~ubuntu-branches/ubuntu/wily/proguard/wily-proposed

/*

 * ProGuard -- shrinking, optimization, obfuscation, and preverification

 *             of Java bytecode.

 *

 * Copyright (c) 2002-2015 Eric Lafortune @ GuardSquare

 *

 * This program 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.

 *

 * This program 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 this program; if not, write to the Free Software Foundation, Inc.,

 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA

 */

package proguard.shrink;

import proguard.classfile.*;

import proguard.classfile.attribute.*;

import proguard.classfile.attribute.visitor.AttributeVisitor;

import proguard.classfile.util.*;

import proguard.classfile.visitor.*;

import java.io.PrintStream;

/**

 * This ClassVisitor     and MemberVisitor prints out the reasons why

 * classes and class members have been marked as being used.

 *

 * @see UsageMarker

 *

 * @author Eric Lafortune

 */

public class ShortestUsagePrinter

extends      SimplifiedVisitor

implements   ClassVisitor,

             MemberVisitor,

             AttributeVisitor

{

    private final ShortestUsageMarker shortestUsageMarker;

    private final boolean             verbose;

    private final PrintStream         ps;

    /**

     * Creates a new UsagePrinter that prints verbosely to <code>System.out</code>.

     * @param shortestUsageMarker the usage marker that was used to mark the

     *                            classes and class members.

     */

    public ShortestUsagePrinter(ShortestUsageMarker shortestUsageMarker)

    {

        this(shortestUsageMarker, true);

    }

    /**

     * Creates a new UsagePrinter that prints to the given stream.

     * @param shortestUsageMarker the usage marker that was used to mark the

     *                            classes and class members.

     * @param verbose             specifies whether the output should be verbose.

     */

    public ShortestUsagePrinter(ShortestUsageMarker shortestUsageMarker,

                                boolean             verbose)

    {

        this(shortestUsageMarker, verbose, System.out);

    }

    /**

     * Creates a new UsagePrinter that prints to the given stream.

     * @param shortestUsageMarker the usage marker that was used to mark the

     *                            classes and class members.

     * @param verbose             specifies whether the output should be verbose.

     * @param printStream         the stream to which to print.

     */

    public ShortestUsagePrinter(ShortestUsageMarker shortestUsageMarker,

                                boolean             verbose,

                                PrintStream         printStream)

    {

        this.shortestUsageMarker = shortestUsageMarker;

        this.verbose             = verbose;

        this.ps                  = printStream;

    }

    // Implementations for ClassVisitor.

    public void visitProgramClass(ProgramClass programClass)

    {

        // Print the name of this class.

        ps.println(ClassUtil.externalClassName(programClass.getName()));

        // Print the reason for keeping this class.

        printReason(programClass);

    }

    public void visitLibraryClass(LibraryClass libraryClass)

    {

        // Print the name of this class.

        ps.println(ClassUtil.externalClassName(libraryClass.getName()));

        // Print the reason for keeping this class.

        ps.println("  is a library class.\n");

    }

    // Implementations for MemberVisitor.

    public void visitProgramField(ProgramClass programClass, ProgramField programField)

    {

        // Print the name of this field.

        String name = programField.getName(programClass);

        String type = programField.getDescriptor(programClass);

        ps.println(ClassUtil.externalClassName(programClass.getName()) +

                   (verbose ?

                        ": " + ClassUtil.externalFullFieldDescription(0, name, type):

                        "."  + name));

        // Print the reason for keeping this method.

        printReason(programField);

    }

    public void visitProgramMethod(ProgramClass programClass, ProgramMethod programMethod)

    {

        // Print the name of this method.

        String name = programMethod.getName(programClass);

        String type = programMethod.getDescriptor(programClass);

        ps.print(ClassUtil.externalClassName(programClass.getName()) +

                 (verbose ?

                      ": " + ClassUtil.externalFullMethodDescription(programClass.getName(), 0, name, type):

                      "."  + name));

        programMethod.attributesAccept(programClass, this);

        ps.println();

        // Print the reason for keeping this method.

        printReason(programMethod);

    }

    public void visitLibraryField(LibraryClass libraryClass, LibraryField libraryField)

    {

        // Print the name of this field.

        String name = libraryField.getName(libraryClass);

        String type = libraryField.getDescriptor(libraryClass);

        ps.println(ClassUtil.externalClassName(libraryClass.getName()) +

                   (verbose ?

                        ": " + ClassUtil.externalFullFieldDescription(0, name, type):

                        "."  + name));

        // Print the reason for keeping this field.

        ps.println("  is a library field.\n");

    }

    public void visitLibraryMethod(LibraryClass libraryClass, LibraryMethod libraryMethod)

    {

        // Print the name of this method.

        String name = libraryMethod.getName(libraryClass);

        String type = libraryMethod.getDescriptor(libraryClass);

        ps.println(ClassUtil.externalClassName(libraryClass.getName()) +

                   (verbose ?

                        ": " + ClassUtil.externalFullMethodDescription(libraryClass.getName(), 0, name, type):

                        "."  + name));

        // Print the reason for keeping this method.

        ps.println("  is a library method.\n");

    }

    // Implementations for AttributeVisitor.

    public void visitAnyAttribute(Clazz clazz, Attribute attribute) {}

    public void visitCodeAttribute(Clazz clazz, Method method, CodeAttribute codeAttribute)

    {

        codeAttribute.attributesAccept(clazz, method, this);

    }

    public void visitLineNumberTableAttribute(Clazz clazz, Method method, CodeAttribute codeAttribute, LineNumberTableAttribute lineNumberTableAttribute)

    {

        ps.print(" (" +

                 lineNumberTableAttribute.getLowestLineNumber() + ":" +

                 lineNumberTableAttribute.getHighestLineNumber() + ")");

    }

    // Small utility methods.

    private void printReason(VisitorAccepter visitorAccepter)

    {

        if (shortestUsageMarker.isUsed(visitorAccepter))

        {

            ShortestUsageMark shortestUsageMark = shortestUsageMarker.getShortestUsageMark(visitorAccepter);

            // Print the reason for keeping this class.

            ps.print("  " + shortestUsageMark.getReason());

            // Print the class or method that is responsible, with its reasons.

            shortestUsageMark.acceptClassVisitor(this);

            shortestUsageMark.acceptMemberVisitor(this);

        }

        else

        {

            ps.println("  is not being kept.\n");

        }

    }

}