// resolve.cc -- symbol resolution for gold
-// Copyright 2006, 2007, 2008, 2009 Free Software Foundation, Inc.
+// Copyright 2006, 2007, 2008, 2009, 2010 Free Software Foundation, Inc.
// Written by Ian Lance Taylor <iant@google.com>.
// This file is part of gold.
// VERSION. Update the VERSION_ field accordingly.
inline void
-Symbol::override_version(const char* aversion)
+Symbol::override_version(const char* version)
{
- if (aversion == NULL)
+ 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
// 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_ = aversion;
+ this->version_ = version;
}
else
{
// 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_ == aversion || this->version_ == NULL);
- this->version_ = aversion;
+ gold_assert(this->version_ == version || this->version_ == NULL);
+ this->version_ = version;
}
}
// is VISIBILITY. Updated the VISIBILITY_ field accordingly.
inline void
-Symbol::override_visibility(elfcpp::STV avisibility)
+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 (avisibility != elfcpp::STV_DEFAULT)
+ if (visibility != elfcpp::STV_DEFAULT)
{
if (this->visibility_ == elfcpp::STV_DEFAULT)
- this->visibility_ = avisibility;
- else if (this->visibility_ > avisibility)
- this->visibility_ = avisibility;
+ this->visibility_ = visibility;
+ else if (this->visibility_ > visibility)
+ this->visibility_ = visibility;
}
}
void
Symbol::override_base(const elfcpp::Sym<size, big_endian>& sym,
unsigned int st_shndx, bool is_ordinary,
- Object* aobject, const char* aversion)
+ Object* object, const char* version)
{
gold_assert(this->source_ == FROM_OBJECT);
- this->u_.from_object.object = aobject;
- this->override_version(aversion);
+ 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 (aobject->is_dynamic())
+ if (object->is_dynamic())
this->in_dyn_ = true;
else
this->in_reg_ = true;
void
Sized_symbol<size>::override(const elfcpp::Sym<size, big_endian>& sym,
unsigned st_shndx, bool is_ordinary,
- Object* aobject, const char* aversion)
+ Object* object, const char* version)
{
- this->override_base(sym, st_shndx, is_ordinary, aobject, aversion);
+ this->override_base(sym, st_shndx, is_ordinary, object, version);
this->value_ = sym.get_st_value();
this->symsize_ = sym.get_st_size();
}
Symbol_table::override(Sized_symbol<size>* tosym,
const elfcpp::Sym<size, big_endian>& fromsym,
unsigned int st_shndx, bool is_ordinary,
- Object* aobject, const char* aversion)
+ Object* object, const char* version)
{
- tosym->override(fromsym, st_shndx, is_ordinary, aobject, aversion);
+ tosym->override(fromsym, st_shndx, is_ordinary, object, version);
if (tosym->has_alias())
{
Symbol* sym = this->weak_aliases_[tosym];
Sized_symbol<size>* ssym = this->get_sized_symbol<size>(sym);
do
{
- ssym->override(fromsym, st_shndx, is_ordinary, aobject, aversion);
+ 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);
}
}
+ // 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. We also check
+ // combinations of weak and strong, which might occur if one case is
+ // inline and the other is not. (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);
+ }
+
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;
+ bool adjust_dyndef;
typename Sized_symbol<size>::Size_type tosize = to->symsize();
- if (Symbol_table::should_override(to, frombits, object,
- &adjust_common_sizes))
+ if (Symbol_table::should_override(to, frombits, OBJECT, object,
+ &adjust_common_sizes,
+ &adjust_dyndef))
{
+ elfcpp::STB tobinding = to->binding();
this->override(to, sym, st_shndx, is_ordinary, object, version);
if (adjust_common_sizes && tosize > to->symsize())
to->set_symsize(tosize);
+ 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);
+ }
}
else
{
if (adjust_common_sizes && sym.get_st_size() > tosize)
to->set_symsize(sym.get_st_size());
+ if (adjust_dyndef)
+ {
+ // We are keeping a DYN DEF after seeing an UNDEF or WEAK UNDEF.
+ // Remember which kind of UNDEF it was.
+ to->set_undef_binding(sym.get_st_bind());
+ }
// The ELF ABI says that even for a reference to a symbol we
// merge the visibility.
to->override_visibility(sym.get_st_visibility());
Symbol_table::report_resolve_problem(false,
_("common of '%s' overriding "
"smaller common"),
- to, object);
+ to, OBJECT, object);
else if (tosize < sym.get_st_size())
Symbol_table::report_resolve_problem(false,
_("common of '%s' overidden by "
"larger common"),
- to, object);
+ to, OBJECT, object);
else
Symbol_table::report_resolve_problem(false,
_("multiple common of '%s'"),
- to, object);
- }
-
- // 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);
+ to, OBJECT, object);
}
}
bool
Symbol_table::should_override(const Symbol* to, unsigned int frombits,
- Object* object, bool* adjust_common_sizes)
+ Defined defined, Object* object,
+ bool* adjust_common_sizes,
+ bool* adjust_dyndef)
{
*adjust_common_sizes = false;
+ *adjust_dyndef = false;
unsigned int tobits;
if (to->source() == Symbol::IS_UNDEFINED)
// --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())
+ || (object != NULL && object->just_symbols()))
return false;
- Symbol_table::report_resolve_problem(true,
- _("multiple definition of '%s'"),
- to, object);
+ if (!parameters->options().muldefs())
+ Symbol_table::report_resolve_problem(true,
+ _("multiple definition of '%s'"),
+ to, defined, object);
return false;
case WEAK_DEF * 16 + DEF:
Symbol_table::report_resolve_problem(false,
_("definition of '%s' overriding "
"common"),
- to, object);
+ to, defined, object);
return true;
case DEF * 16 + WEAK_DEF:
Symbol_table::report_resolve_problem(false,
_("definition of '%s' overriding "
"dynamic common definition"),
- to, object);
+ to, defined, object);
return true;
case DEF * 16 + DYN_DEF:
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 WEAK_UNDEF * 16 + DYN_DEF:
+ // When overriding a weak undef by a dynamic definition,
+ // we need to remember that the original undef was weak.
+ *adjust_dyndef = true;
+ return true;
+
case COMMON * 16 + DYN_DEF:
case WEAK_COMMON * 16 + DYN_DEF:
case DYN_COMMON * 16 + DYN_DEF:
return false;
case UNDEF * 16 + DYN_WEAK_DEF:
- case WEAK_UNDEF * 16 + DYN_WEAK_DEF:
+ // When overriding an undef by a dynamic weak definition,
+ // we need to remember that the original undef was not weak.
+ *adjust_dyndef = true;
+ return true;
+
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 WEAK_UNDEF * 16 + DYN_WEAK_DEF:
+ // When overriding a weak undef by a dynamic definition,
+ // we need to remember that the original undef was weak.
+ *adjust_dyndef = true;
+ return true;
+
case COMMON * 16 + DYN_WEAK_DEF:
case WEAK_COMMON * 16 + DYN_WEAK_DEF:
case DYN_COMMON * 16 + DYN_WEAK_DEF:
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 DYN_DEF * 16 + UNDEF:
+ case DYN_WEAK_DEF * 16 + UNDEF:
+ // For a dynamic def, we need to remember which kind of undef we see.
+ *adjust_dyndef = true;
+ return false;
+
case WEAK_UNDEF * 16 + UNDEF:
case DYN_UNDEF * 16 + UNDEF:
case DYN_WEAK_UNDEF * 16 + UNDEF:
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.
+ // A new weak undefined reference tells us nothing unless the
+ // exisiting symbol is a dynamic weak reference.
+ return false;
+
+ case DYN_WEAK_UNDEF * 16 + WEAK_UNDEF:
+ // A new weak reference overrides an existing dynamic weak reference.
+ // This is necessary because a dynamic weak reference remembers
+ // the old binding, which may not be weak. If we keeps the existing
+ // dynamic weak reference, the weakness may be dropped in the output.
+ return true;
+
+ case DYN_DEF * 16 + WEAK_UNDEF:
+ case DYN_WEAK_DEF * 16 + WEAK_UNDEF:
+ // For a dynamic def, we need to remember which kind of undef we see.
+ *adjust_dyndef = true;
return false;
case DEF * 16 + DYN_UNDEF:
Symbol_table::report_resolve_problem(false,
_("common '%s' overridden by "
"previous definition"),
- to, object);
+ to, defined, object);
return false;
case WEAK_DEF * 16 + COMMON:
// Issue an error or warning due to symbol resolution. IS_ERROR
// indicates an error rather than a warning. MSG is the error
// message; it is expected to have a %s for the symbol name. TO is
-// the existing symbol. OBJECT is where the new symbol was found.
+// the existing symbol. DEFINED/OBJECT is where the new symbol was
+// found.
// FIXME: We should have better location information here. When the
// symbol is defined, we should be able to pull the location from the
void
Symbol_table::report_resolve_problem(bool is_error, const char* msg,
- const Symbol* to, Object* object)
+ const Symbol* to, Defined defined,
+ Object* object)
{
std::string demangled(to->demangled_name());
size_t len = strlen(msg) + demangled.length() + 10;
snprintf(buf, len, msg, demangled.c_str());
const char* objname;
- if (object != NULL)
- objname = object->name().c_str();
- else
- objname = _("command line");
+ switch (defined)
+ {
+ case OBJECT:
+ objname = object->name().c_str();
+ break;
+ case COPY:
+ objname = _("COPY reloc");
+ break;
+ case DEFSYM:
+ case UNDEFINED:
+ objname = _("command line");
+ break;
+ case SCRIPT:
+ objname = _("linker script");
+ break;
+ case PREDEFINED:
+ objname = _("linker defined");
+ break;
+ default:
+ gold_unreachable();
+ }
if (is_error)
gold_error("%s: %s", objname, buf);
// defining special symbols.
bool
-Symbol_table::should_override_with_special(const Symbol* to)
+Symbol_table::should_override_with_special(const Symbol* to, Defined defined)
{
bool adjust_common_sizes;
+ bool adjust_dyn_def;
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);
+ bool ret = Symbol_table::should_override(to, frombits, defined, NULL,
+ &adjust_common_sizes,
+ &adjust_dyn_def);
+ gold_assert(!adjust_common_sizes && !adjust_dyn_def);
return ret;
}
// 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_plt_offset());
gold_assert(!from->has_warning_);
gold_assert(!from->is_copied_from_dynobj_);
gold_assert(!from->is_forced_local_);
// script to restrict this to only the ones needed for implemented
// targets.
-#ifdef HAVE_TARGET_32_LITTLE
+// We have to instantiate both big and little endian versions because
+// these are used by other templates that depends on size only.
+
+#if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
template
void
Symbol_table::resolve<32, false>(
unsigned int orig_st_shndx,
Object* object,
const char* version);
-#endif
-#ifdef HAVE_TARGET_32_BIG
template
void
Symbol_table::resolve<32, true>(
const char* version);
#endif
-#ifdef HAVE_TARGET_64_LITTLE
+#if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
template
void
Symbol_table::resolve<64, false>(
unsigned int orig_st_shndx,
Object* object,
const char* version);
-#endif
-#ifdef HAVE_TARGET_64_BIG
template
void
Symbol_table::resolve<64, true>(