1 /*
  2  * Copyright (c) 2026, Oracle and/or its affiliates. All rights reserved.
  3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  4  *
  5  * This code is free software; you can redistribute it and/or modify it
  6  * under the terms of the GNU General Public License version 2 only, as
  7  * published by the Free Software Foundation.
  8  *
  9  * This code is distributed in the hope that it will be useful, but WITHOUT
 10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 12  * version 2 for more details (a copy is included in the LICENSE file that
 13  * accompanied this code).
 14  *
 15  * You should have received a copy of the GNU General Public License version
 16  * 2 along with this work; if not, write to the Free Software Foundation,
 17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 18  *
 19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 20  * or visit www.oracle.com if you need additional information or have any
 21  * questions.
 22  */
 23 
 24 import java.lang.invoke.MethodHandle;
 25 import java.lang.invoke.MethodHandles;
 26 import java.lang.reflect.Method;
 27 import java.util.function.Function;
 28 import jdk.incubator.code.Reflect;
 29 import jdk.incubator.code.Op;
 30 import jdk.incubator.code.bytecode.BytecodeGenerator;
 31 import jdk.incubator.code.dialect.core.CoreOp;
 32 import org.junit.jupiter.api.Assertions;
 33 import org.junit.jupiter.api.Test;
 34 
 35 /*
 36  * @test
 37  * @bug 8392557
 38  * @modules jdk.incubator.code
 39  * @library ../lib/
 40  * @library ../
 41  * @enablePreview
 42  * @run junit TestIntersectionTargetLambda
 43  */
 44 public class TestIntersectionTargetLambda {
 45 
 46     interface Marker {}
 47 
 48     @Reflect
 49     public static String functionFirst() {
 50         var f = (Function<String, String> & Marker) x -> x;
 51         return f.apply("functionFirst");
 52     }
 53 
 54     @Test
 55     public void testFunctionFirst() throws Throwable {
 56         Method accessMethod = TestIntersectionTargetLambda.class.getDeclaredMethod("functionFirst");
 57         CoreOp.FuncOp model = Op.ofMethod(accessMethod).orElseThrow();
 58         MethodHandle handle = BytecodeGenerator.generate(MethodHandles.lookup(), model);
 59         Assertions.assertEquals(functionFirst(), (String) handle.invokeExact());
 60     }
 61 
 62     @Reflect
 63     public static String markerFirst() {
 64         var f = (Marker & Function<String, String>) x -> x;
 65         return f.apply("markerFirst");
 66     }
 67 
 68     @Test
 69     public void testMarkerFirst() throws Throwable {
 70         Method accessMethod = TestIntersectionTargetLambda.class.getDeclaredMethod("markerFirst");
 71         CoreOp.FuncOp model = Op.ofMethod(accessMethod).orElseThrow();
 72         MethodHandle handle = BytecodeGenerator.generate(MethodHandles.lookup(), model);
 73         Assertions.assertEquals(markerFirst(), (String) handle.invokeExact());
 74     }
 75 
 76     interface Base {
 77         String a();
 78         String b();
 79         String c();
 80     }
 81 
 82     interface A extends Base {
 83         default String a() { return "A"; }
 84     }
 85 
 86     interface B extends Base {
 87         default String b() { return "B"; }
 88     }
 89 
 90     @Reflect
 91     public static String complex() {
 92         var f = (A & B) () -> { return "C"; };
 93         return f.c();
 94     }
 95 
 96     @Test
 97     public void testComplex() throws Throwable {
 98         Method accessMethod = TestIntersectionTargetLambda.class.getDeclaredMethod("complex");
 99         CoreOp.FuncOp model = Op.ofMethod(accessMethod).orElseThrow();
100         MethodHandle handle = BytecodeGenerator.generate(MethodHandles.lookup(), model);
101         Assertions.assertEquals(complex(), (String) handle.invokeExact());
102     }
103 
104     interface X {
105         String get();
106     }
107 
108     interface Y {
109         String get();
110     }
111 
112     interface Z extends X, Y {}
113 
114     @Reflect
115     public static String overrideEquivalent() {
116         Z f = () -> "overrideEquivalent";
117         return f.get();
118     }
119 
120     @Test
121     public void testOverrideEquivalent() throws Throwable {
122         Method accessMethod = TestIntersectionTargetLambda.class.getDeclaredMethod("overrideEquivalent");
123         CoreOp.FuncOp model = Op.ofMethod(accessMethod).orElseThrow();
124         MethodHandle handle = BytecodeGenerator.generate(MethodHandles.lookup(), model);
125         Assertions.assertEquals(overrideEquivalent(), (String) handle.invokeExact());
126     }
127 }