mcs/gmcs/ecore.cs

   1 //
   2 // ecore.cs: Core of the Expression representation for the intermediate tree.
   3 //
   4 // Author:
   5 //   Miguel de Icaza (miguel@ximian.com)
   6 //
   7 // (C) 2001, 2002, 2003 Ximian, Inc.
   8 //
   9 //
  10
  11 namespace Mono.CSharp {
  12         using System;
  13         using System.Collections;
  14         using System.Diagnostics;
  15         using System.Reflection;
  16         using System.Reflection.Emit;
  17         using System.Text;
  18
  19         /// <remarks>
  20         ///   The ExprClass class contains the is used to pass the
  21         ///   classification of an expression (value, variable, namespace,
  22         ///   type, method group, property access, event access, indexer access,
  23         ///   nothing).
  24         /// </remarks>
  25         public enum ExprClass : byte {
  26                 Invalid,
  27
  28                 Value,
  29                 Variable,
  30                 Namespace,
  31                 Type,
  32                 MethodGroup,
  33                 PropertyAccess,
  34                 EventAccess,
  35                 IndexerAccess,
  36                 Nothing,
  37         }
  38
  39         /// <remarks>
  40         ///   This is used to tell Resolve in which types of expressions we're
  41         ///   interested.
  42         /// </remarks>
  43         [Flags]
  44         public enum ResolveFlags {
  45                 // Returns Value, Variable, PropertyAccess, EventAccess or IndexerAccess.
  46                 VariableOrValue         = 1,
  47
  48                 // Returns a type expression.
  49                 Type                    = 2,
  50
  51                 // Returns a method group.
  52                 MethodGroup             = 4,
  53
  54                 // Mask of all the expression class flags.
  55                 MaskExprClass           = 7,
  56
  57                 // Disable control flow analysis while resolving the expression.
  58                 // This is used when resolving the instance expression of a field expression.
  59                 DisableFlowAnalysis     = 8,
  60
  61                 // Set if this is resolving the first part of a MemberAccess.
  62                 Intermediate            = 16,
  63
  64                 // Disable control flow analysis _of struct_ while resolving the expression.
  65                 // This is used when resolving the instance expression of a field expression.
  66                 DisableStructFlowAnalysis       = 32,
  67
  68         }
  69
  70         //
  71         // This is just as a hint to AddressOf of what will be done with the
  72         // address.
  73         [Flags]
  74         public enum AddressOp {
  75                 Store = 1,
  76                 Load  = 2,
  77                 LoadStore = 3
  78         };
  79
  80         /// <summary>
  81         ///   This interface is implemented by variables
  82         /// </summary>
  83         public interface IMemoryLocation {
  84                 /// <summary>
  85                 ///   The AddressOf method should generate code that loads
  86                 ///   the address of the object and leaves it on the stack.
  87                 ///
  88                 ///   The `mode' argument is used to notify the expression
  89                 ///   of whether this will be used to read from the address or
  90                 ///   write to the address.
  91                 ///
  92                 ///   This is just a hint that can be used to provide good error
  93                 ///   reporting, and should have no other side effects.
  94                 /// </summary>
  95                 void AddressOf (EmitContext ec, AddressOp mode);
  96         }
  97
  98         /// <summary>
  99         ///   This interface is implemented by variables
 100         /// </summary>
 101         public interface IVariable {
 102                 VariableInfo VariableInfo {
 103                         get;
 104                 }
 105
 106                 bool VerifyFixed ();
 107         }
 108
 109         /// <remarks>
 110         ///   Base class for expressions
 111         /// </remarks>
 112         public abstract class Expression {
 113                 public ExprClass eclass;
 114                 protected Type type;
 115                 protected Location loc;
 116
 117                 public Type Type {
 118                         get { return type; }
 119                         set { type = value; }
 120                 }
 121
 122                 public virtual Location Location {
 123                         get { return loc; }
 124                 }
 125
 126                 /// <summary>
 127                 ///   Utility wrapper routine for Error, just to beautify the code
 128                 /// </summary>
 129                 public void Error (int error, string s)
 130                 {
 131                         if (loc.IsNull)
 132                                 Report.Error (error, s);
 133                         else
 134                                 Report.Error (error, loc, s);
 135                 }
 136
 137                 // Not nice but we have broken hierarchy
 138                 public virtual void CheckMarshallByRefAccess (Type container) {}
 139
 140                 public virtual string GetSignatureForError ()
 141                 {
 142                         return TypeManager.CSharpName (type);
 143                 }
 144
 145                 public static bool IsAccessorAccessible (Type invocation_type, MethodInfo mi, out bool must_do_cs1540_check)
 146                 {
 147                         MethodAttributes ma = mi.Attributes & MethodAttributes.MemberAccessMask;
 148
 149                         must_do_cs1540_check = false; // by default we do not check for this
 150
 151                         if (ma == MethodAttributes.Public)
 152                                 return true;
 153
 154                         //
 155                         // If only accessible to the current class or children
 156                         //
 157                         if (ma == MethodAttributes.Private)
 158                                 return TypeManager.IsPrivateAccessible (invocation_type, mi.DeclaringType) ||
 159                                         TypeManager.IsNestedChildOf (invocation_type, mi.DeclaringType);
 160
 161                         if (mi.DeclaringType.Assembly == invocation_type.Assembly ||
 162                                         TypeManager.IsFriendAssembly (mi.DeclaringType.Assembly)) {
 163                                 if (ma == MethodAttributes.Assembly || ma == MethodAttributes.FamORAssem)
 164                                         return true;
 165                         } else {
 166                                 if (ma == MethodAttributes.Assembly || ma == MethodAttributes.FamANDAssem)
 167                                         return false;
 168                         }
 169
 170                         // Family and FamANDAssem require that we derive.
 171                         // FamORAssem requires that we derive if in different assemblies.
 172                         if (!TypeManager.IsNestedFamilyAccessible (invocation_type, mi.DeclaringType))
 173                                 return false;
 174
 175                         if (!TypeManager.IsNestedChildOf (invocation_type, mi.DeclaringType))
 176                                 must_do_cs1540_check = true;
 177
 178                         return true;
 179                 }
 180
 181                 /// <summary>
 182                 ///   Performs semantic analysis on the Expression
 183                 /// </summary>
 184                 ///
 185                 /// <remarks>
 186                 ///   The Resolve method is invoked to perform the semantic analysis
 187                 ///   on the node.
 188                 ///
 189                 ///   The return value is an expression (it can be the
 190                 ///   same expression in some cases) or a new
 191                 ///   expression that better represents this node.
 192                 ///
 193                 ///   For example, optimizations of Unary (LiteralInt)
 194                 ///   would return a new LiteralInt with a negated
 195                 ///   value.
 196                 ///
 197                 ///   If there is an error during semantic analysis,
 198                 ///   then an error should be reported (using Report)
 199                 ///   and a null value should be returned.
 200                 ///
 201                 ///   There are two side effects expected from calling
 202                 ///   Resolve(): the the field variable "eclass" should
 203                 ///   be set to any value of the enumeration
 204                 ///   `ExprClass' and the type variable should be set
 205                 ///   to a valid type (this is the type of the
 206                 ///   expression).
 207                 /// </remarks>
 208                 public abstract Expression DoResolve (EmitContext ec);
 209
 210                 public virtual Expression DoResolveLValue (EmitContext ec, Expression right_side)
 211                 {
 212                         return null;
 213                 }
 214
 215                 //
 216                 // This is used if the expression should be resolved as a type or namespace name.
 217                 // the default implementation fails.
 218                 //
 219                 public FullNamedExpression ResolveAsTypeStep (EmitContext ec)
 220                 {
 221                         return ResolveAsTypeStep (ec, false);
 222                 }
 223
 224                 public virtual FullNamedExpression ResolveAsTypeStep (EmitContext ec,  bool silent)
 225                 {
 226                         return null;
 227                 }
 228
 229                 //
 230                 // This is used to resolve the expression as a type, a null
 231                 // value will be returned if the expression is not a type
 232                 // reference
 233                 //
 234                 public TypeExpr ResolveAsTypeTerminal (EmitContext ec)
 235                 {
 236                         return ResolveAsTypeTerminal (ec, false);
 237                 }
 238
 239                 public virtual TypeExpr ResolveAsTypeTerminal (EmitContext ec, bool silent)
 240                 {
 241                         int errors = Report.Errors;
 242
 243                         FullNamedExpression fne = ResolveAsTypeStep (ec, silent);
 244
 245                         if (fne == null)
 246                                 return null;
 247
 248                         if (fne.eclass != ExprClass.Type) {
 249                                 if (!silent && (errors == Report.Errors))
 250                                         fne.Error_UnexpectedKind (null, "type", loc);
 251                                 return null;
 252                         }
 253
 254                         TypeExpr te = fne as TypeExpr;
 255
 256                         if (!te.CheckAccessLevel (ec.DeclSpace)) {
 257                                 ErrorIsInaccesible (loc, TypeManager.CSharpName (te.Type));
 258                                 return null;
 259                         }
 260
 261                         ConstructedType ct = te as ConstructedType;
 262                         if ((ct != null) && !ec.ResolvingTypeTree && !ec.ResolvingGenericMethod &&
 263                             !ct.CheckConstraints (ec))
 264                                 return null;
 265
 266                         te.loc = loc;
 267                         return te;
 268                 }
 269
 270                 public static void ErrorIsInaccesible (Location loc, string name)
 271                 {
 272                         Report.Error (122, loc, "`{0}' is inaccessible due to its protection level", name);
 273                 }
 274
 275                 protected static void Error_CannotAccessProtected (Location loc, MemberInfo m, Type qualifier, Type container)
 276                 {
 277                         Report.Error (1540, loc, "Cannot access protected member `{0}' via a qualifier of type `{1}';"
 278                                 + " the qualifier must be of type `{2}' (or derived from it)",
 279                                 TypeManager.GetFullNameSignature (m),
 280                                 TypeManager.CSharpName (qualifier),
 281                                 TypeManager.CSharpName (container));
 282
 283                 }
 284
 285                 public virtual void Error_ValueCannotBeConverted (Location loc, Type target, bool expl)
 286                 {
 287                         if (Type.Name == target.Name){
 288                                 Report.ExtraInformation (loc,
 289                                         String.Format (
 290                                         "The type {0} has two conflicting definitions, one comes from {1} and the other from {2}",
 291                                         Type.Name, Type.Assembly.FullName, target.Assembly.FullName));
 292
 293                         }
 294
 295                         if (expl) {
 296                                 Report.Error (30, loc, "Cannot convert type `{0}' to `{1}'",
 297                                         GetSignatureForError (), TypeManager.CSharpName (target));
 298                                 return;
 299                         }
 300
 301                         Expression e = (this is EnumConstant) ? ((EnumConstant)this).Child : this;
 302                         bool b = Convert.ExplicitNumericConversion (e, target) != null;
 303
 304                         if (b || Convert.ExplicitReferenceConversionExists (Type, target) || Convert.ExplicitUnsafe (e, target) != null) {
 305                                 Report.Error (266, loc, "Cannot implicitly convert type `{0}' to `{1}'. An explicit conversion exists (are you missing a cast?)",
 306                                         TypeManager.CSharpName (Type), TypeManager.CSharpName (target));
 307                                 return;
 308                         }
 309
 310                         if (Type != TypeManager.string_type && this is Constant && !(this is NullCast)) {
 311                                 Report.Error (31, loc, "Constant value `{0}' cannot be converted to a `{1}'",
 312                                         GetSignatureForError (), TypeManager.CSharpName (target));
 313                                 return;
 314                         }
 315
 316                         Report.Error (29, loc, "Cannot implicitly convert type {0} to `{1}'",
 317                                 Type == TypeManager.anonymous_method_type ?
 318                                 "anonymous method" : "`" + GetSignatureForError () + "'",
 319                                 TypeManager.CSharpName (target));
 320                 }
 321
 322                 protected static void Error_TypeDoesNotContainDefinition (Location loc, Type type, string name)
 323                 {
 324                         Report.Error (117, loc, "`{0}' does not contain a definition for `{1}'",
 325                                 TypeManager.CSharpName (type), name);
 326                 }
 327
 328                 ResolveFlags ExprClassToResolveFlags ()
 329                 {
 330                         switch (eclass) {
 331                         case ExprClass.Type:
 332                         case ExprClass.Namespace:
 333                                 return ResolveFlags.Type;
 334
 335                         case ExprClass.MethodGroup:
 336                                 return ResolveFlags.MethodGroup;
 337
 338                         case ExprClass.Value:
 339                         case ExprClass.Variable:
 340                         case ExprClass.PropertyAccess:
 341                         case ExprClass.EventAccess:
 342                         case ExprClass.IndexerAccess:
 343                                 return ResolveFlags.VariableOrValue;
 344
 345                         default:
 346                                 throw new Exception ("Expression " + GetType () +
 347                                                      " ExprClass is Invalid after resolve");
 348                         }
 349
 350                 }
 351
 352                 /// <summary>
 353                 ///   Resolves an expression and performs semantic analysis on it.
 354                 /// </summary>
 355                 ///
 356                 /// <remarks>
 357                 ///   Currently Resolve wraps DoResolve to perform sanity
 358                 ///   checking and assertion checking on what we expect from Resolve.
 359                 /// </remarks>
 360                 public Expression Resolve (EmitContext ec, ResolveFlags flags)
 361                 {
 362                         if ((flags & ResolveFlags.MaskExprClass) == ResolveFlags.Type)
 363                                 return ResolveAsTypeStep (ec, false);
 364
 365                         bool old_do_flow_analysis = ec.DoFlowAnalysis;
 366                         bool old_omit_struct_analysis = ec.OmitStructFlowAnalysis;
 367                         if ((flags & ResolveFlags.DisableFlowAnalysis) != 0)
 368                                 ec.DoFlowAnalysis = false;
 369                         if ((flags & ResolveFlags.DisableStructFlowAnalysis) != 0)
 370                                 ec.OmitStructFlowAnalysis = true;
 371
 372                         Expression e;
 373                         bool intermediate = (flags & ResolveFlags.Intermediate) == ResolveFlags.Intermediate;
 374                         if (this is SimpleName)
 375                                 e = ((SimpleName) this).DoResolve (ec, intermediate);
 376
 377                         else
 378                                 e = DoResolve (ec);
 379
 380                         ec.DoFlowAnalysis = old_do_flow_analysis;
 381                         ec.OmitStructFlowAnalysis = old_omit_struct_analysis;
 382
 383                         if (e == null)
 384                                 return null;
 385
 386                         if ((flags & e.ExprClassToResolveFlags ()) == 0) {
 387                                 e.Error_UnexpectedKind (flags, loc);
 388                                 return null;
 389                         }
 390
 391                         if (e.type == null && !(e is Namespace)) {
 392                                 throw new Exception (
 393                                         "Expression " + e.GetType () +
 394                                         " did not set its type after Resolve\n" +
 395                                         "called from: " + this.GetType ());
 396                         }
 397
 398                         return e;
 399                 }
 400
 401                 /// <summary>
 402                 ///   Resolves an expression and performs semantic analysis on it.
 403                 /// </summary>
 404                 public Expression Resolve (EmitContext ec)
 405                 {
 406                         Expression e = Resolve (ec, ResolveFlags.VariableOrValue | ResolveFlags.MethodGroup);
 407
 408                         if (e != null && e.eclass == ExprClass.MethodGroup && RootContext.Version == LanguageVersion.ISO_1) {
 409                                 ((MethodGroupExpr) e).ReportUsageError ();
 410                                 return null;
 411                         }
 412                         return e;
 413                 }
 414
 415                 public Constant ResolveAsConstant (EmitContext ec, MemberCore mc)
 416                 {
 417                         Expression e = Resolve (ec);
 418                         if (e != null) {
 419                                 Constant c = e as Constant;
 420                                 if (c != null)
 421                                         return c;
 422
 423                                 EmptyCast empty = e as EmptyCast;
 424                                 if (empty != null) {
 425                                         c = empty.Child as Constant;
 426                                         if (c != null) {
 427                                                 // TODO: not sure about this maybe there is easier way how to use EmptyCast
 428                                                 if (e.Type.IsEnum)
 429                                                         c.Type = e.Type;
 430
 431                                                 return c;
 432                                         }
 433                                 }
 434                         }
 435
 436                         Const.Error_ExpressionMustBeConstant (loc, mc.GetSignatureForError ());
 437                         return null;
 438                 }
 439
 440                 /// <summary>
 441                 ///   Resolves an expression for LValue assignment
 442                 /// </summary>
 443                 ///
 444                 /// <remarks>
 445                 ///   Currently ResolveLValue wraps DoResolveLValue to perform sanity
 446                 ///   checking and assertion checking on what we expect from Resolve
 447                 /// </remarks>
 448                 public Expression ResolveLValue (EmitContext ec, Expression right_side, Location loc)
 449                 {
 450                         int errors = Report.Errors;
 451                         Expression e = DoResolveLValue (ec, right_side);
 452
 453                         if (e == null) {
 454                                 if (errors == Report.Errors)
 455                                         Report.Error (131, loc, "The left-hand side of an assignment or mutating operation must be a variable, property or indexer");
 456                                 return null;
 457                         }
 458
 459                         if (e != null){
 460                                 if (e.eclass == ExprClass.Invalid)
 461                                         throw new Exception ("Expression " + e +
 462                                                              " ExprClass is Invalid after resolve");
 463
 464                                 if (e.eclass == ExprClass.MethodGroup) {
 465                                         ((MethodGroupExpr) e).ReportUsageError ();
 466                                         return null;
 467                                 }
 468
 469                                 if ((e.type == null) && !(e is ConstructedType))
 470                                         throw new Exception ("Expression " + e +
 471                                                              " did not set its type after Resolve");
 472                         }
 473
 474                         return e;
 475                 }
 476
 477                 /// <summary>
 478                 ///   Emits the code for the expression
 479                 /// </summary>
 480                 ///
 481                 /// <remarks>
 482                 ///   The Emit method is invoked to generate the code
 483                 ///   for the expression.
 484                 /// </remarks>
 485                 public abstract void Emit (EmitContext ec);
 486
 487                 public virtual void EmitBranchable (EmitContext ec, Label target, bool onTrue)
 488                 {
 489                         Emit (ec);
 490                         ec.ig.Emit (onTrue ? OpCodes.Brtrue : OpCodes.Brfalse, target);
 491                 }
 492
 493                 /// <summary>
 494                 ///   Protected constructor.  Only derivate types should
 495                 ///   be able to be created
 496                 /// </summary>
 497
 498                 protected Expression ()
 499                 {
 500                         eclass = ExprClass.Invalid;
 501                         type = null;
 502                 }
 503
 504                 /// <summary>
 505                 ///   Returns a literalized version of a literal FieldInfo
 506                 /// </summary>
 507                 ///
 508                 /// <remarks>
 509                 ///   The possible return values are:
 510                 ///      IntConstant, UIntConstant
 511                 ///      LongLiteral, ULongConstant
 512                 ///      FloatConstant, DoubleConstant
 513                 ///      StringConstant
 514                 ///
 515                 ///   The value returned is already resolved.
 516                 /// </remarks>
 517                 public static Constant Constantify (object v, Type t)
 518                 {
 519                         if (t == TypeManager.int32_type)
 520                                 return new IntConstant ((int) v, Location.Null);
 521                         else if (t == TypeManager.uint32_type)
 522                                 return new UIntConstant ((uint) v, Location.Null);
 523                         else if (t == TypeManager.int64_type)
 524                                 return new LongConstant ((long) v, Location.Null);
 525                         else if (t == TypeManager.uint64_type)
 526                                 return new ULongConstant ((ulong) v, Location.Null);
 527                         else if (t == TypeManager.float_type)
 528                                 return new FloatConstant ((float) v, Location.Null);
 529                         else if (t == TypeManager.double_type)
 530                                 return new DoubleConstant ((double) v, Location.Null);
 531                         else if (t == TypeManager.string_type)
 532                                 return new StringConstant ((string) v, Location.Null);
 533                         else if (t == TypeManager.short_type)
 534                                 return new ShortConstant ((short)v, Location.Null);
 535                         else if (t == TypeManager.ushort_type)
 536                                 return new UShortConstant ((ushort)v, Location.Null);
 537                         else if (t == TypeManager.sbyte_type)
 538                                 return new SByteConstant ((sbyte)v, Location.Null);
 539                         else if (t == TypeManager.byte_type)
 540                                 return new ByteConstant ((byte)v, Location.Null);
 541                         else if (t == TypeManager.char_type)
 542                                 return new CharConstant ((char)v, Location.Null);
 543                         else if (t == TypeManager.bool_type)
 544                                 return new BoolConstant ((bool) v, Location.Null);
 545                         else if (t == TypeManager.decimal_type)
 546                                 return new DecimalConstant ((decimal) v, Location.Null);
 547                         else if (TypeManager.IsEnumType (t)){
 548                                 Type real_type = TypeManager.TypeToCoreType (v.GetType ());
 549                                 if (real_type == t)
 550                                         real_type = System.Enum.GetUnderlyingType (real_type);
 551
 552                                 Constant e = Constantify (v, real_type);
 553
 554                                 return new EnumConstant (e, t);
 555                         } else if (v == null && !TypeManager.IsValueType (t))
 556                                 return new NullLiteral (Location.Null);
 557                         else
 558                                 throw new Exception ("Unknown type for constant (" + t +
 559                                                      "), details: " + v);
 560                 }
 561
 562                 /// <summary>
 563                 ///   Returns a fully formed expression after a MemberLookup
 564                 /// </summary>
 565                 ///
 566                 public static Expression ExprClassFromMemberInfo (EmitContext ec, MemberInfo mi, Location loc)
 567                 {
 568                         if (mi is EventInfo)
 569                                 return new EventExpr ((EventInfo) mi, loc);
 570                         else if (mi is FieldInfo)
 571                                 return new FieldExpr ((FieldInfo) mi, loc);
 572                         else if (mi is PropertyInfo)
 573                                 return new PropertyExpr (ec, (PropertyInfo) mi, loc);
 574                         else if (mi is Type){
 575                                 return new TypeExpression ((System.Type) mi, loc);
 576                         }
 577
 578                         return null;
 579                 }
 580
 581                 protected static ArrayList almostMatchedMembers = new ArrayList (4);
 582
 583                 //
 584                 // FIXME: Probably implement a cache for (t,name,current_access_set)?
 585                 //
 586                 // This code could use some optimizations, but we need to do some
 587                 // measurements.  For example, we could use a delegate to `flag' when
 588                 // something can not any longer be a method-group (because it is something
 589                 // else).
 590                 //
 591                 // Return values:
 592                 //     If the return value is an Array, then it is an array of
 593                 //     MethodBases
 594                 //
 595                 //     If the return value is an MemberInfo, it is anything, but a Method
 596                 //
 597                 //     null on error.
 598                 //
 599                 // FIXME: When calling MemberLookup inside an `Invocation', we should pass
 600                 // the arguments here and have MemberLookup return only the methods that
 601                 // match the argument count/type, unlike we are doing now (we delay this
 602                 // decision).
 603                 //
 604                 // This is so we can catch correctly attempts to invoke instance methods
 605                 // from a static body (scan for error 120 in ResolveSimpleName).
 606                 //
 607                 //
 608                 // FIXME: Potential optimization, have a static ArrayList
 609                 //
 610
 611                 public static Expression MemberLookup (EmitContext ec, Type queried_type, string name,
 612                                                        MemberTypes mt, BindingFlags bf, Location loc)
 613                 {
 614                         return MemberLookup (ec, ec.ContainerType, null, queried_type, name, mt, bf, loc);
 615                 }
 616
 617                 //
 618                 // Lookup type `queried_type' for code in class `container_type' with a qualifier of
 619                 // `qualifier_type' or null to lookup members in the current class.
 620                 //
 621
 622                 public static Expression MemberLookup (EmitContext ec, Type container_type,
 623                                                        Type qualifier_type, Type queried_type,
 624                                                        string name, MemberTypes mt,
 625                                                        BindingFlags bf, Location loc)
 626                 {
 627                         almostMatchedMembers.Clear ();
 628
 629                         MemberInfo [] mi = TypeManager.MemberLookup (
 630                                 container_type, qualifier_type, queried_type, mt, bf, name,
 631                                 almostMatchedMembers);
 632
 633                         if (mi == null)
 634                                 return null;
 635
 636                         int count = mi.Length;
 637
 638                         if (mi [0] is MethodBase)
 639                                 return new MethodGroupExpr (mi, loc);
 640
 641                         if (count > 1)
 642                                 return null;
 643
 644                         return ExprClassFromMemberInfo (ec, mi [0], loc);
 645                 }
 646
 647                 public const MemberTypes AllMemberTypes =
 648                         MemberTypes.Constructor |
 649                         MemberTypes.Event       |
 650                         MemberTypes.Field       |
 651                         MemberTypes.Method      |
 652                         MemberTypes.NestedType  |
 653                         MemberTypes.Property;
 654
 655                 public const BindingFlags AllBindingFlags =
 656                         BindingFlags.Public |
 657                         BindingFlags.Static |
 658                         BindingFlags.Instance;
 659
 660                 public static Expression MemberLookup (EmitContext ec, Type queried_type,
 661                                                        string name, Location loc)
 662                 {
 663                         return MemberLookup (ec, ec.ContainerType, null, queried_type, name,
 664                                              AllMemberTypes, AllBindingFlags, loc);
 665                 }
 666
 667                 public static Expression MemberLookup (EmitContext ec, Type qualifier_type,
 668                                                        Type queried_type, string name, Location loc)
 669                 {
 670                         if (ec.ResolvingTypeTree)
 671                                 return MemberLookup (ec, ec.ContainerType, qualifier_type,
 672                                                      queried_type, name, MemberTypes.NestedType,
 673                                                      AllBindingFlags, loc);
 674                         else
 675                                 return MemberLookup (ec, ec.ContainerType, qualifier_type,
 676                                                      queried_type, name, AllMemberTypes,
 677                                                      AllBindingFlags, loc);
 678                 }
 679
 680                 public static Expression MethodLookup (EmitContext ec, Type queried_type,
 681                                                        string name, Location loc)
 682                 {
 683                         return MemberLookup (ec, ec.ContainerType, null, queried_type, name,
 684                                              MemberTypes.Method, AllBindingFlags, loc);
 685                 }
 686
 687                 /// <summary>
 688                 ///   This is a wrapper for MemberLookup that is not used to "probe", but
 689                 ///   to find a final definition.  If the final definition is not found, we
 690                 ///   look for private members and display a useful debugging message if we
 691                 ///   find it.
 692                 /// </summary>
 693                 public static Expression MemberLookupFinal (EmitContext ec, Type qualifier_type,
 694                                                             Type queried_type, string name,
 695                                                             Location loc)
 696                 {
 697                         return MemberLookupFinal (ec, qualifier_type, queried_type, name,
 698                                                   AllMemberTypes, AllBindingFlags, loc);
 699                 }
 700
 701                 public static Expression MemberLookupFinal (EmitContext ec, Type qualifier_type,
 702                                                             Type queried_type, string name,
 703                                                             MemberTypes mt, BindingFlags bf,
 704                                                             Location loc)
 705                 {
 706                         Expression e;
 707
 708                         int errors = Report.Errors;
 709
 710                         e = MemberLookup (ec, ec.ContainerType, qualifier_type, queried_type,
 711                                           name, mt, bf, loc);
 712
 713                         if (e == null && errors == Report.Errors)
 714                                 // No errors were reported by MemberLookup, but there was an error.
 715                                 MemberLookupFailed (ec, qualifier_type, queried_type, name, null, true, loc);
 716
 717                         return e;
 718                 }
 719
 720                 public static void MemberLookupFailed (EmitContext ec, Type qualifier_type,
 721                                                        Type queried_type, string name,
 722                                                        string class_name, bool complain_if_none_found,
 723                                                        Location loc)
 724                 {
 725                         if (almostMatchedMembers.Count != 0) {
 726                                 for (int i = 0; i < almostMatchedMembers.Count; ++i) {
 727                                         MemberInfo m = (MemberInfo) almostMatchedMembers [i];
 728                                         for (int j = 0; j < i; ++j) {
 729                                                 if (m == almostMatchedMembers [j]) {
 730                                                         m = null;
 731                                                         break;
 732                                                 }
 733                                         }
 734                                         if (m == null)
 735                                                 continue;
 736
 737                                         Type declaring_type = m.DeclaringType;
 738
 739                                         Report.SymbolRelatedToPreviousError (m);
 740                                         if (qualifier_type == null) {
 741                                                 Report.Error (38, loc, "Cannot access a nonstatic member of outer type `{0}' via nested type `{1}'",
 742                                                               TypeManager.CSharpName (m.DeclaringType),
 743                                                               TypeManager.CSharpName (ec.ContainerType));
 744                                         } else if (qualifier_type != ec.ContainerType &&
 745                                                    TypeManager.IsNestedFamilyAccessible (ec.ContainerType, declaring_type)) {
 746                                                 // Although a derived class can access protected members of
 747                                                 // its base class it cannot do so through an instance of the
 748                                                 // base class (CS1540).  If the qualifier_type is a base of the
 749                                                 // ec.ContainerType and the lookup succeeds with the latter one,
 750                                                 // then we are in this situation.
 751                                                 Error_CannotAccessProtected (loc, m, qualifier_type, ec.ContainerType);
 752                                         } else {
 753                                                 ErrorIsInaccesible (loc, TypeManager.GetFullNameSignature (m));
 754                                         }
 755                                 }
 756                                 almostMatchedMembers.Clear ();
 757                                 return;
 758                         }
 759
 760                         MemberInfo[] lookup = TypeManager.MemberLookup (queried_type, null, queried_type,
 761                                                                         AllMemberTypes, AllBindingFlags |
 762                                                                         BindingFlags.NonPublic, name, null);
 763
 764                         if (lookup == null) {
 765                                 if (!complain_if_none_found)
 766                                         return;
 767
 768                                 if (class_name != null)
 769                                         Report.Error (103, loc, "The name `{0}' does not exist in the context of `{1}'",
 770                                                 name, class_name);
 771                                 else
 772                                         Error_TypeDoesNotContainDefinition (loc, queried_type, name);
 773                                 return;
 774                         }
 775
 776                         if (TypeManager.MemberLookup (queried_type, null, queried_type,
 777                                                       AllMemberTypes, AllBindingFlags |
 778                                                       BindingFlags.NonPublic, name, null) == null) {
 779                                 if ((lookup.Length == 1) && (lookup [0] is Type)) {
 780                                         Type t = (Type) lookup [0];
 781
 782                                         Report.Error (305, loc,
 783                                                       "Using the generic type `{0}' " +
 784                                                       "requires {1} type arguments",
 785                                                       TypeManager.CSharpName (t),
 786                                                       TypeManager.GetNumberOfTypeArguments (t).ToString ());
 787                                         return;
 788                                 }
 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, String.Format ("The type `{0}' has no constructors defined", TypeManager.CSharpName (queried_type)));
 796                                 return;
 797                         }
 798
 799                         ErrorIsInaccesible (loc, TypeManager.GetFullNameSignature (lookup [0]));
 800                 }
 801
 802                 /// <summary>
 803                 ///   Returns an expression that can be used to invoke operator true
 804                 ///   on the expression if it exists.
 805                 /// </summary>
 806                 static public Expression GetOperatorTrue (EmitContext ec, Expression e, Location loc)
 807                 {
 808                         return GetOperatorTrueOrFalse (ec, e, true, loc);
 809                 }
 810
 811                 /// <summary>
 812                 ///   Returns an expression that can be used to invoke operator false
 813                 ///   on the expression if it exists.
 814                 /// </summary>
 815                 static public Expression GetOperatorFalse (EmitContext ec, Expression e, Location loc)
 816                 {
 817                         return GetOperatorTrueOrFalse (ec, e, false, loc);
 818                 }
 819
 820                 static Expression GetOperatorTrueOrFalse (EmitContext ec, Expression e, bool is_true, Location loc)
 821                 {
 822                         MethodBase method;
 823                         Expression operator_group;
 824
 825                         if (TypeManager.IsNullableType (e.Type))
 826                                 return new Nullable.OperatorTrueOrFalse (e, is_true, loc).Resolve (ec);
 827
 828                         operator_group = MethodLookup (ec, e.Type, is_true ? "op_True" : "op_False", loc);
 829                         if (operator_group == null)
 830                                 return null;
 831
 832                         ArrayList arguments = new ArrayList ();
 833                         arguments.Add (new Argument (e, Argument.AType.Expression));
 834                         method = Invocation.OverloadResolve (
 835                                 ec, (MethodGroupExpr) operator_group, arguments, false, loc);
 836
 837                         if (method == null)
 838                                 return null;
 839
 840                         return new StaticCallExpr ((MethodInfo) method, arguments, loc);
 841                 }
 842
 843                 /// <summary>
 844                 ///   Resolves the expression `e' into a boolean expression: either through
 845                 ///   an implicit conversion, or through an `operator true' invocation
 846                 /// </summary>
 847                 public static Expression ResolveBoolean (EmitContext ec, Expression e, Location loc)
 848                 {
 849                         e = e.Resolve (ec);
 850                         if (e == null)
 851                                 return null;
 852
 853                         if (e.Type == TypeManager.bool_type)
 854                                 return e;
 855
 856                         Expression converted = Convert.ImplicitConversion (ec, e, TypeManager.bool_type, Location.Null);
 857
 858                         if (converted != null)
 859                                 return converted;
 860
 861                         //
 862                         // If no implicit conversion to bool exists, try using `operator true'
 863                         //
 864                         converted = Expression.GetOperatorTrue (ec, e, loc);
 865                         if (converted == null){
 866                                 e.Error_ValueCannotBeConverted (loc, TypeManager.bool_type, false);
 867                                 return null;
 868                         }
 869                         return converted;
 870                 }
 871
 872                 public virtual string ExprClassName
 873                 {
 874                         get {
 875                                 switch (eclass){
 876                                         case ExprClass.Invalid:
 877                                                 return "Invalid";
 878                                         case ExprClass.Value:
 879                                                 return "value";
 880                                         case ExprClass.Variable:
 881                                                 return "variable";
 882                                         case ExprClass.Namespace:
 883                                                 return "namespace";
 884                                         case ExprClass.Type:
 885                                                 return "type";
 886                                         case ExprClass.MethodGroup:
 887                                                 return "method group";
 888                                         case ExprClass.PropertyAccess:
 889                                                 return "property access";
 890                                         case ExprClass.EventAccess:
 891                                                 return "event access";
 892                                         case ExprClass.IndexerAccess:
 893                                                 return "indexer access";
 894                                         case ExprClass.Nothing:
 895                                                 return "null";
 896                                 }
 897                                 throw new Exception ("Should not happen");
 898                         }
 899                 }
 900
 901                 /// <summary>
 902                 ///   Reports that we were expecting `expr' to be of class `expected'
 903                 /// </summary>
 904                 public void Error_UnexpectedKind (EmitContext ec, string expected, Location loc)
 905                 {
 906                         Error_UnexpectedKind (ec, expected, ExprClassName, loc);
 907                 }
 908
 909                 public void Error_UnexpectedKind (EmitContext ec, string expected, string was, Location loc)
 910                 {
 911                         string name = GetSignatureForError ();
 912                         if (ec != null)
 913                                 name = ec.DeclSpace.GetSignatureForError () + '.' + name;
 914
 915                         Report.Error (118, loc, "`{0}' is a `{1}' but a `{2}' was expected",
 916                               name, was, expected);
 917                 }
 918
 919                 public void Error_UnexpectedKind (ResolveFlags flags, Location loc)
 920                 {
 921                         string [] valid = new string [4];
 922                         int count = 0;
 923
 924                         if ((flags & ResolveFlags.VariableOrValue) != 0) {
 925                                 valid [count++] = "variable";
 926                                 valid [count++] = "value";
 927                         }
 928
 929                         if ((flags & ResolveFlags.Type) != 0)
 930                                 valid [count++] = "type";
 931
 932                         if ((flags & ResolveFlags.MethodGroup) != 0)
 933                                 valid [count++] = "method group";
 934
 935                         if (count == 0)
 936                                 valid [count++] = "unknown";
 937
 938                         StringBuilder sb = new StringBuilder (valid [0]);
 939                         for (int i = 1; i < count - 1; i++) {
 940                                 sb.Append ("', `");
 941                                 sb.Append (valid [i]);
 942                         }
 943                         if (count > 1) {
 944                                 sb.Append ("' or `");
 945                                 sb.Append (valid [count - 1]);
 946                         }
 947
 948                         Report.Error (119, loc,
 949                                 "Expression denotes a `{0}', where a `{1}' was expected", ExprClassName, sb.ToString ());
 950                 }
 951
 952                 public static void UnsafeError (Location loc)
 953                 {
 954                         Report.Error (214, loc, "Pointers and fixed size buffers may only be used in an unsafe context");
 955                 }
 956
 957                 //
 958                 // Load the object from the pointer.
 959                 //
 960                 public static void LoadFromPtr (ILGenerator ig, Type t)
 961                 {
 962                         if (t == TypeManager.int32_type)
 963                                 ig.Emit (OpCodes.Ldind_I4);
 964                         else if (t == TypeManager.uint32_type)
 965                                 ig.Emit (OpCodes.Ldind_U4);
 966                         else if (t == TypeManager.short_type)
 967                                 ig.Emit (OpCodes.Ldind_I2);
 968                         else if (t == TypeManager.ushort_type)
 969                                 ig.Emit (OpCodes.Ldind_U2);
 970                         else if (t == TypeManager.char_type)
 971                                 ig.Emit (OpCodes.Ldind_U2);
 972                         else if (t == TypeManager.byte_type)
 973                                 ig.Emit (OpCodes.Ldind_U1);
 974                         else if (t == TypeManager.sbyte_type)
 975                                 ig.Emit (OpCodes.Ldind_I1);
 976                         else if (t == TypeManager.uint64_type)
 977                                 ig.Emit (OpCodes.Ldind_I8);
 978                         else if (t == TypeManager.int64_type)
 979                                 ig.Emit (OpCodes.Ldind_I8);
 980                         else if (t == TypeManager.float_type)
 981                                 ig.Emit (OpCodes.Ldind_R4);
 982                         else if (t == TypeManager.double_type)
 983                                 ig.Emit (OpCodes.Ldind_R8);
 984                         else if (t == TypeManager.bool_type)
 985                                 ig.Emit (OpCodes.Ldind_I1);
 986                         else if (t == TypeManager.intptr_type)
 987                                 ig.Emit (OpCodes.Ldind_I);
 988                         else if (TypeManager.IsEnumType (t)) {
 989                                 if (t == TypeManager.enum_type)
 990                                         ig.Emit (OpCodes.Ldind_Ref);
 991                                 else
 992                                         LoadFromPtr (ig, TypeManager.EnumToUnderlying (t));
 993                         } else if (t.IsValueType || t.IsGenericParameter)
 994                                 ig.Emit (OpCodes.Ldobj, t);
 995                         else if (t.IsPointer)
 996                                 ig.Emit (OpCodes.Ldind_I);
 997                         else
 998                                 ig.Emit (OpCodes.Ldind_Ref);
 999                 }
1000
1001                 //
1002                 // The stack contains the pointer and the value of type `type'
1003                 //
1004                 public static void StoreFromPtr (ILGenerator ig, Type type)
1005                 {
1006                         if (TypeManager.IsEnumType (type))
1007                                 type = TypeManager.EnumToUnderlying (type);
1008                         if (type == TypeManager.int32_type || type == TypeManager.uint32_type)
1009                                 ig.Emit (OpCodes.Stind_I4);
1010                         else if (type == TypeManager.int64_type || type == TypeManager.uint64_type)
1011                                 ig.Emit (OpCodes.Stind_I8);
1012                         else if (type == TypeManager.char_type || type == TypeManager.short_type ||
1013                                  type == TypeManager.ushort_type)
1014                                 ig.Emit (OpCodes.Stind_I2);
1015                         else if (type == TypeManager.float_type)
1016                                 ig.Emit (OpCodes.Stind_R4);
1017                         else if (type == TypeManager.double_type)
1018                                 ig.Emit (OpCodes.Stind_R8);
1019                         else if (type == TypeManager.byte_type || type == TypeManager.sbyte_type ||
1020                                  type == TypeManager.bool_type)
1021                                 ig.Emit (OpCodes.Stind_I1);
1022                         else if (type == TypeManager.intptr_type)
1023                                 ig.Emit (OpCodes.Stind_I);
1024                         else if (type.IsValueType || type.IsGenericParameter)
1025                                 ig.Emit (OpCodes.Stobj, type);
1026                         else
1027                                 ig.Emit (OpCodes.Stind_Ref);
1028                 }
1029
1030                 //
1031                 // Returns the size of type `t' if known, otherwise, 0
1032                 //
1033                 public static int GetTypeSize (Type t)
1034                 {
1035                         t = TypeManager.TypeToCoreType (t);
1036                         if (t == TypeManager.int32_type ||
1037                             t == TypeManager.uint32_type ||
1038                             t == TypeManager.float_type)
1039                                 return 4;
1040                         else if (t == TypeManager.int64_type ||
1041                                  t == TypeManager.uint64_type ||
1042                                  t == TypeManager.double_type)
1043                                 return 8;
1044                         else if (t == TypeManager.byte_type ||
1045                                  t == TypeManager.sbyte_type ||
1046                                  t == TypeManager.bool_type)
1047                                 return 1;
1048                         else if (t == TypeManager.short_type ||
1049                                  t == TypeManager.char_type ||
1050                                  t == TypeManager.ushort_type)
1051                                 return 2;
1052                         else if (t == TypeManager.decimal_type)
1053                                 return 16;
1054                         else
1055                                 return 0;
1056                 }
1057
1058                 public static void Error_NegativeArrayIndex (Location loc)
1059                 {
1060                         Report.Error (248, loc, "Cannot create an array with a negative size");
1061                 }
1062
1063                 protected void Error_CannotCallAbstractBase (string name)
1064                 {
1065                         Report.Error (205, loc, "Cannot call an abstract base member `{0}'", name);
1066                 }
1067
1068                 //
1069                 // Converts `source' to an int, uint, long or ulong.
1070                 //
1071                 public Expression ExpressionToArrayArgument (EmitContext ec, Expression source, Location loc)
1072                 {
1073                         Expression target;
1074
1075                         bool old_checked = ec.CheckState;
1076                         ec.CheckState = true;
1077
1078                         target = Convert.ImplicitConversion (ec, source, TypeManager.int32_type, loc);
1079                         if (target == null){
1080                                 target = Convert.ImplicitConversion (ec, source, TypeManager.uint32_type, loc);
1081                                 if (target == null){
1082                                         target = Convert.ImplicitConversion (ec, source, TypeManager.int64_type, loc);
1083                                         if (target == null){
1084                                                 target = Convert.ImplicitConversion (ec, source, TypeManager.uint64_type, loc);
1085                                                 if (target == null)
1086                                                         source.Error_ValueCannotBeConverted (loc, TypeManager.int32_type, false);
1087                                         }
1088                                 }
1089                         }
1090                         ec.CheckState = old_checked;
1091
1092                         //
1093                         // Only positive constants are allowed at compile time
1094                         //
1095                         if (target is Constant){
1096                                 if (target is IntConstant){
1097                                         if (((IntConstant) target).Value < 0){
1098                                                 Error_NegativeArrayIndex (loc);
1099                                                 return null;
1100                                         }
1101                                 }
1102
1103                                 if (target is LongConstant){
1104                                         if (((LongConstant) target).Value < 0){
1105                                                 Error_NegativeArrayIndex (loc);
1106                                                 return null;
1107                                         }
1108                                 }
1109
1110                         }
1111
1112                         return target;
1113                 }
1114
1115         }
1116
1117         /// <summary>
1118         ///   This is just a base class for expressions that can
1119         ///   appear on statements (invocations, object creation,
1120         ///   assignments, post/pre increment and decrement).  The idea
1121         ///   being that they would support an extra Emition interface that
1122         ///   does not leave a result on the stack.
1123         /// </summary>
1124         public abstract class ExpressionStatement : Expression {
1125
1126                 public virtual ExpressionStatement ResolveStatement (EmitContext ec)
1127                 {
1128                         Expression e = Resolve (ec);
1129                         if (e == null)
1130                                 return null;
1131
1132                         ExpressionStatement es = e as ExpressionStatement;
1133                         if (es == null)
1134                                 Error (201, "Only assignment, call, increment, decrement and new object " +
1135                                        "expressions can be used as a statement");
1136
1137                         return es;
1138                 }
1139
1140                 /// <summary>
1141                 ///   Requests the expression to be emitted in a `statement'
1142                 ///   context.  This means that no new value is left on the
1143                 ///   stack after invoking this method (constrasted with
1144                 ///   Emit that will always leave a value on the stack).
1145                 /// </summary>
1146                 public abstract void EmitStatement (EmitContext ec);
1147         }
1148
1149         /// <summary>
1150         ///   This kind of cast is used to encapsulate the child
1151         ///   whose type is child.Type into an expression that is
1152         ///   reported to return "return_type".  This is used to encapsulate
1153         ///   expressions which have compatible types, but need to be dealt
1154         ///   at higher levels with.
1155         ///
1156         ///   For example, a "byte" expression could be encapsulated in one
1157         ///   of these as an "unsigned int".  The type for the expression
1158         ///   would be "unsigned int".
1159         ///
1160         /// </summary>
1161         public class EmptyCast : Expression {
1162                 protected Expression child;
1163
1164                 public Expression Child {
1165                         get {
1166                                 return child;
1167                         }
1168                 }
1169
1170                 public EmptyCast (Expression child, Type return_type)
1171                 {
1172                         eclass = child.eclass;
1173                         loc = child.Location;
1174                         type = return_type;
1175                         this.child = child;
1176                 }
1177
1178                 public override Expression DoResolve (EmitContext ec)
1179                 {
1180                         // This should never be invoked, we are born in fully
1181                         // initialized state.
1182
1183                         return this;
1184                 }
1185
1186                 public override void Emit (EmitContext ec)
1187                 {
1188                         child.Emit (ec);
1189                 }
1190         }
1191         /// <summary>
1192         ///     This is a numeric cast to a Decimal
1193         /// </summary>
1194         public class CastToDecimal : EmptyCast {
1195
1196                 MethodInfo conversion_operator;
1197
1198                 public CastToDecimal (Expression child)
1199                         : this (child, false)
1200                 {
1201                 }
1202
1203                 public CastToDecimal (Expression child, bool find_explicit)
1204                         : base (child, TypeManager.decimal_type)
1205                 {
1206                         conversion_operator = GetConversionOperator (find_explicit);
1207
1208                         if (conversion_operator == null)
1209                                 throw new InternalErrorException ("Outer conversion routine is out of sync");
1210                 }
1211
1212                 // Returns the implicit operator that converts from
1213                 // 'child.Type' to System.Decimal.
1214                 MethodInfo GetConversionOperator (bool find_explicit)
1215                 {
1216                         string operator_name = find_explicit ? "op_Explicit" : "op_Implicit";
1217
1218                         MemberInfo [] mi = TypeManager.MemberLookup (type, type, type, MemberTypes.Method,
1219                                 BindingFlags.Static | BindingFlags.Public, operator_name, null);
1220
1221                         foreach (MethodInfo oper in mi) {
1222                                 ParameterData pd = TypeManager.GetParameterData (oper);
1223
1224                                 if (pd.ParameterType (0) == child.Type && oper.ReturnType == type)
1225                                         return oper;
1226                         }
1227
1228                         return null;
1229                 }
1230                 public override void Emit (EmitContext ec)
1231                 {
1232                         ILGenerator ig = ec.ig;
1233                         child.Emit (ec);
1234
1235                         ig.Emit (OpCodes.Call, conversion_operator);
1236                 }
1237         }
1238
1239         /// <summary>
1240         ///     This is an explicit numeric cast from a Decimal
1241         /// </summary>
1242         public class CastFromDecimal : EmptyCast
1243         {
1244                 static IDictionary operators;
1245
1246                 public CastFromDecimal (Expression child, Type return_type)
1247                         : base (child, return_type)
1248                 {
1249                         if (child.Type != TypeManager.decimal_type)
1250                                 throw new InternalErrorException (
1251                                         "The expected type is Decimal, instead it is " + child.Type.FullName);
1252                 }
1253
1254                 // Returns the explicit operator that converts from an
1255                 // express of type System.Decimal to 'type'.
1256                 public Expression Resolve ()
1257                 {
1258                         if (operators == null) {
1259                                  MemberInfo[] all_oper = TypeManager.MemberLookup (TypeManager.decimal_type,
1260                                         TypeManager.decimal_type, TypeManager.decimal_type, MemberTypes.Method,
1261                                         BindingFlags.Static | BindingFlags.Public, "op_Explicit", null);
1262
1263                                 operators = new System.Collections.Specialized.HybridDictionary ();
1264                                 foreach (MethodInfo oper in all_oper) {
1265                                         ParameterData pd = TypeManager.GetParameterData (oper);
1266                                         if (pd.ParameterType (0) == TypeManager.decimal_type)
1267                                                 operators.Add (oper.ReturnType, oper);
1268                                 }
1269                         }
1270
1271                         return operators.Contains (type) ? this : null;
1272                 }
1273
1274                 public override void Emit (EmitContext ec)
1275                 {
1276                         ILGenerator ig = ec.ig;
1277                         child.Emit (ec);
1278
1279                         ig.Emit (OpCodes.Call, (MethodInfo)operators [type]);
1280                 }
1281         }
1282
1283         //
1284         // We need to special case this since an empty cast of
1285         // a NullLiteral is still a Constant
1286         //
1287         public class NullCast : Constant {
1288                 public Constant child;
1289
1290                 public NullCast (Constant child, Type return_type):
1291                         base (Location.Null)
1292                 {
1293                         eclass = child.eclass;
1294                         type = return_type;
1295                         this.child = child;
1296                 }
1297
1298                 override public string AsString ()
1299                 {
1300                         return "null";
1301                 }
1302
1303                 public override object GetValue ()
1304                 {
1305                         return null;
1306                 }
1307
1308                 public override Expression DoResolve (EmitContext ec)
1309                 {
1310                         // This should never be invoked, we are born in fully
1311                         // initialized state.
1312
1313                         return this;
1314                 }
1315
1316                 public override void Emit (EmitContext ec)
1317                 {
1318                         child.Emit (ec);
1319                 }
1320
1321                 public override Constant Increment ()
1322                 {
1323                         throw new NotSupportedException ();
1324                 }
1325
1326                 public override bool IsDefaultValue {
1327                         get {
1328                                 throw new NotImplementedException ();
1329                         }
1330                 }
1331
1332                 public override bool IsNegative {
1333                         get {
1334                                 return false;
1335                         }
1336                 }
1337
1338                 public override Constant Reduce (EmitContext ec, Type target_type)
1339                 {
1340                         if (type == target_type)
1341                                 return child.Reduce (ec, target_type);
1342
1343                         return null;
1344                 }
1345
1346         }
1347
1348
1349         /// <summary>
1350         ///  This class is used to wrap literals which belong inside Enums
1351         /// </summary>
1352         public class EnumConstant : Constant {
1353                 public Constant Child;
1354
1355                 public EnumConstant (Constant child, Type enum_type):
1356                         base (child.Location)
1357                 {
1358                         eclass = child.eclass;
1359                         this.Child = child;
1360                         type = enum_type;
1361                 }
1362
1363                 public override Expression DoResolve (EmitContext ec)
1364                 {
1365                         // This should never be invoked, we are born in fully
1366                         // initialized state.
1367
1368                         return this;
1369                 }
1370
1371                 public override void Emit (EmitContext ec)
1372                 {
1373                         Child.Emit (ec);
1374                 }
1375
1376                 public override string GetSignatureForError()
1377                 {
1378                         return TypeManager.CSharpName (Type);
1379                 }
1380
1381                 public override object GetValue ()
1382                 {
1383                         return Child.GetValue ();
1384                 }
1385
1386                 public override object GetTypedValue ()
1387                 {
1388                         // FIXME: runtime is not ready to work with just emited enums
1389                         if (!RootContext.StdLib) {
1390                                 return Child.GetValue ();
1391                         }
1392
1393                         return System.Enum.ToObject (type, Child.GetValue ());
1394                 }
1395
1396                 public override string AsString ()
1397                 {
1398                         return Child.AsString ();
1399                 }
1400
1401                 public override DoubleConstant ConvertToDouble ()
1402                 {
1403                         return Child.ConvertToDouble ();
1404                 }
1405
1406                 public override FloatConstant ConvertToFloat ()
1407                 {
1408                         return Child.ConvertToFloat ();
1409                 }
1410
1411                 public override ULongConstant ConvertToULong ()
1412                 {
1413                         return Child.ConvertToULong ();
1414                 }
1415
1416                 public override LongConstant ConvertToLong ()
1417                 {
1418                         return Child.ConvertToLong ();
1419                 }
1420
1421                 public override UIntConstant ConvertToUInt ()
1422                 {
1423                         return Child.ConvertToUInt ();
1424                 }
1425
1426                 public override IntConstant ConvertToInt ()
1427                 {
1428                         return Child.ConvertToInt ();
1429                 }
1430
1431                 public override Constant Increment()
1432                 {
1433                         return new EnumConstant (Child.Increment (), type);
1434                 }
1435
1436                 public override bool IsDefaultValue {
1437                         get {
1438                                 return Child.IsDefaultValue;
1439                         }
1440                 }
1441
1442                 public override bool IsZeroInteger {
1443                         get { return Child.IsZeroInteger; }
1444                 }
1445
1446                 public override bool IsNegative {
1447                         get {
1448                                 return Child.IsNegative;
1449                         }
1450                 }
1451
1452                 public override Constant Reduce(EmitContext ec, Type target_type)
1453                 {
1454                         if (Child.Type == target_type)
1455                                 return Child;
1456
1457                         return Child.Reduce (ec, target_type);
1458                 }
1459
1460                 public override Constant ToType (Type type, Location loc)
1461                 {
1462                         if (Type == type) {
1463                                 // This is workaround of mono bug. It can be removed when the latest corlib spreads enough
1464                                 if (TypeManager.IsEnumType (type.UnderlyingSystemType))
1465                                         return this;
1466
1467                                 if (type.UnderlyingSystemType != Child.Type)
1468                                         Child = Child.ToType (type.UnderlyingSystemType, loc);
1469                                 return this;
1470                         }
1471
1472                         if (!Convert.ImplicitStandardConversionExists (Convert.ConstantEC, this, type)){
1473                                 Error_ValueCannotBeConverted (loc, type, false);
1474                                 return null;
1475                         }
1476
1477                         return Child.ToType (type, loc);
1478                 }
1479
1480         }
1481
1482         /// <summary>
1483         ///   This kind of cast is used to encapsulate Value Types in objects.
1484         ///
1485         ///   The effect of it is to box the value type emitted by the previous
1486         ///   operation.
1487         /// </summary>
1488         public class BoxedCast : EmptyCast {
1489
1490                 public BoxedCast (Expression expr, Type target_type)
1491                         : base (expr, target_type)
1492                 {
1493                         eclass = ExprClass.Value;
1494                 }
1495
1496                 public override Expression DoResolve (EmitContext ec)
1497                 {
1498                         // This should never be invoked, we are born in fully
1499                         // initialized state.
1500
1501                         return this;
1502                 }
1503
1504                 public override void Emit (EmitContext ec)
1505                 {
1506                         base.Emit (ec);
1507
1508                         ec.ig.Emit (OpCodes.Box, child.Type);
1509                 }
1510         }
1511
1512         public class UnboxCast : EmptyCast {
1513                 public UnboxCast (Expression expr, Type return_type)
1514                         : base (expr, return_type)
1515                 {
1516                 }
1517
1518                 public override Expression DoResolve (EmitContext ec)
1519                 {
1520                         // This should never be invoked, we are born in fully
1521                         // initialized state.
1522
1523                         return this;
1524                 }
1525
1526                 public override void Emit (EmitContext ec)
1527                 {
1528                         Type t = type;
1529                         ILGenerator ig = ec.ig;
1530
1531                         base.Emit (ec);
1532                         if (t.IsGenericParameter)
1533                                 ig.Emit (OpCodes.Unbox_Any, t);
1534                         else {
1535                                 ig.Emit (OpCodes.Unbox, t);
1536
1537                                 LoadFromPtr (ig, t);
1538                         }
1539                 }
1540         }
1541
1542         /// <summary>
1543         ///   This is used to perform explicit numeric conversions.
1544         ///
1545         ///   Explicit numeric conversions might trigger exceptions in a checked
1546         ///   context, so they should generate the conv.ovf opcodes instead of
1547         ///   conv opcodes.
1548         /// </summary>
1549         public class ConvCast : EmptyCast {
1550                 public enum Mode : byte {
1551                         I1_U1, I1_U2, I1_U4, I1_U8, I1_CH,
1552                         U1_I1, U1_CH,
1553                         I2_I1, I2_U1, I2_U2, I2_U4, I2_U8, I2_CH,
1554                         U2_I1, U2_U1, U2_I2, U2_CH,
1555                         I4_I1, I4_U1, I4_I2, I4_U2, I4_U4, I4_U8, I4_CH,
1556                         U4_I1, U4_U1, U4_I2, U4_U2, U4_I4, U4_CH,
1557                         I8_I1, I8_U1, I8_I2, I8_U2, I8_I4, I8_U4, I8_U8, I8_CH,
1558                         U8_I1, U8_U1, U8_I2, U8_U2, U8_I4, U8_U4, U8_I8, U8_CH,
1559                         CH_I1, CH_U1, CH_I2,
1560                         R4_I1, R4_U1, R4_I2, R4_U2, R4_I4, R4_U4, R4_I8, R4_U8, R4_CH,
1561                         R8_I1, R8_U1, R8_I2, R8_U2, R8_I4, R8_U4, R8_I8, R8_U8, R8_CH, R8_R4
1562                 }
1563
1564                 Mode mode;
1565
1566                 public ConvCast (Expression child, Type return_type, Mode m)
1567                         : base (child, return_type)
1568                 {
1569                         mode = m;
1570                 }
1571
1572                 public override Expression DoResolve (EmitContext ec)
1573                 {
1574                         // This should never be invoked, we are born in fully
1575                         // initialized state.
1576
1577                         return this;
1578                 }
1579
1580                 public override string ToString ()
1581                 {
1582                         return String.Format ("ConvCast ({0}, {1})", mode, child);
1583                 }
1584
1585                 public override void Emit (EmitContext ec)
1586                 {
1587                         ILGenerator ig = ec.ig;
1588
1589                         base.Emit (ec);
1590
1591                         if (ec.CheckState){
1592                                 switch (mode){
1593                                 case Mode.I1_U1: ig.Emit (OpCodes.Conv_Ovf_U1); break;
1594                                 case Mode.I1_U2: ig.Emit (OpCodes.Conv_Ovf_U2); break;
1595                                 case Mode.I1_U4: ig.Emit (OpCodes.Conv_Ovf_U4); break;
1596                                 case Mode.I1_U8: ig.Emit (OpCodes.Conv_Ovf_U8); break;
1597                                 case Mode.I1_CH: ig.Emit (OpCodes.Conv_Ovf_U2); break;
1598
1599                                 case Mode.U1_I1: ig.Emit (OpCodes.Conv_Ovf_I1_Un); break;
1600                                 case Mode.U1_CH: /* nothing */ break;
1601
1602                                 case Mode.I2_I1: ig.Emit (OpCodes.Conv_Ovf_I1); break;
1603                                 case Mode.I2_U1: ig.Emit (OpCodes.Conv_Ovf_U1); break;
1604                                 case Mode.I2_U2: ig.Emit (OpCodes.Conv_Ovf_U2); break;
1605                                 case Mode.I2_U4: ig.Emit (OpCodes.Conv_Ovf_U4); break;
1606                                 case Mode.I2_U8: ig.Emit (OpCodes.Conv_Ovf_U8); break;
1607                                 case Mode.I2_CH: ig.Emit (OpCodes.Conv_Ovf_U2); break;
1608
1609                                 case Mode.U2_I1: ig.Emit (OpCodes.Conv_Ovf_I1_Un); break;
1610                                 case Mode.U2_U1: ig.Emit (OpCodes.Conv_Ovf_U1_Un); break;
1611                                 case Mode.U2_I2: ig.Emit (OpCodes.Conv_Ovf_I2_Un); break;
1612                                 case Mode.U2_CH: /* nothing */ break;
1613
1614                                 case Mode.I4_I1: ig.Emit (OpCodes.Conv_Ovf_I1); break;
1615                                 case Mode.I4_U1: ig.Emit (OpCodes.Conv_Ovf_U1); break;
1616                                 case Mode.I4_I2: ig.Emit (OpCodes.Conv_Ovf_I2); break;
1617                                 case Mode.I4_U4: ig.Emit (OpCodes.Conv_Ovf_U4); break;
1618                                 case Mode.I4_U2: ig.Emit (OpCodes.Conv_Ovf_U2); break;
1619                                 case Mode.I4_U8: ig.Emit (OpCodes.Conv_Ovf_U8); break;
1620                                 case Mode.I4_CH: ig.Emit (OpCodes.Conv_Ovf_U2); break;
1621
1622                                 case Mode.U4_I1: ig.Emit (OpCodes.Conv_Ovf_I1_Un); break;
1623                                 case Mode.U4_U1: ig.Emit (OpCodes.Conv_Ovf_U1_Un); break;
1624                                 case Mode.U4_I2: ig.Emit (OpCodes.Conv_Ovf_I2_Un); break;
1625                                 case Mode.U4_U2: ig.Emit (OpCodes.Conv_Ovf_U2_Un); break;
1626                                 case Mode.U4_I4: ig.Emit (OpCodes.Conv_Ovf_I4_Un); break;
1627                                 case Mode.U4_CH: ig.Emit (OpCodes.Conv_Ovf_U2_Un); break;
1628
1629                                 case Mode.I8_I1: ig.Emit (OpCodes.Conv_Ovf_I1); break;
1630                                 case Mode.I8_U1: ig.Emit (OpCodes.Conv_Ovf_U1); break;
1631                                 case Mode.I8_I2: ig.Emit (OpCodes.Conv_Ovf_I2); break;
1632                                 case Mode.I8_U2: ig.Emit (OpCodes.Conv_Ovf_U2); break;
1633                                 case Mode.I8_I4: ig.Emit (OpCodes.Conv_Ovf_I4); break;
1634                                 case Mode.I8_U4: ig.Emit (OpCodes.Conv_Ovf_U4); break;
1635                                 case Mode.I8_U8: ig.Emit (OpCodes.Conv_Ovf_U8); break;
1636                                 case Mode.I8_CH: ig.Emit (OpCodes.Conv_Ovf_U2); break;
1637
1638                                 case Mode.U8_I1: ig.Emit (OpCodes.Conv_Ovf_I1_Un); break;
1639                                 case Mode.U8_U1: ig.Emit (OpCodes.Conv_Ovf_U1_Un); break;
1640                                 case Mode.U8_I2: ig.Emit (OpCodes.Conv_Ovf_I2_Un); break;
1641                                 case Mode.U8_U2: ig.Emit (OpCodes.Conv_Ovf_U2_Un); break;
1642                                 case Mode.U8_I4: ig.Emit (OpCodes.Conv_Ovf_I4_Un); break;
1643                                 case Mode.U8_U4: ig.Emit (OpCodes.Conv_Ovf_U4_Un); break;
1644                                 case Mode.U8_I8: ig.Emit (OpCodes.Conv_Ovf_I8_Un); break;
1645                                 case Mode.U8_CH: ig.Emit (OpCodes.Conv_Ovf_U2_Un); break;
1646
1647                                 case Mode.CH_I1: ig.Emit (OpCodes.Conv_Ovf_I1_Un); break;
1648                                 case Mode.CH_U1: ig.Emit (OpCodes.Conv_Ovf_U1_Un); break;
1649                                 case Mode.CH_I2: ig.Emit (OpCodes.Conv_Ovf_I2_Un); break;
1650
1651                                 case Mode.R4_I1: ig.Emit (OpCodes.Conv_Ovf_I1); break;
1652                                 case Mode.R4_U1: ig.Emit (OpCodes.Conv_Ovf_U1); break;
1653                                 case Mode.R4_I2: ig.Emit (OpCodes.Conv_Ovf_I2); break;
1654                                 case Mode.R4_U2: ig.Emit (OpCodes.Conv_Ovf_U2); break;
1655                                 case Mode.R4_I4: ig.Emit (OpCodes.Conv_Ovf_I4); break;
1656                                 case Mode.R4_U4: ig.Emit (OpCodes.Conv_Ovf_U4); break;
1657                                 case Mode.R4_I8: ig.Emit (OpCodes.Conv_Ovf_I8); break;
1658                                 case Mode.R4_U8: ig.Emit (OpCodes.Conv_Ovf_U8); break;
1659                                 case Mode.R4_CH: ig.Emit (OpCodes.Conv_Ovf_U2); break;
1660
1661                                 case Mode.R8_I1: ig.Emit (OpCodes.Conv_Ovf_I1); break;
1662                                 case Mode.R8_U1: ig.Emit (OpCodes.Conv_Ovf_U1); break;
1663                                 case Mode.R8_I2: ig.Emit (OpCodes.Conv_Ovf_I2); break;
1664                                 case Mode.R8_U2: ig.Emit (OpCodes.Conv_Ovf_U2); break;
1665                                 case Mode.R8_I4: ig.Emit (OpCodes.Conv_Ovf_I4); break;
1666                                 case Mode.R8_U4: ig.Emit (OpCodes.Conv_Ovf_U4); break;
1667                                 case Mode.R8_I8: ig.Emit (OpCodes.Conv_Ovf_I8); break;
1668                                 case Mode.R8_U8: ig.Emit (OpCodes.Conv_Ovf_U8); break;
1669                                 case Mode.R8_CH: ig.Emit (OpCodes.Conv_Ovf_U2); break;
1670                                 case Mode.R8_R4: ig.Emit (OpCodes.Conv_R4); break;
1671                                 }
1672                         } else {
1673                                 switch (mode){
1674                                 case Mode.I1_U1: ig.Emit (OpCodes.Conv_U1); break;
1675                                 case Mode.I1_U2: ig.Emit (OpCodes.Conv_U2); break;
1676                                 case Mode.I1_U4: ig.Emit (OpCodes.Conv_U4); break;
1677                                 case Mode.I1_U8: ig.Emit (OpCodes.Conv_I8); break;
1678                                 case Mode.I1_CH: ig.Emit (OpCodes.Conv_U2); break;
1679
1680                                 case Mode.U1_I1: ig.Emit (OpCodes.Conv_I1); break;
1681                                 case Mode.U1_CH: ig.Emit (OpCodes.Conv_U2); break;
1682
1683                                 case Mode.I2_I1: ig.Emit (OpCodes.Conv_I1); break;
1684                                 case Mode.I2_U1: ig.Emit (OpCodes.Conv_U1); break;
1685                                 case Mode.I2_U2: ig.Emit (OpCodes.Conv_U2); break;
1686                                 case Mode.I2_U4: ig.Emit (OpCodes.Conv_U4); break;
1687                                 case Mode.I2_U8: ig.Emit (OpCodes.Conv_I8); break;
1688                                 case Mode.I2_CH: ig.Emit (OpCodes.Conv_U2); break;
1689
1690                                 case Mode.U2_I1: ig.Emit (OpCodes.Conv_I1); break;
1691                                 case Mode.U2_U1: ig.Emit (OpCodes.Conv_U1); break;
1692                                 case Mode.U2_I2: ig.Emit (OpCodes.Conv_I2); break;
1693                                 case Mode.U2_CH: /* nothing */ break;
1694
1695                                 case Mode.I4_I1: ig.Emit (OpCodes.Conv_I1); break;
1696                                 case Mode.I4_U1: ig.Emit (OpCodes.Conv_U1); break;
1697                                 case Mode.I4_I2: ig.Emit (OpCodes.Conv_I2); break;
1698                                 case Mode.I4_U4: /* nothing */ break;
1699                                 case Mode.I4_U2: ig.Emit (OpCodes.Conv_U2); break;
1700                                 case Mode.I4_U8: ig.Emit (OpCodes.Conv_I8); break;
1701                                 case Mode.I4_CH: ig.Emit (OpCodes.Conv_U2); break;
1702
1703                                 case Mode.U4_I1: ig.Emit (OpCodes.Conv_I1); break;
1704                                 case Mode.U4_U1: ig.Emit (OpCodes.Conv_U1); break;
1705                                 case Mode.U4_I2: ig.Emit (OpCodes.Conv_I2); break;
1706                                 case Mode.U4_U2: ig.Emit (OpCodes.Conv_U2); break;
1707                                 case Mode.U4_I4: /* nothing */ break;
1708                                 case Mode.U4_CH: ig.Emit (OpCodes.Conv_U2); break;
1709
1710                                 case Mode.I8_I1: ig.Emit (OpCodes.Conv_I1); break;
1711                                 case Mode.I8_U1: ig.Emit (OpCodes.Conv_U1); break;
1712                                 case Mode.I8_I2: ig.Emit (OpCodes.Conv_I2); break;
1713                                 case Mode.I8_U2: ig.Emit (OpCodes.Conv_U2); break;
1714                                 case Mode.I8_I4: ig.Emit (OpCodes.Conv_I4); break;
1715                                 case Mode.I8_U4: ig.Emit (OpCodes.Conv_U4); break;
1716                                 case Mode.I8_U8: /* nothing */ break;
1717                                 case Mode.I8_CH: ig.Emit (OpCodes.Conv_U2); break;
1718
1719                                 case Mode.U8_I1: ig.Emit (OpCodes.Conv_I1); break;
1720                                 case Mode.U8_U1: ig.Emit (OpCodes.Conv_U1); break;
1721                                 case Mode.U8_I2: ig.Emit (OpCodes.Conv_I2); break;
1722                                 case Mode.U8_U2: ig.Emit (OpCodes.Conv_U2); break;
1723                                 case Mode.U8_I4: ig.Emit (OpCodes.Conv_I4); break;
1724                                 case Mode.U8_U4: ig.Emit (OpCodes.Conv_U4); break;
1725                                 case Mode.U8_I8: /* nothing */ break;
1726                                 case Mode.U8_CH: ig.Emit (OpCodes.Conv_U2); break;
1727
1728                                 case Mode.CH_I1: ig.Emit (OpCodes.Conv_I1); break;
1729                                 case Mode.CH_U1: ig.Emit (OpCodes.Conv_U1); break;
1730                                 case Mode.CH_I2: ig.Emit (OpCodes.Conv_I2); break;
1731
1732                                 case Mode.R4_I1: ig.Emit (OpCodes.Conv_I1); break;
1733                                 case Mode.R4_U1: ig.Emit (OpCodes.Conv_U1); break;
1734                                 case Mode.R4_I2: ig.Emit (OpCodes.Conv_I2); break;
1735                                 case Mode.R4_U2: ig.Emit (OpCodes.Conv_U2); break;
1736                                 case Mode.R4_I4: ig.Emit (OpCodes.Conv_I4); break;
1737                                 case Mode.R4_U4: ig.Emit (OpCodes.Conv_U4); break;
1738                                 case Mode.R4_I8: ig.Emit (OpCodes.Conv_I8); break;
1739                                 case Mode.R4_U8: ig.Emit (OpCodes.Conv_U8); break;
1740                                 case Mode.R4_CH: ig.Emit (OpCodes.Conv_U2); break;
1741
1742                                 case Mode.R8_I1: ig.Emit (OpCodes.Conv_I1); break;
1743                                 case Mode.R8_U1: ig.Emit (OpCodes.Conv_U1); break;
1744                                 case Mode.R8_I2: ig.Emit (OpCodes.Conv_I2); break;
1745                                 case Mode.R8_U2: ig.Emit (OpCodes.Conv_U2); break;
1746                                 case Mode.R8_I4: ig.Emit (OpCodes.Conv_I4); break;
1747                                 case Mode.R8_U4: ig.Emit (OpCodes.Conv_U4); break;
1748                                 case Mode.R8_I8: ig.Emit (OpCodes.Conv_I8); break;
1749                                 case Mode.R8_U8: ig.Emit (OpCodes.Conv_U8); break;
1750                                 case Mode.R8_CH: ig.Emit (OpCodes.Conv_U2); break;
1751                                 case Mode.R8_R4: ig.Emit (OpCodes.Conv_R4); break;
1752                                 }
1753                         }
1754                 }
1755         }
1756
1757         public class OpcodeCast : EmptyCast {
1758                 OpCode op, op2;
1759                 bool second_valid;
1760
1761                 public OpcodeCast (Expression child, Type return_type, OpCode op)
1762                         : base (child, return_type)
1763
1764                 {
1765                         this.op = op;
1766                         second_valid = false;
1767                 }
1768
1769                 public OpcodeCast (Expression child, Type return_type, OpCode op, OpCode op2)
1770                         : base (child, return_type)
1771
1772                 {
1773                         this.op = op;
1774                         this.op2 = op2;
1775                         second_valid = true;
1776                 }
1777
1778                 public override Expression DoResolve (EmitContext ec)
1779                 {
1780                         // This should never be invoked, we are born in fully
1781                         // initialized state.
1782
1783                         return this;
1784                 }
1785
1786                 public override void Emit (EmitContext ec)
1787                 {
1788                         base.Emit (ec);
1789                         ec.ig.Emit (op);
1790
1791                         if (second_valid)
1792                                 ec.ig.Emit (op2);
1793                 }
1794         }
1795
1796         /// <summary>
1797         ///   This kind of cast is used to encapsulate a child and cast it
1798         ///   to the class requested
1799         /// </summary>
1800         public class ClassCast : EmptyCast {
1801                 public ClassCast (Expression child, Type return_type)
1802                         : base (child, return_type)
1803
1804                 {
1805                 }
1806
1807                 public override Expression DoResolve (EmitContext ec)
1808                 {
1809                         // This should never be invoked, we are born in fully
1810                         // initialized state.
1811
1812                         return this;
1813                 }
1814
1815                 public override void Emit (EmitContext ec)
1816                 {
1817                         base.Emit (ec);
1818
1819                         if (child.Type.IsGenericParameter)
1820                                 ec.ig.Emit (OpCodes.Box, child.Type);
1821
1822                         if (type.IsGenericParameter)
1823                                 ec.ig.Emit (OpCodes.Unbox_Any, type);
1824                         else
1825                                 ec.ig.Emit (OpCodes.Castclass, type);
1826                 }
1827         }
1828
1829         /// <summary>
1830         ///   SimpleName expressions are formed of a single word and only happen at the beginning
1831         ///   of a dotted-name.
1832         /// </summary>
1833         public class SimpleName : Expression {
1834                 public string Name;
1835                 public readonly TypeArguments Arguments;
1836                 bool in_transit;
1837
1838                 public SimpleName (string name, Location l)
1839                 {
1840                         Name = name;
1841                         loc = l;
1842                 }
1843
1844                 public SimpleName (string name, TypeArguments args, Location l)
1845                 {
1846                         Name = name;
1847                         Arguments = args;
1848                         loc = l;
1849                 }
1850
1851                 public SimpleName (string name, TypeParameter[] type_params, Location l)
1852                 {
1853                         Name = name;
1854                         loc = l;
1855
1856                         Arguments = new TypeArguments (l);
1857                         foreach (TypeParameter type_param in type_params)
1858                                 Arguments.Add (new TypeParameterExpr (type_param, l));
1859                 }
1860
1861                 public static string RemoveGenericArity (string name)
1862                 {
1863                         int start = 0;
1864                         StringBuilder sb = new StringBuilder ();
1865                         while (start < name.Length) {
1866                                 int pos = name.IndexOf ('`', start);
1867                                 if (pos < 0) {
1868                                         sb.Append (name.Substring (start));
1869                                         break;
1870                                 }
1871
1872                                 sb.Append (name.Substring (start, pos-start));
1873
1874                                 pos++;
1875                                 while ((pos < name.Length) && Char.IsNumber (name [pos]))
1876                                         pos++;
1877
1878                                 start = pos;
1879                         }
1880
1881                         return sb.ToString ();
1882                 }
1883
1884                 public SimpleName GetMethodGroup ()
1885                 {
1886                         return new SimpleName (RemoveGenericArity (Name), Arguments, loc);
1887                 }
1888
1889                 public static void Error_ObjectRefRequired (EmitContext ec, Location l, string name)
1890                 {
1891                         if (ec.IsFieldInitializer)
1892                                 Report.Error (236, l,
1893                                         "A field initializer cannot reference the nonstatic field, method, or property `{0}'",
1894                                         name);
1895                         else {
1896                                 if (name.LastIndexOf ('.') > 0)
1897                                         name = name.Substring (name.LastIndexOf ('.') + 1);
1898
1899                                 Report.Error (
1900                                         120, l, "`{0}': An object reference is required for the nonstatic field, method or property",
1901                                         name);
1902                         }
1903                 }
1904
1905                 public bool IdenticalNameAndTypeName (EmitContext ec, Expression resolved_to, Location loc)
1906                 {
1907                         return resolved_to != null && resolved_to.Type != null &&
1908                                 resolved_to.Type.Name == Name &&
1909                                 (ec.DeclSpace.LookupType (Name, loc, /* ignore_cs0104 = */ true) != null);
1910                 }
1911
1912                 public override Expression DoResolve (EmitContext ec)
1913                 {
1914                         return SimpleNameResolve (ec, null, false);
1915                 }
1916
1917                 public override Expression DoResolveLValue (EmitContext ec, Expression right_side)
1918                 {
1919                         return SimpleNameResolve (ec, right_side, false);
1920                 }
1921
1922
1923                 public Expression DoResolve (EmitContext ec, bool intermediate)
1924                 {
1925                         return SimpleNameResolve (ec, null, intermediate);
1926                 }
1927
1928                 private bool IsNestedChild (Type t, Type parent)
1929                 {
1930                         if (parent == null)
1931                                 return false;
1932
1933                         while (parent != null) {
1934                                 if (parent.IsGenericInstance)
1935                                         parent = parent.GetGenericTypeDefinition ();
1936
1937                                 if (TypeManager.IsNestedChildOf (t, parent))
1938                                         return true;
1939
1940                                 parent = parent.BaseType;
1941                         }
1942
1943                         return false;
1944                 }
1945
1946                 FullNamedExpression ResolveNested (EmitContext ec, Type t)
1947                 {
1948                         if (!t.IsGenericTypeDefinition)
1949                                 return null;
1950
1951                         DeclSpace ds = ec.DeclSpace;
1952                         while (ds != null) {
1953                                 if (IsNestedChild (t, ds.TypeBuilder))
1954                                         break;
1955
1956                                 ds = ds.Parent;
1957                         }
1958
1959                         if (ds == null)
1960                                 return null;
1961
1962                         Type[] gen_params = t.GetGenericArguments ();
1963
1964                         int arg_count = Arguments != null ? Arguments.Count : 0;
1965
1966                         for (; (ds != null) && ds.IsGeneric; ds = ds.Parent) {
1967                                 if (arg_count + ds.CountTypeParameters == gen_params.Length) {
1968                                         TypeArguments new_args = new TypeArguments (loc);
1969                                         foreach (TypeParameter param in ds.TypeParameters)
1970                                                 new_args.Add (new TypeParameterExpr (param, loc));
1971
1972                                         if (Arguments != null)
1973                                                 new_args.Add (Arguments);
1974
1975                                         return new ConstructedType (t, new_args, loc);
1976                                 }
1977                         }
1978
1979                         return null;
1980                 }
1981
1982                 public override FullNamedExpression ResolveAsTypeStep (EmitContext ec, bool silent)
1983                 {
1984                         FullNamedExpression fne = ec.DeclSpace.LookupGeneric (Name, loc);
1985                         if (fne != null)
1986                                 return fne.ResolveAsTypeStep (ec, silent);
1987
1988                         int errors = Report.Errors;
1989                         fne = ec.DeclSpace.LookupType (Name, loc, /*ignore_cs0104=*/ false);
1990
1991                         if (fne != null) {
1992                                 if (fne.Type == null)
1993                                         return fne;
1994
1995                                 FullNamedExpression nested = ResolveNested (ec, fne.Type);
1996                                 if (nested != null)
1997                                         return nested.ResolveAsTypeStep (ec);
1998
1999                                 if (Arguments != null) {
2000                                         ConstructedType ct = new ConstructedType (fne, Arguments, loc);
2001                                         return ct.ResolveAsTypeStep (ec);
2002                                 }
2003
2004                                 return fne;
2005                         }
2006
2007                         if (silent || errors != Report.Errors)
2008                                 return null;
2009
2010                         MemberCore mc = ec.DeclSpace.GetDefinition (Name);
2011                         if (mc != null) {
2012                                 Error_UnexpectedKind (ec, "type", GetMemberType (mc), loc);
2013                         } else {
2014                                 NamespaceEntry.Error_NamespaceNotFound (loc, Name);
2015                         }
2016
2017                         return null;
2018                 }
2019
2020                 // TODO: I am still not convinced about this. If someone else will need it
2021                 // implement this as virtual property in MemberCore hierarchy
2022                 string GetMemberType (MemberCore mc)
2023                 {
2024                         if (mc is PropertyBase)
2025                                 return "property";
2026                         if (mc is Indexer)
2027                                 return "indexer";
2028                         if (mc is FieldBase)
2029                                 return "field";
2030                         if (mc is MethodCore)
2031                                 return "method";
2032                         if (mc is EnumMember)
2033                                 return "enum";
2034
2035                         return "type";
2036                 }
2037
2038                 Expression SimpleNameResolve (EmitContext ec, Expression right_side, bool intermediate)
2039                 {
2040                         if (in_transit)
2041                                 return null;
2042                         in_transit = true;
2043
2044                         Expression e = DoSimpleNameResolve (ec, right_side, intermediate);
2045                         if (e == null)
2046                                 return null;
2047
2048                         if (ec.CurrentBlock == null || ec.CurrentBlock.CheckInvariantMeaningInBlock (Name, e, Location))
2049                                 return e;
2050
2051                         return null;
2052                 }
2053
2054                 /// <remarks>
2055                 ///   7.5.2: Simple Names.
2056                 ///
2057                 ///   Local Variables and Parameters are handled at
2058                 ///   parse time, so they never occur as SimpleNames.
2059                 ///
2060                 ///   The `intermediate' flag is used by MemberAccess only
2061                 ///   and it is used to inform us that it is ok for us to
2062                 ///   avoid the static check, because MemberAccess might end
2063                 ///   up resolving the Name as a Type name and the access as
2064                 ///   a static type access.
2065                 ///
2066                 ///   ie: Type Type; .... { Type.GetType (""); }
2067                 ///
2068                 ///   Type is both an instance variable and a Type;  Type.GetType
2069                 ///   is the static method not an instance method of type.
2070                 /// </remarks>
2071                 Expression DoSimpleNameResolve (EmitContext ec, Expression right_side, bool intermediate)
2072                 {
2073                         Expression e = null;
2074
2075                         //
2076                         // Stage 1: Performed by the parser (binding to locals or parameters).
2077                         //
2078                         Block current_block = ec.CurrentBlock;
2079                         if (current_block != null){
2080                                 LocalInfo vi = current_block.GetLocalInfo (Name);
2081                                 if (vi != null){
2082                                         LocalVariableReference var = new LocalVariableReference (ec.CurrentBlock, Name, loc);
2083                                         if (right_side != null) {
2084                                                 return var.ResolveLValue (ec, right_side, loc);
2085                                         } else {
2086                                                 ResolveFlags rf = ResolveFlags.VariableOrValue;
2087                                                 if (intermediate)
2088                                                         rf |= ResolveFlags.DisableFlowAnalysis;
2089                                                 return var.Resolve (ec, rf);
2090                                         }
2091                                 }
2092
2093                                 ParameterReference pref = current_block.Toplevel.GetParameterReference (Name, loc);
2094                                 if (pref != null) {
2095                                         if (right_side != null)
2096                                                 return pref.ResolveLValue (ec, right_side, loc);
2097                                         else
2098                                                 return pref.Resolve (ec);
2099                                 }
2100                         }
2101
2102                         //
2103                         // Stage 2: Lookup members
2104                         //
2105
2106                         DeclSpace lookup_ds = ec.DeclSpace;
2107                         Type almost_matched_type = null;
2108                         ArrayList almost_matched = null;
2109                         do {
2110                                 if (lookup_ds.TypeBuilder == null)
2111                                         break;
2112
2113                                 e = MemberLookup (ec, lookup_ds.TypeBuilder, Name, loc);
2114                                 if (e != null)
2115                                         break;
2116
2117                                 if (almost_matched == null && almostMatchedMembers.Count > 0) {
2118                                         almost_matched_type = lookup_ds.TypeBuilder;
2119                                         almost_matched = (ArrayList) almostMatchedMembers.Clone ();
2120                                 }
2121
2122                                 lookup_ds =lookup_ds.Parent;
2123                         } while (lookup_ds != null);
2124
2125                         if (e == null && ec.ContainerType != null)
2126                                 e = MemberLookup (ec, ec.ContainerType, Name, loc);
2127
2128                         if (e == null) {
2129                                 if (almost_matched == null && almostMatchedMembers.Count > 0) {
2130                                         almost_matched_type = ec.ContainerType;
2131                                         almost_matched = (ArrayList) almostMatchedMembers.Clone ();
2132                                 }
2133                                 e = ResolveAsTypeStep (ec, true);
2134                         }
2135
2136                         if (e == null) {
2137                                 if (almost_matched != null)
2138                                         almostMatchedMembers = almost_matched;
2139                                 if (almost_matched_type == null)
2140                                         almost_matched_type = ec.ContainerType;
2141                                 MemberLookupFailed (ec, null, almost_matched_type, ((SimpleName) this).Name, ec.DeclSpace.Name, true, loc);
2142                                 return null;
2143                         }
2144
2145                         if (e is TypeExpr)
2146                                 return e;
2147
2148                         if (e is MemberExpr) {
2149                                 MemberExpr me = (MemberExpr) e;
2150
2151                                 Expression left;
2152                                 if (me.IsInstance) {
2153                                         if (ec.IsStatic || ec.IsFieldInitializer) {
2154                                                 //
2155                                                 // Note that an MemberExpr can be both IsInstance and IsStatic.
2156                                                 // An unresolved MethodGroupExpr can contain both kinds of methods
2157                                                 // and each predicate is true if the MethodGroupExpr contains
2158                                                 // at least one of that kind of method.
2159                                                 //
2160
2161                                                 if (!me.IsStatic &&
2162                                                     (!intermediate || !IdenticalNameAndTypeName (ec, me, loc))) {
2163                                                         Error_ObjectRefRequired (ec, loc, me.GetSignatureForError ());
2164                                                         return null;
2165                                                 }
2166
2167                                                 //
2168                                                 // Pass the buck to MemberAccess and Invocation.
2169                                                 //
2170                                                 left = EmptyExpression.Null;
2171                                         } else {
2172                                                 left = ec.GetThis (loc);
2173                                         }
2174                                 } else {
2175                                         left = new TypeExpression (ec.ContainerType, loc);
2176                                 }
2177
2178                                 e = me.ResolveMemberAccess (ec, left, loc, null);
2179                                 if (e == null)
2180                                         return null;
2181
2182                                 me = e as MemberExpr;
2183                                 if (me == null)
2184                                         return e;
2185
2186                                 if (Arguments != null) {
2187                                         MethodGroupExpr mg = me as MethodGroupExpr;
2188                                         if (mg == null)
2189                                                 return null;
2190
2191                                         return mg.ResolveGeneric (ec, Arguments);
2192                                 }
2193
2194                                 if (!me.IsStatic &&
2195                                     TypeManager.IsNestedFamilyAccessible (me.InstanceExpression.Type, me.DeclaringType) &&
2196                                     me.InstanceExpression.Type != me.DeclaringType &&
2197                                     !TypeManager.IsFamilyAccessible (me.InstanceExpression.Type, me.DeclaringType) &&
2198                                     (!intermediate || !IdenticalNameAndTypeName (ec, e, loc))) {
2199                                         Report.Error (38, loc, "Cannot access a nonstatic member of outer type `{0}' via nested type `{1}'",
2200                                                 TypeManager.CSharpName (me.DeclaringType), TypeManager.CSharpName (me.InstanceExpression.Type));
2201                                         return null;
2202                                 }
2203
2204                                 return (right_side != null)
2205                                         ? me.DoResolveLValue (ec, right_side)
2206                                         : me.DoResolve (ec);
2207                         }
2208
2209                         return e;
2210                 }
2211
2212                 public override void Emit (EmitContext ec)
2213                 {
2214                         //
2215                         // If this is ever reached, then we failed to
2216                         // find the name as a namespace
2217                         //
2218
2219                         Error (103, "The name `" + Name +
2220                                "' does not exist in the class `" +
2221                                ec.DeclSpace.Name + "'");
2222                 }
2223
2224                 public override string ToString ()
2225                 {
2226                         return Name;
2227                 }
2228
2229                 public override string GetSignatureForError ()
2230                 {
2231                         return Name;
2232                 }
2233         }
2234
2235         /// <summary>
2236         ///   Represents a namespace or a type.  The name of the class was inspired by
2237         ///   section 10.8.1 (Fully Qualified Names).
2238         /// </summary>
2239         public abstract class FullNamedExpression : Expression {
2240                 public override FullNamedExpression ResolveAsTypeStep (EmitContext ec, bool silent)
2241                 {
2242                         return this;
2243                 }
2244
2245                 public abstract string FullName {
2246                         get;
2247                 }
2248         }
2249
2250         /// <summary>
2251         ///   Expression that evaluates to a type
2252         /// </summary>
2253         public abstract class TypeExpr : FullNamedExpression {
2254                 override public FullNamedExpression ResolveAsTypeStep (EmitContext ec, bool silent)
2255                 {
2256                         TypeExpr t = DoResolveAsTypeStep (ec);
2257                         if (t == null)
2258                                 return null;
2259
2260                         eclass = ExprClass.Type;
2261                         return t;
2262                 }
2263
2264                 override public Expression DoResolve (EmitContext ec)
2265                 {
2266                         return ResolveAsTypeTerminal (ec);
2267                 }
2268
2269                 override public void Emit (EmitContext ec)
2270                 {
2271                         throw new Exception ("Should never be called");
2272                 }
2273
2274                 public virtual bool CheckAccessLevel (DeclSpace ds)
2275                 {
2276                         return ds.CheckAccessLevel (Type);
2277                 }
2278
2279                 public virtual bool AsAccessible (DeclSpace ds, int flags)
2280                 {
2281                         return ds.AsAccessible (Type, flags);
2282                 }
2283
2284                 public virtual bool IsClass {
2285                         get { return Type.IsClass; }
2286                 }
2287
2288                 public virtual bool IsValueType {
2289                         get { return Type.IsValueType; }
2290                 }
2291
2292                 public virtual bool IsInterface {
2293                         get { return Type.IsInterface; }
2294                 }
2295
2296                 public virtual bool IsSealed {
2297                         get { return Type.IsSealed; }
2298                 }
2299
2300                 public virtual bool CanInheritFrom ()
2301                 {
2302                         if (Type == TypeManager.enum_type ||
2303                             (Type == TypeManager.value_type && RootContext.StdLib) ||
2304                             Type == TypeManager.multicast_delegate_type ||
2305                             Type == TypeManager.delegate_type ||
2306                             Type == TypeManager.array_type)
2307                                 return false;
2308
2309                         return true;
2310                 }
2311
2312                 protected abstract TypeExpr DoResolveAsTypeStep (EmitContext ec);
2313
2314                 public Type ResolveType (EmitContext ec)
2315                 {
2316                         TypeExpr t = ResolveAsTypeTerminal (ec);
2317                         if (t == null)
2318                                 return null;
2319
2320                         if (ec.TestObsoleteMethodUsage) {
2321                                 ObsoleteAttribute obsolete_attr = AttributeTester.GetObsoleteAttribute (t.Type);
2322                                 if (obsolete_attr != null) {
2323                                         AttributeTester.Report_ObsoleteMessage (obsolete_attr, Name, Location);
2324                                 }
2325                         }
2326
2327                         return t.Type;
2328                 }
2329
2330                 public abstract string Name {
2331                         get;
2332                 }
2333
2334                 public override bool Equals (object obj)
2335                 {
2336                         TypeExpr tobj = obj as TypeExpr;
2337                         if (tobj == null)
2338                                 return false;
2339
2340                         return Type == tobj.Type;
2341                 }
2342
2343                 public override int GetHashCode ()
2344                 {
2345                         return Type.GetHashCode ();
2346                 }
2347
2348                 public override string ToString ()
2349                 {
2350                         return Name;
2351                 }
2352         }
2353
2354         /// <summary>
2355         ///   Fully resolved Expression that already evaluated to a type
2356         /// </summary>
2357         public class TypeExpression : TypeExpr {
2358                 public TypeExpression (Type t, Location l)
2359                 {
2360                         Type = t;
2361                         eclass = ExprClass.Type;
2362                         loc = l;
2363                 }
2364
2365                 protected override TypeExpr DoResolveAsTypeStep (EmitContext ec)
2366                 {
2367                         return this;
2368                 }
2369
2370                 public override string Name {
2371                         get { return Type.ToString (); }
2372                 }
2373
2374                 public override string FullName {
2375                         get { return Type.FullName; }
2376                 }
2377         }
2378
2379         /// <summary>
2380         ///   Used to create types from a fully qualified name.  These are just used
2381         ///   by the parser to setup the core types.  A TypeLookupExpression is always
2382         ///   classified as a type.
2383         /// </summary>
2384         public class TypeLookupExpression : TypeExpr {
2385                 string name;
2386
2387                 public TypeLookupExpression (string name)
2388                 {
2389                         this.name = name;
2390                 }
2391
2392                 static readonly char [] dot_array = { '.' };
2393                 protected override TypeExpr DoResolveAsTypeStep (EmitContext ec)
2394                 {
2395                         if (type != null)
2396                                 return this;
2397
2398                         // If name is of the form `N.I', first lookup `N', then search a member `I' in it.
2399                         string rest = null;
2400                         string lookup_name = name;
2401                         int pos = name.IndexOf ('.');
2402                         if (pos >= 0) {
2403                                 rest = name.Substring (pos + 1);
2404                                 lookup_name = name.Substring (0, pos);
2405                         }
2406
2407                         FullNamedExpression resolved = RootNamespace.Global.Lookup (ec.DeclSpace, lookup_name, Location.Null);
2408
2409                         if (resolved != null && rest != null) {
2410                                 // Now handle the rest of the the name.
2411                                 string [] elements = rest.Split (dot_array);
2412                                 string element;
2413                                 int count = elements.Length;
2414                                 int i = 0;
2415                                 while (i < count && resolved != null && resolved is Namespace) {
2416                                         Namespace ns = resolved as Namespace;
2417                                         element = elements [i++];
2418                                         lookup_name += "." + element;
2419                                         resolved = ns.Lookup (ec.DeclSpace, element, Location.Null);
2420                                 }
2421
2422                                 if (resolved != null && resolved is TypeExpr) {
2423                                         Type t = ((TypeExpr) resolved).Type;
2424                                         while (t != null) {
2425                                                 if (!ec.DeclSpace.CheckAccessLevel (t)) {
2426                                                         resolved = null;
2427                                                         lookup_name = t.FullName;
2428                                                         break;
2429                                                 }
2430                                                 if (i == count) {
2431                                                         type = t;
2432                                                         return this;
2433                                                 }
2434                                                 t = TypeManager.GetNestedType (t, elements [i++]);
2435                                         }
2436                                 }
2437                         }
2438
2439                         if (resolved == null) {
2440                                 NamespaceEntry.Error_NamespaceNotFound (loc, lookup_name);
2441                                 return null;
2442                         }
2443
2444                         if (!(resolved is TypeExpr)) {
2445                                 resolved.Error_UnexpectedKind (ec, "type", loc);
2446                                 return null;
2447                         }
2448
2449                         type = ((TypeExpr) resolved).ResolveType (ec);
2450                         return this;
2451                 }
2452
2453                 public override string Name {
2454                         get { return name; }
2455                 }
2456
2457                 public override string FullName {
2458                         get { return name; }
2459                 }
2460         }
2461
2462         /// <summary>
2463         ///   Represents an "unbound generic type", ie. typeof (Foo<>).
2464         ///   See 14.5.11.
2465         /// </summary>
2466         public class UnboundTypeExpression : TypeExpr
2467         {
2468                 MemberName name;
2469
2470                 public UnboundTypeExpression (MemberName name, Location l)
2471                 {
2472                         this.name = name;
2473                         loc = l;
2474                 }
2475
2476                 protected override TypeExpr DoResolveAsTypeStep (EmitContext ec)
2477                 {
2478                         Expression expr;
2479                         if (name.Left != null) {
2480                                 Expression lexpr = name.Left.GetTypeExpression ();
2481                                 expr = new MemberAccess (lexpr, name.Basename, loc);
2482                         } else {
2483                                 expr = new SimpleName (name.Basename, loc);
2484                         }
2485
2486                         FullNamedExpression fne = expr.ResolveAsTypeStep (ec);
2487                         if (fne == null)
2488                                 return null;
2489
2490                         type = fne.Type;
2491                         return new TypeExpression (type, loc);
2492                 }
2493
2494                 public override string Name {
2495                         get { return name.FullName; }
2496                 }
2497
2498                 public override string FullName {
2499                         get { return name.FullName; }
2500                 }
2501         }
2502
2503         public class TypeAliasExpression : TypeExpr {
2504                 FullNamedExpression alias;
2505                 TypeExpr texpr;
2506                 TypeArguments args;
2507                 string name;
2508
2509                 public TypeAliasExpression (FullNamedExpression alias, TypeArguments args, Location l)
2510                 {
2511                         this.alias = alias;
2512                         this.args = args;
2513                         loc = l;
2514
2515                         eclass = ExprClass.Type;
2516                         if (args != null)
2517                                 name = alias.FullName + "<" + args.ToString () + ">";
2518                         else
2519                                 name = alias.FullName;
2520                 }
2521
2522                 public override string Name {
2523                         get { return alias.FullName; }
2524                 }
2525
2526                 public override string FullName {
2527                         get { return name; }
2528                 }
2529
2530                 protected override TypeExpr DoResolveAsTypeStep (EmitContext ec)
2531                 {
2532                         texpr = alias.ResolveAsTypeTerminal (ec);
2533                         if (texpr == null)
2534                                 return null;
2535
2536                         Type type = texpr.ResolveType (ec);
2537                         int num_args = TypeManager.GetNumberOfTypeArguments (type);
2538
2539                         if (args != null) {
2540                                 if (num_args == 0) {
2541                                         Report.Error (308, loc,
2542                                                       "The non-generic type `{0}' cannot " +
2543                                                       "be used with type arguments.",
2544                                                       TypeManager.CSharpName (type));
2545                                         return null;
2546                                 }
2547
2548                                 ConstructedType ctype = new ConstructedType (type, args, loc);
2549                                 return ctype.ResolveAsTypeTerminal (ec);
2550                         } else if (num_args > 0) {
2551                                 Report.Error (305, loc,
2552                                               "Using the generic type `{0}' " +
2553                                               "requires {1} type arguments",
2554                                               TypeManager.CSharpName (type), num_args.ToString ());
2555                                 return null;
2556                         }
2557
2558                         return new TypeExpression (type, loc);
2559                 }
2560
2561                 public override bool CheckAccessLevel (DeclSpace ds)
2562                 {
2563                         return texpr.CheckAccessLevel (ds);
2564                 }
2565
2566                 public override bool AsAccessible (DeclSpace ds, int flags)
2567                 {
2568                         return texpr.AsAccessible (ds, flags);
2569                 }
2570
2571                 public override bool IsClass {
2572                         get { return texpr.IsClass; }
2573                 }
2574
2575                 public override bool IsValueType {
2576                         get { return texpr.IsValueType; }
2577                 }
2578
2579                 public override bool IsInterface {
2580                         get { return texpr.IsInterface; }
2581                 }
2582
2583                 public override bool IsSealed {
2584                         get { return texpr.IsSealed; }
2585                 }
2586         }
2587
2588         /// <summary>
2589         ///   This class denotes an expression which evaluates to a member
2590         ///   of a struct or a class.
2591         /// </summary>
2592         public abstract class MemberExpr : Expression
2593         {
2594                 /// <summary>
2595                 ///   The name of this member.
2596                 /// </summary>
2597                 public abstract string Name {
2598                         get;
2599                 }
2600
2601                 /// <summary>
2602                 ///   Whether this is an instance member.
2603                 /// </summary>
2604                 public abstract bool IsInstance {
2605                         get;
2606                 }
2607
2608                 /// <summary>
2609                 ///   Whether this is a static member.
2610                 /// </summary>
2611                 public abstract bool IsStatic {
2612                         get;
2613                 }
2614
2615                 /// <summary>
2616                 ///   The type which declares this member.
2617                 /// </summary>
2618                 public abstract Type DeclaringType {
2619                         get;
2620                 }
2621
2622                 /// <summary>
2623                 ///   The instance expression associated with this member, if it's a
2624                 ///   non-static member.
2625                 /// </summary>
2626                 public Expression InstanceExpression;
2627
2628                 public static void error176 (Location loc, string name)
2629                 {
2630                         Report.Error (176, loc, "Static member `{0}' cannot be accessed " +
2631                                       "with an instance reference, qualify it with a type name instead", name);
2632                 }
2633
2634                 protected bool CheckIntermediateModification ()
2635                 {
2636                         if (!InstanceExpression.Type.IsValueType)
2637                                 return true;
2638
2639                         if (InstanceExpression is UnboxCast) {
2640                                 Report.Error (445, loc, "Cannot modify the result of an unboxing conversion");
2641                                 return false;
2642                         }
2643
2644                         if (!(InstanceExpression is IMemoryLocation)) {
2645                                 Report.Error (1612, loc, "Cannot modify the return value of `{0}' because it is not a variable",
2646                                         InstanceExpression.GetSignatureForError ());
2647                                 return false;
2648                         }
2649
2650                         return true;
2651                 }
2652
2653                 // TODO: possible optimalization
2654                 // Cache resolved constant result in FieldBuilder <-> expression map
2655                 public virtual Expression ResolveMemberAccess (EmitContext ec, Expression left, Location loc,
2656                                                                SimpleName original)
2657                 {
2658                         //
2659                         // Precondition:
2660                         //   original == null || original.Resolve (...) ==> left
2661                         //
2662
2663                         if (left is TypeExpr) {
2664                                 if (!IsStatic) {
2665                                         SimpleName.Error_ObjectRefRequired (ec, loc, Name);
2666                                         return null;
2667                                 }
2668
2669                                 return this;
2670                         }
2671
2672                         if (!IsInstance) {
2673                                 if (original != null && original.IdenticalNameAndTypeName (ec, left, loc))
2674                                         return this;
2675
2676                                 error176 (loc, GetSignatureForError ());
2677                                 return null;
2678                         }
2679
2680                         InstanceExpression = left;
2681
2682                         return this;
2683                 }
2684
2685                 protected void EmitInstance (EmitContext ec, bool prepare_for_load)
2686                 {
2687                         if (IsStatic)
2688                                 return;
2689
2690                         if (InstanceExpression == EmptyExpression.Null) {
2691                                 SimpleName.Error_ObjectRefRequired (ec, loc, Name);
2692                                 return;
2693                         }
2694
2695                         if (InstanceExpression.Type.IsValueType) {
2696                                 if (InstanceExpression is IMemoryLocation) {
2697                                         ((IMemoryLocation) InstanceExpression).AddressOf (ec, AddressOp.LoadStore);
2698                                 } else {
2699                                         LocalTemporary t = new LocalTemporary (ec, InstanceExpression.Type);
2700                                         InstanceExpression.Emit (ec);
2701                                         t.Store (ec);
2702                                         t.AddressOf (ec, AddressOp.Store);
2703                                 }
2704                         } else
2705                                 InstanceExpression.Emit (ec);
2706
2707                         if (prepare_for_load)
2708                                 ec.ig.Emit (OpCodes.Dup);
2709                 }
2710         }
2711
2712         /// <summary>
2713         ///   MethodGroup Expression.
2714         ///
2715         ///   This is a fully resolved expression that evaluates to a type
2716         /// </summary>
2717         public class MethodGroupExpr : MemberExpr {
2718                 public MethodBase [] Methods;
2719                 bool has_type_arguments = false;
2720                 bool identical_type_name = false;
2721                 bool is_base;
2722
2723                 public MethodGroupExpr (MemberInfo [] mi, Location l)
2724                 {
2725                         Methods = new MethodBase [mi.Length];
2726                         mi.CopyTo (Methods, 0);
2727                         eclass = ExprClass.MethodGroup;
2728                         type = TypeManager.object_type;
2729                         loc = l;
2730                 }
2731
2732                 public MethodGroupExpr (ArrayList list, Location l)
2733                 {
2734                         Methods = new MethodBase [list.Count];
2735
2736                         try {
2737                                 list.CopyTo (Methods, 0);
2738                         } catch {
2739                                 foreach (MemberInfo m in list){
2740                                         if (!(m is MethodBase)){
2741                                                 Console.WriteLine ("Name " + m.Name);
2742                                                 Console.WriteLine ("Found a: " + m.GetType ().FullName);
2743                                         }
2744                                 }
2745                                 throw;
2746                         }
2747
2748                         loc = l;
2749                         eclass = ExprClass.MethodGroup;
2750                         type = TypeManager.object_type;
2751                 }
2752
2753                 public override Type DeclaringType {
2754                         get {
2755                                 //
2756                                 // We assume that the top-level type is in the end
2757                                 //
2758                                 return Methods [Methods.Length - 1].DeclaringType;
2759                                 //return Methods [0].DeclaringType;
2760                         }
2761                 }
2762
2763                 public bool HasTypeArguments {
2764                         get {
2765                                 return has_type_arguments;
2766                         }
2767
2768                         set {
2769                                 has_type_arguments = value;
2770                         }
2771                 }
2772
2773                 public bool IdenticalTypeName {
2774                         get {
2775                                 return identical_type_name;
2776                         }
2777
2778                         set {
2779                                 identical_type_name = value;
2780                         }
2781                 }
2782
2783                 public bool IsBase {
2784                         get {
2785                                 return is_base;
2786                         }
2787                         set {
2788                                 is_base = value;
2789                         }
2790                 }
2791
2792                 public override string GetSignatureForError ()
2793                 {
2794                         return TypeManager.CSharpSignature (Methods [0]);
2795                 }
2796
2797                 public override string Name {
2798                         get {
2799                                 return Methods [0].Name;
2800                         }
2801                 }
2802
2803                 public override bool IsInstance {
2804                         get {
2805                                 foreach (MethodBase mb in Methods)
2806                                         if (!mb.IsStatic)
2807                                                 return true;
2808
2809                                 return false;
2810                         }
2811                 }
2812
2813                 public override bool IsStatic {
2814                         get {
2815                                 foreach (MethodBase mb in Methods)
2816                                         if (mb.IsStatic)
2817                                                 return true;
2818
2819                                 return false;
2820                         }
2821                 }
2822
2823                 public override Expression ResolveMemberAccess (EmitContext ec, Expression left, Location loc,
2824                                                                 SimpleName original)
2825                 {
2826                         if (!(left is TypeExpr) &&
2827                             original != null && original.IdenticalNameAndTypeName (ec, left, loc))
2828                                 IdenticalTypeName = true;
2829
2830                         return base.ResolveMemberAccess (ec, left, loc, original);
2831                 }
2832
2833                 override public Expression DoResolve (EmitContext ec)
2834                 {
2835                         if (!IsInstance)
2836                                 InstanceExpression = null;
2837
2838                         if (InstanceExpression != null) {
2839                                 InstanceExpression = InstanceExpression.DoResolve (ec);
2840                                 if (InstanceExpression == null)
2841                                         return null;
2842                         }
2843
2844                         return this;
2845                 }
2846
2847                 public void ReportUsageError ()
2848                 {
2849                         Report.Error (654, loc, "Method `" + DeclaringType + "." +
2850                                       Name + "()' is referenced without parentheses");
2851                 }
2852
2853                 override public void Emit (EmitContext ec)
2854                 {
2855                         ReportUsageError ();
2856                 }
2857
2858                 bool RemoveMethods (bool keep_static)
2859                 {
2860                         ArrayList smethods = new ArrayList ();
2861
2862                         foreach (MethodBase mb in Methods){
2863                                 if (mb.IsStatic == keep_static)
2864                                         smethods.Add (mb);
2865                         }
2866
2867                         if (smethods.Count == 0)
2868                                 return false;
2869
2870                         Methods = new MethodBase [smethods.Count];
2871                         smethods.CopyTo (Methods, 0);
2872
2873                         return true;
2874                 }
2875
2876                 /// <summary>
2877                 ///   Removes any instance methods from the MethodGroup, returns
2878                 ///   false if the resulting set is empty.
2879                 /// </summary>
2880                 public bool RemoveInstanceMethods ()
2881                 {
2882                         return RemoveMethods (true);
2883                 }
2884
2885                 /// <summary>
2886                 ///   Removes any static methods from the MethodGroup, returns
2887                 ///   false if the resulting set is empty.
2888                 /// </summary>
2889                 public bool RemoveStaticMethods ()
2890                 {
2891                         return RemoveMethods (false);
2892                 }
2893
2894                 public Expression ResolveGeneric (EmitContext ec, TypeArguments args)
2895                 {
2896                         if (args.Resolve (ec) == false)
2897                                 return null;
2898
2899                         Type[] atypes = args.Arguments;
2900
2901                         int first_count = 0;
2902                         MethodInfo first = null;
2903
2904                         ArrayList list = new ArrayList ();
2905                         foreach (MethodBase mb in Methods) {
2906                                 MethodInfo mi = mb as MethodInfo;
2907                                 if ((mi == null) || !mi.HasGenericParameters)
2908                                         continue;
2909
2910                                 Type[] gen_params = mi.GetGenericArguments ();
2911
2912                                 if (first == null) {
2913                                         first = mi;
2914                                         first_count = gen_params.Length;
2915                                 }
2916
2917                                 if (gen_params.Length != atypes.Length)
2918                                         continue;
2919
2920                                 list.Add (mi.MakeGenericMethod (atypes));
2921                         }
2922
2923                         if (list.Count > 0) {
2924                                 MethodGroupExpr new_mg = new MethodGroupExpr (list, Location);
2925                                 new_mg.InstanceExpression = InstanceExpression;
2926                                 new_mg.HasTypeArguments = true;
2927                                 return new_mg;
2928                         }
2929
2930                         if (first != null)
2931                                 Report.Error (
2932                                         305, loc, "Using the generic method `{0}' " +
2933                                         "requires {1} type arguments", Name,
2934                                         first_count.ToString ());
2935                         else
2936                                 Report.Error (
2937                                         308, loc, "The non-generic method `{0}' " +
2938                                         "cannot be used with type arguments", Name);
2939
2940                         return null;
2941                 }
2942         }
2943
2944         /// <summary>
2945         ///   Fully resolved expression that evaluates to a Field
2946         /// </summary>
2947         public class FieldExpr : MemberExpr, IAssignMethod, IMemoryLocation, IVariable {
2948                 public readonly FieldInfo FieldInfo;
2949                 VariableInfo variable_info;
2950
2951                 LocalTemporary temp;
2952                 bool prepared;
2953                 bool in_initializer;
2954
2955                 public FieldExpr (FieldInfo fi, Location l, bool in_initializer):
2956                         this (fi, l)
2957                 {
2958                         this.in_initializer = in_initializer;
2959                 }
2960
2961                 public FieldExpr (FieldInfo fi, Location l)
2962                 {
2963                         FieldInfo = fi;
2964                         eclass = ExprClass.Variable;
2965                         type = TypeManager.TypeToCoreType (fi.FieldType);
2966                         loc = l;
2967                 }
2968
2969                 public override string Name {
2970                         get {
2971                                 return FieldInfo.Name;
2972                         }
2973                 }
2974
2975                 public override bool IsInstance {
2976                         get {
2977                                 return !FieldInfo.IsStatic;
2978                         }
2979                 }
2980
2981                 public override bool IsStatic {
2982                         get {
2983                                 return FieldInfo.IsStatic;
2984                         }
2985                 }
2986
2987                 public override Type DeclaringType {
2988                         get {
2989                                 return FieldInfo.DeclaringType;
2990                         }
2991                 }
2992
2993                 public override string GetSignatureForError ()
2994                 {
2995                         return TypeManager.GetFullNameSignature (FieldInfo);
2996                 }
2997
2998                 public VariableInfo VariableInfo {
2999                         get {
3000                                 return variable_info;
3001                         }
3002                 }
3003
3004                 public override Expression ResolveMemberAccess (EmitContext ec, Expression left, Location loc,
3005                                                                 SimpleName original)
3006                 {
3007                         FieldInfo fi = FieldInfo.Mono_GetGenericFieldDefinition ();
3008
3009                         Type t = fi.FieldType;
3010
3011                         if (fi.IsLiteral || (fi.IsInitOnly && t == TypeManager.decimal_type)) {
3012                                 IConstant ic = TypeManager.GetConstant (fi);
3013                                 if (ic == null) {
3014                                         if (fi.IsLiteral) {
3015                                                 ic = new ExternalConstant (fi);
3016                                         } else {
3017                                                 ic = ExternalConstant.CreateDecimal (fi);
3018                                                 if (ic == null) {
3019                                                         return base.ResolveMemberAccess (ec, left, loc, original);
3020                                                 }
3021                                         }
3022                                         TypeManager.RegisterConstant (fi, ic);
3023                                 }
3024
3025                                 bool left_is_type = left is TypeExpr;
3026                                 if (!left_is_type && (original == null || !original.IdenticalNameAndTypeName (ec, left, loc))) {
3027                                         Report.SymbolRelatedToPreviousError (FieldInfo);
3028                                         error176 (loc, TypeManager.GetFullNameSignature (FieldInfo));
3029                                         return null;
3030                                 }
3031
3032                                 if (ic.ResolveValue ())
3033                                         ic.CheckObsoleteness (loc);
3034
3035                                 return ic.Value;
3036                         }
3037
3038                         if (t.IsPointer && !ec.InUnsafe) {
3039                                 UnsafeError (loc);
3040                                 return null;
3041                         }
3042
3043                         return base.ResolveMemberAccess (ec, left, loc, original);
3044                 }
3045
3046                 override public Expression DoResolve (EmitContext ec)
3047                 {
3048                         if (ec.InRefOutArgumentResolving && FieldInfo.IsInitOnly && !ec.IsConstructor && FieldInfo.FieldType.IsValueType) {
3049                                 if (FieldInfo.FieldType is TypeBuilder) {
3050                                         if (FieldInfo.IsStatic)
3051                                                 Report.Error (1651, loc, "Fields of static readonly field `{0}' cannot be passed ref or out (except in a static constructor)",
3052                                                         GetSignatureForError ());
3053                                         else
3054                                                 Report.Error (1649, loc, "Members of readonly field `{0}.{1}' cannot be passed ref or out (except in a constructor)",
3055                                                         TypeManager.CSharpName (DeclaringType), Name);
3056                                 } else {
3057                                         if (FieldInfo.IsStatic)
3058                                                 Report.Error (199, loc, "A static readonly field `{0}' cannot be passed ref or out (except in a static constructor)",
3059                                                         Name);
3060                                         else
3061                                                 Report.Error (192, loc, "A readonly field `{0}' cannot be passed ref or out (except in a constructor)",
3062                                                         Name);
3063                                 }
3064                                 return null;
3065                         }
3066
3067                         if (!FieldInfo.IsStatic){
3068                                 if (InstanceExpression == null){
3069                                         //
3070                                         // This can happen when referencing an instance field using
3071                                         // a fully qualified type expression: TypeName.InstanceField = xxx
3072                                         //
3073                                         SimpleName.Error_ObjectRefRequired (ec, loc, FieldInfo.Name);
3074                                         return null;
3075                                 }
3076
3077                                 // Resolve the field's instance expression while flow analysis is turned
3078                                 // off: when accessing a field "a.b", we must check whether the field
3079                                 // "a.b" is initialized, not whether the whole struct "a" is initialized.
3080                                 InstanceExpression = InstanceExpression.Resolve (
3081                                         ec, ResolveFlags.VariableOrValue | ResolveFlags.DisableFlowAnalysis);
3082                                 if (InstanceExpression == null)
3083                                         return null;
3084                         }
3085
3086                         if (!in_initializer && !ec.IsFieldInitializer) {
3087                                 ObsoleteAttribute oa;
3088                                 FieldBase f = TypeManager.GetField (FieldInfo);
3089                                 if (f != null) {
3090                                         f.CheckObsoleteness (loc);
3091                                         // To be sure that type is external because we do not register generated fields
3092                                 } else if (!(FieldInfo.DeclaringType is TypeBuilder)) {
3093                                         oa = AttributeTester.GetMemberObsoleteAttribute (FieldInfo);
3094                                         if (oa != null)
3095                                                 AttributeTester.Report_ObsoleteMessage (oa, TypeManager.GetFullNameSignature (FieldInfo), loc);
3096                                 }
3097                         }
3098
3099                         AnonymousContainer am = ec.CurrentAnonymousMethod;
3100                         if (am != null){
3101                                 if (!FieldInfo.IsStatic){
3102                                         if (!am.IsIterator && (ec.TypeContainer is Struct)){
3103                                                 Report.Error (1673, loc,
3104                                                 "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",
3105                                                         "this");
3106                                                 return null;
3107                                         }
3108                                         if ((am.ContainerAnonymousMethod == null) && (InstanceExpression is This))
3109                                                 ec.CaptureField (this);
3110                                 }
3111                         }
3112
3113                         // If the instance expression is a local variable or parameter.
3114                         IVariable var = InstanceExpression as IVariable;
3115                         if ((var == null) || (var.VariableInfo == null))
3116                                 return this;
3117
3118                         VariableInfo vi = var.VariableInfo;
3119                         if (!vi.IsFieldAssigned (ec, FieldInfo.Name, loc))
3120                                 return null;
3121
3122                         variable_info = vi.GetSubStruct (FieldInfo.Name);
3123                         return this;
3124                 }
3125
3126                 void Report_AssignToReadonly (bool is_instance)
3127                 {
3128                         string msg;
3129
3130                         if (is_instance)
3131                                 msg = "A readonly field cannot be assigned to (except in a constructor or a variable initializer)";
3132                         else
3133                                 msg = "A static readonly field cannot be assigned to (except in a static constructor or a variable initializer)";
3134
3135                         Report.Error (is_instance ? 191 : 198, loc, msg);
3136                 }
3137
3138                 override public Expression DoResolveLValue (EmitContext ec, Expression right_side)
3139                 {
3140                         IVariable var = InstanceExpression as IVariable;
3141                         if ((var != null) && (var.VariableInfo != null))
3142                                 var.VariableInfo.SetFieldAssigned (ec, FieldInfo.Name);
3143
3144                         Expression e = DoResolve (ec);
3145
3146                         if (e == null)
3147                                 return null;
3148
3149                         if (!FieldInfo.IsStatic && !CheckIntermediateModification ())
3150                                 return null;
3151
3152                         FieldBase fb = TypeManager.GetField (FieldInfo);
3153                         if (fb != null)
3154                                 fb.SetAssigned ();
3155
3156                         if (!FieldInfo.IsInitOnly)
3157                                 return this;
3158
3159                         //
3160                         // InitOnly fields can only be assigned in constructors
3161                         //
3162
3163                         if (ec.IsConstructor){
3164                                 if (IsStatic && !ec.IsStatic)
3165                                         Report_AssignToReadonly (false);
3166
3167                                 Type ctype;
3168                                 if (ec.TypeContainer.CurrentType != null)
3169                                         ctype = ec.TypeContainer.CurrentType;
3170                                 else
3171                                         ctype = ec.ContainerType;
3172
3173                                 if (TypeManager.IsEqual (ctype, FieldInfo.DeclaringType))
3174                                         return this;
3175                         }
3176
3177                         Report_AssignToReadonly (!IsStatic);
3178
3179                         return null;
3180                 }
3181
3182                 public override void CheckMarshallByRefAccess (Type container)
3183                 {
3184                         if (!IsStatic && Type.IsValueType && !container.IsSubclassOf (TypeManager.mbr_type) && DeclaringType.IsSubclassOf (TypeManager.mbr_type)) {
3185                                 Report.SymbolRelatedToPreviousError (DeclaringType);
3186                                 Report.Error (1690, loc, "Cannot call methods, properties, or indexers on `{0}' because it is a value type member of a marshal-by-reference class",
3187                                         GetSignatureForError ());
3188                         }
3189                 }
3190
3191                 public bool VerifyFixed ()
3192                 {
3193                         IVariable variable = InstanceExpression as IVariable;
3194                         // A variable of the form V.I is fixed when V is a fixed variable of a struct type.
3195                         // We defer the InstanceExpression check after the variable check to avoid a
3196                         // separate null check on InstanceExpression.
3197                         return variable != null && InstanceExpression.Type.IsValueType && variable.VerifyFixed ();
3198                 }
3199
3200                 public override int GetHashCode()
3201                 {
3202                         return FieldInfo.GetHashCode ();
3203                 }
3204
3205                 public override bool Equals (object obj)
3206                 {
3207                         FieldExpr fe = obj as FieldExpr;
3208                         if (fe == null)
3209                                 return false;
3210
3211                         if (FieldInfo != fe.FieldInfo)
3212                                 return false;
3213
3214                         if (InstanceExpression == null || fe.InstanceExpression == null)
3215                                 return true;
3216
3217                         return InstanceExpression.Equals (fe.InstanceExpression);
3218                 }
3219
3220                 public void Emit (EmitContext ec, bool leave_copy)
3221                 {
3222                         ILGenerator ig = ec.ig;
3223                         bool is_volatile = false;
3224
3225                         FieldInfo the_fi = FieldInfo.Mono_GetGenericFieldDefinition ();
3226                         if (the_fi is FieldBuilder){
3227                                 FieldBase f = TypeManager.GetField (the_fi);
3228                                 if (f != null){
3229                                         if ((f.ModFlags & Modifiers.VOLATILE) != 0)
3230                                                 is_volatile = true;
3231
3232                                         f.SetMemberIsUsed ();
3233                                 }
3234                         }
3235
3236                         if (FieldInfo.IsStatic){
3237                                 if (is_volatile)
3238                                         ig.Emit (OpCodes.Volatile);
3239
3240                                 ig.Emit (OpCodes.Ldsfld, FieldInfo);
3241                         } else {
3242                                 if (!prepared)
3243                                         EmitInstance (ec, false);
3244
3245                                 if (is_volatile)
3246                                         ig.Emit (OpCodes.Volatile);
3247
3248                                 IFixedBuffer ff = AttributeTester.GetFixedBuffer (FieldInfo);
3249                                 if (ff != null)
3250                                 {
3251                                         ig.Emit (OpCodes.Ldflda, FieldInfo);
3252                                         ig.Emit (OpCodes.Ldflda, ff.Element);
3253                                 }
3254                                 else {
3255                                         ig.Emit (OpCodes.Ldfld, FieldInfo);
3256                                 }
3257                         }
3258
3259                         if (leave_copy) {
3260                                 ec.ig.Emit (OpCodes.Dup);
3261                                 if (!FieldInfo.IsStatic) {
3262                                         temp = new LocalTemporary (ec, this.Type);
3263                                         temp.Store (ec);
3264                                 }
3265                         }
3266                 }
3267
3268                 public void EmitAssign (EmitContext ec, Expression source, bool leave_copy, bool prepare_for_load)
3269                 {
3270                         FieldAttributes fa = FieldInfo.Attributes;
3271                         bool is_static = (fa & FieldAttributes.Static) != 0;
3272                         bool is_readonly = (fa & FieldAttributes.InitOnly) != 0;
3273                         ILGenerator ig = ec.ig;
3274                         prepared = prepare_for_load;
3275
3276                         if (is_readonly && !ec.IsConstructor){
3277                                 Report_AssignToReadonly (!is_static);
3278                                 return;
3279                         }
3280
3281                         EmitInstance (ec, prepare_for_load);
3282
3283                         source.Emit (ec);
3284                         if (leave_copy) {
3285                                 ec.ig.Emit (OpCodes.Dup);
3286                                 if (!FieldInfo.IsStatic) {
3287                                         temp = new LocalTemporary (ec, this.Type);
3288                                         temp.Store (ec);
3289                                 }
3290                         }
3291
3292                         if (FieldInfo is FieldBuilder){
3293                                 FieldBase f = TypeManager.GetField (FieldInfo);
3294                                 if (f != null){
3295                                         if ((f.ModFlags & Modifiers.VOLATILE) != 0)
3296                                                 ig.Emit (OpCodes.Volatile);
3297
3298                                         f.SetAssigned ();
3299                                 }
3300                         }
3301
3302                         if (is_static)
3303                                 ig.Emit (OpCodes.Stsfld, FieldInfo);
3304                         else
3305                                 ig.Emit (OpCodes.Stfld, FieldInfo);
3306
3307                         if (temp != null)
3308                                 temp.Emit (ec);
3309                 }
3310
3311                 public override void Emit (EmitContext ec)
3312                 {
3313                         Emit (ec, false);
3314                 }
3315
3316                 public void AddressOf (EmitContext ec, AddressOp mode)
3317                 {
3318                         ILGenerator ig = ec.ig;
3319
3320                         if (FieldInfo is FieldBuilder){
3321                                 FieldBase f = TypeManager.GetField (FieldInfo);
3322                                 if (f != null){
3323                                         if ((f.ModFlags & Modifiers.VOLATILE) != 0){
3324                                                 Report.Warning (420, 1, loc, "`{0}': A volatile fields cannot be passed using a ref or out parameter",
3325                                                         f.GetSignatureForError ());
3326                                                 return;
3327                                         }
3328
3329                                         if ((mode & AddressOp.Store) != 0)
3330                                                 f.SetAssigned ();
3331                                         if ((mode & AddressOp.Load) != 0)
3332                                                 f.SetMemberIsUsed ();
3333                                 }
3334                         }
3335
3336                         //
3337                         // Handle initonly fields specially: make a copy and then
3338                         // get the address of the copy.
3339                         //
3340                         bool need_copy;
3341                         if (FieldInfo.IsInitOnly){
3342                                 need_copy = true;
3343                                 if (ec.IsConstructor){
3344                                         if (FieldInfo.IsStatic){
3345                                                 if (ec.IsStatic)
3346                                                         need_copy = false;
3347                                         } else
3348                                                 need_copy = false;
3349                                 }
3350                         } else
3351                                 need_copy = false;
3352
3353                         if (need_copy){
3354                                 LocalBuilder local;
3355                                 Emit (ec);
3356                                 local = ig.DeclareLocal (type);
3357                                 ig.Emit (OpCodes.Stloc, local);
3358                                 ig.Emit (OpCodes.Ldloca, local);
3359                                 return;
3360                         }
3361
3362
3363                         if (FieldInfo.IsStatic){
3364                                 ig.Emit (OpCodes.Ldsflda, FieldInfo);
3365                         } else {
3366                                 EmitInstance (ec, false);
3367                                 ig.Emit (OpCodes.Ldflda, FieldInfo);
3368                         }
3369                 }
3370         }
3371
3372         //
3373         // A FieldExpr whose address can not be taken
3374         //
3375         public class FieldExprNoAddress : FieldExpr, IMemoryLocation {
3376                 public FieldExprNoAddress (FieldInfo fi, Location loc) : base (fi, loc)
3377                 {
3378                 }
3379
3380                 public new void AddressOf (EmitContext ec, AddressOp mode)
3381                 {
3382                         Report.Error (-215, "Report this: Taking the address of a remapped parameter not supported");
3383                 }
3384         }
3385
3386         /// <summary>
3387         ///   Expression that evaluates to a Property.  The Assign class
3388         ///   might set the `Value' expression if we are in an assignment.
3389         ///
3390         ///   This is not an LValue because we need to re-write the expression, we
3391         ///   can not take data from the stack and store it.
3392         /// </summary>
3393         public class PropertyExpr : MemberExpr, IAssignMethod {
3394                 public readonly PropertyInfo PropertyInfo;
3395
3396                 //
3397                 // This is set externally by the  `BaseAccess' class
3398                 //
3399                 public bool IsBase;
3400                 MethodInfo getter, setter;
3401                 bool is_static;
3402
3403                 bool resolved;
3404
3405                 LocalTemporary temp;
3406                 bool prepared;
3407
3408                 internal static PtrHashtable AccessorTable = new PtrHashtable ();
3409
3410                 public PropertyExpr (EmitContext ec, PropertyInfo pi, Location l)
3411                 {
3412                         PropertyInfo = pi;
3413                         eclass = ExprClass.PropertyAccess;
3414                         is_static = false;
3415                         loc = l;
3416
3417                         type = TypeManager.TypeToCoreType (pi.PropertyType);
3418
3419                         ResolveAccessors (ec);
3420                 }
3421
3422                 public override string Name {
3423                         get {
3424                                 return PropertyInfo.Name;
3425                         }
3426                 }
3427
3428                 public override bool IsInstance {
3429                         get {
3430                                 return !is_static;
3431                         }
3432                 }
3433
3434                 public override bool IsStatic {
3435                         get {
3436                                 return is_static;
3437                         }
3438                 }
3439
3440                 public override Type DeclaringType {
3441                         get {
3442                                 return PropertyInfo.DeclaringType;
3443                         }
3444                 }
3445
3446                 public override string GetSignatureForError ()
3447                 {
3448                         return TypeManager.GetFullNameSignature (PropertyInfo);
3449                 }
3450
3451                 void FindAccessors (Type invocation_type)
3452                 {
3453                         BindingFlags flags = BindingFlags.Public | BindingFlags.NonPublic |
3454                                 BindingFlags.Static | BindingFlags.Instance |
3455                                 BindingFlags.DeclaredOnly;
3456
3457                         Type current = PropertyInfo.DeclaringType;
3458                         for (; current != null; current = current.BaseType) {
3459                                 MemberInfo[] group = TypeManager.MemberLookup (
3460                                         invocation_type, invocation_type, current,
3461                                         MemberTypes.Property, flags, PropertyInfo.Name, null);
3462
3463                                 if (group == null)
3464                                         continue;
3465
3466                                 if (group.Length != 1)
3467                                         // Oooops, can this ever happen ?
3468                                         return;
3469
3470                                 PropertyInfo pi = (PropertyInfo) group [0];
3471
3472                                 if (getter == null)
3473                                         getter = pi.GetGetMethod (true);
3474
3475                                 if (setter == null)
3476                                         setter = pi.GetSetMethod (true);
3477
3478                                 MethodInfo accessor = getter != null ? getter : setter;
3479
3480                                 if (!accessor.IsVirtual)
3481                                         return;
3482                         }
3483                 }
3484
3485                 //
3486                 // We also perform the permission checking here, as the PropertyInfo does not
3487                 // hold the information for the accessibility of its setter/getter
3488                 //
3489                 void ResolveAccessors (EmitContext ec)
3490                 {
3491                         FindAccessors (ec.ContainerType);
3492
3493                         if (getter != null) {
3494                                 MethodInfo the_getter = getter;
3495                                 if (the_getter.Mono_IsInflatedMethod)
3496                                         the_getter = the_getter.GetGenericMethodDefinition ();
3497                                 IMethodData md = TypeManager.GetMethod (the_getter);
3498                                 if (md != null)
3499                                         md.SetMemberIsUsed ();
3500
3501                                 AccessorTable [getter] = PropertyInfo;
3502                                 is_static = getter.IsStatic;
3503                         }
3504
3505                         if (setter != null) {
3506                                 MethodInfo the_setter = setter;
3507                                 if (the_setter.Mono_IsInflatedMethod)
3508                                         the_setter = the_setter.GetGenericMethodDefinition ();
3509                                 IMethodData md = TypeManager.GetMethod (the_setter);
3510                                 if (md != null)
3511                                         md.SetMemberIsUsed ();
3512
3513                                 AccessorTable [setter] = PropertyInfo;
3514                                 is_static = setter.IsStatic;
3515                         }
3516                 }
3517
3518                 bool InstanceResolve (EmitContext ec, bool must_do_cs1540_check)
3519                 {
3520                         if (is_static) {
3521                                 InstanceExpression = null;
3522                                 return true;
3523                         }
3524
3525                         if (InstanceExpression == null) {
3526                                 SimpleName.Error_ObjectRefRequired (ec, loc, PropertyInfo.Name);
3527                                 return false;
3528                         }
3529
3530                         InstanceExpression = InstanceExpression.DoResolve (ec);
3531                         if (InstanceExpression == null)
3532                                 return false;
3533
3534                         InstanceExpression.CheckMarshallByRefAccess (ec.ContainerType);
3535
3536                         if (must_do_cs1540_check && InstanceExpression != EmptyExpression.Null &&
3537                                 InstanceExpression.Type != ec.ContainerType &&
3538                                 ec.ContainerType.IsSubclassOf (PropertyInfo.DeclaringType) &&
3539                                 InstanceExpression.Type.IsSubclassOf (PropertyInfo.DeclaringType)) {
3540                                         Error_CannotAccessProtected (loc, PropertyInfo, InstanceExpression.Type, ec.ContainerType);
3541                                         return false;
3542                         }
3543
3544                         return true;
3545                 }
3546
3547                 void Error_PropertyNotFound (MethodInfo mi, bool getter)
3548                 {
3549                         // TODO: correctly we should compare arguments but it will lead to bigger changes
3550                         if (mi is MethodBuilder) {
3551                                 Error_TypeDoesNotContainDefinition (loc, PropertyInfo.DeclaringType, Name);
3552                                 return;
3553                         }
3554
3555                         StringBuilder sig = new StringBuilder (TypeManager.CSharpName (mi.DeclaringType));
3556                         sig.Append ('.');
3557                         ParameterData iparams = TypeManager.GetParameterData (mi);
3558                         sig.Append (getter ? "get_" : "set_");
3559                         sig.Append (Name);
3560                         sig.Append (iparams.GetSignatureForError ());
3561
3562                         Report.SymbolRelatedToPreviousError (mi);
3563                         Report.Error (1546, loc, "Property `{0}' is not supported by the C# language. Try to call the accessor method `{1}' directly",
3564                                 Name, sig.ToString ());
3565                 }
3566
3567                 override public Expression DoResolve (EmitContext ec)
3568                 {
3569                         if (resolved)
3570                                 return this;
3571
3572                         if (getter != null){
3573                                 if (TypeManager.GetArgumentTypes (getter).Length != 0){
3574                                         Error_PropertyNotFound (getter, true);
3575                                         return null;
3576                                 }
3577                         }
3578
3579                         if (getter == null){
3580                                 //
3581                                 // The following condition happens if the PropertyExpr was
3582                                 // created, but is invalid (ie, the property is inaccessible),
3583                                 // and we did not want to embed the knowledge about this in
3584                                 // the caller routine.  This only avoids double error reporting.
3585                                 //
3586                                 if (setter == null)
3587                                         return null;
3588
3589                                 if (InstanceExpression != EmptyExpression.Null) {
3590                                         Report.Error (154, loc, "The property or indexer `{0}' cannot be used in this context because it lacks the `get' accessor",
3591                                                 TypeManager.GetFullNameSignature (PropertyInfo));
3592                                         return null;
3593                                 }
3594                         }
3595
3596                         bool must_do_cs1540_check = false;
3597                         if (getter != null &&
3598                             !IsAccessorAccessible (ec.ContainerType, getter, out must_do_cs1540_check)) {
3599                                 PropertyBase.PropertyMethod pm = TypeManager.GetMethod (getter) as PropertyBase.PropertyMethod;
3600                                 if (pm != null && pm.HasCustomAccessModifier) {
3601                                         Report.SymbolRelatedToPreviousError (pm);
3602                                         Report.Error (271, loc, "The property or indexer `{0}' cannot be used in this context because the get accessor is inaccessible",
3603                                                 TypeManager.CSharpSignature (getter));
3604                                 }
3605                                 else
3606                                         ErrorIsInaccesible (loc, TypeManager.CSharpSignature (getter));
3607                                 return null;
3608                         }
3609
3610                         if (!InstanceResolve (ec, must_do_cs1540_check))
3611                                 return null;
3612
3613                         //
3614                         // Only base will allow this invocation to happen.
3615                         //
3616                         if (IsBase && getter.IsAbstract) {
3617                                 Error_CannotCallAbstractBase (TypeManager.GetFullNameSignature (PropertyInfo));
3618                                 return null;
3619                         }
3620
3621                         if (PropertyInfo.PropertyType.IsPointer && !ec.InUnsafe){
3622                                 UnsafeError (loc);
3623                                 return null;
3624                         }
3625
3626                         resolved = true;
3627
3628                         return this;
3629                 }
3630
3631                 override public Expression DoResolveLValue (EmitContext ec, Expression right_side)
3632                 {
3633                         if (setter == null){
3634                                 //
3635                                 // The following condition happens if the PropertyExpr was
3636                                 // created, but is invalid (ie, the property is inaccessible),
3637                                 // and we did not want to embed the knowledge about this in
3638                                 // the caller routine.  This only avoids double error reporting.
3639                                 //
3640                                 if (getter == null)
3641                                         return null;
3642
3643                                 Report.Error (200, loc, " Property or indexer `{0}' cannot be assigned to (it is read only)",
3644                                               TypeManager.GetFullNameSignature (PropertyInfo));
3645                                 return null;
3646                         }
3647
3648                         if (TypeManager.GetArgumentTypes (setter).Length != 1){
3649                                 Error_PropertyNotFound (setter, false);
3650                                 return null;
3651                         }
3652
3653                         bool must_do_cs1540_check;
3654                         if (!IsAccessorAccessible (ec.ContainerType, setter, out must_do_cs1540_check)) {
3655                                 PropertyBase.PropertyMethod pm = TypeManager.GetMethod (setter) as PropertyBase.PropertyMethod;
3656                                 if (pm != null && pm.HasCustomAccessModifier) {
3657                                         Report.SymbolRelatedToPreviousError (pm);
3658                                         Report.Error (272, loc, "The property or indexer `{0}' cannot be used in this context because the set accessor is inaccessible",
3659                                                 TypeManager.CSharpSignature (setter));
3660                                 }
3661                                 else
3662                                         ErrorIsInaccesible (loc, TypeManager.CSharpSignature (setter));
3663                                 return null;
3664                         }
3665
3666                         if (!InstanceResolve (ec, must_do_cs1540_check))
3667                                 return null;
3668
3669                         //
3670                         // Only base will allow this invocation to happen.
3671                         //
3672                         if (IsBase && setter.IsAbstract){
3673                                 Error_CannotCallAbstractBase (TypeManager.GetFullNameSignature (PropertyInfo));
3674                                 return null;
3675                         }
3676
3677                         //
3678                         // Check that we are not making changes to a temporary memory location
3679                         //
3680                         if (InstanceExpression != null && !CheckIntermediateModification ())
3681                                 return null;
3682
3683                         return this;
3684                 }
3685
3686                 public override void Emit (EmitContext ec)
3687                 {
3688                         Emit (ec, false);
3689                 }
3690
3691                 public void Emit (EmitContext ec, bool leave_copy)
3692                 {
3693                         //
3694                         // Special case: length of single dimension array property is turned into ldlen
3695                         //
3696                         if ((getter == TypeManager.system_int_array_get_length) ||
3697                             (getter == TypeManager.int_array_get_length)){
3698                                 Type iet = InstanceExpression.Type;
3699
3700                                 //
3701                                 // System.Array.Length can be called, but the Type does not
3702                                 // support invoking GetArrayRank, so test for that case first
3703                                 //
3704                                 if (iet != TypeManager.array_type && (iet.GetArrayRank () == 1)) {
3705                                         if (!prepared)
3706                                                 EmitInstance (ec, false);
3707                                         ec.ig.Emit (OpCodes.Ldlen);
3708                                         ec.ig.Emit (OpCodes.Conv_I4);
3709                                         return;
3710                                 }
3711                         }
3712
3713                         Invocation.EmitCall (ec, IsBase, IsStatic, InstanceExpression, getter, null, loc, prepared, false);
3714
3715                         if (leave_copy) {
3716                                 ec.ig.Emit (OpCodes.Dup);
3717                                 if (!is_static) {
3718                                         temp = new LocalTemporary (ec, this.Type);
3719                                         temp.Store (ec);
3720                                 }
3721                         }
3722                 }
3723
3724                 //
3725                 // Implements the IAssignMethod interface for assignments
3726                 //
3727                 public void EmitAssign (EmitContext ec, Expression source, bool leave_copy, bool prepare_for_load)
3728                 {
3729                         Expression my_source = source;
3730
3731                         prepared = prepare_for_load;
3732
3733                         if (prepared) {
3734                                 source.Emit (ec);
3735                                 if (leave_copy) {
3736                                         ec.ig.Emit (OpCodes.Dup);
3737                                         if (!is_static) {
3738                                                 temp = new LocalTemporary (ec, this.Type);
3739                                                 temp.Store (ec);
3740                                         }
3741                                 }
3742                         } else if (leave_copy) {
3743                                 source.Emit (ec);
3744                                 if (!is_static) {
3745                                         temp = new LocalTemporary (ec, this.Type);
3746                                         temp.Store (ec);
3747                                 }
3748                                 my_source = temp;
3749                         }
3750
3751                         ArrayList args = new ArrayList (1);
3752                         args.Add (new Argument (my_source, Argument.AType.Expression));
3753
3754                         Invocation.EmitCall (ec, IsBase, IsStatic, InstanceExpression, setter, args, loc, false, prepared);
3755
3756                         if (temp != null)
3757                                 temp.Emit (ec);
3758                 }
3759         }
3760
3761         /// <summary>
3762         ///   Fully resolved expression that evaluates to an Event
3763         /// </summary>
3764         public class EventExpr : MemberExpr {
3765                 public readonly EventInfo EventInfo;
3766
3767                 bool is_static;
3768                 MethodInfo add_accessor, remove_accessor;
3769
3770                 public EventExpr (EventInfo ei, Location loc)
3771                 {
3772                         EventInfo = ei;
3773                         this.loc = loc;
3774                         eclass = ExprClass.EventAccess;
3775
3776                         add_accessor = TypeManager.GetAddMethod (ei);
3777                         remove_accessor = TypeManager.GetRemoveMethod (ei);
3778
3779                         if (add_accessor.IsStatic || remove_accessor.IsStatic)
3780                                 is_static = true;
3781
3782                         if (EventInfo is MyEventBuilder){
3783                                 MyEventBuilder eb = (MyEventBuilder) EventInfo;
3784                                 type = eb.EventType;
3785                                 eb.SetUsed ();
3786                         } else
3787                                 type = EventInfo.EventHandlerType;
3788                 }
3789
3790                 public override string Name {
3791                         get {
3792                                 return EventInfo.Name;
3793                         }
3794                 }
3795
3796                 public override bool IsInstance {
3797                         get {
3798                                 return !is_static;
3799                         }
3800                 }
3801
3802                 public override bool IsStatic {
3803                         get {
3804                                 return is_static;
3805                         }
3806                 }
3807
3808                 public override Type DeclaringType {
3809                         get {
3810                                 return EventInfo.DeclaringType;
3811                         }
3812                 }
3813
3814                 public override Expression ResolveMemberAccess (EmitContext ec, Expression left, Location loc,
3815                                                                 SimpleName original)
3816                 {
3817                         //
3818                         // If the event is local to this class, we transform ourselves into a FieldExpr
3819                         //
3820
3821                         if (EventInfo.DeclaringType == ec.ContainerType ||
3822                             TypeManager.IsNestedChildOf(ec.ContainerType, EventInfo.DeclaringType)) {
3823                                 MemberInfo mi = TypeManager.GetPrivateFieldOfEvent (EventInfo);
3824
3825                                 if (mi != null) {
3826                                         MemberExpr ml = (MemberExpr) ExprClassFromMemberInfo (ec, mi, loc);
3827
3828                                         if (ml == null) {
3829                                                 Report.Error (-200, loc, "Internal error!!");
3830                                                 return null;
3831                                         }
3832
3833                                         InstanceExpression = null;
3834
3835                                         return ml.ResolveMemberAccess (ec, left, loc, original);
3836                                 }
3837                         }
3838
3839                         return base.ResolveMemberAccess (ec, left, loc, original);
3840                 }
3841
3842
3843                 bool InstanceResolve (EmitContext ec, bool must_do_cs1540_check)
3844                 {
3845                         if (is_static) {
3846                                 InstanceExpression = null;
3847                                 return true;
3848                         }
3849
3850                         if (InstanceExpression == null) {
3851                                 SimpleName.Error_ObjectRefRequired (ec, loc, EventInfo.Name);
3852                                 return false;
3853                         }
3854
3855                         InstanceExpression = InstanceExpression.DoResolve (ec);
3856                         if (InstanceExpression == null)
3857                                 return false;
3858
3859                         //
3860                         // This is using the same mechanism as the CS1540 check in PropertyExpr.
3861                         // However, in the Event case, we reported a CS0122 instead.
3862                         //
3863                         if (must_do_cs1540_check && InstanceExpression != EmptyExpression.Null) {
3864                                 if ((InstanceExpression.Type != ec.ContainerType) &&
3865                                         ec.ContainerType.IsSubclassOf (InstanceExpression.Type)) {
3866                                         ErrorIsInaccesible (loc, TypeManager.CSharpSignature (EventInfo));
3867                                         return false;
3868                                 }
3869                         }
3870
3871                         return true;
3872                 }
3873
3874                 public override Expression DoResolveLValue (EmitContext ec, Expression right_side)
3875                 {
3876                         return DoResolve (ec);
3877                 }
3878
3879                 public override Expression DoResolve (EmitContext ec)
3880                 {
3881                         bool must_do_cs1540_check;
3882                         if (!(IsAccessorAccessible (ec.ContainerType, add_accessor, out must_do_cs1540_check) &&
3883                               IsAccessorAccessible (ec.ContainerType, remove_accessor, out must_do_cs1540_check))) {
3884                                 ErrorIsInaccesible (loc, TypeManager.CSharpSignature (EventInfo));
3885                                 return null;
3886                         }
3887
3888                         if (!InstanceResolve (ec, must_do_cs1540_check))
3889                                 return null;
3890
3891                         return this;
3892                 }
3893
3894                 public override void Emit (EmitContext ec)
3895                 {
3896                         if (InstanceExpression is This)
3897                                 Report.Error (79, loc, "The event `{0}' can only appear on the left hand side of += or -=", GetSignatureForError ());
3898                         else
3899                                 Report.Error (70, loc, "The event `{0}' can only appear on the left hand side of += or -= "+
3900                                               "(except on the defining type)", Name);
3901                 }
3902
3903                 public override string GetSignatureForError ()
3904                 {
3905                         return TypeManager.CSharpSignature (EventInfo);
3906                 }
3907
3908                 public void EmitAddOrRemove (EmitContext ec, Expression source)
3909                 {
3910                         BinaryDelegate source_del = (BinaryDelegate) source;
3911                         Expression handler = source_del.Right;
3912
3913                         Argument arg = new Argument (handler, Argument.AType.Expression);
3914                         ArrayList args = new ArrayList ();
3915
3916                         args.Add (arg);
3917
3918                         if (source_del.IsAddition)
3919                                 Invocation.EmitCall (
3920                                         ec, false, IsStatic, InstanceExpression, add_accessor, args, loc);
3921                         else
3922                                 Invocation.EmitCall (
3923                                         ec, false, IsStatic, InstanceExpression, remove_accessor, args, loc);
3924                 }
3925         }
3926
3927
3928         public class TemporaryVariable : Expression, IMemoryLocation
3929         {
3930                 LocalInfo li;
3931
3932                 public TemporaryVariable (Type type, Location loc)
3933                 {
3934                         this.type = type;
3935                         this.loc = loc;
3936                         eclass = ExprClass.Value;
3937                 }
3938
3939                 public override Expression DoResolve (EmitContext ec)
3940                 {
3941                         if (li != null)
3942                                 return this;
3943
3944                         TypeExpr te = new TypeExpression (type, loc);
3945                         li = ec.CurrentBlock.AddTemporaryVariable (te, loc);
3946                         if (!li.Resolve (ec))
3947                                 return null;
3948
3949                         AnonymousContainer am = ec.CurrentAnonymousMethod;
3950                         if ((am != null) && am.IsIterator)
3951                                 ec.CaptureVariable (li);
3952
3953                         return this;
3954                 }
3955
3956                 public override void Emit (EmitContext ec)
3957                 {
3958                         ILGenerator ig = ec.ig;
3959
3960                         if (li.FieldBuilder != null) {
3961                                 ig.Emit (OpCodes.Ldarg_0);
3962                                 ig.Emit (OpCodes.Ldfld, li.FieldBuilder);
3963                         } else {
3964                                 ig.Emit (OpCodes.Ldloc, li.LocalBuilder);
3965                         }
3966                 }
3967
3968                 public void EmitLoadAddress (EmitContext ec)
3969                 {
3970                         ILGenerator ig = ec.ig;
3971
3972                         if (li.FieldBuilder != null) {
3973                                 ig.Emit (OpCodes.Ldarg_0);
3974                                 ig.Emit (OpCodes.Ldflda, li.FieldBuilder);
3975                         } else {
3976                                 ig.Emit (OpCodes.Ldloca, li.LocalBuilder);
3977                         }
3978                 }
3979
3980                 public void Store (EmitContext ec, Expression right_side)
3981                 {
3982                         if (li.FieldBuilder != null)
3983                                 ec.ig.Emit (OpCodes.Ldarg_0);
3984
3985                         right_side.Emit (ec);
3986                         if (li.FieldBuilder != null) {
3987                                 ec.ig.Emit (OpCodes.Stfld, li.FieldBuilder);
3988                         } else {
3989                                 ec.ig.Emit (OpCodes.Stloc, li.LocalBuilder);
3990                         }
3991                 }
3992
3993                 public void EmitThis (EmitContext ec)
3994                 {
3995                         if (li.FieldBuilder != null) {
3996                                 ec.ig.Emit (OpCodes.Ldarg_0);
3997                         }
3998                 }
3999
4000                 public void EmitStore (ILGenerator ig)
4001                 {
4002                         if (li.FieldBuilder != null)
4003                                 ig.Emit (OpCodes.Stfld, li.FieldBuilder);
4004                         else
4005                                 ig.Emit (OpCodes.Stloc, li.LocalBuilder);
4006                 }
4007
4008                 public void AddressOf (EmitContext ec, AddressOp mode)
4009                 {
4010                         EmitLoadAddress (ec);
4011                 }
4012         }
4013
4014 }