mcs/mcs/ecore.cs

   1 //
   2 // ecore.cs: Core of the Expression representation for the intermediate tree.
   3 //
   4 // Author:
   5 //   Miguel de Icaza (miguel@ximian.com)
   6 //   Marek Safar (marek.safar@seznam.cz)
   7 //
   8 // (C) 2001, 2002, 2003 Ximian, Inc.
   9 //
  10 //
  11
  12 namespace Mono.CSharp {
  13         using System;
  14         using System.Collections;
  15         using System.Diagnostics;
  16         using System.Reflection;
  17         using System.Reflection.Emit;
  18         using System.Text;
  19
  20         /// <remarks>
  21         ///   The ExprClass class contains the is used to pass the
  22         ///   classification of an expression (value, variable, namespace,
  23         ///   type, method group, property access, event access, indexer access,
  24         ///   nothing).
  25         /// </remarks>
  26         public enum ExprClass : byte {
  27                 Invalid,
  28
  29                 Value,
  30                 Variable,
  31                 Namespace,
  32                 Type,
  33                 MethodGroup,
  34                 PropertyAccess,
  35                 EventAccess,
  36                 IndexerAccess,
  37                 Nothing,
  38         }
  39
  40         /// <remarks>
  41         ///   This is used to tell Resolve in which types of expressions we're
  42         ///   interested.
  43         /// </remarks>
  44         [Flags]
  45         public enum ResolveFlags {
  46                 // Returns Value, Variable, PropertyAccess, EventAccess or IndexerAccess.
  47                 VariableOrValue         = 1,
  48
  49                 // Returns a type expression.
  50                 Type                    = 2,
  51
  52                 // Returns a method group.
  53                 MethodGroup             = 4,
  54
  55                 // Mask of all the expression class flags.
  56                 MaskExprClass           = 7,
  57
  58                 // Disable control flow analysis while resolving the expression.
  59                 // This is used when resolving the instance expression of a field expression.
  60                 DisableFlowAnalysis     = 8,
  61
  62                 // Set if this is resolving the first part of a MemberAccess.
  63                 Intermediate            = 16,
  64
  65                 // Disable control flow analysis _of struct_ while resolving the expression.
  66                 // This is used when resolving the instance expression of a field expression.
  67                 DisableStructFlowAnalysis       = 32,
  68
  69         }
  70
  71         //
  72         // This is just as a hint to AddressOf of what will be done with the
  73         // address.
  74         [Flags]
  75         public enum AddressOp {
  76                 Store = 1,
  77                 Load  = 2,
  78                 LoadStore = 3
  79         };
  80
  81         /// <summary>
  82         ///   This interface is implemented by variables
  83         /// </summary>
  84         public interface IMemoryLocation {
  85                 /// <summary>
  86                 ///   The AddressOf method should generate code that loads
  87                 ///   the address of the object and leaves it on the stack.
  88                 ///
  89                 ///   The `mode' argument is used to notify the expression
  90                 ///   of whether this will be used to read from the address or
  91                 ///   write to the address.
  92                 ///
  93                 ///   This is just a hint that can be used to provide good error
  94                 ///   reporting, and should have no other side effects.
  95                 /// </summary>
  96                 void AddressOf (EmitContext ec, AddressOp mode);
  97         }
  98
  99         /// <summary>
 100         ///   This interface is implemented by variables
 101         /// </summary>
 102         public interface IVariable {
 103                 VariableInfo VariableInfo {
 104                         get;
 105                 }
 106
 107                 bool VerifyFixed ();
 108         }
 109
 110         /// <remarks>
 111         ///   Base class for expressions
 112         /// </remarks>
 113         public abstract class Expression {
 114                 public ExprClass eclass;
 115                 protected Type type;
 116                 protected Location loc;
 117
 118                 public Type Type {
 119                         get { return type; }
 120                         set { type = value; }
 121                 }
 122
 123                 public virtual Location Location {
 124                         get { return loc; }
 125                 }
 126
 127                 /// <summary>
 128                 ///   Utility wrapper routine for Error, just to beautify the code
 129                 /// </summary>
 130                 public void Error (int error, string s)
 131                 {
 132                         Report.Error (error, loc, s);
 133                 }
 134
 135                 // Not nice but we have broken hierarchy.
 136                 public virtual void CheckMarshalByRefAccess ()
 137                 {
 138                 }
 139
 140                 public virtual bool GetAttributableValue (Type valueType, out object value)
 141                 {
 142                         Attribute.Error_AttributeArgumentNotValid (loc);
 143                         value = null;
 144                         return false;
 145                 }
 146
 147                 public virtual string GetSignatureForError ()
 148                 {
 149                         return TypeManager.CSharpName (type);
 150                 }
 151
 152                 public static bool IsAccessorAccessible (Type invocation_type, MethodInfo mi, out bool must_do_cs1540_check)
 153                 {
 154                         MethodAttributes ma = mi.Attributes & MethodAttributes.MemberAccessMask;
 155
 156                         must_do_cs1540_check = false; // by default we do not check for this
 157
 158                         //
 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, te.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                                 Report.SymbolRelatedToPreviousError (te.Type);
 273                                 ErrorIsInaccesible (loc, TypeManager.CSharpName (te.Type));
 274                                 return null;
 275                         }
 276
 277                         te.loc = loc;
 278                         return te;
 279                 }
 280
 281                 public static void ErrorIsInaccesible (Location loc, string name)
 282                 {
 283                         Report.Error (122, loc, "`{0}' is inaccessible due to its protection level", name);
 284                 }
 285
 286                 protected static void Error_CannotAccessProtected (Location loc, MemberInfo m, Type qualifier, Type container)
 287                 {
 288                         Report.Error (1540, loc, "Cannot access protected member `{0}' via a qualifier of type `{1}';"
 289                                 + " the qualifier must be of type `{2}' (or derived from it)",
 290                                 TypeManager.GetFullNameSignature (m),
 291                                 TypeManager.CSharpName (qualifier),
 292                                 TypeManager.CSharpName (container));
 293
 294                 }
 295
 296                 public virtual void Error_ValueCannotBeConverted (Location loc, Type target, bool expl)
 297                 {
 298                         if (Type.Name == target.Name){
 299                                 Report.ExtraInformation (loc,
 300                                         String.Format (
 301                                         "The type {0} has two conflicting definitions, one comes from {1} and the other from {2}",
 302                                         Type.Name, Type.Assembly.FullName, target.Assembly.FullName));
 303
 304                         }
 305
 306                         if (expl) {
 307                                 Report.Error (30, loc, "Cannot convert type `{0}' to `{1}'",
 308                                         GetSignatureForError (), TypeManager.CSharpName (target));
 309                                 return;
 310                         }
 311
 312                         Expression e = (this is EnumConstant) ? ((EnumConstant)this).Child : this;
 313                         bool b = Convert.ExplicitNumericConversion (e, target) != null;
 314
 315                         if (b || Convert.ExplicitReferenceConversionExists (Type, target) || Convert.ExplicitUnsafe (e, target) != null) {
 316                                 Report.Error (266, loc, "Cannot implicitly convert type `{0}' to `{1}'. An explicit conversion exists (are you missing a cast?)",
 317                                         TypeManager.CSharpName (Type), TypeManager.CSharpName (target));
 318                                 return;
 319                         }
 320
 321                         if (Type != TypeManager.string_type && this is Constant && !(this is NullCast)) {
 322                                 Report.Error (31, loc, "Constant value `{0}' cannot be converted to a `{1}'",
 323                                         GetSignatureForError (), TypeManager.CSharpName (target));
 324                                 return;
 325                         }
 326
 327                         Report.Error (29, loc, "Cannot implicitly convert type {0} to `{1}'",
 328                                 Type == TypeManager.anonymous_method_type ?
 329                                 "anonymous method" : "`" + GetSignatureForError () + "'",
 330                                 TypeManager.CSharpName (target));
 331                 }
 332
 333                 protected static void Error_TypeDoesNotContainDefinition (Location loc, Type type, string name)
 334                 {
 335                         Report.Error (117, loc, "`{0}' does not contain a definition for `{1}'",
 336                                 TypeManager.CSharpName (type), name);
 337                 }
 338
 339                 ResolveFlags ExprClassToResolveFlags
 340                 {
 341                         get {
 342                                 switch (eclass) {
 343                                         case ExprClass.Type:
 344                                         case ExprClass.Namespace:
 345                                                 return ResolveFlags.Type;
 346
 347                                         case ExprClass.MethodGroup:
 348                                                 return ResolveFlags.MethodGroup;
 349
 350                                         case ExprClass.Value:
 351                                         case ExprClass.Variable:
 352                                         case ExprClass.PropertyAccess:
 353                                         case ExprClass.EventAccess:
 354                                         case ExprClass.IndexerAccess:
 355                                                 return ResolveFlags.VariableOrValue;
 356
 357                                         default:
 358                                                 throw new Exception ("Expression " + GetType () +
 359                                                         " ExprClass is Invalid after resolve");
 360                                 }
 361                         }
 362                 }
 363
 364                 /// <summary>
 365                 ///   Resolves an expression and performs semantic analysis on it.
 366                 /// </summary>
 367                 ///
 368                 /// <remarks>
 369                 ///   Currently Resolve wraps DoResolve to perform sanity
 370                 ///   checking and assertion checking on what we expect from Resolve.
 371                 /// </remarks>
 372                 public Expression Resolve (EmitContext ec, ResolveFlags flags)
 373                 {
 374                         if ((flags & ResolveFlags.MaskExprClass) == ResolveFlags.Type)
 375                                 return ResolveAsTypeStep (ec, false);
 376
 377                         bool old_do_flow_analysis = ec.DoFlowAnalysis;
 378                         bool old_omit_struct_analysis = ec.OmitStructFlowAnalysis;
 379                         if ((flags & ResolveFlags.DisableFlowAnalysis) != 0)
 380                                 ec.DoFlowAnalysis = false;
 381                         if ((flags & ResolveFlags.DisableStructFlowAnalysis) != 0)
 382                                 ec.OmitStructFlowAnalysis = true;
 383
 384                         Expression e;
 385                         if (this is SimpleName) {
 386                                 bool intermediate = (flags & ResolveFlags.Intermediate) == ResolveFlags.Intermediate;
 387                                 e = ((SimpleName) this).DoResolve (ec, intermediate);
 388                         }
 389                         else
 390                                 e = DoResolve (ec);
 391
 392                         ec.DoFlowAnalysis = old_do_flow_analysis;
 393                         ec.OmitStructFlowAnalysis = old_omit_struct_analysis;
 394
 395                         if (e == null)
 396                                 return null;
 397
 398                         if ((flags & e.ExprClassToResolveFlags) == 0) {
 399                                 e.Error_UnexpectedKind (flags, loc);
 400                                 return null;
 401                         }
 402
 403                         if (e.type == null && !(e is Namespace)) {
 404                                 throw new Exception (
 405                                         "Expression " + e.GetType () +
 406                                         " did not set its type after Resolve\n" +
 407                                         "called from: " + this.GetType ());
 408                         }
 409
 410                         return e;
 411                 }
 412
 413                 /// <summary>
 414                 ///   Resolves an expression and performs semantic analysis on it.
 415                 /// </summary>
 416                 public Expression Resolve (EmitContext ec)
 417                 {
 418                         Expression e = Resolve (ec, ResolveFlags.VariableOrValue | ResolveFlags.MethodGroup);
 419
 420                         if (e != null && e.eclass == ExprClass.MethodGroup && RootContext.Version == LanguageVersion.ISO_1) {
 421                                 ((MethodGroupExpr) e).ReportUsageError ();
 422                                 return null;
 423                         }
 424                         return e;
 425                 }
 426
 427                 public Constant ResolveAsConstant (EmitContext ec, MemberCore mc)
 428                 {
 429                         Expression e = Resolve (ec);
 430                         if (e == null)
 431                                 return null;
 432
 433                         Constant c = e as Constant;
 434                         if (c != null)
 435                                 return c;
 436
 437                         Type constant_type = null;
 438                         if (mc is MemberBase) {
 439                                 constant_type = ((MemberBase)mc).MemberType;
 440                         }
 441
 442                         Const.Error_ExpressionMustBeConstant (constant_type, loc, mc.GetSignatureForError ());
 443                         return null;
 444                 }
 445
 446                 /// <summary>
 447                 ///   Resolves an expression for LValue assignment
 448                 /// </summary>
 449                 ///
 450                 /// <remarks>
 451                 ///   Currently ResolveLValue wraps DoResolveLValue to perform sanity
 452                 ///   checking and assertion checking on what we expect from Resolve
 453                 /// </remarks>
 454                 public Expression ResolveLValue (EmitContext ec, Expression right_side, Location loc)
 455                 {
 456                         int errors = Report.Errors;
 457                         bool out_access = right_side == EmptyExpression.OutAccess;
 458
 459                         Expression e = DoResolveLValue (ec, right_side);
 460
 461                         if (e != null && out_access && !(e is IMemoryLocation)) {
 462                                 // FIXME: There's no problem with correctness, the 'Expr = null' handles that.
 463                                 //        Enabling this 'throw' will "only" result in deleting useless code elsewhere,
 464
 465                                 //throw new InternalErrorException ("ResolveLValue didn't return an IMemoryLocation: " +
 466                                 //                                e.GetType () + " " + e.GetSignatureForError ());
 467                                 e = null;
 468                         }
 469
 470                         if (e == null) {
 471                                 if (errors == Report.Errors) {
 472                                         if (out_access)
 473                                                 Report.Error (1510, loc, "A ref or out argument must be an assignable variable");
 474                                         else
 475                                                 Report.Error (131, loc, "The left-hand side of an assignment or mutating operation must be a variable, property or indexer");
 476                                 }
 477                                 return null;
 478                         }
 479
 480                         if (e.eclass == ExprClass.Invalid)
 481                                 throw new Exception ("Expression " + e + " ExprClass is Invalid after resolve");
 482
 483                         if (e.eclass == ExprClass.MethodGroup) {
 484                                 ((MethodGroupExpr) e).ReportUsageError ();
 485                                 return null;
 486                         }
 487
 488                         if (e.type == null)
 489                                 throw new Exception ("Expression " + e + " did not set its type after Resolve");
 490
 491                         return e;
 492                 }
 493
 494                 /// <summary>
 495                 ///   Emits the code for the expression
 496                 /// </summary>
 497                 ///
 498                 /// <remarks>
 499                 ///   The Emit method is invoked to generate the code
 500                 ///   for the expression.
 501                 /// </remarks>
 502                 public abstract void Emit (EmitContext ec);
 503
 504                 public virtual void EmitBranchable (EmitContext ec, Label target, bool onTrue)
 505                 {
 506                         Emit (ec);
 507                         ec.ig.Emit (onTrue ? OpCodes.Brtrue : OpCodes.Brfalse, target);
 508                 }
 509
 510                 /// <summary>
 511                 ///   Protected constructor.  Only derivate types should
 512                 ///   be able to be created
 513                 /// </summary>
 514
 515                 protected Expression ()
 516                 {
 517                         eclass = ExprClass.Invalid;
 518                         type = null;
 519                 }
 520
 521                 /// <summary>
 522                 ///   Returns a literalized version of a literal FieldInfo
 523                 /// </summary>
 524                 ///
 525                 /// <remarks>
 526                 ///   The possible return values are:
 527                 ///      IntConstant, UIntConstant
 528                 ///      LongLiteral, ULongConstant
 529                 ///      FloatConstant, DoubleConstant
 530                 ///      StringConstant
 531                 ///
 532                 ///   The value returned is already resolved.
 533                 /// </remarks>
 534                 public static Constant Constantify (object v, Type t)
 535                 {
 536                         if (t == TypeManager.int32_type)
 537                                 return new IntConstant ((int) v, Location.Null);
 538                         else if (t == TypeManager.uint32_type)
 539                                 return new UIntConstant ((uint) v, Location.Null);
 540                         else if (t == TypeManager.int64_type)
 541                                 return new LongConstant ((long) v, Location.Null);
 542                         else if (t == TypeManager.uint64_type)
 543                                 return new ULongConstant ((ulong) v, Location.Null);
 544                         else if (t == TypeManager.float_type)
 545                                 return new FloatConstant ((float) v, Location.Null);
 546                         else if (t == TypeManager.double_type)
 547                                 return new DoubleConstant ((double) v, Location.Null);
 548                         else if (t == TypeManager.string_type)
 549                                 return new StringConstant ((string) v, Location.Null);
 550                         else if (t == TypeManager.short_type)
 551                                 return new ShortConstant ((short)v, Location.Null);
 552                         else if (t == TypeManager.ushort_type)
 553                                 return new UShortConstant ((ushort)v, Location.Null);
 554                         else if (t == TypeManager.sbyte_type)
 555                                 return new SByteConstant ((sbyte)v, Location.Null);
 556                         else if (t == TypeManager.byte_type)
 557                                 return new ByteConstant ((byte)v, Location.Null);
 558                         else if (t == TypeManager.char_type)
 559                                 return new CharConstant ((char)v, Location.Null);
 560                         else if (t == TypeManager.bool_type)
 561                                 return new BoolConstant ((bool) v, Location.Null);
 562                         else if (t == TypeManager.decimal_type)
 563                                 return new DecimalConstant ((decimal) v, Location.Null);
 564                         else if (TypeManager.IsEnumType (t)){
 565                                 Type real_type = TypeManager.TypeToCoreType (v.GetType ());
 566                                 if (real_type == t)
 567                                         real_type = System.Enum.GetUnderlyingType (real_type);
 568
 569                                 Constant e = Constantify (v, real_type);
 570
 571                                 return new EnumConstant (e, t);
 572                         } else if (v == null && !TypeManager.IsValueType (t))
 573                                 return new NullLiteral (Location.Null);
 574                         else
 575                                 throw new Exception ("Unknown type for constant (" + t +
 576                                                      "), details: " + v);
 577                 }
 578
 579                 /// <summary>
 580                 ///   Returns a fully formed expression after a MemberLookup
 581                 /// </summary>
 582                 ///
 583                 public static Expression ExprClassFromMemberInfo (Type containerType, MemberInfo mi, Location loc)
 584                 {
 585                         if (mi is EventInfo)
 586                                 return new EventExpr ((EventInfo) mi, loc);
 587                         else if (mi is FieldInfo)
 588                                 return new FieldExpr ((FieldInfo) mi, loc);
 589                         else if (mi is PropertyInfo)
 590                                 return new PropertyExpr (containerType, (PropertyInfo) mi, loc);
 591                         else if (mi is Type){
 592                                 return new TypeExpression ((System.Type) mi, loc);
 593                         }
 594
 595                         return null;
 596                 }
 597
 598                 protected static ArrayList almostMatchedMembers = new ArrayList (4);
 599
 600                 //
 601                 // FIXME: Probably implement a cache for (t,name,current_access_set)?
 602                 //
 603                 // This code could use some optimizations, but we need to do some
 604                 // measurements.  For example, we could use a delegate to `flag' when
 605                 // something can not any longer be a method-group (because it is something
 606                 // else).
 607                 //
 608                 // Return values:
 609                 //     If the return value is an Array, then it is an array of
 610                 //     MethodBases
 611                 //
 612                 //     If the return value is an MemberInfo, it is anything, but a Method
 613                 //
 614                 //     null on error.
 615                 //
 616                 // FIXME: When calling MemberLookup inside an `Invocation', we should pass
 617                 // the arguments here and have MemberLookup return only the methods that
 618                 // match the argument count/type, unlike we are doing now (we delay this
 619                 // decision).
 620                 //
 621                 // This is so we can catch correctly attempts to invoke instance methods
 622                 // from a static body (scan for error 120 in ResolveSimpleName).
 623                 //
 624                 //
 625                 // FIXME: Potential optimization, have a static ArrayList
 626                 //
 627
 628                 public static Expression MemberLookup (Type container_type, Type queried_type, string name,
 629                                                        MemberTypes mt, BindingFlags bf, Location loc)
 630                 {
 631                         return MemberLookup (container_type, null, queried_type, name, mt, bf, loc);
 632                 }
 633
 634                 //
 635                 // Lookup type `queried_type' for code in class `container_type' with a qualifier of
 636                 // `qualifier_type' or null to lookup members in the current class.
 637                 //
 638
 639                 public static Expression MemberLookup (Type container_type,
 640                                                        Type qualifier_type, Type queried_type,
 641                                                        string name, MemberTypes mt,
 642                                                        BindingFlags bf, Location loc)
 643                 {
 644                         almostMatchedMembers.Clear ();
 645
 646                         MemberInfo [] mi = TypeManager.MemberLookup (container_type, qualifier_type,
 647                                                                      queried_type, mt, bf, name, almostMatchedMembers);
 648
 649                         if (mi == null)
 650                                 return null;
 651
 652                         int count = mi.Length;
 653
 654                         if (mi [0] is MethodBase)
 655                                 return new MethodGroupExpr (mi, loc);
 656
 657                         if (count > 1)
 658                                 return null;
 659
 660                         return ExprClassFromMemberInfo (container_type, mi [0], loc);
 661                 }
 662
 663                 public const MemberTypes AllMemberTypes =
 664                         MemberTypes.Constructor |
 665                         MemberTypes.Event       |
 666                         MemberTypes.Field       |
 667                         MemberTypes.Method      |
 668                         MemberTypes.NestedType  |
 669                         MemberTypes.Property;
 670
 671                 public const BindingFlags AllBindingFlags =
 672                         BindingFlags.Public |
 673                         BindingFlags.Static |
 674                         BindingFlags.Instance;
 675
 676                 public static Expression MemberLookup (Type container_type, Type queried_type,
 677                                                        string name, Location loc)
 678                 {
 679                         return MemberLookup (container_type, null, queried_type, name,
 680                                              AllMemberTypes, AllBindingFlags, loc);
 681                 }
 682
 683                 public static Expression MemberLookup (Type container_type, Type qualifier_type,
 684                                                        Type queried_type, string name, Location loc)
 685                 {
 686                         return MemberLookup (container_type, qualifier_type, queried_type,
 687                                              name, AllMemberTypes, AllBindingFlags, loc);
 688                 }
 689
 690                 public static Expression MethodLookup (EmitContext ec, Type queried_type,
 691                                                        string name, Location loc)
 692                 {
 693                         return MemberLookup (ec.ContainerType, null, queried_type, name,
 694                                              MemberTypes.Method, AllBindingFlags, loc);
 695                 }
 696
 697                 /// <summary>
 698                 ///   This is a wrapper for MemberLookup that is not used to "probe", but
 699                 ///   to find a final definition.  If the final definition is not found, we
 700                 ///   look for private members and display a useful debugging message if we
 701                 ///   find it.
 702                 /// </summary>
 703                 public static Expression MemberLookupFinal (EmitContext ec, Type qualifier_type,
 704                                                             Type queried_type, string name, Location loc)
 705                 {
 706                         return MemberLookupFinal (ec, qualifier_type, queried_type, name,
 707                                                   AllMemberTypes, AllBindingFlags, loc);
 708                 }
 709
 710                 public static Expression MemberLookupFinal (EmitContext ec, Type qualifier_type,
 711                                                             Type queried_type, string name,
 712                                                             MemberTypes mt, BindingFlags bf,
 713                                                             Location loc)
 714                 {
 715                         Expression e;
 716
 717                         int errors = Report.Errors;
 718
 719                         e = MemberLookup (ec.ContainerType, qualifier_type, queried_type, name, mt, bf, loc);
 720
 721                         if (e == null && errors == Report.Errors)
 722                                 // No errors were reported by MemberLookup, but there was an error.
 723                                 MemberLookupFailed (ec.ContainerType, qualifier_type, queried_type, name, null, true, loc);
 724
 725                         return e;
 726                 }
 727
 728                 public static void MemberLookupFailed (Type container_type, Type qualifier_type,
 729                                                        Type queried_type, string name,
 730                                                        string class_name, bool complain_if_none_found,
 731                                                        Location loc)
 732                 {
 733                         if (almostMatchedMembers.Count != 0) {
 734                                 for (int i = 0; i < almostMatchedMembers.Count; ++i) {
 735                                         MemberInfo m = (MemberInfo) almostMatchedMembers [i];
 736                                         for (int j = 0; j < i; ++j) {
 737                                                 if (m == almostMatchedMembers [j]) {
 738                                                         m = null;
 739                                                         break;
 740                                                 }
 741                                         }
 742                                         if (m == null)
 743                                                 continue;
 744
 745                                         Type declaring_type = m.DeclaringType;
 746
 747                                         Report.SymbolRelatedToPreviousError (m);
 748                                         if (qualifier_type == null) {
 749                                                 Report.Error (38, loc, "Cannot access a nonstatic member of outer type `{0}' via nested type `{1}'",
 750                                                               TypeManager.CSharpName (m.DeclaringType),
 751                                                               TypeManager.CSharpName (container_type));
 752
 753                                         } else if (qualifier_type != container_type &&
 754                                                    TypeManager.IsNestedFamilyAccessible (container_type, declaring_type)) {
 755                                                 // Although a derived class can access protected members of
 756                                                 // its base class it cannot do so through an instance of the
 757                                                 // base class (CS1540).  If the qualifier_type is a base of the
 758                                                 // ec.ContainerType and the lookup succeeds with the latter one,
 759                                                 // then we are in this situation.
 760                                                 Error_CannotAccessProtected (loc, m, qualifier_type, container_type);
 761                                         } else {
 762                                                 Report.SymbolRelatedToPreviousError (m);
 763                                                 ErrorIsInaccesible (loc, TypeManager.GetFullNameSignature (m));
 764                                         }
 765                                 }
 766                                 almostMatchedMembers.Clear ();
 767                                 return;
 768                         }
 769
 770                         MemberInfo[] lookup = null;
 771                         if (queried_type == null) {
 772                                 class_name = "global::";
 773                         } else {
 774                                 lookup = TypeManager.MemberLookup (queried_type, null, queried_type,
 775                                         AllMemberTypes, AllBindingFlags |
 776                                         BindingFlags.NonPublic, name, null);
 777                         }
 778
 779                         if (lookup == null) {
 780                                 if (!complain_if_none_found)
 781                                         return;
 782
 783                                 if (class_name != null)
 784                                         Report.Error (103, loc, "The name `{0}' does not exist in the context of `{1}'",
 785                                                 name, class_name);
 786                                 else
 787                                         Error_TypeDoesNotContainDefinition (loc, queried_type, name);
 788                                 return;
 789                         }
 790
 791                         MemberList ml = TypeManager.FindMembers (queried_type, MemberTypes.Constructor,
 792                                 BindingFlags.Static | BindingFlags.Instance | BindingFlags.Public | BindingFlags.DeclaredOnly, null, null);
 793                         if (name == ".ctor" && ml.Count == 0)
 794                         {
 795                                 Report.Error (143, loc, "The type `{0}' has no constructors defined", TypeManager.CSharpName (queried_type));
 796                                 return;
 797                         }
 798
 799                         Report.SymbolRelatedToPreviousError (lookup [0]);
 800                         ErrorIsInaccesible (loc, TypeManager.GetFullNameSignature (lookup [0]));
 801                 }
 802
 803                 /// <summary>
 804                 ///   Returns an expression that can be used to invoke operator true
 805                 ///   on the expression if it exists.
 806                 /// </summary>
 807                 static public StaticCallExpr GetOperatorTrue (EmitContext ec, Expression e, Location loc)
 808                 {
 809                         return GetOperatorTrueOrFalse (ec, e, true, loc);
 810                 }
 811
 812                 /// <summary>
 813                 ///   Returns an expression that can be used to invoke operator false
 814                 ///   on the expression if it exists.
 815                 /// </summary>
 816                 static public StaticCallExpr GetOperatorFalse (EmitContext ec, Expression e, Location loc)
 817                 {
 818                         return GetOperatorTrueOrFalse (ec, e, false, loc);
 819                 }
 820
 821                 static StaticCallExpr GetOperatorTrueOrFalse (EmitContext ec, Expression e, bool is_true, Location loc)
 822                 {
 823                         MethodBase method;
 824                         Expression operator_group;
 825
 826                         operator_group = MethodLookup (ec, e.Type, is_true ? "op_True" : "op_False", loc);
 827                         if (operator_group == null)
 828                                 return null;
 829
 830                         ArrayList arguments = new ArrayList ();
 831                         arguments.Add (new Argument (e, Argument.AType.Expression));
 832                         method = Invocation.OverloadResolve (
 833                                 ec, (MethodGroupExpr) operator_group, arguments, false, loc);
 834
 835                         if (method == null)
 836                                 return null;
 837
 838                         return new StaticCallExpr ((MethodInfo) method, arguments, loc);
 839                 }
 840
 841                 /// <summary>
 842                 ///   Resolves the expression `e' into a boolean expression: either through
 843                 ///   an implicit conversion, or through an `operator true' invocation
 844                 /// </summary>
 845                 public static Expression ResolveBoolean (EmitContext ec, Expression e, Location loc)
 846                 {
 847                         e = e.Resolve (ec);
 848                         if (e == null)
 849                                 return null;
 850
 851                         if (e.Type == TypeManager.bool_type)
 852                                 return e;
 853
 854                         Expression converted = Convert.ImplicitConversion (ec, e, TypeManager.bool_type, Location.Null);
 855
 856                         if (converted != null)
 857                                 return converted;
 858
 859                         //
 860                         // If no implicit conversion to bool exists, try using `operator true'
 861                         //
 862                         converted = Expression.GetOperatorTrue (ec, e, loc);
 863                         if (converted == null){
 864                                 e.Error_ValueCannotBeConverted (loc, TypeManager.bool_type, false);
 865                                 return null;
 866                         }
 867                         return converted;
 868                 }
 869
 870                 public virtual string ExprClassName
 871                 {
 872                         get {
 873                                 switch (eclass){
 874                                         case ExprClass.Invalid:
 875                                                 return "Invalid";
 876                                         case ExprClass.Value:
 877                                                 return "value";
 878                                         case ExprClass.Variable:
 879                                                 return "variable";
 880                                         case ExprClass.Namespace:
 881                                                 return "namespace";
 882                                         case ExprClass.Type:
 883                                                 return "type";
 884                                         case ExprClass.MethodGroup:
 885                                                 return "method group";
 886                                         case ExprClass.PropertyAccess:
 887                                                 return "property access";
 888                                         case ExprClass.EventAccess:
 889                                                 return "event access";
 890                                         case ExprClass.IndexerAccess:
 891                                                 return "indexer access";
 892                                         case ExprClass.Nothing:
 893                                                 return "null";
 894                                 }
 895                                 throw new Exception ("Should not happen");
 896                         }
 897                 }
 898
 899                 /// <summary>
 900                 ///   Reports that we were expecting `expr' to be of class `expected'
 901                 /// </summary>
 902                 public void Error_UnexpectedKind (DeclSpace ds, string expected, Location loc)
 903                 {
 904                         Error_UnexpectedKind (ds, expected, ExprClassName, loc);
 905                 }
 906
 907                 public void Error_UnexpectedKind (DeclSpace ds, string expected, string was, Location loc)
 908                 {
 909                         string name = GetSignatureForError ();
 910                         if (ds != null)
 911                                 name = ds.GetSignatureForError () + '.' + name;
 912
 913                         Report.Error (118, loc, "`{0}' is a `{1}' but a `{2}' was expected",
 914                               name, was, expected);
 915                 }
 916
 917                 public void Error_UnexpectedKind (ResolveFlags flags, Location loc)
 918                 {
 919                         string [] valid = new string [4];
 920                         int count = 0;
 921
 922                         if ((flags & ResolveFlags.VariableOrValue) != 0) {
 923                                 valid [count++] = "variable";
 924                                 valid [count++] = "value";
 925                         }
 926
 927                         if ((flags & ResolveFlags.Type) != 0)
 928                                 valid [count++] = "type";
 929
 930                         if ((flags & ResolveFlags.MethodGroup) != 0)
 931                                 valid [count++] = "method group";
 932
 933                         if (count == 0)
 934                                 valid [count++] = "unknown";
 935
 936                         StringBuilder sb = new StringBuilder (valid [0]);
 937                         for (int i = 1; i < count - 1; i++) {
 938                                 sb.Append ("', `");
 939                                 sb.Append (valid [i]);
 940                         }
 941                         if (count > 1) {
 942                                 sb.Append ("' or `");
 943                                 sb.Append (valid [count - 1]);
 944                         }
 945
 946                         Report.Error (119, loc,
 947                                 "Expression denotes a `{0}', where a `{1}' was expected", ExprClassName, sb.ToString ());
 948                 }
 949
 950                 public static void UnsafeError (Location loc)
 951                 {
 952                         Report.Error (214, loc, "Pointers and fixed size buffers may only be used in an unsafe context");
 953                 }
 954
 955                 //
 956                 // Load the object from the pointer.
 957                 //
 958                 public static void LoadFromPtr (ILGenerator ig, Type t)
 959                 {
 960                         if (t == TypeManager.int32_type)
 961                                 ig.Emit (OpCodes.Ldind_I4);
 962                         else if (t == TypeManager.uint32_type)
 963                                 ig.Emit (OpCodes.Ldind_U4);
 964                         else if (t == TypeManager.short_type)
 965                                 ig.Emit (OpCodes.Ldind_I2);
 966                         else if (t == TypeManager.ushort_type)
 967                                 ig.Emit (OpCodes.Ldind_U2);
 968                         else if (t == TypeManager.char_type)
 969                                 ig.Emit (OpCodes.Ldind_U2);
 970                         else if (t == TypeManager.byte_type)
 971                                 ig.Emit (OpCodes.Ldind_U1);
 972                         else if (t == TypeManager.sbyte_type)
 973                                 ig.Emit (OpCodes.Ldind_I1);
 974                         else if (t == TypeManager.uint64_type)
 975                                 ig.Emit (OpCodes.Ldind_I8);
 976                         else if (t == TypeManager.int64_type)
 977                                 ig.Emit (OpCodes.Ldind_I8);
 978                         else if (t == TypeManager.float_type)
 979                                 ig.Emit (OpCodes.Ldind_R4);
 980                         else if (t == TypeManager.double_type)
 981                                 ig.Emit (OpCodes.Ldind_R8);
 982                         else if (t == TypeManager.bool_type)
 983                                 ig.Emit (OpCodes.Ldind_I1);
 984                         else if (t == TypeManager.intptr_type)
 985                                 ig.Emit (OpCodes.Ldind_I);
 986                         else if (TypeManager.IsEnumType (t)) {
 987                                 if (t == TypeManager.enum_type)
 988                                         ig.Emit (OpCodes.Ldind_Ref);
 989                                 else
 990                                         LoadFromPtr (ig, TypeManager.EnumToUnderlying (t));
 991                         } else if (t.IsValueType)
 992                                 ig.Emit (OpCodes.Ldobj, t);
 993                         else if (t.IsPointer)
 994                                 ig.Emit (OpCodes.Ldind_I);
 995                         else
 996                                 ig.Emit (OpCodes.Ldind_Ref);
 997                 }
 998
 999                 //
1000                 // The stack contains the pointer and the value of type `type'
1001                 //
1002                 public static void StoreFromPtr (ILGenerator ig, Type type)
1003                 {
1004                         if (TypeManager.IsEnumType (type))
1005                                 type = TypeManager.EnumToUnderlying (type);
1006                         if (type == TypeManager.int32_type || type == TypeManager.uint32_type)
1007                                 ig.Emit (OpCodes.Stind_I4);
1008                         else if (type == TypeManager.int64_type || type == TypeManager.uint64_type)
1009                                 ig.Emit (OpCodes.Stind_I8);
1010                         else if (type == TypeManager.char_type || type == TypeManager.short_type ||
1011                                  type == TypeManager.ushort_type)
1012                                 ig.Emit (OpCodes.Stind_I2);
1013                         else if (type == TypeManager.float_type)
1014                                 ig.Emit (OpCodes.Stind_R4);
1015                         else if (type == TypeManager.double_type)
1016                                 ig.Emit (OpCodes.Stind_R8);
1017                         else if (type == TypeManager.byte_type || type == TypeManager.sbyte_type ||
1018                                  type == TypeManager.bool_type)
1019                                 ig.Emit (OpCodes.Stind_I1);
1020                         else if (type == TypeManager.intptr_type)
1021                                 ig.Emit (OpCodes.Stind_I);
1022                         else if (type.IsValueType)
1023                                 ig.Emit (OpCodes.Stobj, type);
1024                         else
1025                                 ig.Emit (OpCodes.Stind_Ref);
1026                 }
1027
1028                 //
1029                 // Returns the size of type `t' if known, otherwise, 0
1030                 //
1031                 public static int GetTypeSize (Type t)
1032                 {
1033                         t = TypeManager.TypeToCoreType (t);
1034                         if (t == TypeManager.int32_type ||
1035                             t == TypeManager.uint32_type ||
1036                             t == TypeManager.float_type)
1037                                 return 4;
1038                         else if (t == TypeManager.int64_type ||
1039                                  t == TypeManager.uint64_type ||
1040                                  t == TypeManager.double_type)
1041                                 return 8;
1042                         else if (t == TypeManager.byte_type ||
1043                                  t == TypeManager.sbyte_type ||
1044                                  t == TypeManager.bool_type)
1045                                 return 1;
1046                         else if (t == TypeManager.short_type ||
1047                                  t == TypeManager.char_type ||
1048                                  t == TypeManager.ushort_type)
1049                                 return 2;
1050                         else if (t == TypeManager.decimal_type)
1051                                 return 16;
1052                         else
1053                                 return 0;
1054                 }
1055
1056                 public static void Error_NegativeArrayIndex (Location loc)
1057                 {
1058                         Report.Error (248, loc, "Cannot create an array with a negative size");
1059                 }
1060
1061                 protected void Error_CannotCallAbstractBase (string name)
1062                 {
1063                         Report.Error (205, loc, "Cannot call an abstract base member `{0}'", name);
1064                 }
1065
1066                 //
1067                 // Converts `source' to an int, uint, long or ulong.
1068                 //
1069                 public Expression ExpressionToArrayArgument (EmitContext ec, Expression source, Location loc)
1070                 {
1071                         Expression target;
1072
1073                         bool old_checked = ec.CheckState;
1074                         ec.CheckState = true;
1075
1076                         target = Convert.ImplicitConversion (ec, source, TypeManager.int32_type, loc);
1077                         if (target == null){
1078                                 target = Convert.ImplicitConversion (ec, source, TypeManager.uint32_type, loc);
1079                                 if (target == null){
1080                                         target = Convert.ImplicitConversion (ec, source, TypeManager.int64_type, loc);
1081                                         if (target == null){
1082                                                 target = Convert.ImplicitConversion (ec, source, TypeManager.uint64_type, loc);
1083                                                 if (target == null)
1084                                                         source.Error_ValueCannotBeConverted (loc, TypeManager.int32_type, false);
1085                                         }
1086                                 }
1087                         }
1088                         ec.CheckState = old_checked;
1089
1090                         //
1091                         // Only positive constants are allowed at compile time
1092                         //
1093                         if (target is Constant){
1094                                 if (target is IntConstant){
1095                                         if (((IntConstant) target).Value < 0){
1096                                                 Error_NegativeArrayIndex (loc);
1097                                                 return null;
1098                                         }
1099                                 }
1100
1101                                 if (target is LongConstant){
1102                                         if (((LongConstant) target).Value < 0){
1103                                                 Error_NegativeArrayIndex (loc);
1104                                                 return null;
1105                                         }
1106                                 }
1107
1108                         }
1109
1110                         return target;
1111                 }
1112
1113         }
1114
1115         /// <summary>
1116         ///   This is just a base class for expressions that can
1117         ///   appear on statements (invocations, object creation,
1118         ///   assignments, post/pre increment and decrement).  The idea
1119         ///   being that they would support an extra Emition interface that
1120         ///   does not leave a result on the stack.
1121         /// </summary>
1122         public abstract class ExpressionStatement : Expression {
1123
1124                 public virtual ExpressionStatement ResolveStatement (EmitContext ec)
1125                 {
1126                         Expression e = Resolve (ec);
1127                         if (e == null)
1128                                 return null;
1129
1130                         ExpressionStatement es = e as ExpressionStatement;
1131                         if (es == null)
1132                                 Error (201, "Only assignment, call, increment, decrement and new object " +
1133                                        "expressions can be used as a statement");
1134
1135                         return es;
1136                 }
1137
1138                 /// <summary>
1139                 ///   Requests the expression to be emitted in a `statement'
1140                 ///   context.  This means that no new value is left on the
1141                 ///   stack after invoking this method (constrasted with
1142                 ///   Emit that will always leave a value on the stack).
1143                 /// </summary>
1144                 public abstract void EmitStatement (EmitContext ec);
1145         }
1146
1147         /// <summary>
1148         ///   This kind of cast is used to encapsulate the child
1149         ///   whose type is child.Type into an expression that is
1150         ///   reported to return "return_type".  This is used to encapsulate
1151         ///   expressions which have compatible types, but need to be dealt
1152         ///   at higher levels with.
1153         ///
1154         ///   For example, a "byte" expression could be encapsulated in one
1155         ///   of these as an "unsigned int".  The type for the expression
1156         ///   would be "unsigned int".
1157         ///
1158         /// </summary>
1159         public class EmptyCast : Expression {
1160                 protected readonly Expression child;
1161
1162                 public EmptyCast (Expression child, Type return_type)
1163                 {
1164                         eclass = child.eclass;
1165                         loc = child.Location;
1166                         type = return_type;
1167                         this.child = child;
1168                 }
1169
1170                 public override Expression DoResolve (EmitContext ec)
1171                 {
1172                         // This should never be invoked, we are born in fully
1173                         // initialized state.
1174
1175                         return this;
1176                 }
1177
1178                 public override void Emit (EmitContext ec)
1179                 {
1180                         child.Emit (ec);
1181                 }
1182
1183                 public override bool GetAttributableValue (Type valueType, out object value)
1184                 {
1185                         return child.GetAttributableValue (valueType, out value);
1186                 }
1187
1188         }
1189         /// <summary>
1190         ///     This is a numeric cast to a Decimal
1191         /// </summary>
1192         public class CastToDecimal : EmptyCast {
1193
1194                 MethodInfo conversion_operator;
1195
1196                 public CastToDecimal (Expression child)
1197                         : this (child, false)
1198                 {
1199                 }
1200
1201                 public CastToDecimal (Expression child, bool find_explicit)
1202                         : base (child, TypeManager.decimal_type)
1203                 {
1204                         conversion_operator = GetConversionOperator (find_explicit);
1205
1206                         if (conversion_operator == null)
1207                                 throw new InternalErrorException ("Outer conversion routine is out of sync");
1208                 }
1209
1210                 // Returns the implicit operator that converts from
1211                 // 'child.Type' to System.Decimal.
1212                 MethodInfo GetConversionOperator (bool find_explicit)
1213                 {
1214                         string operator_name = find_explicit ? "op_Explicit" : "op_Implicit";
1215
1216                         MemberInfo [] mi = TypeManager.MemberLookup (type, type, type, MemberTypes.Method,
1217                                 BindingFlags.Static | BindingFlags.Public, operator_name, null);
1218
1219                         foreach (MethodInfo oper in mi) {
1220                                 ParameterData pd = TypeManager.GetParameterData (oper);
1221
1222                                 if (pd.ParameterType (0) == child.Type && oper.ReturnType == type)
1223                                         return oper;
1224                         }
1225
1226                         return null;
1227                 }
1228                 public override void Emit (EmitContext ec)
1229                 {
1230                         ILGenerator ig = ec.ig;
1231                         child.Emit (ec);
1232
1233                         ig.Emit (OpCodes.Call, conversion_operator);
1234                 }
1235         }
1236
1237         /// <summary>
1238         ///     This is an explicit numeric cast from a Decimal
1239         /// </summary>
1240         public class CastFromDecimal : EmptyCast
1241         {
1242                 static IDictionary operators;
1243
1244                 public CastFromDecimal (Expression child, Type return_type)
1245                         : base (child, return_type)
1246                 {
1247                         if (child.Type != TypeManager.decimal_type)
1248                                 throw new InternalErrorException (
1249                                         "The expected type is Decimal, instead it is " + child.Type.FullName);
1250                 }
1251
1252                 // Returns the explicit operator that converts from an
1253                 // express of type System.Decimal to 'type'.
1254                 public Expression Resolve ()
1255                 {
1256                         if (operators == null) {
1257                                  MemberInfo[] all_oper = TypeManager.MemberLookup (TypeManager.decimal_type,
1258                                         TypeManager.decimal_type, TypeManager.decimal_type, MemberTypes.Method,
1259                                         BindingFlags.Static | BindingFlags.Public, "op_Explicit", null);
1260
1261                                 operators = new System.Collections.Specialized.HybridDictionary ();
1262                                 foreach (MethodInfo oper in all_oper) {
1263                                         ParameterData pd = TypeManager.GetParameterData (oper);
1264                                         if (pd.ParameterType (0) == TypeManager.decimal_type)
1265                                                 operators.Add (oper.ReturnType, oper);
1266                                 }
1267                         }
1268
1269                         return operators.Contains (type) ? this : null;
1270                 }
1271
1272                 public override void Emit (EmitContext ec)
1273                 {
1274                         ILGenerator ig = ec.ig;
1275                         child.Emit (ec);
1276
1277                         ig.Emit (OpCodes.Call, (MethodInfo)operators [type]);
1278                 }
1279         }
1280
1281         //
1282         // We need to special case this since an empty cast of
1283         // a NullLiteral is still a Constant
1284         //
1285         public class NullCast : Constant {
1286                 public Constant child;
1287
1288                 public NullCast (Constant child, Type return_type):
1289                         base (Location.Null)
1290                 {
1291                         eclass = child.eclass;
1292                         type = return_type;
1293                         this.child = child;
1294                 }
1295
1296                 override public string AsString ()
1297                 {
1298                         return "null";
1299                 }
1300
1301                 public override object GetValue ()
1302                 {
1303                         return null;
1304                 }
1305
1306                 public override Expression DoResolve (EmitContext ec)
1307                 {
1308                         // This should never be invoked, we are born in fully
1309                         // initialized state.
1310
1311                         return this;
1312                 }
1313
1314                 public override void Emit (EmitContext ec)
1315                 {
1316                         child.Emit (ec);
1317                 }
1318
1319                 public override Constant Increment ()
1320                 {
1321                         throw new NotSupportedException ();
1322                 }
1323
1324                 public override bool IsDefaultValue {
1325                         get {
1326                                 return true;
1327                         }
1328                 }
1329
1330                 public override bool IsNegative {
1331                         get {
1332                                 return false;
1333                         }
1334                 }
1335
1336                 public override Constant Reduce (bool inCheckedContext, Type target_type)
1337                 {
1338                         if (type == target_type)
1339                                 return child.Reduce (inCheckedContext, target_type);
1340
1341                         return null;
1342                 }
1343
1344         }
1345
1346
1347         /// <summary>
1348         ///  This class is used to wrap literals which belong inside Enums
1349         /// </summary>
1350         public class EnumConstant : Constant {
1351                 public Constant Child;
1352
1353                 public EnumConstant (Constant child, Type enum_type):
1354                         base (child.Location)
1355                 {
1356                         eclass = child.eclass;
1357                         this.Child = child;
1358                         type = enum_type;
1359                 }
1360
1361                 public override Expression DoResolve (EmitContext ec)
1362                 {
1363                         // This should never be invoked, we are born in fully
1364                         // initialized state.
1365
1366                         return this;
1367                 }
1368
1369                 public override void Emit (EmitContext ec)
1370                 {
1371                         Child.Emit (ec);
1372                 }
1373
1374                 public override bool GetAttributableValue (Type valueType, out object value)
1375                 {
1376                         value = GetTypedValue ();
1377                         return true;
1378                 }
1379
1380                 public override string GetSignatureForError()
1381                 {
1382                         return TypeManager.CSharpName (Type);
1383                 }
1384
1385                 public override object GetValue ()
1386                 {
1387                         return Child.GetValue ();
1388                 }
1389
1390                 public override object GetTypedValue ()
1391                 {
1392                         // FIXME: runtime is not ready to work with just emited enums
1393                         if (!RootContext.StdLib) {
1394                                 return Child.GetValue ();
1395                         }
1396
1397                         return System.Enum.ToObject (type, Child.GetValue ());
1398                 }
1399
1400                 public override string AsString ()
1401                 {
1402                         return Child.AsString ();
1403                 }
1404
1405                 public override DoubleConstant ConvertToDouble ()
1406                 {
1407                         return Child.ConvertToDouble ();
1408                 }
1409
1410                 public override FloatConstant ConvertToFloat ()
1411                 {
1412                         return Child.ConvertToFloat ();
1413                 }
1414
1415                 public override ULongConstant ConvertToULong ()
1416                 {
1417                         return Child.ConvertToULong ();
1418                 }
1419
1420                 public override LongConstant ConvertToLong ()
1421                 {
1422                         return Child.ConvertToLong ();
1423                 }
1424
1425                 public override UIntConstant ConvertToUInt ()
1426                 {
1427                         return Child.ConvertToUInt ();
1428                 }
1429
1430                 public override IntConstant ConvertToInt ()
1431                 {
1432                         return Child.ConvertToInt ();
1433                 }
1434
1435                 public override Constant Increment()
1436                 {
1437                         return new EnumConstant (Child.Increment (), type);
1438                 }
1439
1440                 public override bool IsDefaultValue {
1441                         get {
1442                                 return Child.IsDefaultValue;
1443                         }
1444                 }
1445
1446                 public override bool IsZeroInteger {
1447                         get { return Child.IsZeroInteger; }
1448                 }
1449
1450                 public override bool IsNegative {
1451                         get {
1452                                 return Child.IsNegative;
1453                         }
1454                 }
1455
1456                 public override Constant Reduce(bool inCheckedContext, Type target_type)
1457                 {
1458                         if (Child.Type == target_type)
1459                                 return Child;
1460
1461                         return Child.Reduce (inCheckedContext, target_type);
1462                 }
1463
1464                 public override Constant ToType (Type type, Location loc)
1465                 {
1466                         if (Type == type) {
1467                                 // This is workaround of mono bug. It can be removed when the latest corlib spreads enough
1468                                 if (TypeManager.IsEnumType (type.UnderlyingSystemType))
1469                                         return this;
1470
1471                                 if (type.UnderlyingSystemType != Child.Type)
1472                                         Child = Child.ToType (type.UnderlyingSystemType, loc);
1473                                 return this;
1474                         }
1475
1476                         if (!Convert.ImplicitStandardConversionExists (this, type)){
1477                                 Error_ValueCannotBeConverted (loc, type, false);
1478                                 return null;
1479                         }
1480
1481                         return Child.ToType (type, loc);
1482                 }
1483
1484         }
1485
1486         /// <summary>
1487         ///   This kind of cast is used to encapsulate Value Types in objects.
1488         ///
1489         ///   The effect of it is to box the value type emitted by the previous
1490         ///   operation.
1491         /// </summary>
1492         public class BoxedCast : EmptyCast {
1493
1494                 public BoxedCast (Expression expr, Type target_type)
1495                         : base (expr, target_type)
1496                 {
1497                         eclass = ExprClass.Value;
1498                 }
1499
1500                 public override Expression DoResolve (EmitContext ec)
1501                 {
1502                         // This should never be invoked, we are born in fully
1503                         // initialized state.
1504
1505                         return this;
1506                 }
1507
1508                 public override void Emit (EmitContext ec)
1509                 {
1510                         base.Emit (ec);
1511
1512                         ec.ig.Emit (OpCodes.Box, child.Type);
1513                 }
1514         }
1515
1516         public class UnboxCast : EmptyCast {
1517                 public UnboxCast (Expression expr, Type return_type)
1518                         : base (expr, return_type)
1519                 {
1520                 }
1521
1522                 public override Expression DoResolve (EmitContext ec)
1523                 {
1524                         // This should never be invoked, we are born in fully
1525                         // initialized state.
1526
1527                         return this;
1528                 }
1529
1530                 public override Expression DoResolveLValue (EmitContext ec, Expression right_side)
1531                 {
1532                         if (right_side == EmptyExpression.LValueMemberAccess || right_side == EmptyExpression.LValueMemberOutAccess)
1533                                 Report.Error (445, loc, "Cannot modify the result of an unboxing conversion");
1534                         return base.DoResolveLValue (ec, right_side);
1535                 }
1536
1537                 public override void Emit (EmitContext ec)
1538                 {
1539                         Type t = type;
1540                         ILGenerator ig = ec.ig;
1541
1542                         base.Emit (ec);
1543                         ig.Emit (OpCodes.Unbox, t);
1544
1545                         LoadFromPtr (ig, t);
1546                 }
1547         }
1548
1549         /// <summary>
1550         ///   This is used to perform explicit numeric conversions.
1551         ///
1552         ///   Explicit numeric conversions might trigger exceptions in a checked
1553         ///   context, so they should generate the conv.ovf opcodes instead of
1554         ///   conv opcodes.
1555         /// </summary>
1556         public class ConvCast : EmptyCast {
1557                 public enum Mode : byte {
1558                         I1_U1, I1_U2, I1_U4, I1_U8, I1_CH,
1559                         U1_I1, U1_CH,
1560                         I2_I1, I2_U1, I2_U2, I2_U4, I2_U8, I2_CH,
1561                         U2_I1, U2_U1, U2_I2, U2_CH,
1562                         I4_I1, I4_U1, I4_I2, I4_U2, I4_U4, I4_U8, I4_CH,
1563                         U4_I1, U4_U1, U4_I2, U4_U2, U4_I4, U4_CH,
1564                         I8_I1, I8_U1, I8_I2, I8_U2, I8_I4, I8_U4, I8_U8, I8_CH,
1565                         U8_I1, U8_U1, U8_I2, U8_U2, U8_I4, U8_U4, U8_I8, U8_CH,
1566                         CH_I1, CH_U1, CH_I2,
1567                         R4_I1, R4_U1, R4_I2, R4_U2, R4_I4, R4_U4, R4_I8, R4_U8, R4_CH,
1568                         R8_I1, R8_U1, R8_I2, R8_U2, R8_I4, R8_U4, R8_I8, R8_U8, R8_CH, R8_R4
1569                 }
1570
1571                 Mode mode;
1572
1573                 public ConvCast (Expression child, Type return_type, Mode m)
1574                         : base (child, return_type)
1575                 {
1576                         mode = m;
1577                 }
1578
1579                 public override Expression DoResolve (EmitContext ec)
1580                 {
1581                         // This should never be invoked, we are born in fully
1582                         // initialized state.
1583
1584                         return this;
1585                 }
1586
1587                 public override string ToString ()
1588                 {
1589                         return String.Format ("ConvCast ({0}, {1})", mode, child);
1590                 }
1591
1592                 public override void Emit (EmitContext ec)
1593                 {
1594                         ILGenerator ig = ec.ig;
1595
1596                         base.Emit (ec);
1597
1598                         if (ec.CheckState){
1599                                 switch (mode){
1600                                 case Mode.I1_U1: ig.Emit (OpCodes.Conv_Ovf_U1); break;
1601                                 case Mode.I1_U2: ig.Emit (OpCodes.Conv_Ovf_U2); break;
1602                                 case Mode.I1_U4: ig.Emit (OpCodes.Conv_Ovf_U4); break;
1603                                 case Mode.I1_U8: ig.Emit (OpCodes.Conv_Ovf_U8); break;
1604                                 case Mode.I1_CH: ig.Emit (OpCodes.Conv_Ovf_U2); break;
1605
1606                                 case Mode.U1_I1: ig.Emit (OpCodes.Conv_Ovf_I1_Un); break;
1607                                 case Mode.U1_CH: /* nothing */ break;
1608
1609                                 case Mode.I2_I1: ig.Emit (OpCodes.Conv_Ovf_I1); break;
1610                                 case Mode.I2_U1: ig.Emit (OpCodes.Conv_Ovf_U1); break;
1611                                 case Mode.I2_U2: ig.Emit (OpCodes.Conv_Ovf_U2); break;
1612                                 case Mode.I2_U4: ig.Emit (OpCodes.Conv_Ovf_U4); break;
1613                                 case Mode.I2_U8: ig.Emit (OpCodes.Conv_Ovf_U8); break;
1614                                 case Mode.I2_CH: ig.Emit (OpCodes.Conv_Ovf_U2); break;
1615
1616                                 case Mode.U2_I1: ig.Emit (OpCodes.Conv_Ovf_I1_Un); break;
1617                                 case Mode.U2_U1: ig.Emit (OpCodes.Conv_Ovf_U1_Un); break;
1618                                 case Mode.U2_I2: ig.Emit (OpCodes.Conv_Ovf_I2_Un); break;
1619                                 case Mode.U2_CH: /* nothing */ break;
1620
1621                                 case Mode.I4_I1: ig.Emit (OpCodes.Conv_Ovf_I1); break;
1622                                 case Mode.I4_U1: ig.Emit (OpCodes.Conv_Ovf_U1); break;
1623                                 case Mode.I4_I2: ig.Emit (OpCodes.Conv_Ovf_I2); break;
1624                                 case Mode.I4_U4: ig.Emit (OpCodes.Conv_Ovf_U4); break;
1625                                 case Mode.I4_U2: ig.Emit (OpCodes.Conv_Ovf_U2); break;
1626                                 case Mode.I4_U8: ig.Emit (OpCodes.Conv_Ovf_U8); break;
1627                                 case Mode.I4_CH: ig.Emit (OpCodes.Conv_Ovf_U2); break;
1628
1629                                 case Mode.U4_I1: ig.Emit (OpCodes.Conv_Ovf_I1_Un); break;
1630                                 case Mode.U4_U1: ig.Emit (OpCodes.Conv_Ovf_U1_Un); break;
1631                                 case Mode.U4_I2: ig.Emit (OpCodes.Conv_Ovf_I2_Un); break;
1632                                 case Mode.U4_U2: ig.Emit (OpCodes.Conv_Ovf_U2_Un); break;
1633                                 case Mode.U4_I4: ig.Emit (OpCodes.Conv_Ovf_I4_Un); break;
1634                                 case Mode.U4_CH: ig.Emit (OpCodes.Conv_Ovf_U2_Un); break;
1635
1636                                 case Mode.I8_I1: ig.Emit (OpCodes.Conv_Ovf_I1); break;
1637                                 case Mode.I8_U1: ig.Emit (OpCodes.Conv_Ovf_U1); break;
1638                                 case Mode.I8_I2: ig.Emit (OpCodes.Conv_Ovf_I2); break;
1639                                 case Mode.I8_U2: ig.Emit (OpCodes.Conv_Ovf_U2); break;
1640                                 case Mode.I8_I4: ig.Emit (OpCodes.Conv_Ovf_I4); break;
1641                                 case Mode.I8_U4: ig.Emit (OpCodes.Conv_Ovf_U4); break;
1642                                 case Mode.I8_U8: ig.Emit (OpCodes.Conv_Ovf_U8); break;
1643                                 case Mode.I8_CH: ig.Emit (OpCodes.Conv_Ovf_U2); break;
1644
1645                                 case Mode.U8_I1: ig.Emit (OpCodes.Conv_Ovf_I1_Un); break;
1646                                 case Mode.U8_U1: ig.Emit (OpCodes.Conv_Ovf_U1_Un); break;
1647                                 case Mode.U8_I2: ig.Emit (OpCodes.Conv_Ovf_I2_Un); break;
1648                                 case Mode.U8_U2: ig.Emit (OpCodes.Conv_Ovf_U2_Un); break;
1649                                 case Mode.U8_I4: ig.Emit (OpCodes.Conv_Ovf_I4_Un); break;
1650                                 case Mode.U8_U4: ig.Emit (OpCodes.Conv_Ovf_U4_Un); break;
1651                                 case Mode.U8_I8: ig.Emit (OpCodes.Conv_Ovf_I8_Un); break;
1652                                 case Mode.U8_CH: ig.Emit (OpCodes.Conv_Ovf_U2_Un); break;
1653
1654                                 case Mode.CH_I1: ig.Emit (OpCodes.Conv_Ovf_I1_Un); break;
1655                                 case Mode.CH_U1: ig.Emit (OpCodes.Conv_Ovf_U1_Un); break;
1656                                 case Mode.CH_I2: ig.Emit (OpCodes.Conv_Ovf_I2_Un); break;
1657
1658                                 case Mode.R4_I1: ig.Emit (OpCodes.Conv_Ovf_I1); break;
1659                                 case Mode.R4_U1: ig.Emit (OpCodes.Conv_Ovf_U1); break;
1660                                 case Mode.R4_I2: ig.Emit (OpCodes.Conv_Ovf_I2); break;
1661                                 case Mode.R4_U2: ig.Emit (OpCodes.Conv_Ovf_U2); break;
1662                                 case Mode.R4_I4: ig.Emit (OpCodes.Conv_Ovf_I4); break;
1663                                 case Mode.R4_U4: ig.Emit (OpCodes.Conv_Ovf_U4); break;
1664                                 case Mode.R4_I8: ig.Emit (OpCodes.Conv_Ovf_I8); break;
1665                                 case Mode.R4_U8: ig.Emit (OpCodes.Conv_Ovf_U8); break;
1666                                 case Mode.R4_CH: ig.Emit (OpCodes.Conv_Ovf_U2); break;
1667
1668                                 case Mode.R8_I1: ig.Emit (OpCodes.Conv_Ovf_I1); break;
1669                                 case Mode.R8_U1: ig.Emit (OpCodes.Conv_Ovf_U1); break;
1670                                 case Mode.R8_I2: ig.Emit (OpCodes.Conv_Ovf_I2); break;
1671                                 case Mode.R8_U2: ig.Emit (OpCodes.Conv_Ovf_U2); break;
1672                                 case Mode.R8_I4: ig.Emit (OpCodes.Conv_Ovf_I4); break;
1673                                 case Mode.R8_U4: ig.Emit (OpCodes.Conv_Ovf_U4); break;
1674                                 case Mode.R8_I8: ig.Emit (OpCodes.Conv_Ovf_I8); break;
1675                                 case Mode.R8_U8: ig.Emit (OpCodes.Conv_Ovf_U8); break;
1676                                 case Mode.R8_CH: ig.Emit (OpCodes.Conv_Ovf_U2); break;
1677                                 case Mode.R8_R4: ig.Emit (OpCodes.Conv_R4); break;
1678                                 }
1679                         } else {
1680                                 switch (mode){
1681                                 case Mode.I1_U1: ig.Emit (OpCodes.Conv_U1); break;
1682                                 case Mode.I1_U2: ig.Emit (OpCodes.Conv_U2); break;
1683                                 case Mode.I1_U4: ig.Emit (OpCodes.Conv_U4); break;
1684                                 case Mode.I1_U8: ig.Emit (OpCodes.Conv_I8); break;
1685                                 case Mode.I1_CH: ig.Emit (OpCodes.Conv_U2); break;
1686
1687                                 case Mode.U1_I1: ig.Emit (OpCodes.Conv_I1); break;
1688                                 case Mode.U1_CH: ig.Emit (OpCodes.Conv_U2); break;
1689
1690                                 case Mode.I2_I1: ig.Emit (OpCodes.Conv_I1); break;
1691                                 case Mode.I2_U1: ig.Emit (OpCodes.Conv_U1); break;
1692                                 case Mode.I2_U2: ig.Emit (OpCodes.Conv_U2); break;
1693                                 case Mode.I2_U4: ig.Emit (OpCodes.Conv_U4); break;
1694                                 case Mode.I2_U8: ig.Emit (OpCodes.Conv_I8); break;
1695                                 case Mode.I2_CH: ig.Emit (OpCodes.Conv_U2); break;
1696
1697                                 case Mode.U2_I1: ig.Emit (OpCodes.Conv_I1); break;
1698                                 case Mode.U2_U1: ig.Emit (OpCodes.Conv_U1); break;
1699                                 case Mode.U2_I2: ig.Emit (OpCodes.Conv_I2); break;
1700                                 case Mode.U2_CH: /* nothing */ break;
1701
1702                                 case Mode.I4_I1: ig.Emit (OpCodes.Conv_I1); break;
1703                                 case Mode.I4_U1: ig.Emit (OpCodes.Conv_U1); break;
1704                                 case Mode.I4_I2: ig.Emit (OpCodes.Conv_I2); break;
1705                                 case Mode.I4_U4: /* nothing */ break;
1706                                 case Mode.I4_U2: ig.Emit (OpCodes.Conv_U2); break;
1707                                 case Mode.I4_U8: ig.Emit (OpCodes.Conv_I8); break;
1708                                 case Mode.I4_CH: ig.Emit (OpCodes.Conv_U2); break;
1709
1710                                 case Mode.U4_I1: ig.Emit (OpCodes.Conv_I1); break;
1711                                 case Mode.U4_U1: ig.Emit (OpCodes.Conv_U1); break;
1712                                 case Mode.U4_I2: ig.Emit (OpCodes.Conv_I2); break;
1713                                 case Mode.U4_U2: ig.Emit (OpCodes.Conv_U2); break;
1714                                 case Mode.U4_I4: /* nothing */ break;
1715                                 case Mode.U4_CH: ig.Emit (OpCodes.Conv_U2); break;
1716
1717                                 case Mode.I8_I1: ig.Emit (OpCodes.Conv_I1); break;
1718                                 case Mode.I8_U1: ig.Emit (OpCodes.Conv_U1); break;
1719                                 case Mode.I8_I2: ig.Emit (OpCodes.Conv_I2); break;
1720                                 case Mode.I8_U2: ig.Emit (OpCodes.Conv_U2); break;
1721                                 case Mode.I8_I4: ig.Emit (OpCodes.Conv_I4); break;
1722                                 case Mode.I8_U4: ig.Emit (OpCodes.Conv_U4); break;
1723                                 case Mode.I8_U8: /* nothing */ break;
1724                                 case Mode.I8_CH: ig.Emit (OpCodes.Conv_U2); break;
1725
1726                                 case Mode.U8_I1: ig.Emit (OpCodes.Conv_I1); break;
1727                                 case Mode.U8_U1: ig.Emit (OpCodes.Conv_U1); break;
1728                                 case Mode.U8_I2: ig.Emit (OpCodes.Conv_I2); break;
1729                                 case Mode.U8_U2: ig.Emit (OpCodes.Conv_U2); break;
1730                                 case Mode.U8_I4: ig.Emit (OpCodes.Conv_I4); break;
1731                                 case Mode.U8_U4: ig.Emit (OpCodes.Conv_U4); break;
1732                                 case Mode.U8_I8: /* nothing */ break;
1733                                 case Mode.U8_CH: ig.Emit (OpCodes.Conv_U2); break;
1734
1735                                 case Mode.CH_I1: ig.Emit (OpCodes.Conv_I1); break;
1736                                 case Mode.CH_U1: ig.Emit (OpCodes.Conv_U1); break;
1737                                 case Mode.CH_I2: ig.Emit (OpCodes.Conv_I2); break;
1738
1739                                 case Mode.R4_I1: ig.Emit (OpCodes.Conv_I1); break;
1740                                 case Mode.R4_U1: ig.Emit (OpCodes.Conv_U1); break;
1741                                 case Mode.R4_I2: ig.Emit (OpCodes.Conv_I2); break;
1742                                 case Mode.R4_U2: ig.Emit (OpCodes.Conv_U2); break;
1743                                 case Mode.R4_I4: ig.Emit (OpCodes.Conv_I4); break;
1744                                 case Mode.R4_U4: ig.Emit (OpCodes.Conv_U4); break;
1745                                 case Mode.R4_I8: ig.Emit (OpCodes.Conv_I8); break;
1746                                 case Mode.R4_U8: ig.Emit (OpCodes.Conv_U8); break;
1747                                 case Mode.R4_CH: ig.Emit (OpCodes.Conv_U2); break;
1748
1749                                 case Mode.R8_I1: ig.Emit (OpCodes.Conv_I1); break;
1750                                 case Mode.R8_U1: ig.Emit (OpCodes.Conv_U1); break;
1751                                 case Mode.R8_I2: ig.Emit (OpCodes.Conv_I2); break;
1752                                 case Mode.R8_U2: ig.Emit (OpCodes.Conv_U2); break;
1753                                 case Mode.R8_I4: ig.Emit (OpCodes.Conv_I4); break;
1754                                 case Mode.R8_U4: ig.Emit (OpCodes.Conv_U4); break;
1755                                 case Mode.R8_I8: ig.Emit (OpCodes.Conv_I8); break;
1756                                 case Mode.R8_U8: ig.Emit (OpCodes.Conv_U8); break;
1757                                 case Mode.R8_CH: ig.Emit (OpCodes.Conv_U2); break;
1758                                 case Mode.R8_R4: ig.Emit (OpCodes.Conv_R4); break;
1759                                 }
1760                         }
1761                 }
1762         }
1763
1764         public class OpcodeCast : EmptyCast {
1765                 OpCode op, op2;
1766                 bool second_valid;
1767
1768                 public OpcodeCast (Expression child, Type return_type, OpCode op)
1769                         : base (child, return_type)
1770
1771                 {
1772                         this.op = op;
1773                         second_valid = false;
1774                 }
1775
1776                 public OpcodeCast (Expression child, Type return_type, OpCode op, OpCode op2)
1777                         : base (child, return_type)
1778
1779                 {
1780                         this.op = op;
1781                         this.op2 = op2;
1782                         second_valid = true;
1783                 }
1784
1785                 public override Expression DoResolve (EmitContext ec)
1786                 {
1787                         // This should never be invoked, we are born in fully
1788                         // initialized state.
1789
1790                         return this;
1791                 }
1792
1793                 public override void Emit (EmitContext ec)
1794                 {
1795                         base.Emit (ec);
1796                         ec.ig.Emit (op);
1797
1798                         if (second_valid)
1799                                 ec.ig.Emit (op2);
1800                 }
1801         }
1802
1803         /// <summary>
1804         ///   This kind of cast is used to encapsulate a child and cast it
1805         ///   to the class requested
1806         /// </summary>
1807         public class ClassCast : EmptyCast {
1808                 public ClassCast (Expression child, Type return_type)
1809                         : base (child, return_type)
1810
1811                 {
1812                 }
1813
1814                 public override Expression DoResolve (EmitContext ec)
1815                 {
1816                         // This should never be invoked, we are born in fully
1817                         // initialized state.
1818
1819                         return this;
1820                 }
1821
1822                 public override void Emit (EmitContext ec)
1823                 {
1824                         base.Emit (ec);
1825
1826                         ec.ig.Emit (OpCodes.Castclass, type);
1827                 }
1828
1829         }
1830
1831         /// <summary>
1832         ///   SimpleName expressions are formed of a single word and only happen at the beginning
1833         ///   of a dotted-name.
1834         /// </summary>
1835         public class SimpleName : Expression {
1836                 public string Name;
1837                 bool in_transit;
1838
1839                 public SimpleName (string name, Location l)
1840                 {
1841                         Name = name;
1842                         loc = l;
1843                 }
1844
1845                 public static void Error_ObjectRefRequired (EmitContext ec, Location l, string name)
1846                 {
1847                         if (ec.IsFieldInitializer)
1848                                 Report.Error (236, l,
1849                                         "A field initializer cannot reference the nonstatic field, method, or property `{0}'",
1850                                         name);
1851                         else
1852                                 Report.Error (
1853                                         120, l, "`{0}': An object reference is required for the nonstatic field, method or property",
1854                                         name);
1855                 }
1856
1857                 public bool IdenticalNameAndTypeName (EmitContext ec, Expression resolved_to, Location loc)
1858                 {
1859                         return resolved_to != null && resolved_to.Type != null &&
1860                                 resolved_to.Type.Name == Name &&
1861                                 (ec.DeclContainer.LookupType (Name, loc, /* ignore_cs0104 = */ true) != null);
1862                 }
1863
1864                 public override Expression DoResolve (EmitContext ec)
1865                 {
1866                         return SimpleNameResolve (ec, null, false);
1867                 }
1868
1869                 public override Expression DoResolveLValue (EmitContext ec, Expression right_side)
1870                 {
1871                         return SimpleNameResolve (ec, right_side, false);
1872                 }
1873
1874
1875                 public Expression DoResolve (EmitContext ec, bool intermediate)
1876                 {
1877                         return SimpleNameResolve (ec, null, intermediate);
1878                 }
1879
1880                 public override FullNamedExpression ResolveAsTypeStep (IResolveContext ec, bool silent)
1881                 {
1882                         int errors = Report.Errors;
1883                         FullNamedExpression fne = ec.DeclContainer.LookupType (Name, loc, /*ignore_cs0104=*/ false);
1884                         if (fne != null)
1885                                 return fne;
1886
1887                         if (silent || errors != Report.Errors)
1888                                 return null;
1889
1890                         MemberCore mc = ec.DeclContainer.GetDefinition (Name);
1891                         if (mc != null) {
1892                                 Error_UnexpectedKind (ec.DeclContainer, "type", GetMemberType (mc), loc);
1893                                 return null;
1894                         }
1895
1896                         string ns = ec.DeclContainer.NamespaceEntry.NS.Name;
1897                         string fullname = (ns.Length > 0) ? ns + "." + Name : Name;
1898                         foreach (Assembly a in RootNamespace.Global.Assemblies) {
1899                                 Type type = a.GetType (fullname);
1900                                 if (type != null) {
1901                                         Report.SymbolRelatedToPreviousError (type);
1902                                         Expression.ErrorIsInaccesible (loc, fullname);
1903                                         return null;
1904                                 }
1905                         }
1906
1907                         NamespaceEntry.Error_NamespaceNotFound (loc, Name);
1908                         return null;
1909                 }
1910
1911                 // TODO: I am still not convinced about this. If someone else will need it
1912                 // implement this as virtual property in MemberCore hierarchy
1913                 string GetMemberType (MemberCore mc)
1914                 {
1915                         if (mc is PropertyBase)
1916                                 return "property";
1917                         if (mc is Indexer)
1918                                 return "indexer";
1919                         if (mc is FieldBase)
1920                                 return "field";
1921                         if (mc is MethodCore)
1922                                 return "method";
1923                         if (mc is EnumMember)
1924                                 return "enum";
1925
1926                         return "type";
1927                 }
1928
1929                 Expression SimpleNameResolve (EmitContext ec, Expression right_side, bool intermediate)
1930                 {
1931                         if (in_transit)
1932                                 return null;
1933                         in_transit = true;
1934
1935                         Expression e = DoSimpleNameResolve (ec, right_side, intermediate);
1936                         if (e == null)
1937                                 return null;
1938
1939                         if (ec.CurrentBlock == null || ec.CurrentBlock.CheckInvariantMeaningInBlock (Name, e, Location))
1940                                 return e;
1941
1942                         return null;
1943                 }
1944
1945                 /// <remarks>
1946                 ///   7.5.2: Simple Names.
1947                 ///
1948                 ///   Local Variables and Parameters are handled at
1949                 ///   parse time, so they never occur as SimpleNames.
1950                 ///
1951                 ///   The `intermediate' flag is used by MemberAccess only
1952                 ///   and it is used to inform us that it is ok for us to
1953                 ///   avoid the static check, because MemberAccess might end
1954                 ///   up resolving the Name as a Type name and the access as
1955                 ///   a static type access.
1956                 ///
1957                 ///   ie: Type Type; .... { Type.GetType (""); }
1958                 ///
1959                 ///   Type is both an instance variable and a Type;  Type.GetType
1960                 ///   is the static method not an instance method of type.
1961                 /// </remarks>
1962                 Expression DoSimpleNameResolve (EmitContext ec, Expression right_side, bool intermediate)
1963                 {
1964                         Expression e = null;
1965
1966                         //
1967                         // Stage 1: Performed by the parser (binding to locals or parameters).
1968                         //
1969                         Block current_block = ec.CurrentBlock;
1970                         if (current_block != null){
1971                                 LocalInfo vi = current_block.GetLocalInfo (Name);
1972                                 if (vi != null){
1973                                         LocalVariableReference var = new LocalVariableReference (ec.CurrentBlock, Name, loc);
1974                                         if (right_side != null) {
1975                                                 return var.ResolveLValue (ec, right_side, loc);
1976                                         } else {
1977                                                 ResolveFlags rf = ResolveFlags.VariableOrValue;
1978                                                 if (intermediate)
1979                                                         rf |= ResolveFlags.DisableFlowAnalysis;
1980                                                 return var.Resolve (ec, rf);
1981                                         }
1982                                 }
1983
1984                                 ParameterReference pref = current_block.Toplevel.GetParameterReference (Name, loc);
1985                                 if (pref != null) {
1986                                         if (right_side != null)
1987                                                 return pref.ResolveLValue (ec, right_side, loc);
1988                                         else
1989                                                 return pref.Resolve (ec);
1990                                 }
1991                         }
1992
1993                         //
1994                         // Stage 2: Lookup members
1995                         //
1996
1997                         DeclSpace lookup_ds = ec.DeclContainer;
1998                         Type almost_matched_type = null;
1999                         ArrayList almost_matched = null;
2000                         do {
2001                                 if (lookup_ds.TypeBuilder == null)
2002                                         break;
2003
2004                                 e = MemberLookup (ec.ContainerType, lookup_ds.TypeBuilder, Name, loc);
2005                                 if (e != null)
2006                                         break;
2007
2008                                 if (almost_matched == null && almostMatchedMembers.Count > 0) {
2009                                         almost_matched_type = lookup_ds.TypeBuilder;
2010                                         almost_matched = (ArrayList) almostMatchedMembers.Clone ();
2011                                 }
2012
2013                                 lookup_ds =lookup_ds.Parent;
2014                         } while (lookup_ds != null);
2015
2016                         if (e == null && ec.ContainerType != null)
2017                                 e = MemberLookup (ec.ContainerType, ec.ContainerType, Name, loc);
2018
2019                         if (e == null) {
2020                                 if (almost_matched == null && almostMatchedMembers.Count > 0) {
2021                                         almost_matched_type = ec.ContainerType;
2022                                         almost_matched = (ArrayList) almostMatchedMembers.Clone ();
2023                                 }
2024                                 e = ResolveAsTypeStep (ec, true);
2025                         }
2026
2027                         if (e == null) {
2028                                 if (almost_matched != null)
2029                                         almostMatchedMembers = almost_matched;
2030                                 if (almost_matched_type == null)
2031                                         almost_matched_type = ec.ContainerType;
2032                                 MemberLookupFailed (ec.ContainerType, null, almost_matched_type, ((SimpleName) this).Name, ec.DeclContainer.Name, true, loc);
2033                                 return null;
2034                         }
2035
2036                         if (e is TypeExpr)
2037                                 return e;
2038
2039                         if (e is MemberExpr) {
2040                                 MemberExpr me = (MemberExpr) e;
2041
2042                                 Expression left;
2043                                 if (me.IsInstance) {
2044                                         if (ec.IsStatic || ec.IsFieldInitializer) {
2045                                                 //
2046                                                 // Note that an MemberExpr can be both IsInstance and IsStatic.
2047                                                 // An unresolved MethodGroupExpr can contain both kinds of methods
2048                                                 // and each predicate is true if the MethodGroupExpr contains
2049                                                 // at least one of that kind of method.
2050                                                 //
2051
2052                                                 if (!me.IsStatic &&
2053                                                     (!intermediate || !IdenticalNameAndTypeName (ec, me, loc))) {
2054                                                         Error_ObjectRefRequired (ec, loc, me.GetSignatureForError ());
2055                                                         return EmptyExpression.Null;
2056                                                 }
2057
2058                                                 //
2059                                                 // Pass the buck to MemberAccess and Invocation.
2060                                                 //
2061                                                 left = EmptyExpression.Null;
2062                                         } else {
2063                                                 left = ec.GetThis (loc);
2064                                         }
2065                                 } else {
2066                                         left = new TypeExpression (ec.ContainerType, loc);
2067                                 }
2068
2069                                 e = me.ResolveMemberAccess (ec, left, loc, null);
2070                                 if (e == null)
2071                                         return null;
2072
2073                                 me = e as MemberExpr;
2074                                 if (me == null)
2075                                         return e;
2076
2077                                 if (!me.IsStatic &&
2078                                     TypeManager.IsNestedFamilyAccessible (me.InstanceExpression.Type, me.DeclaringType) &&
2079                                     me.InstanceExpression.Type != me.DeclaringType &&
2080                                     !me.InstanceExpression.Type.IsSubclassOf (me.DeclaringType) &&
2081                                     (!intermediate || !IdenticalNameAndTypeName (ec, e, loc))) {
2082                                         Report.Error (38, loc, "Cannot access a nonstatic member of outer type `{0}' via nested type `{1}'",
2083                                                 TypeManager.CSharpName (me.DeclaringType), TypeManager.CSharpName (me.InstanceExpression.Type));
2084                                         return null;
2085                                 }
2086
2087                                 return (right_side != null)
2088                                         ? me.DoResolveLValue (ec, right_side)
2089                                         : me.DoResolve (ec);
2090                         }
2091
2092                         return e;
2093                 }
2094
2095                 public override void Emit (EmitContext ec)
2096                 {
2097                         //
2098                         // If this is ever reached, then we failed to
2099                         // find the name as a namespace
2100                         //
2101
2102                         Error (103, "The name `" + Name +
2103                                "' does not exist in the class `" +
2104                                ec.DeclContainer.Name + "'");
2105                 }
2106
2107                 public override string ToString ()
2108                 {
2109                         return Name;
2110                 }
2111
2112                 public override string GetSignatureForError ()
2113                 {
2114                         return Name;
2115                 }
2116         }
2117
2118         /// <summary>
2119         ///   Represents a namespace or a type.  The name of the class was inspired by
2120         ///   section 10.8.1 (Fully Qualified Names).
2121         /// </summary>
2122         public abstract class FullNamedExpression : Expression {
2123                 public override FullNamedExpression ResolveAsTypeStep (IResolveContext ec, bool silent)
2124                 {
2125                         return this;
2126                 }
2127
2128                 public abstract string FullName {
2129                         get;
2130                 }
2131         }
2132
2133         /// <summary>
2134         ///   Expression that evaluates to a type
2135         /// </summary>
2136         public abstract class TypeExpr : FullNamedExpression {
2137                 override public FullNamedExpression ResolveAsTypeStep (IResolveContext ec, bool silent)
2138                 {
2139                         TypeExpr t = DoResolveAsTypeStep (ec);
2140                         if (t == null)
2141                                 return null;
2142
2143                         eclass = ExprClass.Type;
2144                         return t;
2145                 }
2146
2147                 override public Expression DoResolve (EmitContext ec)
2148                 {
2149                         return ResolveAsTypeTerminal (ec, false);
2150                 }
2151
2152                 override public void Emit (EmitContext ec)
2153                 {
2154                         throw new Exception ("Should never be called");
2155                 }
2156
2157                 public virtual bool CheckAccessLevel (DeclSpace ds)
2158                 {
2159                         return ds.CheckAccessLevel (Type);
2160                 }
2161
2162                 public virtual bool AsAccessible (DeclSpace ds, int flags)
2163                 {
2164                         return ds.AsAccessible (Type, flags);
2165                 }
2166
2167                 public virtual bool IsClass {
2168                         get { return Type.IsClass; }
2169                 }
2170
2171                 public virtual bool IsValueType {
2172                         get { return Type.IsValueType; }
2173                 }
2174
2175                 public virtual bool IsInterface {
2176                         get { return Type.IsInterface; }
2177                 }
2178
2179                 public virtual bool IsSealed {
2180                         get { return Type.IsSealed; }
2181                 }
2182
2183                 public virtual bool CanInheritFrom ()
2184                 {
2185                         if (Type == TypeManager.enum_type ||
2186                             (Type == TypeManager.value_type && RootContext.StdLib) ||
2187                             Type == TypeManager.multicast_delegate_type ||
2188                             Type == TypeManager.delegate_type ||
2189                             Type == TypeManager.array_type)
2190                                 return false;
2191
2192                         return true;
2193                 }
2194
2195                 protected abstract TypeExpr DoResolveAsTypeStep (IResolveContext ec);
2196
2197                 public abstract string Name {
2198                         get;
2199                 }
2200
2201                 public override bool Equals (object obj)
2202                 {
2203                         TypeExpr tobj = obj as TypeExpr;
2204                         if (tobj == null)
2205                                 return false;
2206
2207                         return Type == tobj.Type;
2208                 }
2209
2210                 public override int GetHashCode ()
2211                 {
2212                         return Type.GetHashCode ();
2213                 }
2214
2215                 public override string ToString ()
2216                 {
2217                         return Name;
2218                 }
2219         }
2220
2221         /// <summary>
2222         ///   Fully resolved Expression that already evaluated to a type
2223         /// </summary>
2224         public class TypeExpression : TypeExpr {
2225                 public TypeExpression (Type t, Location l)
2226                 {
2227                         Type = t;
2228                         eclass = ExprClass.Type;
2229                         loc = l;
2230                 }
2231
2232                 protected override TypeExpr DoResolveAsTypeStep (IResolveContext ec)
2233                 {
2234                         return this;
2235                 }
2236
2237                 public override TypeExpr ResolveAsTypeTerminal (IResolveContext ec, bool silent)
2238                 {
2239                         return this;
2240                 }
2241
2242                 public override string Name {
2243                         get { return Type.ToString (); }
2244                 }
2245
2246                 public override string FullName {
2247                         get { return Type.FullName; }
2248                 }
2249         }
2250
2251         /// <summary>
2252         ///   Used to create types from a fully qualified name.  These are just used
2253         ///   by the parser to setup the core types.  A TypeLookupExpression is always
2254         ///   classified as a type.
2255         /// </summary>
2256         public sealed class TypeLookupExpression : TypeExpr {
2257                 readonly string name;
2258
2259                 public TypeLookupExpression (string name)
2260                 {
2261                         this.name = name;
2262                         eclass = ExprClass.Type;
2263                 }
2264
2265                 public override TypeExpr ResolveAsTypeTerminal (IResolveContext ec, bool silent)
2266                 {
2267                         // It's null for corlib compilation only
2268                         if (type == null)
2269                                 return DoResolveAsTypeStep (ec);
2270
2271                         return this;
2272                 }
2273
2274                 static readonly char [] dot_array = { '.' };
2275                 protected override TypeExpr DoResolveAsTypeStep (IResolveContext ec)
2276                 {
2277                         // If name is of the form `N.I', first lookup `N', then search a member `I' in it.
2278                         string rest = null;
2279                         string lookup_name = name;
2280                         int pos = name.IndexOf ('.');
2281                         if (pos >= 0) {
2282                                 rest = name.Substring (pos + 1);
2283                                 lookup_name = name.Substring (0, pos);
2284                         }
2285
2286                         FullNamedExpression resolved = RootNamespace.Global.Lookup (ec.DeclContainer, lookup_name, Location.Null);
2287
2288                         if (resolved != null && rest != null) {
2289                                 // Now handle the rest of the the name.
2290                                 string [] elements = rest.Split (dot_array);
2291                                 string element;
2292                                 int count = elements.Length;
2293                                 int i = 0;
2294                                 while (i < count && resolved != null && resolved is Namespace) {
2295                                         Namespace ns = resolved as Namespace;
2296                                         element = elements [i++];
2297                                         lookup_name += "." + element;
2298                                         resolved = ns.Lookup (ec.DeclContainer, element, Location.Null);
2299                                 }
2300
2301                                 if (resolved != null && resolved is TypeExpr) {
2302                                         Type t = ((TypeExpr) resolved).Type;
2303                                         while (t != null) {
2304                                                 if (!ec.DeclContainer.CheckAccessLevel (t)) {
2305                                                         resolved = null;
2306                                                         lookup_name = t.FullName;
2307                                                         break;
2308                                                 }
2309                                                 if (i == count) {
2310                                                         type = t;
2311                                                         return this;
2312                                                 }
2313                                                 t = TypeManager.GetNestedType (t, elements [i++]);
2314                                         }
2315                                 }
2316                         }
2317
2318                         if (resolved == null) {
2319                                 NamespaceEntry.Error_NamespaceNotFound (loc, lookup_name);
2320                                 return null;
2321                         }
2322
2323                         if (!(resolved is TypeExpr)) {
2324                                 resolved.Error_UnexpectedKind (ec.DeclContainer, "type", loc);
2325                                 return null;
2326                         }
2327
2328                         type = resolved.Type;
2329                         return this;
2330                 }
2331
2332                 public override string Name {
2333                         get { return name; }
2334                 }
2335
2336                 public override string FullName {
2337                         get { return name; }
2338                 }
2339         }
2340
2341         public class TypeAliasExpression : TypeExpr {
2342                 TypeExpr texpr;
2343
2344                 public TypeAliasExpression (TypeExpr texpr, Location l)
2345                 {
2346                         this.texpr = texpr;
2347                         loc = texpr.Location;
2348
2349                         eclass = ExprClass.Type;
2350                 }
2351
2352                 public override string Name {
2353                         get { return texpr.Name; }
2354                 }
2355
2356                 public override string FullName {
2357                         get { return texpr.FullName; }
2358                 }
2359
2360                 protected override TypeExpr DoResolveAsTypeStep (IResolveContext ec)
2361                 {
2362                         return texpr;
2363                 }
2364
2365                 public override bool CheckAccessLevel (DeclSpace ds)
2366                 {
2367                         return texpr.CheckAccessLevel (ds);
2368                 }
2369
2370                 public override bool AsAccessible (DeclSpace ds, int flags)
2371                 {
2372                         return texpr.AsAccessible (ds, flags);
2373                 }
2374
2375                 public override bool IsClass {
2376                         get { return texpr.IsClass; }
2377                 }
2378
2379                 public override bool IsValueType {
2380                         get { return texpr.IsValueType; }
2381                 }
2382
2383                 public override bool IsInterface {
2384                         get { return texpr.IsInterface; }
2385                 }
2386
2387                 public override bool IsSealed {
2388                         get { return texpr.IsSealed; }
2389                 }
2390         }
2391
2392         /// <summary>
2393         ///   This class denotes an expression which evaluates to a member
2394         ///   of a struct or a class.
2395         /// </summary>
2396         public abstract class MemberExpr : Expression
2397         {
2398                 /// <summary>
2399                 ///   The name of this member.
2400                 /// </summary>
2401                 public abstract string Name {
2402                         get;
2403                 }
2404
2405                 /// <summary>
2406                 ///   Whether this is an instance member.
2407                 /// </summary>
2408                 public abstract bool IsInstance {
2409                         get;
2410                 }
2411
2412                 /// <summary>
2413                 ///   Whether this is a static member.
2414                 /// </summary>
2415                 public abstract bool IsStatic {
2416                         get;
2417                 }
2418
2419                 /// <summary>
2420                 ///   The type which declares this member.
2421                 /// </summary>
2422                 public abstract Type DeclaringType {
2423                         get;
2424                 }
2425
2426                 /// <summary>
2427                 ///   The instance expression associated with this member, if it's a
2428                 ///   non-static member.
2429                 /// </summary>
2430                 public Expression InstanceExpression;
2431
2432                 public static void error176 (Location loc, string name)
2433                 {
2434                         Report.Error (176, loc, "Static member `{0}' cannot be accessed " +
2435                                       "with an instance reference, qualify it with a type name instead", name);
2436                 }
2437
2438                 // TODO: possible optimalization
2439                 // Cache resolved constant result in FieldBuilder <-> expression map
2440                 public virtual Expression ResolveMemberAccess (EmitContext ec, Expression left, Location loc,
2441                                                                SimpleName original)
2442                 {
2443                         //
2444                         // Precondition:
2445                         //   original == null || original.Resolve (...) ==> left
2446                         //
2447
2448                         if (left is TypeExpr) {
2449                                 if (!IsStatic) {
2450                                         SimpleName.Error_ObjectRefRequired (ec, loc, GetSignatureForError ());
2451                                         return null;
2452                                 }
2453
2454                                 return this;
2455                         }
2456
2457                         if (!IsInstance) {
2458                                 if (original != null && original.IdenticalNameAndTypeName (ec, left, loc))
2459                                         return this;
2460
2461                                 error176 (loc, GetSignatureForError ());
2462                                 return null;
2463                         }
2464
2465                         InstanceExpression = left;
2466
2467                         return this;
2468                 }
2469
2470                 protected void EmitInstance (EmitContext ec, bool prepare_for_load)
2471                 {
2472                         if (IsStatic)
2473                                 return;
2474
2475                         if (InstanceExpression == EmptyExpression.Null) {
2476                                 SimpleName.Error_ObjectRefRequired (ec, loc, GetSignatureForError ());
2477                                 return;
2478                         }
2479
2480                         if (InstanceExpression.Type.IsValueType) {
2481                                 if (InstanceExpression is IMemoryLocation) {
2482                                         ((IMemoryLocation) InstanceExpression).AddressOf (ec, AddressOp.LoadStore);
2483                                 } else {
2484                                         LocalTemporary t = new LocalTemporary (InstanceExpression.Type);
2485                                         InstanceExpression.Emit (ec);
2486                                         t.Store (ec);
2487                                         t.AddressOf (ec, AddressOp.Store);
2488                                 }
2489                         } else
2490                                 InstanceExpression.Emit (ec);
2491
2492                         if (prepare_for_load)
2493                                 ec.ig.Emit (OpCodes.Dup);
2494                 }
2495         }
2496
2497         /// <summary>
2498         ///   MethodGroup Expression.
2499         ///
2500         ///   This is a fully resolved expression that evaluates to a type
2501         /// </summary>
2502         public class MethodGroupExpr : MemberExpr {
2503                 public MethodBase [] Methods;
2504                 bool identical_type_name = false;
2505                 bool is_base;
2506
2507                 public MethodGroupExpr (MemberInfo [] mi, Location l)
2508                 {
2509                         Methods = new MethodBase [mi.Length];
2510                         mi.CopyTo (Methods, 0);
2511                         eclass = ExprClass.MethodGroup;
2512                         type = TypeManager.object_type;
2513                         loc = l;
2514                 }
2515
2516                 public MethodGroupExpr (ArrayList list, Location l)
2517                 {
2518                         Methods = new MethodBase [list.Count];
2519
2520                         try {
2521                                 list.CopyTo (Methods, 0);
2522                         } catch {
2523                                 foreach (MemberInfo m in list){
2524                                         if (!(m is MethodBase)){
2525                                                 Console.WriteLine ("Name " + m.Name);
2526                                                 Console.WriteLine ("Found a: " + m.GetType ().FullName);
2527                                         }
2528                                 }
2529                                 throw;
2530                         }
2531
2532                         loc = l;
2533                         eclass = ExprClass.MethodGroup;
2534                         type = TypeManager.object_type;
2535                 }
2536
2537                 public override Type DeclaringType {
2538                         get {
2539                                 //
2540                                 // The methods are arranged in this order:
2541                                 // derived type -> base type
2542                                 //
2543                                 return Methods [0].DeclaringType;
2544                         }
2545                 }
2546
2547                 public bool IdenticalTypeName {
2548                         get {
2549                                 return identical_type_name;
2550                         }
2551
2552                         set {
2553                                 identical_type_name = value;
2554                         }
2555                 }
2556
2557                 public bool IsBase {
2558                         get {
2559                                 return is_base;
2560                         }
2561                         set {
2562                                 is_base = value;
2563                         }
2564                 }
2565
2566                 public override string GetSignatureForError ()
2567                 {
2568                         return TypeManager.CSharpSignature (Methods [0]);
2569                 }
2570
2571                 public override string Name {
2572                         get {
2573                                 return Methods [0].Name;
2574                         }
2575                 }
2576
2577                 public override bool IsInstance {
2578                         get {
2579                                 foreach (MethodBase mb in Methods)
2580                                         if (!mb.IsStatic)
2581                                                 return true;
2582
2583                                 return false;
2584                         }
2585                 }
2586
2587                 public override bool IsStatic {
2588                         get {
2589                                 foreach (MethodBase mb in Methods)
2590                                         if (mb.IsStatic)
2591                                                 return true;
2592
2593                                 return false;
2594                         }
2595                 }
2596
2597                 public override Expression ResolveMemberAccess (EmitContext ec, Expression left, Location loc,
2598                                                                 SimpleName original)
2599                 {
2600                         if (!(left is TypeExpr) &&
2601                             original != null && original.IdenticalNameAndTypeName (ec, left, loc))
2602                                 IdenticalTypeName = true;
2603
2604                         return base.ResolveMemberAccess (ec, left, loc, original);
2605                 }
2606
2607                 override public Expression DoResolve (EmitContext ec)
2608                 {
2609                         if (!IsInstance)
2610                                 InstanceExpression = null;
2611
2612                         if (InstanceExpression != null) {
2613                                 InstanceExpression = InstanceExpression.DoResolve (ec);
2614                                 if (InstanceExpression == null)
2615                                         return null;
2616                         }
2617
2618                         return this;
2619                 }
2620
2621                 public void ReportUsageError ()
2622                 {
2623                         Report.Error (654, loc, "Method `" + DeclaringType + "." +
2624                                       Name + "()' is referenced without parentheses");
2625                 }
2626
2627                 override public void Emit (EmitContext ec)
2628                 {
2629                         ReportUsageError ();
2630                 }
2631
2632                 bool RemoveMethods (bool keep_static)
2633                 {
2634                         ArrayList smethods = new ArrayList ();
2635
2636                         foreach (MethodBase mb in Methods){
2637                                 if (mb.IsStatic == keep_static)
2638                                         smethods.Add (mb);
2639                         }
2640
2641                         if (smethods.Count == 0)
2642                                 return false;
2643
2644                         Methods = new MethodBase [smethods.Count];
2645                         smethods.CopyTo (Methods, 0);
2646
2647                         return true;
2648                 }
2649
2650                 /// <summary>
2651                 ///   Removes any instance methods from the MethodGroup, returns
2652                 ///   false if the resulting set is empty.
2653                 /// </summary>
2654                 public bool RemoveInstanceMethods ()
2655                 {
2656                         return RemoveMethods (true);
2657                 }
2658
2659                 /// <summary>
2660                 ///   Removes any static methods from the MethodGroup, returns
2661                 ///   false if the resulting set is empty.
2662                 /// </summary>
2663                 public bool RemoveStaticMethods ()
2664                 {
2665                         return RemoveMethods (false);
2666                 }
2667         }
2668
2669         /// <summary>
2670         ///   Fully resolved expression that evaluates to a Field
2671         /// </summary>
2672         public class FieldExpr : MemberExpr, IAssignMethod, IMemoryLocation, IVariable {
2673                 public readonly FieldInfo FieldInfo;
2674                 VariableInfo variable_info;
2675
2676                 LocalTemporary temp;
2677                 bool prepared;
2678                 bool in_initializer;
2679
2680                 public FieldExpr (FieldInfo fi, Location l, bool in_initializer):
2681                         this (fi, l)
2682                 {
2683                         this.in_initializer = in_initializer;
2684                 }
2685
2686                 public FieldExpr (FieldInfo fi, Location l)
2687                 {
2688                         FieldInfo = fi;
2689                         eclass = ExprClass.Variable;
2690                         type = fi.FieldType;
2691                         loc = l;
2692                 }
2693
2694                 public override string Name {
2695                         get {
2696                                 return FieldInfo.Name;
2697                         }
2698                 }
2699
2700                 public override bool IsInstance {
2701                         get {
2702                                 return !FieldInfo.IsStatic;
2703                         }
2704                 }
2705
2706                 public override bool IsStatic {
2707                         get {
2708                                 return FieldInfo.IsStatic;
2709                         }
2710                 }
2711
2712                 public override Type DeclaringType {
2713                         get {
2714                                 return FieldInfo.DeclaringType;
2715                         }
2716                 }
2717
2718                 public override string GetSignatureForError ()
2719                 {
2720                         return TypeManager.GetFullNameSignature (FieldInfo);
2721                 }
2722
2723                 public VariableInfo VariableInfo {
2724                         get {
2725                                 return variable_info;
2726                         }
2727                 }
2728
2729                 public override Expression ResolveMemberAccess (EmitContext ec, Expression left, Location loc,
2730                                                                 SimpleName original)
2731                 {
2732                         Type t = FieldInfo.FieldType;
2733
2734                         if (FieldInfo.IsLiteral || (FieldInfo.IsInitOnly && t == TypeManager.decimal_type)) {
2735                                 IConstant ic = TypeManager.GetConstant (FieldInfo);
2736                                 if (ic == null) {
2737                                         if (FieldInfo.IsLiteral) {
2738                                                 ic = new ExternalConstant (FieldInfo);
2739                                         } else {
2740                                                 ic = ExternalConstant.CreateDecimal (FieldInfo);
2741                                                 if (ic == null) {
2742                                                         return base.ResolveMemberAccess (ec, left, loc, original);
2743                                                 }
2744                                         }
2745                                         TypeManager.RegisterConstant (FieldInfo, ic);
2746                                 }
2747
2748                                 bool left_is_type = left is TypeExpr;
2749                                 if (!left_is_type && (original == null || !original.IdenticalNameAndTypeName (ec, left, loc))) {
2750                                         Report.SymbolRelatedToPreviousError (FieldInfo);
2751                                         error176 (loc, TypeManager.GetFullNameSignature (FieldInfo));
2752                                         return null;
2753                                 }
2754
2755                                 if (ic.ResolveValue ()) {
2756                                         if (!ec.IsInObsoleteScope)
2757                                                 ic.CheckObsoleteness (loc);
2758                                 }
2759
2760                                 return ic.Value;
2761                         }
2762
2763                         if (t.IsPointer && !ec.InUnsafe) {
2764                                 UnsafeError (loc);
2765                                 return null;
2766                         }
2767
2768                         return base.ResolveMemberAccess (ec, left, loc, original);
2769                 }
2770
2771                 override public Expression DoResolve (EmitContext ec)
2772                 {
2773                         return DoResolve (ec, false, false);
2774                 }
2775
2776                 Expression DoResolve (EmitContext ec, bool lvalue_instance, bool out_access)
2777                 {
2778                         if (!FieldInfo.IsStatic){
2779                                 if (InstanceExpression == null){
2780                                         //
2781                                         // This can happen when referencing an instance field using
2782                                         // a fully qualified type expression: TypeName.InstanceField = xxx
2783                                         //
2784                                         SimpleName.Error_ObjectRefRequired (ec, loc, GetSignatureForError ());
2785                                         return null;
2786                                 }
2787
2788                                 // Resolve the field's instance expression while flow analysis is turned
2789                                 // off: when accessing a field "a.b", we must check whether the field
2790                                 // "a.b" is initialized, not whether the whole struct "a" is initialized.
2791
2792                                 if (lvalue_instance) {
2793                                         bool old_do_flow_analysis = ec.DoFlowAnalysis;
2794                                         ec.DoFlowAnalysis = false;
2795                                         Expression right_side =
2796                                                 out_access ? EmptyExpression.LValueMemberOutAccess : EmptyExpression.LValueMemberAccess;
2797                                         InstanceExpression = InstanceExpression.ResolveLValue (ec, right_side, loc);
2798                                         ec.DoFlowAnalysis = old_do_flow_analysis;
2799                                 } else {
2800                                         ResolveFlags rf = ResolveFlags.VariableOrValue | ResolveFlags.DisableFlowAnalysis;
2801                                         InstanceExpression = InstanceExpression.Resolve (ec, rf);
2802                                 }
2803
2804                                 if (InstanceExpression == null)
2805                                         return null;
2806
2807                                 InstanceExpression.CheckMarshalByRefAccess ();
2808                         }
2809
2810                         if (!in_initializer && !ec.IsFieldInitializer) {
2811                                 ObsoleteAttribute oa;
2812                                 FieldBase f = TypeManager.GetField (FieldInfo);
2813                                 if (f != null) {
2814                                         if (!ec.IsInObsoleteScope)
2815                                                 f.CheckObsoleteness (loc);
2816
2817                                         // To be sure that type is external because we do not register generated fields
2818                                 } else if (!(FieldInfo.DeclaringType is TypeBuilder)) {
2819                                         oa = AttributeTester.GetMemberObsoleteAttribute (FieldInfo);
2820                                         if (oa != null)
2821                                                 AttributeTester.Report_ObsoleteMessage (oa, TypeManager.GetFullNameSignature (FieldInfo), loc);
2822                                 }
2823                         }
2824
2825                         AnonymousContainer am = ec.CurrentAnonymousMethod;
2826                         if (am != null){
2827                                 if (!FieldInfo.IsStatic){
2828                                         if (!am.IsIterator && (ec.TypeContainer is Struct)){
2829                                                 Report.Error (1673, loc,
2830                                                 "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",
2831                                                         "this");
2832                                                 return null;
2833                                         }
2834                                         if ((am.ContainerAnonymousMethod == null) && (InstanceExpression is This))
2835                                                 ec.CaptureField (this);
2836                                 }
2837                         }
2838
2839                         // If the instance expression is a local variable or parameter.
2840                         IVariable var = InstanceExpression as IVariable;
2841                         if ((var == null) || (var.VariableInfo == null))
2842                                 return this;
2843
2844                         VariableInfo vi = var.VariableInfo;
2845                         if (!vi.IsFieldAssigned (ec, FieldInfo.Name, loc))
2846                                 return null;
2847
2848                         variable_info = vi.GetSubStruct (FieldInfo.Name);
2849                         return this;
2850                 }
2851
2852                 static readonly int [] codes = {
2853                         191,    // instance, write access
2854                         192,    // instance, out access
2855                         198,    // static, write access
2856                         199,    // static, out access
2857                         1648,   // member of value instance, write access
2858                         1649,   // member of value instance, out access
2859                         1650,   // member of value static, write access
2860                         1651    // member of value static, out access
2861                 };
2862
2863                 static readonly string [] msgs = {
2864                         /*0191*/ "A readonly field `{0}' cannot be assigned to (except in a constructor or a variable initializer)",
2865                         /*0192*/ "A readonly field `{0}' cannot be passed ref or out (except in a constructor)",
2866                         /*0198*/ "A static readonly field `{0}' cannot be assigned to (except in a static constructor or a variable initializer)",
2867                         /*0199*/ "A static readonly field `{0}' cannot be passed ref or out (except in a static constructor)",
2868                         /*1648*/ "Members of readonly field `{0}' cannot be modified (except in a constructor or a variable initializer)",
2869                         /*1649*/ "Members of readonly field `{0}' cannot be passed ref or out (except in a constructor)",
2870                         /*1650*/ "Fields of static readonly field `{0}' cannot be assigned to (except in a static constructor or a variable initializer)",
2871                         /*1651*/ "Fields of static readonly field `{0}' cannot be passed ref or out (except in a static constructor)"
2872                 };
2873
2874                 // The return value is always null.  Returning a value simplifies calling code.
2875                 Expression Report_AssignToReadonly (Expression right_side)
2876                 {
2877                         int i = 0;
2878                         if (right_side == EmptyExpression.OutAccess || right_side == EmptyExpression.LValueMemberOutAccess)
2879                                 i += 1;
2880                         if (IsStatic)
2881                                 i += 2;
2882                         if (right_side == EmptyExpression.LValueMemberAccess || right_side == EmptyExpression.LValueMemberOutAccess)
2883                                 i += 4;
2884                         Report.Error (codes [i], loc, msgs [i], GetSignatureForError ());
2885
2886                         return null;
2887                 }
2888
2889                 override public Expression DoResolveLValue (EmitContext ec, Expression right_side)
2890                 {
2891                         IVariable var = InstanceExpression as IVariable;
2892                         if ((var != null) && (var.VariableInfo != null))
2893                                 var.VariableInfo.SetFieldAssigned (ec, FieldInfo.Name);
2894
2895                         bool lvalue_instance = !FieldInfo.IsStatic && FieldInfo.DeclaringType.IsValueType;
2896                         bool out_access = right_side == EmptyExpression.OutAccess || right_side == EmptyExpression.LValueMemberOutAccess;
2897
2898                         Expression e = DoResolve (ec, lvalue_instance, out_access);
2899
2900                         if (e == null)
2901                                 return null;
2902
2903                         FieldBase fb = TypeManager.GetField (FieldInfo);
2904                         if (fb != null)
2905                                 fb.SetAssigned ();
2906
2907                         if (FieldInfo.IsInitOnly) {
2908                                 // InitOnly fields can only be assigned in constructors or initializers
2909                                 if (!ec.IsFieldInitializer && !ec.IsConstructor)
2910                                         return Report_AssignToReadonly (right_side);
2911
2912                                 if (ec.IsConstructor) {
2913                                         // InitOnly fields cannot be assigned-to in a different constructor from their declaring type
2914                                         if (ec.ContainerType != FieldInfo.DeclaringType)
2915                                                 return Report_AssignToReadonly (right_side);
2916                                         // static InitOnly fields cannot be assigned-to in an instance constructor
2917                                         if (IsStatic && !ec.IsStatic)
2918                                                 return Report_AssignToReadonly (right_side);
2919                                         // instance constructors can't modify InitOnly fields of other instances of the same type
2920                                         if (!IsStatic && !(InstanceExpression is This))
2921                                                 return Report_AssignToReadonly (right_side);
2922                                 }
2923                         }
2924
2925                         if (right_side == EmptyExpression.OutAccess &&
2926                             !IsStatic && !(InstanceExpression is This) && DeclaringType.IsSubclassOf (TypeManager.mbr_type)) {
2927                                 Report.SymbolRelatedToPreviousError (DeclaringType);
2928                                 Report.Warning (197, 1, loc,
2929                                                 "Passing `{0}' as ref or out or taking its address may cause a runtime exception because it is a field of a marshal-by-reference class",
2930                                                 GetSignatureForError ());
2931                         }
2932
2933                         return this;
2934                 }
2935
2936                 public override void CheckMarshalByRefAccess ()
2937                 {
2938                         if (!IsStatic && Type.IsValueType && !(InstanceExpression is This) && DeclaringType.IsSubclassOf (TypeManager.mbr_type)) {
2939                                 Report.SymbolRelatedToPreviousError (DeclaringType);
2940                                 Report.Warning (1690, 1, loc, "Cannot call methods, properties, or indexers on `{0}' because it is a value type member of a marshal-by-reference class",
2941                                                 GetSignatureForError ());
2942                         }
2943                 }
2944
2945                 public bool VerifyFixed ()
2946                 {
2947                         IVariable variable = InstanceExpression as IVariable;
2948                         // A variable of the form V.I is fixed when V is a fixed variable of a struct type.
2949                         // We defer the InstanceExpression check after the variable check to avoid a
2950                         // separate null check on InstanceExpression.
2951                         return variable != null && InstanceExpression.Type.IsValueType && variable.VerifyFixed ();
2952                 }
2953
2954                 public override int GetHashCode ()
2955                 {
2956                         return FieldInfo.GetHashCode ();
2957                 }
2958
2959                 public override bool Equals (object obj)
2960                 {
2961                         FieldExpr fe = obj as FieldExpr;
2962                         if (fe == null)
2963                                 return false;
2964
2965                         if (FieldInfo != fe.FieldInfo)
2966                                 return false;
2967
2968                         if (InstanceExpression == null || fe.InstanceExpression == null)
2969                                 return true;
2970
2971                         return InstanceExpression.Equals (fe.InstanceExpression);
2972                 }
2973
2974                 public void Emit (EmitContext ec, bool leave_copy)
2975                 {
2976                         ILGenerator ig = ec.ig;
2977                         bool is_volatile = false;
2978
2979                         FieldBase f = TypeManager.GetField (FieldInfo);
2980                         if (f != null){
2981                                 if ((f.ModFlags & Modifiers.VOLATILE) != 0)
2982                                         is_volatile = true;
2983
2984                                 f.SetMemberIsUsed ();
2985                         }
2986
2987                         if (FieldInfo.IsStatic){
2988                                 if (is_volatile)
2989                                         ig.Emit (OpCodes.Volatile);
2990
2991                                 ig.Emit (OpCodes.Ldsfld, FieldInfo);
2992                         } else {
2993                                 if (!prepared)
2994                                         EmitInstance (ec, false);
2995
2996                                 if (is_volatile)
2997                                         ig.Emit (OpCodes.Volatile);
2998
2999                                 IFixedBuffer ff = AttributeTester.GetFixedBuffer (FieldInfo);
3000                                 if (ff != null)
3001                                 {
3002                                         ig.Emit (OpCodes.Ldflda, FieldInfo);
3003                                         ig.Emit (OpCodes.Ldflda, ff.Element);
3004                                 }
3005                                 else {
3006                                         ig.Emit (OpCodes.Ldfld, FieldInfo);
3007                                 }
3008                         }
3009
3010                         if (leave_copy) {
3011                                 ec.ig.Emit (OpCodes.Dup);
3012                                 if (!FieldInfo.IsStatic) {
3013                                         temp = new LocalTemporary (this.Type);
3014                                         temp.Store (ec);
3015                                 }
3016                         }
3017                 }
3018
3019                 public void EmitAssign (EmitContext ec, Expression source, bool leave_copy, bool prepare_for_load)
3020                 {
3021                         FieldAttributes fa = FieldInfo.Attributes;
3022                         bool is_static = (fa & FieldAttributes.Static) != 0;
3023                         bool is_readonly = (fa & FieldAttributes.InitOnly) != 0;
3024                         ILGenerator ig = ec.ig;
3025                         prepared = prepare_for_load;
3026
3027                         if (is_readonly && !ec.IsConstructor){
3028                                 Report_AssignToReadonly (source);
3029                                 return;
3030                         }
3031
3032                         EmitInstance (ec, prepare_for_load);
3033
3034                         source.Emit (ec);
3035                         if (leave_copy) {
3036                                 ec.ig.Emit (OpCodes.Dup);
3037                                 if (!FieldInfo.IsStatic) {
3038                                         temp = new LocalTemporary (this.Type);
3039                                         temp.Store (ec);
3040                                 }
3041                         }
3042
3043                         if (FieldInfo is FieldBuilder){
3044                                 FieldBase f = TypeManager.GetField (FieldInfo);
3045                                 if (f != null){
3046                                         if ((f.ModFlags & Modifiers.VOLATILE) != 0)
3047                                                 ig.Emit (OpCodes.Volatile);
3048
3049                                         f.SetAssigned ();
3050                                 }
3051                         }
3052
3053                         if (is_static)
3054                                 ig.Emit (OpCodes.Stsfld, FieldInfo);
3055                         else
3056                                 ig.Emit (OpCodes.Stfld, FieldInfo);
3057
3058                         if (temp != null)
3059                                 temp.Emit (ec);
3060                 }
3061
3062                 public override void Emit (EmitContext ec)
3063                 {
3064                         Emit (ec, false);
3065                 }
3066
3067                 public void AddressOf (EmitContext ec, AddressOp mode)
3068                 {
3069                         ILGenerator ig = ec.ig;
3070
3071                         if (FieldInfo is FieldBuilder){
3072                                 FieldBase f = TypeManager.GetField (FieldInfo);
3073                                 if (f != null){
3074                                         if ((f.ModFlags & Modifiers.VOLATILE) != 0){
3075                                                 Report.Warning (420, 1, loc, "`{0}': A volatile fields cannot be passed using a ref or out parameter",
3076                                                         f.GetSignatureForError ());
3077                                                 return;
3078                                         }
3079
3080                                         if ((mode & AddressOp.Store) != 0)
3081                                                 f.SetAssigned ();
3082                                         if ((mode & AddressOp.Load) != 0)
3083                                                 f.SetMemberIsUsed ();
3084                                 }
3085                         }
3086
3087                         //
3088                         // Handle initonly fields specially: make a copy and then
3089                         // get the address of the copy.
3090                         //
3091                         bool need_copy;
3092                         if (FieldInfo.IsInitOnly){
3093                                 need_copy = true;
3094                                 if (ec.IsConstructor){
3095                                         if (FieldInfo.IsStatic){
3096                                                 if (ec.IsStatic)
3097                                                         need_copy = false;
3098                                         } else
3099                                                 need_copy = false;
3100                                 }
3101                         } else
3102                                 need_copy = false;
3103
3104                         if (need_copy){
3105                                 LocalBuilder local;
3106                                 Emit (ec);
3107                                 local = ig.DeclareLocal (type);
3108                                 ig.Emit (OpCodes.Stloc, local);
3109                                 ig.Emit (OpCodes.Ldloca, local);
3110                                 return;
3111                         }
3112
3113
3114                         if (FieldInfo.IsStatic){
3115                                 ig.Emit (OpCodes.Ldsflda, FieldInfo);
3116                         } else {
3117                                 EmitInstance (ec, false);
3118                                 ig.Emit (OpCodes.Ldflda, FieldInfo);
3119                         }
3120                 }
3121         }
3122
3123         //
3124         // A FieldExpr whose address can not be taken
3125         //
3126         public class FieldExprNoAddress : FieldExpr, IMemoryLocation {
3127                 public FieldExprNoAddress (FieldInfo fi, Location loc) : base (fi, loc)
3128                 {
3129                 }
3130
3131                 public new void AddressOf (EmitContext ec, AddressOp mode)
3132                 {
3133                         Report.Error (-215, "Report this: Taking the address of a remapped parameter not supported");
3134                 }
3135         }
3136
3137         /// <summary>
3138         ///   Expression that evaluates to a Property.  The Assign class
3139         ///   might set the `Value' expression if we are in an assignment.
3140         ///
3141         ///   This is not an LValue because we need to re-write the expression, we
3142         ///   can not take data from the stack and store it.
3143         /// </summary>
3144         public class PropertyExpr : MemberExpr, IAssignMethod {
3145                 public readonly PropertyInfo PropertyInfo;
3146
3147                 //
3148                 // This is set externally by the  `BaseAccess' class
3149                 //
3150                 public bool IsBase;
3151                 MethodInfo getter, setter;
3152                 bool is_static;
3153
3154                 bool resolved;
3155
3156                 LocalTemporary temp;
3157                 bool prepared;
3158
3159                 internal static PtrHashtable AccessorTable = new PtrHashtable ();
3160
3161                 public PropertyExpr (Type containerType, PropertyInfo pi, Location l)
3162                 {
3163                         PropertyInfo = pi;
3164                         eclass = ExprClass.PropertyAccess;
3165                         is_static = false;
3166                         loc = l;
3167
3168                         type = TypeManager.TypeToCoreType (pi.PropertyType);
3169
3170                         ResolveAccessors (containerType);
3171                 }
3172
3173                 public override string Name {
3174                         get {
3175                                 return PropertyInfo.Name;
3176                         }
3177                 }
3178
3179                 public override bool IsInstance {
3180                         get {
3181                                 return !is_static;
3182                         }
3183                 }
3184
3185                 public override bool IsStatic {
3186                         get {
3187                                 return is_static;
3188                         }
3189                 }
3190
3191                 public override Type DeclaringType {
3192                         get {
3193                                 return PropertyInfo.DeclaringType;
3194                         }
3195                 }
3196
3197                 public override string GetSignatureForError ()
3198                 {
3199                         return TypeManager.GetFullNameSignature (PropertyInfo);
3200                 }
3201
3202                 void FindAccessors (Type invocation_type)
3203                 {
3204                         const BindingFlags flags = BindingFlags.Public | BindingFlags.NonPublic |
3205                                 BindingFlags.Static | BindingFlags.Instance |
3206                                 BindingFlags.DeclaredOnly;
3207
3208                         Type current = PropertyInfo.DeclaringType;
3209                         for (; current != null; current = current.BaseType) {
3210                                 MemberInfo[] group = TypeManager.MemberLookup (
3211                                         invocation_type, invocation_type, current,
3212                                         MemberTypes.Property, flags, PropertyInfo.Name, null);
3213
3214                                 if (group == null)
3215                                         continue;
3216
3217                                 if (group.Length != 1)
3218                                         // Oooops, can this ever happen ?
3219                                         return;
3220
3221                                 PropertyInfo pi = (PropertyInfo) group [0];
3222
3223                                 if (getter == null)
3224                                         getter = pi.GetGetMethod (true);
3225
3226                                 if (setter == null)
3227                                         setter = pi.GetSetMethod (true);
3228
3229                                 MethodInfo accessor = getter != null ? getter : setter;
3230
3231                                 if (!accessor.IsVirtual)
3232                                         return;
3233                         }
3234                 }
3235
3236                 //
3237                 // We also perform the permission checking here, as the PropertyInfo does not
3238                 // hold the information for the accessibility of its setter/getter
3239                 //
3240                 // TODO: can use TypeManager.GetProperty to boost performance
3241                 void ResolveAccessors (Type containerType)
3242                 {
3243                         FindAccessors (containerType);
3244
3245                         if (getter != null) {
3246                                 IMethodData md = TypeManager.GetMethod (getter);
3247                                 if (md != null)
3248                                         md.SetMemberIsUsed ();
3249
3250                                 AccessorTable [getter] = PropertyInfo;
3251                                 is_static = getter.IsStatic;
3252                         }
3253
3254                         if (setter != null) {
3255                                 IMethodData md = TypeManager.GetMethod (setter);
3256                                 if (md != null)
3257                                         md.SetMemberIsUsed ();
3258
3259                                 AccessorTable [setter] = PropertyInfo;
3260                                 is_static = setter.IsStatic;
3261                         }
3262                 }
3263
3264                 bool InstanceResolve (EmitContext ec, bool lvalue_instance, bool must_do_cs1540_check)
3265                 {
3266                         if (is_static) {
3267                                 InstanceExpression = null;
3268                                 return true;
3269                         }
3270
3271                         if (InstanceExpression == null) {
3272                                 SimpleName.Error_ObjectRefRequired (ec, loc, GetSignatureForError ());
3273                                 return false;
3274                         }
3275
3276                         if (lvalue_instance)
3277                                 InstanceExpression = InstanceExpression.ResolveLValue (ec, EmptyExpression.LValueMemberAccess, loc);
3278                         else
3279                                 InstanceExpression = InstanceExpression.DoResolve (ec);
3280                         if (InstanceExpression == null)
3281                                 return false;
3282
3283                         InstanceExpression.CheckMarshalByRefAccess ();
3284
3285                         if (must_do_cs1540_check && InstanceExpression != EmptyExpression.Null &&
3286                             InstanceExpression.Type != ec.ContainerType &&
3287                             ec.ContainerType.IsSubclassOf (PropertyInfo.DeclaringType) &&
3288                             !InstanceExpression.Type.IsSubclassOf (ec.ContainerType)) {
3289                                 Error_CannotAccessProtected (loc, PropertyInfo, InstanceExpression.Type, ec.ContainerType);
3290                                 return false;
3291                         }
3292
3293                         return true;
3294                 }
3295
3296                 void Error_PropertyNotFound (MethodInfo mi, bool getter)
3297                 {
3298                         // TODO: correctly we should compare arguments but it will lead to bigger changes
3299                         if (mi is MethodBuilder) {
3300                                 Error_TypeDoesNotContainDefinition (loc, PropertyInfo.DeclaringType, Name);
3301                                 return;
3302                         }
3303
3304                         StringBuilder sig = new StringBuilder (TypeManager.CSharpName (mi.DeclaringType));
3305                         sig.Append ('.');
3306                         ParameterData iparams = TypeManager.GetParameterData (mi);
3307                         sig.Append (getter ? "get_" : "set_");
3308                         sig.Append (Name);
3309                         sig.Append (iparams.GetSignatureForError ());
3310
3311                         Report.SymbolRelatedToPreviousError (mi);
3312                         Report.Error (1546, loc, "Property `{0}' is not supported by the C# language. Try to call the accessor method `{1}' directly",
3313                                 Name, sig.ToString ());
3314                 }
3315
3316                 override public Expression DoResolve (EmitContext ec)
3317                 {
3318                         if (resolved)
3319                                 return this;
3320
3321                         if (getter != null){
3322                                 if (TypeManager.GetParameterData (getter).Count != 0){
3323                                         Error_PropertyNotFound (getter, true);
3324                                         return null;
3325                                 }
3326                         }
3327
3328                         if (getter == null){
3329                                 //
3330                                 // The following condition happens if the PropertyExpr was
3331                                 // created, but is invalid (ie, the property is inaccessible),
3332                                 // and we did not want to embed the knowledge about this in
3333                                 // the caller routine.  This only avoids double error reporting.
3334                                 //
3335                                 if (setter == null)
3336                                         return null;
3337
3338                                 if (InstanceExpression != EmptyExpression.Null) {
3339                                         Report.Error (154, loc, "The property or indexer `{0}' cannot be used in this context because it lacks the `get' accessor",
3340                                                 TypeManager.GetFullNameSignature (PropertyInfo));
3341                                         return null;
3342                                 }
3343                         }
3344
3345                         bool must_do_cs1540_check = false;
3346                         if (getter != null &&
3347                             !IsAccessorAccessible (ec.ContainerType, getter, out must_do_cs1540_check)) {
3348                                 PropertyBase.PropertyMethod pm = TypeManager.GetMethod (getter) as PropertyBase.PropertyMethod;
3349                                 if (pm != null && pm.HasCustomAccessModifier) {
3350                                         Report.SymbolRelatedToPreviousError (pm);
3351                                         Report.Error (271, loc, "The property or indexer `{0}' cannot be used in this context because the get accessor is inaccessible",
3352                                                 TypeManager.CSharpSignature (getter));
3353                                 }
3354                                 else {
3355                                         Report.SymbolRelatedToPreviousError (getter);
3356                                         ErrorIsInaccesible (loc, TypeManager.CSharpSignature (getter));
3357                                 }
3358                                 return null;
3359                         }
3360
3361                         if (!InstanceResolve (ec, false, must_do_cs1540_check))
3362                                 return null;
3363
3364                         //
3365                         // Only base will allow this invocation to happen.
3366                         //
3367                         if (IsBase && getter.IsAbstract) {
3368                                 Error_CannotCallAbstractBase (TypeManager.GetFullNameSignature (PropertyInfo));
3369                                 return null;
3370                         }
3371
3372                         if (PropertyInfo.PropertyType.IsPointer && !ec.InUnsafe){
3373                                 UnsafeError (loc);
3374                                 return null;
3375                         }
3376
3377                         resolved = true;
3378
3379                         return this;
3380                 }
3381
3382                 override public Expression DoResolveLValue (EmitContext ec, Expression right_side)
3383                 {
3384                         if (right_side == EmptyExpression.OutAccess) {
3385                                 Report.Error (206, loc, "A property or indexer `{0}' may not be passed as an out or ref parameter",
3386                                               GetSignatureForError ());
3387                                 return null;
3388                         }
3389
3390                         if (right_side == EmptyExpression.LValueMemberAccess || right_side == EmptyExpression.LValueMemberOutAccess) {
3391                                 Report.Error (1612, loc, "Cannot modify the return value of `{0}' because it is not a variable",
3392                                               GetSignatureForError ());
3393                                 return null;
3394                         }
3395
3396                         if (setter == null){
3397                                 //
3398                                 // The following condition happens if the PropertyExpr was
3399                                 // created, but is invalid (ie, the property is inaccessible),
3400                                 // and we did not want to embed the knowledge about this in
3401                                 // the caller routine.  This only avoids double error reporting.
3402                                 //
3403                                 if (getter == null)
3404                                         return null;
3405                                 Report.Error (200, loc, "Property or indexer `{0}' cannot be assigned to (it is read only)",
3406                                               GetSignatureForError ());
3407                                 return null;
3408                         }
3409
3410                         if (TypeManager.GetParameterData (setter).Count != 1){
3411                                 Error_PropertyNotFound (setter, false);
3412                                 return null;
3413                         }
3414
3415                         bool must_do_cs1540_check;
3416                         if (!IsAccessorAccessible (ec.ContainerType, setter, out must_do_cs1540_check)) {
3417                                 PropertyBase.PropertyMethod pm = TypeManager.GetMethod (setter) as PropertyBase.PropertyMethod;
3418                                 if (pm != null && pm.HasCustomAccessModifier) {
3419                                         Report.SymbolRelatedToPreviousError (pm);
3420                                         Report.Error (272, loc, "The property or indexer `{0}' cannot be used in this context because the set accessor is inaccessible",
3421                                                 TypeManager.CSharpSignature (setter));
3422                                 }
3423                                 else {
3424                                         Report.SymbolRelatedToPreviousError (setter);
3425                                         ErrorIsInaccesible (loc, TypeManager.CSharpSignature (setter));
3426                                 }
3427                                 return null;
3428                         }
3429
3430                         if (!InstanceResolve (ec, PropertyInfo.DeclaringType.IsValueType, must_do_cs1540_check))
3431                                 return null;
3432
3433                         //
3434                         // Only base will allow this invocation to happen.
3435                         //
3436                         if (IsBase && setter.IsAbstract){
3437                                 Error_CannotCallAbstractBase (TypeManager.GetFullNameSignature (PropertyInfo));
3438                                 return null;
3439                         }
3440
3441                         return this;
3442                 }
3443
3444                 public override void Emit (EmitContext ec)
3445                 {
3446                         Emit (ec, false);
3447                 }
3448
3449                 public void Emit (EmitContext ec, bool leave_copy)
3450                 {
3451                         //
3452                         // Special case: length of single dimension array property is turned into ldlen
3453                         //
3454                         if ((getter == TypeManager.system_int_array_get_length) ||
3455                             (getter == TypeManager.int_array_get_length)){
3456                                 Type iet = InstanceExpression.Type;
3457
3458                                 //
3459                                 // System.Array.Length can be called, but the Type does not
3460                                 // support invoking GetArrayRank, so test for that case first
3461                                 //
3462                                 if (iet != TypeManager.array_type && (iet.GetArrayRank () == 1)) {
3463                                         if (!prepared)
3464                                                 EmitInstance (ec, false);
3465                                         ec.ig.Emit (OpCodes.Ldlen);
3466                                         ec.ig.Emit (OpCodes.Conv_I4);
3467                                         return;
3468                                 }
3469                         }
3470
3471                         Invocation.EmitCall (ec, IsBase, IsStatic, InstanceExpression, getter, null, loc, prepared, false);
3472
3473                         if (leave_copy) {
3474                                 ec.ig.Emit (OpCodes.Dup);
3475                                 if (!is_static) {
3476                                         temp = new LocalTemporary (this.Type);
3477                                         temp.Store (ec);
3478                                 }
3479                         }
3480                 }
3481
3482                 //
3483                 // Implements the IAssignMethod interface for assignments
3484                 //
3485                 public void EmitAssign (EmitContext ec, Expression source, bool leave_copy, bool prepare_for_load)
3486                 {
3487                         Expression my_source = source;
3488
3489                         prepared = prepare_for_load;
3490
3491                         if (prepared) {
3492                                 source.Emit (ec);
3493                                 if (leave_copy) {
3494                                         ec.ig.Emit (OpCodes.Dup);
3495                                         if (!is_static) {
3496                                                 temp = new LocalTemporary (this.Type);
3497                                                 temp.Store (ec);
3498                                         }
3499                                 }
3500                         } else if (leave_copy) {
3501                                 source.Emit (ec);
3502                                 if (!is_static) {
3503                                         temp = new LocalTemporary (this.Type);
3504                                         temp.Store (ec);
3505                                 }
3506                                 my_source = temp;
3507                         }
3508
3509                         ArrayList args = new ArrayList (1);
3510                         args.Add (new Argument (my_source, Argument.AType.Expression));
3511
3512                         Invocation.EmitCall (ec, IsBase, IsStatic, InstanceExpression, setter, args, loc, false, prepared);
3513
3514                         if (temp != null)
3515                                 temp.Emit (ec);
3516                 }
3517         }
3518
3519         /// <summary>
3520         ///   Fully resolved expression that evaluates to an Event
3521         /// </summary>
3522         public class EventExpr : MemberExpr {
3523                 public readonly EventInfo EventInfo;
3524
3525                 bool is_static;
3526                 MethodInfo add_accessor, remove_accessor;
3527
3528                 public EventExpr (EventInfo ei, Location loc)
3529                 {
3530                         EventInfo = ei;
3531                         this.loc = loc;
3532                         eclass = ExprClass.EventAccess;
3533
3534                         add_accessor = TypeManager.GetAddMethod (ei);
3535                         remove_accessor = TypeManager.GetRemoveMethod (ei);
3536
3537                         if (add_accessor.IsStatic || remove_accessor.IsStatic)
3538                                 is_static = true;
3539
3540                         if (EventInfo is MyEventBuilder){
3541                                 MyEventBuilder eb = (MyEventBuilder) EventInfo;
3542                                 type = eb.EventType;
3543                                 eb.SetUsed ();
3544                         } else
3545                                 type = EventInfo.EventHandlerType;
3546                 }
3547
3548                 public override string Name {
3549                         get {
3550                                 return EventInfo.Name;
3551                         }
3552                 }
3553
3554                 public override bool IsInstance {
3555                         get {
3556                                 return !is_static;
3557                         }
3558                 }
3559
3560                 public override bool IsStatic {
3561                         get {
3562                                 return is_static;
3563                         }
3564                 }
3565
3566                 public override Type DeclaringType {
3567                         get {
3568                                 return EventInfo.DeclaringType;
3569                         }
3570                 }
3571
3572                 public override Expression ResolveMemberAccess (EmitContext ec, Expression left, Location loc,
3573                                                                 SimpleName original)
3574                 {
3575                         //
3576                         // If the event is local to this class, we transform ourselves into a FieldExpr
3577                         //
3578
3579                         if (EventInfo.DeclaringType == ec.ContainerType ||
3580                             TypeManager.IsNestedChildOf(ec.ContainerType, EventInfo.DeclaringType)) {
3581                                 MemberInfo mi = TypeManager.GetPrivateFieldOfEvent (EventInfo);
3582
3583                                 if (mi != null) {
3584                                         MemberExpr ml = (MemberExpr) ExprClassFromMemberInfo (ec.ContainerType, mi, loc);
3585
3586                                         if (ml == null) {
3587                                                 Report.Error (-200, loc, "Internal error!!");
3588                                                 return null;
3589                                         }
3590
3591                                         InstanceExpression = null;
3592
3593                                         return ml.ResolveMemberAccess (ec, left, loc, original);
3594                                 }
3595                         }
3596
3597                         return base.ResolveMemberAccess (ec, left, loc, original);
3598                 }
3599
3600
3601                 bool InstanceResolve (EmitContext ec, bool must_do_cs1540_check)
3602                 {
3603                         if (is_static) {
3604                                 InstanceExpression = null;
3605                                 return true;
3606                         }
3607
3608                         if (InstanceExpression == null) {
3609                                 SimpleName.Error_ObjectRefRequired (ec, loc, GetSignatureForError ());
3610                                 return false;
3611                         }
3612
3613                         InstanceExpression = InstanceExpression.DoResolve (ec);
3614                         if (InstanceExpression == null)
3615                                 return false;
3616
3617                         //
3618                         // This is using the same mechanism as the CS1540 check in PropertyExpr.
3619                         // However, in the Event case, we reported a CS0122 instead.
3620                         //
3621                         if (must_do_cs1540_check && InstanceExpression != EmptyExpression.Null &&
3622                             InstanceExpression.Type != ec.ContainerType &&
3623                             ec.ContainerType.IsSubclassOf (InstanceExpression.Type)) {
3624                                 Report.SymbolRelatedToPreviousError (EventInfo);
3625                                 ErrorIsInaccesible (loc, TypeManager.CSharpSignature (EventInfo));
3626                                 return false;
3627                         }
3628
3629                         return true;
3630                 }
3631
3632                 public override Expression DoResolveLValue (EmitContext ec, Expression right_side)
3633                 {
3634                         return DoResolve (ec);
3635                 }
3636
3637                 public override Expression DoResolve (EmitContext ec)
3638                 {
3639                         bool must_do_cs1540_check;
3640                         if (!(IsAccessorAccessible (ec.ContainerType, add_accessor, out must_do_cs1540_check) &&
3641                               IsAccessorAccessible (ec.ContainerType, remove_accessor, out must_do_cs1540_check))) {
3642                                 Report.SymbolRelatedToPreviousError (EventInfo);
3643                                 ErrorIsInaccesible (loc, TypeManager.CSharpSignature (EventInfo));
3644                                 return null;
3645                         }
3646
3647                         if (!InstanceResolve (ec, must_do_cs1540_check))
3648                                 return null;
3649
3650                         return this;
3651                 }
3652
3653                 public override void Emit (EmitContext ec)
3654                 {
3655                         if (InstanceExpression is This)
3656                                 Report.Error (79, loc, "The event `{0}' can only appear on the left hand side of += or -=", GetSignatureForError ());
3657                         else
3658                                 Report.Error (70, loc, "The event `{0}' can only appear on the left hand side of += or -= "+
3659                                               "(except on the defining type)", Name);
3660                 }
3661
3662                 public override string GetSignatureForError ()
3663                 {
3664                         return TypeManager.CSharpSignature (EventInfo);
3665                 }
3666
3667                 public void EmitAddOrRemove (EmitContext ec, Expression source)
3668                 {
3669                         BinaryDelegate source_del = (BinaryDelegate) source;
3670                         Expression handler = source_del.Right;
3671
3672                         Argument arg = new Argument (handler, Argument.AType.Expression);
3673                         ArrayList args = new ArrayList ();
3674
3675                         args.Add (arg);
3676
3677                         if (source_del.IsAddition)
3678                                 Invocation.EmitCall (
3679                                         ec, false, IsStatic, InstanceExpression, add_accessor, args, loc);
3680                         else
3681                                 Invocation.EmitCall (
3682                                         ec, false, IsStatic, InstanceExpression, remove_accessor, args, loc);
3683                 }
3684         }
3685
3686
3687         public class TemporaryVariable : Expression, IMemoryLocation
3688         {
3689                 LocalInfo li;
3690
3691                 public TemporaryVariable (Type type, Location loc)
3692                 {
3693                         this.type = type;
3694                         this.loc = loc;
3695                         eclass = ExprClass.Value;
3696                 }
3697
3698                 public override Expression DoResolve (EmitContext ec)
3699                 {
3700                         if (li != null)
3701                                 return this;
3702
3703                         TypeExpr te = new TypeExpression (type, loc);
3704                         li = ec.CurrentBlock.AddTemporaryVariable (te, loc);
3705                         if (!li.Resolve (ec))
3706                                 return null;
3707
3708                         AnonymousContainer am = ec.CurrentAnonymousMethod;
3709                         if ((am != null) && am.IsIterator)
3710                                 ec.CaptureVariable (li);
3711
3712                         return this;
3713                 }
3714
3715                 public override void Emit (EmitContext ec)
3716                 {
3717                         ILGenerator ig = ec.ig;
3718
3719                         if (li.FieldBuilder != null) {
3720                                 ig.Emit (OpCodes.Ldarg_0);
3721                                 ig.Emit (OpCodes.Ldfld, li.FieldBuilder);
3722                         } else {
3723                                 ig.Emit (OpCodes.Ldloc, li.LocalBuilder);
3724                         }
3725                 }
3726
3727                 public void EmitLoadAddress (EmitContext ec)
3728                 {
3729                         ILGenerator ig = ec.ig;
3730
3731                         if (li.FieldBuilder != null) {
3732                                 ig.Emit (OpCodes.Ldarg_0);
3733                                 ig.Emit (OpCodes.Ldflda, li.FieldBuilder);
3734                         } else {
3735                                 ig.Emit (OpCodes.Ldloca, li.LocalBuilder);
3736                         }
3737                 }
3738
3739                 public void Store (EmitContext ec, Expression right_side)
3740                 {
3741                         if (li.FieldBuilder != null)
3742                                 ec.ig.Emit (OpCodes.Ldarg_0);
3743
3744                         right_side.Emit (ec);
3745                         if (li.FieldBuilder != null) {
3746                                 ec.ig.Emit (OpCodes.Stfld, li.FieldBuilder);
3747                         } else {
3748                                 ec.ig.Emit (OpCodes.Stloc, li.LocalBuilder);
3749                         }
3750                 }
3751
3752                 public void EmitThis (EmitContext ec)
3753                 {
3754                         if (li.FieldBuilder != null) {
3755                                 ec.ig.Emit (OpCodes.Ldarg_0);
3756                         }
3757                 }
3758
3759                 public void EmitStore (ILGenerator ig)
3760                 {
3761                         if (li.FieldBuilder != null)
3762                                 ig.Emit (OpCodes.Stfld, li.FieldBuilder);
3763                         else
3764                                 ig.Emit (OpCodes.Stloc, li.LocalBuilder);
3765                 }
3766
3767                 public void AddressOf (EmitContext ec, AddressOp mode)
3768                 {
3769                         EmitLoadAddress (ec);
3770                 }
3771         }
3772
3773 }