cn.taketoday.bytecode.ClassVisitor Maven / Gradle / Ivy
/*
* Original Author -> Harry Yang ([email protected]) https://taketoday.cn
* Copyright © TODAY & 2017 - 2022 All Rights Reserved.
*
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER
*
* This program 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.
*
* This program 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 this program. If not, see [http://www.gnu.org/licenses/]
*/
package cn.taketoday.bytecode;
/**
* A visitor to visit a Java class. The methods of this class must be called in the following order:
* {@code visit} [ {@code visitSource} ] [ {@code visitModule} ][ {@code visitNestHost} ][ {@code
* visitOuterClass} ] ( {@code visitAnnotation} | {@code visitTypeAnnotation} | {@code
* visitAttribute} )* ( {@code visitNestMember} | [ {@code * visitPermittedSubclass} ] | {@code
* visitInnerClass} | {@code visitRecordComponent} | {@code visitField} | {@code visitMethod} )*
* {@code visitEnd}.
*
* @author Eric Bruneton
*/
public abstract class ClassVisitor {
/**
* The class visitor to which this visitor must delegate method calls. May be
* null.
*/
protected ClassVisitor cv;
/**
* Constructs a new {@link ClassVisitor}.
*/
public ClassVisitor() {
this(null);
}
/**
* Constructs a new {@link ClassVisitor}.
*
* @param classVisitor the class visitor to which this visitor must delegate method
* calls. May be null.
*/
public ClassVisitor(final ClassVisitor classVisitor) {
this.cv = classVisitor;
}
/**
* Visits the header of the class.
*
* @param version the class version. The minor version is stored in the 16 most significant bits,
* and the major version in the 16 least significant bits.
* @param access the class's access flags (see {@link Opcodes}). This parameter also indicates if
* the class is deprecated {@link Opcodes#ACC_DEPRECATED} or a record {@link
* Opcodes#ACC_RECORD}.
* @param name the internal name of the class (see {@link Type#getInternalName()}).
* @param signature the signature of this class. May be {@literal null} if the class is not a
* generic one, and does not extend or implement generic classes or interfaces.
* @param superName the internal of name of the super class (see {@link Type#getInternalName()}).
* For interfaces, the super class is {@link Object}. May be {@literal null}, but only for the
* {@link Object} class.
* @param interfaces the internal names of the class's interfaces (see {@link
* Type#getInternalName()}). May be {@literal null}.
*/
public void visit(
final int version,
final int access,
final String name,
final String signature,
final String superName,
final String[] interfaces) {
if (cv != null) {
cv.visit(version, access, name, signature, superName, interfaces);
}
}
/**
* Visits the source of the class.
*
* @param source the name of the source file from which the class was compiled. May be {@literal
* null}.
* @param debug additional debug information to compute the correspondence between source and
* compiled elements of the class. May be {@literal null}.
*/
public void visitSource(final String source, final String debug) {
if (cv != null) {
cv.visitSource(source, debug);
}
}
/**
* Visit the module corresponding to the class.
*
* @param name the fully qualified name (using dots) of the module.
* @param access the module access flags, among {@code ACC_OPEN}, {@code ACC_SYNTHETIC} and {@code
* ACC_MANDATED}.
* @param version the module version, or {@literal null}.
* @return a visitor to visit the module values, or {@literal null} if this visitor is not
* interested in visiting this module.
*/
public ModuleVisitor visitModule(final String name, final int access, final String version) {
if (cv != null) {
return cv.visitModule(name, access, version);
}
return null;
}
/**
* Visits the nest host class of the class. A nest is a set of classes of the same package that
* share access to their private members. One of these classes, called the host, lists the other
* members of the nest, which in turn should link to the host of their nest. This method must be
* called only once and only if the visited class is a non-host member of a nest. A class is
* implicitly its own nest, so it's invalid to call this method with the visited class name as
* argument.
*
* @param nestHost the internal name of the host class of the nest.
*/
public void visitNestHost(final String nestHost) {
if (cv != null) {
cv.visitNestHost(nestHost);
}
}
/**
* Visits the enclosing class of the class. This method must be called only if the class has an
* enclosing class.
*
* @param owner internal name of the enclosing class of the class.
* @param name the name of the method that contains the class, or {@literal null} if the class is
* not enclosed in a method of its enclosing class.
* @param descriptor the descriptor of the method that contains the class, or {@literal null} if
* the class is not enclosed in a method of its enclosing class.
*/
public void visitOuterClass(final String owner, final String name, final String descriptor) {
if (cv != null) {
cv.visitOuterClass(owner, name, descriptor);
}
}
/**
* Visits an annotation of the class.
*
* @param descriptor the class descriptor of the annotation class.
* @param visible {@literal true} if the annotation is visible at runtime.
* @return a visitor to visit the annotation values, or {@literal null} if this visitor is not
* interested in visiting this annotation.
*/
public AnnotationVisitor visitAnnotation(final String descriptor, final boolean visible) {
if (cv != null) {
return cv.visitAnnotation(descriptor, visible);
}
return null;
}
/**
* Visits an annotation on a type in the class signature.
*
* @param typeRef a reference to the annotated type. The sort of this type reference must be
* {@link TypeReference#CLASS_TYPE_PARAMETER}, {@link
* TypeReference#CLASS_TYPE_PARAMETER_BOUND} or {@link TypeReference#CLASS_EXTENDS}. See
* {@link TypeReference}.
* @param typePath the path to the annotated type argument, wildcard bound, array element type, or
* static inner type within 'typeRef'. May be {@literal null} if the annotation targets
* 'typeRef' as a whole.
* @param descriptor the class descriptor of the annotation class.
* @param visible {@literal true} if the annotation is visible at runtime.
* @return a visitor to visit the annotation values, or {@literal null} if this visitor is not
* interested in visiting this annotation.
*/
public AnnotationVisitor visitTypeAnnotation(
final int typeRef, final TypePath typePath, final String descriptor, final boolean visible) {
if (cv != null) {
return cv.visitTypeAnnotation(typeRef, typePath, descriptor, visible);
}
return null;
}
/**
* Visits a non standard attribute of the class.
*
* @param attribute an attribute.
*/
public void visitAttribute(final Attribute attribute) {
if (cv != null) {
cv.visitAttribute(attribute);
}
}
/**
* Visits a member of the nest. A nest is a set of classes of the same package that share access
* to their private members. One of these classes, called the host, lists the other members of the
* nest, which in turn should link to the host of their nest. This method must be called only if
* the visited class is the host of a nest. A nest host is implicitly a member of its own nest, so
* it's invalid to call this method with the visited class name as argument.
*
* @param nestMember the internal name of a nest member.
*/
public void visitNestMember(final String nestMember) {
if (cv != null) {
cv.visitNestMember(nestMember);
}
}
/**
* Visits a permitted subclasses. A permitted subclass is one of the allowed subclasses of the
* current class.
*
* @param permittedSubclass the internal name of a permitted subclass.
*/
public void visitPermittedSubclass(final String permittedSubclass) {
if (cv != null) {
cv.visitPermittedSubclass(permittedSubclass);
}
}
/**
* Visits information about an inner class. This inner class is not necessarily a member of the
* class being visited.
*
* @param name the internal name of an inner class (see {@link Type#getInternalName()}).
* @param outerName the internal name of the class to which the inner class belongs (see {@link
* Type#getInternalName()}). May be {@literal null} for not member classes.
* @param innerName the (simple) name of the inner class inside its enclosing class. May be
* {@literal null} for anonymous inner classes.
* @param access the access flags of the inner class as originally declared in the enclosing
* class.
*/
public void visitInnerClass(
final String name, final String outerName, final String innerName, final int access) {
if (cv != null) {
cv.visitInnerClass(name, outerName, innerName, access);
}
}
/**
* Visits a record component of the class.
*
* @param name the record component name.
* @param descriptor the record component descriptor (see {@link Type}).
* @param signature the record component signature. May be {@literal null} if the record component
* type does not use generic types.
* @return a visitor to visit this record component annotations and attributes, or {@literal null}
* if this class visitor is not interested in visiting these annotations and attributes.
*/
public RecordComponentVisitor visitRecordComponent(
final String name, final String descriptor, final String signature) {
if (cv != null) {
return cv.visitRecordComponent(name, descriptor, signature);
}
return null;
}
/**
* Visits a field of the class.
*
* @param access the field's access flags (see {@link Opcodes}). This parameter also indicates if
* the field is synthetic and/or deprecated.
* @param name the field's name.
* @param descriptor the field's descriptor (see {@link Type}).
* @param signature the field's signature. May be {@literal null} if the field's type does not use
* generic types.
* @param value the field's initial value. This parameter, which may be {@literal null} if the
* field does not have an initial value, must be an {@link Integer}, a {@link Float}, a {@link
* Long}, a {@link Double} or a {@link String} (for {@code int}, {@code float}, {@code long}
* or {@code String} fields respectively). This parameter is only used for static
* fields. Its value is ignored for non static fields, which must be initialized through
* bytecode instructions in constructors or methods.
* @return a visitor to visit field annotations and attributes, or {@literal null} if this class
* visitor is not interested in visiting these annotations and attributes.
*/
public FieldVisitor visitField(
final int access,
final String name,
final String descriptor,
final String signature,
final Object value) {
if (cv != null) {
return cv.visitField(access, name, descriptor, signature, value);
}
return null;
}
/**
* Visits a method of the class. This method must return a new {@link MethodVisitor}
* instance (or {@literal null}) each time it is called, i.e., it should not return a previously
* returned visitor.
*
* @param access the method's access flags (see {@link Opcodes}). This parameter also indicates if
* the method is synthetic and/or deprecated.
* @param name the method's name.
* @param descriptor the method's descriptor (see {@link Type}).
* @param signature the method's signature. May be {@literal null} if the method parameters,
* return type and exceptions do not use generic types.
* @param exceptions the internal names of the method's exception classes (see {@link
* Type#getInternalName()}). May be {@literal null}.
* @return an object to visit the byte code of the method, or {@literal null} if this class
* visitor is not interested in visiting the code of this method.
*/
public MethodVisitor visitMethod(
final int access,
final String name,
final String descriptor,
final String signature,
final String[] exceptions) {
if (cv != null) {
return cv.visitMethod(access, name, descriptor, signature, exceptions);
}
return null;
}
/**
* Visits the end of the class. This method, which is the last one to be called, is used to inform
* the visitor that all the fields and methods of the class have been visited.
*/
public void visitEnd() {
if (cv != null) {
cv.visitEnd();
}
}
}
© 2015 - 2025 Weber Informatics LLC | Privacy Policy