// symtab.cc -- the gold symbol table
-// Copyright 2006, 2007 Free Software Foundation, Inc.
+// Copyright 2006, 2007, 2008 Free Software Foundation, Inc.
// Written by Ian Lance Taylor <iant@google.com>.
// This file is part of gold.
#include "gold.h"
#include <stdint.h>
+#include <set>
#include <string>
#include <utility>
+#include "demangle.h"
#include "object.h"
+#include "dwarf_reader.h"
#include "dynobj.h"
#include "output.h"
#include "target.h"
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_got_offset_ = false;
this->has_plt_offset_ = false;
this->has_warning_ = false;
+ this->is_copied_from_dynobj_ = false;
+ this->is_forced_local_ = 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->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.
this->in_reg_ = 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>
this->symsize_ = symsize;
}
+// 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;
+}
+
+// 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 the symbol was forced local in a version script, do not add it.
+ if (this->is_forced_local())
+ return false;
+
+ // 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->export_dynamic() || parameters->output_is_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.
// Class Symbol_table.
-Symbol_table::Symbol_table()
- : saw_undefined_(0), offset_(0), table_(), namepool_(),
- forwarders_(), commons_(), warnings_()
+Symbol_table::Symbol_table(unsigned int count,
+ const Version_script_info& version_script)
+ : saw_undefined_(0), offset_(0), table_(count), namepool_(),
+ forwarders_(), commons_(), forced_locals_(), warnings_(),
+ version_script_(version_script)
{
+ namepool_.reserve(count);
}
Symbol_table::~Symbol_table()
{
}
-// The hash function. The key is always canonicalized, so we use a
-// simple combination of the pointers.
+// The hash function. The key values are Stringpool keys.
-size_t
+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 only called with
-// canonicalized name and version strings, so we can use pointer
-// comparison.
+// The symbol table key equality function. This is called with
+// Stringpool keys.
-bool
+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;
}
-// Make TO a symbol which forwards to FROM.
+// Make TO a symbol which forwards to FROM.
void
Symbol_table::make_forwarder(Symbol* from, Symbol* to)
esym.put_st_info(from->binding(), from->type());
esym.put_st_other(from->visibility(), from->nonvis());
esym.put_st_shndx(from->shndx());
- Symbol_table::resolve(to, esym.sym(), from->object(), version);
+ this->resolve(to, esym.sym(), esym.sym(), from->object(), version);
if (from->in_reg())
to->set_in_reg();
if (from->in_dyn())
to->set_in_dyn();
}
+// Record that a symbol is forced to be local by a version script.
+
+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);
+}
+
// 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.
// 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.
+//
+// SYM and ORIG_SYM are almost always the same. ORIG_SYM is the
+// symbol exactly as it existed in the input file. SYM is usually
+// that as well, but can be modified, for instance if we determine
+// it's in a to-be-discarded section.
template<int size, bool big_endian>
-Symbol*
+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)
+ const elfcpp::Sym<size, big_endian>& sym,
+ const elfcpp::Sym<size, big_endian>& orig_sym)
{
Symbol* const snull = NULL;
std::pair<typename Symbol_table_type::iterator, bool> ins =
was_undefined = ret->is_undefined();
was_common = ret->is_common();
- Symbol_table::resolve(ret, sym, object, version);
+ this->resolve(ret, sym, orig_sym, object, version);
if (def)
{
// NAME/NULL point to NAME/VERSION.
insdef.first->second = ret;
}
- else if (insdef.first->second != ret)
+ else if (insdef.first->second != ret
+ && insdef.first->second->is_undefined())
{
// This is the unfortunate case where we already have
- // entries for both NAME/VERSION and NAME/NULL.
+ // entries for both NAME/VERSION and NAME/NULL. Note
+ // that we don't want to combine them if the existing
+ // symbol is going to override the new one. FIXME: We
+ // currently just test is_undefined, but this may not do
+ // the right thing if the existing symbol is from a
+ // shared library and the new one is from a regular
+ // object.
+
const Sized_symbol<size>* sym2;
sym2 = this->get_sized_symbol SELECT_SIZE_NAME(size) (
insdef.first->second
ret = this->get_sized_symbol SELECT_SIZE_NAME(size) (
insdef.first->second
SELECT_SIZE(size));
- Symbol_table::resolve(ret, sym, object, version);
+ this->resolve(ret, sym, orig_sym, object, version);
ins.first->second = ret;
}
else
if (!was_common && ret->is_common())
this->commons_.push_back(ret);
+ ret->set_is_default(def);
return ret;
}
size_t count,
const char* sym_names,
size_t sym_name_size,
- Symbol** sympointers)
+ typename Sized_relobj<size, big_endian>::Symbols* sympointers)
{
gold_assert(size == relobj->target()->get_size());
gold_assert(size == parameters->get_size());
// name from the version name. If there are two '@' characters,
// this is the default version.
const char* ver = strchr(name, '@');
-
- Symbol* res;
+ 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;
+ }
+ }
+ else if (!version_script_.empty())
+ {
+ // The symbol name did not have a version, but
+ // the version script may assign a version anyway.
+ namelen = strlen(name);
+ def = true;
+ // Check the global: entries from the version script.
+ const std::string& version =
+ version_script_.get_symbol_version(name);
+ if (!version.empty())
+ ver = version.c_str();
+ // Check the local: entries from the version script
+ if (version_script_.symbol_is_local(name))
+ local = true;
+ }
+
+ Sized_symbol<size>* res;
if (ver == NULL)
{
Stringpool::Key name_key;
name = this->namepool_.add(name, true, &name_key);
res = this->add_from_object(relobj, name, name_key, NULL, 0,
- false, *psym);
+ false, *psym, sym);
+ if (local)
+ this->force_local(res);
}
else
{
Stringpool::Key name_key;
- name = this->namepool_.add_prefix(name, ver - name, &name_key);
-
- bool def = false;
- ++ver;
- if (*ver == '@')
- {
- def = true;
- ++ver;
- }
-
+ name = this->namepool_.add_with_length(name, namelen, true,
+ &name_key);
Stringpool::Key ver_key;
ver = this->namepool_.add(ver, true, &ver_key);
res = this->add_from_object(relobj, name, name_key, ver, ver_key,
- def, *psym);
+ def, *psym, sym);
}
- *sympointers++ = res;
+ (*sympointers)[i] = res;
}
}
const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
+ // We keep a list of all STT_OBJECT symbols, so that we can resolve
+ // weak aliases. This is necessary because if the dynamic object
+ // provides the same variable under two names, one of which is a
+ // weak definition, and the regular object refers to the weak
+ // definition, we have to put both the weak definition and the
+ // strong definition into the dynamic symbol table. Given a weak
+ // definition, the only way that we can find the corresponding
+ // strong definition, if any, is to search the symbol table.
+ std::vector<Sized_symbol<size>*> object_symbols;
+
const unsigned char* p = syms;
const unsigned char* vs = versym;
for (size_t i = 0; i < count; ++i, p += sym_size, vs += 2)
const char* name = sym_names + st_name;
+ Sized_symbol<size>* res;
+
if (versym == NULL)
{
Stringpool::Key name_key;
name = this->namepool_.add(name, true, &name_key);
- this->add_from_object(dynobj, name, name_key, NULL, 0,
- false, sym);
- continue;
+ res = this->add_from_object(dynobj, name, name_key, NULL, 0,
+ false, sym, sym);
}
+ else
+ {
+ // Read the version information.
- // Read the version information.
+ unsigned int v = elfcpp::Swap<16, big_endian>::readval(vs);
- unsigned int v = elfcpp::Swap<16, big_endian>::readval(vs);
+ bool hidden = (v & elfcpp::VERSYM_HIDDEN) != 0;
+ v &= elfcpp::VERSYM_VERSION;
- bool hidden = (v & elfcpp::VERSYM_HIDDEN) != 0;
- v &= elfcpp::VERSYM_VERSION;
+ // The Sun documentation says that V can be VER_NDX_LOCAL,
+ // or VER_NDX_GLOBAL, or a version index. The meaning of
+ // VER_NDX_LOCAL is defined as "Symbol has local scope."
+ // The old GNU linker will happily generate VER_NDX_LOCAL
+ // for an undefined symbol. I don't know what the Sun
+ // linker will generate.
- // The Sun documentation says that V can be VER_NDX_LOCAL, or
- // VER_NDX_GLOBAL, or a version index. The meaning of
- // VER_NDX_LOCAL is defined as "Symbol has local scope." The
- // old GNU linker will happily generate VER_NDX_LOCAL for an
- // undefined symbol. I don't know what the Sun linker will
- // generate.
+ if (v == static_cast<unsigned int>(elfcpp::VER_NDX_LOCAL)
+ && sym.get_st_shndx() != elfcpp::SHN_UNDEF)
+ {
+ // This symbol should not be visible outside the object.
+ continue;
+ }
- if (v == static_cast<unsigned int>(elfcpp::VER_NDX_LOCAL)
- && sym.get_st_shndx() != elfcpp::SHN_UNDEF)
- {
- // This symbol should not be visible outside the object.
- continue;
- }
+ // At this point we are definitely going to add this symbol.
+ Stringpool::Key name_key;
+ name = this->namepool_.add(name, true, &name_key);
- // At this point we are definitely going to add this symbol.
- Stringpool::Key name_key;
- name = this->namepool_.add(name, true, &name_key);
+ if (v == static_cast<unsigned int>(elfcpp::VER_NDX_LOCAL)
+ || v == static_cast<unsigned int>(elfcpp::VER_NDX_GLOBAL))
+ {
+ // This symbol does not have a version.
+ res = this->add_from_object(dynobj, name, name_key, NULL, 0,
+ false, sym, sym);
+ }
+ else
+ {
+ if (v >= version_map->size())
+ {
+ dynobj->error(_("versym for symbol %zu out of range: %u"),
+ i, v);
+ continue;
+ }
- if (v == static_cast<unsigned int>(elfcpp::VER_NDX_LOCAL)
- || v == static_cast<unsigned int>(elfcpp::VER_NDX_GLOBAL))
- {
- // This symbol does not have a version.
- this->add_from_object(dynobj, name, name_key, NULL, 0, false, sym);
- continue;
- }
+ const char* version = (*version_map)[v];
+ if (version == NULL)
+ {
+ dynobj->error(_("versym for symbol %zu has no name: %u"),
+ i, v);
+ continue;
+ }
- if (v >= version_map->size())
- {
- dynobj->error(_("versym for symbol %zu out of range: %u"), i, v);
- continue;
+ Stringpool::Key version_key;
+ version = this->namepool_.add(version, true, &version_key);
+
+ // If this is an absolute symbol, and the version name
+ // and symbol name are the same, then this is the
+ // version definition symbol. These symbols exist to
+ // support using -u to pull in particular versions. We
+ // do not want to record a version for them.
+ if (sym.get_st_shndx() == elfcpp::SHN_ABS
+ && name_key == version_key)
+ res = this->add_from_object(dynobj, name, name_key, NULL, 0,
+ false, sym, sym);
+ else
+ {
+ const bool def = (!hidden
+ && (sym.get_st_shndx()
+ != elfcpp::SHN_UNDEF));
+ res = this->add_from_object(dynobj, name, name_key, version,
+ version_key, def, sym, sym);
+ }
+ }
}
- const char* version = (*version_map)[v];
- if (version == NULL)
- {
- dynobj->error(_("versym for symbol %zu has no name: %u"), i, v);
- continue;
- }
+ if (sym.get_st_shndx() != elfcpp::SHN_UNDEF
+ && sym.get_st_type() == elfcpp::STT_OBJECT)
+ object_symbols.push_back(res);
+ }
+
+ this->record_weak_aliases(&object_symbols);
+}
- Stringpool::Key version_key;
- version = this->namepool_.add(version, true, &version_key);
+// This is used to sort weak aliases. We sort them first by section
+// index, then by offset, then by weak ahead of strong.
- // If this is an absolute symbol, and the version name and
- // symbol name are the same, then this is the version definition
- // symbol. These symbols exist to support using -u to pull in
- // particular versions. We do not want to record a version for
- // them.
- if (sym.get_st_shndx() == elfcpp::SHN_ABS && name_key == version_key)
+template<int size>
+class Weak_alias_sorter
+{
+ public:
+ bool operator()(const Sized_symbol<size>*, const Sized_symbol<size>*) const;
+};
+
+template<int size>
+bool
+Weak_alias_sorter<size>::operator()(const Sized_symbol<size>* s1,
+ const Sized_symbol<size>* s2) const
+{
+ if (s1->shndx() != s2->shndx())
+ return s1->shndx() < s2->shndx();
+ if (s1->value() != s2->value())
+ return s1->value() < s2->value();
+ if (s1->binding() != s2->binding())
+ {
+ if (s1->binding() == elfcpp::STB_WEAK)
+ return true;
+ if (s2->binding() == elfcpp::STB_WEAK)
+ return false;
+ }
+ return std::string(s1->name()) < std::string(s2->name());
+}
+
+// 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)
{
- this->add_from_object(dynobj, name, name_key, NULL, 0, false, sym);
- continue;
+ if ((*q)->shndx() != from_sym->shndx()
+ || (*q)->value() != from_sym->value())
+ break;
+
+ this->weak_aliases_[from_sym] = *q;
+ from_sym->set_has_alias();
+ from_sym = *q;
}
- const bool def = !hidden && sym.get_st_shndx() != elfcpp::SHN_UNDEF;
+ if (from_sym != *p)
+ {
+ this->weak_aliases_[from_sym] = *p;
+ from_sym->set_has_alias();
+ }
- this->add_from_object(dynobj, name, name_key, version, version_key,
- def, sym);
+ p = q - 1;
}
}
bool add_to_table = false;
typename Symbol_table_type::iterator add_loc = this->table_.end();
+ // If the caller didn't give us a version, see if we get one from
+ // the version script.
+ if (*pversion == NULL)
+ {
+ const std::string& v(this->version_script_.get_symbol_version(*pname));
+ if (!v.empty())
+ *pversion = v.c_str();
+ }
+
if (only_if_ref)
{
oldsym = this->lookup(*pname, *pversion);
sym->init(name, od, value, symsize, type, binding, visibility, nonvis,
offset_is_from_end);
- if (oldsym != NULL
- && Symbol_table::should_override_with_special(oldsym))
- oldsym->override_with_special(sym);
+ if (oldsym == NULL)
+ {
+ if (binding == elfcpp::STB_LOCAL
+ || this->version_script_.symbol_is_local(name))
+ this->force_local(sym);
+ return sym;
+ }
- return sym;
+ if (Symbol_table::should_override_with_special(oldsym))
+ this->override_with_special(oldsym, sym);
+ delete sym;
+ return oldsym;
}
// Define a symbol based on an Output_segment.
sym->init(name, os, value, symsize, type, binding, visibility, nonvis,
offset_base);
- if (oldsym != NULL
- && Symbol_table::should_override_with_special(oldsym))
- oldsym->override_with_special(sym);
+ if (oldsym == NULL)
+ {
+ if (binding == elfcpp::STB_LOCAL
+ || this->version_script_.symbol_is_local(name))
+ this->force_local(sym);
+ return sym;
+ }
- return sym;
+ if (Symbol_table::should_override_with_special(oldsym))
+ this->override_with_special(oldsym, sym);
+ delete sym;
+ return oldsym;
}
// Define a special symbol with a constant value. It is a multiple
if (sym == NULL)
return NULL;
- gold_assert(version == NULL || oldsym != NULL);
+ gold_assert(version == NULL || version == name || oldsym != NULL);
sym->init(name, value, symsize, type, binding, visibility, nonvis);
- if (oldsym != NULL
- && Symbol_table::should_override_with_special(oldsym))
- oldsym->override_with_special(sym);
+ if (oldsym == NULL)
+ {
+ if (binding == elfcpp::STB_LOCAL
+ || this->version_script_.symbol_is_local(name))
+ this->force_local(sym);
+ return sym;
+ }
- return sym;
+ if (Symbol_table::should_override_with_special(oldsym))
+ this->override_with_special(oldsym, sym);
+ delete sym;
+ return oldsym;
}
// Define a set of symbols in output sections.
}
}
+// 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(
+ const Target* target,
+ 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(target, 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;
+}
+
// 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(const General_options* options,
- const Target* target,
+Symbol_table::set_dynsym_indexes(const Target* target,
unsigned int index,
std::vector<Symbol*>* syms,
Stringpool* dynpool,
// some symbols appear more than once in the symbol table, with
// and without a version.
- if (!sym->needs_dynsym_entry()
- && (!options->export_dynamic()
- || !sym->in_reg()
- || !sym->is_externally_visible()))
+ if (!sym->should_add_dynsym_entry())
sym->set_dynsym_index(-1U);
else if (!sym->has_dynsym_index())
{
dynpool->add(sym->name(), false, NULL);
// Record any version information.
- if (sym->version() != NULL)
- versions->record_version(options, dynpool, sym);
+ if (sym->version() != NULL)
+ versions->record_version(this, dynpool, sym);
}
}
}
// Set the final values for all the symbols. The index of the first
-// global symbol in the output file is INDEX. Record the file offset
-// OFF. Add their names to POOL. Return the new file offset.
+// 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(unsigned int index, off_t off, off_t dynoff,
- size_t dyn_global_index, size_t dyncount,
- Stringpool* pool)
+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(index != 0);
- this->first_global_index_ = index;
+ gold_assert(*plocal_symcount != 0);
+ this->first_global_index_ = *plocal_symcount;
this->dynamic_offset_ = dynoff;
this->first_dynamic_global_index_ = dyn_global_index;
if (parameters->get_size() == 32)
{
#if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_32_LITTLE)
- ret = this->sized_finalize<32>(index, off, pool);
+ ret = this->sized_finalize<32>(off, pool, plocal_symcount);
#else
gold_unreachable();
#endif
else if (parameters->get_size() == 64)
{
#if defined(HAVE_TARGET_64_BIG) || defined(HAVE_TARGET_64_LITTLE)
- ret = this->sized_finalize<64>(index, off, pool);
+ ret = this->sized_finalize<64>(off, pool, plocal_symcount);
#else
gold_unreachable();
#endif
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(unsigned index, off_t off, Stringpool* pool)
+Symbol_table::sized_finalize(off_t off, Stringpool* pool,
+ unsigned int* plocal_symcount)
{
off = align_address(off, size >> 3);
this->offset_ = off;
- size_t orig_index = index;
+ unsigned int index = *plocal_symcount;
+ const unsigned int orig_index = index;
- const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
+ // 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)
{
- Sized_symbol<size>* sym = static_cast<Sized_symbol<size>*>(p->second);
+ Symbol* sym = p->second;
+ if (this->sized_finalize_symbol<size>(sym))
+ this->add_to_final_symtab<size>(sym, pool, &index, &off);
+ }
- // FIXME: Here we need to decide which symbols should go into
- // the output file, based on --strip.
+ this->output_count_ = index - orig_index;
- // 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())
- continue;
+ return off;
+}
- if (!sym->in_reg())
- {
- gold_assert(!sym->has_symtab_index());
- sym->set_symtab_index(-1U);
- gold_assert(sym->dynsym_index() == -1U);
- continue;
- }
+// Finalize the symbol SYM. This returns true if the symbol should be
+// added to the symbol table, false otherwise.
- typename Sized_symbol<size>::Value_type value;
+template<int size>
+bool
+Symbol_table::sized_finalize_symbol(Symbol* unsized_sym)
+{
+ Sized_symbol<size>* sym = static_cast<Sized_symbol<size>*>(unsized_sym);
- switch (sym->source())
- {
- case Symbol::FROM_OBJECT:
- {
- unsigned int shndx = sym->shndx();
+ // 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;
- // FIXME: We need some target specific support here.
- if (shndx >= elfcpp::SHN_LORESERVE
- && shndx != elfcpp::SHN_ABS)
- {
- gold_error(_("%s: unsupported symbol section 0x%x"),
- sym->name(), shndx);
- shndx = elfcpp::SHN_UNDEF;
- }
+ if (!sym->in_reg())
+ {
+ gold_assert(!sym->has_symtab_index());
+ sym->set_symtab_index(-1U);
+ gold_assert(sym->dynsym_index() == -1U);
+ return false;
+ }
- Object* symobj = sym->object();
- if (symobj->is_dynamic())
- {
- value = 0;
- shndx = elfcpp::SHN_UNDEF;
- }
- else if (shndx == elfcpp::SHN_UNDEF)
- value = 0;
- else if (shndx == elfcpp::SHN_ABS)
- value = sym->value();
- else
- {
- Relobj* relobj = static_cast<Relobj*>(symobj);
- off_t secoff;
- Output_section* os = relobj->output_section(shndx, &secoff);
+ typename Sized_symbol<size>::Value_type value;
- if (os == NULL)
- {
- sym->set_symtab_index(-1U);
- gold_assert(sym->dynsym_index() == -1U);
- continue;
- }
+ switch (sym->source())
+ {
+ case Symbol::FROM_OBJECT:
+ {
+ unsigned int shndx = sym->shndx();
- value = sym->value() + os->address() + secoff;
- }
+ // FIXME: We need some target specific support here.
+ if (shndx >= elfcpp::SHN_LORESERVE
+ && shndx != elfcpp::SHN_ABS)
+ {
+ gold_error(_("%s: unsupported symbol section 0x%x"),
+ sym->demangled_name().c_str(), shndx);
+ shndx = elfcpp::SHN_UNDEF;
}
- break;
- case Symbol::IN_OUTPUT_DATA:
+ Object* symobj = sym->object();
+ if (symobj->is_dynamic())
{
- Output_data* od = sym->output_data();
- value = sym->value() + od->address();
- if (sym->offset_is_from_end())
- value += od->data_size();
+ value = 0;
+ shndx = elfcpp::SHN_UNDEF;
}
- break;
-
- case Symbol::IN_OUTPUT_SEGMENT:
+ else if (shndx == elfcpp::SHN_UNDEF)
+ value = 0;
+ else if (shndx == elfcpp::SHN_ABS)
+ value = sym->value();
+ else
{
- Output_segment* os = sym->output_segment();
- value = sym->value() + os->vaddr();
- switch (sym->offset_base())
+ Relobj* relobj = static_cast<Relobj*>(symobj);
+ section_offset_type secoff;
+ Output_section* os = relobj->output_section(shndx, &secoff);
+
+ if (os == NULL)
{
- case Symbol::SEGMENT_START:
- break;
- case Symbol::SEGMENT_END:
- value += os->memsz();
- break;
- case Symbol::SEGMENT_BSS:
- value += os->filesz();
- break;
- default:
- gold_unreachable();
+ sym->set_symtab_index(-1U);
+ gold_assert(sym->dynsym_index() == -1U);
+ return false;
}
+
+ if (sym->type() == elfcpp::STT_TLS)
+ value = sym->value() + os->tls_offset() + secoff;
+ else
+ value = sym->value() + os->address() + secoff;
}
- break;
+ }
+ break;
+
+ case Symbol::IN_OUTPUT_DATA:
+ {
+ Output_data* od = sym->output_data();
+ value = sym->value() + od->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() + 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::CONSTANT:
- value = sym->value();
- break;
+ case Symbol::CONSTANT:
+ value = sym->value();
+ break;
- default:
- gold_unreachable();
- }
+ default:
+ gold_unreachable();
+ }
- sym->set_value(value);
+ sym->set_value(value);
- if (parameters->strip_all())
- sym->set_symtab_index(-1U);
- else
- {
- sym->set_symtab_index(index);
- pool->add(sym->name(), false, NULL);
- ++index;
- off += sym_size;
- }
+ if (parameters->strip_all())
+ {
+ sym->set_symtab_index(-1U);
+ return false;
}
- this->output_count_ = index - orig_index;
-
- return off;
+ return true;
}
// Write out the global symbols.
void
-Symbol_table::write_globals(const Target* target, const Stringpool* sympool,
+Symbol_table::write_globals(const Input_objects* input_objects,
+ const Stringpool* sympool,
const Stringpool* dynpool, Output_file* of) const
{
if (parameters->get_size() == 32)
if (parameters->is_big_endian())
{
#ifdef HAVE_TARGET_32_BIG
- this->sized_write_globals<32, true>(target, sympool, dynpool, of);
+ this->sized_write_globals<32, true>(input_objects, sympool,
+ dynpool, of);
#else
gold_unreachable();
#endif
else
{
#ifdef HAVE_TARGET_32_LITTLE
- this->sized_write_globals<32, false>(target, sympool, dynpool, of);
+ this->sized_write_globals<32, false>(input_objects, sympool,
+ dynpool, of);
#else
gold_unreachable();
#endif
if (parameters->is_big_endian())
{
#ifdef HAVE_TARGET_64_BIG
- this->sized_write_globals<64, true>(target, sympool, dynpool, of);
+ this->sized_write_globals<64, true>(input_objects, sympool,
+ dynpool, of);
#else
gold_unreachable();
#endif
else
{
#ifdef HAVE_TARGET_64_LITTLE
- this->sized_write_globals<64, false>(target, sympool, dynpool, of);
+ this->sized_write_globals<64, false>(input_objects, sympool,
+ dynpool, of);
#else
gold_unreachable();
#endif
template<int size, bool big_endian>
void
-Symbol_table::sized_write_globals(const Target* target,
+Symbol_table::sized_write_globals(const Input_objects* input_objects,
const Stringpool* sympool,
const Stringpool* dynpool,
Output_file* of) const
{
+ const Target* const target = input_objects->target();
+
const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
- unsigned int index = this->first_global_index_;
- const off_t oview_size = this->output_count_ * 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* const psyms = of->get_output_view(this->offset_, oview_size);
- unsigned int dynamic_count = this->dynamic_count_;
- off_t dynamic_size = dynamic_count * sym_size;
- unsigned int first_dynamic_global_index = this->first_dynamic_global_index_;
+ 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_view = NULL;
else
dynamic_view = of->get_output_view(this->dynamic_offset_, dynamic_size);
- unsigned char* ps = psyms;
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(input_objects, sym);
+
unsigned int sym_index = sym->symtab_index();
unsigned int dynsym_index;
if (dynamic_view == NULL)
continue;
}
- if (sym_index == index)
- ++index;
- else if (sym_index != -1U)
- {
- // We have already seen this symbol, because it has a
- // default version.
- gold_assert(sym_index < index);
- if (dynsym_index == -1U)
- continue;
- sym_index = -1U;
- }
-
unsigned int shndx;
typename elfcpp::Elf_types<32>::Elf_Addr value = sym->value();
switch (sym->source())
&& in_shndx != elfcpp::SHN_ABS)
{
gold_error(_("%s: unsupported symbol section 0x%x"),
- sym->name(), in_shndx);
+ sym->demangled_name().c_str(), in_shndx);
shndx = in_shndx;
}
else
else
{
Relobj* relobj = static_cast<Relobj*>(symobj);
- off_t secoff;
+ section_offset_type secoff;
Output_section* os = relobj->output_section(in_shndx,
&secoff);
gold_assert(os != NULL);
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 SELECT_SIZE_ENDIAN_NAME(size, big_endian) (
sym, sym->value(), shndx, sympool, ps
SELECT_SIZE_ENDIAN(size, big_endian));
- ps += sym_size;
}
if (dynsym_index != -1U)
}
}
- gold_assert(ps - psyms == oview_size);
-
of->write_output_view(this->offset_, oview_size, psyms);
if (dynamic_view != NULL)
of->write_output_view(this->dynamic_offset_, dynamic_size, dynamic_view);
osym.put_st_name(pool->get_offset(sym->name()));
osym.put_st_value(value);
osym.put_st_size(sym->symsize());
- osym.put_st_info(elfcpp::elf_st_info(sym->binding(), sym->type()));
+ // 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 the system library
+// directory (the directory were we find libc.so); we assume that
+// those libraries are OK. This heuristic avoids problems in
+// GNU/Linux, in which -ldl can have undefined references satisfied by
+// ld-linux.so.
+
+inline void
+Symbol_table::warn_about_undefined_dynobj_symbol(
+ const Input_objects* input_objects,
+ Symbol* sym) const
+{
+ if (sym->source() == Symbol::FROM_OBJECT
+ && sym->object()->is_dynamic()
+ && sym->shndx() == elfcpp::SHN_UNDEF
+ && sym->binding() != elfcpp::STB_WEAK
+ && !parameters->allow_shlib_undefined()
+ && !input_objects->target()->is_defined_by_abi(sym)
+ && !input_objects->found_in_system_library_directory(sym->object()))
+ {
+ // A very ugly cast.
+ Dynobj* dynobj = static_cast<Dynobj*>(sym->object());
+ if (!dynobj->has_unknown_needed_entries())
+ gold_error(_("%s: undefined reference to '%s'"),
+ sym->object()->name().c_str(),
+ sym->demangled_name().c_str());
+ }
+}
+
// Write out a section symbol. Return the update offset.
void
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.
+ Task_lock_obj<Object> tl(task, locs->object);
+ std::string lineno = Dwarf_line_info::one_addr2line(
+ locs->object, locs->shndx, locs->offset);
+ 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());
+ }
+ }
+}
+
// Warnings functions.
// Add a new warning.
void
Warnings::add_warning(Symbol_table* symtab, const char* name, Object* obj,
- unsigned int shndx)
+ const std::string& warning)
{
name = symtab->canonicalize_name(name);
- this->warnings_[name].set(obj, shndx);
+ this->warnings_[name].set(obj, warning);
}
// Look through the warnings and mark the symbols for which we should
if (sym != NULL
&& sym->source() == Symbol::FROM_OBJECT
&& sym->object() == p->second.object)
- {
- sym->set_has_warning();
-
- // Read the section contents to get the warning text. It
- // would be nicer if we only did this if we have to actually
- // issue a warning. Unfortunately, warnings are issued as
- // we relocate sections. That means that we can not lock
- // the object then, as we might try to issue the same
- // warning multiple times simultaneously.
- {
- Task_locker_obj<Object> tl(*p->second.object);
- const unsigned char* c;
- off_t len;
- c = p->second.object->section_contents(p->second.shndx, &len,
- false);
- p->second.set_text(reinterpret_cast<const char*>(c), len);
- }
- }
+ sym->set_has_warning();
}
}
// 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
size_t count,
const char* sym_names,
size_t sym_name_size,
- Symbol** sympointers);
+ Sized_relobj<32, true>::Symbols* sympointers);
#endif
#ifdef HAVE_TARGET_32_BIG
size_t count,
const char* sym_names,
size_t sym_name_size,
- Symbol** sympointers);
+ Sized_relobj<32, false>::Symbols* sympointers);
#endif
#ifdef HAVE_TARGET_64_LITTLE
size_t count,
const char* sym_names,
size_t sym_name_size,
- Symbol** sympointers);
+ Sized_relobj<64, true>::Symbols* sympointers);
#endif
#ifdef HAVE_TARGET_64_BIG
size_t count,
const char* sym_names,
size_t sym_name_size,
- Symbol** sympointers);
+ Sized_relobj<64, false>::Symbols* sympointers);
#endif
#ifdef HAVE_TARGET_32_LITTLE
const std::vector<const char*>* version_map);
#endif
+#if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
+template
+void
+Symbol_table::define_with_copy_reloc<32>(
+ const Target* target,
+ 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>(
+ const Target* target,
+ Sized_symbol<64>* sym,
+ Output_data* posd,
+ elfcpp::Elf_types<64>::Elf_Addr value);
+#endif
+
#ifdef HAVE_TARGET_32_LITTLE
template
void
size_t relnum, off_t reloffset) const;
#endif
-
} // End namespace gold.