SemanticVersioningClassVisitor.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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.apache.aries.versioning.utils;

import java.lang.reflect.Modifier;
import java.net.URLClassLoader;

import org.objectweb.asm.AnnotationVisitor;
import org.objectweb.asm.Attribute;
import org.objectweb.asm.ClassVisitor;
import org.objectweb.asm.FieldVisitor;
import org.objectweb.asm.MethodVisitor;

public class SemanticVersioningClassVisitor extends ClassVisitor {

    private ClassDeclaration classDeclaration;
    private boolean needVisit = false;
    private URLClassLoader loader = null;
    private SerialVersionClassVisitor cv = null;

    public SemanticVersioningClassVisitor(URLClassLoader newJarLoader, SerialVersionClassVisitor cv) {
      super(SemanticVersioningUtils.ASM4);
      this.loader = newJarLoader;
      this.cv = cv;
    }

    public SemanticVersioningClassVisitor(URLClassLoader newJarLoader) {
      super(SemanticVersioningUtils.ASM4);
      this.loader = newJarLoader;
    }

    public ClassDeclaration getClassDeclaration() {
        return classDeclaration;
    }

    /*
    * (non-Javadoc)
    *
    * @see org.objectweb.asm.ClassAdapter#visit(int, int,
    * java.lang.String, java.lang.String, java.lang.String, java.lang.String)
    */
    // visit the header of the class
    @Override
    public void visit(int version, int access, String name, String signature, String superName, String[] interfaces) {
        // only interested in public class
        if (cv != null) {
            cv.visit(version, access, name, signature, superName, interfaces);
        }
        if (Modifier.isPublic(access) || (Modifier.isProtected(access))) {
            classDeclaration = new ClassDeclaration(access, name, signature, superName, interfaces, loader, cv);
            needVisit = true;

        }
    }

    /*
    * (non-Javadoc)
    *
    * @see org.objectweb.asm.ClassAdapter#visitField(int, java.lang.String,
    * java.lang.String, java.lang.String, java.lang.Object)
    *
    * Grab all protected or public fields
    */
    @Override
    public FieldVisitor visitField(int access, String name, String desc,
                                   String signature, Object value) {
        if (cv != null) {
            cv.visitField(access, name, desc, signature, value);
        }
        if (needVisit) {
            FieldDeclaration fd = new FieldDeclaration(access, name, desc, signature, value);
            classDeclaration.addFields(fd);
        }
        return null;
    }

    /*
    * (non-Javadoc)
    *
    * @see org.objectweb.asm.ClassAdapter#visitMethod(int, java.lang.String,
    * java.lang.String, java.lang.String, java.lang.String[])
    * Get all non-private methods
    */
    @Override
    public MethodVisitor visitMethod(int access, String name, String desc,
                                     String signature, String[] exceptions) {


        if (cv != null) {
            cv.visitMethod(access, name, desc, signature, exceptions);
        }
        if (needVisit && (!SemanticVersioningUtils.CLINIT.equals(name))) {
            MethodDeclaration md = new MethodDeclaration(access, name, desc, signature, exceptions);
            classDeclaration.addMethods(md);
        }
        return null;
    }

    @Override
    public AnnotationVisitor visitAnnotation(String arg0, boolean arg1) {
        return null;
    }

    @Override
    public void visitAttribute(Attribute arg0) {
        // no-op
    }

    @Override
    public void visitEnd() {
        //no-op

    }

    @Override
    public void visitInnerClass(String name, String outerName, String innerName, int access) {
        //no-op
        //The inner class will be scanned on its own. However, the method level class will be excluded, as they won't be public or protected.

    }

    @Override
    public void visitOuterClass(String owner, String name, String desc) {
        //no op

    }

    @Override
    public void visitSource(String arg0, String arg1) {
        //no-op

    }


}