dexlib/src/main/java/org/jf/dexlib/Code/Instruction.java

/*
 * [The "BSD licence"]
 * Copyright (c) 2010 Ben Gruver (JesusFreke)
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

package org.jf.dexlib.Code;

import org.jf.dexlib.Code.Format.Format;
import org.jf.dexlib.DexFile;
import org.jf.dexlib.Util.AnnotatedOutput;

public abstract class Instruction {
    public final Opcode opcode;

    /**
     * Returns the size of this instruction in code blocks, assuming the instruction is located at the given address
     * @param codeAddress the code address where the instruction is located
     * @return The size of this instruction in code blocks
     **/
    public int getSize(int codeAddress) {
        return opcode.format.size/2;
    }

    protected Instruction(Opcode opcode) {
        this.opcode = opcode;
    }

    public abstract Format getFormat();

    public int write(AnnotatedOutput out, int currentCodeAddress) {
        if (out.annotates()) {
            annotateInstruction(out, currentCodeAddress);
        }
        writeInstruction(out, currentCodeAddress);
        return currentCodeAddress + getSize(currentCodeAddress);
    }

    protected void annotateInstruction(AnnotatedOutput out, int currentCodeAddress) {
        out.annotate(getSize(currentCodeAddress)*2, "[0x" + Integer.toHexString(currentCodeAddress) + "] " +
                opcode.name + " instruction");
    }

    protected abstract void writeInstruction(AnnotatedOutput out, int currentCodeAddress);

    public static interface InstructionFactory {
        public Instruction makeInstruction(DexFile dexFile, Opcode opcode, byte[] buffer, int bufferIndex);
    }
}