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 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

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 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

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/*

 * This file is available under and governed by the GNU General Public

 * License version 2 only, as published by the Free Software Foundation.

 * However, the following notice accompanied the original version of this

 * file:

 *

 * ASM: a very small and fast Java bytecode manipulation framework

 * Copyright (c) 2000-2011 INRIA, France Telecom

 * All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 * 1. Redistributions of source code must retain the above copyright

 *    notice, this list of conditions and the following disclaimer.

 * 2. Redistributions in binary form must reproduce the above copyright

 *    notice, this list of conditions and the following disclaimer in the

 *    documentation and/or other materials provided with the distribution.

 * 3. Neither the name of the copyright holders nor the names of its

 *    contributors may be used to endorse or promote products derived from

 *    this software without specific prior written permission.

 *

 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"

 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE

 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE

 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR

 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF

 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS

 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN

 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)

 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF

 * THE POSSIBILITY OF SUCH DAMAGE.

 */

package jdk.internal.org.objectweb.asm.signature;

import jdk.internal.org.objectweb.asm.Opcodes;

/**

 * A visitor to visit a generic signature. The methods of this interface must be called in one of

 * the three following orders (the last one is the only valid order for a {@link SignatureVisitor}

 * that is returned by a method of this interface):

 *

 * <ul>

 *   <li><i>ClassSignature</i> = ( {@code visitFormalTypeParameter} {@code visitClassBound}? {@code

 *       visitInterfaceBound}* )* ({@code visitSuperclass} {@code visitInterface}* )

 *   <li><i>MethodSignature</i> = ( {@code visitFormalTypeParameter} {@code visitClassBound}? {@code

 *       visitInterfaceBound}* )* ({@code visitParameterType}* {@code visitReturnType} {@code

 *       visitExceptionType}* )

 *   <li><i>TypeSignature</i> = {@code visitBaseType} | {@code visitTypeVariable} | {@code

 *       visitArrayType} | ( {@code visitClassType} {@code visitTypeArgument}* ( {@code

 *       visitInnerClassType} {@code visitTypeArgument}* )* {@code visitEnd} ) )

 * </ul>

 *

 * @author Thomas Hallgren

 * @author Eric Bruneton

 */

public abstract class SignatureVisitor {

    /** Wildcard for an "extends" type argument. */

    public static final char EXTENDS = '+';

    /** Wildcard for a "super" type argument. */

    public static final char SUPER = '-';

    /** Wildcard for a normal type argument. */

    public static final char INSTANCEOF = '=';

    /**

      * 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}.

      */

    protected final int api;

    /**

      * Constructs a new {@link SignatureVisitor}.

      *

      * @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}.

      */

    @SuppressWarnings("deprecation")

    public SignatureVisitor(final int api) {

        if (api != Opcodes.ASM8

                && api != Opcodes.ASM7

                && api != Opcodes.ASM6

                && api != Opcodes.ASM5

                && api != Opcodes.ASM4

                && api != Opcodes.ASM9_EXPERIMENTAL) {

            throw new IllegalArgumentException("Unsupported api " + api);

        }

        this.api = api;

    }

    /**

      * Visits a formal type parameter.

      *

      * @param name the name of the formal parameter.

      */

    public void visitFormalTypeParameter(final String name) {}

    /**

      * Visits the class bound of the last visited formal type parameter.

      *

      * @return a non null visitor to visit the signature of the class bound.

      */

    public SignatureVisitor visitClassBound() {

        return this;

    }

    /**

      * Visits an interface bound of the last visited formal type parameter.

      *

      * @return a non null visitor to visit the signature of the interface bound.

      */

    public SignatureVisitor visitInterfaceBound() {

        return this;

    }

    /**

      * Visits the type of the super class.

      *

      * @return a non null visitor to visit the signature of the super class type.

      */

    public SignatureVisitor visitSuperclass() {

        return this;

    }

    /**

      * Visits the type of an interface implemented by the class.

      *

      * @return a non null visitor to visit the signature of the interface type.

      */

    public SignatureVisitor visitInterface() {

        return this;

    }

    /**

      * Visits the type of a method parameter.

      *

      * @return a non null visitor to visit the signature of the parameter type.

      */

    public SignatureVisitor visitParameterType() {

        return this;

    }

    /**

      * Visits the return type of the method.

      *

      * @return a non null visitor to visit the signature of the return type.

      */

    public SignatureVisitor visitReturnType() {

        return this;

    }

    /**

      * Visits the type of a method exception.

      *

      * @return a non null visitor to visit the signature of the exception type.

      */

    public SignatureVisitor visitExceptionType() {

        return this;

    }

    /**

      * Visits a signature corresponding to a primitive type.

      *

      * @param descriptor the descriptor of the primitive type, or 'V' for {@code void} .

      */

    public void visitBaseType(final char descriptor) {}

    /**

      * Visits a signature corresponding to a type variable.

      *

      * @param name the name of the type variable.

      */

    public void visitTypeVariable(final String name) {}

    /**

      * Visits a signature corresponding to an array type.

      *

      * @return a non null visitor to visit the signature of the array element type.

      */

    public SignatureVisitor visitArrayType() {

        return this;

    }

    /**

      * Starts the visit of a signature corresponding to a class or interface type.

      *

      * @param name the internal name of the class or interface.

      */

    public void visitClassType(final String name) {}

    /**

      * Visits an inner class.

      *

      * @param name the local name of the inner class in its enclosing class.

      */

    public void visitInnerClassType(final String name) {}

    /** Visits an unbounded type argument of the last visited class or inner class type. */

    public void visitTypeArgument() {}

    /**

      * Visits a type argument of the last visited class or inner class type.

      *

      * @param wildcard '+', '-' or '='.

      * @return a non null visitor to visit the signature of the type argument.

      */

    public SignatureVisitor visitTypeArgument(final char wildcard) {

        return this;

    }

    /** Ends the visit of a signature corresponding to a class or interface type. */

    public void visitEnd() {}

}