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8065366: Better private method resolution

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Reviewed-by: hseigel, lfoltan, coleenp, ahgross
This commit is contained in:
Karen Kinnear 2014-12-19 11:48:50 -08:00
parent 6485d074d4
commit 4f7ab1448e
2 changed files with 34 additions and 8 deletions
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9
hotspot/src/share/vm/classfile/defaultMethods.cpp
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@ -731,10 +731,12 @@ class FindMethodsByErasedSig : public HierarchyVisitor<FindMethodsByErasedSig> {
Method* m = iklass->find_method(_method_name, _method_signature);
// private interface methods are not candidates for default methods
// invokespecial to private interface methods doesn't use default method logic
// private class methods are not candidates for default methods,
// private methods do not override default methods, so need to perform
// default method inheritance without including private methods
// The overpasses are your supertypes' errors, we do not include them
// future: take access controls into account for superclass methods
if (m != NULL && !m->is_static() && !m->is_overpass() &&
(!iklass->is_interface() || m->is_public())) {
if (m != NULL && !m->is_static() && !m->is_overpass() && !m->is_private()) {
if (_family == NULL) {
_family = new StatefulMethodFamily();
}
@ -745,6 +747,9 @@ class FindMethodsByErasedSig : public HierarchyVisitor<FindMethodsByErasedSig> {
} else {
// This is the rule that methods in classes "win" (bad word) over
// methods in interfaces. This works because of single inheritance
// private methods in classes do not "win", they will be found
// first on searching, but overriding for invokevirtual needs
// to find default method candidates for the same signature
_family->set_target_if_empty(m);
}
}

33
hotspot/src/share/vm/oops/klassVtable.cpp
View File

@ -404,13 +404,15 @@ bool klassVtable::update_inherited_vtable(InstanceKlass* klass, methodHandle tar
// get super_klass for method_holder for the found method
InstanceKlass* super_klass = super_method->method_holder();
if (is_default
// private methods are also never overridden
if (!super_method->is_private() &&
(is_default
|| ((super_klass->is_override(super_method, target_loader, target_classname, THREAD))
|| ((klass->major_version() >= VTABLE_TRANSITIVE_OVERRIDE_VERSION)
&& ((super_klass = find_transitive_override(super_klass,
target_method, i, target_loader,
target_classname, THREAD))
!= (InstanceKlass*)NULL))))
!= (InstanceKlass*)NULL)))))
{
// Package private methods always need a new entry to root their own
// overriding. They may also override other methods.
@ -692,9 +694,15 @@ bool klassVtable::is_miranda_entry_at(int i) {
// check if a method is a miranda method, given a class's methods table,
// its default_method table and its super
// Miranda methods are calculated twice:
// first: before vtable size calculation: including abstract and default
// first: before vtable size calculation: including abstract and superinterface default
// We include potential default methods to give them space in the vtable.
// During the first run, the default_methods list is empty
// This is seen by default method creation
// Second: recalculated during vtable initialization: only abstract
// Second: recalculated during vtable initialization: only include abstract methods.
// During the second run, default_methods is set up, so concrete methods from
// superinterfaces with matching names/signatures to default_methods are already
// in the default_methods list and do not need to be appended to the vtable
// as mirandas
// This is seen by link resolution and selection.
// "miranda" means not static, not defined by this class.
// private methods in interfaces do not belong in the miranda list.
@ -709,8 +717,9 @@ bool klassVtable::is_miranda(Method* m, Array<Method*>* class_methods,
}
Symbol* name = m->name();
Symbol* signature = m->signature();
Method* mo;
if (InstanceKlass::find_instance_method(class_methods, name, signature) == NULL) {
if ((mo = InstanceKlass::find_instance_method(class_methods, name, signature)) == NULL) {
// did not find it in the method table of the current class
if ((default_methods == NULL) ||
InstanceKlass::find_method(default_methods, name, signature) == NULL) {
@ -719,7 +728,7 @@ bool klassVtable::is_miranda(Method* m, Array<Method*>* class_methods,
return true;
}
Method* mo = InstanceKlass::cast(super)->lookup_method(name, signature);
mo = InstanceKlass::cast(super)->lookup_method(name, signature);
while (mo != NULL && mo->access_flags().is_static()
&& mo->method_holder() != NULL
&& mo->method_holder()->super() != NULL)
@ -731,6 +740,18 @@ bool klassVtable::is_miranda(Method* m, Array<Method*>* class_methods,
return true;
}
}
} else {
// if the local class has a private method, the miranda will not
// override it, so a vtable slot is needed
if (mo->access_flags().is_private()) {
// Second round, weed out any superinterface methods that turned
// into default methods, i.e. were concrete not abstract in the end
if ((default_methods == NULL) ||
InstanceKlass::find_method(default_methods, name, signature) == NULL) {
return true;
}
}
}
return false;