net.bytebuddy.utility.OpenedClassReader Maven / Gradle / Ivy
/*
* Copyright 2014 - Present Rafael Winterhalter
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package net.bytebuddy.utility;
import net.bytebuddy.ClassFileVersion;
import net.bytebuddy.build.AccessControllerPlugin;
import net.bytebuddy.utility.privilege.GetSystemPropertyAction;
import org.objectweb.asm.ClassReader;
import org.objectweb.asm.Opcodes;
import java.security.PrivilegedAction;
/**
* A factory for a {@link ClassReader} that does not apply a class file version check if the
* {@code net.bytebuddy.experimental} property is set.
*/
public class OpenedClassReader implements AsmClassReader.Factory {
/**
* Indicates that Byte Buddy should not validate the maximum supported class file version.
*/
public static final String EXPERIMENTAL_PROPERTY = "net.bytebuddy.experimental";
/**
* {@code true} if Byte Buddy is executed in experimental mode.
*/
public static final boolean EXPERIMENTAL;
/**
* Indicates the ASM API version that is used throughout Byte Buddy.
*/
public static final int ASM_API;
/*
* Checks the experimental property.
*/
static {
boolean experimental;
try {
experimental = Boolean.parseBoolean(doPrivileged(new GetSystemPropertyAction(EXPERIMENTAL_PROPERTY)));
} catch (Exception ignored) {
experimental = false;
}
EXPERIMENTAL = experimental;
ASM_API = Opcodes.ASM9;
}
/**
* {@inheritDoc}
*/
public AsmClassReader make(byte[] binaryRepresentation) {
return new AsmClassReader.Default(of(binaryRepresentation));
}
/**
* {@inheritDoc}
*/
public AsmClassReader make(byte[] binaryRepresentation, boolean experimental) {
return new AsmClassReader.Default(of(binaryRepresentation, experimental));
}
/**
* A proxy for {@code java.security.AccessController#doPrivileged} that is activated if available.
*
* @param action The action to execute from a privileged context.
* @param The type of the action's resolved value.
* @return The action's resolved value.
*/
@AccessControllerPlugin.Enhance
private static T doPrivileged(PrivilegedAction action) {
return action.run();
}
/**
* Creates a class reader for the given binary representation of a class file.
*
* @param binaryRepresentation The binary representation of a class file to read.
* @return An appropriate class reader.
*/
public static ClassReader of(byte[] binaryRepresentation) {
return of(binaryRepresentation, EXPERIMENTAL);
}
/**
* Creates a class reader for the given binary representation of a class file.
*
* @param binaryRepresentation The binary representation of a class file to read.
* @param experimental {@code true} if unknown class file versions should also be processed.
* @return An appropriate class reader.
*/
public static ClassReader of(byte[] binaryRepresentation, boolean experimental) {
ClassFileVersion classFileVersion = ClassFileVersion.ofClassFile(binaryRepresentation), latest = ClassFileVersion.latest();
if (classFileVersion.isGreaterThan(latest)) {
if (experimental) {
binaryRepresentation[4] = (byte) (latest.getMinorVersion() >>> 8);
binaryRepresentation[5] = (byte) latest.getMinorVersion();
binaryRepresentation[6] = (byte) (latest.getMajorVersion() >>> 8);
binaryRepresentation[7] = (byte) latest.getMajorVersion();
ClassReader classReader = new ClassReader(binaryRepresentation);
binaryRepresentation[4] = (byte) (classFileVersion.getMinorVersion() >>> 8);
binaryRepresentation[5] = (byte) classFileVersion.getMinorVersion();
binaryRepresentation[6] = (byte) (classFileVersion.getMajorVersion() >>> 8);
binaryRepresentation[7] = (byte) classFileVersion.getMajorVersion();
return classReader;
} else {
throw new IllegalArgumentException(classFileVersion
+ " is not supported by the current version of Byte Buddy which officially supports " + latest
+ " - update Byte Buddy or set " + EXPERIMENTAL_PROPERTY + " as a VM property");
}
} else {
return new ClassReader(binaryRepresentation);
}
}
}