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

   1 //
   2 // ExpressionEvaluator.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.Linq;
  30 using Microsoft.Build.Evaluation;
  31 using Microsoft.Build.Exceptions;
  32 using System.Collections.Generic;
  33 using System.Reflection;
  34 using Microsoft.Build.Execution;
  35 using Microsoft.Build.Framework;
  36 using System.IO;
  37
  38 namespace Microsoft.Build.Internal.Expressions
  39 {
  40         class ExpressionEvaluator
  41         {
  42                 public ExpressionEvaluator (Project project)
  43                 {
  44                         Project = project;
  45                 }
  46
  47                 public ExpressionEvaluator (ProjectInstance project)
  48                 {
  49                         ProjectInstance = project;
  50                 }
  51
  52                 EvaluationContext CreateContext (string source)
  53                 {
  54                         return new EvaluationContext (source, this);
  55                 }
  56
  57                 public Project Project { get; private set; }
  58                 public ProjectInstance ProjectInstance { get; set; }
  59
  60                 List<ITaskItem> evaluated_task_items = new List<ITaskItem> ();
  61
  62                 public IList<ITaskItem> EvaluatedTaskItems {
  63                         get { return evaluated_task_items; }
  64                 }
  65
  66                 public string Evaluate (string source)
  67                 {
  68                         return Evaluate (source, new ExpressionParserManual (source ?? string.Empty, ExpressionValidationType.LaxString).Parse ());
  69                 }
  70
  71                 string Evaluate (string source, ExpressionList exprList)
  72                 {
  73                         if (exprList == null)
  74                                 throw new ArgumentNullException ("exprList");
  75                         return string.Concat (exprList.Select (e => e.EvaluateAsString (CreateContext (source))));
  76                 }
  77
  78                 public bool EvaluateAsBoolean (string source)
  79                 {
  80                         try {
  81                                 var el = new ExpressionParser ().Parse (source, ExpressionValidationType.StrictBoolean);
  82                                 if (el.Count () != 1)
  83                                         throw new InvalidProjectFileException ("Unexpected number of tokens: " + el.Count ());
  84                                 return el.First ().EvaluateAsBoolean (CreateContext (source));
  85                         } catch (yyParser.yyException ex) {
  86                                 throw new InvalidProjectFileException (string.Format ("failed to evaluate expression as boolean: '{0}': {1}", source, ex.Message), ex);
  87                         }
  88                 }
  89         }
  90
  91         class EvaluationContext
  92         {
  93                 public EvaluationContext (string source, ExpressionEvaluator evaluator)
  94                 {
  95                         Source = source;
  96                         Evaluator = evaluator;
  97                 }
  98
  99                 public string Source { get; private set; }
 100
 101                 public ExpressionEvaluator Evaluator { get; private set; }
 102                 public object ContextItem { get; set; }
 103
 104                 Stack<object> evaluating_items = new Stack<object> ();
 105                 Stack<object> evaluating_props = new Stack<object> ();
 106
 107                 public IEnumerable<object> GetItems (string name)
 108                 {
 109                         if (Evaluator.Project != null)
 110                                 return Evaluator.Project.GetItems (name);
 111                         else
 112                                 return Evaluator.ProjectInstance.GetItems (name);
 113                 }
 114
 115                 public IEnumerable<object> GetAllItems ()
 116                 {
 117                         if (Evaluator.Project != null)
 118                                 return Evaluator.Project.AllEvaluatedItems;
 119                         else
 120                                 return Evaluator.ProjectInstance.AllEvaluatedItems;
 121                 }
 122
 123                 public string EvaluateItem (string itemType, object item)
 124                 {
 125                         if (evaluating_items.Contains (item))
 126                                 throw new InvalidProjectFileException (string.Format ("Recursive reference to item '{0}' was found", itemType));
 127                         try {
 128                                 evaluating_items.Push (item);
 129                                 var eval = item as ProjectItem;
 130                                 if (eval != null)
 131                                         return Evaluator.Evaluate (eval.EvaluatedInclude);
 132                                 else {
 133                                         var inst = (ProjectItemInstance) item;
 134                                         if (!Evaluator.EvaluatedTaskItems.Contains (inst))
 135                                                 Evaluator.EvaluatedTaskItems.Add (inst);
 136                                         return Evaluator.Evaluate (inst.EvaluatedInclude);
 137                                 }
 138                         } finally {
 139                                 evaluating_items.Pop ();
 140                         }
 141                 }
 142
 143                 public string EvaluateProperty (string name)
 144                 {
 145                         if (Evaluator.Project != null) {
 146                                 var prop = Evaluator.Project.GetProperty (name);
 147                                 if (prop == null)
 148                                         return null;
 149                                 return EvaluateProperty (prop, prop.Name, prop.EvaluatedValue);
 150                         } else {
 151                                 var prop = Evaluator.ProjectInstance.GetProperty (name);
 152                                 if (prop == null)
 153                                         return null;
 154                                 return EvaluateProperty (prop, prop.Name, prop.EvaluatedValue);
 155                         }
 156                 }
 157
 158                 public string EvaluateProperty (object prop, string name, string value)
 159                 {
 160                         if (evaluating_props.Contains (prop))
 161                                 throw new InvalidProjectFileException (string.Format ("Recursive reference to property '{0}' was found", name));
 162                         try {
 163                                 evaluating_props.Push (prop);
 164                                 // FIXME: needs verification on whether string evaluation is appropriate or not.
 165                                 return Evaluator.Evaluate (value);
 166                         } finally {
 167                                 evaluating_props.Pop ();
 168                         }
 169                 }
 170         }
 171
 172         abstract partial class Expression
 173         {
 174                 public abstract string ExpressionString { get; }
 175                 public abstract string EvaluateAsString (EvaluationContext context);
 176                 public abstract bool EvaluateAsBoolean (EvaluationContext context);
 177                 public abstract object EvaluateAsObject (EvaluationContext context);
 178
 179                 public bool EvaluateStringAsBoolean (EvaluationContext context, string ret)
 180                 {
 181                         if (ret != null) {
 182                                 if (ret.Equals ("TRUE", StringComparison.InvariantCultureIgnoreCase))
 183                                         return true;
 184                                 else if (ret.Equals ("FALSE", StringComparison.InvariantCultureIgnoreCase))
 185                                         return false;
 186                         }
 187                         throw new InvalidProjectFileException (this.Location, string.Format ("Part of condition '{0}' is evaluated as '{1}' and cannot be converted to boolean", context.Source, ret));
 188                 }
 189         }
 190
 191         partial class BinaryExpression : Expression
 192         {
 193                 public override bool EvaluateAsBoolean (EvaluationContext context)
 194                 {
 195                         switch (Operator) {
 196                         case Operator.EQ:
 197                                 return string.Equals (StripStringWrap (Left.EvaluateAsString (context)), StripStringWrap (Right.EvaluateAsString (context)), StringComparison.OrdinalIgnoreCase);
 198                         case Operator.NE:
 199                                 return !string.Equals (StripStringWrap (Left.EvaluateAsString (context)), StripStringWrap (Right.EvaluateAsString (context)), StringComparison.OrdinalIgnoreCase);
 200                         case Operator.And:
 201                         case Operator.Or:
 202                                 // evaluate first, to detect possible syntax error on right expr.
 203                                 var lb = Left.EvaluateAsBoolean (context);
 204                                 var rb = Right.EvaluateAsBoolean (context);
 205                                 return Operator == Operator.And ? (lb && rb) : (lb || rb);
 206                         }
 207                         // comparison expressions - evaluate comparable first, then compare values.
 208                         var left = Left.EvaluateAsObject (context);
 209                         var right = Right.EvaluateAsObject (context);
 210                         if (!(left is IComparable && right is IComparable))
 211                                 throw new InvalidProjectFileException ("expression cannot be evaluated as boolean");
 212                         var result = ((IComparable) left).CompareTo (right);
 213                         switch (Operator) {
 214                         case Operator.GE:
 215                                 return result >= 0;
 216                         case Operator.GT:
 217                                 return result > 0;
 218                         case Operator.LE:
 219                                 return result <= 0;
 220                         case Operator.LT:
 221                                 return result < 0;
 222                         }
 223                         throw new InvalidOperationException ();
 224                 }
 225
 226                 string StripStringWrap (string s)
 227                 {
 228                         if (s == null)
 229                                 return string.Empty;
 230                         s = s.Trim ();
 231                         if (s.Length > 1 && s [0] == '"' && s [s.Length - 1] == '"')
 232                                 return s.Substring (1, s.Length - 2);
 233                         else if (s.Length > 1 && s [0] == '\'' && s [s.Length - 1] == '\'')
 234                                 return s.Substring (1, s.Length - 2);
 235                         return s;
 236                 }
 237
 238                 public override object EvaluateAsObject (EvaluationContext context)
 239                 {
 240                         throw new NotImplementedException ();
 241                 }
 242
 243                 static readonly Dictionary<Operator,string> strings = new Dictionary<Operator, string> () {
 244                         {Operator.EQ, " == "},
 245                         {Operator.NE, " != "},
 246                         {Operator.LT, " < "},
 247                         {Operator.LE, " <= "},
 248                         {Operator.GT, " > "},
 249                         {Operator.GE, " >= "},
 250                         {Operator.And, " And "},
 251                         {Operator.Or, " Or "},
 252                 };
 253
 254                 public override string EvaluateAsString (EvaluationContext context)
 255                 {
 256                         return Left.EvaluateAsString (context) + strings [Operator] + Right.EvaluateAsString (context);
 257                 }
 258         }
 259
 260         partial class BooleanLiteral : Expression
 261         {
 262                 public override string EvaluateAsString (EvaluationContext context)
 263                 {
 264                         return Value ? "True" : "False";
 265                 }
 266
 267                 public override bool EvaluateAsBoolean (EvaluationContext context)
 268                 {
 269                         return Value;
 270                 }
 271
 272                 public override object EvaluateAsObject (EvaluationContext context)
 273                 {
 274                         return Value;
 275                 }
 276         }
 277
 278         partial class NotExpression : Expression
 279         {
 280                 public override string EvaluateAsString (EvaluationContext context)
 281                 {
 282                         // no negation for string
 283                         return "!" + Negated.EvaluateAsString (context);
 284                 }
 285
 286                 public override bool EvaluateAsBoolean (EvaluationContext context)
 287                 {
 288                         return !Negated.EvaluateAsBoolean (context);
 289                 }
 290
 291                 public override object EvaluateAsObject (EvaluationContext context)
 292                 {
 293                         return EvaluateAsString (context);
 294                 }
 295         }
 296
 297         partial class PropertyAccessExpression : Expression
 298         {
 299                 public override bool EvaluateAsBoolean (EvaluationContext context)
 300                 {
 301                         var ret = EvaluateAsString (context);
 302                         return EvaluateStringAsBoolean (context, ret);
 303                 }
 304
 305                 public override string EvaluateAsString (EvaluationContext context)
 306                 {
 307                         var ret = EvaluateAsObject (context);
 308                         return ret == null ? null : ret.ToString ();
 309                 }
 310
 311                 public override object EvaluateAsObject (EvaluationContext context)
 312                 {
 313                         try {
 314                                 return DoEvaluateAsObject (context);
 315                         } catch (TargetInvocationException ex) {
 316                                 throw new InvalidProjectFileException ("Access to property caused an error", ex);
 317                         }
 318                 }
 319
 320                 object DoEvaluateAsObject (EvaluationContext context)
 321                 {
 322                         if (Access.Target == null) {
 323                                 return context.EvaluateProperty (Access.Name.Name);
 324                         } else {
 325                                 if (this.Access.TargetType == PropertyTargetType.Object) {
 326                                         var obj = Access.Target.EvaluateAsObject (context);
 327                                         if (obj == null)
 328                                                 return null;
 329                                         if (Access.Arguments != null) {
 330                                                 var args = Access.Arguments.Select (e => e.EvaluateAsObject (context)).ToArray ();
 331                                                 var method = FindMethod (obj.GetType (), Access.Name.Name, args);
 332                                                 if (method == null)
 333                                                         throw new InvalidProjectFileException (Location, string.Format ("access to undefined method '{0}' of '{1}' at {2}", Access.Name.Name, Access.Target.EvaluateAsString (context), Location));
 334                                                 return method.Invoke (obj, AdjustArgsForCall (method, args));
 335                                         } else {
 336                                                 var prop = obj.GetType ().GetProperty (Access.Name.Name);
 337                                                 if (prop == null)
 338                                                         throw new InvalidProjectFileException (Location, string.Format ("access to undefined property '{0}' of '{1}' at {2}", Access.Name.Name, Access.Target.EvaluateAsString (context), Location));
 339                                                 return prop.GetValue (obj, null);
 340                                         }
 341                                 } else {
 342                                         var type = Type.GetType (Access.Target.EvaluateAsString (context));
 343                                         if (type == null)
 344                                                 throw new InvalidProjectFileException (Location, string.Format ("specified type '{0}' was not found", Access.Target.EvaluateAsString (context)));
 345                                         if (Access.Arguments != null) {
 346                                                 var args = Access.Arguments.Select (e => e.EvaluateAsObject (context)).ToArray ();
 347                                                 var method = FindMethod (type, Access.Name.Name, args);
 348                                                 if (method == null)
 349                                                         throw new InvalidProjectFileException (Location, string.Format ("access to undefined static method '{0}' of '{1}' at {2}", Access.Name.Name, type, Location));
 350                                                 return method.Invoke (null, AdjustArgsForCall (method, args));
 351                                         } else {
 352                                                 var prop = type.GetProperty (Access.Name.Name);
 353                                                 if (prop == null)
 354                                                         throw new InvalidProjectFileException (Location, string.Format ("access to undefined static property '{0}' of '{1}' at {2}", Access.Name.Name, type, Location));
 355                                                 return prop.GetValue (null, null);
 356                                         }
 357                                 }
 358                         }
 359                 }
 360
 361                 MethodInfo FindMethod (Type type, string name, object [] args)
 362                 {
 363                         var methods = type.GetMethods ().Where (m => {
 364                                 if (m.Name != name)
 365                                         return false;
 366                                 var pl = m.GetParameters ();
 367                                 if (pl.Length == args.Length)
 368                                         return true;
 369                                 // calling String.Format() with either set of arguments is valid:
 370                                 // - three strings (two for varargs)
 371                                 // - two strings (happen to be exact match)
 372                                 // - one string (no varargs)
 373                                 if (pl.Length > 0 && pl.Length - 1 <= args.Length &&
 374                                     pl.Last ().GetCustomAttributesData ().Any (a => a.Constructor.DeclaringType == typeof (ParamArrayAttribute)))
 375                                         return true;
 376                                 return false;
 377                                 });
 378                         if (methods.Count () == 1)
 379                                 return methods.First ();
 380                         return args.Any (a => a == null) ?
 381                                 type.GetMethod (name) :
 382                                 type.GetMethod (name, args.Select (o => o.GetType ()).ToArray ());
 383                 }
 384
 385                 object [] AdjustArgsForCall (MethodInfo m, object[] args)
 386                 {
 387                         if (m.GetParameters ().Length == args.Length + 1)
 388                                 return args.Concat (new object[] {Array.CreateInstance (m.GetParameters ().Last ().ParameterType.GetElementType (), 0)}).ToArray ();
 389                         else
 390                                 return args;
 391                 }
 392         }
 393
 394         partial class ItemAccessExpression : Expression
 395         {
 396                 public override bool EvaluateAsBoolean (EvaluationContext context)
 397                 {
 398                         return EvaluateStringAsBoolean (context, EvaluateAsString (context));
 399                 }
 400
 401                 public override string EvaluateAsString (EvaluationContext context)
 402                 {
 403                         string itemType = Application.Name.Name;
 404                         var items = context.GetItems (itemType);
 405                         if (!items.Any ())
 406                                 return null;
 407                         if (Application.Expressions == null)
 408                                 return string.Join (";", items.Select (item => Unwrap (context.EvaluateItem (itemType, item))));
 409                         else
 410                                 return string.Join (";", items.Select (item => {
 411                                         context.ContextItem = item;
 412                                         var ret = Unwrap (string.Concat (Application.Expressions.Select (e => e.EvaluateAsString (context))));
 413                                         context.ContextItem = null;
 414                                         return ret;
 415                                 }));
 416                 }
 417
 418                 static string Unwrap (string ret)
 419                 {
 420                         if (ret.Length < 2 || ret [0] != ret [ret.Length - 1] || ret [0] != '"' && ret [0] != '\'')
 421                                 return ret;
 422                         return ret.Substring (1, ret.Length - 2);
 423                 }
 424
 425                 public override object EvaluateAsObject (EvaluationContext context)
 426                 {
 427                         return EvaluateAsString (context);
 428                 }
 429         }
 430
 431         partial class MetadataAccessExpression : Expression
 432         {
 433                 public override bool EvaluateAsBoolean (EvaluationContext context)
 434                 {
 435                         return EvaluateStringAsBoolean (context, EvaluateAsString (context));
 436                 }
 437
 438                 public override string EvaluateAsString (EvaluationContext context)
 439                 {
 440                         string itemType = this.Access.ItemType != null ? this.Access.ItemType.Name : null;
 441                         string metadataName = Access.Metadata.Name;
 442                         IEnumerable<object> items;
 443                         if (this.Access.ItemType != null)
 444                                 items = context.GetItems (itemType);
 445                         else if (context.ContextItem != null)
 446                                 items = new Object [] { context.ContextItem };
 447                         else
 448                                 items = context.GetAllItems ();
 449
 450                         var values = items.Select (i => (i is ProjectItem) ? ((ProjectItem) i).GetMetadataValue (metadataName) : ((ProjectItemInstance) i).GetMetadataValue (metadataName)).Where (s => !string.IsNullOrEmpty (s));
 451                         return string.Join (";", values);
 452                 }
 453
 454                 public override object EvaluateAsObject (EvaluationContext context)
 455                 {
 456                         return EvaluateAsString (context);
 457                 }
 458         }
 459         partial class StringLiteral : Expression
 460         {
 461                 public override bool EvaluateAsBoolean (EvaluationContext context)
 462                 {
 463                         var ret = EvaluateAsString (context);
 464                         return EvaluateStringAsBoolean (context, ret);
 465                 }
 466
 467                 public override string EvaluateAsString (EvaluationContext context)
 468                 {
 469                         return context.Evaluator.Evaluate (this.Value.Name);
 470                 }
 471
 472                 public override object EvaluateAsObject (EvaluationContext context)
 473                 {
 474                         return EvaluateAsString (context);
 475                 }
 476         }
 477         partial class RawStringLiteral : Expression
 478         {
 479                 public override string EvaluateAsString (EvaluationContext context)
 480                 {
 481                         return Value.Name;
 482                 }
 483
 484                 public override bool EvaluateAsBoolean (EvaluationContext context)
 485                 {
 486                         throw new InvalidProjectFileException ("raw string literal cannot be evaluated as boolean");
 487                 }
 488
 489                 public override object EvaluateAsObject (EvaluationContext context)
 490                 {
 491                         return EvaluateAsString (context);
 492                 }
 493         }
 494
 495         partial class QuotedExpression : Expression
 496         {
 497                 public override string EvaluateAsString (EvaluationContext context)
 498                 {
 499                         return QuoteChar + EvaluateAsStringWithoutQuote (context) + QuoteChar;
 500                 }
 501
 502                 public string EvaluateAsStringWithoutQuote (EvaluationContext context)
 503                 {
 504                         return string.Concat (Contents.Select (e => e.EvaluateAsString (context)));
 505                 }
 506
 507                 public override bool EvaluateAsBoolean (EvaluationContext context)
 508                 {
 509                         var ret = EvaluateAsStringWithoutQuote (context);
 510                         return EvaluateStringAsBoolean (context, ret);
 511                 }
 512
 513                 public override object EvaluateAsObject (EvaluationContext context)
 514                 {
 515                         return EvaluateAsStringWithoutQuote (context);
 516                 }
 517         }
 518
 519         partial class FunctionCallExpression : Expression
 520         {
 521                 public override string EvaluateAsString (EvaluationContext context)
 522                 {
 523                         throw new NotImplementedException ();
 524                 }
 525
 526                 public override bool EvaluateAsBoolean (EvaluationContext context)
 527                 {
 528                         if (string.Equals (Name.Name, "Exists", StringComparison.OrdinalIgnoreCase)) {
 529                                 if (Arguments.Count != 1)
 530                                         throw new InvalidProjectFileException (Location, "Function 'Exists' expects 1 argument");
 531                                 string val = Arguments.First ().EvaluateAsString (context);
 532                                 val = WindowsCompatibilityExtensions.FindMatchingPath (val);
 533                                 return Directory.Exists (val) || System.IO.File.Exists (val);
 534                         }
 535                         if (string.Equals (Name.Name, "HasTrailingSlash", StringComparison.OrdinalIgnoreCase)) {
 536                                 if (Arguments.Count != 1)
 537                                         throw new InvalidProjectFileException (Location, "Function 'HasTrailingSlash' expects 1 argument");
 538                                 string val = Arguments.First ().EvaluateAsString (context);
 539                                 return val.LastOrDefault () == '\\' || val.LastOrDefault () == '/';
 540                         }
 541                         throw new InvalidProjectFileException (Location, string.Format ("Unsupported function '{0}'", Name));
 542                 }
 543
 544                 public override object EvaluateAsObject (EvaluationContext context)
 545                 {
 546                         throw new NotImplementedException ();
 547                 }
 548         }
 549 }
 550