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 * The ASF licenses this file to You under the Apache License, Version 2.0
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package com.sun.org.apache.bcel.internal.generic;

import java.io.DataOutputStream;
import java.io.IOException;

import com.sun.org.apache.bcel.internal.classfile.Constant;
import com.sun.org.apache.bcel.internal.classfile.ConstantClass;
import com.sun.org.apache.bcel.internal.classfile.ConstantPool;
import com.sun.org.apache.bcel.internal.util.ByteSequence;

Abstract super class for instructions that use an index into the constant
pool such as LDC, INVOKEVIRTUAL, etc.
See Also:
ConstantPoolGen
LDC
INVOKEVIRTUAL
Version:
$Id: CPInstruction.java 1749603 2016-06-21 20:50:19Z ggregory $/**
 * 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 1749603 2016-06-21 20:50:19Z ggregory $
 */
public abstract class CPInstruction extends Instruction implements TypedInstruction,
        IndexedInstruction {

    private int index; // index to constant pool

    
Empty constructor needed for the Class.newInstance() statement in
Instruction.readInstruction(). Not to be used otherwise.
/**
     * Empty constructor needed for the Class.newInstance() statement in
     * Instruction.readInstruction(). Not to be used otherwise.
     */
    CPInstruction() {
    }

    
Params:
index – to constant pool/**
     * @param index to constant pool
     */
    protected CPInstruction(final short opcode, final int index) {
        super(opcode, (short) 3);
        setIndex(index);
    }

    
Dump instruction as byte code to stream out.
Params:
out – Output stream/**
     * Dump instruction as byte code to stream out.
     *
     * @param out Output stream
     */
    @Override
    public void dump(final DataOutputStream out) throws IOException {
        out.writeByte(super.getOpcode());
        out.writeShort(index);
    }

    
Long output format:
<name of opcode> "["<opcode number>"]" "("<length of
instruction>")" "<"< constant pool index>">"
Params:
verbose – long/short format switch
Returns:
mnemonic for instruction/**
     * Long output format:
     *
     * &lt;name of opcode&gt; "["&lt;opcode number&gt;"]" "("&lt;length of
     * instruction&gt;")" "&lt;"&lt; constant pool index&gt;"&gt;"
     *
     * @param verbose long/short format switch
     * @return mnemonic for instruction
     */
    @Override
    public String toString(final boolean verbose) {
        return super.toString(verbose) + " " + index;
    }

    
Returns:
mnemonic for instruction with symbolic references resolved/**
     * @return mnemonic for instruction with symbolic references resolved
     */
    @Override
    public String toString(final ConstantPool cp) {
        final Constant c = cp.getConstant(index);
        String str = cp.constantToString(c);
        if (c instanceof ConstantClass) {
            str = str.replace('.', '/');
        }
        return com.sun.org.apache.bcel.internal.Const.getOpcodeName(super.getOpcode()) + " " + str;
    }

    
Read needed data (i.e., index) from file.
Params:
bytes – input stream
wide – wide prefix?/**
     * Read needed data (i.e., index) from file.
     *
     * @param bytes input stream
     * @param wide wide prefix?
     */
    @Override
    protected void initFromFile(final ByteSequence bytes, final boolean wide) throws IOException {
        setIndex(bytes.readUnsignedShort());
        super.setLength(3);
    }

    
Returns:
index in constant pool referred by this instruction./**
     * @return index in constant pool referred by this instruction.
     */
    @Override
    public final int getIndex() {
        return index;
    }

    
Set the index to constant pool.
Params:
index – in constant pool./**
     * Set the index to constant pool.
     *
     * @param index in constant pool.
     */
    @Override
    public void setIndex(final int index) { // TODO could be package-protected?
        if (index < 0) {
            throw new ClassGenException("Negative index value: " + index);
        }
        this.index = index;
    }

    
Returns:
type related with this instruction./**
     * @return type related with this instruction.
     */
    @Override
    public Type getType(final ConstantPoolGen cpg) {
        final ConstantPool cp = cpg.getConstantPool();
        String name = cp.getConstantString(index, com.sun.org.apache.bcel.internal.Const.CONSTANT_Class);
        if (!name.startsWith("[")) {
            name = "L" + name + ";";
        }
        return Type.getType(name);
    }
}