Add a test to ensure serializable lambda creation and basic execution…

… in hidden classes

test/jdk/java/lang/invoke/lambda/LambdaHiddenCaller.java

@@ -0,0 +1,93 @@
+/*
+ * Copyright (c) 2024, 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.
+ */
+
+import java.io.Serializable;
+import java.lang.invoke.MethodHandles;
+import java.lang.invoke.MethodType;
+import java.util.function.IntSupplier;
+
+import org.junit.jupiter.api.BeforeAll;
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+/*
+ * @test
+ * @bug 8343064
+ * @summary Test about when lambda caller/target class is a hidden class
+ * @run junit LambdaHiddenCaller
+ */
+public class LambdaHiddenCaller {
+    static Hooks hiddenCaller;
+
+    @BeforeAll
+    static void setup() throws Throwable {
+        byte[] bytes;
+        try (var in = LambdaHiddenCaller.class.getResourceAsStream("HiddenHooks.class")) {
+            bytes = in.readAllBytes();
+        }
+        var hiddenClassLookup = MethodHandles.lookup().defineHiddenClass(bytes, true);
+        hiddenCaller = (Hooks) hiddenClassLookup.findConstructor(hiddenClassLookup.lookupClass(), MethodType.methodType(void.class))
+                .asType(MethodType.methodType(Hooks.class)).invokeExact();
+    }
+
+    @Test
+    void testStaticMethod() {
+        var is = hiddenCaller.callStaticMethodLambda();
+        assertEquals(42, is.getAsInt());
+    }
+
+    @Test
+    void testSerializableLambda() {
+        var is = hiddenCaller.callSerializableLambda();
+        assertEquals(42, is.getAsInt());
+        assertTrue(Serializable.class.isAssignableFrom(is.getClass()));
+        // We do not guarantee serialization functionalities yet
+    }
+}
+
+/**
+ * Hooks to call hidden class methods easily.
+ */
+interface Hooks {
+    IntSupplier callStaticMethodLambda();
+
+    IntSupplier callSerializableLambda();
+}
+
+class HiddenHooks implements Hooks {
+    private static int compute() {
+        return 42;
+    }
+
+    @Override
+    public IntSupplier callStaticMethodLambda() {
+        return HiddenHooks::compute;
+    }
+
+    @Override
+    public IntSupplier callSerializableLambda() {
+        return (IntSupplier & Serializable) HiddenHooks::compute;
+    }
+}