jaspex.transactifier.ChangeObjectMethodsMethodVisitor.java Source code

Introduction

Here is the source code for jaspex.transactifier.ChangeObjectMethodsMethodVisitor.java

Source

/*
 * jaspex-mls: a Java Software Speculative Parallelization Framework
 * Copyright (C) 2015 Ivo Anjo <ivo.anjo@ist.utl.pt>
 *
 * This file is part of jaspex-mls.
 *
 * jaspex-mls 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 3 of the License, or
 * (at your option) any later version.
 *
 * jaspex-mls 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 jaspex-mls.  If not, see <http://www.gnu.org/licenses/>.
 */

package jaspex.transactifier;

import java.io.IOException;

import asmlib.InfoClass;
import asmlib.Type;

import org.objectweb.asm.*;
import org.objectweb.asm.commons.AnalyzerAdapter;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import static org.objectweb.asm.Opcodes.INVOKEVIRTUAL;

/** MethodVisitor que substitui chamadas a Object.toString() e Object.hashCode() pela classe mais
  * especfica, se a conseguir determinar.
  *
  * Quando uma classe no redefine o hashCode() e o toString(), por alguma razo tanto o javac como
  * o ecj emitem cdigo para chamar Object.toString()/hashCode(), em vez de ser
  * ClasseActual.toString()/hashCode(). Isto faz com que mesmo ao adicionarmos um toString/hashCode
  * transaccional  classe, o cdigo antigo continue a incluir um nonTransactionalActionAttempted,
  * em vez de uma chamada  verso transaccional dos mtodos.
  *
  * O objectivo deste MethodVisitor  simplesmente usar o AnalyzerAdapter para determinar o tipo
  * actualmente no topo da stack quando se corre uma destas operaes, e substituir Object por esse
  * tipo.
  **/
public class ChangeObjectMethodsMethodVisitor extends MethodVisitor {

    @SuppressWarnings("unused")
    private static final Logger Log = LoggerFactory.getLogger(ChangeObjectMethodsMethodVisitor.class);

    private final AnalyzerAdapter _analyzerAdapter;
    private final InfoClass _currentClass;

    public ChangeObjectMethodsMethodVisitor(int access, String name, String desc, String signature,
            String[] exceptions, ClassVisitor cv, InfoClass currentClass) {
        super(Opcodes.ASM4, new AnalyzerAdapter(currentClass.type().asmName(), access, name, desc,
                cv.visitMethod(access, name, desc, signature, exceptions)));
        _analyzerAdapter = (AnalyzerAdapter) mv;
        _currentClass = currentClass;
    }

    @Override
    public void visitMethodInsn(int opcode, String owner, String name, String desc) {
        String fullName = owner + '.' + name + desc;
        if ((opcode == INVOKEVIRTUAL) && (fullName.equals("java/lang/Object.toString()Ljava/lang/String;")
                || fullName.equals("java/lang/Object.hashCode()I"))) {
            Type realOwner = Type.fromAsm((String) _analyzerAdapter.stack.get(_analyzerAdapter.stack.size() - 1));
            try {
                // S fazer alterao se o alvo for uma classe, e no uma interface!
                if (realOwner.equals(_currentClass.type()) || !InfoClass.fromType(realOwner).isInterface()) {
                    owner = realOwner.asmName();
                }
            } catch (IOException e) {
                throw new Error(e);
            }
        }
        mv.visitMethodInsn(opcode, owner, name, desc);
    }

}