mcs/gmcs/ecore.cs

   1 //
   2 // ecore.cs: Core of the Expression representation for the intermediate tree.
   3 //
   4 // Author:
   5 //   Miguel de Icaza (miguel@ximian.com)
   6 //   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                         ObsoleteAttribute obsolete_attr = AttributeTester.GetObsoleteAttribute (te.Type);
 243                         if (obsolete_attr != null && !ec.IsInObsoleteScope) {
 244                                 AttributeTester.Report_ObsoleteMessage (obsolete_attr, te.GetSignatureForError (), Location);
 245                         }
 246
 247                         // Constrains don't need to be checked for overrides
 248                         GenericMethod gm = ec.GenericDeclContainer as GenericMethod;
 249                         if (gm != null && (gm.ModFlags & Modifiers.OVERRIDE) != 0) {
 250                                 te.loc = loc;
 251                                 return te;
 252                         }
 253
 254                         ConstructedType ct = te as ConstructedType;
 255                         if ((ct != null) && !ct.CheckConstraints (ec))
 256                                 return null;
 257
 258                         return te;
 259                 }
 260
 261                 public TypeExpr ResolveAsBaseTerminal (IResolveContext ec, bool silent)
 262                 {
 263                         int errors = Report.Errors;
 264
 265                         FullNamedExpression fne = ResolveAsTypeStep (ec, silent);
 266
 267                         if (fne == null){
 268                                 if (!silent && errors == Report.Errors)
 269                                         Report.Error (118, loc, "Expecting a type.");
 270                                 return null;
 271                         }
 272
 273                         if (fne.eclass != ExprClass.Type) {
 274                                 if (!silent && errors == Report.Errors)
 275                                         fne.Error_UnexpectedKind (null, "type", loc);
 276                                 return null;
 277                         }
 278
 279                         TypeExpr te = fne as TypeExpr;
 280
 281                         if (!te.CheckAccessLevel (ec.DeclContainer)) {
 282                                 Report.SymbolRelatedToPreviousError (te.Type);
 283                                 ErrorIsInaccesible (loc, TypeManager.CSharpName (te.Type));
 284                                 return null;
 285                         }
 286
 287                         te.loc = loc;
 288                         return te;
 289                 }
 290
 291                 public static void ErrorIsInaccesible (Location loc, string name)
 292                 {
 293                         Report.Error (122, loc, "`{0}' is inaccessible due to its protection level", name);
 294                 }
 295
 296                 protected static void Error_CannotAccessProtected (Location loc, MemberInfo m, Type qualifier, Type container)
 297                 {
 298                         Report.Error (1540, loc, "Cannot access protected member `{0}' via a qualifier of type `{1}';"
 299                                 + " the qualifier must be of type `{2}' (or derived from it)",
 300                                 TypeManager.GetFullNameSignature (m),
 301                                 TypeManager.CSharpName (qualifier),
 302                                 TypeManager.CSharpName (container));
 303
 304                 }
 305
 306                 public static void Error_VoidInvalidInTheContext (Location loc)
 307                 {
 308                         Report.Error (1547, loc, "Keyword `void' cannot be used in this context");
 309                 }
 310
 311                 public virtual void Error_ValueCannotBeConverted (Location loc, Type target, bool expl)
 312                 {
 313                         if (Type.FullName == target.FullName){
 314                                 Report.ExtraInformation (loc,
 315                                         String.Format (
 316                                         "The type {0} has two conflicting definitions, one comes from {1} and the other from {2}",
 317                                         Type.FullName, Type.Assembly.FullName, target.Assembly.FullName));
 318
 319                         }
 320
 321                         if (expl) {
 322                                 Report.Error (30, loc, "Cannot convert type `{0}' to `{1}'",
 323                                         GetSignatureForError (), TypeManager.CSharpName (target));
 324                                 return;
 325                         }
 326
 327                         Expression e = (this is EnumConstant) ? ((EnumConstant)this).Child : this;
 328                         bool b = Convert.ExplicitNumericConversion (e, target) != null;
 329
 330                         if (b || Convert.ExplicitReferenceConversionExists (Type, target) || Convert.ExplicitUnsafe (e, target) != null) {
 331                                 Report.Error (266, loc, "Cannot implicitly convert type `{0}' to `{1}'. An explicit conversion exists (are you missing a cast?)",
 332                                         TypeManager.CSharpName (Type), TypeManager.CSharpName (target));
 333                                 return;
 334                         }
 335
 336                         if (Type != TypeManager.string_type && this is Constant && !(this is NullCast)) {
 337                                 Report.Error (31, loc, "Constant value `{0}' cannot be converted to a `{1}'",
 338                                         GetSignatureForError (), TypeManager.CSharpName (target));
 339                                 return;
 340                         }
 341
 342                         Report.Error (29, loc, "Cannot implicitly convert type {0} to `{1}'",
 343                                 Type == TypeManager.anonymous_method_type ?
 344                                 "anonymous method" : "`" + GetSignatureForError () + "'",
 345                                 TypeManager.CSharpName (target));
 346                 }
 347
 348                 protected static void Error_TypeDoesNotContainDefinition (Location loc, Type type, string name)
 349                 {
 350                         Report.Error (117, loc, "`{0}' does not contain a definition for `{1}'",
 351                                 TypeManager.CSharpName (type), name);
 352                 }
 353
 354                 ResolveFlags ExprClassToResolveFlags
 355                 {
 356                         get {
 357                                 switch (eclass) {
 358                                         case ExprClass.Type:
 359                                         case ExprClass.Namespace:
 360                                                 return ResolveFlags.Type;
 361
 362                                         case ExprClass.MethodGroup:
 363                                                 return ResolveFlags.MethodGroup;
 364
 365                                         case ExprClass.Value:
 366                                         case ExprClass.Variable:
 367                                         case ExprClass.PropertyAccess:
 368                                         case ExprClass.EventAccess:
 369                                         case ExprClass.IndexerAccess:
 370                                                 return ResolveFlags.VariableOrValue;
 371
 372                                         default:
 373                                                 throw new Exception ("Expression " + GetType () +
 374                                                         " ExprClass is Invalid after resolve");
 375                                 }
 376                         }
 377                 }
 378
 379                 /// <summary>
 380                 ///   Resolves an expression and performs semantic analysis on it.
 381                 /// </summary>
 382                 ///
 383                 /// <remarks>
 384                 ///   Currently Resolve wraps DoResolve to perform sanity
 385                 ///   checking and assertion checking on what we expect from Resolve.
 386                 /// </remarks>
 387                 public Expression Resolve (EmitContext ec, ResolveFlags flags)
 388                 {
 389                         if ((flags & ResolveFlags.MaskExprClass) == ResolveFlags.Type)
 390                                 return ResolveAsTypeStep (ec, false);
 391
 392                         bool do_flow_analysis = ec.DoFlowAnalysis;
 393                         bool omit_struct_analysis = ec.OmitStructFlowAnalysis;
 394                         if ((flags & ResolveFlags.DisableFlowAnalysis) != 0)
 395                                 do_flow_analysis = false;
 396                         if ((flags & ResolveFlags.DisableStructFlowAnalysis) != 0)
 397                                 omit_struct_analysis = true;
 398
 399                         Expression e;
 400                         using (ec.WithFlowAnalysis (do_flow_analysis, omit_struct_analysis)) {
 401                                 if (this is SimpleName) {
 402                                         bool intermediate = (flags & ResolveFlags.Intermediate) == ResolveFlags.Intermediate;
 403                                         e = ((SimpleName) this).DoResolve (ec, intermediate);
 404                                 } else {
 405                                         e = DoResolve (ec);
 406                                 }
 407                         }
 408
 409                         if (e == null)
 410                                 return null;
 411
 412                         if ((flags & e.ExprClassToResolveFlags) == 0) {
 413                                 e.Error_UnexpectedKind (flags, loc);
 414                                 return null;
 415                         }
 416
 417                         if (e.type == null && !(e is Namespace)) {
 418                                 throw new Exception (
 419                                         "Expression " + e.GetType () +
 420                                         " did not set its type after Resolve\n" +
 421                                         "called from: " + this.GetType ());
 422                         }
 423
 424                         return e;
 425                 }
 426
 427                 /// <summary>
 428                 ///   Resolves an expression and performs semantic analysis on it.
 429                 /// </summary>
 430                 public Expression Resolve (EmitContext ec)
 431                 {
 432                         Expression e = Resolve (ec, ResolveFlags.VariableOrValue | ResolveFlags.MethodGroup);
 433
 434                         if (e != null && e.eclass == ExprClass.MethodGroup && RootContext.Version == LanguageVersion.ISO_1) {
 435                                 ((MethodGroupExpr) e).ReportUsageError ();
 436                                 return null;
 437                         }
 438                         return e;
 439                 }
 440
 441                 public Constant ResolveAsConstant (EmitContext ec, MemberCore mc)
 442                 {
 443                         Expression e = Resolve (ec);
 444                         if (e == null)
 445                                 return null;
 446
 447                         Constant c = e as Constant;
 448                         if (c != null)
 449                                 return c;
 450
 451                         Type constant_type = null;
 452                         if (mc is MemberBase) {
 453                                 constant_type = ((MemberBase)mc).MemberType;
 454                         }
 455
 456                         Const.Error_ExpressionMustBeConstant (constant_type, loc, mc.GetSignatureForError ());
 457                         return null;
 458                 }
 459
 460                 /// <summary>
 461                 ///   Resolves an expression for LValue assignment
 462                 /// </summary>
 463                 ///
 464                 /// <remarks>
 465                 ///   Currently ResolveLValue wraps DoResolveLValue to perform sanity
 466                 ///   checking and assertion checking on what we expect from Resolve
 467                 /// </remarks>
 468                 public Expression ResolveLValue (EmitContext ec, Expression right_side, Location loc)
 469                 {
 470                         int errors = Report.Errors;
 471                         bool out_access = right_side == EmptyExpression.OutAccess;
 472
 473                         Expression e = DoResolveLValue (ec, right_side);
 474
 475                         if (e != null && out_access && !(e is IMemoryLocation)) {
 476                                 // FIXME: There's no problem with correctness, the 'Expr = null' handles that.
 477                                 //        Enabling this 'throw' will "only" result in deleting useless code elsewhere,
 478
 479                                 //throw new InternalErrorException ("ResolveLValue didn't return an IMemoryLocation: " +
 480                                 //                                e.GetType () + " " + e.GetSignatureForError ());
 481                                 e = null;
 482                         }
 483
 484                         if (e == null) {
 485                                 if (errors == Report.Errors) {
 486                                         if (out_access)
 487                                                 Report.Error (1510, loc, "A ref or out argument must be an assignable variable");
 488                                         else
 489                                                 Report.Error (131, loc, "The left-hand side of an assignment or mutating operation must be a variable, property or indexer");
 490                                 }
 491                                 return null;
 492                         }
 493
 494                         if (e.eclass == ExprClass.Invalid)
 495                                 throw new Exception ("Expression " + e + " ExprClass is Invalid after resolve");
 496
 497                         if (e.eclass == ExprClass.MethodGroup) {
 498                                 ((MethodGroupExpr) e).ReportUsageError ();
 499                                 return null;
 500                         }
 501
 502                         if ((e.type == null) && !(e is ConstructedType))
 503                                 throw new Exception ("Expression " + e + " did not set its type after Resolve");
 504
 505                         return e;
 506                 }
 507
 508                 /// <summary>
 509                 ///   Emits the code for the expression
 510                 /// </summary>
 511                 ///
 512                 /// <remarks>
 513                 ///   The Emit method is invoked to generate the code
 514                 ///   for the expression.
 515                 /// </remarks>
 516                 public abstract void Emit (EmitContext ec);
 517
 518                 public virtual void EmitBranchable (EmitContext ec, Label target, bool onTrue)
 519                 {
 520                         Emit (ec);
 521                         ec.ig.Emit (onTrue ? OpCodes.Brtrue : OpCodes.Brfalse, target);
 522                 }
 523
 524                 /// <summary>
 525                 ///   Protected constructor.  Only derivate types should
 526                 ///   be able to be created
 527                 /// </summary>
 528
 529                 protected Expression ()
 530                 {
 531                         eclass = ExprClass.Invalid;
 532                         type = null;
 533                 }
 534
 535                 /// <summary>
 536                 ///   Returns a literalized version of a literal FieldInfo
 537                 /// </summary>
 538                 ///
 539                 /// <remarks>
 540                 ///   The possible return values are:
 541                 ///      IntConstant, UIntConstant
 542                 ///      LongLiteral, ULongConstant
 543                 ///      FloatConstant, DoubleConstant
 544                 ///      StringConstant
 545                 ///
 546                 ///   The value returned is already resolved.
 547                 /// </remarks>
 548                 public static Constant Constantify (object v, Type t)
 549                 {
 550                         if (t == TypeManager.int32_type)
 551                                 return new IntConstant ((int) v, Location.Null);
 552                         else if (t == TypeManager.uint32_type)
 553                                 return new UIntConstant ((uint) v, Location.Null);
 554                         else if (t == TypeManager.int64_type)
 555                                 return new LongConstant ((long) v, Location.Null);
 556                         else if (t == TypeManager.uint64_type)
 557                                 return new ULongConstant ((ulong) v, Location.Null);
 558                         else if (t == TypeManager.float_type)
 559                                 return new FloatConstant ((float) v, Location.Null);
 560                         else if (t == TypeManager.double_type)
 561                                 return new DoubleConstant ((double) v, Location.Null);
 562                         else if (t == TypeManager.string_type)
 563                                 return new StringConstant ((string) v, Location.Null);
 564                         else if (t == TypeManager.short_type)
 565                                 return new ShortConstant ((short)v, Location.Null);
 566                         else if (t == TypeManager.ushort_type)
 567                                 return new UShortConstant ((ushort)v, Location.Null);
 568                         else if (t == TypeManager.sbyte_type)
 569                                 return new SByteConstant ((sbyte)v, Location.Null);
 570                         else if (t == TypeManager.byte_type)
 571                                 return new ByteConstant ((byte)v, Location.Null);
 572                         else if (t == TypeManager.char_type)
 573                                 return new CharConstant ((char)v, Location.Null);
 574                         else if (t == TypeManager.bool_type)
 575                                 return new BoolConstant ((bool) v, Location.Null);
 576                         else if (t == TypeManager.decimal_type)
 577                                 return new DecimalConstant ((decimal) v, Location.Null);
 578                         else if (TypeManager.IsEnumType (t)){
 579                                 Type real_type = TypeManager.TypeToCoreType (v.GetType ());
 580                                 if (real_type == t)
 581                                         real_type = System.Enum.GetUnderlyingType (real_type);
 582
 583                                 Constant e = Constantify (v, real_type);
 584
 585                                 return new EnumConstant (e, t);
 586                         } else if (v == null && !TypeManager.IsValueType (t))
 587                                 return new NullLiteral (Location.Null);
 588                         else
 589                                 throw new Exception ("Unknown type for constant (" + t +
 590                                                      "), details: " + v);
 591                 }
 592
 593                 /// <summary>
 594                 ///   Returns a fully formed expression after a MemberLookup
 595                 /// </summary>
 596                 ///
 597                 public static Expression ExprClassFromMemberInfo (Type containerType, MemberInfo mi, Location loc)
 598                 {
 599                         if (mi is EventInfo)
 600                                 return new EventExpr ((EventInfo) mi, loc);
 601                         else if (mi is FieldInfo)
 602                                 return new FieldExpr ((FieldInfo) mi, loc);
 603                         else if (mi is PropertyInfo)
 604                                 return new PropertyExpr (containerType, (PropertyInfo) mi, loc);
 605                         else if (mi is Type){
 606                                 return new TypeExpression ((System.Type) mi, loc);
 607                         }
 608
 609                         return null;
 610                 }
 611
 612                 protected static ArrayList almostMatchedMembers = new ArrayList (4);
 613
 614                 //
 615                 // FIXME: Probably implement a cache for (t,name,current_access_set)?
 616                 //
 617                 // This code could use some optimizations, but we need to do some
 618                 // measurements.  For example, we could use a delegate to `flag' when
 619                 // something can not any longer be a method-group (because it is something
 620                 // else).
 621                 //
 622                 // Return values:
 623                 //     If the return value is an Array, then it is an array of
 624                 //     MethodBases
 625                 //
 626                 //     If the return value is an MemberInfo, it is anything, but a Method
 627                 //
 628                 //     null on error.
 629                 //
 630                 // FIXME: When calling MemberLookup inside an `Invocation', we should pass
 631                 // the arguments here and have MemberLookup return only the methods that
 632                 // match the argument count/type, unlike we are doing now (we delay this
 633                 // decision).
 634                 //
 635                 // This is so we can catch correctly attempts to invoke instance methods
 636                 // from a static body (scan for error 120 in ResolveSimpleName).
 637                 //
 638                 //
 639                 // FIXME: Potential optimization, have a static ArrayList
 640                 //
 641
 642                 public static Expression MemberLookup (Type container_type, Type queried_type, string name,
 643                                                        MemberTypes mt, BindingFlags bf, Location loc)
 644                 {
 645                         return MemberLookup (container_type, null, queried_type, name, mt, bf, loc);
 646                 }
 647
 648                 //
 649                 // Lookup type `queried_type' for code in class `container_type' with a qualifier of
 650                 // `qualifier_type' or null to lookup members in the current class.
 651                 //
 652
 653                 public static Expression MemberLookup (Type container_type,
 654                                                        Type qualifier_type, Type queried_type,
 655                                                        string name, MemberTypes mt,
 656                                                        BindingFlags bf, Location loc)
 657                 {
 658                         almostMatchedMembers.Clear ();
 659
 660                         MemberInfo [] mi = TypeManager.MemberLookup (container_type, qualifier_type,
 661                                                                      queried_type, mt, bf, name, almostMatchedMembers);
 662
 663                         if (mi == null)
 664                                 return null;
 665
 666                         if (mi.Length > 1) {
 667                                 bool is_interface = qualifier_type != null && qualifier_type.IsInterface;
 668                                 MemberInfo non_method = null;
 669                                 ArrayList methods = new ArrayList (2);
 670
 671                                 foreach (MemberInfo m in mi) {
 672                                         if (m is MethodBase) {
 673                                                 methods.Add (m);
 674                                                 continue;
 675                                         }
 676
 677                                         if (non_method == null) {
 678                                                 non_method = m;
 679                                                 continue;
 680                                         }
 681
 682                                         if (!is_interface)
 683                                                 continue;
 684
 685                                         Report.SymbolRelatedToPreviousError (m);
 686                                         Report.SymbolRelatedToPreviousError (non_method);
 687                                         Report.Error (229, loc, "Ambiguity between `{0}' and `{1}'",
 688                                                 TypeManager.GetFullNameSignature (m), TypeManager.GetFullNameSignature (non_method));
 689                                         return null;
 690                                 }
 691
 692                                 if (non_method != null && is_interface) {
 693                                         MethodBase method = (MethodBase)methods[0];
 694                                         Report.SymbolRelatedToPreviousError (method);
 695                                         Report.SymbolRelatedToPreviousError (non_method);
 696                                         Report.Warning (467, 2, loc, "Ambiguity between method `{0}' and non-method `{1}'. Using method `{0}'",
 697                                                 TypeManager.CSharpSignature (method), TypeManager.GetFullNameSignature (non_method));
 698                                 }
 699
 700                                 if (methods.Count == 0)
 701                                         return new MethodGroupExpr (mi, loc);
 702
 703                                 return new MethodGroupExpr (methods, loc);
 704                         }
 705
 706                         if (mi [0] is MethodBase)
 707                                 return new MethodGroupExpr (mi, loc);
 708
 709                         return ExprClassFromMemberInfo (container_type, mi [0], loc);
 710                 }
 711
 712                 public const MemberTypes AllMemberTypes =
 713                         MemberTypes.Constructor |
 714                         MemberTypes.Event       |
 715                         MemberTypes.Field       |
 716                         MemberTypes.Method      |
 717                         MemberTypes.NestedType  |
 718                         MemberTypes.Property;
 719
 720                 public const BindingFlags AllBindingFlags =
 721                         BindingFlags.Public |
 722                         BindingFlags.Static |
 723                         BindingFlags.Instance;
 724
 725                 public static Expression MemberLookup (Type container_type, Type queried_type,
 726                                                        string name, Location loc)
 727                 {
 728                         return MemberLookup (container_type, null, queried_type, name,
 729                                              AllMemberTypes, AllBindingFlags, loc);
 730                 }
 731
 732                 public static Expression MemberLookup (Type container_type, Type qualifier_type,
 733                                                        Type queried_type, string name, Location loc)
 734                 {
 735                         return MemberLookup (container_type, qualifier_type, queried_type,
 736                                              name, AllMemberTypes, AllBindingFlags, loc);
 737                 }
 738
 739                 public static Expression MethodLookup (EmitContext ec, Type queried_type,
 740                                                        string name, Location loc)
 741                 {
 742                         return MemberLookup (ec.ContainerType, null, queried_type, name,
 743                                              MemberTypes.Method, AllBindingFlags, loc);
 744                 }
 745
 746                 /// <summary>
 747                 ///   This is a wrapper for MemberLookup that is not used to "probe", but
 748                 ///   to find a final definition.  If the final definition is not found, we
 749                 ///   look for private members and display a useful debugging message if we
 750                 ///   find it.
 751                 /// </summary>
 752                 public static Expression MemberLookupFinal (EmitContext ec, Type qualifier_type,
 753                                                             Type queried_type, string name, Location loc)
 754                 {
 755                         return MemberLookupFinal (ec, qualifier_type, queried_type, name,
 756                                                   AllMemberTypes, AllBindingFlags, loc);
 757                 }
 758
 759                 public static Expression MemberLookupFinal (EmitContext ec, Type qualifier_type,
 760                                                             Type queried_type, string name,
 761                                                             MemberTypes mt, BindingFlags bf,
 762                                                             Location loc)
 763                 {
 764                         Expression e;
 765
 766                         int errors = Report.Errors;
 767
 768                         e = MemberLookup (ec.ContainerType, qualifier_type, queried_type, name, mt, bf, loc);
 769
 770                         if (e == null && errors == Report.Errors)
 771                                 // No errors were reported by MemberLookup, but there was an error.
 772                                 MemberLookupFailed (ec.ContainerType, qualifier_type, queried_type, name, null, true, loc);
 773
 774                         return e;
 775                 }
 776
 777                 public static void MemberLookupFailed (Type container_type, Type qualifier_type,
 778                                                        Type queried_type, string name,
 779                                                        string class_name, bool complain_if_none_found,
 780                                                        Location loc)
 781                 {
 782                         if (almostMatchedMembers.Count != 0) {
 783                                 for (int i = 0; i < almostMatchedMembers.Count; ++i) {
 784                                         MemberInfo m = (MemberInfo) almostMatchedMembers [i];
 785                                         for (int j = 0; j < i; ++j) {
 786                                                 if (m == almostMatchedMembers [j]) {
 787                                                         m = null;
 788                                                         break;
 789                                                 }
 790                                         }
 791                                         if (m == null)
 792                                                 continue;
 793
 794                                         Type declaring_type = m.DeclaringType;
 795
 796                                         Report.SymbolRelatedToPreviousError (m);
 797                                         if (qualifier_type == null) {
 798                                                 Report.Error (38, loc, "Cannot access a nonstatic member of outer type `{0}' via nested type `{1}'",
 799                                                               TypeManager.CSharpName (m.DeclaringType),
 800                                                               TypeManager.CSharpName (container_type));
 801
 802                                         } else if (qualifier_type != container_type &&
 803                                                    TypeManager.IsNestedFamilyAccessible (container_type, declaring_type)) {
 804                                                 // Although a derived class can access protected members of
 805                                                 // its base class it cannot do so through an instance of the
 806                                                 // base class (CS1540).  If the qualifier_type is a base of the
 807                                                 // ec.ContainerType and the lookup succeeds with the latter one,
 808                                                 // then we are in this situation.
 809                                                 Error_CannotAccessProtected (loc, m, qualifier_type, container_type);
 810                                         } else {
 811                                                 Report.SymbolRelatedToPreviousError (m);
 812                                                 ErrorIsInaccesible (loc, TypeManager.GetFullNameSignature (m));
 813                                         }
 814                                 }
 815                                 almostMatchedMembers.Clear ();
 816                                 return;
 817                         }
 818
 819                         MemberInfo[] lookup = null;
 820                         if (queried_type == null) {
 821                                 class_name = "global::";
 822                         } else {
 823                                 lookup = TypeManager.MemberLookup (queried_type, null, queried_type,
 824                                         AllMemberTypes, AllBindingFlags |
 825                                         BindingFlags.NonPublic, name, null);
 826                         }
 827
 828                         if (lookup == null) {
 829                                 if (!complain_if_none_found)
 830                                         return;
 831
 832                                 if (class_name != null)
 833                                         Report.Error (103, loc, "The name `{0}' does not exist in the context of `{1}'",
 834                                                 name, class_name);
 835                                 else
 836                                         Error_TypeDoesNotContainDefinition (loc, queried_type, name);
 837                                 return;
 838                         }
 839
 840                         if (TypeManager.MemberLookup (queried_type, null, queried_type,
 841                                                       AllMemberTypes, AllBindingFlags |
 842                                                       BindingFlags.NonPublic, name, null) == null) {
 843                                 if ((lookup.Length == 1) && (lookup [0] is Type)) {
 844                                         Type t = (Type) lookup [0];
 845
 846                                         Report.Error (305, loc,
 847                                                       "Using the generic type `{0}' " +
 848                                                       "requires {1} type arguments",
 849                                                       TypeManager.CSharpName (t),
 850                                                       TypeManager.GetNumberOfTypeArguments (t).ToString ());
 851                                         return;
 852                                 }
 853                         }
 854
 855                         MemberList ml = TypeManager.FindMembers (queried_type, MemberTypes.Constructor,
 856                                                                  BindingFlags.Static | BindingFlags.Instance | BindingFlags.Public | BindingFlags.DeclaredOnly, null, null);
 857                         if (name == ".ctor" && ml.Count == 0)
 858                         {
 859                                 Report.Error (143, loc, "The type `{0}' has no constructors defined", TypeManager.CSharpName (queried_type));
 860                                 return;
 861                         }
 862
 863                         Report.SymbolRelatedToPreviousError (lookup [0]);
 864                         ErrorIsInaccesible (loc, TypeManager.GetFullNameSignature (lookup [0]));
 865                 }
 866
 867                 /// <summary>
 868                 ///   Returns an expression that can be used to invoke operator true
 869                 ///   on the expression if it exists.
 870                 /// </summary>
 871                 static public Expression GetOperatorTrue (EmitContext ec, Expression e, Location loc)
 872                 {
 873                         return GetOperatorTrueOrFalse (ec, e, true, loc);
 874                 }
 875
 876                 /// <summary>
 877                 ///   Returns an expression that can be used to invoke operator false
 878                 ///   on the expression if it exists.
 879                 /// </summary>
 880                 static public Expression GetOperatorFalse (EmitContext ec, Expression e, Location loc)
 881                 {
 882                         return GetOperatorTrueOrFalse (ec, e, false, loc);
 883                 }
 884
 885                 static Expression GetOperatorTrueOrFalse (EmitContext ec, Expression e, bool is_true, Location loc)
 886                 {
 887                         MethodBase method;
 888                         Expression operator_group;
 889
 890                         if (TypeManager.IsNullableType (e.Type))
 891                                 return new Nullable.OperatorTrueOrFalse (e, is_true, loc).Resolve (ec);
 892
 893                         operator_group = MethodLookup (ec, e.Type, is_true ? "op_True" : "op_False", loc);
 894                         if (operator_group == null)
 895                                 return null;
 896
 897                         ArrayList arguments = new ArrayList ();
 898                         arguments.Add (new Argument (e, Argument.AType.Expression));
 899                         method = Invocation.OverloadResolve (
 900                                 ec, (MethodGroupExpr) operator_group, arguments, false, loc);
 901
 902                         if (method == null)
 903                                 return null;
 904
 905                         return new StaticCallExpr ((MethodInfo) method, arguments, loc);
 906                 }
 907
 908                 /// <summary>
 909                 ///   Resolves the expression `e' into a boolean expression: either through
 910                 ///   an implicit conversion, or through an `operator true' invocation
 911                 /// </summary>
 912                 public static Expression ResolveBoolean (EmitContext ec, Expression e, Location loc)
 913                 {
 914                         e = e.Resolve (ec);
 915                         if (e == null)
 916                                 return null;
 917
 918                         if (e.Type == TypeManager.bool_type)
 919                                 return e;
 920
 921                         Expression converted = Convert.ImplicitConversion (ec, e, TypeManager.bool_type, Location.Null);
 922
 923                         if (converted != null)
 924                                 return converted;
 925
 926                         //
 927                         // If no implicit conversion to bool exists, try using `operator true'
 928                         //
 929                         converted = Expression.GetOperatorTrue (ec, e, loc);
 930                         if (converted == null){
 931                                 e.Error_ValueCannotBeConverted (loc, TypeManager.bool_type, false);
 932                                 return null;
 933                         }
 934                         return converted;
 935                 }
 936
 937                 public virtual string ExprClassName
 938                 {
 939                         get {
 940                                 switch (eclass){
 941                                         case ExprClass.Invalid:
 942                                                 return "Invalid";
 943                                         case ExprClass.Value:
 944                                                 return "value";
 945                                         case ExprClass.Variable:
 946                                                 return "variable";
 947                                         case ExprClass.Namespace:
 948                                                 return "namespace";
 949                                         case ExprClass.Type:
 950                                                 return "type";
 951                                         case ExprClass.MethodGroup:
 952                                                 return "method group";
 953                                         case ExprClass.PropertyAccess:
 954                                                 return "property access";
 955                                         case ExprClass.EventAccess:
 956                                                 return "event access";
 957                                         case ExprClass.IndexerAccess:
 958                                                 return "indexer access";
 959                                         case ExprClass.Nothing:
 960                                                 return "null";
 961                                 }
 962                                 throw new Exception ("Should not happen");
 963                         }
 964                 }
 965
 966                 /// <summary>
 967                 ///   Reports that we were expecting `expr' to be of class `expected'
 968                 /// </summary>
 969                 public void Error_UnexpectedKind (DeclSpace ds, string expected, Location loc)
 970                 {
 971                         Error_UnexpectedKind (ds, expected, ExprClassName, loc);
 972                 }
 973
 974                 public void Error_UnexpectedKind (DeclSpace ds, string expected, string was, Location loc)
 975                 {
 976                         string name = GetSignatureForError ();
 977                         if (ds != null)
 978                                 name = ds.GetSignatureForError () + '.' + name;
 979
 980                         Report.Error (118, loc, "`{0}' is a `{1}' but a `{2}' was expected",
 981                               name, was, expected);
 982                 }
 983
 984                 public void Error_UnexpectedKind (ResolveFlags flags, Location loc)
 985                 {
 986                         string [] valid = new string [4];
 987                         int count = 0;
 988
 989                         if ((flags & ResolveFlags.VariableOrValue) != 0) {
 990                                 valid [count++] = "variable";
 991                                 valid [count++] = "value";
 992                         }
 993
 994                         if ((flags & ResolveFlags.Type) != 0)
 995                                 valid [count++] = "type";
 996
 997                         if ((flags & ResolveFlags.MethodGroup) != 0)
 998                                 valid [count++] = "method group";
 999
1000                         if (count == 0)
1001                                 valid [count++] = "unknown";
1002
1003                         StringBuilder sb = new StringBuilder (valid [0]);
1004                         for (int i = 1; i < count - 1; i++) {
1005                                 sb.Append ("', `");
1006                                 sb.Append (valid [i]);
1007                         }
1008                         if (count > 1) {
1009                                 sb.Append ("' or `");
1010                                 sb.Append (valid [count - 1]);
1011                         }
1012
1013                         Report.Error (119, loc,
1014                                 "Expression denotes a `{0}', where a `{1}' was expected", ExprClassName, sb.ToString ());
1015                 }
1016
1017                 public static void UnsafeError (Location loc)
1018                 {
1019                         Report.Error (214, loc, "Pointers and fixed size buffers may only be used in an unsafe context");
1020                 }
1021
1022                 //
1023                 // Load the object from the pointer.
1024                 //
1025                 public static void LoadFromPtr (ILGenerator ig, Type t)
1026                 {
1027                         if (t == TypeManager.int32_type)
1028                                 ig.Emit (OpCodes.Ldind_I4);
1029                         else if (t == TypeManager.uint32_type)
1030                                 ig.Emit (OpCodes.Ldind_U4);
1031                         else if (t == TypeManager.short_type)
1032                                 ig.Emit (OpCodes.Ldind_I2);
1033                         else if (t == TypeManager.ushort_type)
1034                                 ig.Emit (OpCodes.Ldind_U2);
1035                         else if (t == TypeManager.char_type)
1036                                 ig.Emit (OpCodes.Ldind_U2);
1037                         else if (t == TypeManager.byte_type)
1038                                 ig.Emit (OpCodes.Ldind_U1);
1039                         else if (t == TypeManager.sbyte_type)
1040                                 ig.Emit (OpCodes.Ldind_I1);
1041                         else if (t == TypeManager.uint64_type)
1042                                 ig.Emit (OpCodes.Ldind_I8);
1043                         else if (t == TypeManager.int64_type)
1044                                 ig.Emit (OpCodes.Ldind_I8);
1045                         else if (t == TypeManager.float_type)
1046                                 ig.Emit (OpCodes.Ldind_R4);
1047                         else if (t == TypeManager.double_type)
1048                                 ig.Emit (OpCodes.Ldind_R8);
1049                         else if (t == TypeManager.bool_type)
1050                                 ig.Emit (OpCodes.Ldind_I1);
1051                         else if (t == TypeManager.intptr_type)
1052                                 ig.Emit (OpCodes.Ldind_I);
1053                         else if (TypeManager.IsEnumType (t)) {
1054                                 if (t == TypeManager.enum_type)
1055                                         ig.Emit (OpCodes.Ldind_Ref);
1056                                 else
1057                                         LoadFromPtr (ig, TypeManager.EnumToUnderlying (t));
1058                         } else if (t.IsValueType || t.IsGenericParameter)
1059                                 ig.Emit (OpCodes.Ldobj, t);
1060                         else if (t.IsPointer)
1061                                 ig.Emit (OpCodes.Ldind_I);
1062                         else
1063                                 ig.Emit (OpCodes.Ldind_Ref);
1064                 }
1065
1066                 //
1067                 // The stack contains the pointer and the value of type `type'
1068                 //
1069                 public static void StoreFromPtr (ILGenerator ig, Type type)
1070                 {
1071                         if (TypeManager.IsEnumType (type))
1072                                 type = TypeManager.EnumToUnderlying (type);
1073                         if (type == TypeManager.int32_type || type == TypeManager.uint32_type)
1074                                 ig.Emit (OpCodes.Stind_I4);
1075                         else if (type == TypeManager.int64_type || type == TypeManager.uint64_type)
1076                                 ig.Emit (OpCodes.Stind_I8);
1077                         else if (type == TypeManager.char_type || type == TypeManager.short_type ||
1078                                  type == TypeManager.ushort_type)
1079                                 ig.Emit (OpCodes.Stind_I2);
1080                         else if (type == TypeManager.float_type)
1081                                 ig.Emit (OpCodes.Stind_R4);
1082                         else if (type == TypeManager.double_type)
1083                                 ig.Emit (OpCodes.Stind_R8);
1084                         else if (type == TypeManager.byte_type || type == TypeManager.sbyte_type ||
1085                                  type == TypeManager.bool_type)
1086                                 ig.Emit (OpCodes.Stind_I1);
1087                         else if (type == TypeManager.intptr_type)
1088                                 ig.Emit (OpCodes.Stind_I);
1089                         else if (type.IsValueType || type.IsGenericParameter)
1090                                 ig.Emit (OpCodes.Stobj, type);
1091                         else
1092                                 ig.Emit (OpCodes.Stind_Ref);
1093                 }
1094
1095                 //
1096                 // Returns the size of type `t' if known, otherwise, 0
1097                 //
1098                 public static int GetTypeSize (Type t)
1099                 {
1100                         t = TypeManager.TypeToCoreType (t);
1101                         if (t == TypeManager.int32_type ||
1102                             t == TypeManager.uint32_type ||
1103                             t == TypeManager.float_type)
1104                                 return 4;
1105                         else if (t == TypeManager.int64_type ||
1106                                  t == TypeManager.uint64_type ||
1107                                  t == TypeManager.double_type)
1108                                 return 8;
1109                         else if (t == TypeManager.byte_type ||
1110                                  t == TypeManager.sbyte_type ||
1111                                  t == TypeManager.bool_type)
1112                                 return 1;
1113                         else if (t == TypeManager.short_type ||
1114                                  t == TypeManager.char_type ||
1115                                  t == TypeManager.ushort_type)
1116                                 return 2;
1117                         else if (t == TypeManager.decimal_type)
1118                                 return 16;
1119                         else
1120                                 return 0;
1121                 }
1122
1123                 public static void Error_NegativeArrayIndex (Location loc)
1124                 {
1125                         Report.Error (248, loc, "Cannot create an array with a negative size");
1126                 }
1127
1128                 protected void Error_CannotCallAbstractBase (string name)
1129                 {
1130                         Report.Error (205, loc, "Cannot call an abstract base member `{0}'", name);
1131                 }
1132
1133                 //
1134                 // Converts `source' to an int, uint, long or ulong.
1135                 //
1136                 public Expression ExpressionToArrayArgument (EmitContext ec, Expression source, Location loc)
1137                 {
1138                         Expression target;
1139
1140                         using (ec.With (EmitContext.Flags.CheckState, true)) {
1141                                 target = Convert.ImplicitConversion (ec, source, TypeManager.int32_type, loc);
1142                                 if (target == null)
1143                                         target = Convert.ImplicitConversion (ec, source, TypeManager.uint32_type, loc);
1144                                 if (target == null)
1145                                         target = Convert.ImplicitConversion (ec, source, TypeManager.int64_type, loc);
1146                                 if (target == null)
1147                                         target = Convert.ImplicitConversion (ec, source, TypeManager.uint64_type, loc);
1148
1149                                 if (target == null) {
1150                                         source.Error_ValueCannotBeConverted (loc, TypeManager.int32_type, false);
1151                                         return null;
1152                                 }
1153                         }
1154
1155                         //
1156                         // Only positive constants are allowed at compile time
1157                         //
1158                         if (target is Constant){
1159                                 if (target is IntConstant){
1160                                         if (((IntConstant) target).Value < 0){
1161                                                 Error_NegativeArrayIndex (loc);
1162                                                 return null;
1163                                         }
1164                                 }
1165
1166                                 if (target is LongConstant){
1167                                         if (((LongConstant) target).Value < 0){
1168                                                 Error_NegativeArrayIndex (loc);
1169                                                 return null;
1170                                         }
1171                                 }
1172
1173                         }
1174
1175                         return target;
1176                 }
1177
1178         }
1179
1180         /// <summary>
1181         ///   This is just a base class for expressions that can
1182         ///   appear on statements (invocations, object creation,
1183         ///   assignments, post/pre increment and decrement).  The idea
1184         ///   being that they would support an extra Emition interface that
1185         ///   does not leave a result on the stack.
1186         /// </summary>
1187         public abstract class ExpressionStatement : Expression {
1188
1189                 public virtual ExpressionStatement ResolveStatement (EmitContext ec)
1190                 {
1191                         Expression e = Resolve (ec);
1192                         if (e == null)
1193                                 return null;
1194
1195                         ExpressionStatement es = e as ExpressionStatement;
1196                         if (es == null)
1197                                 Error (201, "Only assignment, call, increment, decrement and new object " +
1198                                        "expressions can be used as a statement");
1199
1200                         return es;
1201                 }
1202
1203                 /// <summary>
1204                 ///   Requests the expression to be emitted in a `statement'
1205                 ///   context.  This means that no new value is left on the
1206                 ///   stack after invoking this method (constrasted with
1207                 ///   Emit that will always leave a value on the stack).
1208                 /// </summary>
1209                 public abstract void EmitStatement (EmitContext ec);
1210         }
1211
1212         /// <summary>
1213         ///   This kind of cast is used to encapsulate the child
1214         ///   whose type is child.Type into an expression that is
1215         ///   reported to return "return_type".  This is used to encapsulate
1216         ///   expressions which have compatible types, but need to be dealt
1217         ///   at higher levels with.
1218         ///
1219         ///   For example, a "byte" expression could be encapsulated in one
1220         ///   of these as an "unsigned int".  The type for the expression
1221         ///   would be "unsigned int".
1222         ///
1223         /// </summary>
1224         public class EmptyCast : Expression {
1225                 protected readonly Expression child;
1226
1227                 public EmptyCast (Expression child, Type return_type)
1228                 {
1229                         eclass = child.eclass;
1230                         loc = child.Location;
1231                         type = return_type;
1232                         this.child = child;
1233                 }
1234
1235                 public override Expression DoResolve (EmitContext ec)
1236                 {
1237                         // This should never be invoked, we are born in fully
1238                         // initialized state.
1239
1240                         return this;
1241                 }
1242
1243                 public override void Emit (EmitContext ec)
1244                 {
1245                         child.Emit (ec);
1246                 }
1247
1248                 public override bool GetAttributableValue (Type valueType, out object value)
1249                 {
1250                         return child.GetAttributableValue (valueType, out value);
1251                 }
1252
1253         }
1254         /// <summary>
1255         ///     This is a numeric cast to a Decimal
1256         /// </summary>
1257         public class CastToDecimal : EmptyCast {
1258
1259                 MethodInfo conversion_operator;
1260
1261                 public CastToDecimal (Expression child)
1262                         : this (child, false)
1263                 {
1264                 }
1265
1266                 public CastToDecimal (Expression child, bool find_explicit)
1267                         : base (child, TypeManager.decimal_type)
1268                 {
1269                         conversion_operator = GetConversionOperator (find_explicit);
1270
1271                         if (conversion_operator == null)
1272                                 throw new InternalErrorException ("Outer conversion routine is out of sync");
1273                 }
1274
1275                 // Returns the implicit operator that converts from
1276                 // 'child.Type' to System.Decimal.
1277                 MethodInfo GetConversionOperator (bool find_explicit)
1278                 {
1279                         string operator_name = find_explicit ? "op_Explicit" : "op_Implicit";
1280
1281                         MemberInfo [] mi = TypeManager.MemberLookup (type, type, type, MemberTypes.Method,
1282                                 BindingFlags.Static | BindingFlags.Public, operator_name, null);
1283
1284                         foreach (MethodInfo oper in mi) {
1285                                 ParameterData pd = TypeManager.GetParameterData (oper);
1286
1287                                 if (pd.ParameterType (0) == child.Type && oper.ReturnType == type)
1288                                         return oper;
1289                         }
1290
1291                         return null;
1292                 }
1293                 public override void Emit (EmitContext ec)
1294                 {
1295                         ILGenerator ig = ec.ig;
1296                         child.Emit (ec);
1297
1298                         ig.Emit (OpCodes.Call, conversion_operator);
1299                 }
1300         }
1301
1302         /// <summary>
1303         ///     This is an explicit numeric cast from a Decimal
1304         /// </summary>
1305         public class CastFromDecimal : EmptyCast
1306         {
1307                 static IDictionary operators;
1308
1309                 public CastFromDecimal (Expression child, Type return_type)
1310                         : base (child, return_type)
1311                 {
1312                         if (child.Type != TypeManager.decimal_type)
1313                                 throw new InternalErrorException (
1314                                         "The expected type is Decimal, instead it is " + child.Type.FullName);
1315                 }
1316
1317                 // Returns the explicit operator that converts from an
1318                 // express of type System.Decimal to 'type'.
1319                 public Expression Resolve ()
1320                 {
1321                         if (operators == null) {
1322                                  MemberInfo[] all_oper = TypeManager.MemberLookup (TypeManager.decimal_type,
1323                                         TypeManager.decimal_type, TypeManager.decimal_type, MemberTypes.Method,
1324                                         BindingFlags.Static | BindingFlags.Public, "op_Explicit", null);
1325
1326                                 operators = new System.Collections.Specialized.HybridDictionary ();
1327                                 foreach (MethodInfo oper in all_oper) {
1328                                         ParameterData pd = TypeManager.GetParameterData (oper);
1329                                         if (pd.ParameterType (0) == TypeManager.decimal_type)
1330                                                 operators.Add (oper.ReturnType, oper);
1331                                 }
1332                         }
1333
1334                         return operators.Contains (type) ? this : null;
1335                 }
1336
1337                 public override void Emit (EmitContext ec)
1338                 {
1339                         ILGenerator ig = ec.ig;
1340                         child.Emit (ec);
1341
1342                         ig.Emit (OpCodes.Call, (MethodInfo)operators [type]);
1343                 }
1344         }
1345
1346         //
1347         // We need to special case this since an empty cast of
1348         // a NullLiteral is still a Constant
1349         //
1350         public class NullCast : Constant {
1351                 public Constant child;
1352
1353                 public NullCast (Constant child, Type return_type):
1354                         base (Location.Null)
1355                 {
1356                         eclass = child.eclass;
1357                         type = return_type;
1358                         this.child = child;
1359                 }
1360
1361                 override public string AsString ()
1362                 {
1363                         return "null";
1364                 }
1365
1366                 public override object GetValue ()
1367                 {
1368                         return null;
1369                 }
1370
1371                 public override Expression DoResolve (EmitContext ec)
1372                 {
1373                         // This should never be invoked, we are born in fully
1374                         // initialized state.
1375
1376                         return this;
1377                 }
1378
1379                 public override void Emit (EmitContext ec)
1380                 {
1381                         child.Emit (ec);
1382                 }
1383
1384                 public override Constant Increment ()
1385                 {
1386                         throw new NotSupportedException ();
1387                 }
1388
1389                 public override bool IsDefaultValue {
1390                         get {
1391                                 return true;
1392                         }
1393                 }
1394
1395                 public override bool IsNegative {
1396                         get {
1397                                 return false;
1398                         }
1399                 }
1400
1401                 public override Constant Reduce (bool inCheckedContext, Type target_type)
1402                 {
1403                         if (type == target_type)
1404                                 return child.Reduce (inCheckedContext, target_type);
1405
1406                         return null;
1407                 }
1408
1409         }
1410
1411
1412         /// <summary>
1413         ///  This class is used to wrap literals which belong inside Enums
1414         /// </summary>
1415         public class EnumConstant : Constant {
1416                 public Constant Child;
1417
1418                 public EnumConstant (Constant child, Type enum_type):
1419                         base (child.Location)
1420                 {
1421                         eclass = child.eclass;
1422                         this.Child = child;
1423                         type = enum_type;
1424                 }
1425
1426                 public override Expression DoResolve (EmitContext ec)
1427                 {
1428                         // This should never be invoked, we are born in fully
1429                         // initialized state.
1430
1431                         return this;
1432                 }
1433
1434                 public override void Emit (EmitContext ec)
1435                 {
1436                         Child.Emit (ec);
1437                 }
1438
1439                 public override bool GetAttributableValue (Type valueType, out object value)
1440                 {
1441                         value = GetTypedValue ();
1442                         return true;
1443                 }
1444
1445                 public override string GetSignatureForError()
1446                 {
1447                         return TypeManager.CSharpName (Type);
1448                 }
1449
1450                 public override object GetValue ()
1451                 {
1452                         return Child.GetValue ();
1453                 }
1454
1455                 public override object GetTypedValue ()
1456                 {
1457                         // FIXME: runtime is not ready to work with just emited enums
1458                         if (!RootContext.StdLib) {
1459                                 return Child.GetValue ();
1460                         }
1461
1462                         return System.Enum.ToObject (type, Child.GetValue ());
1463                 }
1464
1465                 public override string AsString ()
1466                 {
1467                         return Child.AsString ();
1468                 }
1469
1470                 public override DoubleConstant ConvertToDouble ()
1471                 {
1472                         return Child.ConvertToDouble ();
1473                 }
1474
1475                 public override FloatConstant ConvertToFloat ()
1476                 {
1477                         return Child.ConvertToFloat ();
1478                 }
1479
1480                 public override ULongConstant ConvertToULong ()
1481                 {
1482                         return Child.ConvertToULong ();
1483                 }
1484
1485                 public override LongConstant ConvertToLong ()
1486                 {
1487                         return Child.ConvertToLong ();
1488                 }
1489
1490                 public override UIntConstant ConvertToUInt ()
1491                 {
1492                         return Child.ConvertToUInt ();
1493                 }
1494
1495                 public override IntConstant ConvertToInt ()
1496                 {
1497                         return Child.ConvertToInt ();
1498                 }
1499
1500                 public override Constant Increment()
1501                 {
1502                         return new EnumConstant (Child.Increment (), type);
1503                 }
1504
1505                 public override bool IsDefaultValue {
1506                         get {
1507                                 return Child.IsDefaultValue;
1508                         }
1509                 }
1510
1511                 public override bool IsZeroInteger {
1512                         get { return Child.IsZeroInteger; }
1513                 }
1514
1515                 public override bool IsNegative {
1516                         get {
1517                                 return Child.IsNegative;
1518                         }
1519                 }
1520
1521                 public override Constant Reduce(bool inCheckedContext, Type target_type)
1522                 {
1523                         if (Child.Type == target_type)
1524                                 return Child;
1525
1526                         return Child.Reduce (inCheckedContext, target_type);
1527                 }
1528
1529                 public override Constant ToType (Type type, Location loc)
1530                 {
1531                         if (Type == type) {
1532                                 // This is workaround of mono bug. It can be removed when the latest corlib spreads enough
1533                                 if (TypeManager.IsEnumType (type.UnderlyingSystemType))
1534                                         return this;
1535
1536                                 if (type.UnderlyingSystemType != Child.Type)
1537                                         Child = Child.ToType (type.UnderlyingSystemType, loc);
1538                                 return this;
1539                         }
1540
1541                         if (!Convert.ImplicitStandardConversionExists (this, type)){
1542                                 Error_ValueCannotBeConverted (loc, type, false);
1543                                 return null;
1544                         }
1545
1546                         return Child.ToType (type, loc);
1547                 }
1548
1549         }
1550
1551         /// <summary>
1552         ///   This kind of cast is used to encapsulate Value Types in objects.
1553         ///
1554         ///   The effect of it is to box the value type emitted by the previous
1555         ///   operation.
1556         /// </summary>
1557         public class BoxedCast : EmptyCast {
1558
1559                 public BoxedCast (Expression expr, Type target_type)
1560                         : base (expr, target_type)
1561                 {
1562                         eclass = ExprClass.Value;
1563                 }
1564
1565                 public override Expression DoResolve (EmitContext ec)
1566                 {
1567                         // This should never be invoked, we are born in fully
1568                         // initialized state.
1569
1570                         return this;
1571                 }
1572
1573                 public override void Emit (EmitContext ec)
1574                 {
1575                         base.Emit (ec);
1576
1577                         ec.ig.Emit (OpCodes.Box, child.Type);
1578                 }
1579         }
1580
1581         public class UnboxCast : EmptyCast {
1582                 public UnboxCast (Expression expr, Type return_type)
1583                         : base (expr, return_type)
1584                 {
1585                 }
1586
1587                 public override Expression DoResolve (EmitContext ec)
1588                 {
1589                         // This should never be invoked, we are born in fully
1590                         // initialized state.
1591
1592                         return this;
1593                 }
1594
1595                 public override Expression DoResolveLValue (EmitContext ec, Expression right_side)
1596                 {
1597                         if (right_side == EmptyExpression.LValueMemberAccess || right_side == EmptyExpression.LValueMemberOutAccess)
1598                                 Report.Error (445, loc, "Cannot modify the result of an unboxing conversion");
1599                         return base.DoResolveLValue (ec, right_side);
1600                 }
1601
1602                 public override void Emit (EmitContext ec)
1603                 {
1604                         Type t = type;
1605                         ILGenerator ig = ec.ig;
1606
1607                         base.Emit (ec);
1608                         if (t.IsGenericParameter || t.IsGenericType && t.IsValueType)
1609                                 ig.Emit (OpCodes.Unbox_Any, t);
1610                         else {
1611                                 ig.Emit (OpCodes.Unbox, t);
1612
1613                                 LoadFromPtr (ig, t);
1614                         }
1615                 }
1616         }
1617
1618         /// <summary>
1619         ///   This is used to perform explicit numeric conversions.
1620         ///
1621         ///   Explicit numeric conversions might trigger exceptions in a checked
1622         ///   context, so they should generate the conv.ovf opcodes instead of
1623         ///   conv opcodes.
1624         /// </summary>
1625         public class ConvCast : EmptyCast {
1626                 public enum Mode : byte {
1627                         I1_U1, I1_U2, I1_U4, I1_U8, I1_CH,
1628                         U1_I1, U1_CH,
1629                         I2_I1, I2_U1, I2_U2, I2_U4, I2_U8, I2_CH,
1630                         U2_I1, U2_U1, U2_I2, U2_CH,
1631                         I4_I1, I4_U1, I4_I2, I4_U2, I4_U4, I4_U8, I4_CH,
1632                         U4_I1, U4_U1, U4_I2, U4_U2, U4_I4, U4_CH,
1633                         I8_I1, I8_U1, I8_I2, I8_U2, I8_I4, I8_U4, I8_U8, I8_CH,
1634                         U8_I1, U8_U1, U8_I2, U8_U2, U8_I4, U8_U4, U8_I8, U8_CH,
1635                         CH_I1, CH_U1, CH_I2,
1636                         R4_I1, R4_U1, R4_I2, R4_U2, R4_I4, R4_U4, R4_I8, R4_U8, R4_CH,
1637                         R8_I1, R8_U1, R8_I2, R8_U2, R8_I4, R8_U4, R8_I8, R8_U8, R8_CH, R8_R4
1638                 }
1639
1640                 Mode mode;
1641
1642                 public ConvCast (Expression child, Type return_type, Mode m)
1643                         : base (child, return_type)
1644                 {
1645                         mode = m;
1646                 }
1647
1648                 public override Expression DoResolve (EmitContext ec)
1649                 {
1650                         // This should never be invoked, we are born in fully
1651                         // initialized state.
1652
1653                         return this;
1654                 }
1655
1656                 public override string ToString ()
1657                 {
1658                         return String.Format ("ConvCast ({0}, {1})", mode, child);
1659                 }
1660
1661                 public override void Emit (EmitContext ec)
1662                 {
1663                         ILGenerator ig = ec.ig;
1664
1665                         base.Emit (ec);
1666
1667                         if (ec.CheckState){
1668                                 switch (mode){
1669                                 case Mode.I1_U1: ig.Emit (OpCodes.Conv_Ovf_U1); break;
1670                                 case Mode.I1_U2: ig.Emit (OpCodes.Conv_Ovf_U2); break;
1671                                 case Mode.I1_U4: ig.Emit (OpCodes.Conv_Ovf_U4); break;
1672                                 case Mode.I1_U8: ig.Emit (OpCodes.Conv_Ovf_U8); break;
1673                                 case Mode.I1_CH: ig.Emit (OpCodes.Conv_Ovf_U2); break;
1674
1675                                 case Mode.U1_I1: ig.Emit (OpCodes.Conv_Ovf_I1_Un); break;
1676                                 case Mode.U1_CH: /* nothing */ break;
1677
1678                                 case Mode.I2_I1: ig.Emit (OpCodes.Conv_Ovf_I1); break;
1679                                 case Mode.I2_U1: ig.Emit (OpCodes.Conv_Ovf_U1); break;
1680                                 case Mode.I2_U2: ig.Emit (OpCodes.Conv_Ovf_U2); break;
1681                                 case Mode.I2_U4: ig.Emit (OpCodes.Conv_Ovf_U4); break;
1682                                 case Mode.I2_U8: ig.Emit (OpCodes.Conv_Ovf_U8); break;
1683                                 case Mode.I2_CH: ig.Emit (OpCodes.Conv_Ovf_U2); break;
1684
1685                                 case Mode.U2_I1: ig.Emit (OpCodes.Conv_Ovf_I1_Un); break;
1686                                 case Mode.U2_U1: ig.Emit (OpCodes.Conv_Ovf_U1_Un); break;
1687                                 case Mode.U2_I2: ig.Emit (OpCodes.Conv_Ovf_I2_Un); break;
1688                                 case Mode.U2_CH: /* nothing */ break;
1689
1690                                 case Mode.I4_I1: ig.Emit (OpCodes.Conv_Ovf_I1); break;
1691                                 case Mode.I4_U1: ig.Emit (OpCodes.Conv_Ovf_U1); break;
1692                                 case Mode.I4_I2: ig.Emit (OpCodes.Conv_Ovf_I2); break;
1693                                 case Mode.I4_U4: ig.Emit (OpCodes.Conv_Ovf_U4); break;
1694                                 case Mode.I4_U2: ig.Emit (OpCodes.Conv_Ovf_U2); break;
1695                                 case Mode.I4_U8: ig.Emit (OpCodes.Conv_Ovf_U8); break;
1696                                 case Mode.I4_CH: ig.Emit (OpCodes.Conv_Ovf_U2); break;
1697
1698                                 case Mode.U4_I1: ig.Emit (OpCodes.Conv_Ovf_I1_Un); break;
1699                                 case Mode.U4_U1: ig.Emit (OpCodes.Conv_Ovf_U1_Un); break;
1700                                 case Mode.U4_I2: ig.Emit (OpCodes.Conv_Ovf_I2_Un); break;
1701                                 case Mode.U4_U2: ig.Emit (OpCodes.Conv_Ovf_U2_Un); break;
1702                                 case Mode.U4_I4: ig.Emit (OpCodes.Conv_Ovf_I4_Un); break;
1703                                 case Mode.U4_CH: ig.Emit (OpCodes.Conv_Ovf_U2_Un); break;
1704
1705                                 case Mode.I8_I1: ig.Emit (OpCodes.Conv_Ovf_I1); break;
1706                                 case Mode.I8_U1: ig.Emit (OpCodes.Conv_Ovf_U1); break;
1707                                 case Mode.I8_I2: ig.Emit (OpCodes.Conv_Ovf_I2); break;
1708                                 case Mode.I8_U2: ig.Emit (OpCodes.Conv_Ovf_U2); break;
1709                                 case Mode.I8_I4: ig.Emit (OpCodes.Conv_Ovf_I4); break;
1710                                 case Mode.I8_U4: ig.Emit (OpCodes.Conv_Ovf_U4); break;
1711                                 case Mode.I8_U8: ig.Emit (OpCodes.Conv_Ovf_U8); break;
1712                                 case Mode.I8_CH: ig.Emit (OpCodes.Conv_Ovf_U2); break;
1713
1714                                 case Mode.U8_I1: ig.Emit (OpCodes.Conv_Ovf_I1_Un); break;
1715                                 case Mode.U8_U1: ig.Emit (OpCodes.Conv_Ovf_U1_Un); break;
1716                                 case Mode.U8_I2: ig.Emit (OpCodes.Conv_Ovf_I2_Un); break;
1717                                 case Mode.U8_U2: ig.Emit (OpCodes.Conv_Ovf_U2_Un); break;
1718                                 case Mode.U8_I4: ig.Emit (OpCodes.Conv_Ovf_I4_Un); break;
1719                                 case Mode.U8_U4: ig.Emit (OpCodes.Conv_Ovf_U4_Un); break;
1720                                 case Mode.U8_I8: ig.Emit (OpCodes.Conv_Ovf_I8_Un); break;
1721                                 case Mode.U8_CH: ig.Emit (OpCodes.Conv_Ovf_U2_Un); break;
1722
1723                                 case Mode.CH_I1: ig.Emit (OpCodes.Conv_Ovf_I1_Un); break;
1724                                 case Mode.CH_U1: ig.Emit (OpCodes.Conv_Ovf_U1_Un); break;
1725                                 case Mode.CH_I2: ig.Emit (OpCodes.Conv_Ovf_I2_Un); break;
1726
1727                                 case Mode.R4_I1: ig.Emit (OpCodes.Conv_Ovf_I1); break;
1728                                 case Mode.R4_U1: ig.Emit (OpCodes.Conv_Ovf_U1); break;
1729                                 case Mode.R4_I2: ig.Emit (OpCodes.Conv_Ovf_I2); break;
1730                                 case Mode.R4_U2: ig.Emit (OpCodes.Conv_Ovf_U2); break;
1731                                 case Mode.R4_I4: ig.Emit (OpCodes.Conv_Ovf_I4); break;
1732                                 case Mode.R4_U4: ig.Emit (OpCodes.Conv_Ovf_U4); break;
1733                                 case Mode.R4_I8: ig.Emit (OpCodes.Conv_Ovf_I8); break;
1734                                 case Mode.R4_U8: ig.Emit (OpCodes.Conv_Ovf_U8); break;
1735                                 case Mode.R4_CH: ig.Emit (OpCodes.Conv_Ovf_U2); break;
1736
1737                                 case Mode.R8_I1: ig.Emit (OpCodes.Conv_Ovf_I1); break;
1738                                 case Mode.R8_U1: ig.Emit (OpCodes.Conv_Ovf_U1); break;
1739                                 case Mode.R8_I2: ig.Emit (OpCodes.Conv_Ovf_I2); break;
1740                                 case Mode.R8_U2: ig.Emit (OpCodes.Conv_Ovf_U2); break;
1741                                 case Mode.R8_I4: ig.Emit (OpCodes.Conv_Ovf_I4); break;
1742                                 case Mode.R8_U4: ig.Emit (OpCodes.Conv_Ovf_U4); break;
1743                                 case Mode.R8_I8: ig.Emit (OpCodes.Conv_Ovf_I8); break;
1744                                 case Mode.R8_U8: ig.Emit (OpCodes.Conv_Ovf_U8); break;
1745                                 case Mode.R8_CH: ig.Emit (OpCodes.Conv_Ovf_U2); break;
1746                                 case Mode.R8_R4: ig.Emit (OpCodes.Conv_R4); break;
1747                                 }
1748                         } else {
1749                                 switch (mode){
1750                                 case Mode.I1_U1: ig.Emit (OpCodes.Conv_U1); break;
1751                                 case Mode.I1_U2: ig.Emit (OpCodes.Conv_U2); break;
1752                                 case Mode.I1_U4: ig.Emit (OpCodes.Conv_U4); break;
1753                                 case Mode.I1_U8: ig.Emit (OpCodes.Conv_I8); break;
1754                                 case Mode.I1_CH: ig.Emit (OpCodes.Conv_U2); break;
1755
1756                                 case Mode.U1_I1: ig.Emit (OpCodes.Conv_I1); break;
1757                                 case Mode.U1_CH: ig.Emit (OpCodes.Conv_U2); break;
1758
1759                                 case Mode.I2_I1: ig.Emit (OpCodes.Conv_I1); break;
1760                                 case Mode.I2_U1: ig.Emit (OpCodes.Conv_U1); break;
1761                                 case Mode.I2_U2: ig.Emit (OpCodes.Conv_U2); break;
1762                                 case Mode.I2_U4: ig.Emit (OpCodes.Conv_U4); break;
1763                                 case Mode.I2_U8: ig.Emit (OpCodes.Conv_I8); break;
1764                                 case Mode.I2_CH: ig.Emit (OpCodes.Conv_U2); break;
1765
1766                                 case Mode.U2_I1: ig.Emit (OpCodes.Conv_I1); break;
1767                                 case Mode.U2_U1: ig.Emit (OpCodes.Conv_U1); break;
1768                                 case Mode.U2_I2: ig.Emit (OpCodes.Conv_I2); break;
1769                                 case Mode.U2_CH: /* nothing */ break;
1770
1771                                 case Mode.I4_I1: ig.Emit (OpCodes.Conv_I1); break;
1772                                 case Mode.I4_U1: ig.Emit (OpCodes.Conv_U1); break;
1773                                 case Mode.I4_I2: ig.Emit (OpCodes.Conv_I2); break;
1774                                 case Mode.I4_U4: /* nothing */ break;
1775                                 case Mode.I4_U2: ig.Emit (OpCodes.Conv_U2); break;
1776                                 case Mode.I4_U8: ig.Emit (OpCodes.Conv_I8); break;
1777                                 case Mode.I4_CH: ig.Emit (OpCodes.Conv_U2); break;
1778
1779                                 case Mode.U4_I1: ig.Emit (OpCodes.Conv_I1); break;
1780                                 case Mode.U4_U1: ig.Emit (OpCodes.Conv_U1); break;
1781                                 case Mode.U4_I2: ig.Emit (OpCodes.Conv_I2); break;
1782                                 case Mode.U4_U2: ig.Emit (OpCodes.Conv_U2); break;
1783                                 case Mode.U4_I4: /* nothing */ break;
1784                                 case Mode.U4_CH: ig.Emit (OpCodes.Conv_U2); break;
1785
1786                                 case Mode.I8_I1: ig.Emit (OpCodes.Conv_I1); break;
1787                                 case Mode.I8_U1: ig.Emit (OpCodes.Conv_U1); break;
1788                                 case Mode.I8_I2: ig.Emit (OpCodes.Conv_I2); break;
1789                                 case Mode.I8_U2: ig.Emit (OpCodes.Conv_U2); break;
1790                                 case Mode.I8_I4: ig.Emit (OpCodes.Conv_I4); break;
1791                                 case Mode.I8_U4: ig.Emit (OpCodes.Conv_U4); break;
1792                                 case Mode.I8_U8: /* nothing */ break;
1793                                 case Mode.I8_CH: ig.Emit (OpCodes.Conv_U2); break;
1794
1795                                 case Mode.U8_I1: ig.Emit (OpCodes.Conv_I1); break;
1796                                 case Mode.U8_U1: ig.Emit (OpCodes.Conv_U1); break;
1797                                 case Mode.U8_I2: ig.Emit (OpCodes.Conv_I2); break;
1798                                 case Mode.U8_U2: ig.Emit (OpCodes.Conv_U2); break;
1799                                 case Mode.U8_I4: ig.Emit (OpCodes.Conv_I4); break;
1800                                 case Mode.U8_U4: ig.Emit (OpCodes.Conv_U4); break;
1801                                 case Mode.U8_I8: /* nothing */ break;
1802                                 case Mode.U8_CH: ig.Emit (OpCodes.Conv_U2); break;
1803
1804                                 case Mode.CH_I1: ig.Emit (OpCodes.Conv_I1); break;
1805                                 case Mode.CH_U1: ig.Emit (OpCodes.Conv_U1); break;
1806                                 case Mode.CH_I2: ig.Emit (OpCodes.Conv_I2); break;
1807
1808                                 case Mode.R4_I1: ig.Emit (OpCodes.Conv_I1); break;
1809                                 case Mode.R4_U1: ig.Emit (OpCodes.Conv_U1); break;
1810                                 case Mode.R4_I2: ig.Emit (OpCodes.Conv_I2); break;
1811                                 case Mode.R4_U2: ig.Emit (OpCodes.Conv_U2); break;
1812                                 case Mode.R4_I4: ig.Emit (OpCodes.Conv_I4); break;
1813                                 case Mode.R4_U4: ig.Emit (OpCodes.Conv_U4); break;
1814                                 case Mode.R4_I8: ig.Emit (OpCodes.Conv_I8); break;
1815                                 case Mode.R4_U8: ig.Emit (OpCodes.Conv_U8); break;
1816                                 case Mode.R4_CH: ig.Emit (OpCodes.Conv_U2); break;
1817
1818                                 case Mode.R8_I1: ig.Emit (OpCodes.Conv_I1); break;
1819                                 case Mode.R8_U1: ig.Emit (OpCodes.Conv_U1); break;
1820                                 case Mode.R8_I2: ig.Emit (OpCodes.Conv_I2); break;
1821                                 case Mode.R8_U2: ig.Emit (OpCodes.Conv_U2); break;
1822                                 case Mode.R8_I4: ig.Emit (OpCodes.Conv_I4); break;
1823                                 case Mode.R8_U4: ig.Emit (OpCodes.Conv_U4); break;
1824                                 case Mode.R8_I8: ig.Emit (OpCodes.Conv_I8); break;
1825                                 case Mode.R8_U8: ig.Emit (OpCodes.Conv_U8); break;
1826                                 case Mode.R8_CH: ig.Emit (OpCodes.Conv_U2); break;
1827                                 case Mode.R8_R4: ig.Emit (OpCodes.Conv_R4); break;
1828                                 }
1829                         }
1830                 }
1831         }
1832
1833         public class OpcodeCast : EmptyCast {
1834                 OpCode op, op2;
1835                 bool second_valid;
1836
1837                 public OpcodeCast (Expression child, Type return_type, OpCode op)
1838                         : base (child, return_type)
1839
1840                 {
1841                         this.op = op;
1842                         second_valid = false;
1843                 }
1844
1845                 public OpcodeCast (Expression child, Type return_type, OpCode op, OpCode op2)
1846                         : base (child, return_type)
1847
1848                 {
1849                         this.op = op;
1850                         this.op2 = op2;
1851                         second_valid = true;
1852                 }
1853
1854                 public override Expression DoResolve (EmitContext ec)
1855                 {
1856                         // This should never be invoked, we are born in fully
1857                         // initialized state.
1858
1859                         return this;
1860                 }
1861
1862                 public override void Emit (EmitContext ec)
1863                 {
1864                         base.Emit (ec);
1865                         ec.ig.Emit (op);
1866
1867                         if (second_valid)
1868                                 ec.ig.Emit (op2);
1869                 }
1870         }
1871
1872         /// <summary>
1873         ///   This kind of cast is used to encapsulate a child and cast it
1874         ///   to the class requested
1875         /// </summary>
1876         public class ClassCast : EmptyCast {
1877                 public ClassCast (Expression child, Type return_type)
1878                         : base (child, return_type)
1879
1880                 {
1881                 }
1882
1883                 public override Expression DoResolve (EmitContext ec)
1884                 {
1885                         // This should never be invoked, we are born in fully
1886                         // initialized state.
1887
1888                         return this;
1889                 }
1890
1891                 public override void Emit (EmitContext ec)
1892                 {
1893                         base.Emit (ec);
1894
1895                         if (child.Type.IsGenericParameter)
1896                                 ec.ig.Emit (OpCodes.Box, child.Type);
1897
1898                         if (type.IsGenericParameter)
1899                                 ec.ig.Emit (OpCodes.Unbox_Any, type);
1900                         else
1901                                 ec.ig.Emit (OpCodes.Castclass, type);
1902                 }
1903         }
1904
1905         /// <summary>
1906         ///   SimpleName expressions are formed of a single word and only happen at the beginning
1907         ///   of a dotted-name.
1908         /// </summary>
1909         public class SimpleName : Expression {
1910                 public string Name;
1911                 public readonly TypeArguments Arguments;
1912                 bool in_transit;
1913
1914                 public SimpleName (string name, Location l)
1915                 {
1916                         Name = name;
1917                         loc = l;
1918                 }
1919
1920                 public SimpleName (string name, TypeArguments args, Location l)
1921                 {
1922                         Name = name;
1923                         Arguments = args;
1924                         loc = l;
1925                 }
1926
1927                 public SimpleName (string name, TypeParameter[] type_params, Location l)
1928                 {
1929                         Name = name;
1930                         loc = l;
1931
1932                         Arguments = new TypeArguments (l);
1933                         foreach (TypeParameter type_param in type_params)
1934                                 Arguments.Add (new TypeParameterExpr (type_param, l));
1935                 }
1936
1937                 public static string RemoveGenericArity (string name)
1938                 {
1939                         int start = 0;
1940                         StringBuilder sb = new StringBuilder ();
1941                         while (start < name.Length) {
1942                                 int pos = name.IndexOf ('`', start);
1943                                 if (pos < 0) {
1944                                         sb.Append (name.Substring (start));
1945                                         break;
1946                                 }
1947
1948                                 sb.Append (name.Substring (start, pos-start));
1949
1950                                 pos++;
1951                                 while ((pos < name.Length) && Char.IsNumber (name [pos]))
1952                                         pos++;
1953
1954                                 start = pos;
1955                         }
1956
1957                         return sb.ToString ();
1958                 }
1959
1960                 public SimpleName GetMethodGroup ()
1961                 {
1962                         return new SimpleName (RemoveGenericArity (Name), Arguments, loc);
1963                 }
1964
1965                 public static void Error_ObjectRefRequired (EmitContext ec, Location l, string name)
1966                 {
1967                         if (ec.IsFieldInitializer)
1968                                 Report.Error (236, l,
1969                                         "A field initializer cannot reference the nonstatic field, method, or property `{0}'",
1970                                         name);
1971                         else
1972                                 Report.Error (
1973                                         120, l, "`{0}': An object reference is required for the nonstatic field, method or property",
1974                                         name);
1975                 }
1976
1977                 public bool IdenticalNameAndTypeName (EmitContext ec, Expression resolved_to, Location loc)
1978                 {
1979                         return resolved_to != null && resolved_to.Type != null &&
1980                                 resolved_to.Type.Name == Name &&
1981                                 (ec.DeclContainer.LookupType (Name, loc, /* ignore_cs0104 = */ true) != null);
1982                 }
1983
1984                 public override Expression DoResolve (EmitContext ec)
1985                 {
1986                         return SimpleNameResolve (ec, null, false);
1987                 }
1988
1989                 public override Expression DoResolveLValue (EmitContext ec, Expression right_side)
1990                 {
1991                         return SimpleNameResolve (ec, right_side, false);
1992                 }
1993
1994
1995                 public Expression DoResolve (EmitContext ec, bool intermediate)
1996                 {
1997                         return SimpleNameResolve (ec, null, intermediate);
1998                 }
1999
2000                 private bool IsNestedChild (Type t, Type parent)
2001                 {
2002                         if (parent == null)
2003                                 return false;
2004
2005                         while (parent != null) {
2006                                 parent = TypeManager.DropGenericTypeArguments (parent);
2007                                 if (TypeManager.IsNestedChildOf (t, parent))
2008                                         return true;
2009
2010                                 parent = parent.BaseType;
2011                         }
2012
2013                         return false;
2014                 }
2015
2016                 FullNamedExpression ResolveNested (IResolveContext ec, Type t)
2017                 {
2018                         if (!t.IsGenericTypeDefinition)
2019                                 return null;
2020
2021                         DeclSpace ds = ec.DeclContainer;
2022                         while (ds != null) {
2023                                 if (IsNestedChild (t, ds.TypeBuilder))
2024                                         break;
2025
2026                                 ds = ds.Parent;
2027                         }
2028
2029                         if (ds == null)
2030                                 return null;
2031
2032                         Type[] gen_params = t.GetGenericArguments ();
2033
2034                         int arg_count = Arguments != null ? Arguments.Count : 0;
2035
2036                         for (; (ds != null) && ds.IsGeneric; ds = ds.Parent) {
2037                                 if (arg_count + ds.CountTypeParameters == gen_params.Length) {
2038                                         TypeArguments new_args = new TypeArguments (loc);
2039                                         foreach (TypeParameter param in ds.TypeParameters)
2040                                                 new_args.Add (new TypeParameterExpr (param, loc));
2041
2042                                         if (Arguments != null)
2043                                                 new_args.Add (Arguments);
2044
2045                                         return new ConstructedType (t, new_args, loc);
2046                                 }
2047                         }
2048
2049                         return null;
2050                 }
2051
2052                 public override FullNamedExpression ResolveAsTypeStep (IResolveContext ec, bool silent)
2053                 {
2054                         FullNamedExpression fne = ec.GenericDeclContainer.LookupGeneric (Name, loc);
2055                         if (fne != null)
2056                                 return fne.ResolveAsTypeStep (ec, silent);
2057
2058                         int errors = Report.Errors;
2059                         fne = ec.DeclContainer.LookupType (Name, loc, /*ignore_cs0104=*/ false);
2060
2061                         if (fne != null) {
2062                                 if (fne.Type == null)
2063                                         return fne;
2064
2065                                 FullNamedExpression nested = ResolveNested (ec, fne.Type);
2066                                 if (nested != null)
2067                                         return nested.ResolveAsTypeStep (ec, false);
2068
2069                                 if (Arguments != null) {
2070                                         ConstructedType ct = new ConstructedType (fne, Arguments, loc);
2071                                         return ct.ResolveAsTypeStep (ec, false);
2072                                 }
2073
2074                                 return fne;
2075                         }
2076
2077                         if (silent || errors != Report.Errors)
2078                                 return null;
2079
2080                         MemberCore mc = ec.DeclContainer.GetDefinition (Name);
2081                         if (mc != null) {
2082                                 Error_UnexpectedKind (ec.DeclContainer, "type", GetMemberType (mc), loc);
2083                                 return null;
2084                         }
2085
2086                         string ns = ec.DeclContainer.NamespaceEntry.NS.Name;
2087                         string fullname = (ns.Length > 0) ? ns + "." + Name : Name;
2088                         foreach (Assembly a in RootNamespace.Global.Assemblies) {
2089                                 Type type = a.GetType (fullname);
2090                                 if (type != null) {
2091                                         Report.SymbolRelatedToPreviousError (type);
2092                                         Expression.ErrorIsInaccesible (loc, fullname);
2093                                         return null;
2094                                 }
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 &&
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                         type = TypeManager.object_type;
2807                         loc = l;
2808                 }
2809
2810                 public MethodGroupExpr (ArrayList list, Location l)
2811                 {
2812                         Methods = new MethodBase [list.Count];
2813
2814                         try {
2815                                 list.CopyTo (Methods, 0);
2816                         } catch {
2817                                 foreach (MemberInfo m in list){
2818                                         if (!(m is MethodBase)){
2819                                                 Console.WriteLine ("Name " + m.Name);
2820                                                 Console.WriteLine ("Found a: " + m.GetType ().FullName);
2821                                         }
2822                                 }
2823                                 throw;
2824                         }
2825
2826                         loc = l;
2827                         eclass = ExprClass.MethodGroup;
2828                         type = TypeManager.object_type;
2829                 }
2830
2831                 public override Type DeclaringType {
2832                         get {
2833                                 //
2834                                 // We assume that the top-level type is in the end
2835                                 //
2836                                 return Methods [Methods.Length - 1].DeclaringType;
2837                                 //return Methods [0].DeclaringType;
2838                         }
2839                 }
2840
2841                 public bool HasTypeArguments {
2842                         get {
2843                                 return has_type_arguments;
2844                         }
2845
2846                         set {
2847                                 has_type_arguments = value;
2848                         }
2849                 }
2850
2851                 public bool IdenticalTypeName {
2852                         get {
2853                                 return identical_type_name;
2854                         }
2855
2856                         set {
2857                                 identical_type_name = value;
2858                         }
2859                 }
2860
2861                 public bool IsBase {
2862                         get {
2863                                 return is_base;
2864                         }
2865                         set {
2866                                 is_base = value;
2867                         }
2868                 }
2869
2870                 public override string GetSignatureForError ()
2871                 {
2872                         return TypeManager.CSharpSignature (Methods [0]);
2873                 }
2874
2875                 public override string Name {
2876                         get {
2877                                 return Methods [0].Name;
2878                         }
2879                 }
2880
2881                 public override bool IsInstance {
2882                         get {
2883                                 foreach (MethodBase mb in Methods)
2884                                         if (!mb.IsStatic)
2885                                                 return true;
2886
2887                                 return false;
2888                         }
2889                 }
2890
2891                 public override bool IsStatic {
2892                         get {
2893                                 foreach (MethodBase mb in Methods)
2894                                         if (mb.IsStatic)
2895                                                 return true;
2896
2897                                 return false;
2898                         }
2899                 }
2900
2901                 public override Expression ResolveMemberAccess (EmitContext ec, Expression left, Location loc,
2902                                                                 SimpleName original)
2903                 {
2904                         if (!(left is TypeExpr) &&
2905                             original != null && original.IdenticalNameAndTypeName (ec, left, loc))
2906                                 IdenticalTypeName = true;
2907
2908                         return base.ResolveMemberAccess (ec, left, loc, original);
2909                 }
2910
2911                 override public Expression DoResolve (EmitContext ec)
2912                 {
2913                         if (!IsInstance)
2914                                 InstanceExpression = null;
2915
2916                         if (InstanceExpression != null) {
2917                                 InstanceExpression = InstanceExpression.DoResolve (ec);
2918                                 if (InstanceExpression == null)
2919                                         return null;
2920                         }
2921
2922                         return this;
2923                 }
2924
2925                 public void ReportUsageError ()
2926                 {
2927                         Report.Error (654, loc, "Method `" + DeclaringType + "." +
2928                                       Name + "()' is referenced without parentheses");
2929                 }
2930
2931                 override public void Emit (EmitContext ec)
2932                 {
2933                         ReportUsageError ();
2934                 }
2935
2936                 bool RemoveMethods (bool keep_static)
2937                 {
2938                         ArrayList smethods = new ArrayList ();
2939
2940                         foreach (MethodBase mb in Methods){
2941                                 if (mb.IsStatic == keep_static)
2942                                         smethods.Add (mb);
2943                         }
2944
2945                         if (smethods.Count == 0)
2946                                 return false;
2947
2948                         Methods = new MethodBase [smethods.Count];
2949                         smethods.CopyTo (Methods, 0);
2950
2951                         return true;
2952                 }
2953
2954                 /// <summary>
2955                 ///   Removes any instance methods from the MethodGroup, returns
2956                 ///   false if the resulting set is empty.
2957                 /// </summary>
2958                 public bool RemoveInstanceMethods ()
2959                 {
2960                         return RemoveMethods (true);
2961                 }
2962
2963                 /// <summary>
2964                 ///   Removes any static methods from the MethodGroup, returns
2965                 ///   false if the resulting set is empty.
2966                 /// </summary>
2967                 public bool RemoveStaticMethods ()
2968                 {
2969                         return RemoveMethods (false);
2970                 }
2971
2972                 public Expression ResolveGeneric (EmitContext ec, TypeArguments args)
2973                 {
2974                         if (args.Resolve (ec) == false)
2975                                 return null;
2976
2977                         Type[] atypes = args.Arguments;
2978
2979                         int first_count = 0;
2980                         MethodInfo first = null;
2981
2982                         ArrayList list = new ArrayList ();
2983                         foreach (MethodBase mb in Methods) {
2984                                 MethodInfo mi = mb as MethodInfo;
2985                                 if ((mi == null) || !mi.IsGenericMethod)
2986                                         continue;
2987
2988                                 Type[] gen_params = mi.GetGenericArguments ();
2989
2990                                 if (first == null) {
2991                                         first = mi;
2992                                         first_count = gen_params.Length;
2993                                 }
2994
2995                                 if (gen_params.Length != atypes.Length)
2996                                         continue;
2997
2998                                 list.Add (mi.MakeGenericMethod (atypes));
2999                         }
3000
3001                         if (list.Count > 0) {
3002                                 MethodGroupExpr new_mg = new MethodGroupExpr (list, Location);
3003                                 new_mg.InstanceExpression = InstanceExpression;
3004                                 new_mg.HasTypeArguments = true;
3005                                 new_mg.IsBase = IsBase;
3006                                 return new_mg;
3007                         }
3008
3009                         if (first != null)
3010                                 Report.Error (
3011                                         305, loc, "Using the generic method `{0}' " +
3012                                         "requires {1} type arguments", Name,
3013                                         first_count.ToString ());
3014                         else
3015                                 Report.Error (
3016                                         308, loc, "The non-generic method `{0}' " +
3017                                         "cannot be used with type arguments", Name);
3018
3019                         return null;
3020                 }
3021         }
3022
3023         /// <summary>
3024         ///   Fully resolved expression that evaluates to a Field
3025         /// </summary>
3026         public class FieldExpr : MemberExpr, IAssignMethod, IMemoryLocation, IVariable {
3027                 public readonly FieldInfo FieldInfo;
3028                 VariableInfo variable_info;
3029
3030                 LocalTemporary temp;
3031                 bool prepared;
3032                 bool in_initializer;
3033
3034                 public FieldExpr (FieldInfo fi, Location l, bool in_initializer):
3035                         this (fi, l)
3036                 {
3037                         this.in_initializer = in_initializer;
3038                 }
3039
3040                 public FieldExpr (FieldInfo fi, Location l)
3041                 {
3042                         FieldInfo = fi;
3043                         eclass = ExprClass.Variable;
3044                         type = TypeManager.TypeToCoreType (fi.FieldType);
3045                         loc = l;
3046                 }
3047
3048                 public override string Name {
3049                         get {
3050                                 return FieldInfo.Name;
3051                         }
3052                 }
3053
3054                 public override bool IsInstance {
3055                         get {
3056                                 return !FieldInfo.IsStatic;
3057                         }
3058                 }
3059
3060                 public override bool IsStatic {
3061                         get {
3062                                 return FieldInfo.IsStatic;
3063                         }
3064                 }
3065
3066                 public override Type DeclaringType {
3067                         get {
3068                                 return FieldInfo.DeclaringType;
3069                         }
3070                 }
3071
3072                 public override string GetSignatureForError ()
3073                 {
3074                         return TypeManager.GetFullNameSignature (FieldInfo);
3075                 }
3076
3077                 public VariableInfo VariableInfo {
3078                         get {
3079                                 return variable_info;
3080                         }
3081                 }
3082
3083                 public override Expression ResolveMemberAccess (EmitContext ec, Expression left, Location loc,
3084                                                                 SimpleName original)
3085                 {
3086                         FieldInfo fi = TypeManager.GetGenericFieldDefinition (FieldInfo);
3087
3088                         Type t = fi.FieldType;
3089
3090                         if (fi.IsLiteral || (fi.IsInitOnly && t == TypeManager.decimal_type)) {
3091                                 IConstant ic = TypeManager.GetConstant (fi);
3092                                 if (ic == null) {
3093                                         if (fi.IsLiteral) {
3094                                                 ic = new ExternalConstant (fi);
3095                                         } else {
3096                                                 ic = ExternalConstant.CreateDecimal (fi);
3097                                                 if (ic == null) {
3098                                                         return base.ResolveMemberAccess (ec, left, loc, original);
3099                                                 }
3100                                         }
3101                                         TypeManager.RegisterConstant (fi, ic);
3102                                 }
3103
3104                                 bool left_is_type = left is TypeExpr;
3105                                 if (!left_is_type && (original == null || !original.IdenticalNameAndTypeName (ec, left, loc))) {
3106                                         Report.SymbolRelatedToPreviousError (FieldInfo);
3107                                         error176 (loc, TypeManager.GetFullNameSignature (FieldInfo));
3108                                         return null;
3109                                 }
3110
3111                                 if (ic.ResolveValue ()) {
3112                                         if (!ec.IsInObsoleteScope)
3113                                                 ic.CheckObsoleteness (loc);
3114                                 }
3115
3116                                 return ic.Value;
3117                         }
3118
3119                         if (t.IsPointer && !ec.InUnsafe) {
3120                                 UnsafeError (loc);
3121                                 return null;
3122                         }
3123
3124                         return base.ResolveMemberAccess (ec, left, loc, original);
3125                 }
3126
3127                 override public Expression DoResolve (EmitContext ec)
3128                 {
3129                         return DoResolve (ec, false, false);
3130                 }
3131
3132                 Expression DoResolve (EmitContext ec, bool lvalue_instance, bool out_access)
3133                 {
3134                         if (!FieldInfo.IsStatic){
3135                                 if (InstanceExpression == null){
3136                                         //
3137                                         // This can happen when referencing an instance field using
3138                                         // a fully qualified type expression: TypeName.InstanceField = xxx
3139                                         //
3140                                         SimpleName.Error_ObjectRefRequired (ec, loc, GetSignatureForError ());
3141                                         return null;
3142                                 }
3143
3144                                 // Resolve the field's instance expression while flow analysis is turned
3145                                 // off: when accessing a field "a.b", we must check whether the field
3146                                 // "a.b" is initialized, not whether the whole struct "a" is initialized.
3147
3148                                 if (lvalue_instance) {
3149                                         using (ec.With (EmitContext.Flags.DoFlowAnalysis, false)) {
3150                                                 Expression right_side =
3151                                                         out_access ? EmptyExpression.LValueMemberOutAccess : EmptyExpression.LValueMemberAccess;
3152                                                 InstanceExpression = InstanceExpression.ResolveLValue (ec, right_side, loc);
3153                                         }
3154                                 } else {
3155                                         ResolveFlags rf = ResolveFlags.VariableOrValue | ResolveFlags.DisableFlowAnalysis;
3156                                         InstanceExpression = InstanceExpression.Resolve (ec, rf);
3157                                 }
3158
3159                                 if (InstanceExpression == null)
3160                                         return null;
3161
3162                                 InstanceExpression.CheckMarshalByRefAccess ();
3163                         }
3164
3165                         if (!in_initializer && !ec.IsFieldInitializer) {
3166                                 ObsoleteAttribute oa;
3167                                 FieldBase f = TypeManager.GetField (FieldInfo);
3168                                 if (f != null) {
3169                                         if (!ec.IsInObsoleteScope)
3170                                                 f.CheckObsoleteness (loc);
3171
3172                                         // To be sure that type is external because we do not register generated fields
3173                                 } else if (!(FieldInfo.DeclaringType is TypeBuilder)) {
3174                                         oa = AttributeTester.GetMemberObsoleteAttribute (FieldInfo);
3175                                         if (oa != null)
3176                                                 AttributeTester.Report_ObsoleteMessage (oa, TypeManager.GetFullNameSignature (FieldInfo), loc);
3177                                 }
3178                         }
3179
3180                         AnonymousContainer am = ec.CurrentAnonymousMethod;
3181                         if (am != null){
3182                                 if (!FieldInfo.IsStatic){
3183                                         if (!am.IsIterator && (ec.TypeContainer is Struct)){
3184                                                 Report.Error (1673, loc,
3185                                                 "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",
3186                                                         "this");
3187                                                 return null;
3188                                         }
3189                                         if ((am.ContainerAnonymousMethod == null) && (InstanceExpression is This))
3190                                                 ec.CaptureField (this);
3191                                 }
3192                         }
3193
3194                         // If the instance expression is a local variable or parameter.
3195                         IVariable var = InstanceExpression as IVariable;
3196                         if ((var == null) || (var.VariableInfo == null))
3197                                 return this;
3198
3199                         VariableInfo vi = var.VariableInfo;
3200                         if (!vi.IsFieldAssigned (ec, FieldInfo.Name, loc))
3201                                 return null;
3202
3203                         variable_info = vi.GetSubStruct (FieldInfo.Name);
3204                         return this;
3205                 }
3206
3207                 static readonly int [] codes = {
3208                         191,    // instance, write access
3209                         192,    // instance, out access
3210                         198,    // static, write access
3211                         199,    // static, out access
3212                         1648,   // member of value instance, write access
3213                         1649,   // member of value instance, out access
3214                         1650,   // member of value static, write access
3215                         1651    // member of value static, out access
3216                 };
3217
3218                 static readonly string [] msgs = {
3219                         /*0191*/ "A readonly field `{0}' cannot be assigned to (except in a constructor or a variable initializer)",
3220                         /*0192*/ "A readonly field `{0}' cannot be passed ref or out (except in a constructor)",
3221                         /*0198*/ "A static readonly field `{0}' cannot be assigned to (except in a static constructor or a variable initializer)",
3222                         /*0199*/ "A static readonly field `{0}' cannot be passed ref or out (except in a static constructor)",
3223                         /*1648*/ "Members of readonly field `{0}' cannot be modified (except in a constructor or a variable initializer)",
3224                         /*1649*/ "Members of readonly field `{0}' cannot be passed ref or out (except in a constructor)",
3225                         /*1650*/ "Fields of static readonly field `{0}' cannot be assigned to (except in a static constructor or a variable initializer)",
3226                         /*1651*/ "Fields of static readonly field `{0}' cannot be passed ref or out (except in a static constructor)"
3227                 };
3228
3229                 // The return value is always null.  Returning a value simplifies calling code.
3230                 Expression Report_AssignToReadonly (Expression right_side)
3231                 {
3232                         int i = 0;
3233                         if (right_side == EmptyExpression.OutAccess || right_side == EmptyExpression.LValueMemberOutAccess)
3234                                 i += 1;
3235                         if (IsStatic)
3236                                 i += 2;
3237                         if (right_side == EmptyExpression.LValueMemberAccess || right_side == EmptyExpression.LValueMemberOutAccess)
3238                                 i += 4;
3239                         Report.Error (codes [i], loc, msgs [i], GetSignatureForError ());
3240
3241                         return null;
3242                 }
3243
3244                 override public Expression DoResolveLValue (EmitContext ec, Expression right_side)
3245                 {
3246                         IVariable var = InstanceExpression as IVariable;
3247                         if ((var != null) && (var.VariableInfo != null))
3248                                 var.VariableInfo.SetFieldAssigned (ec, FieldInfo.Name);
3249
3250                         bool lvalue_instance = !FieldInfo.IsStatic && FieldInfo.DeclaringType.IsValueType;
3251                         bool out_access = right_side == EmptyExpression.OutAccess || right_side == EmptyExpression.LValueMemberOutAccess;
3252
3253                         Expression e = DoResolve (ec, lvalue_instance, out_access);
3254
3255                         if (e == null)
3256                                 return null;
3257
3258                         FieldBase fb = TypeManager.GetField (FieldInfo);
3259                         if (fb != null)
3260                                 fb.SetAssigned ();
3261
3262                         if (FieldInfo.IsInitOnly) {
3263                                 // InitOnly fields can only be assigned in constructors or initializers
3264                                 if (!ec.IsFieldInitializer && !ec.IsConstructor)
3265                                         return Report_AssignToReadonly (right_side);
3266
3267                                 if (ec.IsConstructor) {
3268                                         Type ctype = ec.TypeContainer.CurrentType;
3269                                         if (ctype == null)
3270                                                 ctype = ec.ContainerType;
3271
3272                                         // InitOnly fields cannot be assigned-to in a different constructor from their declaring type
3273                                         if (!TypeManager.IsEqual (ctype, FieldInfo.DeclaringType))
3274                                                 return Report_AssignToReadonly (right_side);
3275                                         // static InitOnly fields cannot be assigned-to in an instance constructor
3276                                         if (IsStatic && !ec.IsStatic)
3277                                                 return Report_AssignToReadonly (right_side);
3278                                         // instance constructors can't modify InitOnly fields of other instances of the same type
3279                                         if (!IsStatic && !(InstanceExpression is This))
3280                                                 return Report_AssignToReadonly (right_side);
3281                                 }
3282                         }
3283
3284                         if (right_side == EmptyExpression.OutAccess &&
3285                             !IsStatic && !(InstanceExpression is This) && DeclaringType.IsSubclassOf (TypeManager.mbr_type)) {
3286                                 Report.SymbolRelatedToPreviousError (DeclaringType);
3287                                 Report.Warning (197, 1, loc,
3288                                                 "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",
3289                                                 GetSignatureForError ());
3290                         }
3291
3292                         return this;
3293                 }
3294
3295                 public override void CheckMarshalByRefAccess ()
3296                 {
3297                         if (!IsStatic && Type.IsValueType && !(InstanceExpression is This) && DeclaringType.IsSubclassOf (TypeManager.mbr_type)) {
3298                                 Report.SymbolRelatedToPreviousError (DeclaringType);
3299                                 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",
3300                                                 GetSignatureForError ());
3301                         }
3302                 }
3303
3304                 public bool VerifyFixed ()
3305                 {
3306                         IVariable variable = InstanceExpression as IVariable;
3307                         // A variable of the form V.I is fixed when V is a fixed variable of a struct type.
3308                         // We defer the InstanceExpression check after the variable check to avoid a
3309                         // separate null check on InstanceExpression.
3310                         return variable != null && InstanceExpression.Type.IsValueType && variable.VerifyFixed ();
3311                 }
3312
3313                 public override int GetHashCode ()
3314                 {
3315                         return FieldInfo.GetHashCode ();
3316                 }
3317
3318                 public override bool Equals (object obj)
3319                 {
3320                         FieldExpr fe = obj as FieldExpr;
3321                         if (fe == null)
3322                                 return false;
3323
3324                         if (FieldInfo != fe.FieldInfo)
3325                                 return false;
3326
3327                         if (InstanceExpression == null || fe.InstanceExpression == null)
3328                                 return true;
3329
3330                         return InstanceExpression.Equals (fe.InstanceExpression);
3331                 }
3332
3333                 public void Emit (EmitContext ec, bool leave_copy)
3334                 {
3335                         ILGenerator ig = ec.ig;
3336                         bool is_volatile = false;
3337
3338                         FieldBase f = TypeManager.GetField (FieldInfo);
3339                         if (f != null){
3340                                 if ((f.ModFlags & Modifiers.VOLATILE) != 0)
3341                                         is_volatile = true;
3342
3343                                 f.SetMemberIsUsed ();
3344                         }
3345
3346                         if (FieldInfo.IsStatic){
3347                                 if (is_volatile)
3348                                         ig.Emit (OpCodes.Volatile);
3349
3350                                 ig.Emit (OpCodes.Ldsfld, FieldInfo);
3351                         } else {
3352                                 if (!prepared)
3353                                         EmitInstance (ec, false);
3354
3355                                 if (is_volatile)
3356                                         ig.Emit (OpCodes.Volatile);
3357
3358                                 IFixedBuffer ff = AttributeTester.GetFixedBuffer (FieldInfo);
3359                                 if (ff != null)
3360                                 {
3361                                         ig.Emit (OpCodes.Ldflda, FieldInfo);
3362                                         ig.Emit (OpCodes.Ldflda, ff.Element);
3363                                 }
3364                                 else {
3365                                         ig.Emit (OpCodes.Ldfld, FieldInfo);
3366                                 }
3367                         }
3368
3369                         if (leave_copy) {
3370                                 ec.ig.Emit (OpCodes.Dup);
3371                                 if (!FieldInfo.IsStatic) {
3372                                         temp = new LocalTemporary (this.Type);
3373                                         temp.Store (ec);
3374                                 }
3375                         }
3376                 }
3377
3378                 public void EmitAssign (EmitContext ec, Expression source, bool leave_copy, bool prepare_for_load)
3379                 {
3380                         FieldAttributes fa = FieldInfo.Attributes;
3381                         bool is_static = (fa & FieldAttributes.Static) != 0;
3382                         bool is_readonly = (fa & FieldAttributes.InitOnly) != 0;
3383                         ILGenerator ig = ec.ig;
3384                         prepared = prepare_for_load;
3385
3386                         if (is_readonly && !ec.IsConstructor){
3387                                 Report_AssignToReadonly (source);
3388                                 return;
3389                         }
3390
3391                         EmitInstance (ec, prepare_for_load);
3392
3393                         source.Emit (ec);
3394                         if (leave_copy) {
3395                                 ec.ig.Emit (OpCodes.Dup);
3396                                 if (!FieldInfo.IsStatic) {
3397                                         temp = new LocalTemporary (this.Type);
3398                                         temp.Store (ec);
3399                                 }
3400                         }
3401
3402                         FieldBase f = TypeManager.GetField (FieldInfo);
3403                         if (f != null){
3404                                 if ((f.ModFlags & Modifiers.VOLATILE) != 0)
3405                                         ig.Emit (OpCodes.Volatile);
3406
3407                                 f.SetAssigned ();
3408                         }
3409
3410                         if (is_static)
3411                                 ig.Emit (OpCodes.Stsfld, FieldInfo);
3412                         else
3413                                 ig.Emit (OpCodes.Stfld, FieldInfo);
3414
3415                         if (temp != null) {
3416                                 temp.Emit (ec);
3417                                 temp.Release (ec);
3418                         }
3419                 }
3420
3421                 public override void Emit (EmitContext ec)
3422                 {
3423                         Emit (ec, false);
3424                 }
3425
3426                 public void AddressOf (EmitContext ec, AddressOp mode)
3427                 {
3428                         ILGenerator ig = ec.ig;
3429
3430                         FieldBase f = TypeManager.GetField (FieldInfo);
3431                         if (f != null){
3432                                 if ((f.ModFlags & Modifiers.VOLATILE) != 0){
3433                                         Report.Warning (420, 1, loc, "`{0}': A volatile fields cannot be passed using a ref or out parameter",
3434                                                         f.GetSignatureForError ());
3435                                         return;
3436                                 }
3437
3438                                 if ((mode & AddressOp.Store) != 0)
3439                                         f.SetAssigned ();
3440                                 if ((mode & AddressOp.Load) != 0)
3441                                         f.SetMemberIsUsed ();
3442                         }
3443
3444                         //
3445                         // Handle initonly fields specially: make a copy and then
3446                         // get the address of the copy.
3447                         //
3448                         bool need_copy;
3449                         if (FieldInfo.IsInitOnly){
3450                                 need_copy = true;
3451                                 if (ec.IsConstructor){
3452                                         if (FieldInfo.IsStatic){
3453                                                 if (ec.IsStatic)
3454                                                         need_copy = false;
3455                                         } else
3456                                                 need_copy = false;
3457                                 }
3458                         } else
3459                                 need_copy = false;
3460
3461                         if (need_copy){
3462                                 LocalBuilder local;
3463                                 Emit (ec);
3464                                 local = ig.DeclareLocal (type);
3465                                 ig.Emit (OpCodes.Stloc, local);
3466                                 ig.Emit (OpCodes.Ldloca, local);
3467                                 return;
3468                         }
3469
3470
3471                         if (FieldInfo.IsStatic){
3472                                 ig.Emit (OpCodes.Ldsflda, FieldInfo);
3473                         } else {
3474                                 if (!prepared)
3475                                         EmitInstance (ec, false);
3476                                 ig.Emit (OpCodes.Ldflda, FieldInfo);
3477                         }
3478                 }
3479         }
3480
3481         //
3482         // A FieldExpr whose address can not be taken
3483         //
3484         public class FieldExprNoAddress : FieldExpr, IMemoryLocation {
3485                 public FieldExprNoAddress (FieldInfo fi, Location loc) : base (fi, loc)
3486                 {
3487                 }
3488
3489                 public new void AddressOf (EmitContext ec, AddressOp mode)
3490                 {
3491                         Report.Error (-215, "Report this: Taking the address of a remapped parameter not supported");
3492                 }
3493         }
3494
3495         /// <summary>
3496         ///   Expression that evaluates to a Property.  The Assign class
3497         ///   might set the `Value' expression if we are in an assignment.
3498         ///
3499         ///   This is not an LValue because we need to re-write the expression, we
3500         ///   can not take data from the stack and store it.
3501         /// </summary>
3502         public class PropertyExpr : MemberExpr, IAssignMethod {
3503                 public readonly PropertyInfo PropertyInfo;
3504
3505                 //
3506                 // This is set externally by the  `BaseAccess' class
3507                 //
3508                 public bool IsBase;
3509                 MethodInfo getter, setter;
3510                 bool is_static;
3511
3512                 bool resolved;
3513
3514                 LocalTemporary temp;
3515                 bool prepared;
3516
3517                 internal static PtrHashtable AccessorTable = new PtrHashtable ();
3518
3519                 public PropertyExpr (Type containerType, PropertyInfo pi, Location l)
3520                 {
3521                         PropertyInfo = pi;
3522                         eclass = ExprClass.PropertyAccess;
3523                         is_static = false;
3524                         loc = l;
3525
3526                         type = TypeManager.TypeToCoreType (pi.PropertyType);
3527
3528                         ResolveAccessors (containerType);
3529                 }
3530
3531                 public override string Name {
3532                         get {
3533                                 return PropertyInfo.Name;
3534                         }
3535                 }
3536
3537                 public override bool IsInstance {
3538                         get {
3539                                 return !is_static;
3540                         }
3541                 }
3542
3543                 public override bool IsStatic {
3544                         get {
3545                                 return is_static;
3546                         }
3547                 }
3548
3549                 public override Type DeclaringType {
3550                         get {
3551                                 return PropertyInfo.DeclaringType;
3552                         }
3553                 }
3554
3555                 public override string GetSignatureForError ()
3556                 {
3557                         return TypeManager.GetFullNameSignature (PropertyInfo);
3558                 }
3559
3560                 void FindAccessors (Type invocation_type)
3561                 {
3562                         const BindingFlags flags = BindingFlags.Public | BindingFlags.NonPublic |
3563                                 BindingFlags.Static | BindingFlags.Instance |
3564                                 BindingFlags.DeclaredOnly;
3565
3566                         Type current = PropertyInfo.DeclaringType;
3567                         for (; current != null; current = current.BaseType) {
3568                                 MemberInfo[] group = TypeManager.MemberLookup (
3569                                         invocation_type, invocation_type, current,
3570                                         MemberTypes.Property, flags, PropertyInfo.Name, null);
3571
3572                                 if (group == null)
3573                                         continue;
3574
3575                                 if (group.Length != 1)
3576                                         // Oooops, can this ever happen ?
3577                                         return;
3578
3579                                 PropertyInfo pi = (PropertyInfo) group [0];
3580
3581                                 if (getter == null)
3582                                         getter = pi.GetGetMethod (true);
3583
3584                                 if (setter == null)
3585                                         setter = pi.GetSetMethod (true);
3586
3587                                 MethodInfo accessor = getter != null ? getter : setter;
3588
3589                                 if (!accessor.IsVirtual)
3590                                         return;
3591                         }
3592                 }
3593
3594                 //
3595                 // We also perform the permission checking here, as the PropertyInfo does not
3596                 // hold the information for the accessibility of its setter/getter
3597                 //
3598                 // TODO: can use TypeManager.GetProperty to boost performance
3599                 void ResolveAccessors (Type containerType)
3600                 {
3601                         FindAccessors (containerType);
3602
3603                         if (getter != null) {
3604                                 MethodBase the_getter = TypeManager.DropGenericMethodArguments (getter);
3605                                 IMethodData md = TypeManager.GetMethod (the_getter);
3606                                 if (md != null)
3607                                         md.SetMemberIsUsed ();
3608
3609                                 AccessorTable [getter] = PropertyInfo;
3610                                 is_static = getter.IsStatic;
3611                         }
3612
3613                         if (setter != null) {
3614                                 MethodBase the_setter = TypeManager.DropGenericMethodArguments (setter);
3615                                 IMethodData md = TypeManager.GetMethod (the_setter);
3616                                 if (md != null)
3617                                         md.SetMemberIsUsed ();
3618
3619                                 AccessorTable [setter] = PropertyInfo;
3620                                 is_static = setter.IsStatic;
3621                         }
3622                 }
3623
3624                 bool InstanceResolve (EmitContext ec, bool lvalue_instance, bool must_do_cs1540_check)
3625                 {
3626                         if (is_static) {
3627                                 InstanceExpression = null;
3628                                 return true;
3629                         }
3630
3631                         if (InstanceExpression == null) {
3632                                 SimpleName.Error_ObjectRefRequired (ec, loc, GetSignatureForError ());
3633                                 return false;
3634                         }
3635
3636                         if (lvalue_instance)
3637                                 InstanceExpression = InstanceExpression.ResolveLValue (ec, EmptyExpression.LValueMemberAccess, loc);
3638                         else
3639                                 InstanceExpression = InstanceExpression.DoResolve (ec);
3640                         if (InstanceExpression == null)
3641                                 return false;
3642
3643                         InstanceExpression.CheckMarshalByRefAccess ();
3644
3645                         if (must_do_cs1540_check && InstanceExpression != EmptyExpression.Null &&
3646                             InstanceExpression.Type != ec.ContainerType &&
3647                             ec.ContainerType.IsSubclassOf (PropertyInfo.DeclaringType) &&
3648                             !InstanceExpression.Type.IsSubclassOf (ec.ContainerType)) {
3649                                 Error_CannotAccessProtected (loc, PropertyInfo, InstanceExpression.Type, ec.ContainerType);
3650                                 return false;
3651                         }
3652
3653                         return true;
3654                 }
3655
3656                 void Error_PropertyNotFound (MethodInfo mi, bool getter)
3657                 {
3658                         // TODO: correctly we should compare arguments but it will lead to bigger changes
3659                         if (mi is MethodBuilder) {
3660                                 Error_TypeDoesNotContainDefinition (loc, PropertyInfo.DeclaringType, Name);
3661                                 return;
3662                         }
3663
3664                         StringBuilder sig = new StringBuilder (TypeManager.CSharpName (mi.DeclaringType));
3665                         sig.Append ('.');
3666                         ParameterData iparams = TypeManager.GetParameterData (mi);
3667                         sig.Append (getter ? "get_" : "set_");
3668                         sig.Append (Name);
3669                         sig.Append (iparams.GetSignatureForError ());
3670
3671                         Report.SymbolRelatedToPreviousError (mi);
3672                         Report.Error (1546, loc, "Property `{0}' is not supported by the C# language. Try to call the accessor method `{1}' directly",
3673                                 Name, sig.ToString ());
3674                 }
3675
3676                 override public Expression DoResolve (EmitContext ec)
3677                 {
3678                         if (resolved)
3679                                 return this;
3680
3681                         if (getter != null){
3682                                 if (TypeManager.GetParameterData (getter).Count != 0){
3683                                         Error_PropertyNotFound (getter, true);
3684                                         return null;
3685                                 }
3686                         }
3687
3688                         if (getter == null){
3689                                 //
3690                                 // The following condition happens if the PropertyExpr was
3691                                 // created, but is invalid (ie, the property is inaccessible),
3692                                 // and we did not want to embed the knowledge about this in
3693                                 // the caller routine.  This only avoids double error reporting.
3694                                 //
3695                                 if (setter == null)
3696                                         return null;
3697
3698                                 if (InstanceExpression != EmptyExpression.Null) {
3699                                         Report.Error (154, loc, "The property or indexer `{0}' cannot be used in this context because it lacks the `get' accessor",
3700                                                 TypeManager.GetFullNameSignature (PropertyInfo));
3701                                         return null;
3702                                 }
3703                         }
3704
3705                         bool must_do_cs1540_check = false;
3706                         if (getter != null &&
3707                             !IsAccessorAccessible (ec.ContainerType, getter, out must_do_cs1540_check)) {
3708                                 PropertyBase.PropertyMethod pm = TypeManager.GetMethod (getter) as PropertyBase.PropertyMethod;
3709                                 if (pm != null && pm.HasCustomAccessModifier) {
3710                                         Report.SymbolRelatedToPreviousError (pm);
3711                                         Report.Error (271, loc, "The property or indexer `{0}' cannot be used in this context because the get accessor is inaccessible",
3712                                                 TypeManager.CSharpSignature (getter));
3713                                 }
3714                                 else {
3715                                         Report.SymbolRelatedToPreviousError (getter);
3716                                         ErrorIsInaccesible (loc, TypeManager.CSharpSignature (getter));
3717                                 }
3718                                 return null;
3719                         }
3720
3721                         if (!InstanceResolve (ec, false, must_do_cs1540_check))
3722                                 return null;
3723
3724                         //
3725                         // Only base will allow this invocation to happen.
3726                         //
3727                         if (IsBase && getter.IsAbstract) {
3728                                 Error_CannotCallAbstractBase (TypeManager.GetFullNameSignature (PropertyInfo));
3729                                 return null;
3730                         }
3731
3732                         if (PropertyInfo.PropertyType.IsPointer && !ec.InUnsafe){
3733                                 UnsafeError (loc);
3734                                 return null;
3735                         }
3736
3737                         resolved = true;
3738
3739                         return this;
3740                 }
3741
3742                 override public Expression DoResolveLValue (EmitContext ec, Expression right_side)
3743                 {
3744                         if (right_side == EmptyExpression.OutAccess) {
3745                                 Report.Error (206, loc, "A property or indexer `{0}' may not be passed as an out or ref parameter",
3746                                               GetSignatureForError ());
3747                                 return null;
3748                         }
3749
3750                         if (right_side == EmptyExpression.LValueMemberAccess || right_side == EmptyExpression.LValueMemberOutAccess) {
3751                                 Report.Error (1612, loc, "Cannot modify the return value of `{0}' because it is not a variable",
3752                                               GetSignatureForError ());
3753                                 return null;
3754                         }
3755
3756                         if (setter == null){
3757                                 //
3758                                 // The following condition happens if the PropertyExpr was
3759                                 // created, but is invalid (ie, the property is inaccessible),
3760                                 // and we did not want to embed the knowledge about this in
3761                                 // the caller routine.  This only avoids double error reporting.
3762                                 //
3763                                 if (getter == null)
3764                                         return null;
3765                                 Report.Error (200, loc, "Property or indexer `{0}' cannot be assigned to (it is read only)",
3766                                               GetSignatureForError ());
3767                                 return null;
3768                         }
3769
3770                         if (TypeManager.GetParameterData (setter).Count != 1){
3771                                 Error_PropertyNotFound (setter, false);
3772                                 return null;
3773                         }
3774
3775                         bool must_do_cs1540_check;
3776                         if (!IsAccessorAccessible (ec.ContainerType, setter, out must_do_cs1540_check)) {
3777                                 PropertyBase.PropertyMethod pm = TypeManager.GetMethod (setter) as PropertyBase.PropertyMethod;
3778                                 if (pm != null && pm.HasCustomAccessModifier) {
3779                                         Report.SymbolRelatedToPreviousError (pm);
3780                                         Report.Error (272, loc, "The property or indexer `{0}' cannot be used in this context because the set accessor is inaccessible",
3781                                                 TypeManager.CSharpSignature (setter));
3782                                 }
3783                                 else {
3784                                         Report.SymbolRelatedToPreviousError (setter);
3785                                         ErrorIsInaccesible (loc, TypeManager.CSharpSignature (setter));
3786                                 }
3787                                 return null;
3788                         }
3789
3790                         if (!InstanceResolve (ec, PropertyInfo.DeclaringType.IsValueType, must_do_cs1540_check))
3791                                 return null;
3792
3793                         //
3794                         // Only base will allow this invocation to happen.
3795                         //
3796                         if (IsBase && setter.IsAbstract){
3797                                 Error_CannotCallAbstractBase (TypeManager.GetFullNameSignature (PropertyInfo));
3798                                 return null;
3799                         }
3800
3801                         return this;
3802                 }
3803
3804                 public override void Emit (EmitContext ec)
3805                 {
3806                         Emit (ec, false);
3807                 }
3808
3809                 public void Emit (EmitContext ec, bool leave_copy)
3810                 {
3811                         //
3812                         // Special case: length of single dimension array property is turned into ldlen
3813                         //
3814                         if ((getter == TypeManager.system_int_array_get_length) ||
3815                             (getter == TypeManager.int_array_get_length)){
3816                                 Type iet = InstanceExpression.Type;
3817
3818                                 //
3819                                 // System.Array.Length can be called, but the Type does not
3820                                 // support invoking GetArrayRank, so test for that case first
3821                                 //
3822                                 if (iet != TypeManager.array_type && (iet.GetArrayRank () == 1)) {
3823                                         if (!prepared)
3824                                                 EmitInstance (ec, false);
3825                                         ec.ig.Emit (OpCodes.Ldlen);
3826                                         ec.ig.Emit (OpCodes.Conv_I4);
3827                                         return;
3828                                 }
3829                         }
3830
3831                         Invocation.EmitCall (ec, IsBase, IsStatic, InstanceExpression, getter, null, loc, prepared, false);
3832
3833                         if (leave_copy) {
3834                                 ec.ig.Emit (OpCodes.Dup);
3835                                 if (!is_static) {
3836                                         temp = new LocalTemporary (this.Type);
3837                                         temp.Store (ec);
3838                                 }
3839                         }
3840                 }
3841
3842                 //
3843                 // Implements the IAssignMethod interface for assignments
3844                 //
3845                 public void EmitAssign (EmitContext ec, Expression source, bool leave_copy, bool prepare_for_load)
3846                 {
3847                         Expression my_source = source;
3848
3849                         prepared = prepare_for_load;
3850
3851                         if (prepared) {
3852                                 source.Emit (ec);
3853                                 if (leave_copy) {
3854                                         ec.ig.Emit (OpCodes.Dup);
3855                                         if (!is_static) {
3856                                                 temp = new LocalTemporary (this.Type);
3857                                                 temp.Store (ec);
3858                                         }
3859                                 }
3860                         } else if (leave_copy) {
3861                                 source.Emit (ec);
3862                                 if (!is_static) {
3863                                         temp = new LocalTemporary (this.Type);
3864                                         temp.Store (ec);
3865                                 }
3866                                 my_source = temp;
3867                         }
3868
3869                         ArrayList args = new ArrayList (1);
3870                         args.Add (new Argument (my_source, Argument.AType.Expression));
3871
3872                         Invocation.EmitCall (ec, IsBase, IsStatic, InstanceExpression, setter, args, loc, false, prepared);
3873
3874                         if (temp != null) {
3875                                 temp.Emit (ec);
3876                                 temp.Release (ec);
3877                         }
3878                 }
3879         }
3880
3881         /// <summary>
3882         ///   Fully resolved expression that evaluates to an Event
3883         /// </summary>
3884         public class EventExpr : MemberExpr {
3885                 public readonly EventInfo EventInfo;
3886
3887                 bool is_static;
3888                 MethodInfo add_accessor, remove_accessor;
3889
3890                 internal static PtrHashtable AccessorTable = new PtrHashtable ();
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 != null)
3901                                 AccessorTable [add_accessor] = ei;
3902                         if (remove_accessor != null)
3903                                 AccessorTable [remove_accessor] = ei;
3904
3905                         if (add_accessor.IsStatic || remove_accessor.IsStatic)
3906                                 is_static = true;
3907
3908                         if (EventInfo is MyEventBuilder){
3909                                 MyEventBuilder eb = (MyEventBuilder) EventInfo;
3910                                 type = eb.EventType;
3911                                 eb.SetUsed ();
3912                         } else
3913                                 type = EventInfo.EventHandlerType;
3914                 }
3915
3916                 public override string Name {
3917                         get {
3918                                 return EventInfo.Name;
3919                         }
3920                 }
3921
3922                 public override bool IsInstance {
3923                         get {
3924                                 return !is_static;
3925                         }
3926                 }
3927
3928                 public override bool IsStatic {
3929                         get {
3930                                 return is_static;
3931                         }
3932                 }
3933
3934                 public override Type DeclaringType {
3935                         get {
3936                                 return EventInfo.DeclaringType;
3937                         }
3938                 }
3939
3940                 public override Expression ResolveMemberAccess (EmitContext ec, Expression left, Location loc,
3941                                                                 SimpleName original)
3942                 {
3943                         //
3944                         // If the event is local to this class, we transform ourselves into a FieldExpr
3945                         //
3946
3947                         if (EventInfo.DeclaringType == ec.ContainerType ||
3948                             TypeManager.IsNestedChildOf(ec.ContainerType, EventInfo.DeclaringType)) {
3949                                 MemberInfo mi = TypeManager.GetPrivateFieldOfEvent (EventInfo);
3950
3951                                 if (mi != null) {
3952                                         MemberExpr ml = (MemberExpr) ExprClassFromMemberInfo (ec.ContainerType, mi, loc);
3953
3954                                         if (ml == null) {
3955                                                 Report.Error (-200, loc, "Internal error!!");
3956                                                 return null;
3957                                         }
3958
3959                                         InstanceExpression = null;
3960
3961                                         return ml.ResolveMemberAccess (ec, left, loc, original);
3962                                 }
3963                         }
3964
3965                         return base.ResolveMemberAccess (ec, left, loc, original);
3966                 }
3967
3968
3969                 bool InstanceResolve (EmitContext ec, bool must_do_cs1540_check)
3970                 {
3971                         if (is_static) {
3972                                 InstanceExpression = null;
3973                                 return true;
3974                         }
3975
3976                         if (InstanceExpression == null) {
3977                                 SimpleName.Error_ObjectRefRequired (ec, loc, GetSignatureForError ());
3978                                 return false;
3979                         }
3980
3981                         InstanceExpression = InstanceExpression.DoResolve (ec);
3982                         if (InstanceExpression == null)
3983                                 return false;
3984
3985                         //
3986                         // This is using the same mechanism as the CS1540 check in PropertyExpr.
3987                         // However, in the Event case, we reported a CS0122 instead.
3988                         //
3989                         if (must_do_cs1540_check && InstanceExpression != EmptyExpression.Null &&
3990                             InstanceExpression.Type != ec.ContainerType &&
3991                             ec.ContainerType.IsSubclassOf (InstanceExpression.Type)) {
3992                                 Report.SymbolRelatedToPreviousError (EventInfo);
3993                                 ErrorIsInaccesible (loc, TypeManager.CSharpSignature (EventInfo));
3994                                 return false;
3995                         }
3996
3997                         return true;
3998                 }
3999
4000                 public override Expression DoResolveLValue (EmitContext ec, Expression right_side)
4001                 {
4002                         return DoResolve (ec);
4003                 }
4004
4005                 public override Expression DoResolve (EmitContext ec)
4006                 {
4007                         bool must_do_cs1540_check;
4008                         if (!(IsAccessorAccessible (ec.ContainerType, add_accessor, out must_do_cs1540_check) &&
4009                               IsAccessorAccessible (ec.ContainerType, remove_accessor, out must_do_cs1540_check))) {
4010                                 Report.SymbolRelatedToPreviousError (EventInfo);
4011                                 ErrorIsInaccesible (loc, TypeManager.CSharpSignature (EventInfo));
4012                                 return null;
4013                         }
4014
4015                         if (!InstanceResolve (ec, must_do_cs1540_check))
4016                                 return null;
4017
4018                         return this;
4019                 }
4020
4021                 public override void Emit (EmitContext ec)
4022                 {
4023                         if (InstanceExpression is This)
4024                                 Report.Error (79, loc, "The event `{0}' can only appear on the left hand side of += or -=", GetSignatureForError ());
4025                         else
4026                                 Report.Error (70, loc, "The event `{0}' can only appear on the left hand side of += or -= "+
4027                                               "(except on the defining type)", Name);
4028                 }
4029
4030                 public override string GetSignatureForError ()
4031                 {
4032                         return TypeManager.CSharpSignature (EventInfo);
4033                 }
4034
4035                 public void EmitAddOrRemove (EmitContext ec, Expression source)
4036                 {
4037                         BinaryDelegate source_del = (BinaryDelegate) source;
4038                         Expression handler = source_del.Right;
4039
4040                         Argument arg = new Argument (handler, Argument.AType.Expression);
4041                         ArrayList args = new ArrayList ();
4042
4043                         args.Add (arg);
4044
4045                         if (source_del.IsAddition)
4046                                 Invocation.EmitCall (
4047                                         ec, false, IsStatic, InstanceExpression, add_accessor, args, loc);
4048                         else
4049                                 Invocation.EmitCall (
4050                                         ec, false, IsStatic, InstanceExpression, remove_accessor, args, loc);
4051                 }
4052         }
4053
4054
4055         public class TemporaryVariable : Expression, IMemoryLocation
4056         {
4057                 LocalInfo li;
4058
4059                 public TemporaryVariable (Type type, Location loc)
4060                 {
4061                         this.type = type;
4062                         this.loc = loc;
4063                         eclass = ExprClass.Value;
4064                 }
4065
4066                 public override Expression DoResolve (EmitContext ec)
4067                 {
4068                         if (li != null)
4069                                 return this;
4070
4071                         TypeExpr te = new TypeExpression (type, loc);
4072                         li = ec.CurrentBlock.AddTemporaryVariable (te, loc);
4073                         if (!li.Resolve (ec))
4074                                 return null;
4075
4076                         AnonymousContainer am = ec.CurrentAnonymousMethod;
4077                         if ((am != null) && am.IsIterator)
4078                                 ec.CaptureVariable (li);
4079
4080                         return this;
4081                 }
4082
4083                 public override void Emit (EmitContext ec)
4084                 {
4085                         ILGenerator ig = ec.ig;
4086
4087                         if (li.FieldBuilder != null) {
4088                                 ig.Emit (OpCodes.Ldarg_0);
4089                                 ig.Emit (OpCodes.Ldfld, li.FieldBuilder);
4090                         } else {
4091                                 ig.Emit (OpCodes.Ldloc, li.LocalBuilder);
4092                         }
4093                 }
4094
4095                 public void EmitLoadAddress (EmitContext ec)
4096                 {
4097                         ILGenerator ig = ec.ig;
4098
4099                         if (li.FieldBuilder != null) {
4100                                 ig.Emit (OpCodes.Ldarg_0);
4101                                 ig.Emit (OpCodes.Ldflda, li.FieldBuilder);
4102                         } else {
4103                                 ig.Emit (OpCodes.Ldloca, li.LocalBuilder);
4104                         }
4105                 }
4106
4107                 public void Store (EmitContext ec, Expression right_side)
4108                 {
4109                         if (li.FieldBuilder != null)
4110                                 ec.ig.Emit (OpCodes.Ldarg_0);
4111
4112                         right_side.Emit (ec);
4113                         if (li.FieldBuilder != null) {
4114                                 ec.ig.Emit (OpCodes.Stfld, li.FieldBuilder);
4115                         } else {
4116                                 ec.ig.Emit (OpCodes.Stloc, li.LocalBuilder);
4117                         }
4118                 }
4119
4120                 public void EmitThis (EmitContext ec)
4121                 {
4122                         if (li.FieldBuilder != null) {
4123                                 ec.ig.Emit (OpCodes.Ldarg_0);
4124                         }
4125                 }
4126
4127                 public void EmitStore (ILGenerator ig)
4128                 {
4129                         if (li.FieldBuilder != null)
4130                                 ig.Emit (OpCodes.Stfld, li.FieldBuilder);
4131                         else
4132                                 ig.Emit (OpCodes.Stloc, li.LocalBuilder);
4133                 }
4134
4135                 public void AddressOf (EmitContext ec, AddressOp mode)
4136                 {
4137                         EmitLoadAddress (ec);
4138                 }
4139         }
4140
4141 }