com.vladium.jcd.cls.attribute

Class LineNumberTableAttribute_info

java.lang.Object

com.vladium.jcd.cls.attribute.Attribute_info

com.vladium.jcd.cls.attribute.LineNumberTableAttribute_info

All Implemented Interfaces:

IClassFormatOutput, java.lang.Cloneable

public final class LineNumberTableAttribute_info
extends Attribute_info

The LineNumberTable attribute is an optional variable-length attribute in the attributes table of a CodeAttribute_info attribute. It may be used by debuggers to determine which part of the JVM code array corresponds to a given line number in the original source file. If LineNumberTable attributes are present in the attributes table of a given Code attribute, then they may appear in any order. Furthermore, multiple LineNumberTable attributes may together represent a given line of a source file; that is, LineNumberTable attributes need not be one-to-one with source lines.

The LineNumberTable attribute has the following format:

 LineNumberTable_attribute {
          u2 attribute_name_index;
          u4 attribute_length;
          u2 line_number_table_length;
          {  u2 start_pc;             
             u2 line_number;             
          } line_number_table[line_number_table_length];
  }
 
 
 LineNumberTable_attribute structure contains the following items:
 
    line_number_table_length
 
 The value of the line_number_table_length item indicates the number of
 entries in the line_number_table array.
 
    line_number_table[]
 
 Each entry in the line_number_table array indicates that the line number
 in the original source file changes at a given point in the code array.

 
 Each line_number_table entry must contain the following two items:
 
    start_pc
 
 The value of the start_pc item must indicate the index into the code array
 at which the code for a new line in the original source file begins. The
 value of start_pc must be less than the value of the code_length item of
 the CodeAttribute_info attribute of which this LineNumberTable
 is an attribute.

 
    line_number
 
 The value of the line_number item must give the corresponding line number
 in the original source file.

Author:

Vlad Roubtsov, (C) 2003

Field Summary

Fields

Modifier and Type	Field and Description
private java.util.List	m_lines

Fields inherited from class com.vladium.jcd.cls.attribute.Attribute_info

ATTRIBUTE_BRIDGE, ATTRIBUTE_CODE, ATTRIBUTE_CONSTANT_VALUE, ATTRIBUTE_EXCEPTIONS, ATTRIBUTE_INNERCLASSES, ATTRIBUTE_LINE_NUMBER_TABLE, ATTRIBUTE_SOURCEFILE, ATTRIBUTE_SYNTHETIC, m_attribute_length, m_name_index

Constructor Summary

Constructors

Constructor and Description
LineNumberTableAttribute_info(int attribute_name_index, long attribute_length, UDataInputStream bytes)

Method Summary

Methods

Modifier and Type	Method and Description
void	accept(IAttributeVisitor visitor, java.lang.Object ctx)
java.lang.Object	clone() Performs a deep copy.
LineNumber_info	get(int offset) Returns LineNumber_info descriptor at a given offset.
long	length() Returns the total length of this attribute when converted to .class format [including the 6-byte header]
int	size() Returns the number of descriptors in this collection [can be 0].
java.lang.String	toString()
void	writeInClassFormat(UDataOutputStream out)

Methods inherited from class com.vladium.jcd.cls.attribute.Attribute_info

getName, new_Attribute_info

Methods inherited from class java.lang.Object

equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

m_lines

private java.util.List m_lines

Constructor Detail

LineNumberTableAttribute_info

LineNumberTableAttribute_info(int attribute_name_index,
                             long attribute_length,
                             UDataInputStream bytes)
                        throws java.io.IOException

Throws:

java.io.IOException

Method Detail

get

public LineNumber_info get(int offset)

Returns LineNumber_info descriptor at a given offset.

Parameters:

offset - line number entry offset [must be in [0, size()) range; input not checked]

Returns:

LineNumber_info descriptor [never null]

Throws:

java.lang.IndexOutOfBoundsException - if 'offset' is outside of valid range

size

public int size()

Returns the number of descriptors in this collection [can be 0].

length

public long length()

Description copied from class: Attribute_info

Returns the total length of this attribute when converted to .class format [including the 6-byte header]

Specified by:

length in class Attribute_info

accept

public void accept(IAttributeVisitor visitor,
          java.lang.Object ctx)

Specified by:

accept in class Attribute_info

toString

public java.lang.String toString()

Specified by:

toString in class Attribute_info

clone

public java.lang.Object clone()

Performs a deep copy.

Overrides:

clone in class Attribute_info

writeInClassFormat

public void writeInClassFormat(UDataOutputStream out)
                        throws java.io.IOException

Specified by:

writeInClassFormat in interface IClassFormatOutput

Overrides:

writeInClassFormat in class Attribute_info

Throws:

java.io.IOException