Signature.java
/*
* 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.bcel.classfile;
import java.io.ByteArrayInputStream;
import java.io.DataInput;
import java.io.DataOutputStream;
import java.io.IOException;
import java.nio.charset.StandardCharsets;
import java.util.Objects;
import org.apache.bcel.Const;
import org.apache.bcel.util.Args;
/**
* This class is derived from <em>Attribute</em> and represents a reference to a GJ attribute.
*
* @see Attribute
*/
public final class Signature extends Attribute {
/**
* Extends ByteArrayInputStream to make 'unreading' chars possible.
*/
private static final class MyByteArrayInputStream extends ByteArrayInputStream {
MyByteArrayInputStream(final String data) {
super(data.getBytes(StandardCharsets.UTF_8));
}
String getData() {
return new String(buf, StandardCharsets.UTF_8);
}
void unread() {
if (pos > 0) {
pos--;
}
}
}
private static boolean identStart(final int ch) {
return ch == 'T' || ch == 'L';
}
// @since 6.0 is no longer final
public static boolean isActualParameterList(final String s) {
return s.startsWith("L") && s.endsWith(">;");
}
// @since 6.0 is no longer final
public static boolean isFormalParameterList(final String s) {
return s.startsWith("<") && s.indexOf(':') > 0;
}
private static void matchGJIdent(final MyByteArrayInputStream in, final StringBuilder buf) {
int ch;
matchIdent(in, buf);
ch = in.read();
if (ch == '<' || ch == '(') { // Parameterized or method
// System.out.println("Enter <");
buf.append((char) ch);
matchGJIdent(in, buf);
while ((ch = in.read()) != '>' && ch != ')') { // List of parameters
if (ch == -1) {
throw new IllegalArgumentException("Illegal signature: " + in.getData() + " reaching EOF");
}
// System.out.println("Still no >");
buf.append(", ");
in.unread();
matchGJIdent(in, buf); // Recursive call
}
// System.out.println("Exit >");
buf.append((char) ch);
} else {
in.unread();
}
ch = in.read();
if (identStart(ch)) {
in.unread();
matchGJIdent(in, buf);
} else if (ch == ')') {
in.unread();
} else if (ch != ';') {
throw new IllegalArgumentException("Illegal signature: " + in.getData() + " read " + (char) ch);
}
}
private static void matchIdent(final MyByteArrayInputStream in, final StringBuilder buf) {
int ch;
if ((ch = in.read()) == -1) {
throw new IllegalArgumentException("Illegal signature: " + in.getData() + " no ident, reaching EOF");
}
// System.out.println("return from ident:" + (char) ch);
if (!identStart(ch)) {
final StringBuilder buf2 = new StringBuilder();
int count = 1;
while (Character.isJavaIdentifierPart((char) ch)) {
buf2.append((char) ch);
count++;
ch = in.read();
}
if (ch == ':') { // Ok, formal parameter
final int skipExpected = "Ljava/lang/Object".length();
final long skipActual = in.skip(skipExpected);
if (skipActual != skipExpected) {
throw new IllegalStateException(String.format("Unexpected skip: expected=%,d, actual=%,d", skipExpected, skipActual));
}
buf.append(buf2);
ch = in.read();
in.unread();
// System.out.println("so far:" + buf2 + ":next:" +(char) ch);
} else {
for (int i = 0; i < count; i++) {
in.unread();
}
}
return;
}
final StringBuilder buf2 = new StringBuilder();
ch = in.read();
do {
buf2.append((char) ch);
ch = in.read();
// System.out.println("within ident:"+ (char) ch);
} while (ch != -1 && (Character.isJavaIdentifierPart((char) ch) || ch == '/'));
buf.append(Utility.pathToPackage(buf2.toString()));
// System.out.println("regular return ident:"+ (char) ch + ":" + buf2);
if (ch != -1) {
in.unread();
}
}
public static String translate(final String s) {
// System.out.println("Sig:" + s);
final StringBuilder buf = new StringBuilder();
matchGJIdent(new MyByteArrayInputStream(s), buf);
return buf.toString();
}
private int signatureIndex;
/**
* Constructs object from file stream.
*
* @param nameIndex Index in constant pool to CONSTANT_Utf8
* @param length Content length in bytes
* @param input Input stream
* @param constantPool Array of constants
* @throws IOException if an I/O error occurs.
*/
Signature(final int nameIndex, final int length, final DataInput input, final ConstantPool constantPool) throws IOException {
this(nameIndex, length, input.readUnsignedShort(), constantPool);
}
/**
* @param nameIndex Index in constant pool to CONSTANT_Utf8
* @param length Content length in bytes
* @param signatureIndex Index in constant pool to CONSTANT_Utf8
* @param constantPool Array of constants
*/
public Signature(final int nameIndex, final int length, final int signatureIndex, final ConstantPool constantPool) {
super(Const.ATTR_SIGNATURE, nameIndex, Args.require(length, 2, "Signature length attribute"), constantPool);
this.signatureIndex = signatureIndex;
// validate:
Objects.requireNonNull(constantPool.getConstantUtf8(signatureIndex), "constantPool.getConstantUtf8(signatureIndex)");
}
/**
* Initialize from another object. Note that both objects use the same references (shallow copy). Use clone() for a
* physical copy.
*
* @param c Source to copy.
*/
public Signature(final Signature c) {
this(c.getNameIndex(), c.getLength(), c.getSignatureIndex(), c.getConstantPool());
}
/**
* Called by objects that are traversing the nodes of the tree implicitly defined by the contents of a Java class.
* I.e., the hierarchy of methods, fields, attributes, etc. spawns a tree of objects.
*
* @param v Visitor object
*/
@Override
public void accept(final Visitor v) {
// System.err.println("Visiting non-standard Signature object");
v.visitSignature(this);
}
/**
* @return deep copy of this attribute
*/
@Override
public Attribute copy(final ConstantPool constantPool) {
return (Attribute) clone();
}
/**
* Dump source file attribute to file stream in binary format.
*
* @param file Output file stream
* @throws IOException if an I/O error occurs.
*/
@Override
public void dump(final DataOutputStream file) throws IOException {
super.dump(file);
file.writeShort(signatureIndex);
}
/**
* @return GJ signature.
*/
public String getSignature() {
return super.getConstantPool().getConstantUtf8(signatureIndex).getBytes();
}
/**
* @return Index in constant pool of source file name.
*/
public int getSignatureIndex() {
return signatureIndex;
}
/**
* @param signatureIndex the index info the constant pool of this signature
*/
public void setSignatureIndex(final int signatureIndex) {
this.signatureIndex = signatureIndex;
}
/**
* @return String representation
*/
@Override
public String toString() {
return "Signature: " + getSignature();
}
}