X-Git-Url: http://drtracing.org/?a=blobdiff_plain;f=gold%2Fsymtab.cc;h=c872f47d38638540278e1dcc05caee1195d88f5d;hb=128e85e3ab36b8e30f6612fb50de3cbb4ede6824;hp=540838509253066e38688eec8881bb6814e8dd04;hpb=f073bbf7e0a9d7ebe5323c660b34c893c5dfedee;p=deliverable%2Fbinutils-gdb.git diff --git a/gold/symtab.cc b/gold/symtab.cc index 5408385092..c872f47d38 100644 --- a/gold/symtab.cc +++ b/gold/symtab.cc @@ -1,6 +1,6 @@ // symtab.cc -- the gold symbol table -// Copyright 2006, 2007, 2008, 2009 Free Software Foundation, Inc. +// Copyright (C) 2006-2016 Free Software Foundation, Inc. // Written by Ian Lance Taylor . // This file is part of gold. @@ -38,8 +38,9 @@ #include "target.h" #include "workqueue.h" #include "symtab.h" -#include "demangle.h" // needed for --dynamic-list-cpp-new +#include "script.h" #include "plugin.h" +#include "incremental.h" namespace gold { @@ -59,24 +60,27 @@ Symbol::init_fields(const char* name, const char* version, this->symtab_index_ = 0; this->dynsym_index_ = 0; this->got_offsets_.init(); - this->plt_offset_ = 0; + this->plt_offset_ = -1U; 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; + this->is_defined_in_discarded_section_ = false; + this->undef_binding_set_ = false; + this->undef_binding_weak_ = false; + this->is_predefined_ = false; + this->is_protected_ = false; } // Return the demangled version of the symbol's name, but only @@ -131,7 +135,8 @@ 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) + unsigned char nonvis, bool offset_is_from_end, + bool is_predefined) { this->init_fields(name, version, type, binding, visibility, nonvis); this->u_.in_output_data.output_data = od; @@ -139,6 +144,7 @@ Symbol::init_base_output_data(const char* name, const char* version, this->source_ = IN_OUTPUT_DATA; this->in_reg_ = true; this->in_real_elf_ = true; + this->is_predefined_ = is_predefined; } // Initialize the fields in the base class Symbol for a symbol defined @@ -149,7 +155,8 @@ 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) + Segment_offset_base offset_base, + bool is_predefined) { this->init_fields(name, version, type, binding, visibility, nonvis); this->u_.in_output_segment.output_segment = os; @@ -157,6 +164,7 @@ Symbol::init_base_output_segment(const char* name, const char* version, this->source_ = IN_OUTPUT_SEGMENT; this->in_reg_ = true; this->in_real_elf_ = true; + this->is_predefined_ = is_predefined; } // Initialize the fields in the base class Symbol for a symbol defined @@ -165,12 +173,14 @@ Symbol::init_base_output_segment(const char* name, const char* version, void Symbol::init_base_constant(const char* name, const char* version, elfcpp::STT type, elfcpp::STB binding, - elfcpp::STV visibility, unsigned char nonvis) + elfcpp::STV visibility, unsigned char nonvis, + bool is_predefined) { this->init_fields(name, version, type, binding, visibility, nonvis); this->source_ = IS_CONSTANT; this->in_reg_ = true; this->in_real_elf_ = true; + this->is_predefined_ = is_predefined; } // Initialize the fields in the base class Symbol for an undefined @@ -225,10 +235,11 @@ Sized_symbol::init_output_data(const char* name, const char* version, elfcpp::STB binding, elfcpp::STV visibility, unsigned char nonvis, - bool offset_is_from_end) + bool offset_is_from_end, + bool is_predefined) { this->init_base_output_data(name, version, od, type, binding, visibility, - nonvis, offset_is_from_end); + nonvis, offset_is_from_end, is_predefined); this->value_ = value; this->symsize_ = symsize; } @@ -244,10 +255,11 @@ Sized_symbol::init_output_segment(const char* name, const char* version, elfcpp::STB binding, elfcpp::STV visibility, unsigned char nonvis, - Segment_offset_base offset_base) + Segment_offset_base offset_base, + bool is_predefined) { this->init_base_output_segment(name, version, os, type, binding, visibility, - nonvis, offset_base); + nonvis, offset_base, is_predefined); this->value_ = value; this->symsize_ = symsize; } @@ -260,9 +272,11 @@ 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) + elfcpp::STV visibility, unsigned char nonvis, + bool is_predefined) { - this->init_base_constant(name, version, type, binding, visibility, nonvis); + this->init_base_constant(name, version, type, binding, visibility, nonvis, + is_predefined); this->value_ = value; this->symsize_ = symsize; } @@ -272,14 +286,40 @@ Sized_symbol::init_constant(const char* name, const char* version, template void Sized_symbol::init_undefined(const char* name, const char* version, - elfcpp::STT type, elfcpp::STB binding, - elfcpp::STV visibility, unsigned char nonvis) + Value_type value, 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->value_ = value; this->symsize_ = 0; } +// Return an allocated string holding the symbol's name as +// name@version. This is used for relocatable links. + +std::string +Symbol::versioned_name() const +{ + gold_assert(this->version_ != NULL); + std::string ret = this->name_; + ret.push_back('@'); + if (this->is_def_) + ret.push_back('@'); + ret += this->version_; + return ret; +} + +// 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 @@ -296,9 +336,14 @@ Sized_symbol::allocate_common(Output_data* od, Value_type value) // Return true if this symbol should be added to the dynamic symbol // table. -inline bool -Symbol::should_add_dynsym_entry() const +bool +Symbol::should_add_dynsym_entry(Symbol_table* symtab) const { + // If the symbol is only present on plugin files, the plugin decided we + // don't need it. + if (!this->in_real_elf()) + return false; + // If the symbol is used by a dynamic relocation, we need to add it. if (this->needs_dynsym_entry()) return true; @@ -315,18 +360,28 @@ Symbol::should_add_dynsym_entry() const bool is_ordinary; unsigned int shndx = this->shndx(&is_ordinary); if (is_ordinary && shndx != elfcpp::SHN_UNDEF - && !relobj->is_section_included(shndx)) + && !relobj->is_section_included(shndx) + && !symtab->is_section_folded(relobj, shndx)) return false; } + // If the symbol was forced dynamic in a --dynamic-list file + // or an --export-dynamic-symbol option, add it. + if (!this->is_from_dynobj() + && (parameters->options().in_dynamic_list(this->name()) + || parameters->options().is_export_dynamic_symbol(this->name()))) + { + if (!this->is_forced_local()) + return true; + gold_warning(_("Cannot export local symbol '%s'"), + this->demangled_name().c_str()); + 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() @@ -366,10 +421,15 @@ Symbol::should_add_dynsym_entry() const } // If exporting all symbols or building a shared library, + // or the symbol should be globally unique (GNU_UNIQUE), // 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()) + if ((parameters->options().export_dynamic() + || parameters->options().shared() + || (parameters->options().gnu_unique() + && this->binding() == elfcpp::STB_GNU_UNIQUE)) && !this->is_from_dynobj() + && !this->is_undefined() && this->is_externally_visible()) return true; @@ -383,8 +443,12 @@ bool Symbol::final_value_is_known() const { // If we are not generating an executable, then no final values are - // known, since they will change at runtime. - if (parameters->options().shared() || parameters->options().relocatable()) + // known, since they will change at runtime, with the exception of + // TLS symbols in a position-independent executable. + if ((parameters->options().output_is_position_independent() + || parameters->options().relocatable()) + && !(this->type() == elfcpp::STT_TLS + && parameters->options().pie())) return false; // If the symbol is not from an object file, and is not undefined, @@ -472,13 +536,39 @@ Symbol::set_output_section(Output_section* os) } } +// Set the symbol's output segment. This is used for pre-defined +// symbols whose segments aren't known until after layout is done +// (e.g., __ehdr_start). + +void +Symbol::set_output_segment(Output_segment* os, Segment_offset_base base) +{ + gold_assert(this->is_predefined_); + this->source_ = IN_OUTPUT_SEGMENT; + this->u_.in_output_segment.output_segment = os; + this->u_.in_output_segment.offset_base = base; +} + +// Set the symbol to undefined. This is used for pre-defined +// symbols whose segments aren't known until after layout is done +// (e.g., __ehdr_start). + +void +Symbol::set_undefined() +{ + this->source_ = IS_UNDEFINED; + this->is_predefined_ = false; +} + // Class Symbol_table. Symbol_table::Symbol_table(unsigned int count, const Version_script_info& version_script) : saw_undefined_(0), offset_(0), table_(count), namepool_(), - forwarders_(), commons_(), tls_commons_(), forced_locals_(), warnings_(), - version_script_(version_script), gc_(NULL) + forwarders_(), commons_(), tls_commons_(), small_commons_(), + large_commons_(), forced_locals_(), warnings_(), + version_script_(version_script), gc_(NULL), icf_(NULL), + target_symbols_() { namepool_.reserve(count); } @@ -487,14 +577,6 @@ 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. @@ -505,11 +587,18 @@ Symbol_table::Symbol_table_eq::operator()(const Symbol_table_key& k1, return k1.first == k2.first && k1.second == k2.second; } -// For symbols that have been listed with -u option, add them to the -// work list to avoid gc'ing them. +bool +Symbol_table::is_section_folded(Relobj* obj, unsigned int shndx) const +{ + return (parameters->options().icf_enabled() + && this->icf_->is_section_folded(obj, shndx)); +} + +// For symbols that have been listed with a -u or --export-dynamic-symbol +// option, add them to the work list to avoid gc'ing them. void -Symbol_table::gc_mark_undef_symbols() +Symbol_table::gc_mark_undef_symbols(Layout* layout) { for (options::String_set::const_iterator p = parameters->options().undefined_begin(); @@ -518,38 +607,59 @@ Symbol_table::gc_mark_undef_symbols() { const char* name = p->c_str(); Symbol* sym = this->lookup(name); - gold_assert (sym != NULL); + 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)); - } + this->gc_mark_symbol(sym); + } + } + + for (options::String_set::const_iterator p = + parameters->options().export_dynamic_symbol_begin(); + p != parameters->options().export_dynamic_symbol_end(); + ++p) + { + const char* name = p->c_str(); + Symbol* sym = this->lookup(name); + // It's not an error if a symbol named by --export-dynamic-symbol + // is undefined. + if (sym != NULL + && sym->source() == Symbol::FROM_OBJECT + && !sym->object()->is_dynamic()) + { + this->gc_mark_symbol(sym); } } + + for (Script_options::referenced_const_iterator p = + layout->script_options()->referenced_begin(); + p != layout->script_options()->referenced_end(); + ++p) + { + Symbol* sym = this->lookup(p->c_str()); + gold_assert(sym != NULL); + if (sym->source() == Symbol::FROM_OBJECT + && !sym->object()->is_dynamic()) + { + this->gc_mark_symbol(sym); + } + } } void -Symbol_table::gc_mark_symbol_for_shlib(Symbol* sym) +Symbol_table::gc_mark_symbol(Symbol* sym) { - if (!sym->is_from_dynobj() - && sym->is_externally_visible()) + // Add the object and section to the work list. + bool is_ordinary; + unsigned int shndx = sym->shndx(&is_ordinary); + if (is_ordinary && shndx != elfcpp::SHN_UNDEF && !sym->object()->is_dynamic()) { - //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)); - } + gold_assert(this->gc_!= NULL); + Relobj* relobj = static_cast(sym->object()); + this->gc_->worklist().push_back(Section_id(relobj, shndx)); } + parameters->target().gc_mark_symbol(this, sym); } // When doing garbage collection, keep symbols that have been seen in @@ -559,16 +669,7 @@ 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)); - } - } + this->gc_mark_symbol(sym); } // Make TO a symbol which forwards to FROM. @@ -639,7 +740,7 @@ Symbol_table::resolve(Sized_symbol* to, const Sized_symbol* from) bool is_ordinary; unsigned int shndx = from->shndx(&is_ordinary); this->resolve(to, esym.sym(), shndx, is_ordinary, shndx, from->object(), - from->version()); + from->version(), true); if (from->in_reg()) to->set_in_reg(); if (from->in_dyn()) @@ -648,7 +749,8 @@ Symbol_table::resolve(Sized_symbol* to, const Sized_symbol* from) this->gc_mark_dyn_syms(to); } -// Record that a symbol is forced to be local by a version script. +// Record that a symbol is forced to be local by a version script or +// by visibility. void Symbol_table::force_local(Symbol* sym) @@ -669,13 +771,12 @@ Symbol_table::force_local(Symbol* sym) // option was used. const char* -Symbol_table::wrap_symbol(Object* object, const char* name, - Stringpool::Key* name_key) +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] == object->target()->wrap_char()) + if (name[0] == parameters->target().wrap_char()) { prefix = name[0]; ++name; @@ -712,19 +813,103 @@ Symbol_table::wrap_symbol(Object* object, const char* name, 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. + + // If the two symbols are from different shared objects, + // 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 if (pdef->second->is_from_dynobj() + && sym->is_from_dynobj() + && pdef->second->is_defined() + && pdef->second->object() != sym->object()) + ; + 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. +// If IS_DEFAULT_VERSION 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 @@ -745,11 +930,11 @@ Symbol_table::wrap_symbol(Object* object, const char* name, template Sized_symbol* Symbol_table::add_from_object(Object* object, - const char *name, + const char* name, Stringpool::Key name_key, - const char *version, + const char* version, Stringpool::Key version_key, - bool def, + bool is_default_version, const elfcpp::Sym& sym, unsigned int st_shndx, bool is_ordinary, @@ -769,7 +954,7 @@ Symbol_table::add_from_object(Object* object, if (orig_st_shndx == elfcpp::SHN_UNDEF && parameters->options().any_wrap()) { - const char* wrap_name = this->wrap_symbol(object, name, &name_key); + 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, @@ -788,14 +973,14 @@ Symbol_table::add_from_object(Object* object, this->table_.insert(std::make_pair(std::make_pair(name_key, version_key), snull)); - std::pair insdef = + std::pair insdefault = std::make_pair(this->table_.end(), false); - if (def) + if (is_default_version) { const Stringpool::Key vnull_key = 0; - insdef = this->table_.insert(std::make_pair(std::make_pair(name_key, - vnull_key), - snull)); + insdefault = 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. @@ -813,76 +998,43 @@ Symbol_table::add_from_object(Object* object, gold_assert(ret != NULL); was_undefined = ret->is_undefined(); - was_common = ret->is_common(); + // Commons from plugins are just placeholders. + was_common = ret->is_common() && ret->object()->pluginobj() == NULL; this->resolve(ret, sym, st_shndx, is_ordinary, orig_st_shndx, object, - version); + version, is_default_version); if (parameters->options().gc_sections()) this->gc_mark_dyn_syms(ret); - if (def) + if (is_default_version) + this->define_default_version(ret, insdefault.second, + insdefault.first); + else { - 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) + bool dummy; + if (version != NULL + && ret->source() == Symbol::FROM_OBJECT + && ret->object() == object + && is_ordinary + && ret->shndx(&dummy) == st_shndx + && ret->is_default()) { - // 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 (insdef.first->second->version() != NULL) - { - gold_assert(insdef.first->second->version() != version); - def = false; - } - else if (ret->visibility() != elfcpp::STV_DEFAULT - && insdef.first->second->is_from_dynobj()) - def = false; - else if (insdef.first->second->visibility() != elfcpp::STV_DEFAULT - && ret->is_from_dynobj()) - def = false; - else - { - const Sized_symbol* sym2; - sym2 = this->get_sized_symbol(insdef.first->second); - Symbol_table::resolve(ret, sym2); - this->make_forwarder(insdef.first->second, ret); - insdef.first->second = ret; - } + // We have seen NAME/VERSION already, and marked it as the + // default version, but now we see a definition for + // NAME/VERSION that is not the default version. This can + // happen when the assembler generates two symbols for + // a symbol as a result of a ".symver foo,foo@VER" + // directive. We see the first unversioned symbol and + // we may mark it as the default version (from a + // version script); then we see the second versioned + // symbol and we need to override the first. + // In any other case, the two symbols should have generated + // a multiple definition error. + // (See PR gold/18703.) + ret->set_is_not_default(); + const Stringpool::Key vnull_key = 0; + this->table_.erase(std::make_pair(name_key, vnull_key)); } - else - def = false; } } else @@ -890,17 +1042,18 @@ Symbol_table::add_from_object(Object* object, // This is the first time we have seen NAME/VERSION. gold_assert(ins.first->second == NULL); - if (def && !insdef.second) + if (is_default_version && !insdefault.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); + ret = this->get_sized_symbol(insdefault.first->second); was_undefined = ret->is_undefined(); - was_common = ret->is_common(); + // Commons from plugins are just placeholders. + was_common = ret->is_common() && ret->object()->pluginobj() == NULL; this->resolve(ret, sym, st_shndx, is_ordinary, orig_st_shndx, object, - version); + version, is_default_version); if (parameters->options().gc_sections()) this->gc_mark_dyn_syms(ret); ins.first->second = ret; @@ -911,22 +1064,23 @@ Symbol_table::add_from_object(Object* object, was_common = false; Sized_target* target = - object->sized_target(); + parameters->sized_target(); if (!target->has_make_symbol()) ret = new Sized_symbol(); else { - ret = target->make_symbol(); + ret = target->make_symbol(name, sym.get_st_type(), object, + st_shndx, sym.get_st_value()); if (ret == NULL) { // This means that we don't want a symbol table // entry after all. - if (!def) + if (!is_default_version) this->table_.erase(ins.first); else { - this->table_.erase(insdef.first); - // Inserting insdef invalidated ins. + this->table_.erase(insdefault.first); + // Inserting INSDEFAULT invalidated INS. this->table_.erase(std::make_pair(name_key, version_key)); } @@ -937,33 +1091,56 @@ Symbol_table::add_from_object(Object* object, ret->init_object(name, version, object, sym, st_shndx, is_ordinary); ins.first->second = ret; - if (def) + if (is_default_version) { // 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; + gold_assert(insdefault.second); + insdefault.first->second = ret; } } + + if (is_default_version) + 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_; + { + ++this->saw_undefined_; + if (parameters->options().has_plugins()) + parameters->options().plugins()->new_undefined_symbol(ret); + } // Keep track of common symbols, to speed up common symbol - // allocation. - if (!was_common && ret->is_common()) + // allocation. Don't record commons from plugin objects; + // we need to wait until we see the real symbol in the + // replacement file. + if (!was_common && ret->is_common() && ret->object()->pluginobj() == NULL) { - if (ret->type() != elfcpp::STT_TLS) - this->commons_.push_back(ret); - else + 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 (def) - ret->set_is_default(); + // 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_GNU_UNIQUE + || ret->binding() == elfcpp::STB_WEAK) + && !parameters->options().relocatable()) + this->force_local(ret); + return ret; } @@ -972,18 +1149,17 @@ Symbol_table::add_from_object(Object* object, template void Symbol_table::add_from_relobj( - Sized_relobj* relobj, + Sized_relobj_file* 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) + typename Sized_relobj_file::Symbols* sympointers, + size_t* defined) { *defined = 0; - gold_assert(size == relobj->target()->get_size()); gold_assert(size == parameters->target().get_size()); const int sym_size = elfcpp::Elf_sizes::sym_size; @@ -1007,6 +1183,11 @@ Symbol_table::add_from_relobj( const char* name = sym_names + st_name; + if (!parameters->options().relocatable() + && strcmp (name, "__gnu_lto_slim") == 0) + gold_info(_("%s: plugin needed to handle lto object"), + relobj->name().c_str()); + bool is_ordinary; unsigned int st_shndx = relobj->adjust_sym_shndx(i + symndx_offset, sym.get_st_shndx(), @@ -1020,10 +1201,15 @@ Symbol_table::add_from_relobj( // A symbol defined in a section which we are not including must // be treated as an undefined symbol. + bool is_defined_in_discarded_section = false; if (st_shndx != elfcpp::SHN_UNDEF && is_ordinary - && !relobj->is_section_included(st_shndx)) - st_shndx = elfcpp::SHN_UNDEF; + && !relobj->is_section_included(st_shndx) + && !this->is_section_folded(relobj, st_shndx)) + { + st_shndx = elfcpp::SHN_UNDEF; + is_defined_in_discarded_section = true; + } // In an object file, an '@' in the name separates the symbol // name from the version name. If there are two '@' characters, @@ -1031,9 +1217,18 @@ Symbol_table::add_from_relobj( 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; + // IS_DEFAULT_VERSION: is the version default? + // IS_FORCED_LOCAL: is the symbol forced local? + bool is_default_version = false; + bool is_forced_local = false; + + // FIXME: For incremental links, we don't store version information, + // so we need to ignore version symbols for now. + if (parameters->incremental_update() && ver != NULL) + { + namelen = ver - name; + ver = NULL; + } if (ver != NULL) { @@ -1042,7 +1237,7 @@ Symbol_table::add_from_relobj( ++ver; if (*ver == '@') { - def = true; + is_default_version = true; ++ver; } ver = this->namepool_.add(ver, true, &ver_key); @@ -1059,21 +1254,21 @@ Symbol_table::add_from_relobj( // 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)) + bool is_global; + if (this->version_script_.get_symbol_version(name, &version, + &is_global)) { - // The version can be empty if the version script is - // only used to force some symbols to be local. - if (!version.empty()) + if (!is_global) + is_forced_local = true; + else if (!version.empty()) { ver = this->namepool_.add_with_length(version.c_str(), version.length(), true, &ver_key); - def = true; + is_default_version = true; } } - else if (this->version_script_.symbol_is_local(name)) - local = true; } } @@ -1084,12 +1279,14 @@ Symbol_table::add_from_relobj( { memcpy(symbuf, p, sym_size); elfcpp::Sym_write sw(symbuf); - if (orig_st_shndx != elfcpp::SHN_UNDEF && is_ordinary) + if (orig_st_shndx != elfcpp::SHN_UNDEF + && is_ordinary + && relobj->e_type() == elfcpp::ET_REL) { - // 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 + // Symbol values in relocatable 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() @@ -1100,24 +1297,57 @@ Symbol_table::add_from_relobj( psym = &sym2; } + // Fix up visibility if object has no-export set. + if (relobj->no_export() + && (orig_st_shndx != elfcpp::SHN_UNDEF || !is_ordinary)) + { + // 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); + is_default_version, *psym, st_shndx, + is_ordinary, orig_st_shndx); - if (local) + if (res == NULL) + continue; + + if (is_forced_local) this->force_local(res); + // Do not treat this symbol as garbage if this symbol will be + // exported to the dynamic symbol table. This is true when + // building a shared library or using --export-dynamic and + // the symbol is externally visible. + if (parameters->options().gc_sections() + && res->is_externally_visible() + && !res->is_from_dynobj() + && (parameters->options().shared() + || parameters->options().export_dynamic() + || parameters->options().in_dynamic_list(res->name()))) + this->gc_mark_symbol(res); + + if (is_defined_in_discarded_section) + res->set_is_defined_in_discarded_section(); + (*sympointers)[i] = res; } } @@ -1133,10 +1363,11 @@ Symbol_table::add_from_pluginobj( elfcpp::Sym* sym) { unsigned int st_shndx = sym->get_st_shndx(); + bool is_ordinary = st_shndx < elfcpp::SHN_LORESERVE; Stringpool::Key ver_key = 0; - bool def = false; - bool local = false; + bool is_default_version = false; + bool is_forced_local = false; if (ver != NULL) { @@ -1153,21 +1384,21 @@ Symbol_table::add_from_pluginobj( // 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)) + bool is_global; + if (this->version_script_.get_symbol_version(name, &version, + &is_global)) { - // The version can be empty if the version script is - // only used to force some symbols to be local. - if (!version.empty()) + if (!is_global) + is_forced_local = true; + else if (!version.empty()) { ver = this->namepool_.add_with_length(version.c_str(), version.length(), true, &ver_key); - def = true; + is_default_version = true; } } - else if (this->version_script_.symbol_is_local(name)) - local = true; } } @@ -1176,10 +1407,14 @@ Symbol_table::add_from_pluginobj( Sized_symbol* res; res = this->add_from_object(obj, name, name_key, ver, ver_key, - def, *sym, st_shndx, true, st_shndx); + is_default_version, *sym, st_shndx, + is_ordinary, st_shndx); - if (local) - this->force_local(res); + if (res == NULL) + return NULL; + + if (is_forced_local) + this->force_local(res); return res; } @@ -1197,12 +1432,11 @@ Symbol_table::add_from_dynobj( const unsigned char* versym, size_t versym_size, const std::vector* version_map, - typename Sized_relobj::Symbols* sympointers, + typename Sized_relobj_file::Symbols* sympointers, size_t* defined) { *defined = 0; - gold_assert(size == dynobj->target()->get_size()); gold_assert(size == parameters->target().get_size()); if (dynobj->just_symbols()) @@ -1211,6 +1445,11 @@ Symbol_table::add_from_dynobj( return; } + // FIXME: For incremental links, we don't store version information, + // so we need to ignore version symbols for now. + if (parameters->incremental_update()) + versym = NULL; + if (versym != NULL && versym_size / 2 < count) { dynobj->error(_("too few symbol versions")); @@ -1248,14 +1487,20 @@ Symbol_table::add_from_dynobj( // 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. + // Likewise, an IFUNC symbol in a shared library must be treated + // as a normal FUNC symbol. elfcpp::Sym* psym = &sym; unsigned char symbuf[sym_size]; elfcpp::Sym sym2(symbuf); - if (sym.get_st_visibility() == elfcpp::STV_PROTECTED) + if (sym.get_st_visibility() == elfcpp::STV_PROTECTED + || sym.get_st_type() == elfcpp::STT_GNU_IFUNC) { memcpy(symbuf, p, sym_size); elfcpp::Sym_write sw(symbuf); - sw.put_st_other(elfcpp::STV_DEFAULT, sym.get_st_nonvis()); + if (sym.get_st_visibility() == elfcpp::STV_PROTECTED) + sw.put_st_other(elfcpp::STV_DEFAULT, sym.get_st_nonvis()); + if (sym.get_st_type() == elfcpp::STT_GNU_IFUNC) + sw.put_st_info(sym.get_st_bind(), elfcpp::STT_FUNC); psym = &sym2; } @@ -1354,15 +1599,19 @@ Symbol_table::add_from_dynobj( st_shndx); else { - const bool def = (!hidden - && st_shndx != elfcpp::SHN_UNDEF); + const bool is_default_version = + !hidden && st_shndx != elfcpp::SHN_UNDEF; res = this->add_from_object(dynobj, name, name_key, version, - version_key, def, *psym, st_shndx, + version_key, is_default_version, + *psym, st_shndx, is_ordinary, st_shndx); } } } + if (res == NULL) + continue; + // 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 @@ -1372,6 +1621,13 @@ Symbol_table::add_from_dynobj( && res->object() == dynobj) object_symbols.push_back(res); + // If the symbol has protected visibility in the dynobj, + // mark it as such if it was not overridden. + if (res->source() == Symbol::FROM_OBJECT + && res->object() == dynobj + && sym.get_st_visibility() == elfcpp::STV_PROTECTED) + res->set_is_protected(); + if (sympointers != NULL) (*sympointers)[i] = res; } @@ -1379,6 +1635,33 @@ Symbol_table::add_from_dynobj( this->record_weak_aliases(&object_symbols); } +// Add a symbol from a incremental object file. + +template +Sized_symbol* +Symbol_table::add_from_incrobj( + Object* obj, + const char* name, + const char* ver, + elfcpp::Sym* sym) +{ + unsigned int st_shndx = sym->get_st_shndx(); + bool is_ordinary = st_shndx < elfcpp::SHN_LORESERVE; + + Stringpool::Key ver_key = 0; + bool is_default_version = false; + + 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, + is_default_version, *sym, st_shndx, + is_ordinary, st_shndx); + + return res; +} + // This is used to sort weak aliases. We sort them first by section // index, then by offset, then by weak ahead of strong. @@ -1467,39 +1750,60 @@ Symbol_table::record_weak_aliases(std::vector*>* symbols) // Create and return a specially defined symbol. If ONLY_IF_REF is // true, then only create the symbol if there is a reference to it. // If this does not return NULL, it sets *POLDSYM to the existing -// symbol if there is one. This canonicalizes *PNAME and *PVERSION. +// 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) + Sized_symbol** poldsym, + bool* resolve_oldsym) { - Symbol* oldsym; - Sized_symbol* sym; - bool add_to_table = false; - typename Symbol_table_type::iterator add_loc = this->table_.end(); + *resolve_oldsym = false; + *poldsym = NULL; // 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)) + bool is_global; + if (this->version_script_.get_symbol_version(*pname, &v, &is_global)) { - if (!v.empty()) - *pversion = v.c_str(); + if (is_global && !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(); - *pversion = oldsym->version(); + if (is_default_version) + *pversion = this->namepool_.add(*pversion, true, NULL); + else + *pversion = oldsym->version(); } else { @@ -1517,19 +1821,57 @@ Symbol_table::define_special_symbol(const char** pname, const char** pversion, version_key), snull)); + std::pair insdefault = + std::make_pair(this->table_.end(), false); + if (is_default_version) + { + const Stringpool::Key vnull = 0; + insdefault = + 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, + insdefault.second, + insdefault.first); + } } else { // We haven't seen this symbol before. gold_assert(ins.first->second == NULL); - add_to_table = true; - add_loc = ins.first; - oldsym = NULL; + + add_to_table = true; + add_loc = ins.first; + + if (is_default_version && !insdefault.second) + { + // We are adding NAME/VERSION, and it is the default + // version. We already have an entry for NAME/NULL. + oldsym = insdefault.first->second; + *resolve_oldsym = true; + } + else + { + oldsym = NULL; + + if (is_default_version) + { + add_def_to_table = true; + add_def_loc = insdefault.first; + } + } } } @@ -1538,12 +1880,10 @@ Symbol_table::define_special_symbol(const char** pname, const char** pversion, sym = new Sized_symbol(); else { - gold_assert(target.get_size() == size); - gold_assert(target.is_big_endian() ? big_endian : !big_endian); - typedef Sized_target My_target; - const My_target* sized_target = - static_cast(&target); - sym = sized_target->make_symbol(); + Sized_target* sized_target = + parameters->sized_target(); + sym = sized_target->make_symbol(*pname, elfcpp::STT_NOTYPE, + NULL, elfcpp::SHN_UNDEF, 0); if (sym == NULL) return NULL; } @@ -1553,6 +1893,9 @@ Symbol_table::define_special_symbol(const char** pname, const char** pversion, else gold_assert(oldsym != NULL); + if (add_def_to_table) + add_def_loc->second = sym; + *poldsym = this->get_sized_symbol(oldsym); return sym; @@ -1563,6 +1906,7 @@ Symbol_table::define_special_symbol(const char** pname, const char** pversion, Symbol* Symbol_table::define_in_output_data(const char* name, const char* version, + Defined defined, Output_data* od, uint64_t value, uint64_t symsize, @@ -1576,7 +1920,7 @@ Symbol_table::define_in_output_data(const char* name, 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, + return this->do_define_in_output_data<32>(name, version, defined, od, value, symsize, type, binding, visibility, nonvis, offset_is_from_end, @@ -1588,7 +1932,7 @@ Symbol_table::define_in_output_data(const char* name, 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, + return this->do_define_in_output_data<64>(name, version, defined, od, value, symsize, type, binding, visibility, nonvis, offset_is_from_end, @@ -1608,6 +1952,7 @@ Sized_symbol* Symbol_table::do_define_in_output_data( const char* name, const char* version, + Defined defined, Output_data* od, typename elfcpp::Elf_types::Elf_Addr value, typename elfcpp::Elf_types::Elf_WXword symsize, @@ -1620,12 +1965,14 @@ Symbol_table::do_define_in_output_data( { 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); + only_if_ref, &oldsym, + &resolve_oldsym); #else gold_unreachable(); #endif @@ -1634,7 +1981,8 @@ Symbol_table::do_define_in_output_data( { #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE) sym = this->define_special_symbol(&name, &version, - only_if_ref, &oldsym); + only_if_ref, &oldsym, + &resolve_oldsym); #else gold_unreachable(); #endif @@ -1644,7 +1992,8 @@ Symbol_table::do_define_in_output_data( return NULL; sym->init_output_data(name, version, od, value, symsize, type, binding, - visibility, nonvis, offset_is_from_end); + visibility, nonvis, offset_is_from_end, + defined == PREDEFINED); if (oldsym == NULL) { @@ -1656,17 +2005,29 @@ Symbol_table::do_define_in_output_data( return sym; } - if (Symbol_table::should_override_with_special(oldsym)) + if (Symbol_table::should_override_with_special(oldsym, type, defined)) this->override_with_special(oldsym, sym); - delete sym; - return oldsym; + + if (resolve_oldsym) + return sym; + else + { + if (defined == PREDEFINED + && (binding == elfcpp::STB_LOCAL + || this->version_script_.symbol_is_local(name))) + this->force_local(oldsym); + 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, + const char* version, + Defined defined, + Output_segment* os, uint64_t value, uint64_t symsize, elfcpp::STT type, @@ -1679,7 +2040,7 @@ Symbol_table::define_in_output_segment(const char* name, 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, + return this->do_define_in_output_segment<32>(name, version, defined, os, value, symsize, type, binding, visibility, nonvis, offset_base, only_if_ref); @@ -1690,7 +2051,7 @@ Symbol_table::define_in_output_segment(const char* name, 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, + return this->do_define_in_output_segment<64>(name, version, defined, os, value, symsize, type, binding, visibility, nonvis, offset_base, only_if_ref); @@ -1709,6 +2070,7 @@ Sized_symbol* Symbol_table::do_define_in_output_segment( const char* name, const char* version, + Defined defined, Output_segment* os, typename elfcpp::Elf_types::Elf_Addr value, typename elfcpp::Elf_types::Elf_WXword symsize, @@ -1721,12 +2083,14 @@ Symbol_table::do_define_in_output_segment( { 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); + only_if_ref, &oldsym, + &resolve_oldsym); #else gold_unreachable(); #endif @@ -1735,7 +2099,8 @@ Symbol_table::do_define_in_output_segment( { #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE) sym = this->define_special_symbol(&name, &version, - only_if_ref, &oldsym); + only_if_ref, &oldsym, + &resolve_oldsym); #else gold_unreachable(); #endif @@ -1745,7 +2110,8 @@ Symbol_table::do_define_in_output_segment( return NULL; sym->init_output_segment(name, version, os, value, symsize, type, binding, - visibility, nonvis, offset_base); + visibility, nonvis, offset_base, + defined == PREDEFINED); if (oldsym == NULL) { @@ -1757,10 +2123,19 @@ Symbol_table::do_define_in_output_segment( return sym; } - if (Symbol_table::should_override_with_special(oldsym)) + if (Symbol_table::should_override_with_special(oldsym, type, defined)) this->override_with_special(oldsym, sym); - delete sym; - return oldsym; + + if (resolve_oldsym) + return sym; + else + { + if (binding == elfcpp::STB_LOCAL + || this->version_script_.symbol_is_local(name)) + this->force_local(oldsym); + delete sym; + return oldsym; + } } // Define a special symbol with a constant value. It is a multiple @@ -1769,6 +2144,7 @@ Symbol_table::do_define_in_output_segment( Symbol* Symbol_table::define_as_constant(const char* name, const char* version, + Defined defined, uint64_t value, uint64_t symsize, elfcpp::STT type, @@ -1781,7 +2157,7 @@ Symbol_table::define_as_constant(const char* name, 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, + return this->do_define_as_constant<32>(name, version, defined, value, symsize, type, binding, visibility, nonvis, only_if_ref, force_override); @@ -1792,7 +2168,7 @@ Symbol_table::define_as_constant(const char* name, 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, + return this->do_define_as_constant<64>(name, version, defined, value, symsize, type, binding, visibility, nonvis, only_if_ref, force_override); @@ -1811,6 +2187,7 @@ Sized_symbol* Symbol_table::do_define_as_constant( const char* name, const char* version, + Defined defined, typename elfcpp::Elf_types::Elf_Addr value, typename elfcpp::Elf_types::Elf_WXword symsize, elfcpp::STT type, @@ -1822,12 +2199,14 @@ Symbol_table::do_define_as_constant( { 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); + only_if_ref, &oldsym, + &resolve_oldsym); #else gold_unreachable(); #endif @@ -1836,7 +2215,8 @@ Symbol_table::do_define_as_constant( { #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE) sym = this->define_special_symbol(&name, &version, - only_if_ref, &oldsym); + only_if_ref, &oldsym, + &resolve_oldsym); #else gold_unreachable(); #endif @@ -1846,7 +2226,7 @@ Symbol_table::do_define_as_constant( return NULL; sym->init_constant(name, version, value, symsize, type, binding, visibility, - nonvis); + nonvis, defined == PREDEFINED); if (oldsym == NULL) { @@ -1864,10 +2244,20 @@ Symbol_table::do_define_as_constant( return sym; } - if (force_override || Symbol_table::should_override_with_special(oldsym)) + if (force_override + || Symbol_table::should_override_with_special(oldsym, type, defined)) this->override_with_special(oldsym, sym); - delete sym; - return oldsym; + + if (resolve_oldsym) + return sym; + else + { + if (binding == elfcpp::STB_LOCAL + || this->version_script_.symbol_is_local(name)) + this->force_local(oldsym); + delete sym; + return oldsym; + } } // Define a set of symbols in output sections. @@ -1881,14 +2271,14 @@ Symbol_table::define_symbols(const Layout* layout, int count, { Output_section* os = layout->find_output_section(p->output_section); if (os != NULL) - this->define_in_output_data(p->name, NULL, os, p->value, + this->define_in_output_data(p->name, NULL, PREDEFINED, 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, + this->define_as_constant(p->name, NULL, PREDEFINED, 0, p->size, + p->type, p->binding, p->visibility, p->nonvis, only_if_ref || p->only_if_ref, false); } @@ -1907,14 +2297,14 @@ Symbol_table::define_symbols(const Layout* layout, int count, p->segment_flags_set, p->segment_flags_clear); if (os != NULL) - this->define_in_output_segment(p->name, NULL, os, p->value, + this->define_in_output_segment(p->name, NULL, PREDEFINED, 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, + this->define_as_constant(p->name, NULL, PREDEFINED, 0, p->size, + p->type, p->binding, p->visibility, p->nonvis, only_if_ref || p->only_if_ref, false); } @@ -1943,7 +2333,7 @@ Symbol_table::define_with_copy_reloc( if (binding == elfcpp::STB_WEAK) binding = elfcpp::STB_GLOBAL; - this->define_in_output_data(csym->name(), csym->version(), + this->define_in_output_data(csym->name(), csym->version(), COPY, posd, value, csym->symsize(), csym->type(), binding, csym->visibility(), csym->nonvis(), @@ -1988,14 +2378,15 @@ Symbol_table::get_copy_source(const Symbol* sym) const // Add any undefined symbols named on the command line. void -Symbol_table::add_undefined_symbols_from_command_line() +Symbol_table::add_undefined_symbols_from_command_line(Layout* layout) { - if (parameters->options().any_undefined()) + if (parameters->options().any_undefined() + || layout->script_options()->any_unreferenced()) { 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>(); + this->do_add_undefined_symbols_from_command_line<32>(layout); #else gold_unreachable(); #endif @@ -2003,7 +2394,7 @@ Symbol_table::add_undefined_symbols_from_command_line() 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>(); + this->do_add_undefined_symbols_from_command_line<64>(layout); #else gold_unreachable(); #endif @@ -2015,47 +2406,65 @@ Symbol_table::add_undefined_symbols_from_command_line() template void -Symbol_table::do_add_undefined_symbols_from_command_line() +Symbol_table::do_add_undefined_symbols_from_command_line(Layout* layout) { for (options::String_set::const_iterator p = parameters->options().undefined_begin(); p != parameters->options().undefined_end(); ++p) - { - const char* name = p->c_str(); + this->add_undefined_symbol_from_command_line(p->c_str()); - if (this->lookup(name) != NULL) - continue; + for (options::String_set::const_iterator p = + parameters->options().export_dynamic_symbol_begin(); + p != parameters->options().export_dynamic_symbol_end(); + ++p) + this->add_undefined_symbol_from_command_line(p->c_str()); - const char* version = NULL; + for (Script_options::referenced_const_iterator p = + layout->script_options()->referenced_begin(); + p != layout->script_options()->referenced_end(); + ++p) + this->add_undefined_symbol_from_command_line(p->c_str()); +} - Sized_symbol* sym; - Sized_symbol* oldsym; - if (parameters->target().is_big_endian()) - { +template +void +Symbol_table::add_undefined_symbol_from_command_line(const char* name) +{ + if (this->lookup(name) != NULL) + return; + + 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); + sym = this->define_special_symbol(&name, &version, + false, &oldsym, + &resolve_oldsym); #else - gold_unreachable(); + gold_unreachable(); #endif - } - else - { + } + else + { #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE) - sym = this->define_special_symbol(&name, &version, - false, &oldsym); + sym = this->define_special_symbol(&name, &version, + false, &oldsym, + &resolve_oldsym); #else - gold_unreachable(); + gold_unreachable(); #endif - } + } - gold_assert(oldsym == NULL); + gold_assert(oldsym == NULL); - sym->init_undefined(name, version, elfcpp::STT_NOTYPE, elfcpp::STB_GLOBAL, - elfcpp::STV_DEFAULT, 0); - ++this->saw_undefined_; - } + sym->init_undefined(name, version, 0, 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 @@ -2069,6 +2478,27 @@ Symbol_table::set_dynsym_indexes(unsigned int index, Stringpool* dynpool, Versions* versions) { + std::vector as_needed_sym; + + // Allow a target to set dynsym indexes. + if (parameters->target().has_custom_set_dynsym_indexes()) + { + std::vector dyn_symbols; + for (Symbol_table_type::iterator p = this->table_.begin(); + p != this->table_.end(); + ++p) + { + Symbol* sym = p->second; + if (!sym->should_add_dynsym_entry(this)) + sym->set_dynsym_index(-1U); + else + dyn_symbols.push_back(sym); + } + + return parameters->target().set_dynsym_indexes(&dyn_symbols, index, syms, + dynpool, versions, this); + } + for (Symbol_table_type::iterator p = this->table_.begin(); p != this->table_.end(); ++p) @@ -2079,7 +2509,7 @@ Symbol_table::set_dynsym_indexes(unsigned int index, // some symbols appear more than once in the symbol table, with // and without a version. - if (!sym->should_add_dynsym_entry()) + if (!sym->should_add_dynsym_entry(this)) sym->set_dynsym_index(-1U); else if (!sym->has_dynsym_index()) { @@ -2088,16 +2518,58 @@ Symbol_table::set_dynsym_indexes(unsigned int 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); + // If the symbol is defined in a dynamic object and is + // referenced strongly in a regular object, then mark the + // dynamic object as needed. This is used to implement + // --as-needed. + if (sym->is_from_dynobj() + && sym->in_reg() + && !sym->is_undef_binding_weak()) + sym->object()->set_is_needed(); + + // Record any version information, except those from + // as-needed libraries not seen to be needed. Note that the + // is_needed state for such libraries can change in this loop. + if (sym->version() != NULL) + { + if (!sym->is_from_dynobj() + || !sym->object()->as_needed() + || sym->object()->is_needed()) + versions->record_version(this, dynpool, sym); + else + as_needed_sym.push_back(sym); + } } } + // Process version information for symbols from as-needed libraries. + for (std::vector::iterator p = as_needed_sym.begin(); + p != as_needed_sym.end(); + ++p) + { + Symbol* sym = *p; + + if (sym->object()->is_needed()) + versions->record_version(this, dynpool, sym); + else + sym->clear_version(); + } + // Finish up the versions. In some cases this may add new dynamic // symbols. index = versions->finalize(this, index, syms); + // Process target-specific symbols. + for (std::vector::iterator p = this->target_symbols_.begin(); + p != this->target_symbols_.end(); + ++p) + { + (*p)->set_dynsym_index(index); + ++index; + syms->push_back(*p); + dynpool->add((*p)->name(), false, NULL); + } + return index; } @@ -2109,7 +2581,7 @@ Symbol_table::set_dynsym_indexes(unsigned int index, 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) + unsigned int* plocal_symcount) { off_t ret; @@ -2155,7 +2627,10 @@ 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); + if (sym->version() == NULL || !parameters->options().relocatable()) + pool->add(sym->name(), false, NULL); + else + pool->add(sym->versioned_name(), true, NULL); ++*pindex; *poff += elfcpp::Elf_sizes::sym_size; } @@ -2200,35 +2675,30 @@ Symbol_table::sized_finalize(off_t off, Stringpool* pool, this->add_to_final_symtab(sym, pool, &index, &off); } + // Now do target-specific symbols. + for (std::vector::iterator p = this->target_symbols_.begin(); + p != this->target_symbols_.end(); + ++p) + { + this->add_to_final_symtab(*p, pool, &index, &off); + } + this->output_count_ = index - orig_index; return off; } -// Finalize the symbol SYM. This returns true if the symbol should be -// added to the symbol table, false otherwise. +// 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 -bool -Symbol_table::sized_finalize_symbol(Symbol* unsized_sym) +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; - - 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; - } - Value_type value; switch (sym->source()) @@ -2238,14 +2708,12 @@ Symbol_table::sized_finalize_symbol(Symbol* unsized_sym) bool is_ordinary; unsigned int shndx = sym->shndx(&is_ordinary); - // FIXME: We need some target specific support here. if (!is_ordinary && shndx != elfcpp::SHN_ABS - && shndx != elfcpp::SHN_COMMON) + && !Symbol::is_common_shndx(shndx)) { - gold_error(_("%s: unsupported symbol section 0x%x"), - sym->demangled_name().c_str(), shndx); - shndx = elfcpp::SHN_UNDEF; + *pstatus = CFVS_UNSUPPORTED_SYMBOL_SECTION; + return 0; } Object* symobj = sym->object(); @@ -2262,27 +2730,47 @@ Symbol_table::sized_finalize_symbol(Symbol* unsized_sym) else if (shndx == elfcpp::SHN_UNDEF) value = 0; else if (!is_ordinary - && (shndx == elfcpp::SHN_ABS || shndx == elfcpp::SHN_COMMON)) + && (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); - if (os == NULL) + 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); + unsigned folded_shndx = folded.second; + + os = folded_obj->output_section(folded_shndx); + gold_assert(os != NULL); + + // Replace (relobj, shndx) with canonical ICF input section. + shndx = folded_shndx; + relobj = folded_obj; + } + + uint64_t secoff64 = relobj->output_section_offset(shndx); + if (os == NULL) { - sym->set_symtab_index(-1U); bool static_or_reloc = (parameters->doing_static_link() || parameters->options().relocatable()); gold_assert(static_or_reloc || sym->dynsym_index() == -1U); - return false; + *pstatus = CFVS_NO_OUTPUT_SECTION; + return 0; } - uint64_t secoff64 = relobj->output_section_offset(shndx); if (secoff64 == -1ULL) { // The section needs special handling (e.g., a merge section). + value = os->output_address(relobj, shndx, sym->value()); } else @@ -2349,9 +2837,70 @@ Symbol_table::sized_finalize_symbol(Symbol* unsized_sym) 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; + } + + // If the symbol is only present on plugin files, the plugin decided we + // don't need it. + if (!sym->in_real_elf()) + { + gold_assert(!sym->has_symtab_index()); + sym->set_symtab_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()) + if (parameters->options().strip_all() + || !parameters->options().should_retain_symbol(sym->name())) { sym->set_symtab_index(-1U); return false; @@ -2363,8 +2912,7 @@ Symbol_table::sized_finalize_symbol(Symbol* unsized_sym) // Write out the global symbols. void -Symbol_table::write_globals(const Input_objects* input_objects, - const Stringpool* sympool, +Symbol_table::write_globals(const Stringpool* sympool, const Stringpool* dynpool, Output_symtab_xindex* symtab_xindex, Output_symtab_xindex* dynsym_xindex, @@ -2374,29 +2922,25 @@ Symbol_table::write_globals(const Input_objects* input_objects, { #ifdef HAVE_TARGET_32_LITTLE case Parameters::TARGET_32_LITTLE: - this->sized_write_globals<32, false>(input_objects, sympool, - dynpool, symtab_xindex, + 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>(input_objects, sympool, - dynpool, symtab_xindex, + 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>(input_objects, sympool, - dynpool, symtab_xindex, + 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>(input_objects, sympool, - dynpool, symtab_xindex, + this->sized_write_globals<64, true>(sympool, dynpool, symtab_xindex, dynsym_xindex, of); break; #endif @@ -2409,8 +2953,7 @@ Symbol_table::write_globals(const Input_objects* input_objects, template void -Symbol_table::sized_write_globals(const Input_objects* input_objects, - const Stringpool* sympool, +Symbol_table::sized_write_globals(const Stringpool* sympool, const Stringpool* dynpool, Output_symtab_xindex* symtab_xindex, Output_symtab_xindex* dynsym_xindex, @@ -2446,7 +2989,7 @@ Symbol_table::sized_write_globals(const Input_objects* input_objects, Sized_symbol* sym = static_cast*>(p->second); // Possibly warn about unresolved symbols in shared libraries. - this->warn_about_undefined_dynobj_symbol(input_objects, sym); + this->warn_about_undefined_dynobj_symbol(sym); unsigned int sym_index = sym->symtab_index(); unsigned int dynsym_index; @@ -2464,6 +3007,20 @@ Symbol_table::sized_write_globals(const Input_objects* input_objects, unsigned int shndx; typename elfcpp::Elf_types::Elf_Addr sym_value = sym->value(); typename elfcpp::Elf_types::Elf_Addr dynsym_value = sym_value; + elfcpp::STB binding = sym->binding(); + + // If --weak-unresolved-symbols is set, change binding of unresolved + // global symbols to STB_WEAK. + if (parameters->options().weak_unresolved_symbols() + && binding == elfcpp::STB_GLOBAL + && sym->is_undefined()) + binding = elfcpp::STB_WEAK; + + // If --no-gnu-unique is set, change STB_GNU_UNIQUE to STB_GLOBAL. + if (binding == elfcpp::STB_GNU_UNIQUE + && !parameters->options().gnu_unique()) + binding = elfcpp::STB_GLOBAL; + switch (sym->source()) { case Symbol::FROM_OBJECT: @@ -2471,10 +3028,9 @@ Symbol_table::sized_write_globals(const Input_objects* input_objects, bool is_ordinary; unsigned int in_shndx = sym->shndx(&is_ordinary); - // FIXME: We need some target specific support here. if (!is_ordinary && in_shndx != elfcpp::SHN_ABS - && in_shndx != elfcpp::SHN_COMMON) + && !Symbol::is_common_shndx(in_shndx)) { gold_error(_("%s: unsupported symbol section 0x%x"), sym->demangled_name().c_str(), in_shndx); @@ -2488,18 +3044,35 @@ Symbol_table::sized_write_globals(const Input_objects* input_objects, if (sym->needs_dynsym_value()) dynsym_value = target.dynsym_value(sym); shndx = elfcpp::SHN_UNDEF; + if (sym->is_undef_binding_weak()) + binding = elfcpp::STB_WEAK; + else + binding = elfcpp::STB_GLOBAL; } else if (symobj->pluginobj() != NULL) shndx = elfcpp::SHN_UNDEF; else if (in_shndx == elfcpp::SHN_UNDEF || (!is_ordinary && (in_shndx == elfcpp::SHN_ABS - || in_shndx == elfcpp::SHN_COMMON))) + || 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(); @@ -2522,15 +3095,24 @@ Symbol_table::sized_write_globals(const Input_objects* input_objects, 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; - } + { + Output_data* od = sym->output_data(); + + shndx = od->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 -= od->address(); + } break; case Symbol::IN_OUTPUT_SEGMENT: @@ -2555,7 +3137,7 @@ Symbol_table::sized_write_globals(const Input_objects* input_objects, gold_assert(sym_index < output_count); unsigned char* ps = psyms + (sym_index * sym_size); this->sized_write_symbol(sym, sym_value, shndx, - sympool, ps); + binding, sympool, ps); } if (dynsym_index != -1U) @@ -2564,7 +3146,57 @@ Symbol_table::sized_write_globals(const Input_objects* input_objects, 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); + binding, dynpool, pd); + // Allow a target to adjust dynamic symbol value. + parameters->target().adjust_dyn_symbol(sym, pd); + } + } + + // Write the target-specific symbols. + for (std::vector::const_iterator p = this->target_symbols_.begin(); + p != this->target_symbols_.end(); + ++p) + { + Sized_symbol* sym = static_cast*>(*p); + + unsigned int sym_index = sym->symtab_index(); + unsigned int dynsym_index; + if (dynamic_view == NULL) + dynsym_index = -1U; + else + dynsym_index = sym->dynsym_index(); + + unsigned int shndx; + switch (sym->source()) + { + 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, + sym->binding(), 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, sym->value(), shndx, + sym->binding(), dynpool, + pd); } } @@ -2582,22 +3214,28 @@ Symbol_table::sized_write_symbol( Sized_symbol* sym, typename elfcpp::Elf_types::Elf_Addr value, unsigned int shndx, + elfcpp::STB binding, const Stringpool* pool, unsigned char* p) const { elfcpp::Sym_write osym(p); - osym.put_st_name(pool->get_offset(sym->name())); + if (sym->version() == NULL || !parameters->options().relocatable()) + osym.put_st_name(pool->get_offset(sym->name())); + else + osym.put_st_name(pool->get_offset(sym->versioned_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()); + elfcpp::STT type = sym->type(); + gold_assert(type != elfcpp::STT_GNU_IFUNC || !sym->is_from_dynobj()); // 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())); + osym.put_st_info(elfcpp::elf_st_info(elfcpp::STB_LOCAL, type)); else - osym.put_st_info(elfcpp::elf_st_info(sym->binding(), sym->type())); + osym.put_st_info(elfcpp::elf_st_info(binding, type)); osym.put_st_other(elfcpp::elf_st_other(sym->visibility(), sym->nonvis())); osym.put_st_shndx(shndx); } @@ -2611,16 +3249,13 @@ Symbol_table::sized_write_symbol( // entry, we aren't going to be able to reliably report whether the // symbol is undefined. -// We also don't warn about libraries found in the system library -// directory (the directory were we find libc.so); we assume that -// those libraries are OK. This heuristic avoids problems in -// GNU/Linux, in which -ldl can have undefined references satisfied by -// ld-linux.so. +// 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( - const Input_objects* input_objects, - Symbol* sym) const +Symbol_table::warn_about_undefined_dynobj_symbol(Symbol* sym) const { bool dummy; if (sym->source() == Symbol::FROM_OBJECT @@ -2629,7 +3264,7 @@ Symbol_table::warn_about_undefined_dynobj_symbol( && sym->binding() != elfcpp::STB_WEAK && !parameters->options().allow_shlib_undefined() && !parameters->target().is_defined_by_abi(sym) - && !input_objects->found_in_system_library_directory(sym->object())) + && !sym->object()->is_in_system_directory()) { // A very ugly cast. Dynobj* dynobj = static_cast(sym->object()); @@ -2641,7 +3276,7 @@ Symbol_table::warn_about_undefined_dynobj_symbol( // Write out a section symbol. Return the update offset. void -Symbol_table::write_section_symbol(const Output_section *os, +Symbol_table::write_section_symbol(const Output_section* os, Output_symtab_xindex* symtab_xindex, Output_file* of, off_t offset) const @@ -2692,7 +3327,10 @@ Symbol_table::sized_write_section_symbol(const Output_section* os, elfcpp::Sym_write osym(pov); osym.put_st_name(0); - osym.put_st_value(os->address()); + 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)); @@ -2726,34 +3364,97 @@ Symbol_table::print_stats() const // 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. +// defined in disjoint source locations. When comparing the source +// location, we consider instances with the same base filename to be +// the same. This is because different object files/shared libraries +// can include the same header file using different paths, and +// different optimization settings can make the line number appear to +// be a couple lines off, and we don't want to report an ODR violation +// in those cases. // 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. +// operator used with std::sort. 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; + // Inputs should be of the form "dirname/filename:linenum" where + // "dirname/" is optional. We want to compare just the filename:linenum. + + // Find the last '/' in each string. + std::string::size_type s1begin = s1.rfind('/'); + std::string::size_type s2begin = s2.rfind('/'); + // If there was no '/' in a string, start at the beginning. + if (s1begin == std::string::npos) + s1begin = 0; + if (s2begin == std::string::npos) + s2begin = 0; + return s1.compare(s1begin, std::string::npos, + s2, s2begin, std::string::npos) < 0; + } +}; + +// Returns all of the lines attached to LOC, not just the one the +// instruction actually came from. +std::vector +Symbol_table::linenos_from_loc(const Task* task, + const Symbol_location& loc) +{ + // 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, loc.object); + + std::vector result; + Symbol_location code_loc = loc; + parameters->target().function_location(&code_loc); + // 16 is the size of the object-cache that one_addr2line should use. + std::string canonical_result = Dwarf_line_info::one_addr2line( + code_loc.object, code_loc.shndx, code_loc.offset, 16, &result); + if (!canonical_result.empty()) + result.push_back(canonical_result); + return result; +} + +// OutputIterator that records if it was ever assigned to. This +// allows it to be used with std::set_intersection() to check for +// intersection rather than computing the intersection. +struct Check_intersection +{ + Check_intersection() + : value_(false) + {} + + bool had_intersection() const + { return this->value_; } + + Check_intersection& operator++() + { return *this; } + + Check_intersection& operator*() + { return *this; } + + template + Check_intersection& operator=(const T&) + { + this->value_ = true; + return *this; } + + private: + bool value_; }; // Check candidate_odr_violations_ to find symbols with the same name -// but apparently different definitions (different source-file/line-no). +// but apparently different definitions (different source-file/line-no +// for each line assigned to the first instruction). void Symbol_table::detect_odr_violations(const Task* task, @@ -2763,39 +3464,76 @@ Symbol_table::detect_odr_violations(const Task* task, 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; + const char* const symbol_name = it->first; - for (Unordered_set::const_iterator - locs = it->second.begin(); - locs != it->second.end(); - ++locs) + std::string first_object_name; + std::vector first_object_linenos; + + Unordered_set::const_iterator + locs = it->second.begin(); + const Unordered_set::const_iterator + locs_end = it->second.end(); + for (; locs != locs_end && first_object_linenos.empty(); ++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); + // Save the line numbers from the first definition to + // compare to the other definitions. Ideally, we'd compare + // every definition to every other, but we don't want to + // take O(N^2) time to do this. This shortcut may cause + // false negatives that appear or disappear depending on the + // link order, but it won't cause false positives. + first_object_name = locs->object->name(); + first_object_linenos = this->linenos_from_loc(task, *locs); } + if (first_object_linenos.empty()) + continue; - if (line_nums.size() > 1) + // Sort by Odr_violation_compare to make std::set_intersection work. + std::string first_object_canonical_result = first_object_linenos.back(); + std::sort(first_object_linenos.begin(), first_object_linenos.end(), + Odr_violation_compare()); + + for (; locs != locs_end; ++locs) { - 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()); + std::vector linenos = + this->linenos_from_loc(task, *locs); + // linenos will be empty if we couldn't parse the debug info. + if (linenos.empty()) + continue; + // Sort by Odr_violation_compare to make std::set_intersection work. + gold_assert(!linenos.empty()); + std::string second_object_canonical_result = linenos.back(); + std::sort(linenos.begin(), linenos.end(), Odr_violation_compare()); + + Check_intersection intersection_result = + std::set_intersection(first_object_linenos.begin(), + first_object_linenos.end(), + linenos.begin(), + linenos.end(), + Check_intersection(), + Odr_violation_compare()); + if (!intersection_result.had_intersection()) + { + gold_warning(_("while linking %s: symbol '%s' defined in " + "multiple places (possible ODR violation):"), + output_file_name, demangle(symbol_name).c_str()); + // This only prints one location from each definition, + // which may not be the location we expect to intersect + // with another definition. We could print the whole + // set of locations, but that seems too verbose. + fprintf(stderr, _(" %s from %s\n"), + first_object_canonical_result.c_str(), + first_object_name.c_str()); + fprintf(stderr, _(" %s from %s\n"), + second_object_canonical_result.c_str(), + locs->object->name().c_str()); + // Only print one broken pair, to avoid needing to + // compare against a list of the disjoint definition + // locations we've found so far. (If we kept comparing + // against just the first one, we'd get a lot of + // redundant complaints about the second definition + // location.) + break; + } } } // We only call one_addr2line() in this function, so we can clear its cache. @@ -2843,6 +3581,12 @@ Warnings::issue_warning(const Symbol* sym, size_t relnum, off_t reloffset) const { gold_assert(sym->has_warning()); + + // We don't want to issue a warning for a relocation against the + // symbol in the same object file in which the symbol is defined. + if (sym->object() == relinfo->object) + return; + Warning_table::const_iterator p = this->warnings_.find(sym->name()); gold_assert(p != this->warnings_.end()); gold_warning_at_location(relinfo, relnum, reloffset, @@ -2869,13 +3613,13 @@ Sized_symbol<64>::allocate_common(Output_data*, Value_type); template void Symbol_table::add_from_relobj<32, false>( - Sized_relobj<32, false>* relobj, + Sized_relobj_file<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, + Sized_relobj_file<32, false>::Symbols* sympointers, size_t* defined); #endif @@ -2883,13 +3627,13 @@ Symbol_table::add_from_relobj<32, false>( template void Symbol_table::add_from_relobj<32, true>( - Sized_relobj<32, true>* relobj, + Sized_relobj_file<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, + Sized_relobj_file<32, true>::Symbols* sympointers, size_t* defined); #endif @@ -2897,13 +3641,13 @@ Symbol_table::add_from_relobj<32, true>( template void Symbol_table::add_from_relobj<64, false>( - Sized_relobj<64, false>* relobj, + Sized_relobj_file<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, + Sized_relobj_file<64, false>::Symbols* sympointers, size_t* defined); #endif @@ -2911,13 +3655,13 @@ Symbol_table::add_from_relobj<64, false>( template void Symbol_table::add_from_relobj<64, true>( - Sized_relobj<64, true>* relobj, + Sized_relobj_file<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, + Sized_relobj_file<64, true>::Symbols* sympointers, size_t* defined); #endif @@ -2973,7 +3717,7 @@ Symbol_table::add_from_dynobj<32, false>( const unsigned char* versym, size_t versym_size, const std::vector* version_map, - Sized_relobj<32, false>::Symbols* sympointers, + Sized_relobj_file<32, false>::Symbols* sympointers, size_t* defined); #endif @@ -2989,7 +3733,7 @@ Symbol_table::add_from_dynobj<32, true>( const unsigned char* versym, size_t versym_size, const std::vector* version_map, - Sized_relobj<32, true>::Symbols* sympointers, + Sized_relobj_file<32, true>::Symbols* sympointers, size_t* defined); #endif @@ -3005,7 +3749,7 @@ Symbol_table::add_from_dynobj<64, false>( const unsigned char* versym, size_t versym_size, const std::vector* version_map, - Sized_relobj<64, false>::Symbols* sympointers, + Sized_relobj_file<64, false>::Symbols* sympointers, size_t* defined); #endif @@ -3021,10 +3765,50 @@ Symbol_table::add_from_dynobj<64, true>( const unsigned char* versym, size_t versym_size, const std::vector* version_map, - Sized_relobj<64, true>::Symbols* sympointers, + Sized_relobj_file<64, true>::Symbols* sympointers, size_t* defined); #endif +#ifdef HAVE_TARGET_32_LITTLE +template +Sized_symbol<32>* +Symbol_table::add_from_incrobj( + Object* obj, + const char* name, + const char* ver, + elfcpp::Sym<32, false>* sym); +#endif + +#ifdef HAVE_TARGET_32_BIG +template +Sized_symbol<32>* +Symbol_table::add_from_incrobj( + Object* obj, + const char* name, + const char* ver, + elfcpp::Sym<32, true>* sym); +#endif + +#ifdef HAVE_TARGET_64_LITTLE +template +Sized_symbol<64>* +Symbol_table::add_from_incrobj( + Object* obj, + const char* name, + const char* ver, + elfcpp::Sym<64, false>* sym); +#endif + +#ifdef HAVE_TARGET_64_BIG +template +Sized_symbol<64>* +Symbol_table::add_from_incrobj( + Object* obj, + const char* name, + const char* ver, + elfcpp::Sym<64, true>* sym); +#endif + #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG) template void @@ -3043,6 +3827,62 @@ Symbol_table::define_with_copy_reloc<64>( elfcpp::Elf_types<64>::Elf_Addr value); #endif +#if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG) +template +void +Sized_symbol<32>::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, + bool is_predefined); + +template +void +Sized_symbol<32>::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, + bool is_predefined); + +template +void +Sized_symbol<32>::init_undefined(const char* name, const char* version, + Value_type value, elfcpp::STT type, + elfcpp::STB binding, elfcpp::STV visibility, + unsigned char nonvis); +#endif + +#if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG) +template +void +Sized_symbol<64>::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, + bool is_predefined); + +template +void +Sized_symbol<64>::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, + bool is_predefined); + +template +void +Sized_symbol<64>::init_undefined(const char* name, const char* version, + Value_type value, elfcpp::STT type, + elfcpp::STB binding, elfcpp::STV visibility, + unsigned char nonvis); +#endif + #ifdef HAVE_TARGET_32_LITTLE template void