X-Git-Url: https://oss.titaniummirror.com/gitweb?p=msp430-binutils.git;a=blobdiff_plain;f=gold%2Fsymtab.cc;fp=gold%2Fsymtab.cc;h=5dbab35b73b4c79509102576456bc08ac822bd22;hp=0000000000000000000000000000000000000000;hb=d5da4f291af551c0b8b79e1d4a9b173d60e5c10e;hpb=7b5ea4fcdf2819e070665ab5610f8b48e3867c10 diff --git a/gold/symtab.cc b/gold/symtab.cc new file mode 100644 index 0000000..5dbab35 --- /dev/null +++ b/gold/symtab.cc @@ -0,0 +1,3287 @@ +// symtab.cc -- the gold symbol table + +// Copyright 2006, 2007, 2008, 2009 Free Software Foundation, Inc. +// Written by Ian Lance Taylor . + +// 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 +#include +#include +#include +#include +#include +#include "demangle.h" + +#include "gc.h" +#include "object.h" +#include "dwarf_reader.h" +#include "dynobj.h" +#include "output.h" +#include "target.h" +#include "workqueue.h" +#include "symtab.h" +#include "demangle.h" // needed for --dynamic-list-cpp-new +#include "plugin.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; + this->in_real_elf_ = 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 +void +Symbol::init_base_object(const char* name, const char* version, Object* object, + const elfcpp::Sym& 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(); + this->in_real_elf_ = object->pluginobj() == NULL; +} + +// 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; + this->in_real_elf_ = 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; + this->in_real_elf_ = 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; + this->in_real_elf_ = 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->dynsym_index_ = -1U; + this->source_ = IS_UNDEFINED; + this->in_reg_ = true; + this->in_real_elf_ = 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 +template +void +Sized_symbol::init_object(const char* name, const char* version, + Object* object, + const elfcpp::Sym& 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 +void +Sized_symbol::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 +void +Sized_symbol::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 +void +Sized_symbol::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 +void +Sized_symbol::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; +} + +// Return true if SHNDX represents a common symbol. + +bool +Symbol::is_common_shndx(unsigned int shndx) +{ + return (shndx == elfcpp::SHN_COMMON + || shndx == parameters->target().small_common_shndx() + || shndx == parameters->target().large_common_shndx()); +} + +// Allocate a common symbol. + +template +void +Sized_symbol::allocate_common(Output_data* od, Value_type value) +{ + this->allocate_base_common(od); + this->value_ = value; +} + +// The ""'s around str ensure str is a string literal, so sizeof works. +#define strprefix(var, str) (strncmp(var, str, sizeof("" str "") - 1) == 0) + +// 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 this symbol's section is not added, the symbol need not be added. + // The section may have been GCed. Note that export_dynamic is being + // overridden here. This should not be done for shared objects. + if (parameters->options().gc_sections() + && !parameters->options().shared() + && this->source() == Symbol::FROM_OBJECT + && !this->object()->is_dynamic()) + { + Relobj* relobj = static_cast(this->object()); + bool is_ordinary; + unsigned int shndx = this->shndx(&is_ordinary); + if (is_ordinary && shndx != elfcpp::SHN_UNDEF + && !relobj->is_section_included(shndx)) + return false; + } + + // If the symbol was forced local in a version script, do not add it. + if (this->is_forced_local()) + return false; + + // If the symbol was forced dynamic in a --dynamic-list file, add it. + if (parameters->options().in_dynamic_list(this->name())) + return true; + + // If dynamic-list-data was specified, add any STT_OBJECT. + if (parameters->options().dynamic_list_data() + && !this->is_from_dynobj() + && this->type() == elfcpp::STT_OBJECT) + return true; + + // If --dynamic-list-cpp-new was specified, add any new/delete symbol. + // If --dynamic-list-cpp-typeinfo was specified, add any typeinfo symbols. + if ((parameters->options().dynamic_list_cpp_new() + || parameters->options().dynamic_list_cpp_typeinfo()) + && !this->is_from_dynobj()) + { + // TODO(csilvers): We could probably figure out if we're an operator + // new/delete or typeinfo without the need to demangle. + char* demangled_name = cplus_demangle(this->name(), + DMGL_ANSI | DMGL_PARAMS); + if (demangled_name == NULL) + { + // Not a C++ symbol, so it can't satisfy these flags + } + else if (parameters->options().dynamic_list_cpp_new() + && (strprefix(demangled_name, "operator new") + || strprefix(demangled_name, "operator delete"))) + { + free(demangled_name); + return true; + } + else if (parameters->options().dynamic_list_cpp_typeinfo() + && (strprefix(demangled_name, "typeinfo name for") + || strprefix(demangled_name, "typeinfo for"))) + { + free(demangled_name); + return true; + } + else + free(demangled_name); + } + + // 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().output_is_position_independent() + || 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()); + gold_assert(this->u_.from_object.object->pluginobj() == NULL); + Relobj* relobj = static_cast(this->u_.from_object.object); + return relobj->output_section(shndx); + } + 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_(), small_commons_(), + large_commons_(), forced_locals_(), warnings_(), + version_script_(version_script), gc_(NULL), icf_(NULL) +{ + 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; +} + +bool +Symbol_table::is_section_folded(Object* obj, unsigned int shndx) const +{ + return (parameters->options().icf_enabled() + && this->icf_->is_section_folded(obj, shndx)); +} + +// For symbols that have been listed with -u option, add them to the +// work list to avoid gc'ing them. + +void +Symbol_table::gc_mark_undef_symbols() +{ + for (options::String_set::const_iterator p = + parameters->options().undefined_begin(); + p != parameters->options().undefined_end(); + ++p) + { + const char* name = p->c_str(); + Symbol* sym = this->lookup(name); + gold_assert (sym != NULL); + if (sym->source() == Symbol::FROM_OBJECT + && !sym->object()->is_dynamic()) + { + Relobj* obj = static_cast(sym->object()); + bool is_ordinary; + unsigned int shndx = sym->shndx(&is_ordinary); + if (is_ordinary) + { + gold_assert(this->gc_ != NULL); + this->gc_->worklist().push(Section_id(obj, shndx)); + } + } + } +} + +void +Symbol_table::gc_mark_symbol_for_shlib(Symbol* sym) +{ + if (!sym->is_from_dynobj() + && sym->is_externally_visible()) + { + //Add the object and section to the work list. + Relobj* obj = static_cast(sym->object()); + bool is_ordinary; + unsigned int shndx = sym->shndx(&is_ordinary); + if (is_ordinary && shndx != elfcpp::SHN_UNDEF) + { + gold_assert(this->gc_!= NULL); + this->gc_->worklist().push(Section_id(obj, shndx)); + } + } +} + +// When doing garbage collection, keep symbols that have been seen in +// dynamic objects. +inline void +Symbol_table::gc_mark_dyn_syms(Symbol* sym) +{ + if (sym->in_dyn() && sym->source() == Symbol::FROM_OBJECT + && !sym->object()->is_dynamic()) + { + Relobj *obj = static_cast(sym->object()); + bool is_ordinary; + unsigned int shndx = sym->shndx(&is_ordinary); + if (is_ordinary && shndx != elfcpp::SHN_UNDEF) + { + gold_assert(this->gc_ != NULL); + this->gc_->worklist().push(Section_id(obj, shndx)); + } + } +} + +// 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_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 +void +Symbol_table::resolve(Sized_symbol* to, const Sized_symbol* from) +{ + unsigned char buf[elfcpp::Elf_sizes::sym_size]; + elfcpp::Sym_write 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(), + from->version()); + if (from->in_reg()) + to->set_in_reg(); + if (from->in_dyn()) + to->set_in_dyn(); + if (parameters->options().gc_sections()) + this->gc_mark_dyn_syms(to); +} + +// Record that a symbol is forced to be local by a version script or +// by visibility. + +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(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] == parameters->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; +} + +// This is called when we see a symbol NAME/VERSION, and the symbol +// already exists in the symbol table, and VERSION is marked as being +// the default version. SYM is the NAME/VERSION symbol we just added. +// DEFAULT_IS_NEW is true if this is the first time we have seen the +// symbol NAME/NULL. PDEF points to the entry for NAME/NULL. + +template +void +Symbol_table::define_default_version(Sized_symbol* sym, + bool default_is_new, + Symbol_table_type::iterator pdef) +{ + if (default_is_new) + { + // This is the first time we have seen NAME/NULL. Make + // NAME/NULL point to NAME/VERSION, and mark SYM as the default + // version. + pdef->second = sym; + sym->set_is_default(); + } + else if (pdef->second == sym) + { + // NAME/NULL already points to NAME/VERSION. Don't mark the + // symbol as the default if it is not already the default. + } + else + { + // This is the unfortunate case where we already have entries + // for both NAME/VERSION and NAME/NULL. We now see a symbol + // NAME/VERSION where VERSION is the default version. We have + // already resolved this new symbol with the existing + // NAME/VERSION symbol. + + // It's possible that NAME/NULL and NAME/VERSION are both + // defined in regular objects. This can only happen if one + // object file defines foo and another defines foo@@ver. This + // is somewhat obscure, but we call it a multiple definition + // error. + + // It's possible that NAME/NULL actually has a version, in which + // case it won't be the same as VERSION. This happens with + // ver_test_7.so in the testsuite for the symbol t2_2. We see + // t2_2@@VER2, so we define both t2_2/VER2 and t2_2/NULL. We + // then see an unadorned t2_2 in an object file and give it + // version VER1 from the version script. This looks like a + // default definition for VER1, so it looks like we should merge + // t2_2/NULL with t2_2/VER1. That doesn't make sense, but it's + // not obvious that this is an error, either. So we just punt. + + // If one of the symbols has non-default visibility, and the + // other is defined in a shared object, then they are different + // symbols. + + // Otherwise, we just resolve the symbols as though they were + // the same. + + if (pdef->second->version() != NULL) + gold_assert(pdef->second->version() != sym->version()); + else if (sym->visibility() != elfcpp::STV_DEFAULT + && pdef->second->is_from_dynobj()) + ; + else if (pdef->second->visibility() != elfcpp::STV_DEFAULT + && sym->is_from_dynobj()) + ; + else + { + const Sized_symbol* symdef; + symdef = this->get_sized_symbol(pdef->second); + Symbol_table::resolve(sym, symdef); + this->make_forwarder(pdef->second, sym); + pdef->second = sym; + sym->set_is_default(); + } + } +} + +// 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 +Sized_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& 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(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 ins = + this->table_.insert(std::make_pair(std::make_pair(name_key, version_key), + snull)); + + std::pair 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* ret; + bool was_undefined; + bool was_common; + if (!ins.second) + { + // We already have an entry for NAME/VERSION. + ret = this->get_sized_symbol(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 (parameters->options().gc_sections()) + this->gc_mark_dyn_syms(ret); + + if (def) + this->define_default_version(ret, insdef.second, + insdef.first); + } + 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(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); + if (parameters->options().gc_sections()) + this->gc_mark_dyn_syms(ret); + ins.first->second = ret; + } + else + { + was_undefined = false; + was_common = false; + + Sized_target* target = + parameters->sized_target(); + if (!target->has_make_symbol()) + ret = new Sized_symbol(); + 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; + } + } + + if (def) + ret->set_is_default(); + } + + // 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->tls_commons_.push_back(ret); + else if (!is_ordinary + && st_shndx == parameters->target().small_common_shndx()) + this->small_commons_.push_back(ret); + else if (!is_ordinary + && st_shndx == parameters->target().large_common_shndx()) + this->large_commons_.push_back(ret); + else + this->commons_.push_back(ret); + } + + // If we're not doing a relocatable link, then any symbol with + // hidden or internal visibility is local. + if ((ret->visibility() == elfcpp::STV_HIDDEN + || ret->visibility() == elfcpp::STV_INTERNAL) + && (ret->binding() == elfcpp::STB_GLOBAL + || ret->binding() == elfcpp::STB_WEAK) + && !parameters->options().relocatable()) + this->force_local(ret); + + return ret; +} + +// Add all the symbols in a relocatable object to the hash table. + +template +void +Symbol_table::add_from_relobj( + Sized_relobj* relobj, + const unsigned char* syms, + size_t count, + size_t symndx_offset, + const char* sym_names, + size_t sym_name_size, + typename Sized_relobj::Symbols* sympointers, + size_t *defined) +{ + *defined = 0; + + gold_assert(size == parameters->target().get_size()); + + const int sym_size = elfcpp::Elf_sizes::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) + { + (*sympointers)[i] = NULL; + + elfcpp::Sym 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; + + if (st_shndx != elfcpp::SHN_UNDEF) + ++*defined; + + // 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, '@'); + Stringpool::Key ver_key = 0; + 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; + } + ver = this->namepool_.add(ver, true, &ver_key); + } + // 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 + { + namelen = strlen(name); + if (!this->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. + std::string version; + if (this->version_script_.get_symbol_version(name, &version)) + { + // The version can be empty if the version script is + // only used to force some symbols to be local. + if (!version.empty()) + { + ver = this->namepool_.add_with_length(version.c_str(), + version.length(), + true, + &ver_key); + def = true; + } + } + else if (this->version_script_.symbol_is_local(name)) + local = true; + } + } + + elfcpp::Sym* psym = &sym; + unsigned char symbuf[sym_size]; + elfcpp::Sym sym2(symbuf); + if (just_symbols) + { + memcpy(symbuf, p, sym_size); + elfcpp::Sym_write 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; + } + + // Fix up visibility if object has no-export set. + if (relobj->no_export()) + { + // We may have copied symbol already above. + if (psym != &sym2) + { + memcpy(symbuf, p, sym_size); + psym = &sym2; + } + + elfcpp::STV visibility = sym2.get_st_visibility(); + if (visibility == elfcpp::STV_DEFAULT + || visibility == elfcpp::STV_PROTECTED) + { + elfcpp::Sym_write sw(symbuf); + unsigned char nonvis = sym2.get_st_nonvis(); + sw.put_st_other(elfcpp::STV_HIDDEN, nonvis); + } + } + + Stringpool::Key name_key; + name = this->namepool_.add_with_length(name, namelen, true, + &name_key); + + Sized_symbol* res; + res = this->add_from_object(relobj, name, name_key, ver, ver_key, + def, *psym, st_shndx, is_ordinary, + orig_st_shndx); + + // If building a shared library using garbage collection, do not + // treat externally visible symbols as garbage. + if (parameters->options().gc_sections() + && parameters->options().shared()) + this->gc_mark_symbol_for_shlib(res); + + if (local) + this->force_local(res); + + (*sympointers)[i] = res; + } +} + +// Add a symbol from a plugin-claimed file. + +template +Symbol* +Symbol_table::add_from_pluginobj( + Sized_pluginobj* obj, + const char* name, + const char* ver, + elfcpp::Sym* sym) +{ + unsigned int st_shndx = sym->get_st_shndx(); + + Stringpool::Key ver_key = 0; + bool def = false; + bool local = false; + + if (ver != NULL) + { + ver = this->namepool_.add(ver, true, &ver_key); + } + // 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 (!this->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. + std::string version; + if (this->version_script_.get_symbol_version(name, &version)) + { + // The version can be empty if the version script is + // only used to force some symbols to be local. + if (!version.empty()) + { + ver = this->namepool_.add_with_length(version.c_str(), + version.length(), + true, + &ver_key); + def = true; + } + } + else if (this->version_script_.symbol_is_local(name)) + local = true; + } + } + + Stringpool::Key name_key; + name = this->namepool_.add(name, true, &name_key); + + Sized_symbol* res; + res = this->add_from_object(obj, name, name_key, ver, ver_key, + def, *sym, st_shndx, true, st_shndx); + + if (local) + this->force_local(res); + + return res; +} + +// Add all the symbols in a dynamic object to the hash table. + +template +void +Symbol_table::add_from_dynobj( + Sized_dynobj* 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* version_map, + typename Sized_relobj::Symbols* sympointers, + size_t* defined) +{ + *defined = 0; + + 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::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*> 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 sym(p); + + if (sympointers != NULL) + (*sympointers)[i] = NULL; + + // 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* psym = &sym; + unsigned char symbuf[sym_size]; + elfcpp::Sym sym2(symbuf); + if (sym.get_st_visibility() == elfcpp::STV_PROTECTED) + { + memcpy(symbuf, p, sym_size); + elfcpp::Sym_write 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); + + if (st_shndx != elfcpp::SHN_UNDEF) + ++*defined; + + Sized_symbol* 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(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(elfcpp::VER_NDX_LOCAL) + || v == static_cast(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); + + if (sympointers != NULL) + (*sympointers)[i] = 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 +class Weak_alias_sorter +{ + public: + bool operator()(const Sized_symbol*, const Sized_symbol*) const; +}; + +template +bool +Weak_alias_sorter::operator()(const Sized_symbol* s1, + const Sized_symbol* 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 +void +Symbol_table::record_weak_aliases(std::vector*>* 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()); + + // Walk through the vector. For each weak definition, record + // aliases. + for (typename std::vector*>::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* from_sym = *p; + typename std::vector*>::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 sets *RESOLVE_OLDSYM if we should +// resolve the newly created symbol to the old one. This +// canonicalizes *PNAME and *PVERSION. + +template +Sized_symbol* +Symbol_table::define_special_symbol(const char** pname, const char** pversion, + bool only_if_ref, + Sized_symbol** poldsym, + bool *resolve_oldsym) +{ + *resolve_oldsym = false; + + // If the caller didn't give us a version, see if we get one from + // the version script. + std::string v; + bool is_default_version = false; + if (*pversion == NULL) + { + if (this->version_script_.get_symbol_version(*pname, &v)) + { + if (!v.empty()) + *pversion = v.c_str(); + + // If we get the version from a version script, then we are + // also the default version. + is_default_version = true; + } + } + + Symbol* oldsym; + Sized_symbol* sym; + + bool add_to_table = false; + typename Symbol_table_type::iterator add_loc = this->table_.end(); + bool add_def_to_table = false; + typename Symbol_table_type::iterator add_def_loc = this->table_.end(); + + if (only_if_ref) + { + oldsym = this->lookup(*pname, *pversion); + if (oldsym == NULL && is_default_version) + oldsym = this->lookup(*pname, NULL); + if (oldsym == NULL || !oldsym->is_undefined()) + return NULL; + + *pname = oldsym->name(); + if (!is_default_version) + *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 ins = + this->table_.insert(std::make_pair(std::make_pair(name_key, + version_key), + snull)); + + std::pair insdef = + std::make_pair(this->table_.end(), false); + if (is_default_version) + { + const Stringpool::Key vnull = 0; + insdef = this->table_.insert(std::make_pair(std::make_pair(name_key, + vnull), + snull)); + } + + if (!ins.second) + { + // We already have a symbol table entry for NAME/VERSION. + oldsym = ins.first->second; + gold_assert(oldsym != NULL); + + if (is_default_version) + { + Sized_symbol* soldsym = + this->get_sized_symbol(oldsym); + this->define_default_version(soldsym, + insdef.second, + insdef.first); + } + } + else + { + // We haven't seen this symbol before. + gold_assert(ins.first->second == NULL); + + add_to_table = true; + add_loc = ins.first; + + if (is_default_version && !insdef.second) + { + // We are adding NAME/VERSION, and it is the default + // version. We already have an entry for NAME/NULL. + oldsym = insdef.first->second; + *resolve_oldsym = true; + } + else + { + oldsym = NULL; + + if (is_default_version) + { + add_def_to_table = true; + add_def_loc = insdef.first; + } + } + } + } + + const Target& target = parameters->target(); + if (!target.has_make_symbol()) + sym = new Sized_symbol(); + else + { + Sized_target* sized_target = + parameters->sized_target(); + sym = sized_target->make_symbol(); + if (sym == NULL) + return NULL; + } + + if (add_to_table) + add_loc->second = sym; + else + gold_assert(oldsym != NULL); + + if (add_def_to_table) + add_def_loc->second = sym; + + *poldsym = this->get_sized_symbol(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 +Sized_symbol* +Symbol_table::do_define_in_output_data( + const char* name, + const char* version, + Output_data* od, + typename elfcpp::Elf_types::Elf_Addr value, + typename elfcpp::Elf_types::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* sym; + Sized_symbol* oldsym; + bool resolve_oldsym; + + if (parameters->target().is_big_endian()) + { +#if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG) + sym = this->define_special_symbol(&name, &version, + only_if_ref, &oldsym, + &resolve_oldsym); +#else + gold_unreachable(); +#endif + } + else + { +#if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE) + sym = this->define_special_symbol(&name, &version, + only_if_ref, &oldsym, + &resolve_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); + + if (resolve_oldsym) + return sym; + else + { + 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 +Sized_symbol* +Symbol_table::do_define_in_output_segment( + const char* name, + const char* version, + Output_segment* os, + typename elfcpp::Elf_types::Elf_Addr value, + typename elfcpp::Elf_types::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* sym; + Sized_symbol* oldsym; + bool resolve_oldsym; + + if (parameters->target().is_big_endian()) + { +#if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG) + sym = this->define_special_symbol(&name, &version, + only_if_ref, &oldsym, + &resolve_oldsym); +#else + gold_unreachable(); +#endif + } + else + { +#if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE) + sym = this->define_special_symbol(&name, &version, + only_if_ref, &oldsym, + &resolve_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); + + if (resolve_oldsym) + return sym; + else + { + 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 +Sized_symbol* +Symbol_table::do_define_as_constant( + const char* name, + const char* version, + typename elfcpp::Elf_types::Elf_Addr value, + typename elfcpp::Elf_types::Elf_WXword symsize, + elfcpp::STT type, + elfcpp::STB binding, + elfcpp::STV visibility, + unsigned char nonvis, + bool only_if_ref, + bool force_override) +{ + Sized_symbol* sym; + Sized_symbol* oldsym; + bool resolve_oldsym; + + if (parameters->target().is_big_endian()) + { +#if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG) + sym = this->define_special_symbol(&name, &version, + only_if_ref, &oldsym, + &resolve_oldsym); +#else + gold_unreachable(); +#endif + } + else + { +#if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE) + sym = this->define_special_symbol(&name, &version, + only_if_ref, &oldsym, + &resolve_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); + + if (resolve_oldsym) + return sym; + else + { + 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 +void +Symbol_table::define_with_copy_reloc( + Sized_symbol* csym, + Output_data* posd, + typename elfcpp::Elf_types::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(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_LITTLE) || 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 +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* sym; + Sized_symbol* oldsym; + bool resolve_oldsym; + if (parameters->target().is_big_endian()) + { +#if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG) + sym = this->define_special_symbol(&name, &version, + false, &oldsym, + &resolve_oldsym); +#else + gold_unreachable(); +#endif + } + else + { +#if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE) + sym = this->define_special_symbol(&name, &version, + false, &oldsym, + &resolve_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* 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 +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::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 +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(sym)) + { + this->add_to_final_symtab(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(sym)) + this->add_to_final_symtab(sym, pool, &index, &off); + } + + this->output_count_ = index - orig_index; + + return off; +} + +// Compute the final value of SYM and store status in location PSTATUS. +// During relaxation, this may be called multiple times for a symbol to +// compute its would-be final value in each relaxation pass. + +template +typename Sized_symbol::Value_type +Symbol_table::compute_final_value( + const Sized_symbol* sym, + Compute_final_value_status* pstatus) const +{ + typedef typename Sized_symbol::Value_type Value_type; + Value_type value; + + switch (sym->source()) + { + case Symbol::FROM_OBJECT: + { + bool is_ordinary; + unsigned int shndx = sym->shndx(&is_ordinary); + + if (!is_ordinary + && shndx != elfcpp::SHN_ABS + && !Symbol::is_common_shndx(shndx)) + { + *pstatus = CFVS_UNSUPPORTED_SYMBOL_SECTION; + return 0; + } + + Object* symobj = sym->object(); + if (symobj->is_dynamic()) + { + value = 0; + shndx = elfcpp::SHN_UNDEF; + } + else if (symobj->pluginobj() != NULL) + { + value = 0; + shndx = elfcpp::SHN_UNDEF; + } + else if (shndx == elfcpp::SHN_UNDEF) + value = 0; + else if (!is_ordinary + && (shndx == elfcpp::SHN_ABS + || Symbol::is_common_shndx(shndx))) + value = sym->value(); + else + { + Relobj* relobj = static_cast(symobj); + Output_section* os = relobj->output_section(shndx); + uint64_t secoff64 = relobj->output_section_offset(shndx); + + if (this->is_section_folded(relobj, shndx)) + { + gold_assert(os == NULL); + // Get the os of the section it is folded onto. + Section_id folded = this->icf_->get_folded_section(relobj, + shndx); + gold_assert(folded.first != NULL); + Relobj* folded_obj = reinterpret_cast(folded.first); + os = folded_obj->output_section(folded.second); + gold_assert(os != NULL); + secoff64 = folded_obj->output_section_offset(folded.second); + } + + if (os == NULL) + { + bool static_or_reloc = (parameters->doing_static_link() || + parameters->options().relocatable()); + gold_assert(static_or_reloc || sym->dynsym_index() == -1U); + + *pstatus = CFVS_NO_OUTPUT_SECTION; + return 0; + } + + if (secoff64 == -1ULL) + { + // The section needs special handling (e.g., a merge section). + + value = os->output_address(relobj, shndx, sym->value()); + } + else + { + Value_type secoff = + convert_types(secoff64); + 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(); + } + + *pstatus = CFVS_OK; + return value; +} + +// Finalize the symbol SYM. This returns true if the symbol should be +// added to the symbol table, false otherwise. + +template +bool +Symbol_table::sized_finalize_symbol(Symbol* unsized_sym) +{ + typedef typename Sized_symbol::Value_type Value_type; + + Sized_symbol* sym = static_cast*>(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; + } + + // Compute final symbol value. + Compute_final_value_status status; + Value_type value = this->compute_final_value(sym, &status); + + switch (status) + { + case CFVS_OK: + break; + case CFVS_UNSUPPORTED_SYMBOL_SECTION: + { + bool is_ordinary; + unsigned int shndx = sym->shndx(&is_ordinary); + gold_error(_("%s: unsupported symbol section 0x%x"), + sym->demangled_name().c_str(), shndx); + } + break; + case CFVS_NO_OUTPUT_SECTION: + sym->set_symtab_index(-1U); + return false; + default: + gold_unreachable(); + } + + sym->set_value(value); + + if (parameters->options().strip_all() + || !parameters->options().should_retain_symbol(sym->name())) + { + sym->set_symtab_index(-1U); + return false; + } + + return true; +} + +// Write out the global symbols. + +void +Symbol_table::write_globals(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>(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>(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>(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>(sympool, dynpool, symtab_xindex, + dynsym_xindex, of); + break; +#endif + default: + gold_unreachable(); + } +} + +// Write out the global symbols. + +template +void +Symbol_table::sized_write_globals(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::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* sym = static_cast*>(p->second); + + // Possibly warn about unresolved symbols in shared libraries. + this->warn_about_undefined_dynobj_symbol(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::Elf_Addr sym_value = sym->value(); + typename elfcpp::Elf_types::Elf_Addr dynsym_value = sym_value; + switch (sym->source()) + { + case Symbol::FROM_OBJECT: + { + bool is_ordinary; + unsigned int in_shndx = sym->shndx(&is_ordinary); + + if (!is_ordinary + && in_shndx != elfcpp::SHN_ABS + && !Symbol::is_common_shndx(in_shndx)) + { + 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 (symobj->pluginobj() != NULL) + shndx = elfcpp::SHN_UNDEF; + else if (in_shndx == elfcpp::SHN_UNDEF + || (!is_ordinary + && (in_shndx == elfcpp::SHN_ABS + || Symbol::is_common_shndx(in_shndx)))) + shndx = in_shndx; + else + { + Relobj* relobj = static_cast(symobj); + Output_section* os = relobj->output_section(in_shndx); + if (this->is_section_folded(relobj, in_shndx)) + { + // This global symbol must be written out even though + // it is folded. + // Get the os of the section it is folded onto. + Section_id folded = + this->icf_->get_folded_section(relobj, in_shndx); + gold_assert(folded.first !=NULL); + Relobj* folded_obj = + reinterpret_cast(folded.first); + os = folded_obj->output_section(folded.second); + gold_assert(os != NULL); + } + 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(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(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 +void +Symbol_table::sized_write_symbol( + Sized_symbol* sym, + typename elfcpp::Elf_types::Elf_Addr value, + unsigned int shndx, + const Stringpool* pool, + unsigned char* p) const +{ + elfcpp::Sym_write osym(p); + osym.put_st_name(pool->get_offset(sym->name())); + osym.put_st_value(value); + // Use a symbol size of zero for undefined symbols from shared libraries. + if (shndx == elfcpp::SHN_UNDEF && sym->is_from_dynobj()) + osym.put_st_size(0); + else + 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 a system library +// directory (e.g., /lib or /usr/lib); we assume that those libraries +// are OK. This heuristic avoids problems on GNU/Linux, in which -ldl +// can have undefined references satisfied by ld-linux.so. + +inline void +Symbol_table::warn_about_undefined_dynobj_symbol(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) + && !sym->object()->is_in_system_directory()) + { + // A very ugly cast. + Dynobj* dynobj = static_cast(sym->object()); + if (!dynobj->has_unknown_needed_entries()) + gold_undefined_symbol(sym); + } +} + +// 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 +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::sym_size; + + unsigned char* pov = of->get_output_view(offset, sym_size); + + elfcpp::Sym_write osym(pov); + osym.put_st_name(0); + if (parameters->options().relocatable()) + osym.put_st_value(0); + else + 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 line_nums; + + for (Unordered_set::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 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::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 +void +Warnings::issue_warning(const Symbol* sym, + const Relocate_info* 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, false>::Symbols* sympointers, + size_t* defined); +#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, true>::Symbols* sympointers, + size_t* defined); +#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, false>::Symbols* sympointers, + size_t* defined); +#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, true>::Symbols* sympointers, + size_t* defined); +#endif + +#ifdef HAVE_TARGET_32_LITTLE +template +Symbol* +Symbol_table::add_from_pluginobj<32, false>( + Sized_pluginobj<32, false>* obj, + const char* name, + const char* ver, + elfcpp::Sym<32, false>* sym); +#endif + +#ifdef HAVE_TARGET_32_BIG +template +Symbol* +Symbol_table::add_from_pluginobj<32, true>( + Sized_pluginobj<32, true>* obj, + const char* name, + const char* ver, + elfcpp::Sym<32, true>* sym); +#endif + +#ifdef HAVE_TARGET_64_LITTLE +template +Symbol* +Symbol_table::add_from_pluginobj<64, false>( + Sized_pluginobj<64, false>* obj, + const char* name, + const char* ver, + elfcpp::Sym<64, false>* sym); +#endif + +#ifdef HAVE_TARGET_64_BIG +template +Symbol* +Symbol_table::add_from_pluginobj<64, true>( + Sized_pluginobj<64, true>* obj, + const char* name, + const char* ver, + elfcpp::Sym<64, true>* sym); +#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* version_map, + Sized_relobj<32, false>::Symbols* sympointers, + size_t* defined); +#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* version_map, + Sized_relobj<32, true>::Symbols* sympointers, + size_t* defined); +#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* version_map, + Sized_relobj<64, false>::Symbols* sympointers, + size_t* defined); +#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* version_map, + Sized_relobj<64, true>::Symbols* sympointers, + size_t* defined); +#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.