mcs/mcs/ecore.cs

   1 //
   2 // ecore.cs: Core of the Expression representation for the intermediate tree.
   3 //
   4 // Author:
   5 //   Miguel de Icaza (miguel@ximian.com)
   6 //   Marek Safar (marek.safar@seznam.cz)
   7 //
   8 // (C) 2001, 2002, 2003 Ximian, Inc.
   9 //
  10 //
  11
  12 namespace Mono.CSharp {
  13         using System;
  14         using System.Collections;
  15         using System.Diagnostics;
  16         using System.Reflection;
  17         using System.Reflection.Emit;
  18         using System.Text;
  19
  20         /// <remarks>
  21         ///   The ExprClass class contains the is used to pass the
  22         ///   classification of an expression (value, variable, namespace,
  23         ///   type, method group, property access, event access, indexer access,
  24         ///   nothing).
  25         /// </remarks>
  26         public enum ExprClass : byte {
  27                 Invalid,
  28
  29                 Value,
  30                 Variable,
  31                 Namespace,
  32                 Type,
  33                 MethodGroup,
  34                 PropertyAccess,
  35                 EventAccess,
  36                 IndexerAccess,
  37                 Nothing,
  38         }
  39
  40         /// <remarks>
  41         ///   This is used to tell Resolve in which types of expressions we're
  42         ///   interested.
  43         /// </remarks>
  44         [Flags]
  45         public enum ResolveFlags {
  46                 // Returns Value, Variable, PropertyAccess, EventAccess or IndexerAccess.
  47                 VariableOrValue         = 1,
  48
  49                 // Returns a type expression.
  50                 Type                    = 2,
  51
  52                 // Returns a method group.
  53                 MethodGroup             = 4,
  54
  55                 // Mask of all the expression class flags.
  56                 MaskExprClass           = 7,
  57
  58                 // Disable control flow analysis while resolving the expression.
  59                 // This is used when resolving the instance expression of a field expression.
  60                 DisableFlowAnalysis     = 8,
  61
  62                 // Set if this is resolving the first part of a MemberAccess.
  63                 Intermediate            = 16,
  64
  65                 // Disable control flow analysis _of struct_ while resolving the expression.
  66                 // This is used when resolving the instance expression of a field expression.
  67                 DisableStructFlowAnalysis       = 32,
  68
  69         }
  70
  71         //
  72         // This is just as a hint to AddressOf of what will be done with the
  73         // address.
  74         [Flags]
  75         public enum AddressOp {
  76                 Store = 1,
  77                 Load  = 2,
  78                 LoadStore = 3
  79         };
  80
  81         /// <summary>
  82         ///   This interface is implemented by variables
  83         /// </summary>
  84         public interface IMemoryLocation {
  85                 /// <summary>
  86                 ///   The AddressOf method should generate code that loads
  87                 ///   the address of the object and leaves it on the stack.
  88                 ///
  89                 ///   The `mode' argument is used to notify the expression
  90                 ///   of whether this will be used to read from the address or
  91                 ///   write to the address.
  92                 ///
  93                 ///   This is just a hint that can be used to provide good error
  94                 ///   reporting, and should have no other side effects.
  95                 /// </summary>
  96                 void AddressOf (EmitContext ec, AddressOp mode);
  97         }
  98
  99         /// <summary>
 100         ///   This interface is implemented by variables
 101         /// </summary>
 102         public interface IVariable {
 103                 VariableInfo VariableInfo {
 104                         get;
 105                 }
 106
 107                 bool VerifyFixed ();
 108         }
 109
 110         /// <remarks>
 111         ///   Base class for expressions
 112         /// </remarks>
 113         public abstract class Expression {
 114                 public ExprClass eclass;
 115                 protected Type type;
 116                 protected Location loc;
 117
 118                 public Type Type {
 119                         get { return type; }
 120                         set { type = value; }
 121                 }
 122
 123                 public virtual Location Location {
 124                         get { return loc; }
 125                 }
 126
 127                 /// <summary>
 128                 ///   Utility wrapper routine for Error, just to beautify the code
 129                 /// </summary>
 130                 public void Error (int error, string s)
 131                 {
 132                         Report.Error (error, loc, s);
 133                 }
 134
 135                 // Not nice but we have broken hierarchy.
 136                 public virtual void CheckMarshalByRefAccess ()
 137                 {
 138                 }
 139
 140                 public virtual bool GetAttributableValue (Type valueType, out object value)
 141                 {
 142                         Attribute.Error_AttributeArgumentNotValid (loc);
 143                         value = null;
 144                         return false;
 145                 }
 146
 147                 public virtual string GetSignatureForError ()
 148                 {
 149                         return TypeManager.CSharpName (type);
 150                 }
 151
 152                 public static bool IsAccessorAccessible (Type invocation_type, MethodInfo mi, out bool must_do_cs1540_check)
 153                 {
 154                         MethodAttributes ma = mi.Attributes & MethodAttributes.MemberAccessMask;
 155
 156                         must_do_cs1540_check = false; // by default we do not check for this
 157
 158                         if (ma == MethodAttributes.Public)
 159                                 return true;
 160
 161                         //
 162                         // If only accessible to the current class or children
 163                         //
 164                         if (ma == MethodAttributes.Private)
 165                                 return TypeManager.IsPrivateAccessible (invocation_type, mi.DeclaringType) ||
 166                                         TypeManager.IsNestedChildOf (invocation_type, mi.DeclaringType);
 167
 168                         if (mi.DeclaringType.Assembly == invocation_type.Assembly ||
 169                                         TypeManager.IsFriendAssembly (mi.DeclaringType.Assembly)) {
 170                                 if (ma == MethodAttributes.Assembly || ma == MethodAttributes.FamORAssem)
 171                                         return true;
 172                         } else {
 173                                 if (ma == MethodAttributes.Assembly || ma == MethodAttributes.FamANDAssem)
 174                                         return false;
 175                         }
 176
 177                         // Family and FamANDAssem require that we derive.
 178                         // FamORAssem requires that we derive if in different assemblies.
 179                         if (!TypeManager.IsNestedFamilyAccessible (invocation_type, mi.DeclaringType))
 180                                 return false;
 181
 182                         if (!TypeManager.IsNestedChildOf (invocation_type, mi.DeclaringType))
 183                                 must_do_cs1540_check = true;
 184
 185                         return true;
 186                 }
 187
 188                 /// <summary>
 189                 ///   Performs semantic analysis on the Expression
 190                 /// </summary>
 191                 ///
 192                 /// <remarks>
 193                 ///   The Resolve method is invoked to perform the semantic analysis
 194                 ///   on the node.
 195                 ///
 196                 ///   The return value is an expression (it can be the
 197                 ///   same expression in some cases) or a new
 198                 ///   expression that better represents this node.
 199                 ///
 200                 ///   For example, optimizations of Unary (LiteralInt)
 201                 ///   would return a new LiteralInt with a negated
 202                 ///   value.
 203                 ///
 204                 ///   If there is an error during semantic analysis,
 205                 ///   then an error should be reported (using Report)
 206                 ///   and a null value should be returned.
 207                 ///
 208                 ///   There are two side effects expected from calling
 209                 ///   Resolve(): the the field variable "eclass" should
 210                 ///   be set to any value of the enumeration
 211                 ///   `ExprClass' and the type variable should be set
 212                 ///   to a valid type (this is the type of the
 213                 ///   expression).
 214                 /// </remarks>
 215                 public abstract Expression DoResolve (EmitContext ec);
 216
 217                 public virtual Expression DoResolveLValue (EmitContext ec, Expression right_side)
 218                 {
 219                         return null;
 220                 }
 221
 222                 //
 223                 // This is used if the expression should be resolved as a type or namespace name.
 224                 // the default implementation fails.
 225                 //
 226                 public virtual FullNamedExpression ResolveAsTypeStep (IResolveContext ec,  bool silent)
 227                 {
 228                         return null;
 229                 }
 230
 231                 //
 232                 // This is used to resolve the expression as a type, a null
 233                 // value will be returned if the expression is not a type
 234                 // reference
 235                 //
 236                 public virtual TypeExpr ResolveAsTypeTerminal (IResolveContext ec, bool silent)
 237                 {
 238                         TypeExpr te = ResolveAsBaseTerminal (ec, silent);
 239                         if (te == null)
 240                                 return null;
 241
 242                         if (!silent) {
 243                                 ObsoleteAttribute obsolete_attr = AttributeTester.GetObsoleteAttribute (te.Type);
 244                                 if (obsolete_attr != null && !ec.IsInObsoleteScope) {
 245                                         AttributeTester.Report_ObsoleteMessage (obsolete_attr, te.GetSignatureForError (), Location);
 246                                 }
 247                         }
 248
 249                         // Constrains don't need to be checked for overrides
 250                         GenericMethod gm = ec.GenericDeclContainer as GenericMethod;
 251                         if (gm != null && (gm.ModFlags & Modifiers.OVERRIDE) != 0) {
 252                                 te.loc = loc;
 253                                 return te;
 254                         }
 255
 256                         ConstructedType ct = te as ConstructedType;
 257                         if ((ct != null) && !ct.CheckConstraints (ec))
 258                                 return null;
 259
 260                         return te;
 261                 }
 262
 263                 public TypeExpr ResolveAsBaseTerminal (IResolveContext ec, bool silent)
 264                 {
 265                         int errors = Report.Errors;
 266
 267                         FullNamedExpression fne = ResolveAsTypeStep (ec, silent);
 268
 269                         if (fne == null)
 270                                 return null;
 271
 272                         if (fne.eclass != ExprClass.Type) {
 273                                 if (!silent && errors == Report.Errors)
 274                                         fne.Error_UnexpectedKind (null, "type", loc);
 275                                 return null;
 276                         }
 277
 278                         TypeExpr te = fne as TypeExpr;
 279
 280                         if (!te.CheckAccessLevel (ec.DeclContainer)) {
 281                                 Report.SymbolRelatedToPreviousError (te.Type);
 282                                 ErrorIsInaccesible (loc, TypeManager.CSharpName (te.Type));
 283                                 return null;
 284                         }
 285
 286                         te.loc = loc;
 287                         return te;
 288                 }
 289
 290                 public static void ErrorIsInaccesible (Location loc, string name)
 291                 {
 292                         Report.Error (122, loc, "`{0}' is inaccessible due to its protection level", name);
 293                 }
 294
 295                 protected static void Error_CannotAccessProtected (Location loc, MemberInfo m, Type qualifier, Type container)
 296                 {
 297                         Report.Error (1540, loc, "Cannot access protected member `{0}' via a qualifier of type `{1}'."
 298                                 + " The qualifier must be of type `{2}' or derived from it",
 299                                 TypeManager.GetFullNameSignature (m),
 300                                 TypeManager.CSharpName (qualifier),
 301                                 TypeManager.CSharpName (container));
 302
 303                 }
 304
 305                 protected void Error_CannotAssign (string to, string roContext)
 306                 {
 307                         Report.Error (1656, loc, "Cannot assign to `{0}' because it is a `{1}'",
 308                                 to, roContext);
 309                 }
 310
 311                 public static void Error_VoidInvalidInTheContext (Location loc)
 312                 {
 313                         Report.Error (1547, loc, "Keyword `void' cannot be used in this context");
 314                 }
 315
 316                 public virtual void Error_ValueCannotBeConverted (EmitContext ec, Location loc, Type target, bool expl)
 317                 {
 318                         if (Type.FullName == target.FullName){
 319                                 Report.ExtraInformation (loc,
 320                                         String.Format (
 321                                         "The type {0} has two conflicting definitions, one comes from {1} and the other from {2}",
 322                                         Type.FullName, Type.Assembly.FullName, target.Assembly.FullName));
 323
 324                         }
 325
 326                         if (expl) {
 327                                 Report.Error (30, loc, "Cannot convert type `{0}' to `{1}'",
 328                                         GetSignatureForError (), TypeManager.CSharpName (target));
 329                                 return;
 330                         }
 331
 332                         Expression e = (this is EnumConstant) ? ((EnumConstant)this).Child : this;
 333                         bool b = Convert.ExplicitNumericConversion (e, target) != null;
 334
 335                         if (b ||
 336                             Convert.ExplicitReferenceConversionExists (Type, target) ||
 337                             Convert.ExplicitUnsafe (e, target) != null ||
 338                             (ec != null && Convert.UserDefinedConversion (ec, this, target, Location.Null, true) != null))
 339                         {
 340                                 Report.Error (266, loc, "Cannot implicitly convert type `{0}' to `{1}'. " +
 341                                               "An explicit conversion exists (are you missing a cast?)",
 342                                         TypeManager.CSharpName (Type), TypeManager.CSharpName (target));
 343                                 return;
 344                         }
 345
 346                         if (Type != TypeManager.string_type && this is Constant && !(this is EmptyConstantCast)) {
 347                                 Report.Error (31, loc, "Constant value `{0}' cannot be converted to a `{1}'",
 348                                         ((Constant)(this)).GetValue ().ToString (), TypeManager.CSharpName (target));
 349                                 return;
 350                         }
 351
 352                         Report.Error (29, loc, "Cannot implicitly convert type {0} to `{1}'",
 353                                 Type == TypeManager.anonymous_method_type ?
 354                                 "anonymous method" : "`" + GetSignatureForError () + "'",
 355                                 TypeManager.CSharpName (target));
 356                 }
 357
 358                 protected static void Error_TypeDoesNotContainDefinition (Location loc, Type type, string name)
 359                 {
 360                         Report.Error (117, loc, "`{0}' does not contain a definition for `{1}'",
 361                                 TypeManager.CSharpName (type), name);
 362                 }
 363
 364                 protected static void Error_ValueAssignment (Location loc)
 365                 {
 366                         Report.Error (131, loc, "The left-hand side of an assignment must be a variable, a property or an indexer");
 367                 }
 368
 369                 ResolveFlags ExprClassToResolveFlags
 370                 {
 371                         get {
 372                                 switch (eclass) {
 373                                         case ExprClass.Type:
 374                                         case ExprClass.Namespace:
 375                                                 return ResolveFlags.Type;
 376
 377                                         case ExprClass.MethodGroup:
 378                                                 return ResolveFlags.MethodGroup;
 379
 380                                         case ExprClass.Value:
 381                                         case ExprClass.Variable:
 382                                         case ExprClass.PropertyAccess:
 383                                         case ExprClass.EventAccess:
 384                                         case ExprClass.IndexerAccess:
 385                                                 return ResolveFlags.VariableOrValue;
 386
 387                                         default:
 388                                                 throw new Exception ("Expression " + GetType () +
 389                                                         " ExprClass is Invalid after resolve");
 390                                 }
 391                         }
 392                 }
 393
 394                 /// <summary>
 395                 ///   Resolves an expression and performs semantic analysis on it.
 396                 /// </summary>
 397                 ///
 398                 /// <remarks>
 399                 ///   Currently Resolve wraps DoResolve to perform sanity
 400                 ///   checking and assertion checking on what we expect from Resolve.
 401                 /// </remarks>
 402                 public Expression Resolve (EmitContext ec, ResolveFlags flags)
 403                 {
 404                         if ((flags & ResolveFlags.MaskExprClass) == ResolveFlags.Type)
 405                                 return ResolveAsTypeStep (ec, false);
 406
 407                         bool do_flow_analysis = ec.DoFlowAnalysis;
 408                         bool omit_struct_analysis = ec.OmitStructFlowAnalysis;
 409                         if ((flags & ResolveFlags.DisableFlowAnalysis) != 0)
 410                                 do_flow_analysis = false;
 411                         if ((flags & ResolveFlags.DisableStructFlowAnalysis) != 0)
 412                                 omit_struct_analysis = true;
 413
 414                         Expression e;
 415                         using (ec.WithFlowAnalysis (do_flow_analysis, omit_struct_analysis)) {
 416                                 if (this is SimpleName) {
 417                                         bool intermediate = (flags & ResolveFlags.Intermediate) == ResolveFlags.Intermediate;
 418                                         e = ((SimpleName) this).DoResolve (ec, intermediate);
 419                                 } else {
 420                                         e = DoResolve (ec);
 421                                 }
 422                         }
 423
 424                         if (e == null)
 425                                 return null;
 426
 427                         if ((flags & e.ExprClassToResolveFlags) == 0) {
 428                                 e.Error_UnexpectedKind (flags, loc);
 429                                 return null;
 430                         }
 431
 432                         if (e.type == null && !(e is Namespace)) {
 433                                 throw new Exception (
 434                                         "Expression " + e.GetType () +
 435                                         " did not set its type after Resolve\n" +
 436                                         "called from: " + this.GetType ());
 437                         }
 438
 439                         return e;
 440                 }
 441
 442                 /// <summary>
 443                 ///   Resolves an expression and performs semantic analysis on it.
 444                 /// </summary>
 445                 public Expression Resolve (EmitContext ec)
 446                 {
 447                         Expression e = Resolve (ec, ResolveFlags.VariableOrValue | ResolveFlags.MethodGroup);
 448
 449                         if (e != null && e.eclass == ExprClass.MethodGroup && RootContext.Version == LanguageVersion.ISO_1) {
 450                                 ((MethodGroupExpr) e).ReportUsageError ();
 451                                 return null;
 452                         }
 453                         return e;
 454                 }
 455
 456                 public Constant ResolveAsConstant (EmitContext ec, MemberCore mc)
 457                 {
 458                         Expression e = Resolve (ec);
 459                         if (e == null)
 460                                 return null;
 461
 462                         Constant c = e as Constant;
 463                         if (c != null)
 464                                 return c;
 465
 466                         Const.Error_ExpressionMustBeConstant (loc, mc.GetSignatureForError ());
 467                         return null;
 468                 }
 469
 470                 /// <summary>
 471                 ///   Resolves an expression for LValue assignment
 472                 /// </summary>
 473                 ///
 474                 /// <remarks>
 475                 ///   Currently ResolveLValue wraps DoResolveLValue to perform sanity
 476                 ///   checking and assertion checking on what we expect from Resolve
 477                 /// </remarks>
 478                 public Expression ResolveLValue (EmitContext ec, Expression right_side, Location loc)
 479                 {
 480                         int errors = Report.Errors;
 481                         bool out_access = right_side == EmptyExpression.OutAccess;
 482
 483                         Expression e = DoResolveLValue (ec, right_side);
 484
 485                         if (e != null && out_access && !(e is IMemoryLocation)) {
 486                                 // FIXME: There's no problem with correctness, the 'Expr = null' handles that.
 487                                 //        Enabling this 'throw' will "only" result in deleting useless code elsewhere,
 488
 489                                 //throw new InternalErrorException ("ResolveLValue didn't return an IMemoryLocation: " +
 490                                 //                                e.GetType () + " " + e.GetSignatureForError ());
 491                                 e = null;
 492                         }
 493
 494                         if (e == null) {
 495                                 if (errors == Report.Errors) {
 496                                         if (out_access)
 497                                                 Report.Error (1510, loc, "A ref or out argument must be an assignable variable");
 498                                         else
 499                                                 Error_ValueAssignment (loc);
 500                                 }
 501                                 return null;
 502                         }
 503
 504                         if (e.eclass == ExprClass.Invalid)
 505                                 throw new Exception ("Expression " + e + " ExprClass is Invalid after resolve");
 506
 507                         if (e.eclass == ExprClass.MethodGroup) {
 508                                 ((MethodGroupExpr) e).ReportUsageError ();
 509                                 return null;
 510                         }
 511
 512                         if ((e.type == null) && !(e is ConstructedType))
 513                                 throw new Exception ("Expression " + e + " did not set its type after Resolve");
 514
 515                         return e;
 516                 }
 517
 518                 /// <summary>
 519                 ///   Emits the code for the expression
 520                 /// </summary>
 521                 ///
 522                 /// <remarks>
 523                 ///   The Emit method is invoked to generate the code
 524                 ///   for the expression.
 525                 /// </remarks>
 526                 public abstract void Emit (EmitContext ec);
 527
 528                 public virtual void EmitBranchable (EmitContext ec, Label target, bool onTrue)
 529                 {
 530                         Emit (ec);
 531                         ec.ig.Emit (onTrue ? OpCodes.Brtrue : OpCodes.Brfalse, target);
 532                 }
 533
 534                 /// <summary>
 535                 ///   Protected constructor.  Only derivate types should
 536                 ///   be able to be created
 537                 /// </summary>
 538
 539                 protected Expression ()
 540                 {
 541                         eclass = ExprClass.Invalid;
 542                         type = null;
 543                 }
 544
 545                 /// <summary>
 546                 ///   Returns a fully formed expression after a MemberLookup
 547                 /// </summary>
 548                 ///
 549                 public static Expression ExprClassFromMemberInfo (Type containerType, MemberInfo mi, Location loc)
 550                 {
 551                         if (mi is EventInfo)
 552                                 return new EventExpr ((EventInfo) mi, loc);
 553                         else if (mi is FieldInfo)
 554                                 return new FieldExpr ((FieldInfo) mi, loc);
 555                         else if (mi is PropertyInfo)
 556                                 return new PropertyExpr (containerType, (PropertyInfo) mi, loc);
 557                         else if (mi is Type){
 558                                 return new TypeExpression ((System.Type) mi, loc);
 559                         }
 560
 561                         return null;
 562                 }
 563
 564                 protected static ArrayList almostMatchedMembers = new ArrayList (4);
 565
 566                 //
 567                 // FIXME: Probably implement a cache for (t,name,current_access_set)?
 568                 //
 569                 // This code could use some optimizations, but we need to do some
 570                 // measurements.  For example, we could use a delegate to `flag' when
 571                 // something can not any longer be a method-group (because it is something
 572                 // else).
 573                 //
 574                 // Return values:
 575                 //     If the return value is an Array, then it is an array of
 576                 //     MethodBases
 577                 //
 578                 //     If the return value is an MemberInfo, it is anything, but a Method
 579                 //
 580                 //     null on error.
 581                 //
 582                 // FIXME: When calling MemberLookup inside an `Invocation', we should pass
 583                 // the arguments here and have MemberLookup return only the methods that
 584                 // match the argument count/type, unlike we are doing now (we delay this
 585                 // decision).
 586                 //
 587                 // This is so we can catch correctly attempts to invoke instance methods
 588                 // from a static body (scan for error 120 in ResolveSimpleName).
 589                 //
 590                 //
 591                 // FIXME: Potential optimization, have a static ArrayList
 592                 //
 593
 594                 public static Expression MemberLookup (Type container_type, Type queried_type, string name,
 595                                                        MemberTypes mt, BindingFlags bf, Location loc)
 596                 {
 597                         return MemberLookup (container_type, null, queried_type, name, mt, bf, loc);
 598                 }
 599
 600                 //
 601                 // Lookup type `queried_type' for code in class `container_type' with a qualifier of
 602                 // `qualifier_type' or null to lookup members in the current class.
 603                 //
 604
 605                 public static Expression MemberLookup (Type container_type,
 606                                                        Type qualifier_type, Type queried_type,
 607                                                        string name, MemberTypes mt,
 608                                                        BindingFlags bf, Location loc)
 609                 {
 610                         almostMatchedMembers.Clear ();
 611
 612                         MemberInfo [] mi = TypeManager.MemberLookup (container_type, qualifier_type,
 613                                                                      queried_type, mt, bf, name, almostMatchedMembers);
 614
 615                         if (mi == null)
 616                                 return null;
 617
 618                         if (mi.Length > 1) {
 619                                 bool is_interface = qualifier_type != null && qualifier_type.IsInterface;
 620                                 MemberInfo non_method = null;
 621                                 ArrayList methods = new ArrayList (2);
 622
 623                                 foreach (MemberInfo m in mi) {
 624                                         if (m is MethodBase) {
 625                                                 methods.Add (m);
 626                                                 continue;
 627                                         }
 628
 629                                         if (non_method == null) {
 630                                                 non_method = m;
 631                                                 continue;
 632                                         }
 633
 634                                         Report.SymbolRelatedToPreviousError (m);
 635                                         Report.SymbolRelatedToPreviousError (non_method);
 636                                         Report.Error (229, loc, "Ambiguity between `{0}' and `{1}'",
 637                                                 TypeManager.GetFullNameSignature (m), TypeManager.GetFullNameSignature (non_method));
 638                                         return null;
 639                                 }
 640
 641                                 if (methods.Count == 0)
 642                                         return null;
 643
 644                                 if (non_method != null) {
 645                                         MethodBase method = (MethodBase) methods [0];
 646
 647                                         if (method.DeclaringType == non_method.DeclaringType) {
 648                                                 // Cannot happen with C# code, but is valid in IL
 649                                                 Report.SymbolRelatedToPreviousError (method);
 650                                                 Report.SymbolRelatedToPreviousError (non_method);
 651                                                 Report.Error (229, loc, "Ambiguity between `{0}' and `{1}'",
 652                                                               TypeManager.GetFullNameSignature (non_method),
 653                                                               TypeManager.CSharpSignature (method));
 654                                                 return null;
 655                                         }
 656
 657                                         if (is_interface) {
 658                                                 Report.SymbolRelatedToPreviousError (method);
 659                                                 Report.SymbolRelatedToPreviousError (non_method);
 660                                                 Report.Warning (467, 2, loc, "Ambiguity between method `{0}' and non-method `{1}'. Using method `{0}'",
 661                                                                 TypeManager.CSharpSignature (method), TypeManager.GetFullNameSignature (non_method));
 662                                         }
 663                                 }
 664
 665                                 return new MethodGroupExpr (methods, loc);
 666                         }
 667
 668                         if (mi [0] is MethodBase)
 669                                 return new MethodGroupExpr (mi, loc);
 670
 671                         return ExprClassFromMemberInfo (container_type, mi [0], loc);
 672                 }
 673
 674                 public const MemberTypes AllMemberTypes =
 675                         MemberTypes.Constructor |
 676                         MemberTypes.Event       |
 677                         MemberTypes.Field       |
 678                         MemberTypes.Method      |
 679                         MemberTypes.NestedType  |
 680                         MemberTypes.Property;
 681
 682                 public const BindingFlags AllBindingFlags =
 683                         BindingFlags.Public |
 684                         BindingFlags.Static |
 685                         BindingFlags.Instance;
 686
 687                 public static Expression MemberLookup (Type container_type, Type queried_type,
 688                                                        string name, Location loc)
 689                 {
 690                         return MemberLookup (container_type, null, queried_type, name,
 691                                              AllMemberTypes, AllBindingFlags, loc);
 692                 }
 693
 694                 public static Expression MemberLookup (Type container_type, Type qualifier_type,
 695                                                        Type queried_type, string name, Location loc)
 696                 {
 697                         return MemberLookup (container_type, qualifier_type, queried_type,
 698                                              name, AllMemberTypes, AllBindingFlags, loc);
 699                 }
 700
 701                 public static Expression MethodLookup (Type container_type, Type queried_type,
 702                                                        string name, Location loc)
 703                 {
 704                         return MemberLookup (container_type, null, queried_type, name,
 705                                              MemberTypes.Method, AllBindingFlags, loc);
 706                 }
 707
 708                 /// <summary>
 709                 ///   This is a wrapper for MemberLookup that is not used to "probe", but
 710                 ///   to find a final definition.  If the final definition is not found, we
 711                 ///   look for private members and display a useful debugging message if we
 712                 ///   find it.
 713                 /// </summary>
 714                 public static Expression MemberLookupFinal (EmitContext ec, Type qualifier_type,
 715                                                             Type queried_type, string name, Location loc)
 716                 {
 717                         return MemberLookupFinal (ec, qualifier_type, queried_type, name,
 718                                                   AllMemberTypes, AllBindingFlags, loc);
 719                 }
 720
 721                 public static Expression MemberLookupFinal (EmitContext ec, Type qualifier_type,
 722                                                             Type queried_type, string name,
 723                                                             MemberTypes mt, BindingFlags bf,
 724                                                             Location loc)
 725                 {
 726                         Expression e;
 727
 728                         int errors = Report.Errors;
 729
 730                         e = MemberLookup (ec.ContainerType, qualifier_type, queried_type, name, mt, bf, loc);
 731
 732                         if (e == null && errors == Report.Errors)
 733                                 // No errors were reported by MemberLookup, but there was an error.
 734                                 MemberLookupFailed (ec.ContainerType, qualifier_type, queried_type, name, null, true, loc);
 735
 736                         return e;
 737                 }
 738
 739                 public static void MemberLookupFailed (Type container_type, Type qualifier_type,
 740                                                        Type queried_type, string name,
 741                                                        string class_name, bool complain_if_none_found,
 742                                                        Location loc)
 743                 {
 744                         if (almostMatchedMembers.Count != 0) {
 745                                 for (int i = 0; i < almostMatchedMembers.Count; ++i) {
 746                                         MemberInfo m = (MemberInfo) almostMatchedMembers [i];
 747                                         for (int j = 0; j < i; ++j) {
 748                                                 if (m == almostMatchedMembers [j]) {
 749                                                         m = null;
 750                                                         break;
 751                                                 }
 752                                         }
 753                                         if (m == null)
 754                                                 continue;
 755
 756                                         Type declaring_type = m.DeclaringType;
 757
 758                                         Report.SymbolRelatedToPreviousError (m);
 759                                         if (qualifier_type == null) {
 760                                                 Report.Error (38, loc, "Cannot access a nonstatic member of outer type `{0}' via nested type `{1}'",
 761                                                               TypeManager.CSharpName (m.DeclaringType),
 762                                                               TypeManager.CSharpName (container_type));
 763
 764                                         } else if (qualifier_type != container_type &&
 765                                                    TypeManager.IsNestedFamilyAccessible (container_type, declaring_type)) {
 766                                                 // Although a derived class can access protected members of
 767                                                 // its base class it cannot do so through an instance of the
 768                                                 // base class (CS1540).  If the qualifier_type is a base of the
 769                                                 // ec.ContainerType and the lookup succeeds with the latter one,
 770                                                 // then we are in this situation.
 771                                                 Error_CannotAccessProtected (loc, m, qualifier_type, container_type);
 772                                         } else {
 773                                                 ErrorIsInaccesible (loc, TypeManager.GetFullNameSignature (m));
 774                                         }
 775                                 }
 776                                 almostMatchedMembers.Clear ();
 777                                 return;
 778                         }
 779
 780                         MemberInfo[] lookup = null;
 781                         if (queried_type == null) {
 782                                 class_name = "global::";
 783                         } else {
 784                                 lookup = TypeManager.MemberLookup (queried_type, null, queried_type,
 785                                         AllMemberTypes, AllBindingFlags |
 786                                         BindingFlags.NonPublic, name, null);
 787                         }
 788
 789                         if (lookup == null) {
 790                                 if (!complain_if_none_found)
 791                                         return;
 792
 793                                 if (class_name != null)
 794                                         Report.Error (103, loc, "The name `{0}' does not exist in the context of `{1}'",
 795                                                 name, class_name);
 796                                 else
 797                                         Error_TypeDoesNotContainDefinition (loc, queried_type, name);
 798                                 return;
 799                         }
 800
 801                         if (TypeManager.MemberLookup (queried_type, null, queried_type,
 802                                                       AllMemberTypes, AllBindingFlags |
 803                                                       BindingFlags.NonPublic, name, null) == null) {
 804                                 if ((lookup.Length == 1) && (lookup [0] is Type)) {
 805                                         Type t = (Type) lookup [0];
 806
 807                                         Report.Error (305, loc,
 808                                                       "Using the generic type `{0}' " +
 809                                                       "requires {1} type arguments",
 810                                                       TypeManager.CSharpName (t),
 811                                                       TypeManager.GetNumberOfTypeArguments (t).ToString ());
 812                                         return;
 813                                 }
 814                         }
 815
 816                         MemberList ml = TypeManager.FindMembers (queried_type, MemberTypes.Constructor,
 817                                                                  BindingFlags.Static | BindingFlags.Instance | BindingFlags.Public | BindingFlags.DeclaredOnly, null, null);
 818                         if (name == ".ctor" && ml.Count == 0)
 819                         {
 820                                 Report.Error (143, loc, "The type `{0}' has no constructors defined", TypeManager.CSharpName (queried_type));
 821                                 return;
 822                         }
 823
 824                         Report.SymbolRelatedToPreviousError (lookup [0]);
 825                         ErrorIsInaccesible (loc, TypeManager.GetFullNameSignature (lookup [0]));
 826                 }
 827
 828                 /// <summary>
 829                 ///   Returns an expression that can be used to invoke operator true
 830                 ///   on the expression if it exists.
 831                 /// </summary>
 832                 static public Expression GetOperatorTrue (EmitContext ec, Expression e, Location loc)
 833                 {
 834                         return GetOperatorTrueOrFalse (ec, e, true, loc);
 835                 }
 836
 837                 /// <summary>
 838                 ///   Returns an expression that can be used to invoke operator false
 839                 ///   on the expression if it exists.
 840                 /// </summary>
 841                 static public Expression GetOperatorFalse (EmitContext ec, Expression e, Location loc)
 842                 {
 843                         return GetOperatorTrueOrFalse (ec, e, false, loc);
 844                 }
 845
 846                 static Expression GetOperatorTrueOrFalse (EmitContext ec, Expression e, bool is_true, Location loc)
 847                 {
 848                         MethodBase method;
 849                         Expression operator_group;
 850
 851 #if GMCS_SOURCE
 852                         if (TypeManager.IsNullableType (e.Type))
 853                                 return new Nullable.OperatorTrueOrFalse (e, is_true, loc).Resolve (ec);
 854 #endif
 855
 856                         operator_group = MethodLookup (ec.ContainerType, e.Type, is_true ? "op_True" : "op_False", loc);
 857                         if (operator_group == null)
 858                                 return null;
 859
 860                         ArrayList arguments = new ArrayList ();
 861                         arguments.Add (new Argument (e, Argument.AType.Expression));
 862                         method = Invocation.OverloadResolve (
 863                                 ec, (MethodGroupExpr) operator_group, arguments, false, loc);
 864
 865                         if (method == null)
 866                                 return null;
 867
 868                         return new StaticCallExpr ((MethodInfo) method, arguments, loc);
 869                 }
 870
 871                 /// <summary>
 872                 ///   Resolves the expression `e' into a boolean expression: either through
 873                 ///   an implicit conversion, or through an `operator true' invocation
 874                 /// </summary>
 875                 public static Expression ResolveBoolean (EmitContext ec, Expression e, Location loc)
 876                 {
 877                         e = e.Resolve (ec);
 878                         if (e == null)
 879                                 return null;
 880
 881                         if (e.Type == TypeManager.bool_type)
 882                                 return e;
 883
 884                         Expression converted = Convert.ImplicitConversion (ec, e, TypeManager.bool_type, Location.Null);
 885
 886                         if (converted != null)
 887                                 return converted;
 888
 889                         //
 890                         // If no implicit conversion to bool exists, try using `operator true'
 891                         //
 892                         converted = Expression.GetOperatorTrue (ec, e, loc);
 893                         if (converted == null){
 894                                 e.Error_ValueCannotBeConverted (ec, loc, TypeManager.bool_type, false);
 895                                 return null;
 896                         }
 897                         return converted;
 898                 }
 899
 900                 public virtual string ExprClassName
 901                 {
 902                         get {
 903                                 switch (eclass){
 904                                         case ExprClass.Invalid:
 905                                                 return "Invalid";
 906                                         case ExprClass.Value:
 907                                                 return "value";
 908                                         case ExprClass.Variable:
 909                                                 return "variable";
 910                                         case ExprClass.Namespace:
 911                                                 return "namespace";
 912                                         case ExprClass.Type:
 913                                                 return "type";
 914                                         case ExprClass.MethodGroup:
 915                                                 return "method group";
 916                                         case ExprClass.PropertyAccess:
 917                                                 return "property access";
 918                                         case ExprClass.EventAccess:
 919                                                 return "event access";
 920                                         case ExprClass.IndexerAccess:
 921                                                 return "indexer access";
 922                                         case ExprClass.Nothing:
 923                                                 return "null";
 924                                 }
 925                                 throw new Exception ("Should not happen");
 926                         }
 927                 }
 928
 929                 /// <summary>
 930                 ///   Reports that we were expecting `expr' to be of class `expected'
 931                 /// </summary>
 932                 public void Error_UnexpectedKind (DeclSpace ds, string expected, Location loc)
 933                 {
 934                         Error_UnexpectedKind (ds, expected, ExprClassName, loc);
 935                 }
 936
 937                 public void Error_UnexpectedKind (DeclSpace ds, string expected, string was, Location loc)
 938                 {
 939                         string name = GetSignatureForError ();
 940                         if (ds != null)
 941                                 name = ds.GetSignatureForError () + '.' + name;
 942
 943                         Report.Error (118, loc, "`{0}' is a `{1}' but a `{2}' was expected",
 944                               name, was, expected);
 945                 }
 946
 947                 public void Error_UnexpectedKind (ResolveFlags flags, Location loc)
 948                 {
 949                         string [] valid = new string [4];
 950                         int count = 0;
 951
 952                         if ((flags & ResolveFlags.VariableOrValue) != 0) {
 953                                 valid [count++] = "variable";
 954                                 valid [count++] = "value";
 955                         }
 956
 957                         if ((flags & ResolveFlags.Type) != 0)
 958                                 valid [count++] = "type";
 959
 960                         if ((flags & ResolveFlags.MethodGroup) != 0)
 961                                 valid [count++] = "method group";
 962
 963                         if (count == 0)
 964                                 valid [count++] = "unknown";
 965
 966                         StringBuilder sb = new StringBuilder (valid [0]);
 967                         for (int i = 1; i < count - 1; i++) {
 968                                 sb.Append ("', `");
 969                                 sb.Append (valid [i]);
 970                         }
 971                         if (count > 1) {
 972                                 sb.Append ("' or `");
 973                                 sb.Append (valid [count - 1]);
 974                         }
 975
 976                         Report.Error (119, loc,
 977                                 "Expression denotes a `{0}', where a `{1}' was expected", ExprClassName, sb.ToString ());
 978                 }
 979
 980                 public static void UnsafeError (Location loc)
 981                 {
 982                         Report.Error (214, loc, "Pointers and fixed size buffers may only be used in an unsafe context");
 983                 }
 984
 985                 //
 986                 // Load the object from the pointer.
 987                 //
 988                 public static void LoadFromPtr (ILGenerator ig, Type t)
 989                 {
 990                         if (t == TypeManager.int32_type)
 991                                 ig.Emit (OpCodes.Ldind_I4);
 992                         else if (t == TypeManager.uint32_type)
 993                                 ig.Emit (OpCodes.Ldind_U4);
 994                         else if (t == TypeManager.short_type)
 995                                 ig.Emit (OpCodes.Ldind_I2);
 996                         else if (t == TypeManager.ushort_type)
 997                                 ig.Emit (OpCodes.Ldind_U2);
 998                         else if (t == TypeManager.char_type)
 999                                 ig.Emit (OpCodes.Ldind_U2);
1000                         else if (t == TypeManager.byte_type)
1001                                 ig.Emit (OpCodes.Ldind_U1);
1002                         else if (t == TypeManager.sbyte_type)
1003                                 ig.Emit (OpCodes.Ldind_I1);
1004                         else if (t == TypeManager.uint64_type)
1005                                 ig.Emit (OpCodes.Ldind_I8);
1006                         else if (t == TypeManager.int64_type)
1007                                 ig.Emit (OpCodes.Ldind_I8);
1008                         else if (t == TypeManager.float_type)
1009                                 ig.Emit (OpCodes.Ldind_R4);
1010                         else if (t == TypeManager.double_type)
1011                                 ig.Emit (OpCodes.Ldind_R8);
1012                         else if (t == TypeManager.bool_type)
1013                                 ig.Emit (OpCodes.Ldind_I1);
1014                         else if (t == TypeManager.intptr_type)
1015                                 ig.Emit (OpCodes.Ldind_I);
1016                         else if (TypeManager.IsEnumType (t)) {
1017                                 if (t == TypeManager.enum_type)
1018                                         ig.Emit (OpCodes.Ldind_Ref);
1019                                 else
1020                                         LoadFromPtr (ig, TypeManager.EnumToUnderlying (t));
1021                         } else if (t.IsValueType || TypeManager.IsGenericParameter (t))
1022                                 ig.Emit (OpCodes.Ldobj, t);
1023                         else if (t.IsPointer)
1024                                 ig.Emit (OpCodes.Ldind_I);
1025                         else
1026                                 ig.Emit (OpCodes.Ldind_Ref);
1027                 }
1028
1029                 //
1030                 // The stack contains the pointer and the value of type `type'
1031                 //
1032                 public static void StoreFromPtr (ILGenerator ig, Type type)
1033                 {
1034                         if (TypeManager.IsEnumType (type))
1035                                 type = TypeManager.EnumToUnderlying (type);
1036                         if (type == TypeManager.int32_type || type == TypeManager.uint32_type)
1037                                 ig.Emit (OpCodes.Stind_I4);
1038                         else if (type == TypeManager.int64_type || type == TypeManager.uint64_type)
1039                                 ig.Emit (OpCodes.Stind_I8);
1040                         else if (type == TypeManager.char_type || type == TypeManager.short_type ||
1041                                  type == TypeManager.ushort_type)
1042                                 ig.Emit (OpCodes.Stind_I2);
1043                         else if (type == TypeManager.float_type)
1044                                 ig.Emit (OpCodes.Stind_R4);
1045                         else if (type == TypeManager.double_type)
1046                                 ig.Emit (OpCodes.Stind_R8);
1047                         else if (type == TypeManager.byte_type || type == TypeManager.sbyte_type ||
1048                                  type == TypeManager.bool_type)
1049                                 ig.Emit (OpCodes.Stind_I1);
1050                         else if (type == TypeManager.intptr_type)
1051                                 ig.Emit (OpCodes.Stind_I);
1052                         else if (type.IsValueType || TypeManager.IsGenericParameter (type))
1053                                 ig.Emit (OpCodes.Stobj, type);
1054                         else
1055                                 ig.Emit (OpCodes.Stind_Ref);
1056                 }
1057
1058                 //
1059                 // Returns the size of type `t' if known, otherwise, 0
1060                 //
1061                 public static int GetTypeSize (Type t)
1062                 {
1063                         t = TypeManager.TypeToCoreType (t);
1064                         if (t == TypeManager.int32_type ||
1065                             t == TypeManager.uint32_type ||
1066                             t == TypeManager.float_type)
1067                                 return 4;
1068                         else if (t == TypeManager.int64_type ||
1069                                  t == TypeManager.uint64_type ||
1070                                  t == TypeManager.double_type)
1071                                 return 8;
1072                         else if (t == TypeManager.byte_type ||
1073                                  t == TypeManager.sbyte_type ||
1074                                  t == TypeManager.bool_type)
1075                                 return 1;
1076                         else if (t == TypeManager.short_type ||
1077                                  t == TypeManager.char_type ||
1078                                  t == TypeManager.ushort_type)
1079                                 return 2;
1080                         else if (t == TypeManager.decimal_type)
1081                                 return 16;
1082                         else
1083                                 return 0;
1084                 }
1085
1086                 public static void Error_NegativeArrayIndex (Location loc)
1087                 {
1088                         Report.Error (248, loc, "Cannot create an array with a negative size");
1089                 }
1090
1091                 protected void Error_CannotCallAbstractBase (string name)
1092                 {
1093                         Report.Error (205, loc, "Cannot call an abstract base member `{0}'", name);
1094                 }
1095
1096                 //
1097                 // Converts `source' to an int, uint, long or ulong.
1098                 //
1099                 public Expression ExpressionToArrayArgument (EmitContext ec, Expression source, Location loc)
1100                 {
1101                         Expression target;
1102
1103                         using (ec.With (EmitContext.Flags.CheckState, true)) {
1104                                 target = Convert.ImplicitConversion (ec, source, TypeManager.int32_type, loc);
1105                                 if (target == null)
1106                                         target = Convert.ImplicitConversion (ec, source, TypeManager.uint32_type, loc);
1107                                 if (target == null)
1108                                         target = Convert.ImplicitConversion (ec, source, TypeManager.int64_type, loc);
1109                                 if (target == null)
1110                                         target = Convert.ImplicitConversion (ec, source, TypeManager.uint64_type, loc);
1111
1112                                 if (target == null) {
1113                                         source.Error_ValueCannotBeConverted (ec, loc, TypeManager.int32_type, false);
1114                                         return null;
1115                                 }
1116                         }
1117
1118                         //
1119                         // Only positive constants are allowed at compile time
1120                         //
1121                         if (target is Constant){
1122                                 if (target is IntConstant){
1123                                         if (((IntConstant) target).Value < 0){
1124                                                 Error_NegativeArrayIndex (loc);
1125                                                 return null;
1126                                         }
1127                                 }
1128
1129                                 if (target is LongConstant){
1130                                         if (((LongConstant) target).Value < 0){
1131                                                 Error_NegativeArrayIndex (loc);
1132                                                 return null;
1133                                         }
1134                                 }
1135
1136                         }
1137
1138                         return target;
1139                 }
1140
1141         }
1142
1143         /// <summary>
1144         ///   This is just a base class for expressions that can
1145         ///   appear on statements (invocations, object creation,
1146         ///   assignments, post/pre increment and decrement).  The idea
1147         ///   being that they would support an extra Emition interface that
1148         ///   does not leave a result on the stack.
1149         /// </summary>
1150         public abstract class ExpressionStatement : Expression {
1151
1152                 public virtual ExpressionStatement ResolveStatement (EmitContext ec)
1153                 {
1154                         Expression e = Resolve (ec);
1155                         if (e == null)
1156                                 return null;
1157
1158                         ExpressionStatement es = e as ExpressionStatement;
1159                         if (es == null)
1160                                 Error (201, "Only assignment, call, increment, decrement and new object " +
1161                                        "expressions can be used as a statement");
1162
1163                         return es;
1164                 }
1165
1166                 /// <summary>
1167                 ///   Requests the expression to be emitted in a `statement'
1168                 ///   context.  This means that no new value is left on the
1169                 ///   stack after invoking this method (constrasted with
1170                 ///   Emit that will always leave a value on the stack).
1171                 /// </summary>
1172                 public abstract void EmitStatement (EmitContext ec);
1173         }
1174
1175         /// <summary>
1176         ///   This kind of cast is used to encapsulate the child
1177         ///   whose type is child.Type into an expression that is
1178         ///   reported to return "return_type".  This is used to encapsulate
1179         ///   expressions which have compatible types, but need to be dealt
1180         ///   at higher levels with.
1181         ///
1182         ///   For example, a "byte" expression could be encapsulated in one
1183         ///   of these as an "unsigned int".  The type for the expression
1184         ///   would be "unsigned int".
1185         ///
1186         /// </summary>
1187         public class EmptyCast : Expression {
1188                 protected readonly Expression child;
1189
1190                 public EmptyCast (Expression child, Type return_type)
1191                 {
1192                         eclass = child.eclass;
1193                         loc = child.Location;
1194                         type = return_type;
1195                         this.child = child;
1196                 }
1197
1198                 public override Expression DoResolve (EmitContext ec)
1199                 {
1200                         // This should never be invoked, we are born in fully
1201                         // initialized state.
1202
1203                         return this;
1204                 }
1205
1206                 public override void Emit (EmitContext ec)
1207                 {
1208                         child.Emit (ec);
1209                 }
1210
1211                 public override bool GetAttributableValue (Type valueType, out object value)
1212                 {
1213                         return child.GetAttributableValue (valueType, out value);
1214                 }
1215
1216         }
1217
1218         /// <summary>
1219         ///    Performs a cast using an operator (op_Explicit or op_Implicit)
1220         /// </summary>
1221         public class OperatorCast : EmptyCast {
1222                 MethodInfo conversion_operator;
1223                 bool find_explicit;
1224
1225                 public OperatorCast (Expression child, Type target_type) : this (child, target_type, false) {}
1226
1227                 public OperatorCast (Expression child, Type target_type, bool find_explicit)
1228                         : base (child, target_type)
1229                 {
1230                         this.find_explicit = find_explicit;
1231                 }
1232
1233                 // Returns the implicit operator that converts from
1234                 // 'child.Type' to our target type (type)
1235                 MethodInfo GetConversionOperator (bool find_explicit)
1236                 {
1237                         string operator_name = find_explicit ? "op_Explicit" : "op_Implicit";
1238
1239                         MemberInfo [] mi;
1240
1241                         mi = TypeManager.MemberLookup (child.Type, child.Type, child.Type, MemberTypes.Method,
1242                                 BindingFlags.Static | BindingFlags.Public, operator_name, null);
1243
1244                         if (mi == null){
1245                                 mi = TypeManager.MemberLookup (type, type, type, MemberTypes.Method,
1246                                                                BindingFlags.Static | BindingFlags.Public, operator_name, null);
1247                         }
1248
1249                         foreach (MethodInfo oper in mi) {
1250                                 ParameterData pd = TypeManager.GetParameterData (oper);
1251
1252                                 if (pd.ParameterType (0) == child.Type && oper.ReturnType == type)
1253                                         return oper;
1254                         }
1255
1256                         return null;
1257
1258
1259                 }
1260                 public override void Emit (EmitContext ec)
1261                 {
1262                         ILGenerator ig = ec.ig;
1263
1264                         child.Emit (ec);
1265                         conversion_operator = GetConversionOperator (find_explicit);
1266
1267                         if (conversion_operator == null)
1268                                 throw new InternalErrorException ("Outer conversion routine is out of sync");
1269
1270                         ig.Emit (OpCodes.Call, conversion_operator);
1271                 }
1272
1273         }
1274
1275         /// <summary>
1276         ///     This is a numeric cast to a Decimal
1277         /// </summary>
1278         public class CastToDecimal : EmptyCast {
1279                 MethodInfo conversion_operator;
1280
1281                 public CastToDecimal (Expression child)
1282                         : this (child, false)
1283                 {
1284                 }
1285
1286                 public CastToDecimal (Expression child, bool find_explicit)
1287                         : base (child, TypeManager.decimal_type)
1288                 {
1289                         conversion_operator = GetConversionOperator (find_explicit);
1290
1291                         if (conversion_operator == null)
1292                                 throw new InternalErrorException ("Outer conversion routine is out of sync");
1293                 }
1294
1295                 // Returns the implicit operator that converts from
1296                 // 'child.Type' to System.Decimal.
1297                 MethodInfo GetConversionOperator (bool find_explicit)
1298                 {
1299                         string operator_name = find_explicit ? "op_Explicit" : "op_Implicit";
1300
1301                         MemberInfo [] mi = TypeManager.MemberLookup (type, type, type, MemberTypes.Method,
1302                                 BindingFlags.Static | BindingFlags.Public, operator_name, null);
1303
1304                         foreach (MethodInfo oper in mi) {
1305                                 ParameterData pd = TypeManager.GetParameterData (oper);
1306
1307                                 if (pd.ParameterType (0) == child.Type && oper.ReturnType == type)
1308                                         return oper;
1309                         }
1310
1311                         return null;
1312                 }
1313                 public override void Emit (EmitContext ec)
1314                 {
1315                         ILGenerator ig = ec.ig;
1316                         child.Emit (ec);
1317
1318                         ig.Emit (OpCodes.Call, conversion_operator);
1319                 }
1320         }
1321
1322         /// <summary>
1323         ///     This is an explicit numeric cast from a Decimal
1324         /// </summary>
1325         public class CastFromDecimal : EmptyCast
1326         {
1327                 static IDictionary operators;
1328
1329                 public CastFromDecimal (Expression child, Type return_type)
1330                         : base (child, return_type)
1331                 {
1332                         if (child.Type != TypeManager.decimal_type)
1333                                 throw new InternalErrorException (
1334                                         "The expected type is Decimal, instead it is " + child.Type.FullName);
1335                 }
1336
1337                 // Returns the explicit operator that converts from an
1338                 // express of type System.Decimal to 'type'.
1339                 public Expression Resolve ()
1340                 {
1341                         if (operators == null) {
1342                                  MemberInfo[] all_oper = TypeManager.MemberLookup (TypeManager.decimal_type,
1343                                         TypeManager.decimal_type, TypeManager.decimal_type, MemberTypes.Method,
1344                                         BindingFlags.Static | BindingFlags.Public, "op_Explicit", null);
1345
1346                                 operators = new System.Collections.Specialized.HybridDictionary ();
1347                                 foreach (MethodInfo oper in all_oper) {
1348                                         ParameterData pd = TypeManager.GetParameterData (oper);
1349                                         if (pd.ParameterType (0) == TypeManager.decimal_type)
1350                                                 operators.Add (oper.ReturnType, oper);
1351                                 }
1352                         }
1353
1354                         return operators.Contains (type) ? this : null;
1355                 }
1356
1357                 public override void Emit (EmitContext ec)
1358                 {
1359                         ILGenerator ig = ec.ig;
1360                         child.Emit (ec);
1361
1362                         ig.Emit (OpCodes.Call, (MethodInfo)operators [type]);
1363                 }
1364         }
1365
1366
1367         //
1368         // Constant specialization of EmptyCast.
1369         // We need to special case this since an empty cast of
1370         // a constant is still a constant.
1371         //
1372         public class EmptyConstantCast : Constant
1373         {
1374                 public readonly Constant child;
1375
1376                 public EmptyConstantCast(Constant child, Type type)
1377                         : base (child.Location)
1378                 {
1379                         eclass = child.eclass;
1380                         this.child = child;
1381                         this.type = type;
1382                 }
1383
1384                 public override string AsString ()
1385                 {
1386                         return child.AsString ();
1387                 }
1388
1389                 public override object GetValue ()
1390                 {
1391                         return child.GetValue ();
1392                 }
1393
1394                 public override Constant ConvertExplicitly (bool inCheckedContext, Type target_type)
1395                 {
1396                         return child.ConvertExplicitly (inCheckedContext, target_type);
1397                 }
1398
1399                 public override Constant Increment ()
1400                 {
1401                         return child.Increment ();
1402                 }
1403
1404                 public override bool IsDefaultValue
1405                 {
1406                         get { return child.IsDefaultValue; }
1407                 }
1408
1409                 public override bool IsNegative
1410                 {
1411                         get { return child.IsNegative; }
1412                 }
1413
1414                 public override void Emit (EmitContext ec)
1415                 {
1416                         child.Emit (ec);
1417                 }
1418
1419                 public override Constant ConvertImplicitly (Type type)
1420                 {
1421                         return child.ConvertImplicitly (type);
1422                 }
1423         }
1424
1425
1426         /// <summary>
1427         ///  This class is used to wrap literals which belong inside Enums
1428         /// </summary>
1429         public class EnumConstant : Constant {
1430                 public Constant Child;
1431
1432                 public EnumConstant (Constant child, Type enum_type):
1433                         base (child.Location)
1434                 {
1435                         eclass = child.eclass;
1436                         this.Child = child;
1437                         type = enum_type;
1438                 }
1439
1440                 public override Expression DoResolve (EmitContext ec)
1441                 {
1442                         // This should never be invoked, we are born in fully
1443                         // initialized state.
1444
1445                         return this;
1446                 }
1447
1448                 public override void Emit (EmitContext ec)
1449                 {
1450                         Child.Emit (ec);
1451                 }
1452
1453                 public override bool GetAttributableValue (Type valueType, out object value)
1454                 {
1455                         value = GetTypedValue ();
1456                         return true;
1457                 }
1458
1459                 public override string GetSignatureForError()
1460                 {
1461                         return TypeManager.CSharpName (Type);
1462                 }
1463
1464                 public override object GetValue ()
1465                 {
1466                         return Child.GetValue ();
1467                 }
1468
1469                 public override object GetTypedValue ()
1470                 {
1471                         // FIXME: runtime is not ready to work with just emited enums
1472                         if (!RootContext.StdLib) {
1473                                 return Child.GetValue ();
1474                         }
1475
1476                         return System.Enum.ToObject (type, Child.GetValue ());
1477                 }
1478
1479                 public override string AsString ()
1480                 {
1481                         string value = System.Enum.GetName (type, Child.GetValue ());
1482                         return value == null ? "0" : value;
1483                 }
1484
1485                 public override Constant Increment()
1486                 {
1487                         return new EnumConstant (Child.Increment (), type);
1488                 }
1489
1490                 public override bool IsDefaultValue {
1491                         get {
1492                                 return Child.IsDefaultValue;
1493                         }
1494                 }
1495
1496                 public override bool IsZeroInteger {
1497                         get { return Child.IsZeroInteger; }
1498                 }
1499
1500                 public override bool IsNegative {
1501                         get {
1502                                 return Child.IsNegative;
1503                         }
1504                 }
1505
1506                 public override Constant ConvertExplicitly(bool inCheckedContext, Type target_type)
1507                 {
1508                         if (Child.Type == target_type)
1509                                 return Child;
1510
1511                         return Child.ConvertExplicitly (inCheckedContext, target_type);
1512                 }
1513
1514                 public override Constant ConvertImplicitly (Type type)
1515                 {
1516                         if (Type == type) {
1517                                 // This is workaround of mono bug. It can be removed when the latest corlib spreads enough
1518                                 if (TypeManager.IsEnumType (type.UnderlyingSystemType))
1519                                         return this;
1520
1521                                 if (type.UnderlyingSystemType != Child.Type)
1522                                         Child = Child.ConvertImplicitly (type.UnderlyingSystemType);
1523                                 return this;
1524                         }
1525
1526                         if (!Convert.ImplicitStandardConversionExists (this, type)){
1527                                 return null;
1528                         }
1529
1530                         return Child.ConvertImplicitly(type);
1531                 }
1532
1533         }
1534
1535         /// <summary>
1536         ///   This kind of cast is used to encapsulate Value Types in objects.
1537         ///
1538         ///   The effect of it is to box the value type emitted by the previous
1539         ///   operation.
1540         /// </summary>
1541         public class BoxedCast : EmptyCast {
1542
1543                 public BoxedCast (Expression expr, Type target_type)
1544                         : base (expr, target_type)
1545                 {
1546                         eclass = ExprClass.Value;
1547                 }
1548
1549                 public override Expression DoResolve (EmitContext ec)
1550                 {
1551                         // This should never be invoked, we are born in fully
1552                         // initialized state.
1553
1554                         return this;
1555                 }
1556
1557                 public override void Emit (EmitContext ec)
1558                 {
1559                         base.Emit (ec);
1560
1561                         ec.ig.Emit (OpCodes.Box, child.Type);
1562                 }
1563         }
1564
1565         public class UnboxCast : EmptyCast {
1566                 public UnboxCast (Expression expr, Type return_type)
1567                         : base (expr, return_type)
1568                 {
1569                 }
1570
1571                 public override Expression DoResolve (EmitContext ec)
1572                 {
1573                         // This should never be invoked, we are born in fully
1574                         // initialized state.
1575
1576                         return this;
1577                 }
1578
1579                 public override Expression DoResolveLValue (EmitContext ec, Expression right_side)
1580                 {
1581                         if (right_side == EmptyExpression.LValueMemberAccess || right_side == EmptyExpression.LValueMemberOutAccess)
1582                                 Report.Error (445, loc, "Cannot modify the result of an unboxing conversion");
1583                         return base.DoResolveLValue (ec, right_side);
1584                 }
1585
1586                 public override void Emit (EmitContext ec)
1587                 {
1588                         Type t = type;
1589                         ILGenerator ig = ec.ig;
1590
1591                         base.Emit (ec);
1592 #if GMCS_SOURCE
1593                         if (t.IsGenericParameter || t.IsGenericType && t.IsValueType)
1594                                 ig.Emit (OpCodes.Unbox_Any, t);
1595                         else
1596 #endif
1597                         {
1598                                 ig.Emit (OpCodes.Unbox, t);
1599
1600                                 LoadFromPtr (ig, t);
1601                         }
1602                 }
1603         }
1604
1605         /// <summary>
1606         ///   This is used to perform explicit numeric conversions.
1607         ///
1608         ///   Explicit numeric conversions might trigger exceptions in a checked
1609         ///   context, so they should generate the conv.ovf opcodes instead of
1610         ///   conv opcodes.
1611         /// </summary>
1612         public class ConvCast : EmptyCast {
1613                 public enum Mode : byte {
1614                         I1_U1, I1_U2, I1_U4, I1_U8, I1_CH,
1615                         U1_I1, U1_CH,
1616                         I2_I1, I2_U1, I2_U2, I2_U4, I2_U8, I2_CH,
1617                         U2_I1, U2_U1, U2_I2, U2_CH,
1618                         I4_I1, I4_U1, I4_I2, I4_U2, I4_U4, I4_U8, I4_CH,
1619                         U4_I1, U4_U1, U4_I2, U4_U2, U4_I4, U4_CH,
1620                         I8_I1, I8_U1, I8_I2, I8_U2, I8_I4, I8_U4, I8_U8, I8_CH,
1621                         U8_I1, U8_U1, U8_I2, U8_U2, U8_I4, U8_U4, U8_I8, U8_CH,
1622                         CH_I1, CH_U1, CH_I2,
1623                         R4_I1, R4_U1, R4_I2, R4_U2, R4_I4, R4_U4, R4_I8, R4_U8, R4_CH,
1624                         R8_I1, R8_U1, R8_I2, R8_U2, R8_I4, R8_U4, R8_I8, R8_U8, R8_CH, R8_R4
1625                 }
1626
1627                 Mode mode;
1628
1629                 public ConvCast (Expression child, Type return_type, Mode m)
1630                         : base (child, return_type)
1631                 {
1632                         mode = m;
1633                 }
1634
1635                 public override Expression DoResolve (EmitContext ec)
1636                 {
1637                         // This should never be invoked, we are born in fully
1638                         // initialized state.
1639
1640                         return this;
1641                 }
1642
1643                 public override string ToString ()
1644                 {
1645                         return String.Format ("ConvCast ({0}, {1})", mode, child);
1646                 }
1647
1648                 public override void Emit (EmitContext ec)
1649                 {
1650                         ILGenerator ig = ec.ig;
1651
1652                         base.Emit (ec);
1653
1654                         if (ec.CheckState){
1655                                 switch (mode){
1656                                 case Mode.I1_U1: ig.Emit (OpCodes.Conv_Ovf_U1); break;
1657                                 case Mode.I1_U2: ig.Emit (OpCodes.Conv_Ovf_U2); break;
1658                                 case Mode.I1_U4: ig.Emit (OpCodes.Conv_Ovf_U4); break;
1659                                 case Mode.I1_U8: ig.Emit (OpCodes.Conv_Ovf_U8); break;
1660                                 case Mode.I1_CH: ig.Emit (OpCodes.Conv_Ovf_U2); break;
1661
1662                                 case Mode.U1_I1: ig.Emit (OpCodes.Conv_Ovf_I1_Un); break;
1663                                 case Mode.U1_CH: /* nothing */ break;
1664
1665                                 case Mode.I2_I1: ig.Emit (OpCodes.Conv_Ovf_I1); break;
1666                                 case Mode.I2_U1: ig.Emit (OpCodes.Conv_Ovf_U1); break;
1667                                 case Mode.I2_U2: ig.Emit (OpCodes.Conv_Ovf_U2); break;
1668                                 case Mode.I2_U4: ig.Emit (OpCodes.Conv_Ovf_U4); break;
1669                                 case Mode.I2_U8: ig.Emit (OpCodes.Conv_Ovf_U8); break;
1670                                 case Mode.I2_CH: ig.Emit (OpCodes.Conv_Ovf_U2); break;
1671
1672                                 case Mode.U2_I1: ig.Emit (OpCodes.Conv_Ovf_I1_Un); break;
1673                                 case Mode.U2_U1: ig.Emit (OpCodes.Conv_Ovf_U1_Un); break;
1674                                 case Mode.U2_I2: ig.Emit (OpCodes.Conv_Ovf_I2_Un); break;
1675                                 case Mode.U2_CH: /* nothing */ break;
1676
1677                                 case Mode.I4_I1: ig.Emit (OpCodes.Conv_Ovf_I1); break;
1678                                 case Mode.I4_U1: ig.Emit (OpCodes.Conv_Ovf_U1); break;
1679                                 case Mode.I4_I2: ig.Emit (OpCodes.Conv_Ovf_I2); break;
1680                                 case Mode.I4_U4: ig.Emit (OpCodes.Conv_Ovf_U4); break;
1681                                 case Mode.I4_U2: ig.Emit (OpCodes.Conv_Ovf_U2); break;
1682                                 case Mode.I4_U8: ig.Emit (OpCodes.Conv_Ovf_U8); break;
1683                                 case Mode.I4_CH: ig.Emit (OpCodes.Conv_Ovf_U2); break;
1684
1685                                 case Mode.U4_I1: ig.Emit (OpCodes.Conv_Ovf_I1_Un); break;
1686                                 case Mode.U4_U1: ig.Emit (OpCodes.Conv_Ovf_U1_Un); break;
1687                                 case Mode.U4_I2: ig.Emit (OpCodes.Conv_Ovf_I2_Un); break;
1688                                 case Mode.U4_U2: ig.Emit (OpCodes.Conv_Ovf_U2_Un); break;
1689                                 case Mode.U4_I4: ig.Emit (OpCodes.Conv_Ovf_I4_Un); break;
1690                                 case Mode.U4_CH: ig.Emit (OpCodes.Conv_Ovf_U2_Un); break;
1691
1692                                 case Mode.I8_I1: ig.Emit (OpCodes.Conv_Ovf_I1); break;
1693                                 case Mode.I8_U1: ig.Emit (OpCodes.Conv_Ovf_U1); break;
1694                                 case Mode.I8_I2: ig.Emit (OpCodes.Conv_Ovf_I2); break;
1695                                 case Mode.I8_U2: ig.Emit (OpCodes.Conv_Ovf_U2); break;
1696                                 case Mode.I8_I4: ig.Emit (OpCodes.Conv_Ovf_I4); break;
1697                                 case Mode.I8_U4: ig.Emit (OpCodes.Conv_Ovf_U4); break;
1698                                 case Mode.I8_U8: ig.Emit (OpCodes.Conv_Ovf_U8); break;
1699                                 case Mode.I8_CH: ig.Emit (OpCodes.Conv_Ovf_U2); break;
1700
1701                                 case Mode.U8_I1: ig.Emit (OpCodes.Conv_Ovf_I1_Un); break;
1702                                 case Mode.U8_U1: ig.Emit (OpCodes.Conv_Ovf_U1_Un); break;
1703                                 case Mode.U8_I2: ig.Emit (OpCodes.Conv_Ovf_I2_Un); break;
1704                                 case Mode.U8_U2: ig.Emit (OpCodes.Conv_Ovf_U2_Un); break;
1705                                 case Mode.U8_I4: ig.Emit (OpCodes.Conv_Ovf_I4_Un); break;
1706                                 case Mode.U8_U4: ig.Emit (OpCodes.Conv_Ovf_U4_Un); break;
1707                                 case Mode.U8_I8: ig.Emit (OpCodes.Conv_Ovf_I8_Un); break;
1708                                 case Mode.U8_CH: ig.Emit (OpCodes.Conv_Ovf_U2_Un); break;
1709
1710                                 case Mode.CH_I1: ig.Emit (OpCodes.Conv_Ovf_I1_Un); break;
1711                                 case Mode.CH_U1: ig.Emit (OpCodes.Conv_Ovf_U1_Un); break;
1712                                 case Mode.CH_I2: ig.Emit (OpCodes.Conv_Ovf_I2_Un); break;
1713
1714                                 case Mode.R4_I1: ig.Emit (OpCodes.Conv_Ovf_I1); break;
1715                                 case Mode.R4_U1: ig.Emit (OpCodes.Conv_Ovf_U1); break;
1716                                 case Mode.R4_I2: ig.Emit (OpCodes.Conv_Ovf_I2); break;
1717                                 case Mode.R4_U2: ig.Emit (OpCodes.Conv_Ovf_U2); break;
1718                                 case Mode.R4_I4: ig.Emit (OpCodes.Conv_Ovf_I4); break;
1719                                 case Mode.R4_U4: ig.Emit (OpCodes.Conv_Ovf_U4); break;
1720                                 case Mode.R4_I8: ig.Emit (OpCodes.Conv_Ovf_I8); break;
1721                                 case Mode.R4_U8: ig.Emit (OpCodes.Conv_Ovf_U8); break;
1722                                 case Mode.R4_CH: ig.Emit (OpCodes.Conv_Ovf_U2); break;
1723
1724                                 case Mode.R8_I1: ig.Emit (OpCodes.Conv_Ovf_I1); break;
1725                                 case Mode.R8_U1: ig.Emit (OpCodes.Conv_Ovf_U1); break;
1726                                 case Mode.R8_I2: ig.Emit (OpCodes.Conv_Ovf_I2); break;
1727                                 case Mode.R8_U2: ig.Emit (OpCodes.Conv_Ovf_U2); break;
1728                                 case Mode.R8_I4: ig.Emit (OpCodes.Conv_Ovf_I4); break;
1729                                 case Mode.R8_U4: ig.Emit (OpCodes.Conv_Ovf_U4); break;
1730                                 case Mode.R8_I8: ig.Emit (OpCodes.Conv_Ovf_I8); break;
1731                                 case Mode.R8_U8: ig.Emit (OpCodes.Conv_Ovf_U8); break;
1732                                 case Mode.R8_CH: ig.Emit (OpCodes.Conv_Ovf_U2); break;
1733                                 case Mode.R8_R4: ig.Emit (OpCodes.Conv_R4); break;
1734                                 }
1735                         } else {
1736                                 switch (mode){
1737                                 case Mode.I1_U1: ig.Emit (OpCodes.Conv_U1); break;
1738                                 case Mode.I1_U2: ig.Emit (OpCodes.Conv_U2); break;
1739                                 case Mode.I1_U4: ig.Emit (OpCodes.Conv_U4); break;
1740                                 case Mode.I1_U8: ig.Emit (OpCodes.Conv_I8); break;
1741                                 case Mode.I1_CH: ig.Emit (OpCodes.Conv_U2); break;
1742
1743                                 case Mode.U1_I1: ig.Emit (OpCodes.Conv_I1); break;
1744                                 case Mode.U1_CH: ig.Emit (OpCodes.Conv_U2); break;
1745
1746                                 case Mode.I2_I1: ig.Emit (OpCodes.Conv_I1); break;
1747                                 case Mode.I2_U1: ig.Emit (OpCodes.Conv_U1); break;
1748                                 case Mode.I2_U2: ig.Emit (OpCodes.Conv_U2); break;
1749                                 case Mode.I2_U4: ig.Emit (OpCodes.Conv_U4); break;
1750                                 case Mode.I2_U8: ig.Emit (OpCodes.Conv_I8); break;
1751                                 case Mode.I2_CH: ig.Emit (OpCodes.Conv_U2); break;
1752
1753                                 case Mode.U2_I1: ig.Emit (OpCodes.Conv_I1); break;
1754                                 case Mode.U2_U1: ig.Emit (OpCodes.Conv_U1); break;
1755                                 case Mode.U2_I2: ig.Emit (OpCodes.Conv_I2); break;
1756                                 case Mode.U2_CH: /* nothing */ break;
1757
1758                                 case Mode.I4_I1: ig.Emit (OpCodes.Conv_I1); break;
1759                                 case Mode.I4_U1: ig.Emit (OpCodes.Conv_U1); break;
1760                                 case Mode.I4_I2: ig.Emit (OpCodes.Conv_I2); break;
1761                                 case Mode.I4_U4: /* nothing */ break;
1762                                 case Mode.I4_U2: ig.Emit (OpCodes.Conv_U2); break;
1763                                 case Mode.I4_U8: ig.Emit (OpCodes.Conv_I8); break;
1764                                 case Mode.I4_CH: ig.Emit (OpCodes.Conv_U2); break;
1765
1766                                 case Mode.U4_I1: ig.Emit (OpCodes.Conv_I1); break;
1767                                 case Mode.U4_U1: ig.Emit (OpCodes.Conv_U1); break;
1768                                 case Mode.U4_I2: ig.Emit (OpCodes.Conv_I2); break;
1769                                 case Mode.U4_U2: ig.Emit (OpCodes.Conv_U2); break;
1770                                 case Mode.U4_I4: /* nothing */ break;
1771                                 case Mode.U4_CH: ig.Emit (OpCodes.Conv_U2); break;
1772
1773                                 case Mode.I8_I1: ig.Emit (OpCodes.Conv_I1); break;
1774                                 case Mode.I8_U1: ig.Emit (OpCodes.Conv_U1); break;
1775                                 case Mode.I8_I2: ig.Emit (OpCodes.Conv_I2); break;
1776                                 case Mode.I8_U2: ig.Emit (OpCodes.Conv_U2); break;
1777                                 case Mode.I8_I4: ig.Emit (OpCodes.Conv_I4); break;
1778                                 case Mode.I8_U4: ig.Emit (OpCodes.Conv_U4); break;
1779                                 case Mode.I8_U8: /* nothing */ break;
1780                                 case Mode.I8_CH: ig.Emit (OpCodes.Conv_U2); break;
1781
1782                                 case Mode.U8_I1: ig.Emit (OpCodes.Conv_I1); break;
1783                                 case Mode.U8_U1: ig.Emit (OpCodes.Conv_U1); break;
1784                                 case Mode.U8_I2: ig.Emit (OpCodes.Conv_I2); break;
1785                                 case Mode.U8_U2: ig.Emit (OpCodes.Conv_U2); break;
1786                                 case Mode.U8_I4: ig.Emit (OpCodes.Conv_I4); break;
1787                                 case Mode.U8_U4: ig.Emit (OpCodes.Conv_U4); break;
1788                                 case Mode.U8_I8: /* nothing */ break;
1789                                 case Mode.U8_CH: ig.Emit (OpCodes.Conv_U2); break;
1790
1791                                 case Mode.CH_I1: ig.Emit (OpCodes.Conv_I1); break;
1792                                 case Mode.CH_U1: ig.Emit (OpCodes.Conv_U1); break;
1793                                 case Mode.CH_I2: ig.Emit (OpCodes.Conv_I2); break;
1794
1795                                 case Mode.R4_I1: ig.Emit (OpCodes.Conv_I1); break;
1796                                 case Mode.R4_U1: ig.Emit (OpCodes.Conv_U1); break;
1797                                 case Mode.R4_I2: ig.Emit (OpCodes.Conv_I2); break;
1798                                 case Mode.R4_U2: ig.Emit (OpCodes.Conv_U2); break;
1799                                 case Mode.R4_I4: ig.Emit (OpCodes.Conv_I4); break;
1800                                 case Mode.R4_U4: ig.Emit (OpCodes.Conv_U4); break;
1801                                 case Mode.R4_I8: ig.Emit (OpCodes.Conv_I8); break;
1802                                 case Mode.R4_U8: ig.Emit (OpCodes.Conv_U8); break;
1803                                 case Mode.R4_CH: ig.Emit (OpCodes.Conv_U2); break;
1804
1805                                 case Mode.R8_I1: ig.Emit (OpCodes.Conv_I1); break;
1806                                 case Mode.R8_U1: ig.Emit (OpCodes.Conv_U1); break;
1807                                 case Mode.R8_I2: ig.Emit (OpCodes.Conv_I2); break;
1808                                 case Mode.R8_U2: ig.Emit (OpCodes.Conv_U2); break;
1809                                 case Mode.R8_I4: ig.Emit (OpCodes.Conv_I4); break;
1810                                 case Mode.R8_U4: ig.Emit (OpCodes.Conv_U4); break;
1811                                 case Mode.R8_I8: ig.Emit (OpCodes.Conv_I8); break;
1812                                 case Mode.R8_U8: ig.Emit (OpCodes.Conv_U8); break;
1813                                 case Mode.R8_CH: ig.Emit (OpCodes.Conv_U2); break;
1814                                 case Mode.R8_R4: ig.Emit (OpCodes.Conv_R4); break;
1815                                 }
1816                         }
1817                 }
1818         }
1819
1820         public class OpcodeCast : EmptyCast {
1821                 OpCode op, op2;
1822                 bool second_valid;
1823
1824                 public OpcodeCast (Expression child, Type return_type, OpCode op)
1825                         : base (child, return_type)
1826
1827                 {
1828                         this.op = op;
1829                         second_valid = false;
1830                 }
1831
1832                 public OpcodeCast (Expression child, Type return_type, OpCode op, OpCode op2)
1833                         : base (child, return_type)
1834
1835                 {
1836                         this.op = op;
1837                         this.op2 = op2;
1838                         second_valid = true;
1839                 }
1840
1841                 public override Expression DoResolve (EmitContext ec)
1842                 {
1843                         // This should never be invoked, we are born in fully
1844                         // initialized state.
1845
1846                         return this;
1847                 }
1848
1849                 public override void Emit (EmitContext ec)
1850                 {
1851                         base.Emit (ec);
1852                         ec.ig.Emit (op);
1853
1854                         if (second_valid)
1855                                 ec.ig.Emit (op2);
1856                 }
1857         }
1858
1859         /// <summary>
1860         ///   This kind of cast is used to encapsulate a child and cast it
1861         ///   to the class requested
1862         /// </summary>
1863         public class ClassCast : EmptyCast {
1864                 public ClassCast (Expression child, Type return_type)
1865                         : base (child, return_type)
1866
1867                 {
1868                 }
1869
1870                 public override Expression DoResolve (EmitContext ec)
1871                 {
1872                         // This should never be invoked, we are born in fully
1873                         // initialized state.
1874
1875                         return this;
1876                 }
1877
1878                 public override void Emit (EmitContext ec)
1879                 {
1880                         base.Emit (ec);
1881
1882                         if (TypeManager.IsGenericParameter (child.Type))
1883                                 ec.ig.Emit (OpCodes.Box, child.Type);
1884
1885 #if GMCS_SOURCE
1886                         if (type.IsGenericParameter)
1887                                 ec.ig.Emit (OpCodes.Unbox_Any, type);
1888                         else
1889 #endif
1890                                 ec.ig.Emit (OpCodes.Castclass, type);
1891                 }
1892         }
1893
1894         /// <summary>
1895         ///   SimpleName expressions are formed of a single word and only happen at the beginning
1896         ///   of a dotted-name.
1897         /// </summary>
1898         public class SimpleName : Expression {
1899                 public string Name;
1900                 public readonly TypeArguments Arguments;
1901                 bool in_transit;
1902
1903                 public SimpleName (string name, Location l)
1904                 {
1905                         Name = name;
1906                         loc = l;
1907                 }
1908
1909                 public SimpleName (string name, TypeArguments args, Location l)
1910                 {
1911                         Name = name;
1912                         Arguments = args;
1913                         loc = l;
1914                 }
1915
1916                 public SimpleName (string name, TypeParameter[] type_params, Location l)
1917                 {
1918                         Name = name;
1919                         loc = l;
1920
1921                         Arguments = new TypeArguments (l);
1922                         foreach (TypeParameter type_param in type_params)
1923                                 Arguments.Add (new TypeParameterExpr (type_param, l));
1924                 }
1925
1926                 public static string RemoveGenericArity (string name)
1927                 {
1928                         int start = 0;
1929                         StringBuilder sb = null;
1930                         do {
1931                                 int pos = name.IndexOf ('`', start);
1932                                 if (pos < 0) {
1933                                         if (start == 0)
1934                                                 return name;
1935
1936                                         sb.Append (name.Substring (start));
1937                                         break;
1938                                 }
1939
1940                                 if (sb == null)
1941                                         sb = new StringBuilder ();
1942                                 sb.Append (name.Substring (start, pos-start));
1943
1944                                 pos++;
1945                                 while ((pos < name.Length) && Char.IsNumber (name [pos]))
1946                                         pos++;
1947
1948                                 start = pos;
1949                         } while (start < name.Length);
1950
1951                         return sb.ToString ();
1952                 }
1953
1954                 public SimpleName GetMethodGroup ()
1955                 {
1956                         return new SimpleName (RemoveGenericArity (Name), Arguments, loc);
1957                 }
1958
1959                 public static void Error_ObjectRefRequired (EmitContext ec, Location l, string name)
1960                 {
1961                         if (ec.IsFieldInitializer)
1962                                 Report.Error (236, l,
1963                                         "A field initializer cannot reference the nonstatic field, method, or property `{0}'",
1964                                         name);
1965                         else
1966                                 Report.Error (
1967                                         120, l, "`{0}': An object reference is required for the nonstatic field, method or property",
1968                                         name);
1969                 }
1970
1971                 public bool IdenticalNameAndTypeName (EmitContext ec, Expression resolved_to, Location loc)
1972                 {
1973                         return resolved_to != null && resolved_to.Type != null &&
1974                                 resolved_to.Type.Name == Name &&
1975                                 (ec.DeclContainer.LookupType (Name, loc, /* ignore_cs0104 = */ true) != null);
1976                 }
1977
1978                 public override Expression DoResolve (EmitContext ec)
1979                 {
1980                         return SimpleNameResolve (ec, null, false);
1981                 }
1982
1983                 public override Expression DoResolveLValue (EmitContext ec, Expression right_side)
1984                 {
1985                         return SimpleNameResolve (ec, right_side, false);
1986                 }
1987
1988
1989                 public Expression DoResolve (EmitContext ec, bool intermediate)
1990                 {
1991                         return SimpleNameResolve (ec, null, intermediate);
1992                 }
1993
1994                 private bool IsNestedChild (Type t, Type parent)
1995                 {
1996                         if (parent == null)
1997                                 return false;
1998
1999                         while (parent != null) {
2000                                 parent = TypeManager.DropGenericTypeArguments (parent);
2001                                 if (TypeManager.IsNestedChildOf (t, parent))
2002                                         return true;
2003
2004                                 parent = parent.BaseType;
2005                         }
2006
2007                         return false;
2008                 }
2009
2010                 FullNamedExpression ResolveNested (IResolveContext ec, Type t)
2011                 {
2012                         if (!TypeManager.IsGenericTypeDefinition (t))
2013                                 return null;
2014
2015                         DeclSpace ds = ec.DeclContainer;
2016                         while (ds != null) {
2017                                 if (IsNestedChild (t, ds.TypeBuilder))
2018                                         break;
2019
2020                                 ds = ds.Parent;
2021                         }
2022
2023                         if (ds == null)
2024                                 return null;
2025
2026                         Type[] gen_params = TypeManager.GetTypeArguments (t);
2027
2028                         int arg_count = Arguments != null ? Arguments.Count : 0;
2029
2030                         for (; (ds != null) && ds.IsGeneric; ds = ds.Parent) {
2031                                 if (arg_count + ds.CountTypeParameters == gen_params.Length) {
2032                                         TypeArguments new_args = new TypeArguments (loc);
2033                                         foreach (TypeParameter param in ds.TypeParameters)
2034                                                 new_args.Add (new TypeParameterExpr (param, loc));
2035
2036                                         if (Arguments != null)
2037                                                 new_args.Add (Arguments);
2038
2039                                         return new ConstructedType (t, new_args, loc);
2040                                 }
2041                         }
2042
2043                         return null;
2044                 }
2045
2046                 public override FullNamedExpression ResolveAsTypeStep (IResolveContext ec, bool silent)
2047                 {
2048                         FullNamedExpression fne = ec.GenericDeclContainer.LookupGeneric (Name, loc);
2049                         if (fne != null)
2050                                 return fne.ResolveAsTypeStep (ec, silent);
2051
2052                         int errors = Report.Errors;
2053                         fne = ec.DeclContainer.LookupType (Name, loc, /*ignore_cs0104=*/ false);
2054
2055                         if (fne != null) {
2056                                 if (fne.Type == null)
2057                                         return fne;
2058
2059                                 FullNamedExpression nested = ResolveNested (ec, fne.Type);
2060                                 if (nested != null)
2061                                         return nested.ResolveAsTypeStep (ec, false);
2062
2063                                 if (Arguments != null) {
2064                                         ConstructedType ct = new ConstructedType (fne, Arguments, loc);
2065                                         return ct.ResolveAsTypeStep (ec, false);
2066                                 }
2067
2068                                 return fne;
2069                         }
2070
2071                         if (silent || errors != Report.Errors)
2072                                 return null;
2073
2074                         MemberCore mc = ec.DeclContainer.GetDefinition (Name);
2075                         if (mc != null) {
2076                                 Error_UnexpectedKind (ec.DeclContainer, "type", GetMemberType (mc), loc);
2077                                 return null;
2078                         }
2079
2080                         string ns = ec.DeclContainer.NamespaceEntry.NS.Name;
2081                         string fullname = (ns.Length > 0) ? ns + "." + Name : Name;
2082                         foreach (Assembly a in RootNamespace.Global.Assemblies) {
2083                                 Type type = a.GetType (fullname);
2084                                 if (type != null) {
2085                                         Report.SymbolRelatedToPreviousError (type);
2086                                         Expression.ErrorIsInaccesible (loc, fullname);
2087                                         return null;
2088                                 }
2089                         }
2090
2091                         Type t = ec.DeclContainer.NamespaceEntry.NS.LookForAnyGenericType (Name);
2092                         if (t != null) {
2093                                 Namespace.Error_InvalidNumberOfTypeArguments (t, loc);
2094                                 return null;
2095                         }
2096
2097                         NamespaceEntry.Error_NamespaceNotFound (loc, Name);
2098                         return null;
2099                 }
2100
2101                 // TODO: I am still not convinced about this. If someone else will need it
2102                 // implement this as virtual property in MemberCore hierarchy
2103                 string GetMemberType (MemberCore mc)
2104                 {
2105                         if (mc is PropertyBase)
2106                                 return "property";
2107                         if (mc is Indexer)
2108                                 return "indexer";
2109                         if (mc is FieldBase)
2110                                 return "field";
2111                         if (mc is MethodCore)
2112                                 return "method";
2113                         if (mc is EnumMember)
2114                                 return "enum";
2115
2116                         return "type";
2117                 }
2118
2119                 Expression SimpleNameResolve (EmitContext ec, Expression right_side, bool intermediate)
2120                 {
2121                         if (in_transit)
2122                                 return null;
2123                         in_transit = true;
2124
2125                         Expression e = DoSimpleNameResolve (ec, right_side, intermediate);
2126                         if (e == null)
2127                                 return null;
2128
2129                         if (ec.CurrentBlock == null || ec.CurrentBlock.CheckInvariantMeaningInBlock (Name, e, Location))
2130                                 return e;
2131
2132                         return null;
2133                 }
2134
2135                 /// <remarks>
2136                 ///   7.5.2: Simple Names.
2137                 ///
2138                 ///   Local Variables and Parameters are handled at
2139                 ///   parse time, so they never occur as SimpleNames.
2140                 ///
2141                 ///   The `intermediate' flag is used by MemberAccess only
2142                 ///   and it is used to inform us that it is ok for us to
2143                 ///   avoid the static check, because MemberAccess might end
2144                 ///   up resolving the Name as a Type name and the access as
2145                 ///   a static type access.
2146                 ///
2147                 ///   ie: Type Type; .... { Type.GetType (""); }
2148                 ///
2149                 ///   Type is both an instance variable and a Type;  Type.GetType
2150                 ///   is the static method not an instance method of type.
2151                 /// </remarks>
2152                 Expression DoSimpleNameResolve (EmitContext ec, Expression right_side, bool intermediate)
2153                 {
2154                         Expression e = null;
2155
2156                         //
2157                         // Stage 1: Performed by the parser (binding to locals or parameters).
2158                         //
2159                         Block current_block = ec.CurrentBlock;
2160                         if (current_block != null){
2161                                 LocalInfo vi = current_block.GetLocalInfo (Name);
2162                                 if (vi != null){
2163                                         if (Arguments != null) {
2164                                                 Report.Error (307, loc,
2165                                                               "The variable `{0}' cannot be used with type arguments",
2166                                                               Name);
2167                                                 return null;
2168                                         }
2169
2170                                         LocalVariableReference var = new LocalVariableReference (ec.CurrentBlock, Name, loc);
2171                                         if (right_side != null) {
2172                                                 return var.ResolveLValue (ec, right_side, loc);
2173                                         } else {
2174                                                 ResolveFlags rf = ResolveFlags.VariableOrValue;
2175                                                 if (intermediate)
2176                                                         rf |= ResolveFlags.DisableFlowAnalysis;
2177                                                 return var.Resolve (ec, rf);
2178                                         }
2179                                 }
2180
2181                                 ParameterReference pref = current_block.Toplevel.GetParameterReference (Name, loc);
2182                                 if (pref != null) {
2183                                         if (Arguments != null) {
2184                                                 Report.Error (307, loc,
2185                                                               "The variable `{0}' cannot be used with type arguments",
2186                                                               Name);
2187                                                 return null;
2188                                         }
2189
2190                                         if (right_side != null)
2191                                                 return pref.ResolveLValue (ec, right_side, loc);
2192                                         else
2193                                                 return pref.Resolve (ec);
2194                                 }
2195                         }
2196
2197                         //
2198                         // Stage 2: Lookup members
2199                         //
2200
2201                         DeclSpace lookup_ds = ec.DeclContainer;
2202                         Type almost_matched_type = null;
2203                         ArrayList almost_matched = null;
2204                         do {
2205                                 if (lookup_ds.TypeBuilder == null)
2206                                         break;
2207
2208                                 e = MemberLookup (ec.ContainerType, lookup_ds.TypeBuilder, Name, loc);
2209                                 if (e != null)
2210                                         break;
2211
2212                                 if (almost_matched == null && almostMatchedMembers.Count > 0) {
2213                                         almost_matched_type = lookup_ds.TypeBuilder;
2214                                         almost_matched = (ArrayList) almostMatchedMembers.Clone ();
2215                                 }
2216
2217                                 lookup_ds =lookup_ds.Parent;
2218                         } while (lookup_ds != null);
2219
2220                         if (e == null && ec.ContainerType != null)
2221                                 e = MemberLookup (ec.ContainerType, ec.ContainerType, Name, loc);
2222
2223                         if (e == null) {
2224                                 if (almost_matched == null && almostMatchedMembers.Count > 0) {
2225                                         almost_matched_type = ec.ContainerType;
2226                                         almost_matched = (ArrayList) almostMatchedMembers.Clone ();
2227                                 }
2228                                 e = ResolveAsTypeStep (ec, true);
2229                         }
2230
2231                         if (e == null) {
2232                                 if (almost_matched != null)
2233                                         almostMatchedMembers = almost_matched;
2234                                 if (almost_matched_type == null)
2235                                         almost_matched_type = ec.ContainerType;
2236                                 MemberLookupFailed (ec.ContainerType, null, almost_matched_type, ((SimpleName) this).Name, ec.DeclContainer.Name, true, loc);
2237                                 return null;
2238                         }
2239
2240                         if (e is TypeExpr) {
2241                                 if (Arguments == null)
2242                                         return e;
2243
2244                                 ConstructedType ct = new ConstructedType (
2245                                         (FullNamedExpression) e, Arguments, loc);
2246                                 return ct.ResolveAsTypeStep (ec, false);
2247                         }
2248
2249                         if (e is MemberExpr) {
2250                                 MemberExpr me = (MemberExpr) e;
2251
2252                                 Expression left;
2253                                 if (me.IsInstance) {
2254                                         if (ec.IsStatic || ec.IsFieldInitializer) {
2255                                                 //
2256                                                 // Note that an MemberExpr can be both IsInstance and IsStatic.
2257                                                 // An unresolved MethodGroupExpr can contain both kinds of methods
2258                                                 // and each predicate is true if the MethodGroupExpr contains
2259                                                 // at least one of that kind of method.
2260                                                 //
2261
2262                                                 if (!me.IsStatic &&
2263                                                     (!intermediate || !IdenticalNameAndTypeName (ec, me, loc))) {
2264                                                         Error_ObjectRefRequired (ec, loc, me.GetSignatureForError ());
2265                                                         return EmptyExpression.Null;
2266                                                 }
2267
2268                                                 //
2269                                                 // Pass the buck to MemberAccess and Invocation.
2270                                                 //
2271                                                 left = EmptyExpression.Null;
2272                                         } else {
2273                                                 left = ec.GetThis (loc);
2274                                         }
2275                                 } else {
2276                                         left = new TypeExpression (ec.ContainerType, loc);
2277                                 }
2278
2279                                 e = me.ResolveMemberAccess (ec, left, loc, null);
2280                                 if (e == null)
2281                                         return null;
2282
2283                                 me = e as MemberExpr;
2284                                 if (me == null)
2285                                         return e;
2286
2287                                 if (Arguments != null) {
2288                                         MethodGroupExpr mg = me as MethodGroupExpr;
2289                                         if (mg == null)
2290                                                 return null;
2291
2292                                         return mg.ResolveGeneric (ec, Arguments);
2293                                 }
2294
2295                                 if (!me.IsStatic && (me.InstanceExpression != null) &&
2296                                     TypeManager.IsNestedFamilyAccessible (me.InstanceExpression.Type, me.DeclaringType) &&
2297                                     me.InstanceExpression.Type != me.DeclaringType &&
2298                                     !TypeManager.IsFamilyAccessible (me.InstanceExpression.Type, me.DeclaringType) &&
2299                                     (!intermediate || !IdenticalNameAndTypeName (ec, e, loc))) {
2300                                         Report.Error (38, loc, "Cannot access a nonstatic member of outer type `{0}' via nested type `{1}'",
2301                                                 TypeManager.CSharpName (me.DeclaringType), TypeManager.CSharpName (me.InstanceExpression.Type));
2302                                         return null;
2303                                 }
2304
2305                                 return (right_side != null)
2306                                         ? me.DoResolveLValue (ec, right_side)
2307                                         : me.DoResolve (ec);
2308                         }
2309
2310                         return e;
2311                 }
2312
2313                 public override void Emit (EmitContext ec)
2314                 {
2315                         //
2316                         // If this is ever reached, then we failed to
2317                         // find the name as a namespace
2318                         //
2319
2320                         Error (103, "The name `" + Name +
2321                                "' does not exist in the class `" +
2322                                ec.DeclContainer.Name + "'");
2323                 }
2324
2325                 public override string ToString ()
2326                 {
2327                         return Name;
2328                 }
2329
2330                 public override string GetSignatureForError ()
2331                 {
2332                         return Name;
2333                 }
2334         }
2335
2336         /// <summary>
2337         ///   Represents a namespace or a type.  The name of the class was inspired by
2338         ///   section 10.8.1 (Fully Qualified Names).
2339         /// </summary>
2340         public abstract class FullNamedExpression : Expression {
2341                 public override FullNamedExpression ResolveAsTypeStep (IResolveContext ec, bool silent)
2342                 {
2343                         return this;
2344                 }
2345
2346                 public abstract string FullName {
2347                         get;
2348                 }
2349         }
2350
2351         /// <summary>
2352         ///   Expression that evaluates to a type
2353         /// </summary>
2354         public abstract class TypeExpr : FullNamedExpression {
2355                 override public FullNamedExpression ResolveAsTypeStep (IResolveContext ec, bool silent)
2356                 {
2357                         TypeExpr t = DoResolveAsTypeStep (ec);
2358                         if (t == null)
2359                                 return null;
2360
2361                         eclass = ExprClass.Type;
2362                         return t;
2363                 }
2364
2365                 override public Expression DoResolve (EmitContext ec)
2366                 {
2367                         return ResolveAsTypeTerminal (ec, false);
2368                 }
2369
2370                 override public void Emit (EmitContext ec)
2371                 {
2372                         throw new Exception ("Should never be called");
2373                 }
2374
2375                 public virtual bool CheckAccessLevel (DeclSpace ds)
2376                 {
2377                         return ds.CheckAccessLevel (Type);
2378                 }
2379
2380                 public virtual bool AsAccessible (DeclSpace ds, int flags)
2381                 {
2382                         return ds.AsAccessible (Type, flags);
2383                 }
2384
2385                 public virtual bool IsClass {
2386                         get { return Type.IsClass; }
2387                 }
2388
2389                 public virtual bool IsValueType {
2390                         get { return Type.IsValueType; }
2391                 }
2392
2393                 public virtual bool IsInterface {
2394                         get { return Type.IsInterface; }
2395                 }
2396
2397                 public virtual bool IsSealed {
2398                         get { return Type.IsSealed; }
2399                 }
2400
2401                 public virtual bool CanInheritFrom ()
2402                 {
2403                         if (Type == TypeManager.enum_type ||
2404                             (Type == TypeManager.value_type && RootContext.StdLib) ||
2405                             Type == TypeManager.multicast_delegate_type ||
2406                             Type == TypeManager.delegate_type ||
2407                             Type == TypeManager.array_type)
2408                                 return false;
2409
2410                         return true;
2411                 }
2412
2413                 protected abstract TypeExpr DoResolveAsTypeStep (IResolveContext ec);
2414
2415                 public abstract string Name {
2416                         get;
2417                 }
2418
2419                 public override bool Equals (object obj)
2420                 {
2421                         TypeExpr tobj = obj as TypeExpr;
2422                         if (tobj == null)
2423                                 return false;
2424
2425                         return Type == tobj.Type;
2426                 }
2427
2428                 public override int GetHashCode ()
2429                 {
2430                         return Type.GetHashCode ();
2431                 }
2432
2433                 public override string ToString ()
2434                 {
2435                         return Name;
2436                 }
2437         }
2438
2439         /// <summary>
2440         ///   Fully resolved Expression that already evaluated to a type
2441         /// </summary>
2442         public class TypeExpression : TypeExpr {
2443                 public TypeExpression (Type t, Location l)
2444                 {
2445                         Type = t;
2446                         eclass = ExprClass.Type;
2447                         loc = l;
2448                 }
2449
2450                 protected override TypeExpr DoResolveAsTypeStep (IResolveContext ec)
2451                 {
2452                         return this;
2453                 }
2454
2455                 public override TypeExpr ResolveAsTypeTerminal (IResolveContext ec, bool silent)
2456                 {
2457                         return this;
2458                 }
2459
2460                 public override string Name {
2461                         get { return Type.ToString (); }
2462                 }
2463
2464                 public override string FullName {
2465                         get { return Type.FullName; }
2466                 }
2467         }
2468
2469         /// <summary>
2470         ///   Used to create types from a fully qualified name.  These are just used
2471         ///   by the parser to setup the core types.  A TypeLookupExpression is always
2472         ///   classified as a type.
2473         /// </summary>
2474         public sealed class TypeLookupExpression : TypeExpr {
2475                 readonly string name;
2476
2477                 public TypeLookupExpression (string name)
2478                 {
2479                         this.name = name;
2480                         eclass = ExprClass.Type;
2481                 }
2482
2483                 public override TypeExpr ResolveAsTypeTerminal (IResolveContext ec, bool silent)
2484                 {
2485                         // It's null for corlib compilation only
2486                         if (type == null)
2487                                 return DoResolveAsTypeStep (ec);
2488
2489                         return this;
2490                 }
2491
2492                 static readonly char [] dot_array = { '.' };
2493                 protected override TypeExpr DoResolveAsTypeStep (IResolveContext ec)
2494                 {
2495                         // If name is of the form `N.I', first lookup `N', then search a member `I' in it.
2496                         string rest = null;
2497                         string lookup_name = name;
2498                         int pos = name.IndexOf ('.');
2499                         if (pos >= 0) {
2500                                 rest = name.Substring (pos + 1);
2501                                 lookup_name = name.Substring (0, pos);
2502                         }
2503
2504                         FullNamedExpression resolved = RootNamespace.Global.Lookup (ec.DeclContainer, lookup_name, Location.Null);
2505
2506                         if (resolved != null && rest != null) {
2507                                 // Now handle the rest of the the name.
2508                                 string [] elements = rest.Split (dot_array);
2509                                 string element;
2510                                 int count = elements.Length;
2511                                 int i = 0;
2512                                 while (i < count && resolved != null && resolved is Namespace) {
2513                                         Namespace ns = resolved as Namespace;
2514                                         element = elements [i++];
2515                                         lookup_name += "." + element;
2516                                         resolved = ns.Lookup (ec.DeclContainer, element, Location.Null);
2517                                 }
2518
2519                                 if (resolved != null && resolved is TypeExpr) {
2520                                         Type t = ((TypeExpr) resolved).Type;
2521                                         while (t != null) {
2522                                                 if (!ec.DeclContainer.CheckAccessLevel (t)) {
2523                                                         resolved = null;
2524                                                         lookup_name = t.FullName;
2525                                                         break;
2526                                                 }
2527                                                 if (i == count) {
2528                                                         type = t;
2529                                                         return this;
2530                                                 }
2531                                                 t = TypeManager.GetNestedType (t, elements [i++]);
2532                                         }
2533                                 }
2534                         }
2535
2536                         if (resolved == null) {
2537                                 NamespaceEntry.Error_NamespaceNotFound (loc, lookup_name);
2538                                 return null;
2539                         }
2540
2541                         if (!(resolved is TypeExpr)) {
2542                                 resolved.Error_UnexpectedKind (ec.DeclContainer, "type", loc);
2543                                 return null;
2544                         }
2545
2546                         type = resolved.Type;
2547                         return this;
2548                 }
2549
2550                 public override string Name {
2551                         get { return name; }
2552                 }
2553
2554                 public override string FullName {
2555                         get { return name; }
2556                 }
2557         }
2558
2559         /// <summary>
2560         ///   Represents an "unbound generic type", ie. typeof (Foo<>).
2561         ///   See 14.5.11.
2562         /// </summary>
2563         public class UnboundTypeExpression : TypeExpr
2564         {
2565                 MemberName name;
2566
2567                 public UnboundTypeExpression (MemberName name, Location l)
2568                 {
2569                         this.name = name;
2570                         loc = l;
2571                 }
2572
2573                 protected override TypeExpr DoResolveAsTypeStep (IResolveContext ec)
2574                 {
2575                         Expression expr;
2576                         if (name.Left != null) {
2577                                 Expression lexpr = name.Left.GetTypeExpression ();
2578                                 expr = new MemberAccess (lexpr, name.Basename);
2579                         } else {
2580                                 expr = new SimpleName (name.Basename, loc);
2581                         }
2582
2583                         FullNamedExpression fne = expr.ResolveAsTypeStep (ec, false);
2584                         if (fne == null)
2585                                 return null;
2586
2587                         type = fne.Type;
2588                         return new TypeExpression (type, loc);
2589                 }
2590
2591                 public override string Name {
2592                         get { return name.FullName; }
2593                 }
2594
2595                 public override string FullName {
2596                         get { return name.FullName; }
2597                 }
2598         }
2599
2600         public class TypeAliasExpression : TypeExpr {
2601                 FullNamedExpression alias;
2602                 TypeExpr texpr;
2603                 TypeArguments args;
2604                 string name;
2605
2606                 public TypeAliasExpression (FullNamedExpression alias, TypeArguments args, Location l)
2607                 {
2608                         this.alias = alias;
2609                         this.args = args;
2610                         loc = l;
2611
2612                         eclass = ExprClass.Type;
2613                         if (args != null)
2614                                 name = alias.FullName + "<" + args.ToString () + ">";
2615                         else
2616                                 name = alias.FullName;
2617                 }
2618
2619                 public override string Name {
2620                         get { return alias.FullName; }
2621                 }
2622
2623                 public override string FullName {
2624                         get { return name; }
2625                 }
2626
2627                 protected override TypeExpr DoResolveAsTypeStep (IResolveContext ec)
2628                 {
2629                         texpr = alias.ResolveAsTypeTerminal (ec, false);
2630                         if (texpr == null)
2631                                 return null;
2632
2633                         Type type = texpr.Type;
2634                         int num_args = TypeManager.GetNumberOfTypeArguments (type);
2635
2636                         if (args != null) {
2637                                 if (num_args == 0) {
2638                                         Report.Error (308, loc,
2639                                                       "The non-generic type `{0}' cannot " +
2640                                                       "be used with type arguments.",
2641                                                       TypeManager.CSharpName (type));
2642                                         return null;
2643                                 }
2644
2645                                 ConstructedType ctype = new ConstructedType (type, args, loc);
2646                                 return ctype.ResolveAsTypeTerminal (ec, false);
2647                         } else if (num_args > 0) {
2648                                 Report.Error (305, loc,
2649                                               "Using the generic type `{0}' " +
2650                                               "requires {1} type arguments",
2651                                               TypeManager.CSharpName (type), num_args.ToString ());
2652                                 return null;
2653                         }
2654
2655                         return texpr;
2656                 }
2657
2658                 public override bool CheckAccessLevel (DeclSpace ds)
2659                 {
2660                         return texpr.CheckAccessLevel (ds);
2661                 }
2662
2663                 public override bool AsAccessible (DeclSpace ds, int flags)
2664                 {
2665                         return texpr.AsAccessible (ds, flags);
2666                 }
2667
2668                 public override bool IsClass {
2669                         get { return texpr.IsClass; }
2670                 }
2671
2672                 public override bool IsValueType {
2673                         get { return texpr.IsValueType; }
2674                 }
2675
2676                 public override bool IsInterface {
2677                         get { return texpr.IsInterface; }
2678                 }
2679
2680                 public override bool IsSealed {
2681                         get { return texpr.IsSealed; }
2682                 }
2683         }
2684
2685         /// <summary>
2686         ///   This class denotes an expression which evaluates to a member
2687         ///   of a struct or a class.
2688         /// </summary>
2689         public abstract class MemberExpr : Expression
2690         {
2691                 /// <summary>
2692                 ///   The name of this member.
2693                 /// </summary>
2694                 public abstract string Name {
2695                         get;
2696                 }
2697
2698                 /// <summary>
2699                 ///   Whether this is an instance member.
2700                 /// </summary>
2701                 public abstract bool IsInstance {
2702                         get;
2703                 }
2704
2705                 /// <summary>
2706                 ///   Whether this is a static member.
2707                 /// </summary>
2708                 public abstract bool IsStatic {
2709                         get;
2710                 }
2711
2712                 /// <summary>
2713                 ///   The type which declares this member.
2714                 /// </summary>
2715                 public abstract Type DeclaringType {
2716                         get;
2717                 }
2718
2719                 /// <summary>
2720                 ///   The instance expression associated with this member, if it's a
2721                 ///   non-static member.
2722                 /// </summary>
2723                 public Expression InstanceExpression;
2724
2725                 public static void error176 (Location loc, string name)
2726                 {
2727                         Report.Error (176, loc, "Static member `{0}' cannot be accessed " +
2728                                       "with an instance reference, qualify it with a type name instead", name);
2729                 }
2730
2731                 // TODO: possible optimalization
2732                 // Cache resolved constant result in FieldBuilder <-> expression map
2733                 public virtual Expression ResolveMemberAccess (EmitContext ec, Expression left, Location loc,
2734                                                                SimpleName original)
2735                 {
2736                         //
2737                         // Precondition:
2738                         //   original == null || original.Resolve (...) ==> left
2739                         //
2740
2741                         if (left is TypeExpr) {
2742                                 if (!IsStatic) {
2743                                         SimpleName.Error_ObjectRefRequired (ec, loc, GetSignatureForError ());
2744                                         return null;
2745                                 }
2746
2747                                 return this;
2748                         }
2749
2750                         if (!IsInstance) {
2751                                 if (original != null && original.IdenticalNameAndTypeName (ec, left, loc))
2752                                         return this;
2753
2754                                 error176 (loc, GetSignatureForError ());
2755                                 return null;
2756                         }
2757
2758                         InstanceExpression = left;
2759
2760                         return this;
2761                 }
2762
2763                 protected void EmitInstance (EmitContext ec, bool prepare_for_load)
2764                 {
2765                         if (IsStatic)
2766                                 return;
2767
2768                         if (InstanceExpression == EmptyExpression.Null) {
2769                                 SimpleName.Error_ObjectRefRequired (ec, loc, GetSignatureForError ());
2770                                 return;
2771                         }
2772
2773                         if (InstanceExpression.Type.IsValueType) {
2774                                 if (InstanceExpression is IMemoryLocation) {
2775                                         ((IMemoryLocation) InstanceExpression).AddressOf (ec, AddressOp.LoadStore);
2776                                 } else {
2777                                         LocalTemporary t = new LocalTemporary (InstanceExpression.Type);
2778                                         InstanceExpression.Emit (ec);
2779                                         t.Store (ec);
2780                                         t.AddressOf (ec, AddressOp.Store);
2781                                 }
2782                         } else
2783                                 InstanceExpression.Emit (ec);
2784
2785                         if (prepare_for_load)
2786                                 ec.ig.Emit (OpCodes.Dup);
2787                 }
2788         }
2789
2790         /// <summary>
2791         ///   MethodGroup Expression.
2792         ///
2793         ///   This is a fully resolved expression that evaluates to a type
2794         /// </summary>
2795         public class MethodGroupExpr : MemberExpr {
2796                 public MethodBase [] Methods;
2797                 bool has_type_arguments = false;
2798                 bool identical_type_name = false;
2799                 bool is_base;
2800
2801                 public MethodGroupExpr (MemberInfo [] mi, Location l)
2802                 {
2803                         Methods = new MethodBase [mi.Length];
2804                         mi.CopyTo (Methods, 0);
2805                         eclass = ExprClass.MethodGroup;
2806
2807                         // Set the type to something that will never be useful, which will
2808                         // trigger the proper conversions.
2809                         type = typeof (MethodGroupExpr);
2810                         loc = l;
2811                 }
2812
2813                 public MethodGroupExpr (ArrayList list, Location l)
2814                 {
2815                         Methods = new MethodBase [list.Count];
2816
2817                         try {
2818                                 list.CopyTo (Methods, 0);
2819                         } catch {
2820                                 foreach (MemberInfo m in list){
2821                                         if (!(m is MethodBase)){
2822                                                 Console.WriteLine ("Name " + m.Name);
2823                                                 Console.WriteLine ("Found a: " + m.GetType ().FullName);
2824                                         }
2825                                 }
2826                                 throw;
2827                         }
2828
2829                         loc = l;
2830                         eclass = ExprClass.MethodGroup;
2831                         type = TypeManager.object_type;
2832                 }
2833
2834                 public override Type DeclaringType {
2835                         get {
2836                                 //
2837                                 // We assume that the top-level type is in the end
2838                                 //
2839                                 return Methods [Methods.Length - 1].DeclaringType;
2840                                 //return Methods [0].DeclaringType;
2841                         }
2842                 }
2843
2844                 public bool HasTypeArguments {
2845                         get {
2846                                 return has_type_arguments;
2847                         }
2848
2849                         set {
2850                                 has_type_arguments = value;
2851                         }
2852                 }
2853
2854                 public bool IdenticalTypeName {
2855                         get {
2856                                 return identical_type_name;
2857                         }
2858
2859                         set {
2860                                 identical_type_name = value;
2861                         }
2862                 }
2863
2864                 public bool IsBase {
2865                         get {
2866                                 return is_base;
2867                         }
2868                         set {
2869                                 is_base = value;
2870                         }
2871                 }
2872
2873                 public override string GetSignatureForError ()
2874                 {
2875                         return TypeManager.CSharpSignature (Methods [0]);
2876                 }
2877
2878                 public override string Name {
2879                         get {
2880                                 return Methods [0].Name;
2881                         }
2882                 }
2883
2884                 public override bool IsInstance {
2885                         get {
2886                                 foreach (MethodBase mb in Methods)
2887                                         if (!mb.IsStatic)
2888                                                 return true;
2889
2890                                 return false;
2891                         }
2892                 }
2893
2894                 public override bool IsStatic {
2895                         get {
2896                                 foreach (MethodBase mb in Methods)
2897                                         if (mb.IsStatic)
2898                                                 return true;
2899
2900                                 return false;
2901                         }
2902                 }
2903
2904                 public override Expression ResolveMemberAccess (EmitContext ec, Expression left, Location loc,
2905                                                                 SimpleName original)
2906                 {
2907                         if (!(left is TypeExpr) &&
2908                             original != null && original.IdenticalNameAndTypeName (ec, left, loc))
2909                                 IdenticalTypeName = true;
2910
2911                         return base.ResolveMemberAccess (ec, left, loc, original);
2912                 }
2913
2914                 override public Expression DoResolve (EmitContext ec)
2915                 {
2916                         if (!IsInstance)
2917                                 InstanceExpression = null;
2918
2919                         if (InstanceExpression != null) {
2920                                 InstanceExpression = InstanceExpression.DoResolve (ec);
2921                                 if (InstanceExpression == null)
2922                                         return null;
2923                         }
2924
2925                         return this;
2926                 }
2927
2928                 public void ReportUsageError ()
2929                 {
2930                         Report.Error (654, loc, "Method `" + DeclaringType + "." +
2931                                       Name + "()' is referenced without parentheses");
2932                 }
2933
2934                 override public void Emit (EmitContext ec)
2935                 {
2936                         ReportUsageError ();
2937                 }
2938
2939                 bool RemoveMethods (bool keep_static)
2940                 {
2941                         ArrayList smethods = new ArrayList ();
2942
2943                         foreach (MethodBase mb in Methods){
2944                                 if (mb.IsStatic == keep_static)
2945                                         smethods.Add (mb);
2946                         }
2947
2948                         if (smethods.Count == 0)
2949                                 return false;
2950
2951                         Methods = new MethodBase [smethods.Count];
2952                         smethods.CopyTo (Methods, 0);
2953
2954                         return true;
2955                 }
2956
2957                 /// <summary>
2958                 ///   Removes any instance methods from the MethodGroup, returns
2959                 ///   false if the resulting set is empty.
2960                 /// </summary>
2961                 public bool RemoveInstanceMethods ()
2962                 {
2963                         return RemoveMethods (true);
2964                 }
2965
2966                 /// <summary>
2967                 ///   Removes any static methods from the MethodGroup, returns
2968                 ///   false if the resulting set is empty.
2969                 /// </summary>
2970                 public bool RemoveStaticMethods ()
2971                 {
2972                         return RemoveMethods (false);
2973                 }
2974
2975                 public Expression ResolveGeneric (EmitContext ec, TypeArguments args)
2976                 {
2977 #if GMCS_SOURCE
2978                         if (args.Resolve (ec) == false)
2979                                 return null;
2980
2981                         Type[] atypes = args.Arguments;
2982
2983                         int first_count = 0;
2984                         MethodInfo first = null;
2985
2986                         ArrayList list = new ArrayList ();
2987                         foreach (MethodBase mb in Methods) {
2988                                 MethodInfo mi = mb as MethodInfo;
2989                                 if ((mi == null) || !mi.IsGenericMethod)
2990                                         continue;
2991
2992                                 Type[] gen_params = mi.GetGenericArguments ();
2993
2994                                 if (first == null) {
2995                                         first = mi;
2996                                         first_count = gen_params.Length;
2997                                 }
2998
2999                                 if (gen_params.Length != atypes.Length)
3000                                         continue;
3001
3002                                 list.Add (mi.MakeGenericMethod (atypes));
3003                         }
3004
3005                         if (list.Count > 0) {
3006                                 MethodGroupExpr new_mg = new MethodGroupExpr (list, Location);
3007                                 new_mg.InstanceExpression = InstanceExpression;
3008                                 new_mg.HasTypeArguments = true;
3009                                 new_mg.IsBase = IsBase;
3010                                 return new_mg;
3011                         }
3012
3013                         if (first != null)
3014                                 Report.Error (
3015                                         305, loc, "Using the generic method `{0}' " +
3016                                         "requires {1} type arguments", Name,
3017                                         first_count.ToString ());
3018                         else
3019                                 Report.Error (
3020                                         308, loc, "The non-generic method `{0}' " +
3021                                         "cannot be used with type arguments", Name);
3022
3023                         return null;
3024 #else
3025                         throw new NotImplementedException ();
3026 #endif
3027                 }
3028         }
3029
3030         /// <summary>
3031         ///   Fully resolved expression that evaluates to a Field
3032         /// </summary>
3033         public class FieldExpr : MemberExpr, IAssignMethod, IMemoryLocation, IVariable {
3034                 public readonly FieldInfo FieldInfo;
3035                 VariableInfo variable_info;
3036
3037                 LocalTemporary temp;
3038                 bool prepared;
3039                 bool in_initializer;
3040
3041                 public FieldExpr (FieldInfo fi, Location l, bool in_initializer):
3042                         this (fi, l)
3043                 {
3044                         this.in_initializer = in_initializer;
3045                 }
3046
3047                 public FieldExpr (FieldInfo fi, Location l)
3048                 {
3049                         FieldInfo = fi;
3050                         eclass = ExprClass.Variable;
3051                         type = TypeManager.TypeToCoreType (fi.FieldType);
3052                         loc = l;
3053                 }
3054
3055                 public override string Name {
3056                         get {
3057                                 return FieldInfo.Name;
3058                         }
3059                 }
3060
3061                 public override bool IsInstance {
3062                         get {
3063                                 return !FieldInfo.IsStatic;
3064                         }
3065                 }
3066
3067                 public override bool IsStatic {
3068                         get {
3069                                 return FieldInfo.IsStatic;
3070                         }
3071                 }
3072
3073                 public override Type DeclaringType {
3074                         get {
3075                                 return FieldInfo.DeclaringType;
3076                         }
3077                 }
3078
3079                 public override string GetSignatureForError ()
3080                 {
3081                         return TypeManager.GetFullNameSignature (FieldInfo);
3082                 }
3083
3084                 public VariableInfo VariableInfo {
3085                         get {
3086                                 return variable_info;
3087                         }
3088                 }
3089
3090                 public override Expression ResolveMemberAccess (EmitContext ec, Expression left, Location loc,
3091                                                                 SimpleName original)
3092                 {
3093                         FieldInfo fi = TypeManager.GetGenericFieldDefinition (FieldInfo);
3094
3095                         Type t = fi.FieldType;
3096
3097                         if (fi.IsLiteral || (fi.IsInitOnly && t == TypeManager.decimal_type)) {
3098                                 IConstant ic = TypeManager.GetConstant (fi);
3099                                 if (ic == null) {
3100                                         if (fi.IsLiteral) {
3101                                                 ic = new ExternalConstant (fi);
3102                                         } else {
3103                                                 ic = ExternalConstant.CreateDecimal (fi);
3104                                                 if (ic == null) {
3105                                                         return base.ResolveMemberAccess (ec, left, loc, original);
3106                                                 }
3107                                         }
3108                                         TypeManager.RegisterConstant (fi, ic);
3109                                 }
3110
3111                                 bool left_is_type = left is TypeExpr;
3112                                 if (!left_is_type && (original == null || !original.IdenticalNameAndTypeName (ec, left, loc))) {
3113                                         Report.SymbolRelatedToPreviousError (FieldInfo);
3114                                         error176 (loc, TypeManager.GetFullNameSignature (FieldInfo));
3115                                         return null;
3116                                 }
3117
3118                                 if (ic.ResolveValue ()) {
3119                                         if (!ec.IsInObsoleteScope)
3120                                                 ic.CheckObsoleteness (loc);
3121                                 }
3122
3123                                 return ic.CreateConstantReference (loc);
3124                         }
3125
3126                         if (t.IsPointer && !ec.InUnsafe) {
3127                                 UnsafeError (loc);
3128                                 return null;
3129                         }
3130
3131                         return base.ResolveMemberAccess (ec, left, loc, original);
3132                 }
3133
3134                 override public Expression DoResolve (EmitContext ec)
3135                 {
3136                         return DoResolve (ec, false, false);
3137                 }
3138
3139                 Expression DoResolve (EmitContext ec, bool lvalue_instance, bool out_access)
3140                 {
3141                         if (!FieldInfo.IsStatic){
3142                                 if (InstanceExpression == null){
3143                                         //
3144                                         // This can happen when referencing an instance field using
3145                                         // a fully qualified type expression: TypeName.InstanceField = xxx
3146                                         //
3147                                         SimpleName.Error_ObjectRefRequired (ec, loc, GetSignatureForError ());
3148                                         return null;
3149                                 }
3150
3151                                 // Resolve the field's instance expression while flow analysis is turned
3152                                 // off: when accessing a field "a.b", we must check whether the field
3153                                 // "a.b" is initialized, not whether the whole struct "a" is initialized.
3154
3155                                 if (lvalue_instance) {
3156                                         using (ec.With (EmitContext.Flags.DoFlowAnalysis, false)) {
3157                                                 Expression right_side =
3158                                                         out_access ? EmptyExpression.LValueMemberOutAccess : EmptyExpression.LValueMemberAccess;
3159                                                 InstanceExpression = InstanceExpression.ResolveLValue (ec, right_side, loc);
3160                                         }
3161                                 } else {
3162                                         ResolveFlags rf = ResolveFlags.VariableOrValue | ResolveFlags.DisableFlowAnalysis;
3163                                         InstanceExpression = InstanceExpression.Resolve (ec, rf);
3164                                 }
3165
3166                                 if (InstanceExpression == null)
3167                                         return null;
3168
3169                                 InstanceExpression.CheckMarshalByRefAccess ();
3170                         }
3171
3172                         if (!in_initializer && !ec.IsFieldInitializer) {
3173                                 ObsoleteAttribute oa;
3174                                 FieldBase f = TypeManager.GetField (FieldInfo);
3175                                 if (f != null) {
3176                                         if (!ec.IsInObsoleteScope)
3177                                                 f.CheckObsoleteness (loc);
3178
3179                                         // To be sure that type is external because we do not register generated fields
3180                                 } else if (!(FieldInfo.DeclaringType is TypeBuilder)) {
3181                                         oa = AttributeTester.GetMemberObsoleteAttribute (FieldInfo);
3182                                         if (oa != null)
3183                                                 AttributeTester.Report_ObsoleteMessage (oa, TypeManager.GetFullNameSignature (FieldInfo), loc);
3184                                 }
3185                         }
3186
3187                         AnonymousContainer am = ec.CurrentAnonymousMethod;
3188                         if (am != null){
3189                                 if (!FieldInfo.IsStatic){
3190                                         if (!am.IsIterator && (ec.TypeContainer is Struct)){
3191                                                 Report.Error (1673, loc,
3192                                                 "Anonymous methods inside structs cannot access instance members of `{0}'. Consider copying `{0}' to a local variable outside the anonymous method and using the local instead",
3193                                                         "this");
3194                                                 return null;
3195                                         }
3196                                 }
3197                         }
3198
3199                         // If the instance expression is a local variable or parameter.
3200                         IVariable var = InstanceExpression as IVariable;
3201                         if ((var == null) || (var.VariableInfo == null))
3202                                 return this;
3203
3204                         VariableInfo vi = var.VariableInfo;
3205                         if (!vi.IsFieldAssigned (ec, FieldInfo.Name, loc))
3206                                 return null;
3207
3208                         variable_info = vi.GetSubStruct (FieldInfo.Name);
3209                         return this;
3210                 }
3211
3212                 static readonly int [] codes = {
3213                         191,    // instance, write access
3214                         192,    // instance, out access
3215                         198,    // static, write access
3216                         199,    // static, out access
3217                         1648,   // member of value instance, write access
3218                         1649,   // member of value instance, out access
3219                         1650,   // member of value static, write access
3220                         1651    // member of value static, out access
3221                 };
3222
3223                 static readonly string [] msgs = {
3224                         /*0191*/ "A readonly field `{0}' cannot be assigned to (except in a constructor or a variable initializer)",
3225                         /*0192*/ "A readonly field `{0}' cannot be passed ref or out (except in a constructor)",
3226                         /*0198*/ "A static readonly field `{0}' cannot be assigned to (except in a static constructor or a variable initializer)",
3227                         /*0199*/ "A static readonly field `{0}' cannot be passed ref or out (except in a static constructor)",
3228                         /*1648*/ "Members of readonly field `{0}' cannot be modified (except in a constructor or a variable initializer)",
3229                         /*1649*/ "Members of readonly field `{0}' cannot be passed ref or out (except in a constructor)",
3230                         /*1650*/ "Fields of static readonly field `{0}' cannot be assigned to (except in a static constructor or a variable initializer)",
3231                         /*1651*/ "Fields of static readonly field `{0}' cannot be passed ref or out (except in a static constructor)"
3232                 };
3233
3234                 // The return value is always null.  Returning a value simplifies calling code.
3235                 Expression Report_AssignToReadonly (Expression right_side)
3236                 {
3237                         int i = 0;
3238                         if (right_side == EmptyExpression.OutAccess || right_side == EmptyExpression.LValueMemberOutAccess)
3239                                 i += 1;
3240                         if (IsStatic)
3241                                 i += 2;
3242                         if (right_side == EmptyExpression.LValueMemberAccess || right_side == EmptyExpression.LValueMemberOutAccess)
3243                                 i += 4;
3244                         Report.Error (codes [i], loc, msgs [i], GetSignatureForError ());
3245
3246                         return null;
3247                 }
3248
3249                 override public Expression DoResolveLValue (EmitContext ec, Expression right_side)
3250                 {
3251                         IVariable var = InstanceExpression as IVariable;
3252                         if ((var != null) && (var.VariableInfo != null))
3253                                 var.VariableInfo.SetFieldAssigned (ec, FieldInfo.Name);
3254
3255                         bool lvalue_instance = !FieldInfo.IsStatic && FieldInfo.DeclaringType.IsValueType;
3256                         bool out_access = right_side == EmptyExpression.OutAccess || right_side == EmptyExpression.LValueMemberOutAccess;
3257
3258                         Expression e = DoResolve (ec, lvalue_instance, out_access);
3259
3260                         if (e == null)
3261                                 return null;
3262
3263                         FieldBase fb = TypeManager.GetField (FieldInfo);
3264                         if (fb != null)
3265                                 fb.SetAssigned ();
3266
3267                         if (FieldInfo.IsInitOnly) {
3268                                 // InitOnly fields can only be assigned in constructors or initializers
3269                                 if (!ec.IsFieldInitializer && !ec.IsConstructor)
3270                                         return Report_AssignToReadonly (right_side);
3271
3272                                 if (ec.IsConstructor) {
3273                                         Type ctype = ec.TypeContainer.CurrentType;
3274                                         if (ctype == null)
3275                                                 ctype = ec.ContainerType;
3276
3277                                         // InitOnly fields cannot be assigned-to in a different constructor from their declaring type
3278                                         if (!TypeManager.IsEqual (ctype, FieldInfo.DeclaringType))
3279                                                 return Report_AssignToReadonly (right_side);
3280                                         // static InitOnly fields cannot be assigned-to in an instance constructor
3281                                         if (IsStatic && !ec.IsStatic)
3282                                                 return Report_AssignToReadonly (right_side);
3283                                         // instance constructors can't modify InitOnly fields of other instances of the same type
3284                                         if (!IsStatic && !(InstanceExpression is This))
3285                                                 return Report_AssignToReadonly (right_side);
3286                                 }
3287                         }
3288
3289                         if (right_side == EmptyExpression.OutAccess &&
3290                             !IsStatic && !(InstanceExpression is This) && DeclaringType.IsSubclassOf (TypeManager.mbr_type)) {
3291                                 Report.SymbolRelatedToPreviousError (DeclaringType);
3292                                 Report.Warning (197, 1, loc,
3293                                                 "Passing `{0}' as ref or out or taking its address may cause a runtime exception because it is a field of a marshal-by-reference class",
3294                                                 GetSignatureForError ());
3295                         }
3296
3297                         return this;
3298                 }
3299
3300                 public override void CheckMarshalByRefAccess ()
3301                 {
3302                         if (!IsStatic && Type.IsValueType && !(InstanceExpression is This) && DeclaringType.IsSubclassOf (TypeManager.mbr_type)) {
3303                                 Report.SymbolRelatedToPreviousError (DeclaringType);
3304                                 Report.Warning (1690, 1, loc, "Cannot call methods, properties, or indexers on `{0}' because it is a value type member of a marshal-by-reference class",
3305                                                 GetSignatureForError ());
3306                         }
3307                 }
3308
3309                 public bool VerifyFixed ()
3310                 {
3311                         IVariable variable = InstanceExpression as IVariable;
3312                         // A variable of the form V.I is fixed when V is a fixed variable of a struct type.
3313                         // We defer the InstanceExpression check after the variable check to avoid a
3314                         // separate null check on InstanceExpression.
3315                         return variable != null && InstanceExpression.Type.IsValueType && variable.VerifyFixed ();
3316                 }
3317
3318                 public override int GetHashCode ()
3319                 {
3320                         return FieldInfo.GetHashCode ();
3321                 }
3322
3323                 public override bool Equals (object obj)
3324                 {
3325                         FieldExpr fe = obj as FieldExpr;
3326                         if (fe == null)
3327                                 return false;
3328
3329                         if (FieldInfo != fe.FieldInfo)
3330                                 return false;
3331
3332                         if (InstanceExpression == null || fe.InstanceExpression == null)
3333                                 return true;
3334
3335                         return InstanceExpression.Equals (fe.InstanceExpression);
3336                 }
3337
3338                 public void Emit (EmitContext ec, bool leave_copy)
3339                 {
3340                         ILGenerator ig = ec.ig;
3341                         bool is_volatile = false;
3342
3343                         FieldBase f = TypeManager.GetField (FieldInfo);
3344                         if (f != null){
3345                                 if ((f.ModFlags & Modifiers.VOLATILE) != 0)
3346                                         is_volatile = true;
3347
3348                                 f.SetMemberIsUsed ();
3349                         }
3350
3351                         if (FieldInfo.IsStatic){
3352                                 if (is_volatile)
3353                                         ig.Emit (OpCodes.Volatile);
3354
3355                                 ig.Emit (OpCodes.Ldsfld, FieldInfo);
3356                         } else {
3357                                 if (!prepared)
3358                                         EmitInstance (ec, false);
3359
3360                                 if (is_volatile)
3361                                         ig.Emit (OpCodes.Volatile);
3362
3363                                 IFixedBuffer ff = AttributeTester.GetFixedBuffer (FieldInfo);
3364                                 if (ff != null)
3365                                 {
3366                                         ig.Emit (OpCodes.Ldflda, FieldInfo);
3367                                         ig.Emit (OpCodes.Ldflda, ff.Element);
3368                                 }
3369                                 else {
3370                                         ig.Emit (OpCodes.Ldfld, FieldInfo);
3371                                 }
3372                         }
3373
3374                         if (leave_copy) {
3375                                 ec.ig.Emit (OpCodes.Dup);
3376                                 if (!FieldInfo.IsStatic) {
3377                                         temp = new LocalTemporary (this.Type);
3378                                         temp.Store (ec);
3379                                 }
3380                         }
3381                 }
3382
3383                 public void EmitAssign (EmitContext ec, Expression source, bool leave_copy, bool prepare_for_load)
3384                 {
3385                         FieldAttributes fa = FieldInfo.Attributes;
3386                         bool is_static = (fa & FieldAttributes.Static) != 0;
3387                         bool is_readonly = (fa & FieldAttributes.InitOnly) != 0;
3388                         ILGenerator ig = ec.ig;
3389                         prepared = prepare_for_load;
3390
3391                         if (is_readonly && !ec.IsConstructor){
3392                                 Report_AssignToReadonly (source);
3393                                 return;
3394                         }
3395
3396                         EmitInstance (ec, prepare_for_load);
3397
3398                         source.Emit (ec);
3399                         if (leave_copy) {
3400                                 ec.ig.Emit (OpCodes.Dup);
3401                                 if (!FieldInfo.IsStatic) {
3402                                         temp = new LocalTemporary (this.Type);
3403                                         temp.Store (ec);
3404                                 }
3405                         }
3406
3407                         FieldBase f = TypeManager.GetField (FieldInfo);
3408                         if (f != null){
3409                                 if ((f.ModFlags & Modifiers.VOLATILE) != 0)
3410                                         ig.Emit (OpCodes.Volatile);
3411
3412                                 f.SetAssigned ();
3413                         }
3414
3415                         if (is_static)
3416                                 ig.Emit (OpCodes.Stsfld, FieldInfo);
3417                         else
3418                                 ig.Emit (OpCodes.Stfld, FieldInfo);
3419
3420                         if (temp != null) {
3421                                 temp.Emit (ec);
3422                                 temp.Release (ec);
3423                         }
3424                 }
3425
3426                 public override void Emit (EmitContext ec)
3427                 {
3428                         Emit (ec, false);
3429                 }
3430
3431                 public void AddressOf (EmitContext ec, AddressOp mode)
3432                 {
3433                         ILGenerator ig = ec.ig;
3434
3435                         FieldBase f = TypeManager.GetField (FieldInfo);
3436                         if (f != null){
3437                                 if ((f.ModFlags & Modifiers.VOLATILE) != 0){
3438                                         Report.Warning (420, 1, loc, "`{0}': A volatile fields cannot be passed using a ref or out parameter",
3439                                                         f.GetSignatureForError ());
3440                                         return;
3441                                 }
3442
3443                                 if ((mode & AddressOp.Store) != 0)
3444                                         f.SetAssigned ();
3445                                 if ((mode & AddressOp.Load) != 0)
3446                                         f.SetMemberIsUsed ();
3447                         }
3448
3449                         //
3450                         // Handle initonly fields specially: make a copy and then
3451                         // get the address of the copy.
3452                         //
3453                         bool need_copy;
3454                         if (FieldInfo.IsInitOnly){
3455                                 need_copy = true;
3456                                 if (ec.IsConstructor){
3457                                         if (FieldInfo.IsStatic){
3458                                                 if (ec.IsStatic)
3459                                                         need_copy = false;
3460                                         } else
3461                                                 need_copy = false;
3462                                 }
3463                         } else
3464                                 need_copy = false;
3465
3466                         if (need_copy){
3467                                 LocalBuilder local;
3468                                 Emit (ec);
3469                                 local = ig.DeclareLocal (type);
3470                                 ig.Emit (OpCodes.Stloc, local);
3471                                 ig.Emit (OpCodes.Ldloca, local);
3472                                 return;
3473                         }
3474
3475
3476                         if (FieldInfo.IsStatic){
3477                                 ig.Emit (OpCodes.Ldsflda, FieldInfo);
3478                         } else {
3479                                 if (!prepared)
3480                                         EmitInstance (ec, false);
3481                                 ig.Emit (OpCodes.Ldflda, FieldInfo);
3482                         }
3483                 }
3484         }
3485
3486         //
3487         // A FieldExpr whose address can not be taken
3488         //
3489         public class FieldExprNoAddress : FieldExpr, IMemoryLocation {
3490                 public FieldExprNoAddress (FieldInfo fi, Location loc) : base (fi, loc)
3491                 {
3492                 }
3493
3494                 public new void AddressOf (EmitContext ec, AddressOp mode)
3495                 {
3496                         Report.Error (-215, "Report this: Taking the address of a remapped parameter not supported");
3497                 }
3498         }
3499
3500         /// <summary>
3501         ///   Expression that evaluates to a Property.  The Assign class
3502         ///   might set the `Value' expression if we are in an assignment.
3503         ///
3504         ///   This is not an LValue because we need to re-write the expression, we
3505         ///   can not take data from the stack and store it.
3506         /// </summary>
3507         public class PropertyExpr : MemberExpr, IAssignMethod {
3508                 public readonly PropertyInfo PropertyInfo;
3509
3510                 //
3511                 // This is set externally by the  `BaseAccess' class
3512                 //
3513                 public bool IsBase;
3514                 MethodInfo getter, setter;
3515                 bool is_static;
3516
3517                 bool resolved;
3518
3519                 LocalTemporary temp;
3520                 bool prepared;
3521
3522                 public PropertyExpr (Type containerType, PropertyInfo pi, Location l)
3523                 {
3524                         PropertyInfo = pi;
3525                         eclass = ExprClass.PropertyAccess;
3526                         is_static = false;
3527                         loc = l;
3528
3529                         type = TypeManager.TypeToCoreType (pi.PropertyType);
3530
3531                         ResolveAccessors (containerType);
3532                 }
3533
3534                 public override string Name {
3535                         get {
3536                                 return PropertyInfo.Name;
3537                         }
3538                 }
3539
3540                 public override bool IsInstance {
3541                         get {
3542                                 return !is_static;
3543                         }
3544                 }
3545
3546                 public override bool IsStatic {
3547                         get {
3548                                 return is_static;
3549                         }
3550                 }
3551
3552                 public override Type DeclaringType {
3553                         get {
3554                                 return PropertyInfo.DeclaringType;
3555                         }
3556                 }
3557
3558                 public override string GetSignatureForError ()
3559                 {
3560                         return TypeManager.GetFullNameSignature (PropertyInfo);
3561                 }
3562
3563                 void FindAccessors (Type invocation_type)
3564                 {
3565                         const BindingFlags flags = BindingFlags.Public | BindingFlags.NonPublic |
3566                                 BindingFlags.Static | BindingFlags.Instance |
3567                                 BindingFlags.DeclaredOnly;
3568
3569                         Type current = PropertyInfo.DeclaringType;
3570                         for (; current != null; current = current.BaseType) {
3571                                 MemberInfo[] group = TypeManager.MemberLookup (
3572                                         invocation_type, invocation_type, current,
3573                                         MemberTypes.Property, flags, PropertyInfo.Name, null);
3574
3575                                 if (group == null)
3576                                         continue;
3577
3578                                 if (group.Length != 1)
3579                                         // Oooops, can this ever happen ?
3580                                         return;
3581
3582                                 PropertyInfo pi = (PropertyInfo) group [0];
3583
3584                                 if (getter == null)
3585                                         getter = pi.GetGetMethod (true);
3586
3587                                 if (setter == null)
3588                                         setter = pi.GetSetMethod (true);
3589
3590                                 MethodInfo accessor = getter != null ? getter : setter;
3591
3592                                 if (!accessor.IsVirtual)
3593                                         return;
3594                         }
3595                 }
3596
3597                 //
3598                 // We also perform the permission checking here, as the PropertyInfo does not
3599                 // hold the information for the accessibility of its setter/getter
3600                 //
3601                 // TODO: Refactor to use some kind of cache together with GetPropertyFromAccessor
3602                 void ResolveAccessors (Type containerType)
3603                 {
3604                         FindAccessors (containerType);
3605
3606                         if (getter != null) {
3607                                 MethodBase the_getter = TypeManager.DropGenericMethodArguments (getter);
3608                                 IMethodData md = TypeManager.GetMethod (the_getter);
3609                                 if (md != null)
3610                                         md.SetMemberIsUsed ();
3611
3612                                 is_static = getter.IsStatic;
3613                         }
3614
3615                         if (setter != null) {
3616                                 MethodBase the_setter = TypeManager.DropGenericMethodArguments (setter);
3617                                 IMethodData md = TypeManager.GetMethod (the_setter);
3618                                 if (md != null)
3619                                         md.SetMemberIsUsed ();
3620
3621                                 is_static = setter.IsStatic;
3622                         }
3623                 }
3624
3625                 bool InstanceResolve (EmitContext ec, bool lvalue_instance, bool must_do_cs1540_check)
3626                 {
3627                         if (is_static) {
3628                                 InstanceExpression = null;
3629                                 return true;
3630                         }
3631
3632                         if (InstanceExpression == null) {
3633                                 SimpleName.Error_ObjectRefRequired (ec, loc, GetSignatureForError ());
3634                                 return false;
3635                         }
3636
3637                         InstanceExpression = InstanceExpression.DoResolve (ec);
3638                         if (lvalue_instance && InstanceExpression != null)
3639                                 InstanceExpression = InstanceExpression.ResolveLValue (ec, EmptyExpression.LValueMemberAccess, loc);
3640
3641                         if (InstanceExpression == null)
3642                                 return false;
3643
3644                         InstanceExpression.CheckMarshalByRefAccess ();
3645
3646                         if (must_do_cs1540_check && (InstanceExpression != EmptyExpression.Null) &&
3647                             !TypeManager.IsInstantiationOfSameGenericType (InstanceExpression.Type, ec.ContainerType) &&
3648                             !TypeManager.IsNestedChildOf (ec.ContainerType, InstanceExpression.Type) &&
3649                             !TypeManager.IsSubclassOf (InstanceExpression.Type, ec.ContainerType)) {
3650                                 Report.SymbolRelatedToPreviousError (PropertyInfo);
3651                                 Error_CannotAccessProtected (loc, PropertyInfo, InstanceExpression.Type, ec.ContainerType);
3652                                 return false;
3653                         }
3654
3655                         return true;
3656                 }
3657
3658                 void Error_PropertyNotFound (MethodInfo mi, bool getter)
3659                 {
3660                         // TODO: correctly we should compare arguments but it will lead to bigger changes
3661                         if (mi is MethodBuilder) {
3662                                 Error_TypeDoesNotContainDefinition (loc, PropertyInfo.DeclaringType, Name);
3663                                 return;
3664                         }
3665
3666                         StringBuilder sig = new StringBuilder (TypeManager.CSharpName (mi.DeclaringType));
3667                         sig.Append ('.');
3668                         ParameterData iparams = TypeManager.GetParameterData (mi);
3669                         sig.Append (getter ? "get_" : "set_");
3670                         sig.Append (Name);
3671                         sig.Append (iparams.GetSignatureForError ());
3672
3673                         Report.SymbolRelatedToPreviousError (mi);
3674                         Report.Error (1546, loc, "Property `{0}' is not supported by the C# language. Try to call the accessor method `{1}' directly",
3675                                 Name, sig.ToString ());
3676                 }
3677
3678                 override public Expression DoResolve (EmitContext ec)
3679                 {
3680                         if (resolved)
3681                                 return this;
3682
3683                         if (getter != null){
3684                                 if (TypeManager.GetParameterData (getter).Count != 0){
3685                                         Error_PropertyNotFound (getter, true);
3686                                         return null;
3687                                 }
3688                         }
3689
3690                         if (getter == null){
3691                                 //
3692                                 // The following condition happens if the PropertyExpr was
3693                                 // created, but is invalid (ie, the property is inaccessible),
3694                                 // and we did not want to embed the knowledge about this in
3695                                 // the caller routine.  This only avoids double error reporting.
3696                                 //
3697                                 if (setter == null)
3698                                         return null;
3699
3700                                 if (InstanceExpression != EmptyExpression.Null) {
3701                                         Report.Error (154, loc, "The property or indexer `{0}' cannot be used in this context because it lacks the `get' accessor",
3702                                                 TypeManager.GetFullNameSignature (PropertyInfo));
3703                                         return null;
3704                                 }
3705                         }
3706
3707                         bool must_do_cs1540_check = false;
3708                         if (getter != null &&
3709                             !IsAccessorAccessible (ec.ContainerType, getter, out must_do_cs1540_check)) {
3710                                 PropertyBase.PropertyMethod pm = TypeManager.GetMethod (getter) as PropertyBase.PropertyMethod;
3711                                 if (pm != null && pm.HasCustomAccessModifier) {
3712                                         Report.SymbolRelatedToPreviousError (pm);
3713                                         Report.Error (271, loc, "The property or indexer `{0}' cannot be used in this context because the get accessor is inaccessible",
3714                                                 TypeManager.CSharpSignature (getter));
3715                                 }
3716                                 else {
3717                                         Report.SymbolRelatedToPreviousError (getter);
3718                                         ErrorIsInaccesible (loc, TypeManager.CSharpSignature (getter));
3719                                 }
3720                                 return null;
3721                         }
3722
3723                         if (!InstanceResolve (ec, false, must_do_cs1540_check))
3724                                 return null;
3725
3726                         //
3727                         // Only base will allow this invocation to happen.
3728                         //
3729                         if (IsBase && getter.IsAbstract) {
3730                                 Error_CannotCallAbstractBase (TypeManager.GetFullNameSignature (PropertyInfo));
3731                                 return null;
3732                         }
3733
3734                         if (PropertyInfo.PropertyType.IsPointer && !ec.InUnsafe){
3735                                 UnsafeError (loc);
3736                                 return null;
3737                         }
3738
3739                         resolved = true;
3740
3741                         return this;
3742                 }
3743
3744                 override public Expression DoResolveLValue (EmitContext ec, Expression right_side)
3745                 {
3746                         if (right_side == EmptyExpression.OutAccess) {
3747                                 Report.Error (206, loc, "A property or indexer `{0}' may not be passed as an out or ref parameter",
3748                                               GetSignatureForError ());
3749                                 return null;
3750                         }
3751
3752                         if (right_side == EmptyExpression.LValueMemberAccess || right_side == EmptyExpression.LValueMemberOutAccess) {
3753                                 Report.Error (1612, loc, "Cannot modify the return value of `{0}' because it is not a variable",
3754                                               GetSignatureForError ());
3755                                 return null;
3756                         }
3757
3758                         if (setter == null){
3759                                 //
3760                                 // The following condition happens if the PropertyExpr was
3761                                 // created, but is invalid (ie, the property is inaccessible),
3762                                 // and we did not want to embed the knowledge about this in
3763                                 // the caller routine.  This only avoids double error reporting.
3764                                 //
3765                                 if (getter == null)
3766                                         return null;
3767                                 Report.Error (200, loc, "Property or indexer `{0}' cannot be assigned to (it is read only)",
3768                                               GetSignatureForError ());
3769                                 return null;
3770                         }
3771
3772                         if (TypeManager.GetParameterData (setter).Count != 1){
3773                                 Error_PropertyNotFound (setter, false);
3774                                 return null;
3775                         }
3776
3777                         bool must_do_cs1540_check;
3778                         if (!IsAccessorAccessible (ec.ContainerType, setter, out must_do_cs1540_check)) {
3779                                 PropertyBase.PropertyMethod pm = TypeManager.GetMethod (setter) as PropertyBase.PropertyMethod;
3780                                 if (pm != null && pm.HasCustomAccessModifier) {
3781                                         Report.SymbolRelatedToPreviousError (pm);
3782                                         Report.Error (272, loc, "The property or indexer `{0}' cannot be used in this context because the set accessor is inaccessible",
3783                                                 TypeManager.CSharpSignature (setter));
3784                                 }
3785                                 else {
3786                                         Report.SymbolRelatedToPreviousError (setter);
3787                                         ErrorIsInaccesible (loc, TypeManager.CSharpSignature (setter));
3788                                 }
3789                                 return null;
3790                         }
3791
3792                         if (!InstanceResolve (ec, PropertyInfo.DeclaringType.IsValueType, must_do_cs1540_check))
3793                                 return null;
3794
3795                         //
3796                         // Only base will allow this invocation to happen.
3797                         //
3798                         if (IsBase && setter.IsAbstract){
3799                                 Error_CannotCallAbstractBase (TypeManager.GetFullNameSignature (PropertyInfo));
3800                                 return null;
3801                         }
3802
3803                         return this;
3804                 }
3805
3806                 public override void Emit (EmitContext ec)
3807                 {
3808                         Emit (ec, false);
3809                 }
3810
3811                 public void Emit (EmitContext ec, bool leave_copy)
3812                 {
3813                         //
3814                         // Special case: length of single dimension array property is turned into ldlen
3815                         //
3816                         if ((getter == TypeManager.system_int_array_get_length) ||
3817                             (getter == TypeManager.int_array_get_length)){
3818                                 Type iet = InstanceExpression.Type;
3819
3820                                 //
3821                                 // System.Array.Length can be called, but the Type does not
3822                                 // support invoking GetArrayRank, so test for that case first
3823                                 //
3824                                 if (iet != TypeManager.array_type && (iet.GetArrayRank () == 1)) {
3825                                         if (!prepared)
3826                                                 EmitInstance (ec, false);
3827                                         ec.ig.Emit (OpCodes.Ldlen);
3828                                         ec.ig.Emit (OpCodes.Conv_I4);
3829                                         return;
3830                                 }
3831                         }
3832
3833                         Invocation.EmitCall (ec, IsBase, IsStatic, InstanceExpression, getter, null, loc, prepared, false);
3834
3835                         if (leave_copy) {
3836                                 ec.ig.Emit (OpCodes.Dup);
3837                                 if (!is_static) {
3838                                         temp = new LocalTemporary (this.Type);
3839                                         temp.Store (ec);
3840                                 }
3841                         }
3842                 }
3843
3844                 //
3845                 // Implements the IAssignMethod interface for assignments
3846                 //
3847                 public void EmitAssign (EmitContext ec, Expression source, bool leave_copy, bool prepare_for_load)
3848                 {
3849                         Expression my_source = source;
3850
3851                         prepared = prepare_for_load;
3852
3853                         if (prepared) {
3854                                 source.Emit (ec);
3855                                 if (leave_copy) {
3856                                         ec.ig.Emit (OpCodes.Dup);
3857                                         if (!is_static) {
3858                                                 temp = new LocalTemporary (this.Type);
3859                                                 temp.Store (ec);
3860                                         }
3861                                 }
3862                         } else if (leave_copy) {
3863                                 source.Emit (ec);
3864                                 if (!is_static) {
3865                                         temp = new LocalTemporary (this.Type);
3866                                         temp.Store (ec);
3867                                 }
3868                                 my_source = temp;
3869                         }
3870
3871                         ArrayList args = new ArrayList (1);
3872                         args.Add (new Argument (my_source, Argument.AType.Expression));
3873
3874                         Invocation.EmitCall (ec, IsBase, IsStatic, InstanceExpression, setter, args, loc, false, prepared);
3875
3876                         if (temp != null) {
3877                                 temp.Emit (ec);
3878                                 temp.Release (ec);
3879                         }
3880                 }
3881         }
3882
3883         /// <summary>
3884         ///   Fully resolved expression that evaluates to an Event
3885         /// </summary>
3886         public class EventExpr : MemberExpr {
3887                 public readonly EventInfo EventInfo;
3888
3889                 bool is_static;
3890                 MethodInfo add_accessor, remove_accessor;
3891
3892                 public EventExpr (EventInfo ei, Location loc)
3893                 {
3894                         EventInfo = ei;
3895                         this.loc = loc;
3896                         eclass = ExprClass.EventAccess;
3897
3898                         add_accessor = TypeManager.GetAddMethod (ei);
3899                         remove_accessor = TypeManager.GetRemoveMethod (ei);
3900                         if (add_accessor.IsStatic || remove_accessor.IsStatic)
3901                                 is_static = true;
3902
3903                         if (EventInfo is MyEventBuilder){
3904                                 MyEventBuilder eb = (MyEventBuilder) EventInfo;
3905                                 type = eb.EventType;
3906                                 eb.SetUsed ();
3907                         } else
3908                                 type = EventInfo.EventHandlerType;
3909                 }
3910
3911                 public override string Name {
3912                         get {
3913                                 return EventInfo.Name;
3914                         }
3915                 }
3916
3917                 public override bool IsInstance {
3918                         get {
3919                                 return !is_static;
3920                         }
3921                 }
3922
3923                 public override bool IsStatic {
3924                         get {
3925                                 return is_static;
3926                         }
3927                 }
3928
3929                 public override Type DeclaringType {
3930                         get {
3931                                 return EventInfo.DeclaringType;
3932                         }
3933                 }
3934
3935                 public override Expression ResolveMemberAccess (EmitContext ec, Expression left, Location loc,
3936                                                                 SimpleName original)
3937                 {
3938                         //
3939                         // If the event is local to this class, we transform ourselves into a FieldExpr
3940                         //
3941
3942                         if (EventInfo.DeclaringType == ec.ContainerType ||
3943                             TypeManager.IsNestedChildOf(ec.ContainerType, EventInfo.DeclaringType)) {
3944                                 MemberInfo mi = TypeManager.GetPrivateFieldOfEvent (EventInfo);
3945
3946                                 if (mi != null) {
3947                                         MemberExpr ml = (MemberExpr) ExprClassFromMemberInfo (ec.ContainerType, mi, loc);
3948
3949                                         if (ml == null) {
3950                                                 Report.Error (-200, loc, "Internal error!!");
3951                                                 return null;
3952                                         }
3953
3954                                         InstanceExpression = null;
3955
3956                                         return ml.ResolveMemberAccess (ec, left, loc, original);
3957                                 }
3958                         }
3959
3960                         return base.ResolveMemberAccess (ec, left, loc, original);
3961                 }
3962
3963
3964                 bool InstanceResolve (EmitContext ec, bool must_do_cs1540_check)
3965                 {
3966                         if (is_static) {
3967                                 InstanceExpression = null;
3968                                 return true;
3969                         }
3970
3971                         if (InstanceExpression == null) {
3972                                 SimpleName.Error_ObjectRefRequired (ec, loc, GetSignatureForError ());
3973                                 return false;
3974                         }
3975
3976                         InstanceExpression = InstanceExpression.DoResolve (ec);
3977                         if (InstanceExpression == null)
3978                                 return false;
3979
3980                         //
3981                         // This is using the same mechanism as the CS1540 check in PropertyExpr.
3982                         // However, in the Event case, we reported a CS0122 instead.
3983                         //
3984                         if (must_do_cs1540_check && InstanceExpression != EmptyExpression.Null &&
3985                             InstanceExpression.Type != ec.ContainerType &&
3986                             ec.ContainerType.IsSubclassOf (InstanceExpression.Type)) {
3987                                 Report.SymbolRelatedToPreviousError (EventInfo);
3988                                 ErrorIsInaccesible (loc, TypeManager.CSharpSignature (EventInfo));
3989                                 return false;
3990                         }
3991
3992                         return true;
3993                 }
3994
3995                 public override Expression DoResolveLValue (EmitContext ec, Expression right_side)
3996                 {
3997                         return DoResolve (ec);
3998                 }
3999
4000                 public override Expression DoResolve (EmitContext ec)
4001                 {
4002                         bool must_do_cs1540_check;
4003                         if (!(IsAccessorAccessible (ec.ContainerType, add_accessor, out must_do_cs1540_check) &&
4004                               IsAccessorAccessible (ec.ContainerType, remove_accessor, out must_do_cs1540_check))) {
4005                                 Report.SymbolRelatedToPreviousError (EventInfo);
4006                                 ErrorIsInaccesible (loc, TypeManager.CSharpSignature (EventInfo));
4007                                 return null;
4008                         }
4009
4010                         if (!InstanceResolve (ec, must_do_cs1540_check))
4011                                 return null;
4012
4013                         return this;
4014                 }
4015
4016                 public override void Emit (EmitContext ec)
4017                 {
4018                         if (InstanceExpression is This)
4019                                 Report.Error (79, loc, "The event `{0}' can only appear on the left hand side of += or -=", GetSignatureForError ());
4020                         else
4021                                 Report.Error (70, loc, "The event `{0}' can only appear on the left hand side of += or -= "+
4022                                               "(except on the defining type)", Name);
4023                 }
4024
4025                 public override string GetSignatureForError ()
4026                 {
4027                         return TypeManager.CSharpSignature (EventInfo);
4028                 }
4029
4030                 public void EmitAddOrRemove (EmitContext ec, Expression source)
4031                 {
4032                         BinaryDelegate source_del = source as BinaryDelegate;
4033                         if (source_del == null) {
4034                                 Emit (ec);
4035                                 return;
4036                         }
4037                         Expression handler = source_del.Right;
4038
4039                         Argument arg = new Argument (handler, Argument.AType.Expression);
4040                         ArrayList args = new ArrayList ();
4041
4042                         args.Add (arg);
4043
4044                         if (source_del.IsAddition)
4045                                 Invocation.EmitCall (
4046                                         ec, false, IsStatic, InstanceExpression, add_accessor, args, loc);
4047                         else
4048                                 Invocation.EmitCall (
4049                                         ec, false, IsStatic, InstanceExpression, remove_accessor, args, loc);
4050                 }
4051         }
4052
4053         public class TemporaryVariable : Expression, IMemoryLocation
4054         {
4055                 LocalInfo li;
4056                 Variable var;
4057
4058                 public TemporaryVariable (Type type, Location loc)
4059                 {
4060                         this.type = type;
4061                         this.loc = loc;
4062                         eclass = ExprClass.Value;
4063                 }
4064
4065                 public override Expression DoResolve (EmitContext ec)
4066                 {
4067                         if (li != null)
4068                                 return this;
4069
4070                         TypeExpr te = new TypeExpression (type, loc);
4071                         li = ec.CurrentBlock.AddTemporaryVariable (te, loc);
4072                         if (!li.Resolve (ec))
4073                                 return null;
4074
4075                         if (ec.MustCaptureVariable (li)) {
4076                                 ScopeInfo scope = li.Block.CreateScopeInfo ();
4077                                 var = scope.AddLocal (li);
4078                                 type = var.Type;
4079                         }
4080
4081                         return this;
4082                 }
4083
4084                 public Variable Variable {
4085                         get { return var != null ? var : li.Variable; }
4086                 }
4087
4088                 public override void Emit (EmitContext ec)
4089                 {
4090                         Variable.EmitInstance (ec);
4091                         Variable.Emit (ec);
4092                 }
4093
4094                 public void EmitLoadAddress (EmitContext ec)
4095                 {
4096                         Variable.EmitInstance (ec);
4097                         Variable.EmitAddressOf (ec);
4098                 }
4099
4100                 public void Store (EmitContext ec, Expression right_side)
4101                 {
4102                         Variable.EmitInstance (ec);
4103                         right_side.Emit (ec);
4104                         Variable.EmitAssign (ec);
4105                 }
4106
4107                 public void EmitThis (EmitContext ec)
4108                 {
4109                         Variable.EmitInstance (ec);
4110                 }
4111
4112                 public void EmitStore (EmitContext ec)
4113                 {
4114                         Variable.EmitAssign (ec);
4115                 }
4116
4117                 public void AddressOf (EmitContext ec, AddressOp mode)
4118                 {
4119                         EmitLoadAddress (ec);
4120                 }
4121         }
4122
4123 }