/*
* Javassist, a Java-bytecode translator toolkit.
* Copyright (C) 1999-2007 Shigeru Chiba. All Rights Reserved.
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (the "License"); you may not use this file except in compliance with
* the License. Alternatively, the contents of this file may be used under
* the terms of the GNU Lesser General Public License Version 2.1 or later.
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*/
package javassist.convert;
import javassist.bytecode.*;
import javassist.ClassPool;
import javassist.CtClass;
import javassist.CtField;
import javassist.NotFoundException;
import javassist.Modifier;
public class TransformReadField extends Transformer {
protected String fieldname;
protected CtClass fieldClass;
protected boolean isPrivate;
protected String methodClassname, methodName;
public TransformReadField(Transformer next, CtField field,
String methodClassname, String methodName)
{
super(next);
this.fieldClass = field.getDeclaringClass();
this.fieldname = field.getName();
this.methodClassname = methodClassname;
this.methodName = methodName;
this.isPrivate = Modifier.isPrivate(field.getModifiers());
}
static String isField(ClassPool pool, ConstPool cp, CtClass fclass,
String fname, boolean is_private, int index) {
if (!cp.getFieldrefName(index).equals(fname))
return null;
try {
CtClass c = pool.get(cp.getFieldrefClassName(index));
if (c == fclass || (!is_private && isFieldInSuper(c, fclass, fname)))
return cp.getFieldrefType(index);
}
catch (NotFoundException e) {}
return null;
}
static boolean isFieldInSuper(CtClass clazz, CtClass fclass, String fname) {
if (!clazz.subclassOf(fclass))
return false;
try {
CtField f = clazz.getField(fname);
return f.getDeclaringClass() == fclass;
}
catch (NotFoundException e) {}
return false;
}
public int transform(CtClass tclazz, int pos, CodeIterator iterator,
ConstPool cp) throws BadBytecode
{
int c = iterator.byteAt(pos);
if (c == GETFIELD || c == GETSTATIC) {
int index = iterator.u16bitAt(pos + 1);
String typedesc = isField(tclazz.getClassPool(), cp,
fieldClass, fieldname, isPrivate, index);
if (typedesc != null) {
if (c == GETSTATIC) {
iterator.move(pos);
pos = iterator.insertGap(1); // insertGap() may insert 4 bytes.
iterator.writeByte(ACONST_NULL, pos);
pos = iterator.next();
}
String type = "(Ljava/lang/Object;)" + typedesc;
int mi = cp.addClassInfo(methodClassname);
int methodref = cp.addMethodrefInfo(mi, methodName, type);
iterator.writeByte(INVOKESTATIC, pos);
iterator.write16bit(methodref, pos + 1);
return pos;
}
}
return pos;
}
}