diff options
Diffstat (limited to 'gold/symtab.cc')
| -rw-r--r-- | gold/symtab.cc | 1567 |
1 files changed, 1567 insertions, 0 deletions
diff --git a/gold/symtab.cc b/gold/symtab.cc new file mode 100644 index 000000000000..01e000d874e7 --- /dev/null +++ b/gold/symtab.cc @@ -0,0 +1,1567 @@ +// symtab.cc -- the gold symbol table + +#include "gold.h" + +#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->symtab_index_ = 0; + this->dynsym_index_ = 0; + 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->needs_dynsym_entry_ = false; + this->in_reg_ = 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.shndx = sym.get_st_shndx(); + this->source_ = FROM_OBJECT; + this->in_reg_ = !object->is_dynamic(); + this->in_dyn_ = object->is_dynamic(); +} + +// Initialize the fields in the base class Symbol for a symbol defined +// in an Output_data. + +void +Symbol::init_base(const char* name, Output_data* od, elfcpp::STT type, + elfcpp::STB binding, elfcpp::STV visibility, + unsigned char nonvis, bool offset_is_from_end) +{ + this->init_fields(name, NULL, type, binding, visibility, nonvis); + this->u_.in_output_data.output_data = od; + this->u_.in_output_data.offset_is_from_end = offset_is_from_end; + this->source_ = IN_OUTPUT_DATA; + this->in_reg_ = true; +} + +// Initialize the fields in the base class Symbol for a symbol defined +// in an Output_segment. + +void +Symbol::init_base(const char* name, Output_segment* os, elfcpp::STT type, + elfcpp::STB binding, elfcpp::STV visibility, + unsigned char nonvis, Segment_offset_base offset_base) +{ + this->init_fields(name, NULL, type, binding, visibility, nonvis); + this->u_.in_output_segment.output_segment = os; + this->u_.in_output_segment.offset_base = offset_base; + this->source_ = IN_OUTPUT_SEGMENT; + this->in_reg_ = true; +} + +// Initialize the fields in the base class Symbol for a symbol defined +// as a constant. + +void +Symbol::init_base(const char* name, elfcpp::STT type, + elfcpp::STB binding, elfcpp::STV visibility, + unsigned char nonvis) +{ + this->init_fields(name, NULL, type, binding, visibility, nonvis); + this->source_ = CONSTANT; + this->in_reg_ = true; +} + +// 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) +{ + gold_assert(from != to); + gold_assert(!from->is_forwarder() && !to->is_forwarder()); + this->forwarders_[from] = to; + from->set_forwarder(); +} + +// Resolve the forwards from FROM, returning the real symbol. + +Symbol* +Symbol_table::resolve_forwards(const Symbol* from) const +{ + gold_assert(from->is_forwarder()); + Unordered_map<const Symbol*, Symbol*>::const_iterator p = + this->forwarders_.find(from); + gold_assert(p != this->forwarders_.end()); + return p->second; +} + +// Look up a symbol by name. + +Symbol* +Symbol_table::lookup(const char* name, const char* version) const +{ + Stringpool::Key name_key; + name = this->namepool_.find(name, &name_key); + if (name == NULL) + return NULL; + + Stringpool::Key version_key = 0; + if (version != NULL) + { + version = this->namepool_.find(version, &version_key); + if (version == NULL) + return NULL; + } + + Symbol_table_key key(name_key, version_key); + Symbol_table::Symbol_table_type::const_iterator p = this->table_.find(key); + if (p == this->table_.end()) + return NULL; + return p->second; +} + +// Resolve a Symbol with another Symbol. This is only used in the +// unusual case where there are references to both an unversioned +// symbol and a symbol with a version, and we then discover that that +// version is the default version. Because this is unusual, we do +// this the slow way, by converting back to an ELF symbol. + +template<int size, bool big_endian> +void +Symbol_table::resolve(Sized_symbol<size>* to, const Sized_symbol<size>* from, + const char* version ACCEPT_SIZE_ENDIAN) +{ + unsigned char buf[elfcpp::Elf_sizes<size>::sym_size]; + elfcpp::Sym_write<size, big_endian> esym(buf); + // We don't bother to set the st_name field. + esym.put_st_value(from->value()); + esym.put_st_size(from->symsize()); + esym.put_st_info(from->binding(), from->type()); + esym.put_st_other(from->visibility(), from->nonvis()); + esym.put_st_shndx(from->shndx()); + Symbol_table::resolve(to, esym.sym(), from->object(), version); +} + +// 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)); + gold_assert(ret != NULL); + + was_undefined = ret->is_undefined(); + was_common = ret->is_common(); + + Symbol_table::resolve(ret, sym, object, version); + + if (def) + { + if (insdef.second) + { + // This is the first time we have seen NAME/NULL. Make + // NAME/NULL point to NAME/VERSION. + insdef.first->second = ret; + } + else if (insdef.first->second != ret) + { + // This is the unfortunate case where we already have + // entries for both NAME/VERSION and NAME/NULL. + const Sized_symbol<size>* sym2; + sym2 = this->get_sized_symbol SELECT_SIZE_NAME(size) ( + insdef.first->second + SELECT_SIZE(size)); + Symbol_table::resolve SELECT_SIZE_ENDIAN_NAME(size, big_endian) ( + ret, sym2, version SELECT_SIZE_ENDIAN(size, big_endian)); + this->make_forwarder(insdef.first->second, ret); + insdef.first->second = ret; + } + } + } + else + { + // This is the first time we have seen NAME/VERSION. + gold_assert(ins.first->second == NULL); + + was_undefined = false; + was_common = false; + + if (def && !insdef.second) + { + // We already have an entry for NAME/NULL. If we override + // it, then change it to NAME/VERSION. + ret = this->get_sized_symbol SELECT_SIZE_NAME(size) ( + insdef.first->second + SELECT_SIZE(size)); + Symbol_table::resolve(ret, sym, object, version); + ins.first->second = ret; + } + else + { + Sized_target<size, big_endian>* target = + object->sized_target SELECT_SIZE_ENDIAN_NAME(size, big_endian) ( + SELECT_SIZE_ENDIAN_ONLY(size, big_endian)); + if (!target->has_make_symbol()) + ret = new Sized_symbol<size>(); + else + { + ret = target->make_symbol(); + if (ret == NULL) + { + // This means that we don't want a symbol table + // entry after all. + if (!def) + this->table_.erase(ins.first); + else + { + this->table_.erase(insdef.first); + // Inserting insdef invalidated ins. + this->table_.erase(std::make_pair(name_key, + version_key)); + } + return NULL; + } + } + + ret->init(name, version, object, sym); + + ins.first->second = ret; + if (def) + { + // This is the first time we have seen NAME/NULL. Point + // it at the new entry for NAME/VERSION. + gold_assert(insdef.second); + insdef.first->second = ret; + } + } + } + + // Record every time we see a new undefined symbol, to speed up + // archive groups. + if (!was_undefined && ret->is_undefined()) + ++this->saw_undefined_; + + // Keep track of common symbols, to speed up common symbol + // allocation. + if (!was_common && ret->is_common()) + this->commons_.push_back(ret); + + return ret; +} + +// Add all the symbols in a relocatable object to the hash table. + +template<int size, bool big_endian> +void +Symbol_table::add_from_relobj( + Sized_relobj<size, big_endian>* relobj, + const unsigned char* syms, + size_t count, + const char* sym_names, + size_t sym_name_size, + 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(const Target* target, const char* name, + const char* version, bool only_if_ref + ACCEPT_SIZE_ENDIAN) +{ + gold_assert(this->size_ == size); + + Symbol* oldsym; + Sized_symbol<size>* sym; + + if (only_if_ref) + { + oldsym = this->lookup(name, version); + if (oldsym == NULL || !oldsym->is_undefined()) + return NULL; + sym = NULL; + + // Canonicalize NAME and VERSION. + name = oldsym->name(); + version = oldsym->version(); + } + else + { + // Canonicalize NAME and VERSION. + Stringpool::Key name_key; + name = this->namepool_.add(name, &name_key); + + Stringpool::Key version_key = 0; + if (version != NULL) + version = this->namepool_.add(version, &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); + sym = NULL; + } + else + { + // We haven't seen this symbol before. + gold_assert(ins.first->second == NULL); + + if (!target->has_make_symbol()) + sym = new Sized_symbol<size>(); + else + { + gold_assert(target->get_size() == size); + gold_assert(target->is_big_endian() ? big_endian : !big_endian); + typedef Sized_target<size, big_endian> My_target; + const My_target* sized_target = + static_cast<const My_target*>(target); + sym = sized_target->make_symbol(); + if (sym == NULL) + return NULL; + } + + ins.first->second = sym; + oldsym = NULL; + } + } + + if (oldsym != NULL) + { + gold_assert(sym == NULL); + + sym = this->get_sized_symbol SELECT_SIZE_NAME(size) (oldsym + SELECT_SIZE(size)); + gold_assert(sym->source() == Symbol::FROM_OBJECT); + const int old_shndx = sym->shndx(); + if (old_shndx != elfcpp::SHN_UNDEF + && old_shndx != 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. + +Symbol* +Symbol_table::define_in_output_data(const Target* target, const char* name, + const char* version, Output_data* od, + uint64_t value, uint64_t symsize, + elfcpp::STT type, elfcpp::STB binding, + elfcpp::STV visibility, + unsigned char nonvis, + bool offset_is_from_end, + bool only_if_ref) +{ + gold_assert(target->get_size() == this->size_); + if (this->size_ == 32) + return this->do_define_in_output_data<32>(target, name, version, od, value, + symsize, type, binding, + visibility, nonvis, + offset_is_from_end, only_if_ref); + else if (this->size_ == 64) + return this->do_define_in_output_data<64>(target, name, version, od, value, + symsize, type, binding, + visibility, nonvis, + offset_is_from_end, only_if_ref); + else + gold_unreachable(); +} + +// Define a symbol in an Output_data, sized version. + +template<int size> +Sized_symbol<size>* +Symbol_table::do_define_in_output_data( + const Target* target, + const char* name, + const char* version, + Output_data* od, + typename elfcpp::Elf_types<size>::Elf_Addr value, + typename elfcpp::Elf_types<size>::Elf_WXword symsize, + elfcpp::STT type, + elfcpp::STB binding, + elfcpp::STV visibility, + unsigned char nonvis, + bool offset_is_from_end, + bool only_if_ref) +{ + Sized_symbol<size>* sym; + + if (target->is_big_endian()) + sym = this->define_special_symbol SELECT_SIZE_ENDIAN_NAME(size, true) ( + target, name, version, only_if_ref + SELECT_SIZE_ENDIAN(size, true)); + else + sym = this->define_special_symbol SELECT_SIZE_ENDIAN_NAME(size, false) ( + target, name, version, only_if_ref + SELECT_SIZE_ENDIAN(size, false)); + + if (sym == NULL) + return NULL; + + sym->init(name, od, value, symsize, type, binding, visibility, nonvis, + offset_is_from_end); + + return sym; +} + +// Define a symbol based on an Output_segment. + +Symbol* +Symbol_table::define_in_output_segment(const Target* target, const char* name, + const char* version, Output_segment* os, + uint64_t value, uint64_t symsize, + elfcpp::STT type, elfcpp::STB binding, + elfcpp::STV visibility, + unsigned char nonvis, + Symbol::Segment_offset_base offset_base, + bool only_if_ref) +{ + gold_assert(target->get_size() == this->size_); + if (this->size_ == 32) + return this->do_define_in_output_segment<32>(target, name, version, os, + value, symsize, type, binding, + visibility, nonvis, + offset_base, only_if_ref); + else if (this->size_ == 64) + return this->do_define_in_output_segment<64>(target, name, version, os, + value, symsize, type, binding, + visibility, nonvis, + offset_base, only_if_ref); + else + gold_unreachable(); +} + +// Define a symbol in an Output_segment, sized version. + +template<int size> +Sized_symbol<size>* +Symbol_table::do_define_in_output_segment( + const Target* target, + const char* name, + const char* version, + Output_segment* os, + typename elfcpp::Elf_types<size>::Elf_Addr value, + typename elfcpp::Elf_types<size>::Elf_WXword symsize, + elfcpp::STT type, + elfcpp::STB binding, + elfcpp::STV visibility, + unsigned char nonvis, + Symbol::Segment_offset_base offset_base, + bool only_if_ref) +{ + Sized_symbol<size>* sym; + + if (target->is_big_endian()) + sym = this->define_special_symbol SELECT_SIZE_ENDIAN_NAME(size, true) ( + target, name, version, only_if_ref + SELECT_SIZE_ENDIAN(size, true)); + else + sym = this->define_special_symbol SELECT_SIZE_ENDIAN_NAME(size, false) ( + target, name, version, only_if_ref + SELECT_SIZE_ENDIAN(size, false)); + + if (sym == NULL) + return NULL; + + sym->init(name, os, value, symsize, type, binding, visibility, nonvis, + offset_base); + + return sym; +} + +// Define a special symbol with a constant value. It is a multiple +// definition error if this symbol is already defined. + +Symbol* +Symbol_table::define_as_constant(const Target* target, const char* name, + const char* version, uint64_t value, + uint64_t symsize, elfcpp::STT type, + elfcpp::STB binding, elfcpp::STV visibility, + unsigned char nonvis, bool only_if_ref) +{ + gold_assert(target->get_size() == this->size_); + if (this->size_ == 32) + return this->do_define_as_constant<32>(target, name, version, value, + symsize, type, binding, visibility, + nonvis, only_if_ref); + else if (this->size_ == 64) + return this->do_define_as_constant<64>(target, name, version, value, + symsize, type, binding, visibility, + nonvis, only_if_ref); + else + gold_unreachable(); +} + +// Define a symbol as a constant, sized version. + +template<int size> +Sized_symbol<size>* +Symbol_table::do_define_as_constant( + const Target* target, + const char* name, + const char* version, + typename elfcpp::Elf_types<size>::Elf_Addr value, + typename elfcpp::Elf_types<size>::Elf_WXword symsize, + elfcpp::STT type, + elfcpp::STB binding, + elfcpp::STV visibility, + unsigned char nonvis, + bool only_if_ref) +{ + Sized_symbol<size>* sym; + + if (target->is_big_endian()) + sym = this->define_special_symbol SELECT_SIZE_ENDIAN_NAME(size, true) ( + target, name, version, only_if_ref + SELECT_SIZE_ENDIAN(size, true)); + else + sym = this->define_special_symbol SELECT_SIZE_ENDIAN_NAME(size, false) ( + target, name, version, only_if_ref + SELECT_SIZE_ENDIAN(size, false)); + + if (sym == NULL) + return NULL; + + sym->init(name, value, symsize, type, binding, visibility, nonvis); + + return sym; +} + +// Define a set of symbols in output sections. + +void +Symbol_table::define_symbols(const Layout* layout, const Target* target, + int count, const Define_symbol_in_section* p) +{ + for (int i = 0; i < count; ++i, ++p) + { + Output_section* os = layout->find_output_section(p->output_section); + if (os != NULL) + this->define_in_output_data(target, p->name, NULL, os, p->value, + p->size, p->type, p->binding, + p->visibility, p->nonvis, + p->offset_is_from_end, p->only_if_ref); + else + this->define_as_constant(target, p->name, NULL, 0, p->size, p->type, + p->binding, p->visibility, p->nonvis, + p->only_if_ref); + } +} + +// Define a set of symbols in output segments. + +void +Symbol_table::define_symbols(const Layout* layout, const Target* target, + int count, const Define_symbol_in_segment* p) +{ + for (int i = 0; i < count; ++i, ++p) + { + Output_segment* os = layout->find_output_segment(p->segment_type, + p->segment_flags_set, + p->segment_flags_clear); + if (os != NULL) + this->define_in_output_segment(target, p->name, NULL, os, p->value, + p->size, p->type, p->binding, + p->visibility, p->nonvis, + p->offset_base, p->only_if_ref); + else + this->define_as_constant(target, p->name, NULL, 0, p->size, p->type, + p->binding, p->visibility, p->nonvis, + p->only_if_ref); + } +} + +// Set the dynamic symbol indexes. INDEX is the index of the first +// global dynamic symbol. Pointers to the symbols are stored into the +// vector SYMS. The names are added to DYNPOOL. This returns an +// updated dynamic symbol index. + +unsigned int +Symbol_table::set_dynsym_indexes(const General_options* options, + const Target* target, + unsigned int index, + std::vector<Symbol*>* syms, + Stringpool* dynpool, + Versions* versions) +{ + for (Symbol_table_type::iterator p = this->table_.begin(); + p != this->table_.end(); + ++p) + { + Symbol* sym = p->second; + + // Note that SYM may already have a dynamic symbol index, since + // some symbols appear more than once in the symbol table, with + // and without a version. + + if (!sym->needs_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(), NULL); + + // Record any version information. + if (sym->version() != NULL) + versions->record_version(options, dynpool, sym); + } + } + + // Finish up the versions. In some cases this may add new dynamic + // symbols. + index = versions->finalize(target, this, index, syms); + + return index; +} + +// Set the final values for all the symbols. The index of the first +// global symbol in the output file is INDEX. Record the file offset +// OFF. Add their names to POOL. Return the new file offset. + +off_t +Symbol_table::finalize(unsigned int index, off_t off, off_t dynoff, + size_t dyn_global_index, size_t dyncount, + Stringpool* pool) +{ + off_t ret; + + gold_assert(index != 0); + this->first_global_index_ = index; + + this->dynamic_offset_ = dynoff; + this->first_dynamic_global_index_ = dyn_global_index; + this->dynamic_count_ = dyncount; + + if (this->size_ == 32) + ret = this->sized_finalize<32>(index, off, pool); + else if (this->size_ == 64) + ret = this->sized_finalize<64>(index, off, pool); + else + gold_unreachable(); + + // Now that we have the final symbol table, we can reliably note + // which symbols should get warnings. + this->warnings_.note_warnings(this); + + return ret; +} + +// Set the final value for all the symbols. This is called after +// Layout::finalize, so all the output sections have their final +// address. + +template<int size> +off_t +Symbol_table::sized_finalize(unsigned index, off_t off, Stringpool* pool) +{ + off = align_address(off, size >> 3); + this->offset_ = off; + + size_t orig_index = index; + + const int sym_size = elfcpp::Elf_sizes<size>::sym_size; + for (Symbol_table_type::iterator p = this->table_.begin(); + p != this->table_.end(); + ++p) + { + Sized_symbol<size>* sym = static_cast<Sized_symbol<size>*>(p->second); + + // FIXME: Here we need to decide which symbols should go into + // the output file, based on --strip. + + // The default version of a symbol may appear twice in the + // symbol table. We only need to finalize it once. + if (sym->has_symtab_index()) + continue; + + if (!sym->in_reg()) + { + gold_assert(!sym->has_symtab_index()); + sym->set_symtab_index(-1U); + gold_assert(sym->dynsym_index() == -1U); + continue; + } + + typename Sized_symbol<size>::Value_type value; + + switch (sym->source()) + { + case Symbol::FROM_OBJECT: + { + unsigned int shndx = sym->shndx(); + + // FIXME: We need some target specific support here. + if (shndx >= elfcpp::SHN_LORESERVE + && shndx != elfcpp::SHN_ABS) + { + fprintf(stderr, _("%s: %s: unsupported symbol section 0x%x\n"), + program_name, sym->name(), shndx); + gold_exit(false); + } + + Object* symobj = sym->object(); + if (symobj->is_dynamic()) + { + value = 0; + shndx = elfcpp::SHN_UNDEF; + } + else if (shndx == elfcpp::SHN_UNDEF) + value = 0; + else if (shndx == elfcpp::SHN_ABS) + value = sym->value(); + else + { + Relobj* relobj = static_cast<Relobj*>(symobj); + off_t secoff; + Output_section* os = relobj->output_section(shndx, &secoff); + + if (os == NULL) + { + sym->set_symtab_index(-1U); + gold_assert(sym->dynsym_index() == -1U); + continue; + } + + value = sym->value() + os->address() + secoff; + } + } + break; + + case Symbol::IN_OUTPUT_DATA: + { + Output_data* od = sym->output_data(); + value = sym->value() + od->address(); + if (sym->offset_is_from_end()) + value += od->data_size(); + } + break; + + case Symbol::IN_OUTPUT_SEGMENT: + { + Output_segment* os = sym->output_segment(); + value = sym->value() + os->vaddr(); + switch (sym->offset_base()) + { + case Symbol::SEGMENT_START: + break; + case Symbol::SEGMENT_END: + value += os->memsz(); + break; + case Symbol::SEGMENT_BSS: + value += os->filesz(); + break; + default: + gold_unreachable(); + } + } + break; + + case Symbol::CONSTANT: + value = sym->value(); + break; + + default: + gold_unreachable(); + } + + sym->set_value(value); + sym->set_symtab_index(index); + pool->add(sym->name(), NULL); + ++index; + off += sym_size; + } + + this->output_count_ = index - orig_index; + + return off; +} + +// Write out the global symbols. + +void +Symbol_table::write_globals(const Target* target, const Stringpool* sympool, + const Stringpool* dynpool, Output_file* of) const +{ + if (this->size_ == 32) + { + if (target->is_big_endian()) + this->sized_write_globals<32, true>(target, sympool, dynpool, of); + else + this->sized_write_globals<32, false>(target, sympool, dynpool, of); + } + else if (this->size_ == 64) + { + if (target->is_big_endian()) + this->sized_write_globals<64, true>(target, sympool, dynpool, of); + else + this->sized_write_globals<64, false>(target, sympool, dynpool, of); + } + else + gold_unreachable(); +} + +// Write out the global symbols. + +template<int size, bool big_endian> +void +Symbol_table::sized_write_globals(const Target*, + const Stringpool* sympool, + const Stringpool* dynpool, + Output_file* of) const +{ + const int sym_size = elfcpp::Elf_sizes<size>::sym_size; + unsigned int index = this->first_global_index_; + const off_t oview_size = this->output_count_ * sym_size; + unsigned char* const psyms = of->get_output_view(this->offset_, oview_size); + + unsigned int dynamic_count = this->dynamic_count_; + off_t dynamic_size = dynamic_count * sym_size; + unsigned int first_dynamic_global_index = this->first_dynamic_global_index_; + unsigned char* dynamic_view; + if (this->dynamic_offset_ == 0) + dynamic_view = NULL; + else + dynamic_view = of->get_output_view(this->dynamic_offset_, dynamic_size); + + unsigned char* ps = psyms; + for (Symbol_table_type::const_iterator p = this->table_.begin(); + p != this->table_.end(); + ++p) + { + Sized_symbol<size>* sym = static_cast<Sized_symbol<size>*>(p->second); + + unsigned int sym_index = sym->symtab_index(); + unsigned int dynsym_index; + if (dynamic_view == NULL) + dynsym_index = -1U; + else + dynsym_index = sym->dynsym_index(); + + if (sym_index == -1U && dynsym_index == -1U) + { + // This symbol is not included in the output file. + continue; + } + + if (sym_index == index) + ++index; + else if (sym_index != -1U) + { + // We have already seen this symbol, because it has a + // default version. + gold_assert(sym_index < index); + if (dynsym_index == -1U) + continue; + sym_index = -1U; + } + + unsigned int shndx; + switch (sym->source()) + { + case Symbol::FROM_OBJECT: + { + unsigned int in_shndx = sym->shndx(); + + // FIXME: We need some target specific support here. + if (in_shndx >= elfcpp::SHN_LORESERVE + && in_shndx != elfcpp::SHN_ABS) + { + fprintf(stderr, _("%s: %s: unsupported symbol section 0x%x\n"), + program_name, sym->name(), in_shndx); + gold_exit(false); + } + + Object* symobj = sym->object(); + if (symobj->is_dynamic()) + { + // FIXME. + shndx = elfcpp::SHN_UNDEF; + } + else if (in_shndx == elfcpp::SHN_UNDEF + || in_shndx == elfcpp::SHN_ABS) + shndx = in_shndx; + else + { + Relobj* relobj = static_cast<Relobj*>(symobj); + off_t secoff; + Output_section* os = relobj->output_section(in_shndx, &secoff); + gold_assert(os != NULL); + shndx = os->out_shndx(); + } + } + break; + + case Symbol::IN_OUTPUT_DATA: + shndx = sym->output_data()->out_shndx(); + break; + + case Symbol::IN_OUTPUT_SEGMENT: + shndx = elfcpp::SHN_ABS; + break; + + case Symbol::CONSTANT: + shndx = elfcpp::SHN_ABS; + break; + + default: + gold_unreachable(); + } + + if (sym_index != -1U) + { + this->sized_write_symbol SELECT_SIZE_ENDIAN_NAME(size, big_endian) ( + sym, shndx, sympool, ps + SELECT_SIZE_ENDIAN(size, big_endian)); + ps += sym_size; + } + + if (dynsym_index != -1U) + { + dynsym_index -= first_dynamic_global_index; + gold_assert(dynsym_index < dynamic_count); + unsigned char* pd = dynamic_view + (dynsym_index * sym_size); + this->sized_write_symbol SELECT_SIZE_ENDIAN_NAME(size, big_endian) ( + sym, shndx, dynpool, pd + SELECT_SIZE_ENDIAN(size, big_endian)); + } + } + + gold_assert(ps - psyms == oview_size); + + of->write_output_view(this->offset_, oview_size, psyms); + if (dynamic_view != NULL) + of->write_output_view(this->dynamic_offset_, dynamic_size, dynamic_view); +} + +// Write out the symbol SYM, in section SHNDX, to P. POOL is the +// strtab holding the name. + +template<int size, bool big_endian> +void +Symbol_table::sized_write_symbol(Sized_symbol<size>* sym, + unsigned int shndx, + const Stringpool* pool, + unsigned char* p + ACCEPT_SIZE_ENDIAN) const +{ + elfcpp::Sym_write<size, big_endian> osym(p); + osym.put_st_name(pool->get_offset(sym->name())); + osym.put_st_value(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); +} + +// Write out a section symbol. Return the update offset. + +void +Symbol_table::write_section_symbol(const Target* target, + const Output_section *os, + Output_file* of, + off_t offset) const +{ + if (this->size_ == 32) + { + if (target->is_big_endian()) + this->sized_write_section_symbol<32, true>(os, of, offset); + else + this->sized_write_section_symbol<32, false>(os, of, offset); + } + else if (this->size_ == 64) + { + if (target->is_big_endian()) + this->sized_write_section_symbol<64, true>(os, of, offset); + else + this->sized_write_section_symbol<64, false>(os, of, offset); + } + else + gold_unreachable(); +} + +// Write out a section symbol, specialized for size and endianness. + +template<int size, bool big_endian> +void +Symbol_table::sized_write_section_symbol(const Output_section* os, + Output_file* of, + off_t offset) const +{ + const int sym_size = elfcpp::Elf_sizes<size>::sym_size; + + unsigned char* pov = of->get_output_view(offset, sym_size); + + elfcpp::Sym_write<size, big_endian> osym(pov); + osym.put_st_name(0); + osym.put_st_value(os->address()); + osym.put_st_size(0); + osym.put_st_info(elfcpp::elf_st_info(elfcpp::STB_LOCAL, + elfcpp::STT_SECTION)); + osym.put_st_other(elfcpp::elf_st_other(elfcpp::STV_DEFAULT, 0)); + osym.put_st_shndx(os->out_shndx()); + + of->write_output_view(offset, sym_size, pov); +} + +// 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(const Symbol* sym, const std::string& location) const +{ + gold_assert(sym->has_warning()); + Warning_table::const_iterator p = this->warnings_.find(sym->name()); + gold_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. |