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/*
* 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.
*
*/
package org.apache.bcel.generic;
import java.io.DataOutputStream;
import java.io.IOException;
import org.apache.bcel.util.ByteSequence;
/**
* RET - Return from subroutine
*
* <PRE>Stack: ... -> ...</PRE>
*
* @version $Id$
*/
public class RET extends Instruction implements IndexedInstruction, TypedInstruction {
private boolean wide;
private int index; // index to local variable containg the return address
/**
* Empty constructor needed for Instruction.readInstruction.
* Not to be used otherwise.
*/
RET() {
}
public RET(final int index) {
super(org.apache.bcel.Const.RET, (short) 2);
setIndex(index); // May set wide as side effect
}
/**
* Dump instruction as byte code to stream out.
* @param out Output stream
*/
@Override
public void dump( final DataOutputStream out ) throws IOException {
if (wide) {
out.writeByte(org.apache.bcel.Const.WIDE);
}
out.writeByte(super.getOpcode());
if (wide) {
out.writeShort(index);
} else {
out.writeByte(index);
}
}
private void setWide() {
wide = index > org.apache.bcel.Const.MAX_BYTE;
if (wide) {
super.setLength(4); // Including the wide byte
} else {
super.setLength(2);
}
}
/**
* Read needed data (e.g. index) from file.
*/
@Override
protected void initFromFile( final ByteSequence bytes, final boolean wide ) throws IOException {
this.wide = wide;
if (wide) {
index = bytes.readUnsignedShort();
super.setLength(4);
} else {
index = bytes.readUnsignedByte();
super.setLength(2);
}
}
/**
* @return index of local variable containg the return address
*/
@Override
public final int getIndex() {
return index;
}
/**
* Set index of local variable containg the return address
*/
@Override
public final void setIndex( final int n ) {
if (n < 0) {
throw new ClassGenException("Negative index value: " + n);
}
index = n;
setWide();
}
/**
* @return mnemonic for instruction
*/
@Override
public String toString( final boolean verbose ) {
return super.toString(verbose) + " " + index;
}
/** @return return address type
*/
@Override
public Type getType( final ConstantPoolGen cp ) {
return ReturnaddressType.NO_TARGET;
}
/**
* Call corresponding visitor method(s). The order is:
* Call visitor methods of implemented interfaces first, then
* call methods according to the class hierarchy in descending order,
* i.e., the most specific visitXXX() call comes last.
*
* @param v Visitor object
*/
@Override
public void accept( final Visitor v ) {
v.visitRET(this);
}
}
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