/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.tomcat.util.bcel.classfile;
import java.io.DataInput;
import java.io.IOException;
import org.apache.tomcat.util.bcel.Const;
/**
* The element_value structure is documented at https://docs.oracle.com/javase/specs/jvms/se11/html/jvms-4.html#jvms-4.7.16.1
*
* <pre>
* element_value {
* u1 tag;
* union {
* u2 const_value_index;
*
* { u2 type_name_index;
* u2 const_name_index;
* } enum_const_value;
*
* u2 class_info_index;
*
* annotation annotation_value;
*
* { u2 num_values;
* element_value values[num_values];
* } array_value;
* } value;
* }
* </pre>
*/
public abstract class ElementValue {
public static final byte STRING = 's';
public static final byte ENUM_CONSTANT = 'e';
public static final byte CLASS = 'c';
public static final byte ANNOTATION = '@';
public static final byte ARRAY = '[';
public static final byte PRIMITIVE_INT = 'I';
public static final byte PRIMITIVE_BYTE = 'B';
public static final byte PRIMITIVE_CHAR = 'C';
public static final byte PRIMITIVE_DOUBLE = 'D';
public static final byte PRIMITIVE_FLOAT = 'F';
public static final byte PRIMITIVE_LONG = 'J';
public static final byte PRIMITIVE_SHORT = 'S';
public static final byte PRIMITIVE_BOOLEAN = 'Z';
static final ElementValue[] EMPTY_ARRAY = {};
/**
* Reads an {@code element_value} as an {@code ElementValue}.
*
* @param input Raw data input.
* @param cpool Constant pool.
* @return a new ElementValue.
* @throws IOException if an I/O error occurs.
*/
public static ElementValue readElementValue(final DataInput input, final ConstantPool cpool) throws IOException {
return readElementValue(input, cpool, 0);
}
/**
* Reads an {@code element_value} as an {@code ElementValue}.
*
* @param input Raw data input.
* @param cpool Constant pool.
* @param arrayNesting level of current array nesting.
* @return a new ElementValue.
* @throws IOException if an I/O error occurs.
* @since 6.7.0
*/
public static ElementValue readElementValue(final DataInput input, final ConstantPool cpool, int arrayNesting)
throws IOException {
final byte tag = input.readByte();
switch (tag) {
case PRIMITIVE_BYTE:
case PRIMITIVE_CHAR:
case PRIMITIVE_DOUBLE:
case PRIMITIVE_FLOAT:
case PRIMITIVE_INT:
case PRIMITIVE_LONG:
case PRIMITIVE_SHORT:
case PRIMITIVE_BOOLEAN:
case STRING:
return new SimpleElementValue(tag, input.readUnsignedShort(), cpool);
case ENUM_CONSTANT:
input.readUnsignedShort(); // Unused type_index
return new EnumElementValue(ENUM_CONSTANT, input.readUnsignedShort(), cpool);
case CLASS:
return new ClassElementValue(CLASS, input.readUnsignedShort(), cpool);
case ANNOTATION:
// TODO isRuntimeVisible
return new AnnotationElementValue(ANNOTATION, new AnnotationEntry(input, cpool), cpool);
case ARRAY:
arrayNesting++;
if (arrayNesting > Const.MAX_ARRAY_DIMENSIONS) {
// JVM spec 4.4.1
throw new ClassFormatException(String.format("Arrays are only valid if they represent %,d or fewer dimensions.",
Integer.valueOf(Const.MAX_ARRAY_DIMENSIONS)));
}
final int numArrayVals = input.readUnsignedShort();
final ElementValue[] evalues = new ElementValue[numArrayVals];
for (int j = 0; j < numArrayVals; j++) {
evalues[j] = readElementValue(input, cpool, arrayNesting);
}
return new ArrayElementValue(ARRAY, evalues, cpool);
default:
throw new ClassFormatException("Unexpected element value kind in annotation: " + tag);
}
}
private final int type;
private final ConstantPool cpool;
ElementValue(final int type, final ConstantPool cpool) {
this.type = type;
this.cpool = cpool;
}
final ConstantPool getConstantPool() {
return cpool;
}
final int getType() {
return type;
}
public abstract String stringifyValue();
}