AsmNullAdapter.java

/**************************************************************************************
 * Copyright (c) Jonas Bon?r, Alexandre Vasseur. All rights reserved.                 *
 * http://aspectwerkz.codehaus.org                                                    *
 * ---------------------------------------------------------------------------------- *
 * The software in this package is published under the terms of the LGPL license      *
 * a copy of which has been included with this distribution in the license.txt file.  *
 **************************************************************************************/
package org.codehaus.aspectwerkz.transform.inlining;

import org.objectweb.asm.*;

/**
 * Visitors that are not writing any bytecode and using a Null ClassVisitor / Code Visitor as a target instead.
 *
 * @author <a href="mailto:alex@gnilux.com">Alexandre Vasseur</a>
 */
public class AsmNullAdapter {

    /**
     * A NullClassAdapter that does nothing.
     * Can be used to speed up ASM and avoid unecessary bytecode writing thru a regular ClassWriter when this is not
     * needed (read only purpose).
     */
    public static class NullClassAdapter implements ClassVisitor {

        public final static ClassVisitor NULL_CLASS_ADAPTER = new NullClassAdapter();

        public void visit(int version, int access, String name, String signature, String superName, String[] interfaces) {
        }

        public void visitInnerClass(String name, String outerName, String innerName, int access) {
        }

        public FieldVisitor visitField(int access, String name, String desc, String signature, Object value) {
            return NullFieldAdapter.NULL_FIELD_ADAPTER;
        }

        public MethodVisitor visitMethod(int access, String name, String desc, String signature, String[] exceptions) {
            return NullMethodAdapter.NULL_METHOD_ADAPTER;
        }

        public void visitSource(String source, String debug) {
        }

        public void visitOuterClass(String owner, String name, String desc) {
        }

        public AnnotationVisitor visitAnnotation(String desc, boolean visible) {
            return NullAnnotationVisitor.NULL_ANNOTATION_ADAPTER;
        }

        public void visitAttribute(Attribute attribute) {
        }

        public void visitEnd() {
        }
    }

    /**
     * A NullMethodAdapter that does nothing.
     * Can be used to speed up ASM and avoid unecessary bytecode writing thru a regular CodeWriter when this is not
     * needed (read only purpose)
     */
    public static class NullMethodAdapter implements MethodVisitor {

        public final static MethodVisitor NULL_METHOD_ADAPTER = new NullMethodAdapter();

        public void visitInsn(int opcode) {
        }

        public void visitIntInsn(int opcode, int operand) {
        }

        public void visitVarInsn(int opcode, int var) {
        }

        public void visitTypeInsn(int opcode, String desc) {
        }

        public void visitFieldInsn(int opcode, String owner, String name, String desc) {
        }

        public void visitMethodInsn(int opcode, String owner, String name, String desc) {
        }

        public void visitJumpInsn(int opcode, Label label) {
        }

        public void visitLabel(Label label) {
        }

        public void visitLdcInsn(Object cst) {
        }

        public void visitIincInsn(int var, int increment) {
        }

        public void visitTableSwitchInsn(int min, int max, Label dflt, Label labels[]) {
        }

        public void visitLookupSwitchInsn(Label dflt, int keys[], Label labels[]) {
        }

        public void visitMultiANewArrayInsn(String desc, int dims) {
        }

        public void visitTryCatchBlock(Label start, Label end, Label handler, String type) {
        }

        public void visitMaxs(int maxStack, int maxLocals) {
        }

        public void visitLocalVariable(String name, String desc, String sig, Label start, Label end, int index) {
        }

        public void visitLineNumber(int line, Label start) {
        }

        public void visitAttribute(Attribute attr) {
        }

        public AnnotationVisitor visitAnnotationDefault() {
            return NullAnnotationVisitor.NULL_ANNOTATION_ADAPTER;
        }

        public AnnotationVisitor visitAnnotation(String desc, boolean visible) {
            return NullAnnotationVisitor.NULL_ANNOTATION_ADAPTER;
        }

        public AnnotationVisitor visitParameterAnnotation(int parameter, String desc, boolean visible) {
            return NullAnnotationVisitor.NULL_ANNOTATION_ADAPTER;
        }

        public void visitCode() {
        }

        public void visitEnd() {
        }
    }

    /**
     * A NullFieldAdapter
     */
    public static class NullFieldAdapter implements FieldVisitor {

        public final static FieldVisitor NULL_FIELD_ADAPTER = new NullFieldAdapter();

        public AnnotationVisitor visitAnnotation(String desc, boolean visible) {
            return NullAnnotationVisitor.NULL_ANNOTATION_ADAPTER;
        }

        public void visitAttribute(Attribute attr) {
        }

        public void visitEnd() {
        }
    }

    /**
     * A NullAnnotationVisitor
     */
    public static class NullAnnotationVisitor implements AnnotationVisitor {

        public final static AnnotationVisitor NULL_ANNOTATION_ADAPTER = new NullAnnotationVisitor();

        public void visit(String name, Object value) {
        }

        public void visitEnum(String name, String desc, String value) {
        }

        public AnnotationVisitor visitAnnotation(String name, String desc) {
            return NULL_ANNOTATION_ADAPTER;
        }

        public AnnotationVisitor visitArray(String name) {
            return NULL_ANNOTATION_ADAPTER;
        }

        public void visitEnd() {
        }
    }
}