/*
 * reserved comment block
 * DO NOT REMOVE OR ALTER!
 */
/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.sun.org.apache.bcel.internal.classfile;

import java.io.DataInput;
import java.io.DataOutputStream;
import java.io.IOException;

This class represents a (PC offset, line number) pair, i.e., a line number in the source that corresponds to a relative address in the byte code. This is used for debugging purposes.
See Also:
  • LineNumberTable
/** * This class represents a (PC offset, line number) pair, i.e., a line number in * the source that corresponds to a relative address in the byte code. This * is used for debugging purposes. * * @see LineNumberTable */
public final class LineNumber implements Cloneable, Node {
Program Counter (PC) corresponds to line
/** Program Counter (PC) corresponds to line */
private short start_pc;
number in source file
/** number in source file */
private short line_number;
Initialize from another object.
Params:
  • c – the object to copy
/** * Initialize from another object. * * @param c the object to copy */
public LineNumber(final LineNumber c) { this(c.getStartPC(), c.getLineNumber()); }
Construct object from file stream.
Params:
  • file – Input stream
Throws:
  • IOException – if an I/O Exception occurs in readUnsignedShort
/** * Construct object from file stream. * * @param file Input stream * @throws IOException if an I/O Exception occurs in readUnsignedShort */
LineNumber(final DataInput file) throws IOException { this(file.readUnsignedShort(), file.readUnsignedShort()); }
Params:
  • start_pc – Program Counter (PC) corresponds to
  • line_number – line number in source file
/** * @param start_pc Program Counter (PC) corresponds to * @param line_number line number in source file */
public LineNumber(final int start_pc, final int line_number) { this.start_pc = (short) start_pc; this.line_number = (short)line_number; }
Called by objects that are traversing the nodes of the tree implicitely defined by the contents of a Java class. I.e., the hierarchy of methods, fields, attributes, etc. spawns a tree of objects.
Params:
  • v – Visitor object
/** * Called by objects that are traversing the nodes of the tree implicitely * defined by the contents of a Java class. I.e., the hierarchy of methods, * fields, attributes, etc. spawns a tree of objects. * * @param v Visitor object */
@Override public void accept( final Visitor v ) { v.visitLineNumber(this); }
Dump line number/pc pair to file stream in binary format.
Params:
  • file – Output file stream
Throws:
  • IOException – if an I/O Exception occurs in writeShort
/** * Dump line number/pc pair to file stream in binary format. * * @param file Output file stream * @throws IOException if an I/O Exception occurs in writeShort */
public void dump( final DataOutputStream file ) throws IOException { file.writeShort(start_pc); file.writeShort(line_number); }
Returns:Corresponding source line
/** * @return Corresponding source line */
public int getLineNumber() { return 0xffff & line_number; }
Returns:PC in code
/** * @return PC in code */
public int getStartPC() { return 0xffff & start_pc; }
Params:
  • line_number – the source line number
/** * @param line_number the source line number */
public void setLineNumber( final int line_number ) { this.line_number = (short) line_number; }
Params:
  • start_pc – the pc for this line number
/** * @param start_pc the pc for this line number */
public void setStartPC( final int start_pc ) { this.start_pc = (short) start_pc; }
Returns:String representation
/** * @return String representation */
@Override public String toString() { return "LineNumber(" + start_pc + ", " + line_number + ")"; }
Returns:deep copy of this object
/** * @return deep copy of this object */
public LineNumber copy() { try { return (LineNumber) clone(); } catch (final CloneNotSupportedException e) { // TODO should this throw? } return null; } }