/* * Copyright (c) 2021, 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 8272564 * @summary Correct resolution of toString() (and other similar calls) on interfaces * @enablePreview * @compile NoObjectToString.java * @run main NoObjectToString */ import java.io.*; import java.lang.classfile.*; import java.lang.classfile.constantpool.*; public class NoObjectToString { public static void main(String... args) throws Exception { NoObjectToString c = new NoObjectToString(); c.run(args); } void run(String... args) throws Exception { //Verify there are no references to Object.toString() in a Test: try (InputStream in = NoObjectToString.class.getResourceAsStream("NoObjectToString$Test.class")) { assert in != null; ClassModel cm = ClassFile.of().parse(in.readAllBytes()); for (PoolEntry pe : cm.constantPool()) { if (pe instanceof MethodRefEntry ref) { String methodDesc = ref.owner().name() + "." + ref.nameAndType().name() + ":" + ref.nameAndType().type(); if ("java/lang/Object.toString:()Ljava/lang/String;".equals(methodDesc)) { throw new AssertionError("Found call to j.l.Object.toString"); } } } } } class Test { void test(I i, J j, K k) { i.toString(); j.toString(); k.toString(); } } interface I { public String toString(); } interface J extends I {} interface K {} }