mcs/mcs/eval.cs

   1 //
   2 // eval.cs: Evaluation and Hosting API for the C# compiler
   3 //
   4 // Authors:
   5 //   Miguel de Icaza (miguel@gnome.org)
   6 //   Marek Safar (marek.safar@gmail.com)
   7 //
   8 // Dual licensed under the terms of the MIT X11 or GNU GPL
   9 //
  10 // Copyright 2001, 2002, 2003 Ximian, Inc (http://www.ximian.com)
  11 // Copyright 2004-2011 Novell, Inc
  12 // Copyright 2011 Xamarin Inc
  13 //
  14
  15 using System;
  16 using System.Threading;
  17 using System.Collections.Generic;
  18 using System.Reflection;
  19 using System.Reflection.Emit;
  20 using System.IO;
  21 using System.Text;
  22 using System.Linq;
  23
  24 namespace Mono.CSharp
  25 {
  26
  27         /// <summary>
  28         /// Experimental!
  29         /// </summary>
  30         public delegate void ValueModificationHandler (string variableName, int row, int column, object value);
  31
  32         /// <summary>
  33         ///   Evaluator: provides an API to evaluate C# statements and
  34         ///   expressions dynamically.
  35         /// </summary>
  36         /// <remarks>
  37         ///   This class exposes static methods to evaluate expressions in the
  38         ///   current program.
  39         ///
  40         ///   To initialize the evaluator with a number of compiler
  41         ///   options call the Init(string[]args) method with a set of
  42         ///   command line options that the compiler recognizes.
  43         ///
  44         ///   To interrupt execution of a statement, you can invoke the
  45         ///   Evaluator.Interrupt method.
  46         /// </remarks>
  47         public class Evaluator {
  48
  49                 enum ParseMode {
  50                         // Parse silently, do not output any error messages
  51                         Silent,
  52
  53                         // Report errors during parse
  54                         ReportErrors,
  55
  56                         // Auto-complete, means that the tokenizer will start producing
  57                         // GETCOMPLETIONS tokens when it reaches a certain point.
  58                         GetCompletions
  59                 }
  60
  61                 static object evaluator_lock = new object ();
  62                 static volatile bool invoking;
  63
  64 #if !STATIC
  65                 static int count;
  66 #endif
  67                 static Thread invoke_thread;
  68
  69                 readonly Dictionary<string, Tuple<FieldSpec, FieldInfo>> fields;
  70
  71                 Type base_class;
  72                 bool inited;
  73                 int startup_files;
  74
  75                 readonly CompilerContext ctx;
  76                 readonly ModuleContainer module;
  77                 readonly ReflectionImporter importer;
  78                 readonly CompilationSourceFile source_file;
  79
  80                 int? listener_id;
  81
  82                 public Evaluator (CompilerContext ctx)
  83                 {
  84                         this.ctx = ctx;
  85
  86                         module = new ModuleContainer (ctx);
  87                         module.Evaluator = this;
  88
  89                         source_file = new CompilationSourceFile (module, null);
  90                         module.AddTypeContainer (source_file);
  91
  92                         startup_files = ctx.SourceFiles.Count;
  93
  94                         // FIXME: Importer needs this assembly for internalsvisibleto
  95                         module.SetDeclaringAssembly (new AssemblyDefinitionDynamic (module, "evaluator"));
  96                         importer = new ReflectionImporter (module, ctx.BuiltinTypes);
  97
  98                         InteractiveBaseClass = typeof (InteractiveBase);
  99                         fields = new Dictionary<string, Tuple<FieldSpec, FieldInfo>> ();
 100                 }
 101
 102                 void Init ()
 103                 {
 104                         var loader = new DynamicLoader (importer, ctx);
 105
 106                         CompilerCallableEntryPoint.Reset ();
 107                         RootContext.ToplevelTypes = module;
 108
 109                         //var startup_files = new List<string> ();
 110                         //foreach (CompilationUnit file in Location.SourceFiles)
 111                         //    startup_files.Add (file.Path);
 112
 113                         loader.LoadReferences (module);
 114                         ctx.BuiltinTypes.CheckDefinitions (module);
 115                         module.InitializePredefinedTypes ();
 116
 117                         inited = true;
 118                 }
 119
 120                 void ParseStartupFiles ()
 121                 {
 122                         Driver d = new Driver (ctx);
 123
 124                         Location.Initialize (ctx.SourceFiles);
 125
 126                         var parser_session = new ParserSession ();
 127                         for (int i = 0; i < startup_files; ++i) {
 128                                 var sf = ctx.SourceFiles [i];
 129                                 d.Parse (sf, module, parser_session, ctx.Report);
 130                         }
 131                 }
 132
 133                 void Reset ()
 134                 {
 135                         CompilerCallableEntryPoint.PartialReset ();
 136
 137                         Location.Reset ();
 138                         Location.Initialize (ctx.SourceFiles);
 139                 }
 140
 141                 /// <summary>
 142                 /// When set evaluator will automatically wait on Task of async methods. When not
 143                 /// set it's called responsibility to handle Task execution
 144                 /// </summary>
 145                 public bool WaitOnTask { get; set; }
 146
 147                 /// <summary>
 148                 ///   If true, turns type expressions into valid expressions
 149                 ///   and calls the describe method on it
 150                 /// </summary>
 151                 public bool DescribeTypeExpressions;
 152
 153                 /// <summary>
 154                 ///   Whether the evaluator will use terse syntax, and the semicolons at the end are optional
 155                 /// </summary>
 156                 public bool Terse = true;
 157
 158                 /// <summary>
 159                 ///   The base class for the classes that host the user generated code
 160                 /// </summary>
 161                 /// <remarks>
 162                 ///
 163                 ///   This is the base class that will host the code
 164                 ///   executed by the Evaluator.  By default
 165                 ///   this is the Mono.CSharp.InteractiveBase class
 166                 ///   which is useful for interactive use.
 167                 ///
 168                 ///   By changing this property you can control the
 169                 ///   base class and the static members that are
 170                 ///   available to your evaluated code.
 171                 /// </remarks>
 172                 public Type InteractiveBaseClass {
 173                         get {
 174                                 return base_class;
 175                         }
 176                         set {
 177                                 base_class = value;
 178
 179                                 if (value != null && typeof (InteractiveBase).IsAssignableFrom (value))
 180                                         InteractiveBase.Evaluator = this;
 181                         }
 182                 }
 183
 184                 /// <summary>
 185                 ///   Interrupts the evaluation of an expression executing in Evaluate.
 186                 /// </summary>
 187                 /// <remarks>
 188                 ///   Use this method to interrupt long-running invocations.
 189                 /// </remarks>
 190                 public void Interrupt ()
 191                 {
 192                         if (!inited || !invoking)
 193                                 return;
 194
 195                         if (invoke_thread != null)
 196                                 invoke_thread.Abort ();
 197                 }
 198
 199                 /// <summary>
 200                 ///   Compiles the input string and returns a delegate that represents the compiled code.
 201                 /// </summary>
 202                 /// <remarks>
 203                 ///
 204                 ///   Compiles the input string as a C# expression or
 205                 ///   statement, unlike the Evaluate method, the
 206                 ///   resulting delegate can be invoked multiple times
 207                 ///   without incurring in the compilation overhead.
 208                 ///
 209                 ///   If the return value of this function is null,
 210                 ///   this indicates that the parsing was complete.
 211                 ///   If the return value is a string it indicates
 212                 ///   that the input string was partial and that the
 213                 ///   invoking code should provide more code before
 214                 ///   the code can be successfully compiled.
 215                 ///
 216                 ///   If you know that you will always get full expressions or
 217                 ///   statements and do not care about partial input, you can use
 218                 ///   the other Compile overload.
 219                 ///
 220                 ///   On success, in addition to returning null, the
 221                 ///   compiled parameter will be set to the delegate
 222                 ///   that can be invoked to execute the code.
 223                 ///
 224                 /// </remarks>
 225                 public string Compile (string input, out CompiledMethod compiled)
 226                 {
 227                         if (input == null || input.Length == 0){
 228                                 compiled = null;
 229                                 return null;
 230                         }
 231
 232                         lock (evaluator_lock){
 233                                 if (!inited) {
 234                                         Init ();
 235                                         ParseStartupFiles ();
 236                                 } else {
 237                                         ctx.Report.Printer.Reset ();
 238                                 }
 239
 240                                 bool partial_input;
 241                                 CSharpParser parser = ParseString (ParseMode.Silent, input, out partial_input);
 242
 243                                 // Terse mode, try to provide the trailing semicolon automatically.
 244                                 if (parser == null && Terse && partial_input){
 245                                         bool ignore;
 246
 247                                         // check if the source would compile with a block, if so, we should not
 248                                         // add the semicolon.
 249                                         var needs_block = ParseString (ParseMode.Silent, input + "{}", out ignore) != null;
 250                                         if (!needs_block)
 251                                                 parser = ParseString (ParseMode.Silent, input + ";", out ignore);
 252                                 }
 253                                 if (parser == null){
 254                                         compiled = null;
 255                                         if (partial_input)
 256                                                 return input;
 257
 258                                         ParseString (ParseMode.ReportErrors, input, out partial_input);
 259                                         return null;
 260                                 }
 261
 262                                 Class parser_result = parser.InteractiveResult;
 263                                 compiled = CompileBlock (parser_result, parser.undo, ctx.Report);
 264                                 return null;
 265                         }
 266                 }
 267
 268                 /// <summary>
 269                 ///   Compiles the input string and returns a delegate that represents the compiled code.
 270                 /// </summary>
 271                 /// <remarks>
 272                 ///
 273                 ///   Compiles the input string as a C# expression or
 274                 ///   statement, unlike the Evaluate method, the
 275                 ///   resulting delegate can be invoked multiple times
 276                 ///   without incurring in the compilation overhead.
 277                 ///
 278                 ///   This method can only deal with fully formed input
 279                 ///   strings and does not provide a completion mechanism.
 280                 ///   If you must deal with partial input (for example for
 281                 ///   interactive use) use the other overload.
 282                 ///
 283                 ///   On success, a delegate is returned that can be used
 284                 ///   to invoke the method.
 285                 ///
 286                 /// </remarks>
 287                 public CompiledMethod Compile (string input)
 288                 {
 289                         CompiledMethod compiled;
 290
 291                         // Ignore partial inputs
 292                         if (Compile (input, out compiled) != null){
 293                                 // Error, the input was partial.
 294                                 return null;
 295                         }
 296
 297                         // Either null (on error) or the compiled method.
 298                         return compiled;
 299                 }
 300
 301                 static MethodInfo listener_proxy_value;
 302                 internal void EmitValueChangedCallback (EmitContext ec, string name, TypeSpec type, Location loc)
 303                 {
 304                         if (listener_id == null)
 305                                 listener_id = ListenerProxy.Register (ModificationListener);
 306
 307                         if (listener_proxy_value == null)
 308                                 listener_proxy_value = typeof (ListenerProxy).GetMethod ("ValueChanged");
 309
 310 #if STATIC
 311                         throw new NotSupportedException ();
 312 #else
 313                         // object value, int row, int col, string name, int listenerId
 314                         if (type.IsStructOrEnum)
 315                                 ec.Emit (OpCodes.Box, type);
 316
 317                         Console.WriteLine ("EMIT: {0} => {1},{2}", name, loc.Row, loc.Column);
 318
 319                         ec.EmitInt (loc.Row);
 320                         ec.EmitInt (loc.Column);
 321                         ec.Emit (OpCodes.Ldstr, name);
 322                         ec.EmitInt (listener_id.Value);
 323                         ec.Emit (OpCodes.Call, listener_proxy_value);
 324 #endif
 325                 }
 326
 327                 /// <summary>
 328                 ///   Evaluates and expression or statement and returns any result values.
 329                 /// </summary>
 330                 /// <remarks>
 331                 ///   Evaluates the input string as a C# expression or
 332                 ///   statement.  If the input string is an expression
 333                 ///   the result will be stored in the result variable
 334                 ///   and the result_set variable will be set to true.
 335                 ///
 336                 ///   It is necessary to use the result/result_set
 337                 ///   pair to identify when a result was set (for
 338                 ///   example, execution of user-provided input can be
 339                 ///   an expression, a statement or others, and
 340                 ///   result_set would only be set if the input was an
 341                 ///   expression.
 342                 ///
 343                 ///   If the return value of this function is null,
 344                 ///   this indicates that the parsing was complete.
 345                 ///   If the return value is a string, it indicates
 346                 ///   that the input is partial and that the user
 347                 ///   should provide an updated string.
 348                 /// </remarks>
 349                 public string Evaluate (string input, out object result, out bool result_set)
 350                 {
 351                         CompiledMethod compiled;
 352
 353                         result_set = false;
 354                         result = null;
 355
 356                         input = Compile (input, out compiled);
 357                         if (input != null)
 358                                 return input;
 359
 360                         if (compiled == null)
 361                                 return null;
 362
 363                         //
 364                         // The code execution does not need to keep the compiler lock
 365                         //
 366                         object retval = typeof (QuitValue);
 367
 368                         try {
 369                                 invoke_thread = System.Threading.Thread.CurrentThread;
 370                                 invoking = true;
 371                                 compiled (ref retval);
 372                         } catch (ThreadAbortException e){
 373                                 Thread.ResetAbort ();
 374                                 Console.WriteLine ("Interrupted!\n{0}", e);
 375                         } finally {
 376                                 invoking = false;
 377
 378                                 if (listener_id != null) {
 379                                         ListenerProxy.Unregister (listener_id.Value);
 380                                         listener_id = null;
 381                                 }
 382                         }
 383
 384                         //
 385                         // We use a reference to a compiler type, in this case
 386                         // Driver as a flag to indicate that this was a statement
 387                         //
 388                         if (!ReferenceEquals (retval, typeof (QuitValue))) {
 389                                 result_set = true;
 390                                 result = retval;
 391                         }
 392
 393                         return null;
 394                 }
 395
 396                 public string [] GetCompletions (string input, out string prefix)
 397                 {
 398                         prefix = "";
 399                         if (input == null || input.Length == 0)
 400                                 return null;
 401
 402                         lock (evaluator_lock){
 403                                 if (!inited)
 404                                         Init ();
 405
 406                                 bool partial_input;
 407                                 CSharpParser parser = ParseString (ParseMode.GetCompletions, input, out partial_input);
 408                                 if (parser == null){
 409                                         return null;
 410                                 }
 411
 412                                 Class host = parser.InteractiveResult;
 413
 414                                 var base_class_imported = importer.ImportType (base_class);
 415                                 var baseclass_list = new List<FullNamedExpression> (1) {
 416                                         new TypeExpression (base_class_imported, host.Location)
 417                                 };
 418                                 host.SetBaseTypes (baseclass_list);
 419
 420 #if NET_4_0
 421                                 var access = AssemblyBuilderAccess.RunAndCollect;
 422 #else
 423                                 var access = AssemblyBuilderAccess.Run;
 424 #endif
 425                                 var a = new AssemblyDefinitionDynamic (module, "completions");
 426                                 a.Create (AppDomain.CurrentDomain, access);
 427                                 module.SetDeclaringAssembly (a);
 428
 429                                 // Need to setup MemberCache
 430                                 host.CreateContainer ();
 431                                 // Need to setup base type
 432                                 host.DefineContainer ();
 433
 434                                 var method = host.Members[0] as Method;
 435                                 BlockContext bc = new BlockContext (method, method.Block, ctx.BuiltinTypes.Void);
 436
 437                                 try {
 438                                         method.Block.Resolve (bc, method);
 439                                 } catch (CompletionResult cr) {
 440                                         prefix = cr.BaseText;
 441                                         return cr.Result;
 442                                 }
 443                         }
 444                         return null;
 445                 }
 446
 447                 /// <summary>
 448                 ///   Executes the given expression or statement.
 449                 /// </summary>
 450                 /// <remarks>
 451                 ///    Executes the provided statement, returns true
 452                 ///    on success, false on parsing errors.  Exceptions
 453                 ///    might be thrown by the called code.
 454                 /// </remarks>
 455                 public bool Run (string statement)
 456                 {
 457                         object result;
 458                         bool result_set;
 459
 460                         return Evaluate (statement, out result, out result_set) == null;
 461                 }
 462
 463                 /// <summary>
 464                 ///   Evaluates and expression or statement and returns the result.
 465                 /// </summary>
 466                 /// <remarks>
 467                 ///   Evaluates the input string as a C# expression or
 468                 ///   statement and returns the value.
 469                 ///
 470                 ///   This method will throw an exception if there is a syntax error,
 471                 ///   of if the provided input is not an expression but a statement.
 472                 /// </remarks>
 473                 public object Evaluate (string input)
 474                 {
 475                         object result;
 476                         bool result_set;
 477
 478                         string r = Evaluate (input, out result, out result_set);
 479
 480                         if (r != null)
 481                                 throw new ArgumentException ("Syntax error on input: partial input");
 482
 483                         if (result_set == false)
 484                                 throw new ArgumentException ("The expression failed to resolve");
 485
 486                         return result;
 487                 }
 488
 489                 /// <summary>
 490                 /// Experimental!
 491                 /// </summary>
 492                 public ValueModificationHandler ModificationListener { get; set; }
 493
 494                 enum InputKind {
 495                         EOF,
 496                         StatementOrExpression,
 497                         CompilationUnit,
 498                         Error
 499                 }
 500
 501                 //
 502                 // Deambiguates the input string to determine if we
 503                 // want to process a statement or if we want to
 504                 // process a compilation unit.
 505                 //
 506                 // This is done using a top-down predictive parser,
 507                 // since the yacc/jay parser can not deambiguage this
 508                 // without more than one lookahead token.   There are very
 509                 // few ambiguities.
 510                 //
 511                 InputKind ToplevelOrStatement (SeekableStreamReader seekable)
 512                 {
 513                         Tokenizer tokenizer = new Tokenizer (seekable, source_file, new ParserSession (), ctx.Report);
 514
 515                         // Prefer contextual block keywords over identifiers
 516                         tokenizer.parsing_block++;
 517
 518                         int t = tokenizer.token ();
 519                         switch (t){
 520                         case Token.EOF:
 521                                 return InputKind.EOF;
 522
 523                         // These are toplevels
 524                         case Token.EXTERN:
 525                         case Token.OPEN_BRACKET:
 526                         case Token.ABSTRACT:
 527                         case Token.CLASS:
 528                         case Token.ENUM:
 529                         case Token.INTERFACE:
 530                         case Token.INTERNAL:
 531                         case Token.NAMESPACE:
 532                         case Token.PRIVATE:
 533                         case Token.PROTECTED:
 534                         case Token.PUBLIC:
 535                         case Token.SEALED:
 536                         case Token.STATIC:
 537                         case Token.STRUCT:
 538                                 return InputKind.CompilationUnit;
 539
 540                         // Definitely expression
 541                         case Token.FIXED:
 542                         case Token.BOOL:
 543                         case Token.BYTE:
 544                         case Token.CHAR:
 545                         case Token.DECIMAL:
 546                         case Token.DOUBLE:
 547                         case Token.FLOAT:
 548                         case Token.INT:
 549                         case Token.LONG:
 550                         case Token.NEW:
 551                         case Token.OBJECT:
 552                         case Token.SBYTE:
 553                         case Token.SHORT:
 554                         case Token.STRING:
 555                         case Token.UINT:
 556                         case Token.ULONG:
 557                                 return InputKind.StatementOrExpression;
 558
 559                         // These need deambiguation help
 560                         case Token.USING:
 561                                 t = tokenizer.token ();
 562                                 if (t == Token.EOF)
 563                                         return InputKind.EOF;
 564
 565                                 if (t == Token.IDENTIFIER)
 566                                         return InputKind.CompilationUnit;
 567                                 return InputKind.StatementOrExpression;
 568
 569
 570                         // Distinguish between:
 571                         //    delegate opt_anonymous_method_signature block
 572                         //    delegate type
 573                         case Token.DELEGATE:
 574                                 t = tokenizer.token ();
 575                                 if (t == Token.EOF)
 576                                         return InputKind.EOF;
 577                                 if (t == Token.OPEN_PARENS || t == Token.OPEN_BRACE)
 578                                         return InputKind.StatementOrExpression;
 579                                 return InputKind.CompilationUnit;
 580
 581                         // Distinguih between:
 582                         //    unsafe block
 583                         //    unsafe as modifier of a type declaration
 584                         case Token.UNSAFE:
 585                                 t = tokenizer.token ();
 586                                 if (t == Token.EOF)
 587                                         return InputKind.EOF;
 588                                 if (t == Token.OPEN_PARENS)
 589                                         return InputKind.StatementOrExpression;
 590                                 return InputKind.CompilationUnit;
 591
 592                         // These are errors: we list explicitly what we had
 593                         // from the grammar, ERROR and then everything else
 594
 595                         case Token.READONLY:
 596                         case Token.OVERRIDE:
 597                         case Token.ERROR:
 598                                 return InputKind.Error;
 599
 600                         // This catches everything else allowed by
 601                         // expressions.  We could add one-by-one use cases
 602                         // if needed.
 603                         default:
 604                                 return InputKind.StatementOrExpression;
 605                         }
 606                 }
 607
 608                 //
 609                 // Parses the string @input and returns a CSharpParser if succeeful.
 610                 //
 611                 // if @silent is set to true then no errors are
 612                 // reported to the user.  This is used to do various calls to the
 613                 // parser and check if the expression is parsable.
 614                 //
 615                 // @partial_input: if @silent is true, then it returns whether the
 616                 // parsed expression was partial, and more data is needed
 617                 //
 618                 CSharpParser ParseString (ParseMode mode, string input, out bool partial_input)
 619                 {
 620                         partial_input = false;
 621                         Reset ();
 622
 623                         var enc = ctx.Settings.Encoding;
 624                         var s = new MemoryStream (enc.GetBytes (input));
 625                         SeekableStreamReader seekable = new SeekableStreamReader (s, enc);
 626
 627                         InputKind kind = ToplevelOrStatement (seekable);
 628                         if (kind == InputKind.Error){
 629                                 if (mode == ParseMode.ReportErrors)
 630                                         ctx.Report.Error (-25, "Detection Parsing Error");
 631                                 partial_input = false;
 632                                 return null;
 633                         }
 634
 635                         if (kind == InputKind.EOF){
 636                                 if (mode == ParseMode.ReportErrors)
 637                                         Console.Error.WriteLine ("Internal error: EOF condition should have been detected in a previous call with silent=true");
 638                                 partial_input = true;
 639                                 return null;
 640
 641                         }
 642                         seekable.Position = 0;
 643
 644                         source_file.DeclarationFound = false;
 645                         CSharpParser parser = new CSharpParser (seekable, source_file, new ParserSession ());
 646
 647                         if (kind == InputKind.StatementOrExpression){
 648                                 parser.Lexer.putback_char = Tokenizer.EvalStatementParserCharacter;
 649                                 parser.Lexer.parsing_block++;
 650                                 ctx.Settings.StatementMode = true;
 651                         } else {
 652                                 parser.Lexer.putback_char = Tokenizer.EvalCompilationUnitParserCharacter;
 653                                 ctx.Settings.StatementMode = false;
 654                         }
 655
 656                         if (mode == ParseMode.GetCompletions)
 657                                 parser.Lexer.CompleteOnEOF = true;
 658
 659                         ReportPrinter old_printer = null;
 660                         if ((mode == ParseMode.Silent || mode == ParseMode.GetCompletions))
 661                                 old_printer = ctx.Report.SetPrinter (new StreamReportPrinter (TextWriter.Null));
 662
 663                         try {
 664                                 parser.parse ();
 665                         } finally {
 666                                 if (ctx.Report.Errors != 0){
 667                                         if (mode != ParseMode.ReportErrors  && parser.UnexpectedEOF)
 668                                                 partial_input = true;
 669
 670                                         if (parser.undo != null)
 671                                                 parser.undo.ExecuteUndo ();
 672
 673                                         parser = null;
 674                                 }
 675
 676                                 if (old_printer != null)
 677                                         ctx.Report.SetPrinter (old_printer);
 678                         }
 679                         return parser;
 680                 }
 681
 682                 CompiledMethod CompileBlock (Class host, Undo undo, Report Report)
 683                 {
 684 #if STATIC
 685                         throw new NotSupportedException ();
 686 #else
 687                         string current_debug_name = "eval-" + count + ".dll";
 688                         ++count;
 689
 690                         AssemblyDefinitionDynamic assembly;
 691                         AssemblyBuilderAccess access;
 692
 693                         if (Environment.GetEnvironmentVariable ("SAVE") != null) {
 694                                 access = AssemblyBuilderAccess.RunAndSave;
 695                                 assembly = new AssemblyDefinitionDynamic (module, current_debug_name, current_debug_name);
 696                                 assembly.Importer = importer;
 697                         } else {
 698 #if NET_4_0
 699                                 access = AssemblyBuilderAccess.RunAndCollect;
 700 #else
 701                                 access = AssemblyBuilderAccess.Run;
 702 #endif
 703                                 assembly = new AssemblyDefinitionDynamic (module, current_debug_name);
 704                         }
 705
 706                         assembly.Create (AppDomain.CurrentDomain, access);
 707
 708                         Method expression_method;
 709                         if (host != null) {
 710                                 var base_class_imported = importer.ImportType (base_class);
 711                                 var baseclass_list = new List<FullNamedExpression> (1) {
 712                                         new TypeExpression (base_class_imported, host.Location)
 713                                 };
 714
 715                                 host.SetBaseTypes (baseclass_list);
 716
 717                                 expression_method = (Method) host.Members[0];
 718
 719                                 if ((expression_method.ModFlags & Modifiers.ASYNC) != 0) {
 720                                         //
 721                                         // Host method is async. When WaitOnTask is set we wrap it with wait
 722                                         //
 723                                         // void AsyncWait (ref object $retval) {
 724                                         //      $retval = Host();
 725                                         //      ((Task)$retval).Wait();  // When WaitOnTask is set
 726                                         // }
 727                                         //
 728                                         var p = new ParametersCompiled (
 729                                                 new Parameter (new TypeExpression (module.Compiler.BuiltinTypes.Object, Location.Null), "$retval", Parameter.Modifier.REF, null, Location.Null)
 730                                         );
 731
 732                                         var method = new Method(host, new TypeExpression(module.Compiler.BuiltinTypes.Void, Location.Null),
 733                                                 Modifiers.PUBLIC | Modifiers.STATIC, new MemberName("AsyncWait"), p, null);
 734
 735                                         method.Block = new ToplevelBlock(method.Compiler, p, Location.Null);
 736                                         method.Block.AddStatement(new StatementExpression (new SimpleAssign(
 737                                                 new SimpleName(p [0].Name, Location.Null),
 738                                                 new Invocation(new SimpleName(expression_method.MemberName.Name, Location.Null), new Arguments(0)),
 739                                                 Location.Null), Location.Null));
 740
 741                                         if (WaitOnTask) {
 742                                                 var task = new Cast (expression_method.TypeExpression, new SimpleName (p [0].Name, Location.Null), Location.Null);
 743
 744                                                 method.Block.AddStatement (new StatementExpression (new Invocation (
 745                                                                 new MemberAccess (task, "Wait", Location.Null),
 746                                                         new Arguments (0)), Location.Null));
 747                                         }
 748
 749                                         host.AddMember(method);
 750
 751                                         expression_method = method;
 752                                 }
 753
 754                                 host.CreateContainer();
 755                                 host.DefineContainer();
 756                                 host.Define();
 757
 758                         } else {
 759                                 expression_method = null;
 760                         }
 761
 762                         module.CreateContainer ();
 763
 764                         // Disable module and source file re-definition checks
 765                         module.EnableRedefinition ();
 766                         source_file.EnableRedefinition ();
 767
 768                         module.Define ();
 769
 770                         if (Report.Errors != 0){
 771                                 if (undo != null)
 772                                         undo.ExecuteUndo ();
 773
 774                                 return null;
 775                         }
 776
 777                         if (host != null){
 778                                 host.PrepareEmit ();
 779                                 host.EmitContainer ();
 780                         }
 781
 782                         module.EmitContainer ();
 783
 784                         if (Report.Errors != 0){
 785                                 if (undo != null)
 786                                         undo.ExecuteUndo ();
 787                                 return null;
 788                         }
 789
 790                         module.CloseContainer ();
 791                         if (host != null)
 792                                 host.CloseContainer ();
 793
 794                         if (access == AssemblyBuilderAccess.RunAndSave)
 795                                 assembly.Save ();
 796
 797                         if (host == null)
 798                                 return null;
 799
 800                         //
 801                         // Unlike Mono, .NET requires that the MethodInfo is fetched, it cant
 802                         // work from MethodBuilders.   Retarded, I know.
 803                         //
 804                         var tt = assembly.Builder.GetType (host.TypeBuilder.Name);
 805                         var mi = tt.GetMethod (expression_method.MemberName.Name);
 806
 807                         //
 808                         // We need to then go from FieldBuilder to FieldInfo
 809                         // or reflection gets confused (it basically gets confused, and variables override each
 810                         // other).
 811                         //
 812                         foreach (var member in host.Members) {
 813                                 var field = member as Field;
 814                                 if (field == null)
 815                                         continue;
 816
 817                                 var fi = tt.GetField (field.Name);
 818
 819                                 Tuple<FieldSpec, FieldInfo> old;
 820
 821                                 // If a previous value was set, nullify it, so that we do
 822                                 // not leak memory
 823                                 if (fields.TryGetValue (field.Name, out old)) {
 824                                         if (old.Item1.MemberType.IsStruct) {
 825                                                 //
 826                                                 // TODO: Clear fields for structs
 827                                                 //
 828                                         } else {
 829                                                 try {
 830                                                         old.Item2.SetValue (null, null);
 831                                                 } catch {
 832                                                 }
 833                                         }
 834                                 }
 835
 836                                 fields[field.Name] = Tuple.Create (field.Spec, fi);
 837                         }
 838
 839                         return (CompiledMethod) System.Delegate.CreateDelegate (typeof (CompiledMethod), mi);
 840 #endif
 841                 }
 842
 843                 /// <summary>
 844                 ///   A sentinel value used to indicate that no value was
 845                 ///   was set by the compiled function.   This is used to
 846                 ///   differentiate between a function not returning a
 847                 ///   value and null.
 848                 /// </summary>
 849                 internal static class QuitValue { }
 850
 851                 internal Tuple<FieldSpec, FieldInfo> LookupField (string name)
 852                 {
 853                         Tuple<FieldSpec, FieldInfo> fi;
 854                         fields.TryGetValue (name, out fi);
 855                         return fi;
 856                 }
 857
 858                 static string Quote (string s)
 859                 {
 860                         if (s.IndexOf ('"') != -1)
 861                                 s = s.Replace ("\"", "\\\"");
 862
 863                         return "\"" + s + "\"";
 864                 }
 865
 866                 public string GetUsing ()
 867                 {
 868                         StringBuilder sb = new StringBuilder ();
 869                         // TODO:
 870                         //foreach (object x in ns.using_alias_list)
 871                         //    sb.AppendFormat ("using {0};\n", x);
 872
 873                         foreach (var ue in source_file.Usings) {
 874                                 sb.AppendFormat ("using {0};", ue.ToString ());
 875                                 sb.Append (Environment.NewLine);
 876                         }
 877
 878                         return sb.ToString ();
 879                 }
 880
 881                 internal List<string> GetUsingList ()
 882                 {
 883                         var res = new List<string> ();
 884
 885                         foreach (var ue in source_file.Usings) {
 886                                 if (ue.Alias != null || ue.ResolvedExpression == null)
 887                                         continue;
 888
 889                                 res.Add (ue.NamespaceExpression.Name);
 890                         }
 891
 892                         return res;
 893                 }
 894
 895                 internal string [] GetVarNames ()
 896                 {
 897                         lock (evaluator_lock){
 898                                 return new List<string> (fields.Keys).ToArray ();
 899                         }
 900                 }
 901
 902                 public string GetVars ()
 903                 {
 904                         lock (evaluator_lock){
 905                                 StringBuilder sb = new StringBuilder ();
 906
 907                                 foreach (var de in fields){
 908                                         var fi = LookupField (de.Key);
 909                                         object value;
 910                                         try {
 911                                                 value = fi.Item2.GetValue (null);
 912                                                 if (value is string)
 913                                                         value = Quote ((string)value);
 914                                         } catch {
 915                                                 value = "<error reading value>";
 916                                         }
 917
 918                                         sb.AppendFormat ("{0} {1} = {2}", fi.Item1.MemberType.GetSignatureForError (), de.Key, value);
 919                                         sb.AppendLine ();
 920                                 }
 921
 922                                 return sb.ToString ();
 923                         }
 924                 }
 925
 926                 /// <summary>
 927                 ///    Loads the given assembly and exposes the API to the user.
 928                 /// </summary>
 929                 public void LoadAssembly (string file)
 930                 {
 931                         var loader = new DynamicLoader (importer, ctx);
 932                         var assembly = loader.LoadAssemblyFile (file, false);
 933                         if (assembly == null)
 934                                 return;
 935
 936                         lock (evaluator_lock){
 937                                 importer.ImportAssembly (assembly, module.GlobalRootNamespace);
 938                         }
 939                 }
 940
 941                 /// <summary>
 942                 ///    Exposes the API of the given assembly to the Evaluator
 943                 /// </summary>
 944                 public void ReferenceAssembly (Assembly a)
 945                 {
 946                         lock (evaluator_lock){
 947                                 importer.ImportAssembly (a, module.GlobalRootNamespace);
 948                         }
 949                 }
 950         }
 951
 952
 953         /// <summary>
 954         ///   A delegate that can be used to invoke the
 955         ///   compiled expression or statement.
 956         /// </summary>
 957         /// <remarks>
 958         ///   Since the Compile methods will compile
 959         ///   statements and expressions into the same
 960         ///   delegate, you can tell if a value was returned
 961         ///   by checking whether the returned value is of type
 962         ///   NoValueSet.
 963         /// </remarks>
 964
 965         public delegate void CompiledMethod (ref object retvalue);
 966
 967         /// <summary>
 968         ///   The default base class for every interaction line
 969         /// </summary>
 970         /// <remarks>
 971         ///   The expressions and statements behave as if they were
 972         ///   a static method of this class.   The InteractiveBase class
 973         ///   contains a number of useful methods, but can be overwritten
 974         ///   by setting the InteractiveBaseType property in the Evaluator
 975         /// </remarks>
 976         public class InteractiveBase {
 977                 /// <summary>
 978                 ///   Determines where the standard output of methods in this class will go.
 979                 /// </summary>
 980                 public static TextWriter Output = Console.Out;
 981
 982                 /// <summary>
 983                 ///   Determines where the standard error of methods in this class will go.
 984                 /// </summary>
 985                 public static TextWriter Error = Console.Error;
 986
 987                 /// <summary>
 988                 ///   The primary prompt used for interactive use.
 989                 /// </summary>
 990                 public static string Prompt             = "csharp> ";
 991
 992                 /// <summary>
 993                 ///   The secondary prompt used for interactive use (used when
 994                 ///   an expression is incomplete).
 995                 /// </summary>
 996                 public static string ContinuationPrompt = "      > ";
 997
 998                 /// <summary>
 999                 ///   Used to signal that the user has invoked the  `quit' statement.
1000                 /// </summary>
1001                 public static bool QuitRequested;
1002
1003                 public static Evaluator Evaluator;
1004
1005                 /// <summary>
1006                 ///   Shows all the variables defined so far.
1007                 /// </summary>
1008                 static public void ShowVars ()
1009                 {
1010                         Output.Write (Evaluator.GetVars ());
1011                         Output.Flush ();
1012                 }
1013
1014                 /// <summary>
1015                 ///   Displays the using statements in effect at this point.
1016                 /// </summary>
1017                 static public void ShowUsing ()
1018                 {
1019                         Output.Write (Evaluator.GetUsing ());
1020                         Output.Flush ();
1021                 }
1022
1023                 /// <summary>
1024                 ///   Times the execution of the given delegate
1025                 /// </summary>
1026                 static public TimeSpan Time (Action a)
1027                 {
1028                         DateTime start = DateTime.Now;
1029                         a ();
1030                         return DateTime.Now - start;
1031                 }
1032
1033                 /// <summary>
1034                 ///   Loads the assemblies from a package
1035                 /// </summary>
1036                 /// <remarks>
1037                 ///   Loads the assemblies from a package.   This is equivalent
1038                 ///   to passing the -pkg: command line flag to the C# compiler
1039                 ///   on the command line.
1040                 /// </remarks>
1041                 static public void LoadPackage (string pkg)
1042                 {
1043                         if (pkg == null){
1044                                 Error.WriteLine ("Invalid package specified");
1045                                 return;
1046                         }
1047
1048                         string pkgout = Driver.GetPackageFlags (pkg, null);
1049
1050                         string [] xargs = pkgout.Trim (new Char [] {' ', '\n', '\r', '\t'}).
1051                                 Split (new Char [] { ' ', '\t'});
1052
1053                         foreach (string s in xargs){
1054                                 if (s.StartsWith ("-r:") || s.StartsWith ("/r:") || s.StartsWith ("/reference:")){
1055                                         string lib = s.Substring (s.IndexOf (':')+1);
1056
1057                                         Evaluator.LoadAssembly (lib);
1058                                         continue;
1059                                 }
1060                         }
1061                 }
1062
1063                 /// <summary>
1064                 ///   Loads the assembly
1065                 /// </summary>
1066                 /// <remarks>
1067                 ///   Loads the specified assembly and makes its types
1068                 ///   available to the evaluator.  This is equivalent
1069                 ///   to passing the -pkg: command line flag to the C#
1070                 ///   compiler on the command line.
1071                 /// </remarks>
1072                 static public void LoadAssembly (string assembly)
1073                 {
1074                         Evaluator.LoadAssembly (assembly);
1075                 }
1076
1077                 static public void print (object obj)
1078                 {
1079                         Output.WriteLine (obj);
1080                 }
1081
1082                 static public void print (string fmt, params object [] args)
1083                 {
1084                         Output.WriteLine (fmt, args);
1085                 }
1086
1087                 /// <summary>
1088                 ///   Returns a list of available static methods.
1089                 /// </summary>
1090                 static public string help {
1091                         get {
1092                                 return "Static methods:\n" +
1093                                         "  Describe (object);       - Describes the object's type\n" +
1094                                         "  LoadPackage (package);   - Loads the given Package (like -pkg:FILE)\n" +
1095                                         "  LoadAssembly (assembly); - Loads the given assembly (like -r:ASSEMBLY)\n" +
1096                                         "  ShowVars ();             - Shows defined local variables.\n" +
1097                                         "  ShowUsing ();            - Show active using declarations.\n" +
1098                                         "  Prompt                   - The prompt used by the C# shell\n" +
1099                                         "  ContinuationPrompt       - The prompt for partial input\n" +
1100                                         "  Time (() => { });        - Times the specified code\n" +
1101                                         "  print (obj);             - Shorthand for Console.WriteLine\n" +
1102                                         "  quit;                    - You'll never believe it - this quits the repl!\n" +
1103                                         "  help;                    - This help text\n";
1104                         }
1105                 }
1106
1107                 /// <summary>
1108                 ///   Indicates to the read-eval-print-loop that the interaction should be finished.
1109                 /// </summary>
1110                 static public object quit {
1111                         get {
1112                                 QuitRequested = true;
1113
1114                                 // To avoid print null at the exit
1115                                 return typeof (Evaluator.QuitValue);
1116                         }
1117                 }
1118
1119                 /// <summary>
1120                 ///   Same as quit - useful in script scenerios
1121                 /// </summary>
1122                 static public void Quit () {
1123                         QuitRequested = true;
1124                 }
1125
1126 #if !NET_2_1
1127                 /// <summary>
1128                 ///   Describes an object or a type.
1129                 /// </summary>
1130                 /// <remarks>
1131                 ///   This method will show a textual representation
1132                 ///   of the object's type.  If the object is a
1133                 ///   System.Type it renders the type directly,
1134                 ///   otherwise it renders the type returned by
1135                 ///   invoking GetType on the object.
1136                 /// </remarks>
1137                 static public string Describe (object x)
1138                 {
1139                         if (x == null)
1140                                 return "<null>";
1141
1142                         var type = x as Type ?? x.GetType ();
1143
1144                         StringWriter sw = new StringWriter ();
1145                         new Outline (type, sw, true, false, false).OutlineType ();
1146                         return sw.ToString ();
1147                 }
1148 #endif
1149         }
1150
1151         class InteractiveMethod : Method
1152         {
1153                 public InteractiveMethod(TypeDefinition parent, FullNamedExpression returnType, Modifiers mod, ParametersCompiled parameters)
1154                         : base(parent, returnType, mod, new MemberName("Host"), parameters, null)
1155                 {
1156                 }
1157
1158                 public void ChangeToAsync ()
1159                 {
1160                         ModFlags |= Modifiers.ASYNC;
1161                         ModFlags &= ~Modifiers.UNSAFE;
1162                         type_expr = new TypeExpression(Module.PredefinedTypes.Task.TypeSpec, Location);
1163                         parameters = ParametersCompiled.EmptyReadOnlyParameters;
1164                 }
1165
1166                 public override string GetSignatureForError()
1167                 {
1168                         return "InteractiveHost";
1169                 }
1170         }
1171
1172         class HoistedEvaluatorVariable : HoistedVariable
1173         {
1174                 public HoistedEvaluatorVariable (Field field)
1175                         : base (null, field)
1176                 {
1177                 }
1178
1179                 protected override FieldExpr GetFieldExpression (EmitContext ec)
1180                 {
1181                         return new FieldExpr (field, field.Location);
1182                 }
1183         }
1184
1185         /// <summary>
1186         ///    A class used to assign values if the source expression is not void
1187         ///
1188         ///    Used by the interactive shell to allow it to call this code to set
1189         ///    the return value for an invocation.
1190         /// </summary>
1191         class OptionalAssign : SimpleAssign {
1192                 public OptionalAssign (Expression s, Location loc)
1193                         : base (null, s, loc)
1194                 {
1195                 }
1196
1197                 public override Location StartLocation {
1198                         get {
1199                                 return Location.Null;
1200                         }
1201                 }
1202
1203                 protected override Expression DoResolve (ResolveContext ec)
1204                 {
1205                         Expression clone = source.Clone (new CloneContext ());
1206
1207                         clone = clone.Resolve (ec);
1208                         if (clone == null)
1209                                 return null;
1210
1211                         //
1212                         // A useful feature for the REPL: if we can resolve the expression
1213                         // as a type, Describe the type;
1214                         //
1215                         if (ec.Module.Evaluator.DescribeTypeExpressions && !(ec.CurrentAnonymousMethod is AsyncInitializer)) {
1216                                 var old_printer = ec.Report.SetPrinter (new SessionReportPrinter ());
1217                                 Expression tclone;
1218                                 try {
1219                                         // Note: clone context cannot be shared otherwise block mapping would leak
1220                                         tclone = source.Clone (new CloneContext ());
1221                                         tclone = tclone.Resolve (ec, ResolveFlags.Type);
1222                                         if (ec.Report.Errors > 0)
1223                                                 tclone = null;
1224                                 } finally {
1225                                         ec.Report.SetPrinter (old_printer);
1226                                 }
1227
1228                                 if (tclone is TypeExpr) {
1229                                         Arguments args = new Arguments (1);
1230                                         args.Add (new Argument (new TypeOf ((TypeExpr) clone, Location)));
1231                                         return new Invocation (new SimpleName ("Describe", Location), args).Resolve (ec);
1232                                 }
1233                         }
1234
1235                         // This means its really a statement.
1236                         if (clone.Type.Kind == MemberKind.Void || clone is DynamicInvocation || clone is Assign) {
1237                                 return clone;
1238                         }
1239
1240                         source = clone;
1241
1242                         var host = (Method) ec.MemberContext.CurrentMemberDefinition;
1243
1244                         if (host.ParameterInfo.IsEmpty) {
1245                                 eclass = ExprClass.Value;
1246                                 type = InternalType.FakeInternalType;
1247                                 return this;
1248                         }
1249
1250                         target = new SimpleName (host.ParameterInfo[0].Name, Location);
1251
1252                         return base.DoResolve (ec);
1253                 }
1254
1255                 public override void EmitStatement(EmitContext ec)
1256                 {
1257                         if (target == null) {
1258                                 source.Emit (ec);
1259                                 return;
1260                         }
1261
1262                         base.EmitStatement(ec);
1263                 }
1264         }
1265
1266         public class Undo
1267         {
1268                 List<Action> undo_actions;
1269
1270                 public void AddTypeContainer (TypeContainer current_container, TypeDefinition tc)
1271                 {
1272                         if (current_container == tc){
1273                                 Console.Error.WriteLine ("Internal error: inserting container into itself");
1274                                 return;
1275                         }
1276
1277                         if (undo_actions == null)
1278                                 undo_actions = new List<Action> ();
1279
1280                         if (current_container.Containers != null)
1281                         {
1282                                 var existing = current_container.Containers.FirstOrDefault (l => l.Basename == tc.Basename);
1283                                 if (existing != null) {
1284                                         current_container.RemoveContainer (existing);
1285                                         undo_actions.Add (() => current_container.AddTypeContainer (existing));
1286                                 }
1287                         }
1288
1289                         undo_actions.Add (() => current_container.RemoveContainer (tc));
1290                 }
1291
1292                 public void ExecuteUndo ()
1293                 {
1294                         if (undo_actions == null)
1295                                 return;
1296
1297                         foreach (var p in undo_actions){
1298                                 p ();
1299                         }
1300
1301                         undo_actions = null;
1302                 }
1303         }
1304
1305         static class ListenerProxy
1306         {
1307                 static readonly Dictionary<int, ValueModificationHandler> listeners = new Dictionary<int, ValueModificationHandler> ();
1308
1309                 static int counter;
1310
1311                 public static int Register (ValueModificationHandler listener)
1312                 {
1313                         lock (listeners) {
1314                                 var id = counter++;
1315                                 listeners.Add (id, listener);
1316                                 return id;
1317                         }
1318                 }
1319
1320                 public static void Unregister (int listenerId)
1321                 {
1322                         lock (listeners) {
1323                                 listeners.Remove (listenerId);
1324                         }
1325                 }
1326
1327                 public static void ValueChanged (object value, int row, int col, string name, int listenerId)
1328                 {
1329                         ValueModificationHandler action;
1330                         lock (listeners) {
1331                                 if (!listeners.TryGetValue (listenerId, out action))
1332                                         return;
1333                         }
1334
1335                         action (name, row, col, value);
1336                 }
1337         }
1338 }