| // symtab.cc -- the gold symbol table |
| |
| #include "gold.h" |
| |
| #include <cassert> |
| #include <stdint.h> |
| #include <string> |
| #include <utility> |
| |
| #include "object.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->got_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->in_dyn_ = false; |
| this->has_got_offset_ = false; |
| this->has_warning_ = false; |
| } |
| |
| // 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.shnum = sym.get_st_shndx(); |
| this->source_ = FROM_OBJECT; |
| 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; |
| } |
| |
| // 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; |
| } |
| |
| // 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; |
| } |
| |
| // 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; |
| } |
| |
| // Class Symbol_table. |
| |
| Symbol_table::Symbol_table() |
| : size_(0), 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) |
| { |
| assert(from != to); |
| 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(Symbol* from) const |
| { |
| assert(from->is_forwarder()); |
| Unordered_map<Symbol*, Symbol*>::const_iterator p = |
| this->forwarders_.find(from); |
| 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 |
| 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->shnum()); |
| Symbol_table::resolve(to, esym.sym(), from->object()); |
| } |
| |
| // 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. |
| |
| template<int size, bool big_endian> |
| Symbol* |
| 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) |
| { |
| 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)); |
| assert(ret != NULL); |
| |
| was_undefined = ret->is_undefined(); |
| was_common = ret->is_common(); |
| |
| Symbol_table::resolve(ret, sym, object); |
| |
| 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 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. |
| assert(ins.first->second == NULL); |
| |
| was_undefined = false; |
| was_common = false; |
| |
| if (def && !insdef.second) |
| { |
| // We already have an entry for NAME/NULL. Make |
| // NAME/VERSION point to it. |
| ret = this->get_sized_symbol SELECT_SIZE_NAME(size) ( |
| insdef.first->second |
| SELECT_SIZE(size)); |
| Symbol_table::resolve(ret, sym, object); |
| 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. |
| 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, |
| Symbol** sympointers) |
| { |
| // We take the size from the first object we see. |
| if (this->get_size() == 0) |
| this->set_size(size); |
| |
| if (size != this->get_size() || size != relobj->target()->get_size()) |
| { |
| fprintf(stderr, _("%s: %s: mixing 32-bit and 64-bit ELF objects\n"), |
| program_name, relobj->name().c_str()); |
| gold_exit(false); |
| } |
| |
| 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) |
| { |
| fprintf(stderr, |
| _("%s: %s: bad global symbol name offset %u at %lu\n"), |
| program_name, relobj->name().c_str(), st_name, |
| static_cast<unsigned long>(i)); |
| gold_exit(false); |
| } |
| |
| 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, '@'); |
| |
| Symbol* res; |
| if (ver == NULL) |
| { |
| Stringpool::Key name_key; |
| name = this->namepool_.add(name, &name_key); |
| res = this->add_from_object(relobj, name, name_key, NULL, 0, |
| false, *psym); |
| } |
| else |
| { |
| Stringpool::Key name_key; |
| name = this->namepool_.add(name, ver - name, &name_key); |
| |
| bool def = false; |
| ++ver; |
| if (*ver == '@') |
| { |
| def = true; |
| ++ver; |
| } |
| |
| Stringpool::Key ver_key; |
| ver = this->namepool_.add(ver, &ver_key); |
| |
| res = this->add_from_object(relobj, name, name_key, ver, ver_key, |
| def, *psym); |
| } |
| |
| *sympointers++ = 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) |
| { |
| // We take the size from the first object we see. |
| if (this->get_size() == 0) |
| this->set_size(size); |
| |
| if (size != this->get_size() || size != dynobj->target()->get_size()) |
| { |
| fprintf(stderr, _("%s: %s: mixing 32-bit and 64-bit ELF objects\n"), |
| program_name, dynobj->name().c_str()); |
| gold_exit(false); |
| } |
| |
| if (versym != NULL && versym_size / 2 < count) |
| { |
| fprintf(stderr, _("%s: %s: too few symbol versions\n"), |
| program_name, dynobj->name().c_str()); |
| gold_exit(false); |
| } |
| |
| const int sym_size = elfcpp::Elf_sizes<size>::sym_size; |
| |
| 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) |
| { |
| fprintf(stderr, _("%s: %s: bad symbol name offset %u at %lu\n"), |
| program_name, dynobj->name().c_str(), st_name, |
| static_cast<unsigned long>(i)); |
| gold_exit(false); |
| } |
| |
| const char* name = sym_names + st_name; |
| |
| if (versym == NULL) |
| { |
| Stringpool::Key name_key; |
| name = this->namepool_.add(name, &name_key); |
| this->add_from_object(dynobj, name, name_key, NULL, 0, |
| false, sym); |
| continue; |
| } |
| |
| // 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; |
| |
| if (v == static_cast<unsigned int>(elfcpp::VER_NDX_LOCAL)) |
| { |
| // 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, &name_key); |
| |
| if (v == static_cast<unsigned int>(elfcpp::VER_NDX_GLOBAL)) |
| { |
| // This symbol does not have a version. |
| this->add_from_object(dynobj, name, name_key, NULL, 0, false, sym); |
| continue; |
| } |
| |
| if (v >= version_map->size()) |
| { |
| fprintf(stderr, |
| _("%s: %s: versym for symbol %zu out of range: %u\n"), |
| program_name, dynobj->name().c_str(), i, v); |
| gold_exit(false); |
| } |
| |
| const char* version = (*version_map)[v]; |
| if (version == NULL) |
| { |
| fprintf(stderr, _("%s: %s: versym for symbol %zu has no name: %u\n"), |
| program_name, dynobj->name().c_str(), i, v); |
| gold_exit(false); |
| } |
| |
| Stringpool::Key version_key; |
| version = this->namepool_.add(version, &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) |
| { |
| this->add_from_object(dynobj, name, name_key, NULL, 0, false, sym); |
| continue; |
| } |
| |
| const bool def = !hidden && sym.get_st_shndx() != elfcpp::SHN_UNDEF; |
| |
| this->add_from_object(dynobj, name, name_key, version, version_key, |
| def, sym); |
| } |
| } |
| |
| // 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. |
| |
| template<int size, bool big_endian> |
| Sized_symbol<size>* |
| Symbol_table::define_special_symbol(Target* target, const char* name, |
| bool only_if_ref |
| ACCEPT_SIZE_ENDIAN) |
| { |
| assert(this->size_ == size); |
| |
| Symbol* oldsym; |
| Sized_symbol<size>* sym; |
| |
| if (only_if_ref) |
| { |
| oldsym = this->lookup(name, NULL); |
| if (oldsym == NULL || !oldsym->is_undefined()) |
| return NULL; |
| sym = NULL; |
| |
| // Canonicalize NAME. |
| name = oldsym->name(); |
| } |
| else |
| { |
| // Canonicalize NAME. |
| Stringpool::Key name_key; |
| name = this->namepool_.add(name, &name_key); |
| |
| Symbol* const snull = NULL; |
| const Stringpool::Key ver_key = 0; |
| std::pair<typename Symbol_table_type::iterator, bool> ins = |
| this->table_.insert(std::make_pair(std::make_pair(name_key, ver_key), |
| snull)); |
| |
| if (!ins.second) |
| { |
| // We already have a symbol table entry for NAME. |
| oldsym = ins.first->second; |
| assert(oldsym != NULL); |
| sym = NULL; |
| } |
| else |
| { |
| // We haven't seen this symbol before. |
| assert(ins.first->second == NULL); |
| |
| if (!target->has_make_symbol()) |
| sym = new Sized_symbol<size>(); |
| else |
| { |
| assert(target->get_size() == size); |
| assert(target->is_big_endian() ? big_endian : !big_endian); |
| typedef Sized_target<size, big_endian> My_target; |
| My_target* sized_target = static_cast<My_target*>(target); |
| sym = sized_target->make_symbol(); |
| if (sym == NULL) |
| return NULL; |
| } |
| |
| ins.first->second = sym; |
| oldsym = NULL; |
| } |
| } |
| |
| if (oldsym != NULL) |
| { |
| assert(sym == NULL); |
| |
| sym = this->get_sized_symbol SELECT_SIZE_NAME(size) (oldsym |
| SELECT_SIZE(size)); |
| assert(sym->source() == Symbol::FROM_OBJECT); |
| const int old_shnum = sym->shnum(); |
| if (old_shnum != elfcpp::SHN_UNDEF |
| && old_shnum != elfcpp::SHN_COMMON |
| && !sym->object()->is_dynamic()) |
| { |
| fprintf(stderr, "%s: linker defined: multiple definition of %s\n", |
| program_name, name); |
| // FIXME: Report old location. Record that we have seen an |
| // error. |
| return NULL; |
| } |
| |
| // Our new definition is going to override the old reference. |
| } |
| |
| return sym; |
| } |
| |
| // Define a symbol based on an Output_data. |
| |
| void |
| Symbol_table::define_in_output_data(Target* target, const char* name, |
| 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) |
| { |
| assert(target->get_size() == this->size_); |
| if (this->size_ == 32) |
| this->do_define_in_output_data<32>(target, name, od, value, symsize, |
| type, binding, visibility, nonvis, |
| offset_is_from_end, only_if_ref); |
| else if (this->size_ == 64) |
| this->do_define_in_output_data<64>(target, name, od, value, symsize, |
| type, binding, visibility, nonvis, |
| offset_is_from_end, only_if_ref); |
| else |
| abort(); |
| } |
| |
| // Define a symbol in an Output_data, sized version. |
| |
| template<int size> |
| void |
| Symbol_table::do_define_in_output_data( |
| Target* target, |
| const char* name, |
| 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; |
| |
| if (target->is_big_endian()) |
| sym = this->define_special_symbol SELECT_SIZE_ENDIAN_NAME(size, true) ( |
| target, name, only_if_ref |
| SELECT_SIZE_ENDIAN(size, true)); |
| else |
| sym = this->define_special_symbol SELECT_SIZE_ENDIAN_NAME(size, false) ( |
| target, name, only_if_ref |
| SELECT_SIZE_ENDIAN(size, false)); |
| |
| if (sym == NULL) |
| return; |
| |
| sym->init(name, od, value, symsize, type, binding, visibility, nonvis, |
| offset_is_from_end); |
| } |
| |
| // Define a symbol based on an Output_segment. |
| |
| void |
| Symbol_table::define_in_output_segment(Target* target, const char* name, |
| 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) |
| { |
| assert(target->get_size() == this->size_); |
| if (this->size_ == 32) |
| this->do_define_in_output_segment<32>(target, name, os, value, symsize, |
| type, binding, visibility, nonvis, |
| offset_base, only_if_ref); |
| else if (this->size_ == 64) |
| this->do_define_in_output_segment<64>(target, name, os, value, symsize, |
| type, binding, visibility, nonvis, |
| offset_base, only_if_ref); |
| else |
| abort(); |
| } |
| |
| // Define a symbol in an Output_segment, sized version. |
| |
| template<int size> |
| void |
| Symbol_table::do_define_in_output_segment( |
| Target* target, |
| const char* name, |
| 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; |
| |
| if (target->is_big_endian()) |
| sym = this->define_special_symbol SELECT_SIZE_ENDIAN_NAME(size, true) ( |
| target, name, only_if_ref |
| SELECT_SIZE_ENDIAN(size, true)); |
| else |
| sym = this->define_special_symbol SELECT_SIZE_ENDIAN_NAME(size, false) ( |
| target, name, only_if_ref |
| SELECT_SIZE_ENDIAN(size, false)); |
| |
| if (sym == NULL) |
| return; |
| |
| sym->init(name, os, value, symsize, type, binding, visibility, nonvis, |
| offset_base); |
| } |
| |
| // Define a special symbol with a constant value. It is a multiple |
| // definition error if this symbol is already defined. |
| |
| void |
| Symbol_table::define_as_constant(Target* target, const char* name, |
| uint64_t value, uint64_t symsize, |
| elfcpp::STT type, elfcpp::STB binding, |
| elfcpp::STV visibility, unsigned char nonvis, |
| bool only_if_ref) |
| { |
| assert(target->get_size() == this->size_); |
| if (this->size_ == 32) |
| this->do_define_as_constant<32>(target, name, value, symsize, |
| type, binding, visibility, nonvis, |
| only_if_ref); |
| else if (this->size_ == 64) |
| this->do_define_as_constant<64>(target, name, value, symsize, |
| type, binding, visibility, nonvis, |
| only_if_ref); |
| else |
| abort(); |
| } |
| |
| // Define a symbol as a constant, sized version. |
| |
| template<int size> |
| void |
| Symbol_table::do_define_as_constant( |
| Target* target, |
| const char* name, |
| 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; |
| |
| if (target->is_big_endian()) |
| sym = this->define_special_symbol SELECT_SIZE_ENDIAN_NAME(size, true) ( |
| target, name, only_if_ref |
| SELECT_SIZE_ENDIAN(size, true)); |
| else |
| sym = this->define_special_symbol SELECT_SIZE_ENDIAN_NAME(size, false) ( |
| target, name, only_if_ref |
| SELECT_SIZE_ENDIAN(size, false)); |
| |
| if (sym == NULL) |
| return; |
| |
| sym->init(name, value, symsize, type, binding, visibility, nonvis); |
| } |
| |
| // Define a set of symbols in output sections. |
| |
| void |
| Symbol_table::define_symbols(const Layout* layout, 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, 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, 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, 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, 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, 0, p->size, p->type, |
| p->binding, p->visibility, p->nonvis, |
| p->only_if_ref); |
| } |
| } |
| |
| // Set the final values for all the symbols. Record the file offset |
| // OFF. Add their names to POOL. Return the new file offset. |
| |
| off_t |
| Symbol_table::finalize(off_t off, Stringpool* pool) |
| { |
| off_t ret; |
| |
| if (this->size_ == 32) |
| ret = this->sized_finalize<32>(off, pool); |
| else if (this->size_ == 64) |
| ret = this->sized_finalize<64>(off, pool); |
| else |
| abort(); |
| |
| // 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(off_t off, Stringpool* pool) |
| { |
| off = align_address(off, size >> 3); |
| this->offset_ = off; |
| |
| const int sym_size = elfcpp::Elf_sizes<size>::sym_size; |
| Symbol_table_type::iterator p = this->table_.begin(); |
| size_t count = 0; |
| while (p != this->table_.end()) |
| { |
| 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. |
| |
| typename Sized_symbol<size>::Value_type value; |
| |
| switch (sym->source()) |
| { |
| case Symbol::FROM_OBJECT: |
| { |
| unsigned int shnum = sym->shnum(); |
| |
| // FIXME: We need some target specific support here. |
| if (shnum >= elfcpp::SHN_LORESERVE |
| && shnum != elfcpp::SHN_ABS) |
| { |
| fprintf(stderr, _("%s: %s: unsupported symbol section 0x%x\n"), |
| program_name, sym->name(), shnum); |
| gold_exit(false); |
| } |
| |
| Object* symobj = sym->object(); |
| if (symobj->is_dynamic()) |
| { |
| value = 0; |
| shnum = elfcpp::SHN_UNDEF; |
| } |
| else if (shnum == elfcpp::SHN_UNDEF) |
| value = 0; |
| else if (shnum == elfcpp::SHN_ABS) |
| value = sym->value(); |
| else |
| { |
| Relobj* relobj = static_cast<Relobj*>(symobj); |
| off_t secoff; |
| Output_section* os = relobj->output_section(shnum, &secoff); |
| |
| if (os == NULL) |
| { |
| // We should be able to erase this symbol from the |
| // symbol table, but at least with gcc 4.0.2 |
| // std::unordered_map::erase doesn't appear to return |
| // the new iterator. |
| // p = this->table_.erase(p); |
| ++p; |
| 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: |
| abort(); |
| } |
| } |
| break; |
| |
| case Symbol::CONSTANT: |
| value = sym->value(); |
| break; |
| |
| default: |
| abort(); |
| } |
| |
| sym->set_value(value); |
| pool->add(sym->name(), NULL); |
| ++count; |
| off += sym_size; |
| ++p; |
| } |
| |
| this->output_count_ = count; |
| |
| return off; |
| } |
| |
| // Write out the global symbols. |
| |
| void |
| Symbol_table::write_globals(const Target* target, const Stringpool* sympool, |
| Output_file* of) const |
| { |
| if (this->size_ == 32) |
| { |
| if (target->is_big_endian()) |
| this->sized_write_globals<32, true>(target, sympool, of); |
| else |
| this->sized_write_globals<32, false>(target, sympool, of); |
| } |
| else if (this->size_ == 64) |
| { |
| if (target->is_big_endian()) |
| this->sized_write_globals<64, true>(target, sympool, of); |
| else |
| this->sized_write_globals<64, false>(target, sympool, of); |
| } |
| else |
| abort(); |
| } |
| |
| // Write out the global symbols. |
| |
| template<int size, bool big_endian> |
| void |
| Symbol_table::sized_write_globals(const Target*, |
| const Stringpool* sympool, |
| Output_file* of) const |
| { |
| const int sym_size = elfcpp::Elf_sizes<size>::sym_size; |
| unsigned char* psyms = of->get_output_view(this->offset_, |
| this->output_count_ * sym_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); |
| |
| unsigned int shndx; |
| switch (sym->source()) |
| { |
| case Symbol::FROM_OBJECT: |
| { |
| unsigned int shnum = sym->shnum(); |
| |
| // FIXME: We need some target specific support here. |
| if (shnum >= elfcpp::SHN_LORESERVE |
| && shnum != elfcpp::SHN_ABS) |
| { |
| fprintf(stderr, _("%s: %s: unsupported symbol section 0x%x\n"), |
| program_name, sym->name(), sym->shnum()); |
| gold_exit(false); |
| } |
| |
| Object* symobj = sym->object(); |
| if (symobj->is_dynamic()) |
| { |
| // FIXME. |
| shndx = elfcpp::SHN_UNDEF; |
| } |
| else if (shnum == elfcpp::SHN_UNDEF || shnum == elfcpp::SHN_ABS) |
| shndx = shnum; |
| else |
| { |
| Relobj* relobj = static_cast<Relobj*>(symobj); |
| off_t secoff; |
| Output_section* os = relobj->output_section(shnum, &secoff); |
| if (os == NULL) |
| continue; |
| |
| 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: |
| abort(); |
| } |
| |
| elfcpp::Sym_write<size, big_endian> osym(ps); |
| osym.put_st_name(sympool->get_offset(sym->name())); |
| osym.put_st_value(sym->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); |
| |
| ps += sym_size; |
| } |
| |
| of->write_output_view(this->offset_, this->output_count_ * sym_size, psyms); |
| } |
| |
| // 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); |
| 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. |
| |
| void |
| Warnings::issue_warning(Symbol* sym, const std::string& location) const |
| { |
| assert(sym->has_warning()); |
| Warning_table::const_iterator p = this->warnings_.find(sym->name()); |
| assert(p != this->warnings_.end()); |
| fprintf(stderr, _("%s: %s: warning: %s\n"), program_name, location.c_str(), |
| 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. |
| |
| 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, |
| Symbol** sympointers); |
| |
| 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, |
| Symbol** sympointers); |
| |
| 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, |
| Symbol** sympointers); |
| |
| 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, |
| Symbol** sympointers); |
| |
| 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); |
| |
| 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); |
| |
| 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); |
| |
| 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); |
| |
| } // End namespace gold. |