/*******************************************************************************
* Copyright (c) 2009, 2017 Mountainminds GmbH & Co. KG and Contributors
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Contributors:
* Evgeny Mandrikov - initial API and implementation
*
*******************************************************************************/
package org.jacoco.core.internal;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import org.objectweb.asm.Opcodes;
/**
* Patching for Java 9 classes, so that ASM can read them.
*/
public final class Java9Support {
/**
* Version of the Java 9 class file format.
*/
public static final int V1_9 = Opcodes.V1_8 + 1;
private Java9Support() {
}
/**
* Reads all bytes from an input stream into a byte array.
*
* @param is
* the input stream to read from
* @return a byte array containing all the bytes from the stream
* @throws IOException
* if an I/O error occurs
*/
public static byte[] readFully(final InputStream is)
throws IOException {
if (is == null) {
throw new IllegalArgumentException();
}
final byte[] buf = new byte[1024];
final ByteArrayOutputStream out = new ByteArrayOutputStream();
while (true) {
int r = is.read(buf);
if (r == -1) {
break;
}
out.write(buf, 0, r);
}
return out.toByteArray();
}
private static void putShort(byte[] b, int index, int s) {
b[index] = (byte) (s >>> 8);
b[index + 1] = (byte) s;
}
private static short readShort(byte[] b, int index) {
return (short) (((b[index] & 0xFF) << 8) | (b[index + 1] & 0xFF));
}
/**
* Determines whether class definition contains {@link #V1_9} version.
*
* @param buffer
* definition of the class
* @return <code>true</code> if class definition contains Java 9 version
*/
public static boolean isPatchRequired(byte[] buffer) {
return readShort(buffer, 6) == V1_9;
}
/**
* Returns new definition of class with version {@link Opcodes#V1_8},
* if it has version {@link #V1_9}.
*
* @param buffer
* definition of the class
* @return new definition of the class
*/
public static byte[] downgradeIfRequired(byte[] buffer) {
return isPatchRequired(buffer) ? downgrade(buffer) : buffer;
}
/**
* Replaces version in the definition of class on {@link Opcodes#V1_8}.
*
* @param b
* definition of the class
* @return new definition of the class
*/
public static byte[] downgrade(byte[] b) {
byte[] result = new byte[b.length];
System.arraycopy(b, 0, result, 0, b.length);
putShort(result, 6, Opcodes.V1_8);
return result;
}
/**
* Replaces version in the definition of class on {@link #V1_9}.
*
* @param b
* definition of the class
*/
public static void upgrade(byte[] b) {
putShort(b, 6, V1_9);
}
}