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                         if (s == null)
  69                                 throw new ArgumentNullException ("s");
  70
  71                         this.inputString = s;
  72                         this.position = 0;
  73                         this.token = new Token (null, TokenType.BOF);
  74
  75                         GetNextToken ();
  76                 }
  77
  78                 private void SkipWhiteSpace ()
  79                 {
  80                         int ch;
  81
  82                         while ((ch = PeekChar ()) != -1) {
  83                                 if (!Char.IsWhiteSpace ((char)ch))
  84                                         break;
  85                                 ReadChar ();
  86                         }
  87                 }
  88
  89                 private int PeekChar ()
  90                 {
  91                         if (position < inputString.Length)
  92                                 return (int) inputString [position];
  93                         else
  94                                 return -1;
  95                 }
  96
  97                 private int ReadChar ()
  98                 {
  99                         if (position < inputString.Length)
 100                                 return (int) inputString [position++];
 101                         else
 102                                 return -1;
 103                 }
 104
 105                 public void Expect (TokenType type)
 106                 {
 107                         if (token.Type != type)
 108                                 throw new ExpressionParseException ("Expected token type of type: " + type + ", got " + token.Type +
 109                                         " (" + token.Value + ") .");
 110
 111                         GetNextToken ();
 112                 }
 113
 114                 public bool IsEOF ()
 115                 {
 116                         return token.Type == TokenType.EOF;
 117                 }
 118
 119                 public bool IsNumber ()
 120                 {
 121                         return token.Type == TokenType.Number;
 122                 }
 123
 124                 public bool IsToken (TokenType type)
 125                 {
 126                         return token.Type == type;
 127                 }
 128
 129                 public bool IsPunctation ()
 130                 {
 131                         return (token.Type >= TokenType.FirstPunct && token.Type < TokenType.LastPunct);
 132                 }
 133
 134                 // FIXME: add 'and' and 'or' tokens
 135                 public void GetNextToken ()
 136                 {
 137                         if (token.Type == TokenType.EOF)
 138                                 throw new ExpressionParseException ("Cannot read past the end of stream.");
 139
 140                         if (IgnoreWhiteSpace)
 141                                 SkipWhiteSpace ();
 142
 143                         tokenPosition = position;
 144
 145                         int i = PeekChar ();
 146
 147                         if (i == -1) {
 148                                 token = new Token (null, TokenType.EOF);
 149                                 return;
 150                         }
 151
 152                         char ch = (char) i;
 153
 154                         if (IgnoreWhiteSpace == false && Char.IsWhiteSpace (ch)) {
 155                                 StringBuilder sb = new StringBuilder ();
 156                                 int ch2;
 157
 158                                 while ((ch2 = PeekChar ()) != -1)  {
 159                                         if (!Char.IsWhiteSpace ((char) ch2))
 160                                                 break;
 161
 162                                         sb.Append ((char)ch2);
 163                                         ReadChar();
 164                                 }
 165
 166                                 token = new Token (sb.ToString (), TokenType.WhiteSpace);
 167                                 return;
 168                         }
 169
 170                         if (Char.IsDigit (ch)) {
 171                                 StringBuilder sb = new StringBuilder ();
 172
 173                                 sb.Append (ch);
 174                                 ReadChar ();
 175
 176                                 while ((i = PeekChar ()) != -1) {
 177                                         ch = (char) i;
 178
 179                                         if (Char.IsDigit (ch) || ch == '.')
 180                                                 sb.Append ((char) ReadChar ());
 181                                         else
 182                                                 break;
 183                                 }
 184
 185                                 token = new Token (sb.ToString (), TokenType.Number);
 186                                 return;
 187                         }
 188
 189                         if (ch == '\'') {
 190                                 StringBuilder sb = new StringBuilder ();
 191                                 string temp;
 192
 193                                 sb.Append (ch);
 194                                 ReadChar ();
 195
 196                                 while ((i = PeekChar ()) != -1) {
 197                                         ch = (char) i;
 198
 199                                         sb.Append ((char) ReadChar ());
 200
 201                                         if (ch == '\'')
 202                                                 break;
 203                                 }
 204
 205                                 temp = sb.ToString ();
 206
 207                                 // FIXME: test extreme cases
 208                                 token = new Token (temp.Substring (1, temp.Length - 2), TokenType.String);
 209
 210                                 return;
 211                         }
 212
 213                         if (ch == '_' || Char.IsLetter (ch)) {
 214                                 StringBuilder sb = new StringBuilder ();
 215
 216                                 sb.Append ((char) ch);
 217                                 ReadChar ();
 218
 219                                 while ((i = PeekChar ()) != -1) {
 220                                         if ((char) i == '_' || Char.IsLetterOrDigit ((char) i))
 221                                                 sb.Append ((char) ReadChar ());
 222                                         else
 223                                                 break;
 224                                 }
 225
 226                                 string temp = sb.ToString ();
 227
 228                                 if (temp.ToLower () == "and")
 229                                         token = new Token (temp, TokenType.And);
 230                                 else if (temp.ToLower () == "or")
 231                                         token = new Token (temp, TokenType.Or);
 232                                 else
 233                                         token = new Token (sb.ToString (), TokenType.String);
 234                                 return;
 235                         }
 236
 237                         ReadChar ();
 238
 239                         if (ch == '!' && PeekChar () == (int) '=') {
 240                                 token = new Token ("!=", TokenType.NotEqual);
 241                                 ReadChar ();
 242                                 return;
 243                         }
 244
 245                         if (ch == '<' && PeekChar () == (int) '=') {
 246                                 token = new Token ("<=", TokenType.LessOrEqual);
 247                                 ReadChar ();
 248                                 return;
 249                         }
 250
 251                         if (ch == '>' && PeekChar () == (int) '=') {
 252                                 token = new Token (">=", TokenType.GreaterOrEqual);
 253                                 ReadChar ();
 254                                 return;
 255                         }
 256
 257                         if (ch == '=' && PeekChar () == (int) '=') {
 258                                 token = new Token ("==", TokenType.Equal);
 259                                 ReadChar ();
 260                                 return;
 261                         }
 262
 263                         if (ch == '-' && PeekChar () == (int) '>') {
 264                                 token = new Token ("->", TokenType.Transform);
 265                                 ReadChar ();
 266                                 return;
 267                         }
 268
 269                         if (ch >= 32 && ch < 128) {
 270                                 if (charIndexToTokenType [ch] != TokenType.Invalid) {
 271                                         token = new Token (new String (ch, 1), charIndexToTokenType [ch]);
 272                                         return;
 273                                 } else
 274                                         throw new ExpressionParseException (String.Format ("Invalid punctuation: {0}", ch));
 275                         }
 276
 277                         throw new ExpressionParseException (String.Format ("Invalid token: {0}", ch));
 278                 }
 279
 280                 public int TokenPosition {
 281                         get { return tokenPosition; }
 282                 }
 283
 284                 public Token Token {
 285                         get { return token; }
 286                 }
 287
 288                 public bool IgnoreWhiteSpace {
 289                         get { return ignoreWhiteSpace; }
 290                         set { ignoreWhiteSpace = value; }
 291                 }
 292
 293                 struct CharToTokenType {
 294                         public char ch;
 295                         public TokenType tokenType;
 296
 297                         public CharToTokenType (char ch, TokenType tokenType)
 298                         {
 299                                 this.ch = ch;
 300                                 this.tokenType = tokenType;
 301                         }
 302                 }
 303
 304                 static CharToTokenType[] charToTokenType = {
 305                         new CharToTokenType ('<', TokenType.Less),
 306                         new CharToTokenType ('>', TokenType.Greater),
 307                         new CharToTokenType ('=', TokenType.Equal),
 308                         new CharToTokenType ('(', TokenType.LeftParen),
 309                         new CharToTokenType (')', TokenType.RightParen),
 310                         new CharToTokenType ('.', TokenType.Dot),
 311                         new CharToTokenType (',', TokenType.Comma),
 312                         new CharToTokenType ('!', TokenType.Not),
 313                         new CharToTokenType ('@', TokenType.Item),
 314                         new CharToTokenType ('$', TokenType.Property),
 315                         new CharToTokenType ('%', TokenType.Metadata),
 316                         new CharToTokenType ('\'', TokenType.Apostrophe),
 317                 };
 318         }
 319 }
 320
 321 #endif