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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * 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

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

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

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

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 *

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package jdk.nashorn.internal.ir;

import jdk.nashorn.internal.codegen.Label;

/**

 * Common base class for jump statements (e.g. {@code break} and {@code continue}).

 */

public abstract class JumpStatement extends Statement implements JoinPredecessor {

    private static final long serialVersionUID = 1L;

    private final String labelName;

    private final LocalVariableConversion conversion;

    /**

     * Constructor

     *

     * @param lineNumber line number

     * @param token      token

     * @param finish     finish

     * @param labelName  label name for break or null if none

     */

    protected JumpStatement(final int lineNumber, final long token, final int finish, final String labelName) {

        super(lineNumber, token, finish);

        this.labelName = labelName;

        this.conversion = null;

    }

    /**

     * Copy constructor.

     * @param jumpStatement the original jump statement.

     * @param conversion a new local variable conversion.

     */

    protected JumpStatement(final JumpStatement jumpStatement, final LocalVariableConversion conversion) {

        super(jumpStatement);

        this.labelName = jumpStatement.labelName;

        this.conversion = conversion;

    }

    @Override

    public boolean hasGoto() {

        return true;

    }

    /**

     * Get the label name for this break node

     * @return label name, or null if none

     */

    public String getLabelName() {

        return labelName;

    }

    @Override

    public void toString(final StringBuilder sb, final boolean printType) {

        sb.append(getStatementName());

        if (labelName != null) {

            sb.append(' ').append(labelName);

        }

    }

    abstract String getStatementName();

    /**

     * Finds the target for this jump statement in a lexical context.

     * @param lc the lexical context

     * @return the target, or null if not found

     */

    public abstract BreakableNode getTarget(final LexicalContext lc);

    /**

     * Returns the label corresponding to this kind of jump statement (either a break or continue label) in the target.

     * @param target the target. Note that it need not be the target of this jump statement, as the method can retrieve

     * a label on any passed target as long as the target has a label of the requisite kind. Of course, it is advisable

     * to invoke the method on a jump statement that targets the breakable.

     * @return the label of the target corresponding to the kind of jump statement.

     * @throws ClassCastException if invoked on the kind of breakable node that this jump statement is not prepared to

     * handle.

     */

    @Override

    public JumpStatement setLocalVariableConversion(final LexicalContext lc, final LocalVariableConversion conversion) {

        if(this.conversion == conversion) {

            return this;

        }

        return createNewJumpStatement(conversion);

    }

    abstract JumpStatement createNewJumpStatement(LocalVariableConversion newConversion);

    @Override

    public LocalVariableConversion getLocalVariableConversion() {

        return conversion;

    }

}