| /* |
| * 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.DataInput; |
| import java.io.DataOutputStream; |
| import java.io.IOException; |
| |
| import org.apache.bcel.Const; |
| |
| /** |
| * 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 $Id$ |
| * @see Code |
| * @see LineNumber |
| */ |
| public final class LineNumberTable extends Attribute { |
| |
| private static final int MAX_LINE_LENGTH = 72; |
| 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(final 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(final int name_index, final int length, final LineNumber[] line_number_table, |
| final ConstantPool constant_pool) { |
| super(Const.ATTR_LINE_NUMBER_TABLE, name_index, length, constant_pool); |
| this.line_number_table = line_number_table; |
| } |
| |
| |
| /** |
| * Construct object from input stream. |
| * @param name_index Index of name |
| * @param length Content length in bytes |
| * @param input Input stream |
| * @param constant_pool Array of constants |
| * @throws IOEXception if an I/O Exception occurs in readUnsignedShort |
| */ |
| LineNumberTable(final int name_index, final int length, final DataInput input, final ConstantPool constant_pool) |
| throws IOException { |
| this(name_index, length, (LineNumber[]) null, constant_pool); |
| final int line_number_table_length = input.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(input); |
| } |
| } |
| |
| |
| /** |
| * 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.visitLineNumberTable(this); |
| } |
| |
| |
| /** |
| * Dump line number table attribute to file stream in binary format. |
| * |
| * @param file Output file stream |
| * @throws IOEXception if an I/O Exception occurs in writeShort |
| */ |
| @Override |
| public final void dump( final DataOutputStream file ) throws IOException { |
| super.dump(file); |
| file.writeShort(line_number_table.length); |
| for (final LineNumber lineNumber : line_number_table) { |
| lineNumber.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( final LineNumber[] line_number_table ) { |
| this.line_number_table = line_number_table; |
| } |
| |
| |
| /** |
| * @return String representation. |
| */ |
| @Override |
| public final String toString() { |
| final StringBuilder buf = new StringBuilder(); |
| final StringBuilder line = new StringBuilder(); |
| final 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() > MAX_LINE_LENGTH) && (i < line_number_table.length - 1)) { |
| line.append(newLine); |
| buf.append(line); |
| 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( final int pos ) { |
| int l = 0; |
| int r = line_number_table.length - 1; |
| if (r < 0) { |
| return -1; |
| } |
| int min_index = -1; |
| int min = -1; |
| /* Do a binary search since the array is ordered. |
| */ |
| do { |
| final int i = (l + r) / 2; |
| final 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( final ConstantPool _constant_pool ) { |
| // TODO could use the lower level constructor and thereby allow |
| // line_number_table to be made final |
| final 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.setConstantPool(_constant_pool); |
| return c; |
| } |
| |
| |
| public final int getTableLength() { |
| return line_number_table == null ? 0 : line_number_table.length; |
| } |
| } |