Support directly invoking interface default methods
With the Java 8 Language one is allowed to directly call default
interface methods of interfaces one (directly) implements through the
use of the super keyword. We support this behavior through the
invoke-super opcode with the target being an interface.
We add 3 tests for this behavior.
Currently only supports slow-path interpreter.
Invoke-super is currently extremely slow.
Bug: 24618811
Change-Id: I7e06e17326f7dbae0116bd7dfefca151f0092bd2
diff --git a/runtime/mirror/class.cc b/runtime/mirror/class.cc
index 66060f2..b49fc74 100644
--- a/runtime/mirror/class.cc
+++ b/runtime/mirror/class.cc
@@ -538,6 +538,71 @@
return nullptr;
}
+ArtMethod* Class::FindVirtualMethodForInterfaceSuper(ArtMethod* method, size_t pointer_size) {
+ DCHECK(method->GetDeclaringClass()->IsInterface());
+ DCHECK(IsInterface()) << "Should only be called on a interface class";
+ // Check if we have one defined on this interface first. This includes searching copied ones to
+ // get any conflict methods. Conflict methods are copied into each subtype from the supertype. We
+ // don't do any indirect method checks here.
+ for (ArtMethod& iface_method : GetVirtualMethods(pointer_size)) {
+ if (method->HasSameNameAndSignature(&iface_method)) {
+ return &iface_method;
+ }
+ }
+
+ std::vector<ArtMethod*> abstract_methods;
+ // Search through the IFTable for a working version. We don't need to check for conflicts
+ // because if there was one it would appear in this classes virtual_methods_ above.
+
+ Thread* self = Thread::Current();
+ StackHandleScope<2> hs(self);
+ MutableHandle<mirror::IfTable> iftable(hs.NewHandle(GetIfTable()));
+ MutableHandle<mirror::Class> iface(hs.NewHandle<mirror::Class>(nullptr));
+ size_t iftable_count = GetIfTableCount();
+ // Find the method. We don't need to check for conflicts because they would have been in the
+ // copied virtuals of this interface. Order matters, traverse in reverse topological order; most
+ // subtypiest interfaces get visited first.
+ for (size_t k = iftable_count; k != 0;) {
+ k--;
+ DCHECK_LT(k, iftable->Count());
+ iface.Assign(iftable->GetInterface(k));
+ // Iterate through every declared method on this interface. Each direct method's name/signature
+ // is unique so the order of the inner loop doesn't matter.
+ for (auto& method_iter : iface->GetDeclaredVirtualMethods(pointer_size)) {
+ ArtMethod* current_method = &method_iter;
+ if (current_method->HasSameNameAndSignature(method)) {
+ if (current_method->IsDefault()) {
+ // Handle JLS soft errors, a default method from another superinterface tree can
+ // "override" an abstract method(s) from another superinterface tree(s). To do this,
+ // ignore any [default] method which are dominated by the abstract methods we've seen so
+ // far. Check if overridden by any in abstract_methods. We do not need to check for
+ // default_conflicts because we would hit those before we get to this loop.
+ bool overridden = false;
+ for (ArtMethod* possible_override : abstract_methods) {
+ DCHECK(possible_override->HasSameNameAndSignature(current_method));
+ if (iface->IsAssignableFrom(possible_override->GetDeclaringClass())) {
+ overridden = true;
+ break;
+ }
+ }
+ if (!overridden) {
+ return current_method;
+ }
+ } else {
+ // Is not default.
+ // This might override another default method. Just stash it for now.
+ abstract_methods.push_back(current_method);
+ }
+ }
+ }
+ }
+ // If we reach here we either never found any declaration of the method (in which case
+ // 'abstract_methods' is empty or we found no non-overriden default methods in which case
+ // 'abstract_methods' contains a number of abstract implementations of the methods. We choose one
+ // of these arbitrarily.
+ return abstract_methods.empty() ? nullptr : abstract_methods[0];
+}
+
ArtMethod* Class::FindClassInitializer(size_t pointer_size) {
for (ArtMethod& method : GetDirectMethods(pointer_size)) {
if (method.IsClassInitializer()) {