1 /* 2 * ProGuard -- shrinking, optimization, obfuscation, and preverification 3 * of Java bytecode. 4 * 5 * Copyright (c) 2002-2009 Eric Lafortune (eric (at) 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.classfile.util; 22 23 import proguard.classfile.ClassConstants; 24 25 26 /** 27 * Utility methods for working with access flags. For convenience, this class 28 * defines access levels, in ascending order: <code>PRIVATE</code>, 29 * <code>PACKAGE_VISIBLE</code>, <code>PROTECTED</code>, and <code>PUBLIC</code>. 30 * 31 * @author Eric Lafortune 32 */ 33 public class AccessUtil 34 { 35 public static final int PRIVATE = 0; 36 public static final int PACKAGE_VISIBLE = 1; 37 public static final int PROTECTED = 2; 38 public static final int PUBLIC = 3; 39 40 41 // The mask of access flags. 42 private static final int ACCESS_MASK = 43 ClassConstants.INTERNAL_ACC_PUBLIC | 44 ClassConstants.INTERNAL_ACC_PRIVATE | 45 ClassConstants.INTERNAL_ACC_PROTECTED; 46 47 48 /** 49 * Returns the corresponding access level of the given access flags. 50 * @param accessFlags the internal access flags. 51 * @return the corresponding access level: <code>PRIVATE</code>, 52 * <code>PACKAGE_VISIBLE</code>, <code>PROTECTED</code>, or 53 * <code>PUBLIC</code>. 54 */ 55 public static int accessLevel(int accessFlags) 56 { 57 switch (accessFlags & ACCESS_MASK) 58 { 59 case ClassConstants.INTERNAL_ACC_PRIVATE: return PRIVATE; 60 default: return PACKAGE_VISIBLE; 61 case ClassConstants.INTERNAL_ACC_PROTECTED: return PROTECTED; 62 case ClassConstants.INTERNAL_ACC_PUBLIC: return PUBLIC; 63 } 64 } 65 66 67 /** 68 * Returns the corresponding access flags of the given access level. 69 * @param accessLevel the access level: <code>PRIVATE</code>, 70 * <code>PACKAGE_VISIBLE</code>, <code>PROTECTED</code>, 71 * or <code>PUBLIC</code>. 72 * @return the corresponding internal access flags, the internal access 73 * flags as a logical bit mask of <code>INTERNAL_ACC_PRIVATE</code>, 74 * <code>INTERNAL_ACC_PROTECTED</code>, and 75 * <code>INTERNAL_ACC_PUBLIC</code>. 76 */ 77 public static int accessFlags(int accessLevel) 78 { 79 switch (accessLevel) 80 { 81 case PRIVATE: return ClassConstants.INTERNAL_ACC_PRIVATE; 82 default: return 0; 83 case PROTECTED: return ClassConstants.INTERNAL_ACC_PROTECTED; 84 case PUBLIC: return ClassConstants.INTERNAL_ACC_PUBLIC; 85 } 86 } 87 88 89 /** 90 * Replaces the access part of the given access flags. 91 * @param accessFlags the internal access flags. 92 * @param accessFlags the new internal access flags. 93 */ 94 public static int replaceAccessFlags(int accessFlags, int newAccessFlags) 95 { 96 // A private class member should not be explicitly final. 97 if (newAccessFlags == ClassConstants.INTERNAL_ACC_PRIVATE) 98 { 99 accessFlags &= ~ClassConstants.INTERNAL_ACC_FINAL; 100 } 101 102 return (accessFlags & ~ACCESS_MASK) | 103 (newAccessFlags & ACCESS_MASK); 104 } 105 } 106
