/*
* Copyright 2000-2004 The Apache Software Foundation
*
* Licensed 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.bcel5_2_0.classfile;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import org.apache.bcel5_2_0.Constants;
/**
* This class represents colection of local variables in a
* method. This attribute is contained in the <em>Code</em> attribute.
*
* @version $Id: LocalVariableTable.java 386056 2006-03-15 11:31:56Z tcurdt $
* @author <A HREF="mailto:m.dahm@gmx.de">M. Dahm</A>
* @see Code
* @see LocalVariable
*/
public class LocalVariableTable extends Attribute {
private int local_variable_table_length; // Table of local
private LocalVariable[] local_variable_table; // variables
/**
* Initialize from another object. Note that both objects use the same
* references (shallow copy). Use copy() for a physical copy.
*/
public LocalVariableTable(LocalVariableTable c) {
this(c.getNameIndex(), c.getLength(), c.getLocalVariableTable(), c.getConstantPool());
}
/**
* @param name_index Index in constant pool to `LocalVariableTable'
* @param length Content length in bytes
* @param local_variable_table Table of local variables
* @param constant_pool Array of constants
*/
public LocalVariableTable(int name_index, int length, LocalVariable[] local_variable_table,
ConstantPool constant_pool) {
super(Constants.ATTR_LOCAL_VARIABLE_TABLE, name_index, length, constant_pool);
setLocalVariableTable(local_variable_table);
}
/**
* Construct object from file stream.
* @param name_index Index in constant pool
* @param length Content length in bytes
* @param file Input stream
* @param constant_pool Array of constants
* @throws IOException
*/
LocalVariableTable(int name_index, int length, DataInputStream file, ConstantPool constant_pool)
throws IOException {
this(name_index, length, (LocalVariable[]) null, constant_pool);
local_variable_table_length = (file.readUnsignedShort());
local_variable_table = new LocalVariable[local_variable_table_length];
for (int i = 0; i < local_variable_table_length; i++) {
local_variable_table[i] = new LocalVariable(file, constant_pool);
}
}
/**
* 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
*/
public void accept( Visitor v ) {
v.visitLocalVariableTable(this);
}
/**
* Dump local variable table attribute to file stream in binary format.
*
* @param file Output file stream
* @throws IOException
*/
public final void dump( DataOutputStream file ) throws IOException {
super.dump(file);
file.writeShort(local_variable_table_length);
for (int i = 0; i < local_variable_table_length; i++) {
local_variable_table[i].dump(file);
}
}
/**
* @return Array of local variables of method.
*/
public final LocalVariable[] getLocalVariableTable() {
return local_variable_table;
}
/**
* @return first matching variable using index
*
* @param index the variable slot
*
* @return the first LocalVariable that matches the slot or null if not found
*
* @deprecated since 5.2 because multiple variables can share the
* same slot, use getLocalVariable(int index, int pc) instead.
*/
public final LocalVariable getLocalVariable( int index ) {
for (int i = 0; i < local_variable_table_length; i++) {
if (local_variable_table[i].getIndex() == index) {
return local_variable_table[i];
}
}
return null;
}
/**
* @return matching variable using index when variable is used at supplied pc
*
* @param index the variable slot
* @param pc the current pc that this variable is alive
*
* @return the LocalVariable that matches or null if not found
*/
public final LocalVariable getLocalVariable( int index, int pc ) {
for (int i = 0; i < local_variable_table_length; i++) {
if (local_variable_table[i].getIndex() == index) {
int start_pc = local_variable_table[i].getStartPC();
int end_pc = start_pc + local_variable_table[i].getLength();
if ((pc >= start_pc) && (pc < end_pc)) {
return local_variable_table[i];
}
}
}
return null;
}
public final void setLocalVariableTable( LocalVariable[] local_variable_table ) {
this.local_variable_table = local_variable_table;
local_variable_table_length = (local_variable_table == null)
? 0
: local_variable_table.length;
}
/**
* @return String representation.
*/
public final String toString() {
StringBuilder buf = new StringBuilder("");
for (int i = 0; i < local_variable_table_length; i++) {
buf.append(local_variable_table[i].toString());
if (i < local_variable_table_length - 1) {
buf.append('\n');
}
}
return buf.toString();
}
/**
* @return deep copy of this attribute
*/
public Attribute copy( ConstantPool _constant_pool ) {
LocalVariableTable c = (LocalVariableTable) clone();
c.local_variable_table = new LocalVariable[local_variable_table_length];
for (int i = 0; i < local_variable_table_length; i++) {
c.local_variable_table[i] = local_variable_table[i].copy();
}
c.constant_pool = _constant_pool;
return c;
}
public final int getTableLength() {
return local_variable_table_length;
}
}