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                 ConditionExpression ParseBooleanAnd ()
  94                 {
  95                         ConditionExpression e = ParseBooleanOr ();
  96
  97                         while (tokenizer.IsToken (TokenType.And)) {
  98                                 tokenizer.GetNextToken ();
  99                                 e = new ConditionAndExpression (e, ParseBooleanOr ());
 100                         }
 101
 102                         return e;
 103                 }
 104
 105                 ConditionExpression ParseBooleanOr ()
 106                 {
 107                         ConditionExpression e = ParseRelationalExpression ();
 108
 109                         while (tokenizer.IsToken (TokenType.Or)) {
 110                                 tokenizer.GetNextToken ();
 111                                 e = new ConditionOrExpression (e, ParseRelationalExpression ());
 112                         }
 113
 114                         return e;
 115                 }
 116
 117                 ConditionExpression ParseRelationalExpression ()
 118                 {
 119                         ConditionExpression e = ParseFactorExpression ();
 120
 121                         Token opToken;
 122                         RelationOperator op;
 123
 124                         if (tokenizer.IsToken (TokenType.Less) ||
 125                                 tokenizer.IsToken (TokenType.Greater) ||
 126                                 tokenizer.IsToken (TokenType.Equal) ||
 127                                 tokenizer.IsToken (TokenType.NotEqual) ||
 128                                 tokenizer.IsToken (TokenType.LessOrEqual) ||
 129                                 tokenizer.IsToken (TokenType.GreaterOrEqual)) {
 130
 131                                 opToken = tokenizer.Token;
 132                                 tokenizer.GetNextToken ();
 133
 134                                 switch (opToken.Type) {
 135                                 case TokenType.Equal:
 136                                         op = RelationOperator.Equal;
 137                                         break;
 138                                 case TokenType.NotEqual:
 139                                         op = RelationOperator.NotEqual;
 140                                         break;
 141                                 case TokenType.Less:
 142                                         op = RelationOperator.Less;
 143                                         break;
 144                                 case TokenType.LessOrEqual:
 145                                         op = RelationOperator.LessOrEqual;
 146                                         break;
 147                                 case TokenType.Greater:
 148                                         op = RelationOperator.Greater;
 149                                         break;
 150                                 case TokenType.GreaterOrEqual:
 151                                         op = RelationOperator.GreaterOrEqual;
 152                                         break;
 153                                 default:
 154                                         throw new ExpressionParseException (String.Format ("Wrong relation operator {0}", opToken.Value));
 155                                 }
 156
 157                                 e =  new ConditionRelationalExpression (e, ParseFactorExpression (), op);
 158                         }
 159
 160                         return e;
 161                 }
 162
 163                 ConditionExpression ParseFactorExpression ()
 164                 {
 165                         ConditionExpression e;
 166                         Token token = tokenizer.Token;
 167                         tokenizer.GetNextToken ();
 168
 169                         if (token.Type == TokenType.LeftParen) {
 170                                 e = ParseExpression ();
 171                                 tokenizer.Expect (TokenType.RightParen);
 172                         } else if (token.Type == TokenType.String && tokenizer.Token.Type == TokenType.LeftParen) {
 173                                 e = ParseFunctionExpression (token.Value);
 174                         } else if (token.Type == TokenType.String) {
 175                                 e = new ConditionFactorExpression (token);
 176                         } else if (token.Type == TokenType.Number) {
 177                                 e = new ConditionFactorExpression (token);
 178                         } else if (token.Type == TokenType.Item || token.Type == TokenType.Property
 179                                         || token.Type == TokenType.Metadata) {
 180                                 e = ParseReferenceExpression (token.Value);
 181                         } else if (token.Type == TokenType.Not) {
 182                                 e = ParseNotExpression ();
 183                         } else
 184                                 throw new ExpressionParseException (String.Format ("Unexpected token {0}, while parsing condition \"{1}\"", token, conditionStr));
 185
 186                         return e;
 187                 }
 188
 189                 ConditionExpression ParseNotExpression ()
 190                 {
 191                         return new ConditionNotExpression (ParseFactorExpression ());
 192                 }
 193
 194                 ConditionExpression ParseFunctionExpression (string function_name)
 195                 {
 196                         return new ConditionFunctionExpression (function_name, ParseFunctionArguments ());
 197                 }
 198
 199                 List <ConditionFactorExpression> ParseFunctionArguments ()
 200                 {
 201                         List <ConditionFactorExpression> list = new List <ConditionFactorExpression> ();
 202                         ConditionFactorExpression e;
 203
 204                         while (true) {
 205                                 tokenizer.GetNextToken ();
 206                                 if (tokenizer.Token.Type == TokenType.RightParen) {
 207                                         tokenizer.GetNextToken ();
 208                                         break;
 209                                 }
 210                                 if (tokenizer.Token.Type == TokenType.Comma)
 211                                         continue;
 212
 213                                 tokenizer.Putback (tokenizer.Token);
 214                                 e = (ConditionFactorExpression) ParseFactorExpression ();
 215                                 list.Add (e);
 216                         }
 217
 218                         return list;
 219                 }
 220
 221                 //@prefix: @ or $
 222                 ConditionExpression ParseReferenceExpression (string prefix)
 223                 {
 224                         StringBuilder sb = new StringBuilder ();
 225
 226                         string ref_type = prefix [0] == '$' ? "a property" : "an item list";
 227                         int token_pos = tokenizer.Token.Position;
 228                         IsAtToken (TokenType.LeftParen, String.Format (
 229                                                 "Expected {0} at position {1} in condition \"{2}\". Missing opening parantheses after the '{3}'.",
 230                                                 ref_type, token_pos, conditionStr, prefix));
 231                         tokenizer.GetNextToken ();
 232
 233                         sb.AppendFormat ("{0}({1}", prefix, tokenizer.Token.Value);
 234
 235                         tokenizer.GetNextToken ();
 236                         if (prefix == "@" && tokenizer.Token.Type == TokenType.Transform) {
 237                                 tokenizer.GetNextToken ();
 238                                 sb.AppendFormat ("->'{0}'", tokenizer.Token.Value);
 239
 240                                 tokenizer.GetNextToken ();
 241                                 if (tokenizer.Token.Type == TokenType.Comma) {
 242                                         tokenizer.GetNextToken ();
 243                                         sb.AppendFormat (", '{0}'", tokenizer.Token.Value);
 244                                         tokenizer.GetNextToken ();
 245                                 }
 246                         }
 247
 248                         IsAtToken (TokenType.RightParen, String.Format (
 249                                                 "Expected {0} at position {1} in condition \"{2}\". Missing closing parantheses'.",
 250                                                 ref_type, token_pos, conditionStr, prefix));
 251                         tokenizer.GetNextToken ();
 252
 253                         sb.Append (")");
 254
 255                         //FIXME: HACKY!
 256                         return new ConditionFactorExpression (new Token (sb.ToString (), TokenType.String, token_pos));
 257                 }
 258
 259                 // used to check current token type
 260                 void IsAtToken (TokenType type, string error_msg)
 261                 {
 262                         if (tokenizer.Token.Type != type) {
 263                                 if (!String.IsNullOrEmpty (error_msg))
 264                                         throw new ExpressionParseException (error_msg);
 265
 266                                 if (tokenizer.Token.Type == TokenType.EOF)
 267                                         throw new ExpressionParseException (String.Format (
 268                                                                 "Expected a \"{0}\" but the condition ended abruptly, while parsing condition \"{1}\"",
 269                                                                 Token.TypeAsString (type), conditionStr));
 270
 271                                 throw new ExpressionParseException (String.Format (
 272                                                                 "Expected \"{0}\" token,  but got {1}, while parsing \"{2}\"",
 273                                                                 Token.TypeAsString (type), tokenizer.Token, conditionStr));
 274                         }
 275                 }
 276         }
 277 }