| // resolve.cc -- symbol resolution for gold |
| |
| // Copyright 2006, 2007, 2008 Free Software Foundation, Inc. |
| // Written by Ian Lance Taylor <iant@google.com>. |
| |
| // 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" |
| |
| 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; |
| } |
| } |
| |
| // Override the fields in Symbol. |
| |
| template<int size, bool big_endian> |
| void |
| Symbol::override_base(const elfcpp::Sym<size, big_endian>& 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->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<int size> |
| template<bool big_endian> |
| void |
| Sized_symbol<size>::override(const elfcpp::Sym<size, big_endian>& 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<int size, bool big_endian> |
| void |
| Symbol_table::override(Sized_symbol<size>* tosym, |
| const elfcpp::Sym<size, big_endian>& 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<size>* ssym = this->get_sized_symbol<size>(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<size>(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 |
| 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<int size, bool big_endian> |
| void |
| Symbol_table::resolve(Sized_symbol<size>* to, |
| const elfcpp::Sym<size, big_endian>& sym, |
| unsigned int st_shndx, bool is_ordinary, |
| unsigned int orig_st_shndx, |
| Object* object, const char* version) |
| { |
| if (object->target()->has_resolve()) |
| { |
| Sized_target<size, big_endian>* sized_target; |
| sized_target = object->sized_target<size, big_endian>(); |
| 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 |
| { |
| // Record that we've seen this symbol in a dynamic object. |
| to->set_in_dyn(); |
| } |
| |
| 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>::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()); |
| } |
| |
| // 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->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<int size> |
| void |
| Sized_symbol<size>::override_with_special(const Sized_symbol<size>* 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<int size> |
| void |
| Symbol_table::override_with_special(Sized_symbol<size>* tosym, |
| const Sized_symbol<size>* fromsym) |
| { |
| tosym->override_with_special(fromsym); |
| if (tosym->has_alias()) |
| { |
| Symbol* sym = this->weak_aliases_[tosym]; |
| gold_assert(sym != NULL); |
| Sized_symbol<size>* ssym = this->get_sized_symbol<size>(sym); |
| do |
| { |
| ssym->override_with_special(fromsym); |
| sym = this->weak_aliases_[ssym]; |
| gold_assert(sym != NULL); |
| ssym = this->get_sized_symbol<size>(sym); |
| } |
| while (ssym != tosym); |
| } |
| if (tosym->binding() == elfcpp::STB_LOCAL) |
| 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. |