mcs/gmcs/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                 // Mask of all the expression class flags.
  55                 MaskExprClass           = 7,
  56
  57                 // Disable control flow analysis while resolving the expression.
  58                 // This is used when resolving the instance expression of a field expression.
  59                 DisableFlowAnalysis     = 8,
  60
  61                 // Set if this is resolving the first part of a MemberAccess.
  62                 Intermediate            = 16
  63         }
  64
  65         //
  66         // This is just as a hint to AddressOf of what will be done with the
  67         // address.
  68         [Flags]
  69         public enum AddressOp {
  70                 Store = 1,
  71                 Load  = 2,
  72                 LoadStore = 3
  73         };
  74
  75         /// <summary>
  76         ///   This interface is implemented by variables
  77         /// </summary>
  78         public interface IMemoryLocation {
  79                 /// <summary>
  80                 ///   The AddressOf method should generate code that loads
  81                 ///   the address of the object and leaves it on the stack.
  82                 ///
  83                 ///   The `mode' argument is used to notify the expression
  84                 ///   of whether this will be used to read from the address or
  85                 ///   write to the address.
  86                 ///
  87                 ///   This is just a hint that can be used to provide good error
  88                 ///   reporting, and should have no other side effects.
  89                 /// </summary>
  90                 void AddressOf (EmitContext ec, AddressOp mode);
  91         }
  92
  93         /// <summary>
  94         ///   We are either a namespace or a type.
  95         ///   If we're a type, `IsType' is true and we may use `Type' to get
  96         ///   a TypeExpr representing that type.
  97         /// </summary>
  98         public interface IAlias {
  99                 bool IsType {
 100                         get;
 101                 }
 102
 103                 string Name {
 104                         get;
 105                 }
 106
 107                 TypeExpr ResolveAsType (EmitContext ec);
 108         }
 109
 110         /// <summary>
 111         ///   This interface is implemented by variables
 112         /// </summary>
 113         public interface IVariable {
 114                 VariableInfo VariableInfo {
 115                         get;
 116                 }
 117
 118                 bool VerifyFixed (bool is_expression);
 119         }
 120
 121         /// <remarks>
 122         ///   Base class for expressions
 123         /// </remarks>
 124         public abstract class Expression {
 125                 public ExprClass eclass;
 126                 protected Type type;
 127                 protected Location loc;
 128
 129                 public Type Type {
 130                         get {
 131                                 return type;
 132                         }
 133
 134                         set {
 135                                 type = value;
 136                         }
 137                 }
 138
 139                 public Location Location {
 140                         get {
 141                                 return loc;
 142                         }
 143                 }
 144
 145                 /// <summary>
 146                 ///   Utility wrapper routine for Error, just to beautify the code
 147                 /// </summary>
 148                 public void Error (int error, string s)
 149                 {
 150                         if (!Location.IsNull (loc))
 151                                 Report.Error (error, loc, s);
 152                         else
 153                                 Report.Error (error, s);
 154                 }
 155
 156                 /// <summary>
 157                 ///   Utility wrapper routine for Warning, just to beautify the code
 158                 /// </summary>
 159                 public void Warning (int code, string format, params object[] args)
 160                 {
 161                         Report.Warning (code, loc, format, args);
 162                 }
 163
 164                 // Not nice but we have broken hierarchy
 165                 public virtual void CheckMarshallByRefAccess (Type container) {}
 166
 167                 /// <summary>
 168                 /// Tests presence of ObsoleteAttribute and report proper error
 169                 /// </summary>
 170                 protected void CheckObsoleteAttribute (Type type)
 171                 {
 172                         ObsoleteAttribute obsolete_attr = AttributeTester.GetObsoleteAttribute (type);
 173                         if (obsolete_attr == null)
 174                                 return;
 175
 176                         AttributeTester.Report_ObsoleteMessage (obsolete_attr, type.FullName, loc);
 177                 }
 178
 179                 public static bool IsAccessorAccessible (Type invocation_type, MethodInfo mi, out bool must_do_cs1540_check)
 180                 {
 181                         MethodAttributes ma = mi.Attributes & MethodAttributes.MemberAccessMask;
 182
 183                         must_do_cs1540_check = false; // by default we do not check for this
 184
 185                         //
 186                         // If only accessible to the current class or children
 187                         //
 188                         if (ma == MethodAttributes.Private) {
 189                                 Type declaring_type = mi.DeclaringType;
 190
 191                                 if (invocation_type != declaring_type)
 192                                         return TypeManager.IsNestedChildOf (invocation_type, declaring_type);
 193
 194                                 return true;
 195                         }
 196                         //
 197                         // FamAndAssem requires that we not only derivate, but we are on the
 198                         // same assembly.
 199                         //
 200                         if (ma == MethodAttributes.FamANDAssem){
 201                                 return (mi.DeclaringType.Assembly != invocation_type.Assembly);
 202                         }
 203
 204                         // Assembly and FamORAssem succeed if we're in the same assembly.
 205                         if ((ma == MethodAttributes.Assembly) || (ma == MethodAttributes.FamORAssem)){
 206                                 if (mi.DeclaringType.Assembly == invocation_type.Assembly)
 207                                         return true;
 208                         }
 209
 210                         // We already know that we aren't in the same assembly.
 211                         if (ma == MethodAttributes.Assembly)
 212                                 return false;
 213
 214                         // Family and FamANDAssem require that we derive.
 215                         if ((ma == MethodAttributes.Family) || (ma == MethodAttributes.FamANDAssem) || (ma == MethodAttributes.FamORAssem)){
 216                                 if (!TypeManager.IsNestedFamilyAccessible (invocation_type, mi.DeclaringType))
 217                                         return false;
 218
 219                                 if (!TypeManager.IsNestedChildOf (invocation_type, mi.DeclaringType))
 220                                         must_do_cs1540_check = true;
 221
 222                                 return true;
 223                         }
 224
 225                         return true;
 226                 }
 227
 228                 /// <summary>
 229                 ///   Performs semantic analysis on the Expression
 230                 /// </summary>
 231                 ///
 232                 /// <remarks>
 233                 ///   The Resolve method is invoked to perform the semantic analysis
 234                 ///   on the node.
 235                 ///
 236                 ///   The return value is an expression (it can be the
 237                 ///   same expression in some cases) or a new
 238                 ///   expression that better represents this node.
 239                 ///
 240                 ///   For example, optimizations of Unary (LiteralInt)
 241                 ///   would return a new LiteralInt with a negated
 242                 ///   value.
 243                 ///
 244                 ///   If there is an error during semantic analysis,
 245                 ///   then an error should be reported (using Report)
 246                 ///   and a null value should be returned.
 247                 ///
 248                 ///   There are two side effects expected from calling
 249                 ///   Resolve(): the the field variable "eclass" should
 250                 ///   be set to any value of the enumeration
 251                 ///   `ExprClass' and the type variable should be set
 252                 ///   to a valid type (this is the type of the
 253                 ///   expression).
 254                 /// </remarks>
 255                 public abstract Expression DoResolve (EmitContext ec);
 256
 257                 public virtual Expression DoResolveLValue (EmitContext ec, Expression right_side)
 258                 {
 259                         return null;
 260                 }
 261
 262                 //
 263                 // This is used if the expression should be resolved as a type or namespace name.
 264                 // the default implementation fails.
 265                 //
 266                 public virtual FullNamedExpression ResolveAsTypeStep (EmitContext ec)
 267                 {
 268                         return null;
 269                 }
 270
 271                 //
 272                 // This is used to resolve the expression as a type, a null
 273                 // value will be returned if the expression is not a type
 274                 // reference
 275                 //
 276                 public virtual TypeExpr ResolveAsTypeTerminal (EmitContext ec)
 277                 {
 278                         int errors = Report.Errors;
 279
 280                         FullNamedExpression fne = ResolveAsTypeStep (ec);
 281
 282                         if (fne == null) {
 283                                 if (errors == Report.Errors)
 284                                         Report.Error (246, Location, "Cannot find type '{0}'", ToString ());
 285                                 return null;
 286                         }
 287
 288                         if (fne.eclass != ExprClass.Type) {
 289                                 if (errors == Report.Errors)
 290                                         Report.Error (118, Location, "'{0}' denotes a '{1}', where a type was expected",
 291                                                       fne.FullName, fne.ExprClassName ());
 292                                 return null;
 293                         }
 294
 295                         TypeExpr te = fne as TypeExpr;
 296
 297                         if (!te.CheckAccessLevel (ec.DeclSpace)) {
 298                                 Report.Error (122, Location, "'{0}' is inaccessible due to its protection level", te.Name);
 299                                 return null;
 300                         }
 301
 302                         return te;
 303                 }
 304
 305                 /// <summary>
 306                 ///   Resolves an expression and performs semantic analysis on it.
 307                 /// </summary>
 308                 ///
 309                 /// <remarks>
 310                 ///   Currently Resolve wraps DoResolve to perform sanity
 311                 ///   checking and assertion checking on what we expect from Resolve.
 312                 /// </remarks>
 313                 public Expression Resolve (EmitContext ec, ResolveFlags flags)
 314                 {
 315                         if ((flags & ResolveFlags.MaskExprClass) == ResolveFlags.Type)
 316                                 return ResolveAsTypeStep (ec);
 317
 318                         bool old_do_flow_analysis = ec.DoFlowAnalysis;
 319                         if ((flags & ResolveFlags.DisableFlowAnalysis) != 0)
 320                                 ec.DoFlowAnalysis = false;
 321
 322                         Expression e;
 323                         bool intermediate = (flags & ResolveFlags.Intermediate) == ResolveFlags.Intermediate;
 324                         if (this is SimpleName)
 325                                 e = ((SimpleName) this).DoResolve (ec, intermediate);
 326
 327                         else
 328                                 e = DoResolve (ec);
 329
 330                         ec.DoFlowAnalysis = old_do_flow_analysis;
 331
 332                         if (e == null)
 333                                 return null;
 334
 335                         if ((e is TypeExpr) || (e is ComposedCast) || (e is Namespace)) {
 336                                 if ((flags & ResolveFlags.Type) == 0) {
 337                                         e.Error_UnexpectedKind (flags, loc);
 338                                         return null;
 339                                 }
 340
 341                                 return e;
 342                         }
 343
 344                         switch (e.eclass) {
 345                         case ExprClass.Type:
 346                         case ExprClass.Namespace:
 347                                 if ((flags & ResolveFlags.VariableOrValue) == 0) {
 348                                         e.Error_UnexpectedKind (flags, loc);
 349                                         return null;
 350                                 }
 351                                 break;
 352
 353                         case ExprClass.MethodGroup:
 354                                 if (RootContext.Version == LanguageVersion.ISO_1){
 355                                         if ((flags & ResolveFlags.MethodGroup) == 0) {
 356                                                 ((MethodGroupExpr) e).ReportUsageError ();
 357                                                 return null;
 358                                         }
 359                                 }
 360                                 break;
 361
 362                         case ExprClass.Value:
 363                         case ExprClass.Variable:
 364                         case ExprClass.PropertyAccess:
 365                         case ExprClass.EventAccess:
 366                         case ExprClass.IndexerAccess:
 367                                 if ((flags & ResolveFlags.VariableOrValue) == 0) {
 368                                         Console.WriteLine ("I got: {0} and {1}", e.GetType (), e);
 369                                         Console.WriteLine ("I am {0} and {1}", this.GetType (), this);
 370                                         FieldInfo fi = ((FieldExpr) e).FieldInfo;
 371
 372                                         Console.WriteLine ("{0} and {1}", fi.DeclaringType, fi.Name);
 373                                         e.Error_UnexpectedKind (flags, loc);
 374                                         return null;
 375                                 }
 376                                 break;
 377
 378                         default:
 379                                 throw new Exception ("Expression " + e.GetType () +
 380                                                      " ExprClass is Invalid after resolve");
 381                         }
 382
 383                         if (e.type == null && !(e is Namespace)) {
 384                                 throw new Exception (
 385                                         "Expression " + e.GetType () +
 386                                         " did not set its type after Resolve\n" +
 387                                         "called from: " + this.GetType ());
 388                         }
 389
 390                         return e;
 391                 }
 392
 393                 /// <summary>
 394                 ///   Resolves an expression and performs semantic analysis on it.
 395                 /// </summary>
 396                 public Expression Resolve (EmitContext ec)
 397                 {
 398                         return Resolve (ec, ResolveFlags.VariableOrValue);
 399                 }
 400
 401                 /// <summary>
 402                 ///   Resolves an expression for LValue assignment
 403                 /// </summary>
 404                 ///
 405                 /// <remarks>
 406                 ///   Currently ResolveLValue wraps DoResolveLValue to perform sanity
 407                 ///   checking and assertion checking on what we expect from Resolve
 408                 /// </remarks>
 409                 public Expression ResolveLValue (EmitContext ec, Expression right_side)
 410                 {
 411                         int errors = Report.Errors;
 412                         Expression e = DoResolveLValue (ec, right_side);
 413
 414                         if (e == null) {
 415                                 if (errors == Report.Errors)
 416                                         Report.Error (131, Location, "The left-hand side of an assignment or mutating operation must be a variable, property or indexer");
 417                                 return null;
 418                         }
 419
 420                         if (e != null){
 421                                 if (e.eclass == ExprClass.Invalid)
 422                                         throw new Exception ("Expression " + e +
 423                                                              " ExprClass is Invalid after resolve");
 424
 425                                 if (e.eclass == ExprClass.MethodGroup) {
 426                                         ((MethodGroupExpr) e).ReportUsageError ();
 427                                         return null;
 428                                 }
 429
 430                                 if ((e.type == null) && !(e is ConstructedType))
 431                                         throw new Exception ("Expression " + e +
 432                                                              " did not set its type after Resolve");
 433                         }
 434
 435                         return e;
 436                 }
 437
 438                 /// <summary>
 439                 ///   Emits the code for the expression
 440                 /// </summary>
 441                 ///
 442                 /// <remarks>
 443                 ///   The Emit method is invoked to generate the code
 444                 ///   for the expression.
 445                 /// </remarks>
 446                 public abstract void Emit (EmitContext ec);
 447
 448                 public virtual void EmitBranchable (EmitContext ec, Label target, bool onTrue)
 449                 {
 450                         Emit (ec);
 451                         ec.ig.Emit (onTrue ? OpCodes.Brtrue : OpCodes.Brfalse, target);
 452                 }
 453
 454                 /// <summary>
 455                 ///   Protected constructor.  Only derivate types should
 456                 ///   be able to be created
 457                 /// </summary>
 458
 459                 protected Expression ()
 460                 {
 461                         eclass = ExprClass.Invalid;
 462                         type = null;
 463                 }
 464
 465                 /// <summary>
 466                 ///   Returns a literalized version of a literal FieldInfo
 467                 /// </summary>
 468                 ///
 469                 /// <remarks>
 470                 ///   The possible return values are:
 471                 ///      IntConstant, UIntConstant
 472                 ///      LongLiteral, ULongConstant
 473                 ///      FloatConstant, DoubleConstant
 474                 ///      StringConstant
 475                 ///
 476                 ///   The value returned is already resolved.
 477                 /// </remarks>
 478                 public static Constant Constantify (object v, Type t)
 479                 {
 480                         if (t == TypeManager.int32_type)
 481                                 return new IntConstant ((int) v);
 482                         else if (t == TypeManager.uint32_type)
 483                                 return new UIntConstant ((uint) v);
 484                         else if (t == TypeManager.int64_type)
 485                                 return new LongConstant ((long) v);
 486                         else if (t == TypeManager.uint64_type)
 487                                 return new ULongConstant ((ulong) v);
 488                         else if (t == TypeManager.float_type)
 489                                 return new FloatConstant ((float) v);
 490                         else if (t == TypeManager.double_type)
 491                                 return new DoubleConstant ((double) v);
 492                         else if (t == TypeManager.string_type)
 493                                 return new StringConstant ((string) v);
 494                         else if (t == TypeManager.short_type)
 495                                 return new ShortConstant ((short)v);
 496                         else if (t == TypeManager.ushort_type)
 497                                 return new UShortConstant ((ushort)v);
 498                         else if (t == TypeManager.sbyte_type)
 499                                 return new SByteConstant (((sbyte)v));
 500                         else if (t == TypeManager.byte_type)
 501                                 return new ByteConstant ((byte)v);
 502                         else if (t == TypeManager.char_type)
 503                                 return new CharConstant ((char)v);
 504                         else if (t == TypeManager.bool_type)
 505                                 return new BoolConstant ((bool) v);
 506                         else if (t == TypeManager.decimal_type)
 507                                 return new DecimalConstant ((decimal) v);
 508                         else if (TypeManager.IsEnumType (t)){
 509                                 Type real_type = TypeManager.TypeToCoreType (v.GetType ());
 510                                 if (real_type == t)
 511                                         real_type = System.Enum.GetUnderlyingType (real_type);
 512
 513                                 Constant e = Constantify (v, real_type);
 514
 515                                 return new EnumConstant (e, t);
 516                         } else if (v == null && !TypeManager.IsValueType (t))
 517                                 return NullLiteral.Null;
 518                         else
 519                                 throw new Exception ("Unknown type for constant (" + t +
 520                                                      "), details: " + v);
 521                 }
 522
 523                 /// <summary>
 524                 ///   Returns a fully formed expression after a MemberLookup
 525                 /// </summary>
 526                 public static Expression ExprClassFromMemberInfo (EmitContext ec, MemberInfo mi, Location loc)
 527                 {
 528                         if (mi is EventInfo)
 529                                 return new EventExpr ((EventInfo) mi, loc);
 530                         else if (mi is FieldInfo)
 531                                 return new FieldExpr ((FieldInfo) mi, loc);
 532                         else if (mi is PropertyInfo)
 533                                 return new PropertyExpr (ec, (PropertyInfo) mi, loc);
 534                         else if (mi is Type){
 535                                 return new TypeExpression ((System.Type) mi, loc);
 536                         }
 537
 538                         return null;
 539                 }
 540
 541                 protected static ArrayList almostMatchedMembers = new ArrayList (4);
 542
 543                 //
 544                 // FIXME: Probably implement a cache for (t,name,current_access_set)?
 545                 //
 546                 // This code could use some optimizations, but we need to do some
 547                 // measurements.  For example, we could use a delegate to `flag' when
 548                 // something can not any longer be a method-group (because it is something
 549                 // else).
 550                 //
 551                 // Return values:
 552                 //     If the return value is an Array, then it is an array of
 553                 //     MethodBases
 554                 //
 555                 //     If the return value is an MemberInfo, it is anything, but a Method
 556                 //
 557                 //     null on error.
 558                 //
 559                 // FIXME: When calling MemberLookup inside an `Invocation', we should pass
 560                 // the arguments here and have MemberLookup return only the methods that
 561                 // match the argument count/type, unlike we are doing now (we delay this
 562                 // decision).
 563                 //
 564                 // This is so we can catch correctly attempts to invoke instance methods
 565                 // from a static body (scan for error 120 in ResolveSimpleName).
 566                 //
 567                 //
 568                 // FIXME: Potential optimization, have a static ArrayList
 569                 //
 570
 571                 public static Expression MemberLookup (EmitContext ec, Type queried_type, string name,
 572                                                        MemberTypes mt, BindingFlags bf, Location loc)
 573                 {
 574                         return MemberLookup (ec, ec.ContainerType, null, queried_type, name, mt, bf, loc);
 575                 }
 576
 577                 //
 578                 // Lookup type `queried_type' for code in class `container_type' with a qualifier of
 579                 // `qualifier_type' or null to lookup members in the current class.
 580                 //
 581
 582                 public static Expression MemberLookup (EmitContext ec, Type container_type,
 583                                                        Type qualifier_type, Type queried_type,
 584                                                        string name, MemberTypes mt,
 585                                                        BindingFlags bf, Location loc)
 586                 {
 587                         almostMatchedMembers.Clear ();
 588
 589                         MemberInfo [] mi = TypeManager.MemberLookup (
 590                                 container_type, qualifier_type,queried_type, mt, bf, name,
 591                                 almostMatchedMembers);
 592
 593                         if (mi == null)
 594                                 return null;
 595
 596                         int count = mi.Length;
 597
 598                         if (mi [0] is MethodBase)
 599                                 return new MethodGroupExpr (mi, loc);
 600
 601                         if (count > 1)
 602                                 return null;
 603
 604                         return ExprClassFromMemberInfo (ec, mi [0], loc);
 605                 }
 606
 607                 public const MemberTypes AllMemberTypes =
 608                         MemberTypes.Constructor |
 609                         MemberTypes.Event       |
 610                         MemberTypes.Field       |
 611                         MemberTypes.Method      |
 612                         MemberTypes.NestedType  |
 613                         MemberTypes.Property;
 614
 615                 public const BindingFlags AllBindingFlags =
 616                         BindingFlags.Public |
 617                         BindingFlags.Static |
 618                         BindingFlags.Instance;
 619
 620                 public static Expression MemberLookup (EmitContext ec, Type queried_type,
 621                                                        string name, Location loc)
 622                 {
 623                         return MemberLookup (ec, ec.ContainerType, null, queried_type, name,
 624                                              AllMemberTypes, AllBindingFlags, loc);
 625                 }
 626
 627                 public static Expression MemberLookup (EmitContext ec, Type qualifier_type,
 628                                                        Type queried_type, string name, Location loc)
 629                 {
 630                         return MemberLookup (ec, ec.ContainerType, qualifier_type, queried_type,
 631                                              name, AllMemberTypes, AllBindingFlags, loc);
 632                 }
 633
 634                 public static Expression MethodLookup (EmitContext ec, Type queried_type,
 635                                                        string name, Location loc)
 636                 {
 637                         return MemberLookup (ec, ec.ContainerType, null, queried_type, name,
 638                                              MemberTypes.Method, AllBindingFlags, loc);
 639                 }
 640
 641                 /// <summary>
 642                 ///   This is a wrapper for MemberLookup that is not used to "probe", but
 643                 ///   to find a final definition.  If the final definition is not found, we
 644                 ///   look for private members and display a useful debugging message if we
 645                 ///   find it.
 646                 /// </summary>
 647                 public static Expression MemberLookupFinal (EmitContext ec, Type qualifier_type,
 648                                                             Type queried_type, string name,
 649                                                             Location loc)
 650                 {
 651                         return MemberLookupFinal (ec, qualifier_type, queried_type, name,
 652                                                   AllMemberTypes, AllBindingFlags, loc);
 653                 }
 654
 655                 public static Expression MemberLookupFinal (EmitContext ec, Type qualifier_type,
 656                                                             Type queried_type, string name,
 657                                                             MemberTypes mt, BindingFlags bf,
 658                                                             Location loc)
 659                 {
 660                         Expression e;
 661
 662                         int errors = Report.Errors;
 663
 664                         e = MemberLookup (ec, ec.ContainerType, qualifier_type, queried_type,
 665                                           name, mt, bf, loc);
 666
 667                         if (e == null && errors == Report.Errors)
 668                                 // No errors were reported by MemberLookup, but there was an error.
 669                                 MemberLookupFailed (ec, qualifier_type, queried_type, name, null, true, loc);
 670
 671                         return e;
 672                 }
 673
 674                 public static void MemberLookupFailed (EmitContext ec, Type qualifier_type,
 675                                                        Type queried_type, string name,
 676                                                        string class_name, bool complain_if_none_found,
 677                                                        Location loc)
 678                 {
 679                         if (almostMatchedMembers.Count != 0) {
 680                                 if (qualifier_type == null) {
 681                                         foreach (MemberInfo m in almostMatchedMembers)
 682                                                 Report.Error (38, loc,
 683                                                               "Cannot access non-static member `{0}' via nested type `{1}'",
 684                                                               TypeManager.GetFullNameSignature (m),
 685                                                               TypeManager.CSharpName (ec.ContainerType));
 686                                         return;
 687                                 }
 688
 689
 690                                 if (qualifier_type != ec.ContainerType) {
 691                                         // Although a derived class can access protected members of
 692                                         // its base class it cannot do so through an instance of the
 693                                         // base class (CS1540).  If the qualifier_type is a base of the
 694                                         // ec.ContainerType and the lookup succeeds with the latter one,
 695                                         // then we are in this situation.
 696                                         for (int i = 0; i < almostMatchedMembers.Count; ++i) {
 697                                                 MemberInfo m = (MemberInfo) almostMatchedMembers [i];
 698                                                 for (int j = 0; j < i; ++j) {
 699                                                         if (m == almostMatchedMembers [j]) {
 700                                                                 m = null;
 701                                                                 break;
 702                                                         }
 703                                                 }
 704                                                 if (m == null)
 705                                                         continue;
 706
 707                                                 Report.SymbolRelatedToPreviousError (m);
 708                                                 Report.Error (1540, loc,
 709                                                               "Cannot access protected member `{0}' via a qualifier of type `{1}';"
 710                                                               + " the qualifier must be of type `{2}' (or derived from it)",
 711                                                               TypeManager.GetFullNameSignature (m),
 712                                                               TypeManager.CSharpName (qualifier_type),
 713                                                               TypeManager.CSharpName (ec.ContainerType));
 714                                         }
 715                                         return;
 716                                 }
 717                                 almostMatchedMembers.Clear ();
 718                         }
 719
 720                         MemberInfo[] mi = TypeManager.MemberLookup (queried_type, null, queried_type,
 721                                                                     AllMemberTypes, AllBindingFlags |
 722                                                                     BindingFlags.NonPublic, name, null);
 723
 724                         if (mi == null) {
 725                                 if (!complain_if_none_found)
 726                                         return;
 727
 728                                 if (class_name != null)
 729                                         Report.Error (103, loc, "The name `" + name + "' could not be " +
 730                                                       "found in `" + class_name + "'");
 731                                 else
 732                                         Report.Error (
 733                                                 117, loc, "`" + queried_type + "' does not contain a " +
 734                                                 "definition for `" + name + "'");
 735                                 return;
 736                         }
 737
 738                         if (TypeManager.MemberLookup (queried_type, null, queried_type,
 739                                                       AllMemberTypes, AllBindingFlags |
 740                                                       BindingFlags.NonPublic, name, null) == null) {
 741                                 if ((mi.Length == 1) && (mi [0] is Type)) {
 742                                         Type t = (Type) mi [0];
 743
 744                                         Report.Error (305, loc,
 745                                                       "Using the generic type `{0}' " +
 746                                                       "requires {1} type arguments",
 747                                                       TypeManager.GetFullName (t),
 748                                                       TypeManager.GetNumberOfTypeArguments (t));
 749                                         return;
 750                                 }
 751                         }
 752
 753                         if (name == ".ctor" && TypeManager.FindMembers (qualifier_type, MemberTypes.Constructor,
 754                                 BindingFlags.Static | BindingFlags.Instance | BindingFlags.Public | BindingFlags.DeclaredOnly, null, null).Count == 0)
 755                         {
 756                                 Report.Error (143, loc, String.Format ("The type '{0}' has no constructors defined", TypeManager.CSharpName (queried_type)));
 757                                 return;
 758                         }
 759
 760                         if (qualifier_type != null) {
 761                                 Report.Error (122, loc, "'{0}' is inaccessible due to its protection level", TypeManager.CSharpName (qualifier_type) + "." + name);
 762                         } else {
 763                                 Report.Error (122, loc, "'{0}' is inaccessible due to its protection level", name);
 764                 }
 765                 }
 766
 767                 /// <summary>
 768                 ///   Returns an expression that can be used to invoke operator true
 769                 ///   on the expression if it exists.
 770                 /// </summary>
 771                 static public Expression GetOperatorTrue (EmitContext ec, Expression e, Location loc)
 772                 {
 773                         return GetOperatorTrueOrFalse (ec, e, true, loc);
 774                 }
 775
 776                 /// <summary>
 777                 ///   Returns an expression that can be used to invoke operator false
 778                 ///   on the expression if it exists.
 779                 /// </summary>
 780                 static public Expression GetOperatorFalse (EmitContext ec, Expression e, Location loc)
 781                 {
 782                         return GetOperatorTrueOrFalse (ec, e, false, loc);
 783                 }
 784
 785                 static Expression GetOperatorTrueOrFalse (EmitContext ec, Expression e, bool is_true, Location loc)
 786                 {
 787                         MethodBase method;
 788                         Expression operator_group;
 789
 790                         if (TypeManager.IsNullableType (e.Type))
 791                                 return new Nullable.OperatorTrueOrFalse (e, is_true, loc).Resolve (ec);
 792
 793                         operator_group = MethodLookup (ec, e.Type, is_true ? "op_True" : "op_False", loc);
 794                         if (operator_group == null)
 795                                 return null;
 796
 797                         ArrayList arguments = new ArrayList ();
 798                         arguments.Add (new Argument (e, Argument.AType.Expression));
 799                         method = Invocation.OverloadResolve (
 800                                 ec, (MethodGroupExpr) operator_group, arguments, false, loc);
 801
 802                         if (method == null)
 803                                 return null;
 804
 805                         return new StaticCallExpr ((MethodInfo) method, arguments, loc);
 806                 }
 807
 808                 /// <summary>
 809                 ///   Resolves the expression `e' into a boolean expression: either through
 810                 ///   an implicit conversion, or through an `operator true' invocation
 811                 /// </summary>
 812                 public static Expression ResolveBoolean (EmitContext ec, Expression e, Location loc)
 813                 {
 814                         e = e.Resolve (ec);
 815                         if (e == null)
 816                                 return null;
 817
 818                         if (e.Type == TypeManager.bool_type)
 819                                 return e;
 820
 821                         Expression converted = Convert.ImplicitConversion (ec, e, TypeManager.bool_type, Location.Null);
 822
 823                         if (converted != null)
 824                                 return converted;
 825
 826                         //
 827                         // If no implicit conversion to bool exists, try using `operator true'
 828                         //
 829                         Expression operator_true = Expression.GetOperatorTrue (ec, e, loc);
 830                         if (operator_true == null){
 831                                 Report.Error (31, loc, "Can not convert the expression to a boolean");
 832                                 return null;
 833                         }
 834                         return operator_true;
 835                 }
 836
 837                 public string ExprClassName ()
 838                 {
 839                         switch (eclass){
 840                         case ExprClass.Invalid:
 841                                 return "Invalid";
 842                         case ExprClass.Value:
 843                                 return "value";
 844                         case ExprClass.Variable:
 845                                 return "variable";
 846                         case ExprClass.Namespace:
 847                                 return "namespace";
 848                         case ExprClass.Type:
 849                                 return "type";
 850                         case ExprClass.MethodGroup:
 851                                 return "method group";
 852                         case ExprClass.PropertyAccess:
 853                                 return "property access";
 854                         case ExprClass.EventAccess:
 855                                 return "event access";
 856                         case ExprClass.IndexerAccess:
 857                                 return "indexer access";
 858                         case ExprClass.Nothing:
 859                                 return "null";
 860                         }
 861                         throw new Exception ("Should not happen");
 862                 }
 863
 864                 /// <summary>
 865                 ///   Reports that we were expecting `expr' to be of class `expected'
 866                 /// </summary>
 867                 public void Error_UnexpectedKind (string expected, Location loc)
 868                 {
 869                         Report.Error (118, loc, "Expression denotes a `" + ExprClassName () +
 870                                "' where a `" + expected + "' was expected");
 871                 }
 872
 873                 public void Error_UnexpectedKind (ResolveFlags flags, Location loc)
 874                 {
 875                         ArrayList valid = new ArrayList (10);
 876
 877                         if ((flags & ResolveFlags.VariableOrValue) != 0) {
 878                                 valid.Add ("variable");
 879                                 valid.Add ("value");
 880                         }
 881
 882                         if ((flags & ResolveFlags.Type) != 0)
 883                                 valid.Add ("type");
 884
 885                         if ((flags & ResolveFlags.MethodGroup) != 0)
 886                                 valid.Add ("method group");
 887
 888                         if (valid.Count == 0)
 889                                 valid.Add ("unknown");
 890
 891                         StringBuilder sb = new StringBuilder ();
 892                         for (int i = 0; i < valid.Count; i++) {
 893                                 if (i > 0)
 894                                         sb.Append (", ");
 895                                 else if (i == valid.Count)
 896                                         sb.Append (" or ");
 897                                 sb.Append (valid [i]);
 898                         }
 899
 900                         Report.Error (119, loc, "Expression denotes a `" + ExprClassName () + "' where " +
 901                                "a `" + sb.ToString () + "' was expected");
 902                 }
 903
 904                 static public void Error_ConstantValueCannotBeConverted (Location l, string val, Type t)
 905                 {
 906                         Report.Error (31, l, "Constant value `" + val + "' cannot be converted to " +
 907                                       TypeManager.CSharpName (t));
 908                 }
 909
 910                 public static void UnsafeError (Location loc)
 911                 {
 912                         Report.Error (214, loc, "Pointers may only be used in an unsafe context");
 913                 }
 914
 915                 /// <summary>
 916                 ///   Converts the IntConstant, UIntConstant, LongConstant or
 917                 ///   ULongConstant into the integral target_type.   Notice
 918                 ///   that we do not return an `Expression' we do return
 919                 ///   a boxed integral type.
 920                 ///
 921                 ///   FIXME: Since I added the new constants, we need to
 922                 ///   also support conversions from CharConstant, ByteConstant,
 923                 ///   SByteConstant, UShortConstant, ShortConstant
 924                 ///
 925                 ///   This is used by the switch statement, so the domain
 926                 ///   of work is restricted to the literals above, and the
 927                 ///   targets are int32, uint32, char, byte, sbyte, ushort,
 928                 ///   short, uint64 and int64
 929                 /// </summary>
 930                 public static object ConvertIntLiteral (Constant c, Type target_type, Location loc)
 931                 {
 932                         if (!Convert.ImplicitStandardConversionExists (Convert.ConstantEC, c, target_type)){
 933                                 Convert.Error_CannotImplicitConversion (loc, c.Type, target_type);
 934                                 return null;
 935                         }
 936
 937                         string s = "";
 938
 939                         if (c.Type == target_type)
 940                                 return ((Constant) c).GetValue ();
 941
 942                         //
 943                         // Make into one of the literals we handle, we dont really care
 944                         // about this value as we will just return a few limited types
 945                         //
 946                         if (c is EnumConstant)
 947                                 c = ((EnumConstant)c).WidenToCompilerConstant ();
 948
 949                         if (c is IntConstant){
 950                                 int v = ((IntConstant) c).Value;
 951
 952                                 if (target_type == TypeManager.uint32_type){
 953                                         if (v >= 0)
 954                                                 return (uint) v;
 955                                 } else if (target_type == TypeManager.char_type){
 956                                         if (v >= Char.MinValue && v <= Char.MaxValue)
 957                                                 return (char) v;
 958                                 } else if (target_type == TypeManager.byte_type){
 959                                         if (v >= Byte.MinValue && v <= Byte.MaxValue)
 960                                                 return (byte) v;
 961                                 } else if (target_type == TypeManager.sbyte_type){
 962                                         if (v >= SByte.MinValue && v <= SByte.MaxValue)
 963                                                 return (sbyte) v;
 964                                 } else if (target_type == TypeManager.short_type){
 965                                         if (v >= Int16.MinValue && v <= UInt16.MaxValue)
 966                                                 return (short) v;
 967                                 } else if (target_type == TypeManager.ushort_type){
 968                                         if (v >= UInt16.MinValue && v <= UInt16.MaxValue)
 969                                                 return (ushort) v;
 970                                 } else if (target_type == TypeManager.int64_type)
 971                                         return (long) v;
 972                                 else if (target_type == TypeManager.uint64_type){
 973                                         if (v > 0)
 974                                                 return (ulong) v;
 975                                 }
 976
 977                                 s = v.ToString ();
 978                         } else if (c is UIntConstant){
 979                                 uint v = ((UIntConstant) c).Value;
 980
 981                                 if (target_type == TypeManager.int32_type){
 982                                         if (v <= Int32.MaxValue)
 983                                                 return (int) v;
 984                                 } else if (target_type == TypeManager.char_type){
 985                                         if (v >= Char.MinValue && v <= Char.MaxValue)
 986                                                 return (char) v;
 987                                 } else if (target_type == TypeManager.byte_type){
 988                                         if (v <= Byte.MaxValue)
 989                                                 return (byte) v;
 990                                 } else if (target_type == TypeManager.sbyte_type){
 991                                         if (v <= SByte.MaxValue)
 992                                                 return (sbyte) v;
 993                                 } else if (target_type == TypeManager.short_type){
 994                                         if (v <= UInt16.MaxValue)
 995                                                 return (short) v;
 996                                 } else if (target_type == TypeManager.ushort_type){
 997                                         if (v <= UInt16.MaxValue)
 998                                                 return (ushort) v;
 999                                 } else if (target_type == TypeManager.int64_type)
1000                                         return (long) v;
1001                                 else if (target_type == TypeManager.uint64_type)
1002                                         return (ulong) v;
1003                                 s = v.ToString ();
1004                         } else if (c is LongConstant){
1005                                 long v = ((LongConstant) c).Value;
1006
1007                                 if (target_type == TypeManager.int32_type){
1008                                         if (v >= UInt32.MinValue && v <= UInt32.MaxValue)
1009                                                 return (int) v;
1010                                 } else if (target_type == TypeManager.uint32_type){
1011                                         if (v >= 0 && v <= UInt32.MaxValue)
1012                                                 return (uint) v;
1013                                 } else if (target_type == TypeManager.char_type){
1014                                         if (v >= Char.MinValue && v <= Char.MaxValue)
1015                                                 return (char) v;
1016                                 } else if (target_type == TypeManager.byte_type){
1017                                         if (v >= Byte.MinValue && v <= Byte.MaxValue)
1018                                                 return (byte) v;
1019                                 } else if (target_type == TypeManager.sbyte_type){
1020                                         if (v >= SByte.MinValue && v <= SByte.MaxValue)
1021                                                 return (sbyte) v;
1022                                 } else if (target_type == TypeManager.short_type){
1023                                         if (v >= Int16.MinValue && v <= UInt16.MaxValue)
1024                                                 return (short) v;
1025                                 } else if (target_type == TypeManager.ushort_type){
1026                                         if (v >= UInt16.MinValue && v <= UInt16.MaxValue)
1027                                                 return (ushort) v;
1028                                 } else if (target_type == TypeManager.uint64_type){
1029                                         if (v > 0)
1030                                                 return (ulong) v;
1031                                 }
1032                                 s = v.ToString ();
1033                         } else if (c is ULongConstant){
1034                                 ulong v = ((ULongConstant) c).Value;
1035
1036                                 if (target_type == TypeManager.int32_type){
1037                                         if (v <= Int32.MaxValue)
1038                                                 return (int) v;
1039                                 } else if (target_type == TypeManager.uint32_type){
1040                                         if (v <= UInt32.MaxValue)
1041                                                 return (uint) v;
1042                                 } else if (target_type == TypeManager.char_type){
1043                                         if (v >= Char.MinValue && v <= Char.MaxValue)
1044                                                 return (char) v;
1045                                 } else if (target_type == TypeManager.byte_type){
1046                                         if (v >= Byte.MinValue && v <= Byte.MaxValue)
1047                                                 return (byte) v;
1048                                 } else if (target_type == TypeManager.sbyte_type){
1049                                         if (v <= (int) SByte.MaxValue)
1050                                                 return (sbyte) v;
1051                                 } else if (target_type == TypeManager.short_type){
1052                                         if (v <= UInt16.MaxValue)
1053                                                 return (short) v;
1054                                 } else if (target_type == TypeManager.ushort_type){
1055                                         if (v <= UInt16.MaxValue)
1056                                                 return (ushort) v;
1057                                 } else if (target_type == TypeManager.int64_type){
1058                                         if (v <= Int64.MaxValue)
1059                                                 return (long) v;
1060                                 }
1061                                 s = v.ToString ();
1062                         } else if (c is ByteConstant){
1063                                 byte v = ((ByteConstant) c).Value;
1064
1065                                 if (target_type == TypeManager.int32_type)
1066                                         return (int) v;
1067                                 else if (target_type == TypeManager.uint32_type)
1068                                         return (uint) v;
1069                                 else if (target_type == TypeManager.char_type)
1070                                         return (char) v;
1071                                 else if (target_type == TypeManager.sbyte_type){
1072                                         if (v <= SByte.MaxValue)
1073                                                 return (sbyte) v;
1074                                 } else if (target_type == TypeManager.short_type)
1075                                         return (short) v;
1076                                 else if (target_type == TypeManager.ushort_type)
1077                                         return (ushort) v;
1078                                 else if (target_type == TypeManager.int64_type)
1079                                         return (long) v;
1080                                 else if (target_type == TypeManager.uint64_type)
1081                                         return (ulong) v;
1082                                 s = v.ToString ();
1083                         } else if (c is SByteConstant){
1084                                 sbyte v = ((SByteConstant) c).Value;
1085
1086                                 if (target_type == TypeManager.int32_type)
1087                                         return (int) v;
1088                                 else if (target_type == TypeManager.uint32_type){
1089                                         if (v >= 0)
1090                                                 return (uint) v;
1091                                 } else if (target_type == TypeManager.char_type){
1092                                         if (v >= 0)
1093                                                 return (char) v;
1094                                 } else if (target_type == TypeManager.byte_type){
1095                                         if (v >= 0)
1096                                                 return (byte) v;
1097                                 } else if (target_type == TypeManager.short_type)
1098                                         return (short) v;
1099                                 else if (target_type == TypeManager.ushort_type){
1100                                         if (v >= 0)
1101                                                 return (ushort) v;
1102                                 } else if (target_type == TypeManager.int64_type)
1103                                         return (long) v;
1104                                 else if (target_type == TypeManager.uint64_type){
1105                                         if (v >= 0)
1106                                                 return (ulong) v;
1107                                 }
1108                                 s = v.ToString ();
1109                         } else if (c is ShortConstant){
1110                                 short v = ((ShortConstant) c).Value;
1111
1112                                 if (target_type == TypeManager.int32_type){
1113                                         return (int) v;
1114                                 } else if (target_type == TypeManager.uint32_type){
1115                                         if (v >= 0)
1116                                                 return (uint) v;
1117                                 } else if (target_type == TypeManager.char_type){
1118                                         if (v >= 0)
1119                                                 return (char) v;
1120                                 } else if (target_type == TypeManager.byte_type){
1121                                         if (v >= Byte.MinValue && v <= Byte.MaxValue)
1122                                                 return (byte) v;
1123                                 } else if (target_type == TypeManager.sbyte_type){
1124                                         if (v >= SByte.MinValue && v <= SByte.MaxValue)
1125                                                 return (sbyte) v;
1126                                 } else if (target_type == TypeManager.ushort_type){
1127                                         if (v >= 0)
1128                                                 return (ushort) v;
1129                                 } else if (target_type == TypeManager.int64_type)
1130                                         return (long) v;
1131                                 else if (target_type == TypeManager.uint64_type)
1132                                         return (ulong) v;
1133
1134                                 s = v.ToString ();
1135                         } else if (c is UShortConstant){
1136                                 ushort v = ((UShortConstant) c).Value;
1137
1138                                 if (target_type == TypeManager.int32_type)
1139                                         return (int) v;
1140                                 else if (target_type == TypeManager.uint32_type)
1141                                         return (uint) v;
1142                                 else if (target_type == TypeManager.char_type){
1143                                         if (v >= Char.MinValue && v <= Char.MaxValue)
1144                                                 return (char) v;
1145                                 } else if (target_type == TypeManager.byte_type){
1146                                         if (v >= Byte.MinValue && v <= Byte.MaxValue)
1147                                                 return (byte) v;
1148                                 } else if (target_type == TypeManager.sbyte_type){
1149                                         if (v <= SByte.MaxValue)
1150                                                 return (byte) v;
1151                                 } else if (target_type == TypeManager.short_type){
1152                                         if (v <= Int16.MaxValue)
1153                                                 return (short) v;
1154                                 } else if (target_type == TypeManager.int64_type)
1155                                         return (long) v;
1156                                 else if (target_type == TypeManager.uint64_type)
1157                                         return (ulong) v;
1158
1159                                 s = v.ToString ();
1160                         } else if (c is CharConstant){
1161                                 char v = ((CharConstant) c).Value;
1162
1163                                 if (target_type == TypeManager.int32_type)
1164                                         return (int) v;
1165                                 else if (target_type == TypeManager.uint32_type)
1166                                         return (uint) v;
1167                                 else if (target_type == TypeManager.byte_type){
1168                                         if (v >= Byte.MinValue && v <= Byte.MaxValue)
1169                                                 return (byte) v;
1170                                 } else if (target_type == TypeManager.sbyte_type){
1171                                         if (v <= SByte.MaxValue)
1172                                                 return (sbyte) v;
1173                                 } else if (target_type == TypeManager.short_type){
1174                                         if (v <= Int16.MaxValue)
1175                                                 return (short) v;
1176                                 } else if (target_type == TypeManager.ushort_type)
1177                                         return (short) v;
1178                                 else if (target_type == TypeManager.int64_type)
1179                                         return (long) v;
1180                                 else if (target_type == TypeManager.uint64_type)
1181                                         return (ulong) v;
1182
1183                                 s = v.ToString ();
1184                         }
1185                         Error_ConstantValueCannotBeConverted (loc, s, target_type);
1186                         return null;
1187                 }
1188
1189                 //
1190                 // Load the object from the pointer.
1191                 //
1192                 public static void LoadFromPtr (ILGenerator ig, Type t)
1193                 {
1194                         if (t == TypeManager.int32_type)
1195                                 ig.Emit (OpCodes.Ldind_I4);
1196                         else if (t == TypeManager.uint32_type)
1197                                 ig.Emit (OpCodes.Ldind_U4);
1198                         else if (t == TypeManager.short_type)
1199                                 ig.Emit (OpCodes.Ldind_I2);
1200                         else if (t == TypeManager.ushort_type)
1201                                 ig.Emit (OpCodes.Ldind_U2);
1202                         else if (t == TypeManager.char_type)
1203                                 ig.Emit (OpCodes.Ldind_U2);
1204                         else if (t == TypeManager.byte_type)
1205                                 ig.Emit (OpCodes.Ldind_U1);
1206                         else if (t == TypeManager.sbyte_type)
1207                                 ig.Emit (OpCodes.Ldind_I1);
1208                         else if (t == TypeManager.uint64_type)
1209                                 ig.Emit (OpCodes.Ldind_I8);
1210                         else if (t == TypeManager.int64_type)
1211                                 ig.Emit (OpCodes.Ldind_I8);
1212                         else if (t == TypeManager.float_type)
1213                                 ig.Emit (OpCodes.Ldind_R4);
1214                         else if (t == TypeManager.double_type)
1215                                 ig.Emit (OpCodes.Ldind_R8);
1216                         else if (t == TypeManager.bool_type)
1217                                 ig.Emit (OpCodes.Ldind_I1);
1218                         else if (t == TypeManager.intptr_type)
1219                                 ig.Emit (OpCodes.Ldind_I);
1220                         else if (TypeManager.IsEnumType (t)) {
1221                                 if (t == TypeManager.enum_type)
1222                                         ig.Emit (OpCodes.Ldind_Ref);
1223                                 else
1224                                         LoadFromPtr (ig, TypeManager.EnumToUnderlying (t));
1225                         } else if (t.IsValueType || t.IsGenericParameter)
1226                                 ig.Emit (OpCodes.Ldobj, t);
1227                         else if (t.IsPointer)
1228                                 ig.Emit (OpCodes.Ldind_I);
1229                         else
1230                                 ig.Emit (OpCodes.Ldind_Ref);
1231                 }
1232
1233                 //
1234                 // The stack contains the pointer and the value of type `type'
1235                 //
1236                 public static void StoreFromPtr (ILGenerator ig, Type type)
1237                 {
1238                         if (TypeManager.IsEnumType (type))
1239                                 type = TypeManager.EnumToUnderlying (type);
1240                         if (type == TypeManager.int32_type || type == TypeManager.uint32_type)
1241                                 ig.Emit (OpCodes.Stind_I4);
1242                         else if (type == TypeManager.int64_type || type == TypeManager.uint64_type)
1243                                 ig.Emit (OpCodes.Stind_I8);
1244                         else if (type == TypeManager.char_type || type == TypeManager.short_type ||
1245                                  type == TypeManager.ushort_type)
1246                                 ig.Emit (OpCodes.Stind_I2);
1247                         else if (type == TypeManager.float_type)
1248                                 ig.Emit (OpCodes.Stind_R4);
1249                         else if (type == TypeManager.double_type)
1250                                 ig.Emit (OpCodes.Stind_R8);
1251                         else if (type == TypeManager.byte_type || type == TypeManager.sbyte_type ||
1252                                  type == TypeManager.bool_type)
1253                                 ig.Emit (OpCodes.Stind_I1);
1254                         else if (type == TypeManager.intptr_type)
1255                                 ig.Emit (OpCodes.Stind_I);
1256                         else if (type.IsValueType || type.IsGenericParameter)
1257                                 ig.Emit (OpCodes.Stobj, type);
1258                         else
1259                                 ig.Emit (OpCodes.Stind_Ref);
1260                 }
1261
1262                 //
1263                 // Returns the size of type `t' if known, otherwise, 0
1264                 //
1265                 public static int GetTypeSize (Type t)
1266                 {
1267                         t = TypeManager.TypeToCoreType (t);
1268                         if (t == TypeManager.int32_type ||
1269                             t == TypeManager.uint32_type ||
1270                             t == TypeManager.float_type)
1271                                 return 4;
1272                         else if (t == TypeManager.int64_type ||
1273                                  t == TypeManager.uint64_type ||
1274                                  t == TypeManager.double_type)
1275                                 return 8;
1276                         else if (t == TypeManager.byte_type ||
1277                                  t == TypeManager.sbyte_type ||
1278                                  t == TypeManager.bool_type)
1279                                 return 1;
1280                         else if (t == TypeManager.short_type ||
1281                                  t == TypeManager.char_type ||
1282                                  t == TypeManager.ushort_type)
1283                                 return 2;
1284                         else if (t == TypeManager.decimal_type)
1285                                 return 16;
1286                         else
1287                                 return 0;
1288                 }
1289
1290                 public static void Error_NegativeArrayIndex (Location loc)
1291                 {
1292                         Report.Error (248, loc, "Cannot create an array with a negative size");
1293                 }
1294
1295                 //
1296                 // Converts `source' to an int, uint, long or ulong.
1297                 //
1298                 public Expression ExpressionToArrayArgument (EmitContext ec, Expression source, Location loc)
1299                 {
1300                         Expression target;
1301
1302                         bool old_checked = ec.CheckState;
1303                         ec.CheckState = true;
1304
1305                         target = Convert.ImplicitConversion (ec, source, TypeManager.int32_type, loc);
1306                         if (target == null){
1307                                 target = Convert.ImplicitConversion (ec, source, TypeManager.uint32_type, loc);
1308                                 if (target == null){
1309                                         target = Convert.ImplicitConversion (ec, source, TypeManager.int64_type, loc);
1310                                         if (target == null){
1311                                                 target = Convert.ImplicitConversion (ec, source, TypeManager.uint64_type, loc);
1312                                                 if (target == null)
1313                                                         Convert.Error_CannotImplicitConversion (loc, source.Type, TypeManager.int32_type);
1314                                         }
1315                                 }
1316                         }
1317                         ec.CheckState = old_checked;
1318
1319                         //
1320                         // Only positive constants are allowed at compile time
1321                         //
1322                         if (target is Constant){
1323                                 if (target is IntConstant){
1324                                         if (((IntConstant) target).Value < 0){
1325                                                 Error_NegativeArrayIndex (loc);
1326                                                 return null;
1327                                         }
1328                                 }
1329
1330                                 if (target is LongConstant){
1331                                         if (((LongConstant) target).Value < 0){
1332                                                 Error_NegativeArrayIndex (loc);
1333                                                 return null;
1334                                         }
1335                                 }
1336
1337                         }
1338
1339                         return target;
1340                 }
1341
1342         }
1343
1344         /// <summary>
1345         ///   This is just a base class for expressions that can
1346         ///   appear on statements (invocations, object creation,
1347         ///   assignments, post/pre increment and decrement).  The idea
1348         ///   being that they would support an extra Emition interface that
1349         ///   does not leave a result on the stack.
1350         /// </summary>
1351         public abstract class ExpressionStatement : Expression {
1352
1353                 public virtual ExpressionStatement ResolveStatement (EmitContext ec)
1354                 {
1355                         Expression e = Resolve (ec);
1356                         if (e == null)
1357                                 return null;
1358
1359                         ExpressionStatement es = e as ExpressionStatement;
1360                         if (es == null)
1361                                 Error (201, "Only assignment, call, increment, decrement and new object " +
1362                                        "expressions can be used as a statement");
1363
1364                         return es;
1365                 }
1366
1367                 /// <summary>
1368                 ///   Requests the expression to be emitted in a `statement'
1369                 ///   context.  This means that no new value is left on the
1370                 ///   stack after invoking this method (constrasted with
1371                 ///   Emit that will always leave a value on the stack).
1372                 /// </summary>
1373                 public abstract void EmitStatement (EmitContext ec);
1374         }
1375
1376         /// <summary>
1377         ///   This kind of cast is used to encapsulate the child
1378         ///   whose type is child.Type into an expression that is
1379         ///   reported to return "return_type".  This is used to encapsulate
1380         ///   expressions which have compatible types, but need to be dealt
1381         ///   at higher levels with.
1382         ///
1383         ///   For example, a "byte" expression could be encapsulated in one
1384         ///   of these as an "unsigned int".  The type for the expression
1385         ///   would be "unsigned int".
1386         ///
1387         /// </summary>
1388         public class EmptyCast : Expression {
1389                 protected Expression child;
1390
1391                 public Expression Child {
1392                         get {
1393                                 return child;
1394                         }
1395                 }
1396
1397                 public EmptyCast (Expression child, Type return_type)
1398                 {
1399                         eclass = child.eclass;
1400                         loc = child.Location;
1401                         type = return_type;
1402                         this.child = child;
1403                 }
1404
1405                 public override Expression DoResolve (EmitContext ec)
1406                 {
1407                         // This should never be invoked, we are born in fully
1408                         // initialized state.
1409
1410                         return this;
1411                 }
1412
1413                 public override void Emit (EmitContext ec)
1414                 {
1415                         child.Emit (ec);
1416                 }
1417         }
1418
1419         //
1420         // We need to special case this since an empty cast of
1421         // a NullLiteral is still a Constant
1422         //
1423         public class NullCast : Constant {
1424                 protected Expression child;
1425
1426                 public NullCast (Expression child, Type return_type)
1427                 {
1428                         eclass = child.eclass;
1429                         type = return_type;
1430                         this.child = child;
1431                 }
1432
1433                 override public string AsString ()
1434                 {
1435                         return "null";
1436                 }
1437
1438                 public override object GetValue ()
1439                 {
1440                         return null;
1441                 }
1442
1443                 public override Expression DoResolve (EmitContext ec)
1444                 {
1445                         // This should never be invoked, we are born in fully
1446                         // initialized state.
1447
1448                         return this;
1449                 }
1450
1451                 public override void Emit (EmitContext ec)
1452                 {
1453                         child.Emit (ec);
1454                 }
1455
1456                 public override bool IsDefaultValue {
1457                         get {
1458                                 throw new NotImplementedException ();
1459                         }
1460                 }
1461
1462                 public override bool IsNegative {
1463                         get {
1464                                 return false;
1465                         }
1466                 }
1467         }
1468
1469
1470         /// <summary>
1471         ///  This class is used to wrap literals which belong inside Enums
1472         /// </summary>
1473         public class EnumConstant : Constant {
1474                 public Constant Child;
1475
1476                 public EnumConstant (Constant child, Type enum_type)
1477                 {
1478                         eclass = child.eclass;
1479                         this.Child = child;
1480                         type = enum_type;
1481                 }
1482
1483                 public override Expression DoResolve (EmitContext ec)
1484                 {
1485                         // This should never be invoked, we are born in fully
1486                         // initialized state.
1487
1488                         return this;
1489                 }
1490
1491                 public override void Emit (EmitContext ec)
1492                 {
1493                         Child.Emit (ec);
1494                 }
1495
1496                 public override object GetValue ()
1497                 {
1498                         return Child.GetValue ();
1499                 }
1500
1501                 public object GetValueAsEnumType ()
1502                 {
1503                         return System.Enum.ToObject (type, Child.GetValue ());
1504                 }
1505
1506                 //
1507                 // Converts from one of the valid underlying types for an enumeration
1508                 // (int32, uint32, int64, uint64, short, ushort, byte, sbyte) to
1509                 // one of the internal compiler literals: Int/UInt/Long/ULong Literals.
1510                 //
1511                 public Constant WidenToCompilerConstant ()
1512                 {
1513                         Type t = TypeManager.EnumToUnderlying (Child.Type);
1514                         object v = ((Constant) Child).GetValue ();;
1515
1516                         if (t == TypeManager.int32_type)
1517                                 return new IntConstant ((int) v);
1518                         if (t == TypeManager.uint32_type)
1519                                 return new UIntConstant ((uint) v);
1520                         if (t == TypeManager.int64_type)
1521                                 return new LongConstant ((long) v);
1522                         if (t == TypeManager.uint64_type)
1523                                 return new ULongConstant ((ulong) v);
1524                         if (t == TypeManager.short_type)
1525                                 return new ShortConstant ((short) v);
1526                         if (t == TypeManager.ushort_type)
1527                                 return new UShortConstant ((ushort) v);
1528                         if (t == TypeManager.byte_type)
1529                                 return new ByteConstant ((byte) v);
1530                         if (t == TypeManager.sbyte_type)
1531                                 return new SByteConstant ((sbyte) v);
1532
1533                         throw new Exception ("Invalid enumeration underlying type: " + t);
1534                 }
1535
1536                 //
1537                 // Extracts the value in the enumeration on its native representation
1538                 //
1539                 public object GetPlainValue ()
1540                 {
1541                         Type t = TypeManager.EnumToUnderlying (Child.Type);
1542                         object v = ((Constant) Child).GetValue ();;
1543
1544                         if (t == TypeManager.int32_type)
1545                                 return (int) v;
1546                         if (t == TypeManager.uint32_type)
1547                                 return (uint) v;
1548                         if (t == TypeManager.int64_type)
1549                                 return (long) v;
1550                         if (t == TypeManager.uint64_type)
1551                                 return (ulong) v;
1552                         if (t == TypeManager.short_type)
1553                                 return (short) v;
1554                         if (t == TypeManager.ushort_type)
1555                                 return (ushort) v;
1556                         if (t == TypeManager.byte_type)
1557                                 return (byte) v;
1558                         if (t == TypeManager.sbyte_type)
1559                                 return (sbyte) v;
1560
1561                         return null;
1562                 }
1563
1564                 public override string AsString ()
1565                 {
1566                         return Child.AsString ();
1567                 }
1568
1569                 public override DoubleConstant ConvertToDouble ()
1570                 {
1571                         return Child.ConvertToDouble ();
1572                 }
1573
1574                 public override FloatConstant ConvertToFloat ()
1575                 {
1576                         return Child.ConvertToFloat ();
1577                 }
1578
1579                 public override ULongConstant ConvertToULong ()
1580                 {
1581                         return Child.ConvertToULong ();
1582                 }
1583
1584                 public override LongConstant ConvertToLong ()
1585                 {
1586                         return Child.ConvertToLong ();
1587                 }
1588
1589                 public override UIntConstant ConvertToUInt ()
1590                 {
1591                         return Child.ConvertToUInt ();
1592                 }
1593
1594                 public override IntConstant ConvertToInt ()
1595                 {
1596                         return Child.ConvertToInt ();
1597                 }
1598
1599                 public override bool IsDefaultValue {
1600                         get {
1601                                 return Child.IsDefaultValue;
1602                         }
1603                 }
1604
1605                 public override bool IsZeroInteger {
1606                         get { return Child.IsZeroInteger; }
1607                 }
1608
1609                 public override bool IsNegative {
1610                         get {
1611                                 return Child.IsNegative;
1612                         }
1613                 }
1614         }
1615
1616         /// <summary>
1617         ///   This kind of cast is used to encapsulate Value Types in objects.
1618         ///
1619         ///   The effect of it is to box the value type emitted by the previous
1620         ///   operation.
1621         /// </summary>
1622         public class BoxedCast : EmptyCast {
1623
1624                 public BoxedCast (Expression expr)
1625                         : base (expr, TypeManager.object_type)
1626                 {
1627                         eclass = ExprClass.Value;
1628                 }
1629
1630                 public BoxedCast (Expression expr, Type target_type)
1631                         : base (expr, target_type)
1632                 {
1633                         eclass = ExprClass.Value;
1634                 }
1635
1636                 public override Expression DoResolve (EmitContext ec)
1637                 {
1638                         // This should never be invoked, we are born in fully
1639                         // initialized state.
1640
1641                         return this;
1642                 }
1643
1644                 public override void Emit (EmitContext ec)
1645                 {
1646                         base.Emit (ec);
1647
1648                         ec.ig.Emit (OpCodes.Box, child.Type);
1649                 }
1650         }
1651
1652         public class UnboxCast : EmptyCast {
1653                 public UnboxCast (Expression expr, Type return_type)
1654                         : base (expr, return_type)
1655                 {
1656                 }
1657
1658                 public override Expression DoResolve (EmitContext ec)
1659                 {
1660                         // This should never be invoked, we are born in fully
1661                         // initialized state.
1662
1663                         return this;
1664                 }
1665
1666                 public override void Emit (EmitContext ec)
1667                 {
1668                         Type t = type;
1669                         ILGenerator ig = ec.ig;
1670
1671                         base.Emit (ec);
1672                         if (t.IsGenericParameter)
1673                                 ig.Emit (OpCodes.Unbox_Any, t);
1674                         else {
1675                                 ig.Emit (OpCodes.Unbox, t);
1676
1677                                 LoadFromPtr (ig, t);
1678                         }
1679                 }
1680         }
1681
1682         /// <summary>
1683         ///   This is used to perform explicit numeric conversions.
1684         ///
1685         ///   Explicit numeric conversions might trigger exceptions in a checked
1686         ///   context, so they should generate the conv.ovf opcodes instead of
1687         ///   conv opcodes.
1688         /// </summary>
1689         public class ConvCast : EmptyCast {
1690                 public enum Mode : byte {
1691                         I1_U1, I1_U2, I1_U4, I1_U8, I1_CH,
1692                         U1_I1, U1_CH,
1693                         I2_I1, I2_U1, I2_U2, I2_U4, I2_U8, I2_CH,
1694                         U2_I1, U2_U1, U2_I2, U2_CH,
1695                         I4_I1, I4_U1, I4_I2, I4_U2, I4_U4, I4_U8, I4_CH,
1696                         U4_I1, U4_U1, U4_I2, U4_U2, U4_I4, U4_CH,
1697                         I8_I1, I8_U1, I8_I2, I8_U2, I8_I4, I8_U4, I8_U8, I8_CH,
1698                         U8_I1, U8_U1, U8_I2, U8_U2, U8_I4, U8_U4, U8_I8, U8_CH,
1699                         CH_I1, CH_U1, CH_I2,
1700                         R4_I1, R4_U1, R4_I2, R4_U2, R4_I4, R4_U4, R4_I8, R4_U8, R4_CH,
1701                         R8_I1, R8_U1, R8_I2, R8_U2, R8_I4, R8_U4, R8_I8, R8_U8, R8_CH, R8_R4
1702                 }
1703
1704                 Mode mode;
1705                 bool checked_state;
1706
1707                 public ConvCast (EmitContext ec, Expression child, Type return_type, Mode m)
1708                         : base (child, return_type)
1709                 {
1710                         checked_state = ec.CheckState;
1711                         mode = m;
1712                 }
1713
1714                 public override Expression DoResolve (EmitContext ec)
1715                 {
1716                         // This should never be invoked, we are born in fully
1717                         // initialized state.
1718
1719                         return this;
1720                 }
1721
1722                 public override string ToString ()
1723                 {
1724                         return String.Format ("ConvCast ({0}, {1})", mode, child);
1725                 }
1726
1727                 public override void Emit (EmitContext ec)
1728                 {
1729                         ILGenerator ig = ec.ig;
1730
1731                         base.Emit (ec);
1732
1733                         if (checked_state){
1734                                 switch (mode){
1735                                 case Mode.I1_U1: ig.Emit (OpCodes.Conv_Ovf_U1); break;
1736                                 case Mode.I1_U2: ig.Emit (OpCodes.Conv_Ovf_U2); break;
1737                                 case Mode.I1_U4: ig.Emit (OpCodes.Conv_Ovf_U4); break;
1738                                 case Mode.I1_U8: ig.Emit (OpCodes.Conv_Ovf_U8); break;
1739                                 case Mode.I1_CH: ig.Emit (OpCodes.Conv_Ovf_U2); break;
1740
1741                                 case Mode.U1_I1: ig.Emit (OpCodes.Conv_Ovf_I1_Un); break;
1742                                 case Mode.U1_CH: /* nothing */ break;
1743
1744                                 case Mode.I2_I1: ig.Emit (OpCodes.Conv_Ovf_I1); break;
1745                                 case Mode.I2_U1: ig.Emit (OpCodes.Conv_Ovf_U1); break;
1746                                 case Mode.I2_U2: ig.Emit (OpCodes.Conv_Ovf_U2); break;
1747                                 case Mode.I2_U4: ig.Emit (OpCodes.Conv_Ovf_U4); break;
1748                                 case Mode.I2_U8: ig.Emit (OpCodes.Conv_Ovf_U8); break;
1749                                 case Mode.I2_CH: ig.Emit (OpCodes.Conv_Ovf_U2); break;
1750
1751                                 case Mode.U2_I1: ig.Emit (OpCodes.Conv_Ovf_I1_Un); break;
1752                                 case Mode.U2_U1: ig.Emit (OpCodes.Conv_Ovf_U1_Un); break;
1753                                 case Mode.U2_I2: ig.Emit (OpCodes.Conv_Ovf_I2_Un); break;
1754                                 case Mode.U2_CH: /* nothing */ break;
1755
1756                                 case Mode.I4_I1: ig.Emit (OpCodes.Conv_Ovf_I1); break;
1757                                 case Mode.I4_U1: ig.Emit (OpCodes.Conv_Ovf_U1); break;
1758                                 case Mode.I4_I2: ig.Emit (OpCodes.Conv_Ovf_I2); break;
1759                                 case Mode.I4_U4: ig.Emit (OpCodes.Conv_Ovf_U4); break;
1760                                 case Mode.I4_U2: ig.Emit (OpCodes.Conv_Ovf_U2); break;
1761                                 case Mode.I4_U8: ig.Emit (OpCodes.Conv_Ovf_U8); break;
1762                                 case Mode.I4_CH: ig.Emit (OpCodes.Conv_Ovf_U2); break;
1763
1764                                 case Mode.U4_I1: ig.Emit (OpCodes.Conv_Ovf_I1_Un); break;
1765                                 case Mode.U4_U1: ig.Emit (OpCodes.Conv_Ovf_U1_Un); break;
1766                                 case Mode.U4_I2: ig.Emit (OpCodes.Conv_Ovf_I2_Un); break;
1767                                 case Mode.U4_U2: ig.Emit (OpCodes.Conv_Ovf_U2_Un); break;
1768                                 case Mode.U4_I4: ig.Emit (OpCodes.Conv_Ovf_I4_Un); break;
1769                                 case Mode.U4_CH: ig.Emit (OpCodes.Conv_Ovf_U2_Un); break;
1770
1771                                 case Mode.I8_I1: ig.Emit (OpCodes.Conv_Ovf_I1); break;
1772                                 case Mode.I8_U1: ig.Emit (OpCodes.Conv_Ovf_U1); break;
1773                                 case Mode.I8_I2: ig.Emit (OpCodes.Conv_Ovf_I2); break;
1774                                 case Mode.I8_U2: ig.Emit (OpCodes.Conv_Ovf_U2); break;
1775                                 case Mode.I8_I4: ig.Emit (OpCodes.Conv_Ovf_I4); break;
1776                                 case Mode.I8_U4: ig.Emit (OpCodes.Conv_Ovf_U4); break;
1777                                 case Mode.I8_U8: ig.Emit (OpCodes.Conv_Ovf_U8); break;
1778                                 case Mode.I8_CH: ig.Emit (OpCodes.Conv_Ovf_U2); break;
1779
1780                                 case Mode.U8_I1: ig.Emit (OpCodes.Conv_Ovf_I1_Un); break;
1781                                 case Mode.U8_U1: ig.Emit (OpCodes.Conv_Ovf_U1_Un); break;
1782                                 case Mode.U8_I2: ig.Emit (OpCodes.Conv_Ovf_I2_Un); break;
1783                                 case Mode.U8_U2: ig.Emit (OpCodes.Conv_Ovf_U2_Un); break;
1784                                 case Mode.U8_I4: ig.Emit (OpCodes.Conv_Ovf_I4_Un); break;
1785                                 case Mode.U8_U4: ig.Emit (OpCodes.Conv_Ovf_U4_Un); break;
1786                                 case Mode.U8_I8: ig.Emit (OpCodes.Conv_Ovf_I8_Un); break;
1787                                 case Mode.U8_CH: ig.Emit (OpCodes.Conv_Ovf_U2_Un); break;
1788
1789                                 case Mode.CH_I1: ig.Emit (OpCodes.Conv_Ovf_I1_Un); break;
1790                                 case Mode.CH_U1: ig.Emit (OpCodes.Conv_Ovf_U1_Un); break;
1791                                 case Mode.CH_I2: ig.Emit (OpCodes.Conv_Ovf_I2_Un); break;
1792
1793                                 case Mode.R4_I1: ig.Emit (OpCodes.Conv_Ovf_I1); break;
1794                                 case Mode.R4_U1: ig.Emit (OpCodes.Conv_Ovf_U1); break;
1795                                 case Mode.R4_I2: ig.Emit (OpCodes.Conv_Ovf_I2); break;
1796                                 case Mode.R4_U2: ig.Emit (OpCodes.Conv_Ovf_U2); break;
1797                                 case Mode.R4_I4: ig.Emit (OpCodes.Conv_Ovf_I4); break;
1798                                 case Mode.R4_U4: ig.Emit (OpCodes.Conv_Ovf_U4); break;
1799                                 case Mode.R4_I8: ig.Emit (OpCodes.Conv_Ovf_I8); break;
1800                                 case Mode.R4_U8: ig.Emit (OpCodes.Conv_Ovf_U8); break;
1801                                 case Mode.R4_CH: ig.Emit (OpCodes.Conv_Ovf_U2); break;
1802
1803                                 case Mode.R8_I1: ig.Emit (OpCodes.Conv_Ovf_I1); break;
1804                                 case Mode.R8_U1: ig.Emit (OpCodes.Conv_Ovf_U1); break;
1805                                 case Mode.R8_I2: ig.Emit (OpCodes.Conv_Ovf_I2); break;
1806                                 case Mode.R8_U2: ig.Emit (OpCodes.Conv_Ovf_U2); break;
1807                                 case Mode.R8_I4: ig.Emit (OpCodes.Conv_Ovf_I4); break;
1808                                 case Mode.R8_U4: ig.Emit (OpCodes.Conv_Ovf_U4); break;
1809                                 case Mode.R8_I8: ig.Emit (OpCodes.Conv_Ovf_I8); break;
1810                                 case Mode.R8_U8: ig.Emit (OpCodes.Conv_Ovf_U8); break;
1811                                 case Mode.R8_CH: ig.Emit (OpCodes.Conv_Ovf_U2); break;
1812                                 case Mode.R8_R4: ig.Emit (OpCodes.Conv_R4); break;
1813                                 }
1814                         } else {
1815                                 switch (mode){
1816                                 case Mode.I1_U1: ig.Emit (OpCodes.Conv_U1); break;
1817                                 case Mode.I1_U2: ig.Emit (OpCodes.Conv_U2); break;
1818                                 case Mode.I1_U4: ig.Emit (OpCodes.Conv_U4); break;
1819                                 case Mode.I1_U8: ig.Emit (OpCodes.Conv_I8); break;
1820                                 case Mode.I1_CH: ig.Emit (OpCodes.Conv_U2); break;
1821
1822                                 case Mode.U1_I1: ig.Emit (OpCodes.Conv_I1); break;
1823                                 case Mode.U1_CH: ig.Emit (OpCodes.Conv_U2); break;
1824
1825                                 case Mode.I2_I1: ig.Emit (OpCodes.Conv_I1); break;
1826                                 case Mode.I2_U1: ig.Emit (OpCodes.Conv_U1); break;
1827                                 case Mode.I2_U2: ig.Emit (OpCodes.Conv_U2); break;
1828                                 case Mode.I2_U4: ig.Emit (OpCodes.Conv_U4); break;
1829                                 case Mode.I2_U8: ig.Emit (OpCodes.Conv_I8); break;
1830                                 case Mode.I2_CH: ig.Emit (OpCodes.Conv_U2); break;
1831
1832                                 case Mode.U2_I1: ig.Emit (OpCodes.Conv_I1); break;
1833                                 case Mode.U2_U1: ig.Emit (OpCodes.Conv_U1); break;
1834                                 case Mode.U2_I2: ig.Emit (OpCodes.Conv_I2); break;
1835                                 case Mode.U2_CH: /* nothing */ break;
1836
1837                                 case Mode.I4_I1: ig.Emit (OpCodes.Conv_I1); break;
1838                                 case Mode.I4_U1: ig.Emit (OpCodes.Conv_U1); break;
1839                                 case Mode.I4_I2: ig.Emit (OpCodes.Conv_I2); break;
1840                                 case Mode.I4_U4: /* nothing */ break;
1841                                 case Mode.I4_U2: ig.Emit (OpCodes.Conv_U2); break;
1842                                 case Mode.I4_U8: ig.Emit (OpCodes.Conv_I8); break;
1843                                 case Mode.I4_CH: ig.Emit (OpCodes.Conv_U2); break;
1844
1845                                 case Mode.U4_I1: ig.Emit (OpCodes.Conv_I1); break;
1846                                 case Mode.U4_U1: ig.Emit (OpCodes.Conv_U1); break;
1847                                 case Mode.U4_I2: ig.Emit (OpCodes.Conv_I2); break;
1848                                 case Mode.U4_U2: ig.Emit (OpCodes.Conv_U2); break;
1849                                 case Mode.U4_I4: /* nothing */ break;
1850                                 case Mode.U4_CH: ig.Emit (OpCodes.Conv_U2); break;
1851
1852                                 case Mode.I8_I1: ig.Emit (OpCodes.Conv_I1); break;
1853                                 case Mode.I8_U1: ig.Emit (OpCodes.Conv_U1); break;
1854                                 case Mode.I8_I2: ig.Emit (OpCodes.Conv_I2); break;
1855                                 case Mode.I8_U2: ig.Emit (OpCodes.Conv_U2); break;
1856                                 case Mode.I8_I4: ig.Emit (OpCodes.Conv_I4); break;
1857                                 case Mode.I8_U4: ig.Emit (OpCodes.Conv_U4); break;
1858                                 case Mode.I8_U8: /* nothing */ break;
1859                                 case Mode.I8_CH: ig.Emit (OpCodes.Conv_U2); break;
1860
1861                                 case Mode.U8_I1: ig.Emit (OpCodes.Conv_I1); break;
1862                                 case Mode.U8_U1: ig.Emit (OpCodes.Conv_U1); break;
1863                                 case Mode.U8_I2: ig.Emit (OpCodes.Conv_I2); break;
1864                                 case Mode.U8_U2: ig.Emit (OpCodes.Conv_U2); break;
1865                                 case Mode.U8_I4: ig.Emit (OpCodes.Conv_I4); break;
1866                                 case Mode.U8_U4: ig.Emit (OpCodes.Conv_U4); break;
1867                                 case Mode.U8_I8: /* nothing */ break;
1868                                 case Mode.U8_CH: ig.Emit (OpCodes.Conv_U2); break;
1869
1870                                 case Mode.CH_I1: ig.Emit (OpCodes.Conv_I1); break;
1871                                 case Mode.CH_U1: ig.Emit (OpCodes.Conv_U1); break;
1872                                 case Mode.CH_I2: ig.Emit (OpCodes.Conv_I2); break;
1873
1874                                 case Mode.R4_I1: ig.Emit (OpCodes.Conv_I1); break;
1875                                 case Mode.R4_U1: ig.Emit (OpCodes.Conv_U1); break;
1876                                 case Mode.R4_I2: ig.Emit (OpCodes.Conv_I2); break;
1877                                 case Mode.R4_U2: ig.Emit (OpCodes.Conv_U2); break;
1878                                 case Mode.R4_I4: ig.Emit (OpCodes.Conv_I4); break;
1879                                 case Mode.R4_U4: ig.Emit (OpCodes.Conv_U4); break;
1880                                 case Mode.R4_I8: ig.Emit (OpCodes.Conv_I8); break;
1881                                 case Mode.R4_U8: ig.Emit (OpCodes.Conv_U8); break;
1882                                 case Mode.R4_CH: ig.Emit (OpCodes.Conv_U2); break;
1883
1884                                 case Mode.R8_I1: ig.Emit (OpCodes.Conv_I1); break;
1885                                 case Mode.R8_U1: ig.Emit (OpCodes.Conv_U1); break;
1886                                 case Mode.R8_I2: ig.Emit (OpCodes.Conv_I2); break;
1887                                 case Mode.R8_U2: ig.Emit (OpCodes.Conv_U2); break;
1888                                 case Mode.R8_I4: ig.Emit (OpCodes.Conv_I4); break;
1889                                 case Mode.R8_U4: ig.Emit (OpCodes.Conv_U4); break;
1890                                 case Mode.R8_I8: ig.Emit (OpCodes.Conv_I8); break;
1891                                 case Mode.R8_U8: ig.Emit (OpCodes.Conv_U8); break;
1892                                 case Mode.R8_CH: ig.Emit (OpCodes.Conv_U2); break;
1893                                 case Mode.R8_R4: ig.Emit (OpCodes.Conv_R4); break;
1894                                 }
1895                         }
1896                 }
1897         }
1898
1899         public class OpcodeCast : EmptyCast {
1900                 OpCode op, op2;
1901                 bool second_valid;
1902
1903                 public OpcodeCast (Expression child, Type return_type, OpCode op)
1904                         : base (child, return_type)
1905
1906                 {
1907                         this.op = op;
1908                         second_valid = false;
1909                 }
1910
1911                 public OpcodeCast (Expression child, Type return_type, OpCode op, OpCode op2)
1912                         : base (child, return_type)
1913
1914                 {
1915                         this.op = op;
1916                         this.op2 = op2;
1917                         second_valid = true;
1918                 }
1919
1920                 public override Expression DoResolve (EmitContext ec)
1921                 {
1922                         // This should never be invoked, we are born in fully
1923                         // initialized state.
1924
1925                         return this;
1926                 }
1927
1928                 public override void Emit (EmitContext ec)
1929                 {
1930                         base.Emit (ec);
1931                         ec.ig.Emit (op);
1932
1933                         if (second_valid)
1934                                 ec.ig.Emit (op2);
1935                 }
1936         }
1937
1938         /// <summary>
1939         ///   This kind of cast is used to encapsulate a child and cast it
1940         ///   to the class requested
1941         /// </summary>
1942         public class ClassCast : EmptyCast {
1943                 public ClassCast (Expression child, Type return_type)
1944                         : base (child, return_type)
1945
1946                 {
1947                 }
1948
1949                 public override Expression DoResolve (EmitContext ec)
1950                 {
1951                         // This should never be invoked, we are born in fully
1952                         // initialized state.
1953
1954                         return this;
1955                 }
1956
1957                 public override void Emit (EmitContext ec)
1958                 {
1959                         base.Emit (ec);
1960
1961                         if (child.Type.IsGenericParameter)
1962                                 ec.ig.Emit (OpCodes.Box, child.Type);
1963
1964                         if (type.IsGenericParameter)
1965                                 ec.ig.Emit (OpCodes.Unbox_Any, type);
1966                         else
1967                                 ec.ig.Emit (OpCodes.Castclass, type);
1968                 }
1969         }
1970
1971         /// <summary>
1972         ///   SimpleName expressions are formed of a single word and only happen at the beginning
1973         ///   of a dotted-name.
1974         /// </summary>
1975         public class SimpleName : Expression {
1976                 public string Name;
1977                 public readonly TypeArguments Arguments;
1978
1979                 public SimpleName (string name, Location l)
1980                 {
1981                         Name = name;
1982                         loc = l;
1983                 }
1984
1985                 public SimpleName (string name, TypeArguments args, Location l)
1986                 {
1987                         Name = name;
1988                         Arguments = args;
1989                         loc = l;
1990                 }
1991
1992                 public SimpleName (string name, TypeParameter[] type_params, Location l)
1993                 {
1994                         Name = name;
1995                         loc = l;
1996
1997                         Arguments = new TypeArguments (l);
1998                         foreach (TypeParameter type_param in type_params)
1999                                 Arguments.Add (new TypeParameterExpr (type_param, l));
2000                 }
2001
2002                 public static string RemoveGenericArity (string name)
2003                 {
2004                         int start = 0;
2005                         StringBuilder sb = new StringBuilder ();
2006                         while (start < name.Length) {
2007                                 int pos = name.IndexOf ('`', start);
2008                                 if (pos < 0) {
2009                                         sb.Append (name.Substring (start));
2010                                         break;
2011                                 }
2012
2013                                 sb.Append (name.Substring (start, pos-start));
2014
2015                                 pos++;
2016                                 while ((pos < name.Length) && Char.IsNumber (name [pos]))
2017                                         pos++;
2018
2019                                 start = pos;
2020                         }
2021
2022                         return sb.ToString ();
2023                 }
2024
2025                 public SimpleName GetMethodGroup ()
2026                 {
2027                         return new SimpleName (RemoveGenericArity (Name), Arguments, loc);
2028                 }
2029
2030                 public static void Error_ObjectRefRequired (EmitContext ec, Location l, string name)
2031                 {
2032                         if (ec.IsFieldInitializer)
2033                                 Report.Error (
2034                                         236, l,
2035                                         "A field initializer cannot reference the non-static field, " +
2036                                         "method or property `"+name+"'");
2037                         else
2038                                 Report.Error (
2039                                         120, l,
2040                                         "An object reference is required " +
2041                                         "for the non-static field `"+name+"'");
2042                 }
2043
2044                 public bool IdenticalNameAndTypeName (EmitContext ec, Expression resolved_to, Location loc)
2045                 {
2046                         return resolved_to != null && resolved_to.Type != null &&
2047                                 resolved_to.Type.Name == Name &&
2048                                 (ec.DeclSpace.LookupType (Name, loc, /* ignore_cs0104 = */ true) != null);
2049                 }
2050
2051                 public override Expression DoResolve (EmitContext ec)
2052                 {
2053                         return SimpleNameResolve (ec, null, false);
2054                 }
2055
2056                 public override Expression DoResolveLValue (EmitContext ec, Expression right_side)
2057                 {
2058                         return SimpleNameResolve (ec, right_side, false);
2059                 }
2060
2061
2062                 public Expression DoResolve (EmitContext ec, bool intermediate)
2063                 {
2064                         return SimpleNameResolve (ec, null, intermediate);
2065                 }
2066
2067                 private bool IsNestedChild (Type t, Type parent)
2068                 {
2069                         if (parent == null)
2070                                 return false;
2071
2072                         while (parent != null) {
2073                                 if (parent.IsGenericInstance)
2074                                         parent = parent.GetGenericTypeDefinition ();
2075
2076                                 if (TypeManager.IsNestedChildOf (t, parent))
2077                                         return true;
2078
2079                                 parent = parent.BaseType;
2080                         }
2081
2082                         return false;
2083                 }
2084
2085                 FullNamedExpression ResolveNested (EmitContext ec, Type t)
2086                 {
2087                         if (!t.IsGenericTypeDefinition)
2088                                 return null;
2089
2090                         DeclSpace ds = ec.DeclSpace;
2091                         while (ds != null) {
2092                                 if (IsNestedChild (t, ds.TypeBuilder))
2093                                         break;
2094
2095                                 ds = ds.Parent;
2096                         }
2097
2098                         if (ds == null)
2099                                 return null;
2100
2101                         Type[] gen_params = t.GetGenericArguments ();
2102
2103                         int arg_count = Arguments != null ? Arguments.Count : 0;
2104
2105                         for (; (ds != null) && ds.IsGeneric; ds = ds.Parent) {
2106                                 if (arg_count + ds.CountTypeParameters == gen_params.Length) {
2107                                         TypeArguments new_args = new TypeArguments (loc);
2108                                         foreach (TypeParameter param in ds.TypeParameters)
2109                                                 new_args.Add (new TypeParameterExpr (param, loc));
2110
2111                                         if (Arguments != null)
2112                                                 new_args.Add (Arguments);
2113
2114                                         return new ConstructedType (t, new_args, loc);
2115                                 }
2116                         }
2117
2118                         return null;
2119                 }
2120
2121                 public override FullNamedExpression ResolveAsTypeStep (EmitContext ec)
2122                 {
2123                         FullNamedExpression dt = ec.DeclSpace.LookupGeneric (Name, loc);
2124                         if (dt != null)
2125                                 return dt.ResolveAsTypeStep (ec);
2126
2127                         int errors = Report.Errors;
2128                         dt = ec.DeclSpace.LookupType (Name, loc, /*ignore_cs0104=*/ false);
2129                         if (Report.Errors != errors)
2130                                 return null;
2131
2132                         if ((dt == null) || (dt.Type == null))
2133                                 return dt;
2134
2135                         FullNamedExpression nested = ResolveNested (ec, dt.Type);
2136                         if (nested != null)
2137                                 return nested.ResolveAsTypeStep (ec);
2138
2139                         if (Arguments != null) {
2140                                 ConstructedType ct = new ConstructedType (dt, Arguments, loc);
2141                                 return ct.ResolveAsTypeStep (ec);
2142                         }
2143
2144                         return dt;
2145                 }
2146
2147                 Expression SimpleNameResolve (EmitContext ec, Expression right_side, bool intermediate)
2148                 {
2149                         Expression e = DoSimpleNameResolve (ec, right_side, intermediate);
2150                         if (e == null)
2151                                 return null;
2152
2153                         Block current_block = ec.CurrentBlock;
2154                         if (current_block != null){
2155                                 if (current_block.IsVariableNameUsedInChildBlock (Name)) {
2156                                         Report.Error (135, Location,
2157                                                       "'{0}' has a different meaning in a child block", Name);
2158                                         return null;
2159                                 }
2160
2161                                 if (!(e is LocalVariableReference) && current_block.IsVariableNameUsedInBlock (Name)) {
2162                                         // Catch some false positives, e.g., when a local variable resolves to a constant.
2163                                         LocalInfo vi = current_block.GetLocalInfo (Name);
2164                                         if (vi == null) {
2165                                                 Report.Error (136, Location, "'{0}' has a different meaning later in the block", Name);
2166                                                 return null;
2167                                         }
2168                                 }
2169                         }
2170
2171                         if (e.Type != null && e.Type.IsPointer && !ec.InUnsafe) {
2172                                 UnsafeError (loc);
2173                                 return null;
2174                         }
2175
2176                         return e;
2177                 }
2178
2179                 /// <remarks>
2180                 ///   7.5.2: Simple Names.
2181                 ///
2182                 ///   Local Variables and Parameters are handled at
2183                 ///   parse time, so they never occur as SimpleNames.
2184                 ///
2185                 ///   The `intermediate' flag is used by MemberAccess only
2186                 ///   and it is used to inform us that it is ok for us to
2187                 ///   avoid the static check, because MemberAccess might end
2188                 ///   up resolving the Name as a Type name and the access as
2189                 ///   a static type access.
2190                 ///
2191                 ///   ie: Type Type; .... { Type.GetType (""); }
2192                 ///
2193                 ///   Type is both an instance variable and a Type;  Type.GetType
2194                 ///   is the static method not an instance method of type.
2195                 /// </remarks>
2196                 Expression DoSimpleNameResolve (EmitContext ec, Expression right_side, bool intermediate)
2197                 {
2198                         Expression e = null;
2199
2200                         //
2201                         // Stage 1: Performed by the parser (binding to locals or parameters).
2202                         //
2203                         Block current_block = ec.CurrentBlock;
2204                         if (current_block != null){
2205                                 LocalInfo vi = current_block.GetLocalInfo (Name);
2206                                 if (vi != null){
2207                                         Expression var;
2208
2209                                         var = new LocalVariableReference (ec.CurrentBlock, Name, loc);
2210
2211                                         if (right_side != null)
2212                                                 return var.ResolveLValue (ec, right_side);
2213                                         else
2214                                                 return var.Resolve (ec);
2215                                 }
2216
2217                                 ParameterReference pref = current_block.GetParameterReference (Name, loc);
2218                                 if (pref != null) {
2219                                         if (right_side != null)
2220                                                 return pref.ResolveLValue (ec, right_side);
2221                                         else
2222                                                 return pref.Resolve (ec);
2223                                 }
2224                         }
2225
2226                         //
2227                         // Stage 2: Lookup members
2228                         //
2229
2230                         DeclSpace lookup_ds = ec.DeclSpace;
2231                         Type almost_matched_type = null;
2232                         ArrayList almost_matched = null;
2233                         do {
2234                                 if (lookup_ds.TypeBuilder == null)
2235                                         break;
2236
2237                                 e = MemberLookup (ec, lookup_ds.TypeBuilder, Name, loc);
2238                                 if (e != null)
2239                                         break;
2240
2241                                 if (almost_matched == null && almostMatchedMembers.Count > 0) {
2242                                         almost_matched_type = lookup_ds.TypeBuilder;
2243                                         almost_matched = (ArrayList) almostMatchedMembers.Clone ();
2244                                 }
2245
2246                                 lookup_ds =lookup_ds.Parent;
2247                         } while (lookup_ds != null);
2248
2249                         if (e == null && ec.ContainerType != null)
2250                                 e = MemberLookup (ec, ec.ContainerType, Name, loc);
2251
2252                         if (e == null) {
2253                                 if (almost_matched == null && almostMatchedMembers.Count > 0) {
2254                                         almost_matched_type = ec.ContainerType;
2255                                         almost_matched = (ArrayList) almostMatchedMembers.Clone ();
2256                                 }
2257                                 e = ResolveAsTypeStep (ec);
2258                         }
2259
2260                         if (e == null) {
2261                                 if (almost_matched != null)
2262                                         almostMatchedMembers = almost_matched;
2263                                 if (almost_matched_type == null)
2264                                         almost_matched_type = ec.ContainerType;
2265                                 MemberLookupFailed (ec, null, almost_matched_type, ((SimpleName) this).Name, ec.DeclSpace.Name, true, loc);
2266                                 return null;
2267                         }
2268
2269                         if (e is TypeExpr)
2270                                 return e;
2271
2272                         if (e is MemberExpr) {
2273                                 MemberExpr me = (MemberExpr) e;
2274                                 Expression left = (ec.IsStatic || ec.IsFieldInitializer)
2275                                         ? (Expression) new TypeExpression (ec.ContainerType, loc)
2276                                         : (Expression) ec.GetThis (loc);
2277
2278                                 e = me.ResolveMemberAccess (ec, left, loc, (intermediate ? this : null), true);
2279                                 if (e == null)
2280                                         return null;
2281
2282                                 me = e as MemberExpr;
2283                                 if (me == null)
2284                                         return e;
2285
2286                                 if (Arguments != null) {
2287                                         MethodGroupExpr mg = me as MethodGroupExpr;
2288                                         if (mg == null)
2289                                                 return null;
2290
2291                                         return mg.ResolveGeneric (ec, Arguments);
2292                                 }
2293
2294                                 // This fails if ResolveMemberAccess() was unable to decide whether
2295                                 // it's a field or a type of the same name.
2296                                 if (!me.IsStatic && me.InstanceExpression == null &&
2297                                     (intermediate && IdenticalNameAndTypeName (ec, e, loc)))
2298                                         return e;
2299
2300                                 if (!me.IsStatic &&
2301                                     TypeManager.IsNestedFamilyAccessible (me.InstanceExpression.Type, me.DeclaringType) &&
2302                                     me.InstanceExpression.Type != me.DeclaringType &&
2303                                     !TypeManager.IsFamilyAccessible (me.InstanceExpression.Type, me.DeclaringType) &&
2304                                     (!intermediate || !IdenticalNameAndTypeName (ec, e, loc))) {
2305                                         Error (38, "Cannot access nonstatic member `" + me.Name + "' of " +
2306                                                "outer type `" + me.DeclaringType + "' via nested type `" +
2307                                                me.InstanceExpression.Type + "'");
2308                                         return null;
2309                                 }
2310
2311                                 return (right_side != null)
2312                                         ? me.DoResolveLValue (ec, right_side)
2313                                         : me.DoResolve (ec);
2314                         }
2315
2316                         return e;
2317                 }
2318
2319                 public override void Emit (EmitContext ec)
2320                 {
2321                         //
2322                         // If this is ever reached, then we failed to
2323                         // find the name as a namespace
2324                         //
2325
2326                         Error (103, "The name `" + Name +
2327                                "' does not exist in the class `" +
2328                                ec.DeclSpace.Name + "'");
2329                 }
2330
2331                 public override string ToString ()
2332                 {
2333                         return Name;
2334                 }
2335         }
2336
2337         /// <summary>
2338         ///   Represents a namespace or a type.  The name of the class was inspired by
2339         ///   section 10.8.1 (Fully Qualified Names).
2340         /// </summary>
2341         public abstract class FullNamedExpression : Expression {
2342                 public override FullNamedExpression ResolveAsTypeStep (EmitContext ec)
2343                 {
2344                         return this;
2345                 }
2346
2347                 public abstract string FullName {
2348                         get;
2349                 }
2350         }
2351
2352         /// <summary>
2353         ///   Fully resolved expression that evaluates to a type
2354         /// </summary>
2355         public abstract class TypeExpr : FullNamedExpression {
2356                 override public FullNamedExpression ResolveAsTypeStep (EmitContext ec)
2357                 {
2358                         TypeExpr t = DoResolveAsTypeStep (ec);
2359                         if (t == null)
2360                                 return null;
2361
2362                         eclass = ExprClass.Type;
2363                         return t;
2364                 }
2365
2366                 override public Expression DoResolve (EmitContext ec)
2367                 {
2368                         return ResolveAsTypeTerminal (ec);
2369                 }
2370
2371                 override public void Emit (EmitContext ec)
2372                 {
2373                         throw new Exception ("Should never be called");
2374                 }
2375
2376                 public virtual bool CheckAccessLevel (DeclSpace ds)
2377                 {
2378                         return ds.CheckAccessLevel (Type);
2379                 }
2380
2381                 public virtual bool AsAccessible (DeclSpace ds, int flags)
2382                 {
2383                         return ds.AsAccessible (Type, flags);
2384                 }
2385
2386                 public virtual bool IsClass {
2387                         get { return Type.IsClass; }
2388                 }
2389
2390                 public virtual bool IsValueType {
2391                         get { return Type.IsValueType; }
2392                 }
2393
2394                 public virtual bool IsInterface {
2395                         get { return Type.IsInterface; }
2396                 }
2397
2398                 public virtual bool IsSealed {
2399                         get { return Type.IsSealed; }
2400                 }
2401
2402                 public virtual bool CanInheritFrom ()
2403                 {
2404                         if (Type == TypeManager.enum_type ||
2405                             (Type == TypeManager.value_type && RootContext.StdLib) ||
2406                             Type == TypeManager.multicast_delegate_type ||
2407                             Type == TypeManager.delegate_type ||
2408                             Type == TypeManager.array_type)
2409                                 return false;
2410
2411                         return true;
2412                 }
2413
2414                 protected abstract TypeExpr DoResolveAsTypeStep (EmitContext ec);
2415
2416                 public virtual Type ResolveType (EmitContext ec)
2417                 {
2418                         TypeExpr t = ResolveAsTypeTerminal (ec);
2419                         if (t == null)
2420                                 return null;
2421
2422                         return t.Type;
2423                 }
2424
2425                 public abstract string Name {
2426                         get;
2427                 }
2428
2429                 public override bool Equals (object obj)
2430                 {
2431                         TypeExpr tobj = obj as TypeExpr;
2432                         if (tobj == null)
2433                                 return false;
2434
2435                         return Type == tobj.Type;
2436                 }
2437
2438                 public override int GetHashCode ()
2439                 {
2440                         return Type.GetHashCode ();
2441                 }
2442
2443                 public override string ToString ()
2444                 {
2445                         return Name;
2446                 }
2447         }
2448
2449         public class TypeExpression : TypeExpr {
2450                 public TypeExpression (Type t, Location l)
2451                 {
2452                         Type = t;
2453                         eclass = ExprClass.Type;
2454                         loc = l;
2455                 }
2456
2457                 protected override TypeExpr DoResolveAsTypeStep (EmitContext ec)
2458                 {
2459                         return this;
2460                 }
2461
2462                 public override string Name {
2463                         get {
2464                                 return Type.ToString ();
2465                         }
2466                 }
2467
2468                 public override string FullName {
2469                         get {
2470                                 return Type.FullName != null ? Type.FullName : Type.Name;
2471                         }
2472                 }
2473         }
2474
2475         /// <summary>
2476         ///   Used to create types from a fully qualified name.  These are just used
2477         ///   by the parser to setup the core types.  A TypeLookupExpression is always
2478         ///   classified as a type.
2479         /// </summary>
2480         public class TypeLookupExpression : TypeExpr {
2481                 string name;
2482
2483                 public TypeLookupExpression (string name)
2484                 {
2485                         this.name = name;
2486                 }
2487
2488                 protected override TypeExpr DoResolveAsTypeStep (EmitContext ec)
2489                 {
2490                         if (type == null) {
2491                                 FullNamedExpression t = ec.DeclSpace.LookupType (name, Location.Null, /*ignore_cs0104=*/ false);
2492                                 if (t == null) {
2493                                         Report.Error (246, loc, "Cannot find type `" + name + "'");
2494                                         return null;
2495                                 }
2496                                 if (!(t is TypeExpr)) {
2497                                         Report.Error (118, Location, "'{0}' denotes a '{1}', where a type was expected",
2498                                                       t.FullName, t.ExprClassName ());
2499
2500                                         return null;
2501                                 }
2502                                 type = ((TypeExpr) t).ResolveType (ec);
2503                         }
2504
2505                         return this;
2506                 }
2507
2508                 public override string Name {
2509                         get {
2510                                 return name;
2511                         }
2512                 }
2513
2514                 public override string FullName {
2515                         get {
2516                                 return name;
2517                         }
2518                 }
2519         }
2520
2521         /// <summary>
2522         ///   Represents an "unbound generic type", ie. typeof (Foo<>).
2523         ///   See 14.5.11.
2524         /// </summary>
2525         public class UnboundTypeExpression : TypeLookupExpression {
2526                 public UnboundTypeExpression (string name)
2527                         : base (name)
2528                 { }
2529         }
2530
2531         public class TypeAliasExpression : TypeExpr {
2532                 FullNamedExpression alias;
2533                 TypeExpr texpr;
2534                 TypeArguments args;
2535                 string name;
2536
2537                 public TypeAliasExpression (FullNamedExpression alias, TypeArguments args, Location l)
2538                 {
2539                         this.alias = alias;
2540                         this.args = args;
2541                         loc = l;
2542
2543                         eclass = ExprClass.Type;
2544                         if (args != null)
2545                                 name = alias.FullName + "<" + args.ToString () + ">";
2546                         else
2547                                 name = alias.FullName;
2548                 }
2549
2550                 public override string Name {
2551                         get { return alias.FullName; }
2552                 }
2553
2554                 public override string FullName {
2555                         get { return name; }
2556                 }
2557
2558                 protected override TypeExpr DoResolveAsTypeStep (EmitContext ec)
2559                 {
2560                         texpr = alias.ResolveAsTypeTerminal (ec);
2561                         if (texpr == null)
2562                                 return null;
2563
2564                         Type type = texpr.Type;
2565                         int num_args = TypeManager.GetNumberOfTypeArguments (type);
2566
2567                         if (args != null) {
2568                                 if (num_args == 0) {
2569                                         Report.Error (308, loc,
2570                                                       "The non-generic type `{0}' cannot " +
2571                                                       "be used with type arguments.",
2572                                                       TypeManager.CSharpName (type));
2573                                         return null;
2574                                 }
2575
2576                                 ConstructedType ctype = new ConstructedType (type, args, loc);
2577                                 return ctype.ResolveAsTypeTerminal (ec);
2578                         } else if (num_args > 0) {
2579                                 Report.Error (305, loc,
2580                                               "Using the generic type `{0}' " +
2581                                               "requires {1} type arguments",
2582                                               TypeManager.GetFullName (type), num_args);
2583                                 return null;
2584                         }
2585
2586                         return new TypeExpression (type, loc);
2587                 }
2588
2589                 public override bool CheckAccessLevel (DeclSpace ds)
2590                 {
2591                         return texpr.CheckAccessLevel (ds);
2592                 }
2593
2594                 public override bool AsAccessible (DeclSpace ds, int flags)
2595                 {
2596                         return texpr.AsAccessible (ds, flags);
2597                 }
2598
2599                 public override bool IsClass {
2600                         get { return texpr.IsClass; }
2601                 }
2602
2603                 public override bool IsValueType {
2604                         get { return texpr.IsValueType; }
2605                 }
2606
2607                 public override bool IsInterface {
2608                         get { return texpr.IsInterface; }
2609                 }
2610
2611                 public override bool IsSealed {
2612                         get { return texpr.IsSealed; }
2613                 }
2614         }
2615
2616         /// <summary>
2617         ///   This class denotes an expression which evaluates to a member
2618         ///   of a struct or a class.
2619         /// </summary>
2620         public abstract class MemberExpr : Expression
2621         {
2622                 /// <summary>
2623                 ///   The name of this member.
2624                 /// </summary>
2625                 public abstract string Name {
2626                         get;
2627                 }
2628
2629                 /// <summary>
2630                 ///   Whether this is an instance member.
2631                 /// </summary>
2632                 public abstract bool IsInstance {
2633                         get;
2634                 }
2635
2636                 /// <summary>
2637                 ///   Whether this is a static member.
2638                 /// </summary>
2639                 public abstract bool IsStatic {
2640                         get;
2641                 }
2642
2643                 /// <summary>
2644                 ///   The type which declares this member.
2645                 /// </summary>
2646                 public abstract Type DeclaringType {
2647                         get;
2648                 }
2649
2650                 /// <summary>
2651                 ///   The instance expression associated with this member, if it's a
2652                 ///   non-static member.
2653                 /// </summary>
2654                 public Expression InstanceExpression;
2655
2656                 public static void error176 (Location loc, string name)
2657                 {
2658                         Report.Error (176, loc, "Static member `" + name + "' cannot be accessed " +
2659                                       "with an instance reference, qualify with a type name instead");
2660                 }
2661
2662
2663                 // TODO: possible optimalization
2664                 // Cache resolved constant result in FieldBuilder <-> expression map
2665                 public virtual Expression ResolveMemberAccess (EmitContext ec, Expression left, Location loc,
2666                                                                 SimpleName original, bool left_is_inferred)
2667                 {
2668                         //
2669                         // Precondition:
2670                         //   original == null || original.Resolve (...) === (left_is_inferred ? this : left)
2671                         //
2672
2673                         if (left is TypeExpr) {
2674                                 if (!IsStatic) {
2675                                         if ((ec.IsFieldInitializer || ec.IsStatic) && left_is_inferred &&
2676                                             original != null && original.IdenticalNameAndTypeName (ec, this, loc))
2677                                                 return this;
2678
2679                                         SimpleName.Error_ObjectRefRequired (ec, loc, Name);
2680                                         return null;
2681                                 }
2682
2683                                 return this;
2684                         }
2685
2686                         if (!IsInstance) {
2687                                 if (left_is_inferred ||
2688                                     (original != null && original.IdenticalNameAndTypeName (ec, left, loc)))
2689                                         return this;
2690
2691                                 error176 (loc, Name);
2692                                 return null;
2693                         }
2694
2695                         InstanceExpression = left;
2696
2697                         return this;
2698                 }
2699         }
2700
2701         /// <summary>
2702         ///   MethodGroup Expression.
2703         ///
2704         ///   This is a fully resolved expression that evaluates to a type
2705         /// </summary>
2706         public class MethodGroupExpr : MemberExpr {
2707                 public MethodBase [] Methods;
2708                 bool has_type_arguments = false;
2709                 bool identical_type_name = false;
2710                 bool is_base;
2711
2712                 public MethodGroupExpr (MemberInfo [] mi, Location l)
2713                 {
2714                         Methods = new MethodBase [mi.Length];
2715                         mi.CopyTo (Methods, 0);
2716                         eclass = ExprClass.MethodGroup;
2717                         type = TypeManager.object_type;
2718                         loc = l;
2719                 }
2720
2721                 public MethodGroupExpr (ArrayList list, Location l)
2722                 {
2723                         Methods = new MethodBase [list.Count];
2724
2725                         try {
2726                                 list.CopyTo (Methods, 0);
2727                         } catch {
2728                                 foreach (MemberInfo m in list){
2729                                         if (!(m is MethodBase)){
2730                                                 Console.WriteLine ("Name " + m.Name);
2731                                                 Console.WriteLine ("Found a: " + m.GetType ().FullName);
2732                                         }
2733                                 }
2734                                 throw;
2735                         }
2736
2737                         loc = l;
2738                         eclass = ExprClass.MethodGroup;
2739                         type = TypeManager.object_type;
2740                 }
2741
2742                 public override Type DeclaringType {
2743                         get {
2744                                 //
2745                                 // We assume that the top-level type is in the end
2746                                 //
2747                                 return Methods [Methods.Length - 1].DeclaringType;
2748                                 //return Methods [0].DeclaringType;
2749                         }
2750                 }
2751
2752                 public bool HasTypeArguments {
2753                         get {
2754                                 return has_type_arguments;
2755                         }
2756
2757                         set {
2758                                 has_type_arguments = value;
2759                         }
2760                 }
2761
2762                 public bool IdenticalTypeName {
2763                         get {
2764                                 return identical_type_name;
2765                         }
2766
2767                         set {
2768                                 identical_type_name = value;
2769                         }
2770                 }
2771
2772                 public bool IsBase {
2773                         get {
2774                                 return is_base;
2775                         }
2776                         set {
2777                                 is_base = value;
2778                         }
2779                 }
2780
2781                 public override string Name {
2782                         get {
2783                                 //return Methods [0].Name;
2784                                 return Methods [Methods.Length - 1].Name;
2785                         }
2786                 }
2787
2788                 public override bool IsInstance {
2789                         get {
2790                                 foreach (MethodBase mb in Methods)
2791                                         if (!mb.IsStatic)
2792                                                 return true;
2793
2794                                 return false;
2795                         }
2796                 }
2797
2798                 public override bool IsStatic {
2799                         get {
2800                                 foreach (MethodBase mb in Methods)
2801                                         if (mb.IsStatic)
2802                                                 return true;
2803
2804                                 return false;
2805                         }
2806                 }
2807
2808                 public override Expression ResolveMemberAccess (EmitContext ec, Expression left, Location loc,
2809                                                                  SimpleName original, bool left_is_inferred)
2810                 {
2811                         if (!left_is_inferred &&
2812                             !(left is TypeExpr) &&
2813                             original != null && original.IdenticalNameAndTypeName (ec, left, loc))
2814                                 IdenticalTypeName = true;
2815
2816                         return base.ResolveMemberAccess (ec, left, loc, original, left_is_inferred);
2817                 }
2818
2819                 override public Expression DoResolve (EmitContext ec)
2820                 {
2821                         if (!IsInstance)
2822                                 InstanceExpression = null;
2823
2824                         if (InstanceExpression != null) {
2825                                 InstanceExpression = InstanceExpression.DoResolve (ec);
2826                                 if (InstanceExpression == null)
2827                                         return null;
2828                         }
2829
2830                         return this;
2831                 }
2832
2833                 public void ReportUsageError ()
2834                 {
2835                         Report.Error (654, loc, "Method `" + DeclaringType + "." +
2836                                       Name + "()' is referenced without parentheses");
2837                 }
2838
2839                 override public void Emit (EmitContext ec)
2840                 {
2841                         ReportUsageError ();
2842                 }
2843
2844                 bool RemoveMethods (bool keep_static)
2845                 {
2846                         ArrayList smethods = new ArrayList ();
2847
2848                         foreach (MethodBase mb in Methods){
2849                                 if (mb.IsStatic == keep_static)
2850                                         smethods.Add (mb);
2851                         }
2852
2853                         if (smethods.Count == 0)
2854                                 return false;
2855
2856                         Methods = new MethodBase [smethods.Count];
2857                         smethods.CopyTo (Methods, 0);
2858
2859                         return true;
2860                 }
2861
2862                 /// <summary>
2863                 ///   Removes any instance methods from the MethodGroup, returns
2864                 ///   false if the resulting set is empty.
2865                 /// </summary>
2866                 public bool RemoveInstanceMethods ()
2867                 {
2868                         return RemoveMethods (true);
2869                 }
2870
2871                 /// <summary>
2872                 ///   Removes any static methods from the MethodGroup, returns
2873                 ///   false if the resulting set is empty.
2874                 /// </summary>
2875                 public bool RemoveStaticMethods ()
2876                 {
2877                         return RemoveMethods (false);
2878                 }
2879
2880                 public Expression ResolveGeneric (EmitContext ec, TypeArguments args)
2881                 {
2882                         if (args.Resolve (ec) == false)
2883                                 return null;
2884
2885                         Type[] atypes = args.Arguments;
2886
2887                         int first_count = 0;
2888                         MethodInfo first = null;
2889
2890                         ArrayList list = new ArrayList ();
2891                         foreach (MethodBase mb in Methods) {
2892                                 MethodInfo mi = mb as MethodInfo;
2893                                 if ((mi == null) || !mi.HasGenericParameters)
2894                                         continue;
2895
2896                                 Type[] gen_params = mi.GetGenericArguments ();
2897
2898                                 if (first == null) {
2899                                         first = mi;
2900                                         first_count = gen_params.Length;
2901                                 }
2902
2903                                 if (gen_params.Length != atypes.Length)
2904                                         continue;
2905
2906                                 list.Add (mi.BindGenericParameters (atypes));
2907                         }
2908
2909                         if (list.Count > 0) {
2910                                 MethodGroupExpr new_mg = new MethodGroupExpr (list, Location);
2911                                 new_mg.InstanceExpression = InstanceExpression;
2912                                 new_mg.HasTypeArguments = true;
2913                                 return new_mg;
2914                         }
2915
2916                         if (first != null)
2917                                 Report.Error (
2918                                         305, loc, "Using the generic method `{0}' " +
2919                                         "requires {1} type arguments", Name,
2920                                         first_count);
2921                         else
2922                                 Report.Error (
2923                                         308, loc, "The non-generic method `{0}' " +
2924                                         "cannot be used with type arguments", Name);
2925
2926                         return null;
2927                 }
2928         }
2929
2930         /// <summary>
2931         ///   Fully resolved expression that evaluates to a Field
2932         /// </summary>
2933         public class FieldExpr : MemberExpr, IAssignMethod, IMemoryLocation, IVariable {
2934                 public readonly FieldInfo FieldInfo;
2935                 VariableInfo variable_info;
2936
2937                 LocalTemporary temp;
2938                 bool prepared;
2939                 bool is_field_initializer;
2940
2941                 public FieldExpr (FieldInfo fi, Location l)
2942                 {
2943                         FieldInfo = fi;
2944                         eclass = ExprClass.Variable;
2945                         type = TypeManager.TypeToCoreType (fi.FieldType);
2946                         loc = l;
2947                 }
2948
2949                 public override string Name {
2950                         get {
2951                                 return FieldInfo.Name;
2952                         }
2953                 }
2954
2955                 public override bool IsInstance {
2956                         get {
2957                                 return !FieldInfo.IsStatic;
2958                         }
2959                 }
2960
2961                 public override bool IsStatic {
2962                         get {
2963                                 return FieldInfo.IsStatic;
2964                         }
2965                 }
2966
2967                 public override Type DeclaringType {
2968                         get {
2969                                 return FieldInfo.DeclaringType;
2970                         }
2971                 }
2972
2973                 public VariableInfo VariableInfo {
2974                         get {
2975                                 return variable_info;
2976                         }
2977                 }
2978
2979                 public override Expression ResolveMemberAccess (EmitContext ec, Expression left, Location loc,
2980                                                                 SimpleName original, bool left_is_inferred)
2981                 {
2982                         bool left_is_type = left is TypeExpr;
2983
2984                         FieldInfo fi = FieldInfo.Mono_GetGenericFieldDefinition ();
2985
2986                         Type decl_type = fi.DeclaringType;
2987
2988                         bool is_emitted = fi is FieldBuilder;
2989                         Type t = fi.FieldType;
2990
2991                         if (is_emitted) {
2992                                 Const c = TypeManager.LookupConstant ((FieldBuilder) fi);
2993
2994                                 if (c != null) {
2995                                         object o;
2996                                         if (!c.LookupConstantValue (out o))
2997                                                 return null;
2998
2999                                         object real_value = ((Constant) c.Expr).GetValue ();
3000
3001                                         Expression exp = Constantify (real_value, t);
3002
3003                                         if (!left_is_inferred && !left_is_type &&
3004                                             (original == null || !original.IdenticalNameAndTypeName (ec, left, loc))) {
3005                                                 Report.SymbolRelatedToPreviousError (c);
3006                                                 error176 (loc, c.GetSignatureForError ());
3007                                                 return null;
3008                                         }
3009
3010                                         return exp;
3011                                 }
3012                         }
3013
3014                         // IsInitOnly is because of MS compatibility, I don't know why but they emit decimal constant as InitOnly
3015                         if (fi.IsInitOnly && !is_emitted && t == TypeManager.decimal_type) {
3016                                 object[] attrs = fi.GetCustomAttributes (TypeManager.decimal_constant_attribute_type, false);
3017                                 if (attrs.Length == 1)
3018                                         return new DecimalConstant (((System.Runtime.CompilerServices.DecimalConstantAttribute) attrs [0]).Value);
3019                         }
3020
3021                         if (fi.IsLiteral) {
3022                                 object o;
3023
3024                                 if (is_emitted)
3025                                         o = TypeManager.GetValue ((FieldBuilder) fi);
3026                                 else
3027                                         o = fi.GetValue (fi);
3028
3029                                 if (decl_type.IsSubclassOf (TypeManager.enum_type)) {
3030                                         if (!left_is_inferred && !left_is_type &&
3031                                             (original == null || !original.IdenticalNameAndTypeName (ec, left, loc))) {
3032                                                 error176 (loc, fi.Name);
3033                                                 return null;
3034                                         }
3035
3036                                         Expression enum_member = MemberLookup (
3037                                                ec, decl_type, "value__", MemberTypes.Field,
3038                                                AllBindingFlags | BindingFlags.NonPublic, loc);
3039
3040                                         Enum en = TypeManager.LookupEnum (decl_type);
3041
3042                                         Constant c;
3043                                         if (en != null)
3044                                                 c = Constantify (o, en.UnderlyingType);
3045                                         else
3046                                                 c = Constantify (o, enum_member.Type);
3047
3048                                         return new EnumConstant (c, decl_type);
3049                                 }
3050
3051                                 Expression exp = Constantify (o, t);
3052
3053                                 if (!left_is_inferred && !left_is_type) {
3054                                         error176 (loc, fi.Name);
3055                                         return null;
3056                                 }
3057
3058                                 return exp;
3059                         }
3060
3061                         if (t.IsPointer && !ec.InUnsafe) {
3062                                 UnsafeError (loc);
3063                                 return null;
3064                         }
3065
3066                         return base.ResolveMemberAccess (ec, left, loc, original, left_is_inferred);
3067                 }
3068
3069                 override public Expression DoResolve (EmitContext ec)
3070                 {
3071                         if (!FieldInfo.IsStatic){
3072                                 if (InstanceExpression == null){
3073                                         //
3074                                         // This can happen when referencing an instance field using
3075                                         // a fully qualified type expression: TypeName.InstanceField = xxx
3076                                         //
3077                                         SimpleName.Error_ObjectRefRequired (ec, loc, FieldInfo.Name);
3078                                         return null;
3079                                 }
3080
3081                                 // Resolve the field's instance expression while flow analysis is turned
3082                                 // off: when accessing a field "a.b", we must check whether the field
3083                                 // "a.b" is initialized, not whether the whole struct "a" is initialized.
3084                                 InstanceExpression = InstanceExpression.Resolve (ec, ResolveFlags.VariableOrValue |
3085                                                                        ResolveFlags.DisableFlowAnalysis);
3086                                 if (InstanceExpression == null)
3087                                         return null;
3088                         }
3089
3090                         ObsoleteAttribute oa;
3091                         FieldBase f = TypeManager.GetField (FieldInfo);
3092                         if (f != null) {
3093                                 oa = f.GetObsoleteAttribute (f.Parent);
3094                                 if (oa != null)
3095                                         AttributeTester.Report_ObsoleteMessage (oa, f.GetSignatureForError (), loc);
3096                                 // To be sure that type is external because we do not register generated fields
3097                         } else if (!(FieldInfo.DeclaringType is TypeBuilder)) {
3098                                 oa = AttributeTester.GetMemberObsoleteAttribute (FieldInfo);
3099                                 if (oa != null)
3100                                         AttributeTester.Report_ObsoleteMessage (oa, TypeManager.GetFullNameSignature (FieldInfo), loc);
3101                         }
3102
3103                         if (ec.CurrentAnonymousMethod != null){
3104                                 if (!FieldInfo.IsStatic){
3105                                         if (ec.TypeContainer is Struct){
3106                                                 Report.Error (1673, loc, "Can not reference instance variables in anonymous methods hosted in structs");
3107                                                 return null;
3108                                         }
3109                                         ec.CaptureField (this);
3110                                 }
3111                         }
3112
3113                         // If the instance expression is a local variable or parameter.
3114                         IVariable var = InstanceExpression as IVariable;
3115                         if ((var == null) || (var.VariableInfo == null))
3116                                 return this;
3117
3118                         VariableInfo vi = var.VariableInfo;
3119                         if (!vi.IsFieldAssigned (ec, FieldInfo.Name, loc))
3120                                 return null;
3121
3122                         variable_info = vi.GetSubStruct (FieldInfo.Name);
3123                         return this;
3124                 }
3125
3126                 void Report_AssignToReadonly (bool is_instance)
3127                 {
3128                         string msg;
3129
3130                         if (is_instance)
3131                                 msg = "Readonly field can not be assigned outside " +
3132                                 "of constructor or variable initializer";
3133                         else
3134                                 msg = "A static readonly field can only be assigned in " +
3135                                 "a static constructor";
3136
3137                         Report.Error (is_instance ? 191 : 198, loc, msg);
3138                 }
3139
3140                 override public Expression DoResolveLValue (EmitContext ec, Expression right_side)
3141                 {
3142                         IVariable var = InstanceExpression as IVariable;
3143                         if ((var != null) && (var.VariableInfo != null))
3144                                 var.VariableInfo.SetFieldAssigned (ec, FieldInfo.Name);
3145
3146                         Expression e = DoResolve (ec);
3147
3148                         if (e == null)
3149                                 return null;
3150
3151                         if (!FieldInfo.IsStatic && (InstanceExpression.Type.IsValueType && !(InstanceExpression is IMemoryLocation))) {
3152                                 // FIXME: Provide better error reporting.
3153                                 Error (1612, "Cannot modify expression because it is not a variable.");
3154                                 return null;
3155                         }
3156
3157                         if (!FieldInfo.IsInitOnly)
3158                                 return this;
3159
3160                         FieldBase fb = TypeManager.GetField (FieldInfo);
3161                         if (fb != null)
3162                                 fb.SetAssigned ();
3163
3164                         //
3165                         // InitOnly fields can only be assigned in constructors
3166                         //
3167
3168                         if (ec.IsConstructor){
3169                                 if (IsStatic && !ec.IsStatic)
3170                                         Report_AssignToReadonly (false);
3171
3172                                 Type ctype;
3173                                 if (!is_field_initializer &&
3174                                     (ec.TypeContainer.CurrentType != null))
3175                                         ctype = ec.TypeContainer.CurrentType;
3176                                 else
3177                                         ctype = ec.ContainerType;
3178
3179                                 if (TypeManager.IsEqual (ctype, FieldInfo.DeclaringType))
3180                                         return this;
3181                         }
3182
3183                         Report_AssignToReadonly (!IsStatic);
3184
3185                         return null;
3186                 }
3187
3188                 public override void CheckMarshallByRefAccess (Type container)
3189                 {
3190                         if (!IsStatic && Type.IsValueType && !container.IsSubclassOf (TypeManager.mbr_type) && DeclaringType.IsSubclassOf (TypeManager.mbr_type)) {
3191                                 Report.SymbolRelatedToPreviousError (DeclaringType);
3192                                 Report.Error (1690, loc, "Cannot call '{0}' method, property, or indexer because it is a value type member of a marshal-by-reference class", Name);
3193                         }
3194                 }
3195
3196                 public bool VerifyFixed (bool is_expression)
3197                 {
3198                         IVariable variable = InstanceExpression as IVariable;
3199                         if ((variable == null) || !variable.VerifyFixed (true))
3200                                 return false;
3201
3202                         return true;
3203                 }
3204
3205                 public override int GetHashCode()
3206                 {
3207                         return FieldInfo.GetHashCode ();
3208                 }
3209
3210                 public override bool Equals (object obj)
3211                 {
3212                         FieldExpr fe = obj as FieldExpr;
3213                         if (fe == null)
3214                                 return false;
3215
3216                         if (FieldInfo != fe.FieldInfo)
3217                                 return false;
3218
3219                         if (InstanceExpression == null || fe.InstanceExpression == null)
3220                                 return true;
3221
3222                         return InstanceExpression.Equals (fe.InstanceExpression);
3223                 }
3224
3225                 public void Emit (EmitContext ec, bool leave_copy)
3226                 {
3227                         ILGenerator ig = ec.ig;
3228                         bool is_volatile = false;
3229
3230                         if (FieldInfo is FieldBuilder){
3231                                 FieldBase f = TypeManager.GetField (FieldInfo);
3232                                 if (f != null){
3233                                         if ((f.ModFlags & Modifiers.VOLATILE) != 0)
3234                                                 is_volatile = true;
3235
3236                                         f.status |= Field.Status.USED;
3237                                 }
3238                         }
3239
3240                         if (FieldInfo.IsStatic){
3241                                 if (is_volatile)
3242                                         ig.Emit (OpCodes.Volatile);
3243
3244                                 ig.Emit (OpCodes.Ldsfld, FieldInfo);
3245                         } else {
3246                                 if (!prepared)
3247                                         EmitInstance (ec);
3248
3249                                 if (is_volatile)
3250                                         ig.Emit (OpCodes.Volatile);
3251
3252                                 IFixedBuffer ff = AttributeTester.GetFixedBuffer (FieldInfo);
3253                                 if (ff != null)
3254                                 {
3255                                         ig.Emit (OpCodes.Ldflda, FieldInfo);
3256                                         ig.Emit (OpCodes.Ldflda, ff.Element);
3257                                 }
3258                                 else {
3259                                         ig.Emit (OpCodes.Ldfld, FieldInfo);
3260                                 }
3261                         }
3262
3263                         if (leave_copy) {
3264                                 ec.ig.Emit (OpCodes.Dup);
3265                                 if (!FieldInfo.IsStatic) {
3266                                         temp = new LocalTemporary (ec, this.Type);
3267                                         temp.Store (ec);
3268                                 }
3269                         }
3270                 }
3271
3272                 public void EmitAssign (EmitContext ec, Expression source, bool leave_copy, bool prepare_for_load)
3273                 {
3274                         FieldAttributes fa = FieldInfo.Attributes;
3275                         bool is_static = (fa & FieldAttributes.Static) != 0;
3276                         bool is_readonly = (fa & FieldAttributes.InitOnly) != 0;
3277                         ILGenerator ig = ec.ig;
3278                         prepared = prepare_for_load;
3279
3280                         if (is_readonly && !ec.IsConstructor){
3281                                 Report_AssignToReadonly (!is_static);
3282                                 return;
3283                         }
3284
3285                         if (!is_static) {
3286                                 EmitInstance (ec);
3287                                 if (prepare_for_load)
3288                                         ig.Emit (OpCodes.Dup);
3289                         }
3290
3291                         source.Emit (ec);
3292                         if (leave_copy) {
3293                                 ec.ig.Emit (OpCodes.Dup);
3294                                 if (!FieldInfo.IsStatic) {
3295                                         temp = new LocalTemporary (ec, this.Type);
3296                                         temp.Store (ec);
3297                                 }
3298                         }
3299
3300                         if (FieldInfo is FieldBuilder){
3301                                 FieldBase f = TypeManager.GetField (FieldInfo);
3302                                 if (f != null){
3303                                         if ((f.ModFlags & Modifiers.VOLATILE) != 0)
3304                                                 ig.Emit (OpCodes.Volatile);
3305
3306                                         f.status |= Field.Status.ASSIGNED;
3307                                 }
3308                         }
3309
3310                         if (is_static)
3311                                 ig.Emit (OpCodes.Stsfld, FieldInfo);
3312                         else
3313                                 ig.Emit (OpCodes.Stfld, FieldInfo);
3314
3315                         if (temp != null)
3316                                 temp.Emit (ec);
3317                 }
3318
3319                 void EmitInstance (EmitContext ec)
3320                 {
3321                         //
3322                         // In case it escapes StaticMemberCheck due to IdenticalTypeAndName.
3323                         // This happens in cases like 'string String', 'int Int32', etc.
3324                         // where the "IdenticalTypeAndName" mechanism is fooled.
3325                         //
3326                         if (InstanceExpression == null) {
3327                                 SimpleName.Error_ObjectRefRequired (ec, loc, FieldInfo.Name);
3328                                 return;
3329                         }
3330
3331                         if (InstanceExpression.Type.IsValueType) {
3332                                 if (InstanceExpression is IMemoryLocation) {
3333                                         ((IMemoryLocation) InstanceExpression).AddressOf (ec, AddressOp.LoadStore);
3334                                 } else {
3335                                         LocalTemporary t = new LocalTemporary (ec, InstanceExpression.Type);
3336                                         InstanceExpression.Emit (ec);
3337                                         t.Store (ec);
3338                                         t.AddressOf (ec, AddressOp.Store);
3339                                 }
3340                         } else
3341                                 InstanceExpression.Emit (ec);
3342                 }
3343
3344                 public override void Emit (EmitContext ec)
3345                 {
3346                         Emit (ec, false);
3347                 }
3348
3349                 public void AddressOf (EmitContext ec, AddressOp mode)
3350                 {
3351                         ILGenerator ig = ec.ig;
3352
3353                         if (FieldInfo is FieldBuilder){
3354                                 FieldBase f = TypeManager.GetField (FieldInfo);
3355                                 if (f != null){
3356                                         if ((f.ModFlags & Modifiers.VOLATILE) != 0){
3357                                                 Error (676, "volatile variable: can not take its address, or pass as ref/out parameter");
3358                                                 return;
3359                                         }
3360
3361                                         if ((mode & AddressOp.Store) != 0)
3362                                                 f.status |= Field.Status.ASSIGNED;
3363                                         if ((mode & AddressOp.Load) != 0)
3364                                                 f.status |= Field.Status.USED;
3365                                 }
3366                         }
3367
3368                         //
3369                         // Handle initonly fields specially: make a copy and then
3370                         // get the address of the copy.
3371                         //
3372                         bool need_copy;
3373                         if (FieldInfo.IsInitOnly){
3374                                 need_copy = true;
3375                                 if (ec.IsConstructor){
3376                                         if (FieldInfo.IsStatic){
3377                                                 if (ec.IsStatic)
3378                                                         need_copy = false;
3379                                         } else
3380                                                 need_copy = false;
3381                                 }
3382                         } else
3383                                 need_copy = false;
3384
3385                         if (need_copy){
3386                                 LocalBuilder local;
3387                                 Emit (ec);
3388                                 local = ig.DeclareLocal (type);
3389                                 ig.Emit (OpCodes.Stloc, local);
3390                                 ig.Emit (OpCodes.Ldloca, local);
3391                                 return;
3392                         }
3393
3394
3395                         if (FieldInfo.IsStatic){
3396                                 ig.Emit (OpCodes.Ldsflda, FieldInfo);
3397                         } else {
3398                                 EmitInstance (ec);
3399                                 ig.Emit (OpCodes.Ldflda, FieldInfo);
3400                         }
3401                 }
3402         }
3403
3404         //
3405         // A FieldExpr whose address can not be taken
3406         //
3407         public class FieldExprNoAddress : FieldExpr, IMemoryLocation {
3408                 public FieldExprNoAddress (FieldInfo fi, Location loc) : base (fi, loc)
3409                 {
3410                 }
3411
3412                 public new void AddressOf (EmitContext ec, AddressOp mode)
3413                 {
3414                         Report.Error (-215, "Report this: Taking the address of a remapped parameter not supported");
3415                 }
3416         }
3417
3418         /// <summary>
3419         ///   Expression that evaluates to a Property.  The Assign class
3420         ///   might set the `Value' expression if we are in an assignment.
3421         ///
3422         ///   This is not an LValue because we need to re-write the expression, we
3423         ///   can not take data from the stack and store it.
3424         /// </summary>
3425         public class PropertyExpr : MemberExpr, IAssignMethod {
3426                 public readonly PropertyInfo PropertyInfo;
3427
3428                 //
3429                 // This is set externally by the  `BaseAccess' class
3430                 //
3431                 public bool IsBase;
3432                 MethodInfo getter, setter;
3433                 bool is_static;
3434
3435                 LocalTemporary temp;
3436                 bool prepared;
3437
3438                 internal static PtrHashtable AccessorTable = new PtrHashtable ();
3439
3440                 public PropertyExpr (EmitContext ec, PropertyInfo pi, Location l)
3441                 {
3442                         PropertyInfo = pi;
3443                         eclass = ExprClass.PropertyAccess;
3444                         is_static = false;
3445                         loc = l;
3446
3447                         type = TypeManager.TypeToCoreType (pi.PropertyType);
3448
3449                         ResolveAccessors (ec);
3450                 }
3451
3452                 public override string Name {
3453                         get {
3454                                 return PropertyInfo.Name;
3455                         }
3456                 }
3457
3458                 public override bool IsInstance {
3459                         get {
3460                                 return !is_static;
3461                         }
3462                 }
3463
3464                 public override bool IsStatic {
3465                         get {
3466                                 return is_static;
3467                         }
3468                 }
3469
3470                 public override Type DeclaringType {
3471                         get {
3472                                 return PropertyInfo.DeclaringType;
3473                         }
3474                 }
3475
3476                 public bool VerifyAssignable ()
3477                 {
3478                         if (setter == null) {
3479                                 Report.Error (200, loc,
3480                                               "The property `" + PropertyInfo.Name +
3481                                               "' can not be assigned to, as it has not set accessor");
3482                                 return false;
3483                         }
3484
3485                         return true;
3486                 }
3487
3488                 void FindAccessors (Type invocation_type)
3489                 {
3490                         BindingFlags flags = BindingFlags.Public | BindingFlags.NonPublic |
3491                                 BindingFlags.Static | BindingFlags.Instance |
3492                                 BindingFlags.DeclaredOnly;
3493
3494                         Type current = PropertyInfo.DeclaringType;
3495                         for (; current != null; current = current.BaseType) {
3496                                 MemberInfo[] group = TypeManager.MemberLookup (
3497                                         invocation_type, invocation_type, current,
3498                                         MemberTypes.Property, flags, PropertyInfo.Name, null);
3499
3500                                 if (group == null)
3501                                         continue;
3502
3503                                 if (group.Length != 1)
3504                                         // Oooops, can this ever happen ?
3505                                         return;
3506
3507                                 PropertyInfo pi = (PropertyInfo) group [0];
3508
3509                                 if (getter == null)
3510                                         getter = pi.GetGetMethod (true);
3511
3512                                 if (setter == null)
3513                                         setter = pi.GetSetMethod (true);
3514
3515                                 MethodInfo accessor = getter != null ? getter : setter;
3516
3517                                 if (!accessor.IsVirtual)
3518                                         return;
3519                         }
3520                 }
3521
3522                 //
3523                 // We also perform the permission checking here, as the PropertyInfo does not
3524                 // hold the information for the accessibility of its setter/getter
3525                 //
3526                 void ResolveAccessors (EmitContext ec)
3527                 {
3528                         FindAccessors (ec.ContainerType);
3529
3530                         if (getter != null) {
3531                                 AccessorTable [getter] = PropertyInfo;
3532                                 is_static = getter.IsStatic;
3533                         }
3534
3535                         if (setter != null) {
3536                                 AccessorTable [setter] = PropertyInfo;
3537                                 is_static = setter.IsStatic;
3538                         }
3539                 }
3540
3541                 bool InstanceResolve (EmitContext ec, bool must_do_cs1540_check)
3542                 {
3543                         if ((InstanceExpression == null) && ec.IsStatic && !is_static) {
3544                                 SimpleName.Error_ObjectRefRequired (ec, loc, PropertyInfo.Name);
3545                                 return false;
3546                         }
3547
3548                         if (InstanceExpression != null) {
3549                                 InstanceExpression = InstanceExpression.DoResolve (ec);
3550                                 if (InstanceExpression == null)
3551                                         return false;
3552
3553                                 InstanceExpression.CheckMarshallByRefAccess (ec.ContainerType);
3554                         }
3555
3556                         if (must_do_cs1540_check && (InstanceExpression != null)) {
3557                                 if ((InstanceExpression.Type != ec.ContainerType) &&
3558                                     ec.ContainerType.IsSubclassOf (InstanceExpression.Type)) {
3559                                         Report.Error (1540, loc, "Cannot access protected member `" +
3560                                                       PropertyInfo.DeclaringType + "." + PropertyInfo.Name +
3561                                                       "' via a qualifier of type `" +
3562                                                       TypeManager.CSharpName (InstanceExpression.Type) +
3563                                                       "'; the qualifier must be of type `" +
3564                                                       TypeManager.CSharpName (ec.ContainerType) +
3565                                                       "' (or derived from it)");
3566                                         return false;
3567                                 }
3568                         }
3569
3570                         return true;
3571                 }
3572
3573                 override public Expression DoResolve (EmitContext ec)
3574                 {
3575                         if (getter != null){
3576                                 if (TypeManager.GetArgumentTypes (getter).Length != 0){
3577                                         Report.Error (
3578                                                 117, loc, "`{0}' does not contain a " +
3579                                                 "definition for `{1}'.", getter.DeclaringType,
3580                                                 Name);
3581                                         return null;
3582                                 }
3583                         }
3584
3585                         if (getter == null){
3586                                 //
3587                                 // The following condition happens if the PropertyExpr was
3588                                 // created, but is invalid (ie, the property is inaccessible),
3589                                 // and we did not want to embed the knowledge about this in
3590                                 // the caller routine.  This only avoids double error reporting.
3591                                 //
3592                                 if (setter == null)
3593                                         return null;
3594
3595                                 Report.Error (154, loc,
3596                                               "The property `" + PropertyInfo.Name +
3597                                               "' can not be used in " +
3598                                               "this context because it lacks a get accessor");
3599                                 return null;
3600                         }
3601
3602                         bool must_do_cs1540_check;
3603                         if (!IsAccessorAccessible (ec.ContainerType, getter, out must_do_cs1540_check)) {
3604                                 PropertyBase.PropertyMethod pm = TypeManager.GetMethod (getter) as PropertyBase.PropertyMethod;
3605                                 if (pm != null && pm.HasCustomAccessModifier) {
3606                                         Report.SymbolRelatedToPreviousError (pm);
3607                                         Report.Error (271, loc, "The property or indexer '{0}' cannot be used in this context because the get accessor is inaccessible",
3608                                                 TypeManager.CSharpSignature (getter));
3609                                 }
3610                                 else
3611                                         Report.Error (122, loc, "'{0}' is inaccessible due to its protection level",
3612                                                 TypeManager.CSharpSignature (getter));
3613                                 return null;
3614                         }
3615
3616                         if (!InstanceResolve (ec, must_do_cs1540_check))
3617                                 return null;
3618
3619                         //
3620                         // Only base will allow this invocation to happen.
3621                         //
3622                         if (IsBase && getter.IsAbstract){
3623                                 Report.Error (205, loc, "Cannot call an abstract base property: " +
3624                                               PropertyInfo.DeclaringType + "." +PropertyInfo.Name);
3625                                 return null;
3626                         }
3627
3628                         if (PropertyInfo.PropertyType.IsPointer && !ec.InUnsafe){
3629                                 UnsafeError (loc);
3630                                 return null;
3631                         }
3632
3633                         return this;
3634                 }
3635
3636                 override public Expression DoResolveLValue (EmitContext ec, Expression right_side)
3637                 {
3638                         if (setter == null){
3639                                 //
3640                                 // The following condition happens if the PropertyExpr was
3641                                 // created, but is invalid (ie, the property is inaccessible),
3642                                 // and we did not want to embed the knowledge about this in
3643                                 // the caller routine.  This only avoids double error reporting.
3644                                 //
3645                                 if (getter == null)
3646                                         return null;
3647
3648                                 // TODO: Print better property name
3649                                 Report.Error (200, loc, "Property or indexer '{0}' cannot be assigned to -- it is read only",
3650                                               PropertyInfo.Name);
3651                                 return null;
3652                         }
3653
3654                         if (TypeManager.GetArgumentTypes (setter).Length != 1){
3655                                 Report.Error (
3656                                         117, loc, "`{0}' does not contain a " +
3657                                         "definition for `{1}'.", getter.DeclaringType,
3658                                         Name);
3659                                 return null;
3660                         }
3661
3662                         bool must_do_cs1540_check;
3663                         if (!IsAccessorAccessible (ec.ContainerType, setter, out must_do_cs1540_check)) {
3664                                 PropertyBase.PropertyMethod pm = TypeManager.GetMethod (setter) as PropertyBase.PropertyMethod;
3665                                 if (pm != null && pm.HasCustomAccessModifier) {
3666                                         Report.SymbolRelatedToPreviousError (pm);
3667                                         Report.Error (272, loc, "The property or indexer '{0}' cannot be used in this context because the set accessor is inaccessible",
3668                                                 TypeManager.CSharpSignature (setter));
3669                                 }
3670                                 else
3671                                         Report.Error (122, loc, "'{0}' is inaccessible due to its protection level",
3672                                                 TypeManager.CSharpSignature (setter));
3673                                 return null;
3674                         }
3675
3676                         if (!InstanceResolve (ec, must_do_cs1540_check))
3677                                 return null;
3678
3679                         //
3680                         // Only base will allow this invocation to happen.
3681                         //
3682                         if (IsBase && setter.IsAbstract){
3683                                 Report.Error (205, loc, "Cannot call an abstract base property: " +
3684                                               PropertyInfo.DeclaringType + "." +PropertyInfo.Name);
3685                                 return null;
3686                         }
3687
3688                         //
3689                         // Check that we are not making changes to a temporary memory location
3690                         //
3691                         if (InstanceExpression != null && InstanceExpression.Type.IsValueType && !(InstanceExpression is IMemoryLocation)) {
3692                                 // FIXME: Provide better error reporting.
3693                                 Error (1612, "Cannot modify expression because it is not a variable.");
3694                                 return null;
3695                         }
3696
3697                         return this;
3698                 }
3699
3700
3701
3702                 public override void Emit (EmitContext ec)
3703                 {
3704                         Emit (ec, false);
3705                 }
3706
3707                 void EmitInstance (EmitContext ec)
3708                 {
3709                         if (is_static)
3710                                 return;
3711
3712                         //
3713                         // In case it escapes StaticMemberCheck due to IdenticalTypeAndName.
3714                         // This happens in cases like 'string String', 'int Int32', etc.
3715                         // where the "IdenticalTypeAndName" mechanism is fooled.
3716                         //
3717                         if (InstanceExpression == null) {
3718                                 SimpleName.Error_ObjectRefRequired (ec, loc, PropertyInfo.Name);
3719                                 return;
3720                         }
3721
3722                         if (InstanceExpression.Type.IsValueType) {
3723                                 if (InstanceExpression is IMemoryLocation) {
3724                                         ((IMemoryLocation) InstanceExpression).AddressOf (ec, AddressOp.LoadStore);
3725                                 } else {
3726                                         LocalTemporary t = new LocalTemporary (ec, InstanceExpression.Type);
3727                                         InstanceExpression.Emit (ec);
3728                                         t.Store (ec);
3729                                         t.AddressOf (ec, AddressOp.Store);
3730                                 }
3731                         } else
3732                                 InstanceExpression.Emit (ec);
3733
3734                         if (prepared)
3735                                 ec.ig.Emit (OpCodes.Dup);
3736                 }
3737
3738
3739                 public void Emit (EmitContext ec, bool leave_copy)
3740                 {
3741                         if (!prepared)
3742                                 EmitInstance (ec);
3743
3744                         //
3745                         // Special case: length of single dimension array property is turned into ldlen
3746                         //
3747                         if ((getter == TypeManager.system_int_array_get_length) ||
3748                             (getter == TypeManager.int_array_get_length)){
3749                                 Type iet = InstanceExpression.Type;
3750
3751                                 //
3752                                 // System.Array.Length can be called, but the Type does not
3753                                 // support invoking GetArrayRank, so test for that case first
3754                                 //
3755                                 if (iet != TypeManager.array_type && (iet.GetArrayRank () == 1)) {
3756                                         ec.ig.Emit (OpCodes.Ldlen);
3757                                         ec.ig.Emit (OpCodes.Conv_I4);
3758                                         return;
3759                                 }
3760                         }
3761
3762                         Invocation.EmitCall (ec, IsBase, IsStatic, new EmptyAddressOf (), getter, null, loc);
3763
3764                         if (!leave_copy)
3765                                 return;
3766
3767                         ec.ig.Emit (OpCodes.Dup);
3768                         if (!is_static) {
3769                                 temp = new LocalTemporary (ec, this.Type);
3770                                 temp.Store (ec);
3771                         }
3772                 }
3773
3774                 //
3775                 // Implements the IAssignMethod interface for assignments
3776                 //
3777                 public void EmitAssign (EmitContext ec, Expression source, bool leave_copy, bool prepare_for_load)
3778                 {
3779                         prepared = prepare_for_load;
3780
3781                         EmitInstance (ec);
3782
3783                         source.Emit (ec);
3784                         if (leave_copy) {
3785                                 ec.ig.Emit (OpCodes.Dup);
3786                                 if (!is_static) {
3787                                         temp = new LocalTemporary (ec, this.Type);
3788                                         temp.Store (ec);
3789                                 }
3790                         }
3791
3792                         ArrayList args = new ArrayList (1);
3793                         args.Add (new Argument (new EmptyAddressOf (), Argument.AType.Expression));
3794
3795                         Invocation.EmitCall (ec, IsBase, IsStatic, new EmptyAddressOf (), setter, args, loc);
3796
3797                         if (temp != null)
3798                                 temp.Emit (ec);
3799                 }
3800         }
3801
3802         /// <summary>
3803         ///   Fully resolved expression that evaluates to an Event
3804         /// </summary>
3805         public class EventExpr : MemberExpr {
3806                 public readonly EventInfo EventInfo;
3807
3808                 bool is_static;
3809                 MethodInfo add_accessor, remove_accessor;
3810
3811                 public EventExpr (EventInfo ei, Location loc)
3812                 {
3813                         EventInfo = ei;
3814                         this.loc = loc;
3815                         eclass = ExprClass.EventAccess;
3816
3817                         add_accessor = TypeManager.GetAddMethod (ei);
3818                         remove_accessor = TypeManager.GetRemoveMethod (ei);
3819
3820                         if (add_accessor.IsStatic || remove_accessor.IsStatic)
3821                                 is_static = true;
3822
3823                         if (EventInfo is MyEventBuilder){
3824                                 MyEventBuilder eb = (MyEventBuilder) EventInfo;
3825                                 type = eb.EventType;
3826                                 eb.SetUsed ();
3827                         } else
3828                                 type = EventInfo.EventHandlerType;
3829                 }
3830
3831                 public override string Name {
3832                         get {
3833                                 return EventInfo.Name;
3834                         }
3835                 }
3836
3837                 public override bool IsInstance {
3838                         get {
3839                                 return !is_static;
3840                         }
3841                 }
3842
3843                 public override bool IsStatic {
3844                         get {
3845                                 return is_static;
3846                         }
3847                 }
3848
3849                 public override Type DeclaringType {
3850                         get {
3851                                 return EventInfo.DeclaringType;
3852                         }
3853                 }
3854
3855                 public override Expression ResolveMemberAccess (EmitContext ec, Expression left, Location loc,
3856                                                                  SimpleName original, bool left_is_inferred)
3857                 {
3858                         //
3859                         // If the event is local to this class, we transform ourselves into a FieldExpr
3860                         //
3861
3862                         if (EventInfo.DeclaringType == ec.ContainerType ||
3863                             TypeManager.IsNestedChildOf(ec.ContainerType, EventInfo.DeclaringType)) {
3864                                 MemberInfo mi = TypeManager.GetPrivateFieldOfEvent (EventInfo);
3865
3866                                 if (mi != null) {
3867                                         MemberExpr ml = (MemberExpr) ExprClassFromMemberInfo (ec, mi, loc);
3868
3869                                         if (ml == null) {
3870                                                 Report.Error (-200, loc, "Internal error!!");
3871                                                 return null;
3872                                         }
3873
3874                                         InstanceExpression = left_is_inferred ? null : left;
3875
3876                                         return ml.ResolveMemberAccess (ec, left, loc, original, left_is_inferred);
3877                                 }
3878                         }
3879
3880                         return base.ResolveMemberAccess (ec, left, loc, original, left_is_inferred);
3881                 }
3882
3883
3884                 bool InstanceResolve (EmitContext ec, bool must_do_cs1540_check)
3885                 {
3886                         if ((InstanceExpression == null) && ec.IsStatic && !is_static) {
3887                                 SimpleName.Error_ObjectRefRequired (ec, loc, EventInfo.Name);
3888                                 return false;
3889                         }
3890
3891                         if (InstanceExpression != null) {
3892                                 InstanceExpression = InstanceExpression.DoResolve (ec);
3893                                 if (InstanceExpression == null)
3894                                         return false;
3895                         }
3896
3897                         //
3898                         // This is using the same mechanism as the CS1540 check in PropertyExpr.
3899                         // However, in the Event case, we reported a CS0122 instead.
3900                         //
3901                         if (must_do_cs1540_check && (InstanceExpression != null)) {
3902                                 if ((InstanceExpression.Type != ec.ContainerType) &&
3903                                         ec.ContainerType.IsSubclassOf (InstanceExpression.Type)) {
3904                                         Report.Error (122, loc, "'{0}' is inaccessible due to its protection level",
3905                                                 DeclaringType.Name + "." + EventInfo.Name);
3906
3907                                         return false;
3908                                 }
3909                         }
3910
3911                         return true;
3912                 }
3913
3914                 public override Expression DoResolveLValue (EmitContext ec, Expression right_side)
3915                 {
3916                         return DoResolve (ec);
3917                 }
3918
3919                 public override Expression DoResolve (EmitContext ec)
3920                 {
3921                         if (InstanceExpression != null) {
3922                                 InstanceExpression = InstanceExpression.DoResolve (ec);
3923                                 if (InstanceExpression == null)
3924                                         return null;
3925                         }
3926
3927                         bool must_do_cs1540_check;
3928                         if (!(IsAccessorAccessible (ec.ContainerType, add_accessor, out must_do_cs1540_check)
3929                                     && IsAccessorAccessible (ec.ContainerType, remove_accessor, out must_do_cs1540_check))) {
3930
3931                                Report.Error (122, loc, "'{0}' is inaccessible due to its protection level",
3932                                                DeclaringType.Name + "." + EventInfo.Name);
3933                                return null;
3934                         }
3935
3936                         if (!InstanceResolve (ec, must_do_cs1540_check))
3937                                 return null;
3938
3939                         return this;
3940                 }
3941
3942                 public override void Emit (EmitContext ec)
3943                 {
3944                         if (InstanceExpression is This)
3945                                 Report.Error (79, loc, "The event `{0}' can only appear on the left hand side of += or -=, try calling the actual delegate", Name);
3946                         else
3947                                 Report.Error (70, loc, "The event `{0}' can only appear on the left hand side of += or -= "+
3948                                               "(except on the defining type)", Name);
3949                 }
3950
3951                 public void EmitAddOrRemove (EmitContext ec, Expression source)
3952                 {
3953                         BinaryDelegate source_del = (BinaryDelegate) source;
3954                         Expression handler = source_del.Right;
3955
3956                         Argument arg = new Argument (handler, Argument.AType.Expression);
3957                         ArrayList args = new ArrayList ();
3958
3959                         args.Add (arg);
3960
3961                         if (source_del.IsAddition)
3962                                 Invocation.EmitCall (
3963                                         ec, false, IsStatic, InstanceExpression, add_accessor, args, loc);
3964                         else
3965                                 Invocation.EmitCall (
3966                                         ec, false, IsStatic, InstanceExpression, remove_accessor, args, loc);
3967                 }
3968         }
3969 }