// resolve.cc -- symbol resolution for gold
-// Copyright 2006, 2007 Free Software Foundation, Inc.
+// Copyright (C) 2006-2020 Free Software Foundation, Inc.
// Written by Ian Lance Taylor <iant@google.com>.
// This file is part of gold.
#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<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;
- if (version != NULL && this->version() != version)
- {
- gold_assert(this->version() == NULL);
- this->version_ = version;
- }
- // FIXME: Handle SHN_XINDEX.
- this->u_.from_object.shndx = sym.get_st_shndx();
- this->type_ = sym.get_st_type();
+ this->u1_.object = object;
+ this->override_version(version);
+ this->u2_.shndx = st_shndx;
+ this->is_ordinary_shndx_ = is_ordinary;
+ // 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->visibility_ = sym.get_st_visibility();
+ this->override_visibility(sym.get_st_visibility());
this->nonvis_ = sym.get_st_nonvis();
if (object->is_dynamic())
this->in_dyn_ = true;
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, object, version);
+ this->override_base(sym, st_shndx, is_ordinary, object, version);
this->value_ = sym.get_st_value();
this->symsize_ = sym.get_st_size();
}
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, object, 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;
- ssym = this->get_sized_symbol SELECT_SIZE_NAME(size) (sym
- SELECT_SIZE(size));
+ Sized_symbol<size>* ssym = this->get_sized_symbol<size>(sym);
do
{
- ssym->override(fromsym, object, version);
+ ssym->override(fromsym, st_shndx, is_ordinary, object, version);
sym = this->weak_aliases_[ssym];
gold_assert(sym != NULL);
- ssym = this->get_sized_symbol SELECT_SIZE_NAME(size) (
- sym SELECT_SIZE(size));
+ ssym = this->get_sized_symbol<size>(sym);
}
while (ssym != tosym);
}
static unsigned int
symbol_to_bits(elfcpp::STB binding, bool is_dynamic,
- unsigned int shndx, elfcpp::STT type)
+ unsigned int shndx, bool is_ordinary)
{
unsigned int bits;
switch (binding)
{
case elfcpp::STB_GLOBAL:
+ case elfcpp::STB_GNU_UNIQUE:
bits = global_flag;
break;
// 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
// define a resolve method.
- gold_error(_("unsupported symbol binding"));
+ gold_error(_("unsupported symbol binding %d"), static_cast<int>(binding));
bits = global_flag;
}
break;
case elfcpp::SHN_COMMON:
- bits |= common_flag;
+ if (!is_ordinary)
+ bits |= common_flag;
break;
default:
- if (type == elfcpp::STT_COMMON)
+ if (!is_ordinary && Symbol::is_common_shndx(shndx))
bits |= common_flag;
else
bits |= def_flag;
}
// Resolve a symbol. This is called the second and subsequent times
-// we see a symbol. TO is the pre-existing symbol. ORIG_SYM is the
-// new symbol, seen in OBJECT. SYM is almost always identical to
-// ORIG_SYM, but may be munged (for instance, if we determine the
-// symbol is in a to-be-discarded section, we'll set sym's shndx to
-// UNDEFINED). VERSION of the version of SYM.
+// 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,
- const elfcpp::Sym<size, big_endian>& orig_sym,
- Object* object, const char* version)
+ unsigned int st_shndx, bool is_ordinary,
+ unsigned int orig_st_shndx,
+ Object* object, const char* version,
+ bool is_default_version)
{
- if (object->target()->has_resolve())
+ 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.
+ if (to->source() == Symbol::FROM_OBJECT
+ && to->object() == object
+ && to->is_defined()
+ && 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;
+
+ if (parameters->target().has_resolve())
{
Sized_target<size, big_endian>* sized_target;
- sized_target = object->sized_target
- SELECT_SIZE_ENDIAN_NAME(size, big_endian) (
- SELECT_SIZE_ENDIAN_ONLY(size, big_endian));
- sized_target->resolve(to, sym, object, version);
- return;
+ sized_target = parameters->sized_target<size, big_endian>();
+ 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();
}
+ else if (st_shndx == elfcpp::SHN_UNDEF
+ && (to->visibility() == elfcpp::STV_HIDDEN
+ || to->visibility() == elfcpp::STV_INTERNAL))
+ {
+ // 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
{
// 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(),
- sym.get_st_shndx(),
- 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();
+ // 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 && !object->is_dynamic())
+ to->set_in_real_elf();
- this->override(to, sym, object, version);
-
- if (adjust_common_sizes && tosize > to->symsize())
- to->set_symsize(tosize);
- }
- else
+ // 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)
{
- if (adjust_common_sizes && sym.get_st_size() > to->symsize())
- to->set_symsize(sym.get_st_size());
+ Pluginobj* obj = to->object()->pluginobj();
+ if (obj != NULL
+ && parameters->options().plugins()->in_replacement_phase())
+ {
+ bool adjust_common = false;
+ typename Sized_symbol<size>::Size_type tosize = 0;
+ typename Sized_symbol<size>::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;
+ }
}
// 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.)
- // We use orig_sym here because we want the symbol exactly as it
- // appears in the object file, not munged via our future processing.
- if (parameters->detect_odr_violations()
- && orig_sym.get_st_bind() == elfcpp::STB_WEAK
- && to->binding() == elfcpp::STB_WEAK
- && orig_sym.get_st_shndx() != elfcpp::SHN_UNDEF
- && to->shndx() != elfcpp::SHN_UNDEF
- && orig_sym.get_st_size() != 0 // Ignore weird 0-sized symbols.
+ // 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.)
+ 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_is_ordinary
+ && to_shndx != elfcpp::SHN_UNDEF
+ && sym.get_st_size() != 0 // Ignore weird 0-sized symbols.
&& to->symsize() != 0
- && (orig_sym.get_st_type() != to->type()
- || orig_sym.get_st_size() != to->symsize())
+ && (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 from_location
- = { object, orig_sym.get_st_shndx(), orig_sym.get_st_value() };
- Symbol_location to_location = { to->object(), to->shndx(), to->value() };
- this->candidate_odr_violations_[to->name()].insert(from_location);
- this->candidate_odr_violations_[to->name()].insert(to_location);
+ Symbol_location fromloc
+ = { object, orig_st_shndx, static_cast<off_t>(sym.get_st_value()) };
+ Symbol_location toloc = { to->object(), to_shndx,
+ static_cast<off_t>(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);
+
+ bool adjust_common_sizes;
+ bool adjust_dyndef;
+ typename Sized_symbol<size>::Size_type tosize = to->symsize();
+ if (Symbol_table::should_override(to, frombits, fromtype, OBJECT,
+ object, &adjust_common_sizes,
+ &adjust_dyndef, is_default_version))
+ {
+ elfcpp::STB orig_tobinding = to->binding();
+ typename Sized_symbol<size>::Value_type tovalue = to->value();
+ this->override(to, sym, st_shndx, is_ordinary, object, version);
+ 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(orig_tobinding);
+ }
+ }
+ else
+ {
+ 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.
+ // 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());
+ }
+
+ // 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())
+ Symbol_table::report_resolve_problem(false,
+ _("common of '%s' overriding "
+ "smaller common"),
+ 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, object);
+ else
+ Symbol_table::report_resolve_problem(false,
+ _("multiple common of '%s'"),
+ to, OBJECT, object);
}
}
bool
Symbol_table::should_override(const Symbol* to, unsigned int frombits,
- Object* object, bool* adjust_common_sizes)
+ elfcpp::STT fromtype, Defined defined,
+ Object* object, bool* adjust_common_sizes,
+ bool* adjust_dyndef, bool is_default_version)
{
*adjust_common_sizes = false;
+ *adjust_dyndef = false;
- unsigned int tobits = symbol_to_bits(to->binding(),
- (to->source() == Symbol::FROM_OBJECT
- && to->object()->is_dynamic()),
- to->shndx(),
- to->type());
+ unsigned int tobits;
+ if (to->source() == Symbol::IS_UNDEFINED)
+ 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);
+ else
+ {
+ bool is_ordinary;
+ unsigned int shndx = to->shndx(&is_ordinary);
+ tobits = symbol_to_bits(to->binding(),
+ to->object()->is_dynamic(),
+ shndx,
+ is_ordinary);
+ }
- // FIXME: Warn if either but not both of TO and SYM are 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"),
+ to, defined, object);
// We use a giant switch table for symbol resolution. This code is
// unwieldy, but: 1) it is efficient; 2) we definitely handle all
{
case DEF * 16 + DEF:
// Two definitions of the same symbol.
- // FIXME: Do a better job of reporting locations.
- gold_error(_("%s: multiple definition of %s"),
- object != NULL ? object->name().c_str() : _("command line"),
- to->name());
- gold_error(_("%s: previous definition here"),
- (to->source() == Symbol::FROM_OBJECT
- ? to->object()->name().c_str()
- : _("command line")));
+
+ // 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 != NULL && object->just_symbols()))
+ return false;
+
+ if (!parameters->options().muldefs())
+ Symbol_table::report_resolve_problem(true,
+ _("multiple definition of '%s'"),
+ to, defined, object);
return false;
case WEAK_DEF * 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.
+ // definition overrides.
+ if (parameters->options().warn_common())
+ Symbol_table::report_resolve_problem(false,
+ _("definition of '%s' overriding "
+ "common"),
+ to, defined, object);
return true;
case DEF * 16 + WEAK_DEF:
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.
+ // object.
+ if (parameters->options().warn_common())
+ Symbol_table::report_resolve_problem(false,
+ _("definition of '%s' overriding "
+ "dynamic common definition"),
+ to, defined, object);
return true;
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:
- 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:
- 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:
+ // 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 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 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:
case DEF * 16 + COMMON:
// A common symbol does not override a definition.
+ if (parameters->options().warn_common())
+ Symbol_table::report_resolve_problem(false,
+ _("common '%s' overridden by "
+ "previous definition"),
+ 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. 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
+// debug info if there is any.
+
+void
+Symbol_table::report_resolve_problem(bool is_error, const char* msg,
+ const Symbol* to, Defined defined,
+ Object* object)
+{
+ std::string demangled(to->demangled_name());
+ size_t len = strlen(msg) + demangled.length() + 10;
+ char* buf = new char[len];
+ snprintf(buf, len, msg, demangled.c_str());
+
+ const char* objname;
+ 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:
+ case INCREMENTAL_BASE:
+ objname = _("linker defined");
+ break;
+ default:
+ gold_unreachable();
+ }
+
+ if (is_error)
+ gold_error("%s: %s", objname, buf);
+ else
+ gold_warning("%s: %s", objname, buf);
+
+ delete[] buf;
+
+ if (to->source() == Symbol::FROM_OBJECT)
+ objname = to->object()->name().c_str();
+ else
+ objname = _("command line");
+ 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 <int size>
+bool
+Sized_symbol<size>::clone(const Sized_symbol<size>* 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.
bool
-Symbol_table::should_override_with_special(const Symbol* to)
+Symbol_table::should_override_with_special(const Symbol* to,
+ elfcpp::STT fromtype,
+ 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, fromtype, defined,
+ NULL, &adjust_common_sizes,
+ &adjust_dyn_def, false);
+ gold_assert(!adjust_common_sizes && !adjust_dyn_def);
return ret;
}
void
Symbol::override_base_with_special(const Symbol* from)
{
- gold_assert(this->name_ == from->name_ || this->has_alias());
+ 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 CONSTANT:
+ case IS_CONSTANT:
+ case IS_UNDEFINED:
break;
default:
gold_unreachable();
break;
}
- if (from->version_ != NULL && this->version_ != from->version_)
+ if (same_name)
{
- gold_assert(this->version_ == NULL);
+ // When overriding a versioned symbol with a special symbol, we
+ // may be changing the version. This will happen if we see a
+ // special symbol such as "_end" defined in a shared object with
+ // one version (from a version script), but we want to define it
+ // here with a different version (from a different version
+ // script).
this->version_ = from->version_;
}
-
this->type_ = from->type_;
this->binding_ = from->binding_;
- this->visibility_ = from->visibility_;
+ this->override_visibility(from->visibility_);
this->nonvis_ = from->nonvis_;
// Special symbols are always considered to be regular symbols.
if (from->needs_dynsym_value_)
this->needs_dynsym_value_ = true;
+ this->is_predefined_ = from->is_predefined_;
+
// 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_got_offset_);
- 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_);
}
// Override a symbol with a special symbol.
{
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));
+ 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 SELECT_SIZE_NAME(size) (
- sym SELECT_SIZE(size));
+ ssym = this->get_sized_symbol<size>(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_GNU_UNIQUE
+ || 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
+// 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>(
Sized_symbol<32>* to,
const elfcpp::Sym<32, false>& sym,
- const elfcpp::Sym<32, false>& orig_sym,
+ unsigned int st_shndx,
+ bool is_ordinary,
+ unsigned int orig_st_shndx,
Object* object,
- const char* version);
-#endif
+ const char* version,
+ bool is_default_version);
-#ifdef HAVE_TARGET_32_BIG
template
void
Symbol_table::resolve<32, true>(
Sized_symbol<32>* to,
const elfcpp::Sym<32, true>& sym,
- const elfcpp::Sym<32, true>& orig_sym,
+ unsigned int st_shndx,
+ bool is_ordinary,
+ unsigned int orig_st_shndx,
Object* object,
- const char* version);
+ const char* version,
+ bool is_default_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>(
Sized_symbol<64>* to,
const elfcpp::Sym<64, false>& sym,
- const elfcpp::Sym<64, false>& orig_sym,
+ unsigned int st_shndx,
+ bool is_ordinary,
+ unsigned int orig_st_shndx,
Object* object,
- const char* version);
-#endif
+ const char* version,
+ bool is_default_version);
-#ifdef HAVE_TARGET_64_BIG
template
void
Symbol_table::resolve<64, true>(
Sized_symbol<64>* to,
const elfcpp::Sym<64, true>& sym,
- const elfcpp::Sym<64, true>& orig_sym,
+ unsigned int st_shndx,
+ 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)
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.
projects / deliverable / binutils-gdb.git / blobdiff