/**************************************************************************************
* Copyright (c) Jonas Bon�r, Alexandre Vasseur. All rights reserved. *
* http://aspectwerkz.codehaus.org *
* ---------------------------------------------------------------------------------- *
* The software in this package is published under the terms of the LGPL license *
* a copy of which has been included with this distribution in the license.txt file. *
**************************************************************************************/
package org.codehaus.aspectwerkz.hook.impl;
import org.codehaus.aspectwerkz.hook.ClassLoaderPatcher;
import org.codehaus.aspectwerkz.hook.ClassLoaderPreProcessor;
import org.objectweb.asm.ClassWriter;
import org.objectweb.asm.CodeVisitor;
import org.objectweb.asm.Attribute;
import org.objectweb.asm.ClassReader;
import org.objectweb.asm.ClassVisitor;
import org.objectweb.asm.ClassAdapter;
import org.objectweb.asm.CodeAdapter;
import org.objectweb.asm.Type;
import org.objectweb.asm.Constants;
import org.objectweb.asm.Label;
import org.objectweb.asm.attrs.Attributes;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.FileOutputStream;
import java.io.File;
import java.util.HashMap;
import java.util.Map;
/**
* Instruments the java.lang.ClassLoader to plug in the Class PreProcessor mechanism using ASM. <p/>We are using a
* lazy initialization of the class preprocessor to allow all class pre processor logic to be in system classpath and
* not in bootclasspath. <p/>This implementation should support IBM custom JRE
*
* @author Chris Nokleberg
* @author <a href="mailto:alex@gnilux.com">Alexandre Vasseur </a>
*/
public class ClassLoaderPreProcessorImpl implements ClassLoaderPreProcessor {
private final static String CLASSLOADER_CLASS_NAME = "java/lang/ClassLoader";
private final static String DEFINECLASS0_METHOD_NAME = "defineClass0";
private final static String DEFINECLASS1_METHOD_NAME = "defineClass1";//For JDK 5
private final static String DEFINECLASS2_METHOD_NAME = "defineClass2";//For JDK 5
private static final String DESC_CORE = "Ljava/lang/String;[BIILjava/security/ProtectionDomain;";
private static final String DESC_PREFIX = "(" + DESC_CORE;
private static final String DESC_HELPER = "(Ljava/lang/ClassLoader;" + DESC_CORE + ")[B";
private static final String DESC_BYTEBUFFER_CORE = "Ljava/lang/String;Ljava/nio/ByteBuffer;IILjava/security/ProtectionDomain;";
private static final String DESC_BYTEBUFFER_PREFIX = "(" + DESC_BYTEBUFFER_CORE;
private static final String DESC_BYTEBUFFER_HELPER = "(Ljava/lang/ClassLoader;" + DESC_BYTEBUFFER_CORE + ")[B";
public ClassLoaderPreProcessorImpl() {
}
/**
* Patch caller side of defineClass0
* byte[] weaved = ..hook.impl.ClassPreProcessorHelper.defineClass0Pre(this, args..);
* klass = defineClass0(name, weaved, 0, weaved.length, protectionDomain);
*
* @param classLoaderBytecode
* @return
*/
public byte[] preProcess(byte[] classLoaderBytecode) {
try {
ClassWriter cw = new ClassWriter(true);
ClassLoaderVisitor cv = new ClassLoaderVisitor(cw);
ClassReader cr = new ClassReader(classLoaderBytecode);
cr.accept(cv, Attributes.getDefaultAttributes(), false);
return cw.toByteArray();
} catch (Exception e) {
System.err.println("failed to patch ClassLoader:");
e.printStackTrace();
return classLoaderBytecode;
}
}
private static class ClassLoaderVisitor extends ClassAdapter {
public ClassLoaderVisitor(ClassVisitor cv) {
super(cv);
}
public CodeVisitor visitMethod(int access, String name, String desc, String[] exceptions, Attribute attrs) {
CodeVisitor cv = super.visitMethod(access, name, desc, exceptions, attrs);
Type[] args = Type.getArgumentTypes(desc);
return new PreProcessingVisitor(cv, access, args);
}
}
/**
* @author Chris Nokleberg
*/
private static class PreProcessingVisitor extends RemappingCodeVisitor {
public PreProcessingVisitor(CodeVisitor cv, int access, Type[] args) {
super(cv, access, args);
}
public void visitMethodInsn(int opcode, String owner, String name, String desc) {
if ((DEFINECLASS0_METHOD_NAME.equals(name) || (DEFINECLASS1_METHOD_NAME.equals(name)))
&& CLASSLOADER_CLASS_NAME.equals(owner)) {
Type[] args = Type.getArgumentTypes(desc);
if (args.length < 5 || !desc.startsWith(DESC_PREFIX)) {
throw new Error("non supported JDK, native call not supported: " + desc);
}
// store all args in local variables
int[] locals = new int[args.length];
for (int i = args.length - 1; i >= 0; i--) {
cv.visitVarInsn(
args[i].getOpcode(Constants.ISTORE),
locals[i] = nextLocal(args[i].getSize())
);
}
for (int i = 0; i < 5; i++) {
cv.visitVarInsn(args[i].getOpcode(Constants.ILOAD), locals[i]);
}
super.visitMethodInsn(
Constants.INVOKESTATIC,
"org/codehaus/aspectwerkz/hook/impl/ClassPreProcessorHelper",
"defineClass0Pre",
DESC_HELPER
);
cv.visitVarInsn(Constants.ASTORE, locals[1]);
cv.visitVarInsn(Constants.ALOAD, 0);
cv.visitVarInsn(Constants.ALOAD, locals[0]); // name
cv.visitVarInsn(Constants.ALOAD, locals[1]); // bytes
cv.visitInsn(Constants.ICONST_0); // offset
cv.visitVarInsn(Constants.ALOAD, locals[1]);
cv.visitInsn(Constants.ARRAYLENGTH); // length
cv.visitVarInsn(Constants.ALOAD, locals[4]); // protection domain
for (int i = 5; i < args.length; i++) {
cv.visitVarInsn(args[i].getOpcode(Constants.ILOAD), locals[i]);
}
} else if (DEFINECLASS2_METHOD_NAME.equals(name) && CLASSLOADER_CLASS_NAME.equals(owner)) {
Type[] args = Type.getArgumentTypes(desc);
if (args.length < 5 || !desc.startsWith(DESC_BYTEBUFFER_PREFIX)) {
throw new Error("non supported JDK, bytebuffer native call not supported: " + desc);
}
// store all args in local variables
int[] locals = new int[args.length];
for (int i = args.length - 1; i >= 0; i--) {
cv.visitVarInsn(
args[i].getOpcode(Constants.ISTORE),
locals[i] = nextLocal(args[i].getSize())
);
}
for (int i = 0; i < 5; i++) {
cv.visitVarInsn(args[i].getOpcode(Constants.ILOAD), locals[i]);
}
super.visitMethodInsn(
Constants.INVOKESTATIC,
"org/codehaus/aspectwerkz/hook/impl/ClassPreProcessorHelper",
"defineClass0Pre",
DESC_BYTEBUFFER_HELPER
);
cv.visitVarInsn(Constants.ASTORE, locals[1]);
cv.visitVarInsn(Constants.ALOAD, 0);
cv.visitVarInsn(Constants.ALOAD, locals[0]); // name
cv.visitVarInsn(Constants.ALOAD, locals[1]); // bytes
cv.visitInsn(Constants.ICONST_0); // offset
cv.visitVarInsn(Constants.ALOAD, locals[1]);
cv.visitMethodInsn(Constants.INVOKEVIRTUAL, "Ljava/nio/Buffer;", "remaining", "()I");
cv.visitVarInsn(Constants.ALOAD, locals[4]); // protection domain
for (int i = 5; i < args.length; i++) {
cv.visitVarInsn(args[i].getOpcode(Constants.ILOAD), locals[i]);
}
// we should rebuild a new ByteBuffer...
}
super.visitMethodInsn(opcode, owner, name, desc);
}
}
/**
* @author Chris Nokleberg
*/
private static class State {
Map locals = new HashMap();
int firstLocal;
int nextLocal;
State(int access, Type[] args) {
nextLocal = ((Constants.ACC_STATIC & access) != 0) ? 0 : 1;
for (int i = 0; i < args.length; i++) {
nextLocal += args[i].getSize();
}
firstLocal = nextLocal;
}
}
/**
* @author Chris Nokleberg
*/
private static class IntRef {
int key;
public boolean equals(Object o) {
return key == ((IntRef) o).key;
}
public int hashCode() {
return key;
}
}
/**
* @author Chris Nokleberg
*/
private static class RemappingCodeVisitor extends CodeAdapter {
private State state;
private IntRef check = new IntRef();
public RemappingCodeVisitor(CodeVisitor v, int access, Type[] args) {
super(v);
state = new State(access, args);
}
public RemappingCodeVisitor(RemappingCodeVisitor wrap) {
super(wrap.cv);
this.state = wrap.state;
}
protected int nextLocal(int size) {
int var = state.nextLocal;
state.nextLocal += size;
return var;
}
private int remap(int var, int size) {
if (var < state.firstLocal) {
return var;
}
check.key = (size == 2) ? ~var : var;
Integer value = (Integer) state.locals.get(check);
if (value == null) {
IntRef ref = new IntRef();
ref.key = check.key;
state.locals.put(ref, value = new Integer(nextLocal(size)));
}
return value.intValue();
}
public void visitIincInsn(int var, int increment) {
cv.visitIincInsn(remap(var, 1), increment);
}
public void visitLocalVariable(String name, String desc, Label start, Label end, int index) {
cv.visitLocalVariable(name, desc, start, end, remap(index, 0));
}
public void visitVarInsn(int opcode, int var) {
int size;
switch (opcode) {
case Constants.LLOAD:
case Constants.LSTORE:
case Constants.DLOAD:
case Constants.DSTORE:
size = 2;
break;
default:
size = 1;
}
cv.visitVarInsn(opcode, remap(var, size));
}
public void visitMaxs(int maxStack, int maxLocals) {
cv.visitMaxs(0, 0);
}
}
public static void main(String args[]) throws Exception {
ClassLoaderPreProcessor me = new ClassLoaderPreProcessorImpl();
InputStream is = ClassLoader.getSystemClassLoader().getParent().getResourceAsStream(
"java/lang/ClassLoader.class"
);
byte[] out = me.preProcess(ClassLoaderPatcher.inputStreamToByteArray(is));
is.close();
File dir = new File("_boot/java/lang/");
dir.mkdirs();
OutputStream os = new FileOutputStream("_boot/java/lang/ClassLoader.class");
os.write(out);
os.close();
}
}