mcs/mcs/ecore.cs

   1 //
   2 // ecore.cs: Core of the Expression representation for the intermediate tree.
   3 //
   4 // Author:
   5 //   Miguel de Icaza (miguel@ximian.com)
   6 //
   7 // (C) 2001, 2002, 2003 Ximian, Inc.
   8 //
   9 //
  10
  11 namespace Mono.CSharp {
  12         using System;
  13         using System.Collections;
  14         using System.Diagnostics;
  15         using System.Reflection;
  16         using System.Reflection.Emit;
  17         using System.Text;
  18
  19         /// <remarks>
  20         ///   The ExprClass class contains the is used to pass the
  21         ///   classification of an expression (value, variable, namespace,
  22         ///   type, method group, property access, event access, indexer access,
  23         ///   nothing).
  24         /// </remarks>
  25         public enum ExprClass : byte {
  26                 Invalid,
  27
  28                 Value,
  29                 Variable,
  30                 Namespace,
  31                 Type,
  32                 MethodGroup,
  33                 PropertyAccess,
  34                 EventAccess,
  35                 IndexerAccess,
  36                 Nothing,
  37         }
  38
  39         /// <remarks>
  40         ///   This is used to tell Resolve in which types of expressions we're
  41         ///   interested.
  42         /// </remarks>
  43         [Flags]
  44         public enum ResolveFlags {
  45                 // Returns Value, Variable, PropertyAccess, EventAccess or IndexerAccess.
  46                 VariableOrValue         = 1,
  47
  48                 // Returns a type expression.
  49                 Type                    = 2,
  50
  51                 // Returns a method group.
  52                 MethodGroup             = 4,
  53
  54                 // Allows SimpleNames to be returned.
  55                 // This is used by MemberAccess to construct long names that can not be
  56                 // partially resolved (namespace-qualified names for example).
  57                 SimpleName              = 8,
  58
  59                 // Mask of all the expression class flags.
  60                 MaskExprClass           = 15,
  61
  62                 // Disable control flow analysis while resolving the expression.
  63                 // This is used when resolving the instance expression of a field expression.
  64                 DisableFlowAnalysis     = 16,
  65
  66                 // Set if this is resolving the first part of a MemberAccess.
  67                 Intermediate            = 32
  68         }
  69
  70         //
  71         // This is just as a hint to AddressOf of what will be done with the
  72         // address.
  73         [Flags]
  74         public enum AddressOp {
  75                 Store = 1,
  76                 Load  = 2,
  77                 LoadStore = 3
  78         };
  79
  80         /// <summary>
  81         ///   This interface is implemented by variables
  82         /// </summary>
  83         public interface IMemoryLocation {
  84                 /// <summary>
  85                 ///   The AddressOf method should generate code that loads
  86                 ///   the address of the object and leaves it on the stack.
  87                 ///
  88                 ///   The `mode' argument is used to notify the expression
  89                 ///   of whether this will be used to read from the address or
  90                 ///   write to the address.
  91                 ///
  92                 ///   This is just a hint that can be used to provide good error
  93                 ///   reporting, and should have no other side effects.
  94                 /// </summary>
  95                 void AddressOf (EmitContext ec, AddressOp mode);
  96         }
  97
  98         /// <summary>
  99         ///   This interface is implemented by variables
 100         /// </summary>
 101         public interface IVariable {
 102                 VariableInfo VariableInfo {
 103                         get;
 104                 }
 105
 106                 bool VerifyFixed (bool is_expression);
 107         }
 108
 109         /// <summary>
 110         ///   This interface denotes an expression which evaluates to a member
 111         ///   of a struct or a class.
 112         /// </summary>
 113         public interface IMemberExpr
 114         {
 115                 /// <summary>
 116                 ///   The name of this member.
 117                 /// </summary>
 118                 string Name {
 119                         get;
 120                 }
 121
 122                 /// <summary>
 123                 ///   Whether this is an instance member.
 124                 /// </summary>
 125                 bool IsInstance {
 126                         get;
 127                 }
 128
 129                 /// <summary>
 130                 ///   Whether this is a static member.
 131                 /// </summary>
 132                 bool IsStatic {
 133                         get;
 134                 }
 135
 136                 /// <summary>
 137                 ///   The type which declares this member.
 138                 /// </summary>
 139                 Type DeclaringType {
 140                         get;
 141                 }
 142
 143                 /// <summary>
 144                 ///   The instance expression associated with this member, if it's a
 145                 ///   non-static member.
 146                 /// </summary>
 147                 Expression InstanceExpression {
 148                         get; set;
 149                 }
 150         }
 151
 152         /// <remarks>
 153         ///   Base class for expressions
 154         /// </remarks>
 155         public abstract class Expression {
 156                 public ExprClass eclass;
 157                 protected Type type;
 158                 protected Location loc;
 159
 160                 public Type Type {
 161                         get {
 162                                 return type;
 163                         }
 164
 165                         set {
 166                                 type = value;
 167                         }
 168                 }
 169
 170                 public Location Location {
 171                         get {
 172                                 return loc;
 173                         }
 174                 }
 175
 176                 /// <summary>
 177                 ///   Utility wrapper routine for Error, just to beautify the code
 178                 /// </summary>
 179                 public void Error (int error, string s)
 180                 {
 181                         if (!Location.IsNull (loc))
 182                                 Report.Error (error, loc, s);
 183                         else
 184                                 Report.Error (error, s);
 185                 }
 186
 187                 /// <summary>
 188                 ///   Utility wrapper routine for Warning, just to beautify the code
 189                 /// </summary>
 190                 public void Warning (int code, string format, params object[] args)
 191                 {
 192                         Report.Warning (code, loc, format, args);
 193                 }
 194
 195                 /// <summary>
 196                 /// Tests presence of ObsoleteAttribute and report proper error
 197                 /// </summary>
 198                 protected void CheckObsoleteAttribute (Type type)
 199                 {
 200                         ObsoleteAttribute obsolete_attr = AttributeTester.GetObsoleteAttribute (type);
 201                         if (obsolete_attr == null)
 202                                 return;
 203
 204                         AttributeTester.Report_ObsoleteMessage (obsolete_attr, type.FullName, loc);
 205                 }
 206
 207                 /// <summary>
 208                 ///   Performs semantic analysis on the Expression
 209                 /// </summary>
 210                 ///
 211                 /// <remarks>
 212                 ///   The Resolve method is invoked to perform the semantic analysis
 213                 ///   on the node.
 214                 ///
 215                 ///   The return value is an expression (it can be the
 216                 ///   same expression in some cases) or a new
 217                 ///   expression that better represents this node.
 218                 ///
 219                 ///   For example, optimizations of Unary (LiteralInt)
 220                 ///   would return a new LiteralInt with a negated
 221                 ///   value.
 222                 ///
 223                 ///   If there is an error during semantic analysis,
 224                 ///   then an error should be reported (using Report)
 225                 ///   and a null value should be returned.
 226                 ///
 227                 ///   There are two side effects expected from calling
 228                 ///   Resolve(): the the field variable "eclass" should
 229                 ///   be set to any value of the enumeration
 230                 ///   `ExprClass' and the type variable should be set
 231                 ///   to a valid type (this is the type of the
 232                 ///   expression).
 233                 /// </remarks>
 234                 public abstract Expression DoResolve (EmitContext ec);
 235
 236                 public virtual Expression DoResolveLValue (EmitContext ec, Expression right_side)
 237                 {
 238                         return DoResolve (ec);
 239                 }
 240
 241                 //
 242                 // This is used if the expression should be resolved as a type.
 243                 // the default implementation fails.   Use this method in
 244                 // those participants in the SimpleName chain system.
 245                 //
 246                 public virtual Expression ResolveAsTypeStep (EmitContext ec)
 247                 {
 248                         return null;
 249                 }
 250
 251                 //
 252                 // This is used to resolve the expression as a type, a null
 253                 // value will be returned if the expression is not a type
 254                 // reference
 255                 //
 256                 public TypeExpr ResolveAsTypeTerminal (EmitContext ec, bool silent)
 257                 {
 258                         int errors = Report.Errors;
 259
 260                         TypeExpr te = ResolveAsTypeStep (ec) as TypeExpr;
 261
 262                         if (te == null || te.eclass != ExprClass.Type) {
 263                                 if (!silent && errors == Report.Errors)
 264                                         Report.Error (246, Location, "Cannot find type '{0}'", ToString ());
 265                                 return null;
 266                         }
 267
 268                         if (!te.CheckAccessLevel (ec.DeclSpace)) {
 269                                 Report.Error (122, Location, "'{0}' is inaccessible due to its protection level", te.Name);
 270                                 return null;
 271                         }
 272
 273                         return te;
 274                 }
 275
 276                 /// <summary>
 277                 ///   Resolves an expression and performs semantic analysis on it.
 278                 /// </summary>
 279                 ///
 280                 /// <remarks>
 281                 ///   Currently Resolve wraps DoResolve to perform sanity
 282                 ///   checking and assertion checking on what we expect from Resolve.
 283                 /// </remarks>
 284                 public Expression Resolve (EmitContext ec, ResolveFlags flags)
 285                 {
 286                         if ((flags & ResolveFlags.MaskExprClass) == ResolveFlags.Type)
 287                                 return ResolveAsTypeStep (ec);
 288
 289                         bool old_do_flow_analysis = ec.DoFlowAnalysis;
 290                         if ((flags & ResolveFlags.DisableFlowAnalysis) != 0)
 291                                 ec.DoFlowAnalysis = false;
 292
 293                         Expression e;
 294                         bool intermediate = (flags & ResolveFlags.Intermediate) == ResolveFlags.Intermediate;
 295                         if (this is SimpleName)
 296                                 e = ((SimpleName) this).DoResolveAllowStatic (ec, intermediate);
 297
 298                         else
 299                                 e = DoResolve (ec);
 300
 301                         ec.DoFlowAnalysis = old_do_flow_analysis;
 302
 303                         if (e == null)
 304                                 return null;
 305
 306                         if (e is SimpleName){
 307                                 SimpleName s = (SimpleName) e;
 308
 309                                 if ((flags & ResolveFlags.SimpleName) == 0) {
 310                                         MemberLookupFailed (ec, null, ec.ContainerType, s.Name,
 311                                                             ec.DeclSpace.Name, loc);
 312                                         return null;
 313                                 }
 314
 315                                 return s;
 316                         }
 317
 318                         if ((e is TypeExpr) || (e is ComposedCast)) {
 319                                 if ((flags & ResolveFlags.Type) == 0) {
 320                                         e.Error_UnexpectedKind (flags, loc);
 321                                         return null;
 322                                 }
 323
 324                                 return e;
 325                         }
 326
 327                         switch (e.eclass) {
 328                         case ExprClass.Type:
 329                                 if ((flags & ResolveFlags.VariableOrValue) == 0) {
 330                                         e.Error_UnexpectedKind (flags, loc);
 331                                         return null;
 332                                 }
 333                                 break;
 334
 335                         case ExprClass.MethodGroup:
 336                                 if (RootContext.Version == LanguageVersion.ISO_1){
 337                                         if ((flags & ResolveFlags.MethodGroup) == 0) {
 338                                                 ((MethodGroupExpr) e).ReportUsageError ();
 339                                                 return null;
 340                                         }
 341                                 }
 342                                 break;
 343
 344                         case ExprClass.Value:
 345                         case ExprClass.Variable:
 346                         case ExprClass.PropertyAccess:
 347                         case ExprClass.EventAccess:
 348                         case ExprClass.IndexerAccess:
 349                                 if ((flags & ResolveFlags.VariableOrValue) == 0) {
 350                                         Console.WriteLine ("I got: {0} and {1}", e.GetType (), e);
 351                                         Console.WriteLine ("I am {0} and {1}", this.GetType (), this);
 352                                         FieldInfo fi = ((FieldExpr) e).FieldInfo;
 353
 354                                         Console.WriteLine ("{0} and {1}", fi.DeclaringType, fi.Name);
 355                                         e.Error_UnexpectedKind (flags, loc);
 356                                         return null;
 357                                 }
 358                                 break;
 359
 360                         default:
 361                                 throw new Exception ("Expression " + e.GetType () +
 362                                                      " ExprClass is Invalid after resolve");
 363                         }
 364
 365                         if (e.type == null)
 366                                 throw new Exception (
 367                                         "Expression " + e.GetType () +
 368                                         " did not set its type after Resolve\n" +
 369                                         "called from: " + this.GetType ());
 370
 371                         return e;
 372                 }
 373
 374                 /// <summary>
 375                 ///   Resolves an expression and performs semantic analysis on it.
 376                 /// </summary>
 377                 public Expression Resolve (EmitContext ec)
 378                 {
 379                         return Resolve (ec, ResolveFlags.VariableOrValue);
 380                 }
 381
 382                 /// <summary>
 383                 ///   Resolves an expression for LValue assignment
 384                 /// </summary>
 385                 ///
 386                 /// <remarks>
 387                 ///   Currently ResolveLValue wraps DoResolveLValue to perform sanity
 388                 ///   checking and assertion checking on what we expect from Resolve
 389                 /// </remarks>
 390                 public Expression ResolveLValue (EmitContext ec, Expression right_side)
 391                 {
 392                         Expression e = DoResolveLValue (ec, right_side);
 393
 394                         if (e != null){
 395                                 if (e is SimpleName){
 396                                         SimpleName s = (SimpleName) e;
 397                                         MemberLookupFailed (ec, null, ec.ContainerType, s.Name,
 398                                                             ec.DeclSpace.Name, loc);
 399                                         return null;
 400                                 }
 401
 402                                 if (e.eclass == ExprClass.Invalid)
 403                                         throw new Exception ("Expression " + e +
 404                                                              " ExprClass is Invalid after resolve");
 405
 406                                 if (e.eclass == ExprClass.MethodGroup) {
 407                                         ((MethodGroupExpr) e).ReportUsageError ();
 408                                         return null;
 409                                 }
 410
 411                                 if (e.type == null)
 412                                         throw new Exception ("Expression " + e +
 413                                                              " did not set its type after Resolve");
 414                         }
 415
 416                         return e;
 417                 }
 418
 419                 /// <summary>
 420                 ///   Emits the code for the expression
 421                 /// </summary>
 422                 ///
 423                 /// <remarks>
 424                 ///   The Emit method is invoked to generate the code
 425                 ///   for the expression.
 426                 /// </remarks>
 427                 public abstract void Emit (EmitContext ec);
 428
 429                 public virtual void EmitBranchable (EmitContext ec, Label target, bool onTrue)
 430                 {
 431                         Emit (ec);
 432                         ec.ig.Emit (onTrue ? OpCodes.Brtrue : OpCodes.Brfalse, target);
 433                 }
 434
 435                 /// <summary>
 436                 ///   Protected constructor.  Only derivate types should
 437                 ///   be able to be created
 438                 /// </summary>
 439
 440                 protected Expression ()
 441                 {
 442                         eclass = ExprClass.Invalid;
 443                         type = null;
 444                 }
 445
 446                 /// <summary>
 447                 ///   Returns a literalized version of a literal FieldInfo
 448                 /// </summary>
 449                 ///
 450                 /// <remarks>
 451                 ///   The possible return values are:
 452                 ///      IntConstant, UIntConstant
 453                 ///      LongLiteral, ULongConstant
 454                 ///      FloatConstant, DoubleConstant
 455                 ///      StringConstant
 456                 ///
 457                 ///   The value returned is already resolved.
 458                 /// </remarks>
 459                 public static Constant Constantify (object v, Type t)
 460                 {
 461                         if (t == TypeManager.int32_type)
 462                                 return new IntConstant ((int) v);
 463                         else if (t == TypeManager.uint32_type)
 464                                 return new UIntConstant ((uint) v);
 465                         else if (t == TypeManager.int64_type)
 466                                 return new LongConstant ((long) v);
 467                         else if (t == TypeManager.uint64_type)
 468                                 return new ULongConstant ((ulong) v);
 469                         else if (t == TypeManager.float_type)
 470                                 return new FloatConstant ((float) v);
 471                         else if (t == TypeManager.double_type)
 472                                 return new DoubleConstant ((double) v);
 473                         else if (t == TypeManager.string_type)
 474                                 return new StringConstant ((string) v);
 475                         else if (t == TypeManager.short_type)
 476                                 return new ShortConstant ((short)v);
 477                         else if (t == TypeManager.ushort_type)
 478                                 return new UShortConstant ((ushort)v);
 479                         else if (t == TypeManager.sbyte_type)
 480                                 return new SByteConstant (((sbyte)v));
 481                         else if (t == TypeManager.byte_type)
 482                                 return new ByteConstant ((byte)v);
 483                         else if (t == TypeManager.char_type)
 484                                 return new CharConstant ((char)v);
 485                         else if (t == TypeManager.bool_type)
 486                                 return new BoolConstant ((bool) v);
 487                         else if (TypeManager.IsEnumType (t)){
 488                                 Type real_type = TypeManager.TypeToCoreType (v.GetType ());
 489                                 if (real_type == t)
 490                                         real_type = System.Enum.GetUnderlyingType (real_type);
 491
 492                                 Constant e = Constantify (v, real_type);
 493
 494                                 return new EnumConstant (e, t);
 495                         } else if (v == null && !TypeManager.IsValueType (t))
 496                                 return NullLiteral.Null;
 497                         else
 498                                 throw new Exception ("Unknown type for constant (" + t +
 499                                                      "), details: " + v);
 500                 }
 501
 502                 /// <summary>
 503                 ///   Returns a fully formed expression after a MemberLookup
 504                 /// </summary>
 505                 public static Expression ExprClassFromMemberInfo (EmitContext ec, MemberInfo mi, Location loc)
 506                 {
 507                         if (mi is EventInfo)
 508                                 return new EventExpr ((EventInfo) mi, loc);
 509                         else if (mi is FieldInfo)
 510                                 return new FieldExpr ((FieldInfo) mi, loc);
 511                         else if (mi is PropertyInfo)
 512                                 return new PropertyExpr (ec, (PropertyInfo) mi, loc);
 513                         else if (mi is Type){
 514                                 return new TypeExpression ((System.Type) mi, loc);
 515                         }
 516
 517                         return null;
 518                 }
 519
 520
 521                 private static ArrayList almostMatchedMembers = new ArrayList (4);
 522
 523                 //
 524                 // FIXME: Probably implement a cache for (t,name,current_access_set)?
 525                 //
 526                 // This code could use some optimizations, but we need to do some
 527                 // measurements.  For example, we could use a delegate to `flag' when
 528                 // something can not any longer be a method-group (because it is something
 529                 // else).
 530                 //
 531                 // Return values:
 532                 //     If the return value is an Array, then it is an array of
 533                 //     MethodBases
 534                 //
 535                 //     If the return value is an MemberInfo, it is anything, but a Method
 536                 //
 537                 //     null on error.
 538                 //
 539                 // FIXME: When calling MemberLookup inside an `Invocation', we should pass
 540                 // the arguments here and have MemberLookup return only the methods that
 541                 // match the argument count/type, unlike we are doing now (we delay this
 542                 // decision).
 543                 //
 544                 // This is so we can catch correctly attempts to invoke instance methods
 545                 // from a static body (scan for error 120 in ResolveSimpleName).
 546                 //
 547                 //
 548                 // FIXME: Potential optimization, have a static ArrayList
 549                 //
 550
 551                 public static Expression MemberLookup (EmitContext ec, Type queried_type, string name,
 552                                                        MemberTypes mt, BindingFlags bf, Location loc)
 553                 {
 554                         return MemberLookup (ec, ec.ContainerType, null, queried_type, name, mt, bf, loc);
 555                 }
 556
 557                 //
 558                 // Lookup type `queried_type' for code in class `container_type' with a qualifier of
 559                 // `qualifier_type' or null to lookup members in the current class.
 560                 //
 561
 562                 public static Expression MemberLookup (EmitContext ec, Type container_type,
 563                                                        Type qualifier_type, Type queried_type,
 564                                                        string name, MemberTypes mt,
 565                                                        BindingFlags bf, Location loc)
 566                 {
 567                         almostMatchedMembers.Clear ();
 568
 569                         MemberInfo [] mi = TypeManager.MemberLookup (container_type, qualifier_type,
 570                                                                      queried_type, mt, bf, name, almostMatchedMembers);
 571
 572                         if (mi == null)
 573                                 return null;
 574
 575                         int count = mi.Length;
 576
 577                         if (mi [0] is MethodBase)
 578                                 return new MethodGroupExpr (mi, loc);
 579
 580                         if (count > 1)
 581                                 return null;
 582
 583                         return ExprClassFromMemberInfo (ec, mi [0], loc);
 584                 }
 585
 586                 public const MemberTypes AllMemberTypes =
 587                         MemberTypes.Constructor |
 588                         MemberTypes.Event       |
 589                         MemberTypes.Field       |
 590                         MemberTypes.Method      |
 591                         MemberTypes.NestedType  |
 592                         MemberTypes.Property;
 593
 594                 public const BindingFlags AllBindingFlags =
 595                         BindingFlags.Public |
 596                         BindingFlags.Static |
 597                         BindingFlags.Instance;
 598
 599                 public static Expression MemberLookup (EmitContext ec, Type queried_type,
 600                                                        string name, Location loc)
 601                 {
 602                         return MemberLookup (ec, ec.ContainerType, null, queried_type, name,
 603                                              AllMemberTypes, AllBindingFlags, loc);
 604                 }
 605
 606                 public static Expression MemberLookup (EmitContext ec, Type qualifier_type,
 607                                                        Type queried_type, string name, Location loc)
 608                 {
 609                         return MemberLookup (ec, ec.ContainerType, qualifier_type, queried_type,
 610                                              name, AllMemberTypes, AllBindingFlags, loc);
 611                 }
 612
 613                 public static Expression MethodLookup (EmitContext ec, Type queried_type,
 614                                                        string name, Location loc)
 615                 {
 616                         return MemberLookup (ec, ec.ContainerType, null, queried_type, name,
 617                                              MemberTypes.Method, AllBindingFlags, loc);
 618                 }
 619
 620                 /// <summary>
 621                 ///   This is a wrapper for MemberLookup that is not used to "probe", but
 622                 ///   to find a final definition.  If the final definition is not found, we
 623                 ///   look for private members and display a useful debugging message if we
 624                 ///   find it.
 625                 /// </summary>
 626                 public static Expression MemberLookupFinal (EmitContext ec, Type qualifier_type,
 627                                                             Type queried_type, string name, Location loc)
 628                 {
 629                         return MemberLookupFinal (ec, qualifier_type, queried_type, name,
 630                                                   AllMemberTypes, AllBindingFlags, loc);
 631                 }
 632
 633                 public static Expression MemberLookupFinal (EmitContext ec, Type qualifier_type,
 634                                                             Type queried_type, string name,
 635                                                             MemberTypes mt, BindingFlags bf,
 636                                                             Location loc)
 637                 {
 638                         Expression e;
 639
 640                         int errors = Report.Errors;
 641
 642                         e = MemberLookup (ec, ec.ContainerType, qualifier_type, queried_type, name, mt, bf, loc);
 643
 644                         if (e == null && errors == Report.Errors)
 645                                 // No errors were reported by MemberLookup, but there was an error.
 646                                 MemberLookupFailed (ec, qualifier_type, queried_type, name, null, loc);
 647
 648                         return e;
 649                 }
 650
 651                 public static void MemberLookupFailed (EmitContext ec, Type qualifier_type,
 652                                                        Type queried_type, string name,
 653                                                        string class_name, Location loc)
 654                 {
 655                         if (almostMatchedMembers.Count != 0) {
 656                                 if (qualifier_type == null) {
 657                                         foreach (MemberInfo m in almostMatchedMembers)
 658                                                 Report.Error (38, loc,
 659                                                               "Cannot access non-static member `{0}' via nested type `{1}'",
 660                                                               TypeManager.GetFullNameSignature (m),
 661                                                               TypeManager.CSharpName (ec.ContainerType));
 662                                         return;
 663                                 }
 664
 665                                 if (qualifier_type != ec.ContainerType) {
 666                                         // Although a derived class can access protected members of
 667                                         // its base class it cannot do so through an instance of the
 668                                         // base class (CS1540).  If the qualifier_type is a parent of the
 669                                         // ec.ContainerType and the lookup succeeds with the latter one,
 670                                         // then we are in this situation.
 671                                         foreach (MemberInfo m in almostMatchedMembers)
 672                                                 Report.Error (1540, loc,
 673                                                               "Cannot access protected member `{0}' via a qualifier of type `{1}';"
 674                                                               + " the qualifier must be of type `{2}' (or derived from it)",
 675                                                               TypeManager.GetFullNameSignature (m),
 676                                                               TypeManager.CSharpName (qualifier_type),
 677                                                               TypeManager.CSharpName (ec.ContainerType));
 678                                         return;
 679                                 }
 680                                 almostMatchedMembers.Clear ();
 681                         }
 682
 683                         object lookup = TypeManager.MemberLookup (queried_type, null, queried_type,
 684                                                                   AllMemberTypes, AllBindingFlags |
 685                                                                   BindingFlags.NonPublic, name, null);
 686
 687                         if (lookup == null) {
 688                                 if (class_name != null)
 689                                         Report.Error (103, loc, "The name `" + name + "' could not be " +
 690                                                       "found in `" + class_name + "'");
 691                                 else
 692                                         Report.Error (
 693                                                 117, loc, "`" + queried_type + "' does not contain a " +
 694                                                 "definition for `" + name + "'");
 695                                 return;
 696                         }
 697
 698                         if (qualifier_type != null)
 699                                 Report.Error (122, loc, "'{0}' is inaccessible due to its protection level", TypeManager.CSharpName (qualifier_type) + "." + name);
 700                         else if (name == ".ctor") {
 701                                 Report.Error (143, loc, String.Format ("The type {0} has no constructors defined",
 702                                                                        TypeManager.CSharpName (queried_type)));
 703                         } else {
 704                                 Report.Error (122, loc, "'{0}' is inaccessible due to its protection level", name);
 705                         }
 706                 }
 707
 708                 static public MemberInfo GetFieldFromEvent (EventExpr event_expr)
 709                 {
 710                         EventInfo ei = event_expr.EventInfo;
 711
 712                         return TypeManager.GetPrivateFieldOfEvent (ei);
 713                 }
 714
 715                 /// <summary>
 716                 ///   Returns an expression that can be used to invoke operator true
 717                 ///   on the expression if it exists.
 718                 /// </summary>
 719                 static public StaticCallExpr GetOperatorTrue (EmitContext ec, Expression e, Location loc)
 720                 {
 721                         return GetOperatorTrueOrFalse (ec, e, true, loc);
 722                 }
 723
 724                 /// <summary>
 725                 ///   Returns an expression that can be used to invoke operator false
 726                 ///   on the expression if it exists.
 727                 /// </summary>
 728                 static public StaticCallExpr GetOperatorFalse (EmitContext ec, Expression e, Location loc)
 729                 {
 730                         return GetOperatorTrueOrFalse (ec, e, false, loc);
 731                 }
 732
 733                 static StaticCallExpr GetOperatorTrueOrFalse (EmitContext ec, Expression e, bool is_true, Location loc)
 734                 {
 735                         MethodBase method;
 736                         Expression operator_group;
 737
 738                         operator_group = MethodLookup (ec, e.Type, is_true ? "op_True" : "op_False", loc);
 739                         if (operator_group == null)
 740                                 return null;
 741
 742                         ArrayList arguments = new ArrayList ();
 743                         arguments.Add (new Argument (e, Argument.AType.Expression));
 744                         method = Invocation.OverloadResolve (
 745                                 ec, (MethodGroupExpr) operator_group, arguments, false, loc);
 746
 747                         if (method == null)
 748                                 return null;
 749
 750                         return new StaticCallExpr ((MethodInfo) method, arguments, loc);
 751                 }
 752
 753                 /// <summary>
 754                 ///   Resolves the expression `e' into a boolean expression: either through
 755                 ///   an implicit conversion, or through an `operator true' invocation
 756                 /// </summary>
 757                 public static Expression ResolveBoolean (EmitContext ec, Expression e, Location loc)
 758                 {
 759                         e = e.Resolve (ec);
 760                         if (e == null)
 761                                 return null;
 762
 763                         Expression converted = e;
 764                         if (e.Type != TypeManager.bool_type)
 765                                 converted = Convert.ImplicitConversion (ec, e, TypeManager.bool_type, new Location (-1));
 766
 767                         //
 768                         // If no implicit conversion to bool exists, try using `operator true'
 769                         //
 770                         if (converted == null){
 771                                 Expression operator_true = Expression.GetOperatorTrue (ec, e, loc);
 772                                 if (operator_true == null){
 773                                         Report.Error (
 774                                                 31, loc, "Can not convert the expression to a boolean");
 775                                         return null;
 776                                 }
 777                                 e = operator_true;
 778                         } else
 779                                 e = converted;
 780
 781                         return e;
 782                 }
 783
 784                 static string ExprClassName (ExprClass c)
 785                 {
 786                         switch (c){
 787                         case ExprClass.Invalid:
 788                                 return "Invalid";
 789                         case ExprClass.Value:
 790                                 return "value";
 791                         case ExprClass.Variable:
 792                                 return "variable";
 793                         case ExprClass.Namespace:
 794                                 return "namespace";
 795                         case ExprClass.Type:
 796                                 return "type";
 797                         case ExprClass.MethodGroup:
 798                                 return "method group";
 799                         case ExprClass.PropertyAccess:
 800                                 return "property access";
 801                         case ExprClass.EventAccess:
 802                                 return "event access";
 803                         case ExprClass.IndexerAccess:
 804                                 return "indexer access";
 805                         case ExprClass.Nothing:
 806                                 return "null";
 807                         }
 808                         throw new Exception ("Should not happen");
 809                 }
 810
 811                 /// <summary>
 812                 ///   Reports that we were expecting `expr' to be of class `expected'
 813                 /// </summary>
 814                 public void Error_UnexpectedKind (string expected, Location loc)
 815                 {
 816                         string kind = "Unknown";
 817
 818                         kind = ExprClassName (eclass);
 819
 820                         Report.Error (118, loc, "Expression denotes a `" + kind +
 821                                "' where a `" + expected + "' was expected");
 822                 }
 823
 824                 public void Error_UnexpectedKind (ResolveFlags flags, Location loc)
 825                 {
 826                         ArrayList valid = new ArrayList (10);
 827
 828                         if ((flags & ResolveFlags.VariableOrValue) != 0) {
 829                                 valid.Add ("variable");
 830                                 valid.Add ("value");
 831                         }
 832
 833                         if ((flags & ResolveFlags.Type) != 0)
 834                                 valid.Add ("type");
 835
 836                         if ((flags & ResolveFlags.MethodGroup) != 0)
 837                                 valid.Add ("method group");
 838
 839                         if ((flags & ResolveFlags.SimpleName) != 0)
 840                                 valid.Add ("simple name");
 841
 842                         if (valid.Count == 0)
 843                                 valid.Add ("unknown");
 844
 845                         StringBuilder sb = new StringBuilder ();
 846                         for (int i = 0; i < valid.Count; i++) {
 847                                 if (i > 0)
 848                                         sb.Append (", ");
 849                                 else if (i == valid.Count)
 850                                         sb.Append (" or ");
 851                                 sb.Append (valid [i]);
 852                         }
 853
 854                         string kind = ExprClassName (eclass);
 855
 856                         Error (119, "Expression denotes a `" + kind + "' where " +
 857                                "a `" + sb.ToString () + "' was expected");
 858                 }
 859
 860                 static public void Error_ConstantValueCannotBeConverted (Location l, string val, Type t)
 861                 {
 862                         Report.Error (31, l, "Constant value `" + val + "' cannot be converted to " +
 863                                       TypeManager.CSharpName (t));
 864                 }
 865
 866                 public static void UnsafeError (Location loc)
 867                 {
 868                         Report.Error (214, loc, "Pointers may only be used in an unsafe context");
 869                 }
 870
 871                 /// <summary>
 872                 ///   Converts the IntConstant, UIntConstant, LongConstant or
 873                 ///   ULongConstant into the integral target_type.   Notice
 874                 ///   that we do not return an `Expression' we do return
 875                 ///   a boxed integral type.
 876                 ///
 877                 ///   FIXME: Since I added the new constants, we need to
 878                 ///   also support conversions from CharConstant, ByteConstant,
 879                 ///   SByteConstant, UShortConstant, ShortConstant
 880                 ///
 881                 ///   This is used by the switch statement, so the domain
 882                 ///   of work is restricted to the literals above, and the
 883                 ///   targets are int32, uint32, char, byte, sbyte, ushort,
 884                 ///   short, uint64 and int64
 885                 /// </summary>
 886                 public static object ConvertIntLiteral (Constant c, Type target_type, Location loc)
 887                 {
 888                         if (!Convert.ImplicitStandardConversionExists (Convert.ConstantEC, c, target_type)){
 889                                 Convert.Error_CannotImplicitConversion (loc, c.Type, target_type);
 890                                 return null;
 891                         }
 892
 893                         string s = "";
 894
 895                         if (c.Type == target_type)
 896                                 return ((Constant) c).GetValue ();
 897
 898                         //
 899                         // Make into one of the literals we handle, we dont really care
 900                         // about this value as we will just return a few limited types
 901                         //
 902                         if (c is EnumConstant)
 903                                 c = ((EnumConstant)c).WidenToCompilerConstant ();
 904
 905                         if (c is IntConstant){
 906                                 int v = ((IntConstant) c).Value;
 907
 908                                 if (target_type == TypeManager.uint32_type){
 909                                         if (v >= 0)
 910                                                 return (uint) v;
 911                                 } else if (target_type == TypeManager.char_type){
 912                                         if (v >= Char.MinValue && v <= Char.MaxValue)
 913                                                 return (char) v;
 914                                 } else if (target_type == TypeManager.byte_type){
 915                                         if (v >= Byte.MinValue && v <= Byte.MaxValue)
 916                                                 return (byte) v;
 917                                 } else if (target_type == TypeManager.sbyte_type){
 918                                         if (v >= SByte.MinValue && v <= SByte.MaxValue)
 919                                                 return (sbyte) v;
 920                                 } else if (target_type == TypeManager.short_type){
 921                                         if (v >= Int16.MinValue && v <= UInt16.MaxValue)
 922                                                 return (short) v;
 923                                 } else if (target_type == TypeManager.ushort_type){
 924                                         if (v >= UInt16.MinValue && v <= UInt16.MaxValue)
 925                                                 return (ushort) v;
 926                                 } else if (target_type == TypeManager.int64_type)
 927                                         return (long) v;
 928                                 else if (target_type == TypeManager.uint64_type){
 929                                         if (v > 0)
 930                                                 return (ulong) v;
 931                                 }
 932
 933                                 s = v.ToString ();
 934                         } else if (c is UIntConstant){
 935                                 uint v = ((UIntConstant) c).Value;
 936
 937                                 if (target_type == TypeManager.int32_type){
 938                                         if (v <= Int32.MaxValue)
 939                                                 return (int) v;
 940                                 } else if (target_type == TypeManager.char_type){
 941                                         if (v >= Char.MinValue && v <= Char.MaxValue)
 942                                                 return (char) v;
 943                                 } else if (target_type == TypeManager.byte_type){
 944                                         if (v <= Byte.MaxValue)
 945                                                 return (byte) v;
 946                                 } else if (target_type == TypeManager.sbyte_type){
 947                                         if (v <= SByte.MaxValue)
 948                                                 return (sbyte) v;
 949                                 } else if (target_type == TypeManager.short_type){
 950                                         if (v <= UInt16.MaxValue)
 951                                                 return (short) v;
 952                                 } else if (target_type == TypeManager.ushort_type){
 953                                         if (v <= UInt16.MaxValue)
 954                                                 return (ushort) v;
 955                                 } else if (target_type == TypeManager.int64_type)
 956                                         return (long) v;
 957                                 else if (target_type == TypeManager.uint64_type)
 958                                         return (ulong) v;
 959                                 s = v.ToString ();
 960                         } else if (c is LongConstant){
 961                                 long v = ((LongConstant) c).Value;
 962
 963                                 if (target_type == TypeManager.int32_type){
 964                                         if (v >= UInt32.MinValue && v <= UInt32.MaxValue)
 965                                                 return (int) v;
 966                                 } else if (target_type == TypeManager.uint32_type){
 967                                         if (v >= 0 && v <= UInt32.MaxValue)
 968                                                 return (uint) v;
 969                                 } else if (target_type == TypeManager.char_type){
 970                                         if (v >= Char.MinValue && v <= Char.MaxValue)
 971                                                 return (char) v;
 972                                 } else if (target_type == TypeManager.byte_type){
 973                                         if (v >= Byte.MinValue && v <= Byte.MaxValue)
 974                                                 return (byte) v;
 975                                 } else if (target_type == TypeManager.sbyte_type){
 976                                         if (v >= SByte.MinValue && v <= SByte.MaxValue)
 977                                                 return (sbyte) v;
 978                                 } else if (target_type == TypeManager.short_type){
 979                                         if (v >= Int16.MinValue && v <= UInt16.MaxValue)
 980                                                 return (short) v;
 981                                 } else if (target_type == TypeManager.ushort_type){
 982                                         if (v >= UInt16.MinValue && v <= UInt16.MaxValue)
 983                                                 return (ushort) v;
 984                                 } else if (target_type == TypeManager.uint64_type){
 985                                         if (v > 0)
 986                                                 return (ulong) v;
 987                                 }
 988                                 s = v.ToString ();
 989                         } else if (c is ULongConstant){
 990                                 ulong v = ((ULongConstant) c).Value;
 991
 992                                 if (target_type == TypeManager.int32_type){
 993                                         if (v <= Int32.MaxValue)
 994                                                 return (int) v;
 995                                 } else if (target_type == TypeManager.uint32_type){
 996                                         if (v <= UInt32.MaxValue)
 997                                                 return (uint) v;
 998                                 } else if (target_type == TypeManager.char_type){
 999                                         if (v >= Char.MinValue && v <= Char.MaxValue)
1000                                                 return (char) v;
1001                                 } else if (target_type == TypeManager.byte_type){
1002                                         if (v >= Byte.MinValue && v <= Byte.MaxValue)
1003                                                 return (byte) v;
1004                                 } else if (target_type == TypeManager.sbyte_type){
1005                                         if (v <= (int) SByte.MaxValue)
1006                                                 return (sbyte) v;
1007                                 } else if (target_type == TypeManager.short_type){
1008                                         if (v <= UInt16.MaxValue)
1009                                                 return (short) v;
1010                                 } else if (target_type == TypeManager.ushort_type){
1011                                         if (v <= UInt16.MaxValue)
1012                                                 return (ushort) v;
1013                                 } else if (target_type == TypeManager.int64_type){
1014                                         if (v <= Int64.MaxValue)
1015                                                 return (long) v;
1016                                 }
1017                                 s = v.ToString ();
1018                         } else if (c is ByteConstant){
1019                                 byte v = ((ByteConstant) c).Value;
1020
1021                                 if (target_type == TypeManager.int32_type)
1022                                         return (int) v;
1023                                 else if (target_type == TypeManager.uint32_type)
1024                                         return (uint) v;
1025                                 else if (target_type == TypeManager.char_type)
1026                                         return (char) v;
1027                                 else if (target_type == TypeManager.sbyte_type){
1028                                         if (v <= SByte.MaxValue)
1029                                                 return (sbyte) v;
1030                                 } else if (target_type == TypeManager.short_type)
1031                                         return (short) v;
1032                                 else if (target_type == TypeManager.ushort_type)
1033                                         return (ushort) v;
1034                                 else if (target_type == TypeManager.int64_type)
1035                                         return (long) v;
1036                                 else if (target_type == TypeManager.uint64_type)
1037                                         return (ulong) v;
1038                                 s = v.ToString ();
1039                         } else if (c is SByteConstant){
1040                                 sbyte v = ((SByteConstant) c).Value;
1041
1042                                 if (target_type == TypeManager.int32_type)
1043                                         return (int) v;
1044                                 else if (target_type == TypeManager.uint32_type){
1045                                         if (v >= 0)
1046                                                 return (uint) v;
1047                                 } else if (target_type == TypeManager.char_type){
1048                                         if (v >= 0)
1049                                                 return (char) v;
1050                                 } else if (target_type == TypeManager.byte_type){
1051                                         if (v >= 0)
1052                                                 return (byte) v;
1053                                 } else if (target_type == TypeManager.short_type)
1054                                         return (short) v;
1055                                 else if (target_type == TypeManager.ushort_type){
1056                                         if (v >= 0)
1057                                                 return (ushort) v;
1058                                 } else if (target_type == TypeManager.int64_type)
1059                                         return (long) v;
1060                                 else if (target_type == TypeManager.uint64_type){
1061                                         if (v >= 0)
1062                                                 return (ulong) v;
1063                                 }
1064                                 s = v.ToString ();
1065                         } else if (c is ShortConstant){
1066                                 short v = ((ShortConstant) c).Value;
1067
1068                                 if (target_type == TypeManager.int32_type){
1069                                         return (int) v;
1070                                 } else if (target_type == TypeManager.uint32_type){
1071                                         if (v >= 0)
1072                                                 return (uint) v;
1073                                 } else if (target_type == TypeManager.char_type){
1074                                         if (v >= 0)
1075                                                 return (char) v;
1076                                 } else if (target_type == TypeManager.byte_type){
1077                                         if (v >= Byte.MinValue && v <= Byte.MaxValue)
1078                                                 return (byte) v;
1079                                 } else if (target_type == TypeManager.sbyte_type){
1080                                         if (v >= SByte.MinValue && v <= SByte.MaxValue)
1081                                                 return (sbyte) v;
1082                                 } else if (target_type == TypeManager.ushort_type){
1083                                         if (v >= 0)
1084                                                 return (ushort) v;
1085                                 } else if (target_type == TypeManager.int64_type)
1086                                         return (long) v;
1087                                 else if (target_type == TypeManager.uint64_type)
1088                                         return (ulong) v;
1089
1090                                 s = v.ToString ();
1091                         } else if (c is UShortConstant){
1092                                 ushort v = ((UShortConstant) c).Value;
1093
1094                                 if (target_type == TypeManager.int32_type)
1095                                         return (int) v;
1096                                 else if (target_type == TypeManager.uint32_type)
1097                                         return (uint) v;
1098                                 else if (target_type == TypeManager.char_type){
1099                                         if (v >= Char.MinValue && v <= Char.MaxValue)
1100                                                 return (char) v;
1101                                 } else if (target_type == TypeManager.byte_type){
1102                                         if (v >= Byte.MinValue && v <= Byte.MaxValue)
1103                                                 return (byte) v;
1104                                 } else if (target_type == TypeManager.sbyte_type){
1105                                         if (v <= SByte.MaxValue)
1106                                                 return (byte) v;
1107                                 } else if (target_type == TypeManager.short_type){
1108                                         if (v <= Int16.MaxValue)
1109                                                 return (short) v;
1110                                 } else if (target_type == TypeManager.int64_type)
1111                                         return (long) v;
1112                                 else if (target_type == TypeManager.uint64_type)
1113                                         return (ulong) v;
1114
1115                                 s = v.ToString ();
1116                         } else if (c is CharConstant){
1117                                 char v = ((CharConstant) c).Value;
1118
1119                                 if (target_type == TypeManager.int32_type)
1120                                         return (int) v;
1121                                 else if (target_type == TypeManager.uint32_type)
1122                                         return (uint) v;
1123                                 else if (target_type == TypeManager.byte_type){
1124                                         if (v >= Byte.MinValue && v <= Byte.MaxValue)
1125                                                 return (byte) v;
1126                                 } else if (target_type == TypeManager.sbyte_type){
1127                                         if (v <= SByte.MaxValue)
1128                                                 return (sbyte) v;
1129                                 } else if (target_type == TypeManager.short_type){
1130                                         if (v <= Int16.MaxValue)
1131                                                 return (short) v;
1132                                 } else if (target_type == TypeManager.ushort_type)
1133                                         return (short) v;
1134                                 else if (target_type == TypeManager.int64_type)
1135                                         return (long) v;
1136                                 else if (target_type == TypeManager.uint64_type)
1137                                         return (ulong) v;
1138
1139                                 s = v.ToString ();
1140                         }
1141                         Error_ConstantValueCannotBeConverted (loc, s, target_type);
1142                         return null;
1143                 }
1144
1145                 //
1146                 // Load the object from the pointer.
1147                 //
1148                 public static void LoadFromPtr (ILGenerator ig, Type t)
1149                 {
1150                         if (t == TypeManager.int32_type)
1151                                 ig.Emit (OpCodes.Ldind_I4);
1152                         else if (t == TypeManager.uint32_type)
1153                                 ig.Emit (OpCodes.Ldind_U4);
1154                         else if (t == TypeManager.short_type)
1155                                 ig.Emit (OpCodes.Ldind_I2);
1156                         else if (t == TypeManager.ushort_type)
1157                                 ig.Emit (OpCodes.Ldind_U2);
1158                         else if (t == TypeManager.char_type)
1159                                 ig.Emit (OpCodes.Ldind_U2);
1160                         else if (t == TypeManager.byte_type)
1161                                 ig.Emit (OpCodes.Ldind_U1);
1162                         else if (t == TypeManager.sbyte_type)
1163                                 ig.Emit (OpCodes.Ldind_I1);
1164                         else if (t == TypeManager.uint64_type)
1165                                 ig.Emit (OpCodes.Ldind_I8);
1166                         else if (t == TypeManager.int64_type)
1167                                 ig.Emit (OpCodes.Ldind_I8);
1168                         else if (t == TypeManager.float_type)
1169                                 ig.Emit (OpCodes.Ldind_R4);
1170                         else if (t == TypeManager.double_type)
1171                                 ig.Emit (OpCodes.Ldind_R8);
1172                         else if (t == TypeManager.bool_type)
1173                                 ig.Emit (OpCodes.Ldind_I1);
1174                         else if (t == TypeManager.intptr_type)
1175                                 ig.Emit (OpCodes.Ldind_I);
1176                         else if (TypeManager.IsEnumType (t)) {
1177                                 if (t == TypeManager.enum_type)
1178                                         ig.Emit (OpCodes.Ldind_Ref);
1179                                 else
1180                                         LoadFromPtr (ig, TypeManager.EnumToUnderlying (t));
1181                         } else if (t.IsValueType)
1182                                 ig.Emit (OpCodes.Ldobj, t);
1183                         else if (t.IsPointer)
1184                                 ig.Emit (OpCodes.Ldind_I);
1185                         else
1186                                 ig.Emit (OpCodes.Ldind_Ref);
1187                 }
1188
1189                 //
1190                 // The stack contains the pointer and the value of type `type'
1191                 //
1192                 public static void StoreFromPtr (ILGenerator ig, Type type)
1193                 {
1194                         if (TypeManager.IsEnumType (type))
1195                                 type = TypeManager.EnumToUnderlying (type);
1196                         if (type == TypeManager.int32_type || type == TypeManager.uint32_type)
1197                                 ig.Emit (OpCodes.Stind_I4);
1198                         else if (type == TypeManager.int64_type || type == TypeManager.uint64_type)
1199                                 ig.Emit (OpCodes.Stind_I8);
1200                         else if (type == TypeManager.char_type || type == TypeManager.short_type ||
1201                                  type == TypeManager.ushort_type)
1202                                 ig.Emit (OpCodes.Stind_I2);
1203                         else if (type == TypeManager.float_type)
1204                                 ig.Emit (OpCodes.Stind_R4);
1205                         else if (type == TypeManager.double_type)
1206                                 ig.Emit (OpCodes.Stind_R8);
1207                         else if (type == TypeManager.byte_type || type == TypeManager.sbyte_type ||
1208                                  type == TypeManager.bool_type)
1209                                 ig.Emit (OpCodes.Stind_I1);
1210                         else if (type == TypeManager.intptr_type)
1211                                 ig.Emit (OpCodes.Stind_I);
1212                         else if (type.IsValueType)
1213                                 ig.Emit (OpCodes.Stobj, type);
1214                         else
1215                                 ig.Emit (OpCodes.Stind_Ref);
1216                 }
1217
1218                 //
1219                 // Returns the size of type `t' if known, otherwise, 0
1220                 //
1221                 public static int GetTypeSize (Type t)
1222                 {
1223                         t = TypeManager.TypeToCoreType (t);
1224                         if (t == TypeManager.int32_type ||
1225                             t == TypeManager.uint32_type ||
1226                             t == TypeManager.float_type)
1227                                 return 4;
1228                         else if (t == TypeManager.int64_type ||
1229                                  t == TypeManager.uint64_type ||
1230                                  t == TypeManager.double_type)
1231                                 return 8;
1232                         else if (t == TypeManager.byte_type ||
1233                                  t == TypeManager.sbyte_type ||
1234                                  t == TypeManager.bool_type)
1235                                 return 1;
1236                         else if (t == TypeManager.short_type ||
1237                                  t == TypeManager.char_type ||
1238                                  t == TypeManager.ushort_type)
1239                                 return 2;
1240                         else if (t == TypeManager.decimal_type)
1241                                 return 16;
1242                         else
1243                                 return 0;
1244                 }
1245
1246                 public static void Error_NegativeArrayIndex (Location loc)
1247                 {
1248                         Report.Error (248, loc, "Cannot create an array with a negative size");
1249                 }
1250
1251                 //
1252                 // Converts `source' to an int, uint, long or ulong.
1253                 //
1254                 public Expression ExpressionToArrayArgument (EmitContext ec, Expression source, Location loc)
1255                 {
1256                         Expression target;
1257
1258                         bool old_checked = ec.CheckState;
1259                         ec.CheckState = true;
1260
1261                         target = Convert.ImplicitConversion (ec, source, TypeManager.int32_type, loc);
1262                         if (target == null){
1263                                 target = Convert.ImplicitConversion (ec, source, TypeManager.uint32_type, loc);
1264                                 if (target == null){
1265                                         target = Convert.ImplicitConversion (ec, source, TypeManager.int64_type, loc);
1266                                         if (target == null){
1267                                                 target = Convert.ImplicitConversion (ec, source, TypeManager.uint64_type, loc);
1268                                                 if (target == null)
1269                                                         Convert.Error_CannotImplicitConversion (loc, source.Type, TypeManager.int32_type);
1270                                         }
1271                                 }
1272                         }
1273                         ec.CheckState = old_checked;
1274
1275                         //
1276                         // Only positive constants are allowed at compile time
1277                         //
1278                         if (target is Constant){
1279                                 if (target is IntConstant){
1280                                         if (((IntConstant) target).Value < 0){
1281                                                 Error_NegativeArrayIndex (loc);
1282                                                 return null;
1283                                         }
1284                                 }
1285
1286                                 if (target is LongConstant){
1287                                         if (((LongConstant) target).Value < 0){
1288                                                 Error_NegativeArrayIndex (loc);
1289                                                 return null;
1290                                         }
1291                                 }
1292
1293                         }
1294
1295                         return target;
1296                 }
1297
1298         }
1299
1300         /// <summary>
1301         ///   This is just a base class for expressions that can
1302         ///   appear on statements (invocations, object creation,
1303         ///   assignments, post/pre increment and decrement).  The idea
1304         ///   being that they would support an extra Emition interface that
1305         ///   does not leave a result on the stack.
1306         /// </summary>
1307         public abstract class ExpressionStatement : Expression {
1308
1309                 public virtual ExpressionStatement ResolveStatement (EmitContext ec)
1310                 {
1311                         Expression e = Resolve (ec);
1312                         if (e == null)
1313                                 return null;
1314
1315                         ExpressionStatement es = e as ExpressionStatement;
1316                         if (es == null)
1317                                 Error (201, "Only assignment, call, increment, decrement and new object " +
1318                                        "expressions can be used as a statement");
1319
1320                         return es;
1321                 }
1322
1323                 /// <summary>
1324                 ///   Requests the expression to be emitted in a `statement'
1325                 ///   context.  This means that no new value is left on the
1326                 ///   stack after invoking this method (constrasted with
1327                 ///   Emit that will always leave a value on the stack).
1328                 /// </summary>
1329                 public abstract void EmitStatement (EmitContext ec);
1330         }
1331
1332         /// <summary>
1333         ///   This kind of cast is used to encapsulate the child
1334         ///   whose type is child.Type into an expression that is
1335         ///   reported to return "return_type".  This is used to encapsulate
1336         ///   expressions which have compatible types, but need to be dealt
1337         ///   at higher levels with.
1338         ///
1339         ///   For example, a "byte" expression could be encapsulated in one
1340         ///   of these as an "unsigned int".  The type for the expression
1341         ///   would be "unsigned int".
1342         ///
1343         /// </summary>
1344         public class EmptyCast : Expression {
1345                 protected Expression child;
1346
1347                 public Expression Child {
1348                         get {
1349                                 return child;
1350                         }
1351                 }
1352
1353                 public EmptyCast (Expression child, Type return_type)
1354                 {
1355                         eclass = child.eclass;
1356                         type = return_type;
1357                         this.child = child;
1358                 }
1359
1360                 public override Expression DoResolve (EmitContext ec)
1361                 {
1362                         // This should never be invoked, we are born in fully
1363                         // initialized state.
1364
1365                         return this;
1366                 }
1367
1368                 public override void Emit (EmitContext ec)
1369                 {
1370                         child.Emit (ec);
1371                 }
1372         }
1373
1374         //
1375         // We need to special case this since an empty cast of
1376         // a NullLiteral is still a Constant
1377         //
1378         public class NullCast : Constant {
1379                 protected Expression child;
1380
1381                 public NullCast (Expression child, Type return_type)
1382                 {
1383                         eclass = child.eclass;
1384                         type = return_type;
1385                         this.child = child;
1386                 }
1387
1388                 override public string AsString ()
1389                 {
1390                         return "null";
1391                 }
1392
1393                 public override object GetValue ()
1394                 {
1395                         return null;
1396                 }
1397
1398                 public override Expression DoResolve (EmitContext ec)
1399                 {
1400                         // This should never be invoked, we are born in fully
1401                         // initialized state.
1402
1403                         return this;
1404                 }
1405
1406                 public override void Emit (EmitContext ec)
1407                 {
1408                         child.Emit (ec);
1409                 }
1410
1411                 public override bool IsNegative {
1412                         get {
1413                                 return false;
1414                         }
1415                 }
1416         }
1417
1418
1419         /// <summary>
1420         ///  This class is used to wrap literals which belong inside Enums
1421         /// </summary>
1422         public class EnumConstant : Constant {
1423                 public Constant Child;
1424
1425                 public EnumConstant (Constant child, Type enum_type)
1426                 {
1427                         eclass = child.eclass;
1428                         this.Child = child;
1429                         type = enum_type;
1430                 }
1431
1432                 public override Expression DoResolve (EmitContext ec)
1433                 {
1434                         // This should never be invoked, we are born in fully
1435                         // initialized state.
1436
1437                         return this;
1438                 }
1439
1440                 public override void Emit (EmitContext ec)
1441                 {
1442                         Child.Emit (ec);
1443                 }
1444
1445                 public override object GetValue ()
1446                 {
1447                         return Child.GetValue ();
1448                 }
1449
1450                 public object GetValueAsEnumType ()
1451                 {
1452                         return System.Enum.ToObject (type, Child.GetValue ());
1453                 }
1454
1455                 //
1456                 // Converts from one of the valid underlying types for an enumeration
1457                 // (int32, uint32, int64, uint64, short, ushort, byte, sbyte) to
1458                 // one of the internal compiler literals: Int/UInt/Long/ULong Literals.
1459                 //
1460                 public Constant WidenToCompilerConstant ()
1461                 {
1462                         Type t = TypeManager.EnumToUnderlying (Child.Type);
1463                         object v = ((Constant) Child).GetValue ();;
1464
1465                         if (t == TypeManager.int32_type)
1466                                 return new IntConstant ((int) v);
1467                         if (t == TypeManager.uint32_type)
1468                                 return new UIntConstant ((uint) v);
1469                         if (t == TypeManager.int64_type)
1470                                 return new LongConstant ((long) v);
1471                         if (t == TypeManager.uint64_type)
1472                                 return new ULongConstant ((ulong) v);
1473                         if (t == TypeManager.short_type)
1474                                 return new ShortConstant ((short) v);
1475                         if (t == TypeManager.ushort_type)
1476                                 return new UShortConstant ((ushort) v);
1477                         if (t == TypeManager.byte_type)
1478                                 return new ByteConstant ((byte) v);
1479                         if (t == TypeManager.sbyte_type)
1480                                 return new SByteConstant ((sbyte) v);
1481
1482                         throw new Exception ("Invalid enumeration underlying type: " + t);
1483                 }
1484
1485                 //
1486                 // Extracts the value in the enumeration on its native representation
1487                 //
1488                 public object GetPlainValue ()
1489                 {
1490                         Type t = TypeManager.EnumToUnderlying (Child.Type);
1491                         object v = ((Constant) Child).GetValue ();;
1492
1493                         if (t == TypeManager.int32_type)
1494                                 return (int) v;
1495                         if (t == TypeManager.uint32_type)
1496                                 return (uint) v;
1497                         if (t == TypeManager.int64_type)
1498                                 return (long) v;
1499                         if (t == TypeManager.uint64_type)
1500                                 return (ulong) v;
1501                         if (t == TypeManager.short_type)
1502                                 return (short) v;
1503                         if (t == TypeManager.ushort_type)
1504                                 return (ushort) v;
1505                         if (t == TypeManager.byte_type)
1506                                 return (byte) v;
1507                         if (t == TypeManager.sbyte_type)
1508                                 return (sbyte) v;
1509
1510                         return null;
1511                 }
1512
1513                 public override string AsString ()
1514                 {
1515                         return Child.AsString ();
1516                 }
1517
1518                 public override DoubleConstant ConvertToDouble ()
1519                 {
1520                         return Child.ConvertToDouble ();
1521                 }
1522
1523                 public override FloatConstant ConvertToFloat ()
1524                 {
1525                         return Child.ConvertToFloat ();
1526                 }
1527
1528                 public override ULongConstant ConvertToULong ()
1529                 {
1530                         return Child.ConvertToULong ();
1531                 }
1532
1533                 public override LongConstant ConvertToLong ()
1534                 {
1535                         return Child.ConvertToLong ();
1536                 }
1537
1538                 public override UIntConstant ConvertToUInt ()
1539                 {
1540                         return Child.ConvertToUInt ();
1541                 }
1542
1543                 public override IntConstant ConvertToInt ()
1544                 {
1545                         return Child.ConvertToInt ();
1546                 }
1547
1548                 public override bool IsZeroInteger {
1549                         get { return Child.IsZeroInteger; }
1550                 }
1551
1552                 public override bool IsNegative {
1553                         get {
1554                                 return Child.IsNegative;
1555                         }
1556                 }
1557         }
1558
1559         /// <summary>
1560         ///   This kind of cast is used to encapsulate Value Types in objects.
1561         ///
1562         ///   The effect of it is to box the value type emitted by the previous
1563         ///   operation.
1564         /// </summary>
1565         public class BoxedCast : EmptyCast {
1566
1567                 public BoxedCast (Expression expr)
1568                         : base (expr, TypeManager.object_type)
1569                 {
1570                         eclass = ExprClass.Value;
1571                 }
1572
1573                 public BoxedCast (Expression expr, Type target_type)
1574                         : base (expr, target_type)
1575                 {
1576                         eclass = ExprClass.Value;
1577                 }
1578
1579                 public override Expression DoResolve (EmitContext ec)
1580                 {
1581                         // This should never be invoked, we are born in fully
1582                         // initialized state.
1583
1584                         return this;
1585                 }
1586
1587                 public override void Emit (EmitContext ec)
1588                 {
1589                         base.Emit (ec);
1590
1591                         ec.ig.Emit (OpCodes.Box, child.Type);
1592                 }
1593         }
1594
1595         public class UnboxCast : EmptyCast {
1596                 public UnboxCast (Expression expr, Type return_type)
1597                         : base (expr, return_type)
1598                 {
1599                 }
1600
1601                 public override Expression DoResolve (EmitContext ec)
1602                 {
1603                         // This should never be invoked, we are born in fully
1604                         // initialized state.
1605
1606                         return this;
1607                 }
1608
1609                 public override void Emit (EmitContext ec)
1610                 {
1611                         Type t = type;
1612                         ILGenerator ig = ec.ig;
1613
1614                         base.Emit (ec);
1615                         ig.Emit (OpCodes.Unbox, t);
1616
1617                         LoadFromPtr (ig, t);
1618                 }
1619         }
1620
1621         /// <summary>
1622         ///   This is used to perform explicit numeric conversions.
1623         ///
1624         ///   Explicit numeric conversions might trigger exceptions in a checked
1625         ///   context, so they should generate the conv.ovf opcodes instead of
1626         ///   conv opcodes.
1627         /// </summary>
1628         public class ConvCast : EmptyCast {
1629                 public enum Mode : byte {
1630                         I1_U1, I1_U2, I1_U4, I1_U8, I1_CH,
1631                         U1_I1, U1_CH,
1632                         I2_I1, I2_U1, I2_U2, I2_U4, I2_U8, I2_CH,
1633                         U2_I1, U2_U1, U2_I2, U2_CH,
1634                         I4_I1, I4_U1, I4_I2, I4_U2, I4_U4, I4_U8, I4_CH,
1635                         U4_I1, U4_U1, U4_I2, U4_U2, U4_I4, U4_CH,
1636                         I8_I1, I8_U1, I8_I2, I8_U2, I8_I4, I8_U4, I8_U8, I8_CH,
1637                         U8_I1, U8_U1, U8_I2, U8_U2, U8_I4, U8_U4, U8_I8, U8_CH,
1638                         CH_I1, CH_U1, CH_I2,
1639                         R4_I1, R4_U1, R4_I2, R4_U2, R4_I4, R4_U4, R4_I8, R4_U8, R4_CH,
1640                         R8_I1, R8_U1, R8_I2, R8_U2, R8_I4, R8_U4, R8_I8, R8_U8, R8_CH, R8_R4
1641                 }
1642
1643                 Mode mode;
1644                 bool checked_state;
1645
1646                 public ConvCast (EmitContext ec, Expression child, Type return_type, Mode m)
1647                         : base (child, return_type)
1648                 {
1649                         checked_state = ec.CheckState;
1650                         mode = m;
1651                 }
1652
1653                 public override Expression DoResolve (EmitContext ec)
1654                 {
1655                         // This should never be invoked, we are born in fully
1656                         // initialized state.
1657
1658                         return this;
1659                 }
1660
1661                 public override string ToString ()
1662                 {
1663                         return String.Format ("ConvCast ({0}, {1})", mode, child);
1664                 }
1665
1666                 public override void Emit (EmitContext ec)
1667                 {
1668                         ILGenerator ig = ec.ig;
1669
1670                         base.Emit (ec);
1671
1672                         if (checked_state){
1673                                 switch (mode){
1674                                 case Mode.I1_U1: ig.Emit (OpCodes.Conv_Ovf_U1); break;
1675                                 case Mode.I1_U2: ig.Emit (OpCodes.Conv_Ovf_U2); break;
1676                                 case Mode.I1_U4: ig.Emit (OpCodes.Conv_Ovf_U4); break;
1677                                 case Mode.I1_U8: ig.Emit (OpCodes.Conv_Ovf_U8); break;
1678                                 case Mode.I1_CH: ig.Emit (OpCodes.Conv_Ovf_U2); break;
1679
1680                                 case Mode.U1_I1: ig.Emit (OpCodes.Conv_Ovf_I1_Un); break;
1681                                 case Mode.U1_CH: /* nothing */ break;
1682
1683                                 case Mode.I2_I1: ig.Emit (OpCodes.Conv_Ovf_I1); break;
1684                                 case Mode.I2_U1: ig.Emit (OpCodes.Conv_Ovf_U1); break;
1685                                 case Mode.I2_U2: ig.Emit (OpCodes.Conv_Ovf_U2); break;
1686                                 case Mode.I2_U4: ig.Emit (OpCodes.Conv_Ovf_U4); break;
1687                                 case Mode.I2_U8: ig.Emit (OpCodes.Conv_Ovf_U8); break;
1688                                 case Mode.I2_CH: ig.Emit (OpCodes.Conv_Ovf_U2); break;
1689
1690                                 case Mode.U2_I1: ig.Emit (OpCodes.Conv_Ovf_I1_Un); break;
1691                                 case Mode.U2_U1: ig.Emit (OpCodes.Conv_Ovf_U1_Un); break;
1692                                 case Mode.U2_I2: ig.Emit (OpCodes.Conv_Ovf_I2_Un); break;
1693                                 case Mode.U2_CH: /* nothing */ break;
1694
1695                                 case Mode.I4_I1: ig.Emit (OpCodes.Conv_Ovf_I1); break;
1696                                 case Mode.I4_U1: ig.Emit (OpCodes.Conv_Ovf_U1); break;
1697                                 case Mode.I4_I2: ig.Emit (OpCodes.Conv_Ovf_I2); break;
1698                                 case Mode.I4_U4: ig.Emit (OpCodes.Conv_Ovf_U4); break;
1699                                 case Mode.I4_U2: ig.Emit (OpCodes.Conv_Ovf_U2); break;
1700                                 case Mode.I4_U8: ig.Emit (OpCodes.Conv_Ovf_U8); break;
1701                                 case Mode.I4_CH: ig.Emit (OpCodes.Conv_Ovf_U2); break;
1702
1703                                 case Mode.U4_I1: ig.Emit (OpCodes.Conv_Ovf_I1_Un); break;
1704                                 case Mode.U4_U1: ig.Emit (OpCodes.Conv_Ovf_U1_Un); break;
1705                                 case Mode.U4_I2: ig.Emit (OpCodes.Conv_Ovf_I2_Un); break;
1706                                 case Mode.U4_U2: ig.Emit (OpCodes.Conv_Ovf_U2_Un); break;
1707                                 case Mode.U4_I4: ig.Emit (OpCodes.Conv_Ovf_I4_Un); break;
1708                                 case Mode.U4_CH: ig.Emit (OpCodes.Conv_Ovf_U2_Un); break;
1709
1710                                 case Mode.I8_I1: ig.Emit (OpCodes.Conv_Ovf_I1); break;
1711                                 case Mode.I8_U1: ig.Emit (OpCodes.Conv_Ovf_U1); break;
1712                                 case Mode.I8_I2: ig.Emit (OpCodes.Conv_Ovf_I2); break;
1713                                 case Mode.I8_U2: ig.Emit (OpCodes.Conv_Ovf_U2); break;
1714                                 case Mode.I8_I4: ig.Emit (OpCodes.Conv_Ovf_I4); break;
1715                                 case Mode.I8_U4: ig.Emit (OpCodes.Conv_Ovf_U4); break;
1716                                 case Mode.I8_U8: ig.Emit (OpCodes.Conv_Ovf_U8); break;
1717                                 case Mode.I8_CH: ig.Emit (OpCodes.Conv_Ovf_U2); break;
1718
1719                                 case Mode.U8_I1: ig.Emit (OpCodes.Conv_Ovf_I1_Un); break;
1720                                 case Mode.U8_U1: ig.Emit (OpCodes.Conv_Ovf_U1_Un); break;
1721                                 case Mode.U8_I2: ig.Emit (OpCodes.Conv_Ovf_I2_Un); break;
1722                                 case Mode.U8_U2: ig.Emit (OpCodes.Conv_Ovf_U2_Un); break;
1723                                 case Mode.U8_I4: ig.Emit (OpCodes.Conv_Ovf_I4_Un); break;
1724                                 case Mode.U8_U4: ig.Emit (OpCodes.Conv_Ovf_U4_Un); break;
1725                                 case Mode.U8_I8: ig.Emit (OpCodes.Conv_Ovf_I8_Un); break;
1726                                 case Mode.U8_CH: ig.Emit (OpCodes.Conv_Ovf_U2_Un); break;
1727
1728                                 case Mode.CH_I1: ig.Emit (OpCodes.Conv_Ovf_I1_Un); break;
1729                                 case Mode.CH_U1: ig.Emit (OpCodes.Conv_Ovf_U1_Un); break;
1730                                 case Mode.CH_I2: ig.Emit (OpCodes.Conv_Ovf_I2_Un); break;
1731
1732                                 case Mode.R4_I1: ig.Emit (OpCodes.Conv_Ovf_I1); break;
1733                                 case Mode.R4_U1: ig.Emit (OpCodes.Conv_Ovf_U1); break;
1734                                 case Mode.R4_I2: ig.Emit (OpCodes.Conv_Ovf_I2); break;
1735                                 case Mode.R4_U2: ig.Emit (OpCodes.Conv_Ovf_U2); break;
1736                                 case Mode.R4_I4: ig.Emit (OpCodes.Conv_Ovf_I4); break;
1737                                 case Mode.R4_U4: ig.Emit (OpCodes.Conv_Ovf_U4); break;
1738                                 case Mode.R4_I8: ig.Emit (OpCodes.Conv_Ovf_I8); break;
1739                                 case Mode.R4_U8: ig.Emit (OpCodes.Conv_Ovf_U8); break;
1740                                 case Mode.R4_CH: ig.Emit (OpCodes.Conv_Ovf_U2); break;
1741
1742                                 case Mode.R8_I1: ig.Emit (OpCodes.Conv_Ovf_I1); break;
1743                                 case Mode.R8_U1: ig.Emit (OpCodes.Conv_Ovf_U1); break;
1744                                 case Mode.R8_I2: ig.Emit (OpCodes.Conv_Ovf_I2); break;
1745                                 case Mode.R8_U2: ig.Emit (OpCodes.Conv_Ovf_U2); break;
1746                                 case Mode.R8_I4: ig.Emit (OpCodes.Conv_Ovf_I4); break;
1747                                 case Mode.R8_U4: ig.Emit (OpCodes.Conv_Ovf_U4); break;
1748                                 case Mode.R8_I8: ig.Emit (OpCodes.Conv_Ovf_I8); break;
1749                                 case Mode.R8_U8: ig.Emit (OpCodes.Conv_Ovf_U8); break;
1750                                 case Mode.R8_CH: ig.Emit (OpCodes.Conv_Ovf_U2); break;
1751                                 case Mode.R8_R4: ig.Emit (OpCodes.Conv_R4); break;
1752                                 }
1753                         } else {
1754                                 switch (mode){
1755                                 case Mode.I1_U1: ig.Emit (OpCodes.Conv_U1); break;
1756                                 case Mode.I1_U2: ig.Emit (OpCodes.Conv_U2); break;
1757                                 case Mode.I1_U4: ig.Emit (OpCodes.Conv_U4); break;
1758                                 case Mode.I1_U8: ig.Emit (OpCodes.Conv_I8); break;
1759                                 case Mode.I1_CH: ig.Emit (OpCodes.Conv_U2); break;
1760
1761                                 case Mode.U1_I1: ig.Emit (OpCodes.Conv_I1); break;
1762                                 case Mode.U1_CH: ig.Emit (OpCodes.Conv_U2); break;
1763
1764                                 case Mode.I2_I1: ig.Emit (OpCodes.Conv_I1); break;
1765                                 case Mode.I2_U1: ig.Emit (OpCodes.Conv_U1); break;
1766                                 case Mode.I2_U2: ig.Emit (OpCodes.Conv_U2); break;
1767                                 case Mode.I2_U4: ig.Emit (OpCodes.Conv_U4); break;
1768                                 case Mode.I2_U8: ig.Emit (OpCodes.Conv_I8); break;
1769                                 case Mode.I2_CH: ig.Emit (OpCodes.Conv_U2); break;
1770
1771                                 case Mode.U2_I1: ig.Emit (OpCodes.Conv_I1); break;
1772                                 case Mode.U2_U1: ig.Emit (OpCodes.Conv_U1); break;
1773                                 case Mode.U2_I2: ig.Emit (OpCodes.Conv_I2); break;
1774                                 case Mode.U2_CH: /* nothing */ break;
1775
1776                                 case Mode.I4_I1: ig.Emit (OpCodes.Conv_I1); break;
1777                                 case Mode.I4_U1: ig.Emit (OpCodes.Conv_U1); break;
1778                                 case Mode.I4_I2: ig.Emit (OpCodes.Conv_I2); break;
1779                                 case Mode.I4_U4: /* nothing */ break;
1780                                 case Mode.I4_U2: ig.Emit (OpCodes.Conv_U2); break;
1781                                 case Mode.I4_U8: ig.Emit (OpCodes.Conv_I8); break;
1782                                 case Mode.I4_CH: ig.Emit (OpCodes.Conv_U2); break;
1783
1784                                 case Mode.U4_I1: ig.Emit (OpCodes.Conv_I1); break;
1785                                 case Mode.U4_U1: ig.Emit (OpCodes.Conv_U1); break;
1786                                 case Mode.U4_I2: ig.Emit (OpCodes.Conv_I2); break;
1787                                 case Mode.U4_U2: ig.Emit (OpCodes.Conv_U2); break;
1788                                 case Mode.U4_I4: /* nothing */ break;
1789                                 case Mode.U4_CH: ig.Emit (OpCodes.Conv_U2); break;
1790
1791                                 case Mode.I8_I1: ig.Emit (OpCodes.Conv_I1); break;
1792                                 case Mode.I8_U1: ig.Emit (OpCodes.Conv_U1); break;
1793                                 case Mode.I8_I2: ig.Emit (OpCodes.Conv_I2); break;
1794                                 case Mode.I8_U2: ig.Emit (OpCodes.Conv_U2); break;
1795                                 case Mode.I8_I4: ig.Emit (OpCodes.Conv_I4); break;
1796                                 case Mode.I8_U4: ig.Emit (OpCodes.Conv_U4); break;
1797                                 case Mode.I8_U8: /* nothing */ break;
1798                                 case Mode.I8_CH: ig.Emit (OpCodes.Conv_U2); break;
1799
1800                                 case Mode.U8_I1: ig.Emit (OpCodes.Conv_I1); break;
1801                                 case Mode.U8_U1: ig.Emit (OpCodes.Conv_U1); break;
1802                                 case Mode.U8_I2: ig.Emit (OpCodes.Conv_I2); break;
1803                                 case Mode.U8_U2: ig.Emit (OpCodes.Conv_U2); break;
1804                                 case Mode.U8_I4: ig.Emit (OpCodes.Conv_I4); break;
1805                                 case Mode.U8_U4: ig.Emit (OpCodes.Conv_U4); break;
1806                                 case Mode.U8_I8: /* nothing */ break;
1807                                 case Mode.U8_CH: ig.Emit (OpCodes.Conv_U2); break;
1808
1809                                 case Mode.CH_I1: ig.Emit (OpCodes.Conv_I1); break;
1810                                 case Mode.CH_U1: ig.Emit (OpCodes.Conv_U1); break;
1811                                 case Mode.CH_I2: ig.Emit (OpCodes.Conv_I2); break;
1812
1813                                 case Mode.R4_I1: ig.Emit (OpCodes.Conv_I1); break;
1814                                 case Mode.R4_U1: ig.Emit (OpCodes.Conv_U1); break;
1815                                 case Mode.R4_I2: ig.Emit (OpCodes.Conv_I2); break;
1816                                 case Mode.R4_U2: ig.Emit (OpCodes.Conv_U2); break;
1817                                 case Mode.R4_I4: ig.Emit (OpCodes.Conv_I4); break;
1818                                 case Mode.R4_U4: ig.Emit (OpCodes.Conv_U4); break;
1819                                 case Mode.R4_I8: ig.Emit (OpCodes.Conv_I8); break;
1820                                 case Mode.R4_U8: ig.Emit (OpCodes.Conv_U8); break;
1821                                 case Mode.R4_CH: ig.Emit (OpCodes.Conv_U2); break;
1822
1823                                 case Mode.R8_I1: ig.Emit (OpCodes.Conv_I1); break;
1824                                 case Mode.R8_U1: ig.Emit (OpCodes.Conv_U1); break;
1825                                 case Mode.R8_I2: ig.Emit (OpCodes.Conv_I2); break;
1826                                 case Mode.R8_U2: ig.Emit (OpCodes.Conv_U2); break;
1827                                 case Mode.R8_I4: ig.Emit (OpCodes.Conv_I4); break;
1828                                 case Mode.R8_U4: ig.Emit (OpCodes.Conv_U4); break;
1829                                 case Mode.R8_I8: ig.Emit (OpCodes.Conv_I8); break;
1830                                 case Mode.R8_U8: ig.Emit (OpCodes.Conv_U8); break;
1831                                 case Mode.R8_CH: ig.Emit (OpCodes.Conv_U2); break;
1832                                 case Mode.R8_R4: ig.Emit (OpCodes.Conv_R4); break;
1833                                 }
1834                         }
1835                 }
1836         }
1837
1838         public class OpcodeCast : EmptyCast {
1839                 OpCode op, op2;
1840                 bool second_valid;
1841
1842                 public OpcodeCast (Expression child, Type return_type, OpCode op)
1843                         : base (child, return_type)
1844
1845                 {
1846                         this.op = op;
1847                         second_valid = false;
1848                 }
1849
1850                 public OpcodeCast (Expression child, Type return_type, OpCode op, OpCode op2)
1851                         : base (child, return_type)
1852
1853                 {
1854                         this.op = op;
1855                         this.op2 = op2;
1856                         second_valid = true;
1857                 }
1858
1859                 public override Expression DoResolve (EmitContext ec)
1860                 {
1861                         // This should never be invoked, we are born in fully
1862                         // initialized state.
1863
1864                         return this;
1865                 }
1866
1867                 public override void Emit (EmitContext ec)
1868                 {
1869                         base.Emit (ec);
1870                         ec.ig.Emit (op);
1871
1872                         if (second_valid)
1873                                 ec.ig.Emit (op2);
1874                 }
1875         }
1876
1877         /// <summary>
1878         ///   This kind of cast is used to encapsulate a child and cast it
1879         ///   to the class requested
1880         /// </summary>
1881         public class ClassCast : EmptyCast {
1882                 public ClassCast (Expression child, Type return_type)
1883                         : base (child, return_type)
1884
1885                 {
1886                 }
1887
1888                 public override Expression DoResolve (EmitContext ec)
1889                 {
1890                         // This should never be invoked, we are born in fully
1891                         // initialized state.
1892
1893                         return this;
1894                 }
1895
1896                 public override void Emit (EmitContext ec)
1897                 {
1898                         base.Emit (ec);
1899
1900                         ec.ig.Emit (OpCodes.Castclass, type);
1901                 }
1902
1903         }
1904
1905         /// <summary>
1906         ///   SimpleName expressions are initially formed of a single
1907         ///   word and it only happens at the beginning of the expression.
1908         /// </summary>
1909         ///
1910         /// <remarks>
1911         ///   The expression will try to be bound to a Field, a Method
1912         ///   group or a Property.  If those fail we pass the name to our
1913         ///   caller and the SimpleName is compounded to perform a type
1914         ///   lookup.  The idea behind this process is that we want to avoid
1915         ///   creating a namespace map from the assemblies, as that requires
1916         ///   the GetExportedTypes function to be called and a hashtable to
1917         ///   be constructed which reduces startup time.  If later we find
1918         ///   that this is slower, we should create a `NamespaceExpr' expression
1919         ///   that fully participates in the resolution process.
1920         ///
1921         ///   For example `System.Console.WriteLine' is decomposed into
1922         ///   MemberAccess (MemberAccess (SimpleName ("System"), "Console"), "WriteLine")
1923         ///
1924         ///   The first SimpleName wont produce a match on its own, so it will
1925         ///   be turned into:
1926         ///   MemberAccess (SimpleName ("System.Console"), "WriteLine").
1927         ///
1928         ///   System.Console will produce a TypeExpr match.
1929         ///
1930         ///   The downside of this is that we might be hitting `LookupType' too many
1931         ///   times with this scheme.
1932         /// </remarks>
1933         public class SimpleName : Expression {
1934                 public string Name;
1935
1936                 //
1937                 // If true, then we are a simple name, not composed with a ".
1938                 //
1939                 bool is_base;
1940
1941                 public SimpleName (string a, string b, Location l)
1942                 {
1943                         Name = String.Concat (a, ".", b);
1944                         loc = l;
1945                         is_base = false;
1946                 }
1947
1948                 public SimpleName (string name, Location l)
1949                 {
1950                         Name = name;
1951                         loc = l;
1952                         is_base = true;
1953                 }
1954
1955                 public static void Error_ObjectRefRequired (EmitContext ec, Location l, string name)
1956                 {
1957                         if (ec.IsFieldInitializer)
1958                                 Report.Error (
1959                                         236, l,
1960                                         "A field initializer cannot reference the non-static field, " +
1961                                         "method or property `"+name+"'");
1962                         else
1963                                 Report.Error (
1964                                         120, l,
1965                                         "An object reference is required " +
1966                                         "for the non-static field `"+name+"'");
1967                 }
1968
1969                 //
1970                 // Checks whether we are trying to access an instance
1971                 // property, method or field from a static body.
1972                 //
1973                 Expression MemberStaticCheck (EmitContext ec, Expression e)
1974                 {
1975                         if (e is IMemberExpr){
1976                                 IMemberExpr member = (IMemberExpr) e;
1977
1978                                 if (!member.IsStatic){
1979                                         Error_ObjectRefRequired (ec, loc, Name);
1980                                         return null;
1981                                 }
1982                         }
1983
1984                         return e;
1985                 }
1986
1987                 public override Expression DoResolve (EmitContext ec)
1988                 {
1989                         return SimpleNameResolve (ec, null, false, false);
1990                 }
1991
1992                 public override Expression DoResolveLValue (EmitContext ec, Expression right_side)
1993                 {
1994                         return SimpleNameResolve (ec, right_side, false, false);
1995                 }
1996
1997
1998                 public Expression DoResolveAllowStatic (EmitContext ec, bool intermediate)
1999                 {
2000                         return SimpleNameResolve (ec, null, true, intermediate);
2001                 }
2002
2003                 public override Expression ResolveAsTypeStep (EmitContext ec)
2004                 {
2005                         DeclSpace ds = ec.DeclSpace;
2006                         NamespaceEntry ns = ds.NamespaceEntry;
2007                         Type t;
2008                         string alias_value;
2009
2010                         //
2011                         // Since we are cheating: we only do the Alias lookup for
2012                         // namespaces if the name does not include any dots in it
2013                         //
2014                         if (ns != null && is_base)
2015                                 alias_value = ns.LookupAlias (Name);
2016                         else
2017                                 alias_value = null;
2018
2019                         if (ec.ResolvingTypeTree){
2020                                 int errors = Report.Errors;
2021                                 Type dt = ds.FindType (loc, Name);
2022
2023                                 if (Report.Errors != errors)
2024                                         return null;
2025
2026                                 if (dt != null)
2027                                         return new TypeExpression (dt, loc);
2028
2029                                 if (alias_value != null){
2030                                         if ((t = RootContext.LookupType (ds, alias_value, true, loc)) != null)
2031                                                 return new TypeExpression (t, loc);
2032                                 }
2033                         }
2034
2035                         if ((t = RootContext.LookupType (ds, Name, true, loc)) != null)
2036                                 return new TypeExpression (t, loc);
2037
2038                         if (alias_value != null) {
2039                                 if ((t = RootContext.LookupType (ds, alias_value, true, loc)) != null)
2040                                         return new TypeExpression (t, loc);
2041
2042                                 // we have alias value, but it isn't Type, so try if it's namespace
2043                                 return new SimpleName (alias_value, loc);
2044                         }
2045
2046                         // No match, maybe our parent can compose us
2047                         // into something meaningful.
2048                         return this;
2049                 }
2050
2051                 Expression SimpleNameResolve (EmitContext ec, Expression right_side,
2052                                               bool allow_static, bool intermediate)
2053                 {
2054                         Expression e = DoSimpleNameResolve (ec, right_side, allow_static, intermediate);
2055                         if (e == null)
2056                                 return null;
2057
2058                         Block current_block = ec.CurrentBlock;
2059                         if (current_block != null){
2060                                 //LocalInfo vi = current_block.GetLocalInfo (Name);
2061                                 if (is_base &&
2062                                     current_block.IsVariableNameUsedInChildBlock(Name)) {
2063                                         Report.Error (135, Location,
2064                                                       "'{0}' has a different meaning in a " +
2065                                                       "child block", Name);
2066                                         return null;
2067                                 }
2068                         }
2069
2070                         return e;
2071                 }
2072
2073                 /// <remarks>
2074                 ///   7.5.2: Simple Names.
2075                 ///
2076                 ///   Local Variables and Parameters are handled at
2077                 ///   parse time, so they never occur as SimpleNames.
2078                 ///
2079                 ///   The `allow_static' flag is used by MemberAccess only
2080                 ///   and it is used to inform us that it is ok for us to
2081                 ///   avoid the static check, because MemberAccess might end
2082                 ///   up resolving the Name as a Type name and the access as
2083                 ///   a static type access.
2084                 ///
2085                 ///   ie: Type Type; .... { Type.GetType (""); }
2086                 ///
2087                 ///   Type is both an instance variable and a Type;  Type.GetType
2088                 ///   is the static method not an instance method of type.
2089                 /// </remarks>
2090                 Expression DoSimpleNameResolve (EmitContext ec, Expression right_side, bool allow_static, bool intermediate)
2091                 {
2092                         Expression e = null;
2093
2094                         //
2095                         // Stage 1: Performed by the parser (binding to locals or parameters).
2096                         //
2097                         Block current_block = ec.CurrentBlock;
2098                         if (current_block != null){
2099                                 LocalInfo vi = current_block.GetLocalInfo (Name);
2100                                 if (vi != null){
2101                                         Expression var;
2102
2103                                         var = new LocalVariableReference (ec.CurrentBlock, Name, loc);
2104
2105                                         if (right_side != null)
2106                                                 return var.ResolveLValue (ec, right_side);
2107                                         else
2108                                                 return var.Resolve (ec);
2109                                 }
2110
2111                                 ParameterReference pref = current_block.GetParameterReference (Name, loc);
2112                                 if (pref != null) {
2113                                         if (right_side != null)
2114                                                 return pref.ResolveLValue (ec, right_side);
2115                                         else
2116                                                 return pref.Resolve (ec);
2117                                 }
2118                         }
2119
2120                         //
2121                         // Stage 2: Lookup members
2122                         //
2123
2124                         DeclSpace lookup_ds = ec.DeclSpace;
2125                         do {
2126                                 if (lookup_ds.TypeBuilder == null)
2127                                         break;
2128
2129                                 e = MemberLookup (ec, lookup_ds.TypeBuilder, Name, loc);
2130                                 if (e != null)
2131                                         break;
2132
2133                                 lookup_ds =lookup_ds.Parent;
2134                         } while (lookup_ds != null);
2135
2136                         if (e == null && ec.ContainerType != null)
2137                                 e = MemberLookup (ec, ec.ContainerType, Name, loc);
2138
2139                         if (e == null) {
2140                                 //
2141                                 // Since we are cheating (is_base is our hint
2142                                 // that we are the beginning of the name): we
2143                                 // only do the Alias lookup for namespaces if
2144                                 // the name does not include any dots in it
2145                                 //
2146                                 NamespaceEntry ns = ec.DeclSpace.NamespaceEntry;
2147                                 if (is_base && ns != null){
2148                                         string alias_value = ns.LookupAlias (Name);
2149                                         if (alias_value != null){
2150                                                 Name = alias_value;
2151                                                 Type t;
2152
2153                                                 if ((t = TypeManager.LookupType (Name)) != null)
2154                                                         return new TypeExpression (t, loc);
2155
2156                                                 // No match, maybe our parent can compose us
2157                                                 // into something meaningful.
2158                                                 return this;
2159                                         }
2160                                 }
2161
2162                                 return ResolveAsTypeStep (ec);
2163                         }
2164
2165                         if (e is TypeExpr)
2166                                 return e;
2167
2168                         if (e is IMemberExpr) {
2169                                 e = MemberAccess.ResolveMemberAccess (ec, e, null, loc, this);
2170                                 if (e == null)
2171                                         return null;
2172
2173                                 IMemberExpr me = e as IMemberExpr;
2174                                 if (me == null)
2175                                         return e;
2176
2177                                 // This fails if ResolveMemberAccess() was unable to decide whether
2178                                 // it's a field or a type of the same name.
2179
2180                                 if (!me.IsStatic && (me.InstanceExpression == null))
2181                                         return e;
2182
2183                                 if (!me.IsStatic &&
2184                                     TypeManager.IsSubclassOrNestedChildOf (me.InstanceExpression.Type, me.DeclaringType) &&
2185                                     me.InstanceExpression.Type != me.DeclaringType &&
2186                                     !me.InstanceExpression.Type.IsSubclassOf (me.DeclaringType) &&
2187                                     (!intermediate || !MemberAccess.IdenticalNameAndTypeName (ec, this, e, loc))) {
2188                                         Error (38, "Cannot access nonstatic member `" + me.Name + "' of " +
2189                                                "outer type `" + me.DeclaringType + "' via nested type `" +
2190                                                me.InstanceExpression.Type + "'");
2191                                         return null;
2192                                 }
2193
2194                                 return (right_side != null)
2195                                         ? e.DoResolveLValue (ec, right_side)
2196                                         : e.DoResolve (ec);
2197                         }
2198
2199                         if (ec.IsStatic || ec.IsFieldInitializer){
2200                                 if (allow_static)
2201                                         return e;
2202
2203                                 return MemberStaticCheck (ec, e);
2204                         } else
2205                                 return e;
2206                 }
2207
2208                 public override void Emit (EmitContext ec)
2209                 {
2210                         //
2211                         // If this is ever reached, then we failed to
2212                         // find the name as a namespace
2213                         //
2214
2215                         Error (103, "The name `" + Name +
2216                                "' does not exist in the class `" +
2217                                ec.DeclSpace.Name + "'");
2218                 }
2219
2220                 public override string ToString ()
2221                 {
2222                         return Name;
2223                 }
2224         }
2225
2226         /// <summary>
2227         ///   Fully resolved expression that evaluates to a type
2228         /// </summary>
2229         public abstract class TypeExpr : Expression {
2230                 override public Expression ResolveAsTypeStep (EmitContext ec)
2231                 {
2232                         TypeExpr t = DoResolveAsTypeStep (ec);
2233                         if (t == null)
2234                                 return null;
2235
2236                         eclass = ExprClass.Type;
2237                         return t;
2238                 }
2239
2240                 override public Expression DoResolve (EmitContext ec)
2241                 {
2242                         return ResolveAsTypeTerminal (ec, false);
2243                 }
2244
2245                 override public void Emit (EmitContext ec)
2246                 {
2247                         throw new Exception ("Should never be called");
2248                 }
2249
2250                 public virtual bool CheckAccessLevel (DeclSpace ds)
2251                 {
2252                         return ds.CheckAccessLevel (Type);
2253                 }
2254
2255                 public virtual bool AsAccessible (DeclSpace ds, int flags)
2256                 {
2257                         return ds.AsAccessible (Type, flags);
2258                 }
2259
2260                 public virtual bool IsClass {
2261                         get { return Type.IsClass; }
2262                 }
2263
2264                 public virtual bool IsValueType {
2265                         get { return Type.IsValueType; }
2266                 }
2267
2268                 public virtual bool IsInterface {
2269                         get { return Type.IsInterface; }
2270                 }
2271
2272                 public virtual bool IsSealed {
2273                         get { return Type.IsSealed; }
2274                 }
2275
2276                 public virtual bool CanInheritFrom ()
2277                 {
2278                         if (Type == TypeManager.enum_type ||
2279                             (Type == TypeManager.value_type && RootContext.StdLib) ||
2280                             Type == TypeManager.multicast_delegate_type ||
2281                             Type == TypeManager.delegate_type ||
2282                             Type == TypeManager.array_type)
2283                                 return false;
2284
2285                         return true;
2286                 }
2287
2288                 public virtual bool IsAttribute {
2289                         get {
2290                                 return Type == TypeManager.attribute_type ||
2291                                         Type.IsSubclassOf (TypeManager.attribute_type);
2292                         }
2293                 }
2294
2295                 public abstract TypeExpr DoResolveAsTypeStep (EmitContext ec);
2296
2297                 public virtual Type ResolveType (EmitContext ec)
2298                 {
2299                         TypeExpr t = ResolveAsTypeTerminal (ec, false);
2300                         if (t == null)
2301                                 return null;
2302
2303                         return t.Type;
2304                 }
2305
2306                 public abstract string Name {
2307                         get;
2308                 }
2309
2310                 public override bool Equals (object obj)
2311                 {
2312                         TypeExpr tobj = obj as TypeExpr;
2313                         if (tobj == null)
2314                                 return false;
2315
2316                         return Type == tobj.Type;
2317                 }
2318
2319                 public override int GetHashCode ()
2320                 {
2321                         return Type.GetHashCode ();
2322                 }
2323
2324                 public override string ToString ()
2325                 {
2326                         return Name;
2327                 }
2328         }
2329
2330         public class TypeExpression : TypeExpr {
2331                 public TypeExpression (Type t, Location l)
2332                 {
2333                         Type = t;
2334                         eclass = ExprClass.Type;
2335                         loc = l;
2336                 }
2337
2338                 public override TypeExpr DoResolveAsTypeStep (EmitContext ec)
2339                 {
2340                         return this;
2341                 }
2342
2343                 public override string Name {
2344                         get {
2345                                 return Type.ToString ();
2346                         }
2347                 }
2348         }
2349
2350         /// <summary>
2351         ///   Used to create types from a fully qualified name.  These are just used
2352         ///   by the parser to setup the core types.  A TypeLookupExpression is always
2353         ///   classified as a type.
2354         /// </summary>
2355         public class TypeLookupExpression : TypeExpr {
2356                 string name;
2357
2358                 public TypeLookupExpression (string name)
2359                 {
2360                         this.name = name;
2361                 }
2362
2363                 public override TypeExpr DoResolveAsTypeStep (EmitContext ec)
2364                 {
2365                         if (type == null)
2366                                 type = RootContext.LookupType (ec.DeclSpace, name, false, Location.Null);
2367                         return this;
2368                 }
2369
2370                 public override string Name {
2371                         get {
2372                                 return name;
2373                         }
2374                 }
2375         }
2376
2377         /// <summary>
2378         ///   MethodGroup Expression.
2379         ///
2380         ///   This is a fully resolved expression that evaluates to a type
2381         /// </summary>
2382         public class MethodGroupExpr : Expression, IMemberExpr {
2383                 public MethodBase [] Methods;
2384                 Expression instance_expression = null;
2385                 bool is_explicit_impl = false;
2386                 bool identical_type_name = false;
2387                 bool is_base;
2388
2389                 public MethodGroupExpr (MemberInfo [] mi, Location l)
2390                 {
2391                         Methods = new MethodBase [mi.Length];
2392                         mi.CopyTo (Methods, 0);
2393                         eclass = ExprClass.MethodGroup;
2394                         type = TypeManager.object_type;
2395                         loc = l;
2396                 }
2397
2398                 public MethodGroupExpr (ArrayList list, Location l)
2399                 {
2400                         Methods = new MethodBase [list.Count];
2401
2402                         try {
2403                                 list.CopyTo (Methods, 0);
2404                         } catch {
2405                                 foreach (MemberInfo m in list){
2406                                         if (!(m is MethodBase)){
2407                                                 Console.WriteLine ("Name " + m.Name);
2408                                                 Console.WriteLine ("Found a: " + m.GetType ().FullName);
2409                                         }
2410                                 }
2411                                 throw;
2412                         }
2413
2414                         loc = l;
2415                         eclass = ExprClass.MethodGroup;
2416                         type = TypeManager.object_type;
2417                 }
2418
2419                 public Type DeclaringType {
2420                         get {
2421                                 //
2422                                 // The methods are arranged in this order:
2423                                 // derived type -> base type
2424                                 //
2425                                 return Methods [0].DeclaringType;
2426                         }
2427                 }
2428
2429                 //
2430                 // `A method group may have associated an instance expression'
2431                 //
2432                 public Expression InstanceExpression {
2433                         get {
2434                                 return instance_expression;
2435                         }
2436
2437                         set {
2438                                 instance_expression = value;
2439                         }
2440                 }
2441
2442                 public bool IsExplicitImpl {
2443                         get {
2444                                 return is_explicit_impl;
2445                         }
2446
2447                         set {
2448                                 is_explicit_impl = value;
2449                         }
2450                 }
2451
2452                 public bool IdenticalTypeName {
2453                         get {
2454                                 return identical_type_name;
2455                         }
2456
2457                         set {
2458                                 identical_type_name = value;
2459                         }
2460                 }
2461
2462                 public bool IsBase {
2463                         get {
2464                                 return is_base;
2465                         }
2466                         set {
2467                                 is_base = value;
2468                         }
2469                 }
2470
2471                 public string Name {
2472                         get {
2473                                 return Methods [0].Name;
2474                         }
2475                 }
2476
2477                 public bool IsInstance {
2478                         get {
2479                                 foreach (MethodBase mb in Methods)
2480                                         if (!mb.IsStatic)
2481                                                 return true;
2482
2483                                 return false;
2484                         }
2485                 }
2486
2487                 public bool IsStatic {
2488                         get {
2489                                 foreach (MethodBase mb in Methods)
2490                                         if (mb.IsStatic)
2491                                                 return true;
2492
2493                                 return false;
2494                         }
2495                 }
2496
2497                 override public Expression DoResolve (EmitContext ec)
2498                 {
2499                         if (!IsInstance)
2500                                 instance_expression = null;
2501
2502                         if (instance_expression != null) {
2503                                 instance_expression = instance_expression.DoResolve (ec);
2504                                 if (instance_expression == null)
2505                                         return null;
2506                         }
2507
2508                         return this;
2509                 }
2510
2511                 public void ReportUsageError ()
2512                 {
2513                         Report.Error (654, loc, "Method `" + DeclaringType + "." +
2514                                       Name + "()' is referenced without parentheses");
2515                 }
2516
2517                 override public void Emit (EmitContext ec)
2518                 {
2519                         ReportUsageError ();
2520                 }
2521
2522                 bool RemoveMethods (bool keep_static)
2523                 {
2524                         ArrayList smethods = new ArrayList ();
2525
2526                         foreach (MethodBase mb in Methods){
2527                                 if (mb.IsStatic == keep_static)
2528                                         smethods.Add (mb);
2529                         }
2530
2531                         if (smethods.Count == 0)
2532                                 return false;
2533
2534                         Methods = new MethodBase [smethods.Count];
2535                         smethods.CopyTo (Methods, 0);
2536
2537                         return true;
2538                 }
2539
2540                 /// <summary>
2541                 ///   Removes any instance methods from the MethodGroup, returns
2542                 ///   false if the resulting set is empty.
2543                 /// </summary>
2544                 public bool RemoveInstanceMethods ()
2545                 {
2546                         return RemoveMethods (true);
2547                 }
2548
2549                 /// <summary>
2550                 ///   Removes any static methods from the MethodGroup, returns
2551                 ///   false if the resulting set is empty.
2552                 /// </summary>
2553                 public bool RemoveStaticMethods ()
2554                 {
2555                         return RemoveMethods (false);
2556                 }
2557         }
2558
2559         /// <summary>
2560         ///   Fully resolved expression that evaluates to a Field
2561         /// </summary>
2562         public class FieldExpr : Expression, IAssignMethod, IMemoryLocation, IMemberExpr, IVariable {
2563                 public readonly FieldInfo FieldInfo;
2564                 Expression instance_expr;
2565                 VariableInfo variable_info;
2566
2567                 LocalTemporary temp;
2568                 bool prepared;
2569
2570                 public FieldExpr (FieldInfo fi, Location l)
2571                 {
2572                         FieldInfo = fi;
2573                         eclass = ExprClass.Variable;
2574                         type = fi.FieldType;
2575                         loc = l;
2576                 }
2577
2578                 public string Name {
2579                         get {
2580                                 return FieldInfo.Name;
2581                         }
2582                 }
2583
2584                 public bool IsInstance {
2585                         get {
2586                                 return !FieldInfo.IsStatic;
2587                         }
2588                 }
2589
2590                 public bool IsStatic {
2591                         get {
2592                                 return FieldInfo.IsStatic;
2593                         }
2594                 }
2595
2596                 public Type DeclaringType {
2597                         get {
2598                                 return FieldInfo.DeclaringType;
2599                         }
2600                 }
2601
2602                 public Expression InstanceExpression {
2603                         get {
2604                                 return instance_expr;
2605                         }
2606
2607                         set {
2608                                 instance_expr = value;
2609                         }
2610                 }
2611
2612                 public VariableInfo VariableInfo {
2613                         get {
2614                                 return variable_info;
2615                         }
2616                 }
2617
2618                 override public Expression DoResolve (EmitContext ec)
2619                 {
2620                         if (!FieldInfo.IsStatic){
2621                                 if (instance_expr == null){
2622                                         //
2623                                         // This can happen when referencing an instance field using
2624                                         // a fully qualified type expression: TypeName.InstanceField = xxx
2625                                         //
2626                                         SimpleName.Error_ObjectRefRequired (ec, loc, FieldInfo.Name);
2627                                         return null;
2628                                 }
2629
2630                                 // Resolve the field's instance expression while flow analysis is turned
2631                                 // off: when accessing a field "a.b", we must check whether the field
2632                                 // "a.b" is initialized, not whether the whole struct "a" is initialized.
2633                                 instance_expr = instance_expr.Resolve (ec, ResolveFlags.VariableOrValue |
2634                                                                        ResolveFlags.DisableFlowAnalysis);
2635                                 if (instance_expr == null)
2636                                         return null;
2637                         }
2638
2639                         ObsoleteAttribute oa;
2640                         FieldBase f = TypeManager.GetField (FieldInfo);
2641                         if (f != null) {
2642                                 oa = f.GetObsoleteAttribute (f.Parent);
2643                                 if (oa != null)
2644                                         AttributeTester.Report_ObsoleteMessage (oa, f.GetSignatureForError (), loc);
2645
2646                         // To be sure that type is external because we do not register generated fields
2647                         } else if (!(FieldInfo.DeclaringType is TypeBuilder)) {
2648                                 oa = AttributeTester.GetMemberObsoleteAttribute (FieldInfo);
2649                                 if (oa != null)
2650                                         AttributeTester.Report_ObsoleteMessage (oa, TypeManager.GetFullNameSignature (FieldInfo), loc);
2651                         }
2652
2653                         if (ec.CurrentAnonymousMethod != null){
2654                                 if (!FieldInfo.IsStatic){
2655                                         if (ec.TypeContainer is Struct){
2656                                                 Report.Error (1673, loc, "Can not reference instance variables in anonymous methods hosted in structs");
2657                                                 return null;
2658                                         }
2659                                         ec.CaptureField (this);
2660                                 }
2661                         }
2662
2663                         // If the instance expression is a local variable or parameter.
2664                         IVariable var = instance_expr as IVariable;
2665                         if ((var == null) || (var.VariableInfo == null))
2666                                 return this;
2667
2668                         VariableInfo vi = var.VariableInfo;
2669                         if (!vi.IsFieldAssigned (ec, FieldInfo.Name, loc))
2670                                 return null;
2671
2672                         variable_info = vi.GetSubStruct (FieldInfo.Name);
2673                         return this;
2674                 }
2675
2676                 void Report_AssignToReadonly (bool is_instance)
2677                 {
2678                         string msg;
2679
2680                         if (is_instance)
2681                                 msg = "Readonly field can not be assigned outside " +
2682                                 "of constructor or variable initializer";
2683                         else
2684                                 msg = "A static readonly field can only be assigned in " +
2685                                 "a static constructor";
2686
2687                         Report.Error (is_instance ? 191 : 198, loc, msg);
2688                 }
2689
2690                 override public Expression DoResolveLValue (EmitContext ec, Expression right_side)
2691                 {
2692                         IVariable var = instance_expr as IVariable;
2693                         if ((var != null) && (var.VariableInfo != null))
2694                                 var.VariableInfo.SetFieldAssigned (ec, FieldInfo.Name);
2695
2696                         Expression e = DoResolve (ec);
2697
2698                         if (e == null)
2699                                 return null;
2700
2701                         if (!FieldInfo.IsStatic && (instance_expr.Type.IsValueType && !(instance_expr is IMemoryLocation))) {
2702                                 // FIXME: Provide better error reporting.
2703                                 Error (1612, "Cannot modify expression because it is not a variable.");
2704                                 return null;
2705                         }
2706
2707                         if (!FieldInfo.IsInitOnly)
2708                                 return this;
2709
2710                         FieldBase fb = TypeManager.GetField (FieldInfo);
2711                         if (fb != null)
2712                                 fb.SetAssigned ();
2713
2714                         //
2715                         // InitOnly fields can only be assigned in constructors
2716                         //
2717
2718                         if (ec.IsConstructor){
2719                                 if (IsStatic && !ec.IsStatic)
2720                                         Report_AssignToReadonly (false);
2721
2722                                 if (ec.ContainerType == FieldInfo.DeclaringType)
2723                                         return this;
2724                         }
2725
2726                         Report_AssignToReadonly (!IsStatic);
2727
2728                         return null;
2729                 }
2730
2731                 public bool VerifyFixed (bool is_expression)
2732                 {
2733                         IVariable variable = instance_expr as IVariable;
2734                         if ((variable == null) || !variable.VerifyFixed (true))
2735                                 return false;
2736
2737                         return true;
2738                 }
2739
2740                 public void Emit (EmitContext ec, bool leave_copy)
2741                 {
2742                         ILGenerator ig = ec.ig;
2743                         bool is_volatile = false;
2744
2745                         if (FieldInfo is FieldBuilder){
2746                                 FieldBase f = TypeManager.GetField (FieldInfo);
2747                                 if (f != null){
2748                                         if ((f.ModFlags & Modifiers.VOLATILE) != 0)
2749                                                 is_volatile = true;
2750
2751                                         f.status |= Field.Status.USED;
2752                                 }
2753                         }
2754
2755                         if (FieldInfo.IsStatic){
2756                                 if (is_volatile)
2757                                         ig.Emit (OpCodes.Volatile);
2758
2759                                 ig.Emit (OpCodes.Ldsfld, FieldInfo);
2760                         } else {
2761                                 if (!prepared)
2762                                         EmitInstance (ec);
2763
2764                                 if (is_volatile)
2765                                         ig.Emit (OpCodes.Volatile);
2766
2767                                 ig.Emit (OpCodes.Ldfld, FieldInfo);
2768                         }
2769
2770                         if (leave_copy) {
2771                                 ec.ig.Emit (OpCodes.Dup);
2772                                 if (!FieldInfo.IsStatic) {
2773                                         temp = new LocalTemporary (ec, this.Type);
2774                                         temp.Store (ec);
2775                                 }
2776                         }
2777                 }
2778
2779                 public void EmitAssign (EmitContext ec, Expression source, bool leave_copy, bool prepare_for_load)
2780                 {
2781                         FieldAttributes fa = FieldInfo.Attributes;
2782                         bool is_static = (fa & FieldAttributes.Static) != 0;
2783                         bool is_readonly = (fa & FieldAttributes.InitOnly) != 0;
2784                         ILGenerator ig = ec.ig;
2785                         prepared = prepare_for_load;
2786
2787                         if (is_readonly && !ec.IsConstructor){
2788                                 Report_AssignToReadonly (!is_static);
2789                                 return;
2790                         }
2791
2792                         if (!is_static) {
2793                                 EmitInstance (ec);
2794                                 if (prepare_for_load)
2795                                         ig.Emit (OpCodes.Dup);
2796                         }
2797
2798                         source.Emit (ec);
2799                         if (leave_copy) {
2800                                 ec.ig.Emit (OpCodes.Dup);
2801                                 if (!FieldInfo.IsStatic) {
2802                                         temp = new LocalTemporary (ec, this.Type);
2803                                         temp.Store (ec);
2804                                 }
2805                         }
2806
2807                         if (FieldInfo is FieldBuilder){
2808                                 FieldBase f = TypeManager.GetField (FieldInfo);
2809                                 if (f != null){
2810                                         if ((f.ModFlags & Modifiers.VOLATILE) != 0)
2811                                                 ig.Emit (OpCodes.Volatile);
2812
2813                                         f.status |= Field.Status.ASSIGNED;
2814                                 }
2815                         }
2816
2817                         if (is_static)
2818                                 ig.Emit (OpCodes.Stsfld, FieldInfo);
2819                         else
2820                                 ig.Emit (OpCodes.Stfld, FieldInfo);
2821
2822                         if (temp != null)
2823                                 temp.Emit (ec);
2824                 }
2825
2826                 void EmitInstance (EmitContext ec)
2827                 {
2828                         if (instance_expr.Type.IsValueType) {
2829                                 if (instance_expr is IMemoryLocation) {
2830                                         ((IMemoryLocation) instance_expr).AddressOf (ec, AddressOp.LoadStore);
2831                                 } else {
2832                                         LocalTemporary t = new LocalTemporary (ec, instance_expr.Type);
2833                                         instance_expr.Emit (ec);
2834                                         t.Store (ec);
2835                                         t.AddressOf (ec, AddressOp.Store);
2836                                 }
2837                         } else
2838                                 instance_expr.Emit (ec);
2839                 }
2840
2841                 public override void Emit (EmitContext ec)
2842                 {
2843                         Emit (ec, false);
2844                 }
2845
2846                 public void AddressOf (EmitContext ec, AddressOp mode)
2847                 {
2848                         ILGenerator ig = ec.ig;
2849
2850                         if (FieldInfo is FieldBuilder){
2851                                 FieldBase f = TypeManager.GetField (FieldInfo);
2852                                 if (f != null){
2853                                         if ((f.ModFlags & Modifiers.VOLATILE) != 0){
2854                                                 Error (676, "volatile variable: can not take its address, or pass as ref/out parameter");
2855                                                 return;
2856                                         }
2857
2858                                         if ((mode & AddressOp.Store) != 0)
2859                                                 f.status |= Field.Status.ASSIGNED;
2860                                         if ((mode & AddressOp.Load) != 0)
2861                                                 f.status |= Field.Status.USED;
2862                                 }
2863                         }
2864
2865                         //
2866                         // Handle initonly fields specially: make a copy and then
2867                         // get the address of the copy.
2868                         //
2869                         bool need_copy;
2870                         if (FieldInfo.IsInitOnly){
2871                                 need_copy = true;
2872                                 if (ec.IsConstructor){
2873                                         if (FieldInfo.IsStatic){
2874                                                 if (ec.IsStatic)
2875                                                         need_copy = false;
2876                                         } else
2877                                                 need_copy = false;
2878                                 }
2879                         } else
2880                                 need_copy = false;
2881
2882                         if (need_copy){
2883                                 LocalBuilder local;
2884                                 Emit (ec);
2885                                 local = ig.DeclareLocal (type);
2886                                 ig.Emit (OpCodes.Stloc, local);
2887                                 ig.Emit (OpCodes.Ldloca, local);
2888                                 return;
2889                         }
2890
2891
2892                         if (FieldInfo.IsStatic){
2893                                 ig.Emit (OpCodes.Ldsflda, FieldInfo);
2894                         } else {
2895                                 EmitInstance (ec);
2896                                 ig.Emit (OpCodes.Ldflda, FieldInfo);
2897                         }
2898                 }
2899         }
2900
2901         //
2902         // A FieldExpr whose address can not be taken
2903         //
2904         public class FieldExprNoAddress : FieldExpr, IMemoryLocation {
2905                 public FieldExprNoAddress (FieldInfo fi, Location loc) : base (fi, loc)
2906                 {
2907                 }
2908
2909                 public new void AddressOf (EmitContext ec, AddressOp mode)
2910                 {
2911                         Report.Error (-215, "Report this: Taking the address of a remapped parameter not supported");
2912                 }
2913         }
2914
2915         /// <summary>
2916         ///   Expression that evaluates to a Property.  The Assign class
2917         ///   might set the `Value' expression if we are in an assignment.
2918         ///
2919         ///   This is not an LValue because we need to re-write the expression, we
2920         ///   can not take data from the stack and store it.
2921         /// </summary>
2922         public class PropertyExpr : ExpressionStatement, IAssignMethod, IMemberExpr {
2923                 public readonly PropertyInfo PropertyInfo;
2924
2925                 //
2926                 // This is set externally by the  `BaseAccess' class
2927                 //
2928                 public bool IsBase;
2929                 MethodInfo getter, setter;
2930                 bool is_static;
2931                 bool must_do_cs1540_check;
2932
2933                 Expression instance_expr;
2934                 LocalTemporary temp;
2935                 bool prepared;
2936
2937                 public PropertyExpr (EmitContext ec, PropertyInfo pi, Location l)
2938                 {
2939                         PropertyInfo = pi;
2940                         eclass = ExprClass.PropertyAccess;
2941                         is_static = false;
2942                         loc = l;
2943
2944                         type = TypeManager.TypeToCoreType (pi.PropertyType);
2945
2946                         ResolveAccessors (ec);
2947                 }
2948
2949                 public string Name {
2950                         get {
2951                                 return PropertyInfo.Name;
2952                         }
2953                 }
2954
2955                 public bool IsInstance {
2956                         get {
2957                                 return !is_static;
2958                         }
2959                 }
2960
2961                 public bool IsStatic {
2962                         get {
2963                                 return is_static;
2964                         }
2965                 }
2966
2967                 public Type DeclaringType {
2968                         get {
2969                                 return PropertyInfo.DeclaringType;
2970                         }
2971                 }
2972
2973                 //
2974                 // The instance expression associated with this expression
2975                 //
2976                 public Expression InstanceExpression {
2977                         set {
2978                                 instance_expr = value;
2979                         }
2980
2981                         get {
2982                                 return instance_expr;
2983                         }
2984                 }
2985
2986                 public bool VerifyAssignable ()
2987                 {
2988                         if (setter == null) {
2989                                 Report.Error (200, loc,
2990                                               "The property `" + PropertyInfo.Name +
2991                                               "' can not be assigned to, as it has not set accessor");
2992                                 return false;
2993                         }
2994
2995                         return true;
2996                 }
2997
2998                 void FindAccessors (Type invocation_type)
2999                 {
3000                         BindingFlags flags = BindingFlags.Public | BindingFlags.NonPublic |
3001                                 BindingFlags.Static | BindingFlags.Instance |
3002                                 BindingFlags.DeclaredOnly;
3003
3004                         Type current = PropertyInfo.DeclaringType;
3005                         for (; current != null; current = current.BaseType) {
3006                                 MemberInfo[] group = TypeManager.MemberLookup (
3007                                         invocation_type, invocation_type, current,
3008                                         MemberTypes.Property, flags, PropertyInfo.Name, null);
3009
3010                                 if (group == null)
3011                                         continue;
3012
3013                                 if (group.Length != 1)
3014                                         // Oooops, can this ever happen ?
3015                                         return;
3016
3017                                 PropertyInfo pi = (PropertyInfo) group [0];
3018
3019                                 if (getter == null)
3020                                         getter = pi.GetGetMethod (true);;
3021
3022                                 if (setter == null)
3023                                         setter = pi.GetSetMethod (true);;
3024
3025                                 MethodInfo accessor = getter != null ? getter : setter;
3026
3027                                 if (!accessor.IsVirtual)
3028                                         return;
3029                         }
3030                 }
3031
3032                 bool IsAccessorAccessible (Type invocation_type, MethodInfo mi)
3033                 {
3034                         MethodAttributes ma = mi.Attributes & MethodAttributes.MemberAccessMask;
3035
3036                         //
3037                         // If only accessible to the current class or children
3038                         //
3039                         if (ma == MethodAttributes.Private) {
3040                                 Type declaring_type = mi.DeclaringType;
3041
3042                                 if (invocation_type != declaring_type)
3043                                         return TypeManager.IsSubclassOrNestedChildOf (invocation_type, declaring_type);
3044
3045                                 return true;
3046                         }
3047                         //
3048                         // FamAndAssem requires that we not only derivate, but we are on the
3049                         // same assembly.
3050                         //
3051                         if (ma == MethodAttributes.FamANDAssem){
3052                                 return (mi.DeclaringType.Assembly != invocation_type.Assembly);
3053                         }
3054
3055                         // Assembly and FamORAssem succeed if we're in the same assembly.
3056                         if ((ma == MethodAttributes.Assembly) || (ma == MethodAttributes.FamORAssem)){
3057                                 if (mi.DeclaringType.Assembly == invocation_type.Assembly)
3058                                         return true;
3059                         }
3060
3061                         // We already know that we aren't in the same assembly.
3062                         if (ma == MethodAttributes.Assembly)
3063                                 return false;
3064
3065                         // Family and FamANDAssem require that we derive.
3066                         if ((ma == MethodAttributes.Family) || (ma == MethodAttributes.FamANDAssem) || (ma == MethodAttributes.FamORAssem)){
3067                                 if (!TypeManager.IsSubclassOrNestedChildOf (invocation_type, mi.DeclaringType))
3068                                         return false;
3069
3070                                 if (!TypeManager.IsNestedChildOf (invocation_type, mi.DeclaringType))
3071                                         must_do_cs1540_check = true;
3072
3073                                 return true;
3074                         }
3075
3076                         return true;
3077                 }
3078
3079                 //
3080                 // We also perform the permission checking here, as the PropertyInfo does not
3081                 // hold the information for the accessibility of its setter/getter
3082                 //
3083                 void ResolveAccessors (EmitContext ec)
3084                 {
3085                         FindAccessors (ec.ContainerType);
3086
3087                         is_static = getter != null ? getter.IsStatic : setter.IsStatic;
3088                 }
3089
3090                 bool InstanceResolve (EmitContext ec)
3091                 {
3092                         if ((instance_expr == null) && ec.IsStatic && !is_static) {
3093                                 SimpleName.Error_ObjectRefRequired (ec, loc, PropertyInfo.Name);
3094                                 return false;
3095                         }
3096
3097                         if (instance_expr != null) {
3098                                 instance_expr = instance_expr.DoResolve (ec);
3099                                 if (instance_expr == null)
3100                                         return false;
3101                         }
3102
3103                         if (must_do_cs1540_check && (instance_expr != null)) {
3104                                 if ((instance_expr.Type != ec.ContainerType) &&
3105                                     ec.ContainerType.IsSubclassOf (instance_expr.Type)) {
3106                                         Report.Error (1540, loc, "Cannot access protected member `" +
3107                                                       PropertyInfo.DeclaringType + "." + PropertyInfo.Name +
3108                                                       "' via a qualifier of type `" +
3109                                                       TypeManager.CSharpName (instance_expr.Type) +
3110                                                       "'; the qualifier must be of type `" +
3111                                                       TypeManager.CSharpName (ec.ContainerType) +
3112                                                       "' (or derived from it)");
3113                                         return false;
3114                                 }
3115                         }
3116
3117                         return true;
3118                 }
3119
3120                 override public Expression DoResolve (EmitContext ec)
3121                 {
3122                         if (getter != null){
3123                                 if (TypeManager.GetArgumentTypes (getter).Length != 0){
3124                                         Report.Error (
3125                                                 117, loc, "`{0}' does not contain a " +
3126                                                 "definition for `{1}'.", getter.DeclaringType,
3127                                                 Name);
3128                                         return null;
3129                                 }
3130                         }
3131
3132                         if (getter == null){
3133                                 //
3134                                 // The following condition happens if the PropertyExpr was
3135                                 // created, but is invalid (ie, the property is inaccessible),
3136                                 // and we did not want to embed the knowledge about this in
3137                                 // the caller routine.  This only avoids double error reporting.
3138                                 //
3139                                 if (setter == null)
3140                                         return null;
3141
3142                                 Report.Error (154, loc,
3143                                               "The property `" + PropertyInfo.Name +
3144                                               "' can not be used in " +
3145                                               "this context because it lacks a get accessor");
3146                                 return null;
3147                         }
3148
3149                         if (!IsAccessorAccessible (ec.ContainerType, getter)) {
3150                                 Report.Error (122, loc, "'{0}.get' is inaccessible due to its protection level", PropertyInfo.Name);
3151                                 return null;
3152                         }
3153
3154                         if (!InstanceResolve (ec))
3155                                 return null;
3156
3157                         //
3158                         // Only base will allow this invocation to happen.
3159                         //
3160                         if (IsBase && getter.IsAbstract){
3161                                 Report.Error (205, loc, "Cannot call an abstract base property: " +
3162                                               PropertyInfo.DeclaringType + "." +PropertyInfo.Name);
3163                                 return null;
3164                         }
3165
3166                         return this;
3167                 }
3168
3169                 override public Expression DoResolveLValue (EmitContext ec, Expression right_side)
3170                 {
3171                         if (setter == null){
3172                                 //
3173                                 // The following condition happens if the PropertyExpr was
3174                                 // created, but is invalid (ie, the property is inaccessible),
3175                                 // and we did not want to embed the knowledge about this in
3176                                 // the caller routine.  This only avoids double error reporting.
3177                                 //
3178                                 if (getter == null)
3179                                         return null;
3180
3181                                 Report.Error (154, loc,
3182                                               "The property `" + PropertyInfo.Name +
3183                                               "' can not be used in " +
3184                                               "this context because it lacks a set accessor");
3185                                 return null;
3186                         }
3187
3188                         if (TypeManager.GetArgumentTypes (setter).Length != 1){
3189                                 Report.Error (
3190                                         117, loc, "`{0}' does not contain a " +
3191                                         "definition for `{1}'.", getter.DeclaringType,
3192                                         Name);
3193                                 return null;
3194                         }
3195
3196                         if (!IsAccessorAccessible (ec.ContainerType, setter)) {
3197                                 Report.Error (122, loc, "'{0}.set' is inaccessible due to its protection level", PropertyInfo.Name);
3198                                 return null;
3199                         }
3200
3201                         if (!InstanceResolve (ec))
3202                                 return null;
3203
3204                         //
3205                         // Only base will allow this invocation to happen.
3206                         //
3207                         if (IsBase && setter.IsAbstract){
3208                                 Report.Error (205, loc, "Cannot call an abstract base property: " +
3209                                               PropertyInfo.DeclaringType + "." +PropertyInfo.Name);
3210                                 return null;
3211                         }
3212
3213                         //
3214                         // Check that we are not making changes to a temporary memory location
3215                         //
3216                         if (instance_expr != null && instance_expr.Type.IsValueType && !(instance_expr is IMemoryLocation)) {
3217                                 // FIXME: Provide better error reporting.
3218                                 Error (1612, "Cannot modify expression because it is not a variable.");
3219                                 return null;
3220                         }
3221
3222                         return this;
3223                 }
3224
3225
3226
3227                 public override void Emit (EmitContext ec)
3228                 {
3229                         Emit (ec, false);
3230                 }
3231
3232                 void EmitInstance (EmitContext ec)
3233                 {
3234                         if (is_static)
3235                                 return;
3236
3237                         if (instance_expr.Type.IsValueType) {
3238                                 if (instance_expr is IMemoryLocation) {
3239                                         ((IMemoryLocation) instance_expr).AddressOf (ec, AddressOp.LoadStore);
3240                                 } else {
3241                                         LocalTemporary t = new LocalTemporary (ec, instance_expr.Type);
3242                                         instance_expr.Emit (ec);
3243                                         t.Store (ec);
3244                                         t.AddressOf (ec, AddressOp.Store);
3245                                 }
3246                         } else
3247                                 instance_expr.Emit (ec);
3248
3249                         if (prepared)
3250                                 ec.ig.Emit (OpCodes.Dup);
3251                 }
3252
3253
3254                 public void Emit (EmitContext ec, bool leave_copy)
3255                 {
3256                         if (!prepared)
3257                                 EmitInstance (ec);
3258
3259                         //
3260                         // Special case: length of single dimension array property is turned into ldlen
3261                         //
3262                         if ((getter == TypeManager.system_int_array_get_length) ||
3263                             (getter == TypeManager.int_array_get_length)){
3264                                 Type iet = instance_expr.Type;
3265
3266                                 //
3267                                 // System.Array.Length can be called, but the Type does not
3268                                 // support invoking GetArrayRank, so test for that case first
3269                                 //
3270                                 if (iet != TypeManager.array_type && (iet.GetArrayRank () == 1)) {
3271                                         ec.ig.Emit (OpCodes.Ldlen);
3272                                         ec.ig.Emit (OpCodes.Conv_I4);
3273                                         return;
3274                                 }
3275                         }
3276
3277                         Invocation.EmitCall (ec, IsBase, IsStatic, new EmptyAddressOf (), getter, null, loc);
3278
3279                         if (!leave_copy)
3280                                 return;
3281
3282                         ec.ig.Emit (OpCodes.Dup);
3283                         if (!is_static) {
3284                                 temp = new LocalTemporary (ec, this.Type);
3285                                 temp.Store (ec);
3286                         }
3287                 }
3288
3289                 //
3290                 // Implements the IAssignMethod interface for assignments
3291                 //
3292                 public void EmitAssign (EmitContext ec, Expression source, bool leave_copy, bool prepare_for_load)
3293                 {
3294                         prepared = prepare_for_load;
3295
3296                         EmitInstance (ec);
3297
3298                         source.Emit (ec);
3299                         if (leave_copy) {
3300                                 ec.ig.Emit (OpCodes.Dup);
3301                                 if (!is_static) {
3302                                         temp = new LocalTemporary (ec, this.Type);
3303                                         temp.Store (ec);
3304                                 }
3305                         }
3306
3307                         ArrayList args = new ArrayList (1);
3308                         args.Add (new Argument (new EmptyAddressOf (), Argument.AType.Expression));
3309
3310                         Invocation.EmitCall (ec, IsBase, IsStatic, new EmptyAddressOf (), setter, args, loc);
3311
3312                         if (temp != null)
3313                                 temp.Emit (ec);
3314                 }
3315
3316                 override public void EmitStatement (EmitContext ec)
3317                 {
3318                         Emit (ec);
3319                         ec.ig.Emit (OpCodes.Pop);
3320                 }
3321         }
3322
3323         /// <summary>
3324         ///   Fully resolved expression that evaluates to an Event
3325         /// </summary>
3326         public class EventExpr : Expression, IMemberExpr {
3327                 public readonly EventInfo EventInfo;
3328                 Expression instance_expr;
3329
3330                 bool is_static;
3331                 MethodInfo add_accessor, remove_accessor;
3332
3333                 public EventExpr (EventInfo ei, Location loc)
3334                 {
3335                         EventInfo = ei;
3336                         this.loc = loc;
3337                         eclass = ExprClass.EventAccess;
3338
3339                         add_accessor = TypeManager.GetAddMethod (ei);
3340                         remove_accessor = TypeManager.GetRemoveMethod (ei);
3341
3342                         if (add_accessor.IsStatic || remove_accessor.IsStatic)
3343                                 is_static = true;
3344
3345                         if (EventInfo is MyEventBuilder){
3346                                 MyEventBuilder eb = (MyEventBuilder) EventInfo;
3347                                 type = eb.EventType;
3348                                 eb.SetUsed ();
3349                         } else
3350                                 type = EventInfo.EventHandlerType;
3351                 }
3352
3353                 public string Name {
3354                         get {
3355                                 return EventInfo.Name;
3356                         }
3357                 }
3358
3359                 public bool IsInstance {
3360                         get {
3361                                 return !is_static;
3362                         }
3363                 }
3364
3365                 public bool IsStatic {
3366                         get {
3367                                 return is_static;
3368                         }
3369                 }
3370
3371                 public Type DeclaringType {
3372                         get {
3373                                 return EventInfo.DeclaringType;
3374                         }
3375                 }
3376
3377                 public Expression InstanceExpression {
3378                         get {
3379                                 return instance_expr;
3380                         }
3381
3382                         set {
3383                                 instance_expr = value;
3384                         }
3385                 }
3386
3387                 public override Expression DoResolve (EmitContext ec)
3388                 {
3389                         if (instance_expr != null) {
3390                                 instance_expr = instance_expr.DoResolve (ec);
3391                                 if (instance_expr == null)
3392                                         return null;
3393                         }
3394
3395
3396                         return this;
3397                 }
3398
3399                 public override void Emit (EmitContext ec)
3400                 {
3401                         Report.Error (70, loc, "The event `" + Name + "' can only appear on the left hand side of += or -= (except on the defining type)");
3402                 }
3403
3404                 public void EmitAddOrRemove (EmitContext ec, Expression source)
3405                 {
3406                         BinaryDelegate source_del = (BinaryDelegate) source;
3407                         Expression handler = source_del.Right;
3408
3409                         Argument arg = new Argument (handler, Argument.AType.Expression);
3410                         ArrayList args = new ArrayList ();
3411
3412                         args.Add (arg);
3413
3414                         if (source_del.IsAddition)
3415                                 Invocation.EmitCall (
3416                                         ec, false, IsStatic, instance_expr, add_accessor, args, loc);
3417                         else
3418                                 Invocation.EmitCall (
3419                                         ec, false, IsStatic, instance_expr, remove_accessor, args, loc);
3420                 }
3421         }
3422 }