X-Git-Url: http://git.efficios.com/?a=blobdiff_plain;f=gold%2Fsymtab.cc;h=99e97210bda18f3ab867925bb434bd3b15fc5f0a;hb=13bff72615e5a93a6e5f28e83a594125e66ccced;hp=d4ac297792a9b4d9089fb7e34b5cc333dbdbb9e3;hpb=badc813953563b5539ce2974242b9c3d3860adab;p=deliverable%2Fbinutils-gdb.git diff --git a/gold/symtab.cc b/gold/symtab.cc index d4ac297792..99e97210bd 100644 --- a/gold/symtab.cc +++ b/gold/symtab.cc @@ -1,6 +1,6 @@ // symtab.cc -- the gold symbol table -// Copyright 2006, 2007, 2008, 2009, 2010, 2011 Free Software Foundation, Inc. +// Copyright (C) 2006-2019 Free Software Foundation, Inc. // Written by Ian Lance Taylor . // This file is part of gold. @@ -40,14 +40,15 @@ #include "symtab.h" #include "script.h" #include "plugin.h" +#include "incremental.h" namespace gold { // Class Symbol. -// Initialize fields in Symbol. This initializes everything except u_ -// and source_. +// Initialize fields in Symbol. This initializes everything except +// u1_, u2_ and source_. void Symbol::init_fields(const char* name, const char* version, @@ -78,6 +79,9 @@ Symbol::init_fields(const char* name, const char* version, 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; + this->non_zero_localentry_ = false; } // Return the demangled version of the symbol's name, but only @@ -116,8 +120,8 @@ Symbol::init_base_object(const char* name, const char* version, Object* object, { 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->u1_.object = object; + this->u2_.shndx = st_shndx; this->is_ordinary_shndx_ = is_ordinary; this->source_ = FROM_OBJECT; this->in_reg_ = !object->is_dynamic(); @@ -132,14 +136,16 @@ 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; - this->u_.in_output_data.offset_is_from_end = offset_is_from_end; + this->u1_.output_data = od; + this->u2_.offset_is_from_end = offset_is_from_end; 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 @@ -150,14 +156,16 @@ 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; - this->u_.in_output_segment.offset_base = offset_base; + this->u1_.output_segment = os; + this->u2_.offset_base = offset_base; 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 @@ -166,12 +174,14 @@ 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 @@ -196,8 +206,8 @@ 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; + this->u1_.output_data = od; + this->u2_.offset_is_from_end = false; } // Initialize the fields in Sized_symbol for SYM in OBJECT. @@ -226,10 +236,11 @@ 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; } @@ -245,10 +256,11 @@ 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; } @@ -261,9 +273,11 @@ 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; } @@ -273,14 +287,30 @@ 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 @@ -307,7 +337,7 @@ 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 +bool Symbol::should_add_dynsym_entry(Symbol_table* symtab) const { // If the symbol is only present on plugin files, the plugin decided we @@ -336,14 +366,23 @@ Symbol::should_add_dynsym_entry(Symbol_table* symtab) const 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() @@ -383,10 +422,15 @@ Symbol::should_add_dynsym_entry(Symbol_table* symtab) 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; @@ -400,9 +444,12 @@ 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().output_is_position_independent() - || 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, @@ -441,19 +488,19 @@ Symbol::output_section() const { case FROM_OBJECT: { - unsigned int shndx = this->u_.from_object.shndx; + unsigned int shndx = this->u2_.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); + gold_assert(!this->u1_.object->is_dynamic()); + gold_assert(this->u1_.object->pluginobj() == NULL); + Relobj* relobj = static_cast(this->u1_.object); return relobj->output_section(shndx); } return NULL; } case IN_OUTPUT_DATA: - return this->u_.in_output_data.output_data->output_section(); + return this->u1_.output_data->output_section(); case IN_OUTPUT_SEGMENT: case IS_CONSTANT: @@ -480,8 +527,8 @@ Symbol::set_output_section(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; + this->u1_.output_data = os; + this->u2_.offset_is_from_end = false; break; case IN_OUTPUT_SEGMENT: case IS_UNDEFINED: @@ -490,14 +537,39 @@ 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->u1_.output_segment = os; + this->u2_.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_(), small_commons_(), + : saw_undefined_(0), offset_(0), has_gnu_output_(false), table_(count), + namepool_(), forwarders_(), commons_(), tls_commons_(), small_commons_(), large_commons_(), forced_locals_(), warnings_(), - version_script_(version_script), gc_(NULL), icf_(NULL) + version_script_(version_script), gc_(NULL), icf_(NULL), + target_symbols_() { namepool_.reserve(count); } @@ -517,14 +589,14 @@ Symbol_table::Symbol_table_eq::operator()(const Symbol_table_key& k1, } bool -Symbol_table::is_section_folded(Object* obj, unsigned int shndx) const +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 -u option, add them to the -// work list to avoid gc'ing them. +// 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(Layout* layout) @@ -540,14 +612,24 @@ Symbol_table::gc_mark_undef_symbols(Layout* layout) 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); } } @@ -561,34 +643,24 @@ Symbol_table::gc_mark_undef_symbols(Layout* layout) 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); } } } 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 @@ -598,16 +670,7 @@ 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. @@ -678,7 +741,7 @@ 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()) @@ -804,6 +867,9 @@ Symbol_table::define_default_version(Sized_symbol* sym, // 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. @@ -815,6 +881,11 @@ Symbol_table::define_default_version(Sized_symbol* sym, 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; @@ -918,8 +989,8 @@ Symbol_table::add_from_object(Object* object, // ins.first->second: the value (Symbol*). // ins.second: true if new entry was inserted, false if not. - Sized_symbol* ret; - bool was_undefined; + Sized_symbol* ret = NULL; + bool was_undefined_in_reg; bool was_common; if (!ins.second) { @@ -927,17 +998,45 @@ Symbol_table::add_from_object(Object* object, ret = this->get_sized_symbol(ins.first->second); gold_assert(ret != NULL); - was_undefined = ret->is_undefined(); - was_common = ret->is_common(); + was_undefined_in_reg = ret->is_undefined() && ret->in_reg(); + // 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 (is_default_version) this->define_default_version(ret, insdefault.second, insdefault.first); + else + { + bool dummy; + if (version != NULL + && ret->source() == Symbol::FROM_OBJECT + && ret->object() == object + && is_ordinary + && ret->shndx(&dummy) == st_shndx + && ret->is_default()) + { + // 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 { @@ -950,18 +1049,44 @@ Symbol_table::add_from_object(Object* object, // it, then change it to NAME/VERSION. ret = this->get_sized_symbol(insdefault.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; + // If the existing symbol already has a version, + // don't override it with the new symbol. + // This should only happen when the new symbol + // is from a shared library. + if (ret->version() != NULL) + { + if (!object->is_dynamic()) + { + gold_warning(_("%s: conflicting default version definition" + " for %s@@%s"), + object->name().c_str(), name, version); + if (ret->source() == Symbol::FROM_OBJECT) + gold_info(_("%s: %s: previous definition of %s@@%s here"), + program_name, + ret->object()->name().c_str(), + name, ret->version()); + } + ret = NULL; + is_default_version = false; + } + else + { + was_undefined_in_reg = ret->is_undefined() && ret->in_reg(); + // 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, is_default_version); + if (parameters->options().gc_sections()) + this->gc_mark_dyn_syms(ret); + ins.first->second = ret; + } } - else + + if (ret == NULL) { - was_undefined = false; + was_undefined_in_reg = false; was_common = false; Sized_target* target = @@ -970,7 +1095,8 @@ Symbol_table::add_from_object(Object* object, 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 @@ -1004,9 +1130,10 @@ Symbol_table::add_from_object(Object* object, ret->set_is_default(); } - // Record every time we see a new undefined symbol, to speed up - // archive groups. - if (!was_undefined && ret->is_undefined()) + // Record every time we see a new undefined symbol, to speed up archive + // groups. We only care about symbols undefined in regular objects here + // because undefined symbols only in dynamic objects should't trigger rescans. + if (!was_undefined_in_reg && ret->is_undefined() && ret->in_reg()) { ++this->saw_undefined_; if (parameters->options().has_plugins()) @@ -1014,8 +1141,10 @@ Symbol_table::add_from_object(Object* object, } // 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->tls_commons_.push_back(ret); @@ -1047,13 +1176,13 @@ 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, + typename Sized_relobj_file::Symbols* sympointers, size_t* defined) { *defined = 0; @@ -1081,6 +1210,13 @@ Symbol_table::add_from_relobj( const char* name = sym_names + st_name; + if (!parameters->options().relocatable() + && name[0] == '_' + && name[1] == '_' + && strcmp (name + (name[2] == '_'), "__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(), @@ -1115,6 +1251,14 @@ Symbol_table::add_from_relobj( 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) { // The symbol name is of the form foo@VERSION or foo@@VERSION @@ -1164,12 +1308,14 @@ 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() @@ -1209,16 +1355,25 @@ Symbol_table::add_from_relobj( res = this->add_from_object(relobj, name, name_key, ver, ver_key, is_default_version, *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 (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(); @@ -1284,6 +1439,9 @@ Symbol_table::add_from_pluginobj( is_default_version, *sym, st_shndx, is_ordinary, st_shndx); + if (res == NULL) + return NULL; + if (is_forced_local) this->force_local(res); @@ -1303,7 +1461,7 @@ 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; @@ -1316,6 +1474,11 @@ 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")); @@ -1353,14 +1516,20 @@ 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; } @@ -1469,6 +1638,9 @@ Symbol_table::add_from_dynobj( } } + 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 @@ -1478,6 +1650,13 @@ 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; } @@ -1485,6 +1664,33 @@ 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. @@ -1581,16 +1787,18 @@ template Sized_symbol* Symbol_table::define_special_symbol(const char** pname, const char** pversion, bool only_if_ref, + elfcpp::STV visibility, Sized_symbol** poldsym, - bool* resolve_oldsym) + bool* resolve_oldsym, bool is_forced_local) { *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 (!is_forced_local && *pversion == NULL) { bool is_global; if (this->version_script_.get_symbol_version(*pname, &v, &is_global)) @@ -1618,11 +1826,26 @@ Symbol_table::define_special_symbol(const char** pname, const char** pversion, oldsym = this->lookup(*pname, *pversion); if (oldsym == NULL && is_default_version) oldsym = this->lookup(*pname, NULL); - if (oldsym == NULL || !oldsym->is_undefined()) + if (oldsym == NULL) return NULL; + if (!oldsym->is_undefined()) + { + // Skip if the old definition is from a regular object. + if (!oldsym->is_from_dynobj()) + return NULL; + + // If the symbol has hidden or internal visibility, ignore + // definition and reference from a dynamic object. + if ((visibility == elfcpp::STV_HIDDEN + || visibility == elfcpp::STV_INTERNAL) + && !oldsym->in_reg()) + return NULL; + } *pname = oldsym->name(); - if (!is_default_version) + if (is_default_version) + *pversion = this->namepool_.add(*pversion, true, NULL); + else *pversion = oldsym->version(); } else @@ -1675,10 +1898,13 @@ Symbol_table::define_special_symbol(const char** pname, const char** pversion, add_to_table = true; add_loc = ins.first; - if (is_default_version && !insdefault.second) + if (is_default_version + && !insdefault.second + && insdefault.first->second->version() == NULL) { // We are adding NAME/VERSION, and it is the default - // version. We already have an entry for NAME/NULL. + // version. We already have an entry for NAME/NULL + // that does not already have a version. oldsym = insdefault.first->second; *resolve_oldsym = true; } @@ -1702,7 +1928,8 @@ Symbol_table::define_special_symbol(const char** pname, const char** pversion, { Sized_target* sized_target = parameters->sized_target(); - sym = sized_target->make_symbol(); + sym = sized_target->make_symbol(*pname, elfcpp::STT_NOTYPE, + NULL, elfcpp::SHN_UNDEF, 0); if (sym == NULL) return NULL; } @@ -1785,13 +2012,17 @@ Symbol_table::do_define_in_output_data( Sized_symbol* sym; Sized_symbol* oldsym; bool resolve_oldsym; + const bool is_forced_local = binding == elfcpp::STB_LOCAL; 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); + only_if_ref, + visibility, + &oldsym, + &resolve_oldsym, + is_forced_local); #else gold_unreachable(); #endif @@ -1800,8 +2031,11 @@ 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, - &resolve_oldsym); + only_if_ref, + visibility, + &oldsym, + &resolve_oldsym, + is_forced_local); #else gold_unreachable(); #endif @@ -1811,25 +2045,28 @@ 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) { - if (binding == elfcpp::STB_LOCAL - || this->version_script_.symbol_is_local(name)) + if (is_forced_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, defined)) + if (Symbol_table::should_override_with_special(oldsym, type, defined)) this->override_with_special(oldsym, sym); if (resolve_oldsym) return sym; else { + if (defined == PREDEFINED + && (is_forced_local || this->version_script_.symbol_is_local(name))) + this->force_local(oldsym); delete sym; return oldsym; } @@ -1898,13 +2135,17 @@ Symbol_table::do_define_in_output_segment( Sized_symbol* sym; Sized_symbol* oldsym; bool resolve_oldsym; + const bool is_forced_local = binding == elfcpp::STB_LOCAL; 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); + only_if_ref, + visibility, + &oldsym, + &resolve_oldsym, + is_forced_local); #else gold_unreachable(); #endif @@ -1913,8 +2154,11 @@ 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, - &resolve_oldsym); + only_if_ref, + visibility, + &oldsym, + &resolve_oldsym, + is_forced_local); #else gold_unreachable(); #endif @@ -1924,25 +2168,27 @@ 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) { - if (binding == elfcpp::STB_LOCAL - || this->version_script_.symbol_is_local(name)) + if (is_forced_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, defined)) + if (Symbol_table::should_override_with_special(oldsym, type, defined)) this->override_with_special(oldsym, sym); if (resolve_oldsym) return sym; else { + if (is_forced_local || this->version_script_.symbol_is_local(name)) + this->force_local(oldsym); delete sym; return oldsym; } @@ -2010,13 +2256,17 @@ Symbol_table::do_define_as_constant( Sized_symbol* sym; Sized_symbol* oldsym; bool resolve_oldsym; + const bool is_forced_local = binding == elfcpp::STB_LOCAL; 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); + only_if_ref, + visibility, + &oldsym, + &resolve_oldsym, + is_forced_local); #else gold_unreachable(); #endif @@ -2025,8 +2275,11 @@ 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, - &resolve_oldsym); + only_if_ref, + visibility, + &oldsym, + &resolve_oldsym, + is_forced_local); #else gold_unreachable(); #endif @@ -2036,7 +2289,7 @@ 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) { @@ -2045,8 +2298,7 @@ Symbol_table::do_define_as_constant( if ((version == NULL || name != version || value != 0) - && (binding == elfcpp::STB_LOCAL - || this->version_script_.symbol_is_local(name))) + && (is_forced_local || this->version_script_.symbol_is_local(name))) this->force_local(sym); else if (version != NULL && (name != version || value != 0)) @@ -2055,13 +2307,15 @@ Symbol_table::do_define_as_constant( } if (force_override - || Symbol_table::should_override_with_special(oldsym, defined)) + || Symbol_table::should_override_with_special(oldsym, type, defined)) this->override_with_special(oldsym, sym); if (resolve_oldsym) return sym; else { + if (is_forced_local || this->version_script_.symbol_is_local(name)) + this->force_local(oldsym); delete sym; return oldsym; } @@ -2221,6 +2475,12 @@ Symbol_table::do_add_undefined_symbols_from_command_line(Layout* layout) ++p) this->add_undefined_symbol_from_command_line(p->c_str()); + 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()); + for (Script_options::referenced_const_iterator p = layout->script_options()->referenced_begin(); p != layout->script_options()->referenced_end(); @@ -2244,8 +2504,11 @@ Symbol_table::add_undefined_symbol_from_command_line(const char* name) { #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG) sym = this->define_special_symbol(&name, &version, - false, &oldsym, - &resolve_oldsym); + false, + elfcpp::STV_DEFAULT, + &oldsym, + &resolve_oldsym, + false); #else gold_unreachable(); #endif @@ -2254,8 +2517,11 @@ Symbol_table::add_undefined_symbol_from_command_line(const char* name) { #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE) sym = this->define_special_symbol(&name, &version, - false, &oldsym, - &resolve_oldsym); + false, + elfcpp::STV_DEFAULT, + &oldsym, + &resolve_oldsym, + false); #else gold_unreachable(); #endif @@ -2263,28 +2529,84 @@ Symbol_table::add_undefined_symbol_from_command_line(const char* name) gold_assert(oldsym == NULL); - sym->init_undefined(name, version, elfcpp::STT_NOTYPE, elfcpp::STB_GLOBAL, + 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 -// 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. +// global dynamic symbol. Pointers to the global 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, + unsigned int* pforced_local_count, std::vector* syms, Stringpool* dynpool, Versions* versions) { + // First process all the symbols which have been forced to be local, + // as they must appear before all global symbols. + unsigned int forced_local_count = 0; + 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 (sym->has_dynsym_index()) + continue; + if (!sym->should_add_dynsym_entry(this)) + sym->set_dynsym_index(-1U); + else + { + sym->set_dynsym_index(index); + ++index; + ++forced_local_count; + dynpool->add(sym->name(), false, NULL); + if (sym->type() == elfcpp::STT_GNU_IFUNC) + this->set_has_gnu_output(); + } + } + *pforced_local_count = forced_local_count; + + // 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->is_forced_local()) + continue; + if (!sym->should_add_dynsym_entry(this)) + sym->set_dynsym_index(-1U); + else + { + dyn_symbols.push_back(sym); + if (sym->type() == elfcpp::STT_GNU_IFUNC + || (sym->binding() == elfcpp::STB_GNU_UNIQUE + && parameters->options().gnu_unique())) + this->set_has_gnu_output(); + } + } + + 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) { Symbol* sym = p->second; + if (sym->is_forced_local()) + continue; + // 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. @@ -2297,16 +2619,31 @@ Symbol_table::set_dynsym_indexes(unsigned int 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); - - // If the symbol is defined in a dynamic object and is - // referenced 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->object()->set_is_needed(); + if (sym->type() == elfcpp::STT_GNU_IFUNC + || (sym->binding() == elfcpp::STB_GNU_UNIQUE + && parameters->options().gnu_unique())) + this->set_has_gnu_output(); + + // 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 + { + if (parameters->options().warn_drop_version()) + gold_warning(_("discarding version information for " + "%s@%s, defined in unused shared library %s " + "(linked with --as-needed)"), + sym->name(), sym->version(), + sym->object()->name().c_str()); + sym->clear_version(); + } + } } } @@ -2314,13 +2651,29 @@ Symbol_table::set_dynsym_indexes(unsigned int index, // 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; } // 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. +// offset. Update *PLOCAL_SYMCOUNT if necessary. DYNOFF and +// DYN_GLOBAL_INDEX refer to the start of the symbols that will be +// written from the global symbol table in Symtab::write_globals(), +// which will include forced-local symbols. DYN_GLOBAL_INDEX is +// not necessarily the same as the sh_info field for the .dynsym +// section, which will point to the first real global symbol. off_t Symbol_table::finalize(off_t off, off_t dynoff, size_t dyn_global_index, @@ -2355,6 +2708,13 @@ Symbol_table::finalize(off_t off, off_t dynoff, size_t dyn_global_index, else gold_unreachable(); + if (this->has_gnu_output_) + { + Target* target = const_cast(¶meters->target()); + if (target->osabi() == elfcpp::ELFOSABI_NONE) + target->set_osabi(elfcpp::ELFOSABI_GNU); + } + // Now that we have the final symbol table, we can reliably note // which symbols should get warnings. this->warnings_.note_warnings(this); @@ -2371,7 +2731,10 @@ 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; } @@ -2403,6 +2766,8 @@ Symbol_table::sized_finalize(off_t off, Stringpool* pool, { this->add_to_final_symtab(sym, pool, &index, &off); ++*plocal_symcount; + if (sym->type() == elfcpp::STT_GNU_IFUNC) + this->set_has_gnu_output(); } } @@ -2413,7 +2778,21 @@ Symbol_table::sized_finalize(off_t off, Stringpool* pool, { Symbol* sym = p->second; if (this->sized_finalize_symbol(sym)) - this->add_to_final_symtab(sym, pool, &index, &off); + { + this->add_to_final_symtab(sym, pool, &index, &off); + if (sym->type() == elfcpp::STT_GNU_IFUNC + || (sym->binding() == elfcpp::STB_GNU_UNIQUE + && parameters->options().gnu_unique())) + this->set_has_gnu_output(); + } + } + + // 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; @@ -2741,6 +3120,19 @@ Symbol_table::sized_write_globals(const Stringpool* sympool, 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: @@ -2815,19 +3207,39 @@ Symbol_table::sized_write_globals(const Stringpool* sympool, 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()) + { + Output_section* os = od->output_section(); + gold_assert(os != NULL); + sym_value -= os->address(); + } + } break; case Symbol::IN_OUTPUT_SEGMENT: - shndx = elfcpp::SHN_ABS; + { + Output_segment* oseg = sym->output_segment(); + Output_section* osect = oseg->first_section(); + if (osect == NULL) + shndx = elfcpp::SHN_ABS; + else + shndx = osect->out_shndx(); + } break; case Symbol::IS_CONSTANT: @@ -2858,6 +3270,56 @@ Symbol_table::sized_write_globals(const Stringpool* sympool, unsigned char* pd = dynamic_view + (dynsym_index * sym_size); this->sized_write_symbol(sym, dynsym_value, shndx, 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); } } @@ -2880,7 +3342,10 @@ Symbol_table::sized_write_symbol( 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()) @@ -2888,10 +3353,7 @@ Symbol_table::sized_write_symbol( else osym.put_st_size(sym->symsize()); elfcpp::STT type = sym->type(); - // Turn IFUNC symbols from shared libraries into normal FUNC symbols. - if (type == elfcpp::STT_GNU_IFUNC - && sym->is_from_dynobj()) - type = elfcpp::STT_FUNC; + 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, type)); @@ -3025,7 +3487,7 @@ 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 +// 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 @@ -3035,7 +3497,7 @@ Symbol_table::print_stats() const // 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 { @@ -3043,32 +3505,79 @@ struct Odr_violation_compare operator()(const std::string& s1, const std::string& s2) const { // Inputs should be of the form "dirname/filename:linenum" where - // "dirname/" is optional. We want to compare just the filename. + // "dirname/" is optional. We want to compare just the filename:linenum. - // Find the last '/' and ':' in each string. + // Find the last '/' in each string. std::string::size_type s1begin = s1.rfind('/'); std::string::size_type s2begin = s2.rfind('/'); - std::string::size_type s1end = s1.rfind(':'); - std::string::size_type s2end = 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; - // If the ':' appeared in the directory name, compare to the end - // of the string. - if (s1end < s1begin) - s1end = s1.size(); - if (s2end < s2begin) - s2end = s2.size(); - // Compare takes lengths, not end indices. - return s1.compare(s1begin, s1end - s1begin, - s2, s2begin, s2end - 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, @@ -3078,48 +3587,76 @@ Symbol_table::detect_odr_violations(const Task* task, it != candidate_odr_violations_.end(); ++it) { - const char* symbol_name = it->first; - // Maps from symbol location to a sample object file we found - // that location in. We use a sorted map so the location order - // is deterministic, but we only store an arbitrary object file - // to avoid copying lots of names. - std::map line_nums; - - for (Unordered_set::const_iterator - locs = it->second.begin(); - locs != it->second.end(); - ++locs) + const char* const symbol_name = it->first; + + 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()) - { - std::string& sample_object = line_nums[lineno]; - if (sample_object.empty()) - sample_object = locs->object->name(); - } + // 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::map::const_iterator it2 = - line_nums.begin(); - it2 != line_nums.end(); - ++it2) - fprintf(stderr, _(" %s from %s\n"), - it2->first.c_str(), it2->second.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. @@ -3167,6 +3704,12 @@ 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, @@ -3193,13 +3736,13 @@ 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 @@ -3207,13 +3750,13 @@ 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 @@ -3221,13 +3764,13 @@ 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 @@ -3235,13 +3778,13 @@ 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 @@ -3297,7 +3840,7 @@ 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 @@ -3313,7 +3856,7 @@ 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 @@ -3329,7 +3872,7 @@ 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 @@ -3345,10 +3888,50 @@ 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 @@ -3367,6 +3950,62 @@ 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