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

   1 using System;
   2 using System.Collections.Generic;
   3 using System.Linq;
   4 using Microsoft.Build.Exceptions;
   5
   6 namespace Microsoft.Build.Internal
   7 {
   8         class ExpressionParserManual
   9         {
  10                 public ExpressionParserManual (string source, ExpressionValidationType validationType)
  11                 {
  12                         this.source = source;
  13                         validation_type = validationType;
  14                 }
  15
  16                 string source;
  17                 ExpressionValidationType validation_type;
  18
  19                 public ExpressionList Parse ()
  20                 {
  21                         return Parse (0, source.Length);
  22                 }
  23
  24                 static readonly char [] token_starters = "$@%('\"".ToCharArray ();
  25
  26                 ExpressionList Parse (int start, int end)
  27                 {
  28                         if (string.IsNullOrWhiteSpace (source))
  29                                 return new ExpressionList ();
  30
  31                         var head = new List<Expression> ();
  32                         var tail = new List<Expression> ();
  33                         while (start < end) {
  34                                 char token = source [start];
  35                                 switch (token) {
  36                                 case '$':
  37                                 case '@':
  38                                 case '%':
  39                                         if (start == end || start + 1 == source.Length || source [start + 1] != '(') {
  40                                                 if (validation_type == ExpressionValidationType.StrictBoolean)
  41                                                         throw new InvalidProjectFileException (string.Format ("missing '(' after '{0}' at {1} in \"{2}\"", source [start], start, source));
  42                                                 else
  43                                                         goto default; // treat as raw literal to the section end
  44                                         }
  45                                         start++;
  46                                         int last = source.LastIndexOf (')', end - 1, end - start - 1);
  47                                         if (last < 0) {
  48                                                 if (validation_type == ExpressionValidationType.StrictBoolean)
  49                                                         throw new InvalidProjectFileException (string.Format ("expression did not have matching ')' since index {0} in \"{1}\"", start, source));
  50                                                 else {
  51                                                         if (token != '(')
  52                                                                 start--;
  53                                                         goto default; // treat as raw literal to the section end
  54                                                 }
  55                                         }
  56                                         start++;
  57                                         if (token == '$')
  58                                                 head.Add (EvaluatePropertyExpression (start, last));
  59                                         else if (token == '%')
  60                                                 head.Add (EvaluateMetadataExpression (start, last));
  61                                         else
  62                                                 head.Add (EvaluateItemExpression (start, last));
  63                                         start = last + 1;
  64                                         break;
  65
  66                                 // Below (until default) are important only for Condition evaluation
  67                                 case '(':
  68                                         if (validation_type == ExpressionValidationType.LaxString)
  69                                                 goto default;
  70                                         start++;
  71                                         last = source.LastIndexOf (')', end - 1, end - start);
  72                                         if (last < 0)
  73                                                 throw new InvalidProjectFileException (string.Format ("expression did not have matching ')' since index {0} in \"{1}\"", start, source));
  74                                         var contents = Parse (start, last).ToArray ();
  75                                         if (contents.Length > 1)
  76                                                 throw new InvalidProjectFileException (string.Format ("unexpected continuous expression within (){0} in \"{1}\"", contents [1].Column > 0 ? " at " + contents [1].Column : null, source));
  77                                         head.Add (contents.First ());
  78                                         break;
  79
  80                                 default:
  81                                         int idx = source.IndexOfAny (token_starters, start + 1);
  82                                         string name = idx < 0 ? source.Substring (start, end - start) : source.Substring (start, idx - start);
  83                                         var val = new NameToken () { Name = name };
  84                                         var literal = new RawStringLiteral () { Value = val };
  85                                         head.Add (new StringLiteralExpression () { Contents = new ExpressionList () { literal } });
  86                                         if (idx >= 0)
  87                                                 start = idx;
  88                                         else
  89                                                 start = end;
  90
  91                                         break;
  92                                 }
  93                                 SkipSpaces (ref start);
  94                         }
  95                         var ret = new ExpressionList ();
  96                         foreach (var e in head.Concat (((IEnumerable<Expression>) tail).Reverse ()))
  97                                 ret.Add (e);
  98                         return ret;
  99                 }
 100
 101                 static readonly string spaces = " \t\r\n";
 102
 103                 void SkipSpaces (ref int start)
 104                 {
 105                         while (start < source.Length && spaces.Contains (source [start]))
 106                                 start++;
 107                 }
 108
 109                 PropertyAccessExpression EvaluatePropertyExpression (int start, int end)
 110                 {
 111                         // member access
 112                         int idx = source.LastIndexOf ('.', start);
 113                         if (idx >= 0) {
 114                                 string name = (idx > 0) ? source.Substring (idx, end - idx) : source.Substring (start, end);
 115                                 return new PropertyAccessExpression () {
 116                                         Access = new PropertyAccess () {
 117                                                 Name = new NameToken () { Name = name },
 118                                                 TargetType = PropertyTargetType.Object,
 119                                                 Target = idx < 0 ? null : Parse (start, idx).FirstOrDefault ()
 120                                                 }
 121                                         };
 122                         } else {
 123                                 // static type access
 124                                 idx = source.IndexOf ("::", start, StringComparison.Ordinal);
 125                                 if (idx >= 0) {
 126                                         throw new NotImplementedException ();
 127
 128                                         string type = source.Substring (start, idx - start);
 129                                         if (type.Length < 2 || type [0] != '[' || type [type.Length - 1] != ']')
 130                                                 throw new InvalidProjectFileException (string.Format ("Static function call misses appropriate type name surrounded by '[' and ']' at {0} in \"{1}\"", start, source));
 131                                         int start2 = idx + 2;
 132                                         int idx2 = source.IndexOf ('(', idx + 2, end - start2);
 133                                         if (idx2 < 0) {
 134                                                 // access to static property
 135                                                 string member = source.Substring (start2, end - start2);
 136                                         } else {
 137                                                 // access to static method
 138                                                 string member = source.Substring (start2, idx2 - start2);
 139                                         }
 140                                 } else {
 141                                         // property access without member specification
 142                                         return new PropertyAccessExpression () {
 143                                                 Access = new PropertyAccess () {
 144                                                         Name = new NameToken () { Name = source.Substring (start, end - start) },
 145                                                         TargetType = PropertyTargetType.Object
 146                                                         }
 147                                                 };
 148                                 }
 149                         }
 150                 }
 151
 152                 ItemAccessExpression EvaluateItemExpression (int start, int end)
 153                 {
 154                         // using property as context and evaluate
 155                         int idx = source.IndexOf ("->", start, StringComparison.Ordinal);
 156                         if (idx > 0) {
 157                                 string name = source.Substring (start, idx - start);
 158                                 return new ItemAccessExpression () {
 159                                         Application = new ItemApplication () {
 160                                                 Name = new NameToken () { Name = name },
 161                                                 Expressions = Parse (idx, end - idx)
 162                                                 }
 163                                         };
 164                         } else {
 165                                 string name = source.Substring (start, end - start);
 166                                 return new ItemAccessExpression () {
 167                                         Application = new ItemApplication () { Name = new NameToken () { Name = name } }
 168                                         };
 169                         }
 170
 171                         throw new NotImplementedException ();
 172                 }
 173
 174                 MetadataAccessExpression EvaluateMetadataExpression (int start, int end)
 175                 {
 176                         throw new NotImplementedException ();
 177                 }
 178         }
 179 }
 180