/*
* 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.verifier.statics;
import org.apache.bcel.classfile.Annotations;
import org.apache.bcel.classfile.BootstrapMethods;
import org.apache.bcel.classfile.Code;
import org.apache.bcel.classfile.CodeException;
import org.apache.bcel.classfile.ConstantClass;
import org.apache.bcel.classfile.ConstantDouble;
import org.apache.bcel.classfile.ConstantFieldref;
import org.apache.bcel.classfile.ConstantFloat;
import org.apache.bcel.classfile.ConstantInteger;
import org.apache.bcel.classfile.ConstantInterfaceMethodref;
import org.apache.bcel.classfile.ConstantLong;
import org.apache.bcel.classfile.ConstantMethodref;
import org.apache.bcel.classfile.ConstantNameAndType;
import org.apache.bcel.classfile.ConstantPool;
import org.apache.bcel.classfile.ConstantString;
import org.apache.bcel.classfile.ConstantUtf8;
import org.apache.bcel.classfile.ConstantValue;
import org.apache.bcel.classfile.Deprecated;
import org.apache.bcel.classfile.EnclosingMethod;
import org.apache.bcel.classfile.ExceptionTable;
import org.apache.bcel.classfile.Field;
import org.apache.bcel.classfile.InnerClass;
import org.apache.bcel.classfile.InnerClasses;
import org.apache.bcel.classfile.JavaClass;
import org.apache.bcel.classfile.LineNumber;
import org.apache.bcel.classfile.LineNumberTable;
import org.apache.bcel.classfile.LocalVariable;
import org.apache.bcel.classfile.LocalVariableTable;
import org.apache.bcel.classfile.LocalVariableTypeTable;
import org.apache.bcel.classfile.Method;
import org.apache.bcel.classfile.MethodParameters;
import org.apache.bcel.classfile.Node;
import org.apache.bcel.classfile.Signature;
import org.apache.bcel.classfile.SourceFile;
import org.apache.bcel.classfile.StackMap;
import org.apache.bcel.classfile.StackMapTable;
import org.apache.bcel.classfile.Synthetic;
import org.apache.bcel.classfile.Unknown;
import org.apache.bcel.verifier.exc.AssertionViolatedException;
/**
* BCEL's Node classes (those from the classfile API that <B>accept()</B> Visitor
* instances) have <B>toString()</B> methods that were not designed to be robust,
* this gap is closed by this class.
* When performing class file verification, it may be useful to output which
* entity (e.g. a <B>Code</B> instance) is not satisfying the verifier's
* constraints, but in this case it could be possible for the <B>toString()</B>
* method to throw a RuntimeException.
* A (new StringRepresentation(Node n)).toString() never throws any exception.
* Note that this class also serves as a placeholder for more sophisticated message
* handling in future versions of JustIce.
*
* @version $Id: StringRepresentation.java 1589677 2014-04-24 11:42:40Z ebourg $
* @author Enver Haase
*/
public class StringRepresentation extends org.apache.bcel.classfile.EmptyVisitor {
/** The string representation, created by a visitXXX() method, output by toString(). */
private String tostring;
/** The node we ask for its string representation. Not really needed; only for debug output. */
private Node n;
/**
* Creates a new StringRepresentation object which is the representation of n.
*
* @see #toString()
*/
public StringRepresentation(Node n) {
this.n = n;
n.accept(this); // assign a string representation to field 'tostring' if we know n's class.
}
/**
* Returns the String representation.
*/
@Override
public String toString() {
// The run-time check below is needed because we don't want to omit inheritance
// of "EmptyVisitor" and provide a thousand empty methods.
// However, in terms of performance this would be a better idea.
// If some new "Node" is defined in BCEL (such as some concrete "Attribute"), we
// want to know that this class has also to be adapted.
if (tostring == null) {
throw new AssertionViolatedException("Please adapt '" + getClass() + "' to deal with objects of class '" + n.getClass() + "'.");
}
return tostring;
}
/**
* Returns the String representation of the Node object obj;
* this is obj.toString() if it does not throw any RuntimeException,
* or else it is a string derived only from obj's class name.
*/
private String toString(Node obj) {
String ret;
try {
ret = obj.toString();
}
catch (RuntimeException e) { // including ClassFormatException, trying to convert the "signature" of a ReturnaddressType LocalVariable (shouldn't occur, but people do crazy things)
String s = obj.getClass().getName();
s = s.substring(s.lastIndexOf(".") + 1);
ret = "<<" + s + ">>";
}
return ret;
}
////////////////////////////////
// Visitor methods start here //
////////////////////////////////
// We don't of course need to call some default implementation:
// e.g. we could also simply output "Code" instead of a possibly
// lengthy Code attribute's toString().
@Override
public void visitCode(Code obj) {
//tostring = toString(obj);
tostring = "<CODE>"; // We don't need real code outputs.
}
@Override
public void visitAnnotation(Annotations obj)
{
//this is invoked whenever an annotation is found
//when verifier is passed over a class
tostring = toString(obj);
}
@Override
public void visitLocalVariableTypeTable(LocalVariableTypeTable obj)
{
//this is invoked whenever a local variable type is found
//when verifier is passed over a class
tostring = toString(obj);
}
@Override
public void visitCodeException(CodeException obj) {
tostring = toString(obj);
}
@Override
public void visitConstantClass(ConstantClass obj) {
tostring = toString(obj);
}
@Override
public void visitConstantDouble(ConstantDouble obj) {
tostring = toString(obj);
}
@Override
public void visitConstantFieldref(ConstantFieldref obj) {
tostring = toString(obj);
}
@Override
public void visitConstantFloat(ConstantFloat obj) {
tostring = toString(obj);
}
@Override
public void visitConstantInteger(ConstantInteger obj) {
tostring = toString(obj);
}
@Override
public void visitConstantInterfaceMethodref(ConstantInterfaceMethodref obj) {
tostring = toString(obj);
}
@Override
public void visitConstantLong(ConstantLong obj) {
tostring = toString(obj);
}
@Override
public void visitConstantMethodref(ConstantMethodref obj) {
tostring = toString(obj);
}
@Override
public void visitConstantNameAndType(ConstantNameAndType obj) {
tostring = toString(obj);
}
@Override
public void visitConstantPool(ConstantPool obj) {
tostring = toString(obj);
}
@Override
public void visitConstantString(ConstantString obj) {
tostring = toString(obj);
}
@Override
public void visitConstantUtf8(ConstantUtf8 obj) {
tostring = toString(obj);
}
@Override
public void visitConstantValue(ConstantValue obj) {
tostring = toString(obj);
}
@Override
public void visitDeprecated(Deprecated obj) {
tostring = toString(obj);
}
@Override
public void visitExceptionTable(ExceptionTable obj) {
tostring = toString(obj);
}
@Override
public void visitField(Field obj) {
tostring = toString(obj);
}
@Override
public void visitInnerClass(InnerClass obj) {
tostring = toString(obj);
}
@Override
public void visitInnerClasses(InnerClasses obj) {
tostring = toString(obj);
}
@Override
public void visitJavaClass(JavaClass obj) {
tostring = toString(obj);
}
@Override
public void visitLineNumber(LineNumber obj) {
tostring = toString(obj);
}
@Override
public void visitLineNumberTable(LineNumberTable obj) {
tostring = "<LineNumberTable: " + toString(obj) + ">";
}
@Override
public void visitLocalVariable(LocalVariable obj) {
tostring = toString(obj);
}
@Override
public void visitLocalVariableTable(LocalVariableTable obj) {
tostring = "<LocalVariableTable: " + toString(obj) + ">";
}
@Override
public void visitMethod(Method obj) {
tostring = toString(obj);
}
@Override
public void visitSignature(Signature obj) {
tostring = toString(obj);
}
@Override
public void visitSourceFile(SourceFile obj) {
tostring = toString(obj);
}
@Override
public void visitStackMap(StackMap obj) {
tostring = toString(obj);
}
@Override
public void visitStackMapTable(StackMapTable obj) {
tostring = toString(obj);
}
@Override
public void visitSynthetic(Synthetic obj) {
tostring = toString(obj);
}
@Override
public void visitUnknown(Unknown obj) {
tostring = toString(obj);
}
@Override
public void visitEnclosingMethod(EnclosingMethod obj) {
tostring = toString(obj);
}
@Override
public void visitBootstrapMethods(BootstrapMethods obj) {
tostring = toString(obj);
}
@Override
public void visitMethodParameters(MethodParameters obj) {
tostring = toString(obj);
}
}