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

   1 //
   2 // ConditionParser.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.Text;
  34
  35 namespace Microsoft.Build.BuildEngine {
  36
  37         internal class ConditionParser {
  38
  39                 ConditionTokenizer tokenizer;
  40                 string conditionStr;
  41
  42                 ConditionParser (string condition)
  43                 {
  44                         tokenizer = new ConditionTokenizer ();
  45                         tokenizer.Tokenize (condition);
  46                         conditionStr = condition;
  47                 }
  48
  49                 public static bool ParseAndEvaluate (string condition, Project context)
  50                 {
  51                         if (String.IsNullOrEmpty (condition))
  52                                 return true;
  53
  54                         try {
  55                                 ConditionExpression ce = ParseCondition (condition);
  56
  57                                 if (!ce.CanEvaluateToBool (context))
  58                                         throw new InvalidProjectFileException (String.Format ("Can not evaluate \"{0}\" to bool.", condition));
  59
  60                                 return ce.BoolEvaluate (context);
  61                         } catch (ExpressionParseException epe) {
  62                                 throw new InvalidProjectFileException (
  63                                                 String.Format ("Unable to parse condition \"{0}\" : {1}", condition, epe.Message),
  64                                                 epe);
  65                         } catch (ExpressionEvaluationException epe) {
  66                                 throw new InvalidProjectFileException (
  67                                                 String.Format ("Unable to evaluate condition \"{0}\" : {1}", condition, epe.Message),
  68                                                 epe);
  69                         }
  70                 }
  71
  72                 public static ConditionExpression ParseCondition (string condition)
  73                 {
  74                         ConditionParser parser = new ConditionParser (condition);
  75                         ConditionExpression e = parser.ParseExpression ();
  76
  77                         if (!parser.tokenizer.IsEOF ())
  78                                 throw new ExpressionParseException (String.Format ("Unexpected token found, {0}, in condition \"{1}\"", parser.tokenizer.Token, condition));
  79
  80                         return e;
  81                 }
  82
  83                 ConditionExpression ParseExpression ()
  84                 {
  85                         return ParseBooleanExpression ();
  86                 }
  87
  88                 ConditionExpression ParseBooleanExpression ()
  89                 {
  90                         return ParseBooleanAnd ();
  91                 }
  92
  93                 public static string And (string a, string b)
  94                 {
  95                         return a + " and " + b;
  96                 }
  97
  98                 ConditionExpression ParseBooleanAnd ()
  99                 {
 100                         ConditionExpression e = ParseBooleanOr ();
 101
 102                         while (tokenizer.IsToken (TokenType.And)) {
 103                                 tokenizer.GetNextToken ();
 104                                 e = new ConditionAndExpression (e, ParseBooleanOr ());
 105                         }
 106
 107                         return e;
 108                 }
 109
 110                 ConditionExpression ParseBooleanOr ()
 111                 {
 112                         ConditionExpression e = ParseRelationalExpression ();
 113
 114                         while (tokenizer.IsToken (TokenType.Or)) {
 115                                 tokenizer.GetNextToken ();
 116                                 e = new ConditionOrExpression (e, ParseRelationalExpression ());
 117                         }
 118
 119                         return e;
 120                 }
 121
 122                 ConditionExpression ParseRelationalExpression ()
 123                 {
 124                         ConditionExpression e = ParseFactorExpression ();
 125
 126                         Token opToken;
 127                         RelationOperator op;
 128
 129                         if (tokenizer.IsToken (TokenType.Less) ||
 130                                 tokenizer.IsToken (TokenType.Greater) ||
 131                                 tokenizer.IsToken (TokenType.Equal) ||
 132                                 tokenizer.IsToken (TokenType.NotEqual) ||
 133                                 tokenizer.IsToken (TokenType.LessOrEqual) ||
 134                                 tokenizer.IsToken (TokenType.GreaterOrEqual)) {
 135
 136                                 opToken = tokenizer.Token;
 137                                 tokenizer.GetNextToken ();
 138
 139                                 switch (opToken.Type) {
 140                                 case TokenType.Equal:
 141                                         op = RelationOperator.Equal;
 142                                         break;
 143                                 case TokenType.NotEqual:
 144                                         op = RelationOperator.NotEqual;
 145                                         break;
 146                                 case TokenType.Less:
 147                                         op = RelationOperator.Less;
 148                                         break;
 149                                 case TokenType.LessOrEqual:
 150                                         op = RelationOperator.LessOrEqual;
 151                                         break;
 152                                 case TokenType.Greater:
 153                                         op = RelationOperator.Greater;
 154                                         break;
 155                                 case TokenType.GreaterOrEqual:
 156                                         op = RelationOperator.GreaterOrEqual;
 157                                         break;
 158                                 default:
 159                                         throw new ExpressionParseException (String.Format ("Wrong relation operator {0}", opToken.Value));
 160                                 }
 161
 162                                 e =  new ConditionRelationalExpression (e, ParseFactorExpression (), op);
 163                         }
 164
 165                         return e;
 166                 }
 167
 168                 ConditionExpression ParseFactorExpression ()
 169                 {
 170                         ConditionExpression e;
 171                         Token token = tokenizer.Token;
 172                         tokenizer.GetNextToken ();
 173
 174                         if (token.Type == TokenType.LeftParen) {
 175                                 e = ParseExpression ();
 176                                 tokenizer.Expect (TokenType.RightParen);
 177                         } else if (token.Type == TokenType.String && tokenizer.Token.Type == TokenType.LeftParen) {
 178                                 e = ParseFunctionExpression (token.Value);
 179                         } else if (token.Type == TokenType.String) {
 180                                 e = new ConditionFactorExpression (token);
 181                         } else if (token.Type == TokenType.Number) {
 182                                 e = new ConditionFactorExpression (token);
 183                         } else if (token.Type == TokenType.Item || token.Type == TokenType.Property
 184                                         || token.Type == TokenType.Metadata) {
 185                                 e = ParseReferenceExpression (token.Value [0]);
 186                         } else if (token.Type == TokenType.Not) {
 187                                 e = ParseNotExpression ();
 188                         } else
 189                                 throw new ExpressionParseException (String.Format ("Unexpected token {0}, while parsing condition \"{1}\"", token, conditionStr));
 190
 191                         return e;
 192                 }
 193
 194                 ConditionExpression ParseNotExpression ()
 195                 {
 196                         return new ConditionNotExpression (ParseFactorExpression ());
 197                 }
 198
 199                 ConditionExpression ParseFunctionExpression (string function_name)
 200                 {
 201                         return new ConditionFunctionExpression (function_name, ParseFunctionArguments ());
 202                 }
 203
 204                 List <ConditionFactorExpression> ParseFunctionArguments ()
 205                 {
 206                         List <ConditionFactorExpression> list = new List <ConditionFactorExpression> ();
 207                         ConditionFactorExpression e;
 208
 209                         while (true) {
 210                                 tokenizer.GetNextToken ();
 211                                 if (tokenizer.Token.Type == TokenType.RightParen) {
 212                                         tokenizer.GetNextToken ();
 213                                         break;
 214                                 }
 215                                 if (tokenizer.Token.Type == TokenType.Comma)
 216                                         continue;
 217
 218                                 tokenizer.Putback (tokenizer.Token);
 219                                 e = (ConditionFactorExpression) ParseFactorExpression ();
 220                                 list.Add (e);
 221                         }
 222
 223                         return list;
 224                 }
 225
 226                 //@prefix: @ or $
 227                 ConditionExpression ParseReferenceExpression (char prefix)
 228                 {
 229                         int token_pos = tokenizer.Token.Position;
 230                         string ref_type = prefix == '$' ? "a property" : "an item list";
 231                         IsAtToken (TokenType.LeftParen, String.Format (
 232                                                 "Expected {0} at position {1} in condition \"{2}\". Missing opening parantheses after the '{3}'.",
 233                                                 ref_type, token_pos, conditionStr, prefix));
 234
 235
 236                         if (prefix == '$') {
 237                                 //
 238                                 // Tjhe scan should consider quoted parenthesis but it breaks on .net as well
 239                                 // we are bug compatible
 240                                 //
 241                                 tokenizer.ScanForClosingParens ();
 242                         } else {
 243                                 tokenizer.GetNextToken ();
 244                         }
 245
 246                         if (tokenizer.IsEOF ())
 247                                 throw new ExpressionParseException ("Missing closing parenthesis in condition " + conditionStr);
 248
 249                         StringBuilder sb = new StringBuilder ();
 250                         sb.AppendFormat ("{0}({1}", prefix, tokenizer.Token.Value);
 251
 252                         tokenizer.GetNextToken ();
 253                         if (prefix == '@' && tokenizer.Token.Type == TokenType.Transform) {
 254                                 tokenizer.GetNextToken ();
 255                                 sb.AppendFormat ("->'{0}'", tokenizer.Token.Value);
 256
 257                                 tokenizer.GetNextToken ();
 258                                 if (tokenizer.Token.Type == TokenType.Comma) {
 259                                         tokenizer.GetNextToken ();
 260                                         sb.AppendFormat (", '{0}'", tokenizer.Token.Value);
 261                                         tokenizer.GetNextToken ();
 262                                 }
 263                         }
 264
 265                         IsAtToken (TokenType.RightParen, "Missing closing parenthesis in condition " + conditionStr);
 266                         tokenizer.GetNextToken ();
 267
 268                         sb.Append (")");
 269
 270                         //FIXME: HACKY!
 271                         return new ConditionFactorExpression (new Token (sb.ToString (), TokenType.String, token_pos));
 272                 }
 273
 274                 // used to check current token type
 275                 void IsAtToken (TokenType type, string error_msg)
 276                 {
 277                         if (tokenizer.Token.Type != type) {
 278                                 if (!String.IsNullOrEmpty (error_msg))
 279                                         throw new ExpressionParseException (error_msg);
 280
 281                                 if (tokenizer.Token.Type == TokenType.EOF)
 282                                         throw new ExpressionParseException (String.Format (
 283                                                                 "Expected a \"{0}\" but the condition ended abruptly, while parsing condition \"{1}\"",
 284                                                                 Token.TypeAsString (type), conditionStr));
 285
 286                                 throw new ExpressionParseException (String.Format (
 287                                                                 "Expected \"{0}\" token,  but got {1}, while parsing \"{2}\"",
 288                                                                 Token.TypeAsString (type), tokenizer.Token, conditionStr));
 289                         }
 290                 }
 291         }
 292 }