/*
* Copyright 2000-2004 The Apache Software Foundation
*
* Licensed 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.classfile.Constant;
import org.apache.bcel.classfile.ConstantClass;
import org.apache.bcel.classfile.ConstantPool;
import org.apache.bcel.util.ByteSequence;
/**
* Abstract super class for instructions that use an index into the
* constant pool such as LDC, INVOKEVIRTUAL, etc.
*
* @see ConstantPoolGen
* @see LDC
* @see INVOKEVIRTUAL
*
* @version $Id: CPInstruction.java 386056 2006-03-15 11:31:56Z tcurdt $
* @author <A HREF="mailto:m.dahm@gmx.de">M. Dahm</A>
*/
public abstract class CPInstruction extends Instruction implements TypedInstruction,
IndexedInstruction {
protected int index; // index to constant pool
/**
* Empty constructor needed for the Class.newInstance() statement in
* Instruction.readInstruction(). Not to be used otherwise.
*/
CPInstruction() {
}
/**
* @param index to constant pool
*/
protected CPInstruction(short opcode, int index) {
super(opcode, (short) 3);
setIndex(index);
}
/**
* Dump instruction as byte code to stream out.
* @param out Output stream
*/
public void dump( DataOutputStream out ) throws IOException {
out.writeByte(opcode);
out.writeShort(index);
}
/**
* Long output format:
*
* <name of opcode> "["<opcode number>"]"
* "("<length of instruction>")" "<"< constant pool index>">"
*
* @param verbose long/short format switch
* @return mnemonic for instruction
*/
public String toString( boolean verbose ) {
return super.toString(verbose) + " " + index;
}
/**
* @return mnemonic for instruction with symbolic references resolved
*/
public String toString( ConstantPool cp ) {
Constant c = cp.getConstant(index);
String str = cp.constantToString(c);
if (c instanceof ConstantClass) {
str = str.replace('.', '/');
}
return org.apache.bcel.Constants.OPCODE_NAMES[opcode] + " " + str;
}
/**
* Read needed data (i.e., index) from file.
* @param bytes input stream
* @param wide wide prefix?
*/
protected void initFromFile( ByteSequence bytes, boolean wide ) throws IOException {
setIndex(bytes.readUnsignedShort());
length = 3;
}
/**
* @return index in constant pool referred by this instruction.
*/
public final int getIndex() {
return index;
}
/**
* Set the index to constant pool.
* @param index in constant pool.
*/
public void setIndex( int index ) {
if (index < 0) {
throw new ClassGenException("Negative index value: " + index);
}
this.index = index;
}
/** @return type related with this instruction.
*/
public Type getType( ConstantPoolGen cpg ) {
ConstantPool cp = cpg.getConstantPool();
String name = cp.getConstantString(index, org.apache.bcel.Constants.CONSTANT_Class);
if (!name.startsWith("[")) {
name = "L" + name + ";";
}
return Type.getType(name);
}
}