rubah.tools.MethodTracer.java Source code

Introduction

Here is the source code for rubah.tools.MethodTracer.java

Source

/*******************************************************************************
 *     Copyright 2014,
 *        Luis Pina <luis@luispina.me>,
 *        Michael Hicks <mwh@cs.umd.edu>
 *     
 *     This file is part of Rubah.
 *
 *     Rubah is free software: you can redistribute it and/or modify
 *     it under the terms of the GNU General Public License as published by
 *     the Free Software Foundation, either version 3 of the License, or
 *     (at your option) any later version.
 *
 *     Rubah is distributed in the hope that it will be useful,
 *     but WITHOUT ANY WARRANTY; without even the implied warranty of
 *     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *     GNU General Public License for more details.
 *
 *     You should have received a copy of the GNU General Public License
 *     along with Rubah.  If not, see <http://www.gnu.org/licenses/>.
 *******************************************************************************/
package rubah.tools;

import java.io.IOException;
import java.io.InputStream;
import java.lang.reflect.Modifier;

import org.objectweb.asm.ClassReader;
import org.objectweb.asm.ClassVisitor;
import org.objectweb.asm.ClassWriter;
import org.objectweb.asm.Label;
import org.objectweb.asm.MethodVisitor;
import org.objectweb.asm.Opcodes;
import org.objectweb.asm.commons.AdviceAdapter;

public class MethodTracer extends ReadWriteTool implements Opcodes {
    public static final String TOOL_NAME = "tracer";
    private String className;
    private String methodName;

    @Override
    protected void foundClassFile(String name, InputStream inputStream) throws IOException {
        ClassReader reader = new ClassReader(inputStream);
        ClassWriter writer = new ClassWriter(ClassWriter.COMPUTE_MAXS);
        ClassVisitor visitor = writer;

        visitor = new MethodTracerClassVisitor(writer);

        reader.accept(visitor, ClassReader.EXPAND_FRAMES);
        this.addFileToOutJar(name, writer.toByteArray());
    }

    private class MethodTracerClassVisitor extends ClassVisitor {

        public MethodTracerClassVisitor(ClassVisitor cv) {
            super(ASM5, cv);
        }

        @Override
        public void visit(int version, int access, String name, String signature, String superName,
                String[] interfaces) {
            MethodTracer.this.className = name;
            super.visit(version, access, name, signature, superName, interfaces);
        }

        @Override
        public MethodVisitor visitMethod(int access, String name, String desc, String signature,
                String[] exceptions) {
            MethodTracer.this.methodName = name + desc;
            MethodVisitor ret = super.visitMethod(access, name, desc, signature, exceptions);

            if (Modifier.isAbstract(access)) {
                return ret;
            }

            return new MethodTracerMethodVisitor(access, name, desc, ret);
        }
    }

    private class MethodTracerMethodVisitor extends AdviceAdapter {
        private Label startFinally = new Label();

        public MethodTracerMethodVisitor(int access, String name, String desc, MethodVisitor mv) {
            super(ASM5, mv, access, name, desc);
        }

        @Override
        public void visitCode() {
            super.visitCode();
            this.mv.visitLabel(this.startFinally);
            this.mv.visitLdcInsn(MethodTracer.this.className);
            this.mv.visitLdcInsn(MethodTracer.this.methodName);
            this.mv.visitMethodInsn(INVOKESTATIC, "rubah/tools/MethodTracer", "print",
                    "(Ljava/lang/String;Ljava/lang/String;)V", false);
        }

        @Override
        public void visitMaxs(int maxStack, int maxLocals) {
            Label endFinally = new Label();
            this.visitTryCatchBlock(this.startFinally, endFinally, endFinally, null);
            this.mv.visitLabel(endFinally);
            this.onFinally(ATHROW);
            this.visitInsn(ATHROW);
            super.visitMaxs(maxStack, maxLocals);
        }

        @Override
        protected void onMethodExit(int opcode) {
            if (opcode != ATHROW) {
                this.onFinally(opcode);
            }
        }

        private void onFinally(int opcode) {
            this.mv.visitFieldInsn(GETSTATIC, "rubah/tools/MethodTracer", "level", "I");
            this.mv.visitInsn(ICONST_1);
            this.mv.visitInsn(ISUB);
            this.mv.visitFieldInsn(PUTSTATIC, "rubah/tools/MethodTracer", "level", "I");
        }

    }

    public static int level = 0;

    public static void print(String className, String methodName) {
        level++;
        StringBuffer buf = new StringBuffer();

        for (int i = 0; i < level; i++) {
            buf.append("|-");
        }

        buf.append(className);
        buf.append(" - ");
        buf.append(methodName);

        System.out.println(buf.toString());
    }
}