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