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1   /**
2    * Redistribution  and use  in source  and binary  forms, with  or without
3    * modification, are permitted provided  that the following conditions are
4    * met :
5    *
6    * . Redistributions  of  source  code  must  retain  the  above copyright
7    *   notice, this list of conditions and the following disclaimer.
8    *
9    * . Redistributions in  binary form  must reproduce  the above  copyright
10   *   notice, this list of conditions  and the following disclaimer in  the
11   *   documentation and/or other materials provided with the distribution.
12   *
13   * . The name of the author may not be used to endorse or promote products
14   *   derived from this software without specific prior written permission.
15   *
16   * THIS SOFTWARE IS  PROVIDED BY THE  AUTHOR ``AS IS''  AND ANY EXPRESS  OR
17   * IMPLIED  WARRANTIES,  INCLUDING,  BUT   NOT  LIMITED  TO,  THE   IMPLIED
18   * WARRANTIES OF MERCHANTABILITY AND  FITNESS FOR A PARTICULAR  PURPOSE ARE
19   * DISCLAIMED.  IN NO  EVENT SHALL  THE AUTHOR  BE LIABLE  FOR ANY  DIRECT,
20   * INDIRECT,  INCIDENTAL,  SPECIAL,  EXEMPLARY,  OR  CONSEQUENTIAL  DAMAGES
21   * (INCLUDING,  BUT  NOT LIMITED  TO,  PROCUREMENT OF  SUBSTITUTE  GOODS OR
22   * SERVICES;  LOSS  OF USE,  DATA,  OR PROFITS;  OR  BUSINESS INTERRUPTION)
23   * HOWEVER CAUSED  AND ON  ANY THEORY  OF LIABILITY,  WHETHER IN  CONTRACT,
24   * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
25   * ANY  WAY  OUT OF  THE  USE OF  THIS  SOFTWARE, EVEN  IF  ADVISED OF  THE
26   * POSSIBILITY OF SUCH DAMAGE.
27   */
28  
29  package cpptools.preprocessor;
30  
31  import java.io.Reader;
32  import java.util.ArrayList;
33  import java.util.List;
34  import java.util.Stack;
35  import cppast.JavaCharStream;
36  import cppast.ParserTokenManager;
37  import cppast.Token;
38  
39  /**
40   * Adapts the two token management systems.
41   *
42   * @author Mathieu Champlon
43   */
44  public final class PreProcessor extends ParserTokenManager implements TokenProvider
45  {
46      private final List<TokenFilter> filters = new ArrayList<TokenFilter>();
47      private final Stack<Token> buffer = new Stack<Token>();
48  
49      /**
50       * Create an adapter.
51       */
52      public PreProcessor()
53      {
54          super( null );
55      }
56  
57      /**
58       * Set a new input.
59       *
60       * @param reader the input reader
61       */
62      public void reset( final Reader reader )
63      {
64          buffer.clear();
65          ReInit( new JavaCharStream( reader ) );
66      }
67  
68      /**
69       * {@inheritDoc}
70       */
71      public Token next()
72      {
73          return super.getNextToken();
74      }
75  
76      /**
77       * {@inheritDoc}
78       */
79      public Token getNextToken()
80      {
81          if( !buffer.empty() )
82              return buffer.pop();
83          final Token token = next();
84          if( filter( token ) )
85              return getNextToken();
86          return token;
87      }
88  
89      private boolean filter( final Token token )
90      {
91          for( TokenFilter filter : filters )
92              if( filter.process( token ) )
93                  return true;
94          return false;
95      }
96  
97      /**
98       * Add a define.
99       *
100      * @param name the name of the symbol
101      * @param value the value of the symbol
102      */
103     public void addDefine( final String name, final String value )
104     {
105         register( name, new Define( buffer, name, value ) );
106     }
107 
108     /**
109      * Add a macro.
110      *
111      * @param name the name of the symbol
112      * @param value the value of the symbol
113      */
114     public void addMacro( final String name, final String value )
115     {
116         register( name, new Macro( this, buffer, name, value ) );
117     }
118 
119     private void register( final String name, final TokenFilter macro )
120     {
121         for( TokenFilter filter : filters )
122             if( filter.matches( name ) )
123                 throw new RuntimeException( "macro redefinition '" + name + "'" );
124         filters.add( macro );
125     }
126 }