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/*
* Copyright (c) 2024, 2025, 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. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* 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.
*/
package compiler.runtime.unloaded;
import java.lang.invoke.MethodHandle;
import java.lang.invoke.MethodHandles;
import java.lang.invoke.MethodType;
import java.util.function.BiPredicate;
import org.objectweb.asm.ClassWriter;
import static org.objectweb.asm.Opcodes.*;
// Operates in bootstrap loader context.
public class TestMHUnloadedHelper {
private static final MethodType METHOD_TYPE = MethodType.methodType(BiPredicate.class,
BiPredicate.class, BiPredicate.class);
static byte[] generateClassFile(Class<?> caller) {
var cw = new ClassWriter(ClassWriter.COMPUTE_MAXS);
String name = caller.getName().replace('.', '/');
cw.visit(V19, ACC_PUBLIC | ACC_SUPER, name, null, "java/lang/Object", null);
{
var mv = cw.visitMethod(ACC_PUBLIC | ACC_STATIC, "test", METHOD_TYPE.toMethodDescriptorString(), null, null);
mv.visitCode();
mv.visitIntInsn(ALOAD, 1);
mv.visitInsn(ARETURN);
mv.visitMaxs(0, 0);
}
return cw.toByteArray();
}
public static MethodHandle generateTest(MethodHandles.Lookup caller) {
// Loaded in the caller context.
byte[] classBytes = generateClassFile(caller.lookupClass());
try {
MethodHandles.Lookup lookup = caller.defineHiddenClass(classBytes, true);
MethodHandle test = lookup.findStatic(lookup.lookupClass(), "test", METHOD_TYPE);
test = MethodHandles.permuteArguments(test, test.type(), 1, 0); // mix arguments
return test;
} catch (Throwable e) {
throw new AssertionError(e);
}
}
static BiPredicate[] ps = new BiPredicate[] { (a, b) -> false,
(a, b) -> true };
public static void test(MethodHandles.Lookup caller) {
MethodHandle test = generateTest(caller);
for (int i = 0; i < 20_000; i++) {
try {
BiPredicate pr = (BiPredicate)test.invokeExact(ps[1], ps[0]);
if (pr != ps[1]) {
throw new AssertionError("mismatch");
}
} catch (Throwable e) {
throw new AssertionError(e);
}
}
}
public static void testConstant(MethodHandles.Lookup caller) {
MethodHandle test = generateTest(caller);
// testMH() { return test(ps2, ps1); } where test(a, b) { return b; }.
test = test.bindTo(ps[1]).bindTo(ps[0]); // make argument concrete types visible to the JIT-compiler
for (int i = 0; i < 20_000; i++) {
try {
BiPredicate pr = (BiPredicate)test.invokeExact();
if (pr != ps[1]) {
throw new AssertionError("mismatch");
}
} catch (Throwable e) {
throw new AssertionError(e);
}
}
}
}
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