    001/*
    002 * Licensed to the Apache Software Foundation (ASF) under one or more
    003 * contributor license agreements.  See the NOTICE file distributed with
    004 * this work for additional information regarding copyright ownership.
    005 * The ASF licenses this file to You under the Apache License, Version 2.0
    006 * (the "License"); you may not use this file except in compliance with
    007 * the License.  You may obtain a copy of the License at
    008 *
    009 *      http://www.apache.org/licenses/LICENSE-2.0
    010 *
    011 *  Unless required by applicable law or agreed to in writing, software
    012 *  distributed under the License is distributed on an "AS IS" BASIS,
    013 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    014 *  See the License for the specific language governing permissions and
    015 *  limitations under the License.
    016 *
    017 */
    018package org.apache.bcel.verifier.statics;
    019
    020
    021import org.apache.bcel.generic.Type;
    022import org.apache.bcel.verifier.exc.AssertionViolatedException;
    023import org.apache.bcel.verifier.exc.LocalVariableInfoInconsistentException;
    024
    025/**
    026 * A utility class holding the information about
    027 * the names and the types of the local variables in
    028 * a given method.
    029 *
    030 * @version $Id$
    031 */
    032public class LocalVariablesInfo{
    033
    034    /** The information about the local variables is stored here. */
    035    private final LocalVariableInfo[] localVariableInfos;
    036
    037    /** The constructor. */
    038    LocalVariablesInfo(final int max_locals) {
    039        localVariableInfos = new LocalVariableInfo[max_locals];
    040        for (int i=0; i<max_locals; i++) {
    041            localVariableInfos[i] = new LocalVariableInfo();
    042        }
    043    }
    044
    045    /** Returns the LocalVariableInfo for the given slot. */
    046    public LocalVariableInfo getLocalVariableInfo(final int slot) {
    047        if (slot < 0 || slot >= localVariableInfos.length) {
    048            throw new AssertionViolatedException("Slot number for local variable information out of range.");
    049        }
    050        return localVariableInfos[slot];
    051    }
    052
    053    /**
    054     * Adds information about the local variable in slot 'slot'. Automatically
    055     * adds information for slot+1 if 't' is Type.LONG or Type.DOUBLE.
    056     * @throws LocalVariableInfoInconsistentException if the new information conflicts
    057     *         with already gathered information.
    058     */
    059    public void add(final int slot, final String name, final int startpc, final int length, final Type t) throws LocalVariableInfoInconsistentException{
    060        // The add operation on LocalVariableInfo may throw the '...Inconsistent...' exception, we don't throw it explicitely here.
    061
    062        if (slot < 0 || slot >= localVariableInfos.length) {
    063            throw new AssertionViolatedException("Slot number for local variable information out of range.");
    064        }
    065
    066        localVariableInfos[slot].add(name, startpc, length, t);
    067        if (t == Type.LONG) {
    068            localVariableInfos[slot+1].add(name, startpc, length, LONG_Upper.theInstance());
    069        }
    070        if (t == Type.DOUBLE) {
    071            localVariableInfos[slot+1].add(name, startpc, length, DOUBLE_Upper.theInstance());
    072        }
    073    }
    074}