8190877: Better handling of abstract classes
Reviewed-by: kvn, vlivanov, rhalade, ahgross, jwilhelm
diff --git a/src/hotspot/share/code/dependencies.cpp b/src/hotspot/share/code/dependencies.cpp
index 79d272e..7f5a054 100644
--- a/src/hotspot/share/code/dependencies.cpp
+++ b/src/hotspot/share/code/dependencies.cpp
@@ -1116,6 +1116,14 @@
_signature = NULL;
initialize(participant);
}
+ ClassHierarchyWalker(Klass* participants[], int num_participants) {
+ _name = NULL;
+ _signature = NULL;
+ initialize(NULL);
+ for (int i = 0; i < num_participants; ++i) {
+ add_participant(participants[i]);
+ }
+ }
// This is common code for two searches: One for concrete subtypes,
// the other for concrete method implementations and overrides.
@@ -1221,6 +1229,24 @@
// Search class hierarchy first.
Method* m = InstanceKlass::cast(k)->find_instance_method(_name, _signature);
if (!Dependencies::is_concrete_method(m, k)) {
+ // Check for re-abstraction of method
+ if (!k->is_interface() && m != NULL && m->is_abstract()) {
+ // Found a matching abstract method 'm' in the class hierarchy.
+ // This is fine iff 'k' is an abstract class and all concrete subtypes
+ // of 'k' override 'm' and are participates of the current search.
+ ClassHierarchyWalker wf(_participants, _num_participants);
+ Klass* w = wf.find_witness_subtype(k);
+ if (w != NULL) {
+ Method* wm = InstanceKlass::cast(w)->find_instance_method(_name, _signature);
+ if (!Dependencies::is_concrete_method(wm, w)) {
+ // Found a concrete subtype 'w' which does not override abstract method 'm'.
+ // Bail out because 'm' could be called with 'w' as receiver (leading to an
+ // AbstractMethodError) and thus the method we are looking for is not unique.
+ _found_methods[_num_participants] = m;
+ return true;
+ }
+ }
+ }
// Check interface defaults also, if any exist.
Array<Method*>* default_methods = InstanceKlass::cast(k)->default_methods();
if (default_methods == NULL)
