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 //
   7 // Dual licensed under the terms of the MIT X11 or GNU GPL
   8 //
   9 // Copyright 2001, 2002, 2003 Ximian, Inc (http://www.ximian.com)
  10 // Copyright 2004, 2005, 2006, 2007, 2008 Novell, Inc
  11 //
  12 using System;
  13 using System.Threading;
  14 using System.Collections.Generic;
  15 using System.Reflection;
  16 using System.Reflection.Emit;
  17 using System.IO;
  18 using System.Globalization;
  19 using System.Text;
  20
  21 namespace Mono.CSharp {
  22
  23         /// <summary>
  24         ///   Evaluator: provides an API to evaluate C# statements and
  25         ///   expressions dynamically.
  26         /// </summary>
  27         /// <remarks>
  28         ///   This class exposes static methods to evaluate expressions in the
  29         ///   current program.
  30         ///
  31         ///   To initialize the evaluator with a number of compiler
  32         ///   options call the Init(string[]args) method with a set of
  33         ///   command line options that the compiler recognizes.
  34         ///
  35         ///   To interrupt execution of a statement, you can invoke the
  36         ///   Evaluator.Interrupt method.
  37         /// </remarks>
  38         public class Evaluator {
  39
  40                 enum ParseMode {
  41                         // Parse silently, do not output any error messages
  42                         Silent,
  43
  44                         // Report errors during parse
  45                         ReportErrors,
  46
  47                         // Auto-complete, means that the tokenizer will start producing
  48                         // GETCOMPLETIONS tokens when it reaches a certain point.
  49                         GetCompletions
  50                 }
  51
  52                 static object evaluator_lock = new object ();
  53
  54                 static string current_debug_name;
  55                 static int count;
  56                 static Thread invoke_thread;
  57
  58                 static List<NamespaceEntry.UsingAliasEntry> using_alias_list = new List<NamespaceEntry.UsingAliasEntry> ();
  59                 internal static List<NamespaceEntry.UsingEntry> using_list = new List<NamespaceEntry.UsingEntry> ();
  60                 static Dictionary<string, Tuple<FieldSpec, FieldInfo>> fields = new Dictionary<string, Tuple<FieldSpec, FieldInfo>> ();
  61
  62                 static TypeSpec interactive_base_class;
  63                 static Driver driver;
  64                 static bool inited;
  65
  66                 static CompilerContext ctx;
  67
  68                 public static TextWriter MessageOutput = Console.Out;
  69
  70                 /// <summary>
  71                 ///   Optional initialization for the Evaluator.
  72                 /// </summary>
  73                 /// <remarks>
  74                 ///  Initializes the Evaluator with the command line options
  75                 ///  that would be processed by the command line compiler.  Only
  76                 ///  the first call to Init will work, any future invocations are
  77                 ///  ignored.
  78                 ///
  79                 ///  You can safely avoid calling this method if your application
  80                 ///  does not need any of the features exposed by the command line
  81                 ///  interface.
  82                 /// </remarks>
  83                 public static void Init (string [] args)
  84                 {
  85                         InitAndGetStartupFiles (args);
  86                 }
  87
  88                 internal static ReportPrinter SetPrinter (ReportPrinter report_printer)
  89                 {
  90                         return ctx.Report.SetPrinter (report_printer);
  91                 }
  92
  93                 /// <summary>
  94                 ///   Optional initialization for the Evaluator.
  95                 /// </summary>
  96                 /// <remarks>
  97                 ///  Initializes the Evaluator with the command line
  98                 ///  options that would be processed by the command
  99                 ///  line compiler.  Only the first call to
 100                 ///  InitAndGetStartupFiles or Init will work, any future
 101                 ///  invocations are ignored.
 102                 ///
 103                 ///  You can safely avoid calling this method if your application
 104                 ///  does not need any of the features exposed by the command line
 105                 ///  interface.
 106                 ///
 107                 ///  This method return an array of strings that contains any
 108                 ///  files that were specified in `args'.
 109                 /// </remarks>
 110                 public static string [] InitAndGetStartupFiles (string [] args)
 111                 {
 112                         lock (evaluator_lock){
 113                                 if (inited)
 114                                         return new string [0];
 115
 116                                 driver = Driver.Create (args, false, new ConsoleReportPrinter ());
 117                                 if (driver == null)
 118                                         throw new Exception ("Failed to create compiler driver with the given arguments");
 119
 120                                 ctx = driver.ctx;
 121
 122                                 RootContext.ToplevelTypes = new ModuleContainer (ctx);
 123
 124                                 driver.ProcessDefaultConfig ();
 125
 126                                 var startup_files = new List<string> ();
 127                                 foreach (CompilationUnit file in Location.SourceFiles)
 128                                         startup_files.Add (file.Path);
 129
 130                                 CompilerCallableEntryPoint.Reset ();
 131                                 var ctypes = TypeManager.InitCoreTypes ();
 132
 133                                 ctx.MetaImporter.Initialize ();
 134
 135                                 RootContext.ToplevelTypes.MakeExecutable ("temp");
 136                                 driver.LoadReferences (RootContext.ToplevelTypes);
 137                                 TypeManager.InitCoreTypes (RootContext.ToplevelTypes, ctypes);
 138                                 TypeManager.InitOptionalCoreTypes (ctx);
 139
 140                                 RootContext.EvalMode = true;
 141                                 inited = true;
 142
 143                                 return startup_files.ToArray ();
 144                         }
 145                 }
 146
 147                 static void Init ()
 148                 {
 149                         Init (new string [0]);
 150                 }
 151
 152                 static void Reset ()
 153                 {
 154                         CompilerCallableEntryPoint.PartialReset ();
 155
 156                         Location.AddFile (null, "{interactive}");
 157                         Location.Initialize ();
 158
 159                         current_debug_name = "interactive" + (count++) + ".dll";
 160                 }
 161
 162                 /// <summary>
 163                 ///   The base class for the classes that host the user generated code
 164                 /// </summary>
 165                 /// <remarks>
 166                 ///
 167                 ///   This is the base class that will host the code
 168                 ///   executed by the Evaluator.  By default
 169                 ///   this is the Mono.CSharp.InteractiveBase class
 170                 ///   which is useful for interactive use.
 171                 ///
 172                 ///   By changing this property you can control the
 173                 ///   base class and the static members that are
 174                 ///   available to your evaluated code.
 175                 /// </remarks>
 176                 static public TypeSpec InteractiveBaseClass {
 177                         get {
 178                                 if (interactive_base_class != null)
 179                                         return interactive_base_class;
 180
 181                                 return ctx.MetaImporter.ImportType (typeof (InteractiveBase));
 182                         }
 183                 }
 184
 185                 public static void SetInteractiveBaseClass (Type type)
 186                 {
 187                         if (type == null)
 188                                 throw new ArgumentNullException ();
 189
 190                         lock (evaluator_lock)
 191                                 interactive_base_class = ctx.MetaImporter.ImportType (type);
 192                 }
 193
 194                 /// <summary>
 195                 ///   Interrupts the evaluation of an expression executing in Evaluate.
 196                 /// </summary>
 197                 /// <remarks>
 198                 ///   Use this method to interrupt long-running invocations.
 199                 /// </remarks>
 200                 public static void Interrupt ()
 201                 {
 202                         if (!inited || !invoking)
 203                                 return;
 204
 205                         if (invoke_thread != null)
 206                                 invoke_thread.Abort ();
 207                 }
 208
 209                 /// <summary>
 210                 ///   Compiles the input string and returns a delegate that represents the compiled code.
 211                 /// </summary>
 212                 /// <remarks>
 213                 ///
 214                 ///   Compiles the input string as a C# expression or
 215                 ///   statement, unlike the Evaluate method, the
 216                 ///   resulting delegate can be invoked multiple times
 217                 ///   without incurring in the compilation overhead.
 218                 ///
 219                 ///   If the return value of this function is null,
 220                 ///   this indicates that the parsing was complete.
 221                 ///   If the return value is a string it indicates
 222                 ///   that the input string was partial and that the
 223                 ///   invoking code should provide more code before
 224                 ///   the code can be successfully compiled.
 225                 ///
 226                 ///   If you know that you will always get full expressions or
 227                 ///   statements and do not care about partial input, you can use
 228                 ///   the other Compile overload.
 229                 ///
 230                 ///   On success, in addition to returning null, the
 231                 ///   compiled parameter will be set to the delegate
 232                 ///   that can be invoked to execute the code.
 233                 ///
 234                 /// </remarks>
 235                 static public string Compile (string input, out CompiledMethod compiled)
 236                 {
 237                         if (input == null || input.Length == 0){
 238                                 compiled = null;
 239                                 return null;
 240                         }
 241
 242                         lock (evaluator_lock){
 243                                 if (!inited)
 244                                         Init ();
 245
 246                         //      RootContext.ToplevelTypes = new ModuleContainer (ctx);
 247
 248                                 bool partial_input;
 249                                 CSharpParser parser = ParseString (ParseMode.Silent, input, out partial_input);
 250                                 if (parser == null){
 251                                         compiled = null;
 252                                         if (partial_input)
 253                                                 return input;
 254
 255                                         ParseString (ParseMode.ReportErrors, input, out partial_input);
 256                                         return null;
 257                                 }
 258
 259                                 object parser_result = parser.InteractiveResult;
 260
 261                                 if (!(parser_result is Class)){
 262                                         int errors = ctx.Report.Errors;
 263
 264                                         NamespaceEntry.VerifyAllUsing ();
 265                                         if (errors == ctx.Report.Errors)
 266                                                 parser.CurrentNamespace.Extract (using_alias_list, using_list);
 267                                 }
 268
 269                                 compiled = CompileBlock (parser_result as Class, parser.undo, ctx.Report);
 270                         }
 271
 272                         return null;
 273                 }
 274
 275                 /// <summary>
 276                 ///   Compiles the input string and returns a delegate that represents the compiled code.
 277                 /// </summary>
 278                 /// <remarks>
 279                 ///
 280                 ///   Compiles the input string as a C# expression or
 281                 ///   statement, unlike the Evaluate method, the
 282                 ///   resulting delegate can be invoked multiple times
 283                 ///   without incurring in the compilation overhead.
 284                 ///
 285                 ///   This method can only deal with fully formed input
 286                 ///   strings and does not provide a completion mechanism.
 287                 ///   If you must deal with partial input (for example for
 288                 ///   interactive use) use the other overload.
 289                 ///
 290                 ///   On success, a delegate is returned that can be used
 291                 ///   to invoke the method.
 292                 ///
 293                 /// </remarks>
 294                 static public CompiledMethod Compile (string input)
 295                 {
 296                         CompiledMethod compiled;
 297
 298                         // Ignore partial inputs
 299                         if (Compile (input, out compiled) != null){
 300                                 // Error, the input was partial.
 301                                 return null;
 302                         }
 303
 304                         // Either null (on error) or the compiled method.
 305                         return compiled;
 306                 }
 307
 308                 //
 309                 // Todo: Should we handle errors, or expect the calling code to setup
 310                 // the recording themselves?
 311                 //
 312
 313                 /// <summary>
 314                 ///   Evaluates and expression or statement and returns any result values.
 315                 /// </summary>
 316                 /// <remarks>
 317                 ///   Evaluates the input string as a C# expression or
 318                 ///   statement.  If the input string is an expression
 319                 ///   the result will be stored in the result variable
 320                 ///   and the result_set variable will be set to true.
 321                 ///
 322                 ///   It is necessary to use the result/result_set
 323                 ///   pair to identify when a result was set (for
 324                 ///   example, execution of user-provided input can be
 325                 ///   an expression, a statement or others, and
 326                 ///   result_set would only be set if the input was an
 327                 ///   expression.
 328                 ///
 329                 ///   If the return value of this function is null,
 330                 ///   this indicates that the parsing was complete.
 331                 ///   If the return value is a string, it indicates
 332                 ///   that the input is partial and that the user
 333                 ///   should provide an updated string.
 334                 /// </remarks>
 335                 public static string Evaluate (string input, out object result, out bool result_set)
 336                 {
 337                         CompiledMethod compiled;
 338
 339                         result_set = false;
 340                         result = null;
 341
 342                         input = Compile (input, out compiled);
 343                         if (input != null)
 344                                 return input;
 345
 346                         if (compiled == null)
 347                                 return null;
 348
 349                         //
 350                         // The code execution does not need to keep the compiler lock
 351                         //
 352                         object retval = typeof (NoValueSet);
 353
 354                         try {
 355                                 invoke_thread = System.Threading.Thread.CurrentThread;
 356                                 invoking = true;
 357                                 compiled (ref retval);
 358                         } catch (ThreadAbortException e){
 359                                 Thread.ResetAbort ();
 360                                 Console.WriteLine ("Interrupted!\n{0}", e);
 361                         } finally {
 362                                 invoking = false;
 363                         }
 364
 365                         //
 366                         // We use a reference to a compiler type, in this case
 367                         // Driver as a flag to indicate that this was a statement
 368                         //
 369                         if (retval != typeof (NoValueSet)){
 370                                 result_set = true;
 371                                 result = retval;
 372                         }
 373
 374                         return null;
 375                 }
 376
 377                 public static string [] GetCompletions (string input, out string prefix)
 378                 {
 379                         prefix = "";
 380                         if (input == null || input.Length == 0)
 381                                 return null;
 382
 383                         lock (evaluator_lock){
 384                                 if (!inited)
 385                                         Init ();
 386
 387                                 bool partial_input;
 388                                 CSharpParser parser = ParseString (ParseMode.GetCompletions, input, out partial_input);
 389                                 if (parser == null){
 390                                         if (CSharpParser.yacc_verbose_flag != 0)
 391                                                 Console.WriteLine ("DEBUG: No completions available");
 392                                         return null;
 393                                 }
 394
 395                                 Class parser_result = parser.InteractiveResult as Class;
 396
 397                                 if (parser_result == null){
 398                                         if (CSharpParser.yacc_verbose_flag != 0)
 399                                                 Console.WriteLine ("Do not know how to cope with !Class yet");
 400                                         return null;
 401                                 }
 402
 403                                 try {
 404                                         var a = RootContext.ToplevelTypes.MakeExecutable ("temp");
 405                                         a.Create (AppDomain.CurrentDomain, AssemblyBuilderAccess.Run);
 406                                         RootContext.ToplevelTypes.Define ();
 407                                         if (ctx.Report.Errors != 0)
 408                                                 return null;
 409
 410                                         MethodOrOperator method = null;
 411                                         foreach (MemberCore member in parser_result.Methods){
 412                                                 if (member.Name != "Host")
 413                                                         continue;
 414
 415                                                 method = (MethodOrOperator) member;
 416                                                 break;
 417                                         }
 418                                         if (method == null)
 419                                                 throw new InternalErrorException ("did not find the the Host method");
 420
 421                                         BlockContext bc = new BlockContext (method, method.Block, method.ReturnType);
 422
 423                                         try {
 424                                                 method.Block.Resolve (null, bc, method);
 425                                         } catch (CompletionResult cr){
 426                                                 prefix = cr.BaseText;
 427                                                 return cr.Result;
 428                                         }
 429                                 } finally {
 430                                         parser.undo.ExecuteUndo ();
 431                                 }
 432
 433                         }
 434                         return null;
 435                 }
 436
 437                 /// <summary>
 438                 ///   Executes the given expression or statement.
 439                 /// </summary>
 440                 /// <remarks>
 441                 ///    Executes the provided statement, returns true
 442                 ///    on success, false on parsing errors.  Exceptions
 443                 ///    might be thrown by the called code.
 444                 /// </remarks>
 445                 public static bool Run (string statement)
 446                 {
 447                         if (!inited)
 448                                 Init ();
 449
 450                         object result;
 451                         bool result_set;
 452
 453                         bool ok = Evaluate (statement, out result, out result_set) == null;
 454
 455                         return ok;
 456                 }
 457
 458                 /// <summary>
 459                 ///   Evaluates and expression or statement and returns the result.
 460                 /// </summary>
 461                 /// <remarks>
 462                 ///   Evaluates the input string as a C# expression or
 463                 ///   statement and returns the value.
 464                 ///
 465                 ///   This method will throw an exception if there is a syntax error,
 466                 ///   of if the provided input is not an expression but a statement.
 467                 /// </remarks>
 468                 public static object Evaluate (string input)
 469                 {
 470                         object result;
 471                         bool result_set;
 472
 473                         string r = Evaluate (input, out result, out result_set);
 474
 475                         if (r != null)
 476                                 throw new ArgumentException ("Syntax error on input: partial input");
 477
 478                         if (result_set == false)
 479                                 throw new ArgumentException ("The expression did not set a result");
 480
 481                         return result;
 482                 }
 483
 484                 enum InputKind {
 485                         EOF,
 486                         StatementOrExpression,
 487                         CompilationUnit,
 488                         Error
 489                 }
 490
 491                 //
 492                 // Deambiguates the input string to determine if we
 493                 // want to process a statement or if we want to
 494                 // process a compilation unit.
 495                 //
 496                 // This is done using a top-down predictive parser,
 497                 // since the yacc/jay parser can not deambiguage this
 498                 // without more than one lookahead token.   There are very
 499                 // few ambiguities.
 500                 //
 501                 static InputKind ToplevelOrStatement (SeekableStreamReader seekable)
 502                 {
 503                         Tokenizer tokenizer = new Tokenizer (seekable, (CompilationUnit) Location.SourceFiles [0], ctx);
 504
 505                         int t = tokenizer.token ();
 506                         switch (t){
 507                         case Token.EOF:
 508                                 return InputKind.EOF;
 509
 510                         // These are toplevels
 511                         case Token.EXTERN:
 512                         case Token.OPEN_BRACKET:
 513                         case Token.ABSTRACT:
 514                         case Token.CLASS:
 515                         case Token.ENUM:
 516                         case Token.INTERFACE:
 517                         case Token.INTERNAL:
 518                         case Token.NAMESPACE:
 519                         case Token.PRIVATE:
 520                         case Token.PROTECTED:
 521                         case Token.PUBLIC:
 522                         case Token.SEALED:
 523                         case Token.STATIC:
 524                         case Token.STRUCT:
 525                                 return InputKind.CompilationUnit;
 526
 527                         // Definitely expression
 528                         case Token.FIXED:
 529                         case Token.BOOL:
 530                         case Token.BYTE:
 531                         case Token.CHAR:
 532                         case Token.DECIMAL:
 533                         case Token.DOUBLE:
 534                         case Token.FLOAT:
 535                         case Token.INT:
 536                         case Token.LONG:
 537                         case Token.NEW:
 538                         case Token.OBJECT:
 539                         case Token.SBYTE:
 540                         case Token.SHORT:
 541                         case Token.STRING:
 542                         case Token.UINT:
 543                         case Token.ULONG:
 544                                 return InputKind.StatementOrExpression;
 545
 546                         // These need deambiguation help
 547                         case Token.USING:
 548                                 t = tokenizer.token ();
 549                                 if (t == Token.EOF)
 550                                         return InputKind.EOF;
 551
 552                                 if (t == Token.IDENTIFIER)
 553                                         return InputKind.CompilationUnit;
 554                                 return InputKind.StatementOrExpression;
 555
 556
 557                         // Distinguish between:
 558                         //    delegate opt_anonymous_method_signature block
 559                         //    delegate type
 560                         case Token.DELEGATE:
 561                                 t = tokenizer.token ();
 562                                 if (t == Token.EOF)
 563                                         return InputKind.EOF;
 564                                 if (t == Token.OPEN_PARENS || t == Token.OPEN_BRACE)
 565                                         return InputKind.StatementOrExpression;
 566                                 return InputKind.CompilationUnit;
 567
 568                         // Distinguih between:
 569                         //    unsafe block
 570                         //    unsafe as modifier of a type declaration
 571                         case Token.UNSAFE:
 572                                 t = tokenizer.token ();
 573                                 if (t == Token.EOF)
 574                                         return InputKind.EOF;
 575                                 if (t == Token.OPEN_PARENS)
 576                                         return InputKind.StatementOrExpression;
 577                                 return InputKind.CompilationUnit;
 578
 579                         // These are errors: we list explicitly what we had
 580                         // from the grammar, ERROR and then everything else
 581
 582                         case Token.READONLY:
 583                         case Token.OVERRIDE:
 584                         case Token.ERROR:
 585                                 return InputKind.Error;
 586
 587                         // This catches everything else allowed by
 588                         // expressions.  We could add one-by-one use cases
 589                         // if needed.
 590                         default:
 591                                 return InputKind.StatementOrExpression;
 592                         }
 593                 }
 594
 595                 //
 596                 // Parses the string @input and returns a CSharpParser if succeeful.
 597                 //
 598                 // if @silent is set to true then no errors are
 599                 // reported to the user.  This is used to do various calls to the
 600                 // parser and check if the expression is parsable.
 601                 //
 602                 // @partial_input: if @silent is true, then it returns whether the
 603                 // parsed expression was partial, and more data is needed
 604                 //
 605                 static CSharpParser ParseString (ParseMode mode, string input, out bool partial_input)
 606                 {
 607                         partial_input = false;
 608                         Reset ();
 609                         queued_fields.Clear ();
 610                         Tokenizer.LocatedToken.Initialize ();
 611
 612                         Stream s = new MemoryStream (Encoding.Default.GetBytes (input));
 613                         SeekableStreamReader seekable = new SeekableStreamReader (s, Encoding.Default);
 614
 615                         InputKind kind = ToplevelOrStatement (seekable);
 616                         if (kind == InputKind.Error){
 617                                 if (mode == ParseMode.ReportErrors)
 618                                         ctx.Report.Error (-25, "Detection Parsing Error");
 619                                 partial_input = false;
 620                                 return null;
 621                         }
 622
 623                         if (kind == InputKind.EOF){
 624                                 if (mode == ParseMode.ReportErrors)
 625                                         Console.Error.WriteLine ("Internal error: EOF condition should have been detected in a previous call with silent=true");
 626                                 partial_input = true;
 627                                 return null;
 628
 629                         }
 630                         seekable.Position = 0;
 631
 632                         CSharpParser parser = new CSharpParser (seekable, Location.SourceFiles [0], RootContext.ToplevelTypes);
 633
 634                         if (kind == InputKind.StatementOrExpression){
 635                                 parser.Lexer.putback_char = Tokenizer.EvalStatementParserCharacter;
 636                                 RootContext.StatementMode = true;
 637                         } else {
 638                                 //
 639                                 // Do not activate EvalCompilationUnitParserCharacter until
 640                                 // I have figured out all the limitations to invoke methods
 641                                 // in the generated classes.  See repl.txt
 642                                 //
 643                                 parser.Lexer.putback_char = Tokenizer.EvalUsingDeclarationsParserCharacter;
 644                                 //parser.Lexer.putback_char = Tokenizer.EvalCompilationUnitParserCharacter;
 645                                 RootContext.StatementMode = false;
 646                         }
 647
 648                         if (mode == ParseMode.GetCompletions)
 649                                 parser.Lexer.CompleteOnEOF = true;
 650
 651                         ReportPrinter old_printer = null;
 652                         if ((mode == ParseMode.Silent || mode == ParseMode.GetCompletions) && CSharpParser.yacc_verbose_flag == 0)
 653                                 old_printer = SetPrinter (new StreamReportPrinter (TextWriter.Null));
 654
 655                         try {
 656                                 parser.parse ();
 657                         } finally {
 658                                 if (ctx.Report.Errors != 0){
 659                                         if (mode != ParseMode.ReportErrors  && parser.UnexpectedEOF)
 660                                                 partial_input = true;
 661
 662                                         parser.undo.ExecuteUndo ();
 663                                         parser = null;
 664                                 }
 665
 666                                 if (old_printer != null)
 667                                         SetPrinter (old_printer);
 668                         }
 669                         return parser;
 670                 }
 671
 672                 //
 673                 // Queue all the fields that we use, as we need to then go from FieldBuilder to FieldInfo
 674                 // or reflection gets confused (it basically gets confused, and variables override each
 675                 // other).
 676                 //
 677                 static List<Field> queued_fields = new List<Field> ();
 678
 679                 //static ArrayList types = new ArrayList ();
 680
 681                 static volatile bool invoking;
 682
 683                 static CompiledMethod CompileBlock (Class host, Undo undo, Report Report)
 684                 {
 685                         AssemblyDefinition assembly;
 686
 687                         if (Environment.GetEnvironmentVariable ("SAVE") != null) {
 688                                 assembly = RootContext.ToplevelTypes.MakeExecutable (current_debug_name, current_debug_name);
 689                         } else {
 690                                 assembly = RootContext.ToplevelTypes.MakeExecutable (current_debug_name);
 691                         }
 692
 693                         assembly.Create (AppDomain.CurrentDomain, AssemblyBuilderAccess.RunAndSave);
 694                         RootContext.ToplevelTypes.Define ();
 695
 696                         if (Report.Errors != 0){
 697                                 undo.ExecuteUndo ();
 698                                 return null;
 699                         }
 700
 701                         TypeBuilder tb = null;
 702                         MethodBuilder mb = null;
 703
 704                         if (host != null){
 705                                 tb = host.TypeBuilder;
 706                                 mb = null;
 707                                 foreach (MemberCore member in host.Methods){
 708                                         if (member.Name != "Host")
 709                                                 continue;
 710
 711                                         MethodOrOperator method = (MethodOrOperator) member;
 712                                         mb = method.MethodBuilder;
 713                                         break;
 714                                 }
 715
 716                                 if (mb == null)
 717                                         throw new Exception ("Internal error: did not find the method builder for the generated method");
 718                         }
 719
 720                         RootContext.ToplevelTypes.Emit ();
 721                         if (Report.Errors != 0){
 722                                 undo.ExecuteUndo ();
 723                                 return null;
 724                         }
 725
 726                         RootContext.ToplevelTypes.CloseType ();
 727
 728                         if (Environment.GetEnvironmentVariable ("SAVE") != null)
 729                                 assembly.Save ();
 730
 731                         if (host == null)
 732                                 return null;
 733
 734                         //
 735                         // Unlike Mono, .NET requires that the MethodInfo is fetched, it cant
 736                         // work from MethodBuilders.   Retarded, I know.
 737                         //
 738                         var tt = assembly.Builder.GetType (tb.Name);
 739                         MethodInfo mi = tt.GetMethod (mb.Name);
 740
 741                         // Pull the FieldInfos from the type, and keep track of them
 742                         foreach (Field field in queued_fields){
 743                                 FieldInfo fi = tt.GetField (field.Name);
 744
 745                                 Tuple<FieldSpec, FieldInfo> old;
 746
 747                                 // If a previous value was set, nullify it, so that we do
 748                                 // not leak memory
 749                                 if (fields.TryGetValue (field.Name, out old)) {
 750                                         if (old.Item1.MemberType.IsStruct) {
 751                                                 //
 752                                                 // TODO: Clear fields for structs
 753                                                 //
 754                                         } else {
 755                                                 try {
 756                                                         old.Item2.SetValue (null, null);
 757                                                 } catch {
 758                                                 }
 759                                         }
 760
 761                                         fields [field.Name] = Tuple.Create (old.Item1, fi);
 762                                 } else {
 763                                         fields.Add (field.Name, Tuple.Create (field.Spec, fi));
 764                                 }
 765                         }
 766                         //types.Add (tb);
 767
 768                         queued_fields.Clear ();
 769
 770                         return (CompiledMethod) System.Delegate.CreateDelegate (typeof (CompiledMethod), mi);
 771                 }
 772
 773                 static internal void LoadAliases (NamespaceEntry ns)
 774                 {
 775                         ns.Populate (using_alias_list, using_list);
 776                 }
 777
 778                 /// <summary>
 779                 ///   A sentinel value used to indicate that no value was
 780                 ///   was set by the compiled function.   This is used to
 781                 ///   differentiate between a function not returning a
 782                 ///   value and null.
 783                 /// </summary>
 784                 public class NoValueSet {
 785                 }
 786
 787                 static internal Tuple<FieldSpec, FieldInfo> LookupField (string name)
 788                 {
 789                         Tuple<FieldSpec, FieldInfo> fi;
 790                         fields.TryGetValue (name, out fi);
 791                         return fi;
 792                 }
 793
 794                 //
 795                 // Puts the FieldBuilder into a queue of names that will be
 796                 // registered.   We can not register FieldBuilders directly
 797                 // we need to fetch the FieldInfo after Reflection cooks the
 798                 // types, or bad things happen (bad means: FieldBuilders behave
 799                 // incorrectly across multiple assemblies, causing assignments to
 800                 // invalid areas
 801                 //
 802                 // This also serves for the parser to register Field classes
 803                 // that should be exposed as global variables
 804                 //
 805                 static internal void QueueField (Field f)
 806                 {
 807                         queued_fields.Add (f);
 808                 }
 809
 810                 static string Quote (string s)
 811                 {
 812                         if (s.IndexOf ('"') != -1)
 813                                 s = s.Replace ("\"", "\\\"");
 814
 815                         return "\"" + s + "\"";
 816                 }
 817
 818                 static public string GetUsing ()
 819                 {
 820                         lock (evaluator_lock){
 821                                 StringBuilder sb = new StringBuilder ();
 822
 823                                 foreach (object x in using_alias_list)
 824                                         sb.Append (String.Format ("using {0};\n", x));
 825
 826                                 foreach (object x in using_list)
 827                                         sb.Append (String.Format ("using {0};\n", x));
 828
 829                                 return sb.ToString ();
 830                         }
 831                 }
 832
 833                 static internal ICollection<string> GetUsingList ()
 834                 {
 835                         var res = new List<string> (using_list.Count);
 836                         foreach (object ue in using_list)
 837                                 res.Add (ue.ToString ());
 838                         return res;
 839                 }
 840
 841                 static internal string [] GetVarNames ()
 842                 {
 843                         lock (evaluator_lock){
 844                                 return new List<string> (fields.Keys).ToArray ();
 845                         }
 846                 }
 847
 848                 static public string GetVars ()
 849                 {
 850                         lock (evaluator_lock){
 851                                 StringBuilder sb = new StringBuilder ();
 852
 853                                 foreach (var de in fields){
 854                                         var fi = LookupField (de.Key);
 855                                         object value;
 856                                         try {
 857                                                 value = fi.Item2.GetValue (null);
 858                                                 if (value is string)
 859                                                         value = Quote ((string)value);
 860                                         } catch {
 861                                                 value = "<error reading value>";
 862                                         }
 863
 864                                         sb.AppendFormat ("{0} {1} = {2}", fi.Item1.MemberType.GetSignatureForError (), de.Key, value);
 865                                         sb.AppendLine ();
 866                                 }
 867
 868                                 return sb.ToString ();
 869                         }
 870                 }
 871
 872                 /// <summary>
 873                 ///    Loads the given assembly and exposes the API to the user.
 874                 /// </summary>
 875                 static public void LoadAssembly (string file)
 876                 {
 877                         lock (evaluator_lock){
 878                                 var a = driver.LoadAssemblyFile (file, false);
 879                                 if (a != null)
 880                                         ctx.MetaImporter.ImportAssembly (a, RootContext.ToplevelTypes.GlobalRootNamespace);
 881                         }
 882                 }
 883
 884                 /// <summary>
 885                 ///    Exposes the API of the given assembly to the Evaluator
 886                 /// </summary>
 887                 static public void ReferenceAssembly (Assembly a)
 888                 {
 889                         lock (evaluator_lock){
 890                                 ctx.MetaImporter.ImportAssembly (a, RootContext.ToplevelTypes.GlobalRootNamespace);
 891                         }
 892                 }
 893
 894                 /// <summary>
 895                 ///   If true, turns type expressions into valid expressions
 896                 ///   and calls the describe method on it
 897                 /// </summary>
 898                 public static bool DescribeTypeExpressions;
 899         }
 900
 901
 902         /// <summary>
 903         ///   A delegate that can be used to invoke the
 904         ///   compiled expression or statement.
 905         /// </summary>
 906         /// <remarks>
 907         ///   Since the Compile methods will compile
 908         ///   statements and expressions into the same
 909         ///   delegate, you can tell if a value was returned
 910         ///   by checking whether the returned value is of type
 911         ///   NoValueSet.
 912         /// </remarks>
 913
 914         public delegate void CompiledMethod (ref object retvalue);
 915
 916         /// <summary>
 917         ///   The default base class for every interaction line
 918         /// </summary>
 919         /// <remarks>
 920         ///   The expressions and statements behave as if they were
 921         ///   a static method of this class.   The InteractiveBase class
 922         ///   contains a number of useful methods, but can be overwritten
 923         ///   by setting the InteractiveBaseType property in the Evaluator
 924         /// </remarks>
 925         public class InteractiveBase {
 926                 /// <summary>
 927                 ///   Determines where the standard output of methods in this class will go.
 928                 /// </summary>
 929                 public static TextWriter Output = Console.Out;
 930
 931                 /// <summary>
 932                 ///   Determines where the standard error of methods in this class will go.
 933                 /// </summary>
 934                 public static TextWriter Error = Console.Error;
 935
 936                 /// <summary>
 937                 ///   The primary prompt used for interactive use.
 938                 /// </summary>
 939                 public static string Prompt             = "csharp> ";
 940
 941                 /// <summary>
 942                 ///   The secondary prompt used for interactive use (used when
 943                 ///   an expression is incomplete).
 944                 /// </summary>
 945                 public static string ContinuationPrompt = "      > ";
 946
 947                 /// <summary>
 948                 ///   Used to signal that the user has invoked the  `quit' statement.
 949                 /// </summary>
 950                 public static bool QuitRequested;
 951
 952                 /// <summary>
 953                 ///   Shows all the variables defined so far.
 954                 /// </summary>
 955                 static public void ShowVars ()
 956                 {
 957                         Output.Write (Evaluator.GetVars ());
 958                         Output.Flush ();
 959                 }
 960
 961                 /// <summary>
 962                 ///   Displays the using statements in effect at this point.
 963                 /// </summary>
 964                 static public void ShowUsing ()
 965                 {
 966                         Output.Write (Evaluator.GetUsing ());
 967                         Output.Flush ();
 968                 }
 969
 970                 public delegate void Simple ();
 971
 972                 /// <summary>
 973                 ///   Times the execution of the given delegate
 974                 /// </summary>
 975                 static public TimeSpan Time (Simple a)
 976                 {
 977                         DateTime start = DateTime.Now;
 978                         a ();
 979                         return DateTime.Now - start;
 980                 }
 981
 982 #if !SMCS_SOURCE
 983                 /// <summary>
 984                 ///   Loads the assemblies from a package
 985                 /// </summary>
 986                 /// <remarks>
 987                 ///   Loads the assemblies from a package.   This is equivalent
 988                 ///   to passing the -pkg: command line flag to the C# compiler
 989                 ///   on the command line.
 990                 /// </remarks>
 991                 static public void LoadPackage (string pkg)
 992                 {
 993                         if (pkg == null){
 994                                 Error.WriteLine ("Invalid package specified");
 995                                 return;
 996                         }
 997
 998                         string pkgout = Driver.GetPackageFlags (pkg, false, RootContext.ToplevelTypes.Compiler.Report);
 999                         if (pkgout == null)
1000                                 return;
1001
1002                         string [] xargs = pkgout.Trim (new Char [] {' ', '\n', '\r', '\t'}).
1003                                 Split (new Char [] { ' ', '\t'});
1004
1005                         foreach (string s in xargs){
1006                                 if (s.StartsWith ("-r:") || s.StartsWith ("/r:") || s.StartsWith ("/reference:")){
1007                                         string lib = s.Substring (s.IndexOf (':')+1);
1008
1009                                         Evaluator.LoadAssembly (lib);
1010                                         continue;
1011                                 }
1012                         }
1013                 }
1014 #endif
1015
1016                 /// <summary>
1017                 ///   Loads the assembly
1018                 /// </summary>
1019                 /// <remarks>
1020                 ///   Loads the specified assembly and makes its types
1021                 ///   available to the evaluator.  This is equivalent
1022                 ///   to passing the -pkg: command line flag to the C#
1023                 ///   compiler on the command line.
1024                 /// </remarks>
1025                 static public void LoadAssembly (string assembly)
1026                 {
1027                         Evaluator.LoadAssembly (assembly);
1028                 }
1029
1030                 /// <summary>
1031                 ///   Returns a list of available static methods.
1032                 /// </summary>
1033                 static public string help {
1034                         get {
1035                                 return "Static methods:\n" +
1036                                         "  Describe (object)       - Describes the object's type\n" +
1037                                         "  LoadPackage (package);  - Loads the given Package (like -pkg:FILE)\n" +
1038                                         "  LoadAssembly (assembly) - Loads the given assembly (like -r:ASSEMBLY)\n" +
1039                                         "  ShowVars ();            - Shows defined local variables.\n" +
1040                                         "  ShowUsing ();           - Show active using declarations.\n" +
1041                                         "  Prompt                  - The prompt used by the C# shell\n" +
1042                                         "  ContinuationPrompt      - The prompt for partial input\n" +
1043                                         "  Time(() -> { })         - Times the specified code\n" +
1044                                         "  quit;                   - You'll never believe it - this quits the repl!\n" +
1045                                         "  help;                   - This help text\n";
1046                         }
1047                 }
1048
1049                 /// <summary>
1050                 ///   Indicates to the read-eval-print-loop that the interaction should be finished.
1051                 /// </summary>
1052                 static public object quit {
1053                         get {
1054                                 QuitRequested = true;
1055
1056                                 // To avoid print null at the exit
1057                                 return typeof (Evaluator.NoValueSet);
1058                         }
1059                 }
1060
1061 #if !NET_2_1
1062                 /// <summary>
1063                 ///   Describes an object or a type.
1064                 /// </summary>
1065                 /// <remarks>
1066                 ///   This method will show a textual representation
1067                 ///   of the object's type.  If the object is a
1068                 ///   System.Type it renders the type directly,
1069                 ///   otherwise it renders the type returned by
1070                 ///   invoking GetType on the object.
1071                 /// </remarks>
1072                 static public string Describe (object x)
1073                 {
1074                         if (x == null)
1075                                 return "<null>";
1076
1077                         var type = x as Type ?? x.GetType ();
1078
1079                         StringWriter sw = new StringWriter ();
1080                         new Outline (type, sw, true, false, false).OutlineType ();
1081                         return sw.ToString ();
1082                 }
1083 #endif
1084         }
1085
1086         class HoistedEvaluatorVariable : HoistedVariable
1087         {
1088                 public HoistedEvaluatorVariable (Field field)
1089                         : base (null, field)
1090                 {
1091                 }
1092
1093                 public override void EmitSymbolInfo ()
1094                 {
1095                 }
1096
1097                 protected override FieldExpr GetFieldExpression (EmitContext ec)
1098                 {
1099                         return new FieldExpr (field, field.Location);
1100                 }
1101         }
1102
1103         /// <summary>
1104         ///    A class used to assign values if the source expression is not void
1105         ///
1106         ///    Used by the interactive shell to allow it to call this code to set
1107         ///    the return value for an invocation.
1108         /// </summary>
1109         class OptionalAssign : SimpleAssign {
1110                 public OptionalAssign (Expression t, Expression s, Location loc)
1111                         : base (t, s, loc)
1112                 {
1113                 }
1114
1115                 protected override Expression DoResolve (ResolveContext ec)
1116                 {
1117                         CloneContext cc = new CloneContext ();
1118                         Expression clone = source.Clone (cc);
1119
1120                         //
1121                         // A useful feature for the REPL: if we can resolve the expression
1122                         // as a type, Describe the type;
1123                         //
1124                         if (Evaluator.DescribeTypeExpressions){
1125                                 var old_printer = Evaluator.SetPrinter (new StreamReportPrinter (TextWriter.Null));
1126                                 clone = clone.Resolve (ec);
1127                                 if (clone == null){
1128                                         clone = source.Clone (cc);
1129                                         clone = clone.Resolve (ec, ResolveFlags.Type);
1130                                         if (clone == null){
1131                                                 Evaluator.SetPrinter (old_printer);
1132                                                 clone = source.Clone (cc);
1133                                                 clone = clone.Resolve (ec);
1134                                                 return null;
1135                                         }
1136
1137                                         Arguments args = new Arguments (1);
1138                                         args.Add (new Argument (new TypeOf ((TypeExpr) clone, Location)));
1139                                         source = new Invocation (new SimpleName ("Describe", Location), args).Resolve (ec);
1140                                 }
1141                                 Evaluator.SetPrinter (old_printer);
1142                         } else {
1143                                 clone = clone.Resolve (ec);
1144                                 if (clone == null)
1145                                         return null;
1146                         }
1147
1148                         // This means its really a statement.
1149                         if (clone.Type == TypeManager.void_type || clone is DynamicInvocation || clone is Assign) {
1150                                 return clone;
1151                         }
1152
1153                         return base.DoResolve (ec);
1154                 }
1155         }
1156
1157         public class Undo {
1158                 List<KeyValuePair<TypeContainer, TypeContainer>> undo_types;
1159
1160                 public Undo ()
1161                 {
1162                         undo_types = new List<KeyValuePair<TypeContainer, TypeContainer>> ();
1163                 }
1164
1165                 public void AddTypeContainer (TypeContainer current_container, TypeContainer tc)
1166                 {
1167                         if (current_container == tc){
1168                                 Console.Error.WriteLine ("Internal error: inserting container into itself");
1169                                 return;
1170                         }
1171
1172                         if (undo_types == null)
1173                                 undo_types = new List<KeyValuePair<TypeContainer, TypeContainer>> ();
1174
1175                         undo_types.Add (new KeyValuePair<TypeContainer, TypeContainer> (current_container, tc));
1176                 }
1177
1178                 public void ExecuteUndo ()
1179                 {
1180                         if (undo_types == null)
1181                                 return;
1182
1183                         foreach (var p in undo_types){
1184                                 TypeContainer current_container = p.Key;
1185
1186                                 current_container.RemoveTypeContainer (p.Value);
1187                         }
1188                         undo_types = null;
1189                 }
1190         }
1191
1192 }
1193