/*
* 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 org.apache.bcel.classfile;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import org.apache.bcel.Constants;
/**
* This class represents a table of line numbers for debugging
* purposes. This attribute is used by the <em>Code</em> attribute. It
* contains pairs of PCs and line numbers.
*
* @version $Id: LineNumberTable.java 1152077 2011-07-29 02:29:42Z dbrosius $
* @author <A HREF="mailto:m.dahm@gmx.de">M. Dahm</A>
* @see Code
* @see LineNumber
*/
public final class LineNumberTable extends Attribute {
private static final long serialVersionUID = -6967221519632128904L;
private int line_number_table_length;
private LineNumber[] line_number_table; // Table of line/numbers pairs
/*
* Initialize from another object. Note that both objects use the same
* references (shallow copy). Use copy() for a physical copy.
*/
public LineNumberTable(LineNumberTable c) {
this(c.getNameIndex(), c.getLength(), c.getLineNumberTable(), c.getConstantPool());
}
/*
* @param name_index Index of name
* @param length Content length in bytes
* @param line_number_table Table of line/numbers pairs
* @param constant_pool Array of constants
*/
public LineNumberTable(int name_index, int length, LineNumber[] line_number_table,
ConstantPool constant_pool) {
super(Constants.ATTR_LINE_NUMBER_TABLE, name_index, length, constant_pool);
setLineNumberTable(line_number_table);
}
/**
* Construct object from file stream.
* @param name_index Index of name
* @param length Content length in bytes
* @param file Input stream
* @param constant_pool Array of constants
* @throws IOException
*/
LineNumberTable(int name_index, int length, DataInputStream file, ConstantPool constant_pool)
throws IOException {
this(name_index, length, (LineNumber[]) null, constant_pool);
line_number_table_length = (file.readUnsignedShort());
line_number_table = new LineNumber[line_number_table_length];
for (int i = 0; i < line_number_table_length; i++) {
line_number_table[i] = new LineNumber(file);
}
}
/**
* 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( Visitor v ) {
v.visitLineNumberTable(this);
}
/**
* Dump line number table attribute to file stream in binary format.
*
* @param file Output file stream
* @throws IOException
*/
@Override
public final void dump( DataOutputStream file ) throws IOException {
super.dump(file);
file.writeShort(line_number_table_length);
for (int i = 0; i < line_number_table_length; i++) {
line_number_table[i].dump(file);
}
}
/**
* @return Array of (pc offset, line number) pairs.
*/
public final LineNumber[] getLineNumberTable() {
return line_number_table;
}
/**
* @param line_number_table the line number entries for this table
*/
public final void setLineNumberTable( LineNumber[] line_number_table ) {
this.line_number_table = line_number_table;
line_number_table_length = (line_number_table == null) ? 0 : line_number_table.length;
}
/**
* @return String representation.
*/
@Override
public final String toString() {
StringBuilder buf = new StringBuilder();
StringBuilder line = new StringBuilder();
String newLine = System.getProperty("line.separator", "\n");
for (int i = 0; i < line_number_table_length; i++) {
line.append(line_number_table[i].toString());
if (i < line_number_table_length - 1) {
line.append(", ");
}
if (line.length() > 72) {
line.append(newLine);
buf.append(line.toString());
line.setLength(0);
}
}
buf.append(line);
return buf.toString();
}
/**
* Map byte code positions to source code lines.
*
* @param pos byte code offset
* @return corresponding line in source code
*/
public int getSourceLine( int pos ) {
int l = 0, r = line_number_table_length - 1;
if (r < 0) {
return -1;
}
int min_index = -1, min = -1;
/* Do a binary search since the array is ordered.
*/
do {
int i = (l + r) / 2;
int j = line_number_table[i].getStartPC();
if (j == pos) {
return line_number_table[i].getLineNumber();
} else if (pos < j) {
r = i - 1;
} else {
l = i + 1;
}
/* If exact match can't be found (which is the most common case)
* return the line number that corresponds to the greatest index less
* than pos.
*/
if (j < pos && j > min) {
min = j;
min_index = i;
}
} while (l <= r);
/* It's possible that we did not find any valid entry for the bytecode
* offset we were looking for.
*/
if (min_index < 0) {
return -1;
}
return line_number_table[min_index].getLineNumber();
}
/**
* @return deep copy of this attribute
*/
@Override
public Attribute copy( ConstantPool _constant_pool ) {
LineNumberTable c = (LineNumberTable) clone();
c.line_number_table = new LineNumber[line_number_table_length];
for (int i = 0; i < line_number_table_length; i++) {
c.line_number_table[i] = line_number_table[i].copy();
}
c.constant_pool = _constant_pool;
return c;
}
public final int getTableLength() {
return line_number_table_length;
}
}