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,
+ Object* object, const char* version)
+{
+ tosym->override(fromsym, object, version);
+ if (tosym->has_alias())
+ {
+ Symbol* sym = this->weak_aliases_[tosym];
+ gold_assert(sym != NULL);
+ Sized_symbol<size>* ssym;
+ ssym = this->get_sized_symbol SELECT_SIZE_NAME(size) (sym
+ SELECT_SIZE(size));
+ do
+ {
+ ssym->override(fromsym, object, version);
+ sym = this->weak_aliases_[ssym];
+ gold_assert(sym != NULL);
+ ssym = this->get_sized_symbol SELECT_SIZE_NAME(size) (
+ sym SELECT_SIZE(size));
+ }
+ 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
{
typename Sized_symbol<size>::Size_type tosize = to->symsize();
- to->override(sym, object, version);
+ this->override(to, sym, object, version);
if (adjust_common_sizes && tosize > to->symsize())
to->set_symsize(tosize);
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;
+ ssym = this->get_sized_symbol SELECT_SIZE_NAME(size) (sym
+ SELECT_SIZE(size));
+ do
+ {
+ ssym->override_with_special(fromsym);
+ sym = this->weak_aliases_[ssym];
+ gold_assert(sym != NULL);
+ ssym = this->get_sized_symbol SELECT_SIZE_NAME(size) (
+ sym SELECT_SIZE(size));
+ }
+ while (ssym != tosym);
+ }
+}
+
// Instantiate the templates we need. We could use the configure
// script to restrict this to only the ones needed for implemented
// targets.
#if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
template
void
-Sized_symbol<32>::override_with_special(const Sized_symbol<32>*);
+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
-Sized_symbol<64>::override_with_special(const Sized_symbol<64>*);
+Symbol_table::override_with_special<64>(Sized_symbol<64>*,
+ const Sized_symbol<64>*);
#endif
} // End namespace gold.
this->is_target_special_ = false;
this->is_def_ = false;
this->is_forwarder_ = false;
+ this->has_alias_ = false;
this->needs_dynsym_entry_ = false;
this->in_reg_ = false;
this->in_dyn_ = false;
esym.put_st_info(from->binding(), from->type());
esym.put_st_other(from->visibility(), from->nonvis());
esym.put_st_shndx(from->shndx());
- Symbol_table::resolve(to, esym.sym(), from->object(), version);
+ this->resolve(to, esym.sym(), from->object(), version);
if (from->in_reg())
to->set_in_reg();
if (from->in_dyn())
// forwarders.
template<int size, bool big_endian>
-Symbol*
+Sized_symbol<size>*
Symbol_table::add_from_object(Object* object,
const char *name,
Stringpool::Key name_key,
was_undefined = ret->is_undefined();
was_common = ret->is_common();
- Symbol_table::resolve(ret, sym, object, version);
+ this->resolve(ret, sym, object, version);
if (def)
{
ret = this->get_sized_symbol SELECT_SIZE_NAME(size) (
insdef.first->second
SELECT_SIZE(size));
- Symbol_table::resolve(ret, sym, object, version);
+ this->resolve(ret, sym, object, version);
ins.first->second = ret;
}
else
// this is the default version.
const char* ver = strchr(name, '@');
- Symbol* res;
+ Sized_symbol<size>* res;
if (ver == NULL)
{
Stringpool::Key name_key;
const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
+ // We keep a list of all STT_OBJECT symbols, so that we can resolve
+ // weak aliases. This is necessary because if the dynamic object
+ // provides the same variable under two names, one of which is a
+ // weak definition, and the regular object refers to the weak
+ // definition, we have to put both the weak definition and the
+ // strong definition into the dynamic symbol table. Given a weak
+ // definition, the only way that we can find the corresponding
+ // strong definition, if any, is to search the symbol table.
+ std::vector<Sized_symbol<size>*> object_symbols;
+
const unsigned char* p = syms;
const unsigned char* vs = versym;
for (size_t i = 0; i < count; ++i, p += sym_size, vs += 2)
const char* name = sym_names + st_name;
+ Sized_symbol<size>* res;
+
if (versym == NULL)
{
Stringpool::Key name_key;
name = this->namepool_.add(name, true, &name_key);
- this->add_from_object(dynobj, name, name_key, NULL, 0,
- false, sym);
- continue;
+ res = this->add_from_object(dynobj, name, name_key, NULL, 0,
+ false, sym);
}
+ else
+ {
+ // Read the version information.
- // Read the version information.
+ unsigned int v = elfcpp::Swap<16, big_endian>::readval(vs);
- unsigned int v = elfcpp::Swap<16, big_endian>::readval(vs);
+ bool hidden = (v & elfcpp::VERSYM_HIDDEN) != 0;
+ v &= elfcpp::VERSYM_VERSION;
- bool hidden = (v & elfcpp::VERSYM_HIDDEN) != 0;
- v &= elfcpp::VERSYM_VERSION;
+ // The Sun documentation says that V can be VER_NDX_LOCAL,
+ // or VER_NDX_GLOBAL, or a version index. The meaning of
+ // VER_NDX_LOCAL is defined as "Symbol has local scope."
+ // The old GNU linker will happily generate VER_NDX_LOCAL
+ // for an undefined symbol. I don't know what the Sun
+ // linker will generate.
- // The Sun documentation says that V can be VER_NDX_LOCAL, or
- // VER_NDX_GLOBAL, or a version index. The meaning of
- // VER_NDX_LOCAL is defined as "Symbol has local scope." The
- // old GNU linker will happily generate VER_NDX_LOCAL for an
- // undefined symbol. I don't know what the Sun linker will
- // generate.
+ if (v == static_cast<unsigned int>(elfcpp::VER_NDX_LOCAL)
+ && sym.get_st_shndx() != elfcpp::SHN_UNDEF)
+ {
+ // This symbol should not be visible outside the object.
+ continue;
+ }
- if (v == static_cast<unsigned int>(elfcpp::VER_NDX_LOCAL)
- && sym.get_st_shndx() != elfcpp::SHN_UNDEF)
- {
- // This symbol should not be visible outside the object.
- continue;
- }
+ // At this point we are definitely going to add this symbol.
+ Stringpool::Key name_key;
+ name = this->namepool_.add(name, true, &name_key);
- // At this point we are definitely going to add this symbol.
- Stringpool::Key name_key;
- name = this->namepool_.add(name, true, &name_key);
+ if (v == static_cast<unsigned int>(elfcpp::VER_NDX_LOCAL)
+ || v == static_cast<unsigned int>(elfcpp::VER_NDX_GLOBAL))
+ {
+ // This symbol does not have a version.
+ res = this->add_from_object(dynobj, name, name_key, NULL, 0,
+ false, sym);
+ }
+ else
+ {
+ if (v >= version_map->size())
+ {
+ dynobj->error(_("versym for symbol %zu out of range: %u"),
+ i, v);
+ continue;
+ }
- if (v == static_cast<unsigned int>(elfcpp::VER_NDX_LOCAL)
- || v == static_cast<unsigned int>(elfcpp::VER_NDX_GLOBAL))
- {
- // This symbol does not have a version.
- this->add_from_object(dynobj, name, name_key, NULL, 0, false, sym);
- continue;
- }
+ const char* version = (*version_map)[v];
+ if (version == NULL)
+ {
+ dynobj->error(_("versym for symbol %zu has no name: %u"),
+ i, v);
+ continue;
+ }
- if (v >= version_map->size())
- {
- dynobj->error(_("versym for symbol %zu out of range: %u"), i, v);
- continue;
+ Stringpool::Key version_key;
+ version = this->namepool_.add(version, true, &version_key);
+
+ // If this is an absolute symbol, and the version name
+ // and symbol name are the same, then this is the
+ // version definition symbol. These symbols exist to
+ // support using -u to pull in particular versions. We
+ // do not want to record a version for them.
+ if (sym.get_st_shndx() == elfcpp::SHN_ABS
+ && name_key == version_key)
+ res = this->add_from_object(dynobj, name, name_key, NULL, 0,
+ false, sym);
+ else
+ {
+ const bool def = (!hidden
+ && (sym.get_st_shndx()
+ != elfcpp::SHN_UNDEF));
+ res = this->add_from_object(dynobj, name, name_key, version,
+ version_key, def, sym);
+ }
+ }
}
- const char* version = (*version_map)[v];
- if (version == NULL)
- {
- dynobj->error(_("versym for symbol %zu has no name: %u"), i, v);
- continue;
- }
+ if (sym.get_st_shndx() != elfcpp::SHN_UNDEF
+ && sym.get_st_type() == elfcpp::STT_OBJECT)
+ object_symbols.push_back(res);
+ }
+
+ this->record_weak_aliases(&object_symbols);
+}
+
+// This is used to sort weak aliases. We sort them first by section
+// index, then by offset, then by weak ahead of strong.
+
+template<int size>
+class Weak_alias_sorter
+{
+ public:
+ bool operator()(const Sized_symbol<size>*, const Sized_symbol<size>*) const;
+};
+
+template<int size>
+bool
+Weak_alias_sorter<size>::operator()(const Sized_symbol<size>* s1,
+ const Sized_symbol<size>* s2) const
+{
+ if (s1->shndx() != s2->shndx())
+ return s1->shndx() < s2->shndx();
+ if (s1->value() != s2->value())
+ return s1->value() < s2->value();
+ if (s1->binding() != s2->binding())
+ {
+ if (s1->binding() == elfcpp::STB_WEAK)
+ return true;
+ if (s2->binding() == elfcpp::STB_WEAK)
+ return false;
+ }
+ return std::string(s1->name()) < std::string(s2->name());
+}
- Stringpool::Key version_key;
- version = this->namepool_.add(version, true, &version_key);
+// SYMBOLS is a list of object symbols from a dynamic object. Look
+// for any weak aliases, and record them so that if we add the weak
+// alias to the dynamic symbol table, we also add the corresponding
+// strong symbol.
- // If this is an absolute symbol, and the version name and
- // symbol name are the same, then this is the version definition
- // symbol. These symbols exist to support using -u to pull in
- // particular versions. We do not want to record a version for
- // them.
- if (sym.get_st_shndx() == elfcpp::SHN_ABS && name_key == version_key)
+template<int size>
+void
+Symbol_table::record_weak_aliases(std::vector<Sized_symbol<size>*>* symbols)
+{
+ // Sort the vector by section index, then by offset, then by weak
+ // ahead of strong.
+ std::sort(symbols->begin(), symbols->end(), Weak_alias_sorter<size>());
+
+ // Walk through the vector. For each weak definition, record
+ // aliases.
+ for (typename std::vector<Sized_symbol<size>*>::const_iterator p =
+ symbols->begin();
+ p != symbols->end();
+ ++p)
+ {
+ if ((*p)->binding() != elfcpp::STB_WEAK)
+ continue;
+
+ // Build a circular list of weak aliases. Each symbol points to
+ // the next one in the circular list.
+
+ Sized_symbol<size>* from_sym = *p;
+ typename std::vector<Sized_symbol<size>*>::const_iterator q;
+ for (q = p + 1; q != symbols->end(); ++q)
{
- this->add_from_object(dynobj, name, name_key, NULL, 0, false, sym);
- continue;
+ if ((*q)->shndx() != from_sym->shndx()
+ || (*q)->value() != from_sym->value())
+ break;
+
+ this->weak_aliases_[from_sym] = *q;
+ from_sym->set_has_alias();
+ from_sym = *q;
}
- const bool def = !hidden && sym.get_st_shndx() != elfcpp::SHN_UNDEF;
+ if (from_sym != *p)
+ {
+ this->weak_aliases_[from_sym] = *p;
+ from_sym->set_has_alias();
+ }
- this->add_from_object(dynobj, name, name_key, version, version_key,
- def, sym);
+ p = q - 1;
}
}
if (oldsym != NULL
&& Symbol_table::should_override_with_special(oldsym))
- oldsym->override_with_special(sym);
+ this->override_with_special(oldsym, sym);
return sym;
}
if (oldsym != NULL
&& Symbol_table::should_override_with_special(oldsym))
- oldsym->override_with_special(sym);
+ this->override_with_special(oldsym, sym);
return sym;
}
if (oldsym != NULL
&& Symbol_table::should_override_with_special(oldsym))
- oldsym->override_with_special(sym);
+ this->override_with_special(oldsym, sym);
return sym;
}
set_forwarder()
{ this->is_forwarder_ = true; }
+ // Return whether this symbol has an alias in the weak aliases table
+ // in Symbol_table.
+ bool
+ has_alias() const
+ { return this->has_alias_; }
+
+ // Mark this symbol as having an alias.
+ void
+ set_has_alias()
+ { this->has_alias_ = true; }
+
// Return whether this symbol needs an entry in the dynamic symbol
// table.
bool
// It forwards to the symbol found in the forwarders_ map of
// Symbol_table.
bool is_forwarder_ : 1;
+ // True if the symbol has an alias in the weak_aliases table in
+ // Symbol_table.
+ bool has_alias_ : 1;
// True if this symbol needs to be in the dynamic symbol table.
bool needs_dynsym_entry_ : 1;
// True if we've seen this symbol in a regular object.
// Add a symbol.
template<int size, bool big_endian>
- Symbol*
+ Sized_symbol<size>*
add_from_object(Object*, const char *name, Stringpool::Key name_key,
const char *version, Stringpool::Key version_key,
bool def, const elfcpp::Sym<size, big_endian>& sym);
// Resolve symbols.
template<int size, bool big_endian>
- static void
+ void
resolve(Sized_symbol<size>* to,
const elfcpp::Sym<size, big_endian>& sym,
Object*, const char* version);
template<int size, bool big_endian>
- static void
+ void
resolve(Sized_symbol<size>* to, const Sized_symbol<size>* from,
const char* version ACCEPT_SIZE_ENDIAN);
static bool
should_override(const Symbol*, unsigned int, Object*, bool*);
+ // Override a symbol.
+ template<int size, bool big_endian>
+ void
+ override(Sized_symbol<size>* tosym,
+ const elfcpp::Sym<size, big_endian>& fromsym,
+ Object* object, const char* version);
+
// Whether we should override a symbol with a special symbol which
// is automatically defined by the linker.
static bool
should_override_with_special(const Symbol*);
+ // Override a symbol with a special symbol.
+ template<int size>
+ void
+ override_with_special(Sized_symbol<size>* tosym,
+ const Sized_symbol<size>* fromsym);
+
+ // Record all weak alias sets for a dynamic object.
+ template<int size>
+ void
+ record_weak_aliases(std::vector<Sized_symbol<size>*>*);
+
// Define a special symbol.
template<int size, bool big_endian>
Sized_symbol<size>*
// Forwarding symbols.
Unordered_map<const Symbol*, Symbol*> forwarders_;
+ // Weak aliases. A symbol in this list points to the next alias.
+ // The aliases point to each other in a circular list.
+ Unordered_map<Symbol*, Symbol*> weak_aliases_;
+
// We don't expect there to be very many common symbols, so we keep
// a list of them. When we find a common symbol we add it to this
// list. It is possible that by the time we process the list the
projects / binutils-gdb.git / commitdiff