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1   /*
2    * reserved comment block
3    * DO NOT REMOVE OR ALTER!
4    */
5   /*
6    * Copyright 2001-2004 The Apache Software Foundation.
7    *
8    * Licensed under the Apache License, Version 2.0 (the "License");
9    * you may not use this file except in compliance with the License.
10   * You may obtain a copy of the License at
11   *
12   *     http://www.apache.org/licenses/LICENSE-2.0
13   *
14   * Unless required by applicable law or agreed to in writing, software
15   * distributed under the License is distributed on an "AS IS" BASIS,
16   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
17   * See the License for the specific language governing permissions and
18   * limitations under the License.
19   */
20  /*
21   * $Id: UnsupportedElement.java,v 1.2.4.1 2005/09/05 09:26:51 pvedula Exp $
22   */
23  
24  package com.sun.org.apache.xalan.internal.xsltc.compiler;
25  
26  import java.util.Vector;
27  
28  import com.sun.org.apache.bcel.internal.generic.ConstantPoolGen;
29  import com.sun.org.apache.bcel.internal.generic.INVOKESTATIC;
30  import com.sun.org.apache.bcel.internal.generic.InstructionList;
31  import com.sun.org.apache.bcel.internal.generic.PUSH;
32  
33  import com.sun.org.apache.xalan.internal.xsltc.compiler.util.ClassGenerator;
34  import com.sun.org.apache.xalan.internal.xsltc.compiler.util.ErrorMsg;
35  import com.sun.org.apache.xalan.internal.xsltc.compiler.util.MethodGenerator;
36  import com.sun.org.apache.xalan.internal.xsltc.compiler.util.Type;
37  import com.sun.org.apache.xalan.internal.xsltc.compiler.util.TypeCheckError;
38  import com.sun.org.apache.xalan.internal.xsltc.compiler.util.Util;
39  
40  /**
41   * @author Morten Jorgensen
42   */
43  final class UnsupportedElement extends SyntaxTreeNode {
44  
45      private Vector _fallbacks = null;
46      private ErrorMsg _message = null;
47      private boolean _isExtension = false;
48  
49      /**
50       * Basic consutrcor - stores element uri/prefix/localname
51       */
52      public UnsupportedElement(String uri, String prefix, String local, boolean isExtension) {
53          super(uri, prefix, local);
54          _isExtension = isExtension;
55      }
56  
57      /**
58       * There are different categories of unsupported elements (believe it
59       * or not): there are elements within the XSLT namespace (these would
60       * be elements that are not yet implemented), there are extensions of
61       * other XSLT processors and there are unrecognised extension elements
62       * of this XSLT processor. The error message passed to this method
63       * should describe the unsupported element itself and what category
64       * the element belongs in.
65       */
66      public void setErrorMessage(ErrorMsg message) {
67          _message = message;
68      }
69  
70      /**
71       * Displays the contents of this element
72       */
73      public void display(int indent) {
74          indent(indent);
75          Util.println("Unsupported element = " + _qname.getNamespace() +
76                       ":" + _qname.getLocalPart());
77          displayContents(indent + IndentIncrement);
78      }
79  
80  
81      /**
82       * Scan and process all fallback children of the unsupported element.
83       */
84      private void processFallbacks(Parser parser) {
85  
86          Vector children = getContents();
87          if (children != null) {
88              final int count = children.size();
89              for (int i = 0; i < count; i++) {
90                  SyntaxTreeNode child = (SyntaxTreeNode)children.elementAt(i);
91                  if (child instanceof Fallback) {
92                      Fallback fallback = (Fallback)child;
93                      fallback.activate();
94                      fallback.parseContents(parser);
95                      if (_fallbacks == null) {
96                          _fallbacks = new Vector();
97                      }
98                      _fallbacks.addElement(child);
99                  }
100             }
101         }
102     }
103 
104     /**
105      * Find any fallback in the descendant nodes; then activate & parse it
106      */
107     public void parseContents(Parser parser) {
108         processFallbacks(parser);
109     }
110 
111     /**
112      * Run type check on the fallback element (if any).
113      */
114     public Type typeCheck(SymbolTable stable) throws TypeCheckError {
115         if (_fallbacks != null) {
116             int count = _fallbacks.size();
117             for (int i = 0; i < count; i++) {
118                 Fallback fallback = (Fallback)_fallbacks.elementAt(i);
119                 fallback.typeCheck(stable);
120             }
121         }
122         return Type.Void;
123     }
124 
125     /**
126      * Translate the fallback element (if any).
127      */
128     public void translate(ClassGenerator classGen, MethodGenerator methodGen) {
129         if (_fallbacks != null) {
130             int count = _fallbacks.size();
131             for (int i = 0; i < count; i++) {
132                 Fallback fallback = (Fallback)_fallbacks.elementAt(i);
133                 fallback.translate(classGen, methodGen);
134             }
135         }
136         // We only go into the else block in forward-compatibility mode, when
137         // the unsupported element has no fallback.
138         else {
139             // If the unsupported element does not have any fallback child, then
140             // at runtime, a runtime error should be raised when the unsupported
141             // element is instantiated. Otherwise, no error is thrown.
142             ConstantPoolGen cpg = classGen.getConstantPool();
143             InstructionList il = methodGen.getInstructionList();
144 
145             final int unsupportedElem = cpg.addMethodref(BASIS_LIBRARY_CLASS, "unsupported_ElementF",
146                                                          "(" + STRING_SIG + "Z)V");
147             il.append(new PUSH(cpg, getQName().toString()));
148             il.append(new PUSH(cpg, _isExtension));
149             il.append(new INVOKESTATIC(unsupportedElem));
150         }
151     }
152 }