001/*
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements.  See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership.  The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License.  You may obtain a copy of the License at
009 *
010 *   https://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing,
013 * software distributed under the License is distributed on an
014 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
015 * KIND, either express or implied.  See the License for the
016 * specific language governing permissions and limitations
017 * under the License.
018 */
019
020package org.apache.bcel.classfile;
021
022import java.io.DataInput;
023import java.io.DataOutputStream;
024import java.io.IOException;
025import java.util.Arrays;
026import java.util.Iterator;
027import java.util.stream.Stream;
028
029import org.apache.bcel.Const;
030import org.apache.bcel.util.Args;
031
032// The new table is used when generic types are about...
033
034//LocalVariableTable_attribute {
035//       u2 attribute_name_index;
036//       u4 attribute_length;
037//       u2 local_variable_table_length;
038//       {  u2 start_pc;
039//          u2 length;
040//          u2 name_index;
041//          u2 descriptor_index;
042//          u2 index;
043//       } local_variable_table[local_variable_table_length];
044//     }
045
046//LocalVariableTypeTable_attribute {
047//    u2 attribute_name_index;
048//    u4 attribute_length;
049//    u2 local_variable_type_table_length;
050//    {
051//      u2 start_pc;
052//      u2 length;
053//      u2 name_index;
054//      u2 signature_index;
055//      u2 index;
056//    } localVariableTypeTable[local_variable_type_table_length];
057//  }
058// J5TODO: Needs some testing !
059
060/**
061 * Represents the LocalVariableTypeTable attribute.
062 *
063 * @since 6.0
064 */
065public class LocalVariableTypeTable extends Attribute implements Iterable<LocalVariable> {
066
067    private static final LocalVariable[] EMPTY_ARRAY = {};
068
069    private LocalVariable[] localVariableTypeTable; // variables
070
071    LocalVariableTypeTable(final int nameIdx, final int len, final DataInput input, final ConstantPool cpool) throws IOException {
072        this(nameIdx, len, (LocalVariable[]) null, cpool);
073        final int localVariableTypeTableLength = input.readUnsignedShort();
074        localVariableTypeTable = new LocalVariable[localVariableTypeTableLength];
075        for (int i = 0; i < localVariableTypeTableLength; i++) {
076            localVariableTypeTable[i] = new LocalVariable(input, cpool);
077        }
078    }
079
080    /**
081     * Constructs a new LocalVariableTypeTable.
082     *
083     * @param nameIndex index into constant pool.
084     * @param length content length in bytes.
085     * @param localVariableTypeTable The local variable type table.
086     * @param constantPool The constant pool.
087     */
088    public LocalVariableTypeTable(final int nameIndex, final int length, final LocalVariable[] localVariableTypeTable, final ConstantPool constantPool) {
089        super(Const.ATTR_LOCAL_VARIABLE_TYPE_TABLE, nameIndex, length, constantPool);
090        this.localVariableTypeTable = localVariableTypeTable != null ? localVariableTypeTable : LocalVariable.EMPTY_ARRAY;
091        Args.requireU2(this.localVariableTypeTable.length, "localVariableTypeTable.length");
092    }
093
094    /**
095     * Constructs a copy.
096     *
097     * @param c The instance to copy.
098     */
099    public LocalVariableTypeTable(final LocalVariableTypeTable c) {
100        this(c.getNameIndex(), c.getLength(), c.getLocalVariableTypeTable(), c.getConstantPool());
101    }
102
103    @Override
104    public void accept(final Visitor v) {
105        v.visitLocalVariableTypeTable(this);
106    }
107
108    /**
109     * @return deep copy of this attribute.
110     */
111    @Override
112    public Attribute copy(final ConstantPool constantPool) {
113        final LocalVariableTypeTable c = (LocalVariableTypeTable) clone();
114        c.localVariableTypeTable = new LocalVariable[localVariableTypeTable.length];
115        Arrays.setAll(c.localVariableTypeTable, i -> localVariableTypeTable[i].copy());
116        c.setConstantPool(constantPool);
117        return c;
118    }
119
120    @Override
121    public final void dump(final DataOutputStream file) throws IOException {
122        super.dump(file);
123        file.writeShort(Args.requireU2(localVariableTypeTable.length, "localVariableTypeTable.length"));
124        for (final LocalVariable variable : localVariableTypeTable) {
125            variable.dump(file);
126        }
127    }
128
129    /**
130     * Gets the local variable for the given index.
131     *
132     * @param index The index.
133     * @return The local variable or null if not found.
134     */
135    public final LocalVariable getLocalVariable(final int index) {
136        for (final LocalVariable variable : localVariableTypeTable) {
137            if (variable.getIndex() == index) {
138                return variable;
139            }
140        }
141        return null;
142    }
143
144    /**
145     * Gets the local variable type table.
146     *
147     * @return The local variable type table.
148     */
149    public final LocalVariable[] getLocalVariableTypeTable() {
150        return localVariableTypeTable;
151    }
152
153    /**
154     * Gets the table length.
155     *
156     * @return The table length.
157     */
158    public final int getTableLength() {
159        return localVariableTypeTable == null ? 0 : localVariableTypeTable.length;
160    }
161
162    @Override
163    public Iterator<LocalVariable> iterator() {
164        return Stream.of(localVariableTypeTable).iterator();
165    }
166
167    /**
168     * Sets the local variable table.
169     *
170     * @param localVariableTable The local variable table to set.
171     */
172    public final void setLocalVariableTable(final LocalVariable[] localVariableTable) {
173        this.localVariableTypeTable = localVariableTable != null ? localVariableTable : EMPTY_ARRAY;
174    }
175
176    /**
177     * @return String representation.
178     */
179    @Override
180    public final String toString() {
181        final StringBuilder buf = new StringBuilder();
182        for (int i = 0; i < localVariableTypeTable.length; i++) {
183            buf.append(localVariableTypeTable[i].toStringShared(true));
184            if (i < localVariableTypeTable.length - 1) {
185                buf.append('\n');
186            }
187        }
188        return buf.toString();
189    }
190}