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.Generic;
  35 using System.Collections.Specialized;
  36 using System.Text;
  37
  38 namespace Microsoft.Build.BuildEngine {
  39
  40         internal sealed class ConditionTokenizer {
  41
  42                 string  inputString = null;
  43                 int     position = 0;
  44                 int     tokenPosition = 0;
  45
  46                 Token   token;
  47                 Token   putback = null;
  48
  49 //              bool    ignoreWhiteSpace = true;
  50
  51                 static TokenType[] charIndexToTokenType = new TokenType[128];
  52                 static Dictionary <string, TokenType> keywords = new Dictionary <string, TokenType> (StringComparer.OrdinalIgnoreCase);
  53
  54                 static ConditionTokenizer ()
  55                 {
  56                         for (int i = 0; i < 128; i++)
  57                                 charIndexToTokenType [i] = TokenType.Invalid;
  58
  59                         foreach (CharToTokenType cht in charToTokenType)
  60                                 charIndexToTokenType [(int) cht.ch] = cht.tokenType;
  61
  62                         keywords.Add ("and", TokenType.And);
  63                         keywords.Add ("or", TokenType.Or);
  64                 }
  65
  66                 public ConditionTokenizer ()
  67                 {
  68 //                      this.ignoreWhiteSpace = true;
  69                 }
  70
  71                 public void Tokenize (string s)
  72                 {
  73                         if (s == null)
  74                                 throw new ArgumentNullException ("s");
  75
  76                         this.inputString = s;
  77                         this.position = 0;
  78                         this.token = new Token (null, TokenType.BOF, 0);
  79
  80                         GetNextToken ();
  81                 }
  82
  83                 void SkipWhiteSpace ()
  84                 {
  85                         int ch;
  86
  87                         while ((ch = PeekChar ()) != -1) {
  88                                 if (!Char.IsWhiteSpace ((char)ch))
  89                                         break;
  90                                 ReadChar ();
  91                         }
  92                 }
  93
  94                 int PeekChar ()
  95                 {
  96                         if (position < inputString.Length)
  97                                 return (int) inputString [position];
  98                         else
  99                                 return -1;
 100                 }
 101
 102                 int ReadChar ()
 103                 {
 104                         if (position < inputString.Length)
 105                                 return (int) inputString [position++];
 106                         else
 107                                 return -1;
 108                 }
 109
 110                 public void Expect (TokenType type)
 111                 {
 112                         if (token.Type != type)
 113                                 throw new ExpressionParseException ("Expected token type of type: " + type + ", got " + token.Type +
 114                                         " (" + token.Value + ") .");
 115
 116                         GetNextToken ();
 117                 }
 118
 119                 public bool IsEOF ()
 120                 {
 121                         return token.Type == TokenType.EOF;
 122                 }
 123
 124                 public bool IsNumber ()
 125                 {
 126                         return token.Type == TokenType.Number;
 127                 }
 128
 129                 public bool IsToken (TokenType type)
 130                 {
 131                         return token.Type == type;
 132                 }
 133
 134                 public bool IsPunctation ()
 135                 {
 136                         return (token.Type >= TokenType.FirstPunct && token.Type < TokenType.LastPunct);
 137                 }
 138
 139                 // FIXME test this
 140                 public void Putback (Token token)
 141                 {
 142                         putback = token;
 143                 }
 144
 145                 public void GetNextToken ()
 146                 {
 147                         if (putback != null) {
 148                                 token = putback;
 149                                 putback = null;
 150                                 return;
 151                         }
 152
 153                         if (token.Type == TokenType.EOF)
 154                                 throw new ExpressionParseException (String.Format (
 155                                                         "Error while parsing condition \"{0}\", ended abruptly.",
 156                                                         inputString));
 157
 158                         SkipWhiteSpace ();
 159
 160                         tokenPosition = position;
 161
 162 //                      int i = PeekChar ();
 163                         int i = ReadChar ();
 164
 165                         if (i == -1) {
 166                                 token = new Token (null, TokenType.EOF, tokenPosition);
 167                                 return;
 168                         }
 169
 170                         char ch = (char) i;
 171
 172
 173                         // FIXME: looks like a hack: if '-' is here '->' won't be tokenized
 174                         // maybe we should treat item reference as a token
 175                         if (ch == '-' && PeekChar () == '>') {
 176                                 ReadChar ();
 177                                 token = new Token ("->", TokenType.Transform, tokenPosition);
 178                         } else if (Char.IsDigit (ch) || ch == '-') {
 179                                 StringBuilder sb = new StringBuilder ();
 180
 181                                 sb.Append (ch);
 182
 183                                 while ((i = PeekChar ()) != -1) {
 184                                         ch = (char) i;
 185
 186                                         if (Char.IsDigit (ch) || ch == '.')
 187                                                 sb.Append ((char) ReadChar ());
 188                                         else
 189                                                 break;
 190                                 }
 191
 192                                 token = new Token (sb.ToString (), TokenType.Number, tokenPosition);
 193                         } else if (ch == '\'' && position < inputString.Length) {
 194                                 StringBuilder sb = new StringBuilder ();
 195                                 string temp;
 196
 197                                 sb.Append (ch);
 198                                 bool is_itemref = (PeekChar () == '@');
 199                                 int num_open_braces = 0;
 200                                 bool in_literal = false;
 201
 202                                 while ((i = PeekChar ()) != -1) {
 203                                         ch = (char) i;
 204                                         if (ch == '(' && !in_literal && is_itemref)
 205                                                 num_open_braces ++;
 206                                         if (ch == ')' && !in_literal && is_itemref)
 207                                                 num_open_braces --;
 208
 209                                         sb.Append ((char) ReadChar ());
 210
 211                                         if (ch == '\'') {
 212                                                 if (num_open_braces == 0)
 213                                                         break;
 214                                                 in_literal = !in_literal;
 215                                         }
 216                                 }
 217
 218                                 temp = sb.ToString ();
 219
 220                                 token = new Token (temp.Substring (1, temp.Length - 2), TokenType.String, tokenPosition);
 221
 222                         } else  if (ch == '_' || Char.IsLetter (ch)) {
 223                                 StringBuilder sb = new StringBuilder ();
 224
 225                                 sb.Append ((char) ch);
 226
 227                                 while ((i = PeekChar ()) != -1) {
 228                                         if ((char) i == '_' || Char.IsLetterOrDigit ((char) i))
 229                                                 sb.Append ((char) ReadChar ());
 230                                         else
 231                                                 break;
 232                                 }
 233
 234                                 string temp = sb.ToString ();
 235
 236                                 if (keywords.ContainsKey (temp))
 237                                         token = new Token (temp, keywords [temp], tokenPosition);
 238                                 else
 239                                         token = new Token (temp, TokenType.String, tokenPosition);
 240
 241                         } else if (ch == '!' && PeekChar () == (int) '=') {
 242                                 token = new Token ("!=", TokenType.NotEqual, tokenPosition);
 243                                 ReadChar ();
 244                         } else if (ch == '<' && PeekChar () == (int) '=') {
 245                                 token = new Token ("<=", TokenType.LessOrEqual, tokenPosition);
 246                                 ReadChar ();
 247                         } else if (ch == '>' && PeekChar () == (int) '=') {
 248                                 token = new Token (">=", TokenType.GreaterOrEqual, tokenPosition);
 249                                 ReadChar ();
 250                         } else if (ch == '=' && PeekChar () == (int) '=') {
 251                                 token = new Token ("==", TokenType.Equal, tokenPosition);
 252                                 ReadChar ();
 253                         } else if (ch >= 32 && ch < 128) {
 254                                 if (charIndexToTokenType [ch] != TokenType.Invalid) {
 255                                         token = new Token (new String (ch, 1), charIndexToTokenType [ch], tokenPosition);
 256                                         return;
 257                                 } else
 258                                         throw new ExpressionParseException (String.Format ("Invalid punctuation: {0}", ch));
 259                         } else
 260                                 throw new ExpressionParseException (String.Format ("Invalid token: {0}", ch));
 261                 }
 262
 263                 public int TokenPosition {
 264                         get { return tokenPosition; }
 265                 }
 266
 267                 public Token Token {
 268                         get { return token; }
 269                 }
 270
 271 /*
 272                 public bool IgnoreWhiteSpace {
 273                         get { return ignoreWhiteSpace; }
 274                         set { ignoreWhiteSpace = value; }
 275                 }
 276 */
 277
 278                 struct CharToTokenType {
 279                         public char ch;
 280                         public TokenType tokenType;
 281
 282                         public CharToTokenType (char ch, TokenType tokenType)
 283                         {
 284                                 this.ch = ch;
 285                                 this.tokenType = tokenType;
 286                         }
 287                 }
 288
 289                 static CharToTokenType[] charToTokenType = {
 290                         new CharToTokenType ('<', TokenType.Less),
 291                         new CharToTokenType ('>', TokenType.Greater),
 292                         new CharToTokenType ('=', TokenType.Equal),
 293                         new CharToTokenType ('(', TokenType.LeftParen),
 294                         new CharToTokenType (')', TokenType.RightParen),
 295                         new CharToTokenType ('.', TokenType.Dot),
 296                         new CharToTokenType (',', TokenType.Comma),
 297                         new CharToTokenType ('!', TokenType.Not),
 298                         new CharToTokenType ('@', TokenType.Item),
 299                         new CharToTokenType ('$', TokenType.Property),
 300                         new CharToTokenType ('%', TokenType.Metadata),
 301                         new CharToTokenType ('\'', TokenType.Apostrophe),
 302                 };
 303         }
 304 }
 305
 306 #endif