1 /* 2 * ProGuard -- shrinking, optimization, obfuscation, and preverification 3 * of Java bytecode. 4 * 5 * Copyright (c) 2002-2014 Eric Lafortune (eric@graphics.cornell.edu) 6 * 7 * This program is free software; you can redistribute it and/or modify it 8 * under the terms of the GNU General Public License as published by the Free 9 * Software Foundation; either version 2 of the License, or (at your option) 10 * any later version. 11 * 12 * This program is distributed in the hope that it will be useful, but WITHOUT 13 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 14 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for 15 * more details. 16 * 17 * You should have received a copy of the GNU General Public License along 18 * with this program; if not, write to the Free Software Foundation, Inc., 19 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 20 */ 21 package proguard.optimize.info; 22 23 import proguard.classfile.*; 24 import proguard.classfile.util.*; 25 import proguard.classfile.visitor.MemberVisitor; 26 27 /** 28 * This MemberVisitor marks all methods that it visits as not having any side 29 * effects. It will make the SideEffectMethodMarker consider them as such 30 * without further analysis. 31 * 32 * @see SideEffectMethodMarker 33 * @author Eric Lafortune 34 */ 35 public class NoSideEffectMethodMarker 36 extends SimplifiedVisitor 37 implements MemberVisitor 38 { 39 // A visitor info flag to indicate the visitor accepter is being kept, 40 // but that it doesn't have any side effects. 41 public static final Object KEPT_BUT_NO_SIDE_EFFECTS = new Object(); 42 43 44 // Implementations for MemberVisitor. 45 visitAnyMember(Clazz Clazz, Member member)46 public void visitAnyMember(Clazz Clazz, Member member) 47 { 48 // Ignore any attempts to mark fields. 49 } 50 51 visitProgramMethod(ProgramClass programClass, ProgramMethod programMethod)52 public void visitProgramMethod(ProgramClass programClass, ProgramMethod programMethod) 53 { 54 markNoSideEffects(programMethod); 55 } 56 57 visitLibraryMethod(LibraryClass libraryClass, LibraryMethod libraryMethod)58 public void visitLibraryMethod(LibraryClass libraryClass, LibraryMethod libraryMethod) 59 { 60 markNoSideEffects(libraryMethod); 61 } 62 63 64 // Small utility methods. 65 markNoSideEffects(Method method)66 private static void markNoSideEffects(Method method) 67 { 68 MethodOptimizationInfo info = MethodOptimizationInfo.getMethodOptimizationInfo(method); 69 if (info != null) 70 { 71 info.setNoSideEffects(); 72 } 73 else 74 { 75 MethodLinker.lastMember(method).setVisitorInfo(KEPT_BUT_NO_SIDE_EFFECTS); 76 } 77 } 78 79 hasNoSideEffects(Method method)80 public static boolean hasNoSideEffects(Method method) 81 { 82 if (MethodLinker.lastVisitorAccepter(method).getVisitorInfo() == KEPT_BUT_NO_SIDE_EFFECTS) 83 { 84 return true; 85 } 86 87 MethodOptimizationInfo info = MethodOptimizationInfo.getMethodOptimizationInfo(method); 88 return info != null && 89 info.hasNoSideEffects(); 90 } 91 } 92