/* * Copyright 2004-2010 Brian S O'Neill * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package org.cojen.classfile; import java.lang.reflect.Modifier; /** * The Modifiers class is an immutable wrapper around a modifier bitmask. The * methods provided to manipulate the bitmask ensure that it is always * legal. i.e. setting it public automatically clears it from being private or * protected. * * @author Brian S O'Neill */ public class Modifiers { public static final Modifiers NONE; public static final Modifiers PUBLIC; public static final Modifiers PUBLIC_ABSTRACT; public static final Modifiers PUBLIC_STATIC; public static final Modifiers PROTECTED; public static final Modifiers PRIVATE; static { NONE = new Modifiers(0); PUBLIC = new Modifiers(Modifier.PUBLIC); PUBLIC_ABSTRACT = new Modifiers(Modifier.PUBLIC | Modifier.ABSTRACT); PUBLIC_STATIC = new Modifiers(Modifier.PUBLIC | Modifier.STATIC); PROTECTED = new Modifiers(Modifier.PROTECTED); PRIVATE = new Modifiers(Modifier.PRIVATE); } /** * Returns a Modifiers object with the given bitmask. */ public static Modifiers getInstance(int bitmask) { switch (bitmask) { case 0: return NONE; case Modifier.PUBLIC: return PUBLIC; case Modifier.PUBLIC | Modifier.ABSTRACT: return PUBLIC_ABSTRACT; case Modifier.PUBLIC | Modifier.STATIC: return PUBLIC_STATIC; case Modifier.PROTECTED: return PROTECTED; case Modifier.PRIVATE: return PRIVATE; } return new Modifiers(bitmask); } private static int toPublic(int bitmask, boolean b) { if (b) { return (bitmask | Modifier.PUBLIC) & (~Modifier.PROTECTED & ~Modifier.PRIVATE); } else { return bitmask & ~Modifier.PUBLIC; } } private static int toPrivate(int bitmask, boolean b) { if (b) { return (bitmask | Modifier.PRIVATE) & (~Modifier.PUBLIC & ~Modifier.PROTECTED); } else { return bitmask & ~Modifier.PRIVATE; } } private static int toProtected(int bitmask, boolean b) { if (b) { return (bitmask | Modifier.PROTECTED) & (~Modifier.PUBLIC & ~Modifier.PRIVATE); } else { return bitmask & ~Modifier.PROTECTED; } } private static int toStatic(int bitmask, boolean b) { if (b) { return bitmask | Modifier.STATIC; } else { return bitmask & ~Modifier.STATIC; } } private static int toFinal(int bitmask, boolean b) { if (b) { return (bitmask | Modifier.FINAL) & (~Modifier.INTERFACE & ~Modifier.ABSTRACT); } else { return bitmask & ~Modifier.FINAL; } } private static int toSynchronized(int bitmask, boolean b) { if (b) { return (bitmask | Modifier.SYNCHRONIZED) & (~Modifier.VOLATILE & ~Modifier.TRANSIENT & ~Modifier.INTERFACE); } else { return bitmask & ~Modifier.SYNCHRONIZED; } } private static int toVolatile(int bitmask, boolean b) { if (b) { return (bitmask | Modifier.VOLATILE) & (~Modifier.SYNCHRONIZED & ~Modifier.NATIVE & ~Modifier.INTERFACE & ~Modifier.ABSTRACT & ~Modifier.STRICT); } else { return bitmask & ~Modifier.VOLATILE; } } private static int toTransient(int bitmask, boolean b) { if (b) { return (bitmask | Modifier.TRANSIENT) & (~Modifier.SYNCHRONIZED & ~Modifier.NATIVE & ~Modifier.INTERFACE & ~Modifier.ABSTRACT & ~Modifier.STRICT); } else { return bitmask & ~Modifier.TRANSIENT; } } private static int toNative(int bitmask, boolean b) { if (b) { return (bitmask | Modifier.NATIVE) & (~Modifier.VOLATILE & ~Modifier.TRANSIENT & ~Modifier.INTERFACE & ~Modifier.ABSTRACT & ~Modifier.STRICT); } else { return bitmask & ~Modifier.NATIVE; } } private static int toInterface(int bitmask, boolean b) { if (b) { return (bitmask | (Modifier.INTERFACE | Modifier.ABSTRACT)) & (~Modifier.FINAL & ~Modifier.SYNCHRONIZED & ~Modifier.VOLATILE & ~Modifier.TRANSIENT & ~Modifier.NATIVE); } else { return bitmask & ~Modifier.INTERFACE; } } private static int toAbstract(int bitmask, boolean b) { if (b) { return (bitmask | Modifier.ABSTRACT) & (~Modifier.FINAL & ~Modifier.VOLATILE & ~Modifier.TRANSIENT & ~Modifier.NATIVE & ~Modifier.SYNCHRONIZED & ~Modifier.STRICT); } else { return bitmask & ~Modifier.ABSTRACT & ~Modifier.INTERFACE; } } private static int toStrict(int bitmask, boolean b) { if (b) { return bitmask | Modifier.STRICT; } else { return bitmask & ~Modifier.STRICT; } } private static int toBridge(int bitmask, boolean b) { // Bridge re-uses the Modifier.VOLATILE modifier, which used to only // apply to fields. if (b) { return (bitmask | Modifier.VOLATILE) & (~Modifier.NATIVE & ~Modifier.INTERFACE & ~Modifier.ABSTRACT); } else { return bitmask & ~Modifier.VOLATILE; } } private static int toEnum(int bitmask, boolean b) { // Enum re-uses the Modifier.NATIVE modifier, which used to only apply // to methods. if (b) { return (bitmask | Modifier.NATIVE) & (~Modifier.ABSTRACT & ~Modifier.INTERFACE & ~Modifier.STRICT & ~Modifier.SYNCHRONIZED); } else { return bitmask & ~Modifier.NATIVE; } } private static int toVarArgs(int bitmask, boolean b) { // Enum re-uses the Modifier.TRANSIENT modifier, which used to only // apply to fields. if (b) { return (bitmask | Modifier.TRANSIENT) & (~Modifier.INTERFACE & ~Modifier.VOLATILE); } else { return bitmask & ~Modifier.TRANSIENT; } } private final int mBitmask; private Modifiers(int bitmask) { mBitmask = bitmask; } /** * Returns the bitmask. */ public final int getBitmask() { return mBitmask; } public boolean isPublic() { return Modifier.isPublic(mBitmask); } public boolean isPrivate() { return Modifier.isPrivate(mBitmask); } public boolean isProtected() { return Modifier.isProtected(mBitmask); } public boolean isStatic() { return Modifier.isStatic(mBitmask); } public boolean isFinal() { return Modifier.isFinal(mBitmask); } public boolean isSynchronized() { return Modifier.isSynchronized(mBitmask); } public boolean isVolatile() { return Modifier.isVolatile(mBitmask); } public boolean isTransient() { return Modifier.isTransient(mBitmask); } public boolean isNative() { return Modifier.isNative(mBitmask); } public boolean isInterface() { return Modifier.isInterface(mBitmask); } public boolean isAbstract() { return Modifier.isAbstract(mBitmask); } public boolean isStrict() { return Modifier.isStrict(mBitmask); } public boolean isBridge() { return Modifier.isVolatile(mBitmask); } public boolean isEnum() { return Modifier.isNative(mBitmask); } public boolean isVarArgs() { return Modifier.isTransient(mBitmask); } /** * When set public, the bitmask is cleared from being private or protected. * * @param b true to set public, false otherwise */ public Modifiers toPublic(boolean b) { return convert(toPublic(mBitmask, b)); } /** * When set private, the bitmask is cleared from being public or protected. * * @param b true to set private, false otherwise */ public Modifiers toPrivate(boolean b) { return convert(toPrivate(mBitmask, b)); } /** * When set protected, the bitmask is cleared from being public or private. * * @param b true to set protected, false otherwise */ public Modifiers toProtected(boolean b) { return convert(toProtected(mBitmask, b)); } /** * @param b true to set static, false otherwise */ public Modifiers toStatic(boolean b) { return convert(toStatic(mBitmask, b)); } /** * When set final, the bitmask is cleared from being an interface or * abstract. * * @param b true to set final, false otherwise */ public Modifiers toFinal(boolean b) { return convert(toFinal(mBitmask, b)); } /** * When set synchronized, non-method settings are cleared. * * @param b true to set synchronized, false otherwise */ public Modifiers toSynchronized(boolean b) { return convert(toSynchronized(mBitmask, b)); } /** * When set volatile, non-field settings are cleared. * * @param b true to set volatile, false otherwise */ public Modifiers toVolatile(boolean b) { return convert(toVolatile(mBitmask, b)); } /** * When set transient, non-field settings are cleared. * * @param b true to set transient, false otherwise */ public Modifiers toTransient(boolean b) { return convert(toTransient(mBitmask, b)); } /** * When set native, non-native-method settings are cleared. * * @param b true to set native, false otherwise */ public Modifiers toNative(boolean b) { return convert(toNative(mBitmask, b)); } /** * When set as an interface, non-interface settings are cleared and the * bitmask is set abstract. * * @param b true to set interface, false otherwise */ public Modifiers toInterface(boolean b) { return convert(toInterface(mBitmask, b)); } /** * When set abstract, the bitmask is cleared from being final, volatile, * transient, native, synchronized, and strictfp. When cleared from being * abstract, the bitmask is also cleared from being an interface. * * @param b true to set abstract, false otherwise */ public Modifiers toAbstract(boolean b) { return convert(toAbstract(mBitmask, b)); } /** * @param b true to set strictfp, false otherwise */ public Modifiers toStrict(boolean b) { return convert(toStrict(mBitmask, b)); } /** * Used to identify if a method is a bridge method. * * @param b true to set bridge, false otherwise */ public Modifiers toBridge(boolean b) { return convert(toBridge(mBitmask, b)); } /** * Used to identify if a field is an enum constant. * * @param b true to set enum, false otherwise */ public Modifiers toEnum(boolean b) { return convert(toEnum(mBitmask, b)); } /** * Used to identify if a method accepts a variable amount of * arguments. * * @param b true to set varargs, false otherwise */ public Modifiers toVarArgs(boolean b) { return convert(toVarArgs(mBitmask, b)); } public int hashCode() { return mBitmask; } public boolean equals(Object obj) { if (this == obj) { return true; } if (obj instanceof Modifiers) { Modifiers other = (Modifiers)obj; return mBitmask == other.mBitmask; } return false; } /** * Returns the string value generated by the Modifier class. * * @see java.lang.reflect.Modifier#toString() */ public String toString() { return Modifier.toString(mBitmask); } private Modifiers convert(int bitmask) { return bitmask == mBitmask ? this : getInstance(bitmask); } }