X-Git-Url: https://oss.titaniummirror.com/gitweb?p=msp430-binutils.git;a=blobdiff_plain;f=gold%2Fresolve.cc;fp=gold%2Fresolve.cc;h=82af9b4c6e83afc800cc6932185a3f573a8ea235;hp=0000000000000000000000000000000000000000;hb=88750007d7869f178f0ba528f41efd3b74c424cf;hpb=6df9443a374e2b81278c61b8afc0a1eef7db280b diff --git a/gold/resolve.cc b/gold/resolve.cc new file mode 100644 index 0000000..82af9b4 --- /dev/null +++ b/gold/resolve.cc @@ -0,0 +1,898 @@ +// resolve.cc -- symbol resolution for gold + +// Copyright 2006, 2007, 2008, 2009 Free Software Foundation, Inc. +// Written by Ian Lance Taylor . + +// This file is part of gold. + +// This program is free software; you can redistribute it and/or modify +// it under the terms of the GNU General Public License as published by +// the Free Software Foundation; either version 3 of the License, or +// (at your option) any later version. + +// This program is distributed in the hope that it will be useful, +// but WITHOUT ANY WARRANTY; without even the implied warranty of +// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +// GNU General Public License for more details. + +// You should have received a copy of the GNU General Public License +// along with this program; if not, write to the Free Software +// Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, +// MA 02110-1301, USA. + +#include "gold.h" + +#include "elfcpp.h" +#include "target.h" +#include "object.h" +#include "symtab.h" +#include "plugin.h" + +namespace gold +{ + +// Symbol methods used in this file. + +// This symbol is being overridden by another symbol whose version is +// VERSION. Update the VERSION_ field accordingly. + +inline void +Symbol::override_version(const char* version) +{ + if (version == NULL) + { + // This is the case where this symbol is NAME/VERSION, and the + // version was not marked as hidden. That makes it the default + // version, so we create NAME/NULL. Later we see another symbol + // NAME/NULL, and that symbol is overriding this one. In this + // case, since NAME/VERSION is the default, we make NAME/NULL + // override NAME/VERSION as well. They are already the same + // Symbol structure. Setting the VERSION_ field to NULL ensures + // that it will be output with the correct, empty, version. + this->version_ = version; + } + else + { + // This is the case where this symbol is NAME/VERSION_ONE, and + // now we see NAME/VERSION_TWO, and NAME/VERSION_TWO is + // overriding NAME. If VERSION_ONE and VERSION_TWO are + // different, then this can only happen when VERSION_ONE is NULL + // and VERSION_TWO is not hidden. + gold_assert(this->version_ == version || this->version_ == NULL); + this->version_ = version; + } +} + +// This symbol is being overidden by another symbol whose visibility +// is VISIBILITY. Updated the VISIBILITY_ field accordingly. + +inline void +Symbol::override_visibility(elfcpp::STV visibility) +{ + // The rule for combining visibility is that we always choose the + // most constrained visibility. In order of increasing constraint, + // visibility goes PROTECTED, HIDDEN, INTERNAL. This is the reverse + // of the numeric values, so the effect is that we always want the + // smallest non-zero value. + if (visibility != elfcpp::STV_DEFAULT) + { + if (this->visibility_ == elfcpp::STV_DEFAULT) + this->visibility_ = visibility; + else if (this->visibility_ > visibility) + this->visibility_ = visibility; + } +} + +// Override the fields in Symbol. + +template +void +Symbol::override_base(const elfcpp::Sym& sym, + unsigned int st_shndx, bool is_ordinary, + Object* object, const char* version) +{ + gold_assert(this->source_ == FROM_OBJECT); + this->u_.from_object.object = object; + this->override_version(version); + this->u_.from_object.shndx = st_shndx; + this->is_ordinary_shndx_ = is_ordinary; + 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(); + if (object->is_dynamic()) + this->in_dyn_ = true; + else + this->in_reg_ = true; +} + +// Override the fields in Sized_symbol. + +template +template +void +Sized_symbol::override(const elfcpp::Sym& sym, + unsigned st_shndx, bool is_ordinary, + Object* object, const char* version) +{ + this->override_base(sym, st_shndx, is_ordinary, object, version); + this->value_ = sym.get_st_value(); + this->symsize_ = sym.get_st_size(); +} + +// Override TOSYM with symbol FROMSYM, defined in OBJECT, with version +// VERSION. This handles all aliases of TOSYM. + +template +void +Symbol_table::override(Sized_symbol* tosym, + const elfcpp::Sym& fromsym, + unsigned int st_shndx, bool is_ordinary, + Object* object, const char* version) +{ + tosym->override(fromsym, st_shndx, is_ordinary, object, version); + if (tosym->has_alias()) + { + Symbol* sym = this->weak_aliases_[tosym]; + gold_assert(sym != NULL); + Sized_symbol* ssym = this->get_sized_symbol(sym); + do + { + ssym->override(fromsym, st_shndx, is_ordinary, object, version); + sym = this->weak_aliases_[ssym]; + gold_assert(sym != NULL); + ssym = this->get_sized_symbol(sym); + } + while (ssym != tosym); + } +} + +// The resolve functions build a little code for each symbol. +// Bit 0: 0 for global, 1 for weak. +// Bit 1: 0 for regular object, 1 for shared object +// Bits 2-3: 0 for normal, 1 for undefined, 2 for common +// This gives us values from 0 to 11. + +static const int global_or_weak_shift = 0; +static const unsigned int global_flag = 0 << global_or_weak_shift; +static const unsigned int weak_flag = 1 << global_or_weak_shift; + +static const int regular_or_dynamic_shift = 1; +static const unsigned int regular_flag = 0 << regular_or_dynamic_shift; +static const unsigned int dynamic_flag = 1 << regular_or_dynamic_shift; + +static const int def_undef_or_common_shift = 2; +static const unsigned int def_flag = 0 << def_undef_or_common_shift; +static const unsigned int undef_flag = 1 << def_undef_or_common_shift; +static const unsigned int common_flag = 2 << def_undef_or_common_shift; + +// This convenience function combines all the flags based on facts +// about the symbol. + +static unsigned int +symbol_to_bits(elfcpp::STB binding, bool is_dynamic, + unsigned int shndx, bool is_ordinary, elfcpp::STT type) +{ + unsigned int bits; + + switch (binding) + { + case elfcpp::STB_GLOBAL: + bits = global_flag; + break; + + case elfcpp::STB_WEAK: + bits = weak_flag; + break; + + case elfcpp::STB_LOCAL: + // We should only see externally visible symbols in the symbol + // table. + gold_error(_("invalid STB_LOCAL symbol in external symbols")); + bits = global_flag; + + default: + // Any target which wants to handle STB_LOOS, etc., needs to + // define a resolve method. + gold_error(_("unsupported symbol binding")); + bits = global_flag; + } + + if (is_dynamic) + bits |= dynamic_flag; + else + bits |= regular_flag; + + switch (shndx) + { + case elfcpp::SHN_UNDEF: + bits |= undef_flag; + break; + + case elfcpp::SHN_COMMON: + if (!is_ordinary) + bits |= common_flag; + break; + + default: + if (type == elfcpp::STT_COMMON) + bits |= common_flag; + else if (!is_ordinary && Symbol::is_common_shndx(shndx)) + bits |= common_flag; + else + bits |= def_flag; + break; + } + + return bits; +} + +// Resolve a symbol. This is called the second and subsequent times +// we see a symbol. TO is the pre-existing symbol. ST_SHNDX is the +// section index for SYM, possibly adjusted for many sections. +// IS_ORDINARY is whether ST_SHNDX is a normal section index rather +// than a special code. ORIG_ST_SHNDX is the original section index, +// before any munging because of discarded sections, except that all +// non-ordinary section indexes are mapped to SHN_UNDEF. VERSION is +// the version of SYM. + +template +void +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) +{ + if (parameters->target().has_resolve()) + { + Sized_target* sized_target; + sized_target = parameters->sized_target(); + sized_target->resolve(to, sym, object, version); + return; + } + + if (!object->is_dynamic()) + { + // Record that we've seen this symbol in a regular object. + to->set_in_reg(); + } + else if (st_shndx == elfcpp::SHN_UNDEF + && (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()); + return; + } + else + { + // Record that we've seen this symbol in a dynamic object. + to->set_in_dyn(); + } + + // Record if we've seen this symbol in a real ELF object (i.e., the + // symbol is referenced from outside the world known to the plugin). + if (object->pluginobj() == NULL) + to->set_in_real_elf(); + + // If we're processing replacement files, allow new symbols to override + // the placeholders from the plugin objects. + 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; + } + } + + unsigned int frombits = symbol_to_bits(sym.get_st_bind(), + object->is_dynamic(), + st_shndx, is_ordinary, + sym.get_st_type()); + + bool adjust_common_sizes; + if (Symbol_table::should_override(to, frombits, object, + &adjust_common_sizes)) + { + typename Sized_symbol::Size_type tosize = to->symsize(); + + this->override(to, sym, st_shndx, is_ordinary, object, version); + + if (adjust_common_sizes && tosize > to->symsize()) + to->set_symsize(tosize); + } + else + { + if (adjust_common_sizes && sym.get_st_size() > to->symsize()) + to->set_symsize(sym.get_st_size()); + // The ELF ABI says that even for a reference to a symbol we + // merge the visibility. + to->override_visibility(sym.get_st_visibility()); + } + + // A new weak undefined reference, merging with an old weak + // reference, could be a One Definition Rule (ODR) violation -- + // especially if the types or sizes of the references differ. We'll + // store such pairs and look them up later to make sure they + // actually refer to the same lines of code. (Note: not all ODR + // violations can be found this way, and not everything this finds + // is an ODR violation. But it's helpful to warn about.) + bool to_is_ordinary; + if (parameters->options().detect_odr_violations() + && 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 + && sym.get_st_size() != 0 // Ignore weird 0-sized symbols. + && to->symsize() != 0 + && (sym.get_st_type() != to->type() + || sym.get_st_size() != to->symsize()) + // C does not have a concept of ODR, so we only need to do this + // on C++ symbols. These have (mangled) names starting with _Z. + && 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() }; + this->candidate_odr_violations_[to->name()].insert(fromloc); + this->candidate_odr_violations_[to->name()].insert(toloc); + } +} + +// Handle the core of symbol resolution. This is called with the +// existing symbol, TO, and a bitflag describing the new symbol. This +// returns true if we should override the existing symbol with the new +// one, and returns false otherwise. It sets *ADJUST_COMMON_SIZES to +// true if we should set the symbol size to the maximum of the TO and +// FROM sizes. It handles error conditions. + +bool +Symbol_table::should_override(const Symbol* to, unsigned int frombits, + Object* object, bool* adjust_common_sizes) +{ + *adjust_common_sizes = false; + + unsigned int tobits; + if (to->source() == Symbol::IS_UNDEFINED) + tobits = symbol_to_bits(to->binding(), false, elfcpp::SHN_UNDEF, true, + to->type()); + else if (to->source() != Symbol::FROM_OBJECT) + tobits = symbol_to_bits(to->binding(), false, elfcpp::SHN_ABS, false, + to->type()); + else + { + bool is_ordinary; + unsigned int shndx = to->shndx(&is_ordinary); + tobits = symbol_to_bits(to->binding(), + to->object()->is_dynamic(), + shndx, + is_ordinary, + to->type()); + } + + // FIXME: Warn if either but not both of TO and SYM are STT_TLS. + + // We use a giant switch table for symbol resolution. This code is + // unwieldy, but: 1) it is efficient; 2) we definitely handle all + // cases; 3) it is easy to change the handling of a particular case. + // The alternative would be a series of conditionals, but it is easy + // to get the ordering wrong. This could also be done as a table, + // but that is no easier to understand than this large switch + // statement. + + // These are the values generated by the bit codes. + enum + { + DEF = global_flag | regular_flag | def_flag, + WEAK_DEF = weak_flag | regular_flag | def_flag, + DYN_DEF = global_flag | dynamic_flag | def_flag, + DYN_WEAK_DEF = weak_flag | dynamic_flag | def_flag, + UNDEF = global_flag | regular_flag | undef_flag, + WEAK_UNDEF = weak_flag | regular_flag | undef_flag, + DYN_UNDEF = global_flag | dynamic_flag | undef_flag, + DYN_WEAK_UNDEF = weak_flag | dynamic_flag | undef_flag, + COMMON = global_flag | regular_flag | common_flag, + WEAK_COMMON = weak_flag | regular_flag | common_flag, + DYN_COMMON = global_flag | dynamic_flag | common_flag, + DYN_WEAK_COMMON = weak_flag | dynamic_flag | common_flag + }; + + switch (tobits * 16 + frombits) + { + case DEF * 16 + DEF: + // Two definitions of the same symbol. + + // If either symbol is defined by an object included using + // --just-symbols, then don't warn. This is for compatibility + // with the GNU linker. FIXME: This is a hack. + if ((to->source() == Symbol::FROM_OBJECT && to->object()->just_symbols()) + || object->just_symbols()) + return false; + + // FIXME: Do a better job of reporting locations. + gold_error(_("%s: multiple definition of %s"), + object != NULL ? object->name().c_str() : _("command line"), + to->demangled_name().c_str()); + gold_error(_("%s: previous definition here"), + (to->source() == Symbol::FROM_OBJECT + ? to->object()->name().c_str() + : _("command line"))); + return false; + + case WEAK_DEF * 16 + DEF: + // We've seen a weak definition, and now we see a strong + // definition. In the original SVR4 linker, this was treated as + // a multiple definition error. In the Solaris linker and the + // GNU linker, a weak definition followed by a regular + // definition causes the weak definition to be overridden. We + // are currently compatible with the GNU linker. In the future + // we should add a target specific option to change this. + // FIXME. + return true; + + case DYN_DEF * 16 + DEF: + case DYN_WEAK_DEF * 16 + DEF: + // We've seen a definition in a dynamic object, and now we see a + // definition in a regular object. The definition in the + // regular object overrides the definition in the dynamic + // object. + return true; + + case UNDEF * 16 + DEF: + case WEAK_UNDEF * 16 + DEF: + case DYN_UNDEF * 16 + DEF: + case DYN_WEAK_UNDEF * 16 + DEF: + // We've seen an undefined reference, and now we see a + // definition. We use the definition. + return true; + + case COMMON * 16 + DEF: + case WEAK_COMMON * 16 + DEF: + case DYN_COMMON * 16 + DEF: + case DYN_WEAK_COMMON * 16 + DEF: + // We've seen a common symbol and now we see a definition. The + // definition overrides. FIXME: We should optionally issue, version a + // warning. + return true; + + case DEF * 16 + WEAK_DEF: + case WEAK_DEF * 16 + WEAK_DEF: + // We've seen a definition and now we see a weak definition. We + // ignore the new weak definition. + return false; + + case DYN_DEF * 16 + WEAK_DEF: + case DYN_WEAK_DEF * 16 + WEAK_DEF: + // We've seen a dynamic definition and now we see a regular weak + // definition. The regular weak definition overrides. + return true; + + case UNDEF * 16 + WEAK_DEF: + case WEAK_UNDEF * 16 + WEAK_DEF: + case DYN_UNDEF * 16 + WEAK_DEF: + case DYN_WEAK_UNDEF * 16 + WEAK_DEF: + // A weak definition of a currently undefined symbol. + return true; + + case COMMON * 16 + WEAK_DEF: + case WEAK_COMMON * 16 + WEAK_DEF: + // A weak definition does not override a common definition. + return false; + + case DYN_COMMON * 16 + WEAK_DEF: + case DYN_WEAK_COMMON * 16 + WEAK_DEF: + // A weak definition does override a definition in a dynamic + // object. FIXME: We should optionally issue a warning. + return true; + + case DEF * 16 + DYN_DEF: + case WEAK_DEF * 16 + DYN_DEF: + case DYN_DEF * 16 + DYN_DEF: + case DYN_WEAK_DEF * 16 + DYN_DEF: + // Ignore a dynamic definition if we already have a definition. + return false; + + case UNDEF * 16 + DYN_DEF: + case WEAK_UNDEF * 16 + DYN_DEF: + case DYN_UNDEF * 16 + DYN_DEF: + case DYN_WEAK_UNDEF * 16 + DYN_DEF: + // Use a dynamic definition if we have a reference. + return true; + + 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; + + case UNDEF * 16 + DYN_WEAK_DEF: + case WEAK_UNDEF * 16 + DYN_WEAK_DEF: + case DYN_UNDEF * 16 + DYN_WEAK_DEF: + case DYN_WEAK_UNDEF * 16 + DYN_WEAK_DEF: + // Use a weak dynamic definition if we have a reference. + return true; + + 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 DEF * 16 + UNDEF: + case WEAK_DEF * 16 + UNDEF: + case DYN_DEF * 16 + UNDEF: + case DYN_WEAK_DEF * 16 + UNDEF: + case UNDEF * 16 + UNDEF: + // A new undefined reference tells us nothing. + return false; + + case WEAK_UNDEF * 16 + UNDEF: + case DYN_UNDEF * 16 + UNDEF: + case DYN_WEAK_UNDEF * 16 + UNDEF: + // A strong undef overrides a dynamic or weak undef. + return true; + + case COMMON * 16 + UNDEF: + case WEAK_COMMON * 16 + UNDEF: + case DYN_COMMON * 16 + UNDEF: + case DYN_WEAK_COMMON * 16 + UNDEF: + // A new undefined reference tells us nothing. + return false; + + case DEF * 16 + WEAK_UNDEF: + case WEAK_DEF * 16 + WEAK_UNDEF: + case DYN_DEF * 16 + WEAK_UNDEF: + case DYN_WEAK_DEF * 16 + WEAK_UNDEF: + case UNDEF * 16 + WEAK_UNDEF: + case WEAK_UNDEF * 16 + WEAK_UNDEF: + case DYN_UNDEF * 16 + WEAK_UNDEF: + case DYN_WEAK_UNDEF * 16 + WEAK_UNDEF: + case COMMON * 16 + WEAK_UNDEF: + case WEAK_COMMON * 16 + WEAK_UNDEF: + case DYN_COMMON * 16 + WEAK_UNDEF: + case DYN_WEAK_COMMON * 16 + WEAK_UNDEF: + // A new weak undefined reference tells us nothing. + return false; + + case DEF * 16 + DYN_UNDEF: + case WEAK_DEF * 16 + DYN_UNDEF: + case DYN_DEF * 16 + DYN_UNDEF: + case DYN_WEAK_DEF * 16 + DYN_UNDEF: + case UNDEF * 16 + DYN_UNDEF: + case WEAK_UNDEF * 16 + DYN_UNDEF: + case DYN_UNDEF * 16 + DYN_UNDEF: + case DYN_WEAK_UNDEF * 16 + DYN_UNDEF: + case COMMON * 16 + DYN_UNDEF: + case WEAK_COMMON * 16 + DYN_UNDEF: + case DYN_COMMON * 16 + DYN_UNDEF: + case DYN_WEAK_COMMON * 16 + DYN_UNDEF: + // A new dynamic undefined reference tells us nothing. + return false; + + case DEF * 16 + DYN_WEAK_UNDEF: + case WEAK_DEF * 16 + DYN_WEAK_UNDEF: + case DYN_DEF * 16 + DYN_WEAK_UNDEF: + case DYN_WEAK_DEF * 16 + DYN_WEAK_UNDEF: + case UNDEF * 16 + DYN_WEAK_UNDEF: + case WEAK_UNDEF * 16 + DYN_WEAK_UNDEF: + case DYN_UNDEF * 16 + DYN_WEAK_UNDEF: + case DYN_WEAK_UNDEF * 16 + DYN_WEAK_UNDEF: + case COMMON * 16 + DYN_WEAK_UNDEF: + case WEAK_COMMON * 16 + DYN_WEAK_UNDEF: + case DYN_COMMON * 16 + DYN_WEAK_UNDEF: + case DYN_WEAK_COMMON * 16 + DYN_WEAK_UNDEF: + // A new weak dynamic undefined reference tells us nothing. + return false; + + case DEF * 16 + COMMON: + // A common symbol does not override a definition. + return false; + + case WEAK_DEF * 16 + COMMON: + case DYN_DEF * 16 + COMMON: + case DYN_WEAK_DEF * 16 + COMMON: + // A common symbol does override a weak definition or a dynamic + // definition. + return true; + + case UNDEF * 16 + COMMON: + case WEAK_UNDEF * 16 + COMMON: + case DYN_UNDEF * 16 + COMMON: + case DYN_WEAK_UNDEF * 16 + COMMON: + // A common symbol is a definition for a reference. + return true; + + case COMMON * 16 + COMMON: + // Set the size to the maximum. + *adjust_common_sizes = true; + return false; + + case WEAK_COMMON * 16 + COMMON: + // I'm not sure just what a weak common symbol means, but + // presumably it can be overridden by a regular common symbol. + return true; + + case DYN_COMMON * 16 + COMMON: + case DYN_WEAK_COMMON * 16 + COMMON: + // Use the real common symbol, but adjust the size if necessary. + *adjust_common_sizes = true; + return true; + + case DEF * 16 + WEAK_COMMON: + case WEAK_DEF * 16 + WEAK_COMMON: + case DYN_DEF * 16 + WEAK_COMMON: + case DYN_WEAK_DEF * 16 + WEAK_COMMON: + // Whatever a weak common symbol is, it won't override a + // definition. + return false; + + case UNDEF * 16 + WEAK_COMMON: + case WEAK_UNDEF * 16 + WEAK_COMMON: + case DYN_UNDEF * 16 + WEAK_COMMON: + case DYN_WEAK_UNDEF * 16 + WEAK_COMMON: + // A weak common symbol is better than an undefined symbol. + return true; + + case COMMON * 16 + WEAK_COMMON: + case WEAK_COMMON * 16 + WEAK_COMMON: + case DYN_COMMON * 16 + WEAK_COMMON: + case DYN_WEAK_COMMON * 16 + WEAK_COMMON: + // Ignore a weak common symbol in the presence of a real common + // symbol. + return false; + + case DEF * 16 + DYN_COMMON: + case WEAK_DEF * 16 + DYN_COMMON: + case DYN_DEF * 16 + DYN_COMMON: + case DYN_WEAK_DEF * 16 + DYN_COMMON: + // Ignore a dynamic common symbol in the presence of a + // definition. + return false; + + case UNDEF * 16 + DYN_COMMON: + case WEAK_UNDEF * 16 + DYN_COMMON: + case DYN_UNDEF * 16 + DYN_COMMON: + case DYN_WEAK_UNDEF * 16 + DYN_COMMON: + // A dynamic common symbol is a definition of sorts. + return true; + + case COMMON * 16 + DYN_COMMON: + case WEAK_COMMON * 16 + DYN_COMMON: + case DYN_COMMON * 16 + DYN_COMMON: + case DYN_WEAK_COMMON * 16 + DYN_COMMON: + // Set the size to the maximum. + *adjust_common_sizes = true; + return false; + + case DEF * 16 + DYN_WEAK_COMMON: + case WEAK_DEF * 16 + DYN_WEAK_COMMON: + case DYN_DEF * 16 + DYN_WEAK_COMMON: + case DYN_WEAK_DEF * 16 + DYN_WEAK_COMMON: + // A common symbol is ignored in the face of a definition. + return false; + + case UNDEF * 16 + DYN_WEAK_COMMON: + case WEAK_UNDEF * 16 + DYN_WEAK_COMMON: + case DYN_UNDEF * 16 + DYN_WEAK_COMMON: + case DYN_WEAK_UNDEF * 16 + DYN_WEAK_COMMON: + // I guess a weak common symbol is better than a definition. + return true; + + case COMMON * 16 + DYN_WEAK_COMMON: + case WEAK_COMMON * 16 + DYN_WEAK_COMMON: + case DYN_COMMON * 16 + DYN_WEAK_COMMON: + case DYN_WEAK_COMMON * 16 + DYN_WEAK_COMMON: + // Set the size to the maximum. + *adjust_common_sizes = true; + return false; + + default: + gold_unreachable(); + } +} + +// 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. + +bool +Symbol_table::should_override_with_special(const Symbol* to) +{ + bool adjust_common_sizes; + unsigned int frombits = global_flag | regular_flag | def_flag; + bool ret = Symbol_table::should_override(to, frombits, NULL, + &adjust_common_sizes); + gold_assert(!adjust_common_sizes); + return ret; +} + +// Override symbol base with a special symbol. + +void +Symbol::override_base_with_special(const Symbol* from) +{ + gold_assert(this->name_ == from->name_ || this->has_alias()); + + 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; + break; + case IS_CONSTANT: + case IS_UNDEFINED: + break; + default: + gold_unreachable(); + break; + } + + this->override_version(from->version_); + this->type_ = from->type_; + this->binding_ = from->binding_; + this->override_visibility(from->visibility_); + this->nonvis_ = from->nonvis_; + + // Special symbols are always considered to be regular symbols. + this->in_reg_ = true; + + if (from->needs_dynsym_entry_) + this->needs_dynsym_entry_ = true; + if (from->needs_dynsym_value_) + this->needs_dynsym_value_ = true; + + // We shouldn't see these flags. If we do, we need to handle them + // somehow. + gold_assert(!from->is_target_special_ || this->is_target_special_); + gold_assert(!from->is_forwarder_); + gold_assert(!from->has_plt_offset_); + gold_assert(!from->has_warning_); + gold_assert(!from->is_copied_from_dynobj_); + gold_assert(!from->is_forced_local_); +} + +// Override a symbol with a special symbol. + +template +void +Sized_symbol::override_with_special(const Sized_symbol* from) +{ + this->override_base_with_special(from); + this->value_ = from->value_; + this->symsize_ = from->symsize_; +} + +// Override TOSYM with the special symbol FROMSYM. This handles all +// aliases of TOSYM. + +template +void +Symbol_table::override_with_special(Sized_symbol* tosym, + const Sized_symbol* fromsym) +{ + tosym->override_with_special(fromsym); + if (tosym->has_alias()) + { + Symbol* sym = this->weak_aliases_[tosym]; + gold_assert(sym != NULL); + Sized_symbol* ssym = this->get_sized_symbol(sym); + do + { + ssym->override_with_special(fromsym); + sym = this->weak_aliases_[ssym]; + gold_assert(sym != NULL); + ssym = this->get_sized_symbol(sym); + } + while (ssym != tosym); + } + if (tosym->binding() == elfcpp::STB_LOCAL + || ((tosym->visibility() == elfcpp::STV_HIDDEN + || tosym->visibility() == elfcpp::STV_INTERNAL) + && (tosym->binding() == elfcpp::STB_GLOBAL + || tosym->binding() == elfcpp::STB_WEAK) + && !parameters->options().relocatable())) + this->force_local(tosym); +} + +// Instantiate the templates we need. We could use the configure +// script to restrict this to only the ones needed for implemented +// targets. + +#ifdef HAVE_TARGET_32_LITTLE +template +void +Symbol_table::resolve<32, false>( + Sized_symbol<32>* to, + const elfcpp::Sym<32, false>& sym, + unsigned int st_shndx, + bool is_ordinary, + unsigned int orig_st_shndx, + Object* object, + const char* version); +#endif + +#ifdef HAVE_TARGET_32_BIG +template +void +Symbol_table::resolve<32, true>( + Sized_symbol<32>* to, + const elfcpp::Sym<32, true>& sym, + unsigned int st_shndx, + bool is_ordinary, + unsigned int orig_st_shndx, + Object* object, + const char* version); +#endif + +#ifdef HAVE_TARGET_64_LITTLE +template +void +Symbol_table::resolve<64, false>( + Sized_symbol<64>* to, + const elfcpp::Sym<64, false>& sym, + unsigned int st_shndx, + bool is_ordinary, + unsigned int orig_st_shndx, + Object* object, + const char* version); +#endif + +#ifdef HAVE_TARGET_64_BIG +template +void +Symbol_table::resolve<64, true>( + Sized_symbol<64>* to, + const elfcpp::Sym<64, true>& sym, + unsigned int st_shndx, + bool is_ordinary, + unsigned int orig_st_shndx, + Object* object, + const char* version); +#endif + +#if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG) +template +void +Symbol_table::override_with_special<32>(Sized_symbol<32>*, + const Sized_symbol<32>*); +#endif + +#if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG) +template +void +Symbol_table::override_with_special<64>(Sized_symbol<64>*, + const Sized_symbol<64>*); +#endif + +} // End namespace gold.