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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
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package java.lang.classfile.instruction;

import java.lang.classfile.CodeBuilder;
import java.lang.classfile.CodeElement;
import java.lang.classfile.CodeModel;
import java.lang.classfile.CodeTransform;
import java.lang.classfile.Label;
import java.lang.classfile.PseudoInstruction;
import java.lang.classfile.attribute.CodeAttribute;

import jdk.internal.classfile.impl.LabelImpl;

/**
 * A pseudo-instruction which indicates that the specified label corresponds to
 * the current position in the {@code Code} attribute.  Delivered as a {@link
 * CodeElement} during traversal of the elements of a {@link CodeModel}.
 * <p>
 * This can be used to inspect the target position of labels across {@linkplain
 * CodeTransform transformations}, as {@linkplain CodeAttribute#labelToBci bci}
 * is not stable.
 * <p>
 * When passed to a {@link CodeBuilder}, this pseudo-instruction sets the
 * specified label to be bound at the current position in the builder.
 * <p>
 * By design, {@code LabelTarget} cannot be created by users and can only be
 * read from a code model.  Use {@link CodeBuilder#labelBinding
 * CodeBuilder::labelBinding} to bind arbitrary labels to a {@code CodeBuilder}.
 * <p>
 * For a {@code CodeBuilder cob}, a {@code LabelTarget lt}, these two calls are
 * equivalent:
 * {@snippet lang=java :
 * cob.with(lt); // @link substring="with" target="CodeBuilder#with"
 * // @link substring="labelBinding" target="CodeBuilder#labelBinding" :
 * cob.labelBinding(lt.label()); // @link regex="label(?=\()" target="#label"
 * }
 *
 * @see Label
 * @see CodeBuilder#labelBinding CodeBuilder::labelBinding
 * @since 24
 */
public sealed interface LabelTarget extends PseudoInstruction
        permits LabelImpl {

    /**
     * {@return the label corresponding to this target}
     */
    Label label();
}
