/*
    * 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.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.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.Node;
  import org.apache.bcel.classfile.Signature;
  import org.apache.bcel.classfile.SourceFile;
  import org.apache.bcel.classfile.StackMap;
  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 1152072 2011-07-29 01:54:05Z dbrosius $
   * @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 visitSynthetic(Synthetic obj) {
         tostring = toString(obj);
     }
 
     @Override
     public void visitUnknown(Unknown obj) {
         tostring = toString(obj);
     }
 }