/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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.
*
*/
import java.io.File;
import java.io.FileOutputStream;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.util.Date;
import java.util.Hashtable;
import java.util.StringTokenizer;
import org.apache.bcel.Constants;
import org.apache.bcel.Repository;
import org.apache.bcel.classfile.Attribute;
import org.apache.bcel.classfile.ClassParser;
import org.apache.bcel.classfile.Code;
import org.apache.bcel.classfile.ConstantValue;
import org.apache.bcel.classfile.Deprecated;
import org.apache.bcel.classfile.ExceptionTable;
import org.apache.bcel.classfile.Field;
import org.apache.bcel.classfile.JavaClass;
import org.apache.bcel.classfile.Method;
import org.apache.bcel.classfile.Synthetic;
import org.apache.bcel.classfile.Utility;
import org.apache.bcel.generic.BranchHandle;
import org.apache.bcel.generic.BranchInstruction;
import org.apache.bcel.generic.CodeExceptionGen;
import org.apache.bcel.generic.ConstantPoolGen;
import org.apache.bcel.generic.Instruction;
import org.apache.bcel.generic.InstructionHandle;
import org.apache.bcel.generic.InstructionList;
import org.apache.bcel.generic.LineNumberGen;
import org.apache.bcel.generic.LocalVariableGen;
import org.apache.bcel.generic.MethodGen;
import org.apache.bcel.generic.ObjectType;
import org.apache.bcel.generic.Select;
import org.apache.bcel.generic.TABLESWITCH;
/**
* Disassemble Java class object into the <a href="http://jasmin.sourceforge.net">
* Jasmin</a> format.
*
* @version $Id: JasminVisitor.java 1589627 2014-04-24 07:49:36Z ebourg $
* @author <A HREF="mailto:m.dahm@gmx.de">M. Dahm</A>
*/
public class JasminVisitor extends org.apache.bcel.classfile.EmptyVisitor {
private JavaClass clazz;
private PrintWriter out;
private String class_name;
private ConstantPoolGen cp;
public JasminVisitor(JavaClass clazz, OutputStream out) {
this.clazz = clazz;
this.out = new PrintWriter(out);
class_name = clazz.getClassName();
cp = new ConstantPoolGen(clazz.getConstantPool());
}
/**
* Start traversal using DefaultVisitor pattern.
*/
public void disassemble() {
new org.apache.bcel.classfile.DescendingVisitor(clazz, this).visit();
out.close();
}
@Override
public void visitJavaClass(JavaClass clazz) {
out.println(";; Produced by JasminVisitor (BCEL)");
out.println(";; http://commons.apache.org/bcel/");
out.println(";; " + new Date() + "\n");
out.println(".source " + clazz.getSourceFileName());
out.println("." + Utility.classOrInterface(clazz.getAccessFlags()) + " " +
Utility.accessToString(clazz.getAccessFlags(), true) +
" " + clazz.getClassName().replace('.', '/'));
out.println(".super " + clazz.getSuperclassName().replace('.', '/'));
String[] interfaces = clazz.getInterfaceNames();
for(int i=0; i < interfaces.length; i++) {
out.println(".implements " + interfaces[i].replace('.', '/'));
}
out.print("\n");
}
@Override
public void visitField(Field field) {
out.print(".field " + Utility.accessToString(field.getAccessFlags()) +
" \"" +field.getName() + "\"" + field.getSignature());
if(field.getAttributes().length == 0) {
out.print("\n");
}
}
@Override
public void visitConstantValue(ConstantValue cv) {
out.println(" = " + cv);
}
private Method _method;
/**
* Unfortunately Jasmin expects ".end method" after each method. Thus we've to check
* for every of the method's attributes if it's the last one and print ".end method"
* then.
*/
private void printEndMethod(Attribute attr) {
Attribute[] attributes = _method.getAttributes();
if(attr == attributes[attributes.length - 1]) {
out.println(".end method");
}
}
@Override
public void visitDeprecated(Deprecated attribute) { printEndMethod(attribute); }
@Override
public void visitSynthetic(Synthetic attribute) {
if(_method != null) {
printEndMethod(attribute);
}
}
@Override
public void visitMethod(Method method) {
this._method = method; // Remember for use in subsequent visitXXX calls
out.println("\n.method " + Utility.accessToString(_method.getAccessFlags()) +
" " + _method.getName() + _method.getSignature());
Attribute[] attributes = _method.getAttributes();
if((attributes == null) || (attributes.length == 0)) {
out.println(".end method");
}
}
@Override
public void visitExceptionTable(ExceptionTable e) {
String[] names = e.getExceptionNames();
for(int i=0; i < names.length; i++) {
out.println(".throws " + names[i].replace('.', '/'));
}
printEndMethod(e);
}
private Hashtable<InstructionHandle, String> map;
@Override
public void visitCode(Code code) {
int label_counter = 0;
out.println(".limit stack " + code.getMaxStack());
out.println(".limit locals " + code.getMaxLocals());
MethodGen mg = new MethodGen(_method, class_name, cp);
InstructionList il = mg.getInstructionList();
InstructionHandle[] ihs = il.getInstructionHandles();
/* Pass 1: Give all referenced instruction handles a symbolic name, i.e. a
* label.
*/
map = new Hashtable<InstructionHandle, String>();
for(int i=0; i < ihs.length; i++) {
if(ihs[i] instanceof BranchHandle) {
BranchInstruction bi = (BranchInstruction)ihs[i].getInstruction();
if(bi instanceof Select) { // Special cases LOOKUPSWITCH and TABLESWITCH
InstructionHandle[] targets = ((Select)bi).getTargets();
for(int j=0; j < targets.length; j++) {
put(targets[j], "Label" + label_counter++ + ":");
}
}
InstructionHandle ih = bi.getTarget();
put(ih, "Label" + label_counter++ + ":");
}
}
LocalVariableGen[] lvs = mg.getLocalVariables();
for(int i=0; i < lvs.length; i++) {
InstructionHandle ih = lvs[i].getStart();
put(ih, "Label" + label_counter++ + ":");
ih = lvs[i].getEnd();
put(ih, "Label" + label_counter++ + ":");
}
CodeExceptionGen[] ehs = mg.getExceptionHandlers();
for(int i=0; i < ehs.length; i++) {
CodeExceptionGen c = ehs[i];
InstructionHandle ih = c.getStartPC();
put(ih, "Label" + label_counter++ + ":");
ih = c.getEndPC();
put(ih, "Label" + label_counter++ + ":");
ih = c.getHandlerPC();
put(ih, "Label" + label_counter++ + ":");
}
LineNumberGen[] lns = mg.getLineNumbers();
for(int i=0; i < lns.length; i++) {
InstructionHandle ih = lns[i].getInstruction();
put(ih, ".line " + lns[i].getSourceLine());
}
/* Pass 2: Output code.
*/
for(int i=0; i < lvs.length; i++) {
LocalVariableGen l = lvs[i];
out.println(".var " + l.getIndex() + " is " + l.getName() + " " +
l.getType().getSignature() +
" from " + get(l.getStart()) +
" to " + get(l.getEnd()));
}
out.print("\n");
for(int i=0; i < ihs.length; i++) {
InstructionHandle ih = ihs[i];
Instruction inst = ih.getInstruction();
String str = map.get(ih);
if(str != null) {
out.println(str);
}
if(inst instanceof BranchInstruction) {
if(inst instanceof Select) { // Special cases LOOKUPSWITCH and TABLESWITCH
Select s = (Select)inst;
int[] matchs = s.getMatchs();
InstructionHandle[] targets = s.getTargets();
if(s instanceof TABLESWITCH) {
out.println("\ttableswitch " + matchs[0] + " " +
matchs[matchs.length - 1]);
for(int j=0; j < targets.length; j++) {
out.println("\t\t" + get(targets[j]));
}
} else { // LOOKUPSWITCH
out.println("\tlookupswitch ");
for(int j=0; j < targets.length; j++) {
out.println("\t\t" + matchs[j] + " : " + get(targets[j]));
}
}
out.println("\t\tdefault: " + get(s.getTarget())); // Applies for both
} else {
BranchInstruction bi = (BranchInstruction)inst;
ih = bi.getTarget();
str = get(ih);
out.println("\t" + Constants.OPCODE_NAMES[bi.getOpcode()] + " " + str);
}
} else {
out.println("\t" + inst.toString(cp.getConstantPool()));
}
}
out.print("\n");
for(int i=0; i < ehs.length; i++) {
CodeExceptionGen c = ehs[i];
ObjectType caught = c.getCatchType();
String class_name = (caught == null)? // catch any exception, used when compiling finally
"all" : caught.getClassName().replace('.', '/');
out.println(".catch " + class_name + " from " +
get(c.getStartPC()) + " to " + get(c.getEndPC()) +
" using " + get(c.getHandlerPC()));
}
printEndMethod(code);
}
private String get(InstructionHandle ih) {
String str = new StringTokenizer(map.get(ih), "\n").nextToken();
return str.substring(0, str.length() - 1);
}
private void put(InstructionHandle ih, String line) {
String str = map.get(ih);
if(str == null) {
map.put(ih, line);
} else {
if(line.startsWith("Label") || str.endsWith(line)) {
return;
}
map.put(ih, str + "\n" + line); // append
}
}
public static void main(String[] argv) {
JavaClass java_class;
try {
if(argv.length == 0) {
System.err.println("disassemble: No input files specified");
} else {
for(int i=0; i < argv.length; i++) {
if((java_class = Repository.lookupClass(argv[i])) == null) {
java_class = new ClassParser(argv[i]).parse();
}
String class_name = java_class.getClassName();
int index = class_name.lastIndexOf('.');
String path = class_name.substring(0, index + 1).replace('.', File.separatorChar);
class_name = class_name.substring(index + 1);
if(!path.equals("")) {
File f = new File(path);
f.mkdirs();
}
String name = path + class_name + ".j";
FileOutputStream out = new FileOutputStream(name);
new JasminVisitor(java_class, out).disassemble();
System.out.println("File dumped to: " + name);
}
}
} catch(Exception e) {
e.printStackTrace();
}
}
}