1 /* 2 * Copyright (C) 2019 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.util.function.Consumer; 18 19 public class Main { 20 public static final boolean PRINT = false; 21 22 public static class PtrCls { doNothingPtr()23 public static void doNothingPtr() {} 24 } 25 26 public static class IdxCls { doNothingIdx()27 public static void doNothingIdx() {} 28 } 29 DbgPrint(String str)30 public static void DbgPrint(String str) { 31 if (PRINT) { 32 System.out.println(str); 33 } 34 } 35 GetId(Class<?> k, String name)36 public static long GetId(Class<?> k, String name) { 37 return GetMethodId(true, k, name, "()V"); 38 } 39 main(String[] args)40 public static void main(String[] args) { 41 System.loadLibrary(args[0]); 42 System.out.println("JNI Type is: " + GetJniType()); 43 long expect_ptr_id = GetId(PtrCls.class, "doNothingPtr"); 44 DbgPrint(String.format("expected_ptr_id is 0x%x", expect_ptr_id)); 45 if (expect_ptr_id % 4 != 0) { 46 throw new Error("ID " + expect_ptr_id + " is not aligned!"); 47 } else { 48 System.out.println("pointer ID looks like a pointer!"); 49 } 50 SetToIndexIds(); 51 System.out.println("JNI Type is: " + GetJniType()); 52 long expect_idx_id = GetId(IdxCls.class, "doNothingIdx"); 53 DbgPrint(String.format("expected_idx_id is 0x%x", expect_idx_id)); 54 if (expect_idx_id % 2 != 1) { 55 throw new Error("ID " + expect_ptr_id + " is not odd!"); 56 } else { 57 System.out.println("index ID looks like an index!"); 58 } 59 long again_ptr_id = GetId(PtrCls.class, "doNothingPtr"); 60 if (expect_ptr_id != again_ptr_id) { 61 throw new Error( 62 "Got different id values for same method. " + expect_ptr_id + " vs " + again_ptr_id); 63 } else { 64 System.out.println("pointer ID remains a pointer!"); 65 } 66 long well_known_id = GetMethodId(false, Consumer.class, "accept", "(Ljava/lang/Object;)V"); 67 DbgPrint(String.format("well_known_id is 0x%x", well_known_id)); 68 if (well_known_id % 2 != 1) { 69 throw new Error("WKC ID " + well_known_id + " is not odd!"); 70 } else { 71 System.out.println("index WKC ID looks like an index!"); 72 } 73 } 74 GetJniType()75 private static native String GetJniType(); SetToIndexIds()76 private static native void SetToIndexIds(); GetMethodId(boolean is_static, Class k, String name, String sig)77 private static native long GetMethodId(boolean is_static, Class k, String name, String sig); 78 } 79