NULL) |
| return NULL; |
| |
| gold_assert(version == NULL || oldsym != NULL); |
| sym->init(name, os, value, symsize, type, binding, visibility, nonvis, |
| offset_base); |
| |
| if (oldsym != NULL |
| && Symbol_table::should_override_with_special(oldsym)) |
| this->override_with_special(oldsym, sym); |
| |
| return sym; |
| } |
| |
| // Define a special symbol with a constant value. It is a multiple |
| // definition error if this symbol is already defined. |
| |
| Symbol* |
| Symbol_table::define_as_constant(const Target* target, const char* name, |
| const char* version, uint64_t value, |
| uint64_t symsize, elfcpp::STT type, |
| elfcpp::STB binding, elfcpp::STV visibility, |
| unsigned char nonvis, bool only_if_ref) |
| { |
| if (parameters->get_size() == 32) |
| { |
| #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG) |
| return this->do_define_as_constant<32>(target, name, version, value, |
| symsize, type, binding, |
| visibility, nonvis, only_if_ref); |
| #else |
| gold_unreachable(); |
| #endif |
| } |
| else if (parameters->get_size() == 64) |
| { |
| #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG) |
| return this->do_define_as_constant<64>(target, name, version, value, |
| symsize, type, binding, |
| visibility, nonvis, only_if_ref); |
| #else |
| gold_unreachable(); |
| #endif |
| } |
| else |
| gold_unreachable(); |
| } |
| |
| // Define a symbol as a constant, sized version. |
| |
| template<int size> |
| Sized_symbol<size>* |
| Symbol_table::do_define_as_constant( |
| const Target* target, |
| const char* name, |
| const char* version, |
| typename elfcpp::Elf_types<size>::Elf_Addr value, |
| typename elfcpp::Elf_types<size>::Elf_WXword symsize, |
| elfcpp::STT type, |
| elfcpp::STB binding, |
| elfcpp::STV visibility, |
| unsigned char nonvis, |
| bool only_if_ref) |
| { |
| Sized_symbol<size>* sym; |
| Sized_symbol<size>* oldsym; |
| |
| if (parameters->is_big_endian()) |
| { |
| #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG) |
| sym = this->define_special_symbol SELECT_SIZE_ENDIAN_NAME(size, true) ( |
| target, &name, &version, only_if_ref, &oldsym |
| SELECT_SIZE_ENDIAN(size, true)); |
| #else |
| gold_unreachable(); |
| #endif |
| } |
| else |
| { |
| #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE) |
| sym = this->define_special_symbol SELECT_SIZE_ENDIAN_NAME(size, false) ( |
| target, &name, &version, only_if_ref, &oldsym |
| SELECT_SIZE_ENDIAN(size, false)); |
| #else |
| gold_unreachable(); |
| #endif |
| } |
| |
| if (sym == NULL) |
| return NULL; |
| |
| gold_assert(version == NULL || oldsym != NULL); |
| sym->init(name, value, symsize, type, binding, visibility, nonvis); |
| |
| if (oldsym != NULL |
| && Symbol_table::should_override_with_special(oldsym)) |
| this->override_with_special(oldsym, sym); |
| |
| return sym; |
| } |
| |
| // Define a set of symbols in output sections. |
| |
| void |
| Symbol_table::define_symbols(const Layout* layout, const Target* target, |
| int count, const Define_symbol_in_section* p) |
| { |
| for (int i = 0; i < count; ++i, ++p) |
| { |
| Output_section* os = layout->find_output_section(p->output_section); |
| if (os != NULL) |
| this->define_in_output_data(target, p->name, NULL, os, p->value, |
| p->size, p->type, p->binding, |
| p->visibility, p->nonvis, |
| p->offset_is_from_end, p->only_if_ref); |
| else |
| this->define_as_constant(target, p->name, NULL, 0, p->size, p->type, |
| p->binding, p->visibility, p->nonvis, |
| p->only_if_ref); |
| } |
| } |
| |
| // Define a set of symbols in output segments. |
| |
| void |
| Symbol_table::define_symbols(const Layout* layout, const Target* target, |
| int count, const Define_symbol_in_segment* p) |
| { |
| for (int i = 0; i < count; ++i, ++p) |
| { |
| Output_segment* os = layout->find_output_segment(p->segment_type, |
| p->segment_flags_set, |
| p->segment_flags_clear); |
| if (os != NULL) |
| this->define_in_output_segment(target, p->name, NULL, os, p->value, |
| p->size, p->type, p->binding, |
| p->visibility, p->nonvis, |
| p->offset_base, p->only_if_ref); |
| else |
| this->define_as_constant(target, p->name, NULL, 0, p->size, p->type, |
| p->binding, p->visibility, p->nonvis, |
| p->only_if_ref); |
| } |
| } |
| |
| // Define CSYM using a COPY reloc. POSD is the Output_data where the |
| // symbol should be defined--typically a .dyn.bss section. VALUE is |
| // the offset within POSD. |
| |
| template<int size> |
| void |
| Symbol_table::define_with_copy_reloc(const Target* target, |
| Sized_symbol<size>* csym, |
| Output_data* posd, uint64_t value) |
| { |
| gold_assert(csym->is_from_dynobj()); |
| gold_assert(!csym->is_copied_from_dynobj()); |
| Object* object = csym->object(); |
| gold_assert(object->is_dynamic()); |
| Dynobj* dynobj = static_cast<Dynobj*>(object); |
| |
| // Our copied variable has to override any variable in a shared |
| // library. |
| elfcpp::STB binding = csym->binding(); |
| if (binding == elfcpp::STB_WEAK) |
| binding = elfcpp::STB_GLOBAL; |
| |
| this->define_in_output_data(target, csym->name(), csym->version(), |
| posd, value, csym->symsize(), |
| csym->type(), binding, |
| csym->visibility(), csym->nonvis(), |
| false, false); |
| |
| csym->set_is_copied_from_dynobj(); |
| csym->set_needs_dynsym_entry(); |
| |
| this->copied_symbol_dynobjs_[csym] = dynobj; |
| |
| // We have now defined all aliases, but we have not entered them all |
| // in the copied_symbol_dynobjs_ map. |
| if (csym->has_alias()) |
| { |
| Symbol* sym = csym; |
| while (true) |
| { |
| sym = this->weak_aliases_[sym]; |
| if (sym == csym) |
| break; |
| gold_assert(sym->output_data() == posd); |
| |
| sym->set_is_copied_from_dynobj(); |
| this->copied_symbol_dynobjs_[sym] = dynobj; |
| } |
| } |
| } |
| |
| // SYM is defined using a COPY reloc. Return the dynamic object where |
| // the original definition was found. |
| |
| Dynobj* |
| Symbol_table::get_copy_source(const Symbol* sym) const |
| { |
| gold_assert(sym->is_copied_from_dynobj()); |
| Copied_symbol_dynobjs::const_iterator p = |
| this->copied_symbol_dynobjs_.find(sym); |
| gold_assert(p != this->copied_symbol_dynobjs_.end()); |
| return p->second; |
| } |
| |
| // Set the dynamic symbol indexes. INDEX is the index of the first |
| // global dynamic symbol. Pointers to the symbols are stored into the |
| // vector SYMS. The names are added to DYNPOOL. This returns an |
| // updated dynamic symbol index. |
| |
| unsigned int |
| Symbol_table::set_dynsym_indexes(const Target* target, |
| unsigned int index, |
| std::vector<Symbol*>* syms, |
| Stringpool* dynpool, |
| Versions* versions) |
| { |
| for (Symbol_table_type::iterator p = this->table_.begin(); |
| p != this->table_.end(); |
| ++p) |
| { |
| Symbol* sym = p->second; |
| |
| // Note that SYM may already have a dynamic symbol index, since |
| // some symbols appear more than once in the symbol table, with |
| // and without a version. |
| |
| if (!sym->should_add_dynsym_entry()) |
| sym->set_dynsym_index(-1U); |
| else if (!sym->has_dynsym_index()) |
| { |
| sym->set_dynsym_index(index); |
| ++index; |
| syms->push_back(sym); |
| dynpool->add(sym->name(), false, NULL); |
| |
| // Record any version information. |
| if (sym->version() != NULL) |
| versions->record_version(this, dynpool, sym); |
| } |
| } |
| |
| // Finish up the versions. In some cases this may add new dynamic |
| // symbols. |
| index = versions->finalize(target, this, index, syms); |
| |
| return index; |
| } |
| |
| // Set the final values for all the symbols. The index of the first |
| // global symbol in the output file is INDEX. Record the file offset |
| // OFF. Add their names to POOL. Return the new file offset. |
| |
| off_t |
| Symbol_table::finalize(unsigned int index, off_t off, off_t dynoff, |
| size_t dyn_global_index, size_t dyncount, |
| Stringpool* pool) |
| { |
| off_t ret; |
| |
| gold_assert(index != 0); |
| this->first_global_index_ = index; |
| |
| this->dynamic_offset_ = dynoff; |
| this->first_dynamic_global_index_ = dyn_global_index; |
| this->dynamic_count_ = dyncount; |
| |
| if (parameters->get_size() == 32) |
| { |
| #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_32_LITTLE) |
| ret = this->sized_finalize<32>(index, off, pool); |
| #else |
| gold_unreachable(); |
| #endif |
| } |
| else if (parameters->get_size() == 64) |
| { |
| #if defined(HAVE_TARGET_64_BIG) || defined(HAVE_TARGET_64_LITTLE) |
| ret = this->sized_finalize<64>(index, off, pool); |
| #else |
| gold_unreachable(); |
| #endif |
| } |
| else |
| gold_unreachable(); |
| |
| // Now that we have the final symbol table, we can reliably note |
| // which symbols should get warnings. |
| this->warnings_.note_warnings(this); |
| |
| return ret; |
| } |
| |
| // Set the final value for all the symbols. This is called after |
| // Layout::finalize, so all the output sections have their final |
| // address. |
| |
| template<int size> |
| off_t |
| Symbol_table::sized_finalize(unsigned index, off_t off, Stringpool* pool) |
| { |
| off = align_address(off, size >> 3); |
| this->offset_ = off; |
| |
| size_t orig_index = index; |
| |
| const int sym_size = elfcpp::Elf_sizes<size>::sym_size; |
| for (Symbol_table_type::iterator p = this->table_.begin(); |
| p != this->table_.end(); |
| ++p) |
| { |
| Sized_symbol<size>* sym = static_cast<Sized_symbol<size>*>(p->second); |
| |
| // FIXME: Here we need to decide which symbols should go into |
| // the output file, based on --strip. |
| |
| // The default version of a symbol may appear twice in the |
| // symbol table. We only need to finalize it once. |
| if (sym->has_symtab_index()) |
| continue; |
| |
| if (!sym->in_reg()) |
| { |
| gold_assert(!sym->has_symtab_index()); |
| sym->set_symtab_index(-1U); |
| gold_assert(sym->dynsym_index() == -1U); |
| continue; |
| } |
| |
| typename Sized_symbol<size>::Value_type value; |
| |
| switch (sym->source()) |
| { |
| case Symbol::FROM_OBJECT: |
| { |
| unsigned int shndx = sym->shndx(); |
| |
| // FIXME: We need some target specific support here. |
| if (shndx >= elfcpp::SHN_LORESERVE |
| && shndx != elfcpp::SHN_ABS) |
| { |
| gold_error(_("%s: unsupported symbol section 0x%x"), |
| sym->demangled_name().c_str(), shndx); |
| shndx = elfcpp::SHN_UNDEF; |
| } |
| |
| Object* symobj = sym->object(); |
| if (symobj->is_dynamic()) |
| { |
| value = 0; |
| shndx = elfcpp::SHN_UNDEF; |
| } |
| else if (shndx == elfcpp::SHN_UNDEF) |
| value = 0; |
| else if (shndx == elfcpp::SHN_ABS) |
| value = sym->value(); |
| else |
| { |
| Relobj* relobj = static_cast<Relobj*>(symobj); |
| off_t secoff; |
| Output_section* os = relobj->output_section(shndx, &secoff); |
| |
| if (os == NULL) |
| { |
| sym->set_symtab_index(-1U); |
| gold_assert(sym->dynsym_index() == -1U); |
| continue; |
| } |
| |
| value = sym->value() + os->address() + secoff; |
| } |
| } |
| break; |
| |
| case Symbol::IN_OUTPUT_DATA: |
| { |
| Output_data* od = sym->output_data(); |
| value = sym->value() + od->address(); |
| if (sym->offset_is_from_end()) |
| value += od->data_size(); |
| } |
| break; |
| |
| case Symbol::IN_OUTPUT_SEGMENT: |
| { |
| Output_segment* os = sym->output_segment(); |
| value = sym->value() + os->vaddr(); |
| switch (sym->offset_base()) |
| { |
| case Symbol::SEGMENT_START: |
| break; |
| case Symbol::SEGMENT_END: |
| value += os->memsz(); |
| break; |
| case Symbol::SEGMENT_BSS: |
| value += os->filesz(); |
| break; |
| default: |
| gold_unreachable(); |
| } |
| } |
| break; |
| |
| case Symbol::CONSTANT: |
| value = sym->value(); |
| break; |
| |
| default: |
| gold_unreachable(); |
| } |
| |
| sym->set_value(value); |
| |
| if (parameters->strip_all()) |
| sym->set_symtab_index(-1U); |
| else |
| { |
| sym->set_symtab_index(index); |
| pool->add(sym->name(), false, NULL); |
| ++index; |
| off += sym_size; |
| } |
| } |
| |
| this->output_count_ = index - orig_index; |
| |
| return off; |
| } |
| |
| // Write out the global symbols. |
| |
| void |
| Symbol_table::write_globals(const Input_objects* input_objects, |
| const Stringpool* sympool, |
| const Stringpool* dynpool, Output_file* of) const |
| { |
| if (parameters->get_size() == 32) |
| { |
| if (parameters->is_big_endian()) |
| { |
| #ifdef HAVE_TARGET_32_BIG |
| this->sized_write_globals<32, true>(input_objects, sympool, |
| dynpool, of); |
| #else |
| gold_unreachable(); |
| #endif |
| } |
| else |
| { |
| #ifdef HAVE_TARGET_32_LITTLE |
| this->sized_write_globals<32, false>(input_objects, sympool, |
| dynpool, of); |
| #else |
| gold_unreachable(); |
| #endif |
| } |
| } |
| else if (parameters->get_size() == 64) |
| { |
| if (parameters->is_big_endian()) |
| { |
| #ifdef HAVE_TARGET_64_BIG |
| this->sized_write_globals<64, true>(input_objects, sympool, |
| dynpool, of); |
| #else |
| gold_unreachable(); |
| #endif |
| } |
| else |
| { |
| #ifdef HAVE_TARGET_64_LITTLE |
| this->sized_write_globals<64, false>(input_objects, sympool, |
| dynpool, of); |
| #else |
| gold_unreachable(); |
| #endif |
| } |
| } |
| else |
| gold_unreachable(); |
| } |
| |
| // Write out the global symbols. |
| |
| template<int size, bool big_endian> |
| void |
| Symbol_table::sized_write_globals(const Input_objects* input_objects, |
| const Stringpool* sympool, |
| const Stringpool* dynpool, |
| Output_file* of) const |
| { |
| const Target* const target = input_objects->target(); |
| |
| const int sym_size = elfcpp::Elf_sizes<size>::sym_size; |
| unsigned int index = this->first_global_index_; |
| const off_t oview_size = this->output_count_ * sym_size; |
| unsigned char* const psyms = of->get_output_view(this->offset_, oview_size); |
| |
| unsigned int dynamic_count = this->dynamic_count_; |
| off_t dynamic_size = dynamic_count * sym_size; |
| unsigned int first_dynamic_global_index = this->first_dynamic_global_index_; |
| unsigned char* dynamic_view; |
| if (this->dynamic_offset_ == 0) |
| dynamic_view = NULL; |
| else |
| dynamic_view = of->get_output_view(this->dynamic_offset_, dynamic_size); |
| |
| unsigned char* ps = psyms; |
| for (Symbol_table_type::const_iterator p = this->table_.begin(); |
| p != this->table_.end(); |
| ++p) |
| { |
| Sized_symbol<size>* sym = static_cast<Sized_symbol<size>*>(p->second); |
| |
| // Possibly warn about unresolved symbols in shared libraries. |
| this->warn_about_undefined_dynobj_symbol(input_objects, sym); |
| |
| unsigned int sym_index = sym->symtab_index(); |
| unsigned int dynsym_index; |
| if (dynamic_view == NULL) |
| dynsym_index = -1U; |
| else |
| dynsym_index = sym->dynsym_index(); |
| |
| if (sym_index == -1U && dynsym_index == -1U) |
| { |
| // This symbol is not included in the output file. |
| continue; |
| } |
| |
| if (sym_index == index) |
| ++index; |
| else if (sym_index != -1U) |
| { |
| // We have already seen this symbol, because it has a |
| // default version. |
| gold_assert(sym_index < index); |
| if (dynsym_index == -1U) |
| continue; |
| sym_index = -1U; |
| } |
| |
| unsigned int shndx; |
| typename elfcpp::Elf_types<32>::Elf_Addr value = sym->value(); |
| switch (sym->source()) |
| { |
| case Symbol::FROM_OBJECT: |
| { |
| unsigned int in_shndx = sym->shndx(); |
| |
| // FIXME: We need some target specific support here. |
| if (in_shndx >= elfcpp::SHN_LORESERVE |
| && in_shndx != elfcpp::SHN_ABS) |
| { |
| gold_error(_("%s: unsupported symbol section 0x%x"), |
| sym->demangled_name().c_str(), in_shndx); |
| shndx = in_shndx; |
| } |
| else |
| { |
| Object* symobj = sym->object(); |
| if (symobj->is_dynamic()) |
| { |
| if (sym->needs_dynsym_value()) |
| value = target->dynsym_value(sym); |
| shndx = elfcpp::SHN_UNDEF; |
| } |
| else if (in_shndx == elfcpp::SHN_UNDEF |
| || in_shndx == elfcpp::SHN_ABS) |
| shndx = in_shndx; |
| else |
| { |
| Relobj* relobj = static_cast<Relobj*>(symobj); |
| off_t secoff; |
| Output_section* os = relobj->output_section(in_shndx, |
| &secoff); |
| gold_assert(os != NULL); |
| shndx = os->out_shndx(); |
| } |
| } |
| } |
| break; |
| |
| case Symbol::IN_OUTPUT_DATA: |
| shndx = sym->output_data()->out_shndx(); |
| break; |
| |
| case Symbol::IN_OUTPUT_SEGMENT: |
| shndx = elfcpp::SHN_ABS; |
| break; |
| |
| case Symbol::CONSTANT: |
| shndx = elfcpp::SHN_ABS; |
| break; |
| |
| default: |
| gold_unreachable(); |
| } |
| |
| if (sym_index != -1U) |
| { |
| this->sized_write_symbol SELECT_SIZE_ENDIAN_NAME(size, big_endian) ( |
| sym, sym->value(), shndx, sympool, ps |
| SELECT_SIZE_ENDIAN(size, big_endian)); |
| ps += sym_size; |
| } |
| |
| if (dynsym_index != -1U) |
| { |
| dynsym_index -= first_dynamic_global_index; |
| gold_assert(dynsym_index < dynamic_count); |
| unsigned char* pd = dynamic_view + (dynsym_index * sym_size); |
| this->sized_write_symbol SELECT_SIZE_ENDIAN_NAME(size, big_endian) ( |
| sym, value, shndx, dynpool, pd |
| SELECT_SIZE_ENDIAN(size, big_endian)); |
| } |
| } |
| |
| gold_assert(ps - psyms == oview_size); |
| |
| of->write_output_view(this->offset_, oview_size, psyms); |
| if (dynamic_view != NULL) |
| of->write_output_view(this->dynamic_offset_, dynamic_size, dynamic_view); |
| } |
| |
| // Write out the symbol SYM, in section SHNDX, to P. POOL is the |
| // strtab holding the name. |
| |
| template<int size, bool big_endian> |
| void |
| Symbol_table::sized_write_symbol( |
| Sized_symbol<size>* sym, |
| typename elfcpp::Elf_types<size>::Elf_Addr value, |
| unsigned int shndx, |
| const Stringpool* pool, |
| unsigned char* p |
| ACCEPT_SIZE_ENDIAN) const |
| { |
| elfcpp::Sym_write<size, big_endian> osym(p); |
| osym.put_st_name(pool->get_offset(sym->name())); |
| osym.put_st_value(value); |
| osym.put_st_size(sym->symsize()); |
| osym.put_st_info(elfcpp::elf_st_info(sym->binding(), sym->type())); |
| osym.put_st_other(elfcpp::elf_st_other(sym->visibility(), sym->nonvis())); |
| osym.put_st_shndx(shndx); |
| } |
| |
| // Check for unresolved symbols in shared libraries. This is |
| // controlled by the --allow-shlib-undefined option. |
| |
| // We only warn about libraries for which we have seen all the |
| // DT_NEEDED entries. We don't try to track down DT_NEEDED entries |
| // which were not seen in this link. If we didn't see a DT_NEEDED |
| // entry, we aren't going to be able to reliably report whether the |
| // symbol is undefined. |
| |
| // We also don't warn about libraries found in the system library |
| // directory (the directory were we find libc.so); we assume that |
| // those libraries are OK. This heuristic avoids problems in |
| // GNU/Linux, in which -ldl can have undefined references satisfied by |
| // ld-linux.so. |
| |
| inline void |
| Symbol_table::warn_about_undefined_dynobj_symbol( |
| const Input_objects* input_objects, |
| Symbol* sym) const |
| { |
| if (sym->source() == Symbol::FROM_OBJECT |
| && sym->object()->is_dynamic() |
| && sym->shndx() == elfcpp::SHN_UNDEF |
| && sym->binding() != elfcpp::STB_WEAK |
| && !parameters->allow_shlib_undefined() |
| && !input_objects->target()->is_defined_by_abi(sym) |
| && !input_objects->found_in_system_library_directory(sym->object())) |
| { |
| // A very ugly cast. |
| Dynobj* dynobj = static_cast<Dynobj*>(sym->object()); |
| if (!dynobj->has_unknown_needed_entries()) |
| gold_error(_("%s: undefined reference to '%s'"), |
| sym->object()->name().c_str(), |
| sym->demangled_name().c_str()); |
| } |
| } |
| |
| // Write out a section symbol. Return the update offset. |
| |
| void |
| Symbol_table::write_section_symbol(const Output_section *os, |
| Output_file* of, |
| off_t offset) const |
| { |
| if (parameters->get_size() == 32) |
| { |
| if (parameters->is_big_endian()) |
| { |
| #ifdef HAVE_TARGET_32_BIG |
| this->sized_write_section_symbol<32, true>(os, of, offset); |
| #else |
| gold_unreachable(); |
| #endif |
| } |
| else |
| { |
| #ifdef HAVE_TARGET_32_LITTLE |
| this->sized_write_section_symbol<32, false>(os, of, offset); |
| #else |
| gold_unreachable(); |
| #endif |
| } |
| } |
| else if (parameters->get_size() == 64) |
| { |
| if (parameters->is_big_endian()) |
| { |
| #ifdef HAVE_TARGET_64_BIG |
| this->sized_write_section_symbol<64, true>(os, of, offset); |
| #else |
| gold_unreachable(); |
| #endif |
| } |
| else |
| { |
| #ifdef HAVE_TARGET_64_LITTLE |
| this->sized_write_section_symbol<64, false>(os, of, offset); |
| #else |
| gold_unreachable(); |
| #endif |
| } |
| } |
| else |
| gold_unreachable(); |
| } |
| |
| // Write out a section symbol, specialized for size and endianness. |
| |
| template<int size, bool big_endian> |
| void |
| Symbol_table::sized_write_section_symbol(const Output_section* os, |
| Output_file* of, |
| off_t offset) const |
| { |
| const int sym_size = elfcpp::Elf_sizes<size>::sym_size; |
| |
| unsigned char* pov = of->get_output_view(offset, sym_size); |
| |
| elfcpp::Sym_write<size, big_endian> osym(pov); |
| osym.put_st_name(0); |
| osym.put_st_value(os->address()); |
| osym.put_st_size(0); |
| osym.put_st_info(elfcpp::elf_st_info(elfcpp::STB_LOCAL, |
| elfcpp::STT_SECTION)); |
| osym.put_st_other(elfcpp::elf_st_other(elfcpp::STV_DEFAULT, 0)); |
| osym.put_st_shndx(os->out_shndx()); |
| |
| of->write_output_view(offset, sym_size, pov); |
| } |
| |
| // We check for ODR violations by looking for symbols with the same |
| // name for which the debugging information reports that they were |
| // defined in different source locations. When comparing the source |
| // location, we consider instances with the same base filename and |
| // line number to be the same. This is because different object |
| // files/shared libraries can include the same header file using |
| // different paths, and we don't want to report an ODR violation in |
| // that case. |
| |
| // This struct is used to compare line information, as returned by |
| // Dwarf_line_info::one_addr2line. It imlements a < comparison |
| // operator used with std::set. |
| |
| struct Odr_violation_compare |
| { |
| bool |
| operator()(const std::string& s1, const std::string& s2) const |
| { |
| std::string::size_type pos1 = s1.rfind('/'); |
| std::string::size_type pos2 = s2.rfind('/'); |
| if (pos1 == std::string::npos |
| || pos2 == std::string::npos) |
| return s1 < s2; |
| return s1.compare(pos1, std::string::npos, |
| s2, pos2, std::string::npos) < 0; |
| } |
| }; |
| |
| // Check candidate_odr_violations_ to find symbols with the same name |
| // but apparently different definitions (different source-file/line-no). |
| |
| void |
| Symbol_table::detect_odr_violations(const char* output_file_name) const |
| { |
| for (Odr_map::const_iterator it = candidate_odr_violations_.begin(); |
| it != candidate_odr_violations_.end(); |
| ++it) |
| { |
| const char* symbol_name = it->first; |
| // We use a sorted set so the output is deterministic. |
| std::set<std::string, Odr_violation_compare> line_nums; |
| |
| for (Unordered_set<Symbol_location, Symbol_location_hash>::const_iterator |
| locs = it->second.begin(); |
| locs != it->second.end(); |
| ++locs) |
| { |
| // We need to lock the object in order to read it. This |
| // means that we can not run inside a Task. If we want to |
| // run this in a Task for better performance, we will need |
| // one Task for object, plus appropriate locking to ensure |
| // that we don't conflict with other uses of the object. |
| locs->object->lock(); |
| std::string lineno = Dwarf_line_info::one_addr2line( |
| locs->object, locs->shndx, locs->offset); |
| locs->object->unlock(); |
| if (!lineno.empty()) |
| line_nums.insert(lineno); |
| } |
| |
| if (line_nums.size() > 1) |
| { |
| gold_warning(_("while linking %s: symbol '%s' defined in multiple " |
| "places (possible ODR violation):"), |
| output_file_name, demangle(symbol_name).c_str()); |
| for (std::set<std::string>::const_iterator it2 = line_nums.begin(); |
| it2 != line_nums.end(); |
| ++it2) |
| fprintf(stderr, " %s\n", it2->c_str()); |
| } |
| } |
| } |
| |
| // Warnings functions. |
| |
| // Add a new warning. |
| |
| void |
| Warnings::add_warning(Symbol_table* symtab, const char* name, Object* obj, |
| unsigned int shndx) |
| { |
| name = symtab->canonicalize_name(name); |
| this->warnings_[name].set(obj, shndx); |
| } |
| |
| // Look through the warnings and mark the symbols for which we should |
| // warn. This is called during Layout::finalize when we know the |
| // sources for all the symbols. |
| |
| void |
| Warnings::note_warnings(Symbol_table* symtab) |
| { |
| for (Warning_table::iterator p = this->warnings_.begin(); |
| p != this->warnings_.end(); |
| ++p) |
| { |
| Symbol* sym = symtab->lookup(p->first, NULL); |
| if (sym != NULL |
| && sym->source() == Symbol::FROM_OBJECT |
| && sym->object() == p->second.object) |
| { |
| sym->set_has_warning(); |
| |
| // Read the section contents to get the warning text. It |
| // would be nicer if we only did this if we have to actually |
| // issue a warning. Unfortunately, warnings are issued as |
| // we relocate sections. That means that we can not lock |
| // the object then, as we might try to issue the same |
| // warning multiple times simultaneously. |
| { |
| Task_locker_obj<Object> tl(*p->second.object); |
| const unsigned char* c; |
| off_t len; |
| c = p->second.object->section_contents(p->second.shndx, &len, |
| false); |
| p->second.set_text(reinterpret_cast<const char*>(c), len); |
| } |
| } |
| } |
| } |
| |
| // Issue a warning. This is called when we see a relocation against a |
| // symbol for which has a warning. |
| |
| template<int size, bool big_endian> |
| void |
| Warnings::issue_warning(const Symbol* sym, |
| const Relocate_info<size, big_endian>* relinfo, |
| size_t relnum, off_t reloffset) const |
| { |
| gold_assert(sym->has_warning()); |
| Warning_table::const_iterator p = this->warnings_.find(sym->name()); |
| gold_assert(p != this->warnings_.end()); |
| gold_warning_at_location(relinfo, relnum, reloffset, |
| "%s", p->second.text.c_str()); |
| } |
| |
| // Instantiate the templates we need. We could use the configure |
| // script to restrict this to only the ones needed for implemented |
| // targets. |
| |
| #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG) |
| template |
| void |
| Sized_symbol<32>::allocate_common(Output_data*, Value_type); |
| #endif |
| |
| #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG) |
| template |
| void |
| Sized_symbol<64>::allocate_common(Output_data*, Value_type); |
| #endif |
| |
| #ifdef HAVE_TARGET_32_LITTLE |
| template |
| void |
| Symbol_table::add_from_relobj<32, false>( |
| Sized_relobj<32, false>* relobj, |
| const unsigned char* syms, |
| size_t count, |
| const char* sym_names, |
| size_t sym_name_size, |
| Sized_relobj<32, true>::Symbols* sympointers); |
| #endif |
| |
| #ifdef HAVE_TARGET_32_BIG |
| template |
| void |
| Symbol_table::add_from_relobj<32, true>( |
| Sized_relobj<32, true>* relobj, |
| const unsigned char* syms, |
| size_t count, |
| const char* sym_names, |
| size_t sym_name_size, |
| Sized_relobj<32, false>::Symbols* sympointers); |
| #endif |
| |
| #ifdef HAVE_TARGET_64_LITTLE |
| template |
| void |
| Symbol_table::add_from_relobj<64, false>( |
| Sized_relobj<64, false>* relobj, |
| const unsigned char* syms, |
| size_t count, |
| const char* sym_names, |
| size_t sym_name_size, |
| Sized_relobj<64, true>::Symbols* sympointers); |
| #endif |
| |
| #ifdef HAVE_TARGET_64_BIG |
| template |
| void |
| Symbol_table::add_from_relobj<64, true>( |
| Sized_relobj<64, true>* relobj, |
| const unsigned char* syms, |
| size_t count, |
| const char* sym_names, |
| size_t sym_name_size, |
| Sized_relobj<64, false>::Symbols* sympointers); |
| #endif |
| |
| #ifdef HAVE_TARGET_32_LITTLE |
| template |
| void |
| Symbol_table::add_from_dynobj<32, false>( |
| Sized_dynobj<32, false>* dynobj, |
| const unsigned char* syms, |
| size_t count, |
| const char* sym_names, |
| size_t sym_name_size, |
| const unsigned char* versym, |
| size_t versym_size, |
| const std::vector<const char*>* version_map); |
| #endif |
| |
| #ifdef HAVE_TARGET_32_BIG |
| template |
| void |
| Symbol_table::add_from_dynobj<32, true>( |
| Sized_dynobj<32, true>* dynobj, |
| const unsigned char* syms, |
| size_t count, |
| const char* sym_names, |
| size_t sym_name_size, |
| const unsigned char* versym, |
| size_t versym_size, |
| const std::vector<const char*>* version_map); |
| #endif |
| |
| #ifdef HAVE_TARGET_64_LITTLE |
| template |
| void |
| Symbol_table::add_from_dynobj<64, false>( |
| Sized_dynobj<64, false>* dynobj, |
| const unsigned char* syms, |
| size_t count, |
| const char* sym_names, |
| size_t sym_name_size, |
| const unsigned char* versym, |
| size_t versym_size, |
| const std::vector<const char*>* version_map); |
| #endif |
| |
| #ifdef HAVE_TARGET_64_BIG |
| template |
| void |
| Symbol_table::add_from_dynobj<64, true>( |
| Sized_dynobj<64, true>* dynobj, |
| const unsigned char* syms, |
| size_t count, |
| const char* sym_names, |
| size_t sym_name_size, |
| const unsigned char* versym, |
| size_t versym_size, |
| const std::vector<const char*>* version_map); |
| #endif |
| |
| #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG) |
| template |
| void |
| Symbol_table::define_with_copy_reloc<32>(const Target* target, |
| Sized_symbol<32>* sym, |
| Output_data* posd, uint64_t value); |
| #endif |
| |
| #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG) |
| template |
| void |
| Symbol_table::define_with_copy_reloc<64>(const Target* target, |
| Sized_symbol<64>* sym, |
| Output_data* posd, uint64_t value); |
| #endif |
| |
| #ifdef HAVE_TARGET_32_LITTLE |
| template |
| void |
| Warnings::issue_warning<32, false>(const Symbol* sym, |
| const Relocate_info<32, false>* relinfo, |
| size_t relnum, off_t reloffset) const; |
| #endif |
| |
| #ifdef HAVE_TARGET_32_BIG |
| template |
| void |
| Warnings::issue_warning<32, true>(const Symbol* sym, |
| const Relocate_info<32, true>* relinfo, |
| size_t relnum, off_t reloffset) const; |
| #endif |
| |
| #ifdef HAVE_TARGET_64_LITTLE |
| template |
| void |
| Warnings::issue_warning<64, false>(const Symbol* sym, |
| const Relocate_info<64, false>* relinfo, |
| size_t relnum, off_t reloffset) const; |
| #endif |
| |
| #ifdef HAVE_TARGET_64_BIG |
| template |
| void |
| Warnings::issue_warning<64, true>(const Symbol* sym, |
| const Relocate_info<64, true>* relinfo, |
| size_t relnum, off_t reloffset) const; |
| #endif |
| |
| } // End namespace gold. |