org.brutusin.instrumentation.utils.Helper.java Source code

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Here is the source code for org.brutusin.instrumentation.utils.Helper.java

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/*
 * Copyright 2014 brutusin.org
 *
 * 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.brutusin.instrumentation.utils;

import java.io.PrintWriter;
import java.io.StringWriter;
import java.util.List;
import org.objectweb.asm.ClassReader;
import org.objectweb.asm.Opcodes;
import org.objectweb.asm.Type;
import org.objectweb.asm.tree.ClassNode;
import org.objectweb.asm.tree.InsnList;
import org.objectweb.asm.tree.MethodNode;
import org.objectweb.asm.util.Printer;
import org.objectweb.asm.util.Textifier;
import org.objectweb.asm.util.TraceMethodVisitor;

public class Helper {

    public static Object getSource(Class declaringClass, String name, Class... paramTypes) {

        if (name.equals("<init>")) {
            try {
                return declaringClass.getConstructor(paramTypes);
            } catch (Exception e) {
                // Anonymous classes
                return "init()";
            }
        }
        if (name.equals("<clinit>")) {
            return "clinit()";
        }
        try {
            return declaringClass.getDeclaredMethod(name, paramTypes);
        } catch (Exception e) {
            return name;
        }
    }

    public static int getArgumentPosition(int offset, Type[] arguments, int argNo) {
        int ret = argNo + offset;
        for (int i = 0; i < arguments.length && i < argNo; i++) {
            char charType = arguments[i].getDescriptor().charAt(0);
            if (charType == 'J' || charType == 'D') {
                ret++;
            }
        }
        return ret;
    }

    public static boolean isAbstract(MethodNode m) {
        return (m.access & Opcodes.ACC_ABSTRACT) != 0;
    }

    public static boolean isStatic(MethodNode m) {
        return (m.access & Opcodes.ACC_STATIC) != 0;
    }

    public static boolean isPublic(MethodNode m) {
        return (m.access & Opcodes.ACC_PUBLIC) != 0;
    }

    public static void viewByteCode(byte[] bytecode) {
        ClassReader cr = new ClassReader(bytecode);
        ClassNode cn = new ClassNode();
        cr.accept(cn, 0);
        final List<MethodNode> mns = cn.methods;
        Printer printer = new Textifier();
        TraceMethodVisitor mp = new TraceMethodVisitor(printer);
        for (MethodNode mn : mns) {
            InsnList inList = mn.instructions;
            System.out.println(mn.name);
            for (int i = 0; i < inList.size(); i++) {
                inList.get(i).accept(mp);
                StringWriter sw = new StringWriter();
                printer.print(new PrintWriter(sw));
                printer.getText().clear();
                System.out.print(sw.toString());
            }
        }
    }
}