org.apache.tomcat.util.bcel.classfile.StackMapEntry Maven / Gradle / Ivy
/*
* 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.tomcat.util.bcel.classfile;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import java.io.Serializable;
/**
* This class represents a stack map entry recording the types of
* local variables and the the of stack items at a given byte code offset.
* See CLDC specification §5.3.1.2
*
* @version $Id: StackMapEntry.java 1181133 2011-10-10 18:49:14Z markt $
* @author M. Dahm
* @see StackMap
* @see StackMapType
*/
public final class StackMapEntry implements Cloneable, Serializable {
private static final long serialVersionUID = 1L;
private int byte_code_offset;
private int number_of_locals;
private StackMapType[] types_of_locals;
private int number_of_stack_items;
private StackMapType[] types_of_stack_items;
/**
* Construct object from file stream.
* @param file Input stream
* @throws IOException
*/
StackMapEntry(DataInputStream file, ConstantPool constant_pool) throws IOException {
this(file.readShort(), file.readShort(), null, -1, null);
types_of_locals = new StackMapType[number_of_locals];
for (int i = 0; i < number_of_locals; i++) {
types_of_locals[i] = new StackMapType(file, constant_pool);
}
number_of_stack_items = file.readShort();
types_of_stack_items = new StackMapType[number_of_stack_items];
for (int i = 0; i < number_of_stack_items; i++) {
types_of_stack_items[i] = new StackMapType(file, constant_pool);
}
}
public StackMapEntry(int byte_code_offset, int number_of_locals,
StackMapType[] types_of_locals, int number_of_stack_items,
StackMapType[] types_of_stack_items) {
this.byte_code_offset = byte_code_offset;
this.number_of_locals = number_of_locals;
this.types_of_locals = types_of_locals;
this.number_of_stack_items = number_of_stack_items;
this.types_of_stack_items = types_of_stack_items;
}
/**
* Dump stack map entry
*
* @param file Output file stream
* @throws IOException
*/
public final void dump( DataOutputStream file ) throws IOException {
file.writeShort(byte_code_offset);
file.writeShort(number_of_locals);
for (int i = 0; i < number_of_locals; i++) {
types_of_locals[i].dump(file);
}
file.writeShort(number_of_stack_items);
for (int i = 0; i < number_of_stack_items; i++) {
types_of_stack_items[i].dump(file);
}
}
/**
* @return String representation.
*/
@Override
public final String toString() {
StringBuilder buf = new StringBuilder(64);
buf.append("(offset=").append(byte_code_offset);
if (number_of_locals > 0) {
buf.append(", locals={");
for (int i = 0; i < number_of_locals; i++) {
buf.append(types_of_locals[i]);
if (i < number_of_locals - 1) {
buf.append(", ");
}
}
buf.append("}");
}
if (number_of_stack_items > 0) {
buf.append(", stack items={");
for (int i = 0; i < number_of_stack_items; i++) {
buf.append(types_of_stack_items[i]);
if (i < number_of_stack_items - 1) {
buf.append(", ");
}
}
buf.append("}");
}
buf.append(")");
return buf.toString();
}
/**
* @return deep copy of this object
*/
public StackMapEntry copy() {
try {
return (StackMapEntry) clone();
} catch (CloneNotSupportedException e) {
}
return null;
}
}