mcs/mcs/ecore.cs

   1 //
   2 // ecore.cs: Core of the Expression representation for the intermediate tree.
   3 //
   4 // Author:
   5 //   Miguel de Icaza (miguel@ximian.com)
   6 //
   7 // (C) 2001, 2002, 2003 Ximian, Inc.
   8 //
   9 //
  10
  11 namespace Mono.CSharp {
  12         using System;
  13         using System.Collections;
  14         using System.Diagnostics;
  15         using System.Reflection;
  16         using System.Reflection.Emit;
  17         using System.Text;
  18
  19         /// <remarks>
  20         ///   The ExprClass class contains the is used to pass the
  21         ///   classification of an expression (value, variable, namespace,
  22         ///   type, method group, property access, event access, indexer access,
  23         ///   nothing).
  24         /// </remarks>
  25         public enum ExprClass : byte {
  26                 Invalid,
  27
  28                 Value,
  29                 Variable,
  30                 Namespace,
  31                 Type,
  32                 MethodGroup,
  33                 PropertyAccess,
  34                 EventAccess,
  35                 IndexerAccess,
  36                 Nothing,
  37         }
  38
  39         /// <remarks>
  40         ///   This is used to tell Resolve in which types of expressions we're
  41         ///   interested.
  42         /// </remarks>
  43         [Flags]
  44         public enum ResolveFlags {
  45                 // Returns Value, Variable, PropertyAccess, EventAccess or IndexerAccess.
  46                 VariableOrValue         = 1,
  47
  48                 // Returns a type expression.
  49                 Type                    = 2,
  50
  51                 // Returns a method group.
  52                 MethodGroup             = 4,
  53
  54                 // Mask of all the expression class flags.
  55                 MaskExprClass           = 7,
  56
  57                 // Disable control flow analysis while resolving the expression.
  58                 // This is used when resolving the instance expression of a field expression.
  59                 DisableFlowAnalysis     = 8,
  60
  61                 // Set if this is resolving the first part of a MemberAccess.
  62                 Intermediate            = 16,
  63
  64                 // Disable control flow analysis _of struct_ while resolving the expression.
  65                 // This is used when resolving the instance expression of a field expression.
  66                 DisableStructFlowAnalysis       = 32,
  67
  68         }
  69
  70         //
  71         // This is just as a hint to AddressOf of what will be done with the
  72         // address.
  73         [Flags]
  74         public enum AddressOp {
  75                 Store = 1,
  76                 Load  = 2,
  77                 LoadStore = 3
  78         };
  79
  80         /// <summary>
  81         ///   This interface is implemented by variables
  82         /// </summary>
  83         public interface IMemoryLocation {
  84                 /// <summary>
  85                 ///   The AddressOf method should generate code that loads
  86                 ///   the address of the object and leaves it on the stack.
  87                 ///
  88                 ///   The `mode' argument is used to notify the expression
  89                 ///   of whether this will be used to read from the address or
  90                 ///   write to the address.
  91                 ///
  92                 ///   This is just a hint that can be used to provide good error
  93                 ///   reporting, and should have no other side effects.
  94                 /// </summary>
  95                 void AddressOf (EmitContext ec, AddressOp mode);
  96         }
  97
  98         /// <summary>
  99         ///   This interface is implemented by variables
 100         /// </summary>
 101         public interface IVariable {
 102                 VariableInfo VariableInfo {
 103                         get;
 104                 }
 105
 106                 bool VerifyFixed ();
 107         }
 108
 109         /// <remarks>
 110         ///   Base class for expressions
 111         /// </remarks>
 112         public abstract class Expression {
 113                 public ExprClass eclass;
 114                 protected Type type;
 115                 protected Location loc;
 116
 117                 public Type Type {
 118                         get { return type; }
 119                         set { type = value; }
 120                 }
 121
 122                 public virtual Location Location {
 123                         get { return loc; }
 124                 }
 125
 126                 /// <summary>
 127                 ///   Utility wrapper routine for Error, just to beautify the code
 128                 /// </summary>
 129                 public void Error (int error, string s)
 130                 {
 131                         if (loc.IsNull)
 132                                 Report.Error (error, s);
 133                         else
 134                                 Report.Error (error, loc, s);
 135                 }
 136
 137                 // Not nice but we have broken hierarchy
 138                 public virtual void CheckMarshallByRefAccess (Type container) {}
 139
 140                 public virtual bool GetAttributableValue (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                         //
 159                         // If only accessible to the current class or children
 160                         //
 161                         if (ma == MethodAttributes.Private)
 162                                 return invocation_type == mi.DeclaringType ||
 163                                         TypeManager.IsNestedChildOf (invocation_type, mi.DeclaringType);
 164
 165                         if (mi.DeclaringType.Assembly == invocation_type.Assembly) {
 166                                 if (ma == MethodAttributes.Assembly || ma == MethodAttributes.FamORAssem)
 167                                         return true;
 168                         } else {
 169                                 if (ma == MethodAttributes.Assembly || ma == MethodAttributes.FamANDAssem)
 170                                         return false;
 171                         }
 172
 173                         // Family and FamANDAssem require that we derive.
 174                         // FamORAssem requires that we derive if in different assemblies.
 175                         if (ma == MethodAttributes.Family ||
 176                             ma == MethodAttributes.FamANDAssem ||
 177                             ma == MethodAttributes.FamORAssem) {
 178                                 if (!TypeManager.IsNestedFamilyAccessible (invocation_type, mi.DeclaringType))
 179                                         return false;
 180
 181                                 if (!TypeManager.IsNestedChildOf (invocation_type, mi.DeclaringType))
 182                                         must_do_cs1540_check = true;
 183
 184                                 return true;
 185                         }
 186
 187                         return true;
 188                 }
 189
 190                 /// <summary>
 191                 ///   Performs semantic analysis on the Expression
 192                 /// </summary>
 193                 ///
 194                 /// <remarks>
 195                 ///   The Resolve method is invoked to perform the semantic analysis
 196                 ///   on the node.
 197                 ///
 198                 ///   The return value is an expression (it can be the
 199                 ///   same expression in some cases) or a new
 200                 ///   expression that better represents this node.
 201                 ///
 202                 ///   For example, optimizations of Unary (LiteralInt)
 203                 ///   would return a new LiteralInt with a negated
 204                 ///   value.
 205                 ///
 206                 ///   If there is an error during semantic analysis,
 207                 ///   then an error should be reported (using Report)
 208                 ///   and a null value should be returned.
 209                 ///
 210                 ///   There are two side effects expected from calling
 211                 ///   Resolve(): the the field variable "eclass" should
 212                 ///   be set to any value of the enumeration
 213                 ///   `ExprClass' and the type variable should be set
 214                 ///   to a valid type (this is the type of the
 215                 ///   expression).
 216                 /// </remarks>
 217                 public abstract Expression DoResolve (EmitContext ec);
 218
 219                 public virtual Expression DoResolveLValue (EmitContext ec, Expression right_side)
 220                 {
 221                         return null;
 222                 }
 223
 224                 //
 225                 // This is used if the expression should be resolved as a type or namespace name.
 226                 // the default implementation fails.
 227                 //
 228                 public virtual FullNamedExpression ResolveAsTypeStep (IResolveContext ec,  bool silent)
 229                 {
 230                         return null;
 231                 }
 232
 233                 //
 234                 // This is used to resolve the expression as a type, a null
 235                 // value will be returned if the expression is not a type
 236                 // reference
 237                 //
 238                 public virtual TypeExpr ResolveAsTypeTerminal (IResolveContext ec, bool silent)
 239                 {
 240                         TypeExpr te = ResolveAsBaseTerminal (ec, silent);
 241                         if (te == null)
 242                                 return null;
 243
 244                         ObsoleteAttribute obsolete_attr = AttributeTester.GetObsoleteAttribute (te.Type);
 245                         if (obsolete_attr != null && !ec.IsInObsoleteScope) {
 246                                 AttributeTester.Report_ObsoleteMessage (obsolete_attr, GetSignatureForError (), Location);
 247                         }
 248                         return te;
 249                 }
 250
 251                 public TypeExpr ResolveAsBaseTerminal (IResolveContext ec, bool silent)
 252                 {
 253                         int errors = Report.Errors;
 254
 255                         FullNamedExpression fne = ResolveAsTypeStep (ec, silent);
 256
 257                         if (fne == null){
 258                                 if (!silent && errors == Report.Errors)
 259                                         Report.Error (118, loc, "Expecting a type.");
 260                                 return null;
 261                         }
 262
 263                         if (fne.eclass != ExprClass.Type) {
 264                                 if (!silent && errors == Report.Errors)
 265                                         fne.Error_UnexpectedKind (null, "type", loc);
 266                                 return null;
 267                         }
 268
 269                         TypeExpr te = fne as TypeExpr;
 270
 271                         if (!te.CheckAccessLevel (ec.DeclContainer)) {
 272                                 ErrorIsInaccesible (loc, TypeManager.CSharpName (te.Type));
 273                                 return null;
 274                         }
 275
 276                         te.loc = loc;
 277                         return te;
 278                 }
 279
 280                 public static void ErrorIsInaccesible (Location loc, string name)
 281                 {
 282                         Report.Error (122, loc, "`{0}' is inaccessible due to its protection level", name);
 283                 }
 284
 285                 protected static void Error_CannotAccessProtected (Location loc, MemberInfo m, Type qualifier, Type container)
 286                 {
 287                         Report.Error (1540, loc, "Cannot access protected member `{0}' via a qualifier of type `{1}';"
 288                                 + " the qualifier must be of type `{2}' (or derived from it)",
 289                                 TypeManager.GetFullNameSignature (m),
 290                                 TypeManager.CSharpName (qualifier),
 291                                 TypeManager.CSharpName (container));
 292
 293                 }
 294
 295                 public virtual void Error_ValueCannotBeConverted (Location loc, Type target, bool expl)
 296                 {
 297                         if (Type.Name == target.Name){
 298                                 Report.ExtraInformation (loc,
 299                                         String.Format (
 300                                         "The type {0} has two conflicting definitions, one comes from {1} and the other from {2}",
 301                                         Type.Name, Type.Assembly.FullName, target.Assembly.FullName));
 302
 303                         }
 304
 305                         if (expl) {
 306                                 Report.Error (30, loc, "Cannot convert type `{0}' to `{1}'",
 307                                         GetSignatureForError (), TypeManager.CSharpName (target));
 308                                 return;
 309                         }
 310
 311                         Expression e = (this is EnumConstant) ? ((EnumConstant)this).Child : this;
 312                         bool b = Convert.ExplicitNumericConversion (e, target) != null;
 313
 314                         if (b || Convert.ExplicitReferenceConversionExists (Type, target) || Convert.ExplicitUnsafe (e, target) != null) {
 315                                 Report.Error (266, loc, "Cannot implicitly convert type `{0}' to `{1}'. An explicit conversion exists (are you missing a cast?)",
 316                                         TypeManager.CSharpName (Type), TypeManager.CSharpName (target));
 317                                 return;
 318                         }
 319
 320                         if (Type != TypeManager.string_type && this is Constant && !(this is NullCast)) {
 321                                 Report.Error (31, loc, "Constant value `{0}' cannot be converted to a `{1}'",
 322                                         GetSignatureForError (), TypeManager.CSharpName (target));
 323                                 return;
 324                         }
 325
 326                         Report.Error (29, loc, "Cannot implicitly convert type {0} to `{1}'",
 327                                 Type == TypeManager.anonymous_method_type ?
 328                                 "anonymous method" : "`" + GetSignatureForError () + "'",
 329                                 TypeManager.CSharpName (target));
 330                 }
 331
 332                 protected static void Error_TypeDoesNotContainDefinition (Location loc, Type type, string name)
 333                 {
 334                         Report.Error (117, loc, "`{0}' does not contain a definition for `{1}'",
 335                                 TypeManager.CSharpName (type), name);
 336                 }
 337
 338                 ResolveFlags ExprClassToResolveFlags
 339                 {
 340                         get {
 341                                 switch (eclass) {
 342                                         case ExprClass.Type:
 343                                         case ExprClass.Namespace:
 344                                                 return ResolveFlags.Type;
 345
 346                                         case ExprClass.MethodGroup:
 347                                                 return ResolveFlags.MethodGroup;
 348
 349                                         case ExprClass.Value:
 350                                         case ExprClass.Variable:
 351                                         case ExprClass.PropertyAccess:
 352                                         case ExprClass.EventAccess:
 353                                         case ExprClass.IndexerAccess:
 354                                                 return ResolveFlags.VariableOrValue;
 355
 356                                         default:
 357                                                 throw new Exception ("Expression " + GetType () +
 358                                                         " ExprClass is Invalid after resolve");
 359                                 }
 360                         }
 361                 }
 362
 363                 /// <summary>
 364                 ///   Resolves an expression and performs semantic analysis on it.
 365                 /// </summary>
 366                 ///
 367                 /// <remarks>
 368                 ///   Currently Resolve wraps DoResolve to perform sanity
 369                 ///   checking and assertion checking on what we expect from Resolve.
 370                 /// </remarks>
 371                 public Expression Resolve (EmitContext ec, ResolveFlags flags)
 372                 {
 373                         if ((flags & ResolveFlags.MaskExprClass) == ResolveFlags.Type)
 374                                 return ResolveAsTypeStep (ec, false);
 375
 376                         bool old_do_flow_analysis = ec.DoFlowAnalysis;
 377                         bool old_omit_struct_analysis = ec.OmitStructFlowAnalysis;
 378                         if ((flags & ResolveFlags.DisableFlowAnalysis) != 0)
 379                                 ec.DoFlowAnalysis = false;
 380                         if ((flags & ResolveFlags.DisableStructFlowAnalysis) != 0)
 381                                 ec.OmitStructFlowAnalysis = true;
 382
 383                         Expression e;
 384                         if (this is SimpleName) {
 385                                 bool intermediate = (flags & ResolveFlags.Intermediate) == ResolveFlags.Intermediate;
 386                                 e = ((SimpleName) this).DoResolve (ec, intermediate);
 387                         }
 388                         else
 389                                 e = DoResolve (ec);
 390
 391                         ec.DoFlowAnalysis = old_do_flow_analysis;
 392                         ec.OmitStructFlowAnalysis = old_omit_struct_analysis;
 393
 394                         if (e == null)
 395                                 return null;
 396
 397                         if ((flags & e.ExprClassToResolveFlags) == 0) {
 398                                 e.Error_UnexpectedKind (flags, loc);
 399                                 return null;
 400                         }
 401
 402                         if (e.type == null && !(e is Namespace)) {
 403                                 throw new Exception (
 404                                         "Expression " + e.GetType () +
 405                                         " did not set its type after Resolve\n" +
 406                                         "called from: " + this.GetType ());
 407                         }
 408
 409                         return e;
 410                 }
 411
 412                 /// <summary>
 413                 ///   Resolves an expression and performs semantic analysis on it.
 414                 /// </summary>
 415                 public Expression Resolve (EmitContext ec)
 416                 {
 417                         Expression e = Resolve (ec, ResolveFlags.VariableOrValue | ResolveFlags.MethodGroup);
 418
 419                         if (e != null && e.eclass == ExprClass.MethodGroup && RootContext.Version == LanguageVersion.ISO_1) {
 420                                 ((MethodGroupExpr) e).ReportUsageError ();
 421                                 return null;
 422                         }
 423                         return e;
 424                 }
 425
 426                 public Constant ResolveAsConstant (EmitContext ec, MemberCore mc)
 427                 {
 428                         Expression e = Resolve (ec);
 429                         if (e == null)
 430                                 return null;
 431
 432                         Constant c = e as Constant;
 433                         if (c != null)
 434                                 return c;
 435
 436                         EmptyCast empty = e as EmptyCast;
 437                         if (empty != null) {
 438                                 c = empty.Child as Constant;
 439                                 if (c != null) {
 440                                         // TODO: not sure about this maybe there is easier way how to use EmptyCast
 441                                         if (e.Type.IsEnum)
 442                                                 c.Type = e.Type;
 443
 444                                         return c;
 445                                 }
 446                         }
 447                         Const.Error_ExpressionMustBeConstant (loc, mc.GetSignatureForError ());
 448                         return null;
 449                 }
 450
 451                 /// <summary>
 452                 ///   Resolves an expression for LValue assignment
 453                 /// </summary>
 454                 ///
 455                 /// <remarks>
 456                 ///   Currently ResolveLValue wraps DoResolveLValue to perform sanity
 457                 ///   checking and assertion checking on what we expect from Resolve
 458                 /// </remarks>
 459                 public Expression ResolveLValue (EmitContext ec, Expression right_side, Location loc)
 460                 {
 461                         int errors = Report.Errors;
 462                         Expression e = DoResolveLValue (ec, right_side);
 463
 464                         if (e == null) {
 465                                 if (errors == Report.Errors)
 466                                         Report.Error (131, loc, "The left-hand side of an assignment or mutating operation must be a variable, property or indexer");
 467                                 return null;
 468                         }
 469
 470                         if (e != null){
 471                                 if (e.eclass == ExprClass.Invalid)
 472                                         throw new Exception ("Expression " + e +
 473                                                              " ExprClass is Invalid after resolve");
 474
 475                                 if (e.eclass == ExprClass.MethodGroup) {
 476                                         ((MethodGroupExpr) e).ReportUsageError ();
 477                                         return null;
 478                                 }
 479
 480                                 if (e.type == null)
 481                                         throw new Exception ("Expression " + e +
 482                                                              " did not set its type after Resolve");
 483                         }
 484
 485                         return e;
 486                 }
 487
 488                 /// <summary>
 489                 ///   Emits the code for the expression
 490                 /// </summary>
 491                 ///
 492                 /// <remarks>
 493                 ///   The Emit method is invoked to generate the code
 494                 ///   for the expression.
 495                 /// </remarks>
 496                 public abstract void Emit (EmitContext ec);
 497
 498                 public virtual void EmitBranchable (EmitContext ec, Label target, bool onTrue)
 499                 {
 500                         Emit (ec);
 501                         ec.ig.Emit (onTrue ? OpCodes.Brtrue : OpCodes.Brfalse, target);
 502                 }
 503
 504                 /// <summary>
 505                 ///   Protected constructor.  Only derivate types should
 506                 ///   be able to be created
 507                 /// </summary>
 508
 509                 protected Expression ()
 510                 {
 511                         eclass = ExprClass.Invalid;
 512                         type = null;
 513                 }
 514
 515                 /// <summary>
 516                 ///   Returns a literalized version of a literal FieldInfo
 517                 /// </summary>
 518                 ///
 519                 /// <remarks>
 520                 ///   The possible return values are:
 521                 ///      IntConstant, UIntConstant
 522                 ///      LongLiteral, ULongConstant
 523                 ///      FloatConstant, DoubleConstant
 524                 ///      StringConstant
 525                 ///
 526                 ///   The value returned is already resolved.
 527                 /// </remarks>
 528                 public static Constant Constantify (object v, Type t)
 529                 {
 530                         if (t == TypeManager.int32_type)
 531                                 return new IntConstant ((int) v, Location.Null);
 532                         else if (t == TypeManager.uint32_type)
 533                                 return new UIntConstant ((uint) v, Location.Null);
 534                         else if (t == TypeManager.int64_type)
 535                                 return new LongConstant ((long) v, Location.Null);
 536                         else if (t == TypeManager.uint64_type)
 537                                 return new ULongConstant ((ulong) v, Location.Null);
 538                         else if (t == TypeManager.float_type)
 539                                 return new FloatConstant ((float) v, Location.Null);
 540                         else if (t == TypeManager.double_type)
 541                                 return new DoubleConstant ((double) v, Location.Null);
 542                         else if (t == TypeManager.string_type)
 543                                 return new StringConstant ((string) v, Location.Null);
 544                         else if (t == TypeManager.short_type)
 545                                 return new ShortConstant ((short)v, Location.Null);
 546                         else if (t == TypeManager.ushort_type)
 547                                 return new UShortConstant ((ushort)v, Location.Null);
 548                         else if (t == TypeManager.sbyte_type)
 549                                 return new SByteConstant ((sbyte)v, Location.Null);
 550                         else if (t == TypeManager.byte_type)
 551                                 return new ByteConstant ((byte)v, Location.Null);
 552                         else if (t == TypeManager.char_type)
 553                                 return new CharConstant ((char)v, Location.Null);
 554                         else if (t == TypeManager.bool_type)
 555                                 return new BoolConstant ((bool) v, Location.Null);
 556                         else if (t == TypeManager.decimal_type)
 557                                 return new DecimalConstant ((decimal) v, Location.Null);
 558                         else if (TypeManager.IsEnumType (t)){
 559                                 Type real_type = TypeManager.TypeToCoreType (v.GetType ());
 560                                 if (real_type == t)
 561                                         real_type = System.Enum.GetUnderlyingType (real_type);
 562
 563                                 Constant e = Constantify (v, real_type);
 564
 565                                 return new EnumConstant (e, t);
 566                         } else if (v == null && !TypeManager.IsValueType (t))
 567                                 return new NullLiteral (Location.Null);
 568                         else
 569                                 throw new Exception ("Unknown type for constant (" + t +
 570                                                      "), details: " + v);
 571                 }
 572
 573                 /// <summary>
 574                 ///   Returns a fully formed expression after a MemberLookup
 575                 /// </summary>
 576                 ///
 577                 public static Expression ExprClassFromMemberInfo (Type containerType, MemberInfo mi, Location loc)
 578                 {
 579                         if (mi is EventInfo)
 580                                 return new EventExpr ((EventInfo) mi, loc);
 581                         else if (mi is FieldInfo)
 582                                 return new FieldExpr ((FieldInfo) mi, loc);
 583                         else if (mi is PropertyInfo)
 584                                 return new PropertyExpr (containerType, (PropertyInfo) mi, loc);
 585                         else if (mi is Type){
 586                                 return new TypeExpression ((System.Type) mi, loc);
 587                         }
 588
 589                         return null;
 590                 }
 591
 592                 protected static ArrayList almostMatchedMembers = new ArrayList (4);
 593
 594                 //
 595                 // FIXME: Probably implement a cache for (t,name,current_access_set)?
 596                 //
 597                 // This code could use some optimizations, but we need to do some
 598                 // measurements.  For example, we could use a delegate to `flag' when
 599                 // something can not any longer be a method-group (because it is something
 600                 // else).
 601                 //
 602                 // Return values:
 603                 //     If the return value is an Array, then it is an array of
 604                 //     MethodBases
 605                 //
 606                 //     If the return value is an MemberInfo, it is anything, but a Method
 607                 //
 608                 //     null on error.
 609                 //
 610                 // FIXME: When calling MemberLookup inside an `Invocation', we should pass
 611                 // the arguments here and have MemberLookup return only the methods that
 612                 // match the argument count/type, unlike we are doing now (we delay this
 613                 // decision).
 614                 //
 615                 // This is so we can catch correctly attempts to invoke instance methods
 616                 // from a static body (scan for error 120 in ResolveSimpleName).
 617                 //
 618                 //
 619                 // FIXME: Potential optimization, have a static ArrayList
 620                 //
 621
 622                 public static Expression MemberLookup (Type container_type, Type queried_type, string name,
 623                                                        MemberTypes mt, BindingFlags bf, Location loc)
 624                 {
 625                         return MemberLookup (container_type, null, queried_type, name, mt, bf, loc);
 626                 }
 627
 628                 //
 629                 // Lookup type `queried_type' for code in class `container_type' with a qualifier of
 630                 // `qualifier_type' or null to lookup members in the current class.
 631                 //
 632
 633                 public static Expression MemberLookup (Type container_type,
 634                                                        Type qualifier_type, Type queried_type,
 635                                                        string name, MemberTypes mt,
 636                                                        BindingFlags bf, Location loc)
 637                 {
 638                         almostMatchedMembers.Clear ();
 639
 640                         MemberInfo [] mi = TypeManager.MemberLookup (container_type, qualifier_type,
 641                                                                      queried_type, mt, bf, name, almostMatchedMembers);
 642
 643                         if (mi == null)
 644                                 return null;
 645
 646                         int count = mi.Length;
 647
 648                         if (mi [0] is MethodBase)
 649                                 return new MethodGroupExpr (mi, loc);
 650
 651                         if (count > 1)
 652                                 return null;
 653
 654                         return ExprClassFromMemberInfo (container_type, mi [0], loc);
 655                 }
 656
 657                 public const MemberTypes AllMemberTypes =
 658                         MemberTypes.Constructor |
 659                         MemberTypes.Event       |
 660                         MemberTypes.Field       |
 661                         MemberTypes.Method      |
 662                         MemberTypes.NestedType  |
 663                         MemberTypes.Property;
 664
 665                 public const BindingFlags AllBindingFlags =
 666                         BindingFlags.Public |
 667                         BindingFlags.Static |
 668                         BindingFlags.Instance;
 669
 670                 public static Expression MemberLookup (Type container_type, Type queried_type,
 671                                                        string name, Location loc)
 672                 {
 673                         return MemberLookup (container_type, null, queried_type, name,
 674                                              AllMemberTypes, AllBindingFlags, loc);
 675                 }
 676
 677                 public static Expression MemberLookup (Type container_type, Type qualifier_type,
 678                                                        Type queried_type, string name, Location loc)
 679                 {
 680                         return MemberLookup (container_type, qualifier_type, queried_type,
 681                                              name, AllMemberTypes, AllBindingFlags, loc);
 682                 }
 683
 684                 public static Expression MethodLookup (EmitContext ec, Type queried_type,
 685                                                        string name, Location loc)
 686                 {
 687                         return MemberLookup (ec.ContainerType, null, queried_type, name,
 688                                              MemberTypes.Method, AllBindingFlags, loc);
 689                 }
 690
 691                 /// <summary>
 692                 ///   This is a wrapper for MemberLookup that is not used to "probe", but
 693                 ///   to find a final definition.  If the final definition is not found, we
 694                 ///   look for private members and display a useful debugging message if we
 695                 ///   find it.
 696                 /// </summary>
 697                 public static Expression MemberLookupFinal (EmitContext ec, Type qualifier_type,
 698                                                             Type queried_type, string name, Location loc)
 699                 {
 700                         return MemberLookupFinal (ec, qualifier_type, queried_type, name,
 701                                                   AllMemberTypes, AllBindingFlags, loc);
 702                 }
 703
 704                 public static Expression MemberLookupFinal (EmitContext ec, Type qualifier_type,
 705                                                             Type queried_type, string name,
 706                                                             MemberTypes mt, BindingFlags bf,
 707                                                             Location loc)
 708                 {
 709                         Expression e;
 710
 711                         int errors = Report.Errors;
 712
 713                         e = MemberLookup (ec.ContainerType, qualifier_type, queried_type, name, mt, bf, loc);
 714
 715                         if (e == null && errors == Report.Errors)
 716                                 // No errors were reported by MemberLookup, but there was an error.
 717                                 MemberLookupFailed (ec.ContainerType, qualifier_type, queried_type, name, null, true, loc);
 718
 719                         return e;
 720                 }
 721
 722                 public static void MemberLookupFailed (Type container_type, Type qualifier_type,
 723                                                        Type queried_type, string name,
 724                                                        string class_name, bool complain_if_none_found,
 725                                                        Location loc)
 726                 {
 727                         if (almostMatchedMembers.Count != 0) {
 728                                 for (int i = 0; i < almostMatchedMembers.Count; ++i) {
 729                                         MemberInfo m = (MemberInfo) almostMatchedMembers [i];
 730                                         for (int j = 0; j < i; ++j) {
 731                                                 if (m == almostMatchedMembers [j]) {
 732                                                         m = null;
 733                                                         break;
 734                                                 }
 735                                         }
 736                                         if (m == null)
 737                                                 continue;
 738
 739                                         Type declaring_type = m.DeclaringType;
 740
 741                                         Report.SymbolRelatedToPreviousError (m);
 742                                         if (qualifier_type == null) {
 743                                                 Report.Error (38, loc, "Cannot access a nonstatic member of outer type `{0}' via nested type `{1}'",
 744                                                               TypeManager.CSharpName (m.DeclaringType),
 745                                                               TypeManager.CSharpName (container_type));
 746
 747                                         } else if (qualifier_type != container_type &&
 748                                                    TypeManager.IsNestedFamilyAccessible (container_type, declaring_type)) {
 749                                                 // Although a derived class can access protected members of
 750                                                 // its base class it cannot do so through an instance of the
 751                                                 // base class (CS1540).  If the qualifier_type is a base of the
 752                                                 // ec.ContainerType and the lookup succeeds with the latter one,
 753                                                 // then we are in this situation.
 754                                                 Error_CannotAccessProtected (loc, m, qualifier_type, container_type);
 755                                         } else {
 756                                                 ErrorIsInaccesible (loc, TypeManager.GetFullNameSignature (m));
 757                                         }
 758                                 }
 759                                 almostMatchedMembers.Clear ();
 760                                 return;
 761                         }
 762
 763                         MemberInfo[] lookup = TypeManager.MemberLookup (queried_type, null, queried_type,
 764                                                                   AllMemberTypes, AllBindingFlags |
 765                                                                   BindingFlags.NonPublic, name, null);
 766
 767                         if (lookup == null) {
 768                                 if (!complain_if_none_found)
 769                                         return;
 770
 771                                 if (class_name != null)
 772                                         Report.Error (103, loc, "The name `{0}' does not exist in the context of `{1}'",
 773                                                 name, class_name);
 774                                 else
 775                                         Error_TypeDoesNotContainDefinition (loc, queried_type, name);
 776                                 return;
 777                         }
 778
 779                         MemberList ml = TypeManager.FindMembers (queried_type, MemberTypes.Constructor,
 780                                 BindingFlags.Static | BindingFlags.Instance | BindingFlags.Public | BindingFlags.DeclaredOnly, null, null);
 781                         if (name == ".ctor" && ml.Count == 0)
 782                         {
 783                                 Report.Error (143, loc, "The type `{0}' has no constructors defined", TypeManager.CSharpName (queried_type));
 784                                 return;
 785                         }
 786
 787                         ErrorIsInaccesible (loc, TypeManager.GetFullNameSignature (lookup [0]));
 788                 }
 789
 790                 /// <summary>
 791                 ///   Returns an expression that can be used to invoke operator true
 792                 ///   on the expression if it exists.
 793                 /// </summary>
 794                 static public StaticCallExpr GetOperatorTrue (EmitContext ec, Expression e, Location loc)
 795                 {
 796                         return GetOperatorTrueOrFalse (ec, e, true, loc);
 797                 }
 798
 799                 /// <summary>
 800                 ///   Returns an expression that can be used to invoke operator false
 801                 ///   on the expression if it exists.
 802                 /// </summary>
 803                 static public StaticCallExpr GetOperatorFalse (EmitContext ec, Expression e, Location loc)
 804                 {
 805                         return GetOperatorTrueOrFalse (ec, e, false, loc);
 806                 }
 807
 808                 static StaticCallExpr GetOperatorTrueOrFalse (EmitContext ec, Expression e, bool is_true, Location loc)
 809                 {
 810                         MethodBase method;
 811                         Expression operator_group;
 812
 813                         operator_group = MethodLookup (ec, e.Type, is_true ? "op_True" : "op_False", loc);
 814                         if (operator_group == null)
 815                                 return null;
 816
 817                         ArrayList arguments = new ArrayList ();
 818                         arguments.Add (new Argument (e, Argument.AType.Expression));
 819                         method = Invocation.OverloadResolve (
 820                                 ec, (MethodGroupExpr) operator_group, arguments, false, loc);
 821
 822                         if (method == null)
 823                                 return null;
 824
 825                         return new StaticCallExpr ((MethodInfo) method, arguments, loc);
 826                 }
 827
 828                 /// <summary>
 829                 ///   Resolves the expression `e' into a boolean expression: either through
 830                 ///   an implicit conversion, or through an `operator true' invocation
 831                 /// </summary>
 832                 public static Expression ResolveBoolean (EmitContext ec, Expression e, Location loc)
 833                 {
 834                         e = e.Resolve (ec);
 835                         if (e == null)
 836                                 return null;
 837
 838                         if (e.Type == TypeManager.bool_type)
 839                                 return e;
 840
 841                         Expression converted = Convert.ImplicitConversion (ec, e, TypeManager.bool_type, Location.Null);
 842
 843                         if (converted != null)
 844                                 return converted;
 845
 846                         //
 847                         // If no implicit conversion to bool exists, try using `operator true'
 848                         //
 849                         converted = Expression.GetOperatorTrue (ec, e, loc);
 850                         if (converted == null){
 851                                 e.Error_ValueCannotBeConverted (loc, TypeManager.bool_type, false);
 852                                 return null;
 853                         }
 854                         return converted;
 855                 }
 856
 857                 public virtual string ExprClassName
 858                 {
 859                         get {
 860                                 switch (eclass){
 861                                         case ExprClass.Invalid:
 862                                                 return "Invalid";
 863                                         case ExprClass.Value:
 864                                                 return "value";
 865                                         case ExprClass.Variable:
 866                                                 return "variable";
 867                                         case ExprClass.Namespace:
 868                                                 return "namespace";
 869                                         case ExprClass.Type:
 870                                                 return "type";
 871                                         case ExprClass.MethodGroup:
 872                                                 return "method group";
 873                                         case ExprClass.PropertyAccess:
 874                                                 return "property access";
 875                                         case ExprClass.EventAccess:
 876                                                 return "event access";
 877                                         case ExprClass.IndexerAccess:
 878                                                 return "indexer access";
 879                                         case ExprClass.Nothing:
 880                                                 return "null";
 881                                 }
 882                                 throw new Exception ("Should not happen");
 883                         }
 884                 }
 885
 886                 /// <summary>
 887                 ///   Reports that we were expecting `expr' to be of class `expected'
 888                 /// </summary>
 889                 public void Error_UnexpectedKind (DeclSpace ds, string expected, Location loc)
 890                 {
 891                         Error_UnexpectedKind (ds, expected, ExprClassName, loc);
 892                 }
 893
 894                 public void Error_UnexpectedKind (DeclSpace ds, string expected, string was, Location loc)
 895                 {
 896                         string name = GetSignatureForError ();
 897                         if (ds != null)
 898                                 name = ds.GetSignatureForError () + '.' + name;
 899
 900                         Report.Error (118, loc, "`{0}' is a `{1}' but a `{2}' was expected",
 901                               name, was, expected);
 902                 }
 903
 904                 public void Error_UnexpectedKind (ResolveFlags flags, Location loc)
 905                 {
 906                         string [] valid = new string [4];
 907                         int count = 0;
 908
 909                         if ((flags & ResolveFlags.VariableOrValue) != 0) {
 910                                 valid [count++] = "variable";
 911                                 valid [count++] = "value";
 912                         }
 913
 914                         if ((flags & ResolveFlags.Type) != 0)
 915                                 valid [count++] = "type";
 916
 917                         if ((flags & ResolveFlags.MethodGroup) != 0)
 918                                 valid [count++] = "method group";
 919
 920                         if (count == 0)
 921                                 valid [count++] = "unknown";
 922
 923                         StringBuilder sb = new StringBuilder (valid [0]);
 924                         for (int i = 1; i < count - 1; i++) {
 925                                 sb.Append ("', `");
 926                                 sb.Append (valid [i]);
 927                         }
 928                         if (count > 1) {
 929                                 sb.Append ("' or `");
 930                                 sb.Append (valid [count - 1]);
 931                         }
 932
 933                         Report.Error (119, loc,
 934                                 "Expression denotes a `{0}', where a `{1}' was expected", ExprClassName, sb.ToString ());
 935                 }
 936
 937                 public static void UnsafeError (Location loc)
 938                 {
 939                         Report.Error (214, loc, "Pointers and fixed size buffers may only be used in an unsafe context");
 940                 }
 941
 942                 //
 943                 // Load the object from the pointer.
 944                 //
 945                 public static void LoadFromPtr (ILGenerator ig, Type t)
 946                 {
 947                         if (t == TypeManager.int32_type)
 948                                 ig.Emit (OpCodes.Ldind_I4);
 949                         else if (t == TypeManager.uint32_type)
 950                                 ig.Emit (OpCodes.Ldind_U4);
 951                         else if (t == TypeManager.short_type)
 952                                 ig.Emit (OpCodes.Ldind_I2);
 953                         else if (t == TypeManager.ushort_type)
 954                                 ig.Emit (OpCodes.Ldind_U2);
 955                         else if (t == TypeManager.char_type)
 956                                 ig.Emit (OpCodes.Ldind_U2);
 957                         else if (t == TypeManager.byte_type)
 958                                 ig.Emit (OpCodes.Ldind_U1);
 959                         else if (t == TypeManager.sbyte_type)
 960                                 ig.Emit (OpCodes.Ldind_I1);
 961                         else if (t == TypeManager.uint64_type)
 962                                 ig.Emit (OpCodes.Ldind_I8);
 963                         else if (t == TypeManager.int64_type)
 964                                 ig.Emit (OpCodes.Ldind_I8);
 965                         else if (t == TypeManager.float_type)
 966                                 ig.Emit (OpCodes.Ldind_R4);
 967                         else if (t == TypeManager.double_type)
 968                                 ig.Emit (OpCodes.Ldind_R8);
 969                         else if (t == TypeManager.bool_type)
 970                                 ig.Emit (OpCodes.Ldind_I1);
 971                         else if (t == TypeManager.intptr_type)
 972                                 ig.Emit (OpCodes.Ldind_I);
 973                         else if (TypeManager.IsEnumType (t)) {
 974                                 if (t == TypeManager.enum_type)
 975                                         ig.Emit (OpCodes.Ldind_Ref);
 976                                 else
 977                                         LoadFromPtr (ig, TypeManager.EnumToUnderlying (t));
 978                         } else if (t.IsValueType)
 979                                 ig.Emit (OpCodes.Ldobj, t);
 980                         else if (t.IsPointer)
 981                                 ig.Emit (OpCodes.Ldind_I);
 982                         else
 983                                 ig.Emit (OpCodes.Ldind_Ref);
 984                 }
 985
 986                 //
 987                 // The stack contains the pointer and the value of type `type'
 988                 //
 989                 public static void StoreFromPtr (ILGenerator ig, Type type)
 990                 {
 991                         if (TypeManager.IsEnumType (type))
 992                                 type = TypeManager.EnumToUnderlying (type);
 993                         if (type == TypeManager.int32_type || type == TypeManager.uint32_type)
 994                                 ig.Emit (OpCodes.Stind_I4);
 995                         else if (type == TypeManager.int64_type || type == TypeManager.uint64_type)
 996                                 ig.Emit (OpCodes.Stind_I8);
 997                         else if (type == TypeManager.char_type || type == TypeManager.short_type ||
 998                                  type == TypeManager.ushort_type)
 999                                 ig.Emit (OpCodes.Stind_I2);
1000                         else if (type == TypeManager.float_type)
1001                                 ig.Emit (OpCodes.Stind_R4);
1002                         else if (type == TypeManager.double_type)
1003                                 ig.Emit (OpCodes.Stind_R8);
1004                         else if (type == TypeManager.byte_type || type == TypeManager.sbyte_type ||
1005                                  type == TypeManager.bool_type)
1006                                 ig.Emit (OpCodes.Stind_I1);
1007                         else if (type == TypeManager.intptr_type)
1008                                 ig.Emit (OpCodes.Stind_I);
1009                         else if (type.IsValueType)
1010                                 ig.Emit (OpCodes.Stobj, type);
1011                         else
1012                                 ig.Emit (OpCodes.Stind_Ref);
1013                 }
1014
1015                 //
1016                 // Returns the size of type `t' if known, otherwise, 0
1017                 //
1018                 public static int GetTypeSize (Type t)
1019                 {
1020                         t = TypeManager.TypeToCoreType (t);
1021                         if (t == TypeManager.int32_type ||
1022                             t == TypeManager.uint32_type ||
1023                             t == TypeManager.float_type)
1024                                 return 4;
1025                         else if (t == TypeManager.int64_type ||
1026                                  t == TypeManager.uint64_type ||
1027                                  t == TypeManager.double_type)
1028                                 return 8;
1029                         else if (t == TypeManager.byte_type ||
1030                                  t == TypeManager.sbyte_type ||
1031                                  t == TypeManager.bool_type)
1032                                 return 1;
1033                         else if (t == TypeManager.short_type ||
1034                                  t == TypeManager.char_type ||
1035                                  t == TypeManager.ushort_type)
1036                                 return 2;
1037                         else if (t == TypeManager.decimal_type)
1038                                 return 16;
1039                         else
1040                                 return 0;
1041                 }
1042
1043                 public static void Error_NegativeArrayIndex (Location loc)
1044                 {
1045                         Report.Error (248, loc, "Cannot create an array with a negative size");
1046                 }
1047
1048                 protected void Error_CannotCallAbstractBase (string name)
1049                 {
1050                         Report.Error (205, loc, "Cannot call an abstract base member `{0}'", name);
1051                 }
1052
1053                 //
1054                 // Converts `source' to an int, uint, long or ulong.
1055                 //
1056                 public Expression ExpressionToArrayArgument (EmitContext ec, Expression source, Location loc)
1057                 {
1058                         Expression target;
1059
1060                         bool old_checked = ec.CheckState;
1061                         ec.CheckState = true;
1062
1063                         target = Convert.ImplicitConversion (ec, source, TypeManager.int32_type, loc);
1064                         if (target == null){
1065                                 target = Convert.ImplicitConversion (ec, source, TypeManager.uint32_type, loc);
1066                                 if (target == null){
1067                                         target = Convert.ImplicitConversion (ec, source, TypeManager.int64_type, loc);
1068                                         if (target == null){
1069                                                 target = Convert.ImplicitConversion (ec, source, TypeManager.uint64_type, loc);
1070                                                 if (target == null)
1071                                                         source.Error_ValueCannotBeConverted (loc, TypeManager.int32_type, false);
1072                                         }
1073                                 }
1074                         }
1075                         ec.CheckState = old_checked;
1076
1077                         //
1078                         // Only positive constants are allowed at compile time
1079                         //
1080                         if (target is Constant){
1081                                 if (target is IntConstant){
1082                                         if (((IntConstant) target).Value < 0){
1083                                                 Error_NegativeArrayIndex (loc);
1084                                                 return null;
1085                                         }
1086                                 }
1087
1088                                 if (target is LongConstant){
1089                                         if (((LongConstant) target).Value < 0){
1090                                                 Error_NegativeArrayIndex (loc);
1091                                                 return null;
1092                                         }
1093                                 }
1094
1095                         }
1096
1097                         return target;
1098                 }
1099
1100         }
1101
1102         /// <summary>
1103         ///   This is just a base class for expressions that can
1104         ///   appear on statements (invocations, object creation,
1105         ///   assignments, post/pre increment and decrement).  The idea
1106         ///   being that they would support an extra Emition interface that
1107         ///   does not leave a result on the stack.
1108         /// </summary>
1109         public abstract class ExpressionStatement : Expression {
1110
1111                 public virtual ExpressionStatement ResolveStatement (EmitContext ec)
1112                 {
1113                         Expression e = Resolve (ec);
1114                         if (e == null)
1115                                 return null;
1116
1117                         ExpressionStatement es = e as ExpressionStatement;
1118                         if (es == null)
1119                                 Error (201, "Only assignment, call, increment, decrement and new object " +
1120                                        "expressions can be used as a statement");
1121
1122                         return es;
1123                 }
1124
1125                 /// <summary>
1126                 ///   Requests the expression to be emitted in a `statement'
1127                 ///   context.  This means that no new value is left on the
1128                 ///   stack after invoking this method (constrasted with
1129                 ///   Emit that will always leave a value on the stack).
1130                 /// </summary>
1131                 public abstract void EmitStatement (EmitContext ec);
1132         }
1133
1134         /// <summary>
1135         ///   This kind of cast is used to encapsulate the child
1136         ///   whose type is child.Type into an expression that is
1137         ///   reported to return "return_type".  This is used to encapsulate
1138         ///   expressions which have compatible types, but need to be dealt
1139         ///   at higher levels with.
1140         ///
1141         ///   For example, a "byte" expression could be encapsulated in one
1142         ///   of these as an "unsigned int".  The type for the expression
1143         ///   would be "unsigned int".
1144         ///
1145         /// </summary>
1146         public class EmptyCast : Expression {
1147                 protected readonly Expression child;
1148
1149                 public Expression Child {
1150                         get {
1151                                 return child;
1152                         }
1153                 }
1154
1155                 public EmptyCast (Expression child, Type return_type)
1156                 {
1157                         eclass = child.eclass;
1158                         loc = child.Location;
1159                         type = return_type;
1160                         this.child = child;
1161                 }
1162
1163                 public override Expression DoResolve (EmitContext ec)
1164                 {
1165                         // This should never be invoked, we are born in fully
1166                         // initialized state.
1167
1168                         return this;
1169                 }
1170
1171                 public override void Emit (EmitContext ec)
1172                 {
1173                         child.Emit (ec);
1174                 }
1175
1176                 public override bool GetAttributableValue (out object value)
1177                 {
1178                         return child.GetAttributableValue (out value);
1179                 }
1180
1181         }
1182         /// <summary>
1183         ///     This is a numeric cast to a Decimal
1184         /// </summary>
1185         public class CastToDecimal : EmptyCast {
1186
1187                 MethodInfo conversion_operator;
1188
1189                 public CastToDecimal (Expression child)
1190                         : this (child, false)
1191                 {
1192                 }
1193
1194                 public CastToDecimal (Expression child, bool find_explicit)
1195                         : base (child, TypeManager.decimal_type)
1196                 {
1197                         conversion_operator = GetConversionOperator (find_explicit);
1198
1199                         if (conversion_operator == null)
1200                                 throw new InternalErrorException ("Outer conversion routine is out of sync");
1201                 }
1202
1203                 // Returns the implicit operator that converts from
1204                 // 'child.Type' to System.Decimal.
1205                 MethodInfo GetConversionOperator (bool find_explicit)
1206                 {
1207                         string operator_name = find_explicit ? "op_Explicit" : "op_Implicit";
1208
1209                         MemberInfo [] mi = TypeManager.MemberLookup (type, type, type, MemberTypes.Method,
1210                                 BindingFlags.Static | BindingFlags.Public, operator_name, null);
1211
1212                         foreach (MethodInfo oper in mi) {
1213                                 ParameterData pd = TypeManager.GetParameterData (oper);
1214
1215                                 if (pd.ParameterType (0) == child.Type && oper.ReturnType == type)
1216                                         return oper;
1217                         }
1218
1219                         return null;
1220                 }
1221                 public override void Emit (EmitContext ec)
1222                 {
1223                         ILGenerator ig = ec.ig;
1224                         child.Emit (ec);
1225
1226                         ig.Emit (OpCodes.Call, conversion_operator);
1227                 }
1228         }
1229
1230         /// <summary>
1231         ///     This is an explicit numeric cast from a Decimal
1232         /// </summary>
1233         public class CastFromDecimal : EmptyCast
1234         {
1235                 static IDictionary operators;
1236
1237                 public CastFromDecimal (Expression child, Type return_type)
1238                         : base (child, return_type)
1239                 {
1240                         if (child.Type != TypeManager.decimal_type)
1241                                 throw new InternalErrorException (
1242                                         "The expected type is Decimal, instead it is " + child.Type.FullName);
1243                 }
1244
1245                 // Returns the explicit operator that converts from an
1246                 // express of type System.Decimal to 'type'.
1247                 public Expression Resolve ()
1248                 {
1249                         if (operators == null) {
1250                                  MemberInfo[] all_oper = TypeManager.MemberLookup (TypeManager.decimal_type,
1251                                         TypeManager.decimal_type, TypeManager.decimal_type, MemberTypes.Method,
1252                                         BindingFlags.Static | BindingFlags.Public, "op_Explicit", null);
1253
1254                                 operators = new System.Collections.Specialized.HybridDictionary ();
1255                                 foreach (MethodInfo oper in all_oper) {
1256                                         ParameterData pd = TypeManager.GetParameterData (oper);
1257                                         if (pd.ParameterType (0) == TypeManager.decimal_type)
1258                                                 operators.Add (oper.ReturnType, oper);
1259                                 }
1260                         }
1261
1262                         return operators.Contains (type) ? this : null;
1263                 }
1264
1265                 public override void Emit (EmitContext ec)
1266                 {
1267                         ILGenerator ig = ec.ig;
1268                         child.Emit (ec);
1269
1270                         ig.Emit (OpCodes.Call, (MethodInfo)operators [type]);
1271                 }
1272         }
1273
1274         //
1275         // We need to special case this since an empty cast of
1276         // a NullLiteral is still a Constant
1277         //
1278         public class NullCast : Constant {
1279                 public Constant child;
1280
1281                 public NullCast (Constant child, Type return_type):
1282                         base (Location.Null)
1283                 {
1284                         eclass = child.eclass;
1285                         type = return_type;
1286                         this.child = child;
1287                 }
1288
1289                 override public string AsString ()
1290                 {
1291                         return "null";
1292                 }
1293
1294                 public override object GetValue ()
1295                 {
1296                         return null;
1297                 }
1298
1299                 public override Expression DoResolve (EmitContext ec)
1300                 {
1301                         // This should never be invoked, we are born in fully
1302                         // initialized state.
1303
1304                         return this;
1305                 }
1306
1307                 public override void Emit (EmitContext ec)
1308                 {
1309                         child.Emit (ec);
1310                 }
1311
1312                 public override Constant Increment ()
1313                 {
1314                         throw new NotSupportedException ();
1315                 }
1316
1317                 public override bool IsDefaultValue {
1318                         get {
1319                                 return true;
1320                         }
1321                 }
1322
1323                 public override bool IsNegative {
1324                         get {
1325                                 return false;
1326                         }
1327                 }
1328
1329                 public override Constant Reduce (EmitContext ec, Type target_type)
1330                 {
1331                         if (type == target_type)
1332                                 return child.Reduce (ec, target_type);
1333
1334                         return null;
1335                 }
1336
1337         }
1338
1339
1340         /// <summary>
1341         ///  This class is used to wrap literals which belong inside Enums
1342         /// </summary>
1343         public class EnumConstant : Constant {
1344                 public Constant Child;
1345
1346                 public EnumConstant (Constant child, Type enum_type):
1347                         base (child.Location)
1348                 {
1349                         eclass = child.eclass;
1350                         this.Child = child;
1351                         type = enum_type;
1352                 }
1353
1354                 public override Expression DoResolve (EmitContext ec)
1355                 {
1356                         // This should never be invoked, we are born in fully
1357                         // initialized state.
1358
1359                         return this;
1360                 }
1361
1362                 public override void Emit (EmitContext ec)
1363                 {
1364                         Child.Emit (ec);
1365                 }
1366
1367                 public override string GetSignatureForError()
1368                 {
1369                         return TypeManager.CSharpName (Type);
1370                 }
1371
1372                 public override object GetValue ()
1373                 {
1374                         return Child.GetValue ();
1375                 }
1376
1377                 public override object GetTypedValue ()
1378                 {
1379                         // FIXME: runtime is not ready to work with just emited enums
1380                         if (!RootContext.StdLib) {
1381                                 return Child.GetValue ();
1382                         }
1383
1384                         return System.Enum.ToObject (type, Child.GetValue ());
1385                 }
1386
1387                 public override string AsString ()
1388                 {
1389                         return Child.AsString ();
1390                 }
1391
1392                 public override DoubleConstant ConvertToDouble ()
1393                 {
1394                         return Child.ConvertToDouble ();
1395                 }
1396
1397                 public override FloatConstant ConvertToFloat ()
1398                 {
1399                         return Child.ConvertToFloat ();
1400                 }
1401
1402                 public override ULongConstant ConvertToULong ()
1403                 {
1404                         return Child.ConvertToULong ();
1405                 }
1406
1407                 public override LongConstant ConvertToLong ()
1408                 {
1409                         return Child.ConvertToLong ();
1410                 }
1411
1412                 public override UIntConstant ConvertToUInt ()
1413                 {
1414                         return Child.ConvertToUInt ();
1415                 }
1416
1417                 public override IntConstant ConvertToInt ()
1418                 {
1419                         return Child.ConvertToInt ();
1420                 }
1421
1422                 public override Constant Increment()
1423                 {
1424                         return new EnumConstant (Child.Increment (), type);
1425                 }
1426
1427                 public override bool IsDefaultValue {
1428                         get {
1429                                 return Child.IsDefaultValue;
1430                         }
1431                 }
1432
1433                 public override bool IsZeroInteger {
1434                         get { return Child.IsZeroInteger; }
1435                 }
1436
1437                 public override bool IsNegative {
1438                         get {
1439                                 return Child.IsNegative;
1440                         }
1441                 }
1442
1443                 public override Constant Reduce(EmitContext ec, Type target_type)
1444                 {
1445                         if (Child.Type == target_type)
1446                                 return Child;
1447
1448                         return Child.Reduce (ec, target_type);
1449                 }
1450
1451                 public override Constant ToType (Type type, Location loc)
1452                 {
1453                         if (Type == type) {
1454                                 // This is workaround of mono bug. It can be removed when the latest corlib spreads enough
1455                                 if (TypeManager.IsEnumType (type.UnderlyingSystemType))
1456                                         return this;
1457
1458                                 if (type.UnderlyingSystemType != Child.Type)
1459                                         Child = Child.ToType (type.UnderlyingSystemType, loc);
1460                                 return this;
1461                         }
1462
1463                         if (!Convert.ImplicitStandardConversionExists (this, type)){
1464                                 Error_ValueCannotBeConverted (loc, type, false);
1465                                 return null;
1466                         }
1467
1468                         return Child.ToType (type, loc);
1469                 }
1470
1471         }
1472
1473         /// <summary>
1474         ///   This kind of cast is used to encapsulate Value Types in objects.
1475         ///
1476         ///   The effect of it is to box the value type emitted by the previous
1477         ///   operation.
1478         /// </summary>
1479         public class BoxedCast : EmptyCast {
1480
1481                 public BoxedCast (Expression expr, Type target_type)
1482                         : base (expr, target_type)
1483                 {
1484                         eclass = ExprClass.Value;
1485                 }
1486
1487                 public override Expression DoResolve (EmitContext ec)
1488                 {
1489                         // This should never be invoked, we are born in fully
1490                         // initialized state.
1491
1492                         return this;
1493                 }
1494
1495                 public override void Emit (EmitContext ec)
1496                 {
1497                         base.Emit (ec);
1498
1499                         ec.ig.Emit (OpCodes.Box, child.Type);
1500                 }
1501         }
1502
1503         public class UnboxCast : EmptyCast {
1504                 public UnboxCast (Expression expr, Type return_type)
1505                         : base (expr, return_type)
1506                 {
1507                 }
1508
1509                 public override Expression DoResolve (EmitContext ec)
1510                 {
1511                         // This should never be invoked, we are born in fully
1512                         // initialized state.
1513
1514                         return this;
1515                 }
1516
1517                 public override Expression DoResolveLValue (EmitContext ec, Expression right_side)
1518                 {
1519                         if (right_side == EmptyExpression.LValueMemberAccess)
1520                                 Report.Error (445, loc, "Cannot modify the result of an unboxing conversion");
1521                         return base.DoResolveLValue (ec, right_side);
1522                 }
1523
1524                 public override void Emit (EmitContext ec)
1525                 {
1526                         Type t = type;
1527                         ILGenerator ig = ec.ig;
1528
1529                         base.Emit (ec);
1530                         ig.Emit (OpCodes.Unbox, t);
1531
1532                         LoadFromPtr (ig, t);
1533                 }
1534         }
1535
1536         /// <summary>
1537         ///   This is used to perform explicit numeric conversions.
1538         ///
1539         ///   Explicit numeric conversions might trigger exceptions in a checked
1540         ///   context, so they should generate the conv.ovf opcodes instead of
1541         ///   conv opcodes.
1542         /// </summary>
1543         public class ConvCast : EmptyCast {
1544                 public enum Mode : byte {
1545                         I1_U1, I1_U2, I1_U4, I1_U8, I1_CH,
1546                         U1_I1, U1_CH,
1547                         I2_I1, I2_U1, I2_U2, I2_U4, I2_U8, I2_CH,
1548                         U2_I1, U2_U1, U2_I2, U2_CH,
1549                         I4_I1, I4_U1, I4_I2, I4_U2, I4_U4, I4_U8, I4_CH,
1550                         U4_I1, U4_U1, U4_I2, U4_U2, U4_I4, U4_CH,
1551                         I8_I1, I8_U1, I8_I2, I8_U2, I8_I4, I8_U4, I8_U8, I8_CH,
1552                         U8_I1, U8_U1, U8_I2, U8_U2, U8_I4, U8_U4, U8_I8, U8_CH,
1553                         CH_I1, CH_U1, CH_I2,
1554                         R4_I1, R4_U1, R4_I2, R4_U2, R4_I4, R4_U4, R4_I8, R4_U8, R4_CH,
1555                         R8_I1, R8_U1, R8_I2, R8_U2, R8_I4, R8_U4, R8_I8, R8_U8, R8_CH, R8_R4
1556                 }
1557
1558                 Mode mode;
1559
1560                 public ConvCast (Expression child, Type return_type, Mode m)
1561                         : base (child, return_type)
1562                 {
1563                         mode = m;
1564                 }
1565
1566                 public override Expression DoResolve (EmitContext ec)
1567                 {
1568                         // This should never be invoked, we are born in fully
1569                         // initialized state.
1570
1571                         return this;
1572                 }
1573
1574                 public override string ToString ()
1575                 {
1576                         return String.Format ("ConvCast ({0}, {1})", mode, child);
1577                 }
1578
1579                 public override void Emit (EmitContext ec)
1580                 {
1581                         ILGenerator ig = ec.ig;
1582
1583                         base.Emit (ec);
1584
1585                         if (ec.CheckState){
1586                                 switch (mode){
1587                                 case Mode.I1_U1: ig.Emit (OpCodes.Conv_Ovf_U1); break;
1588                                 case Mode.I1_U2: ig.Emit (OpCodes.Conv_Ovf_U2); break;
1589                                 case Mode.I1_U4: ig.Emit (OpCodes.Conv_Ovf_U4); break;
1590                                 case Mode.I1_U8: ig.Emit (OpCodes.Conv_Ovf_U8); break;
1591                                 case Mode.I1_CH: ig.Emit (OpCodes.Conv_Ovf_U2); break;
1592
1593                                 case Mode.U1_I1: ig.Emit (OpCodes.Conv_Ovf_I1_Un); break;
1594                                 case Mode.U1_CH: /* nothing */ break;
1595
1596                                 case Mode.I2_I1: ig.Emit (OpCodes.Conv_Ovf_I1); break;
1597                                 case Mode.I2_U1: ig.Emit (OpCodes.Conv_Ovf_U1); break;
1598                                 case Mode.I2_U2: ig.Emit (OpCodes.Conv_Ovf_U2); break;
1599                                 case Mode.I2_U4: ig.Emit (OpCodes.Conv_Ovf_U4); break;
1600                                 case Mode.I2_U8: ig.Emit (OpCodes.Conv_Ovf_U8); break;
1601                                 case Mode.I2_CH: ig.Emit (OpCodes.Conv_Ovf_U2); break;
1602
1603                                 case Mode.U2_I1: ig.Emit (OpCodes.Conv_Ovf_I1_Un); break;
1604                                 case Mode.U2_U1: ig.Emit (OpCodes.Conv_Ovf_U1_Un); break;
1605                                 case Mode.U2_I2: ig.Emit (OpCodes.Conv_Ovf_I2_Un); break;
1606                                 case Mode.U2_CH: /* nothing */ break;
1607
1608                                 case Mode.I4_I1: ig.Emit (OpCodes.Conv_Ovf_I1); break;
1609                                 case Mode.I4_U1: ig.Emit (OpCodes.Conv_Ovf_U1); break;
1610                                 case Mode.I4_I2: ig.Emit (OpCodes.Conv_Ovf_I2); break;
1611                                 case Mode.I4_U4: ig.Emit (OpCodes.Conv_Ovf_U4); break;
1612                                 case Mode.I4_U2: ig.Emit (OpCodes.Conv_Ovf_U2); break;
1613                                 case Mode.I4_U8: ig.Emit (OpCodes.Conv_Ovf_U8); break;
1614                                 case Mode.I4_CH: ig.Emit (OpCodes.Conv_Ovf_U2); break;
1615
1616                                 case Mode.U4_I1: ig.Emit (OpCodes.Conv_Ovf_I1_Un); break;
1617                                 case Mode.U4_U1: ig.Emit (OpCodes.Conv_Ovf_U1_Un); break;
1618                                 case Mode.U4_I2: ig.Emit (OpCodes.Conv_Ovf_I2_Un); break;
1619                                 case Mode.U4_U2: ig.Emit (OpCodes.Conv_Ovf_U2_Un); break;
1620                                 case Mode.U4_I4: ig.Emit (OpCodes.Conv_Ovf_I4_Un); break;
1621                                 case Mode.U4_CH: ig.Emit (OpCodes.Conv_Ovf_U2_Un); break;
1622
1623                                 case Mode.I8_I1: ig.Emit (OpCodes.Conv_Ovf_I1); break;
1624                                 case Mode.I8_U1: ig.Emit (OpCodes.Conv_Ovf_U1); break;
1625                                 case Mode.I8_I2: ig.Emit (OpCodes.Conv_Ovf_I2); break;
1626                                 case Mode.I8_U2: ig.Emit (OpCodes.Conv_Ovf_U2); break;
1627                                 case Mode.I8_I4: ig.Emit (OpCodes.Conv_Ovf_I4); break;
1628                                 case Mode.I8_U4: ig.Emit (OpCodes.Conv_Ovf_U4); break;
1629                                 case Mode.I8_U8: ig.Emit (OpCodes.Conv_Ovf_U8); break;
1630                                 case Mode.I8_CH: ig.Emit (OpCodes.Conv_Ovf_U2); break;
1631
1632                                 case Mode.U8_I1: ig.Emit (OpCodes.Conv_Ovf_I1_Un); break;
1633                                 case Mode.U8_U1: ig.Emit (OpCodes.Conv_Ovf_U1_Un); break;
1634                                 case Mode.U8_I2: ig.Emit (OpCodes.Conv_Ovf_I2_Un); break;
1635                                 case Mode.U8_U2: ig.Emit (OpCodes.Conv_Ovf_U2_Un); break;
1636                                 case Mode.U8_I4: ig.Emit (OpCodes.Conv_Ovf_I4_Un); break;
1637                                 case Mode.U8_U4: ig.Emit (OpCodes.Conv_Ovf_U4_Un); break;
1638                                 case Mode.U8_I8: ig.Emit (OpCodes.Conv_Ovf_I8_Un); break;
1639                                 case Mode.U8_CH: ig.Emit (OpCodes.Conv_Ovf_U2_Un); break;
1640
1641                                 case Mode.CH_I1: ig.Emit (OpCodes.Conv_Ovf_I1_Un); break;
1642                                 case Mode.CH_U1: ig.Emit (OpCodes.Conv_Ovf_U1_Un); break;
1643                                 case Mode.CH_I2: ig.Emit (OpCodes.Conv_Ovf_I2_Un); break;
1644
1645                                 case Mode.R4_I1: ig.Emit (OpCodes.Conv_Ovf_I1); break;
1646                                 case Mode.R4_U1: ig.Emit (OpCodes.Conv_Ovf_U1); break;
1647                                 case Mode.R4_I2: ig.Emit (OpCodes.Conv_Ovf_I2); break;
1648                                 case Mode.R4_U2: ig.Emit (OpCodes.Conv_Ovf_U2); break;
1649                                 case Mode.R4_I4: ig.Emit (OpCodes.Conv_Ovf_I4); break;
1650                                 case Mode.R4_U4: ig.Emit (OpCodes.Conv_Ovf_U4); break;
1651                                 case Mode.R4_I8: ig.Emit (OpCodes.Conv_Ovf_I8); break;
1652                                 case Mode.R4_U8: ig.Emit (OpCodes.Conv_Ovf_U8); break;
1653                                 case Mode.R4_CH: ig.Emit (OpCodes.Conv_Ovf_U2); break;
1654
1655                                 case Mode.R8_I1: ig.Emit (OpCodes.Conv_Ovf_I1); break;
1656                                 case Mode.R8_U1: ig.Emit (OpCodes.Conv_Ovf_U1); break;
1657                                 case Mode.R8_I2: ig.Emit (OpCodes.Conv_Ovf_I2); break;
1658                                 case Mode.R8_U2: ig.Emit (OpCodes.Conv_Ovf_U2); break;
1659                                 case Mode.R8_I4: ig.Emit (OpCodes.Conv_Ovf_I4); break;
1660                                 case Mode.R8_U4: ig.Emit (OpCodes.Conv_Ovf_U4); break;
1661                                 case Mode.R8_I8: ig.Emit (OpCodes.Conv_Ovf_I8); break;
1662                                 case Mode.R8_U8: ig.Emit (OpCodes.Conv_Ovf_U8); break;
1663                                 case Mode.R8_CH: ig.Emit (OpCodes.Conv_Ovf_U2); break;
1664                                 case Mode.R8_R4: ig.Emit (OpCodes.Conv_R4); break;
1665                                 }
1666                         } else {
1667                                 switch (mode){
1668                                 case Mode.I1_U1: ig.Emit (OpCodes.Conv_U1); break;
1669                                 case Mode.I1_U2: ig.Emit (OpCodes.Conv_U2); break;
1670                                 case Mode.I1_U4: ig.Emit (OpCodes.Conv_U4); break;
1671                                 case Mode.I1_U8: ig.Emit (OpCodes.Conv_I8); break;
1672                                 case Mode.I1_CH: ig.Emit (OpCodes.Conv_U2); break;
1673
1674                                 case Mode.U1_I1: ig.Emit (OpCodes.Conv_I1); break;
1675                                 case Mode.U1_CH: ig.Emit (OpCodes.Conv_U2); break;
1676
1677                                 case Mode.I2_I1: ig.Emit (OpCodes.Conv_I1); break;
1678                                 case Mode.I2_U1: ig.Emit (OpCodes.Conv_U1); break;
1679                                 case Mode.I2_U2: ig.Emit (OpCodes.Conv_U2); break;
1680                                 case Mode.I2_U4: ig.Emit (OpCodes.Conv_U4); break;
1681                                 case Mode.I2_U8: ig.Emit (OpCodes.Conv_I8); break;
1682                                 case Mode.I2_CH: ig.Emit (OpCodes.Conv_U2); break;
1683
1684                                 case Mode.U2_I1: ig.Emit (OpCodes.Conv_I1); break;
1685                                 case Mode.U2_U1: ig.Emit (OpCodes.Conv_U1); break;
1686                                 case Mode.U2_I2: ig.Emit (OpCodes.Conv_I2); break;
1687                                 case Mode.U2_CH: /* nothing */ break;
1688
1689                                 case Mode.I4_I1: ig.Emit (OpCodes.Conv_I1); break;
1690                                 case Mode.I4_U1: ig.Emit (OpCodes.Conv_U1); break;
1691                                 case Mode.I4_I2: ig.Emit (OpCodes.Conv_I2); break;
1692                                 case Mode.I4_U4: /* nothing */ break;
1693                                 case Mode.I4_U2: ig.Emit (OpCodes.Conv_U2); break;
1694                                 case Mode.I4_U8: ig.Emit (OpCodes.Conv_I8); break;
1695                                 case Mode.I4_CH: ig.Emit (OpCodes.Conv_U2); break;
1696
1697                                 case Mode.U4_I1: ig.Emit (OpCodes.Conv_I1); break;
1698                                 case Mode.U4_U1: ig.Emit (OpCodes.Conv_U1); break;
1699                                 case Mode.U4_I2: ig.Emit (OpCodes.Conv_I2); break;
1700                                 case Mode.U4_U2: ig.Emit (OpCodes.Conv_U2); break;
1701                                 case Mode.U4_I4: /* nothing */ break;
1702                                 case Mode.U4_CH: ig.Emit (OpCodes.Conv_U2); break;
1703
1704                                 case Mode.I8_I1: ig.Emit (OpCodes.Conv_I1); break;
1705                                 case Mode.I8_U1: ig.Emit (OpCodes.Conv_U1); break;
1706                                 case Mode.I8_I2: ig.Emit (OpCodes.Conv_I2); break;
1707                                 case Mode.I8_U2: ig.Emit (OpCodes.Conv_U2); break;
1708                                 case Mode.I8_I4: ig.Emit (OpCodes.Conv_I4); break;
1709                                 case Mode.I8_U4: ig.Emit (OpCodes.Conv_U4); break;
1710                                 case Mode.I8_U8: /* nothing */ break;
1711                                 case Mode.I8_CH: ig.Emit (OpCodes.Conv_U2); break;
1712
1713                                 case Mode.U8_I1: ig.Emit (OpCodes.Conv_I1); break;
1714                                 case Mode.U8_U1: ig.Emit (OpCodes.Conv_U1); break;
1715                                 case Mode.U8_I2: ig.Emit (OpCodes.Conv_I2); break;
1716                                 case Mode.U8_U2: ig.Emit (OpCodes.Conv_U2); break;
1717                                 case Mode.U8_I4: ig.Emit (OpCodes.Conv_I4); break;
1718                                 case Mode.U8_U4: ig.Emit (OpCodes.Conv_U4); break;
1719                                 case Mode.U8_I8: /* nothing */ break;
1720                                 case Mode.U8_CH: ig.Emit (OpCodes.Conv_U2); break;
1721
1722                                 case Mode.CH_I1: ig.Emit (OpCodes.Conv_I1); break;
1723                                 case Mode.CH_U1: ig.Emit (OpCodes.Conv_U1); break;
1724                                 case Mode.CH_I2: ig.Emit (OpCodes.Conv_I2); break;
1725
1726                                 case Mode.R4_I1: ig.Emit (OpCodes.Conv_I1); break;
1727                                 case Mode.R4_U1: ig.Emit (OpCodes.Conv_U1); break;
1728                                 case Mode.R4_I2: ig.Emit (OpCodes.Conv_I2); break;
1729                                 case Mode.R4_U2: ig.Emit (OpCodes.Conv_U2); break;
1730                                 case Mode.R4_I4: ig.Emit (OpCodes.Conv_I4); break;
1731                                 case Mode.R4_U4: ig.Emit (OpCodes.Conv_U4); break;
1732                                 case Mode.R4_I8: ig.Emit (OpCodes.Conv_I8); break;
1733                                 case Mode.R4_U8: ig.Emit (OpCodes.Conv_U8); break;
1734                                 case Mode.R4_CH: ig.Emit (OpCodes.Conv_U2); break;
1735
1736                                 case Mode.R8_I1: ig.Emit (OpCodes.Conv_I1); break;
1737                                 case Mode.R8_U1: ig.Emit (OpCodes.Conv_U1); break;
1738                                 case Mode.R8_I2: ig.Emit (OpCodes.Conv_I2); break;
1739                                 case Mode.R8_U2: ig.Emit (OpCodes.Conv_U2); break;
1740                                 case Mode.R8_I4: ig.Emit (OpCodes.Conv_I4); break;
1741                                 case Mode.R8_U4: ig.Emit (OpCodes.Conv_U4); break;
1742                                 case Mode.R8_I8: ig.Emit (OpCodes.Conv_I8); break;
1743                                 case Mode.R8_U8: ig.Emit (OpCodes.Conv_U8); break;
1744                                 case Mode.R8_CH: ig.Emit (OpCodes.Conv_U2); break;
1745                                 case Mode.R8_R4: ig.Emit (OpCodes.Conv_R4); break;
1746                                 }
1747                         }
1748                 }
1749         }
1750
1751         public class OpcodeCast : EmptyCast {
1752                 OpCode op, op2;
1753                 bool second_valid;
1754
1755                 public OpcodeCast (Expression child, Type return_type, OpCode op)
1756                         : base (child, return_type)
1757
1758                 {
1759                         this.op = op;
1760                         second_valid = false;
1761                 }
1762
1763                 public OpcodeCast (Expression child, Type return_type, OpCode op, OpCode op2)
1764                         : base (child, return_type)
1765
1766                 {
1767                         this.op = op;
1768                         this.op2 = op2;
1769                         second_valid = true;
1770                 }
1771
1772                 public override Expression DoResolve (EmitContext ec)
1773                 {
1774                         // This should never be invoked, we are born in fully
1775                         // initialized state.
1776
1777                         return this;
1778                 }
1779
1780                 public override void Emit (EmitContext ec)
1781                 {
1782                         base.Emit (ec);
1783                         ec.ig.Emit (op);
1784
1785                         if (second_valid)
1786                                 ec.ig.Emit (op2);
1787                 }
1788         }
1789
1790         /// <summary>
1791         ///   This kind of cast is used to encapsulate a child and cast it
1792         ///   to the class requested
1793         /// </summary>
1794         public class ClassCast : EmptyCast {
1795                 public ClassCast (Expression child, Type return_type)
1796                         : base (child, return_type)
1797
1798                 {
1799                 }
1800
1801                 public override Expression DoResolve (EmitContext ec)
1802                 {
1803                         // This should never be invoked, we are born in fully
1804                         // initialized state.
1805
1806                         return this;
1807                 }
1808
1809                 public override void Emit (EmitContext ec)
1810                 {
1811                         base.Emit (ec);
1812
1813                         ec.ig.Emit (OpCodes.Castclass, type);
1814                 }
1815
1816         }
1817
1818         /// <summary>
1819         ///   SimpleName expressions are formed of a single word and only happen at the beginning
1820         ///   of a dotted-name.
1821         /// </summary>
1822         public class SimpleName : Expression {
1823                 public string Name;
1824                 bool in_transit;
1825
1826                 public SimpleName (string name, Location l)
1827                 {
1828                         Name = name;
1829                         loc = l;
1830                 }
1831
1832                 public static void Error_ObjectRefRequired (EmitContext ec, Location l, string name)
1833                 {
1834                         if (ec.IsFieldInitializer)
1835                                 Report.Error (236, l,
1836                                         "A field initializer cannot reference the nonstatic field, method, or property `{0}'",
1837                                         name);
1838                         else {
1839                                 if (name.LastIndexOf ('.') > 0)
1840                                         name = name.Substring (name.LastIndexOf ('.') + 1);
1841
1842                                 Report.Error (
1843                                         120, l, "`{0}': An object reference is required for the nonstatic field, method or property",
1844                                         name);
1845                         }
1846                 }
1847
1848                 public bool IdenticalNameAndTypeName (EmitContext ec, Expression resolved_to, Location loc)
1849                 {
1850                         return resolved_to != null && resolved_to.Type != null &&
1851                                 resolved_to.Type.Name == Name &&
1852                                 (ec.DeclContainer.LookupType (Name, loc, /* ignore_cs0104 = */ true) != null);
1853                 }
1854
1855                 public override Expression DoResolve (EmitContext ec)
1856                 {
1857                         return SimpleNameResolve (ec, null, false);
1858                 }
1859
1860                 public override Expression DoResolveLValue (EmitContext ec, Expression right_side)
1861                 {
1862                         return SimpleNameResolve (ec, right_side, false);
1863                 }
1864
1865
1866                 public Expression DoResolve (EmitContext ec, bool intermediate)
1867                 {
1868                         return SimpleNameResolve (ec, null, intermediate);
1869                 }
1870
1871                 public override FullNamedExpression ResolveAsTypeStep (IResolveContext ec, bool silent)
1872                 {
1873                         int errors = Report.Errors;
1874                         FullNamedExpression fne = ec.DeclContainer.LookupType (Name, loc, /*ignore_cs0104=*/ false);
1875                         if (fne != null)
1876                                 return fne;
1877
1878                         if (silent || errors != Report.Errors)
1879                                 return null;
1880
1881                         MemberCore mc = ec.DeclContainer.GetDefinition (Name);
1882                         if (mc != null) {
1883                                 Error_UnexpectedKind (ec.DeclContainer, "type", GetMemberType (mc), loc);
1884                         } else {
1885                                 NamespaceEntry.Error_NamespaceNotFound (loc, Name);
1886                         }
1887
1888                         return null;
1889                 }
1890
1891                 // TODO: I am still not convinced about this. If someone else will need it
1892                 // implement this as virtual property in MemberCore hierarchy
1893                 string GetMemberType (MemberCore mc)
1894                 {
1895                         if (mc is PropertyBase)
1896                                 return "property";
1897                         if (mc is Indexer)
1898                                 return "indexer";
1899                         if (mc is FieldBase)
1900                                 return "field";
1901                         if (mc is MethodCore)
1902                                 return "method";
1903                         if (mc is EnumMember)
1904                                 return "enum";
1905
1906                         return "type";
1907                 }
1908
1909                 Expression SimpleNameResolve (EmitContext ec, Expression right_side, bool intermediate)
1910                 {
1911                         if (in_transit)
1912                                 return null;
1913                         in_transit = true;
1914
1915                         Expression e = DoSimpleNameResolve (ec, right_side, intermediate);
1916                         if (e == null)
1917                                 return null;
1918
1919                         if (ec.CurrentBlock == null || ec.CurrentBlock.CheckInvariantMeaningInBlock (Name, e, Location))
1920                                 return e;
1921
1922                         return null;
1923                 }
1924
1925                 /// <remarks>
1926                 ///   7.5.2: Simple Names.
1927                 ///
1928                 ///   Local Variables and Parameters are handled at
1929                 ///   parse time, so they never occur as SimpleNames.
1930                 ///
1931                 ///   The `intermediate' flag is used by MemberAccess only
1932                 ///   and it is used to inform us that it is ok for us to
1933                 ///   avoid the static check, because MemberAccess might end
1934                 ///   up resolving the Name as a Type name and the access as
1935                 ///   a static type access.
1936                 ///
1937                 ///   ie: Type Type; .... { Type.GetType (""); }
1938                 ///
1939                 ///   Type is both an instance variable and a Type;  Type.GetType
1940                 ///   is the static method not an instance method of type.
1941                 /// </remarks>
1942                 Expression DoSimpleNameResolve (EmitContext ec, Expression right_side, bool intermediate)
1943                 {
1944                         Expression e = null;
1945
1946                         //
1947                         // Stage 1: Performed by the parser (binding to locals or parameters).
1948                         //
1949                         Block current_block = ec.CurrentBlock;
1950                         if (current_block != null){
1951                                 LocalInfo vi = current_block.GetLocalInfo (Name);
1952                                 if (vi != null){
1953                                         LocalVariableReference var = new LocalVariableReference (ec.CurrentBlock, Name, loc);
1954                                         if (right_side != null) {
1955                                                 return var.ResolveLValue (ec, right_side, loc);
1956                                         } else {
1957                                                 ResolveFlags rf = ResolveFlags.VariableOrValue;
1958                                                 if (intermediate)
1959                                                         rf |= ResolveFlags.DisableFlowAnalysis;
1960                                                 return var.Resolve (ec, rf);
1961                                         }
1962                                 }
1963
1964                                 ParameterReference pref = current_block.Toplevel.GetParameterReference (Name, loc);
1965                                 if (pref != null) {
1966                                         if (right_side != null)
1967                                                 return pref.ResolveLValue (ec, right_side, loc);
1968                                         else
1969                                                 return pref.Resolve (ec);
1970                                 }
1971                         }
1972
1973                         //
1974                         // Stage 2: Lookup members
1975                         //
1976
1977                         DeclSpace lookup_ds = ec.DeclContainer;
1978                         Type almost_matched_type = null;
1979                         ArrayList almost_matched = null;
1980                         do {
1981                                 if (lookup_ds.TypeBuilder == null)
1982                                         break;
1983
1984                                 e = MemberLookup (ec.ContainerType, lookup_ds.TypeBuilder, Name, loc);
1985                                 if (e != null)
1986                                         break;
1987
1988                                 if (almost_matched == null && almostMatchedMembers.Count > 0) {
1989                                         almost_matched_type = lookup_ds.TypeBuilder;
1990                                         almost_matched = (ArrayList) almostMatchedMembers.Clone ();
1991                                 }
1992
1993                                 lookup_ds =lookup_ds.Parent;
1994                         } while (lookup_ds != null);
1995
1996                         if (e == null && ec.ContainerType != null)
1997                                 e = MemberLookup (ec.ContainerType, ec.ContainerType, Name, loc);
1998
1999                         if (e == null) {
2000                                 if (almost_matched == null && almostMatchedMembers.Count > 0) {
2001                                         almost_matched_type = ec.ContainerType;
2002                                         almost_matched = (ArrayList) almostMatchedMembers.Clone ();
2003                                 }
2004                                 e = ResolveAsTypeStep (ec, true);
2005                         }
2006
2007                         if (e == null) {
2008                                 if (almost_matched != null)
2009                                         almostMatchedMembers = almost_matched;
2010                                 if (almost_matched_type == null)
2011                                         almost_matched_type = ec.ContainerType;
2012                                 MemberLookupFailed (ec.ContainerType, null, almost_matched_type, ((SimpleName) this).Name, ec.DeclContainer.Name, true, loc);
2013                                 return null;
2014                         }
2015
2016                         if (e is TypeExpr)
2017                                 return e;
2018
2019                         if (e is MemberExpr) {
2020                                 MemberExpr me = (MemberExpr) e;
2021
2022                                 Expression left;
2023                                 if (me.IsInstance) {
2024                                         if (ec.IsStatic || ec.IsFieldInitializer) {
2025                                                 //
2026                                                 // Note that an MemberExpr can be both IsInstance and IsStatic.
2027                                                 // An unresolved MethodGroupExpr can contain both kinds of methods
2028                                                 // and each predicate is true if the MethodGroupExpr contains
2029                                                 // at least one of that kind of method.
2030                                                 //
2031
2032                                                 if (!me.IsStatic &&
2033                                                     (!intermediate || !IdenticalNameAndTypeName (ec, me, loc))) {
2034                                                         Error_ObjectRefRequired (ec, loc, me.GetSignatureForError ());
2035                                                         return EmptyExpression.Null;
2036                                                 }
2037
2038                                                 //
2039                                                 // Pass the buck to MemberAccess and Invocation.
2040                                                 //
2041                                                 left = EmptyExpression.Null;
2042                                         } else {
2043                                                 left = ec.GetThis (loc);
2044                                         }
2045                                 } else {
2046                                         left = new TypeExpression (ec.ContainerType, loc);
2047                                 }
2048
2049                                 e = me.ResolveMemberAccess (ec, left, loc, null);
2050                                 if (e == null)
2051                                         return null;
2052
2053                                 me = e as MemberExpr;
2054                                 if (me == null)
2055                                         return e;
2056
2057                                 if (!me.IsStatic &&
2058                                     TypeManager.IsNestedFamilyAccessible (me.InstanceExpression.Type, me.DeclaringType) &&
2059                                     me.InstanceExpression.Type != me.DeclaringType &&
2060                                     !me.InstanceExpression.Type.IsSubclassOf (me.DeclaringType) &&
2061                                     (!intermediate || !IdenticalNameAndTypeName (ec, e, loc))) {
2062                                         Report.Error (38, loc, "Cannot access a nonstatic member of outer type `{0}' via nested type `{1}'",
2063                                                 TypeManager.CSharpName (me.DeclaringType), TypeManager.CSharpName (me.InstanceExpression.Type));
2064                                         return null;
2065                                 }
2066
2067                                 return (right_side != null)
2068                                         ? me.DoResolveLValue (ec, right_side)
2069                                         : me.DoResolve (ec);
2070                         }
2071
2072                         return e;
2073                 }
2074
2075                 public override void Emit (EmitContext ec)
2076                 {
2077                         //
2078                         // If this is ever reached, then we failed to
2079                         // find the name as a namespace
2080                         //
2081
2082                         Error (103, "The name `" + Name +
2083                                "' does not exist in the class `" +
2084                                ec.DeclContainer.Name + "'");
2085                 }
2086
2087                 public override string ToString ()
2088                 {
2089                         return Name;
2090                 }
2091
2092                 public override string GetSignatureForError ()
2093                 {
2094                         return Name;
2095                 }
2096         }
2097
2098         /// <summary>
2099         ///   Represents a namespace or a type.  The name of the class was inspired by
2100         ///   section 10.8.1 (Fully Qualified Names).
2101         /// </summary>
2102         public abstract class FullNamedExpression : Expression {
2103                 public override FullNamedExpression ResolveAsTypeStep (IResolveContext ec, bool silent)
2104                 {
2105                         return this;
2106                 }
2107
2108                 public abstract string FullName {
2109                         get;
2110                 }
2111         }
2112
2113         /// <summary>
2114         ///   Expression that evaluates to a type
2115         /// </summary>
2116         public abstract class TypeExpr : FullNamedExpression {
2117                 override public FullNamedExpression ResolveAsTypeStep (IResolveContext ec, bool silent)
2118                 {
2119                         TypeExpr t = DoResolveAsTypeStep (ec);
2120                         if (t == null)
2121                                 return null;
2122
2123                         eclass = ExprClass.Type;
2124                         return t;
2125                 }
2126
2127                 override public Expression DoResolve (EmitContext ec)
2128                 {
2129                         return ResolveAsTypeTerminal (ec, false);
2130                 }
2131
2132                 override public void Emit (EmitContext ec)
2133                 {
2134                         throw new Exception ("Should never be called");
2135                 }
2136
2137                 public virtual bool CheckAccessLevel (DeclSpace ds)
2138                 {
2139                         return ds.CheckAccessLevel (Type);
2140                 }
2141
2142                 public virtual bool AsAccessible (DeclSpace ds, int flags)
2143                 {
2144                         return ds.AsAccessible (Type, flags);
2145                 }
2146
2147                 public virtual bool IsClass {
2148                         get { return Type.IsClass; }
2149                 }
2150
2151                 public virtual bool IsValueType {
2152                         get { return Type.IsValueType; }
2153                 }
2154
2155                 public virtual bool IsInterface {
2156                         get { return Type.IsInterface; }
2157                 }
2158
2159                 public virtual bool IsSealed {
2160                         get { return Type.IsSealed; }
2161                 }
2162
2163                 public virtual bool CanInheritFrom ()
2164                 {
2165                         if (Type == TypeManager.enum_type ||
2166                             (Type == TypeManager.value_type && RootContext.StdLib) ||
2167                             Type == TypeManager.multicast_delegate_type ||
2168                             Type == TypeManager.delegate_type ||
2169                             Type == TypeManager.array_type)
2170                                 return false;
2171
2172                         return true;
2173                 }
2174
2175                 public abstract TypeExpr DoResolveAsTypeStep (IResolveContext ec);
2176
2177                 public abstract string Name {
2178                         get;
2179                 }
2180
2181                 public override bool Equals (object obj)
2182                 {
2183                         TypeExpr tobj = obj as TypeExpr;
2184                         if (tobj == null)
2185                                 return false;
2186
2187                         return Type == tobj.Type;
2188                 }
2189
2190                 public override int GetHashCode ()
2191                 {
2192                         return Type.GetHashCode ();
2193                 }
2194
2195                 public override string ToString ()
2196                 {
2197                         return Name;
2198                 }
2199         }
2200
2201         /// <summary>
2202         ///   Fully resolved Expression that already evaluated to a type
2203         /// </summary>
2204         public class TypeExpression : TypeExpr {
2205                 public TypeExpression (Type t, Location l)
2206                 {
2207                         Type = t;
2208                         eclass = ExprClass.Type;
2209                         loc = l;
2210                 }
2211
2212                 public override TypeExpr DoResolveAsTypeStep (IResolveContext ec)
2213                 {
2214                         return this;
2215                 }
2216
2217                 public override TypeExpr ResolveAsTypeTerminal (IResolveContext ec, bool silent)
2218                 {
2219                         return this;
2220                 }
2221
2222                 public override string Name {
2223                         get { return Type.ToString (); }
2224                 }
2225
2226                 public override string FullName {
2227                         get { return Type.FullName; }
2228                 }
2229         }
2230
2231         /// <summary>
2232         ///   Used to create types from a fully qualified name.  These are just used
2233         ///   by the parser to setup the core types.  A TypeLookupExpression is always
2234         ///   classified as a type.
2235         /// </summary>
2236         public sealed class TypeLookupExpression : TypeExpr {
2237                 readonly string name;
2238
2239                 public TypeLookupExpression (string name)
2240                 {
2241                         this.name = name;
2242                         eclass = ExprClass.Type;
2243                 }
2244
2245                 public override TypeExpr ResolveAsTypeTerminal (IResolveContext ec, bool silent)
2246                 {
2247                         // It's null for corlib compilation only
2248                         if (type == null)
2249                                 return DoResolveAsTypeStep (ec);
2250
2251                         return this;
2252                 }
2253
2254                 static readonly char [] dot_array = { '.' };
2255                 public override TypeExpr DoResolveAsTypeStep (IResolveContext ec)
2256                 {
2257                         // If name is of the form `N.I', first lookup `N', then search a member `I' in it.
2258                         string rest = null;
2259                         string lookup_name = name;
2260                         int pos = name.IndexOf ('.');
2261                         if (pos >= 0) {
2262                                 rest = name.Substring (pos + 1);
2263                                 lookup_name = name.Substring (0, pos);
2264                         }
2265
2266                         FullNamedExpression resolved = RootNamespace.Global.Lookup (ec.DeclContainer, lookup_name, Location.Null);
2267
2268                         if (resolved != null && rest != null) {
2269                                 // Now handle the rest of the the name.
2270                                 string [] elements = rest.Split (dot_array);
2271                                 string element;
2272                                 int count = elements.Length;
2273                                 int i = 0;
2274                                 while (i < count && resolved != null && resolved is Namespace) {
2275                                         Namespace ns = resolved as Namespace;
2276                                         element = elements [i++];
2277                                         lookup_name += "." + element;
2278                                         resolved = ns.Lookup (ec.DeclContainer, element, Location.Null);
2279                                 }
2280
2281                                 if (resolved != null && resolved is TypeExpr) {
2282                                         Type t = ((TypeExpr) resolved).Type;
2283                                         while (t != null) {
2284                                                 if (!ec.DeclContainer.CheckAccessLevel (t)) {
2285                                                         resolved = null;
2286                                                         lookup_name = t.FullName;
2287                                                         break;
2288                                                 }
2289                                                 if (i == count) {
2290                                                         type = t;
2291                                                         return this;
2292                                                 }
2293                                                 t = TypeManager.GetNestedType (t, elements [i++]);
2294                                         }
2295                                 }
2296                         }
2297
2298                         if (resolved == null) {
2299                                 NamespaceEntry.Error_NamespaceNotFound (loc, lookup_name);
2300                                 return null;
2301                         }
2302
2303                         if (!(resolved is TypeExpr)) {
2304                                 resolved.Error_UnexpectedKind (ec.DeclContainer, "type", loc);
2305                                 return null;
2306                         }
2307
2308                         type = resolved.Type;
2309                         return this;
2310                 }
2311
2312                 public override string Name {
2313                         get { return name; }
2314                 }
2315
2316                 public override string FullName {
2317                         get { return name; }
2318                 }
2319         }
2320
2321         public class TypeAliasExpression : TypeExpr {
2322                 TypeExpr texpr;
2323
2324                 public TypeAliasExpression (TypeExpr texpr, Location l)
2325                 {
2326                         this.texpr = texpr;
2327                         loc = texpr.Location;
2328
2329                         eclass = ExprClass.Type;
2330                 }
2331
2332                 public override string Name {
2333                         get { return texpr.Name; }
2334                 }
2335
2336                 public override string FullName {
2337                         get { return texpr.FullName; }
2338                 }
2339
2340                 public override TypeExpr DoResolveAsTypeStep (IResolveContext ec)
2341                 {
2342                         return texpr;
2343                 }
2344
2345                 public override bool CheckAccessLevel (DeclSpace ds)
2346                 {
2347                         return texpr.CheckAccessLevel (ds);
2348                 }
2349
2350                 public override bool AsAccessible (DeclSpace ds, int flags)
2351                 {
2352                         return texpr.AsAccessible (ds, flags);
2353                 }
2354
2355                 public override bool IsClass {
2356                         get { return texpr.IsClass; }
2357                 }
2358
2359                 public override bool IsValueType {
2360                         get { return texpr.IsValueType; }
2361                 }
2362
2363                 public override bool IsInterface {
2364                         get { return texpr.IsInterface; }
2365                 }
2366
2367                 public override bool IsSealed {
2368                         get { return texpr.IsSealed; }
2369                 }
2370         }
2371
2372         /// <summary>
2373         ///   This class denotes an expression which evaluates to a member
2374         ///   of a struct or a class.
2375         /// </summary>
2376         public abstract class MemberExpr : Expression
2377         {
2378                 /// <summary>
2379                 ///   The name of this member.
2380                 /// </summary>
2381                 public abstract string Name {
2382                         get;
2383                 }
2384
2385                 /// <summary>
2386                 ///   Whether this is an instance member.
2387                 /// </summary>
2388                 public abstract bool IsInstance {
2389                         get;
2390                 }
2391
2392                 /// <summary>
2393                 ///   Whether this is a static member.
2394                 /// </summary>
2395                 public abstract bool IsStatic {
2396                         get;
2397                 }
2398
2399                 /// <summary>
2400                 ///   The type which declares this member.
2401                 /// </summary>
2402                 public abstract Type DeclaringType {
2403                         get;
2404                 }
2405
2406                 /// <summary>
2407                 ///   The instance expression associated with this member, if it's a
2408                 ///   non-static member.
2409                 /// </summary>
2410                 public Expression InstanceExpression;
2411
2412                 public static void error176 (Location loc, string name)
2413                 {
2414                         Report.Error (176, loc, "Static member `{0}' cannot be accessed " +
2415                                       "with an instance reference, qualify it with a type name instead", name);
2416                 }
2417
2418                 // TODO: possible optimalization
2419                 // Cache resolved constant result in FieldBuilder <-> expression map
2420                 public virtual Expression ResolveMemberAccess (EmitContext ec, Expression left, Location loc,
2421                                                                SimpleName original)
2422                 {
2423                         //
2424                         // Precondition:
2425                         //   original == null || original.Resolve (...) ==> left
2426                         //
2427
2428                         if (left is TypeExpr) {
2429                                 if (!IsStatic) {
2430                                         SimpleName.Error_ObjectRefRequired (ec, loc, Name);
2431                                         return null;
2432                                 }
2433
2434                                 return this;
2435                         }
2436
2437                         if (!IsInstance) {
2438                                 if (original != null && original.IdenticalNameAndTypeName (ec, left, loc))
2439                                         return this;
2440
2441                                 error176 (loc, GetSignatureForError ());
2442                                 return null;
2443                         }
2444
2445                         InstanceExpression = left;
2446
2447                         return this;
2448                 }
2449
2450                 protected void EmitInstance (EmitContext ec, bool prepare_for_load)
2451                 {
2452                         if (IsStatic)
2453                                 return;
2454
2455                         if (InstanceExpression == EmptyExpression.Null) {
2456                                 SimpleName.Error_ObjectRefRequired (ec, loc, Name);
2457                                 return;
2458                         }
2459
2460                         if (InstanceExpression.Type.IsValueType) {
2461                                 if (InstanceExpression is IMemoryLocation) {
2462                                         ((IMemoryLocation) InstanceExpression).AddressOf (ec, AddressOp.LoadStore);
2463                                 } else {
2464                                         LocalTemporary t = new LocalTemporary (ec, InstanceExpression.Type);
2465                                         InstanceExpression.Emit (ec);
2466                                         t.Store (ec);
2467                                         t.AddressOf (ec, AddressOp.Store);
2468                                 }
2469                         } else
2470                                 InstanceExpression.Emit (ec);
2471
2472                         if (prepare_for_load)
2473                                 ec.ig.Emit (OpCodes.Dup);
2474                 }
2475         }
2476
2477         /// <summary>
2478         ///   MethodGroup Expression.
2479         ///
2480         ///   This is a fully resolved expression that evaluates to a type
2481         /// </summary>
2482         public class MethodGroupExpr : MemberExpr {
2483                 public MethodBase [] Methods;
2484                 bool identical_type_name = false;
2485                 bool is_base;
2486
2487                 public MethodGroupExpr (MemberInfo [] mi, Location l)
2488                 {
2489                         Methods = new MethodBase [mi.Length];
2490                         mi.CopyTo (Methods, 0);
2491                         eclass = ExprClass.MethodGroup;
2492                         type = TypeManager.object_type;
2493                         loc = l;
2494                 }
2495
2496                 public MethodGroupExpr (ArrayList list, Location l)
2497                 {
2498                         Methods = new MethodBase [list.Count];
2499
2500                         try {
2501                                 list.CopyTo (Methods, 0);
2502                         } catch {
2503                                 foreach (MemberInfo m in list){
2504                                         if (!(m is MethodBase)){
2505                                                 Console.WriteLine ("Name " + m.Name);
2506                                                 Console.WriteLine ("Found a: " + m.GetType ().FullName);
2507                                         }
2508                                 }
2509                                 throw;
2510                         }
2511
2512                         loc = l;
2513                         eclass = ExprClass.MethodGroup;
2514                         type = TypeManager.object_type;
2515                 }
2516
2517                 public override Type DeclaringType {
2518                         get {
2519                                 //
2520                                 // The methods are arranged in this order:
2521                                 // derived type -> base type
2522                                 //
2523                                 return Methods [0].DeclaringType;
2524                         }
2525                 }
2526
2527                 public bool IdenticalTypeName {
2528                         get {
2529                                 return identical_type_name;
2530                         }
2531
2532                         set {
2533                                 identical_type_name = value;
2534                         }
2535                 }
2536
2537                 public bool IsBase {
2538                         get {
2539                                 return is_base;
2540                         }
2541                         set {
2542                                 is_base = value;
2543                         }
2544                 }
2545
2546                 public override string GetSignatureForError ()
2547                 {
2548                         return TypeManager.CSharpSignature (Methods [0]);
2549                 }
2550
2551                 public override string Name {
2552                         get {
2553                                 return Methods [0].Name;
2554                         }
2555                 }
2556
2557                 public override bool IsInstance {
2558                         get {
2559                                 foreach (MethodBase mb in Methods)
2560                                         if (!mb.IsStatic)
2561                                                 return true;
2562
2563                                 return false;
2564                         }
2565                 }
2566
2567                 public override bool IsStatic {
2568                         get {
2569                                 foreach (MethodBase mb in Methods)
2570                                         if (mb.IsStatic)
2571                                                 return true;
2572
2573                                 return false;
2574                         }
2575                 }
2576
2577                 public override Expression ResolveMemberAccess (EmitContext ec, Expression left, Location loc,
2578                                                                 SimpleName original)
2579                 {
2580                         if (!(left is TypeExpr) &&
2581                             original != null && original.IdenticalNameAndTypeName (ec, left, loc))
2582                                 IdenticalTypeName = true;
2583
2584                         return base.ResolveMemberAccess (ec, left, loc, original);
2585                 }
2586
2587                 override public Expression DoResolve (EmitContext ec)
2588                 {
2589                         if (!IsInstance)
2590                                 InstanceExpression = null;
2591
2592                         if (InstanceExpression != null) {
2593                                 InstanceExpression = InstanceExpression.DoResolve (ec);
2594                                 if (InstanceExpression == null)
2595                                         return null;
2596                         }
2597
2598                         return this;
2599                 }
2600
2601                 public void ReportUsageError ()
2602                 {
2603                         Report.Error (654, loc, "Method `" + DeclaringType + "." +
2604                                       Name + "()' is referenced without parentheses");
2605                 }
2606
2607                 override public void Emit (EmitContext ec)
2608                 {
2609                         ReportUsageError ();
2610                 }
2611
2612                 bool RemoveMethods (bool keep_static)
2613                 {
2614                         ArrayList smethods = new ArrayList ();
2615
2616                         foreach (MethodBase mb in Methods){
2617                                 if (mb.IsStatic == keep_static)
2618                                         smethods.Add (mb);
2619                         }
2620
2621                         if (smethods.Count == 0)
2622                                 return false;
2623
2624                         Methods = new MethodBase [smethods.Count];
2625                         smethods.CopyTo (Methods, 0);
2626
2627                         return true;
2628                 }
2629
2630                 /// <summary>
2631                 ///   Removes any instance methods from the MethodGroup, returns
2632                 ///   false if the resulting set is empty.
2633                 /// </summary>
2634                 public bool RemoveInstanceMethods ()
2635                 {
2636                         return RemoveMethods (true);
2637                 }
2638
2639                 /// <summary>
2640                 ///   Removes any static methods from the MethodGroup, returns
2641                 ///   false if the resulting set is empty.
2642                 /// </summary>
2643                 public bool RemoveStaticMethods ()
2644                 {
2645                         return RemoveMethods (false);
2646                 }
2647         }
2648
2649         /// <summary>
2650         ///   Fully resolved expression that evaluates to a Field
2651         /// </summary>
2652         public class FieldExpr : MemberExpr, IAssignMethod, IMemoryLocation, IVariable {
2653                 public readonly FieldInfo FieldInfo;
2654                 VariableInfo variable_info;
2655
2656                 LocalTemporary temp;
2657                 bool prepared;
2658                 bool in_initializer;
2659
2660                 public FieldExpr (FieldInfo fi, Location l, bool in_initializer):
2661                         this (fi, l)
2662                 {
2663                         this.in_initializer = in_initializer;
2664                 }
2665
2666                 public FieldExpr (FieldInfo fi, Location l)
2667                 {
2668                         FieldInfo = fi;
2669                         eclass = ExprClass.Variable;
2670                         type = fi.FieldType;
2671                         loc = l;
2672                 }
2673
2674                 public override string Name {
2675                         get {
2676                                 return FieldInfo.Name;
2677                         }
2678                 }
2679
2680                 public override bool IsInstance {
2681                         get {
2682                                 return !FieldInfo.IsStatic;
2683                         }
2684                 }
2685
2686                 public override bool IsStatic {
2687                         get {
2688                                 return FieldInfo.IsStatic;
2689                         }
2690                 }
2691
2692                 public override Type DeclaringType {
2693                         get {
2694                                 return FieldInfo.DeclaringType;
2695                         }
2696                 }
2697
2698                 public override string GetSignatureForError ()
2699                 {
2700                         return TypeManager.GetFullNameSignature (FieldInfo);
2701                 }
2702
2703                 public VariableInfo VariableInfo {
2704                         get {
2705                                 return variable_info;
2706                         }
2707                 }
2708
2709                 public override Expression ResolveMemberAccess (EmitContext ec, Expression left, Location loc,
2710                                                                 SimpleName original)
2711                 {
2712                         Type t = FieldInfo.FieldType;
2713
2714                         if (FieldInfo.IsLiteral || (FieldInfo.IsInitOnly && t == TypeManager.decimal_type)) {
2715                                 IConstant ic = TypeManager.GetConstant (FieldInfo);
2716                                 if (ic == null) {
2717                                         if (FieldInfo.IsLiteral) {
2718                                                 ic = new ExternalConstant (FieldInfo);
2719                                         } else {
2720                                                 ic = ExternalConstant.CreateDecimal (FieldInfo);
2721                                                 if (ic == null) {
2722                                                         return base.ResolveMemberAccess (ec, left, loc, original);
2723                                                 }
2724                                         }
2725                                         TypeManager.RegisterConstant (FieldInfo, ic);
2726                                 }
2727
2728                                 bool left_is_type = left is TypeExpr;
2729                                 if (!left_is_type && (original == null || !original.IdenticalNameAndTypeName (ec, left, loc))) {
2730                                         Report.SymbolRelatedToPreviousError (FieldInfo);
2731                                         error176 (loc, TypeManager.GetFullNameSignature (FieldInfo));
2732                                         return null;
2733                                 }
2734
2735                                 if (ic.ResolveValue ()) {
2736                                         if (!ec.IsInObsoleteScope)
2737                                                 ic.CheckObsoleteness (loc);
2738                                 }
2739
2740                                 return ic.Value;
2741                         }
2742
2743                         if (t.IsPointer && !ec.InUnsafe) {
2744                                 UnsafeError (loc);
2745                                 return null;
2746                         }
2747
2748                         return base.ResolveMemberAccess (ec, left, loc, original);
2749                 }
2750
2751                 override public Expression DoResolve (EmitContext ec)
2752                 {
2753                         return DoResolve (ec, false);
2754                 }
2755
2756                 Expression DoResolve (EmitContext ec, bool lvalue_instance)
2757                 {
2758                         if (ec.InRefOutArgumentResolving && FieldInfo.IsInitOnly && !ec.IsConstructor && FieldInfo.FieldType.IsValueType) {
2759                                 if (FieldInfo.FieldType is TypeBuilder) {
2760                                         if (FieldInfo.IsStatic)
2761                                                 Report.Error (1651, loc, "Fields of static readonly field `{0}' cannot be passed ref or out (except in a static constructor)",
2762                                                         GetSignatureForError ());
2763                                         else
2764                                                 Report.Error (1649, loc, "Members of readonly field `{0}.{1}' cannot be passed ref or out (except in a constructor)",
2765                                                         TypeManager.CSharpName (DeclaringType), Name);
2766                                 } else {
2767                                         if (FieldInfo.IsStatic)
2768                                                 Report.Error (199, loc, "A static readonly field `{0}' cannot be passed ref or out (except in a static constructor)",
2769                                                         Name);
2770                                         else
2771                                                 Report.Error (192, loc, "A readonly field `{0}' cannot be passed ref or out (except in a constructor)",
2772                                                         Name);
2773                                 }
2774                                 return null;
2775                         }
2776
2777                         if (!FieldInfo.IsStatic){
2778                                 if (InstanceExpression == null){
2779                                         //
2780                                         // This can happen when referencing an instance field using
2781                                         // a fully qualified type expression: TypeName.InstanceField = xxx
2782                                         //
2783                                         SimpleName.Error_ObjectRefRequired (ec, loc, FieldInfo.Name);
2784                                         return null;
2785                                 }
2786
2787                                 // Resolve the field's instance expression while flow analysis is turned
2788                                 // off: when accessing a field "a.b", we must check whether the field
2789                                 // "a.b" is initialized, not whether the whole struct "a" is initialized.
2790
2791                                 if (lvalue_instance) {
2792                                         bool old_do_flow_analysis = ec.DoFlowAnalysis;
2793                                         ec.DoFlowAnalysis = false;
2794                                         InstanceExpression = InstanceExpression.ResolveLValue (ec, EmptyExpression.LValueMemberAccess, loc);
2795                                         ec.DoFlowAnalysis = old_do_flow_analysis;
2796                                 } else {
2797                                         ResolveFlags rf = ResolveFlags.VariableOrValue | ResolveFlags.DisableFlowAnalysis;
2798                                         InstanceExpression = InstanceExpression.Resolve (ec, rf);
2799                                 }
2800
2801                                 if (InstanceExpression == null)
2802                                         return null;
2803                         }
2804
2805                         if (!in_initializer && !ec.IsFieldInitializer) {
2806                                 ObsoleteAttribute oa;
2807                                 FieldBase f = TypeManager.GetField (FieldInfo);
2808                                 if (f != null) {
2809                                         if (!ec.IsInObsoleteScope)
2810                                                 f.CheckObsoleteness (loc);
2811
2812                                         // To be sure that type is external because we do not register generated fields
2813                                 } else if (!(FieldInfo.DeclaringType is TypeBuilder)) {
2814                                         oa = AttributeTester.GetMemberObsoleteAttribute (FieldInfo);
2815                                         if (oa != null)
2816                                                 AttributeTester.Report_ObsoleteMessage (oa, TypeManager.GetFullNameSignature (FieldInfo), loc);
2817                                 }
2818                         }
2819
2820                         AnonymousContainer am = ec.CurrentAnonymousMethod;
2821                         if (am != null){
2822                                 if (!FieldInfo.IsStatic){
2823                                         if (!am.IsIterator && (ec.TypeContainer is Struct)){
2824                                                 Report.Error (1673, loc,
2825                                                 "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",
2826                                                         "this");
2827                                                 return null;
2828                                         }
2829                                         if ((am.ContainerAnonymousMethod == null) && (InstanceExpression is This))
2830                                                 ec.CaptureField (this);
2831                                 }
2832                         }
2833
2834                         // If the instance expression is a local variable or parameter.
2835                         IVariable var = InstanceExpression as IVariable;
2836                         if ((var == null) || (var.VariableInfo == null))
2837                                 return this;
2838
2839                         VariableInfo vi = var.VariableInfo;
2840                         if (!vi.IsFieldAssigned (ec, FieldInfo.Name, loc))
2841                                 return null;
2842
2843                         variable_info = vi.GetSubStruct (FieldInfo.Name);
2844                         return this;
2845                 }
2846
2847                 void Report_AssignToReadonly (Expression right_side)
2848                 {
2849                         int code;
2850                         string msg;
2851                         bool need_error_sig = false;
2852                         if (right_side == EmptyExpression.LValueMemberAccess) {
2853                                 if (IsStatic) {
2854                                         code = 1650;
2855                                         msg = "Fields of static readonly field `{0}' cannot be assigned to (except in a static constructor or a variable initializer)";
2856                                 } else {
2857                                         code = 1648;
2858                                         msg = "Members of readonly field `{0}' cannot be modified (except in a constructor or a variable initializer)";
2859                                 }
2860                                 need_error_sig = true;
2861                         } else if (IsStatic) {
2862                                 code = 198;
2863                                 msg = "A static readonly field cannot be assigned to (except in a static constructor or a variable initializer)";
2864                         } else {
2865                                 code = 191;
2866                                 msg = "A readonly field cannot be assigned to (except in a constructor or a variable initializer)";
2867                         }
2868
2869                         if (need_error_sig)
2870                                 Report.Error (code, loc, msg, GetSignatureForError ());
2871                         else
2872                                 Report.Error (code, loc, msg);
2873                 }
2874
2875                 override public Expression DoResolveLValue (EmitContext ec, Expression right_side)
2876                 {
2877                         IVariable var = InstanceExpression as IVariable;
2878                         if ((var != null) && (var.VariableInfo != null))
2879                                 var.VariableInfo.SetFieldAssigned (ec, FieldInfo.Name);
2880
2881                         bool lvalue_instance = !FieldInfo.IsStatic && FieldInfo.DeclaringType.IsValueType;
2882
2883                         Expression e = DoResolve (ec, lvalue_instance);
2884
2885                         if (e == null)
2886                                 return null;
2887
2888                         FieldBase fb = TypeManager.GetField (FieldInfo);
2889                         if (fb != null)
2890                                 fb.SetAssigned ();
2891
2892                         if (!FieldInfo.IsInitOnly)
2893                                 return this;
2894
2895                         //
2896                         // InitOnly fields can only be assigned in constructors
2897                         //
2898
2899                         if (ec.IsConstructor){
2900                                 if (IsStatic && !ec.IsStatic)
2901                                         Report_AssignToReadonly (right_side);
2902
2903                                 if (ec.ContainerType == FieldInfo.DeclaringType)
2904                                         return this;
2905                         }
2906
2907                         Report_AssignToReadonly (right_side);
2908
2909                         return null;
2910                 }
2911
2912                 public override void CheckMarshallByRefAccess (Type container)
2913                 {
2914                         if (!IsStatic && Type.IsValueType && !container.IsSubclassOf (TypeManager.mbr_type) && DeclaringType.IsSubclassOf (TypeManager.mbr_type)) {
2915                                 Report.SymbolRelatedToPreviousError (DeclaringType);
2916                                 Report.Error (1690, loc, "Cannot call methods, properties, or indexers on `{0}' because it is a value type member of a marshal-by-reference class",
2917                                         GetSignatureForError ());
2918                         }
2919                 }
2920
2921                 public bool VerifyFixed ()
2922                 {
2923                         IVariable variable = InstanceExpression as IVariable;
2924                         // A variable of the form V.I is fixed when V is a fixed variable of a struct type.
2925                         // We defer the InstanceExpression check after the variable check to avoid a
2926                         // separate null check on InstanceExpression.
2927                         return variable != null && InstanceExpression.Type.IsValueType && variable.VerifyFixed ();
2928                 }
2929
2930                 public override int GetHashCode()
2931                 {
2932                         return FieldInfo.GetHashCode ();
2933                 }
2934
2935                 public override bool Equals (object obj)
2936                 {
2937                         FieldExpr fe = obj as FieldExpr;
2938                         if (fe == null)
2939                                 return false;
2940
2941                         if (FieldInfo != fe.FieldInfo)
2942                                 return false;
2943
2944                         if (InstanceExpression == null || fe.InstanceExpression == null)
2945                                 return true;
2946
2947                         return InstanceExpression.Equals (fe.InstanceExpression);
2948                 }
2949
2950                 public void Emit (EmitContext ec, bool leave_copy)
2951                 {
2952                         ILGenerator ig = ec.ig;
2953                         bool is_volatile = false;
2954
2955                         if (FieldInfo is FieldBuilder){
2956                                 FieldBase f = TypeManager.GetField (FieldInfo);
2957                                 if (f != null){
2958                                         if ((f.ModFlags & Modifiers.VOLATILE) != 0)
2959                                                 is_volatile = true;
2960
2961                                         f.SetMemberIsUsed ();
2962                                 }
2963                         }
2964
2965                         if (FieldInfo.IsStatic){
2966                                 if (is_volatile)
2967                                         ig.Emit (OpCodes.Volatile);
2968
2969                                 ig.Emit (OpCodes.Ldsfld, FieldInfo);
2970                         } else {
2971                                 if (!prepared)
2972                                         EmitInstance (ec, false);
2973
2974                                 if (is_volatile)
2975                                         ig.Emit (OpCodes.Volatile);
2976
2977                                 IFixedBuffer ff = AttributeTester.GetFixedBuffer (FieldInfo);
2978                                 if (ff != null)
2979                                 {
2980                                         ig.Emit (OpCodes.Ldflda, FieldInfo);
2981                                         ig.Emit (OpCodes.Ldflda, ff.Element);
2982                                 }
2983                                 else {
2984                                         ig.Emit (OpCodes.Ldfld, FieldInfo);
2985                                 }
2986                         }
2987
2988                         if (leave_copy) {
2989                                 ec.ig.Emit (OpCodes.Dup);
2990                                 if (!FieldInfo.IsStatic) {
2991                                         temp = new LocalTemporary (ec, this.Type);
2992                                         temp.Store (ec);
2993                                 }
2994                         }
2995                 }
2996
2997                 public void EmitAssign (EmitContext ec, Expression source, bool leave_copy, bool prepare_for_load)
2998                 {
2999                         FieldAttributes fa = FieldInfo.Attributes;
3000                         bool is_static = (fa & FieldAttributes.Static) != 0;
3001                         bool is_readonly = (fa & FieldAttributes.InitOnly) != 0;
3002                         ILGenerator ig = ec.ig;
3003                         prepared = prepare_for_load;
3004
3005                         if (is_readonly && !ec.IsConstructor){
3006                                 Report_AssignToReadonly (source);
3007                                 return;
3008                         }
3009
3010                         EmitInstance (ec, prepare_for_load);
3011
3012                         source.Emit (ec);
3013                         if (leave_copy) {
3014                                 ec.ig.Emit (OpCodes.Dup);
3015                                 if (!FieldInfo.IsStatic) {
3016                                         temp = new LocalTemporary (ec, this.Type);
3017                                         temp.Store (ec);
3018                                 }
3019                         }
3020
3021                         if (FieldInfo is FieldBuilder){
3022                                 FieldBase f = TypeManager.GetField (FieldInfo);
3023                                 if (f != null){
3024                                         if ((f.ModFlags & Modifiers.VOLATILE) != 0)
3025                                                 ig.Emit (OpCodes.Volatile);
3026
3027                                         f.SetAssigned ();
3028                                 }
3029                         }
3030
3031                         if (is_static)
3032                                 ig.Emit (OpCodes.Stsfld, FieldInfo);
3033                         else
3034                                 ig.Emit (OpCodes.Stfld, FieldInfo);
3035
3036                         if (temp != null)
3037                                 temp.Emit (ec);
3038                 }
3039
3040                 public override void Emit (EmitContext ec)
3041                 {
3042                         Emit (ec, false);
3043                 }
3044
3045                 public void AddressOf (EmitContext ec, AddressOp mode)
3046                 {
3047                         ILGenerator ig = ec.ig;
3048
3049                         if (FieldInfo is FieldBuilder){
3050                                 FieldBase f = TypeManager.GetField (FieldInfo);
3051                                 if (f != null){
3052                                         if ((f.ModFlags & Modifiers.VOLATILE) != 0){
3053                                                 Report.Warning (420, 1, loc, "`{0}': A volatile fields cannot be passed using a ref or out parameter",
3054                                                         f.GetSignatureForError ());
3055                                                 return;
3056                                         }
3057
3058                                         if ((mode & AddressOp.Store) != 0)
3059                                                 f.SetAssigned ();
3060                                         if ((mode & AddressOp.Load) != 0)
3061                                                 f.SetMemberIsUsed ();
3062                                 }
3063                         }
3064
3065                         //
3066                         // Handle initonly fields specially: make a copy and then
3067                         // get the address of the copy.
3068                         //
3069                         bool need_copy;
3070                         if (FieldInfo.IsInitOnly){
3071                                 need_copy = true;
3072                                 if (ec.IsConstructor){
3073                                         if (FieldInfo.IsStatic){
3074                                                 if (ec.IsStatic)
3075                                                         need_copy = false;
3076                                         } else
3077                                                 need_copy = false;
3078                                 }
3079                         } else
3080                                 need_copy = false;
3081
3082                         if (need_copy){
3083                                 LocalBuilder local;
3084                                 Emit (ec);
3085                                 local = ig.DeclareLocal (type);
3086                                 ig.Emit (OpCodes.Stloc, local);
3087                                 ig.Emit (OpCodes.Ldloca, local);
3088                                 return;
3089                         }
3090
3091
3092                         if (FieldInfo.IsStatic){
3093                                 ig.Emit (OpCodes.Ldsflda, FieldInfo);
3094                         } else {
3095                                 EmitInstance (ec, false);
3096                                 ig.Emit (OpCodes.Ldflda, FieldInfo);
3097                         }
3098                 }
3099         }
3100
3101         //
3102         // A FieldExpr whose address can not be taken
3103         //
3104         public class FieldExprNoAddress : FieldExpr, IMemoryLocation {
3105                 public FieldExprNoAddress (FieldInfo fi, Location loc) : base (fi, loc)
3106                 {
3107                 }
3108
3109                 public new void AddressOf (EmitContext ec, AddressOp mode)
3110                 {
3111                         Report.Error (-215, "Report this: Taking the address of a remapped parameter not supported");
3112                 }
3113         }
3114
3115         /// <summary>
3116         ///   Expression that evaluates to a Property.  The Assign class
3117         ///   might set the `Value' expression if we are in an assignment.
3118         ///
3119         ///   This is not an LValue because we need to re-write the expression, we
3120         ///   can not take data from the stack and store it.
3121         /// </summary>
3122         public class PropertyExpr : MemberExpr, IAssignMethod {
3123                 public readonly PropertyInfo PropertyInfo;
3124
3125                 //
3126                 // This is set externally by the  `BaseAccess' class
3127                 //
3128                 public bool IsBase;
3129                 MethodInfo getter, setter;
3130                 bool is_static;
3131
3132                 bool resolved;
3133
3134                 LocalTemporary temp;
3135                 bool prepared;
3136
3137                 internal static PtrHashtable AccessorTable = new PtrHashtable ();
3138
3139                 public PropertyExpr (Type containerType, PropertyInfo pi, Location l)
3140                 {
3141                         PropertyInfo = pi;
3142                         eclass = ExprClass.PropertyAccess;
3143                         is_static = false;
3144                         loc = l;
3145
3146                         type = TypeManager.TypeToCoreType (pi.PropertyType);
3147
3148                         ResolveAccessors (containerType);
3149                 }
3150
3151                 public override string Name {
3152                         get {
3153                                 return PropertyInfo.Name;
3154                         }
3155                 }
3156
3157                 public override bool IsInstance {
3158                         get {
3159                                 return !is_static;
3160                         }
3161                 }
3162
3163                 public override bool IsStatic {
3164                         get {
3165                                 return is_static;
3166                         }
3167                 }
3168
3169                 public override Type DeclaringType {
3170                         get {
3171                                 return PropertyInfo.DeclaringType;
3172                         }
3173                 }
3174
3175                 public override string GetSignatureForError ()
3176                 {
3177                         return TypeManager.GetFullNameSignature (PropertyInfo);
3178                 }
3179
3180                 void FindAccessors (Type invocation_type)
3181                 {
3182                         const BindingFlags flags = BindingFlags.Public | BindingFlags.NonPublic |
3183                                 BindingFlags.Static | BindingFlags.Instance |
3184                                 BindingFlags.DeclaredOnly;
3185
3186                         Type current = PropertyInfo.DeclaringType;
3187                         for (; current != null; current = current.BaseType) {
3188                                 MemberInfo[] group = TypeManager.MemberLookup (
3189                                         invocation_type, invocation_type, current,
3190                                         MemberTypes.Property, flags, PropertyInfo.Name, null);
3191
3192                                 if (group == null)
3193                                         continue;
3194
3195                                 if (group.Length != 1)
3196                                         // Oooops, can this ever happen ?
3197                                         return;
3198
3199                                 PropertyInfo pi = (PropertyInfo) group [0];
3200
3201                                 if (getter == null)
3202                                         getter = pi.GetGetMethod (true);
3203
3204                                 if (setter == null)
3205                                         setter = pi.GetSetMethod (true);
3206
3207                                 MethodInfo accessor = getter != null ? getter : setter;
3208
3209                                 if (!accessor.IsVirtual)
3210                                         return;
3211                         }
3212                 }
3213
3214                 //
3215                 // We also perform the permission checking here, as the PropertyInfo does not
3216                 // hold the information for the accessibility of its setter/getter
3217                 //
3218                 // TODO: can use TypeManager.GetProperty to boost performance
3219                 void ResolveAccessors (Type containerType)
3220                 {
3221                         FindAccessors (containerType);
3222
3223                         if (getter != null) {
3224                                 IMethodData md = TypeManager.GetMethod (getter);
3225                                 if (md != null)
3226                                         md.SetMemberIsUsed ();
3227
3228                                 AccessorTable [getter] = PropertyInfo;
3229                                 is_static = getter.IsStatic;
3230                         }
3231
3232                         if (setter != null) {
3233                                 IMethodData md = TypeManager.GetMethod (setter);
3234                                 if (md != null)
3235                                         md.SetMemberIsUsed ();
3236
3237                                 AccessorTable [setter] = PropertyInfo;
3238                                 is_static = setter.IsStatic;
3239                         }
3240                 }
3241
3242                 bool InstanceResolve (EmitContext ec, bool lvalue_instance, bool must_do_cs1540_check)
3243                 {
3244                         if (is_static) {
3245                                 InstanceExpression = null;
3246                                 return true;
3247                         }
3248
3249                         if (InstanceExpression == null) {
3250                                 SimpleName.Error_ObjectRefRequired (ec, loc, PropertyInfo.Name);
3251                                 return false;
3252                         }
3253
3254                         if (lvalue_instance)
3255                                 InstanceExpression = InstanceExpression.ResolveLValue (ec, EmptyExpression.LValueMemberAccess, loc);
3256                         else
3257                                 InstanceExpression = InstanceExpression.DoResolve (ec);
3258                         if (InstanceExpression == null)
3259                                 return false;
3260
3261                         InstanceExpression.CheckMarshallByRefAccess (ec.ContainerType);
3262
3263                         if (must_do_cs1540_check && InstanceExpression != EmptyExpression.Null &&
3264                             InstanceExpression.Type != ec.ContainerType &&
3265                             ec.ContainerType.IsSubclassOf (PropertyInfo.DeclaringType) &&
3266                             !InstanceExpression.Type.IsSubclassOf (ec.ContainerType)) {
3267                                 Error_CannotAccessProtected (loc, PropertyInfo, InstanceExpression.Type, ec.ContainerType);
3268                                 return false;
3269                         }
3270
3271                         return true;
3272                 }
3273
3274                 void Error_PropertyNotFound (MethodInfo mi, bool getter)
3275                 {
3276                         // TODO: correctly we should compare arguments but it will lead to bigger changes
3277                         if (mi is MethodBuilder) {
3278                                 Error_TypeDoesNotContainDefinition (loc, PropertyInfo.DeclaringType, Name);
3279                                 return;
3280                         }
3281
3282                         StringBuilder sig = new StringBuilder (TypeManager.CSharpName (mi.DeclaringType));
3283                         sig.Append ('.');
3284                         ParameterData iparams = TypeManager.GetParameterData (mi);
3285                         sig.Append (getter ? "get_" : "set_");
3286                         sig.Append (Name);
3287                         sig.Append (iparams.GetSignatureForError ());
3288
3289                         Report.SymbolRelatedToPreviousError (mi);
3290                         Report.Error (1546, loc, "Property `{0}' is not supported by the C# language. Try to call the accessor method `{1}' directly",
3291                                 Name, sig.ToString ());
3292                 }
3293
3294                 override public Expression DoResolve (EmitContext ec)
3295                 {
3296                         if (resolved)
3297                                 return this;
3298
3299                         if (getter != null){
3300                                 if (TypeManager.GetParameterData (getter).Count != 0){
3301                                         Error_PropertyNotFound (getter, true);
3302                                         return null;
3303                                 }
3304                         }
3305
3306                         if (getter == null){
3307                                 //
3308                                 // The following condition happens if the PropertyExpr was
3309                                 // created, but is invalid (ie, the property is inaccessible),
3310                                 // and we did not want to embed the knowledge about this in
3311                                 // the caller routine.  This only avoids double error reporting.
3312                                 //
3313                                 if (setter == null)
3314                                         return null;
3315
3316                                 if (InstanceExpression != EmptyExpression.Null) {
3317                                         Report.Error (154, loc, "The property or indexer `{0}' cannot be used in this context because it lacks the `get' accessor",
3318                                                 TypeManager.GetFullNameSignature (PropertyInfo));
3319                                         return null;
3320                                 }
3321                         }
3322
3323                         bool must_do_cs1540_check = false;
3324                         if (getter != null &&
3325                             !IsAccessorAccessible (ec.ContainerType, getter, out must_do_cs1540_check)) {
3326                                 PropertyBase.PropertyMethod pm = TypeManager.GetMethod (getter) as PropertyBase.PropertyMethod;
3327                                 if (pm != null && pm.HasCustomAccessModifier) {
3328                                         Report.SymbolRelatedToPreviousError (pm);
3329                                         Report.Error (271, loc, "The property or indexer `{0}' cannot be used in this context because the get accessor is inaccessible",
3330                                                 TypeManager.CSharpSignature (getter));
3331                                 }
3332                                 else
3333                                         ErrorIsInaccesible (loc, TypeManager.CSharpSignature (getter));
3334                                 return null;
3335                         }
3336
3337                         if (!InstanceResolve (ec, false, must_do_cs1540_check))
3338                                 return null;
3339
3340                         //
3341                         // Only base will allow this invocation to happen.
3342                         //
3343                         if (IsBase && getter.IsAbstract) {
3344                                 Error_CannotCallAbstractBase (TypeManager.GetFullNameSignature (PropertyInfo));
3345                                 return null;
3346                         }
3347
3348                         if (PropertyInfo.PropertyType.IsPointer && !ec.InUnsafe){
3349                                 UnsafeError (loc);
3350                                 return null;
3351                         }
3352
3353                         resolved = true;
3354
3355                         return this;
3356                 }
3357
3358                 override public Expression DoResolveLValue (EmitContext ec, Expression right_side)
3359                 {
3360                         if (right_side == EmptyExpression.OutAccess) {
3361                                 Report.Error (206, loc, "A property or indexer `{0}' may not be passed as an out or ref parameter",
3362                                               GetSignatureForError ());
3363                                 return null;
3364                         }
3365
3366                         if (right_side == EmptyExpression.LValueMemberAccess) {
3367                                 Report.Error (1612, loc, "Cannot modify the return value of `{0}' because it is not a variable",
3368                                               GetSignatureForError ());
3369                                 return null;
3370                         }
3371
3372                         if (setter == null){
3373                                 //
3374                                 // The following condition happens if the PropertyExpr was
3375                                 // created, but is invalid (ie, the property is inaccessible),
3376                                 // and we did not want to embed the knowledge about this in
3377                                 // the caller routine.  This only avoids double error reporting.
3378                                 //
3379                                 if (getter == null)
3380                                         return null;
3381                                 Report.Error (200, loc, "Property or indexer `{0}' cannot be assigned to (it is read only)",
3382                                               GetSignatureForError ());
3383                                 return null;
3384                         }
3385
3386                         if (TypeManager.GetParameterData (setter).Count != 1){
3387                                 Error_PropertyNotFound (setter, false);
3388                                 return null;
3389                         }
3390
3391                         bool must_do_cs1540_check;
3392                         if (!IsAccessorAccessible (ec.ContainerType, setter, out must_do_cs1540_check)) {
3393                                 PropertyBase.PropertyMethod pm = TypeManager.GetMethod (setter) as PropertyBase.PropertyMethod;
3394                                 if (pm != null && pm.HasCustomAccessModifier) {
3395                                         Report.SymbolRelatedToPreviousError (pm);
3396                                         Report.Error (272, loc, "The property or indexer `{0}' cannot be used in this context because the set accessor is inaccessible",
3397                                                 TypeManager.CSharpSignature (setter));
3398                                 }
3399                                 else
3400                                         ErrorIsInaccesible (loc, TypeManager.CSharpSignature (setter));
3401                                 return null;
3402                         }
3403
3404                         if (!InstanceResolve (ec, PropertyInfo.DeclaringType.IsValueType, must_do_cs1540_check))
3405                                 return null;
3406
3407                         //
3408                         // Only base will allow this invocation to happen.
3409                         //
3410                         if (IsBase && setter.IsAbstract){
3411                                 Error_CannotCallAbstractBase (TypeManager.GetFullNameSignature (PropertyInfo));
3412                                 return null;
3413                         }
3414
3415                         return this;
3416                 }
3417
3418                 public override void Emit (EmitContext ec)
3419                 {
3420                         Emit (ec, false);
3421                 }
3422
3423                 public void Emit (EmitContext ec, bool leave_copy)
3424                 {
3425                         //
3426                         // Special case: length of single dimension array property is turned into ldlen
3427                         //
3428                         if ((getter == TypeManager.system_int_array_get_length) ||
3429                             (getter == TypeManager.int_array_get_length)){
3430                                 Type iet = InstanceExpression.Type;
3431
3432                                 //
3433                                 // System.Array.Length can be called, but the Type does not
3434                                 // support invoking GetArrayRank, so test for that case first
3435                                 //
3436                                 if (iet != TypeManager.array_type && (iet.GetArrayRank () == 1)) {
3437                                         if (!prepared)
3438                                                 EmitInstance (ec, false);
3439                                         ec.ig.Emit (OpCodes.Ldlen);
3440                                         ec.ig.Emit (OpCodes.Conv_I4);
3441                                         return;
3442                                 }
3443                         }
3444
3445                         Invocation.EmitCall (ec, IsBase, IsStatic, InstanceExpression, getter, null, loc, prepared, false);
3446
3447                         if (leave_copy) {
3448                                 ec.ig.Emit (OpCodes.Dup);
3449                                 if (!is_static) {
3450                                         temp = new LocalTemporary (ec, this.Type);
3451                                         temp.Store (ec);
3452                                 }
3453                         }
3454                 }
3455
3456                 //
3457                 // Implements the IAssignMethod interface for assignments
3458                 //
3459                 public void EmitAssign (EmitContext ec, Expression source, bool leave_copy, bool prepare_for_load)
3460                 {
3461                         Expression my_source = source;
3462
3463                         prepared = prepare_for_load;
3464
3465                         if (prepared) {
3466                                 source.Emit (ec);
3467                                 if (leave_copy) {
3468                                         ec.ig.Emit (OpCodes.Dup);
3469                                         if (!is_static) {
3470                                                 temp = new LocalTemporary (ec, this.Type);
3471                                                 temp.Store (ec);
3472                                         }
3473                                 }
3474                         } else if (leave_copy) {
3475                                 source.Emit (ec);
3476                                 if (!is_static) {
3477                                         temp = new LocalTemporary (ec, this.Type);
3478                                         temp.Store (ec);
3479                                 }
3480                                 my_source = temp;
3481                         }
3482
3483                         ArrayList args = new ArrayList (1);
3484                         args.Add (new Argument (my_source, Argument.AType.Expression));
3485
3486                         Invocation.EmitCall (ec, IsBase, IsStatic, InstanceExpression, setter, args, loc, false, prepared);
3487
3488                         if (temp != null)
3489                                 temp.Emit (ec);
3490                 }
3491         }
3492
3493         /// <summary>
3494         ///   Fully resolved expression that evaluates to an Event
3495         /// </summary>
3496         public class EventExpr : MemberExpr {
3497                 public readonly EventInfo EventInfo;
3498
3499                 bool is_static;
3500                 MethodInfo add_accessor, remove_accessor;
3501
3502                 public EventExpr (EventInfo ei, Location loc)
3503                 {
3504                         EventInfo = ei;
3505                         this.loc = loc;
3506                         eclass = ExprClass.EventAccess;
3507
3508                         add_accessor = TypeManager.GetAddMethod (ei);
3509                         remove_accessor = TypeManager.GetRemoveMethod (ei);
3510
3511                         if (add_accessor.IsStatic || remove_accessor.IsStatic)
3512                                 is_static = true;
3513
3514                         if (EventInfo is MyEventBuilder){
3515                                 MyEventBuilder eb = (MyEventBuilder) EventInfo;
3516                                 type = eb.EventType;
3517                                 eb.SetUsed ();
3518                         } else
3519                                 type = EventInfo.EventHandlerType;
3520                 }
3521
3522                 public override string Name {
3523                         get {
3524                                 return EventInfo.Name;
3525                         }
3526                 }
3527
3528                 public override bool IsInstance {
3529                         get {
3530                                 return !is_static;
3531                         }
3532                 }
3533
3534                 public override bool IsStatic {
3535                         get {
3536                                 return is_static;
3537                         }
3538                 }
3539
3540                 public override Type DeclaringType {
3541                         get {
3542                                 return EventInfo.DeclaringType;
3543                         }
3544                 }
3545
3546                 public override Expression ResolveMemberAccess (EmitContext ec, Expression left, Location loc,
3547                                                                 SimpleName original)
3548                 {
3549                         //
3550                         // If the event is local to this class, we transform ourselves into a FieldExpr
3551                         //
3552
3553                         if (EventInfo.DeclaringType == ec.ContainerType ||
3554                             TypeManager.IsNestedChildOf(ec.ContainerType, EventInfo.DeclaringType)) {
3555                                 MemberInfo mi = TypeManager.GetPrivateFieldOfEvent (EventInfo);
3556
3557                                 if (mi != null) {
3558                                         MemberExpr ml = (MemberExpr) ExprClassFromMemberInfo (ec.ContainerType, mi, loc);
3559
3560                                         if (ml == null) {
3561                                                 Report.Error (-200, loc, "Internal error!!");
3562                                                 return null;
3563                                         }
3564
3565                                         InstanceExpression = null;
3566
3567                                         return ml.ResolveMemberAccess (ec, left, loc, original);
3568                                 }
3569                         }
3570
3571                         return base.ResolveMemberAccess (ec, left, loc, original);
3572                 }
3573
3574
3575                 bool InstanceResolve (EmitContext ec, bool must_do_cs1540_check)
3576                 {
3577                         if (is_static) {
3578                                 InstanceExpression = null;
3579                                 return true;
3580                         }
3581
3582                         if (InstanceExpression == null) {
3583                                 SimpleName.Error_ObjectRefRequired (ec, loc, EventInfo.Name);
3584                                 return false;
3585                         }
3586
3587                         InstanceExpression = InstanceExpression.DoResolve (ec);
3588                         if (InstanceExpression == null)
3589                                 return false;
3590
3591                         //
3592                         // This is using the same mechanism as the CS1540 check in PropertyExpr.
3593                         // However, in the Event case, we reported a CS0122 instead.
3594                         //
3595                         if (must_do_cs1540_check && InstanceExpression != EmptyExpression.Null &&
3596                             InstanceExpression.Type != ec.ContainerType &&
3597                             ec.ContainerType.IsSubclassOf (InstanceExpression.Type)) {
3598                                 ErrorIsInaccesible (loc, TypeManager.CSharpSignature (EventInfo));
3599                                 return false;
3600                         }
3601
3602                         return true;
3603                 }
3604
3605                 public override Expression DoResolveLValue (EmitContext ec, Expression right_side)
3606                 {
3607                         return DoResolve (ec);
3608                 }
3609
3610                 public override Expression DoResolve (EmitContext ec)
3611                 {
3612                         bool must_do_cs1540_check;
3613                         if (!(IsAccessorAccessible (ec.ContainerType, add_accessor, out must_do_cs1540_check) &&
3614                               IsAccessorAccessible (ec.ContainerType, remove_accessor, out must_do_cs1540_check))) {
3615                                 ErrorIsInaccesible (loc, TypeManager.CSharpSignature (EventInfo));
3616                                 return null;
3617                         }
3618
3619                         if (!InstanceResolve (ec, must_do_cs1540_check))
3620                                 return null;
3621
3622                         return this;
3623                 }
3624
3625                 public override void Emit (EmitContext ec)
3626                 {
3627                         if (InstanceExpression is This)
3628                                 Report.Error (79, loc, "The event `{0}' can only appear on the left hand side of += or -=", GetSignatureForError ());
3629                         else
3630                                 Report.Error (70, loc, "The event `{0}' can only appear on the left hand side of += or -= "+
3631                                               "(except on the defining type)", Name);
3632                 }
3633
3634                 public override string GetSignatureForError ()
3635                 {
3636                         return TypeManager.CSharpSignature (EventInfo);
3637                 }
3638
3639                 public void EmitAddOrRemove (EmitContext ec, Expression source)
3640                 {
3641                         BinaryDelegate source_del = (BinaryDelegate) source;
3642                         Expression handler = source_del.Right;
3643
3644                         Argument arg = new Argument (handler, Argument.AType.Expression);
3645                         ArrayList args = new ArrayList ();
3646
3647                         args.Add (arg);
3648
3649                         if (source_del.IsAddition)
3650                                 Invocation.EmitCall (
3651                                         ec, false, IsStatic, InstanceExpression, add_accessor, args, loc);
3652                         else
3653                                 Invocation.EmitCall (
3654                                         ec, false, IsStatic, InstanceExpression, remove_accessor, args, loc);
3655                 }
3656         }
3657
3658
3659         public class TemporaryVariable : Expression, IMemoryLocation
3660         {
3661                 LocalInfo li;
3662
3663                 public TemporaryVariable (Type type, Location loc)
3664                 {
3665                         this.type = type;
3666                         this.loc = loc;
3667                         eclass = ExprClass.Value;
3668                 }
3669
3670                 public override Expression DoResolve (EmitContext ec)
3671                 {
3672                         if (li != null)
3673                                 return this;
3674
3675                         TypeExpr te = new TypeExpression (type, loc);
3676                         li = ec.CurrentBlock.AddTemporaryVariable (te, loc);
3677                         if (!li.Resolve (ec))
3678                                 return null;
3679
3680                         AnonymousContainer am = ec.CurrentAnonymousMethod;
3681                         if ((am != null) && am.IsIterator)
3682                                 ec.CaptureVariable (li);
3683
3684                         return this;
3685                 }
3686
3687                 public override void Emit (EmitContext ec)
3688                 {
3689                         ILGenerator ig = ec.ig;
3690
3691                         if (li.FieldBuilder != null) {
3692                                 ig.Emit (OpCodes.Ldarg_0);
3693                                 ig.Emit (OpCodes.Ldfld, li.FieldBuilder);
3694                         } else {
3695                                 ig.Emit (OpCodes.Ldloc, li.LocalBuilder);
3696                         }
3697                 }
3698
3699                 public void EmitLoadAddress (EmitContext ec)
3700                 {
3701                         ILGenerator ig = ec.ig;
3702
3703                         if (li.FieldBuilder != null) {
3704                                 ig.Emit (OpCodes.Ldarg_0);
3705                                 ig.Emit (OpCodes.Ldflda, li.FieldBuilder);
3706                         } else {
3707                                 ig.Emit (OpCodes.Ldloca, li.LocalBuilder);
3708                         }
3709                 }
3710
3711                 public void Store (EmitContext ec, Expression right_side)
3712                 {
3713                         if (li.FieldBuilder != null)
3714                                 ec.ig.Emit (OpCodes.Ldarg_0);
3715
3716                         right_side.Emit (ec);
3717                         if (li.FieldBuilder != null) {
3718                                 ec.ig.Emit (OpCodes.Stfld, li.FieldBuilder);
3719                         } else {
3720                                 ec.ig.Emit (OpCodes.Stloc, li.LocalBuilder);
3721                         }
3722                 }
3723
3724                 public void EmitThis (EmitContext ec)
3725                 {
3726                         if (li.FieldBuilder != null) {
3727                                 ec.ig.Emit (OpCodes.Ldarg_0);
3728                         }
3729                 }
3730
3731                 public void EmitStore (ILGenerator ig)
3732                 {
3733                         if (li.FieldBuilder != null)
3734                                 ig.Emit (OpCodes.Stfld, li.FieldBuilder);
3735                         else
3736                                 ig.Emit (OpCodes.Stloc, li.LocalBuilder);
3737                 }
3738
3739                 public void AddressOf (EmitContext ec, AddressOp mode)
3740                 {
3741                         EmitLoadAddress (ec);
3742                 }
3743         }
3744
3745 }