mcs/class/Microsoft.Build/Microsoft.Build.Internal/ExpressionTokenizer.cs

   1 //
   2 // ExpressionTokenizer.cs
   3 //
   4 // Author:
   5 //   Atsushi Enomoto (atsushi@xamarin.com)
   6 //
   7 // Copyright (C) 2013 Xamarin Inc. (http://www.xamarin.com)
   8 //
   9 // Permission is hereby granted, free of charge, to any person obtaining
  10 // a copy of this software and associated documentation files (the
  11 // "Software"), to deal in the Software without restriction, including
  12 // without limitation the rights to use, copy, modify, merge, publish,
  13 // distribute, sublicense, and/or sell copies of the Software, and to
  14 // permit persons to whom the Software is furnished to do so, subject to
  15 // the following conditions:
  16 //
  17 // The above copyright notice and this permission notice shall be
  18 // included in all copies or substantial portions of the Software.
  19 //
  20 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  21 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  22 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  23 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  24 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  25 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  26 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  27 //
  28 using System;
  29 using System.Collections.Generic;
  30 using Microsoft.Build.Evaluation;
  31
  32 namespace Microsoft.Build.Internal
  33 {
  34         enum ExpressionValidationType
  35         {
  36                 LaxString,
  37                 StrictBoolean,
  38         }
  39
  40         enum TokenizerMode
  41         {
  42                 Default,
  43                 InsideItemOrProperty,
  44         }
  45
  46         class ExpressionTokenizer : yyParser.yyInput
  47         {
  48                 public ExpressionTokenizer (string source, ExpressionValidationType validationType)
  49                 {
  50                         this.source = source;
  51                         current_token_position = -1;
  52                         validation_type = validationType;
  53                         modes.Push (TokenizerMode.Default);
  54                 }
  55
  56                 string source;
  57                 ExpressionValidationType validation_type;
  58
  59                 int current_token;
  60                 string error;
  61                 int pos, current_token_position;
  62                 object token_value;
  63                 Stack<TokenizerMode> modes = new Stack<TokenizerMode> ();
  64
  65                 TokenizerMode CurrentTokenizerMode {
  66                         get { return modes.Peek (); }
  67                 }
  68
  69                 public bool advance ()
  70                 {
  71                         if (pos == source.Length)
  72                                 return false;
  73
  74                         error = null;
  75                         token_value = null;
  76
  77                         while (pos < source.Length) {
  78                                 if (spaces.IndexOf (source [pos]) >= 0)
  79                                         pos++;
  80                                 else
  81                                         break;
  82                         }
  83                         if (pos == source.Length)
  84                                 return false;
  85                         current_token_position = pos;
  86
  87                         switch (source [pos++]) {
  88                         case '.':
  89                                 TokenForItemPropertyValue (".", Token.DOT);
  90                                 break;
  91                         case ',':
  92                                 TokenForItemPropertyValue (",", Token.COMMA);
  93                                 break;
  94                         case '[':
  95                                 TokenForItemPropertyValue ("[", Token.BRACE_OPEN);
  96                                 break;
  97                         case ']':
  98                                 TokenForItemPropertyValue ("]", Token.BRACE_CLOSE);
  99                                 break;
 100                         case '(':
 101                                 modes.Push (TokenizerMode.Default);
 102                                 TokenForItemPropertyValue ("(", Token.PAREN_OPEN);
 103                                 break;
 104                         case ')':
 105                                 if (modes.Count > 0) {
 106                                         modes.Pop ();
 107                                         current_token = Token.PAREN_CLOSE;
 108                                 } else {
 109                                         token_value = ")";
 110                                         current_token = Token.NAME;
 111                                 }
 112                                 break;
 113                         case '-':
 114                                 if (pos < source.Length && source [pos] == '>') {
 115                                         current_token = Token.ARROW;
 116                                         pos++;
 117                                 } else
 118                                         ErrorOnStrictBoolean ("-", "'-' is not followed by '>'.");
 119                                 break;
 120                         case '=':
 121                                 if (pos < source.Length && source [pos] == '=') {
 122                                         current_token = Token.EQ;
 123                                         pos++;
 124                                 } else
 125                                         ErrorOnStrictBoolean ("=", "'=' is not followed by '='.");
 126                                 break;
 127                         case ':':
 128                                 if (pos < source.Length && source [pos] == ':') {
 129                                         current_token = Token.COLON2;
 130                                 } else
 131                                         ErrorOnStrictBoolean (":", "':' is not followed by ':'.");
 132                                 pos++;
 133                                 break;
 134                         case '!':
 135                                 if (pos < source.Length && source [pos] == '=') {
 136                                         pos++;
 137                                         current_token = Token.NE;
 138                                 } else
 139                                         TokenForItemPropertyValue ("!", Token.NOT);
 140                                 break;
 141                         case '>':
 142                                 if (pos < source.Length && source [pos] == '=') {
 143                                         pos++;
 144                                         current_token = Token.GE;
 145                                 } else
 146                                         current_token = Token.GT;
 147                                 break;
 148                         case '<':
 149                                 if (pos < source.Length && source [pos] == '=') {
 150                                         pos++;
 151                                         current_token = Token.LE;
 152                                 } else
 153                                         current_token = Token.LT;
 154                                 break;
 155                         case '$':
 156                                 if (pos < source.Length && source [pos] == '(') {
 157                                         modes.Push (TokenizerMode.InsideItemOrProperty);
 158                                         current_token = Token.PROP_OPEN;
 159                                         pos++;
 160                                 } else
 161                                         ErrorOnStrictBoolean ("$", "property reference '$' is not followed by '('.");
 162                                 break;
 163                         case '@':
 164                                 if (pos < source.Length && source [pos] == '(') {
 165                                         modes.Push (TokenizerMode.InsideItemOrProperty);
 166                                         current_token = Token.ITEM_OPEN;
 167                                         pos++;
 168                                 } else
 169                                         ErrorOnStrictBoolean ("@", "item reference '@' is not followed by '('.");
 170                                 break;
 171                         case '%':
 172                                 if (pos < source.Length && source [pos] == '(') {
 173                                         modes.Push (TokenizerMode.InsideItemOrProperty);
 174                                         current_token = Token.METADATA_OPEN;
 175                                         pos++;
 176                                 } else
 177                                         ErrorOnStrictBoolean ("%", "metadata reference '%' is not followed by '('.");
 178                                 break;
 179                         case '"':
 180                         case '\'':
 181                                 pos = source.IndexOf (source [pos - 1], pos);
 182                                 if (pos < 0) {
 183                                         ErrorOnStrictBoolean ("'", "unterminated string literal");
 184                                         pos = source.Length;
 185                                 }
 186                                 token_value = source.Substring (current_token_position + 1, pos - current_token_position - 1);
 187                                 current_token = Token.STRING_LITERAL;
 188                                 pos++;
 189                                 break;
 190                         default:
 191                                 pos = source.IndexOfAny (token_starter_chars, pos);
 192                                 if (pos < 0)
 193                                         pos = source.Length;
 194                                 var val = source.Substring (current_token_position, pos - current_token_position);
 195                                 if (val.Equals ("AND", StringComparison.OrdinalIgnoreCase))
 196                                         current_token = Token.AND;
 197                                 else if (val.Equals ("OR", StringComparison.OrdinalIgnoreCase))
 198                                         current_token = Token.OR;
 199                                 else if (val.Equals ("TRUE", StringComparison.OrdinalIgnoreCase))
 200                                         current_token = Token.TRUE_LITERAL;
 201                                 else if (val.Equals ("FALSE", StringComparison.OrdinalIgnoreCase))
 202                                         current_token = Token.FALSE_LITERAL;
 203                                 else {
 204                                         current_token = Token.NAME;
 205                                         token_value = ProjectCollection.Unescape (val);
 206                                         break;
 207                                 }
 208                                 break;
 209                         }
 210                         return true;
 211                 }
 212                 string spaces = " \t\r\n";
 213
 214                 static readonly char [] token_starter_chars = ".,[]()-=:!><$@%\"' ".ToCharArray ();
 215
 216                 void ReadStringLiteral (string source, char c)
 217                 {
 218                         while (pos < source.Length && source [pos] != c)
 219                                 pos++;
 220                         if (source [pos - 1] != c)
 221                                 ErrorOnStrictBoolean (c.ToString (), string.Format ("missing string literal terminator [{0}]", c));
 222                         else {
 223                                 current_token = Token.NAME;
 224                                 token_value = source.Substring (current_token_position + 1, pos - current_token_position - 2);
 225                                 token_value = ProjectCollection.Unescape ((string) token_value);
 226                         }
 227                 }
 228
 229                 void TokenForItemPropertyValue (string value, int token)
 230                 {
 231                         if (true)//CurrentTokenizerMode == TokenizerMode.InsideItemOrProperty)
 232                                 current_token = token;
 233                         else {
 234                                 current_token = Token.NAME;
 235                                 token_value = value;
 236                         }
 237                 }
 238
 239                 void ErrorOnStrictBoolean (string value, string message)
 240                 {
 241                         if (validation_type == ExpressionValidationType.StrictBoolean) {
 242                                 current_token = Token.ERROR;
 243                                 error = message;
 244                         } else {
 245                                 current_token = Token.NAME;
 246                                 token_value = value;
 247                         }
 248                 }
 249
 250                 public int token ()
 251                 {
 252                         return current_token;
 253                 }
 254
 255                 public object value ()
 256                 {
 257                         if (current_token == Token.NAME || current_token == Token.STRING_LITERAL)
 258                                 return new NameToken () { Name = (string) token_value, Column = current_token_position };
 259                         else if (error != null)
 260                                 return new ErrorToken () { Message = error, Column = current_token_position };
 261                         else
 262                                 return new Location () { Column = current_token_position };
 263                 }
 264         }
 265
 266         class NameToken : Location
 267         {
 268                 public string Name { get; set; }
 269
 270                 public override string ToString ()
 271                 {
 272                         return string.Format ("[NameToken: Value={0}]", Name);
 273                 }
 274         }
 275
 276         class ErrorToken : Location
 277         {
 278                 public string Message { get; set; }
 279         }
 280
 281         interface ILocation
 282         {
 283                 //int Line { get; }
 284                 int Column { get; }
 285                 //string File { get; }
 286
 287                 string ToLocationString ();
 288         }
 289
 290         class Location : ILocation
 291         {
 292                 //public int Line { get; set; }
 293                 public int Column { get; set; }
 294                 //public string File { get; set; }
 295
 296                 public string ToLocationString ()
 297                 {
 298                         return "at " + Column;
 299                 }
 300         }
 301 }