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binutils-gdb/gold/symtab.cc
Ian Lance Taylor 8a5e3e08a6 * layout.cc (Layout::make_output_section): Call 
Target::new_output_section.
	(Layout::attach_allocated_section_to_segment): Put large section
	sections in a separate load segment with the large segment flag
	set.
	(Layout::segment_precedes): Sort large data segments after other
	load segments.
	(align_file_offset): New static function.
	(Layout::set_segment_offsets): Use align_file_offset.
	* output.h (class Output_section): Add is_small_section_ and
	is_large_section_ fields.
	(Output_section::is_small_section): New function.
	(Output_section::set_is_small_section):  New function.
	(Output_section::is_large_section): New function.
	(Output_section::set_is_large_section): New function.
	(Output_section::is_large_data_section): New function.
	(class Output_segment): Add is_large_data_segment_ field.
	(Output_segment::is_large_data_segment): New function.
	(Output_segment::set_is_large_data_segment): New function.
	* output.cc (Output_section::Output_section): Initialize new
	fields.
	(Output_segment::Output_segment): Likewise.
	(Output_segment::add_output_section): Add assertion that large
	data sections always go in large data segments.  Force small data
	sections to the end of the list of data sections.  Force small BSS
	sections to the start of the list of BSS sections.  For large BSS
	sections to the end of the list of BSS sections.
	* symtab.h (class Symbol): Declare is_common_shndx.
	(Symbol::is_defined): Check Symbol::is_common_shndx.
	(Symbol::is_common): Likewise.
	(class Symbol_table): Define enum Commons_section_type.  Update
	declarations.  Add small_commons_ and large_commons_ fields.
	* symtab.cc (Symbol::is_common_shndx): New function.
	(Symbol_table::Symbol_table): Initialize new fields.
	(Symbol_table::add_from_object): Put small and large common
	symbols in the right list.
	(Symbol_table::sized_finalized_symbol): Check
	Symbol::is_common_shndx.
	(Symbol_table::sized_write_globals): Likewise.
	* common.cc (Symbol_table::do_allocate_commons): Allocate new
	common symbol lists.  Don't call do_allocate_commons_list if the
	list is empty.
	(Symbol_table::do_allocate_commons_list): Remove is_tls
	parameter.  Add comons_section_type parameter.  Change all
	callers.  Handle small and large common symbols.
	* object.cc (Sized_relobj::do_finalize_local_symbols): Check
	Symbol::is_common_shndx.
	* resolve.cc (symbol_to_bits): Likewise.
	* target.h (Target::small_common_shndx): New function.
	(Target::small_common_section_flags): New function.
	(Target::large_common_shndx): New function.
	(Target::large_common_section_flags): New function.
	(Target::new_output_section): New function.
	(Target::Target_info): Add small_common_shndx, large_common_shndx,
	small_common_section_flags, and large_common_section_flags
	fields.
	(Target::do_new_output_section): New virtual function.
	* arm.cc (Target_arm::arm_info): Initialize new fields.
	* i386.cc (Target_i386::i386_info): Likewise.
	* powerpc.cc (Target_powerpc::powerpc_info) [all versions]:
	Likewise.
	* sparc.c (Target_sparc::sparc_info) [all versions]: Likewise.
	* x86_64.cc (Target_x86_64::x86_64_info): Likewise.
	(Target_x86_64::do_new_output_section): New function.
	* configure.ac: Define conditional MCMODEL_MEDIUM.
	* testsuite/Makefile.am (check_PROGRAMS): Add large.
	(large_SOURCES, large_CFLAGS, large_DEPENDENCIES): Define.
	(large_LDFLAGS): Define.
	* testsuite/large.c: New file.
	* testsuite/testfile.cc (Target_test::test_target_info):
	Initialize new fields.
	* configure, testsuite/Makefile.in: Rebuild.
2009-06-22 06:51:53 +00:00

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// symtab.cc -- the gold symbol table
// Copyright 2006, 2007, 2008, 2009 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 <cstring>
#include <stdint.h>
#include <algorithm>
#include <set>
#include <string>
#include <utility>
#include "demangle.h"
#include "gc.h"
#include "object.h"
#include "dwarf_reader.h"
#include "dynobj.h"
#include "output.h"
#include "target.h"
#include "workqueue.h"
#include "symtab.h"
#include "demangle.h" // needed for --dynamic-list-cpp-new
#include "plugin.h"
namespace gold
{
// Class Symbol.
// Initialize fields in Symbol. This initializes everything except u_
// and source_.
void
Symbol::init_fields(const char* name, const char* version,
elfcpp::STT type, elfcpp::STB binding,
elfcpp::STV visibility, unsigned char nonvis)
{
this->name_ = name;
this->version_ = version;
this->symtab_index_ = 0;
this->dynsym_index_ = 0;
this->got_offsets_.init();
this->plt_offset_ = 0;
this->type_ = type;
this->binding_ = binding;
this->visibility_ = visibility;
this->nonvis_ = nonvis;
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;
this->has_plt_offset_ = false;
this->has_warning_ = false;
this->is_copied_from_dynobj_ = false;
this->is_forced_local_ = false;
this->is_ordinary_shndx_ = false;
this->in_real_elf_ = false;
}
// Return the demangled version of the symbol's name, but only
// if the --demangle flag was set.
static std::string
demangle(const char* name)
{
if (!parameters->options().do_demangle())
return name;
// cplus_demangle allocates memory for the result it returns,
// and returns NULL if the name is already demangled.
char* demangled_name = cplus_demangle(name, DMGL_ANSI | DMGL_PARAMS);
if (demangled_name == NULL)
return name;
std::string retval(demangled_name);
free(demangled_name);
return retval;
}
std::string
Symbol::demangled_name() const
{
return demangle(this->name());
}
// Initialize the fields in the base class Symbol for SYM in OBJECT.
template<int size, bool big_endian>
void
Symbol::init_base_object(const char* name, const char* version, Object* object,
const elfcpp::Sym<size, big_endian>& sym,
unsigned int st_shndx, bool is_ordinary)
{
this->init_fields(name, version, sym.get_st_type(), sym.get_st_bind(),
sym.get_st_visibility(), sym.get_st_nonvis());
this->u_.from_object.object = object;
this->u_.from_object.shndx = st_shndx;
this->is_ordinary_shndx_ = is_ordinary;
this->source_ = FROM_OBJECT;
this->in_reg_ = !object->is_dynamic();
this->in_dyn_ = object->is_dynamic();
this->in_real_elf_ = object->pluginobj() == NULL;
}
// Initialize the fields in the base class Symbol for a symbol defined
// in an Output_data.
void
Symbol::init_base_output_data(const char* name, const char* version,
Output_data* od, elfcpp::STT type,
elfcpp::STB binding, elfcpp::STV visibility,
unsigned char nonvis, bool offset_is_from_end)
{
this->init_fields(name, version, type, binding, visibility, nonvis);
this->u_.in_output_data.output_data = od;
this->u_.in_output_data.offset_is_from_end = offset_is_from_end;
this->source_ = IN_OUTPUT_DATA;
this->in_reg_ = true;
this->in_real_elf_ = true;
}
// Initialize the fields in the base class Symbol for a symbol defined
// in an Output_segment.
void
Symbol::init_base_output_segment(const char* name, const char* version,
Output_segment* os, elfcpp::STT type,
elfcpp::STB binding, elfcpp::STV visibility,
unsigned char nonvis,
Segment_offset_base offset_base)
{
this->init_fields(name, version, type, binding, visibility, nonvis);
this->u_.in_output_segment.output_segment = os;
this->u_.in_output_segment.offset_base = offset_base;
this->source_ = IN_OUTPUT_SEGMENT;
this->in_reg_ = true;
this->in_real_elf_ = true;
}
// Initialize the fields in the base class Symbol for a symbol defined
// as a constant.
void
Symbol::init_base_constant(const char* name, const char* version,
elfcpp::STT type, elfcpp::STB binding,
elfcpp::STV visibility, unsigned char nonvis)
{
this->init_fields(name, version, type, binding, visibility, nonvis);
this->source_ = IS_CONSTANT;
this->in_reg_ = true;
this->in_real_elf_ = true;
}
// Initialize the fields in the base class Symbol for an undefined
// symbol.
void
Symbol::init_base_undefined(const char* name, const char* version,
elfcpp::STT type, elfcpp::STB binding,
elfcpp::STV visibility, unsigned char nonvis)
{
this->init_fields(name, version, type, binding, visibility, nonvis);
this->dynsym_index_ = -1U;
this->source_ = IS_UNDEFINED;
this->in_reg_ = true;
this->in_real_elf_ = true;
}
// Allocate a common symbol in the base.
void
Symbol::allocate_base_common(Output_data* od)
{
gold_assert(this->is_common());
this->source_ = IN_OUTPUT_DATA;
this->u_.in_output_data.output_data = od;
this->u_.in_output_data.offset_is_from_end = false;
}
// Initialize the fields in Sized_symbol for SYM in OBJECT.
template<int size>
template<bool big_endian>
void
Sized_symbol<size>::init_object(const char* name, const char* version,
Object* object,
const elfcpp::Sym<size, big_endian>& sym,
unsigned int st_shndx, bool is_ordinary)
{
this->init_base_object(name, version, object, sym, st_shndx, is_ordinary);
this->value_ = sym.get_st_value();
this->symsize_ = sym.get_st_size();
}
// Initialize the fields in Sized_symbol for a symbol defined in an
// Output_data.
template<int size>
void
Sized_symbol<size>::init_output_data(const char* name, const char* version,
Output_data* od, Value_type value,
Size_type symsize, elfcpp::STT type,
elfcpp::STB binding,
elfcpp::STV visibility,
unsigned char nonvis,
bool offset_is_from_end)
{
this->init_base_output_data(name, version, od, type, binding, visibility,
nonvis, offset_is_from_end);
this->value_ = value;
this->symsize_ = symsize;
}
// Initialize the fields in Sized_symbol for a symbol defined in an
// Output_segment.
template<int size>
void
Sized_symbol<size>::init_output_segment(const char* name, const char* version,
Output_segment* os, Value_type value,
Size_type symsize, elfcpp::STT type,
elfcpp::STB binding,
elfcpp::STV visibility,
unsigned char nonvis,
Segment_offset_base offset_base)
{
this->init_base_output_segment(name, version, os, type, binding, visibility,
nonvis, offset_base);
this->value_ = value;
this->symsize_ = symsize;
}
// Initialize the fields in Sized_symbol for a symbol defined as a
// constant.
template<int size>
void
Sized_symbol<size>::init_constant(const char* name, const char* version,
Value_type value, Size_type symsize,
elfcpp::STT type, elfcpp::STB binding,
elfcpp::STV visibility, unsigned char nonvis)
{
this->init_base_constant(name, version, type, binding, visibility, nonvis);
this->value_ = value;
this->symsize_ = symsize;
}
// Initialize the fields in Sized_symbol for an undefined symbol.
template<int size>
void
Sized_symbol<size>::init_undefined(const char* name, const char* version,
elfcpp::STT type, elfcpp::STB binding,
elfcpp::STV visibility, unsigned char nonvis)
{
this->init_base_undefined(name, version, type, binding, visibility, nonvis);
this->value_ = 0;
this->symsize_ = 0;
}
// Return true if SHNDX represents a common symbol.
bool
Symbol::is_common_shndx(unsigned int shndx)
{
return (shndx == elfcpp::SHN_COMMON
|| shndx == parameters->target().small_common_shndx()
|| shndx == parameters->target().large_common_shndx());
}
// Allocate a common symbol.
template<int size>
void
Sized_symbol<size>::allocate_common(Output_data* od, Value_type value)
{
this->allocate_base_common(od);
this->value_ = value;
}
// The ""'s around str ensure str is a string literal, so sizeof works.
#define strprefix(var, str) (strncmp(var, str, sizeof("" str "") - 1) == 0)
// Return true if this symbol should be added to the dynamic symbol
// table.
inline bool
Symbol::should_add_dynsym_entry() const
{
// If the symbol is used by a dynamic relocation, we need to add it.
if (this->needs_dynsym_entry())
return true;
// If this symbol's section is not added, the symbol need not be added.
// The section may have been GCed. Note that export_dynamic is being
// overridden here. This should not be done for shared objects.
if (parameters->options().gc_sections()
&& !parameters->options().shared()
&& this->source() == Symbol::FROM_OBJECT
&& !this->object()->is_dynamic())
{
Relobj* relobj = static_cast<Relobj*>(this->object());
bool is_ordinary;
unsigned int shndx = this->shndx(&is_ordinary);
if (is_ordinary && shndx != elfcpp::SHN_UNDEF
&& !relobj->is_section_included(shndx))
return false;
}
// If the symbol was forced local in a version script, do not add it.
if (this->is_forced_local())
return false;
// If the symbol was forced dynamic in a --dynamic-list file, add it.
if (parameters->options().in_dynamic_list(this->name()))
return true;
// If dynamic-list-data was specified, add any STT_OBJECT.
if (parameters->options().dynamic_list_data()
&& !this->is_from_dynobj()
&& this->type() == elfcpp::STT_OBJECT)
return true;
// If --dynamic-list-cpp-new was specified, add any new/delete symbol.
// If --dynamic-list-cpp-typeinfo was specified, add any typeinfo symbols.
if ((parameters->options().dynamic_list_cpp_new()
|| parameters->options().dynamic_list_cpp_typeinfo())
&& !this->is_from_dynobj())
{
// TODO(csilvers): We could probably figure out if we're an operator
// new/delete or typeinfo without the need to demangle.
char* demangled_name = cplus_demangle(this->name(),
DMGL_ANSI | DMGL_PARAMS);
if (demangled_name == NULL)
{
// Not a C++ symbol, so it can't satisfy these flags
}
else if (parameters->options().dynamic_list_cpp_new()
&& (strprefix(demangled_name, "operator new")
|| strprefix(demangled_name, "operator delete")))
{
free(demangled_name);
return true;
}
else if (parameters->options().dynamic_list_cpp_typeinfo()
&& (strprefix(demangled_name, "typeinfo name for")
|| strprefix(demangled_name, "typeinfo for")))
{
free(demangled_name);
return true;
}
else
free(demangled_name);
}
// If exporting all symbols or building a shared library,
// and the symbol is defined in a regular object and is
// externally visible, we need to add it.
if ((parameters->options().export_dynamic() || parameters->options().shared())
&& !this->is_from_dynobj()
&& this->is_externally_visible())
return true;
return false;
}
// Return true if the final value of this symbol is known at link
// time.
bool
Symbol::final_value_is_known() const
{
// If we are not generating an executable, then no final values are
// known, since they will change at runtime.
if (parameters->options().shared() || parameters->options().relocatable())
return false;
// If the symbol is not from an object file, and is not undefined,
// then it is defined, and known.
if (this->source_ != FROM_OBJECT)
{
if (this->source_ != IS_UNDEFINED)
return true;
}
else
{
// If the symbol is from a dynamic object, then the final value
// is not known.
if (this->object()->is_dynamic())
return false;
// If the symbol is not undefined (it is defined or common),
// then the final value is known.
if (!this->is_undefined())
return true;
}
// If the symbol is undefined, then whether the final value is known
// depends on whether we are doing a static link. If we are doing a
// dynamic link, then the final value could be filled in at runtime.
// This could reasonably be the case for a weak undefined symbol.
return parameters->doing_static_link();
}
// Return the output section where this symbol is defined.
Output_section*
Symbol::output_section() const
{
switch (this->source_)
{
case FROM_OBJECT:
{
unsigned int shndx = this->u_.from_object.shndx;
if (shndx != elfcpp::SHN_UNDEF && this->is_ordinary_shndx_)
{
gold_assert(!this->u_.from_object.object->is_dynamic());
gold_assert(this->u_.from_object.object->pluginobj() == NULL);
Relobj* relobj = static_cast<Relobj*>(this->u_.from_object.object);
return relobj->output_section(shndx);
}
return NULL;
}
case IN_OUTPUT_DATA:
return this->u_.in_output_data.output_data->output_section();
case IN_OUTPUT_SEGMENT:
case IS_CONSTANT:
case IS_UNDEFINED:
return NULL;
default:
gold_unreachable();
}
}
// Set the symbol's output section. This is used for symbols defined
// in scripts. This should only be called after the symbol table has
// been finalized.
void
Symbol::set_output_section(Output_section* os)
{
switch (this->source_)
{
case FROM_OBJECT:
case IN_OUTPUT_DATA:
gold_assert(this->output_section() == os);
break;
case IS_CONSTANT:
this->source_ = IN_OUTPUT_DATA;
this->u_.in_output_data.output_data = os;
this->u_.in_output_data.offset_is_from_end = false;
break;
case IN_OUTPUT_SEGMENT:
case IS_UNDEFINED:
default:
gold_unreachable();
}
}
// Class Symbol_table.
Symbol_table::Symbol_table(unsigned int count,
const Version_script_info& version_script)
: saw_undefined_(0), offset_(0), table_(count), namepool_(),
forwarders_(), commons_(), tls_commons_(), small_commons_(),
large_commons_(), forced_locals_(), warnings_(),
version_script_(version_script), gc_(NULL)
{
namepool_.reserve(count);
}
Symbol_table::~Symbol_table()
{
}
// The hash function. The key values are Stringpool keys.
inline size_t
Symbol_table::Symbol_table_hash::operator()(const Symbol_table_key& key) const
{
return key.first ^ key.second;
}
// The symbol table key equality function. This is called with
// Stringpool keys.
inline bool
Symbol_table::Symbol_table_eq::operator()(const Symbol_table_key& k1,
const Symbol_table_key& k2) const
{
return k1.first == k2.first && k1.second == k2.second;
}
// For symbols that have been listed with -u option, add them to the
// work list to avoid gc'ing them.
void
Symbol_table::gc_mark_undef_symbols()
{
for (options::String_set::const_iterator p =
parameters->options().undefined_begin();
p != parameters->options().undefined_end();
++p)
{
const char* name = p->c_str();
Symbol* sym = this->lookup(name);
gold_assert (sym != NULL);
if (sym->source() == Symbol::FROM_OBJECT
&& !sym->object()->is_dynamic())
{
Relobj* obj = static_cast<Relobj*>(sym->object());
bool is_ordinary;
unsigned int shndx = sym->shndx(&is_ordinary);
if (is_ordinary)
{
gold_assert(this->gc_ != NULL);
this->gc_->worklist().push(Section_id(obj, shndx));
}
}
}
}
void
Symbol_table::gc_mark_symbol_for_shlib(Symbol* sym)
{
if (!sym->is_from_dynobj()
&& sym->is_externally_visible())
{
//Add the object and section to the work list.
Relobj* obj = static_cast<Relobj*>(sym->object());
bool is_ordinary;
unsigned int shndx = sym->shndx(&is_ordinary);
if (is_ordinary && shndx != elfcpp::SHN_UNDEF)
{
gold_assert(this->gc_!= NULL);
this->gc_->worklist().push(Section_id(obj, shndx));
}
}
}
// When doing garbage collection, keep symbols that have been seen in
// dynamic objects.
inline void
Symbol_table::gc_mark_dyn_syms(Symbol* sym)
{
if (sym->in_dyn() && sym->source() == Symbol::FROM_OBJECT
&& !sym->object()->is_dynamic())
{
Relobj *obj = static_cast<Relobj*>(sym->object());
bool is_ordinary;
unsigned int shndx = sym->shndx(&is_ordinary);
if (is_ordinary && shndx != elfcpp::SHN_UNDEF)
{
gold_assert(this->gc_ != NULL);
this->gc_->worklist().push(Section_id(obj, shndx));
}
}
}
// Make TO a symbol which forwards to FROM.
void
Symbol_table::make_forwarder(Symbol* from, Symbol* to)
{
gold_assert(from != to);
gold_assert(!from->is_forwarder() && !to->is_forwarder());
this->forwarders_[from] = to;
from->set_forwarder();
}
// Resolve the forwards from FROM, returning the real symbol.
Symbol*
Symbol_table::resolve_forwards(const Symbol* from) const
{
gold_assert(from->is_forwarder());
Unordered_map<const Symbol*, Symbol*>::const_iterator p =
this->forwarders_.find(from);
gold_assert(p != this->forwarders_.end());
return p->second;
}
// Look up a symbol by name.
Symbol*
Symbol_table::lookup(const char* name, const char* version) const
{
Stringpool::Key name_key;
name = this->namepool_.find(name, &name_key);
if (name == NULL)
return NULL;
Stringpool::Key version_key = 0;
if (version != NULL)
{
version = this->namepool_.find(version, &version_key);
if (version == NULL)
return NULL;
}
Symbol_table_key key(name_key, version_key);
Symbol_table::Symbol_table_type::const_iterator p = this->table_.find(key);
if (p == this->table_.end())
return NULL;
return p->second;
}
// Resolve a Symbol with another Symbol. This is only used in the
// unusual case where there are references to both an unversioned
// symbol and a symbol with a version, and we then discover that that
// version is the default version. Because this is unusual, we do
// this the slow way, by converting back to an ELF symbol.
template<int size, bool big_endian>
void
Symbol_table::resolve(Sized_symbol<size>* to, const Sized_symbol<size>* from)
{
unsigned char buf[elfcpp::Elf_sizes<size>::sym_size];
elfcpp::Sym_write<size, big_endian> esym(buf);
// We don't bother to set the st_name or the st_shndx field.
esym.put_st_value(from->value());
esym.put_st_size(from->symsize());
esym.put_st_info(from->binding(), from->type());
esym.put_st_other(from->visibility(), from->nonvis());
bool is_ordinary;
unsigned int shndx = from->shndx(&is_ordinary);
this->resolve(to, esym.sym(), shndx, is_ordinary, shndx, from->object(),
from->version());
if (from->in_reg())
to->set_in_reg();
if (from->in_dyn())
to->set_in_dyn();
if (parameters->options().gc_sections())
this->gc_mark_dyn_syms(to);
}
// Record that a symbol is forced to be local by a version script or
// by visibility.
void
Symbol_table::force_local(Symbol* sym)
{
if (!sym->is_defined() && !sym->is_common())
return;
if (sym->is_forced_local())
{
// We already got this one.
return;
}
sym->set_is_forced_local();
this->forced_locals_.push_back(sym);
}
// Adjust NAME for wrapping, and update *NAME_KEY if necessary. This
// is only called for undefined symbols, when at least one --wrap
// option was used.
const char*
Symbol_table::wrap_symbol(Object* object, const char* name,
Stringpool::Key* name_key)
{
// For some targets, we need to ignore a specific character when
// wrapping, and add it back later.
char prefix = '\0';
if (name[0] == object->target()->wrap_char())
{
prefix = name[0];
++name;
}
if (parameters->options().is_wrap(name))
{
// Turn NAME into __wrap_NAME.
std::string s;
if (prefix != '\0')
s += prefix;
s += "__wrap_";
s += name;
// This will give us both the old and new name in NAMEPOOL_, but
// that is OK. Only the versions we need will wind up in the
// real string table in the output file.
return this->namepool_.add(s.c_str(), true, name_key);
}
const char* const real_prefix = "__real_";
const size_t real_prefix_length = strlen(real_prefix);
if (strncmp(name, real_prefix, real_prefix_length) == 0
&& parameters->options().is_wrap(name + real_prefix_length))
{
// Turn __real_NAME into NAME.
std::string s;
if (prefix != '\0')
s += prefix;
s += name + real_prefix_length;
return this->namepool_.add(s.c_str(), true, name_key);
}
return name;
}
// This is called when we see a symbol NAME/VERSION, and the symbol
// already exists in the symbol table, and VERSION is marked as being
// the default version. SYM is the NAME/VERSION symbol we just added.
// DEFAULT_IS_NEW is true if this is the first time we have seen the
// symbol NAME/NULL. PDEF points to the entry for NAME/NULL.
template<int size, bool big_endian>
void
Symbol_table::define_default_version(Sized_symbol<size>* sym,
bool default_is_new,
Symbol_table_type::iterator pdef)
{
if (default_is_new)
{
// This is the first time we have seen NAME/NULL. Make
// NAME/NULL point to NAME/VERSION, and mark SYM as the default
// version.
pdef->second = sym;
sym->set_is_default();
}
else if (pdef->second == sym)
{
// NAME/NULL already points to NAME/VERSION. Don't mark the
// symbol as the default if it is not already the default.
}
else
{
// This is the unfortunate case where we already have entries
// for both NAME/VERSION and NAME/NULL. We now see a symbol
// NAME/VERSION where VERSION is the default version. We have
// already resolved this new symbol with the existing
// NAME/VERSION symbol.
// It's possible that NAME/NULL and NAME/VERSION are both
// defined in regular objects. This can only happen if one
// object file defines foo and another defines foo@@ver. This
// is somewhat obscure, but we call it a multiple definition
// error.
// It's possible that NAME/NULL actually has a version, in which
// case it won't be the same as VERSION. This happens with
// ver_test_7.so in the testsuite for the symbol t2_2. We see
// t2_2@@VER2, so we define both t2_2/VER2 and t2_2/NULL. We
// then see an unadorned t2_2 in an object file and give it
// version VER1 from the version script. This looks like a
// default definition for VER1, so it looks like we should merge
// t2_2/NULL with t2_2/VER1. That doesn't make sense, but it's
// not obvious that this is an error, either. So we just punt.
// If one of the symbols has non-default visibility, and the
// other is defined in a shared object, then they are different
// symbols.
// Otherwise, we just resolve the symbols as though they were
// the same.
if (pdef->second->version() != NULL)
gold_assert(pdef->second->version() != sym->version());
else if (sym->visibility() != elfcpp::STV_DEFAULT
&& pdef->second->is_from_dynobj())
;
else if (pdef->second->visibility() != elfcpp::STV_DEFAULT
&& sym->is_from_dynobj())
;
else
{
const Sized_symbol<size>* symdef;
symdef = this->get_sized_symbol<size>(pdef->second);
Symbol_table::resolve<size, big_endian>(sym, symdef);
this->make_forwarder(pdef->second, sym);
pdef->second = sym;
sym->set_is_default();
}
}
}
// Add one symbol from OBJECT to the symbol table. NAME is symbol
// name and VERSION is the version; both are canonicalized. DEF is
// whether this is the default version. ST_SHNDX is the symbol's
// section index; IS_ORDINARY is whether this is a normal section
// rather than a special code.
// If DEF is true, then this is the definition of a default version of
// a symbol. That means that any lookup of NAME/NULL and any lookup
// of NAME/VERSION should always return the same symbol. This is
// obvious for references, but in particular we want to do this for
// definitions: overriding NAME/NULL should also override
// NAME/VERSION. If we don't do that, it would be very hard to
// override functions in a shared library which uses versioning.
// We implement this by simply making both entries in the hash table
// point to the same Symbol structure. That is easy enough if this is
// the first time we see NAME/NULL or NAME/VERSION, but it is possible
// that we have seen both already, in which case they will both have
// independent entries in the symbol table. We can't simply change
// the symbol table entry, because we have pointers to the entries
// attached to the object files. So we mark the entry attached to the
// object file as a forwarder, and record it in the forwarders_ map.
// Note that entries in the hash table will never be marked as
// forwarders.
//
// ORIG_ST_SHNDX and ST_SHNDX are almost always the same.
// ORIG_ST_SHNDX is the section index in the input file, or SHN_UNDEF
// for a special section code. ST_SHNDX may be modified if the symbol
// is defined in a section being discarded.
template<int size, bool big_endian>
Sized_symbol<size>*
Symbol_table::add_from_object(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,
unsigned int st_shndx,
bool is_ordinary,
unsigned int orig_st_shndx)
{
// Print a message if this symbol is being traced.
if (parameters->options().is_trace_symbol(name))
{
if (orig_st_shndx == elfcpp::SHN_UNDEF)
gold_info(_("%s: reference to %s"), object->name().c_str(), name);
else
gold_info(_("%s: definition of %s"), object->name().c_str(), name);
}
// For an undefined symbol, we may need to adjust the name using
// --wrap.
if (orig_st_shndx == elfcpp::SHN_UNDEF
&& parameters->options().any_wrap())
{
const char* wrap_name = this->wrap_symbol(object, name, &name_key);
if (wrap_name != name)
{
// If we see a reference to malloc with version GLIBC_2.0,
// and we turn it into a reference to __wrap_malloc, then we
// discard the version number. Otherwise the user would be
// required to specify the correct version for
// __wrap_malloc.
version = NULL;
version_key = 0;
name = wrap_name;
}
}
Symbol* const snull = NULL;
std::pair<typename Symbol_table_type::iterator, bool> ins =
this->table_.insert(std::make_pair(std::make_pair(name_key, version_key),
snull));
std::pair<typename Symbol_table_type::iterator, bool> insdef =
std::make_pair(this->table_.end(), false);
if (def)
{
const Stringpool::Key vnull_key = 0;
insdef = this->table_.insert(std::make_pair(std::make_pair(name_key,
vnull_key),
snull));
}
// ins.first: an iterator, which is a pointer to a pair.
// ins.first->first: the key (a pair of name and version).
// ins.first->second: the value (Symbol*).
// ins.second: true if new entry was inserted, false if not.
Sized_symbol<size>* ret;
bool was_undefined;
bool was_common;
if (!ins.second)
{
// We already have an entry for NAME/VERSION.
ret = this->get_sized_symbol<size>(ins.first->second);
gold_assert(ret != NULL);
was_undefined = ret->is_undefined();
was_common = ret->is_common();
this->resolve(ret, sym, st_shndx, is_ordinary, orig_st_shndx, object,
version);
if (parameters->options().gc_sections())
this->gc_mark_dyn_syms(ret);
if (def)
this->define_default_version<size, big_endian>(ret, insdef.second,
insdef.first);
}
else
{
// This is the first time we have seen NAME/VERSION.
gold_assert(ins.first->second == NULL);
if (def && !insdef.second)
{
// We already have an entry for NAME/NULL. If we override
// it, then change it to NAME/VERSION.
ret = this->get_sized_symbol<size>(insdef.first->second);
was_undefined = ret->is_undefined();
was_common = ret->is_common();
this->resolve(ret, sym, st_shndx, is_ordinary, orig_st_shndx, object,
version);
if (parameters->options().gc_sections())
this->gc_mark_dyn_syms(ret);
ins.first->second = ret;
}
else
{
was_undefined = false;
was_common = false;
Sized_target<size, big_endian>* target =
object->sized_target<size, big_endian>();
if (!target->has_make_symbol())
ret = new Sized_symbol<size>();
else
{
ret = target->make_symbol();
if (ret == NULL)
{
// This means that we don't want a symbol table
// entry after all.
if (!def)
this->table_.erase(ins.first);
else
{
this->table_.erase(insdef.first);
// Inserting insdef invalidated ins.
this->table_.erase(std::make_pair(name_key,
version_key));
}
return NULL;
}
}
ret->init_object(name, version, object, sym, st_shndx, is_ordinary);
ins.first->second = ret;
if (def)
{
// This is the first time we have seen NAME/NULL. Point
// it at the new entry for NAME/VERSION.
gold_assert(insdef.second);
insdef.first->second = ret;
}
}
if (def)
ret->set_is_default();
}
// Record every time we see a new undefined symbol, to speed up
// archive groups.
if (!was_undefined && ret->is_undefined())
++this->saw_undefined_;
// Keep track of common symbols, to speed up common symbol
// allocation.
if (!was_common && ret->is_common())
{
if (ret->type() == elfcpp::STT_TLS)
this->tls_commons_.push_back(ret);
else if (!is_ordinary
&& st_shndx == parameters->target().small_common_shndx())
this->small_commons_.push_back(ret);
else if (!is_ordinary
&& st_shndx == parameters->target().large_common_shndx())
this->large_commons_.push_back(ret);
else
this->commons_.push_back(ret);
}
// If we're not doing a relocatable link, then any symbol with
// hidden or internal visibility is local.
if ((ret->visibility() == elfcpp::STV_HIDDEN
|| ret->visibility() == elfcpp::STV_INTERNAL)
&& (ret->binding() == elfcpp::STB_GLOBAL
|| ret->binding() == elfcpp::STB_WEAK)
&& !parameters->options().relocatable())
this->force_local(ret);
return ret;
}
// Add all the symbols in a relocatable object to the hash table.
template<int size, bool big_endian>
void
Symbol_table::add_from_relobj(
Sized_relobj<size, big_endian>* relobj,
const unsigned char* syms,
size_t count,
size_t symndx_offset,
const char* sym_names,
size_t sym_name_size,
typename Sized_relobj<size, big_endian>::Symbols* sympointers,
size_t *defined)
{
*defined = 0;
gold_assert(size == relobj->target()->get_size());
gold_assert(size == parameters->target().get_size());
const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
const bool just_symbols = relobj->just_symbols();
const unsigned char* p = syms;
for (size_t i = 0; i < count; ++i, p += sym_size)
{
(*sympointers)[i] = NULL;
elfcpp::Sym<size, big_endian> sym(p);
unsigned int st_name = sym.get_st_name();
if (st_name >= sym_name_size)
{
relobj->error(_("bad global symbol name offset %u at %zu"),
st_name, i);
continue;
}
const char* name = sym_names + st_name;
bool is_ordinary;
unsigned int st_shndx = relobj->adjust_sym_shndx(i + symndx_offset,
sym.get_st_shndx(),
&is_ordinary);
unsigned int orig_st_shndx = st_shndx;
if (!is_ordinary)
orig_st_shndx = elfcpp::SHN_UNDEF;
if (st_shndx != elfcpp::SHN_UNDEF)
++*defined;
// A symbol defined in a section which we are not including must
// be treated as an undefined symbol.
if (st_shndx != elfcpp::SHN_UNDEF
&& is_ordinary
&& !relobj->is_section_included(st_shndx))
st_shndx = elfcpp::SHN_UNDEF;
// In an object file, an '@' in the name separates the symbol
// name from the version name. If there are two '@' characters,
// this is the default version.
const char* ver = strchr(name, '@');
Stringpool::Key ver_key = 0;
int namelen = 0;
// DEF: is the version default? LOCAL: is the symbol forced local?
bool def = false;
bool local = false;
if (ver != NULL)
{
// The symbol name is of the form foo@VERSION or foo@@VERSION
namelen = ver - name;
++ver;
if (*ver == '@')
{
def = true;
++ver;
}
ver = this->namepool_.add(ver, true, &ver_key);
}
// We don't want to assign a version to an undefined symbol,
// even if it is listed in the version script. FIXME: What
// about a common symbol?
else
{
namelen = strlen(name);
if (!this->version_script_.empty()
&& st_shndx != elfcpp::SHN_UNDEF)
{
// The symbol name did not have a version, but the
// version script may assign a version anyway.
std::string version;
if (this->version_script_.get_symbol_version(name, &version))
{
// The version can be empty if the version script is
// only used to force some symbols to be local.
if (!version.empty())
{
ver = this->namepool_.add_with_length(version.c_str(),
version.length(),
true,
&ver_key);
def = true;
}
}
else if (this->version_script_.symbol_is_local(name))
local = true;
}
}
elfcpp::Sym<size, big_endian>* psym = &sym;
unsigned char symbuf[sym_size];
elfcpp::Sym<size, big_endian> sym2(symbuf);
if (just_symbols)
{
memcpy(symbuf, p, sym_size);
elfcpp::Sym_write<size, big_endian> sw(symbuf);
if (orig_st_shndx != elfcpp::SHN_UNDEF && is_ordinary)
{
// Symbol values in object files are section relative.
// This is normally what we want, but since here we are
// converting the symbol to absolute we need to add the
// section address. The section address in an object
// file is normally zero, but people can use a linker
// script to change it.
sw.put_st_value(sym.get_st_value()
+ relobj->section_address(orig_st_shndx));
}
st_shndx = elfcpp::SHN_ABS;
is_ordinary = false;
psym = &sym2;
}
// Fix up visibility if object has no-export set.
if (relobj->no_export())
{
// We may have copied symbol already above.
if (psym != &sym2)
{
memcpy(symbuf, p, sym_size);
psym = &sym2;
}
elfcpp::STV visibility = sym2.get_st_visibility();
if (visibility == elfcpp::STV_DEFAULT
|| visibility == elfcpp::STV_PROTECTED)
{
elfcpp::Sym_write<size, big_endian> sw(symbuf);
unsigned char nonvis = sym2.get_st_nonvis();
sw.put_st_other(elfcpp::STV_HIDDEN, nonvis);
}
}
Stringpool::Key name_key;
name = this->namepool_.add_with_length(name, namelen, true,
&name_key);
Sized_symbol<size>* res;
res = this->add_from_object(relobj, name, name_key, ver, ver_key,
def, *psym, st_shndx, is_ordinary,
orig_st_shndx);
// If building a shared library using garbage collection, do not
// treat externally visible symbols as garbage.
if (parameters->options().gc_sections()
&& parameters->options().shared())
this->gc_mark_symbol_for_shlib(res);
if (local)
this->force_local(res);
(*sympointers)[i] = res;
}
}
// Add a symbol from a plugin-claimed file.
template<int size, bool big_endian>
Symbol*
Symbol_table::add_from_pluginobj(
Sized_pluginobj<size, big_endian>* obj,
const char* name,
const char* ver,
elfcpp::Sym<size, big_endian>* sym)
{
unsigned int st_shndx = sym->get_st_shndx();
Stringpool::Key ver_key = 0;
bool def = false;
bool local = false;
if (ver != NULL)
{
ver = this->namepool_.add(ver, true, &ver_key);
}
// We don't want to assign a version to an undefined symbol,
// even if it is listed in the version script. FIXME: What
// about a common symbol?
else
{
if (!this->version_script_.empty()
&& st_shndx != elfcpp::SHN_UNDEF)
{
// The symbol name did not have a version, but the
// version script may assign a version anyway.
std::string version;
if (this->version_script_.get_symbol_version(name, &version))
{
// The version can be empty if the version script is
// only used to force some symbols to be local.
if (!version.empty())
{
ver = this->namepool_.add_with_length(version.c_str(),
version.length(),
true,
&ver_key);
def = true;
}
}
else if (this->version_script_.symbol_is_local(name))
local = true;
}
}
Stringpool::Key name_key;
name = this->namepool_.add(name, true, &name_key);
Sized_symbol<size>* res;
res = this->add_from_object(obj, name, name_key, ver, ver_key,
def, *sym, st_shndx, true, st_shndx);
if (local)
this->force_local(res);
return res;
}
// Add all the symbols in a dynamic object to the hash table.
template<int size, bool big_endian>
void
Symbol_table::add_from_dynobj(
Sized_dynobj<size, big_endian>* dynobj,
const unsigned char* syms,
size_t count,
const char* sym_names,
size_t sym_name_size,
const unsigned char* versym,
size_t versym_size,
const std::vector<const char*>* version_map,
typename Sized_relobj<size, big_endian>::Symbols* sympointers,
size_t* defined)
{
*defined = 0;
gold_assert(size == dynobj->target()->get_size());
gold_assert(size == parameters->target().get_size());
if (dynobj->just_symbols())
{
gold_error(_("--just-symbols does not make sense with a shared object"));
return;
}
if (versym != NULL && versym_size / 2 < count)
{
dynobj->error(_("too few symbol versions"));
return;
}
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)
{
elfcpp::Sym<size, big_endian> sym(p);
if (sympointers != NULL)
(*sympointers)[i] = NULL;
// Ignore symbols with local binding or that have
// internal or hidden visibility.
if (sym.get_st_bind() == elfcpp::STB_LOCAL
|| sym.get_st_visibility() == elfcpp::STV_INTERNAL
|| sym.get_st_visibility() == elfcpp::STV_HIDDEN)
continue;
// A protected symbol in a shared library must be treated as a
// normal symbol when viewed from outside the shared library.
// Implement this by overriding the visibility here.
elfcpp::Sym<size, big_endian>* psym = &sym;
unsigned char symbuf[sym_size];
elfcpp::Sym<size, big_endian> sym2(symbuf);
if (sym.get_st_visibility() == elfcpp::STV_PROTECTED)
{
memcpy(symbuf, p, sym_size);
elfcpp::Sym_write<size, big_endian> sw(symbuf);
sw.put_st_other(elfcpp::STV_DEFAULT, sym.get_st_nonvis());
psym = &sym2;
}
unsigned int st_name = psym->get_st_name();
if (st_name >= sym_name_size)
{
dynobj->error(_("bad symbol name offset %u at %zu"),
st_name, i);
continue;
}
const char* name = sym_names + st_name;
bool is_ordinary;
unsigned int st_shndx = dynobj->adjust_sym_shndx(i, psym->get_st_shndx(),
&is_ordinary);
if (st_shndx != elfcpp::SHN_UNDEF)
++*defined;
Sized_symbol<size>* res;
if (versym == NULL)
{
Stringpool::Key name_key;
name = this->namepool_.add(name, true, &name_key);
res = this->add_from_object(dynobj, name, name_key, NULL, 0,
false, *psym, st_shndx, is_ordinary,
st_shndx);
}
else
{
// Read the version information.
unsigned int v = elfcpp::Swap<16, big_endian>::readval(vs);
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.
if (v == static_cast<unsigned int>(elfcpp::VER_NDX_LOCAL)
&& 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);
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, *psym, st_shndx, is_ordinary,
st_shndx);
}
else
{
if (v >= version_map->size())
{
dynobj->error(_("versym for symbol %zu out of range: %u"),
i, v);
continue;
}
const char* version = (*version_map)[v];
if (version == NULL)
{
dynobj->error(_("versym for symbol %zu has no name: %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 (st_shndx == elfcpp::SHN_ABS
&& !is_ordinary
&& name_key == version_key)
res = this->add_from_object(dynobj, name, name_key, NULL, 0,
false, *psym, st_shndx, is_ordinary,
st_shndx);
else
{
const bool def = (!hidden
&& st_shndx != elfcpp::SHN_UNDEF);
res = this->add_from_object(dynobj, name, name_key, version,
version_key, def, *psym, st_shndx,
is_ordinary, st_shndx);
}
}
}
// Note that it is possible that RES was overridden by an
// earlier object, in which case it can't be aliased here.
if (st_shndx != elfcpp::SHN_UNDEF
&& is_ordinary
&& psym->get_st_type() == elfcpp::STT_OBJECT
&& res->source() == Symbol::FROM_OBJECT
&& res->object() == dynobj)
object_symbols.push_back(res);
if (sympointers != NULL)
(*sympointers)[i] = 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
{
bool is_ordinary;
unsigned int s1_shndx = s1->shndx(&is_ordinary);
gold_assert(is_ordinary);
unsigned int s2_shndx = s2->shndx(&is_ordinary);
gold_assert(is_ordinary);
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());
}
// 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.
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)
{
bool dummy;
if ((*q)->shndx(&dummy) != from_sym->shndx(&dummy)
|| (*q)->value() != from_sym->value())
break;
this->weak_aliases_[from_sym] = *q;
from_sym->set_has_alias();
from_sym = *q;
}
if (from_sym != *p)
{
this->weak_aliases_[from_sym] = *p;
from_sym->set_has_alias();
}
p = q - 1;
}
}
// Create and return a specially defined symbol. If ONLY_IF_REF is
// true, then only create the symbol if there is a reference to it.
// If this does not return NULL, it sets *POLDSYM to the existing
// symbol if there is one. This sets *RESOLVE_OLDSYM if we should
// resolve the newly created symbol to the old one. This
// canonicalizes *PNAME and *PVERSION.
template<int size, bool big_endian>
Sized_symbol<size>*
Symbol_table::define_special_symbol(const char** pname, const char** pversion,
bool only_if_ref,
Sized_symbol<size>** poldsym,
bool *resolve_oldsym)
{
*resolve_oldsym = false;
// If the caller didn't give us a version, see if we get one from
// the version script.
std::string v;
bool is_default_version = false;
if (*pversion == NULL)
{
if (this->version_script_.get_symbol_version(*pname, &v))
{
if (!v.empty())
*pversion = v.c_str();
// If we get the version from a version script, then we are
// also the default version.
is_default_version = true;
}
}
Symbol* oldsym;
Sized_symbol<size>* sym;
bool add_to_table = false;
typename Symbol_table_type::iterator add_loc = this->table_.end();
bool add_def_to_table = false;
typename Symbol_table_type::iterator add_def_loc = this->table_.end();
if (only_if_ref)
{
oldsym = this->lookup(*pname, *pversion);
if (oldsym == NULL && is_default_version)
oldsym = this->lookup(*pname, NULL);
if (oldsym == NULL || !oldsym->is_undefined())
return NULL;
*pname = oldsym->name();
if (!is_default_version)
*pversion = oldsym->version();
}
else
{
// Canonicalize NAME and VERSION.
Stringpool::Key name_key;
*pname = this->namepool_.add(*pname, true, &name_key);
Stringpool::Key version_key = 0;
if (*pversion != NULL)
*pversion = this->namepool_.add(*pversion, true, &version_key);
Symbol* const snull = NULL;
std::pair<typename Symbol_table_type::iterator, bool> ins =
this->table_.insert(std::make_pair(std::make_pair(name_key,
version_key),
snull));
std::pair<typename Symbol_table_type::iterator, bool> insdef =
std::make_pair(this->table_.end(), false);
if (is_default_version)
{
const Stringpool::Key vnull = 0;
insdef = this->table_.insert(std::make_pair(std::make_pair(name_key,
vnull),
snull));
}
if (!ins.second)
{
// We already have a symbol table entry for NAME/VERSION.
oldsym = ins.first->second;
gold_assert(oldsym != NULL);
if (is_default_version)
{
Sized_symbol<size>* soldsym =
this->get_sized_symbol<size>(oldsym);
this->define_default_version<size, big_endian>(soldsym,
insdef.second,
insdef.first);
}
}
else
{
// We haven't seen this symbol before.
gold_assert(ins.first->second == NULL);
add_to_table = true;
add_loc = ins.first;
if (is_default_version && !insdef.second)
{
// We are adding NAME/VERSION, and it is the default
// version. We already have an entry for NAME/NULL.
oldsym = insdef.first->second;
*resolve_oldsym = true;
}
else
{
oldsym = NULL;
if (is_default_version)
{
add_def_to_table = true;
add_def_loc = insdef.first;
}
}
}
}
const Target& target = parameters->target();
if (!target.has_make_symbol())
sym = new Sized_symbol<size>();
else
{
gold_assert(target.get_size() == size);
gold_assert(target.is_big_endian() ? big_endian : !big_endian);
typedef Sized_target<size, big_endian> My_target;
const My_target* sized_target =
static_cast<const My_target*>(&target);
sym = sized_target->make_symbol();
if (sym == NULL)
return NULL;
}
if (add_to_table)
add_loc->second = sym;
else
gold_assert(oldsym != NULL);
if (add_def_to_table)
add_def_loc->second = sym;
*poldsym = this->get_sized_symbol<size>(oldsym);
return sym;
}
// Define a symbol based on an Output_data.
Symbol*
Symbol_table::define_in_output_data(const char* name,
const char* version,
Output_data* od,
uint64_t value,
uint64_t symsize,
elfcpp::STT type,
elfcpp::STB binding,
elfcpp::STV visibility,
unsigned char nonvis,
bool offset_is_from_end,
bool only_if_ref)
{
if (parameters->target().get_size() == 32)
{
#if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
return this->do_define_in_output_data<32>(name, version, od,
value, symsize, type, binding,
visibility, nonvis,
offset_is_from_end,
only_if_ref);
#else
gold_unreachable();
#endif
}
else if (parameters->target().get_size() == 64)
{
#if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
return this->do_define_in_output_data<64>(name, version, od,
value, symsize, type, binding,
visibility, nonvis,
offset_is_from_end,
only_if_ref);
#else
gold_unreachable();
#endif
}
else
gold_unreachable();
}
// Define a symbol in an Output_data, sized version.
template<int size>
Sized_symbol<size>*
Symbol_table::do_define_in_output_data(
const char* name,
const char* version,
Output_data* od,
typename elfcpp::Elf_types<size>::Elf_Addr value,
typename elfcpp::Elf_types<size>::Elf_WXword symsize,
elfcpp::STT type,
elfcpp::STB binding,
elfcpp::STV visibility,
unsigned char nonvis,
bool offset_is_from_end,
bool only_if_ref)
{
Sized_symbol<size>* sym;
Sized_symbol<size>* oldsym;
bool resolve_oldsym;
if (parameters->target().is_big_endian())
{
#if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
sym = this->define_special_symbol<size, true>(&name, &version,
only_if_ref, &oldsym,
&resolve_oldsym);
#else
gold_unreachable();
#endif
}
else
{
#if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
sym = this->define_special_symbol<size, false>(&name, &version,
only_if_ref, &oldsym,
&resolve_oldsym);
#else
gold_unreachable();
#endif
}
if (sym == NULL)
return NULL;
sym->init_output_data(name, version, od, value, symsize, type, binding,
visibility, nonvis, offset_is_from_end);
if (oldsym == NULL)
{
if (binding == elfcpp::STB_LOCAL
|| this->version_script_.symbol_is_local(name))
this->force_local(sym);
else if (version != NULL)
sym->set_is_default();
return sym;
}
if (Symbol_table::should_override_with_special(oldsym))
this->override_with_special(oldsym, sym);
if (resolve_oldsym)
return sym;
else
{
delete sym;
return oldsym;
}
}
// Define a symbol based on an Output_segment.
Symbol*
Symbol_table::define_in_output_segment(const char* name,
const char* version, Output_segment* os,
uint64_t value,
uint64_t symsize,
elfcpp::STT type,
elfcpp::STB binding,
elfcpp::STV visibility,
unsigned char nonvis,
Symbol::Segment_offset_base offset_base,
bool only_if_ref)
{
if (parameters->target().get_size() == 32)
{
#if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
return this->do_define_in_output_segment<32>(name, version, os,
value, symsize, type,
binding, visibility, nonvis,
offset_base, only_if_ref);
#else
gold_unreachable();
#endif
}
else if (parameters->target().get_size() == 64)
{
#if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
return this->do_define_in_output_segment<64>(name, version, os,
value, symsize, type,
binding, visibility, nonvis,
offset_base, only_if_ref);
#else
gold_unreachable();
#endif
}
else
gold_unreachable();
}
// Define a symbol in an Output_segment, sized version.
template<int size>
Sized_symbol<size>*
Symbol_table::do_define_in_output_segment(
const char* name,
const char* version,
Output_segment* os,
typename elfcpp::Elf_types<size>::Elf_Addr value,
typename elfcpp::Elf_types<size>::Elf_WXword symsize,
elfcpp::STT type,
elfcpp::STB binding,
elfcpp::STV visibility,
unsigned char nonvis,
Symbol::Segment_offset_base offset_base,
bool only_if_ref)
{
Sized_symbol<size>* sym;
Sized_symbol<size>* oldsym;
bool resolve_oldsym;
if (parameters->target().is_big_endian())
{
#if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
sym = this->define_special_symbol<size, true>(&name, &version,
only_if_ref, &oldsym,
&resolve_oldsym);
#else
gold_unreachable();
#endif
}
else
{
#if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
sym = this->define_special_symbol<size, false>(&name, &version,
only_if_ref, &oldsym,
&resolve_oldsym);
#else
gold_unreachable();
#endif
}
if (sym == NULL)
return NULL;
sym->init_output_segment(name, version, os, value, symsize, type, binding,
visibility, nonvis, offset_base);
if (oldsym == NULL)
{
if (binding == elfcpp::STB_LOCAL
|| this->version_script_.symbol_is_local(name))
this->force_local(sym);
else if (version != NULL)
sym->set_is_default();
return sym;
}
if (Symbol_table::should_override_with_special(oldsym))
this->override_with_special(oldsym, sym);
if (resolve_oldsym)
return sym;
else
{
delete sym;
return oldsym;
}
}
// Define a special symbol with a constant value. It is a multiple
// definition error if this symbol is already defined.
Symbol*
Symbol_table::define_as_constant(const char* name,
const char* version,
uint64_t value,
uint64_t symsize,
elfcpp::STT type,
elfcpp::STB binding,
elfcpp::STV visibility,
unsigned char nonvis,
bool only_if_ref,
bool force_override)
{
if (parameters->target().get_size() == 32)
{
#if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
return this->do_define_as_constant<32>(name, version, value,
symsize, type, binding,
visibility, nonvis, only_if_ref,
force_override);
#else
gold_unreachable();
#endif
}
else if (parameters->target().get_size() == 64)
{
#if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
return this->do_define_as_constant<64>(name, version, value,
symsize, type, binding,
visibility, nonvis, only_if_ref,
force_override);
#else
gold_unreachable();
#endif
}
else
gold_unreachable();
}
// Define a symbol as a constant, sized version.
template<int size>
Sized_symbol<size>*
Symbol_table::do_define_as_constant(
const char* name,
const char* version,
typename elfcpp::Elf_types<size>::Elf_Addr value,
typename elfcpp::Elf_types<size>::Elf_WXword symsize,
elfcpp::STT type,
elfcpp::STB binding,
elfcpp::STV visibility,
unsigned char nonvis,
bool only_if_ref,
bool force_override)
{
Sized_symbol<size>* sym;
Sized_symbol<size>* oldsym;
bool resolve_oldsym;
if (parameters->target().is_big_endian())
{
#if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
sym = this->define_special_symbol<size, true>(&name, &version,
only_if_ref, &oldsym,
&resolve_oldsym);
#else
gold_unreachable();
#endif
}
else
{
#if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
sym = this->define_special_symbol<size, false>(&name, &version,
only_if_ref, &oldsym,
&resolve_oldsym);
#else
gold_unreachable();
#endif
}
if (sym == NULL)
return NULL;
sym->init_constant(name, version, value, symsize, type, binding, visibility,
nonvis);
if (oldsym == NULL)
{
// Version symbols are absolute symbols with name == version.
// We don't want to force them to be local.
if ((version == NULL
|| name != version
|| value != 0)
&& (binding == elfcpp::STB_LOCAL
|| this->version_script_.symbol_is_local(name)))
this->force_local(sym);
else if (version != NULL
&& (name != version || value != 0))
sym->set_is_default();
return sym;
}
if (force_override || Symbol_table::should_override_with_special(oldsym))
this->override_with_special(oldsym, sym);
if (resolve_oldsym)
return sym;
else
{
delete sym;
return oldsym;
}
}
// Define a set of symbols in output sections.
void
Symbol_table::define_symbols(const Layout* layout, int count,
const Define_symbol_in_section* p,
bool only_if_ref)
{
for (int i = 0; i < count; ++i, ++p)
{
Output_section* os = layout->find_output_section(p->output_section);
if (os != NULL)
this->define_in_output_data(p->name, NULL, os, p->value,
p->size, p->type, p->binding,
p->visibility, p->nonvis,
p->offset_is_from_end,
only_if_ref || p->only_if_ref);
else
this->define_as_constant(p->name, NULL, 0, p->size, p->type,
p->binding, p->visibility, p->nonvis,
only_if_ref || p->only_if_ref,
false);
}
}
// Define a set of symbols in output segments.
void
Symbol_table::define_symbols(const Layout* layout, int count,
const Define_symbol_in_segment* p,
bool only_if_ref)
{
for (int i = 0; i < count; ++i, ++p)
{
Output_segment* os = layout->find_output_segment(p->segment_type,
p->segment_flags_set,
p->segment_flags_clear);
if (os != NULL)
this->define_in_output_segment(p->name, NULL, os, p->value,
p->size, p->type, p->binding,
p->visibility, p->nonvis,
p->offset_base,
only_if_ref || p->only_if_ref);
else
this->define_as_constant(p->name, NULL, 0, p->size, p->type,
p->binding, p->visibility, p->nonvis,
only_if_ref || p->only_if_ref,
false);
}
}
// Define CSYM using a COPY reloc. POSD is the Output_data where the
// symbol should be defined--typically a .dyn.bss section. VALUE is
// the offset within POSD.
template<int size>
void
Symbol_table::define_with_copy_reloc(
Sized_symbol<size>* csym,
Output_data* posd,
typename elfcpp::Elf_types<size>::Elf_Addr value)
{
gold_assert(csym->is_from_dynobj());
gold_assert(!csym->is_copied_from_dynobj());
Object* object = csym->object();
gold_assert(object->is_dynamic());
Dynobj* dynobj = static_cast<Dynobj*>(object);
// Our copied variable has to override any variable in a shared
// library.
elfcpp::STB binding = csym->binding();
if (binding == elfcpp::STB_WEAK)
binding = elfcpp::STB_GLOBAL;
this->define_in_output_data(csym->name(), csym->version(),
posd, value, csym->symsize(),
csym->type(), binding,
csym->visibility(), csym->nonvis(),
false, false);
csym->set_is_copied_from_dynobj();
csym->set_needs_dynsym_entry();
this->copied_symbol_dynobjs_[csym] = dynobj;
// We have now defined all aliases, but we have not entered them all
// in the copied_symbol_dynobjs_ map.
if (csym->has_alias())
{
Symbol* sym = csym;
while (true)
{
sym = this->weak_aliases_[sym];
if (sym == csym)
break;
gold_assert(sym->output_data() == posd);
sym->set_is_copied_from_dynobj();
this->copied_symbol_dynobjs_[sym] = dynobj;
}
}
}
// SYM is defined using a COPY reloc. Return the dynamic object where
// the original definition was found.
Dynobj*
Symbol_table::get_copy_source(const Symbol* sym) const
{
gold_assert(sym->is_copied_from_dynobj());
Copied_symbol_dynobjs::const_iterator p =
this->copied_symbol_dynobjs_.find(sym);
gold_assert(p != this->copied_symbol_dynobjs_.end());
return p->second;
}
// Add any undefined symbols named on the command line.
void
Symbol_table::add_undefined_symbols_from_command_line()
{
if (parameters->options().any_undefined())
{
if (parameters->target().get_size() == 32)
{
#if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
this->do_add_undefined_symbols_from_command_line<32>();
#else
gold_unreachable();
#endif
}
else if (parameters->target().get_size() == 64)
{
#if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
this->do_add_undefined_symbols_from_command_line<64>();
#else
gold_unreachable();
#endif
}
else
gold_unreachable();
}
}
template<int size>
void
Symbol_table::do_add_undefined_symbols_from_command_line()
{
for (options::String_set::const_iterator p =
parameters->options().undefined_begin();
p != parameters->options().undefined_end();
++p)
{
const char* name = p->c_str();
if (this->lookup(name) != NULL)
continue;
const char* version = NULL;
Sized_symbol<size>* sym;
Sized_symbol<size>* oldsym;
bool resolve_oldsym;
if (parameters->target().is_big_endian())
{
#if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
sym = this->define_special_symbol<size, true>(&name, &version,
false, &oldsym,
&resolve_oldsym);
#else
gold_unreachable();
#endif
}
else
{
#if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
sym = this->define_special_symbol<size, false>(&name, &version,
false, &oldsym,
&resolve_oldsym);
#else
gold_unreachable();
#endif
}
gold_assert(oldsym == NULL);
sym->init_undefined(name, version, elfcpp::STT_NOTYPE, elfcpp::STB_GLOBAL,
elfcpp::STV_DEFAULT, 0);
++this->saw_undefined_;
}
}
// Set the dynamic symbol indexes. INDEX is the index of the first
// global dynamic symbol. Pointers to the symbols are stored into the
// vector SYMS. The names are added to DYNPOOL. This returns an
// updated dynamic symbol index.
unsigned int
Symbol_table::set_dynsym_indexes(unsigned int index,
std::vector<Symbol*>* syms,
Stringpool* dynpool,
Versions* versions)
{
for (Symbol_table_type::iterator p = this->table_.begin();
p != this->table_.end();
++p)
{
Symbol* sym = p->second;
// Note that SYM may already have a dynamic symbol index, since
// some symbols appear more than once in the symbol table, with
// and without a version.
if (!sym->should_add_dynsym_entry())
sym->set_dynsym_index(-1U);
else if (!sym->has_dynsym_index())
{
sym->set_dynsym_index(index);
++index;
syms->push_back(sym);
dynpool->add(sym->name(), false, NULL);
// Record any version information.
if (sym->version() != NULL)
versions->record_version(this, dynpool, sym);
}
}
// Finish up the versions. In some cases this may add new dynamic
// symbols.
index = versions->finalize(this, index, syms);
return index;
}
// Set the final values for all the symbols. The index of the first
// global symbol in the output file is *PLOCAL_SYMCOUNT. Record the
// file offset OFF. Add their names to POOL. Return the new file
// offset. Update *PLOCAL_SYMCOUNT if necessary.
off_t
Symbol_table::finalize(off_t off, off_t dynoff, size_t dyn_global_index,
size_t dyncount, Stringpool* pool,
unsigned int *plocal_symcount)
{
off_t ret;
gold_assert(*plocal_symcount != 0);
this->first_global_index_ = *plocal_symcount;
this->dynamic_offset_ = dynoff;
this->first_dynamic_global_index_ = dyn_global_index;
this->dynamic_count_ = dyncount;
if (parameters->target().get_size() == 32)
{
#if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_32_LITTLE)
ret = this->sized_finalize<32>(off, pool, plocal_symcount);
#else
gold_unreachable();
#endif
}
else if (parameters->target().get_size() == 64)
{
#if defined(HAVE_TARGET_64_BIG) || defined(HAVE_TARGET_64_LITTLE)
ret = this->sized_finalize<64>(off, pool, plocal_symcount);
#else
gold_unreachable();
#endif
}
else
gold_unreachable();
// Now that we have the final symbol table, we can reliably note
// which symbols should get warnings.
this->warnings_.note_warnings(this);
return ret;
}
// SYM is going into the symbol table at *PINDEX. Add the name to
// POOL, update *PINDEX and *POFF.
template<int size>
void
Symbol_table::add_to_final_symtab(Symbol* sym, Stringpool* pool,
unsigned int* pindex, off_t* poff)
{
sym->set_symtab_index(*pindex);
pool->add(sym->name(), false, NULL);
++*pindex;
*poff += elfcpp::Elf_sizes<size>::sym_size;
}
// Set the final value for all the symbols. This is called after
// Layout::finalize, so all the output sections have their final
// address.
template<int size>
off_t
Symbol_table::sized_finalize(off_t off, Stringpool* pool,
unsigned int* plocal_symcount)
{
off = align_address(off, size >> 3);
this->offset_ = off;
unsigned int index = *plocal_symcount;
const unsigned int orig_index = index;
// First do all the symbols which have been forced to be local, as
// they must appear before all global symbols.
for (Forced_locals::iterator p = this->forced_locals_.begin();
p != this->forced_locals_.end();
++p)
{
Symbol* sym = *p;
gold_assert(sym->is_forced_local());
if (this->sized_finalize_symbol<size>(sym))
{
this->add_to_final_symtab<size>(sym, pool, &index, &off);
++*plocal_symcount;
}
}
// Now do all the remaining symbols.
for (Symbol_table_type::iterator p = this->table_.begin();
p != this->table_.end();
++p)
{
Symbol* sym = p->second;
if (this->sized_finalize_symbol<size>(sym))
this->add_to_final_symtab<size>(sym, pool, &index, &off);
}
this->output_count_ = index - orig_index;
return off;
}
// Finalize the symbol SYM. This returns true if the symbol should be
// added to the symbol table, false otherwise.
template<int size>
bool
Symbol_table::sized_finalize_symbol(Symbol* unsized_sym)
{
typedef typename Sized_symbol<size>::Value_type Value_type;
Sized_symbol<size>* sym = static_cast<Sized_symbol<size>*>(unsized_sym);
// The default version of a symbol may appear twice in the symbol
// table. We only need to finalize it once.
if (sym->has_symtab_index())
return false;
if (!sym->in_reg())
{
gold_assert(!sym->has_symtab_index());
sym->set_symtab_index(-1U);
gold_assert(sym->dynsym_index() == -1U);
return false;
}
Value_type value;
switch (sym->source())
{
case Symbol::FROM_OBJECT:
{
bool is_ordinary;
unsigned int shndx = sym->shndx(&is_ordinary);
if (!is_ordinary
&& shndx != elfcpp::SHN_ABS
&& !Symbol::is_common_shndx(shndx))
{
gold_error(_("%s: unsupported symbol section 0x%x"),
sym->demangled_name().c_str(), shndx);
shndx = elfcpp::SHN_UNDEF;
}
Object* symobj = sym->object();
if (symobj->is_dynamic())
{
value = 0;
shndx = elfcpp::SHN_UNDEF;
}
else if (symobj->pluginobj() != NULL)
{
value = 0;
shndx = elfcpp::SHN_UNDEF;
}
else if (shndx == elfcpp::SHN_UNDEF)
value = 0;
else if (!is_ordinary
&& (shndx == elfcpp::SHN_ABS
|| Symbol::is_common_shndx(shndx)))
value = sym->value();
else
{
Relobj* relobj = static_cast<Relobj*>(symobj);
Output_section* os = relobj->output_section(shndx);
if (os == NULL)
{
sym->set_symtab_index(-1U);
bool static_or_reloc = (parameters->doing_static_link() ||
parameters->options().relocatable());
gold_assert(static_or_reloc || sym->dynsym_index() == -1U);
return false;
}
uint64_t secoff64 = relobj->output_section_offset(shndx);
if (secoff64 == -1ULL)
{
// The section needs special handling (e.g., a merge section).
value = os->output_address(relobj, shndx, sym->value());
}
else
{
Value_type secoff =
convert_types<Value_type, uint64_t>(secoff64);
if (sym->type() == elfcpp::STT_TLS)
value = sym->value() + os->tls_offset() + secoff;
else
value = sym->value() + os->address() + secoff;
}
}
}
break;
case Symbol::IN_OUTPUT_DATA:
{
Output_data* od = sym->output_data();
value = sym->value();
if (sym->type() != elfcpp::STT_TLS)
value += od->address();
else
{
Output_section* os = od->output_section();
gold_assert(os != NULL);
value += os->tls_offset() + (od->address() - os->address());
}
if (sym->offset_is_from_end())
value += od->data_size();
}
break;
case Symbol::IN_OUTPUT_SEGMENT:
{
Output_segment* os = sym->output_segment();
value = sym->value();
if (sym->type() != elfcpp::STT_TLS)
value += os->vaddr();
switch (sym->offset_base())
{
case Symbol::SEGMENT_START:
break;
case Symbol::SEGMENT_END:
value += os->memsz();
break;
case Symbol::SEGMENT_BSS:
value += os->filesz();
break;
default:
gold_unreachable();
}
}
break;
case Symbol::IS_CONSTANT:
value = sym->value();
break;
case Symbol::IS_UNDEFINED:
value = 0;
break;
default:
gold_unreachable();
}
sym->set_value(value);
if (parameters->options().strip_all())
{
sym->set_symtab_index(-1U);
return false;
}
return true;
}
// Write out the global symbols.
void
Symbol_table::write_globals(const Stringpool* sympool,
const Stringpool* dynpool,
Output_symtab_xindex* symtab_xindex,
Output_symtab_xindex* dynsym_xindex,
Output_file* of) const
{
switch (parameters->size_and_endianness())
{
#ifdef HAVE_TARGET_32_LITTLE
case Parameters::TARGET_32_LITTLE:
this->sized_write_globals<32, false>(sympool, dynpool, symtab_xindex,
dynsym_xindex, of);
break;
#endif
#ifdef HAVE_TARGET_32_BIG
case Parameters::TARGET_32_BIG:
this->sized_write_globals<32, true>(sympool, dynpool, symtab_xindex,
dynsym_xindex, of);
break;
#endif
#ifdef HAVE_TARGET_64_LITTLE
case Parameters::TARGET_64_LITTLE:
this->sized_write_globals<64, false>(sympool, dynpool, symtab_xindex,
dynsym_xindex, of);
break;
#endif
#ifdef HAVE_TARGET_64_BIG
case Parameters::TARGET_64_BIG:
this->sized_write_globals<64, true>(sympool, dynpool, symtab_xindex,
dynsym_xindex, of);
break;
#endif
default:
gold_unreachable();
}
}
// Write out the global symbols.
template<int size, bool big_endian>
void
Symbol_table::sized_write_globals(const Stringpool* sympool,
const Stringpool* dynpool,
Output_symtab_xindex* symtab_xindex,
Output_symtab_xindex* dynsym_xindex,
Output_file* of) const
{
const Target& target = parameters->target();
const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
const unsigned int output_count = this->output_count_;
const section_size_type oview_size = output_count * sym_size;
const unsigned int first_global_index = this->first_global_index_;
unsigned char* psyms;
if (this->offset_ == 0 || output_count == 0)
psyms = NULL;
else
psyms = of->get_output_view(this->offset_, oview_size);
const unsigned int dynamic_count = this->dynamic_count_;
const section_size_type dynamic_size = dynamic_count * sym_size;
const unsigned int first_dynamic_global_index =
this->first_dynamic_global_index_;
unsigned char* dynamic_view;
if (this->dynamic_offset_ == 0 || dynamic_count == 0)
dynamic_view = NULL;
else
dynamic_view = of->get_output_view(this->dynamic_offset_, dynamic_size);
for (Symbol_table_type::const_iterator p = this->table_.begin();
p != this->table_.end();
++p)
{
Sized_symbol<size>* sym = static_cast<Sized_symbol<size>*>(p->second);
// Possibly warn about unresolved symbols in shared libraries.
this->warn_about_undefined_dynobj_symbol(sym);
unsigned int sym_index = sym->symtab_index();
unsigned int dynsym_index;
if (dynamic_view == NULL)
dynsym_index = -1U;
else
dynsym_index = sym->dynsym_index();
if (sym_index == -1U && dynsym_index == -1U)
{
// This symbol is not included in the output file.
continue;
}
unsigned int shndx;
typename elfcpp::Elf_types<size>::Elf_Addr sym_value = sym->value();
typename elfcpp::Elf_types<size>::Elf_Addr dynsym_value = sym_value;
switch (sym->source())
{
case Symbol::FROM_OBJECT:
{
bool is_ordinary;
unsigned int in_shndx = sym->shndx(&is_ordinary);
if (!is_ordinary
&& in_shndx != elfcpp::SHN_ABS
&& !Symbol::is_common_shndx(in_shndx))
{
gold_error(_("%s: unsupported symbol section 0x%x"),
sym->demangled_name().c_str(), in_shndx);
shndx = in_shndx;
}
else
{
Object* symobj = sym->object();
if (symobj->is_dynamic())
{
if (sym->needs_dynsym_value())
dynsym_value = target.dynsym_value(sym);
shndx = elfcpp::SHN_UNDEF;
}
else if (symobj->pluginobj() != NULL)
shndx = elfcpp::SHN_UNDEF;
else if (in_shndx == elfcpp::SHN_UNDEF
|| (!is_ordinary
&& (in_shndx == elfcpp::SHN_ABS
|| Symbol::is_common_shndx(in_shndx))))
shndx = in_shndx;
else
{
Relobj* relobj = static_cast<Relobj*>(symobj);
Output_section* os = relobj->output_section(in_shndx);
gold_assert(os != NULL);
shndx = os->out_shndx();
if (shndx >= elfcpp::SHN_LORESERVE)
{
if (sym_index != -1U)
symtab_xindex->add(sym_index, shndx);
if (dynsym_index != -1U)
dynsym_xindex->add(dynsym_index, shndx);
shndx = elfcpp::SHN_XINDEX;
}
// In object files symbol values are section
// relative.
if (parameters->options().relocatable())
sym_value -= os->address();
}
}
}
break;
case Symbol::IN_OUTPUT_DATA:
shndx = sym->output_data()->out_shndx();
if (shndx >= elfcpp::SHN_LORESERVE)
{
if (sym_index != -1U)
symtab_xindex->add(sym_index, shndx);
if (dynsym_index != -1U)
dynsym_xindex->add(dynsym_index, shndx);
shndx = elfcpp::SHN_XINDEX;
}
break;
case Symbol::IN_OUTPUT_SEGMENT:
shndx = elfcpp::SHN_ABS;
break;
case Symbol::IS_CONSTANT:
shndx = elfcpp::SHN_ABS;
break;
case Symbol::IS_UNDEFINED:
shndx = elfcpp::SHN_UNDEF;
break;
default:
gold_unreachable();
}
if (sym_index != -1U)
{
sym_index -= first_global_index;
gold_assert(sym_index < output_count);
unsigned char* ps = psyms + (sym_index * sym_size);
this->sized_write_symbol<size, big_endian>(sym, sym_value, shndx,
sympool, ps);
}
if (dynsym_index != -1U)
{
dynsym_index -= first_dynamic_global_index;
gold_assert(dynsym_index < dynamic_count);
unsigned char* pd = dynamic_view + (dynsym_index * sym_size);
this->sized_write_symbol<size, big_endian>(sym, dynsym_value, shndx,
dynpool, pd);
}
}
of->write_output_view(this->offset_, oview_size, psyms);
if (dynamic_view != NULL)
of->write_output_view(this->dynamic_offset_, dynamic_size, dynamic_view);
}
// Write out the symbol SYM, in section SHNDX, to P. POOL is the
// strtab holding the name.
template<int size, bool big_endian>
void
Symbol_table::sized_write_symbol(
Sized_symbol<size>* sym,
typename elfcpp::Elf_types<size>::Elf_Addr value,
unsigned int shndx,
const Stringpool* pool,
unsigned char* p) const
{
elfcpp::Sym_write<size, big_endian> osym(p);
osym.put_st_name(pool->get_offset(sym->name()));
osym.put_st_value(value);
// Use a symbol size of zero for undefined symbols from shared libraries.
if (shndx == elfcpp::SHN_UNDEF && sym->is_from_dynobj())
osym.put_st_size(0);
else
osym.put_st_size(sym->symsize());
// A version script may have overridden the default binding.
if (sym->is_forced_local())
osym.put_st_info(elfcpp::elf_st_info(elfcpp::STB_LOCAL, sym->type()));
else
osym.put_st_info(elfcpp::elf_st_info(sym->binding(), sym->type()));
osym.put_st_other(elfcpp::elf_st_other(sym->visibility(), sym->nonvis()));
osym.put_st_shndx(shndx);
}
// Check for unresolved symbols in shared libraries. This is
// controlled by the --allow-shlib-undefined option.
// We only warn about libraries for which we have seen all the
// DT_NEEDED entries. We don't try to track down DT_NEEDED entries
// which were not seen in this link. If we didn't see a DT_NEEDED
// entry, we aren't going to be able to reliably report whether the
// symbol is undefined.
// We also don't warn about libraries found in a system library
// directory (e.g., /lib or /usr/lib); we assume that those libraries
// are OK. This heuristic avoids problems on GNU/Linux, in which -ldl
// can have undefined references satisfied by ld-linux.so.
inline void
Symbol_table::warn_about_undefined_dynobj_symbol(Symbol* sym) const
{
bool dummy;
if (sym->source() == Symbol::FROM_OBJECT
&& sym->object()->is_dynamic()
&& sym->shndx(&dummy) == elfcpp::SHN_UNDEF
&& sym->binding() != elfcpp::STB_WEAK
&& !parameters->options().allow_shlib_undefined()
&& !parameters->target().is_defined_by_abi(sym)
&& !sym->object()->is_in_system_directory())
{
// A very ugly cast.
Dynobj* dynobj = static_cast<Dynobj*>(sym->object());
if (!dynobj->has_unknown_needed_entries())
gold_undefined_symbol(sym);
}
}
// Write out a section symbol. Return the update offset.
void
Symbol_table::write_section_symbol(const Output_section *os,
Output_symtab_xindex* symtab_xindex,
Output_file* of,
off_t offset) const
{
switch (parameters->size_and_endianness())
{
#ifdef HAVE_TARGET_32_LITTLE
case Parameters::TARGET_32_LITTLE:
this->sized_write_section_symbol<32, false>(os, symtab_xindex, of,
offset);
break;
#endif
#ifdef HAVE_TARGET_32_BIG
case Parameters::TARGET_32_BIG:
this->sized_write_section_symbol<32, true>(os, symtab_xindex, of,
offset);
break;
#endif
#ifdef HAVE_TARGET_64_LITTLE
case Parameters::TARGET_64_LITTLE:
this->sized_write_section_symbol<64, false>(os, symtab_xindex, of,
offset);
break;
#endif
#ifdef HAVE_TARGET_64_BIG
case Parameters::TARGET_64_BIG:
this->sized_write_section_symbol<64, true>(os, symtab_xindex, of,
offset);
break;
#endif
default:
gold_unreachable();
}
}
// Write out a section symbol, specialized for size and endianness.
template<int size, bool big_endian>
void
Symbol_table::sized_write_section_symbol(const Output_section* os,
Output_symtab_xindex* symtab_xindex,
Output_file* of,
off_t offset) const
{
const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
unsigned char* pov = of->get_output_view(offset, sym_size);
elfcpp::Sym_write<size, big_endian> osym(pov);
osym.put_st_name(0);
if (parameters->options().relocatable())
osym.put_st_value(0);
else
osym.put_st_value(os->address());
osym.put_st_size(0);
osym.put_st_info(elfcpp::elf_st_info(elfcpp::STB_LOCAL,
elfcpp::STT_SECTION));
osym.put_st_other(elfcpp::elf_st_other(elfcpp::STV_DEFAULT, 0));
unsigned int shndx = os->out_shndx();
if (shndx >= elfcpp::SHN_LORESERVE)
{
symtab_xindex->add(os->symtab_index(), shndx);
shndx = elfcpp::SHN_XINDEX;
}
osym.put_st_shndx(shndx);
of->write_output_view(offset, sym_size, pov);
}
// Print statistical information to stderr. This is used for --stats.
void
Symbol_table::print_stats() const
{
#if defined(HAVE_TR1_UNORDERED_MAP) || defined(HAVE_EXT_HASH_MAP)
fprintf(stderr, _("%s: symbol table entries: %zu; buckets: %zu\n"),
program_name, this->table_.size(), this->table_.bucket_count());
#else
fprintf(stderr, _("%s: symbol table entries: %zu\n"),
program_name, this->table_.size());
#endif
this->namepool_.print_stats("symbol table stringpool");
}
// We check for ODR violations by looking for symbols with the same
// name for which the debugging information reports that they were
// defined in different source locations. When comparing the source
// location, we consider instances with the same base filename and
// line number to be the same. This is because different object
// files/shared libraries can include the same header file using
// different paths, and we don't want to report an ODR violation in
// that case.
// This struct is used to compare line information, as returned by
// Dwarf_line_info::one_addr2line. It implements a < comparison
// operator used with std::set.
struct Odr_violation_compare
{
bool
operator()(const std::string& s1, const std::string& s2) const
{
std::string::size_type pos1 = s1.rfind('/');
std::string::size_type pos2 = s2.rfind('/');
if (pos1 == std::string::npos
|| pos2 == std::string::npos)
return s1 < s2;
return s1.compare(pos1, std::string::npos,
s2, pos2, std::string::npos) < 0;
}
};
// Check candidate_odr_violations_ to find symbols with the same name
// but apparently different definitions (different source-file/line-no).
void
Symbol_table::detect_odr_violations(const Task* task,
const char* output_file_name) const
{
for (Odr_map::const_iterator it = candidate_odr_violations_.begin();
it != candidate_odr_violations_.end();
++it)
{
const char* symbol_name = it->first;
// We use a sorted set so the output is deterministic.
std::set<std::string, Odr_violation_compare> line_nums;
for (Unordered_set<Symbol_location, Symbol_location_hash>::const_iterator
locs = it->second.begin();
locs != it->second.end();
++locs)
{
// We need to lock the object in order to read it. This
// means that we have to run in a singleton Task. If we
// want to run this in a general Task for better
// performance, we will need one Task for object, plus
// appropriate locking to ensure that we don't conflict with
// other uses of the object. Also note, one_addr2line is not
// currently thread-safe.
Task_lock_obj<Object> tl(task, locs->object);
// 16 is the size of the object-cache that one_addr2line should use.
std::string lineno = Dwarf_line_info::one_addr2line(
locs->object, locs->shndx, locs->offset, 16);
if (!lineno.empty())
line_nums.insert(lineno);
}
if (line_nums.size() > 1)
{
gold_warning(_("while linking %s: symbol '%s' defined in multiple "
"places (possible ODR violation):"),
output_file_name, demangle(symbol_name).c_str());
for (std::set<std::string>::const_iterator it2 = line_nums.begin();
it2 != line_nums.end();
++it2)
fprintf(stderr, " %s\n", it2->c_str());
}
}
// We only call one_addr2line() in this function, so we can clear its cache.
Dwarf_line_info::clear_addr2line_cache();
}
// Warnings functions.
// Add a new warning.
void
Warnings::add_warning(Symbol_table* symtab, const char* name, Object* obj,
const std::string& warning)
{
name = symtab->canonicalize_name(name);
this->warnings_[name].set(obj, warning);
}
// Look through the warnings and mark the symbols for which we should
// warn. This is called during Layout::finalize when we know the
// sources for all the symbols.
void
Warnings::note_warnings(Symbol_table* symtab)
{
for (Warning_table::iterator p = this->warnings_.begin();
p != this->warnings_.end();
++p)
{
Symbol* sym = symtab->lookup(p->first, NULL);
if (sym != NULL
&& sym->source() == Symbol::FROM_OBJECT
&& sym->object() == p->second.object)
sym->set_has_warning();
}
}
// Issue a warning. This is called when we see a relocation against a
// symbol for which has a warning.
template<int size, bool big_endian>
void
Warnings::issue_warning(const Symbol* sym,
const Relocate_info<size, big_endian>* relinfo,
size_t relnum, off_t reloffset) const
{
gold_assert(sym->has_warning());
Warning_table::const_iterator p = this->warnings_.find(sym->name());
gold_assert(p != this->warnings_.end());
gold_warning_at_location(relinfo, relnum, reloffset,
"%s", p->second.text.c_str());
}
// 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>::allocate_common(Output_data*, Value_type);
#endif
#if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
template
void
Sized_symbol<64>::allocate_common(Output_data*, Value_type);
#endif
#ifdef HAVE_TARGET_32_LITTLE
template
void
Symbol_table::add_from_relobj<32, false>(
Sized_relobj<32, false>* relobj,
const unsigned char* syms,
size_t count,
size_t symndx_offset,
const char* sym_names,
size_t sym_name_size,
Sized_relobj<32, false>::Symbols* sympointers,
size_t* defined);
#endif
#ifdef HAVE_TARGET_32_BIG
template
void
Symbol_table::add_from_relobj<32, true>(
Sized_relobj<32, true>* relobj,
const unsigned char* syms,
size_t count,
size_t symndx_offset,
const char* sym_names,
size_t sym_name_size,
Sized_relobj<32, true>::Symbols* sympointers,
size_t* defined);
#endif
#ifdef HAVE_TARGET_64_LITTLE
template
void
Symbol_table::add_from_relobj<64, false>(
Sized_relobj<64, false>* relobj,
const unsigned char* syms,
size_t count,
size_t symndx_offset,
const char* sym_names,
size_t sym_name_size,
Sized_relobj<64, false>::Symbols* sympointers,
size_t* defined);
#endif
#ifdef HAVE_TARGET_64_BIG
template
void
Symbol_table::add_from_relobj<64, true>(
Sized_relobj<64, true>* relobj,
const unsigned char* syms,
size_t count,
size_t symndx_offset,
const char* sym_names,
size_t sym_name_size,
Sized_relobj<64, true>::Symbols* sympointers,
size_t* defined);
#endif
#ifdef HAVE_TARGET_32_LITTLE
template
Symbol*
Symbol_table::add_from_pluginobj<32, false>(
Sized_pluginobj<32, false>* obj,
const char* name,
const char* ver,
elfcpp::Sym<32, false>* sym);
#endif
#ifdef HAVE_TARGET_32_BIG
template
Symbol*
Symbol_table::add_from_pluginobj<32, true>(
Sized_pluginobj<32, true>* obj,
const char* name,
const char* ver,
elfcpp::Sym<32, true>* sym);
#endif
#ifdef HAVE_TARGET_64_LITTLE
template
Symbol*
Symbol_table::add_from_pluginobj<64, false>(
Sized_pluginobj<64, false>* obj,
const char* name,
const char* ver,
elfcpp::Sym<64, false>* sym);
#endif
#ifdef HAVE_TARGET_64_BIG
template
Symbol*
Symbol_table::add_from_pluginobj<64, true>(
Sized_pluginobj<64, true>* obj,
const char* name,
const char* ver,
elfcpp::Sym<64, true>* sym);
#endif
#ifdef HAVE_TARGET_32_LITTLE
template
void
Symbol_table::add_from_dynobj<32, false>(
Sized_dynobj<32, false>* dynobj,
const unsigned char* syms,
size_t count,
const char* sym_names,
size_t sym_name_size,
const unsigned char* versym,
size_t versym_size,
const std::vector<const char*>* version_map,
Sized_relobj<32, false>::Symbols* sympointers,
size_t* defined);
#endif
#ifdef HAVE_TARGET_32_BIG
template
void
Symbol_table::add_from_dynobj<32, true>(
Sized_dynobj<32, true>* dynobj,
const unsigned char* syms,
size_t count,
const char* sym_names,
size_t sym_name_size,
const unsigned char* versym,
size_t versym_size,
const std::vector<const char*>* version_map,
Sized_relobj<32, true>::Symbols* sympointers,
size_t* defined);
#endif
#ifdef HAVE_TARGET_64_LITTLE
template
void
Symbol_table::add_from_dynobj<64, false>(
Sized_dynobj<64, false>* dynobj,
const unsigned char* syms,
size_t count,
const char* sym_names,
size_t sym_name_size,
const unsigned char* versym,
size_t versym_size,
const std::vector<const char*>* version_map,
Sized_relobj<64, false>::Symbols* sympointers,
size_t* defined);
#endif
#ifdef HAVE_TARGET_64_BIG
template
void
Symbol_table::add_from_dynobj<64, true>(
Sized_dynobj<64, true>* dynobj,
const unsigned char* syms,
size_t count,
const char* sym_names,
size_t sym_name_size,
const unsigned char* versym,
size_t versym_size,
const std::vector<const char*>* version_map,
Sized_relobj<64, true>::Symbols* sympointers,
size_t* defined);
#endif
#if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
template
void
Symbol_table::define_with_copy_reloc<32>(
Sized_symbol<32>* sym,
Output_data* posd,
elfcpp::Elf_types<32>::Elf_Addr value);
#endif
#if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
template
void
Symbol_table::define_with_copy_reloc<64>(
Sized_symbol<64>* sym,
Output_data* posd,
elfcpp::Elf_types<64>::Elf_Addr value);
#endif
#ifdef HAVE_TARGET_32_LITTLE
template
void
Warnings::issue_warning<32, false>(const Symbol* sym,
const Relocate_info<32, false>* relinfo,
size_t relnum, off_t reloffset) const;
#endif
#ifdef HAVE_TARGET_32_BIG
template
void
Warnings::issue_warning<32, true>(const Symbol* sym,
const Relocate_info<32, true>* relinfo,
size_t relnum, off_t reloffset) const;
#endif
#ifdef HAVE_TARGET_64_LITTLE
template
void
Warnings::issue_warning<64, false>(const Symbol* sym,
const Relocate_info<64, false>* relinfo,
size_t relnum, off_t reloffset) const;
#endif
#ifdef HAVE_TARGET_64_BIG
template
void
Warnings::issue_warning<64, true>(const Symbol* sym,
const Relocate_info<64, true>* relinfo,
size_t relnum, off_t reloffset) const;
#endif
} // End namespace gold.
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