1 /******************************************************************************* 2 * Copyright (c) 2009, 2017 Mountainminds GmbH & Co. KG and Contributors 3 * All rights reserved. This program and the accompanying materials 4 * are made available under the terms of the Eclipse Public License v1.0 5 * which accompanies this distribution, and is available at 6 * http://www.eclipse.org/legal/epl-v10.html 7 * 8 * Contributors: 9 * Evgeny Mandrikov - initial API and implementation 10 * 11 *******************************************************************************/ 12 package org.jacoco.core.internal; 13 14 import java.io.ByteArrayOutputStream; 15 import java.io.IOException; 16 import java.io.InputStream; 17 18 import org.objectweb.asm.Opcodes; 19 20 /** 21 * Patching for Java 9 classes, so that ASM can read them. 22 */ 23 public final class Java9Support { 24 25 /** 26 * Version of the Java 9 class file format. 27 */ 28 public static final int V1_9 = Opcodes.V1_8 + 1; 29 Java9Support()30 private Java9Support() { 31 } 32 33 /** 34 * Reads all bytes from an input stream into a byte array. 35 * 36 * @param is 37 * the input stream to read from 38 * @return a byte array containing all the bytes from the stream 39 * @throws IOException 40 * if an I/O error occurs 41 */ readFully(final InputStream is)42 public static byte[] readFully(final InputStream is) 43 throws IOException { 44 if (is == null) { 45 throw new IllegalArgumentException(); 46 } 47 final byte[] buf = new byte[1024]; 48 final ByteArrayOutputStream out = new ByteArrayOutputStream(); 49 while (true) { 50 int r = is.read(buf); 51 if (r == -1) { 52 break; 53 } 54 out.write(buf, 0, r); 55 } 56 return out.toByteArray(); 57 } 58 putShort(byte[] b, int index, int s)59 private static void putShort(byte[] b, int index, int s) { 60 b[index] = (byte) (s >>> 8); 61 b[index + 1] = (byte) s; 62 } 63 readShort(byte[] b, int index)64 private static short readShort(byte[] b, int index) { 65 return (short) (((b[index] & 0xFF) << 8) | (b[index + 1] & 0xFF)); 66 } 67 68 /** 69 * Determines whether class definition contains {@link #V1_9} version. 70 * 71 * @param buffer 72 * definition of the class 73 * @return <code>true</code> if class definition contains Java 9 version 74 */ isPatchRequired(byte[] buffer)75 public static boolean isPatchRequired(byte[] buffer) { 76 return readShort(buffer, 6) == V1_9; 77 } 78 79 /** 80 * Returns new definition of class with version {@link Opcodes#V1_8}, 81 * if it has version {@link #V1_9}. 82 * 83 * @param buffer 84 * definition of the class 85 * @return new definition of the class 86 */ downgradeIfRequired(byte[] buffer)87 public static byte[] downgradeIfRequired(byte[] buffer) { 88 return isPatchRequired(buffer) ? downgrade(buffer) : buffer; 89 } 90 91 /** 92 * Replaces version in the definition of class on {@link Opcodes#V1_8}. 93 * 94 * @param b 95 * definition of the class 96 * @return new definition of the class 97 */ downgrade(byte[] b)98 public static byte[] downgrade(byte[] b) { 99 byte[] result = new byte[b.length]; 100 System.arraycopy(b, 0, result, 0, b.length); 101 putShort(result, 6, Opcodes.V1_8); 102 return result; 103 } 104 105 /** 106 * Replaces version in the definition of class on {@link #V1_9}. 107 * 108 * @param b 109 * definition of the class 110 */ upgrade(byte[] b)111 public static void upgrade(byte[] b) { 112 putShort(b, 6, V1_9); 113 } 114 115 } 116