icom.weaver.JpaTopLevelConstructorMethodAdapter.java Source code

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Here is the source code for icom.weaver.JpaTopLevelConstructorMethodAdapter.java

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/*
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER
 * 
 * Copyright (c) 2010, Oracle Corporation All Rights Reserved.
 * 
 * The contents of this file are subject to the terms of either the GNU
 * General Public License Version 2 only ("GPL") or the Common Development
 * and Distribution License ("CDDL") (collectively, the "License").  You
 * may not use this file except in compliance with the License.  You can obtain
 * a copy of the License at http://openjdk.java.net/legal/gplv2+ce.html.
 * See the License for the specific language governing permission and
 * limitations under the License.
 *
 * When distributing the software, include this License Header Notice in each
 * file and include the License file at openICOM/bootstrap/legal/LICENSE.txt.
 * Oracle designates this particular file as subject to the "Classpath" exception
 * as provided by Oracle in the GPL Version 2 section of the License file that
 * accompanied this code.  If applicable, add the following below the License
 * Header, with the fields enclosed by brackets [ ] replaced by your own
 * identifying information:  "Portions Copyrighted [year]
 * [name of copyright owner].
 *
 * Contributor(s): Oracle Corporation
 * 
 * If you wish your version of this file to be governed by only the CDDL or
 * only the GPL Version 2, indicate your decision by adding "[Contributor]
 * elects to include this software in this distribution under the [CDDL or GPL
 * Version 2] license."  If you don't indicate a single choice of license, a
 * recipient has the option to distribute your version of this file under
 * either the CDDL, the GPL Version 2 or to extend the choice of license to
 * its licensees as provided above.  However, if you add GPL Version 2 code
 * and therefore, elected the GPL Version 2 license, then the option applies
 * only if the new code is made subject to such option by the copyright
 * holder.
 */
package icom.weaver;

import org.objectweb.asm.MethodAdapter;
import org.objectweb.asm.MethodVisitor;
import org.objectweb.asm.Opcodes;
import org.objectweb.asm.Type;

public class JpaTopLevelConstructorMethodAdapter extends MethodAdapter implements Opcodes, Descriptors {

    ClassDefinition classDefn;
    String methodName;
    String methodDescriptor;
    int numArguments;
    boolean otherThanThisObject;

    public JpaTopLevelConstructorMethodAdapter(MethodVisitor mv, ClassDefinition classDefn, String methodName,
            String methodDescriptor) {
        super(mv);
        this.classDefn = classDefn;
        this.methodName = methodName;
        this.methodDescriptor = methodDescriptor;
        MethodType methodType = new MethodType(methodDescriptor);
        Type[] argTypes = methodType.getArgumentTypes();
        numArguments = argTypes.length;
    }

    public void visitCode() {
        if (classDefn.icomTopLevelEntityClass) {
            if (numArguments == 0) {
                mv.visitVarInsn(ALOAD, 0);
                mv.visitMethodInsn(INVOKESPECIAL, icomAbstractEntity, "<init>", "()V");
            } else if (numArguments == 1) {
                mv.visitVarInsn(ALOAD, 0);
                mv.visitVarInsn(ALOAD, 1);
                mv.visitMethodInsn(INVOKESPECIAL, icomAbstractEntity, "<init>", "(Ljava/lang/Object;)V");
            }
        } else if (classDefn.icomTopLevelIdentifiableClass) {
            mv.visitVarInsn(ALOAD, 0);
            mv.visitMethodInsn(INVOKESPECIAL, icomAbstractIdentifiable, "<init>", "()V");
        } else if (classDefn.icomTopLevelNonIdentifiableClass) {
            mv.visitVarInsn(ALOAD, 0);
            mv.visitMethodInsn(INVOKESPECIAL, icomAbstractNonIdentifiable, "<init>", "()V");
        }
        super.visitCode();
    }

    public void visitTypeInsn(int opcode, String type) {
        if (opcode == NEW) {
            otherThanThisObject = true;
        }
        super.visitTypeInsn(opcode, type);
    }

    public void visitMethodInsn(int opcode, String owner, String name, String desc) {
        if (opcode == INVOKESPECIAL) {
            if (!otherThanThisObject) {
                // suppress <init> of "java/lang/Object" since superclass is replaced by icomAbstract...
                if (owner.equals("java/lang/Object") && name.equals("<init>")) {
                    MethodType methodType = new MethodType(desc);
                    Type[] argTypes = methodType.getArgumentTypes();
                    if (argTypes.length == 0) {
                        // stack has (..., [this])
                        // pop                         
                        mv.visitInsn(POP);
                        // stack has (..., )
                        return;
                    }
                }
            }
        }
        super.visitMethodInsn(opcode, owner, name, desc);
    }

}