| /* |
| * ProGuard -- shrinking, optimization, obfuscation, and preverification |
| * of Java bytecode. |
| * |
| * Copyright (c) 2002-2013 Eric Lafortune (eric@graphics.cornell.edu) |
| * |
| * 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.optimize; |
| |
| import proguard.classfile.*; |
| import proguard.classfile.util.MethodLinker; |
| import proguard.classfile.visitor.*; |
| import proguard.optimize.info.NoSideEffectMethodMarker; |
| |
| |
| /** |
| * This <code>ClassVisitor</code> and <code>MemberVisitor</code> |
| * marks classes and class members it visits. The marked elements |
| * will remain unchanged as necessary in the optimization step. |
| * |
| * @see NoSideEffectMethodMarker |
| * @author Eric Lafortune |
| */ |
| public class KeepMarker |
| implements ClassVisitor, |
| MemberVisitor |
| { |
| // A visitor info flag to indicate the visitor accepter is being kept. |
| private static final Object KEPT = new Object(); |
| |
| |
| // Implementations for ClassVisitor. |
| |
| public void visitProgramClass(ProgramClass programClass) |
| { |
| markAsKept(programClass); |
| } |
| |
| |
| public void visitLibraryClass(LibraryClass libraryClass) |
| { |
| markAsKept(libraryClass); |
| } |
| |
| |
| // Implementations for MemberVisitor. |
| |
| public void visitProgramField(ProgramClass programClass, ProgramField programField) |
| { |
| markAsKept(programField); |
| } |
| |
| |
| public void visitProgramMethod(ProgramClass programClass, ProgramMethod programMethod) |
| { |
| markAsKept(MethodLinker.lastMember(programMethod)); |
| } |
| |
| |
| public void visitLibraryField(LibraryClass libraryClass, LibraryField libraryField) |
| { |
| markAsKept(libraryField); |
| } |
| |
| |
| public void visitLibraryMethod(LibraryClass libraryClass, LibraryMethod libraryMethod) |
| { |
| markAsKept(MethodLinker.lastMember(libraryMethod)); |
| } |
| |
| |
| // Small utility methods. |
| |
| private static void markAsKept(VisitorAccepter visitorAccepter) |
| { |
| visitorAccepter.setVisitorInfo(KEPT); |
| } |
| |
| |
| public static boolean isKept(VisitorAccepter visitorAccepter) |
| { |
| // We're also checking for the constant in NoSideEffectMethodMarker, |
| // to keep things simple. |
| Object visitorInfo = |
| MethodLinker.lastVisitorAccepter(visitorAccepter).getVisitorInfo(); |
| |
| return visitorInfo == KEPT || |
| visitorInfo == NoSideEffectMethodMarker.KEPT_BUT_NO_SIDE_EFFECTS; |
| } |
| } |