scouter.javassist.bytecode.ExceptionsAttribute Maven / Gradle / Ivy
/*
* Javassist, a Java-bytecode translator toolkit.
* Copyright (C) 1999- 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,
* or the Apache License Version 2.0.
*
* 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 scouter.javassist.bytecode;
import java.io.DataInputStream;
import java.io.IOException;
import java.util.Map;
import scouter.javassist.bytecode.AttributeInfo;
import scouter.javassist.bytecode.ByteArray;
import scouter.javassist.bytecode.ConstPool;
/**
* Exceptions_attribute.
*/
public class ExceptionsAttribute extends AttributeInfo {
/**
* The name of this attribute "Exceptions".
*/
public static final String tag = "Exceptions";
ExceptionsAttribute(ConstPool cp, int n, DataInputStream in)
throws IOException
{
super(cp, n, in);
}
/**
* Constructs a copy of an exceptions attribute.
*
* @param cp constant pool table.
* @param src source attribute.
*/
private ExceptionsAttribute(ConstPool cp, ExceptionsAttribute src,
Map classnames) {
super(cp, tag);
copyFrom(src, classnames);
}
/**
* Constructs a new exceptions attribute.
*
* @param cp constant pool table.
*/
public ExceptionsAttribute(ConstPool cp) {
super(cp, tag);
byte[] data = new byte[2];
data[0] = data[1] = 0; // empty
this.info = data;
}
/**
* Makes a copy. Class names are replaced according to the
* given Map object.
*
* @param newCp the constant pool table used by the new copy.
* @param classnames pairs of replaced and substituted
* class names. It can be null.
*/
public AttributeInfo copy(ConstPool newCp, Map classnames) {
return new ExceptionsAttribute(newCp, this, classnames);
}
/**
* Copies the contents from a source attribute.
* Specified class names are replaced during the copy.
*
* @param srcAttr source Exceptions attribute
* @param classnames pairs of replaced and substituted
* class names.
*/
private void copyFrom(ExceptionsAttribute srcAttr, Map classnames) {
ConstPool srcCp = srcAttr.constPool;
ConstPool destCp = this.constPool;
byte[] src = srcAttr.info;
int num = src.length;
byte[] dest = new byte[num];
dest[0] = src[0];
dest[1] = src[1]; // the number of elements.
for (int i = 2; i < num; i += 2) {
int index = ByteArray.readU16bit(src, i);
ByteArray.write16bit(srcCp.copy(index, destCp, classnames),
dest, i);
}
this.info = dest;
}
/**
* Returns exception_index_table[].
*/
public int[] getExceptionIndexes() {
byte[] blist = info;
int n = blist.length;
if (n <= 2)
return null;
int[] elist = new int[n / 2 - 1];
int k = 0;
for (int j = 2; j < n; j += 2)
elist[k++] = ((blist[j] & 0xff) << 8) | (blist[j + 1] & 0xff);
return elist;
}
/**
* Returns the names of exceptions that the method may throw.
*/
public String[] getExceptions() {
byte[] blist = info;
int n = blist.length;
if (n <= 2)
return null;
String[] elist = new String[n / 2 - 1];
int k = 0;
for (int j = 2; j < n; j += 2) {
int index = ((blist[j] & 0xff) << 8) | (blist[j + 1] & 0xff);
elist[k++] = constPool.getClassInfo(index);
}
return elist;
}
/**
* Sets exception_index_table[].
*/
public void setExceptionIndexes(int[] elist) {
int n = elist.length;
byte[] blist = new byte[n * 2 + 2];
ByteArray.write16bit(n, blist, 0);
for (int i = 0; i < n; ++i)
ByteArray.write16bit(elist[i], blist, i * 2 + 2);
info = blist;
}
/**
* Sets the names of exceptions that the method may throw.
*/
public void setExceptions(String[] elist) {
int n = elist.length;
byte[] blist = new byte[n * 2 + 2];
ByteArray.write16bit(n, blist, 0);
for (int i = 0; i < n; ++i)
ByteArray.write16bit(constPool.addClassInfo(elist[i]),
blist, i * 2 + 2);
info = blist;
}
/**
* Returns number_of_exceptions.
*/
public int tableLength() { return info.length / 2 - 1; }
/**
* Returns the value of exception_index_table[nth].
*/
public int getException(int nth) {
int index = nth * 2 + 2; // nth >= 0
return ((info[index] & 0xff) << 8) | (info[index + 1] & 0xff);
}
}