code: /*
   * 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.
   */
  /*
   * $Id$
   */
  
  package org.apache.xalan.xsltc.compiler;
  
  import java.util.Vector;
  
  import org.apache.bcel.generic.ConstantPoolGen;
  import org.apache.bcel.generic.INVOKESTATIC;
  import org.apache.bcel.generic.InstructionList;
  import org.apache.bcel.generic.PUSH;
  
  import org.apache.xalan.xsltc.compiler.util.ClassGenerator;
  import org.apache.xalan.xsltc.compiler.util.ErrorMsg;
  import org.apache.xalan.xsltc.compiler.util.MethodGenerator;
  import org.apache.xalan.xsltc.compiler.util.Type;
  import org.apache.xalan.xsltc.compiler.util.TypeCheckError;
  import org.apache.xalan.xsltc.compiler.util.Util;
  
  /**
   * @author Morten Jorgensen
   */
  final class UnsupportedElement extends SyntaxTreeNode {
  
      private Vector _fallbacks = null;
      private ErrorMsg _message = null;
      private boolean _isExtension = false;
  
      /**
       * Basic consutrcor - stores element uri/prefix/localname
       */
      public UnsupportedElement(String uri, String prefix, String local, boolean isExtension) {
  	super(uri, prefix, local);
  	_isExtension = isExtension;
      }
  
      /**
       * There are different categories of unsupported elements (believe it
       * or not): there are elements within the XSLT namespace (these would
       * be elements that are not yet implemented), there are extensions of
       * other XSLT processors and there are unrecognised extension elements
       * of this XSLT processor. The error message passed to this method
       * should describe the unsupported element itself and what category
       * the element belongs in.
       */
      public void setErrorMessage(ErrorMsg message) {
  	_message = message;
      }
  
      /**
       * Displays the contents of this element
       */
      public void display(int indent) {
  	indent(indent);
  	Util.println("Unsupported element = " + _qname.getNamespace() +
  		     ":" + _qname.getLocalPart());
  	displayContents(indent + IndentIncrement);
      }
  
  
      /**
       * Scan and process all fallback children of the unsupported element.
       */
      private void processFallbacks(Parser parser) {
  
  	Vector children = getContents();
  	if (children != null) {
  	    final int count = children.size();
  	    for (int i = 0; i < count; i++) {
  		SyntaxTreeNode child = (SyntaxTreeNode)children.elementAt(i);
  		if (child instanceof Fallback) {
  		    Fallback fallback = (Fallback)child;
  		    fallback.activate();
  		    fallback.parseContents(parser);
  		    if (_fallbacks == null) {
  		    	_fallbacks = new Vector();
  		    }
  		    _fallbacks.addElement(child);
  		}
  	    }
  	}
      }
  
      /**
       * Find any fallback in the descendant nodes; then activate & parse it
       */
      public void parseContents(Parser parser) {
      	processFallbacks(parser);
      }
  
      /**
       * Run type check on the fallback element (if any).
       */
      public Type typeCheck(SymbolTable stable) throws TypeCheckError {	
  	if (_fallbacks != null) {
  	    int count = _fallbacks.size();
  	    for (int i = 0; i < count; i++) {
  	        Fallback fallback = (Fallback)_fallbacks.elementAt(i);
  	        fallback.typeCheck(stable);
  	    }
  	}
  	return Type.Void;
      }
  
      /**
       * Translate the fallback element (if any).
       */
      public void translate(ClassGenerator classGen, MethodGenerator methodGen) {
  	if (_fallbacks != null) {
  	    int count = _fallbacks.size();
  	    for (int i = 0; i < count; i++) {
  	        Fallback fallback = (Fallback)_fallbacks.elementAt(i);
  	        fallback.translate(classGen, methodGen);
  	    }
  	}
  	// We only go into the else block in forward-compatibility mode, when
  	// the unsupported element has no fallback.
  	else {		
  	    // If the unsupported element does not have any fallback child, then
  	    // at runtime, a runtime error should be raised when the unsupported
  	    // element is instantiated. Otherwise, no error is thrown.
  	    ConstantPoolGen cpg = classGen.getConstantPool();
  	    InstructionList il = methodGen.getInstructionList();
  	    
  	    final int unsupportedElem = cpg.addMethodref(BASIS_LIBRARY_CLASS, "unsupported_ElementF",
                                                           "(" + STRING_SIG + "Z)V");	 
  	    il.append(new PUSH(cpg, getQName().toString()));
  	    il.append(new PUSH(cpg, _isExtension));
  	    il.append(new INVOKESTATIC(unsupportedElem));		
  	}
      }
  }
  