X-Git-Url: http://git.efficios.com/?a=blobdiff_plain;f=gold%2Fresolve.cc;h=a10895641fd023bec185ccf688c9f5cb833a6619;hb=488d02fe7729dda5b9414a3942df68e0c316ce53;hp=2a688769bed17b2d1bec307125337d59f62c9bf5;hpb=f7c5b166f66958163526aa5688d8a7e3d0686694;p=deliverable%2Fbinutils-gdb.git diff --git a/gold/resolve.cc b/gold/resolve.cc index 2a688769be..a10895641f 100644 --- a/gold/resolve.cc +++ b/gold/resolve.cc @@ -1,6 +1,6 @@ // resolve.cc -- symbol resolution for gold -// 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. @@ -92,11 +92,13 @@ Symbol::override_base(const elfcpp::Sym& sym, Object* object, const char* version) { gold_assert(this->source_ == FROM_OBJECT); - this->u_.from_object.object = object; + this->u1_.object = object; this->override_version(version); - this->u_.from_object.shndx = st_shndx; + this->u2_.shndx = st_shndx; this->is_ordinary_shndx_ = is_ordinary; - this->type_ = sym.get_st_type(); + // Don't override st_type from plugin placeholder symbols. + if (object->pluginobj() == NULL) + this->type_ = sym.get_st_type(); this->binding_ = sym.get_st_bind(); this->override_visibility(sym.get_st_visibility()); this->nonvis_ = sym.get_st_nonvis(); @@ -171,7 +173,7 @@ static const unsigned int common_flag = 2 << def_undef_or_common_shift; static unsigned int symbol_to_bits(elfcpp::STB binding, bool is_dynamic, - unsigned int shndx, bool is_ordinary, elfcpp::STT type) + unsigned int shndx, bool is_ordinary) { unsigned int bits; @@ -191,6 +193,7 @@ symbol_to_bits(elfcpp::STB binding, bool is_dynamic, // table. gold_error(_("invalid STB_LOCAL symbol in external symbols")); bits = global_flag; + break; default: // Any target which wants to handle STB_LOOS, etc., needs to @@ -216,9 +219,7 @@ symbol_to_bits(elfcpp::STB binding, bool is_dynamic, break; default: - if (type == elfcpp::STT_COMMON) - bits |= common_flag; - else if (!is_ordinary && Symbol::is_common_shndx(shndx)) + if (!is_ordinary && Symbol::is_common_shndx(shndx)) bits |= common_flag; else bits |= def_flag; @@ -243,20 +244,31 @@ Symbol_table::resolve(Sized_symbol* to, const elfcpp::Sym& sym, unsigned int st_shndx, bool is_ordinary, unsigned int orig_st_shndx, - Object* object, const char* version) + Object* object, const char* version, + bool is_default_version) { + bool to_is_ordinary; + const unsigned int to_shndx = to->shndx(&to_is_ordinary); + // It's possible for a symbol to be defined in an object file // using .symver to give it a version, and for there to also be // a linker script giving that symbol the same version. We // don't want to give a multiple-definition error for this // harmless redefinition. - bool to_is_ordinary; if (to->source() == Symbol::FROM_OBJECT && to->object() == object - && is_ordinary && to->is_defined() - && to->shndx(&to_is_ordinary) == st_shndx + && is_ordinary && to_is_ordinary + && to_shndx == st_shndx + && to->value() == sym.get_st_value()) + return; + + // Likewise for an absolute symbol defined twice with the same value. + if (!is_ordinary + && st_shndx == elfcpp::SHN_ABS + && !to_is_ordinary + && to_shndx == elfcpp::SHN_ABS && to->value() == sym.get_st_value()) return; @@ -264,12 +276,21 @@ Symbol_table::resolve(Sized_symbol* to, { Sized_target* sized_target; sized_target = parameters->sized_target(); - sized_target->resolve(to, sym, object, version); - return; + if (sized_target->resolve(to, sym, object, version)) + return; } if (!object->is_dynamic()) { + if (sym.get_st_type() == elfcpp::STT_COMMON + && (is_ordinary || !Symbol::is_common_shndx(st_shndx))) + { + gold_warning(_("STT_COMMON symbol '%s' in %s " + "is not in a common section"), + to->demangled_name().c_str(), + to->object()->name().c_str()); + return; + } // Record that we've seen this symbol in a regular object. to->set_in_reg(); } @@ -277,15 +298,10 @@ Symbol_table::resolve(Sized_symbol* to, && (to->visibility() == elfcpp::STV_HIDDEN || to->visibility() == elfcpp::STV_INTERNAL)) { - // A dynamic object cannot reference a hidden or internal symbol - // defined in another object. - gold_warning(_("%s symbol '%s' in %s is referenced by DSO %s"), - (to->visibility() == elfcpp::STV_HIDDEN - ? "hidden" - : "internal"), - to->demangled_name().c_str(), - to->object()->name().c_str(), - object->name().c_str()); + // The symbol is hidden, so a reference from a shared object + // cannot bind to it. We tried issuing a warning in this case, + // but that produces false positives when the symbol is + // actually resolved in a different shared object (PR 15574). return; } else @@ -301,14 +317,33 @@ Symbol_table::resolve(Sized_symbol* to, // If we're processing replacement files, allow new symbols to override // the placeholders from the plugin objects. + // Treat common symbols specially since it is possible that an ELF + // file increased the size of the alignment. if (to->source() == Symbol::FROM_OBJECT) { Pluginobj* obj = to->object()->pluginobj(); if (obj != NULL && parameters->options().plugins()->in_replacement_phase()) { - this->override(to, sym, st_shndx, is_ordinary, object, version); - return; + bool adjust_common = false; + typename Sized_symbol::Size_type tosize = 0; + typename Sized_symbol::Value_type tovalue = 0; + if (to->is_common() + && !is_ordinary && Symbol::is_common_shndx(st_shndx)) + { + adjust_common = true; + tosize = to->symsize(); + tovalue = to->value(); + } + this->override(to, sym, st_shndx, is_ordinary, object, version); + if (adjust_common) + { + if (tosize > to->symsize()) + to->set_symsize(tosize); + if (tovalue > to->value()) + to->set_value(tovalue); + } + return; } } @@ -325,8 +360,8 @@ Symbol_table::resolve(Sized_symbol* to, && (sym.get_st_bind() == elfcpp::STB_WEAK || to->binding() == elfcpp::STB_WEAK) && orig_st_shndx != elfcpp::SHN_UNDEF - && to->shndx(&to_is_ordinary) != elfcpp::SHN_UNDEF && to_is_ordinary + && to_shndx != elfcpp::SHN_UNDEF && sym.get_st_size() != 0 // Ignore weird 0-sized symbols. && to->symsize() != 0 && (sym.get_st_type() != to->type() @@ -336,40 +371,55 @@ Symbol_table::resolve(Sized_symbol* to, && to->name()[0] == '_' && to->name()[1] == 'Z') { Symbol_location fromloc - = { object, orig_st_shndx, sym.get_st_value() }; - Symbol_location toloc = { to->object(), to->shndx(&to_is_ordinary), - to->value() }; + = { object, orig_st_shndx, static_cast(sym.get_st_value()) }; + Symbol_location toloc = { to->object(), to_shndx, + static_cast(to->value()) }; this->candidate_odr_violations_[to->name()].insert(fromloc); this->candidate_odr_violations_[to->name()].insert(toloc); } + // Plugins don't provide a symbol type, so adopt the existing type + // if the FROM symbol is from a plugin. + elfcpp::STT fromtype = (object->pluginobj() != NULL + ? to->type() + : sym.get_st_type()); unsigned int frombits = symbol_to_bits(sym.get_st_bind(), object->is_dynamic(), - st_shndx, is_ordinary, - sym.get_st_type()); + st_shndx, is_ordinary); bool adjust_common_sizes; bool adjust_dyndef; typename Sized_symbol::Size_type tosize = to->symsize(); - if (Symbol_table::should_override(to, frombits, sym.get_st_type(), OBJECT, + if (Symbol_table::should_override(to, frombits, fromtype, OBJECT, object, &adjust_common_sizes, - &adjust_dyndef)) + &adjust_dyndef, is_default_version)) { - elfcpp::STB tobinding = to->binding(); + elfcpp::STB orig_tobinding = to->binding(); + typename Sized_symbol::Value_type tovalue = to->value(); this->override(to, sym, st_shndx, is_ordinary, object, version); - if (adjust_common_sizes && tosize > to->symsize()) - to->set_symsize(tosize); + if (adjust_common_sizes) + { + if (tosize > to->symsize()) + to->set_symsize(tosize); + if (tovalue > to->value()) + to->set_value(tovalue); + } if (adjust_dyndef) { // We are overriding an UNDEF or WEAK UNDEF with a DYN DEF. // Remember which kind of UNDEF it was for future reference. - to->set_undef_binding(tobinding); + to->set_undef_binding(orig_tobinding); } } else { - if (adjust_common_sizes && sym.get_st_size() > tosize) - to->set_symsize(sym.get_st_size()); + if (adjust_common_sizes) + { + if (sym.get_st_size() > tosize) + to->set_symsize(sym.get_st_size()); + if (sym.get_st_value() > to->value()) + to->set_value(sym.get_st_value()); + } if (adjust_dyndef) { // We are keeping a DYN DEF after seeing an UNDEF or WEAK UNDEF. @@ -381,6 +431,11 @@ Symbol_table::resolve(Sized_symbol* to, to->override_visibility(sym.get_st_visibility()); } + // If we have a non-WEAK reference from a regular object to a + // dynamic object, mark the dynamic object as needed. + if (to->is_from_dynobj() && to->in_reg() && !to->is_undef_binding_weak()) + to->object()->set_is_needed(); + if (adjust_common_sizes && parameters->options().warn_common()) { if (tosize > sym.get_st_size()) @@ -411,18 +466,16 @@ bool Symbol_table::should_override(const Symbol* to, unsigned int frombits, elfcpp::STT fromtype, Defined defined, Object* object, bool* adjust_common_sizes, - bool* adjust_dyndef) + bool* adjust_dyndef, bool is_default_version) { *adjust_common_sizes = false; *adjust_dyndef = false; unsigned int tobits; if (to->source() == Symbol::IS_UNDEFINED) - tobits = symbol_to_bits(to->binding(), false, elfcpp::SHN_UNDEF, true, - to->type()); + tobits = symbol_to_bits(to->binding(), false, elfcpp::SHN_UNDEF, true); else if (to->source() != Symbol::FROM_OBJECT) - tobits = symbol_to_bits(to->binding(), false, elfcpp::SHN_ABS, false, - to->type()); + tobits = symbol_to_bits(to->binding(), false, elfcpp::SHN_ABS, false); else { bool is_ordinary; @@ -430,13 +483,11 @@ Symbol_table::should_override(const Symbol* to, unsigned int frombits, tobits = symbol_to_bits(to->binding(), to->object()->is_dynamic(), shndx, - is_ordinary, - to->type()); + is_ordinary); } - if (to->type() == elfcpp::STT_TLS - ? fromtype != elfcpp::STT_TLS - : fromtype == elfcpp::STT_TLS) + if ((to->type() == elfcpp::STT_TLS) ^ (fromtype == elfcpp::STT_TLS) + && !to->is_placeholder()) Symbol_table::report_resolve_problem(true, _("symbol '%s' used as both __thread " "and non-__thread"), @@ -562,9 +613,26 @@ Symbol_table::should_override(const Symbol* to, unsigned int frombits, case DEF * 16 + DYN_DEF: case WEAK_DEF * 16 + DYN_DEF: + // Ignore a dynamic definition if we already have a definition. + return false; + case DYN_DEF * 16 + DYN_DEF: case DYN_WEAK_DEF * 16 + DYN_DEF: - // Ignore a dynamic definition if we already have a definition. + // Ignore a dynamic definition if we already have a definition, + // unless the existing definition is an unversioned definition + // in the same dynamic object, and the new definition is a + // default version. + if (to->object() == object + && to->version() == NULL + && is_default_version) + return true; + // Or, if the existing definition is in an unused --as-needed library, + // and the reference is weak, let the new definition override. + if (to->in_reg() + && to->is_undef_binding_weak() + && to->object()->as_needed() + && !to->object()->is_needed()) + return true; return false; case UNDEF * 16 + DYN_DEF: @@ -581,16 +649,12 @@ Symbol_table::should_override(const Symbol* to, unsigned int frombits, case COMMON * 16 + DYN_DEF: case WEAK_COMMON * 16 + DYN_DEF: - case DYN_COMMON * 16 + DYN_DEF: - case DYN_WEAK_COMMON * 16 + DYN_DEF: // Ignore a dynamic definition if we already have a common // definition. return false; case DEF * 16 + DYN_WEAK_DEF: case WEAK_DEF * 16 + DYN_WEAK_DEF: - case DYN_DEF * 16 + DYN_WEAK_DEF: - case DYN_WEAK_DEF * 16 + DYN_WEAK_DEF: // Ignore a weak dynamic definition if we already have a // definition. return false; @@ -614,12 +678,25 @@ Symbol_table::should_override(const Symbol* to, unsigned int frombits, case COMMON * 16 + DYN_WEAK_DEF: case WEAK_COMMON * 16 + DYN_WEAK_DEF: - case DYN_COMMON * 16 + DYN_WEAK_DEF: - case DYN_WEAK_COMMON * 16 + DYN_WEAK_DEF: // Ignore a weak dynamic definition if we already have a common // definition. return false; + case DYN_COMMON * 16 + DYN_DEF: + case DYN_WEAK_COMMON * 16 + DYN_DEF: + case DYN_DEF * 16 + DYN_WEAK_DEF: + case DYN_WEAK_DEF * 16 + DYN_WEAK_DEF: + case DYN_COMMON * 16 + DYN_WEAK_DEF: + case DYN_WEAK_COMMON * 16 + DYN_WEAK_DEF: + // If the existing definition is in an unused --as-needed library, + // and the reference is weak, let a new dynamic definition override. + if (to->in_reg() + && to->is_undef_binding_weak() + && to->object()->as_needed() + && !to->object()->is_needed()) + return true; + return false; + case DEF * 16 + UNDEF: case WEAK_DEF * 16 + UNDEF: case UNDEF * 16 + UNDEF: @@ -871,6 +948,61 @@ Symbol_table::report_resolve_problem(bool is_error, const char* msg, gold_info("%s: %s: previous definition here", program_name, objname); } +// Completely override existing symbol. Everything bar name_, +// version_, and is_forced_local_ flag are copied. version_ is +// cleared if from->version_ is clear. Returns true if this symbol +// should be forced local. +bool +Symbol::clone(const Symbol* from) +{ + // Don't allow cloning after dynamic linking info is attached to symbols. + // We aren't prepared to merge such. + gold_assert(!this->has_symtab_index() && !from->has_symtab_index()); + gold_assert(!this->has_dynsym_index() && !from->has_dynsym_index()); + gold_assert(this->got_offset_list() == NULL + && from->got_offset_list() == NULL); + gold_assert(!this->has_plt_offset() && !from->has_plt_offset()); + + if (!from->version_) + this->version_ = from->version_; + this->u1_ = from->u1_; + this->u2_ = from->u2_; + this->type_ = from->type_; + this->binding_ = from->binding_; + this->visibility_ = from->visibility_; + this->nonvis_ = from->nonvis_; + this->source_ = from->source_; + this->is_def_ = from->is_def_; + this->is_forwarder_ = from->is_forwarder_; + this->has_alias_ = from->has_alias_; + this->needs_dynsym_entry_ = from->needs_dynsym_entry_; + this->in_reg_ = from->in_reg_; + this->in_dyn_ = from->in_dyn_; + this->needs_dynsym_value_ = from->needs_dynsym_value_; + this->has_warning_ = from->has_warning_; + this->is_copied_from_dynobj_ = from->is_copied_from_dynobj_; + this->is_ordinary_shndx_ = from->is_ordinary_shndx_; + this->in_real_elf_ = from->in_real_elf_; + this->is_defined_in_discarded_section_ + = from->is_defined_in_discarded_section_; + this->undef_binding_set_ = from->undef_binding_set_; + this->undef_binding_weak_ = from->undef_binding_weak_; + this->is_predefined_ = from->is_predefined_; + this->is_protected_ = from->is_protected_; + this->non_zero_localentry_ = from->non_zero_localentry_; + + return !this->is_forced_local_ && from->is_forced_local_; +} + +template +bool +Sized_symbol::clone(const Sized_symbol* from) +{ + this->value_ = from->value_; + this->symsize_ = from->symsize_; + return Symbol::clone(from); +} + // A special case of should_override which is only called for a strong // defined symbol from a regular object file. This is used when // defining special symbols. @@ -885,7 +1017,7 @@ Symbol_table::should_override_with_special(const Symbol* to, unsigned int frombits = global_flag | regular_flag | def_flag; bool ret = Symbol_table::should_override(to, frombits, fromtype, defined, NULL, &adjust_common_sizes, - &adjust_dyn_def); + &adjust_dyn_def, false); gold_assert(!adjust_common_sizes && !adjust_dyn_def); return ret; } @@ -898,17 +1030,18 @@ Symbol::override_base_with_special(const Symbol* from) bool same_name = this->name_ == from->name_; gold_assert(same_name || this->has_alias()); + // If we are overriding an undef, remember the original binding. + if (this->is_undefined()) + this->set_undef_binding(this->binding_); + this->source_ = from->source_; switch (from->source_) { case FROM_OBJECT: - this->u_.from_object = from->u_.from_object; - break; case IN_OUTPUT_DATA: - this->u_.in_output_data = from->u_.in_output_data; - break; case IN_OUTPUT_SEGMENT: - this->u_.in_output_segment = from->u_.in_output_segment; + this->u1_ = from->u1_; + this->u2_ = from->u2_; break; case IS_CONSTANT: case IS_UNDEFINED: @@ -1013,7 +1146,8 @@ Symbol_table::resolve<32, false>( bool is_ordinary, unsigned int orig_st_shndx, Object* object, - const char* version); + const char* version, + bool is_default_version); template void @@ -1024,7 +1158,8 @@ Symbol_table::resolve<32, true>( bool is_ordinary, unsigned int orig_st_shndx, Object* object, - const char* version); + const char* version, + bool is_default_version); #endif #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG) @@ -1037,7 +1172,8 @@ Symbol_table::resolve<64, false>( bool is_ordinary, unsigned int orig_st_shndx, Object* object, - const char* version); + const char* version, + bool is_default_version); template void @@ -1048,7 +1184,8 @@ Symbol_table::resolve<64, true>( bool is_ordinary, unsigned int orig_st_shndx, Object* object, - const char* version); + const char* version, + bool is_default_version); #endif #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG) @@ -1065,4 +1202,11 @@ Symbol_table::override_with_special<64>(Sized_symbol<64>*, const Sized_symbol<64>*); #endif +template +bool +Sized_symbol<32>::clone(const Sized_symbol<32>*); + +template +bool +Sized_symbol<64>::clone(const Sized_symbol<64>*); } // End namespace gold.