de.enough.polish.postcompile.java5.CloneMethodVisitor.java Source code

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Here is the source code for de.enough.polish.postcompile.java5.CloneMethodVisitor.java

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/*
 * Created on Aug 16, 2006 at 12:51:15 PM.
 * 
 * Copyright (c) 2007 Michael Koch / Enough Software
 *
 * This file is part of J2ME Polish.
 *
 * J2ME Polish is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 * 
 * J2ME Polish is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with J2ME Polish; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 * 
 * Commercial licenses are also available, please
 * refer to the accompanying LICENSE.txt or visit
 * http://www.j2mepolish.org for details.
 */
package de.enough.polish.postcompile.java5;

import org.objectweb.asm.MethodVisitor;
import org.objectweb.asm.Opcodes;
import org.objectweb.asm.Type;
import org.objectweb.asm.commons.GeneratorAdapter;
import org.objectweb.asm.commons.Method;

public class CloneMethodVisitor extends GeneratorAdapter implements Opcodes {
    private static final Type TYPE_SYSTEM = Type.getType("Ljava/lang/System;");

    private static final Method METHOD_ARRAYCOPY = Method
            .getMethod("void arraycopy(java.lang.Object, int, java.lang.Object, int, int)");

    private static final Method METHOD_CLONE = Method.getMethod("java.lang.Object clone()");

    private Type enumArrayDesc;

    public CloneMethodVisitor(MethodVisitor mv, int access, String name, String desc, Type enumType) {
        super(mv, access, name, desc);

        this.enumArrayDesc = Type.getType("[" + enumType.toString());
    }

    public void visitMethodInsn(int opcode, String owner, String name, String desc) {
        Method method = new Method(name, desc);

        // Rewrite TYPE[].clone() calles.
        if (INVOKEVIRTUAL == opcode && this.enumArrayDesc.getDescriptor().equals(owner)
                && METHOD_CLONE.equals(method)) {
            dup();
            arrayLength();
            dup();
            newArray(Type.INT_TYPE);
            dupX2();
            swap();
            push(0);
            dupX2();
            swap();
            invokeStatic(TYPE_SYSTEM, METHOD_ARRAYCOPY);
            return;
        }

        super.visitMethodInsn(opcode, owner, name, desc);
    }

    /* (non-Javadoc)
     * @see org.objectweb.asm.MethodAdapter#visitTypeInsn(int, java.lang.String)
     */
    public void visitTypeInsn(int opcode, String type) {
        // JDK 6u10 and up use already System.arraycopy() instead of clone()
        // inside the values() method of an enum type but need to be fixed.
        if (ANEWARRAY == opcode) {
            visitIntInsn(NEWARRAY, T_INT);
            return;
        }

        super.visitTypeInsn(opcode, type);
    }
}