code: // ASM: a very small and fast Java bytecode manipulation framework
  // Copyright (c) 2000-2011 INRIA, France Telecom
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  package clojure.asm;
  
  /**
   * A visitor to visit a Java class. The methods of this class must be called in the following order:
   * <tt>visit</tt> [ <tt>visitSource</tt> ] [ <tt>visitModule</tt> ][ <tt>visitNestHost</tt> ][
   * <tt>visitOuterClass</tt> ] ( <tt>visitAnnotation</tt> | <tt>visitTypeAnnotation</tt> |
   * <tt>visitAttribute</tt> )* ( <tt>visitNestMember</tt> | <tt>visitInnerClass</tt> |
   * <tt>visitField</tt> | <tt>visitMethod</tt> )* <tt>visitEnd</tt>.
   *
   * @author Eric Bruneton
   */
  public abstract class ClassVisitor {
  
    /**
     * The ASM API version implemented by this visitor. The value of this field must be one of {@link
     * Opcodes#ASM4}, {@link Opcodes#ASM5}, {@link Opcodes#ASM6} or {@link Opcodes#ASM7_EXPERIMENTAL}.
     */
    protected final int api;
  
    /** The class visitor to which this visitor must delegate method calls. May be null. */
    protected ClassVisitor cv;
  
    /**
     * Constructs a new {@link ClassVisitor}.
     *
     * @param api the ASM API version implemented by this visitor. Must be one of {@link
     *     Opcodes#ASM4}, {@link Opcodes#ASM5}, {@link Opcodes#ASM6} or {@link
     *     Opcodes#ASM7_EXPERIMENTAL}.
     */
    public ClassVisitor(final int api) {
      this(api, null);
    }
  
    /**
     * Constructs a new {@link ClassVisitor}.
     *
     * @param api the ASM API version implemented by this visitor. Must be one of {@link
     *     Opcodes#ASM4}, {@link Opcodes#ASM5}, {@link Opcodes#ASM6} or {@link
     *     Opcodes#ASM7_EXPERIMENTAL}.
     * @param classVisitor the class visitor to which this visitor must delegate method calls. May be
     *     null.
     */
    public ClassVisitor(final int api, final ClassVisitor classVisitor) {
      if (api != Opcodes.ASM6
          && api != Opcodes.ASM5
          && api != Opcodes.ASM4
          && api != Opcodes.ASM7_EXPERIMENTAL) {
        throw new IllegalArgumentException();
      }
      this.api = api;
      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.
     * @param name the internal name of the class (see {@link Type#getInternalName()}).
     * @param signature the signature of this class. May be <tt>null</tt> 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 <tt>null</tt>, but only for the
     *     {@link Object} class.
     * @param interfaces the internal names of the class's interfaces (see {@link
     *     Type#getInternalName()}). May be <tt>null</tt>.
     */
    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
     *     <tt>null</tt>.
     * @param debug additional debug information to compute the correspondence between source and
     *     compiled elements of the class. May be <tt>null</tt>.
     */
    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 <tt>null</tt>.
     * @return a visitor to visit the module values, or <tt>null</tt> if this visitor is not
     *     interested in visiting this module.
     */
    public ModuleVisitor visitModule(final String name, final int access, final String version) {
      if (api < Opcodes.ASM6) {
        throw new UnsupportedOperationException();
      }
      if (cv != null) {
        return cv.visitModule(name, access, version);
      }
      return null;
    }
  
    /**
     * <b>Experimental, use at your own risk. This method will be renamed when it becomes stable, this
     * will break existing code using it</b>. 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.
     * @deprecated This API is experimental.
     */
    @Deprecated
    public void visitNestHostExperimental(final String nestHost) {
      if (api < Opcodes.ASM7_EXPERIMENTAL) {
        throw new UnsupportedOperationException();
      }
      if (cv != null) {
        cv.visitNestHostExperimental(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 <tt>null</tt> 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 <tt>null</tt> 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 <tt>true</tt> if the annotation is visible at runtime.
     * @return a visitor to visit the annotation values, or <tt>null</tt> 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 <tt>null</tt> if the annotation targets
     *     'typeRef' as a whole.
     * @param descriptor the class descriptor of the annotation class.
     * @param visible <tt>true</tt> if the annotation is visible at runtime.
     * @return a visitor to visit the annotation values, or <tt>null</tt> 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 (api < Opcodes.ASM5) {
        throw new UnsupportedOperationException();
      }
      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);
      }
    }
  
    /**
     * <b>Experimental, use at your own risk. This method will be renamed when it becomes stable, this
     * will break existing code using it</b>. 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.
     * @deprecated This API is experimental.
     */
    @Deprecated
    public void visitNestMemberExperimental(final String nestMember) {
      if (api < Opcodes.ASM7_EXPERIMENTAL) {
        throw new UnsupportedOperationException();
      }
      if (cv != null) {
        cv.visitNestMemberExperimental(nestMember);
      }
    }
  
    /**
     * 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 <tt>null</tt> for not member classes.
     * @param innerName the (simple) name of the inner class inside its enclosing class. May be
     *     <tt>null</tt> 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 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 <tt>null</tt> if the field's type does not use
     *     generic types.
     * @param value the field's initial value. This parameter, which may be <tt>null</tt> 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 <tt>int</tt>, <tt>float</tt>,
     *     <tt>long</tt> or <tt>String</tt> fields respectively). <i>This parameter is only used for
     *     static fields</i>. 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 <tt>null</tt> 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 <i>must</i> return a new {@link MethodVisitor}
     * instance (or <tt>null</tt>) 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 <tt>null</tt> 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 <tt>null</tt>.
     * @return an object to visit the byte code of the method, or <tt>null</tt> 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();
      }
    }
  }
  