LocalVariablesInfo xref

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    1   /*
    2    * Copyright  2000-2004 The Apache Software Foundation
    3    *
    4    *  Licensed under the Apache License, Version 2.0 (the "License");
    5    *  you may not use this file except in compliance with the License.
    6    *  You may obtain a copy of the License at
    7    *
    8    *      http://www.apache.org/licenses/LICENSE-2.0
    9    *
    10   *  Unless required by applicable law or agreed to in writing, software
    11   *  distributed under the License is distributed on an "AS IS" BASIS,
    12   *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    13   *  See the License for the specific language governing permissions and
    14   *  limitations under the License.
    15   *
    16   */
    17  package org.apache.bcel.verifier.statics;
    18
    19
    20  import org.apache.bcel.generic.Type;
    21  import org.apache.bcel.verifier.exc.AssertionViolatedException;
    22  import org.apache.bcel.verifier.exc.LocalVariableInfoInconsistentException;
    23
    24  /***
    25   * A utility class holding the information about
    26   * the names and the types of the local variables in
    27   * a given method.
    28   *
    29   * @version $Id: LocalVariablesInfo.java 386056 2006-03-15 11:31:56Z tcurdt $
    30   * @author Enver Haase
    31   */
    32  public class LocalVariablesInfo{
    33
    34  	/*** The information about the local variables is stored here. */
    35  	private LocalVariableInfo[] localVariableInfos;
    36
    37  	/*** The constructor. */
    38  	LocalVariablesInfo(int max_locals){
    39  		localVariableInfos = new LocalVariableInfo[max_locals];
    40  		for (int i=0; i<max_locals; i++){
    41  			localVariableInfos[i] = new LocalVariableInfo();
    42  		}
    43  	}
    44
    45  	/*** Returns the LocalVariableInfo for the given slot. */
    46  	public LocalVariableInfo getLocalVariableInfo(int slot){
    47  		if (slot < 0 || slot >= localVariableInfos.length){
    48  			throw new AssertionViolatedException("Slot number for local variable information out of range.");
    49  		}
    50  		return localVariableInfos[slot];
    51  	}
    52
    53  	/***
    54  	 * Adds information about the local variable in slot 'slot'. Automatically
    55  	 * adds information for slot+1 if 't' is Type.LONG or Type.DOUBLE.
    56  	 * @throws LocalVariableInfoInconsistentException if the new information conflicts
    57  	 *         with already gathered information.
    58  	 */
    59  	public void add(int slot, String name, int startpc, int length, Type t) throws LocalVariableInfoInconsistentException{
    60  		// The add operation on LocalVariableInfo may throw the '...Inconsistent...' exception, we don't throw it explicitely here.
    61
    62  		if (slot < 0 || slot >= localVariableInfos.length){
    63  			throw new AssertionViolatedException("Slot number for local variable information out of range.");
    64  		}
    65
    66  		localVariableInfos[slot].add(name, startpc, length, t);
    67  		if (t == Type.LONG) {
    68              localVariableInfos[slot+1].add(name, startpc, length, LONG_Upper.theInstance());
    69          }
    70  		if (t == Type.DOUBLE) {
    71              localVariableInfos[slot+1].add(name, startpc, length, DOUBLE_Upper.theInstance());
    72          }
    73  	}
    74  }