1 /*
2  * Copyright (C) 2023 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 import java.lang.invoke.*;
18 import dalvik.system.VMRuntime;
19 
20 public class Main {
main(String... args)21     public static void main(String... args) throws Throwable {
22         System.loadLibrary(args[0]);
23         enableHiddenApiChecks();
24         // MH.identity(...) methods were marked as hidden in aosp/321456.
25         VMRuntime.getRuntime().setTargetSdkVersion(28);
26 
27         MethodHandle intIdentity = MethodHandles.identity(int.class);
28 
29         int value = 42;
30         int returnedValue = (int) intIdentity.invokeExact(value);
31 
32         if (returnedValue != value) {
33             System.out.printf("Expected: %d, but identity MH returned %d\n",
34                 value, returnedValue);
35             throw new AssertionError("identity fail");
36         }
37 
38         value = 101;
39         MethodHandle intConstant = MethodHandles.constant(int.class, value);
40         returnedValue = (int) intConstant.invokeExact();
41 
42         if (returnedValue != value) {
43             System.out.printf("Expected: %d, but constant MH returned %d\n",
44                 value, returnedValue);
45             throw new AssertionError("constant failed");
46         }
47 
48         int secondCallValue = (int) intConstant.invokeExact();
49         if (secondCallValue != value) {
50             System.out.printf("Expected: %d, but constant MH returned %d on subsequent call\n",
51                 value, returnedValue);
52             throw new AssertionError("constant failed");
53         }
54     }
55 
enableHiddenApiChecks()56     private static native void enableHiddenApiChecks();
57 }
58