gcc-4.4.0/libjava/classpath/tools/external/asm/org/objectweb/asm/optimizer/Shrinker.java

/***
 * ASM: a very small and fast Java bytecode manipulation framework
 * Copyright (c) 2000-2005 INRIA, France Telecom
 * 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. Neither the name of the copyright holders nor the names of its
 *    contributors may be used to endorse or promote products derived from
 *    this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "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 COPYRIGHT OWNER OR CONTRIBUTORS 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.objectweb.asm.optimizer;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.util.Comparator;
import java.util.Iterator;
import java.util.Set;
import java.util.TreeSet;

import org.objectweb.asm.ClassReader;
import org.objectweb.asm.ClassWriter;

/**
 * A class file shrinker utility.
 * 
 * @author Eric Bruneton
 */
public class Shrinker {

    public static void main(final String[] args) throws IOException {
        NameMapping mapping = new NameMapping(args[0]);
        File f = new File(args[1]);
        File d = new File(args[2]);
        optimize(f, d, mapping);
        Iterator i = mapping.unused.iterator();
        while (i.hasNext()) {
            System.out.println("INFO: unused mapping " + i.next());
        }
    }

    static void optimize(final File f, final File d, final NameMapping mapping)
            throws IOException
    {
        if (f.isDirectory()) {
            File[] files = f.listFiles();
            for (int i = 0; i < files.length; ++i) {
                optimize(files[i], d, mapping);
            }
        } else if (f.getName().endsWith(".class")) {
            ConstantPool cp = new ConstantPool();
            ClassReader cr = new ClassReader(new FileInputStream(f));
            ClassWriter cw = new ClassWriter(false);
            ClassConstantsCollector ccc = new ClassConstantsCollector(cw, cp);
            ClassOptimizer co = new ClassOptimizer(ccc, mapping);
            cr.accept(co, true);

            Set constants = new TreeSet(new ConstantComparator());
            constants.addAll(cp.values());

            cr = new ClassReader(cw.toByteArray());
            cw = new ClassWriter(false);
            Iterator i = constants.iterator();
            while (i.hasNext()) {
                Constant c = (Constant) i.next();
                c.write(cw);
            }
            cr.accept(cw, true);

            String n = mapping.map(co.getClassName());
            File g = new File(d, n + ".class");
            if (!g.exists() || g.lastModified() < f.lastModified()) {
                g.getParentFile().mkdirs();
                OutputStream os = new FileOutputStream(g);
                os.write(cw.toByteArray());
                os.close();
            }
        }
    }

    static class ConstantComparator implements Comparator {

        public int compare(final Object o1, final Object o2) {
            Constant c1 = (Constant) o1;
            Constant c2 = (Constant) o2;
            int d = getSort(c1) - getSort(c2);
            if (d == 0) {
                switch (c1.type) {
                    case 'I':
                        return new Integer(c1.intVal).compareTo(new Integer(c2.intVal));
                    case 'J':
                        return new Long(c1.longVal).compareTo(new Long(c2.longVal));
                    case 'F':
                        return new Float(c1.floatVal).compareTo(new Float(c2.floatVal));
                    case 'D':
                        return new Double(c1.doubleVal).compareTo(new Double(c2.doubleVal));
                    case 's':
                    case 'S':
                    case 'C':
                        return c1.strVal1.compareTo(c2.strVal1);
                    case 'T':
                        d = c1.strVal1.compareTo(c2.strVal1);
                        if (d == 0) {
                            d = c1.strVal2.compareTo(c2.strVal2);
                        }
                        break;
                    default:
                        d = c1.strVal1.compareTo(c2.strVal1);
                        if (d == 0) {
                            d = c1.strVal2.compareTo(c2.strVal2);
                            if (d == 0) {
                                d = c1.strVal3.compareTo(c2.strVal3);
                            }
                        }
                }
            }
            return d;
        }

        private int getSort(Constant c) {
            switch (c.type) {
                case 'I':
                    return 0;
                case 'J':
                    return 1;
                case 'F':
                    return 2;
                case 'D':
                    return 3;
                case 's':
                    return 4;
                case 'S':
                    return 5;
                case 'C':
                    return 6;
                case 'T':
                    return 7;
                case 'G':
                    return 8;
                case 'M':
                    return 9;
                default:
                    return 10;
            }
        }
    }
}