* symtab.cc (Symbol_table::define_default_version): New function,

broken out of add_from_object.
	(Symbol_table::add_from_object): Call define_default_version.
	(Symbol_table::define_special_symbol): Add resolve_oldsym
	parameter.  Change all callers.  If the version for a symbol comes
	from a version script, resolve it with the symbol with the same
	name with no version.  Also add the symbol without a version if
	appropriate.
	(do_define_in_output_data): If resolving with oldsym, don't delete
	sym.
	(do_define_in_output_segment): Likewise.
	(do_define_as_constant): Likewise.
	* symtab.h (class Symbol_table): Update declarations.
This commit is contained in:
Ian Lance Taylor 2009-03-17 07:07:21 +00:00
parent b646ddd43a
commit 8c50070107
3 changed files with 234 additions and 109 deletions

View File

@ -1,3 +1,19 @@
2009-03-17 Ian Lance Taylor <iant@google.com>
* symtab.cc (Symbol_table::define_default_version): New function,
broken out of add_from_object.
(Symbol_table::add_from_object): Call define_default_version.
(Symbol_table::define_special_symbol): Add resolve_oldsym
parameter. Change all callers. If the version for a symbol comes
from a version script, resolve it with the symbol with the same
name with no version. Also add the symbol without a version if
appropriate.
(do_define_in_output_data): If resolving with oldsym, don't delete
sym.
(do_define_in_output_segment): Likewise.
(do_define_as_constant): Likewise.
* symtab.h (class Symbol_table): Update declarations.
2009-03-13 Ian Lance Taylor <iant@google.com>
* readsyms.cc (Read_symbols::incompatible_warning): New function.

View File

@ -713,6 +713,82 @@ Symbol_table::wrap_symbol(Object* object, const char* name,
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
@ -822,69 +898,8 @@ Symbol_table::add_from_object(Object* object,
this->gc_mark_dyn_syms(ret);
if (def)
{
if (insdef.second)
{
// This is the first time we have seen NAME/NULL. Make
// NAME/NULL point to NAME/VERSION.
insdef.first->second = ret;
}
else if (insdef.first->second != ret)
{
// 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 (insdef.first->second->version() != NULL)
{
gold_assert(insdef.first->second->version() != version);
def = false;
}
else if (ret->visibility() != elfcpp::STV_DEFAULT
&& insdef.first->second->is_from_dynobj())
def = false;
else if (insdef.first->second->visibility() != elfcpp::STV_DEFAULT
&& ret->is_from_dynobj())
def = false;
else
{
const Sized_symbol<size>* sym2;
sym2 = this->get_sized_symbol<size>(insdef.first->second);
Symbol_table::resolve<size, big_endian>(ret, sym2);
this->make_forwarder(insdef.first->second, ret);
insdef.first->second = ret;
}
}
else
def = false;
}
this->define_default_version<size, big_endian>(ret, insdef.second,
insdef.first);
}
else
{
@ -946,6 +961,9 @@ Symbol_table::add_from_object(Object* object,
insdef.first->second = ret;
}
}
if (def)
ret->set_is_default();
}
// Record every time we see a new undefined symbol, to speed up
@ -972,8 +990,6 @@ Symbol_table::add_from_object(Object* object,
&& !parameters->options().relocatable())
this->force_local(ret);
if (def)
ret->set_is_default();
return ret;
}
@ -1477,39 +1493,55 @@ Symbol_table::record_weak_aliases(std::vector<Sized_symbol<size>*>* symbols)
// 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 canonicalizes *PNAME and *PVERSION.
// 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)
Sized_symbol<size>** poldsym,
bool *resolve_oldsym)
{
Symbol* oldsym;
Sized_symbol<size>* sym;
bool add_to_table = false;
typename Symbol_table_type::iterator add_loc = this->table_.end();
*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();
*pversion = oldsym->version();
if (!is_default_version)
*pversion = oldsym->version();
}
else
{
@ -1527,19 +1559,56 @@ Symbol_table::define_special_symbol(const char** pname, const char** pversion,
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;
oldsym = 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;
}
}
}
}
@ -1563,6 +1632,9 @@ Symbol_table::define_special_symbol(const char** pname, const char** pversion,
else
gold_assert(oldsym != NULL);
if (add_def_to_table)
add_def_loc->second = sym;
*poldsym = this->get_sized_symbol<size>(oldsym);
return sym;
@ -1630,12 +1702,14 @@ Symbol_table::do_define_in_output_data(
{
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);
only_if_ref, &oldsym,
&resolve_oldsym);
#else
gold_unreachable();
#endif
@ -1644,7 +1718,8 @@ Symbol_table::do_define_in_output_data(
{
#if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
sym = this->define_special_symbol<size, false>(&name, &version,
only_if_ref, &oldsym);
only_if_ref, &oldsym,
&resolve_oldsym);
#else
gold_unreachable();
#endif
@ -1668,8 +1743,14 @@ Symbol_table::do_define_in_output_data(
if (Symbol_table::should_override_with_special(oldsym))
this->override_with_special(oldsym, sym);
delete sym;
return oldsym;
if (resolve_oldsym)
return sym;
else
{
delete sym;
return oldsym;
}
}
// Define a symbol based on an Output_segment.
@ -1731,12 +1812,14 @@ Symbol_table::do_define_in_output_segment(
{
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);
only_if_ref, &oldsym,
&resolve_oldsym);
#else
gold_unreachable();
#endif
@ -1745,7 +1828,8 @@ Symbol_table::do_define_in_output_segment(
{
#if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
sym = this->define_special_symbol<size, false>(&name, &version,
only_if_ref, &oldsym);
only_if_ref, &oldsym,
&resolve_oldsym);
#else
gold_unreachable();
#endif
@ -1769,8 +1853,14 @@ Symbol_table::do_define_in_output_segment(
if (Symbol_table::should_override_with_special(oldsym))
this->override_with_special(oldsym, sym);
delete sym;
return oldsym;
if (resolve_oldsym)
return sym;
else
{
delete sym;
return oldsym;
}
}
// Define a special symbol with a constant value. It is a multiple
@ -1832,12 +1922,14 @@ Symbol_table::do_define_as_constant(
{
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);
only_if_ref, &oldsym,
&resolve_oldsym);
#else
gold_unreachable();
#endif
@ -1846,7 +1938,8 @@ Symbol_table::do_define_as_constant(
{
#if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
sym = this->define_special_symbol<size, false>(&name, &version,
only_if_ref, &oldsym);
only_if_ref, &oldsym,
&resolve_oldsym);
#else
gold_unreachable();
#endif
@ -1876,8 +1969,14 @@ Symbol_table::do_define_as_constant(
if (force_override || Symbol_table::should_override_with_special(oldsym))
this->override_with_special(oldsym, sym);
delete sym;
return oldsym;
if (resolve_oldsym)
return sym;
else
{
delete sym;
return oldsym;
}
}
// Define a set of symbols in output sections.
@ -2041,11 +2140,13 @@ Symbol_table::do_add_undefined_symbols_from_command_line()
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);
false, &oldsym,
&resolve_oldsym);
#else
gold_unreachable();
#endif
@ -2054,7 +2155,8 @@ Symbol_table::do_add_undefined_symbols_from_command_line()
{
#if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
sym = this->define_special_symbol<size, false>(&name, &version,
false, &oldsym);
false, &oldsym,
&resolve_oldsym);
#else
gold_unreachable();
#endif

View File

@ -1367,6 +1367,25 @@ class Symbol_table
// The type of the list of common symbols.
typedef std::vector<Symbol*> Commons_type;
// The type of the symbol hash table.
typedef std::pair<Stringpool::Key, Stringpool::Key> Symbol_table_key;
struct Symbol_table_hash
{
size_t
operator()(const Symbol_table_key&) const;
};
struct Symbol_table_eq
{
bool
operator()(const Symbol_table_key&, const Symbol_table_key&) const;
};
typedef Unordered_map<Symbol_table_key, Symbol*, Symbol_table_hash,
Symbol_table_eq> Symbol_table_type;
// Make FROM a forwarder symbol to TO.
void
make_forwarder(Symbol* from, Symbol* to);
@ -1380,6 +1399,12 @@ class Symbol_table
unsigned int st_shndx, bool is_ordinary,
unsigned int orig_st_shndx);
// Define a default symbol.
template<int size, bool big_endian>
void
define_default_version(Sized_symbol<size>*, bool,
Symbol_table_type::iterator);
// Resolve symbols.
template<int size, bool big_endian>
void
@ -1435,7 +1460,8 @@ class Symbol_table
template<int size, bool big_endian>
Sized_symbol<size>*
define_special_symbol(const char** pname, const char** pversion,
bool only_if_ref, Sized_symbol<size>** poldsym);
bool only_if_ref, Sized_symbol<size>** poldsym,
bool* resolve_oldsym);
// Define a symbol in an Output_data, sized version.
template<int size>
@ -1531,25 +1557,6 @@ class Symbol_table
sized_write_section_symbol(const Output_section*, Output_symtab_xindex*,
Output_file*, off_t) const;
// The type of the symbol hash table.
typedef std::pair<Stringpool::Key, Stringpool::Key> Symbol_table_key;
struct Symbol_table_hash
{
size_t
operator()(const Symbol_table_key&) const;
};
struct Symbol_table_eq
{
bool
operator()(const Symbol_table_key&, const Symbol_table_key&) const;
};
typedef Unordered_map<Symbol_table_key, Symbol*, Symbol_table_hash,
Symbol_table_eq> Symbol_table_type;
// The type of the list of symbols which have been forced local.
typedef std::vector<Symbol*> Forced_locals;