1 /* 2 * Licensed to the Apache Software Foundation (ASF) under one 3 * or more contributor license agreements. See the NOTICE file 4 * distributed with this work for additional information 5 * regarding copyright ownership. The ASF licenses this file 6 * to you under the Apache License, Version 2.0 (the 7 * "License"); you may not use this file except in compliance 8 * with the License. You may obtain a copy of the License at 9 * 10 * https://www.apache.org/licenses/LICENSE-2.0 11 * 12 * Unless required by applicable law or agreed to in writing, 13 * software distributed under the License is distributed on an 14 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 15 * KIND, either express or implied. See the License for the 16 * specific language governing permissions and limitations 17 * under the License. 18 */ 19 package org.apache.bcel.verifier.statics; 20 21 import java.util.Arrays; 22 23 import org.apache.bcel.generic.Type; 24 import org.apache.bcel.verifier.exc.AssertionViolatedException; 25 import org.apache.bcel.verifier.exc.LocalVariableInfoInconsistentException; 26 27 /** 28 * A utility class holding the information about the names and the types of the local variables in a given method. 29 */ 30 public class LocalVariablesInfo { 31 32 /** The information about the local variables is stored here. */ 33 private final LocalVariableInfo[] localVariableInfos; 34 35 /** The constructor. */ 36 LocalVariablesInfo(final int maxLocals) { 37 localVariableInfos = new LocalVariableInfo[maxLocals]; 38 Arrays.setAll(localVariableInfos, i -> new LocalVariableInfo()); 39 } 40 41 /** 42 * Adds information about the local variable in slot 'slot'. Automatically adds information for slot+1 if 't' is 43 * Type.LONG or Type.DOUBLE. 44 * 45 * @param slot Slot number for local variable information 46 * @param name variable name 47 * @param startPc Range in which the variable is valid. 48 * @param length length of ... 49 * @param type variable type 50 * @throws LocalVariableInfoInconsistentException if the new information conflicts with already gathered information. 51 */ 52 public void add(final int slot, final String name, final int startPc, final int length, final Type type) throws LocalVariableInfoInconsistentException { 53 // The add operation on LocalVariableInfo may throw the '...Inconsistent...' exception, we don't throw it explicitly 54 // here. 55 56 if (slot < 0 || slot >= localVariableInfos.length) { 57 throw new AssertionViolatedException("Slot number for local variable information out of range."); 58 } 59 60 localVariableInfos[slot].add(name, startPc, length, type); 61 if (type == Type.LONG) { 62 localVariableInfos[slot + 1].add(name, startPc, length, LONG_Upper.theInstance()); 63 } 64 if (type == Type.DOUBLE) { 65 localVariableInfos[slot + 1].add(name, startPc, length, DOUBLE_Upper.theInstance()); 66 } 67 } 68 69 /** 70 * Returns the LocalVariableInfo for the given slot. 71 * 72 * @param slot Slot to query. 73 * @return The LocalVariableInfo for the given slot. 74 */ 75 public LocalVariableInfo getLocalVariableInfo(final int slot) { 76 if (slot < 0 || slot >= localVariableInfos.length) { 77 throw new AssertionViolatedException("Slot number for local variable information out of range."); 78 } 79 return localVariableInfos[slot]; 80 } 81 }