mcs/class/Microsoft.Build.Engine/Microsoft.Build.BuildEngine/ConditionTokenizer.cs

   1 //
   2 // ConditionTokenizer.cs
   3 //
   4 // Author:
   5 //   Marek Sieradzki (marek.sieradzki@gmail.com)
   6 //   Jaroslaw Kowalski <jaak@jkowalski.net>
   7 //
   8 // (C) 2006 Marek Sieradzki
   9 // (C) 2004-2006 Jaroslaw Kowalski
  10 //
  11 // Permission is hereby granted, free of charge, to any person obtaining
  12 // a copy of this software and associated documentation files (the
  13 // "Software"), to deal in the Software without restriction, including
  14 // without limitation the rights to use, copy, modify, merge, publish,
  15 // distribute, sublicense, and/or sell copies of the Software, and to
  16 // permit persons to whom the Software is furnished to do so, subject to
  17 // the following conditions:
  18 //
  19 // The above copyright notice and this permission notice shall be
  20 // included in all copies or substantial portions of the Software.
  21 //
  22 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  23 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  24 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  25 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  26 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  27 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  28 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  29
  30 #if NET_2_0
  31
  32 using System;
  33 using System.Collections;
  34 using System.Collections.Specialized;
  35 using System.Text;
  36
  37 namespace Microsoft.Build.BuildEngine {
  38
  39         internal sealed class ConditionTokenizer {
  40                 string  inputString = null;
  41                 int     position = 0;
  42                 int     tokenPosition = 0;
  43
  44                 Token   token;
  45
  46                 bool    ignoreWhiteSpace = true;
  47
  48                 static TokenType[] charIndexToTokenType = new TokenType[128];
  49                 static Hashtable keywordToTokenType = CollectionsUtil.CreateCaseInsensitiveHashtable ();
  50
  51                 static ConditionTokenizer ()
  52                 {
  53                         for (int i = 0; i < 128; i++)
  54                                 charIndexToTokenType [i] = TokenType.Invalid;
  55
  56                         foreach (CharToTokenType cht in charToTokenType)
  57                                 charIndexToTokenType [(int) cht.ch] = cht.tokenType;
  58
  59                 }
  60
  61                 public ConditionTokenizer ()
  62                 {
  63                         this.ignoreWhiteSpace = true;
  64                 }
  65
  66                 public void Tokenize (string s)
  67                 {
  68                         this.inputString = s;
  69                         this.position = 0;
  70                         this.token = new Token (null, TokenType.BOF);
  71
  72                         GetNextToken ();
  73                 }
  74
  75                 private void SkipWhiteSpace ()
  76                 {
  77                         int ch;
  78
  79                         while ((ch = PeekChar ()) != -1) {
  80                                 if (!Char.IsWhiteSpace ((char)ch))
  81                                         break;
  82                                 ReadChar ();
  83                         }
  84                 }
  85
  86                 private int PeekChar ()
  87                 {
  88                         if (position < inputString.Length)
  89                                 return (int) inputString [position];
  90                         else
  91                                 return -1;
  92                 }
  93
  94                 private int ReadChar ()
  95                 {
  96                         if (position < inputString.Length)
  97                                 return (int) inputString [position++];
  98                         else
  99                                 return -1;
 100                 }
 101
 102                 public void Expect (TokenType type)
 103                 {
 104                         if (token.Type != type)
 105                                 throw new ExpressionParseException ("Expected token type of type: " + type + ", got " + token.Type +
 106                                         " (" + token.Value + ") .");
 107
 108                         GetNextToken ();
 109                 }
 110
 111                 public bool IsEOF ()
 112                 {
 113                         return token.Type == TokenType.EOF;
 114                 }
 115
 116                 public bool IsNumber ()
 117                 {
 118                         return token.Type == TokenType.Number;
 119                 }
 120
 121                 public bool IsToken (TokenType type)
 122                 {
 123                         return token.Type == type;
 124                 }
 125
 126                 public bool IsPunctation ()
 127                 {
 128                         return (token.Type >= TokenType.FirstPunct && token.Type < TokenType.LastPunct);
 129                 }
 130
 131                 // FIXME: add 'and' and 'or' tokens
 132                 public void GetNextToken ()
 133                 {
 134                         if (token.Type == TokenType.EOF)
 135                                 throw new ExpressionParseException ("Cannot read past the end of stream.");
 136
 137                         if (IgnoreWhiteSpace)
 138                                 SkipWhiteSpace ();
 139
 140                         tokenPosition = position;
 141
 142                         int i = PeekChar ();
 143
 144                         if (i == -1) {
 145                                 token = new Token (null, TokenType.EOF);
 146                                 return;
 147                         }
 148
 149                         char ch = (char) i;
 150
 151                         if (IgnoreWhiteSpace == false && Char.IsWhiteSpace (ch)) {
 152                                 StringBuilder sb = new StringBuilder ();
 153                                 int ch2;
 154
 155                                 while ((ch2 = PeekChar ()) != -1)  {
 156                                         if (!Char.IsWhiteSpace ((char) ch2))
 157                                                 break;
 158
 159                                         sb.Append ((char)ch2);
 160                                         ReadChar();
 161                                 }
 162
 163                                 token = new Token (sb.ToString (), TokenType.WhiteSpace);
 164                                 return;
 165                         }
 166
 167                         if (Char.IsDigit (ch)) {
 168                                 StringBuilder sb = new StringBuilder ();
 169
 170                                 sb.Append (ch);
 171                                 ReadChar ();
 172
 173                                 while ((i = PeekChar ()) != -1) {
 174                                         ch = (char) i;
 175
 176                                         if (Char.IsDigit (ch) || ch == '.')
 177                                                 sb.Append ((char) ReadChar ());
 178                                         else
 179                                                 break;
 180                                 }
 181
 182                                 token = new Token (sb.ToString (), TokenType.Number);
 183                                 return;
 184                         }
 185
 186                         if (ch == '\'') {
 187                                 StringBuilder sb = new StringBuilder ();
 188                                 string temp;
 189
 190                                 sb.Append (ch);
 191                                 ReadChar ();
 192
 193                                 while ((i = PeekChar ()) != -1) {
 194                                         ch = (char) i;
 195
 196                                         sb.Append ((char) ReadChar ());
 197
 198                                         if (ch == '\'')
 199                                                 break;
 200                                 }
 201
 202                                 temp = sb.ToString ();
 203
 204                                 // FIXME: test extreme cases
 205                                 token = new Token (temp.Substring (1, temp.Length - 2), TokenType.String);
 206
 207                                 return;
 208                         }
 209
 210                         if (ch == '_' || Char.IsLetter (ch)) {
 211                                 StringBuilder sb = new StringBuilder ();
 212
 213                                 sb.Append ((char) ch);
 214                                 ReadChar ();
 215
 216                                 while ((i = PeekChar ()) != -1) {
 217                                         if ((char) i == '_' || Char.IsLetterOrDigit ((char) i))
 218                                                 sb.Append ((char) ReadChar ());
 219                                         else
 220                                                 break;
 221                                 }
 222
 223                                 string temp = sb.ToString ();
 224
 225                                 if (temp.ToLower () == "and")
 226                                         token = new Token (temp, TokenType.And);
 227                                 else if (temp.ToLower () == "or")
 228                                         token = new Token (temp, TokenType.Or);
 229                                 else
 230                                         token = new Token (sb.ToString (), TokenType.String);
 231                                 return;
 232                         }
 233
 234                         ReadChar ();
 235
 236                         if (ch == '!' && PeekChar () == (int) '=') {
 237                                 token = new Token ("!=", TokenType.NotEqual);
 238                                 ReadChar ();
 239                                 return;
 240                         }
 241
 242                         if (ch == '<' && PeekChar () == (int) '=') {
 243                                 token = new Token ("<=", TokenType.LessOrEqual);
 244                                 ReadChar ();
 245                                 return;
 246                         }
 247
 248                         if (ch == '>' && PeekChar () == (int) '=') {
 249                                 token = new Token (">=", TokenType.GreaterThanOrEqual);
 250                                 ReadChar ();
 251                                 return;
 252                         }
 253
 254                         if (ch == '=' && PeekChar () == (int) '=') {
 255                                 token = new Token ("==", TokenType.Equal);
 256                                 ReadChar ();
 257                                 return;
 258                         }
 259
 260                         if (ch == '-' && PeekChar () == (int) '>') {
 261                                 token = new Token ("->", TokenType.Transform);
 262                                 ReadChar ();
 263                                 return;
 264                         }
 265
 266                         if (ch >= 32 && ch < 128) {
 267                                 if (charIndexToTokenType [ch] != TokenType.Invalid) {
 268                                         token = new Token (new String (ch, 1), charIndexToTokenType [ch]);
 269                                         return;
 270                                 } else
 271                                         throw new ExpressionParseException (String.Format ("Invalid punctuation: {0}", ch));
 272                         }
 273
 274                         throw new ExpressionParseException (String.Format ("Invalid token: {0}", ch));
 275                 }
 276
 277                 public int TokenPosition {
 278                         get { return tokenPosition; }
 279                 }
 280
 281                 public Token Token {
 282                         get { return token; }
 283                 }
 284
 285                 public bool IgnoreWhiteSpace {
 286                         get { return ignoreWhiteSpace; }
 287                         set { ignoreWhiteSpace = value; }
 288                 }
 289
 290                 struct CharToTokenType {
 291                         public char ch;
 292                         public TokenType tokenType;
 293
 294                         public CharToTokenType (char ch, TokenType tokenType)
 295                         {
 296                                 this.ch = ch;
 297                                 this.tokenType = tokenType;
 298                         }
 299                 }
 300
 301                 static CharToTokenType[] charToTokenType = {
 302                         new CharToTokenType ('<', TokenType.LessThan),
 303                         new CharToTokenType ('>', TokenType.GreaterThan),
 304                         new CharToTokenType ('=', TokenType.Equal),
 305                         new CharToTokenType ('(', TokenType.LeftParen),
 306                         new CharToTokenType (')', TokenType.RightParen),
 307                         new CharToTokenType ('.', TokenType.Dot),
 308                         new CharToTokenType (',', TokenType.Comma),
 309                         new CharToTokenType ('!', TokenType.Not),
 310                         new CharToTokenType ('@', TokenType.Item),
 311                         new CharToTokenType ('$', TokenType.Property),
 312                         new CharToTokenType ('%', TokenType.Metadata),
 313                         new CharToTokenType ('\'', TokenType.Apostrophe),
 314                 };
 315         }
 316 }
 317
 318 #endif