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 020import java.util.Arrays; 021 022import org.apache.bcel.generic.Type; 023import org.apache.bcel.verifier.exc.AssertionViolatedException; 024import org.apache.bcel.verifier.exc.LocalVariableInfoInconsistentException; 025 026/** 027 * A utility class holding the information about the names and the types of the local variables in a given method. 028 */ 029public class LocalVariablesInfo { 030 031 /** The information about the local variables is stored here. */ 032 private final LocalVariableInfo[] localVariableInfos; 033 034 /** The constructor. */ 035 LocalVariablesInfo(final int max_locals) { 036 localVariableInfos = new LocalVariableInfo[max_locals]; 037 Arrays.setAll(localVariableInfos, i -> new LocalVariableInfo()); 038 } 039 040 /** 041 * Adds information about the local variable in slot 'slot'. Automatically adds information for slot+1 if 't' is 042 * Type.LONG or Type.DOUBLE. 043 * 044 * @param name variable name 045 * @param startPc Range in which the variable is valid. 046 * @param length length of ... 047 * @param type variable type 048 * @throws LocalVariableInfoInconsistentException if the new information conflicts with already gathered information. 049 */ 050 public void add(final int slot, final String name, final int startPc, final int length, final Type type) throws LocalVariableInfoInconsistentException { 051 // The add operation on LocalVariableInfo may throw the '...Inconsistent...' exception, we don't throw it explicitely 052 // here. 053 054 if (slot < 0 || slot >= localVariableInfos.length) { 055 throw new AssertionViolatedException("Slot number for local variable information out of range."); 056 } 057 058 localVariableInfos[slot].add(name, startPc, length, type); 059 if (type == Type.LONG) { 060 localVariableInfos[slot + 1].add(name, startPc, length, LONG_Upper.theInstance()); 061 } 062 if (type == Type.DOUBLE) { 063 localVariableInfos[slot + 1].add(name, startPc, length, DOUBLE_Upper.theInstance()); 064 } 065 } 066 067 /** 068 * Returns the LocalVariableInfo for the given slot. 069 * 070 * @param slot Slot to query. 071 * @return The LocalVariableInfo for the given slot. 072 */ 073 public LocalVariableInfo getLocalVariableInfo(final int slot) { 074 if (slot < 0 || slot >= localVariableInfos.length) { 075 throw new AssertionViolatedException("Slot number for local variable information out of range."); 076 } 077 return localVariableInfos[slot]; 078 } 079}