8031695: CHA ignores default methods during analysis leading to incorrect code generation

Reviewed-by: jrose, acorn, hseigel, lfoltan

src/share/vm/code/dependencies.cpp

@@ -1161,11 +1161,9 @@ bool Dependencies::is_concrete_method(Method* m) {
 
   // We could also return false if m does not yet appear to be
   // executed, if the VM version supports this distinction also.
+  // Default methods are considered "concrete" as well.
   return !m->is_abstract() &&
-         !InstanceKlass::cast(m->method_holder())->is_interface();
-         // TODO: investigate whether default methods should be
-         // considered as "concrete" in this situation.  For now they
-         // are not.
+         !m->is_overpass(); // error functions aren't concrete
 }
 
 

test/compiler/inlining/DefaultAndConcreteMethodsCHA.java

+/*
+ * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/**
+ * @test
+ * @bug 8031695
+ * @summary CHA ignores default methods during analysis leading to incorrect code generation
+ *
+ * @run main/othervm -Xbatch DefaultAndConcreteMethodsCHA
+ */
+interface I {
+    default int m() { return 0; }
+}
+
+class A implements I {}
+
+class C extends A { }
+class D extends A { public int m() { return 1; } }
+
+public class DefaultAndConcreteMethodsCHA {
+    public static int test(A obj) {
+        return obj.m();
+    }
+    public static void main(String[] args) {
+        for (int i = 0; i < 10000; i++) {
+            int idC = test(new C());
+            if (idC != 0) {
+                throw new Error("C.m didn't invoke I.m: id "+idC);
+            }
+
+            int idD = test(new D());
+            if (idD != 1) {
+                throw new Error("D.m didn't invoke D.m: id "+idD);
+            }
+        }
+
+    }
+}