Asm.java Source code

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Here is the source code for Asm.java

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/*
 * Copyright (C) 2014 The Android Open Source Project
 *
 * 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.
 */

import org.objectweb.asm.*;
import org.objectweb.asm.tree.*;
import java.io.*;
import java.util.*;

public class Asm {
    /*
        
    Overall class access flags:
        
        0x0001 |  // public
        0x0010 |  // final
        0x0020 |  // super
        0x0200 |  // interface
        0x0400 |  // abstract
        0x1000 |  // synthetic
        0x2000 |  // annotation
        0x4000 ;  // enum
        
    */

    public final static int INTERFACE_DEFINED_BITS = 0x0001 | // public, may be set.
            0x0010 | // final, must not be set.
            0x0020 | // super, must not be set.
            0x0200 | // interface, must be set.
            0x0400 | // abstract, must be set.
            0x1000 | // synthetic, may be set.
            0x2000 | // annotation, may be set (annotation implies interface)
            0x4000; // enum, must not be set.

    public final static int CLASS_DEFINED_BITS = 0x0001 | // public, may be set.
            0x0010 | // final, may be set.
            0x0020 | // super, may be set.
            0x0200 | // interface, must not be set.
            0x0400 | // abstract, may be set.
            0x1000 | // synthetic, may be set.
            0x2000 | // annotation, must not be set.
            0x4000; // enum, may be set.

    public final static int FIELD_DEFINED_BITS = 0x0001 | // public
            0x0002 | // private
            0x0004 | // protected
            0x0008 | // static
            0x0010 | // final
            0x0040 | // volatile
            0x0080 | // transient
            0x1000 | // synthetic
            0x4000; // enum

    public final static int METHOD_DEFINED_BITS = 0x0001 | // public
            0x0002 | // private
            0x0004 | // protected
            0x0008 | // static
            0x0010 | // final
            0x0020 | // synchronized
            0x0040 | // bridge
            0x0080 | // varargs
            0x0100 | // native
            0x0400 | // abstract
            0x0800 | // strictfp
            0x1000; // synthetic

    public static void main(String args[]) throws Exception {
        modify("Inf");
        modify("NonInf");
    }

    private static void modify(String clazz) throws Exception {
        ClassNode classNode = new ClassNode();
        ClassReader cr = new ClassReader(clazz);
        cr.accept(classNode, 0);

        modify(classNode);

        ClassWriter cw = new ClassWriter(0);
        classNode.accept(cw);
        byte[] b = cw.toByteArray();
        OutputStream out = new FileOutputStream(clazz + ".out");
        out.write(b, 0, b.length);
        out.close();
    }

    private static void modify(ClassNode classNode) throws Exception {
        int classFlagsOr = 0xFFFF;
        // Check whether classNode is an interface or class.
        if ((classNode.access & Opcodes.ACC_INTERFACE) == 0) {
            classFlagsOr ^= CLASS_DEFINED_BITS;
        } else {
            classFlagsOr ^= INTERFACE_DEFINED_BITS;
        }
        classNode.access |= classFlagsOr;

        // Fields.
        int fieldFlagsOr = 0xFFFF ^ FIELD_DEFINED_BITS;
        for (FieldNode fieldNode : (List<FieldNode>) classNode.fields) {
            fieldNode.access |= fieldFlagsOr;
        }

        // Methods.
        int methodFlagsOr = 0xFFFF ^ METHOD_DEFINED_BITS;
        for (MethodNode methodNode : (List<MethodNode>) classNode.methods) {
            methodNode.access |= methodFlagsOr;
        }
    }
}