--- /dev/null 2020-01-27 10:49:57.000000000 -0800 +++ new/test/jdk/sun/misc/UnsafeFieldOffsets.java 2020-01-27 10:49:57.000000000 -0800 @@ -0,0 +1,121 @@ +/* + * Copyright (c) 2020, 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 + * @summary Ensure that sun.misc.Unsafe::objectFieldOffset and staticFieldOffset + * throw UnsupportedOperationException on Field of a hidden class + * @modules jdk.unsupported + * @run main UnsafeFieldOffsets + */ + +import sun.misc.Unsafe; + +import java.io.IOException; +import java.io.UncheckedIOException; +import java.lang.invoke.MethodHandles; +import java.lang.reflect.Field; +import java.nio.file.Files; +import java.nio.file.Path; +import java.nio.file.Paths; + +public class UnsafeFieldOffsets { + static class Fields { + static final Object STATIC_FINAL = new Object(); + static Object STATIC_NON_FINAL = new Object(); + final Object FINAL = new Object(); + Object NON_FINAL = new Object(); + } + + private static Unsafe UNSAFE = getUnsafe(); + private static final Class HIDDEN_CLASS = defineHiddenClass(); + + private static Unsafe getUnsafe() { + try { + Field f = Unsafe.class.getDeclaredField("theUnsafe"); + f.setAccessible(true); + return (Unsafe) f.get(null); + } catch (ReflectiveOperationException e) { + throw new RuntimeException(e); + } + } + + private static Class defineHiddenClass() { + String classes = System.getProperty("test.classes"); + Path cf = Paths.get(classes, "UnsafeFieldOffsets$Fields.class"); + try { + byte[] bytes = Files.readAllBytes(cf); + Class c = MethodHandles.lookup().defineHiddenClass(bytes, true).lookupClass(); + if (!c.isHiddenClass()) + throw new RuntimeException("Expected hidden class: " + c); + return c; + } catch (IOException e) { + throw new UncheckedIOException(e); + } catch (IllegalAccessException e) { + throw new RuntimeException(e); + } + } + + public static void main(String[] args) throws Exception { + // non-hidden class + testStaticField(Fields.class, "STATIC_FINAL"); + testStaticField(Fields.class, "STATIC_NON_FINAL"); + testInstanceField(Fields.class, "FINAL"); + testInstanceField(Fields.class, "NON_FINAL"); + + // hidden class + testStaticField(HIDDEN_CLASS, "STATIC_FINAL"); + testStaticField(HIDDEN_CLASS, "STATIC_NON_FINAL"); + testInstanceField(HIDDEN_CLASS, "FINAL"); + testInstanceField(HIDDEN_CLASS, "NON_FINAL"); + } + + private static void testStaticField(Class c, String name) throws Exception { + Field f = c.getDeclaredField(name); + try { + UNSAFE.staticFieldOffset(f); + assertNonHiddenClass(c); + } catch (UnsupportedOperationException e) { + assertHiddenClass(c); + } + } + + private static void testInstanceField(Class c, String name) throws Exception { + Field f = c.getDeclaredField(name); + try { + UNSAFE.objectFieldOffset(f); + assertNonHiddenClass(c); + } catch (UnsupportedOperationException e) { + assertHiddenClass(c); + } + } + + private static void assertNonHiddenClass(Class c) { + if (c.isHiddenClass()) + throw new RuntimeException("Expected UOE but not thrown: " + c); + } + + private static void assertHiddenClass(Class c) { + if (!c.isHiddenClass()) + throw new RuntimeException("Expected hidden class but is not: " + c); + } +}