src/java.base/share/classes/java/lang/classfile/attribute/LineNumberTableAttribute.java

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package java.lang.classfile.attribute;

import java.lang.classfile.Attribute;
import java.lang.classfile.AttributeMapper;
import java.lang.classfile.AttributeMapper.AttributeStability;
import java.lang.classfile.Attributes;
import java.lang.classfile.ClassFile;
import java.lang.classfile.CodeBuilder;
import java.lang.classfile.CodeModel;
import java.lang.classfile.instruction.LineNumber;
import java.util.List;

import jdk.internal.classfile.impl.BoundAttribute;
import jdk.internal.classfile.impl.UnboundAttribute;

/**
 * Models the {@link Attributes#lineNumberTable() LineNumberTable} attribute
 * (JVMS {@jvms 4.7.12}), which records the mapping between indexes into
 * the {@code code} array and line numbers in the source file.  Its entries are
 * delivered as {@link LineNumber} when traversing the elements of a {@link
 * CodeModel}, which is toggled by {@link ClassFile.LineNumbersOption}.
 * <p>
 * This attribute only appears on {@code Code} attributes, and permits {@linkplain
 * AttributeMapper#allowMultiple() multiple instances} in a {@code Code}
 * attribute.  It has a data dependency on {@linkplain AttributeStability#LABELS
 * labels}.
 * <p>
 * This attribute cannot be sent to a {@link CodeBuilder}; its entries can be
 * constructed with {@link LineNumber}, resulting in at most one attribute
 * instance in the built {@code Code} attribute.
 * <p>
 * The attribute was introduced in the Java Platform version 1.0.2, major
 * version {@value ClassFile#JAVA_1_VERSION}.
 *
 * @see Attributes#lineNumberTable()
 * @jvms 4.7.12 The {@code LineNumberTable} Attribute
 * @since 24
 */
public sealed interface LineNumberTableAttribute
        extends Attribute<LineNumberTableAttribute>
        permits BoundAttribute.BoundLineNumberTableAttribute,
                UnboundAttribute.UnboundLineNumberTableAttribute {

    /**
     * {@return the table mapping bytecode offsets to source line numbers}
     */
    List<LineNumberInfo> lineNumbers();

    /**
     * {@return a {@code LineNumberTable} attribute}
     *
     * @apiNote
     * The created attribute cannot be written to a {@link CodeBuilder}.  Call
     * {@link CodeBuilder#lineNumber CodeBuilder::lineNumber} in the correct
     * order instead.
     *
     * @param lines the line number descriptions
     */
    static LineNumberTableAttribute of(List<LineNumberInfo> lines) {
        return new UnboundAttribute.UnboundLineNumberTableAttribute(lines);
    }
}