001/*
002 * Forge Mod Loader
003 * Copyright (c) 2012-2013 cpw.
004 * All rights reserved. This program and the accompanying materials
005 * are made available under the terms of the GNU Lesser Public License v2.1
006 * which accompanies this distribution, and is available at
007 * http://www.gnu.org/licenses/old-licenses/gpl-2.0.html
008 * 
009 * Contributors:
010 *     cpw - implementation
011 */
012
013package cpw.mods.fml.common.discovery.asm;
014
015import java.util.LinkedList;
016
017import org.objectweb.asm.Label;
018import org.objectweb.asm.MethodVisitor;
019import org.objectweb.asm.Opcodes;
020
021import com.google.common.collect.Lists;
022
023public class ModMethodVisitor extends MethodVisitor
024{
025
026    private ASMModParser discoverer;
027    private boolean inCode;
028    private LinkedList<Label> labels = Lists.newLinkedList();
029    private String foundProperties;
030    private boolean validProperties;
031
032    public ModMethodVisitor(String name, ASMModParser discoverer)
033    {
034        super(Opcodes.ASM4);
035        this.discoverer = discoverer;
036    }
037    @Override
038    public void visitCode()
039    {
040        labels.clear();
041    }
042    
043    @Override
044    public void visitLdcInsn(Object cst)
045    {
046        if (cst instanceof String && labels.size() == 1)
047        {
048            foundProperties = (String) cst;
049        }
050    }
051    @Override
052    public void visitInsn(int opcode)
053    {
054        if (Opcodes.ARETURN == opcode && labels.size() == 1 && foundProperties != null)
055        {
056            validProperties = true;
057        }
058    }
059    @Override
060    public void visitLabel(Label label)
061    {
062        labels.push(label);
063    }
064    
065    @Override
066    public void visitEnd()
067    {
068        if (validProperties)
069        {
070            discoverer.setBaseModProperties(foundProperties);
071        }
072    }
073}