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1   /*
2    * Licensed to the Apache Software Foundation (ASF) under one or more
3    * contributor license agreements.  See the NOTICE file distributed with
4    * this work for additional information regarding copyright ownership.
5    * The ASF licenses this file to You under the Apache License, Version 2.0
6    * (the "License"); you may not use this file except in compliance with
7    * the License.  You may obtain a copy of the License at
8    *
9    *      http://www.apache.org/licenses/LICENSE-2.0
10   *
11   *  Unless required by applicable law or agreed to in writing, software
12   *  distributed under the License is distributed on an "AS IS" BASIS,
13   *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14   *  See the License for the specific language governing permissions and
15   *  limitations under the License. 
16   *
17   */ 
18  package org.apache.bcel.verifier.statics;
19  
20  
21  import org.apache.bcel.generic.Type;
22  import org.apache.bcel.verifier.exc.AssertionViolatedException;
23  import org.apache.bcel.verifier.exc.LocalVariableInfoInconsistentException;
24  
25  /**
26   * A utility class holding the information about
27   * the names and the types of the local variables in
28   * a given method.
29   *
30   * @version $Id: LocalVariablesInfo.html 898356 2014-02-18 05:44:40Z ggregory $
31   * @author Enver Haase
32   */
33  public class LocalVariablesInfo{
34  	
35  	/** The information about the local variables is stored here. */
36  	private LocalVariableInfo[] localVariableInfos;
37  
38  	/** The constructor. */
39  	LocalVariablesInfo(int max_locals){
40  		localVariableInfos = new LocalVariableInfo[max_locals];
41  		for (int i=0; i<max_locals; i++){
42  			localVariableInfos[i] = new LocalVariableInfo();
43  		}
44  	}
45  
46  	/** Returns the LocalVariableInfo for the given slot. */
47  	public LocalVariableInfo getLocalVariableInfo(int slot){
48  		if (slot < 0 || slot >= localVariableInfos.length){
49  			throw new AssertionViolatedException("Slot number for local variable information out of range.");
50  		}
51  		return localVariableInfos[slot];
52  	}
53  
54  	/**
55  	 * Adds information about the local variable in slot 'slot'. Automatically 
56  	 * adds information for slot+1 if 't' is Type.LONG or Type.DOUBLE.
57  	 * @throws LocalVariableInfoInconsistentException if the new information conflicts
58  	 *         with already gathered information.
59  	 */
60  	public void add(int slot, String name, int startpc, int length, Type t) throws LocalVariableInfoInconsistentException{
61  		// The add operation on LocalVariableInfo may throw the '...Inconsistent...' exception, we don't throw it explicitely here.
62  		
63  		if (slot < 0 || slot >= localVariableInfos.length){
64  			throw new AssertionViolatedException("Slot number for local variable information out of range.");
65  		}
66  
67  		localVariableInfos[slot].add(name, startpc, length, t);
68  		if (t == Type.LONG) {
69              localVariableInfos[slot+1].add(name, startpc, length, LONG_Upper.theInstance());
70          }
71  		if (t == Type.DOUBLE) {
72              localVariableInfos[slot+1].add(name, startpc, length, DOUBLE_Upper.theInstance());
73          }
74  	}
75  }