| // symtab.cc -- the gold symbol table |
| |
| // Copyright 2006, 2007, 2008 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 <cstring> |
| #include <stdint.h> |
| #include <algorithm> |
| #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_offsets_.init(); |
| 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_plt_offset_ = false; |
| this->has_warning_ = false; |
| this->is_copied_from_dynobj_ = false; |
| this->is_forced_local_ = false; |
| this->is_ordinary_shndx_ = 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->options().do_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_object(const char* name, const char* version, Object* object, |
| const elfcpp::Sym<size, big_endian>& sym, |
| unsigned int st_shndx, bool is_ordinary) |
| { |
| 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; |
| this->u_.from_object.shndx = st_shndx; |
| this->is_ordinary_shndx_ = is_ordinary; |
| 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_output_data(const char* name, const char* version, |
| Output_data* od, elfcpp::STT type, |
| elfcpp::STB binding, elfcpp::STV visibility, |
| unsigned char nonvis, bool offset_is_from_end) |
| { |
| this->init_fields(name, version, 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_output_segment(const char* name, const char* version, |
| Output_segment* os, elfcpp::STT type, |
| elfcpp::STB binding, elfcpp::STV visibility, |
| unsigned char nonvis, |
| Segment_offset_base offset_base) |
| { |
| this->init_fields(name, version, 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_constant(const char* name, const char* version, |
| elfcpp::STT type, elfcpp::STB binding, |
| elfcpp::STV visibility, unsigned char nonvis) |
| { |
| this->init_fields(name, version, type, binding, visibility, nonvis); |
| this->source_ = IS_CONSTANT; |
| this->in_reg_ = true; |
| } |
| |
| // Initialize the fields in the base class Symbol for an undefined |
| // symbol. |
| |
| void |
| Symbol::init_base_undefined(const char* name, const char* version, |
| elfcpp::STT type, elfcpp::STB binding, |
| elfcpp::STV visibility, unsigned char nonvis) |
| { |
| this->init_fields(name, version, type, binding, visibility, nonvis); |
| this->source_ = IS_UNDEFINED; |
| 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_object(const char* name, const char* version, |
| Object* object, |
| const elfcpp::Sym<size, big_endian>& sym, |
| unsigned int st_shndx, bool is_ordinary) |
| { |
| this->init_base_object(name, version, object, sym, st_shndx, is_ordinary); |
| 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_output_data(const char* name, const char* version, |
| 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_output_data(name, version, 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_output_segment(const char* name, const char* version, |
| 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_output_segment(name, version, 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_constant(const char* name, const char* version, |
| Value_type value, Size_type symsize, |
| elfcpp::STT type, elfcpp::STB binding, |
| elfcpp::STV visibility, unsigned char nonvis) |
| { |
| this->init_base_constant(name, version, type, binding, visibility, nonvis); |
| this->value_ = value; |
| this->symsize_ = symsize; |
| } |
| |
| // Initialize the fields in Sized_symbol for an undefined symbol. |
| |
| template<int size> |
| void |
| Sized_symbol<size>::init_undefined(const char* name, const char* version, |
| elfcpp::STT type, elfcpp::STB binding, |
| elfcpp::STV visibility, unsigned char nonvis) |
| { |
| this->init_base_undefined(name, version, type, binding, visibility, nonvis); |
| this->value_ = 0; |
| this->symsize_ = 0; |
| } |
| |
| // 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 the symbol was forced local in a version script, do not add it. |
| if (this->is_forced_local()) |
| return false; |
| |
| // 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->options().export_dynamic() || parameters->options().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->options().shared() || parameters->options().relocatable()) |
| return false; |
| |
| // If the symbol is not from an object file, and is not undefined, |
| // then it is defined, and known. |
| if (this->source_ != FROM_OBJECT) |
| { |
| if (this->source_ != IS_UNDEFINED) |
| return true; |
| } |
| else |
| { |
| // 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(); |
| } |
| |
| // Return the output section where this symbol is defined. |
| |
| Output_section* |
| Symbol::output_section() const |
| { |
| switch (this->source_) |
| { |
| case FROM_OBJECT: |
| { |
| unsigned int shndx = this->u_.from_object.shndx; |
| if (shndx != elfcpp::SHN_UNDEF && this->is_ordinary_shndx_) |
| { |
| gold_assert(!this->u_.from_object.object->is_dynamic()); |
| Relobj* relobj = static_cast<Relobj*>(this->u_.from_object.object); |
| section_offset_type dummy; |
| return relobj->output_section(shndx, &dummy); |
| } |
| return NULL; |
| } |
| |
| case IN_OUTPUT_DATA: |
| return this->u_.in_output_data.output_data->output_section(); |
| |
| case IN_OUTPUT_SEGMENT: |
| case IS_CONSTANT: |
| case IS_UNDEFINED: |
| return NULL; |
| |
| default: |
| gold_unreachable(); |
| } |
| } |
| |
| // Set the symbol's output section. This is used for symbols defined |
| // in scripts. This should only be called after the symbol table has |
| // been finalized. |
| |
| void |
| Symbol::set_output_section(Output_section* os) |
| { |
| switch (this->source_) |
| { |
| case FROM_OBJECT: |
| case IN_OUTPUT_DATA: |
| gold_assert(this->output_section() == os); |
| break; |
| case IS_CONSTANT: |
| this->source_ = IN_OUTPUT_DATA; |
| this->u_.in_output_data.output_data = os; |
| this->u_.in_output_data.offset_is_from_end = false; |
| break; |
| case IN_OUTPUT_SEGMENT: |
| case IS_UNDEFINED: |
| default: |
| gold_unreachable(); |
| } |
| } |
| |
| // Class Symbol_table. |
| |
| Symbol_table::Symbol_table(unsigned int count, |
| const Version_script_info& version_script) |
| : saw_undefined_(0), offset_(0), table_(count), namepool_(), |
| forwarders_(), commons_(), tls_commons_(), forced_locals_(), warnings_(), |
| version_script_(version_script) |
| { |
| namepool_.reserve(count); |
| } |
| |
| Symbol_table::~Symbol_table() |
| { |
| } |
| |
| // The hash function. The key values are Stringpool keys. |
| |
| inline 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 called with |
| // Stringpool keys. |
| |
| inline 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) |
| { |
| 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 or the st_shndx 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()); |
| bool is_ordinary; |
| unsigned int shndx = from->shndx(&is_ordinary); |
| this->resolve(to, esym.sym(), shndx, is_ordinary, shndx, from->object(), |
| version); |
| if (from->in_reg()) |
| to->set_in_reg(); |
| if (from->in_dyn()) |
| to->set_in_dyn(); |
| } |
| |
| // Record that a symbol is forced to be local by a version script. |
| |
| void |
| Symbol_table::force_local(Symbol* sym) |
| { |
| if (!sym->is_defined() && !sym->is_common()) |
| return; |
| if (sym->is_forced_local()) |
| { |
| // We already got this one. |
| return; |
| } |
| sym->set_is_forced_local(); |
| this->forced_locals_.push_back(sym); |
| } |
| |
| // Adjust NAME for wrapping, and update *NAME_KEY if necessary. This |
| // is only called for undefined symbols, when at least one --wrap |
| // option was used. |
| |
| const char* |
| Symbol_table::wrap_symbol(Object* object, const char* name, |
| Stringpool::Key* name_key) |
| { |
| // For some targets, we need to ignore a specific character when |
| // wrapping, and add it back later. |
| char prefix = '\0'; |
| if (name[0] == object->target()->wrap_char()) |
| { |
| prefix = name[0]; |
| ++name; |
| } |
| |
| if (parameters->options().is_wrap(name)) |
| { |
| // Turn NAME into __wrap_NAME. |
| std::string s; |
| if (prefix != '\0') |
| s += prefix; |
| s += "__wrap_"; |
| s += name; |
| |
| // This will give us both the old and new name in NAMEPOOL_, but |
| // that is OK. Only the versions we need will wind up in the |
| // real string table in the output file. |
| return this->namepool_.add(s.c_str(), true, name_key); |
| } |
| |
| const char* const real_prefix = "__real_"; |
| const size_t real_prefix_length = strlen(real_prefix); |
| if (strncmp(name, real_prefix, real_prefix_length) == 0 |
| && parameters->options().is_wrap(name + real_prefix_length)) |
| { |
| // Turn __real_NAME into NAME. |
| std::string s; |
| if (prefix != '\0') |
| s += prefix; |
| s += name + real_prefix_length; |
| return this->namepool_.add(s.c_str(), true, name_key); |
| } |
| |
| return name; |
| } |
| |
| // 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. ST_SHNDX is the symbol's |
| // section index; IS_ORDINARY is whether this is a normal section |
| // rather than a special code. |
| |
| // 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. |
| // |
| // ORIG_ST_SHNDX and ST_SHNDX are almost always the same. |
| // ORIG_ST_SHNDX is the section index in the input file, or SHN_UNDEF |
| // for a special section code. ST_SHNDX may be modified if the symbol |
| // is defined in a section being discarded. |
| |
| 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, |
| unsigned int st_shndx, |
| bool is_ordinary, |
| unsigned int orig_st_shndx) |
| { |
| // Print a message if this symbol is being traced. |
| if (parameters->options().is_trace_symbol(name)) |
| { |
| if (orig_st_shndx == elfcpp::SHN_UNDEF) |
| gold_info(_("%s: reference to %s"), object->name().c_str(), name); |
| else |
| gold_info(_("%s: definition of %s"), object->name().c_str(), name); |
| } |
| |
| // For an undefined symbol, we may need to adjust the name using |
| // --wrap. |
| if (orig_st_shndx == elfcpp::SHN_UNDEF |
| && parameters->options().any_wrap()) |
| { |
| const char* wrap_name = this->wrap_symbol(object, name, &name_key); |
| if (wrap_name != name) |
| { |
| // If we see a reference to malloc with version GLIBC_2.0, |
| // and we turn it into a reference to __wrap_malloc, then we |
| // discard the version number. Otherwise the user would be |
| // required to specify the correct version for |
| // __wrap_malloc. |
| version = NULL; |
| version_key = 0; |
| name = wrap_name; |
| } |
| } |
| |
| 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<size>(ins.first->second); |
| gold_assert(ret != NULL); |
| |
| was_undefined = ret->is_undefined(); |
| was_common = ret->is_common(); |
| |
| this->resolve(ret, sym, st_shndx, is_ordinary, orig_st_shndx, 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 |
| && insdef.first->second->is_undefined()) |
| { |
| // This is the unfortunate case where we already have |
| // entries for both NAME/VERSION and NAME/NULL. Note |
| // that we don't want to combine them if the existing |
| // symbol is going to override the new one. FIXME: We |
| // currently just test is_undefined, but this may not do |
| // the right thing if the existing symbol is from a |
| // shared library and the new one is from a regular |
| // object. |
| |
| const Sized_symbol<size>* sym2; |
| sym2 = this->get_sized_symbol<size>(insdef.first->second); |
| Symbol_table::resolve<size, big_endian>(ret, sym2, version); |
| this->make_forwarder(insdef.first->second, ret); |
| insdef.first->second = ret; |
| } |
| else |
| def = false; |
| } |
| } |
| else |
| { |
| // This is the first time we have seen NAME/VERSION. |
| gold_assert(ins.first->second == NULL); |
| |
| 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<size>(insdef.first->second); |
| |
| was_undefined = ret->is_undefined(); |
| was_common = ret->is_common(); |
| |
| this->resolve(ret, sym, st_shndx, is_ordinary, orig_st_shndx, object, |
| version); |
| ins.first->second = ret; |
| } |
| else |
| { |
| was_undefined = false; |
| was_common = false; |
| |
| Sized_target<size, big_endian>* target = |
| object->sized_target<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_object(name, version, object, sym, st_shndx, is_ordinary); |
| |
| 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()) |
| { |
| if (ret->type() != elfcpp::STT_TLS) |
| this->commons_.push_back(ret); |
| else |
| this->tls_commons_.push_back(ret); |
| } |
| |
| if (def) |
| ret->set_is_default(); |
| 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, |
| size_t symndx_offset, |
| 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->target().get_size()); |
| |
| const int sym_size = elfcpp::Elf_sizes<size>::sym_size; |
| |
| const bool just_symbols = relobj->just_symbols(); |
| |
| const unsigned char* p = syms; |
| for (size_t i = 0; i < count; ++i, p += sym_size) |
| { |
| elfcpp::Sym<size, big_endian> sym(p); |
| |
| unsigned int st_name = sym.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; |
| |
| bool is_ordinary; |
| unsigned int st_shndx = relobj->adjust_sym_shndx(i + symndx_offset, |
| sym.get_st_shndx(), |
| &is_ordinary); |
| unsigned int orig_st_shndx = st_shndx; |
| if (!is_ordinary) |
| orig_st_shndx = elfcpp::SHN_UNDEF; |
| |
| // A symbol defined in a section which we are not including must |
| // be treated as an undefined symbol. |
| if (st_shndx != elfcpp::SHN_UNDEF |
| && is_ordinary |
| && !relobj->is_section_included(st_shndx)) |
| st_shndx = elfcpp::SHN_UNDEF; |
| |
| // 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, '@'); |
| int namelen = 0; |
| // DEF: is the version default? LOCAL: is the symbol forced local? |
| bool def = false; |
| bool local = false; |
| |
| if (ver != NULL) |
| { |
| // The symbol name is of the form foo@VERSION or foo@@VERSION |
| namelen = ver - name; |
| ++ver; |
| if (*ver == '@') |
| { |
| def = true; |
| ++ver; |
| } |
| } |
| // We don't want to assign a version to an undefined symbol, |
| // even if it is listed in the version script. FIXME: What |
| // about a common symbol? |
| else if (!version_script_.empty() |
| && st_shndx != elfcpp::SHN_UNDEF) |
| { |
| // The symbol name did not have a version, but |
| // the version script may assign a version anyway. |
| namelen = strlen(name); |
| def = true; |
| // Check the global: entries from the version script. |
| const std::string& version = |
| version_script_.get_symbol_version(name); |
| if (!version.empty()) |
| ver = version.c_str(); |
| // Check the local: entries from the version script |
| if (version_script_.symbol_is_local(name)) |
| local = true; |
| } |
| |
| elfcpp::Sym<size, big_endian>* psym = &sym; |
| unsigned char symbuf[sym_size]; |
| elfcpp::Sym<size, big_endian> sym2(symbuf); |
| if (just_symbols) |
| { |
| memcpy(symbuf, p, sym_size); |
| elfcpp::Sym_write<size, big_endian> sw(symbuf); |
| if (orig_st_shndx != elfcpp::SHN_UNDEF && is_ordinary) |
| { |
| // Symbol values in object files are section relative. |
| // This is normally what we want, but since here we are |
| // converting the symbol to absolute we need to add the |
| // section address. The section address in an object |
| // file is normally zero, but people can use a linker |
| // script to change it. |
| sw.put_st_value(sym.get_st_value() |
| + relobj->section_address(orig_st_shndx)); |
| } |
| st_shndx = elfcpp::SHN_ABS; |
| is_ordinary = false; |
| psym = &sym2; |
| } |
| |
| 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, st_shndx, is_ordinary, |
| orig_st_shndx); |
| if (local) |
| this->force_local(res); |
| } |
| else |
| { |
| Stringpool::Key name_key; |
| name = this->namepool_.add_with_length(name, namelen, true, |
| &name_key); |
| 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, st_shndx, is_ordinary, |
| orig_st_shndx); |
| } |
| |
| (*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->target().get_size()); |
| |
| if (dynobj->just_symbols()) |
| { |
| gold_error(_("--just-symbols does not make sense with a shared object")); |
| return; |
| } |
| |
| 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 or that have |
| // internal or hidden visibility. |
| if (sym.get_st_bind() == elfcpp::STB_LOCAL |
| || sym.get_st_visibility() == elfcpp::STV_INTERNAL |
| || sym.get_st_visibility() == elfcpp::STV_HIDDEN) |
| continue; |
| |
| // A protected symbol in a shared library must be treated as a |
| // normal symbol when viewed from outside the shared library. |
| // Implement this by overriding the visibility here. |
| elfcpp::Sym<size, big_endian>* psym = &sym; |
| unsigned char symbuf[sym_size]; |
| elfcpp::Sym<size, big_endian> sym2(symbuf); |
| if (sym.get_st_visibility() == elfcpp::STV_PROTECTED) |
| { |
| memcpy(symbuf, p, sym_size); |
| elfcpp::Sym_write<size, big_endian> sw(symbuf); |
| sw.put_st_other(elfcpp::STV_DEFAULT, sym.get_st_nonvis()); |
| psym = &sym2; |
| } |
| |
| unsigned int st_name = psym->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; |
| |
| bool is_ordinary; |
| unsigned int st_shndx = dynobj->adjust_sym_shndx(i, psym->get_st_shndx(), |
| &is_ordinary); |
| |
| 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, *psym, st_shndx, is_ordinary, |
| st_shndx); |
| } |
| 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) |
| && 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, *psym, st_shndx, is_ordinary, |
| st_shndx); |
| } |
| 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 (st_shndx == elfcpp::SHN_ABS |
| && !is_ordinary |
| && name_key == version_key) |
| res = this->add_from_object(dynobj, name, name_key, NULL, 0, |
| false, *psym, st_shndx, is_ordinary, |
| st_shndx); |
| else |
| { |
| const bool def = (!hidden |
| && st_shndx != elfcpp::SHN_UNDEF); |
| res = this->add_from_object(dynobj, name, name_key, version, |
| version_key, def, *psym, st_shndx, |
| is_ordinary, st_shndx); |
| } |
| } |
| } |
| |
| // Note that it is possible that RES was overridden by an |
| // earlier object, in which case it can't be aliased here. |
| if (st_shndx != elfcpp::SHN_UNDEF |
| && is_ordinary |
| && psym->get_st_type() == elfcpp::STT_OBJECT |
| && res->source() == Symbol::FROM_OBJECT |
| && res->object() == dynobj) |
| 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 |
| { |
| bool is_ordinary; |
| unsigned int s1_shndx = s1->shndx(&is_ordinary); |
| gold_assert(is_ordinary); |
| unsigned int s2_shndx = s2->shndx(&is_ordinary); |
| gold_assert(is_ordinary); |
| 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) |
| { |
| bool dummy; |
| if ((*q)->shndx(&dummy) != from_sym->shndx(&dummy) |
| || (*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 char** pname, const char** pversion, |
| bool only_if_ref, |
| Sized_symbol<size>** poldsym) |
| { |
| Symbol* oldsym; |
| Sized_symbol<size>* sym; |
| bool add_to_table = false; |
| typename Symbol_table_type::iterator add_loc = this->table_.end(); |
| |
| // If the caller didn't give us a version, see if we get one from |
| // the version script. |
| if (*pversion == NULL) |
| { |
| const std::string& v(this->version_script_.get_symbol_version(*pname)); |
| if (!v.empty()) |
| *pversion = v.c_str(); |
| } |
| |
| 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; |
| } |
| } |
| |
| const Target& target = parameters->target(); |
| 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<size>(oldsym); |
| |
| return sym; |
| } |
| |
| // Define a symbol based on an Output_data. |
| |
| Symbol* |
| Symbol_table::define_in_output_data(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->target().get_size() == 32) |
| { |
| #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG) |
| return this->do_define_in_output_data<32>(name, version, od, |
| value, symsize, type, binding, |
| visibility, nonvis, |
| offset_is_from_end, |
| only_if_ref); |
| #else |
| gold_unreachable(); |
| #endif |
| } |
| else if (parameters->target().get_size() == 64) |
| { |
| #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG) |
| return this->do_define_in_output_data<64>(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 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->target().is_big_endian()) |
| { |
| #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG) |
| sym = this->define_special_symbol<size, true>(&name, &version, |
| only_if_ref, &oldsym); |
| #else |
| gold_unreachable(); |
| #endif |
| } |
| else |
| { |
| #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE) |
| sym = this->define_special_symbol<size, false>(&name, &version, |
| only_if_ref, &oldsym); |
| #else |
| gold_unreachable(); |
| #endif |
| } |
| |
| if (sym == NULL) |
| return NULL; |
| |
| sym->init_output_data(name, version, od, value, symsize, type, binding, |
| visibility, nonvis, offset_is_from_end); |
| |
| if (oldsym == NULL) |
| { |
| if (binding == elfcpp::STB_LOCAL |
| || this->version_script_.symbol_is_local(name)) |
| this->force_local(sym); |
| else if (version != NULL) |
| sym->set_is_default(); |
| return sym; |
| } |
| |
| if (Symbol_table::should_override_with_special(oldsym)) |
| this->override_with_special(oldsym, sym); |
| delete sym; |
| return oldsym; |
| } |
| |
| // Define a symbol based on an Output_segment. |
| |
| Symbol* |
| Symbol_table::define_in_output_segment(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->target().get_size() == 32) |
| { |
| #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG) |
| return this->do_define_in_output_segment<32>(name, version, os, |
| value, symsize, type, |
| binding, visibility, nonvis, |
| offset_base, only_if_ref); |
| #else |
| gold_unreachable(); |
| #endif |
| } |
| else if (parameters->target().get_size() == 64) |
| { |
| #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG) |
| return this->do_define_in_output_segment<64>(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 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->target().is_big_endian()) |
| { |
| #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG) |
| sym = this->define_special_symbol<size, true>(&name, &version, |
| only_if_ref, &oldsym); |
| #else |
| gold_unreachable(); |
| #endif |
| } |
| else |
| { |
| #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE) |
| sym = this->define_special_symbol<size, false>(&name, &version, |
| only_if_ref, &oldsym); |
| #else |
| gold_unreachable(); |
| #endif |
| } |
| |
| if (sym == NULL) |
| return NULL; |
| |
| sym->init_output_segment(name, version, os, value, symsize, type, binding, |
| visibility, nonvis, offset_base); |
| |
| if (oldsym == NULL) |
| { |
| if (binding == elfcpp::STB_LOCAL |
| || this->version_script_.symbol_is_local(name)) |
| this->force_local(sym); |
| else if (version != NULL) |
| sym->set_is_default(); |
| return sym; |
| } |
| |
| if (Symbol_table::should_override_with_special(oldsym)) |
| this->override_with_special(oldsym, sym); |
| delete sym; |
| return oldsym; |
| } |
| |
| // 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 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, |
| bool force_override) |
| { |
| if (parameters->target().get_size() == 32) |
| { |
| #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG) |
| return this->do_define_as_constant<32>(name, version, value, |
| symsize, type, binding, |
| visibility, nonvis, only_if_ref, |
| force_override); |
| #else |
| gold_unreachable(); |
| #endif |
| } |
| else if (parameters->target().get_size() == 64) |
| { |
| #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG) |
| return this->do_define_as_constant<64>(name, version, value, |
| symsize, type, binding, |
| visibility, nonvis, only_if_ref, |
| force_override); |
| #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 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, |
| bool force_override) |
| { |
| Sized_symbol<size>* sym; |
| Sized_symbol<size>* oldsym; |
| |
| if (parameters->target().is_big_endian()) |
| { |
| #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG) |
| sym = this->define_special_symbol<size, true>(&name, &version, |
| only_if_ref, &oldsym); |
| #else |
| gold_unreachable(); |
| #endif |
| } |
| else |
| { |
| #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE) |
| sym = this->define_special_symbol<size, false>(&name, &version, |
| only_if_ref, &oldsym); |
| #else |
| gold_unreachable(); |
| #endif |
| } |
| |
| if (sym == NULL) |
| return NULL; |
| |
| sym->init_constant(name, version, value, symsize, type, binding, visibility, |
| nonvis); |
| |
| if (oldsym == NULL) |
| { |
| // Version symbols are absolute symbols with name == version. |
| // We don't want to force them to be local. |
| if ((version == NULL |
| || name != version |
| || value != 0) |
| && (binding == elfcpp::STB_LOCAL |
| || this->version_script_.symbol_is_local(name))) |
| this->force_local(sym); |
| else if (version != NULL |
| && (name != version || value != 0)) |
| sym->set_is_default(); |
| return sym; |
| } |
| |
| if (force_override || Symbol_table::should_override_with_special(oldsym)) |
| this->override_with_special(oldsym, sym); |
| delete sym; |
| return oldsym; |
| } |
| |
| // Define a set of symbols in output sections. |
| |
| void |
| Symbol_table::define_symbols(const Layout* layout, int count, |
| const Define_symbol_in_section* p, |
| bool only_if_ref) |
| { |
| 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(p->name, NULL, os, p->value, |
| p->size, p->type, p->binding, |
| p->visibility, p->nonvis, |
| p->offset_is_from_end, |
| only_if_ref || p->only_if_ref); |
| else |
| this->define_as_constant(p->name, NULL, 0, p->size, p->type, |
| p->binding, p->visibility, p->nonvis, |
| only_if_ref || p->only_if_ref, |
| false); |
| } |
| } |
| |
| // Define a set of symbols in output segments. |
| |
| void |
| Symbol_table::define_symbols(const Layout* layout, int count, |
| const Define_symbol_in_segment* p, |
| bool only_if_ref) |
| { |
| 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(p->name, NULL, os, p->value, |
| p->size, p->type, p->binding, |
| p->visibility, p->nonvis, |
| p->offset_base, |
| only_if_ref || p->only_if_ref); |
| else |
| this->define_as_constant(p->name, NULL, 0, p->size, p->type, |
| p->binding, p->visibility, p->nonvis, |
| only_if_ref || p->only_if_ref, |
| false); |
| } |
| } |
| |
| // 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( |
| Sized_symbol<size>* csym, |
| Output_data* posd, |
| typename elfcpp::Elf_types<size>::Elf_Addr 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(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; |
| } |
| |
| // Add any undefined symbols named on the command line. |
| |
| void |
| Symbol_table::add_undefined_symbols_from_command_line() |
| { |
| if (parameters->options().any_undefined()) |
| { |
| if (parameters->target().get_size() == 32) |
| { |
| #if defined(HAVE_TARGET_32_LITTL) || defined(HAVE_TARGET_32_BIG) |
| this->do_add_undefined_symbols_from_command_line<32>(); |
| #else |
| gold_unreachable(); |
| #endif |
| } |
| else if (parameters->target().get_size() == 64) |
| { |
| #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG) |
| this->do_add_undefined_symbols_from_command_line<64>(); |
| #else |
| gold_unreachable(); |
| #endif |
| } |
| else |
| gold_unreachable(); |
| } |
| } |
| |
| template<int size> |
| void |
| Symbol_table::do_add_undefined_symbols_from_command_line() |
| { |
| for (options::String_set::const_iterator p = |
| parameters->options().undefined_begin(); |
| p != parameters->options().undefined_end(); |
| ++p) |
| { |
| const char* name = p->c_str(); |
| |
| if (this->lookup(name) != NULL) |
| continue; |
| |
| const char* version = NULL; |
| |
| Sized_symbol<size>* sym; |
| Sized_symbol<size>* oldsym; |
| if (parameters->target().is_big_endian()) |
| { |
| #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG) |
| sym = this->define_special_symbol<size, true>(&name, &version, |
| false, &oldsym); |
| #else |
| gold_unreachable(); |
| #endif |
| } |
| else |
| { |
| #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE) |
| sym = this->define_special_symbol<size, false>(&name, &version, |
| false, &oldsym); |
| #else |
| gold_unreachable(); |
| #endif |
| } |
| |
| gold_assert(oldsym == NULL); |
| |
| sym->init_undefined(name, version, elfcpp::STT_NOTYPE, elfcpp::STB_GLOBAL, |
| elfcpp::STV_DEFAULT, 0); |
| ++this->saw_undefined_; |
| } |
| } |
| |
| // 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(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(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 *PLOCAL_SYMCOUNT. Record the |
| // file offset OFF. Add their names to POOL. Return the new file |
| // offset. Update *PLOCAL_SYMCOUNT if necessary. |
| |
| off_t |
| Symbol_table::finalize(off_t off, off_t dynoff, size_t dyn_global_index, |
| size_t dyncount, Stringpool* pool, |
| unsigned int *plocal_symcount) |
| { |
| off_t ret; |
| |
| gold_assert(*plocal_symcount != 0); |
| this->first_global_index_ = *plocal_symcount; |
| |
| this->dynamic_offset_ = dynoff; |
| this->first_dynamic_global_index_ = dyn_global_index; |
| this->dynamic_count_ = dyncount; |
| |
| if (parameters->target().get_size() == 32) |
| { |
| #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_32_LITTLE) |
| ret = this->sized_finalize<32>(off, pool, plocal_symcount); |
| #else |
| gold_unreachable(); |
| #endif |
| } |
| else if (parameters->target().get_size() == 64) |
| { |
| #if defined(HAVE_TARGET_64_BIG) || defined(HAVE_TARGET_64_LITTLE) |
| ret = this->sized_finalize<64>(off, pool, plocal_symcount); |
| #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; |
| } |
| |
| // SYM is going into the symbol table at *PINDEX. Add the name to |
| // POOL, update *PINDEX and *POFF. |
| |
| template<int size> |
| void |
| Symbol_table::add_to_final_symtab(Symbol* sym, Stringpool* pool, |
| unsigned int* pindex, off_t* poff) |
| { |
| sym->set_symtab_index(*pindex); |
| pool->add(sym->name(), false, NULL); |
| ++*pindex; |
| *poff += elfcpp::Elf_sizes<size>::sym_size; |
| } |
| |
| // 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(off_t off, Stringpool* pool, |
| unsigned int* plocal_symcount) |
| { |
| off = align_address(off, size >> 3); |
| this->offset_ = off; |
| |
| unsigned int index = *plocal_symcount; |
| const unsigned int orig_index = index; |
| |
| // First do all the symbols which have been forced to be local, as |
| // they must appear before all global symbols. |
| for (Forced_locals::iterator p = this->forced_locals_.begin(); |
| p != this->forced_locals_.end(); |
| ++p) |
| { |
| Symbol* sym = *p; |
| gold_assert(sym->is_forced_local()); |
| if (this->sized_finalize_symbol<size>(sym)) |
| { |
| this->add_to_final_symtab<size>(sym, pool, &index, &off); |
| ++*plocal_symcount; |
| } |
| } |
| |
| // Now do all the remaining symbols. |
| for (Symbol_table_type::iterator p = this->table_.begin(); |
| p != this->table_.end(); |
| ++p) |
| { |
| Symbol* sym = p->second; |
| if (this->sized_finalize_symbol<size>(sym)) |
| this->add_to_final_symtab<size>(sym, pool, &index, &off); |
| } |
| |
| this->output_count_ = index - orig_index; |
| |
| return off; |
| } |
| |
| // Finalize the symbol SYM. This returns true if the symbol should be |
| // added to the symbol table, false otherwise. |
| |
| template<int size> |
| bool |
| Symbol_table::sized_finalize_symbol(Symbol* unsized_sym) |
| { |
| Sized_symbol<size>* sym = static_cast<Sized_symbol<size>*>(unsized_sym); |
| |
| // 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()) |
| return false; |
| |
| if (!sym->in_reg()) |
| { |
| gold_assert(!sym->has_symtab_index()); |
| sym->set_symtab_index(-1U); |
| gold_assert(sym->dynsym_index() == -1U); |
| return false; |
| } |
| |
| typename Sized_symbol<size>::Value_type value; |
| |
| switch (sym->source()) |
| { |
| case Symbol::FROM_OBJECT: |
| { |
| bool is_ordinary; |
| unsigned int shndx = sym->shndx(&is_ordinary); |
| |
| // FIXME: We need some target specific support here. |
| if (!is_ordinary |
| && shndx != elfcpp::SHN_ABS |
| && shndx != elfcpp::SHN_COMMON) |
| { |
| 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 (!is_ordinary |
| && (shndx == elfcpp::SHN_ABS || shndx == elfcpp::SHN_COMMON)) |
| value = sym->value(); |
| else |
| { |
| Relobj* relobj = static_cast<Relobj*>(symobj); |
| section_offset_type secoff; |
| Output_section* os = relobj->output_section(shndx, &secoff); |
| |
| if (os == NULL) |
| { |
| sym->set_symtab_index(-1U); |
| gold_assert(sym->dynsym_index() == -1U); |
| return false; |
| } |
| |
| if (sym->type() == elfcpp::STT_TLS) |
| value = sym->value() + os->tls_offset() + secoff; |
| else |
| value = sym->value() + os->address() + secoff; |
| } |
| } |
| break; |
| |
| case Symbol::IN_OUTPUT_DATA: |
| { |
| Output_data* od = sym->output_data(); |
| value = sym->value(); |
| if (sym->type() != elfcpp::STT_TLS) |
| value += od->address(); |
| else |
| { |
| Output_section* os = od->output_section(); |
| gold_assert(os != NULL); |
| value += os->tls_offset() + (od->address() - os->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(); |
| if (sym->type() != elfcpp::STT_TLS) |
| 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::IS_CONSTANT: |
| value = sym->value(); |
| break; |
| |
| case Symbol::IS_UNDEFINED: |
| value = 0; |
| break; |
| |
| default: |
| gold_unreachable(); |
| } |
| |
| sym->set_value(value); |
| |
| if (parameters->options().strip_all()) |
| { |
| sym->set_symtab_index(-1U); |
| return false; |
| } |
| |
| return true; |
| } |
| |
| // Write out the global symbols. |
| |
| void |
| Symbol_table::write_globals(const Input_objects* input_objects, |
| const Stringpool* sympool, |
| const Stringpool* dynpool, |
| Output_symtab_xindex* symtab_xindex, |
| Output_symtab_xindex* dynsym_xindex, |
| Output_file* of) const |
| { |
| switch (parameters->size_and_endianness()) |
| { |
| #ifdef HAVE_TARGET_32_LITTLE |
| case Parameters::TARGET_32_LITTLE: |
| this->sized_write_globals<32, false>(input_objects, sympool, |
| dynpool, symtab_xindex, |
| dynsym_xindex, of); |
| break; |
| #endif |
| #ifdef HAVE_TARGET_32_BIG |
| case Parameters::TARGET_32_BIG: |
| this->sized_write_globals<32, true>(input_objects, sympool, |
| dynpool, symtab_xindex, |
| dynsym_xindex, of); |
| break; |
| #endif |
| #ifdef HAVE_TARGET_64_LITTLE |
| case Parameters::TARGET_64_LITTLE: |
| this->sized_write_globals<64, false>(input_objects, sympool, |
| dynpool, symtab_xindex, |
| dynsym_xindex, of); |
| break; |
| #endif |
| #ifdef HAVE_TARGET_64_BIG |
| case Parameters::TARGET_64_BIG: |
| this->sized_write_globals<64, true>(input_objects, sympool, |
| dynpool, symtab_xindex, |
| dynsym_xindex, of); |
| break; |
| #endif |
| default: |
| 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_symtab_xindex* symtab_xindex, |
| Output_symtab_xindex* dynsym_xindex, |
| Output_file* of) const |
| { |
| const Target& target = parameters->target(); |
| |
| const int sym_size = elfcpp::Elf_sizes<size>::sym_size; |
| |
| const unsigned int output_count = this->output_count_; |
| const section_size_type oview_size = output_count * sym_size; |
| const unsigned int first_global_index = this->first_global_index_; |
| unsigned char* psyms; |
| if (this->offset_ == 0 || output_count == 0) |
| psyms = NULL; |
| else |
| psyms = of->get_output_view(this->offset_, oview_size); |
| |
| const unsigned int dynamic_count = this->dynamic_count_; |
| const section_size_type dynamic_size = dynamic_count * sym_size; |
| const unsigned int first_dynamic_global_index = |
| this->first_dynamic_global_index_; |
| unsigned char* dynamic_view; |
| if (this->dynamic_offset_ == 0 || dynamic_count == 0) |
| dynamic_view = NULL; |
| else |
| dynamic_view = of->get_output_view(this->dynamic_offset_, dynamic_size); |
| |
| 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; |
| } |
| |
| unsigned int shndx; |
| typename elfcpp::Elf_types<size>::Elf_Addr sym_value = sym->value(); |
| typename elfcpp::Elf_types<size>::Elf_Addr dynsym_value = sym_value; |
| switch (sym->source()) |
| { |
| case Symbol::FROM_OBJECT: |
| { |
| bool is_ordinary; |
| unsigned int in_shndx = sym->shndx(&is_ordinary); |
| |
| // FIXME: We need some target specific support here. |
| if (!is_ordinary |
| && in_shndx != elfcpp::SHN_ABS |
| && in_shndx != elfcpp::SHN_COMMON) |
| { |
| 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()) |
| dynsym_value = target.dynsym_value(sym); |
| shndx = elfcpp::SHN_UNDEF; |
| } |
| else if (in_shndx == elfcpp::SHN_UNDEF |
| || (!is_ordinary |
| && (in_shndx == elfcpp::SHN_ABS |
| || in_shndx == elfcpp::SHN_COMMON))) |
| shndx = in_shndx; |
| else |
| { |
| Relobj* relobj = static_cast<Relobj*>(symobj); |
| section_offset_type secoff; |
| Output_section* os = relobj->output_section(in_shndx, |
| &secoff); |
| gold_assert(os != NULL); |
| shndx = os->out_shndx(); |
| |
| if (shndx >= elfcpp::SHN_LORESERVE) |
| { |
| if (sym_index != -1U) |
| symtab_xindex->add(sym_index, shndx); |
| if (dynsym_index != -1U) |
| dynsym_xindex->add(dynsym_index, shndx); |
| shndx = elfcpp::SHN_XINDEX; |
| } |
| |
| // In object files symbol values are section |
| // relative. |
| if (parameters->options().relocatable()) |
| sym_value -= os->address(); |
| } |
| } |
| } |
| break; |
| |
| case Symbol::IN_OUTPUT_DATA: |
| shndx = sym->output_data()->out_shndx(); |
| if (shndx >= elfcpp::SHN_LORESERVE) |
| { |
| if (sym_index != -1U) |
| symtab_xindex->add(sym_index, shndx); |
| if (dynsym_index != -1U) |
| dynsym_xindex->add(dynsym_index, shndx); |
| shndx = elfcpp::SHN_XINDEX; |
| } |
| break; |
| |
| case Symbol::IN_OUTPUT_SEGMENT: |
| shndx = elfcpp::SHN_ABS; |
| break; |
| |
| case Symbol::IS_CONSTANT: |
| shndx = elfcpp::SHN_ABS; |
| break; |
| |
| case Symbol::IS_UNDEFINED: |
| shndx = elfcpp::SHN_UNDEF; |
| break; |
| |
| default: |
| gold_unreachable(); |
| } |
| |
| if (sym_index != -1U) |
| { |
| sym_index -= first_global_index; |
| gold_assert(sym_index < output_count); |
| unsigned char* ps = psyms + (sym_index * sym_size); |
| this->sized_write_symbol<size, big_endian>(sym, sym_value, shndx, |
| sympool, ps); |
| } |
| |
| 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<size, big_endian>(sym, dynsym_value, shndx, |
| dynpool, pd); |
| } |
| } |
| |
| 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) 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()); |
| // A version script may have overridden the default binding. |
| if (sym->is_forced_local()) |
| osym.put_st_info(elfcpp::elf_st_info(elfcpp::STB_LOCAL, sym->type())); |
| else |
| 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 |
| { |
| bool dummy; |
| if (sym->source() == Symbol::FROM_OBJECT |
| && sym->object()->is_dynamic() |
| && sym->shndx(&dummy) == elfcpp::SHN_UNDEF |
| && sym->binding() != elfcpp::STB_WEAK |
| && !parameters->options().allow_shlib_undefined() |
| && !parameters->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_symtab_xindex* symtab_xindex, |
| Output_file* of, |
| off_t offset) const |
| { |
| switch (parameters->size_and_endianness()) |
| { |
| #ifdef HAVE_TARGET_32_LITTLE |
| case Parameters::TARGET_32_LITTLE: |
| this->sized_write_section_symbol<32, false>(os, symtab_xindex, of, |
| offset); |
| break; |
| #endif |
| #ifdef HAVE_TARGET_32_BIG |
| case Parameters::TARGET_32_BIG: |
| this->sized_write_section_symbol<32, true>(os, symtab_xindex, of, |
| offset); |
| break; |
| #endif |
| #ifdef HAVE_TARGET_64_LITTLE |
| case Parameters::TARGET_64_LITTLE: |
| this->sized_write_section_symbol<64, false>(os, symtab_xindex, of, |
| offset); |
| break; |
| #endif |
| #ifdef HAVE_TARGET_64_BIG |
| case Parameters::TARGET_64_BIG: |
| this->sized_write_section_symbol<64, true>(os, symtab_xindex, of, |
| offset); |
| break; |
| #endif |
| default: |
| 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_symtab_xindex* symtab_xindex, |
| 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)); |
| |
| unsigned int shndx = os->out_shndx(); |
| if (shndx >= elfcpp::SHN_LORESERVE) |
| { |
| symtab_xindex->add(os->symtab_index(), shndx); |
| shndx = elfcpp::SHN_XINDEX; |
| } |
| osym.put_st_shndx(shndx); |
| |
| of->write_output_view(offset, sym_size, pov); |
| } |
| |
| // Print statistical information to stderr. This is used for --stats. |
| |
| void |
| Symbol_table::print_stats() const |
| { |
| #if defined(HAVE_TR1_UNORDERED_MAP) || defined(HAVE_EXT_HASH_MAP) |
| fprintf(stderr, _("%s: symbol table entries: %zu; buckets: %zu\n"), |
| program_name, this->table_.size(), this->table_.bucket_count()); |
| #else |
| fprintf(stderr, _("%s: symbol table entries: %zu\n"), |
| program_name, this->table_.size()); |
| #endif |
| this->namepool_.print_stats("symbol table stringpool"); |
| } |
| |
| // 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 implements 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 Task* task, |
| 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 have to run in a singleton Task. If we |
| // want to run this in a general 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. Also note, one_addr2line is not |
| // currently thread-safe. |
| Task_lock_obj<Object> tl(task, locs->object); |
| // 16 is the size of the object-cache that one_addr2line should use. |
| std::string lineno = Dwarf_line_info::one_addr2line( |
| locs->object, locs->shndx, locs->offset, 16); |
| 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()); |
| } |
| } |
| // We only call one_addr2line() in this function, so we can clear its cache. |
| Dwarf_line_info::clear_addr2line_cache(); |
| } |
| |
| // Warnings functions. |
| |
| // Add a new warning. |
| |
| void |
| Warnings::add_warning(Symbol_table* symtab, const char* name, Object* obj, |
| const std::string& warning) |
| { |
| name = symtab->canonicalize_name(name); |
| this->warnings_[name].set(obj, warning); |
| } |
| |
| // 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(); |
| } |
| } |
| |
| // 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, |
| size_t symndx_offset, |
| 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, |
| size_t symndx_offset, |
| 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, |
| size_t symndx_offset, |
| 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, |
| size_t symndx_offset, |
| 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>( |
| Sized_symbol<32>* sym, |
| Output_data* posd, |
| elfcpp::Elf_types<32>::Elf_Addr value); |
| #endif |
| |
| #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG) |
| template |
| void |
| Symbol_table::define_with_copy_reloc<64>( |
| Sized_symbol<64>* sym, |
| Output_data* posd, |
| elfcpp::Elf_types<64>::Elf_Addr 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. |