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 Expression 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 Expression GetOperatorFalse (EmitContext ec, Expression e, Location loc)
 828                 {
 829                         return GetOperatorTrueOrFalse (ec, e, false, loc);
 830                 }
 831
 832                 static Expression GetOperatorTrueOrFalse (EmitContext ec, Expression e, bool is_true, Location loc)
 833                 {
 834                         MethodBase method;
 835                         Expression operator_group;
 836
 837                         if (TypeManager.IsNullableType (e.Type))
 838                                 return new Nullable.OperatorTrueOrFalse (e, is_true, loc).Resolve (ec);
 839
 840                         operator_group = MethodLookup (ec, e.Type, is_true ? "op_True" : "op_False", loc);
 841                         if (operator_group == null)
 842                                 return null;
 843
 844                         ArrayList arguments = new ArrayList ();
 845                         arguments.Add (new Argument (e, Argument.AType.Expression));
 846                         method = Invocation.OverloadResolve (
 847                                 ec, (MethodGroupExpr) operator_group, arguments, false, loc);
 848
 849                         if (method == null)
 850                                 return null;
 851
 852                         return new StaticCallExpr ((MethodInfo) method, arguments, loc);
 853                 }
 854
 855                 /// <summary>
 856                 ///   Resolves the expression `e' into a boolean expression: either through
 857                 ///   an implicit conversion, or through an `operator true' invocation
 858                 /// </summary>
 859                 public static Expression ResolveBoolean (EmitContext ec, Expression e, Location loc)
 860                 {
 861                         e = e.Resolve (ec);
 862                         if (e == null)
 863                                 return null;
 864
 865                         if (e.Type == TypeManager.bool_type)
 866                                 return e;
 867
 868                         Expression converted = Convert.ImplicitConversion (ec, e, TypeManager.bool_type, new Location (-1));
 869
 870                         if (converted != null)
 871                                 return converted;
 872
 873                         //
 874                         // If no implicit conversion to bool exists, try using `operator true'
 875                         //
 876                         Expression operator_true = Expression.GetOperatorTrue (ec, e, loc);
 877                         if (operator_true == null){
 878                                 Report.Error (31, loc, "Can not convert the expression to a boolean");
 879                                 return null;
 880                         }
 881                         return operator_true;
 882                 }
 883
 884                 public string ExprClassName ()
 885                 {
 886                         switch (eclass){
 887                         case ExprClass.Invalid:
 888                                 return "Invalid";
 889                         case ExprClass.Value:
 890                                 return "value";
 891                         case ExprClass.Variable:
 892                                 return "variable";
 893                         case ExprClass.Namespace:
 894                                 return "namespace";
 895                         case ExprClass.Type:
 896                                 return "type";
 897                         case ExprClass.MethodGroup:
 898                                 return "method group";
 899                         case ExprClass.PropertyAccess:
 900                                 return "property access";
 901                         case ExprClass.EventAccess:
 902                                 return "event access";
 903                         case ExprClass.IndexerAccess:
 904                                 return "indexer access";
 905                         case ExprClass.Nothing:
 906                                 return "null";
 907                         }
 908                         throw new Exception ("Should not happen");
 909                 }
 910
 911                 /// <summary>
 912                 ///   Reports that we were expecting `expr' to be of class `expected'
 913                 /// </summary>
 914                 public void Error_UnexpectedKind (string expected, Location loc)
 915                 {
 916                         Report.Error (118, loc, "Expression denotes a `" + ExprClassName () +
 917                                "' where a `" + expected + "' was expected");
 918                 }
 919
 920                 public void Error_UnexpectedKind (ResolveFlags flags, Location loc)
 921                 {
 922                         ArrayList valid = new ArrayList (10);
 923
 924                         if ((flags & ResolveFlags.VariableOrValue) != 0) {
 925                                 valid.Add ("variable");
 926                                 valid.Add ("value");
 927                         }
 928
 929                         if ((flags & ResolveFlags.Type) != 0)
 930                                 valid.Add ("type");
 931
 932                         if ((flags & ResolveFlags.MethodGroup) != 0)
 933                                 valid.Add ("method group");
 934
 935                         if (valid.Count == 0)
 936                                 valid.Add ("unknown");
 937
 938                         StringBuilder sb = new StringBuilder ();
 939                         for (int i = 0; i < valid.Count; i++) {
 940                                 if (i > 0)
 941                                         sb.Append (", ");
 942                                 else if (i == valid.Count)
 943                                         sb.Append (" or ");
 944                                 sb.Append (valid [i]);
 945                         }
 946
 947                         Report.Error (119, loc, "Expression denotes a `" + ExprClassName () + "' where " +
 948                                "a `" + sb.ToString () + "' was expected");
 949                 }
 950
 951                 static public void Error_ConstantValueCannotBeConverted (Location l, string val, Type t)
 952                 {
 953                         Report.Error (31, l, "Constant value `" + val + "' cannot be converted to " +
 954                                       TypeManager.CSharpName (t));
 955                 }
 956
 957                 public static void UnsafeError (Location loc)
 958                 {
 959                         Report.Error (214, loc, "Pointers may only be used in an unsafe context");
 960                 }
 961
 962                 /// <summary>
 963                 ///   Converts the IntConstant, UIntConstant, LongConstant or
 964                 ///   ULongConstant into the integral target_type.   Notice
 965                 ///   that we do not return an `Expression' we do return
 966                 ///   a boxed integral type.
 967                 ///
 968                 ///   FIXME: Since I added the new constants, we need to
 969                 ///   also support conversions from CharConstant, ByteConstant,
 970                 ///   SByteConstant, UShortConstant, ShortConstant
 971                 ///
 972                 ///   This is used by the switch statement, so the domain
 973                 ///   of work is restricted to the literals above, and the
 974                 ///   targets are int32, uint32, char, byte, sbyte, ushort,
 975                 ///   short, uint64 and int64
 976                 /// </summary>
 977                 public static object ConvertIntLiteral (Constant c, Type target_type, Location loc)
 978                 {
 979                         if (!Convert.ImplicitStandardConversionExists (Convert.ConstantEC, c, target_type)){
 980                                 Convert.Error_CannotImplicitConversion (loc, c.Type, target_type);
 981                                 return null;
 982                         }
 983
 984                         string s = "";
 985
 986                         if (c.Type == target_type)
 987                                 return ((Constant) c).GetValue ();
 988
 989                         //
 990                         // Make into one of the literals we handle, we dont really care
 991                         // about this value as we will just return a few limited types
 992                         //
 993                         if (c is EnumConstant)
 994                                 c = ((EnumConstant)c).WidenToCompilerConstant ();
 995
 996                         if (c is IntConstant){
 997                                 int v = ((IntConstant) c).Value;
 998
 999                                 if (target_type == TypeManager.uint32_type){
1000                                         if (v >= 0)
1001                                                 return (uint) v;
1002                                 } else if (target_type == TypeManager.char_type){
1003                                         if (v >= Char.MinValue && v <= Char.MaxValue)
1004                                                 return (char) v;
1005                                 } else if (target_type == TypeManager.byte_type){
1006                                         if (v >= Byte.MinValue && v <= Byte.MaxValue)
1007                                                 return (byte) v;
1008                                 } else if (target_type == TypeManager.sbyte_type){
1009                                         if (v >= SByte.MinValue && v <= SByte.MaxValue)
1010                                                 return (sbyte) v;
1011                                 } else if (target_type == TypeManager.short_type){
1012                                         if (v >= Int16.MinValue && v <= UInt16.MaxValue)
1013                                                 return (short) v;
1014                                 } else if (target_type == TypeManager.ushort_type){
1015                                         if (v >= UInt16.MinValue && v <= UInt16.MaxValue)
1016                                                 return (ushort) v;
1017                                 } else if (target_type == TypeManager.int64_type)
1018                                         return (long) v;
1019                                 else if (target_type == TypeManager.uint64_type){
1020                                         if (v > 0)
1021                                                 return (ulong) v;
1022                                 }
1023
1024                                 s = v.ToString ();
1025                         } else if (c is UIntConstant){
1026                                 uint v = ((UIntConstant) c).Value;
1027
1028                                 if (target_type == TypeManager.int32_type){
1029                                         if (v <= Int32.MaxValue)
1030                                                 return (int) v;
1031                                 } else if (target_type == TypeManager.char_type){
1032                                         if (v >= Char.MinValue && v <= Char.MaxValue)
1033                                                 return (char) v;
1034                                 } else if (target_type == TypeManager.byte_type){
1035                                         if (v <= Byte.MaxValue)
1036                                                 return (byte) v;
1037                                 } else if (target_type == TypeManager.sbyte_type){
1038                                         if (v <= SByte.MaxValue)
1039                                                 return (sbyte) v;
1040                                 } else if (target_type == TypeManager.short_type){
1041                                         if (v <= UInt16.MaxValue)
1042                                                 return (short) v;
1043                                 } else if (target_type == TypeManager.ushort_type){
1044                                         if (v <= UInt16.MaxValue)
1045                                                 return (ushort) v;
1046                                 } else if (target_type == TypeManager.int64_type)
1047                                         return (long) v;
1048                                 else if (target_type == TypeManager.uint64_type)
1049                                         return (ulong) v;
1050                                 s = v.ToString ();
1051                         } else if (c is LongConstant){
1052                                 long v = ((LongConstant) c).Value;
1053
1054                                 if (target_type == TypeManager.int32_type){
1055                                         if (v >= UInt32.MinValue && v <= UInt32.MaxValue)
1056                                                 return (int) v;
1057                                 } else if (target_type == TypeManager.uint32_type){
1058                                         if (v >= 0 && v <= UInt32.MaxValue)
1059                                                 return (uint) v;
1060                                 } else if (target_type == TypeManager.char_type){
1061                                         if (v >= Char.MinValue && v <= Char.MaxValue)
1062                                                 return (char) v;
1063                                 } else if (target_type == TypeManager.byte_type){
1064                                         if (v >= Byte.MinValue && v <= Byte.MaxValue)
1065                                                 return (byte) v;
1066                                 } else if (target_type == TypeManager.sbyte_type){
1067                                         if (v >= SByte.MinValue && v <= SByte.MaxValue)
1068                                                 return (sbyte) v;
1069                                 } else if (target_type == TypeManager.short_type){
1070                                         if (v >= Int16.MinValue && v <= UInt16.MaxValue)
1071                                                 return (short) v;
1072                                 } else if (target_type == TypeManager.ushort_type){
1073                                         if (v >= UInt16.MinValue && v <= UInt16.MaxValue)
1074                                                 return (ushort) v;
1075                                 } else if (target_type == TypeManager.uint64_type){
1076                                         if (v > 0)
1077                                                 return (ulong) v;
1078                                 }
1079                                 s = v.ToString ();
1080                         } else if (c is ULongConstant){
1081                                 ulong v = ((ULongConstant) c).Value;
1082
1083                                 if (target_type == TypeManager.int32_type){
1084                                         if (v <= Int32.MaxValue)
1085                                                 return (int) v;
1086                                 } else if (target_type == TypeManager.uint32_type){
1087                                         if (v <= UInt32.MaxValue)
1088                                                 return (uint) v;
1089                                 } else if (target_type == TypeManager.char_type){
1090                                         if (v >= Char.MinValue && v <= Char.MaxValue)
1091                                                 return (char) v;
1092                                 } else if (target_type == TypeManager.byte_type){
1093                                         if (v >= Byte.MinValue && v <= Byte.MaxValue)
1094                                                 return (byte) v;
1095                                 } else if (target_type == TypeManager.sbyte_type){
1096                                         if (v <= (int) SByte.MaxValue)
1097                                                 return (sbyte) v;
1098                                 } else if (target_type == TypeManager.short_type){
1099                                         if (v <= UInt16.MaxValue)
1100                                                 return (short) v;
1101                                 } else if (target_type == TypeManager.ushort_type){
1102                                         if (v <= UInt16.MaxValue)
1103                                                 return (ushort) v;
1104                                 } else if (target_type == TypeManager.int64_type){
1105                                         if (v <= Int64.MaxValue)
1106                                                 return (long) v;
1107                                 }
1108                                 s = v.ToString ();
1109                         } else if (c is ByteConstant){
1110                                 byte v = ((ByteConstant) c).Value;
1111
1112                                 if (target_type == TypeManager.int32_type)
1113                                         return (int) v;
1114                                 else if (target_type == TypeManager.uint32_type)
1115                                         return (uint) v;
1116                                 else if (target_type == TypeManager.char_type)
1117                                         return (char) v;
1118                                 else if (target_type == TypeManager.sbyte_type){
1119                                         if (v <= SByte.MaxValue)
1120                                                 return (sbyte) v;
1121                                 } else if (target_type == TypeManager.short_type)
1122                                         return (short) v;
1123                                 else if (target_type == TypeManager.ushort_type)
1124                                         return (ushort) v;
1125                                 else if (target_type == TypeManager.int64_type)
1126                                         return (long) v;
1127                                 else if (target_type == TypeManager.uint64_type)
1128                                         return (ulong) v;
1129                                 s = v.ToString ();
1130                         } else if (c is SByteConstant){
1131                                 sbyte v = ((SByteConstant) c).Value;
1132
1133                                 if (target_type == TypeManager.int32_type)
1134                                         return (int) v;
1135                                 else if (target_type == TypeManager.uint32_type){
1136                                         if (v >= 0)
1137                                                 return (uint) v;
1138                                 } else if (target_type == TypeManager.char_type){
1139                                         if (v >= 0)
1140                                                 return (char) v;
1141                                 } else if (target_type == TypeManager.byte_type){
1142                                         if (v >= 0)
1143                                                 return (byte) v;
1144                                 } else if (target_type == TypeManager.short_type)
1145                                         return (short) v;
1146                                 else if (target_type == TypeManager.ushort_type){
1147                                         if (v >= 0)
1148                                                 return (ushort) v;
1149                                 } else if (target_type == TypeManager.int64_type)
1150                                         return (long) v;
1151                                 else if (target_type == TypeManager.uint64_type){
1152                                         if (v >= 0)
1153                                                 return (ulong) v;
1154                                 }
1155                                 s = v.ToString ();
1156                         } else if (c is ShortConstant){
1157                                 short v = ((ShortConstant) c).Value;
1158
1159                                 if (target_type == TypeManager.int32_type){
1160                                         return (int) v;
1161                                 } else if (target_type == TypeManager.uint32_type){
1162                                         if (v >= 0)
1163                                                 return (uint) v;
1164                                 } else if (target_type == TypeManager.char_type){
1165                                         if (v >= 0)
1166                                                 return (char) v;
1167                                 } else if (target_type == TypeManager.byte_type){
1168                                         if (v >= Byte.MinValue && v <= Byte.MaxValue)
1169                                                 return (byte) v;
1170                                 } else if (target_type == TypeManager.sbyte_type){
1171                                         if (v >= SByte.MinValue && v <= SByte.MaxValue)
1172                                                 return (sbyte) v;
1173                                 } else if (target_type == TypeManager.ushort_type){
1174                                         if (v >= 0)
1175                                                 return (ushort) v;
1176                                 } else if (target_type == TypeManager.int64_type)
1177                                         return (long) v;
1178                                 else if (target_type == TypeManager.uint64_type)
1179                                         return (ulong) v;
1180
1181                                 s = v.ToString ();
1182                         } else if (c is UShortConstant){
1183                                 ushort v = ((UShortConstant) c).Value;
1184
1185                                 if (target_type == TypeManager.int32_type)
1186                                         return (int) v;
1187                                 else if (target_type == TypeManager.uint32_type)
1188                                         return (uint) v;
1189                                 else if (target_type == TypeManager.char_type){
1190                                         if (v >= Char.MinValue && v <= Char.MaxValue)
1191                                                 return (char) v;
1192                                 } else if (target_type == TypeManager.byte_type){
1193                                         if (v >= Byte.MinValue && v <= Byte.MaxValue)
1194                                                 return (byte) v;
1195                                 } else if (target_type == TypeManager.sbyte_type){
1196                                         if (v <= SByte.MaxValue)
1197                                                 return (byte) v;
1198                                 } else if (target_type == TypeManager.short_type){
1199                                         if (v <= Int16.MaxValue)
1200                                                 return (short) v;
1201                                 } else if (target_type == TypeManager.int64_type)
1202                                         return (long) v;
1203                                 else if (target_type == TypeManager.uint64_type)
1204                                         return (ulong) v;
1205
1206                                 s = v.ToString ();
1207                         } else if (c is CharConstant){
1208                                 char v = ((CharConstant) c).Value;
1209
1210                                 if (target_type == TypeManager.int32_type)
1211                                         return (int) v;
1212                                 else if (target_type == TypeManager.uint32_type)
1213                                         return (uint) v;
1214                                 else if (target_type == TypeManager.byte_type){
1215                                         if (v >= Byte.MinValue && v <= Byte.MaxValue)
1216                                                 return (byte) v;
1217                                 } else if (target_type == TypeManager.sbyte_type){
1218                                         if (v <= SByte.MaxValue)
1219                                                 return (sbyte) v;
1220                                 } else if (target_type == TypeManager.short_type){
1221                                         if (v <= Int16.MaxValue)
1222                                                 return (short) v;
1223                                 } else if (target_type == TypeManager.ushort_type)
1224                                         return (short) v;
1225                                 else if (target_type == TypeManager.int64_type)
1226                                         return (long) v;
1227                                 else if (target_type == TypeManager.uint64_type)
1228                                         return (ulong) v;
1229
1230                                 s = v.ToString ();
1231                         }
1232                         Error_ConstantValueCannotBeConverted (loc, s, target_type);
1233                         return null;
1234                 }
1235
1236                 //
1237                 // Load the object from the pointer.
1238                 //
1239                 public static void LoadFromPtr (ILGenerator ig, Type t)
1240                 {
1241                         if (t == TypeManager.int32_type)
1242                                 ig.Emit (OpCodes.Ldind_I4);
1243                         else if (t == TypeManager.uint32_type)
1244                                 ig.Emit (OpCodes.Ldind_U4);
1245                         else if (t == TypeManager.short_type)
1246                                 ig.Emit (OpCodes.Ldind_I2);
1247                         else if (t == TypeManager.ushort_type)
1248                                 ig.Emit (OpCodes.Ldind_U2);
1249                         else if (t == TypeManager.char_type)
1250                                 ig.Emit (OpCodes.Ldind_U2);
1251                         else if (t == TypeManager.byte_type)
1252                                 ig.Emit (OpCodes.Ldind_U1);
1253                         else if (t == TypeManager.sbyte_type)
1254                                 ig.Emit (OpCodes.Ldind_I1);
1255                         else if (t == TypeManager.uint64_type)
1256                                 ig.Emit (OpCodes.Ldind_I8);
1257                         else if (t == TypeManager.int64_type)
1258                                 ig.Emit (OpCodes.Ldind_I8);
1259                         else if (t == TypeManager.float_type)
1260                                 ig.Emit (OpCodes.Ldind_R4);
1261                         else if (t == TypeManager.double_type)
1262                                 ig.Emit (OpCodes.Ldind_R8);
1263                         else if (t == TypeManager.bool_type)
1264                                 ig.Emit (OpCodes.Ldind_I1);
1265                         else if (t == TypeManager.intptr_type)
1266                                 ig.Emit (OpCodes.Ldind_I);
1267                         else if (TypeManager.IsEnumType (t)) {
1268                                 if (t == TypeManager.enum_type)
1269                                         ig.Emit (OpCodes.Ldind_Ref);
1270                                 else
1271                                         LoadFromPtr (ig, TypeManager.EnumToUnderlying (t));
1272                         } else if (t.IsValueType || t.IsGenericParameter)
1273                                 ig.Emit (OpCodes.Ldobj, t);
1274                         else if (t.IsPointer)
1275                                 ig.Emit (OpCodes.Ldind_I);
1276                         else
1277                                 ig.Emit (OpCodes.Ldind_Ref);
1278                 }
1279
1280                 //
1281                 // The stack contains the pointer and the value of type `type'
1282                 //
1283                 public static void StoreFromPtr (ILGenerator ig, Type type)
1284                 {
1285                         if (TypeManager.IsEnumType (type))
1286                                 type = TypeManager.EnumToUnderlying (type);
1287                         if (type == TypeManager.int32_type || type == TypeManager.uint32_type)
1288                                 ig.Emit (OpCodes.Stind_I4);
1289                         else if (type == TypeManager.int64_type || type == TypeManager.uint64_type)
1290                                 ig.Emit (OpCodes.Stind_I8);
1291                         else if (type == TypeManager.char_type || type == TypeManager.short_type ||
1292                                  type == TypeManager.ushort_type)
1293                                 ig.Emit (OpCodes.Stind_I2);
1294                         else if (type == TypeManager.float_type)
1295                                 ig.Emit (OpCodes.Stind_R4);
1296                         else if (type == TypeManager.double_type)
1297                                 ig.Emit (OpCodes.Stind_R8);
1298                         else if (type == TypeManager.byte_type || type == TypeManager.sbyte_type ||
1299                                  type == TypeManager.bool_type)
1300                                 ig.Emit (OpCodes.Stind_I1);
1301                         else if (type == TypeManager.intptr_type)
1302                                 ig.Emit (OpCodes.Stind_I);
1303                         else if (type.IsValueType || type.IsGenericParameter)
1304                                 ig.Emit (OpCodes.Stobj, type);
1305                         else
1306                                 ig.Emit (OpCodes.Stind_Ref);
1307                 }
1308
1309                 //
1310                 // Returns the size of type `t' if known, otherwise, 0
1311                 //
1312                 public static int GetTypeSize (Type t)
1313                 {
1314                         t = TypeManager.TypeToCoreType (t);
1315                         if (t == TypeManager.int32_type ||
1316                             t == TypeManager.uint32_type ||
1317                             t == TypeManager.float_type)
1318                                 return 4;
1319                         else if (t == TypeManager.int64_type ||
1320                                  t == TypeManager.uint64_type ||
1321                                  t == TypeManager.double_type)
1322                                 return 8;
1323                         else if (t == TypeManager.byte_type ||
1324                                  t == TypeManager.sbyte_type ||
1325                                  t == TypeManager.bool_type)
1326                                 return 1;
1327                         else if (t == TypeManager.short_type ||
1328                                  t == TypeManager.char_type ||
1329                                  t == TypeManager.ushort_type)
1330                                 return 2;
1331                         else if (t == TypeManager.decimal_type)
1332                                 return 16;
1333                         else
1334                                 return 0;
1335                 }
1336
1337                 public static void Error_NegativeArrayIndex (Location loc)
1338                 {
1339                         Report.Error (248, loc, "Cannot create an array with a negative size");
1340                 }
1341
1342                 //
1343                 // Converts `source' to an int, uint, long or ulong.
1344                 //
1345                 public Expression ExpressionToArrayArgument (EmitContext ec, Expression source, Location loc)
1346                 {
1347                         Expression target;
1348
1349                         bool old_checked = ec.CheckState;
1350                         ec.CheckState = true;
1351
1352                         target = Convert.ImplicitConversion (ec, source, TypeManager.int32_type, loc);
1353                         if (target == null){
1354                                 target = Convert.ImplicitConversion (ec, source, TypeManager.uint32_type, loc);
1355                                 if (target == null){
1356                                         target = Convert.ImplicitConversion (ec, source, TypeManager.int64_type, loc);
1357                                         if (target == null){
1358                                                 target = Convert.ImplicitConversion (ec, source, TypeManager.uint64_type, loc);
1359                                                 if (target == null)
1360                                                         Convert.Error_CannotImplicitConversion (loc, source.Type, TypeManager.int32_type);
1361                                         }
1362                                 }
1363                         }
1364                         ec.CheckState = old_checked;
1365
1366                         //
1367                         // Only positive constants are allowed at compile time
1368                         //
1369                         if (target is Constant){
1370                                 if (target is IntConstant){
1371                                         if (((IntConstant) target).Value < 0){
1372                                                 Error_NegativeArrayIndex (loc);
1373                                                 return null;
1374                                         }
1375                                 }
1376
1377                                 if (target is LongConstant){
1378                                         if (((LongConstant) target).Value < 0){
1379                                                 Error_NegativeArrayIndex (loc);
1380                                                 return null;
1381                                         }
1382                                 }
1383
1384                         }
1385
1386                         return target;
1387                 }
1388
1389         }
1390
1391         /// <summary>
1392         ///   This is just a base class for expressions that can
1393         ///   appear on statements (invocations, object creation,
1394         ///   assignments, post/pre increment and decrement).  The idea
1395         ///   being that they would support an extra Emition interface that
1396         ///   does not leave a result on the stack.
1397         /// </summary>
1398         public abstract class ExpressionStatement : Expression {
1399
1400                 public virtual ExpressionStatement ResolveStatement (EmitContext ec)
1401                 {
1402                         Expression e = Resolve (ec);
1403                         if (e == null)
1404                                 return null;
1405
1406                         ExpressionStatement es = e as ExpressionStatement;
1407                         if (es == null)
1408                                 Error (201, "Only assignment, call, increment, decrement and new object " +
1409                                        "expressions can be used as a statement");
1410
1411                         return es;
1412                 }
1413
1414                 /// <summary>
1415                 ///   Requests the expression to be emitted in a `statement'
1416                 ///   context.  This means that no new value is left on the
1417                 ///   stack after invoking this method (constrasted with
1418                 ///   Emit that will always leave a value on the stack).
1419                 /// </summary>
1420                 public abstract void EmitStatement (EmitContext ec);
1421         }
1422
1423         /// <summary>
1424         ///   This kind of cast is used to encapsulate the child
1425         ///   whose type is child.Type into an expression that is
1426         ///   reported to return "return_type".  This is used to encapsulate
1427         ///   expressions which have compatible types, but need to be dealt
1428         ///   at higher levels with.
1429         ///
1430         ///   For example, a "byte" expression could be encapsulated in one
1431         ///   of these as an "unsigned int".  The type for the expression
1432         ///   would be "unsigned int".
1433         ///
1434         /// </summary>
1435         public class EmptyCast : Expression {
1436                 protected Expression child;
1437
1438                 public Expression Child {
1439                         get {
1440                                 return child;
1441                         }
1442                 }
1443
1444                 public EmptyCast (Expression child, Type return_type)
1445                 {
1446                         eclass = child.eclass;
1447                         type = return_type;
1448                         this.child = child;
1449                 }
1450
1451                 public override Expression DoResolve (EmitContext ec)
1452                 {
1453                         // This should never be invoked, we are born in fully
1454                         // initialized state.
1455
1456                         return this;
1457                 }
1458
1459                 public override void Emit (EmitContext ec)
1460                 {
1461                         child.Emit (ec);
1462                 }
1463         }
1464
1465         //
1466         // We need to special case this since an empty cast of
1467         // a NullLiteral is still a Constant
1468         //
1469         public class NullCast : Constant {
1470                 protected Expression child;
1471
1472                 public NullCast (Expression child, Type return_type)
1473                 {
1474                         eclass = child.eclass;
1475                         type = return_type;
1476                         this.child = child;
1477                 }
1478
1479                 override public string AsString ()
1480                 {
1481                         return "null";
1482                 }
1483
1484                 public override object GetValue ()
1485                 {
1486                         return null;
1487                 }
1488
1489                 public override Expression DoResolve (EmitContext ec)
1490                 {
1491                         // This should never be invoked, we are born in fully
1492                         // initialized state.
1493
1494                         return this;
1495                 }
1496
1497                 public override void Emit (EmitContext ec)
1498                 {
1499                         child.Emit (ec);
1500                 }
1501
1502                 public override bool IsNegative {
1503                         get {
1504                                 return false;
1505                         }
1506                 }
1507         }
1508
1509
1510         /// <summary>
1511         ///  This class is used to wrap literals which belong inside Enums
1512         /// </summary>
1513         public class EnumConstant : Constant {
1514                 public Constant Child;
1515
1516                 public EnumConstant (Constant child, Type enum_type)
1517                 {
1518                         eclass = child.eclass;
1519                         this.Child = child;
1520                         type = enum_type;
1521                 }
1522
1523                 public override Expression DoResolve (EmitContext ec)
1524                 {
1525                         // This should never be invoked, we are born in fully
1526                         // initialized state.
1527
1528                         return this;
1529                 }
1530
1531                 public override void Emit (EmitContext ec)
1532                 {
1533                         Child.Emit (ec);
1534                 }
1535
1536                 public override object GetValue ()
1537                 {
1538                         return Child.GetValue ();
1539                 }
1540
1541                 public object GetValueAsEnumType ()
1542                 {
1543                         return System.Enum.ToObject (type, Child.GetValue ());
1544                 }
1545
1546                 //
1547                 // Converts from one of the valid underlying types for an enumeration
1548                 // (int32, uint32, int64, uint64, short, ushort, byte, sbyte) to
1549                 // one of the internal compiler literals: Int/UInt/Long/ULong Literals.
1550                 //
1551                 public Constant WidenToCompilerConstant ()
1552                 {
1553                         Type t = TypeManager.EnumToUnderlying (Child.Type);
1554                         object v = ((Constant) Child).GetValue ();;
1555
1556                         if (t == TypeManager.int32_type)
1557                                 return new IntConstant ((int) v);
1558                         if (t == TypeManager.uint32_type)
1559                                 return new UIntConstant ((uint) v);
1560                         if (t == TypeManager.int64_type)
1561                                 return new LongConstant ((long) v);
1562                         if (t == TypeManager.uint64_type)
1563                                 return new ULongConstant ((ulong) v);
1564                         if (t == TypeManager.short_type)
1565                                 return new ShortConstant ((short) v);
1566                         if (t == TypeManager.ushort_type)
1567                                 return new UShortConstant ((ushort) v);
1568                         if (t == TypeManager.byte_type)
1569                                 return new ByteConstant ((byte) v);
1570                         if (t == TypeManager.sbyte_type)
1571                                 return new SByteConstant ((sbyte) v);
1572
1573                         throw new Exception ("Invalid enumeration underlying type: " + t);
1574                 }
1575
1576                 //
1577                 // Extracts the value in the enumeration on its native representation
1578                 //
1579                 public object GetPlainValue ()
1580                 {
1581                         Type t = TypeManager.EnumToUnderlying (Child.Type);
1582                         object v = ((Constant) Child).GetValue ();;
1583
1584                         if (t == TypeManager.int32_type)
1585                                 return (int) v;
1586                         if (t == TypeManager.uint32_type)
1587                                 return (uint) v;
1588                         if (t == TypeManager.int64_type)
1589                                 return (long) v;
1590                         if (t == TypeManager.uint64_type)
1591                                 return (ulong) v;
1592                         if (t == TypeManager.short_type)
1593                                 return (short) v;
1594                         if (t == TypeManager.ushort_type)
1595                                 return (ushort) v;
1596                         if (t == TypeManager.byte_type)
1597                                 return (byte) v;
1598                         if (t == TypeManager.sbyte_type)
1599                                 return (sbyte) v;
1600
1601                         return null;
1602                 }
1603
1604                 public override string AsString ()
1605                 {
1606                         return Child.AsString ();
1607                 }
1608
1609                 public override DoubleConstant ConvertToDouble ()
1610                 {
1611                         return Child.ConvertToDouble ();
1612                 }
1613
1614                 public override FloatConstant ConvertToFloat ()
1615                 {
1616                         return Child.ConvertToFloat ();
1617                 }
1618
1619                 public override ULongConstant ConvertToULong ()
1620                 {
1621                         return Child.ConvertToULong ();
1622                 }
1623
1624                 public override LongConstant ConvertToLong ()
1625                 {
1626                         return Child.ConvertToLong ();
1627                 }
1628
1629                 public override UIntConstant ConvertToUInt ()
1630                 {
1631                         return Child.ConvertToUInt ();
1632                 }
1633
1634                 public override IntConstant ConvertToInt ()
1635                 {
1636                         return Child.ConvertToInt ();
1637                 }
1638
1639                 public override bool IsZeroInteger {
1640                         get { return Child.IsZeroInteger; }
1641                 }
1642
1643                 public override bool IsNegative {
1644                         get {
1645                                 return Child.IsNegative;
1646                         }
1647                 }
1648         }
1649
1650         /// <summary>
1651         ///   This kind of cast is used to encapsulate Value Types in objects.
1652         ///
1653         ///   The effect of it is to box the value type emitted by the previous
1654         ///   operation.
1655         /// </summary>
1656         public class BoxedCast : EmptyCast {
1657
1658                 public BoxedCast (Expression expr)
1659                         : base (expr, TypeManager.object_type)
1660                 {
1661                         eclass = ExprClass.Value;
1662                 }
1663
1664                 public BoxedCast (Expression expr, Type target_type)
1665                         : base (expr, target_type)
1666                 {
1667                         eclass = ExprClass.Value;
1668                 }
1669
1670                 public override Expression DoResolve (EmitContext ec)
1671                 {
1672                         // This should never be invoked, we are born in fully
1673                         // initialized state.
1674
1675                         return this;
1676                 }
1677
1678                 public override void Emit (EmitContext ec)
1679                 {
1680                         base.Emit (ec);
1681
1682                         ec.ig.Emit (OpCodes.Box, child.Type);
1683                 }
1684         }
1685
1686         public class UnboxCast : EmptyCast {
1687                 public UnboxCast (Expression expr, Type return_type)
1688                         : base (expr, return_type)
1689                 {
1690                 }
1691
1692                 public override Expression DoResolve (EmitContext ec)
1693                 {
1694                         // This should never be invoked, we are born in fully
1695                         // initialized state.
1696
1697                         return this;
1698                 }
1699
1700                 public override void Emit (EmitContext ec)
1701                 {
1702                         Type t = type;
1703                         ILGenerator ig = ec.ig;
1704
1705                         base.Emit (ec);
1706                         if (t.IsGenericParameter)
1707                                 ig.Emit (OpCodes.Unbox_Any, t);
1708                         else {
1709                                 ig.Emit (OpCodes.Unbox, t);
1710
1711                                 LoadFromPtr (ig, t);
1712                         }
1713                 }
1714         }
1715
1716         /// <summary>
1717         ///   This is used to perform explicit numeric conversions.
1718         ///
1719         ///   Explicit numeric conversions might trigger exceptions in a checked
1720         ///   context, so they should generate the conv.ovf opcodes instead of
1721         ///   conv opcodes.
1722         /// </summary>
1723         public class ConvCast : EmptyCast {
1724                 public enum Mode : byte {
1725                         I1_U1, I1_U2, I1_U4, I1_U8, I1_CH,
1726                         U1_I1, U1_CH,
1727                         I2_I1, I2_U1, I2_U2, I2_U4, I2_U8, I2_CH,
1728                         U2_I1, U2_U1, U2_I2, U2_CH,
1729                         I4_I1, I4_U1, I4_I2, I4_U2, I4_U4, I4_U8, I4_CH,
1730                         U4_I1, U4_U1, U4_I2, U4_U2, U4_I4, U4_CH,
1731                         I8_I1, I8_U1, I8_I2, I8_U2, I8_I4, I8_U4, I8_U8, I8_CH,
1732                         U8_I1, U8_U1, U8_I2, U8_U2, U8_I4, U8_U4, U8_I8, U8_CH,
1733                         CH_I1, CH_U1, CH_I2,
1734                         R4_I1, R4_U1, R4_I2, R4_U2, R4_I4, R4_U4, R4_I8, R4_U8, R4_CH,
1735                         R8_I1, R8_U1, R8_I2, R8_U2, R8_I4, R8_U4, R8_I8, R8_U8, R8_CH, R8_R4
1736                 }
1737
1738                 Mode mode;
1739                 bool checked_state;
1740
1741                 public ConvCast (EmitContext ec, Expression child, Type return_type, Mode m)
1742                         : base (child, return_type)
1743                 {
1744                         checked_state = ec.CheckState;
1745                         mode = m;
1746                 }
1747
1748                 public override Expression DoResolve (EmitContext ec)
1749                 {
1750                         // This should never be invoked, we are born in fully
1751                         // initialized state.
1752
1753                         return this;
1754                 }
1755
1756                 public override string ToString ()
1757                 {
1758                         return String.Format ("ConvCast ({0}, {1})", mode, child);
1759                 }
1760
1761                 public override void Emit (EmitContext ec)
1762                 {
1763                         ILGenerator ig = ec.ig;
1764
1765                         base.Emit (ec);
1766
1767                         if (checked_state){
1768                                 switch (mode){
1769                                 case Mode.I1_U1: ig.Emit (OpCodes.Conv_Ovf_U1); break;
1770                                 case Mode.I1_U2: ig.Emit (OpCodes.Conv_Ovf_U2); break;
1771                                 case Mode.I1_U4: ig.Emit (OpCodes.Conv_Ovf_U4); break;
1772                                 case Mode.I1_U8: ig.Emit (OpCodes.Conv_Ovf_U8); break;
1773                                 case Mode.I1_CH: ig.Emit (OpCodes.Conv_Ovf_U2); break;
1774
1775                                 case Mode.U1_I1: ig.Emit (OpCodes.Conv_Ovf_I1_Un); break;
1776                                 case Mode.U1_CH: /* nothing */ break;
1777
1778                                 case Mode.I2_I1: ig.Emit (OpCodes.Conv_Ovf_I1); break;
1779                                 case Mode.I2_U1: ig.Emit (OpCodes.Conv_Ovf_U1); break;
1780                                 case Mode.I2_U2: ig.Emit (OpCodes.Conv_Ovf_U2); break;
1781                                 case Mode.I2_U4: ig.Emit (OpCodes.Conv_Ovf_U4); break;
1782                                 case Mode.I2_U8: ig.Emit (OpCodes.Conv_Ovf_U8); break;
1783                                 case Mode.I2_CH: ig.Emit (OpCodes.Conv_Ovf_U2); break;
1784
1785                                 case Mode.U2_I1: ig.Emit (OpCodes.Conv_Ovf_I1_Un); break;
1786                                 case Mode.U2_U1: ig.Emit (OpCodes.Conv_Ovf_U1_Un); break;
1787                                 case Mode.U2_I2: ig.Emit (OpCodes.Conv_Ovf_I2_Un); break;
1788                                 case Mode.U2_CH: /* nothing */ break;
1789
1790                                 case Mode.I4_I1: ig.Emit (OpCodes.Conv_Ovf_I1); break;
1791                                 case Mode.I4_U1: ig.Emit (OpCodes.Conv_Ovf_U1); break;
1792                                 case Mode.I4_I2: ig.Emit (OpCodes.Conv_Ovf_I2); break;
1793                                 case Mode.I4_U4: ig.Emit (OpCodes.Conv_Ovf_U4); break;
1794                                 case Mode.I4_U2: ig.Emit (OpCodes.Conv_Ovf_U2); break;
1795                                 case Mode.I4_U8: ig.Emit (OpCodes.Conv_Ovf_U8); break;
1796                                 case Mode.I4_CH: ig.Emit (OpCodes.Conv_Ovf_U2); break;
1797
1798                                 case Mode.U4_I1: ig.Emit (OpCodes.Conv_Ovf_I1_Un); break;
1799                                 case Mode.U4_U1: ig.Emit (OpCodes.Conv_Ovf_U1_Un); break;
1800                                 case Mode.U4_I2: ig.Emit (OpCodes.Conv_Ovf_I2_Un); break;
1801                                 case Mode.U4_U2: ig.Emit (OpCodes.Conv_Ovf_U2_Un); break;
1802                                 case Mode.U4_I4: ig.Emit (OpCodes.Conv_Ovf_I4_Un); break;
1803                                 case Mode.U4_CH: ig.Emit (OpCodes.Conv_Ovf_U2_Un); break;
1804
1805                                 case Mode.I8_I1: ig.Emit (OpCodes.Conv_Ovf_I1); break;
1806                                 case Mode.I8_U1: ig.Emit (OpCodes.Conv_Ovf_U1); break;
1807                                 case Mode.I8_I2: ig.Emit (OpCodes.Conv_Ovf_I2); break;
1808                                 case Mode.I8_U2: ig.Emit (OpCodes.Conv_Ovf_U2); break;
1809                                 case Mode.I8_I4: ig.Emit (OpCodes.Conv_Ovf_I4); break;
1810                                 case Mode.I8_U4: ig.Emit (OpCodes.Conv_Ovf_U4); break;
1811                                 case Mode.I8_U8: ig.Emit (OpCodes.Conv_Ovf_U8); break;
1812                                 case Mode.I8_CH: ig.Emit (OpCodes.Conv_Ovf_U2); break;
1813
1814                                 case Mode.U8_I1: ig.Emit (OpCodes.Conv_Ovf_I1_Un); break;
1815                                 case Mode.U8_U1: ig.Emit (OpCodes.Conv_Ovf_U1_Un); break;
1816                                 case Mode.U8_I2: ig.Emit (OpCodes.Conv_Ovf_I2_Un); break;
1817                                 case Mode.U8_U2: ig.Emit (OpCodes.Conv_Ovf_U2_Un); break;
1818                                 case Mode.U8_I4: ig.Emit (OpCodes.Conv_Ovf_I4_Un); break;
1819                                 case Mode.U8_U4: ig.Emit (OpCodes.Conv_Ovf_U4_Un); break;
1820                                 case Mode.U8_I8: ig.Emit (OpCodes.Conv_Ovf_I8_Un); break;
1821                                 case Mode.U8_CH: ig.Emit (OpCodes.Conv_Ovf_U2_Un); break;
1822
1823                                 case Mode.CH_I1: ig.Emit (OpCodes.Conv_Ovf_I1_Un); break;
1824                                 case Mode.CH_U1: ig.Emit (OpCodes.Conv_Ovf_U1_Un); break;
1825                                 case Mode.CH_I2: ig.Emit (OpCodes.Conv_Ovf_I2_Un); break;
1826
1827                                 case Mode.R4_I1: ig.Emit (OpCodes.Conv_Ovf_I1); break;
1828                                 case Mode.R4_U1: ig.Emit (OpCodes.Conv_Ovf_U1); break;
1829                                 case Mode.R4_I2: ig.Emit (OpCodes.Conv_Ovf_I2); break;
1830                                 case Mode.R4_U2: ig.Emit (OpCodes.Conv_Ovf_U2); break;
1831                                 case Mode.R4_I4: ig.Emit (OpCodes.Conv_Ovf_I4); break;
1832                                 case Mode.R4_U4: ig.Emit (OpCodes.Conv_Ovf_U4); break;
1833                                 case Mode.R4_I8: ig.Emit (OpCodes.Conv_Ovf_I8); break;
1834                                 case Mode.R4_U8: ig.Emit (OpCodes.Conv_Ovf_U8); break;
1835                                 case Mode.R4_CH: ig.Emit (OpCodes.Conv_Ovf_U2); break;
1836
1837                                 case Mode.R8_I1: ig.Emit (OpCodes.Conv_Ovf_I1); break;
1838                                 case Mode.R8_U1: ig.Emit (OpCodes.Conv_Ovf_U1); break;
1839                                 case Mode.R8_I2: ig.Emit (OpCodes.Conv_Ovf_I2); break;
1840                                 case Mode.R8_U2: ig.Emit (OpCodes.Conv_Ovf_U2); break;
1841                                 case Mode.R8_I4: ig.Emit (OpCodes.Conv_Ovf_I4); break;
1842                                 case Mode.R8_U4: ig.Emit (OpCodes.Conv_Ovf_U4); break;
1843                                 case Mode.R8_I8: ig.Emit (OpCodes.Conv_Ovf_I8); break;
1844                                 case Mode.R8_U8: ig.Emit (OpCodes.Conv_Ovf_U8); break;
1845                                 case Mode.R8_CH: ig.Emit (OpCodes.Conv_Ovf_U2); break;
1846                                 case Mode.R8_R4: ig.Emit (OpCodes.Conv_R4); break;
1847                                 }
1848                         } else {
1849                                 switch (mode){
1850                                 case Mode.I1_U1: ig.Emit (OpCodes.Conv_U1); break;
1851                                 case Mode.I1_U2: ig.Emit (OpCodes.Conv_U2); break;
1852                                 case Mode.I1_U4: ig.Emit (OpCodes.Conv_U4); break;
1853                                 case Mode.I1_U8: ig.Emit (OpCodes.Conv_I8); break;
1854                                 case Mode.I1_CH: ig.Emit (OpCodes.Conv_U2); break;
1855
1856                                 case Mode.U1_I1: ig.Emit (OpCodes.Conv_I1); break;
1857                                 case Mode.U1_CH: ig.Emit (OpCodes.Conv_U2); break;
1858
1859                                 case Mode.I2_I1: ig.Emit (OpCodes.Conv_I1); break;
1860                                 case Mode.I2_U1: ig.Emit (OpCodes.Conv_U1); break;
1861                                 case Mode.I2_U2: ig.Emit (OpCodes.Conv_U2); break;
1862                                 case Mode.I2_U4: ig.Emit (OpCodes.Conv_U4); break;
1863                                 case Mode.I2_U8: ig.Emit (OpCodes.Conv_I8); break;
1864                                 case Mode.I2_CH: ig.Emit (OpCodes.Conv_U2); break;
1865
1866                                 case Mode.U2_I1: ig.Emit (OpCodes.Conv_I1); break;
1867                                 case Mode.U2_U1: ig.Emit (OpCodes.Conv_U1); break;
1868                                 case Mode.U2_I2: ig.Emit (OpCodes.Conv_I2); break;
1869                                 case Mode.U2_CH: /* nothing */ break;
1870
1871                                 case Mode.I4_I1: ig.Emit (OpCodes.Conv_I1); break;
1872                                 case Mode.I4_U1: ig.Emit (OpCodes.Conv_U1); break;
1873                                 case Mode.I4_I2: ig.Emit (OpCodes.Conv_I2); break;
1874                                 case Mode.I4_U4: /* nothing */ break;
1875                                 case Mode.I4_U2: ig.Emit (OpCodes.Conv_U2); break;
1876                                 case Mode.I4_U8: ig.Emit (OpCodes.Conv_I8); break;
1877                                 case Mode.I4_CH: ig.Emit (OpCodes.Conv_U2); break;
1878
1879                                 case Mode.U4_I1: ig.Emit (OpCodes.Conv_I1); break;
1880                                 case Mode.U4_U1: ig.Emit (OpCodes.Conv_U1); break;
1881                                 case Mode.U4_I2: ig.Emit (OpCodes.Conv_I2); break;
1882                                 case Mode.U4_U2: ig.Emit (OpCodes.Conv_U2); break;
1883                                 case Mode.U4_I4: /* nothing */ break;
1884                                 case Mode.U4_CH: ig.Emit (OpCodes.Conv_U2); break;
1885
1886                                 case Mode.I8_I1: ig.Emit (OpCodes.Conv_I1); break;
1887                                 case Mode.I8_U1: ig.Emit (OpCodes.Conv_U1); break;
1888                                 case Mode.I8_I2: ig.Emit (OpCodes.Conv_I2); break;
1889                                 case Mode.I8_U2: ig.Emit (OpCodes.Conv_U2); break;
1890                                 case Mode.I8_I4: ig.Emit (OpCodes.Conv_I4); break;
1891                                 case Mode.I8_U4: ig.Emit (OpCodes.Conv_U4); break;
1892                                 case Mode.I8_U8: /* nothing */ break;
1893                                 case Mode.I8_CH: ig.Emit (OpCodes.Conv_U2); break;
1894
1895                                 case Mode.U8_I1: ig.Emit (OpCodes.Conv_I1); break;
1896                                 case Mode.U8_U1: ig.Emit (OpCodes.Conv_U1); break;
1897                                 case Mode.U8_I2: ig.Emit (OpCodes.Conv_I2); break;
1898                                 case Mode.U8_U2: ig.Emit (OpCodes.Conv_U2); break;
1899                                 case Mode.U8_I4: ig.Emit (OpCodes.Conv_I4); break;
1900                                 case Mode.U8_U4: ig.Emit (OpCodes.Conv_U4); break;
1901                                 case Mode.U8_I8: /* nothing */ break;
1902                                 case Mode.U8_CH: ig.Emit (OpCodes.Conv_U2); break;
1903
1904                                 case Mode.CH_I1: ig.Emit (OpCodes.Conv_I1); break;
1905                                 case Mode.CH_U1: ig.Emit (OpCodes.Conv_U1); break;
1906                                 case Mode.CH_I2: ig.Emit (OpCodes.Conv_I2); break;
1907
1908                                 case Mode.R4_I1: ig.Emit (OpCodes.Conv_I1); break;
1909                                 case Mode.R4_U1: ig.Emit (OpCodes.Conv_U1); break;
1910                                 case Mode.R4_I2: ig.Emit (OpCodes.Conv_I2); break;
1911                                 case Mode.R4_U2: ig.Emit (OpCodes.Conv_U2); break;
1912                                 case Mode.R4_I4: ig.Emit (OpCodes.Conv_I4); break;
1913                                 case Mode.R4_U4: ig.Emit (OpCodes.Conv_U4); break;
1914                                 case Mode.R4_I8: ig.Emit (OpCodes.Conv_I8); break;
1915                                 case Mode.R4_U8: ig.Emit (OpCodes.Conv_U8); break;
1916                                 case Mode.R4_CH: ig.Emit (OpCodes.Conv_U2); break;
1917
1918                                 case Mode.R8_I1: ig.Emit (OpCodes.Conv_I1); break;
1919                                 case Mode.R8_U1: ig.Emit (OpCodes.Conv_U1); break;
1920                                 case Mode.R8_I2: ig.Emit (OpCodes.Conv_I2); break;
1921                                 case Mode.R8_U2: ig.Emit (OpCodes.Conv_U2); break;
1922                                 case Mode.R8_I4: ig.Emit (OpCodes.Conv_I4); break;
1923                                 case Mode.R8_U4: ig.Emit (OpCodes.Conv_U4); break;
1924                                 case Mode.R8_I8: ig.Emit (OpCodes.Conv_I8); break;
1925                                 case Mode.R8_U8: ig.Emit (OpCodes.Conv_U8); break;
1926                                 case Mode.R8_CH: ig.Emit (OpCodes.Conv_U2); break;
1927                                 case Mode.R8_R4: ig.Emit (OpCodes.Conv_R4); break;
1928                                 }
1929                         }
1930                 }
1931         }
1932
1933         public class OpcodeCast : EmptyCast {
1934                 OpCode op, op2;
1935                 bool second_valid;
1936
1937                 public OpcodeCast (Expression child, Type return_type, OpCode op)
1938                         : base (child, return_type)
1939
1940                 {
1941                         this.op = op;
1942                         second_valid = false;
1943                 }
1944
1945                 public OpcodeCast (Expression child, Type return_type, OpCode op, OpCode op2)
1946                         : base (child, return_type)
1947
1948                 {
1949                         this.op = op;
1950                         this.op2 = op2;
1951                         second_valid = true;
1952                 }
1953
1954                 public override Expression DoResolve (EmitContext ec)
1955                 {
1956                         // This should never be invoked, we are born in fully
1957                         // initialized state.
1958
1959                         return this;
1960                 }
1961
1962                 public override void Emit (EmitContext ec)
1963                 {
1964                         base.Emit (ec);
1965                         ec.ig.Emit (op);
1966
1967                         if (second_valid)
1968                                 ec.ig.Emit (op2);
1969                 }
1970         }
1971
1972         /// <summary>
1973         ///   This kind of cast is used to encapsulate a child and cast it
1974         ///   to the class requested
1975         /// </summary>
1976         public class ClassCast : EmptyCast {
1977                 public ClassCast (Expression child, Type return_type)
1978                         : base (child, return_type)
1979
1980                 {
1981                 }
1982
1983                 public override Expression DoResolve (EmitContext ec)
1984                 {
1985                         // This should never be invoked, we are born in fully
1986                         // initialized state.
1987
1988                         return this;
1989                 }
1990
1991                 public override void Emit (EmitContext ec)
1992                 {
1993                         base.Emit (ec);
1994
1995                         if (child.Type.IsGenericParameter)
1996                                 ec.ig.Emit (OpCodes.Box, child.Type);
1997
1998                         if (type.IsGenericParameter)
1999                                 ec.ig.Emit (OpCodes.Unbox_Any, type);
2000                         else
2001                                 ec.ig.Emit (OpCodes.Castclass, type);
2002                 }
2003         }
2004
2005         /// <summary>
2006         ///   SimpleName expressions are formed of a single word and only happen at the beginning
2007         ///   of a dotted-name.
2008         /// </summary>
2009         public class SimpleName : Expression {
2010                 public string Name;
2011                 public readonly TypeArguments Arguments;
2012
2013                 public SimpleName (string name, Location l)
2014                 {
2015                         Name = name;
2016                         loc = l;
2017                 }
2018
2019                 public SimpleName (string name, TypeArguments args, Location l)
2020                 {
2021                         Name = name;
2022                         Arguments = args;
2023                         loc = l;
2024                 }
2025
2026                 public static void Error_ObjectRefRequired (EmitContext ec, Location l, string name)
2027                 {
2028                         if (ec.IsFieldInitializer)
2029                                 Report.Error (
2030                                         236, l,
2031                                         "A field initializer cannot reference the non-static field, " +
2032                                         "method or property `"+name+"'");
2033                         else
2034                                 Report.Error (
2035                                         120, l,
2036                                         "An object reference is required " +
2037                                         "for the non-static field `"+name+"'");
2038                 }
2039
2040                 //
2041                 // Checks whether we are trying to access an instance
2042                 // property, method or field from a static body.
2043                 //
2044                 Expression MemberStaticCheck (EmitContext ec, Expression e)
2045                 {
2046                         if (e is IMemberExpr){
2047                                 IMemberExpr member = (IMemberExpr) e;
2048
2049                                 if (!member.IsStatic){
2050                                         Error_ObjectRefRequired (ec, loc, Name);
2051                                         return null;
2052                                 }
2053                         }
2054
2055                         return e;
2056                 }
2057
2058                 public override Expression DoResolve (EmitContext ec)
2059                 {
2060                         return SimpleNameResolve (ec, null, false, false);
2061                 }
2062
2063                 public override Expression DoResolveLValue (EmitContext ec, Expression right_side)
2064                 {
2065                         return SimpleNameResolve (ec, right_side, false, false);
2066                 }
2067
2068
2069                 public Expression DoResolveAllowStatic (EmitContext ec, bool intermediate)
2070                 {
2071                         return SimpleNameResolve (ec, null, true, intermediate);
2072                 }
2073
2074                 public override FullNamedExpression ResolveAsTypeStep (EmitContext ec)
2075                 {
2076                         DeclSpace ds = ec.DeclSpace;
2077                         FullNamedExpression dt;
2078
2079                         dt = ds.LookupGeneric (Name, loc);
2080                         if (dt != null)
2081                                 return dt.ResolveAsTypeStep (ec);
2082
2083                         int errors = Report.Errors;
2084                         dt = ec.ResolvingTypeTree
2085                                 ? ds.FindType (loc, Name)
2086                                 : ds.LookupType (Name, true, loc);
2087                         if (Report.Errors != errors)
2088                                 return null;
2089
2090                         return dt;
2091                 }
2092
2093                 Expression SimpleNameResolve (EmitContext ec, Expression right_side,
2094                                               bool allow_static, bool intermediate)
2095                 {
2096                         Expression e = DoSimpleNameResolve (ec, right_side, allow_static, intermediate);
2097                         if (e == null)
2098                                 return null;
2099
2100                         Block current_block = ec.CurrentBlock;
2101                         if (current_block != null){
2102                                 if (current_block.IsVariableNameUsedInChildBlock (Name)) {
2103                                         Report.Error (135, Location,
2104                                                       "'{0}' has a different meaning in a child block", Name);
2105                                         return null;
2106                                 }
2107                         }
2108
2109                         if (e.Type != null && e.Type.IsPointer && !ec.InUnsafe) {
2110                                 UnsafeError (loc);
2111                                 return null;
2112                         }
2113
2114                         return e;
2115                 }
2116
2117                 /// <remarks>
2118                 ///   7.5.2: Simple Names.
2119                 ///
2120                 ///   Local Variables and Parameters are handled at
2121                 ///   parse time, so they never occur as SimpleNames.
2122                 ///
2123                 ///   The `allow_static' flag is used by MemberAccess only
2124                 ///   and it is used to inform us that it is ok for us to
2125                 ///   avoid the static check, because MemberAccess might end
2126                 ///   up resolving the Name as a Type name and the access as
2127                 ///   a static type access.
2128                 ///
2129                 ///   ie: Type Type; .... { Type.GetType (""); }
2130                 ///
2131                 ///   Type is both an instance variable and a Type;  Type.GetType
2132                 ///   is the static method not an instance method of type.
2133                 /// </remarks>
2134                 Expression DoSimpleNameResolve (EmitContext ec, Expression right_side, bool allow_static, bool intermediate)
2135                 {
2136                         Expression e = null;
2137
2138                         //
2139                         // Stage 1: Performed by the parser (binding to locals or parameters).
2140                         //
2141                         Block current_block = ec.CurrentBlock;
2142                         if (current_block != null){
2143                                 LocalInfo vi = current_block.GetLocalInfo (Name);
2144                                 if (vi != null){
2145                                         Expression var;
2146
2147                                         var = new LocalVariableReference (ec.CurrentBlock, Name, loc);
2148
2149                                         if (right_side != null)
2150                                                 return var.ResolveLValue (ec, right_side);
2151                                         else
2152                                                 return var.Resolve (ec);
2153                                 }
2154
2155                                 ParameterReference pref = current_block.GetParameterReference (Name, loc);
2156                                 if (pref != null) {
2157                                         if (right_side != null)
2158                                                 return pref.ResolveLValue (ec, right_side);
2159                                         else
2160                                                 return pref.Resolve (ec);
2161                                 }
2162                         }
2163
2164                         //
2165                         // Stage 2: Lookup members
2166                         //
2167
2168                         DeclSpace lookup_ds = ec.DeclSpace;
2169                         Type almost_matched_type = null;
2170                         ArrayList almost_matched = null;
2171                         do {
2172                                 if (lookup_ds.TypeBuilder == null)
2173                                         break;
2174
2175                                 e = MemberLookup (ec, lookup_ds.TypeBuilder, Name, loc);
2176                                 if (e != null)
2177                                         break;
2178
2179                                 if (almost_matched == null && almostMatchedMembers.Count > 0) {
2180                                         almost_matched_type = lookup_ds.TypeBuilder;
2181                                         almost_matched = (ArrayList) almostMatchedMembers.Clone ();
2182                                 }
2183
2184                                 lookup_ds =lookup_ds.Parent;
2185                         } while (lookup_ds != null);
2186
2187                         if (e == null && ec.ContainerType != null)
2188                                 e = MemberLookup (ec, ec.ContainerType, Name, loc);
2189
2190                         if (e == null) {
2191                                 if (almost_matched == null && almostMatchedMembers.Count > 0) {
2192                                         almost_matched_type = ec.ContainerType;
2193                                         almost_matched = (ArrayList) almostMatchedMembers.Clone ();
2194                                 }
2195                                 e = ResolveAsTypeStep (ec);
2196                         }
2197
2198                         if (e == null) {
2199                                 if (almost_matched != null)
2200                                         almostMatchedMembers = almost_matched;
2201                                 if (almost_matched_type == null)
2202                                         almost_matched_type = ec.ContainerType;
2203                                 MemberLookupFailed (ec, null, almost_matched_type, ((SimpleName) this).Name, ec.DeclSpace.Name, loc);
2204                                 return null;
2205                         }
2206
2207                         if (e is TypeExpr)
2208                                 return e;
2209
2210                         if (e is IMemberExpr) {
2211                                 e = MemberAccess.ResolveMemberAccess (ec, e, null, loc, this);
2212                                 if (e == null)
2213                                         return null;
2214
2215                                 IMemberExpr me = e as IMemberExpr;
2216                                 if (me == null)
2217                                         return e;
2218
2219                                 if (Arguments != null) {
2220                                         MethodGroupExpr mg = me as MethodGroupExpr;
2221                                         if (mg == null)
2222                                                 return null;
2223
2224                                         return mg.ResolveGeneric (ec, Arguments);
2225                                 }
2226
2227                                 // This fails if ResolveMemberAccess() was unable to decide whether
2228                                 // it's a field or a type of the same name.
2229
2230                                 if (!me.IsStatic && (me.InstanceExpression == null))
2231                                         return e;
2232
2233                                 if (!me.IsStatic &&
2234                                     TypeManager.IsNestedFamilyAccessible (me.InstanceExpression.Type, me.DeclaringType) &&
2235                                     me.InstanceExpression.Type != me.DeclaringType &&
2236                                     !TypeManager.IsFamilyAccessible (me.InstanceExpression.Type, me.DeclaringType) &&
2237                                     (!intermediate || !MemberAccess.IdenticalNameAndTypeName (ec, this, e, loc))) {
2238                                         Error (38, "Cannot access nonstatic member `" + me.Name + "' of " +
2239                                                "outer type `" + me.DeclaringType + "' via nested type `" +
2240                                                me.InstanceExpression.Type + "'");
2241                                         return null;
2242                                 }
2243
2244                                 return (right_side != null)
2245                                         ? e.DoResolveLValue (ec, right_side)
2246                                         : e.DoResolve (ec);
2247                         }
2248
2249                         if (ec.IsStatic || ec.IsFieldInitializer){
2250                                 if (allow_static)
2251                                         return e;
2252
2253                                 return MemberStaticCheck (ec, e);
2254                         } else
2255                                 return e;
2256                 }
2257
2258                 public override void Emit (EmitContext ec)
2259                 {
2260                         //
2261                         // If this is ever reached, then we failed to
2262                         // find the name as a namespace
2263                         //
2264
2265                         Error (103, "The name `" + Name +
2266                                "' does not exist in the class `" +
2267                                ec.DeclSpace.Name + "'");
2268                 }
2269
2270                 public override string ToString ()
2271                 {
2272                         return Name;
2273                 }
2274         }
2275
2276         /// <summary>
2277         ///   Represents a namespace or a type.  The name of the class was inspired by
2278         ///   section 10.8.1 (Fully Qualified Names).
2279         /// </summary>
2280         public abstract class FullNamedExpression : Expression {
2281                 public abstract string FullName {
2282                         get;
2283                 }
2284         }
2285
2286         /// <summary>
2287         ///   Fully resolved expression that evaluates to a type
2288         /// </summary>
2289         public abstract class TypeExpr : FullNamedExpression {
2290                 override public FullNamedExpression ResolveAsTypeStep (EmitContext ec)
2291                 {
2292                         TypeExpr t = DoResolveAsTypeStep (ec);
2293                         if (t == null)
2294                                 return null;
2295
2296                         eclass = ExprClass.Type;
2297                         return t;
2298                 }
2299
2300                 override public Expression DoResolve (EmitContext ec)
2301                 {
2302                         return ResolveAsTypeTerminal (ec);
2303                 }
2304
2305                 override public void Emit (EmitContext ec)
2306                 {
2307                         throw new Exception ("Should never be called");
2308                 }
2309
2310                 public virtual bool CheckAccessLevel (DeclSpace ds)
2311                 {
2312                         return ds.CheckAccessLevel (Type);
2313                 }
2314
2315                 public virtual bool AsAccessible (DeclSpace ds, int flags)
2316                 {
2317                         return ds.AsAccessible (Type, flags);
2318                 }
2319
2320                 public virtual bool IsClass {
2321                         get { return Type.IsClass; }
2322                 }
2323
2324                 public virtual bool IsValueType {
2325                         get { return Type.IsValueType; }
2326                 }
2327
2328                 public virtual bool IsInterface {
2329                         get { return Type.IsInterface; }
2330                 }
2331
2332                 public virtual bool IsSealed {
2333                         get { return Type.IsSealed; }
2334                 }
2335
2336                 public virtual bool CanInheritFrom ()
2337                 {
2338                         if (Type == TypeManager.enum_type ||
2339                             (Type == TypeManager.value_type && RootContext.StdLib) ||
2340                             Type == TypeManager.multicast_delegate_type ||
2341                             Type == TypeManager.delegate_type ||
2342                             Type == TypeManager.array_type)
2343                                 return false;
2344
2345                         return true;
2346                 }
2347
2348                 public virtual bool IsAttribute {
2349                         get {
2350                                 return Type == TypeManager.attribute_type ||
2351                                         Type.IsSubclassOf (TypeManager.attribute_type);
2352                         }
2353                 }
2354
2355                 protected abstract TypeExpr DoResolveAsTypeStep (EmitContext ec);
2356
2357                 public virtual Type ResolveType (EmitContext ec)
2358                 {
2359                         TypeExpr t = ResolveAsTypeTerminal (ec);
2360                         if (t == null)
2361                                 return null;
2362
2363                         return t.Type;
2364                 }
2365
2366                 public abstract string Name {
2367                         get;
2368                 }
2369
2370                 public override bool Equals (object obj)
2371                 {
2372                         TypeExpr tobj = obj as TypeExpr;
2373                         if (tobj == null)
2374                                 return false;
2375
2376                         return Type == tobj.Type;
2377                 }
2378
2379                 public override int GetHashCode ()
2380                 {
2381                         return Type.GetHashCode ();
2382                 }
2383
2384                 public override string ToString ()
2385                 {
2386                         return Name;
2387                 }
2388         }
2389
2390         public class TypeExpression : TypeExpr {
2391                 public TypeExpression (Type t, Location l)
2392                 {
2393                         Type = t;
2394                         eclass = ExprClass.Type;
2395                         loc = l;
2396                 }
2397
2398                 protected override TypeExpr DoResolveAsTypeStep (EmitContext ec)
2399                 {
2400                         return this;
2401                 }
2402
2403                 public override string Name {
2404                         get {
2405                                 return Type.ToString ();
2406                         }
2407                 }
2408
2409                 public override string FullName {
2410                         get {
2411                                 return Type.FullName != null ? Type.FullName : Type.Name;
2412                         }
2413                 }
2414         }
2415
2416         /// <summary>
2417         ///   Used to create types from a fully qualified name.  These are just used
2418         ///   by the parser to setup the core types.  A TypeLookupExpression is always
2419         ///   classified as a type.
2420         /// </summary>
2421         public class TypeLookupExpression : TypeExpr {
2422                 string name;
2423
2424                 public TypeLookupExpression (string name)
2425                 {
2426                         this.name = name;
2427                 }
2428
2429                 protected override TypeExpr DoResolveAsTypeStep (EmitContext ec)
2430                 {
2431                         if (type == null) {
2432                                 FullNamedExpression t = ec.DeclSpace.LookupType (name, false, Location.Null);
2433                                 if (t == null)
2434                                         return null;
2435                                 if (!(t is TypeExpr))
2436                                         return null;
2437                                 type = ((TypeExpr) t).ResolveType (ec);
2438                         }
2439
2440                         return this;
2441                 }
2442
2443                 public override string Name {
2444                         get {
2445                                 return name;
2446                         }
2447                 }
2448
2449                 public override string FullName {
2450                         get {
2451                                 return name;
2452                         }
2453                 }
2454         }
2455
2456         /// <summary>
2457         ///   Represents an "unbound generic type", ie. typeof (Foo<>).
2458         ///   See 14.5.11.
2459         /// </summary>
2460         public class UnboundTypeExpression : TypeLookupExpression {
2461                 public UnboundTypeExpression (string name)
2462                         : base (name)
2463                 { }
2464         }
2465
2466         public class TypeAliasExpression : TypeExpr {
2467                 FullNamedExpression alias;
2468                 TypeExpr texpr;
2469                 TypeArguments args;
2470                 string name;
2471
2472                 public TypeAliasExpression (FullNamedExpression alias, TypeArguments args, Location l)
2473                 {
2474                         this.alias = alias;
2475                         this.args = args;
2476                         loc = l;
2477
2478                         eclass = ExprClass.Type;
2479                         if (args != null)
2480                                 name = alias.FullName + "<" + args.ToString () + ">";
2481                         else
2482                                 name = alias.FullName;
2483                 }
2484
2485                 public override string Name {
2486                         get { return alias.FullName; }
2487                 }
2488
2489                 public override string FullName {
2490                         get { return name; }
2491                 }
2492
2493                 protected override TypeExpr DoResolveAsTypeStep (EmitContext ec)
2494                 {
2495                         texpr = alias.ResolveAsTypeTerminal (ec);
2496                         if (texpr == null)
2497                                 return null;
2498
2499                         Type type = texpr.Type;
2500                         int num_args = TypeManager.GetNumberOfTypeArguments (type);
2501
2502                         if (args != null) {
2503                                 if (num_args == 0) {
2504                                         Report.Error (308, loc,
2505                                                       "The non-generic type `{0}' cannot " +
2506                                                       "be used with type arguments.",
2507                                                       TypeManager.CSharpName (type));
2508                                         return null;
2509                                 }
2510
2511                                 ConstructedType ctype = new ConstructedType (type, args, loc);
2512                                 return ctype.ResolveAsTypeTerminal (ec);
2513                         } else if (num_args > 0) {
2514                                 Report.Error (305, loc,
2515                                               "Using the generic type `{0}' " +
2516                                               "requires {1} type arguments",
2517                                               TypeManager.GetFullName (type), num_args);
2518                                 return null;
2519                         }
2520
2521                         return new TypeExpression (type, loc);
2522                 }
2523
2524                 public override bool CheckAccessLevel (DeclSpace ds)
2525                 {
2526                         return texpr.CheckAccessLevel (ds);
2527                 }
2528
2529                 public override bool AsAccessible (DeclSpace ds, int flags)
2530                 {
2531                         return texpr.AsAccessible (ds, flags);
2532                 }
2533
2534                 public override bool IsClass {
2535                         get { return texpr.IsClass; }
2536                 }
2537
2538                 public override bool IsValueType {
2539                         get { return texpr.IsValueType; }
2540                 }
2541
2542                 public override bool IsInterface {
2543                         get { return texpr.IsInterface; }
2544                 }
2545
2546                 public override bool IsSealed {
2547                         get { return texpr.IsSealed; }
2548                 }
2549
2550                 public override bool IsAttribute {
2551                         get { return texpr.IsAttribute; }
2552                 }
2553         }
2554
2555         /// <summary>
2556         ///   MethodGroup Expression.
2557         ///
2558         ///   This is a fully resolved expression that evaluates to a type
2559         /// </summary>
2560         public class MethodGroupExpr : Expression, IMemberExpr {
2561                 public MethodBase [] Methods;
2562                 Expression instance_expression = null;
2563                 bool is_explicit_impl = false;
2564                 bool has_type_arguments = false;
2565                 bool identical_type_name = false;
2566                 bool is_base;
2567
2568                 public MethodGroupExpr (MemberInfo [] mi, Location l)
2569                 {
2570                         Methods = new MethodBase [mi.Length];
2571                         mi.CopyTo (Methods, 0);
2572                         eclass = ExprClass.MethodGroup;
2573                         type = TypeManager.object_type;
2574                         loc = l;
2575                 }
2576
2577                 public MethodGroupExpr (ArrayList list, Location l)
2578                 {
2579                         Methods = new MethodBase [list.Count];
2580
2581                         try {
2582                                 list.CopyTo (Methods, 0);
2583                         } catch {
2584                                 foreach (MemberInfo m in list){
2585                                         if (!(m is MethodBase)){
2586                                                 Console.WriteLine ("Name " + m.Name);
2587                                                 Console.WriteLine ("Found a: " + m.GetType ().FullName);
2588                                         }
2589                                 }
2590                                 throw;
2591                         }
2592
2593                         loc = l;
2594                         eclass = ExprClass.MethodGroup;
2595                         type = TypeManager.object_type;
2596                 }
2597
2598                 public Type DeclaringType {
2599                         get {
2600                                 //
2601                                 // We assume that the top-level type is in the end
2602                                 //
2603                                 return Methods [Methods.Length - 1].DeclaringType;
2604                                 //return Methods [0].DeclaringType;
2605                         }
2606                 }
2607
2608                 //
2609                 // `A method group may have associated an instance expression'
2610                 //
2611                 public Expression InstanceExpression {
2612                         get {
2613                                 return instance_expression;
2614                         }
2615
2616                         set {
2617                                 instance_expression = value;
2618                         }
2619                 }
2620
2621                 public bool IsExplicitImpl {
2622                         get {
2623                                 return is_explicit_impl;
2624                         }
2625
2626                         set {
2627                                 is_explicit_impl = value;
2628                         }
2629                 }
2630
2631                 public bool HasTypeArguments {
2632                         get {
2633                                 return has_type_arguments;
2634                         }
2635
2636                         set {
2637                                 has_type_arguments = value;
2638                         }
2639                 }
2640
2641                 public bool IdenticalTypeName {
2642                         get {
2643                                 return identical_type_name;
2644                         }
2645
2646                         set {
2647                                 identical_type_name = value;
2648                         }
2649                 }
2650
2651                 public bool IsBase {
2652                         get {
2653                                 return is_base;
2654                         }
2655                         set {
2656                                 is_base = value;
2657                         }
2658                 }
2659
2660                 public string Name {
2661                         get {
2662                                 //return Methods [0].Name;
2663                                 return Methods [Methods.Length - 1].Name;
2664                         }
2665                 }
2666
2667                 public bool IsInstance {
2668                         get {
2669                                 foreach (MethodBase mb in Methods)
2670                                         if (!mb.IsStatic)
2671                                                 return true;
2672
2673                                 return false;
2674                         }
2675                 }
2676
2677                 public bool IsStatic {
2678                         get {
2679                                 foreach (MethodBase mb in Methods)
2680                                         if (mb.IsStatic)
2681                                                 return true;
2682
2683                                 return false;
2684                         }
2685                 }
2686
2687                 override public Expression DoResolve (EmitContext ec)
2688                 {
2689                         if (!IsInstance)
2690                                 instance_expression = null;
2691
2692                         if (instance_expression != null) {
2693                                 instance_expression = instance_expression.DoResolve (ec);
2694                                 if (instance_expression == null)
2695                                         return null;
2696                         }
2697
2698                         return this;
2699                 }
2700
2701                 public void ReportUsageError ()
2702                 {
2703                         Report.Error (654, loc, "Method `" + DeclaringType + "." +
2704                                       Name + "()' is referenced without parentheses");
2705                 }
2706
2707                 override public void Emit (EmitContext ec)
2708                 {
2709                         ReportUsageError ();
2710                 }
2711
2712                 bool RemoveMethods (bool keep_static)
2713                 {
2714                         ArrayList smethods = new ArrayList ();
2715
2716                         foreach (MethodBase mb in Methods){
2717                                 if (mb.IsStatic == keep_static)
2718                                         smethods.Add (mb);
2719                         }
2720
2721                         if (smethods.Count == 0)
2722                                 return false;
2723
2724                         Methods = new MethodBase [smethods.Count];
2725                         smethods.CopyTo (Methods, 0);
2726
2727                         return true;
2728                 }
2729
2730                 /// <summary>
2731                 ///   Removes any instance methods from the MethodGroup, returns
2732                 ///   false if the resulting set is empty.
2733                 /// </summary>
2734                 public bool RemoveInstanceMethods ()
2735                 {
2736                         return RemoveMethods (true);
2737                 }
2738
2739                 /// <summary>
2740                 ///   Removes any static methods from the MethodGroup, returns
2741                 ///   false if the resulting set is empty.
2742                 /// </summary>
2743                 public bool RemoveStaticMethods ()
2744                 {
2745                         return RemoveMethods (false);
2746                 }
2747
2748                 public Expression ResolveGeneric (EmitContext ec, TypeArguments args)
2749                 {
2750                         if (args.Resolve (ec) == false)
2751                                 return null;
2752
2753                         Type[] atypes = args.Arguments;
2754
2755                         int first_count = 0;
2756                         MethodInfo first = null;
2757
2758                         ArrayList list = new ArrayList ();
2759                         foreach (MethodBase mb in Methods) {
2760                                 MethodInfo mi = mb as MethodInfo;
2761                                 if ((mi == null) || !mi.HasGenericParameters)
2762                                         continue;
2763
2764                                 Type[] gen_params = mi.GetGenericArguments ();
2765
2766                                 if (first == null) {
2767                                         first = mi;
2768                                         first_count = gen_params.Length;
2769                                 }
2770
2771                                 if (gen_params.Length != atypes.Length)
2772                                         continue;
2773
2774                                 list.Add (mi.BindGenericParameters (atypes));
2775                         }
2776
2777                         if (list.Count > 0) {
2778                                 MethodGroupExpr new_mg = new MethodGroupExpr (list, Location);
2779                                 new_mg.InstanceExpression = InstanceExpression;
2780                                 new_mg.HasTypeArguments = true;
2781                                 return new_mg;
2782                         }
2783
2784                         if (first != null)
2785                                 Report.Error (
2786                                         305, loc, "Using the generic method `{0}' " +
2787                                         "requires {1} type arguments", Name,
2788                                         first_count);
2789                         else
2790                                 Report.Error (
2791                                         308, loc, "The non-generic method `{0}' " +
2792                                         "cannot be used with type arguments", Name);
2793
2794                         return null;
2795                 }
2796         }
2797
2798         /// <summary>
2799         ///   Fully resolved expression that evaluates to a Field
2800         /// </summary>
2801         public class FieldExpr : Expression, IAssignMethod, IMemoryLocation, IMemberExpr, IVariable {
2802                 public readonly FieldInfo FieldInfo;
2803                 Expression instance_expr;
2804                 VariableInfo variable_info;
2805
2806                 LocalTemporary temp;
2807                 bool prepared;
2808                 bool is_field_initializer;
2809
2810                 public FieldExpr (FieldInfo fi, Location l)
2811                 {
2812                         FieldInfo = fi;
2813                         eclass = ExprClass.Variable;
2814                         type = TypeManager.TypeToCoreType (fi.FieldType);
2815                         loc = l;
2816                 }
2817
2818                 public string Name {
2819                         get {
2820                                 return FieldInfo.Name;
2821                         }
2822                 }
2823
2824                 public bool IsInstance {
2825                         get {
2826                                 return !FieldInfo.IsStatic;
2827                         }
2828                 }
2829
2830                 public bool IsStatic {
2831                         get {
2832                                 return FieldInfo.IsStatic;
2833                         }
2834                 }
2835
2836                 public Type DeclaringType {
2837                         get {
2838                                 return FieldInfo.DeclaringType;
2839                         }
2840                 }
2841
2842                 public Expression InstanceExpression {
2843                         get {
2844                                 return instance_expr;
2845                         }
2846
2847                         set {
2848                                 instance_expr = value;
2849                         }
2850                 }
2851
2852                 public bool IsFieldInitializer {
2853                         get {
2854                                 return is_field_initializer;
2855                         }
2856
2857                         set {
2858                                 is_field_initializer = value;
2859                         }
2860                 }
2861
2862                 public VariableInfo VariableInfo {
2863                         get {
2864                                 return variable_info;
2865                         }
2866                 }
2867
2868                 override public Expression DoResolve (EmitContext ec)
2869                 {
2870                         if (!FieldInfo.IsStatic){
2871                                 if (instance_expr == null){
2872                                         //
2873                                         // This can happen when referencing an instance field using
2874                                         // a fully qualified type expression: TypeName.InstanceField = xxx
2875                                         //
2876                                         SimpleName.Error_ObjectRefRequired (ec, loc, FieldInfo.Name);
2877                                         return null;
2878                                 }
2879
2880                                 // Resolve the field's instance expression while flow analysis is turned
2881                                 // off: when accessing a field "a.b", we must check whether the field
2882                                 // "a.b" is initialized, not whether the whole struct "a" is initialized.
2883                                 instance_expr = instance_expr.Resolve (ec, ResolveFlags.VariableOrValue |
2884                                                                        ResolveFlags.DisableFlowAnalysis);
2885                                 if (instance_expr == null)
2886                                         return null;
2887                         }
2888
2889                         ObsoleteAttribute oa;
2890                         FieldBase f = TypeManager.GetField (FieldInfo);
2891                         if (f != null) {
2892                                 oa = f.GetObsoleteAttribute (f.Parent);
2893                                 if (oa != null)
2894                                         AttributeTester.Report_ObsoleteMessage (oa, f.GetSignatureForError (), loc);
2895                                 // To be sure that type is external because we do not register generated fields
2896                         } else if (!(FieldInfo.DeclaringType is TypeBuilder)) {
2897                                 oa = AttributeTester.GetMemberObsoleteAttribute (FieldInfo);
2898                                 if (oa != null)
2899                                         AttributeTester.Report_ObsoleteMessage (oa, TypeManager.GetFullNameSignature (FieldInfo), loc);
2900                         }
2901
2902                         if (ec.CurrentAnonymousMethod != null){
2903                                 if (!FieldInfo.IsStatic){
2904                                         if (ec.TypeContainer is Struct){
2905                                                 Report.Error (1673, loc, "Can not reference instance variables in anonymous methods hosted in structs");
2906                                                 return null;
2907                                         }
2908                                         ec.CaptureField (this);
2909                                 }
2910                         }
2911
2912                         // If the instance expression is a local variable or parameter.
2913                         IVariable var = instance_expr as IVariable;
2914                         if ((var == null) || (var.VariableInfo == null))
2915                                 return this;
2916
2917                         VariableInfo vi = var.VariableInfo;
2918                         if (!vi.IsFieldAssigned (ec, FieldInfo.Name, loc))
2919                                 return null;
2920
2921                         variable_info = vi.GetSubStruct (FieldInfo.Name);
2922                         return this;
2923                 }
2924
2925                 void Report_AssignToReadonly (bool is_instance)
2926                 {
2927                         string msg;
2928
2929                         if (is_instance)
2930                                 msg = "Readonly field can not be assigned outside " +
2931                                 "of constructor or variable initializer";
2932                         else
2933                                 msg = "A static readonly field can only be assigned in " +
2934                                 "a static constructor";
2935
2936                         Report.Error (is_instance ? 191 : 198, loc, msg);
2937                 }
2938
2939                 override public Expression DoResolveLValue (EmitContext ec, Expression right_side)
2940                 {
2941                         IVariable var = instance_expr as IVariable;
2942                         if ((var != null) && (var.VariableInfo != null))
2943                                 var.VariableInfo.SetFieldAssigned (ec, FieldInfo.Name);
2944
2945                         Expression e = DoResolve (ec);
2946
2947                         if (e == null)
2948                                 return null;
2949
2950                         if (!FieldInfo.IsStatic && (instance_expr.Type.IsValueType && !(instance_expr is IMemoryLocation))) {
2951                                 // FIXME: Provide better error reporting.
2952                                 Error (1612, "Cannot modify expression because it is not a variable.");
2953                                 return null;
2954                         }
2955
2956                         if (!FieldInfo.IsInitOnly)
2957                                 return this;
2958
2959                         FieldBase fb = TypeManager.GetField (FieldInfo);
2960                         if (fb != null)
2961                                 fb.SetAssigned ();
2962
2963                         //
2964                         // InitOnly fields can only be assigned in constructors
2965                         //
2966
2967                         if (ec.IsConstructor){
2968                                 if (IsStatic && !ec.IsStatic)
2969                                         Report_AssignToReadonly (false);
2970
2971                                 Type ctype;
2972                                 if (!is_field_initializer &&
2973                                     (ec.TypeContainer.CurrentType != null))
2974                                         ctype = ec.TypeContainer.CurrentType;
2975                                 else
2976                                         ctype = ec.ContainerType;
2977
2978                                 if (TypeManager.IsEqual (ctype, FieldInfo.DeclaringType))
2979                                         return this;
2980                         }
2981
2982                         Report_AssignToReadonly (!IsStatic);
2983
2984                         return null;
2985                 }
2986
2987                 public override void CheckMarshallByRefAccess (Type container)
2988                 {
2989                         if (!IsStatic && Type.IsValueType && !container.IsSubclassOf (TypeManager.mbr_type) && DeclaringType.IsSubclassOf (TypeManager.mbr_type)) {
2990                                 Report.SymbolRelatedToPreviousError (DeclaringType);
2991                                 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);
2992                         }
2993                 }
2994
2995                 public bool VerifyFixed (bool is_expression)
2996                 {
2997                         IVariable variable = instance_expr as IVariable;
2998                         if ((variable == null) || !variable.VerifyFixed (true))
2999                                 return false;
3000
3001                         return true;
3002                 }
3003
3004                 public void Emit (EmitContext ec, bool leave_copy)
3005                 {
3006                         ILGenerator ig = ec.ig;
3007                         bool is_volatile = false;
3008
3009                         if (FieldInfo is FieldBuilder){
3010                                 FieldBase f = TypeManager.GetField (FieldInfo);
3011                                 if (f != null){
3012                                         if ((f.ModFlags & Modifiers.VOLATILE) != 0)
3013                                                 is_volatile = true;
3014
3015                                         f.status |= Field.Status.USED;
3016                                 }
3017                         }
3018
3019                         if (FieldInfo.IsStatic){
3020                                 if (is_volatile)
3021                                         ig.Emit (OpCodes.Volatile);
3022
3023                                 ig.Emit (OpCodes.Ldsfld, FieldInfo);
3024                         } else {
3025                                 if (!prepared)
3026                                         EmitInstance (ec);
3027
3028                                 if (is_volatile)
3029                                         ig.Emit (OpCodes.Volatile);
3030
3031                                 ig.Emit (OpCodes.Ldfld, FieldInfo);
3032                         }
3033
3034                         if (leave_copy) {
3035                                 ec.ig.Emit (OpCodes.Dup);
3036                                 if (!FieldInfo.IsStatic) {
3037                                         temp = new LocalTemporary (ec, this.Type);
3038                                         temp.Store (ec);
3039                                 }
3040                         }
3041                 }
3042
3043                 public void EmitAssign (EmitContext ec, Expression source, bool leave_copy, bool prepare_for_load)
3044                 {
3045                         FieldAttributes fa = FieldInfo.Attributes;
3046                         bool is_static = (fa & FieldAttributes.Static) != 0;
3047                         bool is_readonly = (fa & FieldAttributes.InitOnly) != 0;
3048                         ILGenerator ig = ec.ig;
3049                         prepared = prepare_for_load;
3050
3051                         if (is_readonly && !ec.IsConstructor){
3052                                 Report_AssignToReadonly (!is_static);
3053                                 return;
3054                         }
3055
3056                         if (!is_static) {
3057                                 EmitInstance (ec);
3058                                 if (prepare_for_load)
3059                                         ig.Emit (OpCodes.Dup);
3060                         }
3061
3062                         source.Emit (ec);
3063                         if (leave_copy) {
3064                                 ec.ig.Emit (OpCodes.Dup);
3065                                 if (!FieldInfo.IsStatic) {
3066                                         temp = new LocalTemporary (ec, this.Type);
3067                                         temp.Store (ec);
3068                                 }
3069                         }
3070
3071                         if (FieldInfo is FieldBuilder){
3072                                 FieldBase f = TypeManager.GetField (FieldInfo);
3073                                 if (f != null){
3074                                         if ((f.ModFlags & Modifiers.VOLATILE) != 0)
3075                                                 ig.Emit (OpCodes.Volatile);
3076
3077                                         f.status |= Field.Status.ASSIGNED;
3078                                 }
3079                         }
3080
3081                         if (is_static)
3082                                 ig.Emit (OpCodes.Stsfld, FieldInfo);
3083                         else
3084                                 ig.Emit (OpCodes.Stfld, FieldInfo);
3085
3086                         if (temp != null)
3087                                 temp.Emit (ec);
3088                 }
3089
3090                 void EmitInstance (EmitContext ec)
3091                 {
3092                         if (instance_expr.Type.IsValueType) {
3093                                 if (instance_expr is IMemoryLocation) {
3094                                         ((IMemoryLocation) instance_expr).AddressOf (ec, AddressOp.LoadStore);
3095                                 } else {
3096                                         LocalTemporary t = new LocalTemporary (ec, instance_expr.Type);
3097                                         instance_expr.Emit (ec);
3098                                         t.Store (ec);
3099                                         t.AddressOf (ec, AddressOp.Store);
3100                                 }
3101                         } else
3102                                 instance_expr.Emit (ec);
3103                 }
3104
3105                 public override void Emit (EmitContext ec)
3106                 {
3107                         Emit (ec, false);
3108                 }
3109
3110                 public void AddressOf (EmitContext ec, AddressOp mode)
3111                 {
3112                         ILGenerator ig = ec.ig;
3113
3114                         if (FieldInfo is FieldBuilder){
3115                                 FieldBase f = TypeManager.GetField (FieldInfo);
3116                                 if (f != null){
3117                                         if ((f.ModFlags & Modifiers.VOLATILE) != 0){
3118                                                 Error (676, "volatile variable: can not take its address, or pass as ref/out parameter");
3119                                                 return;
3120                                         }
3121
3122                                         if ((mode & AddressOp.Store) != 0)
3123                                                 f.status |= Field.Status.ASSIGNED;
3124                                         if ((mode & AddressOp.Load) != 0)
3125                                                 f.status |= Field.Status.USED;
3126                                 }
3127                         }
3128
3129                         //
3130                         // Handle initonly fields specially: make a copy and then
3131                         // get the address of the copy.
3132                         //
3133                         bool need_copy;
3134                         if (FieldInfo.IsInitOnly){
3135                                 need_copy = true;
3136                                 if (ec.IsConstructor){
3137                                         if (FieldInfo.IsStatic){
3138                                                 if (ec.IsStatic)
3139                                                         need_copy = false;
3140                                         } else
3141                                                 need_copy = false;
3142                                 }
3143                         } else
3144                                 need_copy = false;
3145
3146                         if (need_copy){
3147                                 LocalBuilder local;
3148                                 Emit (ec);
3149                                 local = ig.DeclareLocal (type);
3150                                 ig.Emit (OpCodes.Stloc, local);
3151                                 ig.Emit (OpCodes.Ldloca, local);
3152                                 return;
3153                         }
3154
3155
3156                         if (FieldInfo.IsStatic){
3157                                 ig.Emit (OpCodes.Ldsflda, FieldInfo);
3158                         } else {
3159                                 EmitInstance (ec);
3160                                 ig.Emit (OpCodes.Ldflda, FieldInfo);
3161                         }
3162                 }
3163         }
3164
3165         //
3166         // A FieldExpr whose address can not be taken
3167         //
3168         public class FieldExprNoAddress : FieldExpr, IMemoryLocation {
3169                 public FieldExprNoAddress (FieldInfo fi, Location loc) : base (fi, loc)
3170                 {
3171                 }
3172
3173                 public new void AddressOf (EmitContext ec, AddressOp mode)
3174                 {
3175                         Report.Error (-215, "Report this: Taking the address of a remapped parameter not supported");
3176                 }
3177         }
3178
3179         /// <summary>
3180         ///   Expression that evaluates to a Property.  The Assign class
3181         ///   might set the `Value' expression if we are in an assignment.
3182         ///
3183         ///   This is not an LValue because we need to re-write the expression, we
3184         ///   can not take data from the stack and store it.
3185         /// </summary>
3186         public class PropertyExpr : ExpressionStatement, IAssignMethod, IMemberExpr {
3187                 public readonly PropertyInfo PropertyInfo;
3188
3189                 //
3190                 // This is set externally by the  `BaseAccess' class
3191                 //
3192                 public bool IsBase;
3193                 MethodInfo getter, setter;
3194                 bool is_static;
3195
3196                 Expression instance_expr;
3197                 LocalTemporary temp;
3198                 bool prepared;
3199
3200                 internal static PtrHashtable AccessorTable = new PtrHashtable ();
3201
3202                 public PropertyExpr (EmitContext ec, PropertyInfo pi, Location l)
3203                 {
3204                         PropertyInfo = pi;
3205                         eclass = ExprClass.PropertyAccess;
3206                         is_static = false;
3207                         loc = l;
3208
3209                         type = TypeManager.TypeToCoreType (pi.PropertyType);
3210
3211                         ResolveAccessors (ec);
3212                 }
3213
3214                 public string Name {
3215                         get {
3216                                 return PropertyInfo.Name;
3217                         }
3218                 }
3219
3220                 public bool IsInstance {
3221                         get {
3222                                 return !is_static;
3223                         }
3224                 }
3225
3226                 public bool IsStatic {
3227                         get {
3228                                 return is_static;
3229                         }
3230                 }
3231
3232                 public Type DeclaringType {
3233                         get {
3234                                 return PropertyInfo.DeclaringType;
3235                         }
3236                 }
3237
3238                 //
3239                 // The instance expression associated with this expression
3240                 //
3241                 public Expression InstanceExpression {
3242                         set {
3243                                 instance_expr = value;
3244                         }
3245
3246                         get {
3247                                 return instance_expr;
3248                         }
3249                 }
3250
3251                 public bool VerifyAssignable ()
3252                 {
3253                         if (setter == null) {
3254                                 Report.Error (200, loc,
3255                                               "The property `" + PropertyInfo.Name +
3256                                               "' can not be assigned to, as it has not set accessor");
3257                                 return false;
3258                         }
3259
3260                         return true;
3261                 }
3262
3263                 void FindAccessors (Type invocation_type)
3264                 {
3265                         BindingFlags flags = BindingFlags.Public | BindingFlags.NonPublic |
3266                                 BindingFlags.Static | BindingFlags.Instance |
3267                                 BindingFlags.DeclaredOnly;
3268
3269                         Type current = PropertyInfo.DeclaringType;
3270                         for (; current != null; current = current.BaseType) {
3271                                 MemberInfo[] group = TypeManager.MemberLookup (
3272                                         invocation_type, invocation_type, current,
3273                                         MemberTypes.Property, flags, PropertyInfo.Name, null);
3274
3275                                 if (group == null)
3276                                         continue;
3277
3278                                 if (group.Length != 1)
3279                                         // Oooops, can this ever happen ?
3280                                         return;
3281
3282                                 PropertyInfo pi = (PropertyInfo) group [0];
3283
3284                                 if (getter == null)
3285                                         getter = pi.GetGetMethod (true);
3286
3287                                 if (setter == null)
3288                                         setter = pi.GetSetMethod (true);
3289
3290                                 MethodInfo accessor = getter != null ? getter : setter;
3291
3292                                 if (!accessor.IsVirtual)
3293                                         return;
3294                         }
3295                 }
3296
3297                 //
3298                 // We also perform the permission checking here, as the PropertyInfo does not
3299                 // hold the information for the accessibility of its setter/getter
3300                 //
3301                 void ResolveAccessors (EmitContext ec)
3302                 {
3303                         FindAccessors (ec.ContainerType);
3304
3305                         if (getter != null) {
3306                                 AccessorTable [getter] = PropertyInfo;
3307                                 is_static = getter.IsStatic;
3308                         }
3309
3310                         if (setter != null) {
3311                                 AccessorTable [setter] = PropertyInfo;
3312                                 is_static = setter.IsStatic;
3313                         }
3314                 }
3315
3316                 bool InstanceResolve (EmitContext ec, bool must_do_cs1540_check)
3317                 {
3318                         if ((instance_expr == null) && ec.IsStatic && !is_static) {
3319                                 SimpleName.Error_ObjectRefRequired (ec, loc, PropertyInfo.Name);
3320                                 return false;
3321                         }
3322
3323                         if (instance_expr != null) {
3324                                 instance_expr = instance_expr.DoResolve (ec);
3325                                 if (instance_expr == null)
3326                                         return false;
3327
3328                                 instance_expr.CheckMarshallByRefAccess (ec.ContainerType);
3329                         }
3330
3331                         if (must_do_cs1540_check && (instance_expr != null)) {
3332                                 if ((instance_expr.Type != ec.ContainerType) &&
3333                                     ec.ContainerType.IsSubclassOf (instance_expr.Type)) {
3334                                         Report.Error (1540, loc, "Cannot access protected member `" +
3335                                                       PropertyInfo.DeclaringType + "." + PropertyInfo.Name +
3336                                                       "' via a qualifier of type `" +
3337                                                       TypeManager.CSharpName (instance_expr.Type) +
3338                                                       "'; the qualifier must be of type `" +
3339                                                       TypeManager.CSharpName (ec.ContainerType) +
3340                                                       "' (or derived from it)");
3341                                         return false;
3342                                 }
3343                         }
3344
3345                         return true;
3346                 }
3347
3348                 override public Expression DoResolve (EmitContext ec)
3349                 {
3350                         if (getter != null){
3351                                 if (TypeManager.GetArgumentTypes (getter).Length != 0){
3352                                         Report.Error (
3353                                                 117, loc, "`{0}' does not contain a " +
3354                                                 "definition for `{1}'.", getter.DeclaringType,
3355                                                 Name);
3356                                         return null;
3357                                 }
3358                         }
3359
3360                         if (getter == null){
3361                                 //
3362                                 // The following condition happens if the PropertyExpr was
3363                                 // created, but is invalid (ie, the property is inaccessible),
3364                                 // and we did not want to embed the knowledge about this in
3365                                 // the caller routine.  This only avoids double error reporting.
3366                                 //
3367                                 if (setter == null)
3368                                         return null;
3369
3370                                 Report.Error (154, loc,
3371                                               "The property `" + PropertyInfo.Name +
3372                                               "' can not be used in " +
3373                                               "this context because it lacks a get accessor");
3374                                 return null;
3375                         }
3376
3377                         bool must_do_cs1540_check;
3378                         if (!IsAccessorAccessible (ec.ContainerType, getter, out must_do_cs1540_check)) {
3379                                 Report.Error (122, loc, "'{0}.get' is inaccessible due to its protection level", PropertyInfo.Name);
3380                                 return null;
3381                         }
3382
3383                         if (!InstanceResolve (ec, must_do_cs1540_check))
3384                                 return null;
3385
3386                         //
3387                         // Only base will allow this invocation to happen.
3388                         //
3389                         if (IsBase && getter.IsAbstract){
3390                                 Report.Error (205, loc, "Cannot call an abstract base property: " +
3391                                               PropertyInfo.DeclaringType + "." +PropertyInfo.Name);
3392                                 return null;
3393                         }
3394
3395                         return this;
3396                 }
3397
3398                 override public Expression DoResolveLValue (EmitContext ec, Expression right_side)
3399                 {
3400                         if (setter == null){
3401                                 //
3402                                 // The following condition happens if the PropertyExpr was
3403                                 // created, but is invalid (ie, the property is inaccessible),
3404                                 // and we did not want to embed the knowledge about this in
3405                                 // the caller routine.  This only avoids double error reporting.
3406                                 //
3407                                 if (getter == null)
3408                                         return null;
3409
3410                                 Report.Error (154, loc,
3411                                               "The property `" + PropertyInfo.Name +
3412                                               "' can not be used in " +
3413                                               "this context because it lacks a set accessor");
3414                                 return null;
3415                         }
3416
3417                         if (TypeManager.GetArgumentTypes (setter).Length != 1){
3418                                 Report.Error (
3419                                         117, loc, "`{0}' does not contain a " +
3420                                         "definition for `{1}'.", getter.DeclaringType,
3421                                         Name);
3422                                 return null;
3423                         }
3424
3425                         bool must_do_cs1540_check;
3426                         if (!IsAccessorAccessible (ec.ContainerType, setter, out must_do_cs1540_check)) {
3427                                 Report.Error (122, loc, "'{0}.set' is inaccessible due to its protection level", PropertyInfo.Name);
3428                                 return null;
3429                         }
3430
3431                         if (!InstanceResolve (ec, must_do_cs1540_check))
3432                                 return null;
3433
3434                         //
3435                         // Only base will allow this invocation to happen.
3436                         //
3437                         if (IsBase && setter.IsAbstract){
3438                                 Report.Error (205, loc, "Cannot call an abstract base property: " +
3439                                               PropertyInfo.DeclaringType + "." +PropertyInfo.Name);
3440                                 return null;
3441                         }
3442
3443                         //
3444                         // Check that we are not making changes to a temporary memory location
3445                         //
3446                         if (instance_expr != null && instance_expr.Type.IsValueType && !(instance_expr is IMemoryLocation)) {
3447                                 // FIXME: Provide better error reporting.
3448                                 Error (1612, "Cannot modify expression because it is not a variable.");
3449                                 return null;
3450                         }
3451
3452                         return this;
3453                 }
3454
3455
3456
3457                 public override void Emit (EmitContext ec)
3458                 {
3459                         Emit (ec, false);
3460                 }
3461
3462                 void EmitInstance (EmitContext ec)
3463                 {
3464                         if (is_static)
3465                                 return;
3466
3467                         if (instance_expr.Type.IsValueType) {
3468                                 if (instance_expr is IMemoryLocation) {
3469                                         ((IMemoryLocation) instance_expr).AddressOf (ec, AddressOp.LoadStore);
3470                                 } else {
3471                                         LocalTemporary t = new LocalTemporary (ec, instance_expr.Type);
3472                                         instance_expr.Emit (ec);
3473                                         t.Store (ec);
3474                                         t.AddressOf (ec, AddressOp.Store);
3475                                 }
3476                         } else
3477                                 instance_expr.Emit (ec);
3478
3479                         if (prepared)
3480                                 ec.ig.Emit (OpCodes.Dup);
3481                 }
3482
3483
3484                 public void Emit (EmitContext ec, bool leave_copy)
3485                 {
3486                         if (!prepared)
3487                                 EmitInstance (ec);
3488
3489                         //
3490                         // Special case: length of single dimension array property is turned into ldlen
3491                         //
3492                         if ((getter == TypeManager.system_int_array_get_length) ||
3493                             (getter == TypeManager.int_array_get_length)){
3494                                 Type iet = instance_expr.Type;
3495
3496                                 //
3497                                 // System.Array.Length can be called, but the Type does not
3498                                 // support invoking GetArrayRank, so test for that case first
3499                                 //
3500                                 if (iet != TypeManager.array_type && (iet.GetArrayRank () == 1)) {
3501                                         ec.ig.Emit (OpCodes.Ldlen);
3502                                         ec.ig.Emit (OpCodes.Conv_I4);
3503                                         return;
3504                                 }
3505                         }
3506
3507                         Invocation.EmitCall (ec, IsBase, IsStatic, new EmptyAddressOf (), getter, null, loc);
3508
3509                         if (!leave_copy)
3510                                 return;
3511
3512                         ec.ig.Emit (OpCodes.Dup);
3513                         if (!is_static) {
3514                                 temp = new LocalTemporary (ec, this.Type);
3515                                 temp.Store (ec);
3516                         }
3517                 }
3518
3519                 //
3520                 // Implements the IAssignMethod interface for assignments
3521                 //
3522                 public void EmitAssign (EmitContext ec, Expression source, bool leave_copy, bool prepare_for_load)
3523                 {
3524                         prepared = prepare_for_load;
3525
3526                         EmitInstance (ec);
3527
3528                         source.Emit (ec);
3529                         if (leave_copy) {
3530                                 ec.ig.Emit (OpCodes.Dup);
3531                                 if (!is_static) {
3532                                         temp = new LocalTemporary (ec, this.Type);
3533                                         temp.Store (ec);
3534                                 }
3535                         }
3536
3537                         ArrayList args = new ArrayList (1);
3538                         args.Add (new Argument (new EmptyAddressOf (), Argument.AType.Expression));
3539
3540                         Invocation.EmitCall (ec, IsBase, IsStatic, new EmptyAddressOf (), setter, args, loc);
3541
3542                         if (temp != null)
3543                                 temp.Emit (ec);
3544                 }
3545
3546                 override public void EmitStatement (EmitContext ec)
3547                 {
3548                         Emit (ec);
3549                         ec.ig.Emit (OpCodes.Pop);
3550                 }
3551         }
3552
3553         /// <summary>
3554         ///   Fully resolved expression that evaluates to an Event
3555         /// </summary>
3556         public class EventExpr : Expression, IMemberExpr {
3557                 public readonly EventInfo EventInfo;
3558                 Expression instance_expr;
3559
3560                 bool is_static;
3561                 MethodInfo add_accessor, remove_accessor;
3562
3563                 public EventExpr (EventInfo ei, Location loc)
3564                 {
3565                         EventInfo = ei;
3566                         this.loc = loc;
3567                         eclass = ExprClass.EventAccess;
3568
3569                         add_accessor = TypeManager.GetAddMethod (ei);
3570                         remove_accessor = TypeManager.GetRemoveMethod (ei);
3571
3572                         if (add_accessor.IsStatic || remove_accessor.IsStatic)
3573                                 is_static = true;
3574
3575                         if (EventInfo is MyEventBuilder){
3576                                 MyEventBuilder eb = (MyEventBuilder) EventInfo;
3577                                 type = eb.EventType;
3578                                 eb.SetUsed ();
3579                         } else
3580                                 type = EventInfo.EventHandlerType;
3581                 }
3582
3583                 public string Name {
3584                         get {
3585                                 return EventInfo.Name;
3586                         }
3587                 }
3588
3589                 public bool IsInstance {
3590                         get {
3591                                 return !is_static;
3592                         }
3593                 }
3594
3595                 public bool IsStatic {
3596                         get {
3597                                 return is_static;
3598                         }
3599                 }
3600
3601                 public Type DeclaringType {
3602                         get {
3603                                 return EventInfo.DeclaringType;
3604                         }
3605                 }
3606
3607                 public Expression InstanceExpression {
3608                         get {
3609                                 return instance_expr;
3610                         }
3611
3612                         set {
3613                                 instance_expr = value;
3614                         }
3615                 }
3616
3617                 bool InstanceResolve (EmitContext ec, bool must_do_cs1540_check)
3618                 {
3619                         if ((instance_expr == null) && ec.IsStatic && !is_static) {
3620                                 SimpleName.Error_ObjectRefRequired (ec, loc, EventInfo.Name);
3621                                 return false;
3622                         }
3623
3624                         if (instance_expr != null) {
3625                                 instance_expr = instance_expr.DoResolve (ec);
3626                                 if (instance_expr == null)
3627                                         return false;
3628                         }
3629
3630                         //
3631                         // This is using the same mechanism as the CS1540 check in PropertyExpr.
3632                         // However, in the Event case, we reported a CS0122 instead.
3633                         //
3634                         if (must_do_cs1540_check && (instance_expr != null)) {
3635                                 if ((instance_expr.Type != ec.ContainerType) &&
3636                                         ec.ContainerType.IsSubclassOf (instance_expr.Type)) {
3637                                         Report.Error (122, loc, "'{0}' is inaccessible due to its protection level",
3638                                                 DeclaringType.Name + "." + EventInfo.Name);
3639
3640                                         return false;
3641                                 }
3642                         }
3643
3644                         return true;
3645                 }
3646
3647                 public override Expression DoResolve (EmitContext ec)
3648                 {
3649                         if (instance_expr != null) {
3650                                 instance_expr = instance_expr.DoResolve (ec);
3651                                 if (instance_expr == null)
3652                                         return null;
3653                         }
3654
3655                         bool must_do_cs1540_check;
3656                         if (!(IsAccessorAccessible (ec.ContainerType, add_accessor, out must_do_cs1540_check)
3657                                     && IsAccessorAccessible (ec.ContainerType, remove_accessor, out must_do_cs1540_check))) {
3658
3659                                Report.Error (122, loc, "'{0}' is inaccessible due to its protection level",
3660                                                DeclaringType.Name + "." + EventInfo.Name);
3661                                return null;
3662                         }
3663
3664                         if (!InstanceResolve (ec, must_do_cs1540_check))
3665                                 return null;
3666
3667                         return this;
3668                 }
3669
3670                 public override void Emit (EmitContext ec)
3671                 {
3672                         if (instance_expr is This)
3673                                 Report.Error (79, loc, "The event `{0}' can only appear on the left hand side of += or -=, try calling the actual delegate", Name);
3674                         else
3675                                 Report.Error (70, loc, "The event `{0}' can only appear on the left hand side of += or -= "+
3676                                               "(except on the defining type)", Name);
3677                 }
3678
3679                 public void EmitAddOrRemove (EmitContext ec, Expression source)
3680                 {
3681                         BinaryDelegate source_del = (BinaryDelegate) source;
3682                         Expression handler = source_del.Right;
3683
3684                         Argument arg = new Argument (handler, Argument.AType.Expression);
3685                         ArrayList args = new ArrayList ();
3686
3687                         args.Add (arg);
3688
3689                         if (source_del.IsAddition)
3690                                 Invocation.EmitCall (
3691                                         ec, false, IsStatic, instance_expr, add_accessor, args, loc);
3692                         else
3693                                 Invocation.EmitCall (
3694                                         ec, false, IsStatic, instance_expr, remove_accessor, args, loc);
3695                 }
3696         }
3697 }