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