mcs/mcs/expression.cs

   1 //
   2 // expression.cs: Expression representation for the IL tree.
   3 //
   4 // Author:
   5 //   Miguel de Icaza (miguel@ximian.com)
   6 //   Marek Safar (marek.safar@gmail.com)
   7 //
   8 // Copyright 2001, 2002, 2003 Ximian, Inc.
   9 // Copyright 2003-2008 Novell, Inc.
  10 //
  11 #define USE_OLD
  12
  13 namespace Mono.CSharp {
  14         using System;
  15         using System.Collections.Generic;
  16         using System.Reflection;
  17         using System.Reflection.Emit;
  18         using System.Text;
  19         using System.Linq;
  20         using SLE = System.Linq.Expressions;
  21
  22         //
  23         // This is an user operator expression, automatically created during
  24         // resolve phase
  25         //
  26         public class UserOperatorCall : Expression {
  27                 public delegate Expression ExpressionTreeExpression (ResolveContext ec, MethodGroupExpr mg);
  28
  29                 protected readonly Arguments arguments;
  30                 protected readonly MethodGroupExpr mg;
  31                 readonly ExpressionTreeExpression expr_tree;
  32
  33                 public UserOperatorCall (MethodGroupExpr mg, Arguments args, ExpressionTreeExpression expr_tree, Location loc)
  34                 {
  35                         this.mg = mg;
  36                         this.arguments = args;
  37                         this.expr_tree = expr_tree;
  38
  39                         type = mg.BestCandidate.ReturnType;
  40                         eclass = ExprClass.Value;
  41                         this.loc = loc;
  42                 }
  43
  44                 public override Expression CreateExpressionTree (ResolveContext ec)
  45                 {
  46                         if (expr_tree != null)
  47                                 return expr_tree (ec, mg);
  48
  49                         Arguments args = Arguments.CreateForExpressionTree (ec, arguments,
  50                                 new NullLiteral (loc),
  51                                 mg.CreateExpressionTree (ec));
  52
  53                         return CreateExpressionFactoryCall (ec, "Call", args);
  54                 }
  55
  56                 protected override void CloneTo (CloneContext context, Expression target)
  57                 {
  58                         // Nothing to clone
  59                 }
  60
  61                 protected override Expression DoResolve (ResolveContext ec)
  62                 {
  63                         //
  64                         // We are born fully resolved
  65                         //
  66                         return this;
  67                 }
  68
  69                 public override void Emit (EmitContext ec)
  70                 {
  71                         mg.EmitCall (ec, arguments);
  72                 }
  73
  74                 public override SLE.Expression MakeExpression (BuilderContext ctx)
  75                 {
  76                         var method = mg.BestCandidate.GetMetaInfo () as MethodInfo;
  77                         return SLE.Expression.Call (method, Arguments.MakeExpression (arguments, ctx));
  78                 }
  79
  80                 public MethodGroupExpr Method {
  81                         get { return mg; }
  82                 }
  83         }
  84
  85         public class ParenthesizedExpression : ShimExpression
  86         {
  87                 public ParenthesizedExpression (Expression expr)
  88                         : base (expr)
  89                 {
  90                         loc = expr.Location;
  91                 }
  92
  93                 protected override Expression DoResolve (ResolveContext ec)
  94                 {
  95                         return expr.Resolve (ec);
  96                 }
  97
  98                 public override Expression DoResolveLValue (ResolveContext ec, Expression right_side)
  99                 {
 100                         return expr.DoResolveLValue (ec, right_side);
 101                 }
 102         }
 103
 104         //
 105         //   Unary implements unary expressions.
 106         //
 107         public class Unary : Expression
 108         {
 109                 public enum Operator : byte {
 110                         UnaryPlus, UnaryNegation, LogicalNot, OnesComplement,
 111                         AddressOf,  TOP
 112                 }
 113
 114                 static TypeSpec[][] predefined_operators;
 115
 116                 public readonly Operator Oper;
 117                 public Expression Expr;
 118                 Expression enum_conversion;
 119
 120                 public Unary (Operator op, Expression expr, Location loc)
 121                 {
 122                         Oper = op;
 123                         Expr = expr;
 124                         this.loc = loc;
 125                 }
 126
 127                 // <summary>
 128                 //   This routine will attempt to simplify the unary expression when the
 129                 //   argument is a constant.
 130                 // </summary>
 131                 Constant TryReduceConstant (ResolveContext ec, Constant e)
 132                 {
 133                         if (e is EmptyConstantCast)
 134                                 return TryReduceConstant (ec, ((EmptyConstantCast) e).child);
 135
 136                         if (e is SideEffectConstant) {
 137                                 Constant r = TryReduceConstant (ec, ((SideEffectConstant) e).value);
 138                                 return r == null ? null : new SideEffectConstant (r, e, r.Location);
 139                         }
 140
 141                         TypeSpec expr_type = e.Type;
 142
 143                         switch (Oper){
 144                         case Operator.UnaryPlus:
 145                                 // Unary numeric promotions
 146                                 if (expr_type == TypeManager.byte_type)
 147                                         return new IntConstant (((ByteConstant)e).Value, e.Location);
 148                                 if (expr_type == TypeManager.sbyte_type)
 149                                         return new IntConstant (((SByteConstant)e).Value, e.Location);
 150                                 if (expr_type == TypeManager.short_type)
 151                                         return new IntConstant (((ShortConstant)e).Value, e.Location);
 152                                 if (expr_type == TypeManager.ushort_type)
 153                                         return new IntConstant (((UShortConstant)e).Value, e.Location);
 154                                 if (expr_type == TypeManager.char_type)
 155                                         return new IntConstant (((CharConstant)e).Value, e.Location);
 156
 157                                 // Predefined operators
 158                                 if (expr_type == TypeManager.int32_type || expr_type == TypeManager.uint32_type ||
 159                                     expr_type == TypeManager.int64_type || expr_type == TypeManager.uint64_type ||
 160                                     expr_type == TypeManager.float_type || expr_type == TypeManager.double_type ||
 161                                     expr_type == TypeManager.decimal_type) {
 162                                         return e;
 163                                 }
 164
 165                                 return null;
 166
 167                         case Operator.UnaryNegation:
 168                                 // Unary numeric promotions
 169                                 if (expr_type == TypeManager.byte_type)
 170                                         return new IntConstant (-((ByteConstant)e).Value, e.Location);
 171                                 if (expr_type == TypeManager.sbyte_type)
 172                                         return new IntConstant (-((SByteConstant)e).Value, e.Location);
 173                                 if (expr_type == TypeManager.short_type)
 174                                         return new IntConstant (-((ShortConstant)e).Value, e.Location);
 175                                 if (expr_type == TypeManager.ushort_type)
 176                                         return new IntConstant (-((UShortConstant)e).Value, e.Location);
 177                                 if (expr_type == TypeManager.char_type)
 178                                         return new IntConstant (-((CharConstant)e).Value, e.Location);
 179
 180                                 // Predefined operators
 181                                 if (expr_type == TypeManager.int32_type) {
 182                                         int value = ((IntConstant)e).Value;
 183                                         if (value == int.MinValue) {
 184                                                 if (ec.ConstantCheckState) {
 185                                                         ConstantFold.Error_CompileTimeOverflow (ec, loc);
 186                                                         return null;
 187                                                 }
 188                                                 return e;
 189                                         }
 190                                         return new IntConstant (-value, e.Location);
 191                                 }
 192                                 if (expr_type == TypeManager.int64_type) {
 193                                         long value = ((LongConstant)e).Value;
 194                                         if (value == long.MinValue) {
 195                                                 if (ec.ConstantCheckState) {
 196                                                         ConstantFold.Error_CompileTimeOverflow (ec, loc);
 197                                                         return null;
 198                                                 }
 199                                                 return e;
 200                                         }
 201                                         return new LongConstant (-value, e.Location);
 202                                 }
 203
 204                                 if (expr_type == TypeManager.uint32_type) {
 205                                         UIntLiteral uil = e as UIntLiteral;
 206                                         if (uil != null) {
 207                                                 if (uil.Value == int.MaxValue + (uint) 1)
 208                                                         return new IntLiteral (int.MinValue, e.Location);
 209                                                 return new LongLiteral (-uil.Value, e.Location);
 210                                         }
 211                                         return new LongConstant (-((UIntConstant)e).Value, e.Location);
 212                                 }
 213
 214                                 if (expr_type == TypeManager.uint64_type) {
 215                                         ULongLiteral ull = e as ULongLiteral;
 216                                         if (ull != null && ull.Value == 9223372036854775808)
 217                                                 return new LongLiteral (long.MinValue, e.Location);
 218                                         return null;
 219                                 }
 220
 221                                 if (expr_type == TypeManager.float_type) {
 222                                         FloatLiteral fl = e as FloatLiteral;
 223                                         // For better error reporting
 224                                         if (fl != null)
 225                                                 return new FloatLiteral (-fl.Value, e.Location);
 226
 227                                         return new FloatConstant (-((FloatConstant)e).Value, e.Location);
 228                                 }
 229                                 if (expr_type == TypeManager.double_type) {
 230                                         DoubleLiteral dl = e as DoubleLiteral;
 231                                         // For better error reporting
 232                                         if (dl != null)
 233                                                 return new DoubleLiteral (-dl.Value, e.Location);
 234
 235                                         return new DoubleConstant (-((DoubleConstant)e).Value, e.Location);
 236                                 }
 237                                 if (expr_type == TypeManager.decimal_type)
 238                                         return new DecimalConstant (-((DecimalConstant)e).Value, e.Location);
 239
 240                                 return null;
 241
 242                         case Operator.LogicalNot:
 243                                 if (expr_type != TypeManager.bool_type)
 244                                         return null;
 245
 246                                 bool b = (bool)e.GetValue ();
 247                                 return new BoolConstant (!b, e.Location);
 248
 249                         case Operator.OnesComplement:
 250                                 // Unary numeric promotions
 251                                 if (expr_type == TypeManager.byte_type)
 252                                         return new IntConstant (~((ByteConstant)e).Value, e.Location);
 253                                 if (expr_type == TypeManager.sbyte_type)
 254                                         return new IntConstant (~((SByteConstant)e).Value, e.Location);
 255                                 if (expr_type == TypeManager.short_type)
 256                                         return new IntConstant (~((ShortConstant)e).Value, e.Location);
 257                                 if (expr_type == TypeManager.ushort_type)
 258                                         return new IntConstant (~((UShortConstant)e).Value, e.Location);
 259                                 if (expr_type == TypeManager.char_type)
 260                                         return new IntConstant (~((CharConstant)e).Value, e.Location);
 261
 262                                 // Predefined operators
 263                                 if (expr_type == TypeManager.int32_type)
 264                                         return new IntConstant (~((IntConstant)e).Value, e.Location);
 265                                 if (expr_type == TypeManager.uint32_type)
 266                                         return new UIntConstant (~((UIntConstant)e).Value, e.Location);
 267                                 if (expr_type == TypeManager.int64_type)
 268                                         return new LongConstant (~((LongConstant)e).Value, e.Location);
 269                                 if (expr_type == TypeManager.uint64_type){
 270                                         return new ULongConstant (~((ULongConstant)e).Value, e.Location);
 271                                 }
 272                                 if (e is EnumConstant) {
 273                                         e = TryReduceConstant (ec, ((EnumConstant)e).Child);
 274                                         if (e != null)
 275                                                 e = new EnumConstant (e, expr_type);
 276                                         return e;
 277                                 }
 278                                 return null;
 279                         }
 280                         throw new Exception ("Can not constant fold: " + Oper.ToString());
 281                 }
 282
 283                 protected Expression ResolveOperator (ResolveContext ec, Expression expr)
 284                 {
 285                         eclass = ExprClass.Value;
 286
 287                         if (predefined_operators == null)
 288                                 CreatePredefinedOperatorsTable ();
 289
 290                         TypeSpec expr_type = expr.Type;
 291                         Expression best_expr;
 292
 293                         //
 294                         // Primitive types first
 295                         //
 296                         if (TypeManager.IsPrimitiveType (expr_type)) {
 297                                 best_expr = ResolvePrimitivePredefinedType (expr);
 298                                 if (best_expr == null)
 299                                         return null;
 300
 301                                 type = best_expr.Type;
 302                                 Expr = best_expr;
 303                                 return this;
 304                         }
 305
 306                         //
 307                         // E operator ~(E x);
 308                         //
 309                         if (Oper == Operator.OnesComplement && TypeManager.IsEnumType (expr_type))
 310                                 return ResolveEnumOperator (ec, expr);
 311
 312                         return ResolveUserType (ec, expr);
 313                 }
 314
 315                 protected virtual Expression ResolveEnumOperator (ResolveContext ec, Expression expr)
 316                 {
 317                         TypeSpec underlying_type = EnumSpec.GetUnderlyingType (expr.Type);
 318                         Expression best_expr = ResolvePrimitivePredefinedType (EmptyCast.Create (expr, underlying_type));
 319                         if (best_expr == null)
 320                                 return null;
 321
 322                         Expr = best_expr;
 323                         enum_conversion = Convert.ExplicitNumericConversion (new EmptyExpression (best_expr.Type), underlying_type);
 324                         type = expr.Type;
 325                         return EmptyCast.Create (this, type);
 326                 }
 327
 328                 public override Expression CreateExpressionTree (ResolveContext ec)
 329                 {
 330                         return CreateExpressionTree (ec, null);
 331                 }
 332
 333                 Expression CreateExpressionTree (ResolveContext ec, MethodGroupExpr user_op)
 334                 {
 335                         string method_name;
 336                         switch (Oper) {
 337                         case Operator.AddressOf:
 338                                 Error_PointerInsideExpressionTree (ec);
 339                                 return null;
 340                         case Operator.UnaryNegation:
 341                                 if (ec.HasSet (ResolveContext.Options.CheckedScope) && user_op == null && !IsFloat (type))
 342                                         method_name = "NegateChecked";
 343                                 else
 344                                         method_name = "Negate";
 345                                 break;
 346                         case Operator.OnesComplement:
 347                         case Operator.LogicalNot:
 348                                 method_name = "Not";
 349                                 break;
 350                         case Operator.UnaryPlus:
 351                                 method_name = "UnaryPlus";
 352                                 break;
 353                         default:
 354                                 throw new InternalErrorException ("Unknown unary operator " + Oper.ToString ());
 355                         }
 356
 357                         Arguments args = new Arguments (2);
 358                         args.Add (new Argument (Expr.CreateExpressionTree (ec)));
 359                         if (user_op != null)
 360                                 args.Add (new Argument (user_op.CreateExpressionTree (ec)));
 361                         return CreateExpressionFactoryCall (ec, method_name, args);
 362                 }
 363
 364                 static void CreatePredefinedOperatorsTable ()
 365                 {
 366                         predefined_operators = new TypeSpec [(int) Operator.TOP] [];
 367
 368                         //
 369                         // 7.6.1 Unary plus operator
 370                         //
 371                         predefined_operators [(int) Operator.UnaryPlus] = new TypeSpec [] {
 372                                 TypeManager.int32_type, TypeManager.uint32_type,
 373                                 TypeManager.int64_type, TypeManager.uint64_type,
 374                                 TypeManager.float_type, TypeManager.double_type,
 375                                 TypeManager.decimal_type
 376                         };
 377
 378                         //
 379                         // 7.6.2 Unary minus operator
 380                         //
 381                         predefined_operators [(int) Operator.UnaryNegation] = new TypeSpec [] {
 382                                 TypeManager.int32_type,
 383                                 TypeManager.int64_type,
 384                                 TypeManager.float_type, TypeManager.double_type,
 385                                 TypeManager.decimal_type
 386                         };
 387
 388                         //
 389                         // 7.6.3 Logical negation operator
 390                         //
 391                         predefined_operators [(int) Operator.LogicalNot] = new TypeSpec [] {
 392                                 TypeManager.bool_type
 393                         };
 394
 395                         //
 396                         // 7.6.4 Bitwise complement operator
 397                         //
 398                         predefined_operators [(int) Operator.OnesComplement] = new TypeSpec [] {
 399                                 TypeManager.int32_type, TypeManager.uint32_type,
 400                                 TypeManager.int64_type, TypeManager.uint64_type
 401                         };
 402                 }
 403
 404                 //
 405                 // Unary numeric promotions
 406                 //
 407                 static Expression DoNumericPromotion (Operator op, Expression expr)
 408                 {
 409                         TypeSpec expr_type = expr.Type;
 410                         if ((op == Operator.UnaryPlus || op == Operator.UnaryNegation || op == Operator.OnesComplement) &&
 411                                 expr_type == TypeManager.byte_type || expr_type == TypeManager.sbyte_type ||
 412                                 expr_type == TypeManager.short_type || expr_type == TypeManager.ushort_type ||
 413                                 expr_type == TypeManager.char_type)
 414                                 return Convert.ImplicitNumericConversion (expr, TypeManager.int32_type);
 415
 416                         if (op == Operator.UnaryNegation && expr_type == TypeManager.uint32_type)
 417                                 return Convert.ImplicitNumericConversion (expr, TypeManager.int64_type);
 418
 419                         return expr;
 420                 }
 421
 422                 protected override Expression DoResolve (ResolveContext ec)
 423                 {
 424                         if (Oper == Operator.AddressOf) {
 425                                 return ResolveAddressOf (ec);
 426                         }
 427
 428                         Expr = Expr.Resolve (ec);
 429                         if (Expr == null)
 430                                 return null;
 431
 432                         if (Expr.Type == InternalType.Dynamic) {
 433                                 Arguments args = new Arguments (1);
 434                                 args.Add (new Argument (Expr));
 435                                 return new DynamicUnaryConversion (GetOperatorExpressionTypeName (), args, loc).Resolve (ec);
 436                         }
 437
 438                         if (TypeManager.IsNullableType (Expr.Type))
 439                                 return new Nullable.LiftedUnaryOperator (Oper, Expr, loc).Resolve (ec);
 440
 441                         //
 442                         // Attempt to use a constant folding operation.
 443                         //
 444                         Constant cexpr = Expr as Constant;
 445                         if (cexpr != null) {
 446                                 cexpr = TryReduceConstant (ec, cexpr);
 447                                 if (cexpr != null)
 448                                         return cexpr.Resolve (ec);
 449                         }
 450
 451                         Expression expr = ResolveOperator (ec, Expr);
 452                         if (expr == null)
 453                                 Error_OperatorCannotBeApplied (ec, loc, OperName (Oper), Expr.Type);
 454
 455                         //
 456                         // Reduce unary operator on predefined types
 457                         //
 458                         if (expr == this && Oper == Operator.UnaryPlus)
 459                                 return Expr;
 460
 461                         return expr;
 462                 }
 463
 464                 public override Expression DoResolveLValue (ResolveContext ec, Expression right)
 465                 {
 466                         return null;
 467                 }
 468
 469                 public override void Emit (EmitContext ec)
 470                 {
 471                         EmitOperator (ec, type);
 472                 }
 473
 474                 protected void EmitOperator (EmitContext ec, TypeSpec type)
 475                 {
 476                         switch (Oper) {
 477                         case Operator.UnaryPlus:
 478                                 Expr.Emit (ec);
 479                                 break;
 480
 481                         case Operator.UnaryNegation:
 482                                 if (ec.HasSet (EmitContext.Options.CheckedScope) && !IsFloat (type)) {
 483                                         ec.Emit (OpCodes.Ldc_I4_0);
 484                                         if (type == TypeManager.int64_type)
 485                                                 ec.Emit (OpCodes.Conv_U8);
 486                                         Expr.Emit (ec);
 487                                         ec.Emit (OpCodes.Sub_Ovf);
 488                                 } else {
 489                                         Expr.Emit (ec);
 490                                         ec.Emit (OpCodes.Neg);
 491                                 }
 492
 493                                 break;
 494
 495                         case Operator.LogicalNot:
 496                                 Expr.Emit (ec);
 497                                 ec.Emit (OpCodes.Ldc_I4_0);
 498                                 ec.Emit (OpCodes.Ceq);
 499                                 break;
 500
 501                         case Operator.OnesComplement:
 502                                 Expr.Emit (ec);
 503                                 ec.Emit (OpCodes.Not);
 504                                 break;
 505
 506                         case Operator.AddressOf:
 507                                 ((IMemoryLocation)Expr).AddressOf (ec, AddressOp.LoadStore);
 508                                 break;
 509
 510                         default:
 511                                 throw new Exception ("This should not happen: Operator = "
 512                                                      + Oper.ToString ());
 513                         }
 514
 515                         //
 516                         // Same trick as in Binary expression
 517                         //
 518                         if (enum_conversion != null)
 519                                 enum_conversion.Emit (ec);
 520                 }
 521
 522                 public override void EmitBranchable (EmitContext ec, Label target, bool on_true)
 523                 {
 524                         if (Oper == Operator.LogicalNot)
 525                                 Expr.EmitBranchable (ec, target, !on_true);
 526                         else
 527                                 base.EmitBranchable (ec, target, on_true);
 528                 }
 529
 530                 public override void EmitSideEffect (EmitContext ec)
 531                 {
 532                         Expr.EmitSideEffect (ec);
 533                 }
 534
 535                 public static void Error_OperatorCannotBeApplied (ResolveContext ec, Location loc, string oper, TypeSpec t)
 536                 {
 537                         ec.Report.Error (23, loc, "The `{0}' operator cannot be applied to operand of type `{1}'",
 538                                 oper, TypeManager.CSharpName (t));
 539                 }
 540
 541                 //
 542                 // Converts operator to System.Linq.Expressions.ExpressionType enum name
 543                 //
 544                 string GetOperatorExpressionTypeName ()
 545                 {
 546                         switch (Oper) {
 547                         case Operator.OnesComplement:
 548                                 return "OnesComplement";
 549                         case Operator.LogicalNot:
 550                                 return "Not";
 551                         case Operator.UnaryNegation:
 552                                 return "Negate";
 553                         case Operator.UnaryPlus:
 554                                 return "UnaryPlus";
 555                         default:
 556                                 throw new NotImplementedException ("Unknown express type operator " + Oper.ToString ());
 557                         }
 558                 }
 559
 560                 static bool IsFloat (TypeSpec t)
 561                 {
 562                         return t == TypeManager.float_type || t == TypeManager.double_type;
 563                 }
 564
 565                 //
 566                 // Returns a stringified representation of the Operator
 567                 //
 568                 public static string OperName (Operator oper)
 569                 {
 570                         switch (oper) {
 571                         case Operator.UnaryPlus:
 572                                 return "+";
 573                         case Operator.UnaryNegation:
 574                                 return "-";
 575                         case Operator.LogicalNot:
 576                                 return "!";
 577                         case Operator.OnesComplement:
 578                                 return "~";
 579                         case Operator.AddressOf:
 580                                 return "&";
 581                         }
 582
 583                         throw new NotImplementedException (oper.ToString ());
 584                 }
 585
 586                 public override SLE.Expression MakeExpression (BuilderContext ctx)
 587                 {
 588                         var expr = Expr.MakeExpression (ctx);
 589                         bool is_checked = ctx.HasSet (BuilderContext.Options.CheckedScope);
 590
 591                         switch (Oper) {
 592                         case Operator.UnaryNegation:
 593                                 return is_checked ? SLE.Expression.NegateChecked (expr) : SLE.Expression.Negate (expr);
 594                         case Operator.LogicalNot:
 595                                 return SLE.Expression.Not (expr);
 596 #if NET_4_0
 597                         case Operator.OnesComplement:
 598                                 return SLE.Expression.OnesComplement (expr);
 599 #endif
 600                         default:
 601                                 throw new NotImplementedException (Oper.ToString ());
 602                         }
 603                 }
 604
 605                 public static void Reset ()
 606                 {
 607                         predefined_operators = null;
 608                 }
 609
 610                 Expression ResolveAddressOf (ResolveContext ec)
 611                 {
 612                         if (!ec.IsUnsafe)
 613                                 UnsafeError (ec, loc);
 614
 615                         Expr = Expr.DoResolveLValue (ec, EmptyExpression.UnaryAddress);
 616                         if (Expr == null || Expr.eclass != ExprClass.Variable) {
 617                                 ec.Report.Error (211, loc, "Cannot take the address of the given expression");
 618                                 return null;
 619                         }
 620
 621                         if (!TypeManager.VerifyUnmanaged (ec.Compiler, Expr.Type, loc)) {
 622                                 return null;
 623                         }
 624
 625                         IVariableReference vr = Expr as IVariableReference;
 626                         bool is_fixed;
 627                         if (vr != null) {
 628                                 VariableInfo vi = vr.VariableInfo;
 629                                 if (vi != null) {
 630                                         if (vi.LocalInfo != null)
 631                                                 vi.LocalInfo.Used = true;
 632
 633                                         //
 634                                         // A variable is considered definitely assigned if you take its address.
 635                                         //
 636                                         vi.SetAssigned (ec);
 637                                 }
 638
 639                                 is_fixed = vr.IsFixed;
 640                                 vr.SetHasAddressTaken ();
 641
 642                                 if (vr.IsHoisted) {
 643                                         AnonymousMethodExpression.Error_AddressOfCapturedVar (ec, vr, loc);
 644                                 }
 645                         } else {
 646                                 IFixedExpression fe = Expr as IFixedExpression;
 647                                 is_fixed = fe != null && fe.IsFixed;
 648                         }
 649
 650                         if (!is_fixed && !ec.HasSet (ResolveContext.Options.FixedInitializerScope)) {
 651                                 ec.Report.Error (212, loc, "You can only take the address of unfixed expression inside of a fixed statement initializer");
 652                         }
 653
 654                         type = PointerContainer.MakeType (Expr.Type);
 655                         eclass = ExprClass.Value;
 656                         return this;
 657                 }
 658
 659                 Expression ResolvePrimitivePredefinedType (Expression expr)
 660                 {
 661                         expr = DoNumericPromotion (Oper, expr);
 662                         TypeSpec expr_type = expr.Type;
 663                         TypeSpec[] predefined = predefined_operators [(int) Oper];
 664                         foreach (TypeSpec t in predefined) {
 665                                 if (t == expr_type)
 666                                         return expr;
 667                         }
 668                         return null;
 669                 }
 670
 671                 //
 672                 // Perform user-operator overload resolution
 673                 //
 674                 protected virtual Expression ResolveUserOperator (ResolveContext ec, Expression expr)
 675                 {
 676                         CSharp.Operator.OpType op_type;
 677                         switch (Oper) {
 678                         case Operator.LogicalNot:
 679                                 op_type = CSharp.Operator.OpType.LogicalNot; break;
 680                         case Operator.OnesComplement:
 681                                 op_type = CSharp.Operator.OpType.OnesComplement; break;
 682                         case Operator.UnaryNegation:
 683                                 op_type = CSharp.Operator.OpType.UnaryNegation; break;
 684                         case Operator.UnaryPlus:
 685                                 op_type = CSharp.Operator.OpType.UnaryPlus; break;
 686                         default:
 687                                 throw new InternalErrorException (Oper.ToString ());
 688                         }
 689
 690                         var methods = MemberCache.GetUserOperator (expr.Type, op_type, false);
 691                         if (methods == null)
 692                                 return null;
 693
 694                         var user_op = new MethodGroupExpr (methods, expr.Type, loc);
 695
 696                         Arguments args = new Arguments (1);
 697                         args.Add (new Argument (expr));
 698                         user_op = user_op.OverloadResolve (ec, ref args, false, expr.Location);
 699
 700                         if (user_op == null)
 701                                 return null;
 702
 703                         Expr = args [0].Expr;
 704                         return new UserOperatorCall (user_op, args, CreateExpressionTree, expr.Location);
 705                 }
 706
 707                 //
 708                 // Unary user type overload resolution
 709                 //
 710                 Expression ResolveUserType (ResolveContext ec, Expression expr)
 711                 {
 712                         Expression best_expr = ResolveUserOperator (ec, expr);
 713                         if (best_expr != null)
 714                                 return best_expr;
 715
 716                         TypeSpec[] predefined = predefined_operators [(int) Oper];
 717                         foreach (TypeSpec t in predefined) {
 718                                 Expression oper_expr = Convert.ImplicitUserConversion (ec, expr, t, expr.Location);
 719                                 if (oper_expr == null)
 720                                         continue;
 721
 722                                 //
 723                                 // decimal type is predefined but has user-operators
 724                                 //
 725                                 if (oper_expr.Type == TypeManager.decimal_type)
 726                                         oper_expr = ResolveUserType (ec, oper_expr);
 727                                 else
 728                                         oper_expr = ResolvePrimitivePredefinedType (oper_expr);
 729
 730                                 if (oper_expr == null)
 731                                         continue;
 732
 733                                 if (best_expr == null) {
 734                                         best_expr = oper_expr;
 735                                         continue;
 736                                 }
 737
 738                                 int result = MethodGroupExpr.BetterTypeConversion (ec, best_expr.Type, t);
 739                                 if (result == 0) {
 740                                         ec.Report.Error (35, loc, "Operator `{0}' is ambiguous on an operand of type `{1}'",
 741                                                 OperName (Oper), TypeManager.CSharpName (expr.Type));
 742                                         break;
 743                                 }
 744
 745                                 if (result == 2)
 746                                         best_expr = oper_expr;
 747                         }
 748
 749                         if (best_expr == null)
 750                                 return null;
 751
 752                         //
 753                         // HACK: Decimal user-operator is included in standard operators
 754                         //
 755                         if (best_expr.Type == TypeManager.decimal_type)
 756                                 return best_expr;
 757
 758                         Expr = best_expr;
 759                         type = best_expr.Type;
 760                         return this;
 761                 }
 762
 763                 protected override void CloneTo (CloneContext clonectx, Expression t)
 764                 {
 765                         Unary target = (Unary) t;
 766
 767                         target.Expr = Expr.Clone (clonectx);
 768                 }
 769         }
 770
 771         //
 772         // Unary operators are turned into Indirection expressions
 773         // after semantic analysis (this is so we can take the address
 774         // of an indirection).
 775         //
 776         public class Indirection : Expression, IMemoryLocation, IAssignMethod, IFixedExpression {
 777                 Expression expr;
 778                 LocalTemporary temporary;
 779                 bool prepared;
 780
 781                 public Indirection (Expression expr, Location l)
 782                 {
 783                         this.expr = expr;
 784                         loc = l;
 785                 }
 786
 787                 public override Expression CreateExpressionTree (ResolveContext ec)
 788                 {
 789                         Error_PointerInsideExpressionTree (ec);
 790                         return null;
 791                 }
 792
 793                 protected override void CloneTo (CloneContext clonectx, Expression t)
 794                 {
 795                         Indirection target = (Indirection) t;
 796                         target.expr = expr.Clone (clonectx);
 797                 }
 798
 799                 public override void Emit (EmitContext ec)
 800                 {
 801                         if (!prepared)
 802                                 expr.Emit (ec);
 803
 804                         ec.EmitLoadFromPtr (Type);
 805                 }
 806
 807                 public void Emit (EmitContext ec, bool leave_copy)
 808                 {
 809                         Emit (ec);
 810                         if (leave_copy) {
 811                                 ec.Emit (OpCodes.Dup);
 812                                 temporary = new LocalTemporary (expr.Type);
 813                                 temporary.Store (ec);
 814                         }
 815                 }
 816
 817                 public void EmitAssign (EmitContext ec, Expression source, bool leave_copy, bool prepare_for_load)
 818                 {
 819                         prepared = prepare_for_load;
 820
 821                         expr.Emit (ec);
 822
 823                         if (prepare_for_load)
 824                                 ec.Emit (OpCodes.Dup);
 825
 826                         source.Emit (ec);
 827                         if (leave_copy) {
 828                                 ec.Emit (OpCodes.Dup);
 829                                 temporary = new LocalTemporary (expr.Type);
 830                                 temporary.Store (ec);
 831                         }
 832
 833                         ec.EmitStoreFromPtr (type);
 834
 835                         if (temporary != null) {
 836                                 temporary.Emit (ec);
 837                                 temporary.Release (ec);
 838                         }
 839                 }
 840
 841                 public void AddressOf (EmitContext ec, AddressOp Mode)
 842                 {
 843                         expr.Emit (ec);
 844                 }
 845
 846                 public override Expression DoResolveLValue (ResolveContext ec, Expression right_side)
 847                 {
 848                         return DoResolve (ec);
 849                 }
 850
 851                 protected override Expression DoResolve (ResolveContext ec)
 852                 {
 853                         expr = expr.Resolve (ec);
 854                         if (expr == null)
 855                                 return null;
 856
 857                         if (!ec.IsUnsafe)
 858                                 UnsafeError (ec, loc);
 859
 860                         if (!expr.Type.IsPointer) {
 861                                 ec.Report.Error (193, loc, "The * or -> operator must be applied to a pointer");
 862                                 return null;
 863                         }
 864
 865                         if (expr.Type == TypeManager.void_ptr_type) {
 866                                 ec.Report.Error (242, loc, "The operation in question is undefined on void pointers");
 867                                 return null;
 868                         }
 869
 870                         type = TypeManager.GetElementType (expr.Type);
 871                         eclass = ExprClass.Variable;
 872                         return this;
 873                 }
 874
 875                 public bool IsFixed {
 876                         get { return true; }
 877                 }
 878
 879                 public override string ToString ()
 880                 {
 881                         return "*(" + expr + ")";
 882                 }
 883         }
 884
 885         /// <summary>
 886         ///   Unary Mutator expressions (pre and post ++ and --)
 887         /// </summary>
 888         ///
 889         /// <remarks>
 890         ///   UnaryMutator implements ++ and -- expressions.   It derives from
 891         ///   ExpressionStatement becuase the pre/post increment/decrement
 892         ///   operators can be used in a statement context.
 893         ///
 894         /// FIXME: Idea, we could split this up in two classes, one simpler
 895         /// for the common case, and one with the extra fields for more complex
 896         /// classes (indexers require temporary access;  overloaded require method)
 897         ///
 898         /// </remarks>
 899         public class UnaryMutator : ExpressionStatement
 900         {
 901                 class DynamicPostMutator : Expression, IAssignMethod
 902                 {
 903                         LocalTemporary temp;
 904                         Expression expr;
 905
 906                         public DynamicPostMutator (Expression expr)
 907                         {
 908                                 this.expr = expr;
 909                                 this.type = expr.Type;
 910                                 this.loc = expr.Location;
 911                         }
 912
 913                         public override Expression CreateExpressionTree (ResolveContext ec)
 914                         {
 915                                 throw new NotImplementedException ("ET");
 916                         }
 917
 918                         protected override Expression DoResolve (ResolveContext rc)
 919                         {
 920                                 eclass = expr.eclass;
 921                                 return this;
 922                         }
 923
 924                         public override Expression DoResolveLValue (ResolveContext ec, Expression right_side)
 925                         {
 926                                 expr.DoResolveLValue (ec, right_side);
 927                                 return DoResolve (ec);
 928                         }
 929
 930                         public override void Emit (EmitContext ec)
 931                         {
 932                                 temp.Emit (ec);
 933                         }
 934
 935                         public void Emit (EmitContext ec, bool leave_copy)
 936                         {
 937                                 throw new NotImplementedException ();
 938                         }
 939
 940                         //
 941                         // Emits target assignment using unmodified source value
 942                         //
 943                         public void EmitAssign (EmitContext ec, Expression source, bool leave_copy, bool prepare_for_load)
 944                         {
 945                                 //
 946                                 // Allocate temporary variable to keep original value before it's modified
 947                                 //
 948                                 temp = new LocalTemporary (type);
 949                                 expr.Emit (ec);
 950                                 temp.Store (ec);
 951
 952                                 ((IAssignMethod) expr).EmitAssign (ec, source, false, prepare_for_load);
 953
 954                                 if (leave_copy)
 955                                         Emit (ec);
 956
 957                                 temp.Release (ec);
 958                                 temp = null;
 959                         }
 960                 }
 961
 962                 [Flags]
 963                 public enum Mode : byte {
 964                         IsIncrement    = 0,
 965                         IsDecrement    = 1,
 966                         IsPre          = 0,
 967                         IsPost         = 2,
 968
 969                         PreIncrement   = 0,
 970                         PreDecrement   = IsDecrement,
 971                         PostIncrement  = IsPost,
 972                         PostDecrement  = IsPost | IsDecrement
 973                 }
 974
 975                 Mode mode;
 976                 bool is_expr, recurse;
 977
 978                 Expression expr;
 979
 980                 // Holds the real operation
 981                 Expression operation;
 982
 983                 public UnaryMutator (Mode m, Expression e, Location loc)
 984                 {
 985                         mode = m;
 986                         this.loc = loc;
 987                         expr = e;
 988                 }
 989
 990                 public override Expression CreateExpressionTree (ResolveContext ec)
 991                 {
 992                         return new SimpleAssign (this, this).CreateExpressionTree (ec);
 993                 }
 994
 995                 protected override Expression DoResolve (ResolveContext ec)
 996                 {
 997                         expr = expr.Resolve (ec);
 998
 999                         if (expr == null)
1000                                 return null;
1001
1002                         if (expr.Type == InternalType.Dynamic) {
1003                                 //
1004                                 // Handle postfix unary operators using local
1005                                 // temporary variable
1006                                 //
1007                                 if ((mode & Mode.IsPost) != 0)
1008                                         expr = new DynamicPostMutator (expr);
1009
1010                                 Arguments args = new Arguments (1);
1011                                 args.Add (new Argument (expr));
1012                                 return new SimpleAssign (expr, new DynamicUnaryConversion (GetOperatorExpressionTypeName (), args, loc)).Resolve (ec);
1013                         }
1014
1015                         if (TypeManager.IsNullableType (expr.Type))
1016                                 return new Nullable.LiftedUnaryMutator (mode, expr, loc).Resolve (ec);
1017
1018                         eclass = ExprClass.Value;
1019                         type = expr.Type;
1020                         return ResolveOperator (ec);
1021                 }
1022
1023                 void EmitCode (EmitContext ec, bool is_expr)
1024                 {
1025                         recurse = true;
1026                         this.is_expr = is_expr;
1027                         ((IAssignMethod) expr).EmitAssign (ec, this, is_expr && (mode == Mode.PreIncrement || mode == Mode.PreDecrement), true);
1028                 }
1029
1030                 public override void Emit (EmitContext ec)
1031                 {
1032                         //
1033                         // We use recurse to allow ourselfs to be the source
1034                         // of an assignment. This little hack prevents us from
1035                         // having to allocate another expression
1036                         //
1037                         if (recurse) {
1038                                 ((IAssignMethod) expr).Emit (ec, is_expr && (mode == Mode.PostIncrement || mode == Mode.PostDecrement));
1039
1040                                 operation.Emit (ec);
1041
1042                                 recurse = false;
1043                                 return;
1044                         }
1045
1046                         EmitCode (ec, true);
1047                 }
1048
1049                 public override void EmitStatement (EmitContext ec)
1050                 {
1051                         EmitCode (ec, false);
1052                 }
1053
1054                 //
1055                 // Converts operator to System.Linq.Expressions.ExpressionType enum name
1056                 //
1057                 string GetOperatorExpressionTypeName ()
1058                 {
1059                         return IsDecrement ? "Decrement" : "Increment";
1060                 }
1061
1062                 bool IsDecrement {
1063                         get { return (mode & Mode.IsDecrement) != 0; }
1064                 }
1065
1066                 //
1067                 //   Returns whether an object of type `t' can be incremented
1068                 //   or decremented with add/sub (ie, basically whether we can
1069                 //   use pre-post incr-decr operations on it, but it is not a
1070                 //   System.Decimal, which we require operator overloading to catch)
1071                 //
1072                 static bool IsPredefinedOperator (TypeSpec t)
1073                 {
1074                         return (TypeManager.IsPrimitiveType (t) && t != TypeManager.bool_type) ||
1075                                 TypeManager.IsEnumType (t) ||
1076                                 t.IsPointer && t != TypeManager.void_ptr_type;
1077                 }
1078
1079 #if NET_4_0
1080                 public override SLE.Expression MakeExpression (BuilderContext ctx)
1081                 {
1082                         var target = ((RuntimeValueExpression) expr).MetaObject.Expression;
1083                         var source = SLE.Expression.Convert (operation.MakeExpression (ctx), target.Type);
1084                         return SLE.Expression.Assign (target, source);
1085                 }
1086 #endif
1087
1088                 protected override void CloneTo (CloneContext clonectx, Expression t)
1089                 {
1090                         UnaryMutator target = (UnaryMutator) t;
1091
1092                         target.expr = expr.Clone (clonectx);
1093                 }
1094
1095                 Expression ResolveOperator (ResolveContext ec)
1096                 {
1097                         if (expr is RuntimeValueExpression) {
1098                                 operation = expr;
1099                         } else {
1100                                 // Use itself at the top of the stack
1101                                 operation = new EmptyExpression (type);
1102                         }
1103
1104                         //
1105                         // The operand of the prefix/postfix increment decrement operators
1106                         // should be an expression that is classified as a variable,
1107                         // a property access or an indexer access
1108                         //
1109                         if (expr.eclass == ExprClass.Variable || expr.eclass == ExprClass.IndexerAccess || expr.eclass == ExprClass.PropertyAccess) {
1110                                 expr = expr.ResolveLValue (ec, expr);
1111                         } else {
1112                                 ec.Report.Error (1059, loc, "The operand of an increment or decrement operator must be a variable, property or indexer");
1113                         }
1114
1115                         //
1116                         // 1. Check predefined types
1117                         //
1118                         if (IsPredefinedOperator (type)) {
1119                                 // TODO: Move to IntConstant once I get rid of int32_type
1120                                 var one = new IntConstant (1, loc);
1121
1122                                 // TODO: Cache this based on type when using EmptyExpression in
1123                                 // context cache
1124                                 Binary.Operator op = IsDecrement ? Binary.Operator.Subtraction : Binary.Operator.Addition;
1125                                 operation = new Binary (op, operation, one, loc);
1126                                 operation = operation.Resolve (ec);
1127                                 if (operation != null && operation.Type != type)
1128                                         operation = Convert.ExplicitNumericConversion (operation, type);
1129
1130                                 return this;
1131                         }
1132
1133                         //
1134                         // Step 2: Perform Operator Overload location
1135                         //
1136                         var user_op = IsDecrement ? Operator.OpType.Decrement : Operator.OpType.Increment;
1137                         var methods = MemberCache.GetUserOperator (type, user_op, false);
1138
1139                         if (methods != null) {
1140                                 Arguments args = new Arguments (1);
1141                                 args.Add (new Argument (expr));
1142
1143                                 var mg = new MethodGroupExpr (methods, type, loc);
1144                                 mg = mg.OverloadResolve (ec, ref args, false, loc);
1145                                 if (mg == null)
1146                                         return null;
1147
1148                                 args[0].Expr = operation;
1149                                 operation = new UserOperatorCall (mg, args, null, loc);
1150                                 operation = Convert.ImplicitConversionRequired (ec, operation, type, loc);
1151                                 return this;
1152                         }
1153
1154                         string name = IsDecrement ?
1155                                 Operator.GetName (Operator.OpType.Decrement) :
1156                                 Operator.GetName (Operator.OpType.Increment);
1157
1158                         Unary.Error_OperatorCannotBeApplied (ec, loc, name, type);
1159                         return null;
1160                 }
1161         }
1162
1163         /// <summary>
1164         ///   Base class for the `Is' and `As' classes.
1165         /// </summary>
1166         ///
1167         /// <remarks>
1168         ///   FIXME: Split this in two, and we get to save the `Operator' Oper
1169         ///   size.
1170         /// </remarks>
1171         public abstract class Probe : Expression {
1172                 public Expression ProbeType;
1173                 protected Expression expr;
1174                 protected TypeExpr probe_type_expr;
1175
1176                 public Probe (Expression expr, Expression probe_type, Location l)
1177                 {
1178                         ProbeType = probe_type;
1179                         loc = l;
1180                         this.expr = expr;
1181                 }
1182
1183                 public Expression Expr {
1184                         get {
1185                                 return expr;
1186                         }
1187                 }
1188
1189                 protected override Expression DoResolve (ResolveContext ec)
1190                 {
1191                         probe_type_expr = ProbeType.ResolveAsTypeTerminal (ec, false);
1192                         if (probe_type_expr == null)
1193                                 return null;
1194
1195                         expr = expr.Resolve (ec);
1196                         if (expr == null)
1197                                 return null;
1198
1199                         if (probe_type_expr.Type.IsStatic) {
1200                                 ec.Report.Error (-244, loc, "The `{0}' operator cannot be applied to an operand of a static type",
1201                                         OperatorName);
1202                         }
1203
1204                         if (expr.Type.IsPointer || probe_type_expr.Type.IsPointer) {
1205                                 ec.Report.Error (244, loc, "The `{0}' operator cannot be applied to an operand of pointer type",
1206                                         OperatorName);
1207                                 return null;
1208                         }
1209
1210                         if (expr.Type == InternalType.AnonymousMethod) {
1211                                 ec.Report.Error (837, loc, "The `{0}' operator cannot be applied to a lambda expression or anonymous method",
1212                                         OperatorName);
1213                                 return null;
1214                         }
1215
1216                         return this;
1217                 }
1218
1219                 protected abstract string OperatorName { get; }
1220
1221                 protected override void CloneTo (CloneContext clonectx, Expression t)
1222                 {
1223                         Probe target = (Probe) t;
1224
1225                         target.expr = expr.Clone (clonectx);
1226                         target.ProbeType = ProbeType.Clone (clonectx);
1227                 }
1228
1229         }
1230
1231         /// <summary>
1232         ///   Implementation of the `is' operator.
1233         /// </summary>
1234         public class Is : Probe {
1235                 Nullable.Unwrap expr_unwrap;
1236
1237                 public Is (Expression expr, Expression probe_type, Location l)
1238                         : base (expr, probe_type, l)
1239                 {
1240                 }
1241
1242                 public override Expression CreateExpressionTree (ResolveContext ec)
1243                 {
1244                         Arguments args = Arguments.CreateForExpressionTree (ec, null,
1245                                 expr.CreateExpressionTree (ec),
1246                                 new TypeOf (probe_type_expr, loc));
1247
1248                         return CreateExpressionFactoryCall (ec, "TypeIs", args);
1249                 }
1250
1251                 public override void Emit (EmitContext ec)
1252                 {
1253                         if (expr_unwrap != null) {
1254                                 expr_unwrap.EmitCheck (ec);
1255                                 return;
1256                         }
1257
1258                         expr.Emit (ec);
1259                         ec.Emit (OpCodes.Isinst, probe_type_expr.Type);
1260                         ec.Emit (OpCodes.Ldnull);
1261                         ec.Emit (OpCodes.Cgt_Un);
1262                 }
1263
1264                 public override void EmitBranchable (EmitContext ec, Label target, bool on_true)
1265                 {
1266                         if (expr_unwrap != null) {
1267                                 expr_unwrap.EmitCheck (ec);
1268                         } else {
1269                                 expr.Emit (ec);
1270                                 ec.Emit (OpCodes.Isinst, probe_type_expr.Type);
1271                         }
1272                         ec.Emit (on_true ? OpCodes.Brtrue : OpCodes.Brfalse, target);
1273                 }
1274
1275                 Expression CreateConstantResult (ResolveContext ec, bool result)
1276                 {
1277                         if (result)
1278                                 ec.Report.Warning (183, 1, loc, "The given expression is always of the provided (`{0}') type",
1279                                         TypeManager.CSharpName (probe_type_expr.Type));
1280                         else
1281                                 ec.Report.Warning (184, 1, loc, "The given expression is never of the provided (`{0}') type",
1282                                         TypeManager.CSharpName (probe_type_expr.Type));
1283
1284                         return ReducedExpression.Create (new BoolConstant (result, loc).Resolve (ec), this);
1285                 }
1286
1287                 protected override Expression DoResolve (ResolveContext ec)
1288                 {
1289                         if (base.DoResolve (ec) == null)
1290                                 return null;
1291
1292                         TypeSpec d = expr.Type;
1293                         bool d_is_nullable = false;
1294
1295                         //
1296                         // If E is a method group or the null literal, or if the type of E is a reference
1297                         // type or a nullable type and the value of E is null, the result is false
1298                         //
1299                         if (expr.IsNull || expr.eclass == ExprClass.MethodGroup)
1300                                 return CreateConstantResult (ec, false);
1301
1302                         if (TypeManager.IsNullableType (d)) {
1303                                 var ut = Nullable.NullableInfo.GetUnderlyingType (d);
1304                                 if (!ut.IsGenericParameter) {
1305                                         d = ut;
1306                                         d_is_nullable = true;
1307                                 }
1308                         }
1309
1310                         type = TypeManager.bool_type;
1311                         eclass = ExprClass.Value;
1312                         TypeSpec t = probe_type_expr.Type;
1313                         bool t_is_nullable = false;
1314                         if (TypeManager.IsNullableType (t)) {
1315                                 var ut = Nullable.NullableInfo.GetUnderlyingType (t);
1316                                 if (!ut.IsGenericParameter) {
1317                                         t = ut;
1318                                         t_is_nullable = true;
1319                                 }
1320                         }
1321
1322                         if (TypeManager.IsStruct (t)) {
1323                                 if (d == t) {
1324                                         //
1325                                         // D and T are the same value types but D can be null
1326                                         //
1327                                         if (d_is_nullable && !t_is_nullable) {
1328                                                 expr_unwrap = Nullable.Unwrap.Create (expr, false);
1329                                                 return this;
1330                                         }
1331
1332                                         //
1333                                         // The result is true if D and T are the same value types
1334                                         //
1335                                         return CreateConstantResult (ec, true);
1336                                 }
1337
1338                                 var tp = d as TypeParameterSpec;
1339                                 if (tp != null)
1340                                         return ResolveGenericParameter (ec, t, tp);
1341
1342                                 //
1343                                 // An unboxing conversion exists
1344                                 //
1345                                 if (Convert.ExplicitReferenceConversionExists (d, t))
1346                                         return this;
1347                         } else {
1348                                 if (TypeManager.IsGenericParameter (t))
1349                                         return ResolveGenericParameter (ec, d, (TypeParameterSpec) t);
1350
1351                                 if (TypeManager.IsStruct (d)) {
1352                                         if (Convert.ImplicitBoxingConversion (null, d, t) != null)
1353                                                 return CreateConstantResult (ec, true);
1354                                 } else {
1355                                         if (TypeManager.IsGenericParameter (d))
1356                                                 return ResolveGenericParameter (ec, t, (TypeParameterSpec) d);
1357
1358                                         if (TypeManager.ContainsGenericParameters (d))
1359                                                 return this;
1360
1361                                         if (Convert.ImplicitReferenceConversionExists (expr, t) ||
1362                                                 Convert.ExplicitReferenceConversionExists (d, t)) {
1363                                                 return this;
1364                                         }
1365                                 }
1366                         }
1367
1368                         return CreateConstantResult (ec, false);
1369                 }
1370
1371                 Expression ResolveGenericParameter (ResolveContext ec, TypeSpec d, TypeParameterSpec t)
1372                 {
1373                         if (t.IsReferenceType) {
1374                                 if (TypeManager.IsStruct (d))
1375                                         return CreateConstantResult (ec, false);
1376                         }
1377
1378                         if (TypeManager.IsGenericParameter (expr.Type)) {
1379                                 if (t.IsValueType && expr.Type == t)
1380                                         return CreateConstantResult (ec, true);
1381
1382                                 expr = new BoxedCast (expr, d);
1383                         }
1384
1385                         return this;
1386                 }
1387
1388                 protected override string OperatorName {
1389                         get { return "is"; }
1390                 }
1391         }
1392
1393         /// <summary>
1394         ///   Implementation of the `as' operator.
1395         /// </summary>
1396         public class As : Probe {
1397                 bool do_isinst;
1398                 Expression resolved_type;
1399
1400                 public As (Expression expr, Expression probe_type, Location l)
1401                         : base (expr, probe_type, l)
1402                 {
1403                 }
1404
1405                 public override Expression CreateExpressionTree (ResolveContext ec)
1406                 {
1407                         Arguments args = Arguments.CreateForExpressionTree (ec, null,
1408                                 expr.CreateExpressionTree (ec),
1409                                 new TypeOf (probe_type_expr, loc));
1410
1411                         return CreateExpressionFactoryCall (ec, "TypeAs", args);
1412                 }
1413
1414                 public override void Emit (EmitContext ec)
1415                 {
1416                         expr.Emit (ec);
1417
1418                         if (do_isinst)
1419                                 ec.Emit (OpCodes.Isinst, type);
1420
1421                         if (TypeManager.IsGenericParameter (type) || TypeManager.IsNullableType (type))
1422                                 ec.Emit (OpCodes.Unbox_Any, type);
1423                 }
1424
1425                 protected override Expression DoResolve (ResolveContext ec)
1426                 {
1427                         if (resolved_type == null) {
1428                                 resolved_type = base.DoResolve (ec);
1429
1430                                 if (resolved_type == null)
1431                                         return null;
1432                         }
1433
1434                         type = probe_type_expr.Type;
1435                         eclass = ExprClass.Value;
1436                         TypeSpec etype = expr.Type;
1437
1438                         if (!TypeManager.IsReferenceType (type) && !TypeManager.IsNullableType (type)) {
1439                                 if (TypeManager.IsGenericParameter (type)) {
1440                                         ec.Report.Error (413, loc,
1441                                                 "The `as' operator cannot be used with a non-reference type parameter `{0}'. Consider adding `class' or a reference type constraint",
1442                                                 probe_type_expr.GetSignatureForError ());
1443                                 } else {
1444                                         ec.Report.Error (77, loc,
1445                                                 "The `as' operator cannot be used with a non-nullable value type `{0}'",
1446                                                 TypeManager.CSharpName (type));
1447                                 }
1448                                 return null;
1449                         }
1450
1451                         if (expr.IsNull && TypeManager.IsNullableType (type)) {
1452                                 return Nullable.LiftedNull.CreateFromExpression (ec, this);
1453                         }
1454
1455                         Expression e = Convert.ImplicitConversion (ec, expr, type, loc);
1456                         if (e != null){
1457                                 expr = e;
1458                                 do_isinst = false;
1459                                 return this;
1460                         }
1461
1462                         if (Convert.ExplicitReferenceConversionExists (etype, type)){
1463                                 if (TypeManager.IsGenericParameter (etype))
1464                                         expr = new BoxedCast (expr, etype);
1465
1466                                 do_isinst = true;
1467                                 return this;
1468                         }
1469
1470                         if (TypeManager.ContainsGenericParameters (etype) ||
1471                             TypeManager.ContainsGenericParameters (type)) {
1472                                 expr = new BoxedCast (expr, etype);
1473                                 do_isinst = true;
1474                                 return this;
1475                         }
1476
1477                         ec.Report.Error (39, loc, "Cannot convert type `{0}' to `{1}' via a built-in conversion",
1478                                 TypeManager.CSharpName (etype), TypeManager.CSharpName (type));
1479
1480                         return null;
1481                 }
1482
1483                 protected override string OperatorName {
1484                         get { return "as"; }
1485                 }
1486         }
1487
1488         //
1489         // This represents a typecast in the source language.
1490         //
1491         public class Cast : ShimExpression {
1492                 Expression target_type;
1493
1494                 public Cast (Expression cast_type, Expression expr, Location loc)
1495                         : base (expr)
1496                 {
1497                         this.target_type = cast_type;
1498                         this.loc = loc;
1499                 }
1500
1501                 public Expression TargetType {
1502                         get { return target_type; }
1503                 }
1504
1505                 protected override Expression DoResolve (ResolveContext ec)
1506                 {
1507                         expr = expr.Resolve (ec);
1508                         if (expr == null)
1509                                 return null;
1510
1511                         TypeExpr target = target_type.ResolveAsTypeTerminal (ec, false);
1512                         if (target == null)
1513                                 return null;
1514
1515                         type = target.Type;
1516
1517                         if (type.IsStatic) {
1518                                 ec.Report.Error (716, loc, "Cannot convert to static type `{0}'", TypeManager.CSharpName (type));
1519                                 return null;
1520                         }
1521
1522                         eclass = ExprClass.Value;
1523
1524                         Constant c = expr as Constant;
1525                         if (c != null) {
1526                                 c = c.TryReduce (ec, type, loc);
1527                                 if (c != null)
1528                                         return c;
1529                         }
1530
1531                         if (type.IsPointer && !ec.IsUnsafe) {
1532                                 UnsafeError (ec, loc);
1533                         } else if (expr.Type == InternalType.Dynamic) {
1534                                 Arguments arg = new Arguments (1);
1535                                 arg.Add (new Argument (expr));
1536                                 return new DynamicConversion (type, CSharpBinderFlags.ConvertExplicit, arg, loc).Resolve (ec);
1537                         }
1538
1539                         var res = Convert.ExplicitConversion (ec, expr, type, loc);
1540                         if (res == expr)
1541                                 return EmptyCast.Create (res, type);
1542
1543                         return res;
1544                 }
1545
1546                 protected override void CloneTo (CloneContext clonectx, Expression t)
1547                 {
1548                         Cast target = (Cast) t;
1549
1550                         target.target_type = target_type.Clone (clonectx);
1551                         target.expr = expr.Clone (clonectx);
1552                 }
1553         }
1554
1555         public class ImplicitCast : ShimExpression
1556         {
1557                 bool arrayAccess;
1558
1559                 public ImplicitCast (Expression expr, TypeSpec target, bool arrayAccess)
1560                         : base (expr)
1561                 {
1562                         this.loc = expr.Location;
1563                         this.type = target;
1564                         this.arrayAccess = arrayAccess;
1565                 }
1566
1567                 protected override Expression DoResolve (ResolveContext ec)
1568                 {
1569                         expr = expr.Resolve (ec);
1570                         if (expr == null)
1571                                 return null;
1572
1573                         if (arrayAccess)
1574                                 expr = ConvertExpressionToArrayIndex (ec, expr);
1575                         else
1576                                 expr = Convert.ImplicitConversionRequired (ec, expr, type, loc);
1577
1578                         return expr;
1579                 }
1580         }
1581
1582         //
1583         // C# 2.0 Default value expression
1584         //
1585         public class DefaultValueExpression : Expression
1586         {
1587                 Expression expr;
1588
1589                 public DefaultValueExpression (Expression expr, Location loc)
1590                 {
1591                         this.expr = expr;
1592                         this.loc = loc;
1593                 }
1594
1595                 public override Expression CreateExpressionTree (ResolveContext ec)
1596                 {
1597                         Arguments args = new Arguments (2);
1598                         args.Add (new Argument (this));
1599                         args.Add (new Argument (new TypeOf (new TypeExpression (type, loc), loc)));
1600                         return CreateExpressionFactoryCall (ec, "Constant", args);
1601                 }
1602
1603                 protected override Expression DoResolve (ResolveContext ec)
1604                 {
1605                         TypeExpr texpr = expr.ResolveAsTypeTerminal (ec, false);
1606                         if (texpr == null)
1607                                 return null;
1608
1609                         type = texpr.Type;
1610
1611                         if (type.IsStatic) {
1612                                 ec.Report.Error (-244, loc, "The `default value' operator cannot be applied to an operand of a static type");
1613                         }
1614
1615                         if (type.IsPointer)
1616                                 return new NullLiteral (Location).ConvertImplicitly (ec, type);
1617
1618                         if (TypeManager.IsReferenceType (type))
1619                                 return new NullConstant (type, loc);
1620
1621                         Constant c = New.Constantify (type);
1622                         if (c != null)
1623                                 return c.Resolve (ec);
1624
1625                         eclass = ExprClass.Variable;
1626                         return this;
1627                 }
1628
1629                 public override void Emit (EmitContext ec)
1630                 {
1631                         LocalTemporary temp_storage = new LocalTemporary(type);
1632
1633                         temp_storage.AddressOf(ec, AddressOp.LoadStore);
1634                         ec.Emit(OpCodes.Initobj, type);
1635                         temp_storage.Emit(ec);
1636                 }
1637
1638                 protected override void CloneTo (CloneContext clonectx, Expression t)
1639                 {
1640                         DefaultValueExpression target = (DefaultValueExpression) t;
1641
1642                         target.expr = expr.Clone (clonectx);
1643                 }
1644         }
1645
1646         /// <summary>
1647         ///   Binary operators
1648         /// </summary>
1649         public class Binary : Expression, IDynamicBinder
1650         {
1651                 protected class PredefinedOperator {
1652                         protected readonly TypeSpec left;
1653                         protected readonly TypeSpec right;
1654                         public readonly Operator OperatorsMask;
1655                         public TypeSpec ReturnType;
1656
1657                         public PredefinedOperator (TypeSpec ltype, TypeSpec rtype, Operator op_mask)
1658                                 : this (ltype, rtype, op_mask, ltype)
1659                         {
1660                         }
1661
1662                         public PredefinedOperator (TypeSpec type, Operator op_mask, TypeSpec return_type)
1663                                 : this (type, type, op_mask, return_type)
1664                         {
1665                         }
1666
1667                         public PredefinedOperator (TypeSpec type, Operator op_mask)
1668                                 : this (type, type, op_mask, type)
1669                         {
1670                         }
1671
1672                         public PredefinedOperator (TypeSpec ltype, TypeSpec rtype, Operator op_mask, TypeSpec return_type)
1673                         {
1674                                 if ((op_mask & Operator.ValuesOnlyMask) != 0)
1675                                         throw new InternalErrorException ("Only masked values can be used");
1676
1677                                 this.left = ltype;
1678                                 this.right = rtype;
1679                                 this.OperatorsMask = op_mask;
1680                                 this.ReturnType = return_type;
1681                         }
1682
1683                         public virtual Expression ConvertResult (ResolveContext ec, Binary b)
1684                         {
1685                                 b.type = ReturnType;
1686
1687                                 b.left = Convert.ImplicitConversion (ec, b.left, left, b.left.Location);
1688                                 b.right = Convert.ImplicitConversion (ec, b.right, right, b.right.Location);
1689
1690                                 //
1691                                 // A user operators does not support multiple user conversions, but decimal type
1692                                 // is considered to be predefined type therefore we apply predefined operators rules
1693                                 // and then look for decimal user-operator implementation
1694                                 //
1695                                 if (left == TypeManager.decimal_type)
1696                                         return b.ResolveUserOperator (ec, b.left.Type, b.right.Type);
1697
1698                                 var c = b.right as Constant;
1699                                 if (c != null) {
1700                                         if (c.IsDefaultValue && (b.oper == Operator.Addition || b.oper == Operator.BitwiseOr || b.oper == Operator.Subtraction))
1701                                                 return ReducedExpression.Create (b.left, b).Resolve (ec);
1702                                         if ((b.oper == Operator.Multiply || b.oper == Operator.Division) && c.IsOneInteger)
1703                                                 return ReducedExpression.Create (b.left, b).Resolve (ec);
1704                                         return b;
1705                                 }
1706
1707                                 c = b.left as Constant;
1708                                 if (c != null) {
1709                                         if (c.IsDefaultValue && (b.oper == Operator.Addition || b.oper == Operator.BitwiseOr))
1710                                                 return ReducedExpression.Create (b.right, b).Resolve (ec);
1711                                         if (b.oper == Operator.Multiply && c.IsOneInteger)
1712                                                 return ReducedExpression.Create (b.right, b).Resolve (ec);
1713                                         return b;
1714                                 }
1715
1716                                 return b;
1717                         }
1718
1719                         public bool IsPrimitiveApplicable (TypeSpec ltype, TypeSpec rtype)
1720                         {
1721                                 //
1722                                 // We are dealing with primitive types only
1723                                 //
1724                                 return left == ltype && ltype == rtype;
1725                         }
1726
1727                         public virtual bool IsApplicable (ResolveContext ec, Expression lexpr, Expression rexpr)
1728                         {
1729                                 if (TypeManager.IsEqual (left, lexpr.Type) &&
1730                                         TypeManager.IsEqual (right, rexpr.Type))
1731                                         return true;
1732
1733                                 return Convert.ImplicitConversionExists (ec, lexpr, left) &&
1734                                         Convert.ImplicitConversionExists (ec, rexpr, right);
1735                         }
1736
1737                         public PredefinedOperator ResolveBetterOperator (ResolveContext ec, PredefinedOperator best_operator)
1738                         {
1739                                 int result = 0;
1740                                 if (left != null && best_operator.left != null) {
1741                                         result = MethodGroupExpr.BetterTypeConversion (ec, best_operator.left, left);
1742                                 }
1743
1744                                 //
1745                                 // When second arguments are same as the first one, the result is same
1746                                 //
1747                                 if (right != null && (left != right || best_operator.left != best_operator.right)) {
1748                                         result |= MethodGroupExpr.BetterTypeConversion (ec, best_operator.right, right);
1749                                 }
1750
1751                                 if (result == 0 || result > 2)
1752                                         return null;
1753
1754                                 return result == 1 ? best_operator : this;
1755                         }
1756                 }
1757
1758                 class PredefinedStringOperator : PredefinedOperator {
1759                         public PredefinedStringOperator (TypeSpec type, Operator op_mask)
1760                                 : base (type, op_mask, type)
1761                         {
1762                                 ReturnType = TypeManager.string_type;
1763                         }
1764
1765                         public PredefinedStringOperator (TypeSpec ltype, TypeSpec rtype, Operator op_mask)
1766                                 : base (ltype, rtype, op_mask)
1767                         {
1768                                 ReturnType = TypeManager.string_type;
1769                         }
1770
1771                         public override Expression ConvertResult (ResolveContext ec, Binary b)
1772                         {
1773                                 //
1774                                 // Use original expression for nullable arguments
1775                                 //
1776                                 Nullable.Unwrap unwrap = b.left as Nullable.Unwrap;
1777                                 if (unwrap != null)
1778                                         b.left = unwrap.Original;
1779
1780                                 unwrap = b.right as Nullable.Unwrap;
1781                                 if (unwrap != null)
1782                                         b.right = unwrap.Original;
1783
1784                                 b.left = Convert.ImplicitConversion (ec, b.left, left, b.left.Location);
1785                                 b.right = Convert.ImplicitConversion (ec, b.right, right, b.right.Location);
1786
1787                                 //
1788                                 // Start a new concat expression using converted expression
1789                                 //
1790                                 return StringConcat.Create (ec, b.left, b.right, b.loc);
1791                         }
1792                 }
1793
1794                 class PredefinedShiftOperator : PredefinedOperator {
1795                         public PredefinedShiftOperator (TypeSpec ltype, Operator op_mask) :
1796                                 base (ltype, TypeManager.int32_type, op_mask)
1797                         {
1798                         }
1799
1800                         public override Expression ConvertResult (ResolveContext ec, Binary b)
1801                         {
1802                                 b.left = Convert.ImplicitConversion (ec, b.left, left, b.left.Location);
1803
1804                                 Expression expr_tree_expr = Convert.ImplicitConversion (ec, b.right, TypeManager.int32_type, b.right.Location);
1805
1806                                 int right_mask = left == TypeManager.int32_type || left == TypeManager.uint32_type ? 0x1f : 0x3f;
1807
1808                                 //
1809                                 // b = b.left >> b.right & (0x1f|0x3f)
1810                                 //
1811                                 b.right = new Binary (Operator.BitwiseAnd,
1812                                         b.right, new IntConstant (right_mask, b.right.Location), b.loc).Resolve (ec);
1813
1814                                 //
1815                                 // Expression tree representation does not use & mask
1816                                 //
1817                                 b.right = ReducedExpression.Create (b.right, expr_tree_expr).Resolve (ec);
1818                                 b.type = ReturnType;
1819
1820                                 //
1821                                 // Optimize shift by 0
1822                                 //
1823                                 var c = b.right as Constant;
1824                                 if (c != null && c.IsDefaultValue)
1825                                         return ReducedExpression.Create (b.left, b).Resolve (ec);
1826
1827                                 return b;
1828                         }
1829                 }
1830
1831                 class PredefinedPointerOperator : PredefinedOperator {
1832                         public PredefinedPointerOperator (TypeSpec ltype, TypeSpec rtype, Operator op_mask)
1833                                 : base (ltype, rtype, op_mask)
1834                         {
1835                         }
1836
1837                         public PredefinedPointerOperator (TypeSpec ltype, TypeSpec rtype, Operator op_mask, TypeSpec retType)
1838                                 : base (ltype, rtype, op_mask, retType)
1839                         {
1840                         }
1841
1842                         public PredefinedPointerOperator (TypeSpec type, Operator op_mask, TypeSpec return_type)
1843                                 : base (type, op_mask, return_type)
1844                         {
1845                         }
1846
1847                         public override bool IsApplicable (ResolveContext ec, Expression lexpr, Expression rexpr)
1848                         {
1849                                 if (left == null) {
1850                                         if (!lexpr.Type.IsPointer)
1851                                                 return false;
1852                                 } else {
1853                                         if (!Convert.ImplicitConversionExists (ec, lexpr, left))
1854                                                 return false;
1855                                 }
1856
1857                                 if (right == null) {
1858                                         if (!rexpr.Type.IsPointer)
1859                                                 return false;
1860                                 } else {
1861                                         if (!Convert.ImplicitConversionExists (ec, rexpr, right))
1862                                                 return false;
1863                                 }
1864
1865                                 return true;
1866                         }
1867
1868                         public override Expression ConvertResult (ResolveContext ec, Binary b)
1869                         {
1870                                 if (left != null) {
1871                                         b.left = EmptyCast.Create (b.left, left);
1872                                 } else if (right != null) {
1873                                         b.right = EmptyCast.Create (b.right, right);
1874                                 }
1875
1876                                 TypeSpec r_type = ReturnType;
1877                                 Expression left_arg, right_arg;
1878                                 if (r_type == null) {
1879                                         if (left == null) {
1880                                                 left_arg = b.left;
1881                                                 right_arg = b.right;
1882                                                 r_type = b.left.Type;
1883                                         } else {
1884                                                 left_arg = b.right;
1885                                                 right_arg = b.left;
1886                                                 r_type = b.right.Type;
1887                                         }
1888                                 } else {
1889                                         left_arg = b.left;
1890                                         right_arg = b.right;
1891                                 }
1892
1893                                 return new PointerArithmetic (b.oper, left_arg, right_arg, r_type, b.loc).Resolve (ec);
1894                         }
1895                 }
1896
1897                 [Flags]
1898                 public enum Operator {
1899                         Multiply        = 0 | ArithmeticMask,
1900                         Division        = 1 | ArithmeticMask,
1901                         Modulus         = 2 | ArithmeticMask,
1902                         Addition        = 3 | ArithmeticMask | AdditionMask,
1903                         Subtraction = 4 | ArithmeticMask | SubtractionMask,
1904
1905                         LeftShift       = 5 | ShiftMask,
1906                         RightShift      = 6 | ShiftMask,
1907
1908                         LessThan        = 7 | ComparisonMask | RelationalMask,
1909                         GreaterThan     = 8 | ComparisonMask | RelationalMask,
1910                         LessThanOrEqual         = 9 | ComparisonMask | RelationalMask,
1911                         GreaterThanOrEqual      = 10 | ComparisonMask | RelationalMask,
1912                         Equality        = 11 | ComparisonMask | EqualityMask,
1913                         Inequality      = 12 | ComparisonMask | EqualityMask,
1914
1915                         BitwiseAnd      = 13 | BitwiseMask,
1916                         ExclusiveOr     = 14 | BitwiseMask,
1917                         BitwiseOr       = 15 | BitwiseMask,
1918
1919                         LogicalAnd      = 16 | LogicalMask,
1920                         LogicalOr       = 17 | LogicalMask,
1921
1922                         //
1923                         // Operator masks
1924                         //
1925                         ValuesOnlyMask  = ArithmeticMask - 1,
1926                         ArithmeticMask  = 1 << 5,
1927                         ShiftMask               = 1 << 6,
1928                         ComparisonMask  = 1 << 7,
1929                         EqualityMask    = 1 << 8,
1930                         BitwiseMask             = 1 << 9,
1931                         LogicalMask             = 1 << 10,
1932                         AdditionMask    = 1 << 11,
1933                         SubtractionMask = 1 << 12,
1934                         RelationalMask  = 1 << 13
1935                 }
1936
1937                 readonly Operator oper;
1938                 protected Expression left, right;
1939                 readonly bool is_compound;
1940                 Expression enum_conversion;
1941
1942                 static PredefinedOperator[] standard_operators;
1943                 static PredefinedOperator[] pointer_operators;
1944
1945                 public Binary (Operator oper, Expression left, Expression right, bool isCompound, Location loc)
1946                         : this (oper, left, right, loc)
1947                 {
1948                         this.is_compound = isCompound;
1949                 }
1950
1951                 public Binary (Operator oper, Expression left, Expression right, Location loc)
1952                 {
1953                         this.oper = oper;
1954                         this.left = left;
1955                         this.right = right;
1956                         this.loc = loc;
1957                 }
1958
1959                 public Operator Oper {
1960                         get {
1961                                 return oper;
1962                         }
1963                 }
1964
1965                 /// <summary>
1966                 ///   Returns a stringified representation of the Operator
1967                 /// </summary>
1968                 string OperName (Operator oper)
1969                 {
1970                         string s;
1971                         switch (oper){
1972                         case Operator.Multiply:
1973                                 s = "*";
1974                                 break;
1975                         case Operator.Division:
1976                                 s = "/";
1977                                 break;
1978                         case Operator.Modulus:
1979                                 s = "%";
1980                                 break;
1981                         case Operator.Addition:
1982                                 s = "+";
1983                                 break;
1984                         case Operator.Subtraction:
1985                                 s = "-";
1986                                 break;
1987                         case Operator.LeftShift:
1988                                 s = "<<";
1989                                 break;
1990                         case Operator.RightShift:
1991                                 s = ">>";
1992                                 break;
1993                         case Operator.LessThan:
1994                                 s = "<";
1995                                 break;
1996                         case Operator.GreaterThan:
1997                                 s = ">";
1998                                 break;
1999                         case Operator.LessThanOrEqual:
2000                                 s = "<=";
2001                                 break;
2002                         case Operator.GreaterThanOrEqual:
2003                                 s = ">=";
2004                                 break;
2005                         case Operator.Equality:
2006                                 s = "==";
2007                                 break;
2008                         case Operator.Inequality:
2009                                 s = "!=";
2010                                 break;
2011                         case Operator.BitwiseAnd:
2012                                 s = "&";
2013                                 break;
2014                         case Operator.BitwiseOr:
2015                                 s = "|";
2016                                 break;
2017                         case Operator.ExclusiveOr:
2018                                 s = "^";
2019                                 break;
2020                         case Operator.LogicalOr:
2021                                 s = "||";
2022                                 break;
2023                         case Operator.LogicalAnd:
2024                                 s = "&&";
2025                                 break;
2026                         default:
2027                                 s = oper.ToString ();
2028                                 break;
2029                         }
2030
2031                         if (is_compound)
2032                                 return s + "=";
2033
2034                         return s;
2035                 }
2036
2037                 public static void Error_OperatorCannotBeApplied (ResolveContext ec, Expression left, Expression right, Operator oper, Location loc)
2038                 {
2039                         new Binary (oper, left, right, loc).Error_OperatorCannotBeApplied (ec, left, right);
2040                 }
2041
2042                 public static void Error_OperatorCannotBeApplied (ResolveContext ec, Expression left, Expression right, string oper, Location loc)
2043                 {
2044                         string l, r;
2045                         l = TypeManager.CSharpName (left.Type);
2046                         r = TypeManager.CSharpName (right.Type);
2047
2048                         ec.Report.Error (19, loc, "Operator `{0}' cannot be applied to operands of type `{1}' and `{2}'",
2049                                 oper, l, r);
2050                 }
2051
2052                 protected void Error_OperatorCannotBeApplied (ResolveContext ec, Expression left, Expression right)
2053                 {
2054                         Error_OperatorCannotBeApplied (ec, left, right, OperName (oper), loc);
2055                 }
2056
2057                 //
2058                 // Converts operator to System.Linq.Expressions.ExpressionType enum name
2059                 //
2060                 string GetOperatorExpressionTypeName ()
2061                 {
2062                         switch (oper) {
2063                         case Operator.Addition:
2064                                 return is_compound ? "AddAssign" : "Add";
2065                         case Operator.BitwiseAnd:
2066                                 return is_compound ? "AndAssign" : "And";
2067                         case Operator.BitwiseOr:
2068                                 return is_compound ? "OrAssign" : "Or";
2069                         case Operator.Division:
2070                                 return is_compound ? "DivideAssign" : "Divide";
2071                         case Operator.ExclusiveOr:
2072                                 return is_compound ? "ExclusiveOrAssign" : "ExclusiveOr";
2073                         case Operator.Equality:
2074                                 return "Equal";
2075                         case Operator.GreaterThan:
2076                                 return "GreaterThan";
2077                         case Operator.GreaterThanOrEqual:
2078                                 return "GreaterThanOrEqual";
2079                         case Operator.Inequality:
2080                                 return "NotEqual";
2081                         case Operator.LeftShift:
2082                                 return is_compound ? "LeftShiftAssign" : "LeftShift";
2083                         case Operator.LessThan:
2084                                 return "LessThan";
2085                         case Operator.LessThanOrEqual:
2086                                 return "LessThanOrEqual";
2087                         case Operator.LogicalAnd:
2088                                 return "And";
2089                         case Operator.LogicalOr:
2090                                 return "Or";
2091                         case Operator.Modulus:
2092                                 return is_compound ? "ModuloAssign" : "Modulo";
2093                         case Operator.Multiply:
2094                                 return is_compound ? "MultiplyAssign" : "Multiply";
2095                         case Operator.RightShift:
2096                                 return is_compound ? "RightShiftAssign" : "RightShift";
2097                         case Operator.Subtraction:
2098                                 return is_compound ? "SubtractAssign" : "Subtract";
2099                         default:
2100                                 throw new NotImplementedException ("Unknown expression type operator " + oper.ToString ());
2101                         }
2102                 }
2103
2104                 static CSharp.Operator.OpType ConvertBinaryToUserOperator (Operator op)
2105                 {
2106                         switch (op) {
2107                         case Operator.Addition:
2108                                 return CSharp.Operator.OpType.Addition;
2109                         case Operator.BitwiseAnd:
2110                         case Operator.LogicalAnd:
2111                                 return CSharp.Operator.OpType.BitwiseAnd;
2112                         case Operator.BitwiseOr:
2113                         case Operator.LogicalOr:
2114                                 return CSharp.Operator.OpType.BitwiseOr;
2115                         case Operator.Division:
2116                                 return CSharp.Operator.OpType.Division;
2117                         case Operator.Equality:
2118                                 return CSharp.Operator.OpType.Equality;
2119                         case Operator.ExclusiveOr:
2120                                 return CSharp.Operator.OpType.ExclusiveOr;
2121                         case Operator.GreaterThan:
2122                                 return CSharp.Operator.OpType.GreaterThan;
2123                         case Operator.GreaterThanOrEqual:
2124                                 return CSharp.Operator.OpType.GreaterThanOrEqual;
2125                         case Operator.Inequality:
2126                                 return CSharp.Operator.OpType.Inequality;
2127                         case Operator.LeftShift:
2128                                 return CSharp.Operator.OpType.LeftShift;
2129                         case Operator.LessThan:
2130                                 return CSharp.Operator.OpType.LessThan;
2131                         case Operator.LessThanOrEqual:
2132                                 return CSharp.Operator.OpType.LessThanOrEqual;
2133                         case Operator.Modulus:
2134                                 return CSharp.Operator.OpType.Modulus;
2135                         case Operator.Multiply:
2136                                 return CSharp.Operator.OpType.Multiply;
2137                         case Operator.RightShift:
2138                                 return CSharp.Operator.OpType.RightShift;
2139                         case Operator.Subtraction:
2140                                 return CSharp.Operator.OpType.Subtraction;
2141                         default:
2142                                 throw new InternalErrorException (op.ToString ());
2143                         }
2144                 }
2145
2146                 public static void EmitOperatorOpcode (EmitContext ec, Operator oper, TypeSpec l)
2147                 {
2148                         OpCode opcode;
2149
2150                         switch (oper){
2151                         case Operator.Multiply:
2152                                 if (ec.HasSet (EmitContext.Options.CheckedScope)) {
2153                                         if (l == TypeManager.int32_type || l == TypeManager.int64_type)
2154                                                 opcode = OpCodes.Mul_Ovf;
2155                                         else if (!IsFloat (l))
2156                                                 opcode = OpCodes.Mul_Ovf_Un;
2157                                         else
2158                                                 opcode = OpCodes.Mul;
2159                                 } else
2160                                         opcode = OpCodes.Mul;
2161
2162                                 break;
2163
2164                         case Operator.Division:
2165                                 if (IsUnsigned (l))
2166                                         opcode = OpCodes.Div_Un;
2167                                 else
2168                                         opcode = OpCodes.Div;
2169                                 break;
2170
2171                         case Operator.Modulus:
2172                                 if (IsUnsigned (l))
2173                                         opcode = OpCodes.Rem_Un;
2174                                 else
2175                                         opcode = OpCodes.Rem;
2176                                 break;
2177
2178                         case Operator.Addition:
2179                                 if (ec.HasSet (EmitContext.Options.CheckedScope)) {
2180                                         if (l == TypeManager.int32_type || l == TypeManager.int64_type)
2181                                                 opcode = OpCodes.Add_Ovf;
2182                                         else if (!IsFloat (l))
2183                                                 opcode = OpCodes.Add_Ovf_Un;
2184                                         else
2185                                                 opcode = OpCodes.Add;
2186                                 } else
2187                                         opcode = OpCodes.Add;
2188                                 break;
2189
2190                         case Operator.Subtraction:
2191                                 if (ec.HasSet (EmitContext.Options.CheckedScope)) {
2192                                         if (l == TypeManager.int32_type || l == TypeManager.int64_type)
2193                                                 opcode = OpCodes.Sub_Ovf;
2194                                         else if (!IsFloat (l))
2195                                                 opcode = OpCodes.Sub_Ovf_Un;
2196                                         else
2197                                                 opcode = OpCodes.Sub;
2198                                 } else
2199                                         opcode = OpCodes.Sub;
2200                                 break;
2201
2202                         case Operator.RightShift:
2203                                 if (IsUnsigned (l))
2204                                         opcode = OpCodes.Shr_Un;
2205                                 else
2206                                         opcode = OpCodes.Shr;
2207                                 break;
2208
2209                         case Operator.LeftShift:
2210                                 opcode = OpCodes.Shl;
2211                                 break;
2212
2213                         case Operator.Equality:
2214                                 opcode = OpCodes.Ceq;
2215                                 break;
2216
2217                         case Operator.Inequality:
2218                                 ec.Emit (OpCodes.Ceq);
2219                                 ec.Emit (OpCodes.Ldc_I4_0);
2220
2221                                 opcode = OpCodes.Ceq;
2222                                 break;
2223
2224                         case Operator.LessThan:
2225                                 if (IsUnsigned (l))
2226                                         opcode = OpCodes.Clt_Un;
2227                                 else
2228                                         opcode = OpCodes.Clt;
2229                                 break;
2230
2231                         case Operator.GreaterThan:
2232                                 if (IsUnsigned (l))
2233                                         opcode = OpCodes.Cgt_Un;
2234                                 else
2235                                         opcode = OpCodes.Cgt;
2236                                 break;
2237
2238                         case Operator.LessThanOrEqual:
2239                                 if (IsUnsigned (l) || IsFloat (l))
2240                                         ec.Emit (OpCodes.Cgt_Un);
2241                                 else
2242                                         ec.Emit (OpCodes.Cgt);
2243                                 ec.Emit (OpCodes.Ldc_I4_0);
2244
2245                                 opcode = OpCodes.Ceq;
2246                                 break;
2247
2248                         case Operator.GreaterThanOrEqual:
2249                                 if (IsUnsigned (l) || IsFloat (l))
2250                                         ec.Emit (OpCodes.Clt_Un);
2251                                 else
2252                                         ec.Emit (OpCodes.Clt);
2253
2254                                 ec.Emit (OpCodes.Ldc_I4_0);
2255
2256                                 opcode = OpCodes.Ceq;
2257                                 break;
2258
2259                         case Operator.BitwiseOr:
2260                                 opcode = OpCodes.Or;
2261                                 break;
2262
2263                         case Operator.BitwiseAnd:
2264                                 opcode = OpCodes.And;
2265                                 break;
2266
2267                         case Operator.ExclusiveOr:
2268                                 opcode = OpCodes.Xor;
2269                                 break;
2270
2271                         default:
2272                                 throw new InternalErrorException (oper.ToString ());
2273                         }
2274
2275                         ec.Emit (opcode);
2276                 }
2277
2278                 static bool IsUnsigned (TypeSpec t)
2279                 {
2280                         if (t.IsPointer)
2281                                 return true;
2282
2283                         return (t == TypeManager.uint32_type || t == TypeManager.uint64_type ||
2284                                 t == TypeManager.ushort_type || t == TypeManager.byte_type);
2285                 }
2286
2287                 static bool IsFloat (TypeSpec t)
2288                 {
2289                         return t == TypeManager.float_type || t == TypeManager.double_type;
2290                 }
2291
2292                 public static void Reset ()
2293                 {
2294                         pointer_operators = standard_operators = null;
2295                 }
2296
2297                 Expression ResolveOperator (ResolveContext ec)
2298                 {
2299                         TypeSpec l = left.Type;
2300                         TypeSpec r = right.Type;
2301                         Expression expr;
2302                         bool primitives_only = false;
2303
2304                         if (standard_operators == null)
2305                                 CreateStandardOperatorsTable ();
2306
2307                         //
2308                         // Handles predefined primitive types
2309                         //
2310                         if (TypeManager.IsPrimitiveType (l) && TypeManager.IsPrimitiveType (r)) {
2311                                 if ((oper & Operator.ShiftMask) == 0) {
2312                                         if (l != TypeManager.bool_type && !DoBinaryOperatorPromotion (ec))
2313                                                 return null;
2314
2315                                         primitives_only = true;
2316                                 }
2317                         } else {
2318                                 // Pointers
2319                                 if (l.IsPointer || r.IsPointer)
2320                                         return ResolveOperatorPointer (ec, l, r);
2321
2322                                 // Enums
2323                                 bool lenum = TypeManager.IsEnumType (l);
2324                                 bool renum = TypeManager.IsEnumType (r);
2325                                 if (lenum || renum) {
2326                                         expr = ResolveOperatorEnum (ec, lenum, renum, l, r);
2327
2328                                         // TODO: Can this be ambiguous
2329                                         if (expr != null)
2330                                                 return expr;
2331                                 }
2332
2333                                 // Delegates
2334                                 if ((oper == Operator.Addition || oper == Operator.Subtraction || (oper & Operator.EqualityMask) != 0) &&
2335                                          (TypeManager.IsDelegateType (l) || TypeManager.IsDelegateType (r))) {
2336
2337                                         expr = ResolveOperatorDelegate (ec, l, r);
2338
2339                                         // TODO: Can this be ambiguous
2340                                         if (expr != null)
2341                                                 return expr;
2342                                 }
2343
2344                                 // User operators
2345                                 expr = ResolveUserOperator (ec, l, r);
2346                                 if (expr != null)
2347                                         return expr;
2348
2349                                 // Predefined reference types equality
2350                                 if ((oper & Operator.EqualityMask) != 0) {
2351                                         expr = ResolveOperatorEqualityRerefence (ec, l, r);
2352                                         if (expr != null)
2353                                                 return expr;
2354                                 }
2355                         }
2356
2357                         return ResolveOperatorPredefined (ec, standard_operators, primitives_only, null);
2358                 }
2359
2360                 // at least one of 'left' or 'right' is an enumeration constant (EnumConstant or SideEffectConstant or ...)
2361                 // if 'left' is not an enumeration constant, create one from the type of 'right'
2362                 Constant EnumLiftUp (ResolveContext ec, Constant left, Constant right, Location loc)
2363                 {
2364                         switch (oper) {
2365                         case Operator.BitwiseOr:
2366                         case Operator.BitwiseAnd:
2367                         case Operator.ExclusiveOr:
2368                         case Operator.Equality:
2369                         case Operator.Inequality:
2370                         case Operator.LessThan:
2371                         case Operator.LessThanOrEqual:
2372                         case Operator.GreaterThan:
2373                         case Operator.GreaterThanOrEqual:
2374                                 if (TypeManager.IsEnumType (left.Type))
2375                                         return left;
2376
2377                                 if (left.IsZeroInteger)
2378                                         return left.TryReduce (ec, right.Type, loc);
2379
2380                                 break;
2381
2382                         case Operator.Addition:
2383                         case Operator.Subtraction:
2384                                 return left;
2385
2386                         case Operator.Multiply:
2387                         case Operator.Division:
2388                         case Operator.Modulus:
2389                         case Operator.LeftShift:
2390                         case Operator.RightShift:
2391                                 if (TypeManager.IsEnumType (right.Type) || TypeManager.IsEnumType (left.Type))
2392                                         break;
2393                                 return left;
2394                         }
2395                         Error_OperatorCannotBeApplied (ec, this.left, this.right);
2396                         return null;
2397                 }
2398
2399                 //
2400                 // The `|' operator used on types which were extended is dangerous
2401                 //
2402                 void CheckBitwiseOrOnSignExtended (ResolveContext ec)
2403                 {
2404                         OpcodeCast lcast = left as OpcodeCast;
2405                         if (lcast != null) {
2406                                 if (IsUnsigned (lcast.UnderlyingType))
2407                                         lcast = null;
2408                         }
2409
2410                         OpcodeCast rcast = right as OpcodeCast;
2411                         if (rcast != null) {
2412                                 if (IsUnsigned (rcast.UnderlyingType))
2413                                         rcast = null;
2414                         }
2415
2416                         if (lcast == null && rcast == null)
2417                                 return;
2418
2419                         // FIXME: consider constants
2420
2421                         ec.Report.Warning (675, 3, loc,
2422                                 "The operator `|' used on the sign-extended type `{0}'. Consider casting to a smaller unsigned type first",
2423                                 TypeManager.CSharpName (lcast != null ? lcast.UnderlyingType : rcast.UnderlyingType));
2424                 }
2425
2426                 static void CreatePointerOperatorsTable ()
2427                 {
2428                         var temp = new List<PredefinedPointerOperator> ();
2429
2430                         //
2431                         // Pointer arithmetic:
2432                         //
2433                         // T* operator + (T* x, int y);         T* operator - (T* x, int y);
2434                         // T* operator + (T* x, uint y);        T* operator - (T* x, uint y);
2435                         // T* operator + (T* x, long y);        T* operator - (T* x, long y);
2436                         // T* operator + (T* x, ulong y);       T* operator - (T* x, ulong y);
2437                         //
2438                         temp.Add (new PredefinedPointerOperator (null, TypeManager.int32_type, Operator.AdditionMask | Operator.SubtractionMask));
2439                         temp.Add (new PredefinedPointerOperator (null, TypeManager.uint32_type, Operator.AdditionMask | Operator.SubtractionMask));
2440                         temp.Add (new PredefinedPointerOperator (null, TypeManager.int64_type, Operator.AdditionMask | Operator.SubtractionMask));
2441                         temp.Add (new PredefinedPointerOperator (null, TypeManager.uint64_type, Operator.AdditionMask | Operator.SubtractionMask));
2442
2443                         //
2444                         // T* operator + (int y,   T* x);
2445                         // T* operator + (uint y,  T *x);
2446                         // T* operator + (long y,  T *x);
2447                         // T* operator + (ulong y, T *x);
2448                         //
2449                         temp.Add (new PredefinedPointerOperator (TypeManager.int32_type, null, Operator.AdditionMask, null));
2450                         temp.Add (new PredefinedPointerOperator (TypeManager.uint32_type, null, Operator.AdditionMask, null));
2451                         temp.Add (new PredefinedPointerOperator (TypeManager.int64_type, null, Operator.AdditionMask, null));
2452                         temp.Add (new PredefinedPointerOperator (TypeManager.uint64_type, null, Operator.AdditionMask, null));
2453
2454                         //
2455                         // long operator - (T* x, T *y)
2456                         //
2457                         temp.Add (new PredefinedPointerOperator (null, Operator.SubtractionMask, TypeManager.int64_type));
2458
2459                         pointer_operators = temp.ToArray ();
2460                 }
2461
2462                 static void CreateStandardOperatorsTable ()
2463                 {
2464                         var temp = new List<PredefinedOperator> ();
2465                         TypeSpec bool_type = TypeManager.bool_type;
2466
2467                         temp.Add (new PredefinedOperator (TypeManager.int32_type, Operator.ArithmeticMask | Operator.BitwiseMask));
2468                         temp.Add (new PredefinedOperator (TypeManager.uint32_type, Operator.ArithmeticMask | Operator.BitwiseMask));
2469                         temp.Add (new PredefinedOperator (TypeManager.int64_type, Operator.ArithmeticMask | Operator.BitwiseMask));
2470                         temp.Add (new PredefinedOperator (TypeManager.uint64_type, Operator.ArithmeticMask | Operator.BitwiseMask));
2471                         temp.Add (new PredefinedOperator (TypeManager.float_type, Operator.ArithmeticMask));
2472                         temp.Add (new PredefinedOperator (TypeManager.double_type, Operator.ArithmeticMask));
2473                         temp.Add (new PredefinedOperator (TypeManager.decimal_type, Operator.ArithmeticMask));
2474
2475                         temp.Add (new PredefinedOperator (TypeManager.int32_type, Operator.ComparisonMask, bool_type));
2476                         temp.Add (new PredefinedOperator (TypeManager.uint32_type, Operator.ComparisonMask, bool_type));
2477                         temp.Add (new PredefinedOperator (TypeManager.int64_type, Operator.ComparisonMask, bool_type));
2478                         temp.Add (new PredefinedOperator (TypeManager.uint64_type, Operator.ComparisonMask, bool_type));
2479                         temp.Add (new PredefinedOperator (TypeManager.float_type, Operator.ComparisonMask, bool_type));
2480                         temp.Add (new PredefinedOperator (TypeManager.double_type, Operator.ComparisonMask, bool_type));
2481                         temp.Add (new PredefinedOperator (TypeManager.decimal_type, Operator.ComparisonMask, bool_type));
2482
2483                         temp.Add (new PredefinedStringOperator (TypeManager.string_type, Operator.AdditionMask));
2484                         temp.Add (new PredefinedStringOperator (TypeManager.string_type, TypeManager.object_type, Operator.AdditionMask));
2485                         temp.Add (new PredefinedStringOperator (TypeManager.object_type, TypeManager.string_type, Operator.AdditionMask));
2486
2487                         temp.Add (new PredefinedOperator (bool_type,
2488                                 Operator.BitwiseMask | Operator.LogicalMask | Operator.EqualityMask, bool_type));
2489
2490                         temp.Add (new PredefinedShiftOperator (TypeManager.int32_type, Operator.ShiftMask));
2491                         temp.Add (new PredefinedShiftOperator (TypeManager.uint32_type, Operator.ShiftMask));
2492                         temp.Add (new PredefinedShiftOperator (TypeManager.int64_type, Operator.ShiftMask));
2493                         temp.Add (new PredefinedShiftOperator (TypeManager.uint64_type, Operator.ShiftMask));
2494
2495                         standard_operators = temp.ToArray ();
2496                 }
2497
2498                 //
2499                 // Rules used during binary numeric promotion
2500                 //
2501                 static bool DoNumericPromotion (ResolveContext rc, ref Expression prim_expr, ref Expression second_expr, TypeSpec type)
2502                 {
2503                         Expression temp;
2504                         TypeSpec etype;
2505
2506                         Constant c = prim_expr as Constant;
2507                         if (c != null) {
2508                                 temp = c.ConvertImplicitly (rc, type);
2509                                 if (temp != null) {
2510                                         prim_expr = temp;
2511                                         return true;
2512                                 }
2513                         }
2514
2515                         if (type == TypeManager.uint32_type) {
2516                                 etype = prim_expr.Type;
2517                                 if (etype == TypeManager.int32_type || etype == TypeManager.short_type || etype == TypeManager.sbyte_type) {
2518                                         type = TypeManager.int64_type;
2519
2520                                         if (type != second_expr.Type) {
2521                                                 c = second_expr as Constant;
2522                                                 if (c != null)
2523                                                         temp = c.ConvertImplicitly (rc, type);
2524                                                 else
2525                                                         temp = Convert.ImplicitNumericConversion (second_expr, type);
2526                                                 if (temp == null)
2527                                                         return false;
2528                                                 second_expr = temp;
2529                                         }
2530                                 }
2531                         } else if (type == TypeManager.uint64_type) {
2532                                 //
2533                                 // A compile-time error occurs if the other operand is of type sbyte, short, int, or long
2534                                 //
2535                                 if (type == TypeManager.int32_type || type == TypeManager.int64_type ||
2536                                         type == TypeManager.short_type || type == TypeManager.sbyte_type)
2537                                         return false;
2538                         }
2539
2540                         temp = Convert.ImplicitNumericConversion (prim_expr, type);
2541                         if (temp == null)
2542                                 return false;
2543
2544                         prim_expr = temp;
2545                         return true;
2546                 }
2547
2548                 //
2549                 // 7.2.6.2 Binary numeric promotions
2550                 //
2551                 public bool DoBinaryOperatorPromotion (ResolveContext ec)
2552                 {
2553                         TypeSpec ltype = left.Type;
2554                         TypeSpec rtype = right.Type;
2555                         Expression temp;
2556
2557                         foreach (TypeSpec t in ConstantFold.BinaryPromotionsTypes) {
2558                                 if (t == ltype)
2559                                         return t == rtype || DoNumericPromotion (ec, ref right, ref left, t);
2560
2561                                 if (t == rtype)
2562                                         return t == ltype || DoNumericPromotion (ec, ref left, ref right, t);
2563                         }
2564
2565                         TypeSpec int32 = TypeManager.int32_type;
2566                         if (ltype != int32) {
2567                                 Constant c = left as Constant;
2568                                 if (c != null)
2569                                         temp = c.ConvertImplicitly (ec, int32);
2570                                 else
2571                                         temp = Convert.ImplicitNumericConversion (left, int32);
2572
2573                                 if (temp == null)
2574                                         return false;
2575                                 left = temp;
2576                         }
2577
2578                         if (rtype != int32) {
2579                                 Constant c = right as Constant;
2580                                 if (c != null)
2581                                         temp = c.ConvertImplicitly (ec, int32);
2582                                 else
2583                                         temp = Convert.ImplicitNumericConversion (right, int32);
2584
2585                                 if (temp == null)
2586                                         return false;
2587                                 right = temp;
2588                         }
2589
2590                         return true;
2591                 }
2592
2593                 protected override Expression DoResolve (ResolveContext ec)
2594                 {
2595                         if (left == null)
2596                                 return null;
2597
2598                         if ((oper == Operator.Subtraction) && (left is ParenthesizedExpression)) {
2599                                 left = ((ParenthesizedExpression) left).Expr;
2600                                 left = left.Resolve (ec, ResolveFlags.VariableOrValue | ResolveFlags.Type);
2601                                 if (left == null)
2602                                         return null;
2603
2604                                 if (left.eclass == ExprClass.Type) {
2605                                         ec.Report.Error (75, loc, "To cast a negative value, you must enclose the value in parentheses");
2606                                         return null;
2607                                 }
2608                         } else
2609                                 left = left.Resolve (ec);
2610
2611                         if (left == null)
2612                                 return null;
2613
2614                         Constant lc = left as Constant;
2615
2616                         if (lc != null && lc.Type == TypeManager.bool_type &&
2617                                 ((oper == Operator.LogicalAnd && lc.IsDefaultValue) ||
2618                                  (oper == Operator.LogicalOr && !lc.IsDefaultValue))) {
2619
2620                                 // FIXME: resolve right expression as unreachable
2621                                 // right.Resolve (ec);
2622
2623                                 ec.Report.Warning (429, 4, loc, "Unreachable expression code detected");
2624                                 return left;
2625                         }
2626
2627                         right = right.Resolve (ec);
2628                         if (right == null)
2629                                 return null;
2630
2631                         eclass = ExprClass.Value;
2632                         Constant rc = right as Constant;
2633
2634                         // The conversion rules are ignored in enum context but why
2635                         if (!ec.HasSet (ResolveContext.Options.EnumScope) && lc != null && rc != null && (TypeManager.IsEnumType (left.Type) || TypeManager.IsEnumType (right.Type))) {
2636                                 lc = EnumLiftUp (ec, lc, rc, loc);
2637                                 if (lc != null)
2638                                         rc = EnumLiftUp (ec, rc, lc, loc);
2639                         }
2640
2641                         if (rc != null && lc != null) {
2642                                 int prev_e = ec.Report.Errors;
2643                                 Expression e = ConstantFold.BinaryFold (ec, oper, lc, rc, loc);
2644                                 if (e != null)
2645                                         e = e.Resolve (ec);
2646
2647                                 if (e != null || ec.Report.Errors != prev_e)
2648                                         return e;
2649                         }
2650
2651                         // Comparison warnings
2652                         if ((oper & Operator.ComparisonMask) != 0) {
2653                                 if (left.Equals (right)) {
2654                                         ec.Report.Warning (1718, 3, loc, "A comparison made to same variable. Did you mean to compare something else?");
2655                                 }
2656                                 CheckUselessComparison (ec, lc, right.Type);
2657                                 CheckUselessComparison (ec, rc, left.Type);
2658                         }
2659
2660                         if (left.Type == InternalType.Dynamic || right.Type == InternalType.Dynamic) {
2661                                 Arguments args = new Arguments (2);
2662                                 args.Add (new Argument (left));
2663                                 args.Add (new Argument (right));
2664                                 return new DynamicExpressionStatement (this, args, loc).Resolve (ec);
2665                         }
2666
2667                         if (RootContext.Version >= LanguageVersion.ISO_2 &&
2668                                 ((TypeManager.IsNullableType (left.Type) && (right is NullLiteral || TypeManager.IsNullableType (right.Type) || TypeManager.IsValueType (right.Type))) ||
2669                                 (TypeManager.IsValueType (left.Type) && right is NullLiteral) ||
2670                                 (TypeManager.IsNullableType (right.Type) && (left is NullLiteral || TypeManager.IsNullableType (left.Type) || TypeManager.IsValueType (left.Type))) ||
2671                                 (TypeManager.IsValueType (right.Type) && left is NullLiteral)))
2672                                 return new Nullable.LiftedBinaryOperator (oper, left, right, loc).Resolve (ec);
2673
2674                         return DoResolveCore (ec, left, right);
2675                 }
2676
2677                 protected Expression DoResolveCore (ResolveContext ec, Expression left_orig, Expression right_orig)
2678                 {
2679                         Expression expr = ResolveOperator (ec);
2680                         if (expr == null)
2681                                 Error_OperatorCannotBeApplied (ec, left_orig, right_orig);
2682
2683                         if (left == null || right == null)
2684                                 throw new InternalErrorException ("Invalid conversion");
2685
2686                         if (oper == Operator.BitwiseOr)
2687                                 CheckBitwiseOrOnSignExtended (ec);
2688
2689                         return expr;
2690                 }
2691
2692                 public override SLE.Expression MakeExpression (BuilderContext ctx)
2693                 {
2694                         var le = left.MakeExpression (ctx);
2695                         var re = right.MakeExpression (ctx);
2696                         bool is_checked = ctx.HasSet (BuilderContext.Options.CheckedScope);
2697
2698                         switch (oper) {
2699                         case Operator.Addition:
2700                                 return is_checked ? SLE.Expression.AddChecked (le, re) : SLE.Expression.Add (le, re);
2701                         case Operator.BitwiseAnd:
2702                                 return SLE.Expression.And (le, re);
2703                         case Operator.BitwiseOr:
2704                                 return SLE.Expression.Or (le, re);
2705                         case Operator.Division:
2706                                 return SLE.Expression.Divide (le, re);
2707                         case Operator.Equality:
2708                                 return SLE.Expression.Equal (le, re);
2709                         case Operator.ExclusiveOr:
2710                                 return SLE.Expression.ExclusiveOr (le, re);
2711                         case Operator.GreaterThan:
2712                                 return SLE.Expression.GreaterThan (le, re);
2713                         case Operator.GreaterThanOrEqual:
2714                                 return SLE.Expression.GreaterThanOrEqual (le, re);
2715                         case Operator.Inequality:
2716                                 return SLE.Expression.NotEqual (le, re);
2717                         case Operator.LeftShift:
2718                                 return SLE.Expression.LeftShift (le, re);
2719                         case Operator.LessThan:
2720                                 return SLE.Expression.LessThan (le, re);
2721                         case Operator.LessThanOrEqual:
2722                                 return SLE.Expression.LessThanOrEqual (le, re);
2723                         case Operator.LogicalAnd:
2724                                 return SLE.Expression.AndAlso (le, re);
2725                         case Operator.LogicalOr:
2726                                 return SLE.Expression.OrElse (le, re);
2727                         case Operator.Modulus:
2728                                 return SLE.Expression.Modulo (le, re);
2729                         case Operator.Multiply:
2730                                 return is_checked ? SLE.Expression.MultiplyChecked (le, re) : SLE.Expression.Multiply (le, re);
2731                         case Operator.RightShift:
2732                                 return SLE.Expression.RightShift (le, re);
2733                         case Operator.Subtraction:
2734                                 return is_checked ? SLE.Expression.SubtractChecked (le, re) : SLE.Expression.Subtract (le, re);
2735                         default:
2736                                 throw new NotImplementedException (oper.ToString ());
2737                         }
2738                 }
2739
2740                 //
2741                 // D operator + (D x, D y)
2742                 // D operator - (D x, D y)
2743                 // bool operator == (D x, D y)
2744                 // bool operator != (D x, D y)
2745                 //
2746                 Expression ResolveOperatorDelegate (ResolveContext ec, TypeSpec l, TypeSpec r)
2747                 {
2748                         bool is_equality = (oper & Operator.EqualityMask) != 0;
2749                         if (!TypeManager.IsEqual (l, r) && !TypeSpecComparer.Variant.IsEqual (r, l)) {
2750                                 Expression tmp;
2751                                 if (right.eclass == ExprClass.MethodGroup || (r == InternalType.AnonymousMethod && !is_equality)) {
2752                                         tmp = Convert.ImplicitConversionRequired (ec, right, l, loc);
2753                                         if (tmp == null)
2754                                                 return null;
2755                                         right = tmp;
2756                                         r = right.Type;
2757                                 } else if (left.eclass == ExprClass.MethodGroup || (l == InternalType.AnonymousMethod && !is_equality)) {
2758                                         tmp = Convert.ImplicitConversionRequired (ec, left, r, loc);
2759                                         if (tmp == null)
2760                                                 return null;
2761                                         left = tmp;
2762                                         l = left.Type;
2763                                 } else {
2764                                         return null;
2765                                 }
2766                         }
2767
2768                         MethodSpec method;
2769                         Arguments args = new Arguments (2);
2770                         args.Add (new Argument (left));
2771                         args.Add (new Argument (right));
2772
2773                         if (oper == Operator.Addition) {
2774                                 if (TypeManager.delegate_combine_delegate_delegate == null) {
2775                                         TypeManager.delegate_combine_delegate_delegate = TypeManager.GetPredefinedMethod (
2776                                                 TypeManager.delegate_type, "Combine", loc, TypeManager.delegate_type, TypeManager.delegate_type);
2777                                 }
2778
2779                                 method = TypeManager.delegate_combine_delegate_delegate;
2780                         } else if (oper == Operator.Subtraction) {
2781                                 if (TypeManager.delegate_remove_delegate_delegate == null) {
2782                                         TypeManager.delegate_remove_delegate_delegate = TypeManager.GetPredefinedMethod (
2783                                                 TypeManager.delegate_type, "Remove", loc, TypeManager.delegate_type, TypeManager.delegate_type);
2784                                 }
2785
2786                                 method = TypeManager.delegate_remove_delegate_delegate;
2787                         } else if (oper == Operator.Equality) {
2788                                 if (TypeManager.delegate_equal == null) {
2789                                         TypeManager.delegate_equal = TypeManager.GetPredefinedMethod (
2790                                                 TypeManager.delegate_type,
2791                                                 new MemberFilter (CSharp.Operator.GetMetadataName (CSharp.Operator.OpType.Equality), 0, MemberKind.Operator,
2792                                                         ParametersCompiled.CreateFullyResolved (new [] { TypeManager.delegate_type, TypeManager.delegate_type }), TypeManager.bool_type), loc);
2793                                 }
2794
2795                                 method = TypeManager.delegate_equal;
2796                         } else {
2797                                 if (TypeManager.delegate_inequal == null) {
2798                                         TypeManager.delegate_inequal = TypeManager.GetPredefinedMethod (
2799                                                 TypeManager.delegate_type,
2800                                                 new MemberFilter (CSharp.Operator.GetMetadataName (CSharp.Operator.OpType.Inequality), 0, MemberKind.Operator,
2801                                                         ParametersCompiled.CreateFullyResolved (new [] { TypeManager.delegate_type, TypeManager.delegate_type }), TypeManager.bool_type), loc);
2802                                 }
2803
2804                                 method = TypeManager.delegate_inequal;
2805                         }
2806
2807                         if (method == null)
2808                                 return new EmptyExpression (TypeManager.decimal_type);
2809
2810                         MethodGroupExpr mg = MethodGroupExpr.CreatePredefined (method, TypeManager.delegate_type, loc);
2811                         Expression expr = new UserOperatorCall (mg, args, CreateExpressionTree, loc);
2812                         if (expr.Type != TypeManager.bool_type) {
2813                                 expr = new ClassCast (expr, l);
2814                         }
2815
2816                         return expr;
2817                 }
2818
2819                 //
2820                 // Enumeration operators
2821                 //
2822                 Expression ResolveOperatorEnum (ResolveContext ec, bool lenum, bool renum, TypeSpec ltype, TypeSpec rtype)
2823                 {
2824                         //
2825                         // bool operator == (E x, E y);
2826                         // bool operator != (E x, E y);
2827                         // bool operator < (E x, E y);
2828                         // bool operator > (E x, E y);
2829                         // bool operator <= (E x, E y);
2830                         // bool operator >= (E x, E y);
2831                         //
2832                         // E operator & (E x, E y);
2833                         // E operator | (E x, E y);
2834                         // E operator ^ (E x, E y);
2835                         //
2836                         // U operator - (E e, E f)
2837                         // E operator - (E e, U x)
2838                         //
2839                         // E operator + (U x, E e)
2840                         // E operator + (E e, U x)
2841                         //
2842                         if (!((oper & (Operator.ComparisonMask | Operator.BitwiseMask)) != 0 ||
2843                                 (oper == Operator.Subtraction && lenum) ||
2844                                 (oper == Operator.Addition && (lenum != renum || type != null))))       // type != null for lifted null
2845                                 return null;
2846
2847                         Expression ltemp = left;
2848                         Expression rtemp = right;
2849                         TypeSpec underlying_type;
2850                         Expression expr;
2851
2852                         if ((oper & (Operator.ComparisonMask | Operator.BitwiseMask)) != 0) {
2853                                 if (renum) {
2854                                         expr = Convert.ImplicitConversion (ec, left, rtype, loc);
2855                                         if (expr != null) {
2856                                                 left = expr;
2857                                                 ltype = expr.Type;
2858                                         }
2859                                 } else if (lenum) {
2860                                         expr = Convert.ImplicitConversion (ec, right, ltype, loc);
2861                                         if (expr != null) {
2862                                                 right = expr;
2863                                                 rtype = expr.Type;
2864                                         }
2865                                 }
2866                         }
2867
2868                         if (TypeManager.IsEqual (ltype, rtype)) {
2869                                 underlying_type = EnumSpec.GetUnderlyingType (ltype);
2870
2871                                 if (left is Constant)
2872                                         left = ((Constant) left).ConvertExplicitly (false, underlying_type).Resolve (ec);
2873                                 else
2874                                         left = EmptyCast.Create (left, underlying_type);
2875
2876                                 if (right is Constant)
2877                                         right = ((Constant) right).ConvertExplicitly (false, underlying_type).Resolve (ec);
2878                                 else
2879                                         right = EmptyCast.Create (right, underlying_type);
2880                         } else if (lenum) {
2881                                 underlying_type = EnumSpec.GetUnderlyingType (ltype);
2882
2883                                 if (oper != Operator.Subtraction && oper != Operator.Addition) {
2884                                         Constant c = right as Constant;
2885                                         if (c == null || !c.IsDefaultValue)
2886                                                 return null;
2887                                 } else {
2888                                         if (!Convert.ImplicitStandardConversionExists (right, underlying_type))
2889                                                 return null;
2890
2891                                         right = Convert.ImplicitConversionStandard (ec, right, underlying_type, right.Location);
2892                                 }
2893
2894                                 if (left is Constant)
2895                                         left = ((Constant) left).ConvertExplicitly (false, underlying_type).Resolve (ec);
2896                                 else
2897                                         left = EmptyCast.Create (left, underlying_type);
2898
2899                         } else if (renum) {
2900                                 underlying_type = EnumSpec.GetUnderlyingType (rtype);
2901
2902                                 if (oper != Operator.Addition) {
2903                                         Constant c = left as Constant;
2904                                         if (c == null || !c.IsDefaultValue)
2905                                                 return null;
2906                                 } else {
2907                                         if (!Convert.ImplicitStandardConversionExists (left, underlying_type))
2908                                                 return null;
2909
2910                                         left = Convert.ImplicitConversionStandard (ec, left, underlying_type, left.Location);
2911                                 }
2912
2913                                 if (right is Constant)
2914                                         right = ((Constant) right).ConvertExplicitly (false, underlying_type).Resolve (ec);
2915                                 else
2916                                         right = EmptyCast.Create (right, underlying_type);
2917
2918                         } else {
2919                                 return null;
2920                         }
2921
2922                         //
2923                         // C# specification uses explicit cast syntax which means binary promotion
2924                         // should happen, however it seems that csc does not do that
2925                         //
2926                         if (!DoBinaryOperatorPromotion (ec)) {
2927                                 left = ltemp;
2928                                 right = rtemp;
2929                                 return null;
2930                         }
2931
2932                         TypeSpec res_type = null;
2933                         if ((oper & Operator.BitwiseMask) != 0 || oper == Operator.Subtraction || oper == Operator.Addition) {
2934                                 TypeSpec promoted_type = lenum ? left.Type : right.Type;
2935                                 enum_conversion = Convert.ExplicitNumericConversion (
2936                                         new EmptyExpression (promoted_type), underlying_type);
2937
2938                                 if (oper == Operator.Subtraction && renum && lenum)
2939                                         res_type = underlying_type;
2940                                 else if (oper == Operator.Addition && renum)
2941                                         res_type = rtype;
2942                                 else
2943                                         res_type = ltype;
2944                         }
2945
2946                         expr = ResolveOperatorPredefined (ec, standard_operators, true, res_type);
2947                         if (!is_compound || expr == null)
2948                                 return expr;
2949
2950                         //
2951                         // Section: 7.16.2
2952                         //
2953
2954                         //
2955                         // If the return type of the selected operator is implicitly convertible to the type of x
2956                         //
2957                         if (Convert.ImplicitConversionExists (ec, expr, ltype))
2958                                 return expr;
2959
2960                         //
2961                         // Otherwise, if the selected operator is a predefined operator, if the return type of the
2962                         // selected operator is explicitly convertible to the type of x, and if y is implicitly
2963                         // convertible to the type of x or the operator is a shift operator, then the operation
2964                         // is evaluated as x = (T)(x op y), where T is the type of x
2965                         //
2966                         expr = Convert.ExplicitConversion (ec, expr, ltype, loc);
2967                         if (expr == null)
2968                                 return null;
2969
2970                         if (Convert.ImplicitConversionExists (ec, ltemp, ltype))
2971                                 return expr;
2972
2973                         return null;
2974                 }
2975
2976                 //
2977                 // 7.9.6 Reference type equality operators
2978                 //
2979                 Expression ResolveOperatorEqualityRerefence (ResolveContext ec, TypeSpec l, TypeSpec r)
2980                 {
2981                         //
2982                         // bool operator != (object a, object b)
2983                         // bool operator == (object a, object b)
2984                         //
2985                         // bool operator != (string a, string b)
2986                         // bool operator == (string a, string b)
2987                         //
2988
2989                         // TODO: this method is almost equivalent to Convert.ImplicitReferenceConversion
2990
2991                         if (left.eclass == ExprClass.MethodGroup || right.eclass == ExprClass.MethodGroup)
2992                                 return null;
2993
2994                         type = TypeManager.bool_type;
2995
2996                         var lgen = l as TypeParameterSpec;
2997
2998                         if (l == r) {
2999                                 if (l is InternalType)
3000                                         return null;
3001
3002                                 if (lgen != null) {
3003                                         //
3004                                         // Only allow to compare same reference type parameter
3005                                         //
3006                                         if (TypeManager.IsReferenceType (l)) {
3007                                                 left = new BoxedCast (left, TypeManager.object_type);
3008                                                 right = new BoxedCast (right, TypeManager.object_type);
3009                                                 return this;
3010                                         }
3011
3012                                         return null;
3013                                 }
3014
3015                                 if (TypeManager.IsValueType (l))
3016                                         return null;
3017
3018                                 if (l == TypeManager.string_type) {
3019                                         Arguments args = new Arguments (2);
3020                                         args.Add (new Argument (left));
3021                                         args.Add (new Argument (right));
3022
3023                                         MethodSpec method;
3024                                         if (oper == Operator.Equality) {
3025                                                 if (TypeManager.string_equal == null) {
3026                                                         TypeManager.string_equal = TypeManager.GetPredefinedMethod (TypeManager.string_type,
3027                                                                 new MemberFilter (CSharp.Operator.GetMetadataName (CSharp.Operator.OpType.Equality), 0, MemberKind.Operator, null, type), loc);
3028                                                 }
3029
3030                                                 method = TypeManager.string_equal;
3031                                         } else {
3032                                                 if (TypeManager.string_inequal == null) {
3033                                                         TypeManager.string_inequal = TypeManager.GetPredefinedMethod (TypeManager.string_type,
3034                                                                 new MemberFilter (CSharp.Operator.GetMetadataName (CSharp.Operator.OpType.Inequality), 0, MemberKind.Operator, null, type), loc);
3035                                                 }
3036
3037                                                 method = TypeManager.string_inequal;
3038                                         }
3039
3040                                         if (method == null)
3041                                                 return new EmptyExpression (type);
3042
3043                                         var mg = MethodGroupExpr.CreatePredefined (method, TypeManager.string_type, loc);
3044                                         return new UserOperatorCall (mg, args, CreateExpressionTree, loc);
3045                                 }
3046
3047                                 if (l == TypeManager.delegate_type || l == TypeManager.multicast_delegate_type) {
3048                                         Arguments args = new Arguments (2);
3049                                         args.Add (new Argument (left));
3050                                         args.Add (new Argument (right));
3051
3052                                         MethodSpec method;
3053                                         if (oper == Operator.Equality) {
3054                                                 if (TypeManager.delegate_equal == null) {
3055                                                         TypeManager.delegate_equal = TypeManager.GetPredefinedMethod (TypeManager.delegate_type,
3056                                                                 new MemberFilter (CSharp.Operator.GetMetadataName (CSharp.Operator.OpType.Equality), 0, MemberKind.Operator, null, type), loc);
3057                                                 }
3058
3059                                                 method = TypeManager.delegate_equal;
3060                                         } else {
3061                                                 if (TypeManager.delegate_inequal == null) {
3062                                                         TypeManager.delegate_inequal = TypeManager.GetPredefinedMethod (TypeManager.delegate_type,
3063                                                                 new MemberFilter (CSharp.Operator.GetMetadataName (CSharp.Operator.OpType.Inequality), 0, MemberKind.Operator, null, type), loc);
3064                                                 }
3065
3066                                                 method = TypeManager.delegate_inequal;
3067                                         }
3068
3069                                         if (method == null)
3070                                                 return new EmptyExpression (type);
3071
3072                                         var mg = MethodGroupExpr.CreatePredefined (method, TypeManager.delegate_type, loc);
3073                                         return new UserOperatorCall (mg, args, CreateExpressionTree, loc);
3074                                 }
3075
3076                                 return this;
3077                         }
3078
3079                         var rgen = r as TypeParameterSpec;
3080
3081                         //
3082                         // a, Both operands are reference-type values or the value null
3083                         // b, One operand is a value of type T where T is a type-parameter and
3084                         // the other operand is the value null. Furthermore T does not have the
3085                         // value type constrain
3086                         //
3087                         if (left is NullLiteral || right is NullLiteral) {
3088                                 if (lgen != null) {
3089                                         if (lgen.HasSpecialStruct)
3090                                                 return null;
3091
3092                                         left = new BoxedCast (left, TypeManager.object_type);
3093                                         return this;
3094                                 }
3095
3096                                 if (rgen != null) {
3097                                         if (rgen.HasSpecialStruct)
3098                                                 return null;
3099
3100                                         right = new BoxedCast (right, TypeManager.object_type);
3101                                         return this;
3102                                 }
3103                         }
3104
3105                         //
3106                         // An interface is converted to the object before the
3107                         // standard conversion is applied. It's not clear from the
3108                         // standard but it looks like it works like that.
3109                         //
3110                         if (lgen != null) {
3111                                 if (!TypeManager.IsReferenceType (l))
3112                                         return null;
3113
3114                                 l = TypeManager.object_type;
3115                                 left = new BoxedCast (left, l);
3116                         } else if (l.IsInterface) {
3117                                 l = TypeManager.object_type;
3118                         } else if (TypeManager.IsStruct (l)) {
3119                                 return null;
3120                         }
3121
3122                         if (rgen != null) {
3123                                 if (!TypeManager.IsReferenceType (r))
3124                                         return null;
3125
3126                                 r = TypeManager.object_type;
3127                                 right = new BoxedCast (right, r);
3128                         } else if (r.IsInterface) {
3129                                 r = TypeManager.object_type;
3130                         } else if (TypeManager.IsStruct (r)) {
3131                                 return null;
3132                         }
3133
3134
3135                         const string ref_comparison = "Possible unintended reference comparison. " +
3136                                 "Consider casting the {0} side of the expression to `string' to compare the values";
3137
3138                         //
3139                         // A standard implicit conversion exists from the type of either
3140                         // operand to the type of the other operand
3141                         //
3142                         if (Convert.ImplicitReferenceConversionExists (left, r)) {
3143                                 if (l == TypeManager.string_type)
3144                                         ec.Report.Warning (253, 2, loc, ref_comparison, "right");
3145
3146                                 return this;
3147                         }
3148
3149                         if (Convert.ImplicitReferenceConversionExists (right, l)) {
3150                                 if (r == TypeManager.string_type)
3151                                         ec.Report.Warning (252, 2, loc, ref_comparison, "left");
3152
3153                                 return this;
3154                         }
3155
3156                         return null;
3157                 }
3158
3159
3160                 Expression ResolveOperatorPointer (ResolveContext ec, TypeSpec l, TypeSpec r)
3161                 {
3162                         //
3163                         // bool operator == (void* x, void* y);
3164                         // bool operator != (void* x, void* y);
3165                         // bool operator < (void* x, void* y);
3166                         // bool operator > (void* x, void* y);
3167                         // bool operator <= (void* x, void* y);
3168                         // bool operator >= (void* x, void* y);
3169                         //
3170                         if ((oper & Operator.ComparisonMask) != 0) {
3171                                 Expression temp;
3172                                 if (!l.IsPointer) {
3173                                         temp = Convert.ImplicitConversion (ec, left, r, left.Location);
3174                                         if (temp == null)
3175                                                 return null;
3176                                         left = temp;
3177                                 }
3178
3179                                 if (!r.IsPointer) {
3180                                         temp = Convert.ImplicitConversion (ec, right, l, right.Location);
3181                                         if (temp == null)
3182                                                 return null;
3183                                         right = temp;
3184                                 }
3185
3186                                 type = TypeManager.bool_type;
3187                                 return this;
3188                         }
3189
3190                         if (pointer_operators == null)
3191                                 CreatePointerOperatorsTable ();
3192
3193                         return ResolveOperatorPredefined (ec, pointer_operators, false, null);
3194                 }
3195
3196                 //
3197                 // Build-in operators method overloading
3198                 //
3199                 protected virtual Expression ResolveOperatorPredefined (ResolveContext ec, PredefinedOperator [] operators, bool primitives_only, TypeSpec enum_type)
3200                 {
3201                         PredefinedOperator best_operator = null;
3202                         TypeSpec l = left.Type;
3203                         TypeSpec r = right.Type;
3204                         Operator oper_mask = oper & ~Operator.ValuesOnlyMask;
3205
3206                         foreach (PredefinedOperator po in operators) {
3207                                 if ((po.OperatorsMask & oper_mask) == 0)
3208                                         continue;
3209
3210                                 if (primitives_only) {
3211                                         if (!po.IsPrimitiveApplicable (l, r))
3212                                                 continue;
3213                                 } else {
3214                                         if (!po.IsApplicable (ec, left, right))
3215                                                 continue;
3216                                 }
3217
3218                                 if (best_operator == null) {
3219                                         best_operator = po;
3220                                         if (primitives_only)
3221                                                 break;
3222
3223                                         continue;
3224                                 }
3225
3226                                 best_operator = po.ResolveBetterOperator (ec, best_operator);
3227
3228                                 if (best_operator == null) {
3229                                         ec.Report.Error (34, loc, "Operator `{0}' is ambiguous on operands of type `{1}' and `{2}'",
3230                                                 OperName (oper), TypeManager.CSharpName (l), TypeManager.CSharpName (r));
3231
3232                                         best_operator = po;
3233                                         break;
3234                                 }
3235                         }
3236
3237                         if (best_operator == null)
3238                                 return null;
3239
3240                         Expression expr = best_operator.ConvertResult (ec, this);
3241
3242                         //
3243                         // Optimize &/&& constant expressions with 0 value
3244                         //
3245                         if (oper == Operator.BitwiseAnd || oper == Operator.LogicalAnd) {
3246                                 Constant rc = right as Constant;
3247                                 Constant lc = left as Constant;
3248                                 if ((lc != null && lc.IsDefaultValue) || (rc != null && rc.IsDefaultValue)) {
3249                                         //
3250                                         // The result is a constant with side-effect
3251                                         //
3252                                         Constant side_effect = rc == null ?
3253                                                 new SideEffectConstant (lc, right, loc) :
3254                                                 new SideEffectConstant (rc, left, loc);
3255
3256                                         return ReducedExpression.Create (side_effect.Resolve (ec), expr);
3257                                 }
3258                         }
3259
3260                         if (enum_type == null)
3261                                 return expr;
3262
3263                         //
3264                         // HACK: required by enum_conversion
3265                         //
3266                         expr.Type = enum_type;
3267                         return EmptyCast.Create (expr, enum_type);
3268                 }
3269
3270                 //
3271                 // Performs user-operator overloading
3272                 //
3273                 protected virtual Expression ResolveUserOperator (ResolveContext ec, TypeSpec l, TypeSpec r)
3274                 {
3275                         var op = ConvertBinaryToUserOperator (oper);
3276                         IList<MemberSpec> left_operators = MemberCache.GetUserOperator (l, op, false);
3277                         IList<MemberSpec> right_operators = null;
3278
3279                         if (l != r) {
3280                                 right_operators = MemberCache.GetUserOperator (r, op, false);
3281                                 if (right_operators == null && left_operators == null)
3282                                         return null;
3283                         } else if (left_operators == null) {
3284                                 return null;
3285                         }
3286
3287                         Arguments args = new Arguments (2);
3288                         Argument larg = new Argument (left);
3289                         args.Add (larg);
3290                         Argument rarg = new Argument (right);
3291                         args.Add (rarg);
3292
3293                         //
3294                         // User-defined operator implementations always take precedence
3295                         // over predefined operator implementations
3296                         //
3297                         if (left_operators != null && right_operators != null) {
3298                                 left_operators = CombineUserOperators (left_operators, right_operators);
3299                         } else if (right_operators != null) {
3300                                 left_operators = right_operators;
3301                         }
3302
3303                         var mg = new MethodGroupExpr (left_operators, l, loc);
3304                         mg = mg.OverloadResolve (ec, ref args, true, loc);
3305                         if (mg == null)
3306                                 return null;
3307
3308                         Expression oper_expr;
3309
3310                         // TODO: CreateExpressionTree is allocated every time
3311                         if ((oper & Operator.LogicalMask) != 0) {
3312                                 oper_expr = new ConditionalLogicalOperator (mg, args, CreateExpressionTree,
3313                                         oper == Operator.LogicalAnd, loc).Resolve (ec);
3314                         } else {
3315                                 oper_expr = new UserOperatorCall (mg, args, CreateExpressionTree, loc);
3316                         }
3317
3318                         left = larg.Expr;
3319                         right = rarg.Expr;
3320                         return oper_expr;
3321                 }
3322
3323                 //
3324                 // Merge two sets of user operators into one, they are mostly distinguish
3325                 // expect when they share base type and it contains an operator
3326                 //
3327                 static IList<MemberSpec> CombineUserOperators (IList<MemberSpec> left, IList<MemberSpec> right)
3328                 {
3329                         var combined = new List<MemberSpec> (left.Count + right.Count);
3330                         combined.AddRange (left);
3331                         foreach (var r in right) {
3332                                 bool same = false;
3333                                 foreach (var l in left) {
3334                                         if (l.DeclaringType == r.DeclaringType) {
3335                                                 same = true;
3336                                                 break;
3337                                         }
3338                                 }
3339
3340                                 if (!same)
3341                                         combined.Add (r);
3342                         }
3343
3344                         return combined;
3345                 }
3346
3347                 public override TypeExpr ResolveAsTypeTerminal (IMemberContext ec, bool silent)
3348                 {
3349                         return null;
3350                 }
3351
3352                 private void CheckUselessComparison (ResolveContext ec, Constant c, TypeSpec type)
3353                 {
3354                         if (c == null || !IsTypeIntegral (type)
3355                                 || c is StringConstant
3356                                 || c is BoolConstant
3357                                 || c is FloatConstant
3358                                 || c is DoubleConstant
3359                                 || c is DecimalConstant
3360                                 )
3361                                 return;
3362
3363                         long value = 0;
3364
3365                         if (c is ULongConstant) {
3366                                 ulong uvalue = ((ULongConstant) c).Value;
3367                                 if (uvalue > long.MaxValue) {
3368                                         if (type == TypeManager.byte_type ||
3369                                             type == TypeManager.sbyte_type ||
3370                                             type == TypeManager.short_type ||
3371                                             type == TypeManager.ushort_type ||
3372                                             type == TypeManager.int32_type ||
3373                                             type == TypeManager.uint32_type ||
3374                                             type == TypeManager.int64_type ||
3375                                                 type == TypeManager.char_type)
3376                                                 WarnUselessComparison (ec, type);
3377                                         return;
3378                                 }
3379                                 value = (long) uvalue;
3380                         }
3381                         else if (c is ByteConstant)
3382                                 value = ((ByteConstant) c).Value;
3383                         else if (c is SByteConstant)
3384                                 value = ((SByteConstant) c).Value;
3385                         else if (c is ShortConstant)
3386                                 value = ((ShortConstant) c).Value;
3387                         else if (c is UShortConstant)
3388                                 value = ((UShortConstant) c).Value;
3389                         else if (c is IntConstant)
3390                                 value = ((IntConstant) c).Value;
3391                         else if (c is UIntConstant)
3392                                 value = ((UIntConstant) c).Value;
3393                         else if (c is LongConstant)
3394                                 value = ((LongConstant) c).Value;
3395                         else if (c is CharConstant)
3396                                 value = ((CharConstant)c).Value;
3397
3398                         if (value == 0)
3399                                 return;
3400
3401                         if (IsValueOutOfRange (value, type))
3402                                 WarnUselessComparison (ec, type);
3403                 }
3404
3405                 static bool IsValueOutOfRange (long value, TypeSpec type)
3406                 {
3407                         if (IsTypeUnsigned (type) && value < 0)
3408                                 return true;
3409                         return type == TypeManager.sbyte_type && (value >= 0x80 || value < -0x80) ||
3410                                 type == TypeManager.byte_type && value >= 0x100 ||
3411                                 type == TypeManager.short_type && (value >= 0x8000 || value < -0x8000) ||
3412                                 type == TypeManager.ushort_type && value >= 0x10000 ||
3413                                 type == TypeManager.int32_type && (value >= 0x80000000 || value < -0x80000000) ||
3414                                 type == TypeManager.uint32_type && value >= 0x100000000;
3415                 }
3416
3417                 private static bool IsTypeIntegral (TypeSpec type)
3418                 {
3419                         return type == TypeManager.uint64_type ||
3420                                 type == TypeManager.int64_type ||
3421                                 type == TypeManager.uint32_type ||
3422                                 type == TypeManager.int32_type ||
3423                                 type == TypeManager.ushort_type ||
3424                                 type == TypeManager.short_type ||
3425                                 type == TypeManager.sbyte_type ||
3426                                 type == TypeManager.byte_type ||
3427                                 type == TypeManager.char_type;
3428                 }
3429
3430                 private static bool IsTypeUnsigned (TypeSpec type)
3431                 {
3432                         return type == TypeManager.uint64_type ||
3433                                 type == TypeManager.uint32_type ||
3434                                 type == TypeManager.ushort_type ||
3435                                 type == TypeManager.byte_type ||
3436                                 type == TypeManager.char_type;
3437                 }
3438
3439                 private void WarnUselessComparison (ResolveContext ec, TypeSpec type)
3440                 {
3441                         ec.Report.Warning (652, 2, loc, "A comparison between a constant and a variable is useless. The constant is out of the range of the variable type `{0}'",
3442                                 TypeManager.CSharpName (type));
3443                 }
3444
3445                 /// <remarks>
3446                 ///   EmitBranchable is called from Statement.EmitBoolExpression in the
3447                 ///   context of a conditional bool expression.  This function will return
3448                 ///   false if it is was possible to use EmitBranchable, or true if it was.
3449                 ///
3450                 ///   The expression's code is generated, and we will generate a branch to `target'
3451                 ///   if the resulting expression value is equal to isTrue
3452                 /// </remarks>
3453                 public override void EmitBranchable (EmitContext ec, Label target, bool on_true)
3454                 {
3455                         //
3456                         // This is more complicated than it looks, but its just to avoid
3457                         // duplicated tests: basically, we allow ==, !=, >, <, >= and <=
3458                         // but on top of that we want for == and != to use a special path
3459                         // if we are comparing against null
3460                         //
3461                         if ((oper & Operator.EqualityMask) != 0 && (left is Constant || right is Constant)) {
3462                                 bool my_on_true = oper == Operator.Inequality ? on_true : !on_true;
3463
3464                                 //
3465                                 // put the constant on the rhs, for simplicity
3466                                 //
3467                                 if (left is Constant) {
3468                                         Expression swap = right;
3469                                         right = left;
3470                                         left = swap;
3471                                 }
3472
3473                                 //
3474                                 // brtrue/brfalse works with native int only
3475                                 //
3476                                 if (((Constant) right).IsZeroInteger && right.Type != TypeManager.int64_type && right.Type != TypeManager.uint64_type) {
3477                                         left.EmitBranchable (ec, target, my_on_true);
3478                                         return;
3479                                 }
3480                                 if (right.Type == TypeManager.bool_type) {
3481                                         // right is a boolean, and it's not 'false' => it is 'true'
3482                                         left.EmitBranchable (ec, target, !my_on_true);
3483                                         return;
3484                                 }
3485
3486                         } else if (oper == Operator.LogicalAnd) {
3487
3488                                 if (on_true) {
3489                                         Label tests_end = ec.DefineLabel ();
3490
3491                                         left.EmitBranchable (ec, tests_end, false);
3492                                         right.EmitBranchable (ec, target, true);
3493                                         ec.MarkLabel (tests_end);
3494                                 } else {
3495                                         //
3496                                         // This optimizes code like this
3497                                         // if (true && i > 4)
3498                                         //
3499                                         if (!(left is Constant))
3500                                                 left.EmitBranchable (ec, target, false);
3501
3502                                         if (!(right is Constant))
3503                                                 right.EmitBranchable (ec, target, false);
3504                                 }
3505
3506                                 return;
3507
3508                         } else if (oper == Operator.LogicalOr){
3509                                 if (on_true) {
3510                                         left.EmitBranchable (ec, target, true);
3511                                         right.EmitBranchable (ec, target, true);
3512
3513                                 } else {
3514                                         Label tests_end = ec.DefineLabel ();
3515                                         left.EmitBranchable (ec, tests_end, true);
3516                                         right.EmitBranchable (ec, target, false);
3517                                         ec.MarkLabel (tests_end);
3518                                 }
3519
3520                                 return;
3521
3522                         } else if ((oper & Operator.ComparisonMask) == 0) {
3523                                 base.EmitBranchable (ec, target, on_true);
3524                                 return;
3525                         }
3526
3527                         left.Emit (ec);
3528                         right.Emit (ec);
3529
3530                         TypeSpec t = left.Type;
3531                         bool is_float = IsFloat (t);
3532                         bool is_unsigned = is_float || IsUnsigned (t);
3533
3534                         switch (oper){
3535                         case Operator.Equality:
3536                                 if (on_true)
3537                                         ec.Emit (OpCodes.Beq, target);
3538                                 else
3539                                         ec.Emit (OpCodes.Bne_Un, target);
3540                                 break;
3541
3542                         case Operator.Inequality:
3543                                 if (on_true)
3544                                         ec.Emit (OpCodes.Bne_Un, target);
3545                                 else
3546                                         ec.Emit (OpCodes.Beq, target);
3547                                 break;
3548
3549                         case Operator.LessThan:
3550                                 if (on_true)
3551                                         if (is_unsigned && !is_float)
3552                                                 ec.Emit (OpCodes.Blt_Un, target);
3553                                         else
3554                                                 ec.Emit (OpCodes.Blt, target);
3555                                 else
3556                                         if (is_unsigned)
3557                                                 ec.Emit (OpCodes.Bge_Un, target);
3558                                         else
3559                                                 ec.Emit (OpCodes.Bge, target);
3560                                 break;
3561
3562                         case Operator.GreaterThan:
3563                                 if (on_true)
3564                                         if (is_unsigned && !is_float)
3565                                                 ec.Emit (OpCodes.Bgt_Un, target);
3566                                         else
3567                                                 ec.Emit (OpCodes.Bgt, target);
3568                                 else
3569                                         if (is_unsigned)
3570                                                 ec.Emit (OpCodes.Ble_Un, target);
3571                                         else
3572                                                 ec.Emit (OpCodes.Ble, target);
3573                                 break;
3574
3575                         case Operator.LessThanOrEqual:
3576                                 if (on_true)
3577                                         if (is_unsigned && !is_float)
3578                                                 ec.Emit (OpCodes.Ble_Un, target);
3579                                         else
3580                                                 ec.Emit (OpCodes.Ble, target);
3581                                 else
3582                                         if (is_unsigned)
3583                                                 ec.Emit (OpCodes.Bgt_Un, target);
3584                                         else
3585                                                 ec.Emit (OpCodes.Bgt, target);
3586                                 break;
3587
3588
3589                         case Operator.GreaterThanOrEqual:
3590                                 if (on_true)
3591                                         if (is_unsigned && !is_float)
3592                                                 ec.Emit (OpCodes.Bge_Un, target);
3593                                         else
3594                                                 ec.Emit (OpCodes.Bge, target);
3595                                 else
3596                                         if (is_unsigned)
3597                                                 ec.Emit (OpCodes.Blt_Un, target);
3598                                         else
3599                                                 ec.Emit (OpCodes.Blt, target);
3600                                 break;
3601                         default:
3602                                 throw new InternalErrorException (oper.ToString ());
3603                         }
3604                 }
3605
3606                 public override void Emit (EmitContext ec)
3607                 {
3608                         EmitOperator (ec, left.Type);
3609                 }
3610
3611                 protected virtual void EmitOperator (EmitContext ec, TypeSpec l)
3612                 {
3613                         //
3614                         // Handle short-circuit operators differently
3615                         // than the rest
3616                         //
3617                         if ((oper & Operator.LogicalMask) != 0) {
3618                                 Label load_result = ec.DefineLabel ();
3619                                 Label end = ec.DefineLabel ();
3620
3621                                 bool is_or = oper == Operator.LogicalOr;
3622                                 left.EmitBranchable (ec, load_result, is_or);
3623                                 right.Emit (ec);
3624                                 ec.Emit (OpCodes.Br_S, end);
3625
3626                                 ec.MarkLabel (load_result);
3627                                 ec.Emit (is_or ? OpCodes.Ldc_I4_1 : OpCodes.Ldc_I4_0);
3628                                 ec.MarkLabel (end);
3629                                 return;
3630                         }
3631
3632                         //
3633                         // Optimize zero-based operations which cannot be optimized at expression level
3634                         //
3635                         if (oper == Operator.Subtraction) {
3636                                 var lc = left as IntegralConstant;
3637                                 if (lc != null && lc.IsDefaultValue) {
3638                                         right.Emit (ec);
3639                                         ec.Emit (OpCodes.Neg);
3640                                         return;
3641                                 }
3642                         }
3643
3644                         left.Emit (ec);
3645                         right.Emit (ec);
3646                         EmitOperatorOpcode (ec, oper, l);
3647
3648                         //
3649                         // Nullable enum could require underlying type cast and we cannot simply wrap binary
3650                         // expression because that would wrap lifted binary operation
3651                         //
3652                         if (enum_conversion != null)
3653                                 enum_conversion.Emit (ec);
3654                 }
3655
3656                 public override void EmitSideEffect (EmitContext ec)
3657                 {
3658                         if ((oper & Operator.LogicalMask) != 0 ||
3659                                 (ec.HasSet (EmitContext.Options.CheckedScope) && (oper == Operator.Multiply || oper == Operator.Addition || oper == Operator.Subtraction))) {
3660                                 base.EmitSideEffect (ec);
3661                         } else {
3662                                 left.EmitSideEffect (ec);
3663                                 right.EmitSideEffect (ec);
3664                         }
3665                 }
3666
3667                 protected override void CloneTo (CloneContext clonectx, Expression t)
3668                 {
3669                         Binary target = (Binary) t;
3670
3671                         target.left = left.Clone (clonectx);
3672                         target.right = right.Clone (clonectx);
3673                 }
3674
3675                 public Expression CreateCallSiteBinder (ResolveContext ec, Arguments args)
3676                 {
3677                         Arguments binder_args = new Arguments (4);
3678
3679                         MemberAccess sle = new MemberAccess (new MemberAccess (
3680                                 new QualifiedAliasMember (QualifiedAliasMember.GlobalAlias, "System", loc), "Linq", loc), "Expressions", loc);
3681
3682                         CSharpBinderFlags flags = 0;
3683                         if (ec.HasSet (ResolveContext.Options.CheckedScope))
3684                                 flags = CSharpBinderFlags.CheckedContext;
3685
3686                         if ((oper & Operator.LogicalMask) != 0)
3687                                 flags |= CSharpBinderFlags.BinaryOperationLogical;
3688
3689                         binder_args.Add (new Argument (new EnumConstant (new IntLiteral ((int) flags, loc), TypeManager.binder_flags)));
3690                         binder_args.Add (new Argument (new MemberAccess (new MemberAccess (sle, "ExpressionType", loc), GetOperatorExpressionTypeName (), loc)));
3691                         binder_args.Add (new Argument (new TypeOf (new TypeExpression (ec.CurrentType, loc), loc)));
3692                         binder_args.Add (new Argument (new ImplicitlyTypedArrayCreation (args.CreateDynamicBinderArguments (ec), loc)));
3693
3694                         return new Invocation (DynamicExpressionStatement.GetBinder ("BinaryOperation", loc), binder_args);
3695                 }
3696
3697                 public override Expression CreateExpressionTree (ResolveContext ec)
3698                 {
3699                         return CreateExpressionTree (ec, null);
3700                 }
3701
3702                 Expression CreateExpressionTree (ResolveContext ec, MethodGroupExpr method)
3703                 {
3704                         string method_name;
3705                         bool lift_arg = false;
3706
3707                         switch (oper) {
3708                         case Operator.Addition:
3709                                 if (method == null && ec.HasSet (ResolveContext.Options.CheckedScope) && !IsFloat (type))
3710                                         method_name = "AddChecked";
3711                                 else
3712                                         method_name = "Add";
3713                                 break;
3714                         case Operator.BitwiseAnd:
3715                                 method_name = "And";
3716                                 break;
3717                         case Operator.BitwiseOr:
3718                                 method_name = "Or";
3719                                 break;
3720                         case Operator.Division:
3721                                 method_name = "Divide";
3722                                 break;
3723                         case Operator.Equality:
3724                                 method_name = "Equal";
3725                                 lift_arg = true;
3726                                 break;
3727                         case Operator.ExclusiveOr:
3728                                 method_name = "ExclusiveOr";
3729                                 break;
3730                         case Operator.GreaterThan:
3731                                 method_name = "GreaterThan";
3732                                 lift_arg = true;
3733                                 break;
3734                         case Operator.GreaterThanOrEqual:
3735                                 method_name = "GreaterThanOrEqual";
3736                                 lift_arg = true;
3737                                 break;
3738                         case Operator.Inequality:
3739                                 method_name = "NotEqual";
3740                                 lift_arg = true;
3741                                 break;
3742                         case Operator.LeftShift:
3743                                 method_name = "LeftShift";
3744                                 break;
3745                         case Operator.LessThan:
3746                                 method_name = "LessThan";
3747                                 lift_arg = true;
3748                                 break;
3749                         case Operator.LessThanOrEqual:
3750                                 method_name = "LessThanOrEqual";
3751                                 lift_arg = true;
3752                                 break;
3753                         case Operator.LogicalAnd:
3754                                 method_name = "AndAlso";
3755                                 break;
3756                         case Operator.LogicalOr:
3757                                 method_name = "OrElse";
3758                                 break;
3759                         case Operator.Modulus:
3760                                 method_name = "Modulo";
3761                                 break;
3762                         case Operator.Multiply:
3763                                 if (method == null && ec.HasSet (ResolveContext.Options.CheckedScope) && !IsFloat (type))
3764                                         method_name = "MultiplyChecked";
3765                                 else
3766                                         method_name = "Multiply";
3767                                 break;
3768                         case Operator.RightShift:
3769                                 method_name = "RightShift";
3770                                 break;
3771                         case Operator.Subtraction:
3772                                 if (method == null && ec.HasSet (ResolveContext.Options.CheckedScope) && !IsFloat (type))
3773                                         method_name = "SubtractChecked";
3774                                 else
3775                                         method_name = "Subtract";
3776                                 break;
3777
3778                         default:
3779                                 throw new InternalErrorException ("Unknown expression tree binary operator " + oper);
3780                         }
3781
3782                         Arguments args = new Arguments (2);
3783                         args.Add (new Argument (left.CreateExpressionTree (ec)));
3784                         args.Add (new Argument (right.CreateExpressionTree (ec)));
3785                         if (method != null) {
3786                                 if (lift_arg)
3787                                         args.Add (new Argument (new BoolConstant (false, loc)));
3788
3789                                 args.Add (new Argument (method.CreateExpressionTree (ec)));
3790                         }
3791
3792                         return CreateExpressionFactoryCall (ec, method_name, args);
3793                 }
3794         }
3795
3796         //
3797         // Represents the operation a + b [+ c [+ d [+ ...]]], where a is a string
3798         // b, c, d... may be strings or objects.
3799         //
3800         public class StringConcat : Expression {
3801                 Arguments arguments;
3802                 static IList<MemberSpec> concat_members;
3803
3804                 public StringConcat (Expression left, Expression right, Location loc)
3805                 {
3806                         this.loc = loc;
3807                         type = TypeManager.string_type;
3808                         eclass = ExprClass.Value;
3809
3810                         arguments = new Arguments (2);
3811                 }
3812
3813                 public static StringConcat Create (ResolveContext rc, Expression left, Expression right, Location loc)
3814                 {
3815                         if (left.eclass == ExprClass.Unresolved || right.eclass == ExprClass.Unresolved)
3816                                 throw new ArgumentException ();
3817
3818                         var s = new StringConcat (left, right, loc);
3819                         s.Append (rc, left);
3820                         s.Append (rc, right);
3821                         return s;
3822                 }
3823
3824                 public override Expression CreateExpressionTree (ResolveContext ec)
3825                 {
3826                         Argument arg = arguments [0];
3827                         return CreateExpressionAddCall (ec, arg, arg.CreateExpressionTree (ec), 1);
3828                 }
3829
3830                 //
3831                 // Creates nested calls tree from an array of arguments used for IL emit
3832                 //
3833                 Expression CreateExpressionAddCall (ResolveContext ec, Argument left, Expression left_etree, int pos)
3834                 {
3835                         Arguments concat_args = new Arguments (2);
3836                         Arguments add_args = new Arguments (3);
3837
3838                         concat_args.Add (left);
3839                         add_args.Add (new Argument (left_etree));
3840
3841                         concat_args.Add (arguments [pos]);
3842                         add_args.Add (new Argument (arguments [pos].CreateExpressionTree (ec)));
3843
3844                         MethodGroupExpr method = CreateConcatMethodGroup ();
3845                         if (method == null)
3846                                 return null;
3847
3848                         method = method.OverloadResolve (ec, ref concat_args, false, loc);
3849                         if (method == null)
3850                                 return null;
3851
3852                         add_args.Add (new Argument (method.CreateExpressionTree (ec)));
3853
3854                         Expression expr = CreateExpressionFactoryCall (ec, "Add", add_args);
3855                         if (++pos == arguments.Count)
3856                                 return expr;
3857
3858                         left = new Argument (new EmptyExpression (method.BestCandidate.ReturnType));
3859                         return CreateExpressionAddCall (ec, left, expr, pos);
3860                 }
3861
3862                 protected override Expression DoResolve (ResolveContext ec)
3863                 {
3864                         return this;
3865                 }
3866
3867                 void Append (ResolveContext rc, Expression operand)
3868                 {
3869                         //
3870                         // Constant folding
3871                         //
3872                         StringConstant sc = operand as StringConstant;
3873                         if (sc != null) {
3874                                 if (arguments.Count != 0) {
3875                                         Argument last_argument = arguments [arguments.Count - 1];
3876                                         StringConstant last_expr_constant = last_argument.Expr as StringConstant;
3877                                         if (last_expr_constant != null) {
3878                                                 last_argument.Expr = new StringConstant (
3879                                                         last_expr_constant.Value + sc.Value, sc.Location).Resolve (rc);
3880                                                 return;
3881                                         }
3882                                 }
3883                         } else {
3884                                 //
3885                                 // Multiple (3+) concatenation are resolved as multiple StringConcat instances
3886                                 //
3887                                 StringConcat concat_oper = operand as StringConcat;
3888                                 if (concat_oper != null) {
3889                                         arguments.AddRange (concat_oper.arguments);
3890                                         return;
3891                                 }
3892                         }
3893
3894                         arguments.Add (new Argument (operand));
3895                 }
3896
3897                 MethodGroupExpr CreateConcatMethodGroup ()
3898                 {
3899                         if (concat_members == null) {
3900                                 concat_members = MemberCache.FindMembers (type,
3901                                         MemberFilter.Method ("Concat", -1, null, type), BindingRestriction.DeclaredOnly);
3902                         }
3903
3904                         return new MethodGroupExpr (concat_members, type, loc);
3905                 }
3906
3907                 public override void Emit (EmitContext ec)
3908                 {
3909                         var mg = CreateConcatMethodGroup ();
3910                         mg = mg.OverloadResolve (new ResolveContext (ec.MemberContext), ref arguments, false, loc);
3911                         if (mg != null)
3912                                 mg.EmitCall (ec, arguments);
3913                 }
3914
3915                 public override SLE.Expression MakeExpression (BuilderContext ctx)
3916                 {
3917                         if (arguments.Count != 2)
3918                                 throw new NotImplementedException ("arguments.Count != 2");
3919
3920                         var concat = typeof (string).GetMethod ("Concat", new[] { typeof (object), typeof (object) });
3921                         return SLE.Expression.Add (arguments[0].Expr.MakeExpression (ctx), arguments[1].Expr.MakeExpression (ctx), concat);
3922                 }
3923
3924                 public static void Reset ()
3925                 {
3926                         concat_members = null;
3927                 }
3928         }
3929
3930         //
3931         // User-defined conditional logical operator
3932         //
3933         public class ConditionalLogicalOperator : UserOperatorCall {
3934                 readonly bool is_and;
3935                 Expression oper;
3936
3937                 public ConditionalLogicalOperator (MethodGroupExpr oper_method, Arguments arguments,
3938                         ExpressionTreeExpression expr_tree, bool is_and, Location loc)
3939                         : base (oper_method, arguments, expr_tree, loc)
3940                 {
3941                         this.is_and = is_and;
3942                         eclass = ExprClass.Unresolved;
3943                 }
3944
3945                 protected override Expression DoResolve (ResolveContext ec)
3946                 {
3947                         var method = mg.BestCandidate;
3948                         type = method.ReturnType;
3949                         AParametersCollection pd = method.Parameters;
3950                         if (!TypeManager.IsEqual (type, type) || !TypeManager.IsEqual (type, pd.Types [0]) || !TypeManager.IsEqual (type, pd.Types [1])) {
3951                                 ec.Report.Error (217, loc,
3952                                         "A user-defined operator `{0}' must have parameters and return values of the same type in order to be applicable as a short circuit operator",
3953                                         TypeManager.CSharpSignature (method));
3954                                 return null;
3955                         }
3956
3957                         Expression left_dup = new EmptyExpression (type);
3958                         Expression op_true = GetOperatorTrue (ec, left_dup, loc);
3959                         Expression op_false = GetOperatorFalse (ec, left_dup, loc);
3960                         if (op_true == null || op_false == null) {
3961                                 ec.Report.Error (218, loc,
3962                                         "The type `{0}' must have operator `true' and operator `false' defined when `{1}' is used as a short circuit operator",
3963                                         TypeManager.CSharpName (type), TypeManager.CSharpSignature (method));
3964                                 return null;
3965                         }
3966
3967                         oper = is_and ? op_false : op_true;
3968                         eclass = ExprClass.Value;
3969                         return this;
3970                 }
3971
3972                 public override void Emit (EmitContext ec)
3973                 {
3974                         Label end_target = ec.DefineLabel ();
3975
3976                         //
3977                         // Emit and duplicate left argument
3978                         //
3979                         arguments [0].Expr.Emit (ec);
3980                         ec.Emit (OpCodes.Dup);
3981                         arguments.RemoveAt (0);
3982
3983                         oper.EmitBranchable (ec, end_target, true);
3984                         base.Emit (ec);
3985                         ec.MarkLabel (end_target);
3986                 }
3987         }
3988
3989         public class PointerArithmetic : Expression {
3990                 Expression left, right;
3991                 Binary.Operator op;
3992
3993                 //
3994                 // We assume that `l' is always a pointer
3995                 //
3996                 public PointerArithmetic (Binary.Operator op, Expression l, Expression r, TypeSpec t, Location loc)
3997                 {
3998                         type = t;
3999                         this.loc = loc;
4000                         left = l;
4001                         right = r;
4002                         this.op = op;
4003                 }
4004
4005                 public override Expression CreateExpressionTree (ResolveContext ec)
4006                 {
4007                         Error_PointerInsideExpressionTree (ec);
4008                         return null;
4009                 }
4010
4011                 protected override Expression DoResolve (ResolveContext ec)
4012                 {
4013                         eclass = ExprClass.Variable;
4014
4015                         if (left.Type == TypeManager.void_ptr_type) {
4016                                 ec.Report.Error (242, loc, "The operation in question is undefined on void pointers");
4017                                 return null;
4018                         }
4019
4020                         return this;
4021                 }
4022
4023                 public override void Emit (EmitContext ec)
4024                 {
4025                         TypeSpec op_type = left.Type;
4026
4027                         // It must be either array or fixed buffer
4028                         TypeSpec element;
4029                         if (TypeManager.HasElementType (op_type)) {
4030                                 element = TypeManager.GetElementType (op_type);
4031                         } else {
4032                                 FieldExpr fe = left as FieldExpr;
4033                                 if (fe != null)
4034                                         element = ((FixedFieldSpec) (fe.Spec)).ElementType;
4035                                 else
4036                                         element = op_type;
4037                         }
4038
4039                         int size = GetTypeSize (element);
4040                         TypeSpec rtype = right.Type;
4041
4042                         if ((op & Binary.Operator.SubtractionMask) != 0 && rtype.IsPointer){
4043                                 //
4044                                 // handle (pointer - pointer)
4045                                 //
4046                                 left.Emit (ec);
4047                                 right.Emit (ec);
4048                                 ec.Emit (OpCodes.Sub);
4049
4050                                 if (size != 1){
4051                                         if (size == 0)
4052                                                 ec.Emit (OpCodes.Sizeof, element);
4053                                         else
4054                                                 ec.EmitInt (size);
4055                                         ec.Emit (OpCodes.Div);
4056                                 }
4057                                 ec.Emit (OpCodes.Conv_I8);
4058                         } else {
4059                                 //
4060                                 // handle + and - on (pointer op int)
4061                                 //
4062                                 Constant left_const = left as Constant;
4063                                 if (left_const != null) {
4064                                         //
4065                                         // Optimize ((T*)null) pointer operations
4066                                         //
4067                                         if (left_const.IsDefaultValue) {
4068                                                 left = EmptyExpression.Null;
4069                                         } else {
4070                                                 left_const = null;
4071                                         }
4072                                 }
4073
4074                                 left.Emit (ec);
4075
4076                                 var right_const = right as Constant;
4077                                 if (right_const != null) {
4078                                         //
4079                                         // Optimize 0-based arithmetic
4080                                         //
4081                                         if (right_const.IsDefaultValue)
4082                                                 return;
4083
4084                                         if (size != 0)
4085                                                 right = new IntConstant (size, right.Location);
4086                                         else
4087                                                 right = new SizeOf (new TypeExpression (element, right.Location), right.Location);
4088
4089                                         // TODO: Should be the checks resolve context sensitive?
4090                                         ResolveContext rc = new ResolveContext (ec.MemberContext, ResolveContext.Options.UnsafeScope);
4091                                         right = new Binary (Binary.Operator.Multiply, right, right_const, loc).Resolve (rc);
4092                                         if (right == null)
4093                                                 return;
4094                                 }
4095
4096                                 right.Emit (ec);
4097                                 if (rtype == TypeManager.sbyte_type || rtype == TypeManager.byte_type ||
4098                                         rtype == TypeManager.short_type || rtype == TypeManager.ushort_type) {
4099                                         ec.Emit (OpCodes.Conv_I);
4100                                 } else if (rtype == TypeManager.uint32_type) {
4101                                         ec.Emit (OpCodes.Conv_U);
4102                                 }
4103
4104                                 if (right_const == null && size != 1){
4105                                         if (size == 0)
4106                                                 ec.Emit (OpCodes.Sizeof, element);
4107                                         else
4108                                                 ec.EmitInt (size);
4109                                         if (rtype == TypeManager.int64_type || rtype == TypeManager.uint64_type)
4110                                                 ec.Emit (OpCodes.Conv_I8);
4111
4112                                         Binary.EmitOperatorOpcode (ec, Binary.Operator.Multiply, rtype);
4113                                 }
4114
4115                                 if (left_const == null) {
4116                                         if (rtype == TypeManager.int64_type)
4117                                                 ec.Emit (OpCodes.Conv_I);
4118                                         else if (rtype == TypeManager.uint64_type)
4119                                                 ec.Emit (OpCodes.Conv_U);
4120
4121                                         Binary.EmitOperatorOpcode (ec, op, op_type);
4122                                 }
4123                         }
4124                 }
4125         }
4126
4127         //
4128         // A boolean-expression is an expression that yields a result
4129         // of type bool
4130         //
4131         public class BooleanExpression : ShimExpression
4132         {
4133                 public BooleanExpression (Expression expr)
4134                         : base (expr)
4135                 {
4136                         this.loc = expr.Location;
4137                 }
4138
4139                 public override Expression CreateExpressionTree (ResolveContext ec)
4140                 {
4141                         // TODO: We should emit IsTrue (v4) instead of direct user operator
4142                         // call but that would break csc compatibility
4143                         return base.CreateExpressionTree (ec);
4144                 }
4145
4146                 protected override Expression DoResolve (ResolveContext ec)
4147                 {
4148                         // A boolean-expression is required to be of a type
4149                         // that can be implicitly converted to bool or of
4150                         // a type that implements operator true
4151
4152                         expr = expr.Resolve (ec);
4153                         if (expr == null)
4154                                 return null;
4155
4156                         Assign ass = expr as Assign;
4157                         if (ass != null && ass.Source is Constant) {
4158                                 ec.Report.Warning (665, 3, loc,
4159                                         "Assignment in conditional expression is always constant. Did you mean to use `==' instead ?");
4160                         }
4161
4162                         if (expr.Type == TypeManager.bool_type)
4163                                 return expr;
4164
4165                         if (expr.Type == InternalType.Dynamic) {
4166                                 Arguments args = new Arguments (1);
4167                                 args.Add (new Argument (expr));
4168                                 return new DynamicUnaryConversion ("IsTrue", args, loc).Resolve (ec);
4169                         }
4170
4171                         type = TypeManager.bool_type;
4172                         Expression converted = Convert.ImplicitConversion (ec, expr, type, loc);
4173                         if (converted != null)
4174                                 return converted;
4175
4176                         //
4177                         // If no implicit conversion to bool exists, try using `operator true'
4178                         //
4179                         converted = GetOperatorTrue (ec, expr, loc);
4180                         if (converted == null) {
4181                                 expr.Error_ValueCannotBeConverted (ec, loc, type, false);
4182                                 return null;
4183                         }
4184
4185                         return converted;
4186                 }
4187         }
4188
4189         /// <summary>
4190         ///   Implements the ternary conditional operator (?:)
4191         /// </summary>
4192         public class Conditional : Expression {
4193                 Expression expr, true_expr, false_expr;
4194
4195                 public Conditional (BooleanExpression expr, Expression true_expr, Expression false_expr, Location loc)
4196                 {
4197                         this.expr = expr;
4198                         this.true_expr = true_expr;
4199                         this.false_expr = false_expr;
4200                         this.loc = loc;
4201                 }
4202
4203                 public Expression Expr {
4204                         get {
4205                                 return expr;
4206                         }
4207                 }
4208
4209                 public Expression TrueExpr {
4210                         get {
4211                                 return true_expr;
4212                         }
4213                 }
4214
4215                 public Expression FalseExpr {
4216                         get {
4217                                 return false_expr;
4218                         }
4219                 }
4220
4221                 public override Expression CreateExpressionTree (ResolveContext ec)
4222                 {
4223                         Arguments args = new Arguments (3);
4224                         args.Add (new Argument (expr.CreateExpressionTree (ec)));
4225                         args.Add (new Argument (true_expr.CreateExpressionTree (ec)));
4226                         args.Add (new Argument (false_expr.CreateExpressionTree (ec)));
4227                         return CreateExpressionFactoryCall (ec, "Condition", args);
4228                 }
4229
4230                 protected override Expression DoResolve (ResolveContext ec)
4231                 {
4232                         expr = expr.Resolve (ec);
4233                         true_expr = true_expr.Resolve (ec);
4234                         false_expr = false_expr.Resolve (ec);
4235
4236                         if (true_expr == null || false_expr == null || expr == null)
4237                                 return null;
4238
4239                         eclass = ExprClass.Value;
4240                         TypeSpec true_type = true_expr.Type;
4241                         TypeSpec false_type = false_expr.Type;
4242                         type = true_type;
4243
4244                         //
4245                         // First, if an implicit conversion exists from true_expr
4246                         // to false_expr, then the result type is of type false_expr.Type
4247                         //
4248                         if (!TypeManager.IsEqual (true_type, false_type)) {
4249                                 Expression conv = Convert.ImplicitConversion (ec, true_expr, false_type, loc);
4250                                 if (conv != null) {
4251                                         //
4252                                         // Check if both can convert implicitly to each other's type
4253                                         //
4254                                         if (Convert.ImplicitConversion (ec, false_expr, true_type, loc) != null) {
4255                                                 ec.Report.Error (172, true_expr.Location,
4256                                                         "Type of conditional expression cannot be determined as `{0}' and `{1}' convert implicitly to each other",
4257                                                         TypeManager.CSharpName (true_type), TypeManager.CSharpName (false_type));
4258                                                 return null;
4259                                         }
4260                                         type = false_type;
4261                                         true_expr = conv;
4262                                 } else if ((conv = Convert.ImplicitConversion (ec, false_expr, true_type, loc)) != null) {
4263                                         false_expr = conv;
4264                                 } else {
4265                                         ec.Report.Error (173, true_expr.Location,
4266                                                 "Type of conditional expression cannot be determined because there is no implicit conversion between `{0}' and `{1}'",
4267                                                 TypeManager.CSharpName (true_type), TypeManager.CSharpName (false_type));
4268                                         return null;
4269                                 }
4270                         }
4271
4272                         // Dead code optimalization
4273                         Constant c = expr as Constant;
4274                         if (c != null){
4275                                 bool is_false = c.IsDefaultValue;
4276                                 ec.Report.Warning (429, 4, is_false ? true_expr.Location : false_expr.Location, "Unreachable expression code detected");
4277                                 return ReducedExpression.Create (is_false ? false_expr : true_expr, this).Resolve (ec);
4278                         }
4279
4280                         return this;
4281                 }
4282
4283                 public override TypeExpr ResolveAsTypeTerminal (IMemberContext ec, bool silent)
4284                 {
4285                         return null;
4286                 }
4287
4288                 public override void Emit (EmitContext ec)
4289                 {
4290                         Label false_target = ec.DefineLabel ();
4291                         Label end_target = ec.DefineLabel ();
4292
4293                         expr.EmitBranchable (ec, false_target, false);
4294                         true_expr.Emit (ec);
4295
4296                         if (type.IsInterface) {
4297                                 LocalBuilder temp = ec.GetTemporaryLocal (type);
4298                                 ec.Emit (OpCodes.Stloc, temp);
4299                                 ec.Emit (OpCodes.Ldloc, temp);
4300                                 ec.FreeTemporaryLocal (temp, type);
4301                         }
4302
4303                         ec.Emit (OpCodes.Br, end_target);
4304                         ec.MarkLabel (false_target);
4305                         false_expr.Emit (ec);
4306                         ec.MarkLabel (end_target);
4307                 }
4308
4309                 protected override void CloneTo (CloneContext clonectx, Expression t)
4310                 {
4311                         Conditional target = (Conditional) t;
4312
4313                         target.expr = expr.Clone (clonectx);
4314                         target.true_expr = true_expr.Clone (clonectx);
4315                         target.false_expr = false_expr.Clone (clonectx);
4316                 }
4317         }
4318
4319         public abstract class VariableReference : Expression, IAssignMethod, IMemoryLocation, IVariableReference {
4320                 LocalTemporary temp;
4321
4322                 #region Abstract
4323                 public abstract HoistedVariable GetHoistedVariable (AnonymousExpression ae);
4324                 public abstract bool IsFixed { get; }
4325                 public abstract bool IsRef { get; }
4326                 public abstract string Name { get; }
4327                 public abstract void SetHasAddressTaken ();
4328
4329                 //
4330                 // Variable IL data, it has to be protected to encapsulate hoisted variables
4331                 //
4332                 protected abstract ILocalVariable Variable { get; }
4333
4334                 //
4335                 // Variable flow-analysis data
4336                 //
4337                 public abstract VariableInfo VariableInfo { get; }
4338                 #endregion
4339
4340                 public virtual void AddressOf (EmitContext ec, AddressOp mode)
4341                 {
4342                         HoistedVariable hv = GetHoistedVariable (ec);
4343                         if (hv != null) {
4344                                 hv.AddressOf (ec, mode);
4345                                 return;
4346                         }
4347
4348                         Variable.EmitAddressOf (ec);
4349                 }
4350
4351                 public HoistedVariable GetHoistedVariable (ResolveContext rc)
4352                 {
4353                         return GetHoistedVariable (rc.CurrentAnonymousMethod);
4354                 }
4355
4356                 public HoistedVariable GetHoistedVariable (EmitContext ec)
4357                 {
4358                         return GetHoistedVariable (ec.CurrentAnonymousMethod);
4359                 }
4360
4361                 public override string GetSignatureForError ()
4362                 {
4363                         return Name;
4364                 }
4365
4366                 public override void Emit (EmitContext ec)
4367                 {
4368                         Emit (ec, false);
4369                 }
4370
4371                 public override void EmitSideEffect (EmitContext ec)
4372                 {
4373                         // do nothing
4374                 }
4375
4376                 //
4377                 // This method is used by parameters that are references, that are
4378                 // being passed as references:  we only want to pass the pointer (that
4379                 // is already stored in the parameter, not the address of the pointer,
4380                 // and not the value of the variable).
4381                 //
4382                 public void EmitLoad (EmitContext ec)
4383                 {
4384                         Variable.Emit (ec);
4385                 }
4386
4387                 public void Emit (EmitContext ec, bool leave_copy)
4388                 {
4389                         Report.Debug (64, "VARIABLE EMIT", this, Variable, type, IsRef, loc);
4390
4391                         HoistedVariable hv = GetHoistedVariable (ec);
4392                         if (hv != null) {
4393                                 hv.Emit (ec, leave_copy);
4394                                 return;
4395                         }
4396
4397                         EmitLoad (ec);
4398
4399                         if (IsRef) {
4400                                 //
4401                                 // If we are a reference, we loaded on the stack a pointer
4402                                 // Now lets load the real value
4403                                 //
4404                                 ec.EmitLoadFromPtr (type);
4405                         }
4406
4407                         if (leave_copy) {
4408                                 ec.Emit (OpCodes.Dup);
4409
4410                                 if (IsRef) {
4411                                         temp = new LocalTemporary (Type);
4412                                         temp.Store (ec);
4413                                 }
4414                         }
4415                 }
4416
4417                 public void EmitAssign (EmitContext ec, Expression source, bool leave_copy,
4418                                         bool prepare_for_load)
4419                 {
4420                         HoistedVariable hv = GetHoistedVariable (ec);
4421                         if (hv != null) {
4422                                 hv.EmitAssign (ec, source, leave_copy, prepare_for_load);
4423                                 return;
4424                         }
4425
4426                         New n_source = source as New;
4427                         if (n_source != null) {
4428                                 if (!n_source.Emit (ec, this)) {
4429                                         if (leave_copy)
4430                                                 EmitLoad (ec);
4431                                         return;
4432                                 }
4433                         } else {
4434                                 if (IsRef)
4435                                         EmitLoad (ec);
4436
4437                                 source.Emit (ec);
4438                         }
4439
4440                         if (leave_copy) {
4441                                 ec.Emit (OpCodes.Dup);
4442                                 if (IsRef) {
4443                                         temp = new LocalTemporary (Type);
4444                                         temp.Store (ec);
4445                                 }
4446                         }
4447
4448                         if (IsRef)
4449                                 ec.EmitStoreFromPtr (type);
4450                         else
4451                                 Variable.EmitAssign (ec);
4452
4453                         if (temp != null) {
4454                                 temp.Emit (ec);
4455                                 temp.Release (ec);
4456                         }
4457                 }
4458
4459                 public bool IsHoisted {
4460                         get { return GetHoistedVariable ((AnonymousExpression) null) != null; }
4461                 }
4462         }
4463
4464         /// <summary>
4465         ///   Local variables
4466         /// </summary>
4467         public class LocalVariableReference : VariableReference {
4468                 readonly string name;
4469                 public Block Block;
4470                 public LocalInfo local_info;
4471                 bool is_readonly;
4472
4473                 public LocalVariableReference (Block block, string name, Location l)
4474                 {
4475                         Block = block;
4476                         this.name = name;
4477                         loc = l;
4478                 }
4479
4480                 //
4481                 // Setting `is_readonly' to false will allow you to create a writable
4482                 // reference to a read-only variable.  This is used by foreach and using.
4483                 //
4484                 public LocalVariableReference (Block block, string name, Location l,
4485                                                LocalInfo local_info, bool is_readonly)
4486                         : this (block, name, l)
4487                 {
4488                         this.local_info = local_info;
4489                         this.is_readonly = is_readonly;
4490                 }
4491
4492                 public override VariableInfo VariableInfo {
4493                         get { return local_info.VariableInfo; }
4494                 }
4495
4496                 public override HoistedVariable GetHoistedVariable (AnonymousExpression ae)
4497                 {
4498                         return local_info.HoistedVariant;
4499                 }
4500
4501                 //
4502                 // A local variable is always fixed
4503                 //
4504                 public override bool IsFixed {
4505                         get { return true; }
4506                 }
4507
4508                 public override bool IsRef {
4509                         get { return false; }
4510                 }
4511
4512                 public bool IsReadOnly {
4513                         get { return is_readonly; }
4514                 }
4515
4516                 public override string Name {
4517                         get { return name; }
4518                 }
4519
4520                 public bool VerifyAssigned (ResolveContext ec)
4521                 {
4522                         VariableInfo variable_info = local_info.VariableInfo;
4523                         return variable_info == null || variable_info.IsAssigned (ec, loc);
4524                 }
4525
4526                 void ResolveLocalInfo ()
4527                 {
4528                         if (local_info == null) {
4529                                 local_info = Block.GetLocalInfo (Name);
4530                                 type = local_info.VariableType;
4531                                 is_readonly = local_info.ReadOnly;
4532                         }
4533                 }
4534
4535                 public override void SetHasAddressTaken ()
4536                 {
4537                         local_info.AddressTaken = true;
4538                 }
4539
4540                 public override Expression CreateExpressionTree (ResolveContext ec)
4541                 {
4542                         HoistedVariable hv = GetHoistedVariable (ec);
4543                         if (hv != null)
4544                                 return hv.CreateExpressionTree ();
4545
4546                         Arguments arg = new Arguments (1);
4547                         arg.Add (new Argument (this));
4548                         return CreateExpressionFactoryCall (ec, "Constant", arg);
4549                 }
4550
4551                 Expression DoResolveBase (ResolveContext ec)
4552                 {
4553                         Expression e = Block.GetConstantExpression (Name);
4554                         if (e != null)
4555                                 return e.Resolve (ec);
4556
4557                         VerifyAssigned (ec);
4558
4559                         //
4560                         // If we are referencing a variable from the external block
4561                         // flag it for capturing
4562                         //
4563                         if (ec.MustCaptureVariable (local_info)) {
4564                                 if (local_info.AddressTaken)
4565                                         AnonymousMethodExpression.Error_AddressOfCapturedVar (ec, this, loc);
4566
4567                                 if (ec.IsVariableCapturingRequired) {
4568                                         AnonymousMethodStorey storey = local_info.Block.Explicit.CreateAnonymousMethodStorey (ec);
4569                                         storey.CaptureLocalVariable (ec, local_info);
4570                                 }
4571                         }
4572
4573                         eclass = ExprClass.Variable;
4574                         type = local_info.VariableType;
4575                         return this;
4576                 }
4577
4578                 protected override Expression DoResolve (ResolveContext ec)
4579                 {
4580                         ResolveLocalInfo ();
4581                         local_info.Used = true;
4582
4583                         if (type == null && local_info.Type is VarExpr) {
4584                             local_info.VariableType = TypeManager.object_type;
4585                                 Error_VariableIsUsedBeforeItIsDeclared (ec.Report, Name);
4586                             return null;
4587                         }
4588
4589                         return DoResolveBase (ec);
4590                 }
4591
4592                 public override Expression DoResolveLValue (ResolveContext ec, Expression right_side)
4593                 {
4594                         ResolveLocalInfo ();
4595
4596                         // is out param
4597                         if (right_side == EmptyExpression.OutAccess.Instance)
4598                                 local_info.Used = true;
4599
4600                         // Infer implicitly typed local variable
4601                         if (type == null) {
4602                                 VarExpr ve = local_info.Type as VarExpr;
4603                                 if (ve != null) {
4604                                         if (!ve.InferType (ec, right_side))
4605                                                 return null;
4606                                         type = local_info.VariableType = ve.Type;
4607                                 }
4608                         }
4609
4610                         if (is_readonly) {
4611                                 int code;
4612                                 string msg;
4613                                 if (right_side == EmptyExpression.OutAccess.Instance) {
4614                                         code = 1657; msg = "Cannot pass `{0}' as a ref or out argument because it is a `{1}'";
4615                                 } else if (right_side == EmptyExpression.LValueMemberAccess) {
4616                                         code = 1654; msg = "Cannot assign to members of `{0}' because it is a `{1}'";
4617                                 } else if (right_side == EmptyExpression.LValueMemberOutAccess) {
4618                                         code = 1655; msg = "Cannot pass members of `{0}' as ref or out arguments because it is a `{1}'";
4619                                 } else if (right_side == EmptyExpression.UnaryAddress) {
4620                                         code = 459; msg = "Cannot take the address of {1} `{0}'";
4621                                 } else {
4622                                         code = 1656; msg = "Cannot assign to `{0}' because it is a `{1}'";
4623                                 }
4624                                 ec.Report.Error (code, loc, msg, Name, local_info.GetReadOnlyContext ());
4625                         } else if (VariableInfo != null) {
4626                                 VariableInfo.SetAssigned (ec);
4627                         }
4628
4629                         return DoResolveBase (ec);
4630                 }
4631
4632                 public override int GetHashCode ()
4633                 {
4634                         return Name.GetHashCode ();
4635                 }
4636
4637                 public override bool Equals (object obj)
4638                 {
4639                         LocalVariableReference lvr = obj as LocalVariableReference;
4640                         if (lvr == null)
4641                                 return false;
4642
4643                         return Name == lvr.Name && Block == lvr.Block;
4644                 }
4645
4646                 protected override ILocalVariable Variable {
4647                         get { return local_info; }
4648                 }
4649
4650                 public override string ToString ()
4651                 {
4652                         return String.Format ("{0} ({1}:{2})", GetType (), Name, loc);
4653                 }
4654
4655                 protected override void CloneTo (CloneContext clonectx, Expression t)
4656                 {
4657                         LocalVariableReference target = (LocalVariableReference) t;
4658
4659                         target.Block = clonectx.LookupBlock (Block);
4660                         if (local_info != null)
4661                                 target.local_info = clonectx.LookupVariable (local_info);
4662                 }
4663         }
4664
4665         /// <summary>
4666         ///   This represents a reference to a parameter in the intermediate
4667         ///   representation.
4668         /// </summary>
4669         public class ParameterReference : VariableReference {
4670                 readonly ToplevelParameterInfo pi;
4671
4672                 public ParameterReference (ToplevelParameterInfo pi, Location loc)
4673                 {
4674                         this.pi = pi;
4675                         this.loc = loc;
4676                 }
4677
4678                 public override bool IsRef {
4679                         get { return (pi.Parameter.ModFlags & Parameter.Modifier.ISBYREF) != 0; }
4680                 }
4681
4682                 bool HasOutModifier {
4683                         get { return pi.Parameter.ModFlags == Parameter.Modifier.OUT; }
4684                 }
4685
4686                 public override HoistedVariable GetHoistedVariable (AnonymousExpression ae)
4687                 {
4688                         return pi.Parameter.HoistedVariant;
4689                 }
4690
4691                 //
4692                 // A ref or out parameter is classified as a moveable variable, even
4693                 // if the argument given for the parameter is a fixed variable
4694                 //
4695                 public override bool IsFixed {
4696                         get { return !IsRef; }
4697                 }
4698
4699                 public override string Name {
4700                         get { return Parameter.Name; }
4701                 }
4702
4703                 public Parameter Parameter {
4704                         get { return pi.Parameter; }
4705                 }
4706
4707                 public override VariableInfo VariableInfo {
4708                         get { return pi.VariableInfo; }
4709                 }
4710
4711                 protected override ILocalVariable Variable {
4712                         get { return Parameter; }
4713                 }
4714
4715                 public bool IsAssigned (ResolveContext ec, Location loc)
4716                 {
4717                         // HACK: Variables are not captured in probing mode
4718                         if (ec.IsInProbingMode)
4719                                 return true;
4720
4721                         if (!ec.DoFlowAnalysis || !HasOutModifier || ec.CurrentBranching.IsAssigned (VariableInfo))
4722                                 return true;
4723
4724                         ec.Report.Error (269, loc, "Use of unassigned out parameter `{0}'", Name);
4725                         return false;
4726                 }
4727
4728                 public override void SetHasAddressTaken ()
4729                 {
4730                         Parameter.HasAddressTaken = true;
4731                 }
4732
4733                 void SetAssigned (ResolveContext ec)
4734                 {
4735                         if (HasOutModifier && ec.DoFlowAnalysis)
4736                                 ec.CurrentBranching.SetAssigned (VariableInfo);
4737                 }
4738
4739                 bool DoResolveBase (ResolveContext ec)
4740                 {
4741                         type = pi.ParameterType;
4742                         eclass = ExprClass.Variable;
4743
4744                         AnonymousExpression am = ec.CurrentAnonymousMethod;
4745                         if (am == null)
4746                                 return true;
4747
4748                         Block b = ec.CurrentBlock;
4749                         while (b != null) {
4750                                 b = b.Toplevel;
4751                                 IParameterData[] p = b.Toplevel.Parameters.FixedParameters;
4752                                 for (int i = 0; i < p.Length; ++i) {
4753                                         if (p [i] != Parameter)
4754                                                 continue;
4755
4756                                         //
4757                                         // Don't capture local parameters
4758                                         //
4759                                         if (b == ec.CurrentBlock.Toplevel && !am.IsIterator)
4760                                                 return true;
4761
4762                                         if (IsRef) {
4763                                                 ec.Report.Error (1628, loc,
4764                                                         "Parameter `{0}' cannot be used inside `{1}' when using `ref' or `out' modifier",
4765                                                         Name, am.ContainerType);
4766                                         }
4767
4768                                         if (pi.Parameter.HasAddressTaken)
4769                                                 AnonymousMethodExpression.Error_AddressOfCapturedVar (ec, this, loc);
4770
4771                                         if (ec.IsVariableCapturingRequired && !b.Toplevel.IsExpressionTree) {
4772                                                 AnonymousMethodStorey storey = pi.Block.CreateAnonymousMethodStorey (ec);
4773                                                 storey.CaptureParameter (ec, this);
4774                                         }
4775
4776                                         return true;
4777                                 }
4778
4779                                 b = b.Parent;
4780                         }
4781
4782                         return true;
4783                 }
4784
4785                 public override int GetHashCode ()
4786                 {
4787                         return Name.GetHashCode ();
4788                 }
4789
4790                 public override bool Equals (object obj)
4791                 {
4792                         ParameterReference pr = obj as ParameterReference;
4793                         if (pr == null)
4794                                 return false;
4795
4796                         return Name == pr.Name;
4797                 }
4798
4799                 public override void AddressOf (EmitContext ec, AddressOp mode)
4800                 {
4801                         //
4802                         // ParameterReferences might already be a reference
4803                         //
4804                         if (IsRef) {
4805                                 EmitLoad (ec);
4806                                 return;
4807                         }
4808
4809                         base.AddressOf (ec, mode);
4810                 }
4811
4812                 protected override void CloneTo (CloneContext clonectx, Expression target)
4813                 {
4814                         // Nothing to clone
4815                 }
4816
4817                 public override Expression CreateExpressionTree (ResolveContext ec)
4818                 {
4819                         HoistedVariable hv = GetHoistedVariable (ec);
4820                         if (hv != null)
4821                                 return hv.CreateExpressionTree ();
4822
4823                         return Parameter.ExpressionTreeVariableReference ();
4824                 }
4825
4826                 //
4827                 // Notice that for ref/out parameters, the type exposed is not the
4828                 // same type exposed externally.
4829                 //
4830                 // for "ref int a":
4831                 //   externally we expose "int&"
4832                 //   here we expose       "int".
4833                 //
4834                 // We record this in "is_ref".  This means that the type system can treat
4835                 // the type as it is expected, but when we generate the code, we generate
4836                 // the alternate kind of code.
4837                 //
4838                 protected override Expression DoResolve (ResolveContext ec)
4839                 {
4840                         if (!DoResolveBase (ec))
4841                                 return null;
4842
4843                         // HACK: Variables are not captured in probing mode
4844                         if (ec.IsInProbingMode)
4845                                 return this;
4846
4847                         if (HasOutModifier && ec.DoFlowAnalysis &&
4848                             (!ec.OmitStructFlowAnalysis || !VariableInfo.TypeInfo.IsStruct) && !IsAssigned (ec, loc))
4849                                 return null;
4850
4851                         return this;
4852                 }
4853
4854                 override public Expression DoResolveLValue (ResolveContext ec, Expression right_side)
4855                 {
4856                         if (!DoResolveBase (ec))
4857                                 return null;
4858
4859                         SetAssigned (ec);
4860                         return this;
4861                 }
4862
4863                 static public void EmitLdArg (EmitContext ec, int x)
4864                 {
4865                         switch (x) {
4866                         case 0: ec.Emit (OpCodes.Ldarg_0); break;
4867                         case 1: ec.Emit (OpCodes.Ldarg_1); break;
4868                         case 2: ec.Emit (OpCodes.Ldarg_2); break;
4869                         case 3: ec.Emit (OpCodes.Ldarg_3); break;
4870                         default:
4871                                 if (x > byte.MaxValue)
4872                                         ec.Emit (OpCodes.Ldarg, x);
4873                                 else
4874                                         ec.Emit (OpCodes.Ldarg_S, (byte) x);
4875                                 break;
4876                         }
4877                 }
4878         }
4879
4880         /// <summary>
4881         ///   Invocation of methods or delegates.
4882         /// </summary>
4883         public class Invocation : ExpressionStatement
4884         {
4885                 protected Arguments arguments;
4886                 protected Expression expr;
4887                 protected MethodGroupExpr mg;
4888                 bool arguments_resolved;
4889
4890                 //
4891                 // arguments is an ArrayList, but we do not want to typecast,
4892                 // as it might be null.
4893                 //
4894                 public Invocation (Expression expr, Arguments arguments)
4895                 {
4896                         SimpleName sn = expr as SimpleName;
4897                         if (sn != null)
4898                                 this.expr = sn.GetMethodGroup ();
4899                         else
4900                                 this.expr = expr;
4901
4902                         this.arguments = arguments;
4903                         if (expr != null)
4904                                 loc = expr.Location;
4905                 }
4906
4907                 public Invocation (Expression expr, Arguments arguments, bool arguments_resolved)
4908                         : this (expr, arguments)
4909                 {
4910                         this.arguments_resolved = arguments_resolved;
4911                 }
4912
4913                 public override Expression CreateExpressionTree (ResolveContext ec)
4914                 {
4915                         Expression instance = mg.IsInstance ?
4916                                 mg.InstanceExpression.CreateExpressionTree (ec) :
4917                                 new NullLiteral (loc);
4918
4919                         var args = Arguments.CreateForExpressionTree (ec, arguments,
4920                                 instance,
4921                                 mg.CreateExpressionTree (ec));
4922
4923                         return CreateExpressionFactoryCall (ec, "Call", args);
4924                 }
4925
4926                 protected override Expression DoResolve (ResolveContext ec)
4927                 {
4928                         Expression member_expr = expr.Resolve (ec, ResolveFlags.VariableOrValue | ResolveFlags.MethodGroup);
4929                         if (member_expr == null)
4930                                 return null;
4931
4932                         //
4933                         // Next, evaluate all the expressions in the argument list
4934                         //
4935                         bool dynamic_arg = false;
4936                         if (arguments != null && !arguments_resolved)
4937                                 arguments.Resolve (ec, out dynamic_arg);
4938
4939                         TypeSpec expr_type = member_expr.Type;
4940                         mg = member_expr as MethodGroupExpr;
4941
4942                         bool dynamic_member = expr_type == InternalType.Dynamic;
4943
4944                         if (!dynamic_member) {
4945                                 Expression invoke = null;
4946
4947                                 if (mg == null) {
4948                                         if (expr_type != null && TypeManager.IsDelegateType (expr_type)) {
4949                                                 invoke = new DelegateInvocation (member_expr, arguments, loc);
4950                                                 invoke = invoke.Resolve (ec);
4951                                                 if (invoke == null || !dynamic_arg)
4952                                                         return invoke;
4953                                         } else {
4954                                                 MemberExpr me = member_expr as MemberExpr;
4955                                                 if (me == null) {
4956                                                         member_expr.Error_UnexpectedKind (ec, ResolveFlags.MethodGroup, loc);
4957                                                         return null;
4958                                                 }
4959
4960                                                 mg = ec.LookupExtensionMethod (me.Type, me.Name, -1, loc);
4961                                                 if (mg == null) {
4962                                                         ec.Report.Error (1955, loc, "The member `{0}' cannot be used as method or delegate",
4963                                                                 member_expr.GetSignatureForError ());
4964                                                         return null;
4965                                                 }
4966
4967                                                 ((ExtensionMethodGroupExpr) mg).ExtensionExpression = me.InstanceExpression;
4968                                         }
4969                                 }
4970
4971                                 if (invoke == null) {
4972                                         mg = DoResolveOverload (ec);
4973                                         if (mg == null)
4974                                                 return null;
4975                                 }
4976                         }
4977
4978                         if (dynamic_arg || dynamic_member)
4979                                 return DoResolveDynamic (ec, member_expr);
4980
4981                         var method = mg.BestCandidate;
4982                         if (method != null) {
4983                                 type = method.ReturnType;
4984                         }
4985
4986                         //
4987                         // Only base will allow this invocation to happen.
4988                         //
4989                         if (mg.IsBase && method.IsAbstract){
4990                                 Error_CannotCallAbstractBase (ec, TypeManager.CSharpSignature (method));
4991                                 return null;
4992                         }
4993
4994                         if (arguments == null && method.DeclaringType == TypeManager.object_type && method.Name == Destructor.MetadataName) {
4995                                 if (mg.IsBase)
4996                                         ec.Report.Error (250, loc, "Do not directly call your base class Finalize method. It is called automatically from your destructor");
4997                                 else
4998                                         ec.Report.Error (245, loc, "Destructors and object.Finalize cannot be called directly. Consider calling IDisposable.Dispose if available");
4999                                 return null;
5000                         }
5001
5002                         IsSpecialMethodInvocation (ec, method, loc);
5003
5004                         if (mg.InstanceExpression != null)
5005                                 mg.InstanceExpression.CheckMarshalByRefAccess (ec);
5006
5007                         eclass = ExprClass.Value;
5008                         return this;
5009                 }
5010
5011                 Expression DoResolveDynamic (ResolveContext ec, Expression memberExpr)
5012                 {
5013                         Arguments args;
5014                         DynamicMemberBinder dmb = memberExpr as DynamicMemberBinder;
5015                         if (dmb != null) {
5016                                 args = dmb.Arguments;
5017                                 if (arguments != null)
5018                                         args.AddRange (arguments);
5019                         } else if (mg == null) {
5020                                 if (arguments == null)
5021                                         args = new Arguments (1);
5022                                 else
5023                                         args = arguments;
5024
5025                                 args.Insert (0, new Argument (memberExpr));
5026                                 this.expr = null;
5027                         } else {
5028                                 if (mg.IsBase) {
5029                                         ec.Report.Error (1971, loc,
5030                                                 "The base call to method `{0}' cannot be dynamically dispatched. Consider casting the dynamic arguments or eliminating the base access",
5031                                                 mg.Name);
5032                                         return null;
5033                                 }
5034
5035                                 if (arguments == null)
5036                                         args = new Arguments (1);
5037                                 else
5038                                         args = arguments;
5039
5040                                 MemberAccess ma = expr as MemberAccess;
5041                                 if (ma != null) {
5042                                         var left_type = ma.Left as TypeExpr;
5043                                         if (left_type != null) {
5044                                                 args.Insert (0, new Argument (new TypeOf (left_type, loc).Resolve (ec), Argument.AType.DynamicTypeName));
5045                                         } else {
5046                                                 args.Insert (0, new Argument (ma.Left));
5047                                         }
5048                                 } else {        // is SimpleName
5049                                         if (ec.IsStatic) {
5050                                                 args.Insert (0, new Argument (new TypeOf (new TypeExpression (ec.CurrentType, loc), loc).Resolve (ec), Argument.AType.DynamicTypeName));
5051                                         } else {
5052                                                 args.Insert (0, new Argument (new This (loc).Resolve (ec)));
5053                                         }
5054                                 }
5055                         }
5056
5057                         return new DynamicInvocation (expr as ATypeNameExpression, args, loc).Resolve (ec);
5058                 }
5059
5060                 protected virtual MethodGroupExpr DoResolveOverload (ResolveContext ec)
5061                 {
5062                         return mg.OverloadResolve (ec, ref arguments, false, loc);
5063                 }
5064
5065                 public static bool IsSpecialMethodInvocation (ResolveContext ec, MethodSpec method, Location loc)
5066                 {
5067                         if (!method.IsReservedMethod)
5068                                 return false;
5069
5070                         if (ec.HasSet (ResolveContext.Options.InvokeSpecialName))
5071                                 return false;
5072
5073                         ec.Report.SymbolRelatedToPreviousError (method);
5074                         ec.Report.Error (571, loc, "`{0}': cannot explicitly call operator or accessor",
5075                                 method.GetSignatureForError ());
5076
5077                         return true;
5078                 }
5079
5080                 static Type[] GetVarargsTypes (MethodSpec mb, Arguments arguments)
5081                 {
5082                         AParametersCollection pd = mb.Parameters;
5083
5084                         Argument a = arguments [pd.Count - 1];
5085                         Arglist list = (Arglist) a.Expr;
5086
5087                         return list.ArgumentTypes;
5088                 }
5089
5090                 /// <remarks>
5091                 ///   is_base tells whether we want to force the use of the `call'
5092                 ///   opcode instead of using callvirt.  Call is required to call
5093                 ///   a specific method, while callvirt will always use the most
5094                 ///   recent method in the vtable.
5095                 ///
5096                 ///   is_static tells whether this is an invocation on a static method
5097                 ///
5098                 ///   instance_expr is an expression that represents the instance
5099                 ///   it must be non-null if is_static is false.
5100                 ///
5101                 ///   method is the method to invoke.
5102                 ///
5103                 ///   Arguments is the list of arguments to pass to the method or constructor.
5104                 /// </remarks>
5105                 public static void EmitCall (EmitContext ec, Expression instance_expr,
5106                                              MethodSpec method, Arguments Arguments, Location loc)
5107                 {
5108                         EmitCall (ec, instance_expr, method, Arguments, loc, false, false);
5109                 }
5110
5111                 // `dup_args' leaves an extra copy of the arguments on the stack
5112                 // `omit_args' does not leave any arguments at all.
5113                 // So, basically, you could make one call with `dup_args' set to true,
5114                 // and then another with `omit_args' set to true, and the two calls
5115                 // would have the same set of arguments. However, each argument would
5116                 // only have been evaluated once.
5117                 public static void EmitCall (EmitContext ec, Expression instance_expr,
5118                                              MethodSpec method, Arguments Arguments, Location loc,
5119                                              bool dup_args, bool omit_args)
5120                 {
5121                         LocalTemporary this_arg = null;
5122
5123                         TypeSpec decl_type = method.DeclaringType;
5124
5125                         // Speed up the check by not doing it on not allowed targets
5126                         if (method.ReturnType == TypeManager.void_type && method.IsConditionallyExcluded (loc))
5127                                 return;
5128
5129                         OpCode call_op;
5130                         TypeSpec iexpr_type;
5131
5132                         if (method.IsStatic) {
5133                                 iexpr_type = null;
5134                                 call_op = OpCodes.Call;
5135                         } else {
5136                                 iexpr_type = instance_expr.Type;
5137
5138                                 if (decl_type.IsStruct || decl_type.IsEnum || (instance_expr is This && !method.IsVirtual) || (instance_expr is BaseThis)) {
5139                                         call_op = OpCodes.Call;
5140                                 } else {
5141                                         call_op = OpCodes.Callvirt;
5142                                 }
5143
5144                                 //
5145                                 // If this is ourselves, push "this"
5146                                 //
5147                                 if (!omit_args) {
5148                                         TypeSpec t = iexpr_type;
5149
5150                                         //
5151                                         // Push the instance expression
5152                                         //
5153                                         if ((iexpr_type.IsStruct && (call_op == OpCodes.Callvirt || (call_op == OpCodes.Call && decl_type == iexpr_type))) ||
5154                                                 iexpr_type.IsGenericParameter || TypeManager.IsNullableType (decl_type)) {
5155                                                 //
5156                                                 // If the expression implements IMemoryLocation, then
5157                                                 // we can optimize and use AddressOf on the
5158                                                 // return.
5159                                                 //
5160                                                 // If not we have to use some temporary storage for
5161                                                 // it.
5162                                                 var iml = instance_expr as IMemoryLocation;
5163                                                 if (iml != null) {
5164                                                         iml.AddressOf (ec, AddressOp.LoadStore);
5165                                                 } else {
5166                                                         LocalTemporary temp = new LocalTemporary (iexpr_type);
5167                                                         instance_expr.Emit (ec);
5168                                                         temp.Store (ec);
5169                                                         temp.AddressOf (ec, AddressOp.Load);
5170                                                 }
5171
5172                                                 // avoid the overhead of doing this all the time.
5173                                                 if (dup_args)
5174                                                         t = ReferenceContainer.MakeType (iexpr_type);
5175                                         } else if (iexpr_type.IsEnum || iexpr_type.IsStruct) {
5176                                                 instance_expr.Emit (ec);
5177                                                 ec.Emit (OpCodes.Box, iexpr_type);
5178                                                 t = iexpr_type = TypeManager.object_type;
5179                                         } else {
5180                                                 instance_expr.Emit (ec);
5181                                         }
5182
5183                                         if (dup_args) {
5184                                                 ec.Emit (OpCodes.Dup);
5185                                                 if (Arguments != null && Arguments.Count != 0) {
5186                                                         this_arg = new LocalTemporary (t);
5187                                                         this_arg.Store (ec);
5188                                                 }
5189                                         }
5190                                 }
5191                         }
5192
5193                         if (!omit_args && Arguments != null)
5194                                 Arguments.Emit (ec, dup_args, this_arg);
5195
5196                         if (call_op == OpCodes.Callvirt && (iexpr_type.IsGenericParameter || iexpr_type.IsStruct)) {
5197                                 ec.Emit (OpCodes.Constrained, iexpr_type);
5198                         }
5199
5200                         if (method.Parameters.HasArglist) {
5201                                 Type[] varargs_types = GetVarargsTypes (method, Arguments);
5202                                 ec.Emit (call_op, method, varargs_types);
5203                                 return;
5204                         }
5205
5206                         //
5207                         // If you have:
5208                         // this.DoFoo ();
5209                         // and DoFoo is not virtual, you can omit the callvirt,
5210                         // because you don't need the null checking behavior.
5211                         //
5212                         ec.Emit (call_op, method);
5213                 }
5214
5215                 public override void Emit (EmitContext ec)
5216                 {
5217                         mg.EmitCall (ec, arguments);
5218                 }
5219
5220                 public override void EmitStatement (EmitContext ec)
5221                 {
5222                         Emit (ec);
5223
5224                         //
5225                         // Pop the return value if there is one
5226                         //
5227                         if (type != TypeManager.void_type)
5228                                 ec.Emit (OpCodes.Pop);
5229                 }
5230
5231                 protected override void CloneTo (CloneContext clonectx, Expression t)
5232                 {
5233                         Invocation target = (Invocation) t;
5234
5235                         if (arguments != null)
5236                                 target.arguments = arguments.Clone (clonectx);
5237
5238                         target.expr = expr.Clone (clonectx);
5239                 }
5240
5241                 public override SLE.Expression MakeExpression (BuilderContext ctx)
5242                 {
5243                         return MakeExpression (ctx, mg.InstanceExpression, mg.BestCandidate, arguments);
5244                 }
5245
5246                 public static SLE.Expression MakeExpression (BuilderContext ctx, Expression instance, MethodSpec mi, Arguments args)
5247                 {
5248                         var instance_expr = instance == null ? null : instance.MakeExpression (ctx);
5249                         return SLE.Expression.Call (instance_expr, (MethodInfo) mi.GetMetaInfo (), Arguments.MakeExpression (args, ctx));
5250                 }
5251         }
5252
5253         /// <summary>
5254         ///    Implements the new expression
5255         /// </summary>
5256         public class New : ExpressionStatement, IMemoryLocation {
5257                 protected Arguments Arguments;
5258
5259                 //
5260                 // During bootstrap, it contains the RequestedType,
5261                 // but if `type' is not null, it *might* contain a NewDelegate
5262                 // (because of field multi-initialization)
5263                 //
5264                 protected Expression RequestedType;
5265
5266                 protected MethodGroupExpr method;
5267
5268                 public New (Expression requested_type, Arguments arguments, Location l)
5269                 {
5270                         RequestedType = requested_type;
5271                         Arguments = arguments;
5272                         loc = l;
5273                 }
5274
5275                 /// <summary>
5276                 /// Converts complex core type syntax like 'new int ()' to simple constant
5277                 /// </summary>
5278                 public static Constant Constantify (TypeSpec t)
5279                 {
5280                         if (t == TypeManager.int32_type)
5281                                 return new IntConstant (0, Location.Null);
5282                         if (t == TypeManager.uint32_type)
5283                                 return new UIntConstant (0, Location.Null);
5284                         if (t == TypeManager.int64_type)
5285                                 return new LongConstant (0, Location.Null);
5286                         if (t == TypeManager.uint64_type)
5287                                 return new ULongConstant (0, Location.Null);
5288                         if (t == TypeManager.float_type)
5289                                 return new FloatConstant (0, Location.Null);
5290                         if (t == TypeManager.double_type)
5291                                 return new DoubleConstant (0, Location.Null);
5292                         if (t == TypeManager.short_type)
5293                                 return new ShortConstant (0, Location.Null);
5294                         if (t == TypeManager.ushort_type)
5295                                 return new UShortConstant (0, Location.Null);
5296                         if (t == TypeManager.sbyte_type)
5297                                 return new SByteConstant (0, Location.Null);
5298                         if (t == TypeManager.byte_type)
5299                                 return new ByteConstant (0, Location.Null);
5300                         if (t == TypeManager.char_type)
5301                                 return new CharConstant ('\0', Location.Null);
5302                         if (t == TypeManager.bool_type)
5303                                 return new BoolConstant (false, Location.Null);
5304                         if (t == TypeManager.decimal_type)
5305                                 return new DecimalConstant (0, Location.Null);
5306                         if (TypeManager.IsEnumType (t))
5307                                 return new EnumConstant (Constantify (EnumSpec.GetUnderlyingType (t)), t);
5308                         if (TypeManager.IsNullableType (t))
5309                                 return Nullable.LiftedNull.Create (t, Location.Null);
5310
5311                         return null;
5312                 }
5313
5314                 //
5315                 // Checks whether the type is an interface that has the
5316                 // [ComImport, CoClass] attributes and must be treated
5317                 // specially
5318                 //
5319                 public Expression CheckComImport (ResolveContext ec)
5320                 {
5321                         if (!type.IsInterface)
5322                                 return null;
5323
5324                         //
5325                         // Turn the call into:
5326                         // (the-interface-stated) (new class-referenced-in-coclassattribute ())
5327                         //
5328                         var real_class = type.MemberDefinition.GetAttributeCoClass ();
5329                         if (real_class == null)
5330                                 return null;
5331
5332                         New proxy = new New (new TypeExpression (real_class, loc), Arguments, loc);
5333                         Cast cast = new Cast (new TypeExpression (type, loc), proxy, loc);
5334                         return cast.Resolve (ec);
5335                 }
5336
5337                 public override Expression CreateExpressionTree (ResolveContext ec)
5338                 {
5339                         Arguments args;
5340                         if (method == null) {
5341                                 args = new Arguments (1);
5342                                 args.Add (new Argument (new TypeOf (new TypeExpression (type, loc), loc)));
5343                         } else {
5344                                 args = Arguments.CreateForExpressionTree (ec,
5345                                         Arguments,
5346                                         method.CreateExpressionTree (ec));
5347                         }
5348
5349                         return CreateExpressionFactoryCall (ec, "New", args);
5350                 }
5351
5352                 protected override Expression DoResolve (ResolveContext ec)
5353                 {
5354                         TypeExpr texpr = RequestedType.ResolveAsTypeTerminal (ec, false);
5355                         if (texpr == null)
5356                                 return null;
5357
5358                         type = texpr.Type;
5359
5360                         if (type.IsPointer) {
5361                                 ec.Report.Error (1919, loc, "Unsafe type `{0}' cannot be used in an object creation expression",
5362                                         TypeManager.CSharpName (type));
5363                                 return null;
5364                         }
5365
5366                         if (Arguments == null) {
5367                                 Constant c = Constantify (type);
5368                                 if (c != null)
5369                                         return ReducedExpression.Create (c.Resolve (ec), this);
5370                         }
5371
5372                         if (TypeManager.IsDelegateType (type)) {
5373                                 return (new NewDelegate (type, Arguments, loc)).Resolve (ec);
5374                         }
5375
5376                         var tparam = type as TypeParameterSpec;
5377                         if (tparam != null) {
5378                                 if (!tparam.HasSpecialConstructor && !tparam.HasSpecialStruct) {
5379                                         ec.Report.Error (304, loc,
5380                                                 "Cannot create an instance of the variable type `{0}' because it does not have the new() constraint",
5381                                                 TypeManager.CSharpName (type));
5382                                 }
5383
5384                                 if ((Arguments != null) && (Arguments.Count != 0)) {
5385                                         ec.Report.Error (417, loc,
5386                                                 "`{0}': cannot provide arguments when creating an instance of a variable type",
5387                                                 TypeManager.CSharpName (type));
5388                                 }
5389
5390                                 if (TypeManager.activator_create_instance == null) {
5391                                         TypeSpec activator_type = TypeManager.CoreLookupType (ec.Compiler, "System", "Activator", MemberKind.Class, true);
5392                                         if (activator_type != null) {
5393                                                 TypeManager.activator_create_instance = TypeManager.GetPredefinedMethod (
5394                                                         activator_type, MemberFilter.Method ("CreateInstance", 1, ParametersCompiled.EmptyReadOnlyParameters, null), loc);
5395                                         }
5396                                 }
5397
5398                                 eclass = ExprClass.Value;
5399                                 return this;
5400                         }
5401
5402                         if (type.IsStatic) {
5403                                 ec.Report.SymbolRelatedToPreviousError (type);
5404                                 ec.Report.Error (712, loc, "Cannot create an instance of the static class `{0}'", TypeManager.CSharpName (type));
5405                                 return null;
5406                         }
5407
5408                         if (type.IsInterface || type.IsAbstract){
5409                                 if (!TypeManager.IsGenericType (type)) {
5410                                         RequestedType = CheckComImport (ec);
5411                                         if (RequestedType != null)
5412                                                 return RequestedType;
5413                                 }
5414
5415                                 ec.Report.SymbolRelatedToPreviousError (type);
5416                                 ec.Report.Error (144, loc, "Cannot create an instance of the abstract class or interface `{0}'", TypeManager.CSharpName (type));
5417                                 return null;
5418                         }
5419
5420                         bool is_struct = TypeManager.IsStruct (type);
5421                         eclass = ExprClass.Value;
5422
5423                         //
5424                         // SRE returns a match for .ctor () on structs (the object constructor),
5425                         // so we have to manually ignore it.
5426                         //
5427                         if (is_struct && Arguments == null)
5428                                 return this;
5429
5430                         // For member-lookup, treat 'new Foo (bar)' as call to 'foo.ctor (bar)', where 'foo' is of type 'Foo'.
5431                         Expression ml = MemberLookupFinal (ec, type, type, ConstructorInfo.ConstructorName, 0,
5432                                 MemberKind.Constructor, BindingRestriction.AccessibleOnly | BindingRestriction.DeclaredOnly, loc);
5433
5434                         bool dynamic;
5435                         if (Arguments != null) {
5436                                 Arguments.Resolve (ec, out dynamic);
5437                         } else {
5438                                 dynamic = false;
5439                         }
5440
5441                         if (ml == null)
5442                                 return null;
5443
5444                         method = ml as MethodGroupExpr;
5445                         if (method == null) {
5446                                 ml.Error_UnexpectedKind (ec, ResolveFlags.MethodGroup, loc);
5447                                 return null;
5448                         }
5449
5450                         method = method.OverloadResolve (ec, ref Arguments, false, loc);
5451                         if (method == null)
5452                                 return null;
5453
5454                         if (dynamic) {
5455                                 Arguments.Insert (0, new Argument (new TypeOf (texpr, loc).Resolve (ec), Argument.AType.DynamicTypeName));
5456                                 return new DynamicConstructorBinder (type, Arguments, loc).Resolve (ec);
5457                         }
5458
5459                         return this;
5460                 }
5461
5462                 bool DoEmitTypeParameter (EmitContext ec)
5463                 {
5464                         var ctor_factory = TypeManager.activator_create_instance.MakeGenericMethod (type);
5465                         var tparam = (TypeParameterSpec) type;
5466
5467                         if (tparam.IsReferenceType) {
5468                                 ec.Emit (OpCodes.Call, ctor_factory);
5469                                 return true;
5470                         }
5471
5472                         // Allow DoEmit() to be called multiple times.
5473                         // We need to create a new LocalTemporary each time since
5474                         // you can't share LocalBuilders among ILGeneators.
5475                         LocalTemporary temp = new LocalTemporary (type);
5476
5477                         Label label_activator = ec.DefineLabel ();
5478                         Label label_end = ec.DefineLabel ();
5479
5480                         temp.AddressOf (ec, AddressOp.Store);
5481                         ec.Emit (OpCodes.Initobj, type);
5482
5483                         temp.Emit (ec);
5484                         ec.Emit (OpCodes.Box, type);
5485                         ec.Emit (OpCodes.Brfalse, label_activator);
5486
5487                         temp.AddressOf (ec, AddressOp.Store);
5488                         ec.Emit (OpCodes.Initobj, type);
5489                         temp.Emit (ec);
5490                         ec.Emit (OpCodes.Br_S, label_end);
5491
5492                         ec.MarkLabel (label_activator);
5493
5494                         ec.Emit (OpCodes.Call, ctor_factory);
5495                         ec.MarkLabel (label_end);
5496                         return true;
5497                 }
5498
5499                 //
5500                 // This Emit can be invoked in two contexts:
5501                 //    * As a mechanism that will leave a value on the stack (new object)
5502                 //    * As one that wont (init struct)
5503                 //
5504                 // If we are dealing with a ValueType, we have a few
5505                 // situations to deal with:
5506                 //
5507                 //    * The target is a ValueType, and we have been provided
5508                 //      the instance (this is easy, we are being assigned).
5509                 //
5510                 //    * The target of New is being passed as an argument,
5511                 //      to a boxing operation or a function that takes a
5512                 //      ValueType.
5513                 //
5514                 //      In this case, we need to create a temporary variable
5515                 //      that is the argument of New.
5516                 //
5517                 // Returns whether a value is left on the stack
5518                 //
5519                 // *** Implementation note ***
5520                 //
5521                 // To benefit from this optimization, each assignable expression
5522                 // has to manually cast to New and call this Emit.
5523                 //
5524                 // TODO: It's worth to implement it for arrays and fields
5525                 //
5526                 public virtual bool Emit (EmitContext ec, IMemoryLocation target)
5527                 {
5528                         bool is_value_type = TypeManager.IsValueType (type);
5529                         VariableReference vr = target as VariableReference;
5530
5531                         if (target != null && is_value_type && (vr != null || method == null)) {
5532                                 target.AddressOf (ec, AddressOp.Store);
5533                         } else if (vr != null && vr.IsRef) {
5534                                 vr.EmitLoad (ec);
5535                         }
5536
5537                         if (Arguments != null)
5538                                 Arguments.Emit (ec);
5539
5540                         if (is_value_type) {
5541                                 if (method == null) {
5542                                         ec.Emit (OpCodes.Initobj, type);
5543                                         return false;
5544                                 }
5545
5546                                 if (vr != null) {
5547                                         ec.Emit (OpCodes.Call, method.BestCandidate);
5548                                         return false;
5549                                 }
5550                         }
5551
5552                         if (type is TypeParameterSpec)
5553                                 return DoEmitTypeParameter (ec);
5554
5555                         ec.Emit (OpCodes.Newobj, method.BestCandidate);
5556                         return true;
5557                 }
5558
5559                 public override void Emit (EmitContext ec)
5560                 {
5561                         LocalTemporary v = null;
5562                         if (method == null && TypeManager.IsValueType (type)) {
5563                                 // TODO: Use temporary variable from pool
5564                                 v = new LocalTemporary (type);
5565                         }
5566
5567                         if (!Emit (ec, v))
5568                                 v.Emit (ec);
5569                 }
5570
5571                 public override void EmitStatement (EmitContext ec)
5572                 {
5573                         LocalTemporary v = null;
5574                         if (method == null && TypeManager.IsValueType (type)) {
5575                                 // TODO: Use temporary variable from pool
5576                                 v = new LocalTemporary (type);
5577                         }
5578
5579                         if (Emit (ec, v))
5580                                 ec.Emit (OpCodes.Pop);
5581                 }
5582
5583                 public virtual bool HasInitializer {
5584                         get {
5585                                 return false;
5586                         }
5587                 }
5588
5589                 public void AddressOf (EmitContext ec, AddressOp mode)
5590                 {
5591                         EmitAddressOf (ec, mode);
5592                 }
5593
5594                 protected virtual IMemoryLocation EmitAddressOf (EmitContext ec, AddressOp mode)
5595                 {
5596                         LocalTemporary value_target = new LocalTemporary (type);
5597
5598                         if (type is TypeParameterSpec) {
5599                                 DoEmitTypeParameter (ec);
5600                                 value_target.Store (ec);
5601                                 value_target.AddressOf (ec, mode);
5602                                 return value_target;
5603                         }
5604
5605                         if (!TypeManager.IsStruct (type)){
5606                                 //
5607                                 // We throw an exception.  So far, I believe we only need to support
5608                                 // value types:
5609                                 // foreach (int j in new StructType ())
5610                                 // see bug 42390
5611                                 //
5612                                 throw new Exception ("AddressOf should not be used for classes");
5613                         }
5614
5615                         value_target.AddressOf (ec, AddressOp.Store);
5616
5617                         if (method == null) {
5618                                 ec.Emit (OpCodes.Initobj, type);
5619                         } else {
5620                                 if (Arguments != null)
5621                                         Arguments.Emit (ec);
5622
5623                                 ec.Emit (OpCodes.Call, method.BestCandidate);
5624                         }
5625
5626                         value_target.AddressOf (ec, mode);
5627                         return value_target;
5628                 }
5629
5630                 protected override void CloneTo (CloneContext clonectx, Expression t)
5631                 {
5632                         New target = (New) t;
5633
5634                         target.RequestedType = RequestedType.Clone (clonectx);
5635                         if (Arguments != null){
5636                                 target.Arguments = Arguments.Clone (clonectx);
5637                         }
5638                 }
5639
5640                 public override SLE.Expression MakeExpression (BuilderContext ctx)
5641                 {
5642                         return SLE.Expression.New ((ConstructorInfo) method.BestCandidate.GetMetaInfo (), Arguments.MakeExpression (Arguments, ctx));
5643                 }
5644         }
5645
5646         public class ArrayInitializer : Expression
5647         {
5648                 List<Expression> elements;
5649
5650                 public ArrayInitializer (List<Expression> init, Location loc)
5651                 {
5652                         elements = init;
5653                         this.loc = loc;
5654                 }
5655
5656                 public ArrayInitializer (int count, Location loc)
5657                 {
5658                         elements = new List<Expression> (count);
5659                         this.loc = loc;
5660                 }
5661
5662                 public ArrayInitializer (Location loc)
5663                         : this (4, loc)
5664                 {
5665                 }
5666
5667                 public void Add (Expression expr)
5668                 {
5669                         elements.Add (expr);
5670                 }
5671
5672                 public override Expression CreateExpressionTree (ResolveContext ec)
5673                 {
5674                         throw new NotSupportedException ("ET");
5675                 }
5676
5677                 protected override void CloneTo (CloneContext clonectx, Expression t)
5678                 {
5679                         var target = (ArrayInitializer) t;
5680
5681                         target.elements = new List<Expression> (elements.Count);
5682                         foreach (var element in elements)
5683                                 target.elements.Add (element.Clone (clonectx));
5684                 }
5685
5686                 public int Count {
5687                         get { return elements.Count; }
5688                 }
5689
5690                 protected override Expression DoResolve (ResolveContext rc)
5691                 {
5692                         var current_field = rc.CurrentMemberDefinition as FieldBase;
5693                         return new ArrayCreation (new TypeExpression (current_field.MemberType, current_field.Location), this).Resolve (rc);
5694                 }
5695
5696                 public override void Emit (EmitContext ec)
5697                 {
5698                         throw new InternalErrorException ("Missing Resolve call");
5699                 }
5700
5701                 public Expression this [int index] {
5702                         get { return elements [index]; }
5703                 }
5704         }
5705
5706         /// <summary>
5707         ///   14.5.10.2: Represents an array creation expression.
5708         /// </summary>
5709         ///
5710         /// <remarks>
5711         ///   There are two possible scenarios here: one is an array creation
5712         ///   expression that specifies the dimensions and optionally the
5713         ///   initialization data and the other which does not need dimensions
5714         ///   specified but where initialization data is mandatory.
5715         /// </remarks>
5716         public class ArrayCreation : Expression
5717         {
5718                 FullNamedExpression requested_base_type;
5719                 ArrayInitializer initializers;
5720
5721                 //
5722                 // The list of Argument types.
5723                 // This is used to construct the `newarray' or constructor signature
5724                 //
5725                 protected List<Expression> arguments;
5726
5727                 protected TypeSpec array_element_type;
5728                 int num_arguments = 0;
5729                 protected int dimensions;
5730                 protected readonly ComposedTypeSpecifier rank;
5731                 Expression first_emit;
5732                 LocalTemporary first_emit_temp;
5733
5734                 protected List<Expression> array_data;
5735
5736                 Dictionary<int, int> bounds;
5737
5738                 // The number of constants in array initializers
5739                 int const_initializers_count;
5740                 bool only_constant_initializers;
5741
5742                 public ArrayCreation (FullNamedExpression requested_base_type, List<Expression> exprs, ComposedTypeSpecifier rank, ArrayInitializer initializers, Location l)
5743                         : this (requested_base_type, rank, initializers, l)
5744                 {
5745                         arguments = new List<Expression> (exprs);
5746                         num_arguments = arguments.Count;
5747                 }
5748
5749                 //
5750                 // For expressions like int[] foo = new int[] { 1, 2, 3 };
5751                 //
5752                 public ArrayCreation (FullNamedExpression requested_base_type, ComposedTypeSpecifier rank, ArrayInitializer initializers, Location loc)
5753                 {
5754                         this.requested_base_type = requested_base_type;
5755                         this.rank = rank;
5756                         this.initializers = initializers;
5757                         this.loc = loc;
5758
5759                         if (rank != null)
5760                                 num_arguments = rank.Dimension;
5761                 }
5762
5763                 //
5764                 // For compiler generated single dimensional arrays only
5765                 //
5766                 public ArrayCreation (FullNamedExpression requested_base_type, ArrayInitializer initializers, Location loc)
5767                         : this (requested_base_type, ComposedTypeSpecifier.SingleDimension, initializers, loc)
5768                 {
5769                 }
5770
5771                 //
5772                 // For expressions like int[] foo = { 1, 2, 3 };
5773                 //
5774                 public ArrayCreation (FullNamedExpression requested_base_type, ArrayInitializer initializers)
5775                         : this (requested_base_type, null, initializers, initializers.Location)
5776                 {
5777                 }
5778
5779                 protected override void Error_NegativeArrayIndex (ResolveContext ec, Location loc)
5780                 {
5781                         ec.Report.Error (248, loc, "Cannot create an array with a negative size");
5782                 }
5783
5784                 bool CheckIndices (ResolveContext ec, ArrayInitializer probe, int idx, bool specified_dims, int child_bounds)
5785                 {
5786                         if (initializers != null && bounds == null) {
5787                                 //
5788                                 // We use this to store all the date values in the order in which we
5789                                 // will need to store them in the byte blob later
5790                                 //
5791                                 array_data = new List<Expression> ();
5792                                 bounds = new Dictionary<int, int> ();
5793                         }
5794
5795                         if (specified_dims) {
5796                                 Expression a = arguments [idx];
5797                                 a = a.Resolve (ec);
5798                                 if (a == null)
5799                                         return false;
5800
5801                                 a = ConvertExpressionToArrayIndex (ec, a);
5802                                 if (a == null)
5803                                         return false;
5804
5805                                 arguments[idx] = a;
5806
5807                                 if (initializers != null) {
5808                                         Constant c = a as Constant;
5809                                         if (c == null && a is ArrayIndexCast)
5810                                                 c = ((ArrayIndexCast) a).Child as Constant;
5811
5812                                         if (c == null) {
5813                                                 ec.Report.Error (150, a.Location, "A constant value is expected");
5814                                                 return false;
5815                                         }
5816
5817                                         int value;
5818                                         try {
5819                                                 value = System.Convert.ToInt32 (c.GetValue ());
5820                                         } catch {
5821                                                 ec.Report.Error (150, a.Location, "A constant value is expected");
5822                                                 return false;
5823                                         }
5824
5825                                         // TODO: probe.Count does not fit ulong in
5826                                         if (value != probe.Count) {
5827                                                 ec.Report.Error (847, loc, "An array initializer of length `{0}' was expected", value.ToString ());
5828                                                 return false;
5829                                         }
5830
5831                                         bounds[idx] = value;
5832                                 }
5833                         }
5834
5835                         if (initializers == null)
5836                                 return true;
5837
5838                         only_constant_initializers = true;
5839                         for (int i = 0; i < probe.Count; ++i) {
5840                                 var o = probe [i];
5841                                 if (o is ArrayInitializer) {
5842                                         var sub_probe = o as ArrayInitializer;
5843                                         if (idx + 1 >= dimensions){
5844                                                 ec.Report.Error (623, loc, "Array initializers can only be used in a variable or field initializer. Try using a new expression instead");
5845                                                 return false;
5846                                         }
5847
5848                                         bool ret = CheckIndices (ec, sub_probe, idx + 1, specified_dims, child_bounds - 1);
5849                                         if (!ret)
5850                                                 return false;
5851                                 } else if (child_bounds > 1) {
5852                                         ec.Report.Error (846, o.Location, "A nested array initializer was expected");
5853                                 } else {
5854                                         Expression element = ResolveArrayElement (ec, o);
5855                                         if (element == null)
5856                                                 continue;
5857
5858                                         // Initializers with the default values can be ignored
5859                                         Constant c = element as Constant;
5860                                         if (c != null) {
5861                                                 if (!c.IsDefaultInitializer (array_element_type)) {
5862                                                         ++const_initializers_count;
5863                                                 }
5864                                         } else {
5865                                                 only_constant_initializers = false;
5866                                         }
5867
5868                                         array_data.Add (element);
5869                                 }
5870                         }
5871
5872                         return true;
5873                 }
5874
5875                 public override Expression CreateExpressionTree (ResolveContext ec)
5876                 {
5877                         Arguments args;
5878
5879                         if (array_data == null) {
5880                                 args = new Arguments (arguments.Count + 1);
5881                                 args.Add (new Argument (new TypeOf (new TypeExpression (array_element_type, loc), loc)));
5882                                 foreach (Expression a in arguments)
5883                                         args.Add (new Argument (a.CreateExpressionTree (ec)));
5884
5885                                 return CreateExpressionFactoryCall (ec, "NewArrayBounds", args);
5886                         }
5887
5888                         if (dimensions > 1) {
5889                                 ec.Report.Error (838, loc, "An expression tree cannot contain a multidimensional array initializer");
5890                                 return null;
5891                         }
5892
5893                         args = new Arguments (array_data == null ? 1 : array_data.Count + 1);
5894                         args.Add (new Argument (new TypeOf (new TypeExpression (array_element_type, loc), loc)));
5895                         if (array_data != null) {
5896                                 for (int i = 0; i < array_data.Count; ++i) {
5897                                         Expression e = array_data [i];
5898                                         args.Add (new Argument (e.CreateExpressionTree (ec)));
5899                                 }
5900                         }
5901
5902                         return CreateExpressionFactoryCall (ec, "NewArrayInit", args);
5903                 }
5904
5905                 public void UpdateIndices ()
5906                 {
5907                         int i = 0;
5908                         for (var probe = initializers; probe != null;) {
5909                                 if (probe.Count > 0 && probe [0] is ArrayInitializer) {
5910                                         Expression e = new IntConstant (probe.Count, Location.Null);
5911                                         arguments.Add (e);
5912
5913                                         bounds [i++] = probe.Count;
5914
5915                                         probe = (ArrayInitializer) probe[0];
5916
5917                                 } else {
5918                                         Expression e = new IntConstant (probe.Count, Location.Null);
5919                                         arguments.Add (e);
5920
5921                                         bounds [i++] = probe.Count;
5922                                         return;
5923                                 }
5924                         }
5925                 }
5926
5927                 protected virtual Expression ResolveArrayElement (ResolveContext ec, Expression element)
5928                 {
5929                         element = element.Resolve (ec);
5930                         if (element == null)
5931                                 return null;
5932
5933                         if (element is CompoundAssign.TargetExpression) {
5934                                 if (first_emit != null)
5935                                         throw new InternalErrorException ("Can only handle one mutator at a time");
5936                                 first_emit = element;
5937                                 element = first_emit_temp = new LocalTemporary (element.Type);
5938                         }
5939
5940                         return Convert.ImplicitConversionRequired (
5941                                 ec, element, array_element_type, loc);
5942                 }
5943
5944                 protected bool ResolveInitializers (ResolveContext ec)
5945                 {
5946                         if (arguments != null) {
5947                                 bool res = true;
5948                                 for (int i = 0; i < arguments.Count; ++i) {
5949                                         res &= CheckIndices (ec, initializers, i, true, dimensions);
5950                                         if (initializers != null)
5951                                                 break;
5952                                 }
5953
5954                                 return res;
5955                         }
5956
5957                         arguments = new List<Expression> ();
5958
5959                         if (!CheckIndices (ec, initializers, 0, false, dimensions))
5960                                 return false;
5961
5962                         UpdateIndices ();
5963
5964                         return true;
5965                 }
5966
5967                 //
5968                 // Resolved the type of the array
5969                 //
5970                 bool ResolveArrayType (ResolveContext ec)
5971                 {
5972                         if (requested_base_type is VarExpr) {
5973                                 ec.Report.Error (820, loc, "An implicitly typed local variable declarator cannot use an array initializer");
5974                                 return false;
5975                         }
5976
5977                         //
5978                         // Lookup the type
5979                         //
5980                         FullNamedExpression array_type_expr;
5981                         if (num_arguments > 0) {
5982                                 array_type_expr = new ComposedCast (requested_base_type, rank);
5983                         } else {
5984                                 array_type_expr = requested_base_type;
5985                         }
5986
5987                         array_type_expr = array_type_expr.ResolveAsTypeTerminal (ec, false);
5988                         if (array_type_expr == null)
5989                                 return false;
5990
5991                         type = array_type_expr.Type;
5992                         var ac = type as ArrayContainer;
5993                         if (ac == null) {
5994                                 ec.Report.Error (622, loc, "Can only use array initializer expressions to assign to array types. Try using a new expression instead");
5995                                 return false;
5996                         }
5997
5998                         array_element_type = ac.Element;
5999                         dimensions = ac.Rank;
6000
6001                         return true;
6002                 }
6003
6004                 protected override Expression DoResolve (ResolveContext ec)
6005                 {
6006                         if (type != null)
6007                                 return this;
6008
6009                         if (!ResolveArrayType (ec))
6010                                 return null;
6011
6012                         //
6013                         // validate the initializers and fill in any missing bits
6014                         //
6015                         if (!ResolveInitializers (ec))
6016                                 return null;
6017
6018                         eclass = ExprClass.Value;
6019                         return this;
6020                 }
6021
6022                 byte [] MakeByteBlob ()
6023                 {
6024                         int factor;
6025                         byte [] data;
6026                         byte [] element;
6027                         int count = array_data.Count;
6028
6029                         TypeSpec element_type = array_element_type;
6030                         if (TypeManager.IsEnumType (element_type))
6031                                 element_type = EnumSpec.GetUnderlyingType (element_type);
6032
6033                         factor = GetTypeSize (element_type);
6034                         if (factor == 0)
6035                                 throw new Exception ("unrecognized type in MakeByteBlob: " + element_type);
6036
6037                         data = new byte [(count * factor + 3) & ~3];
6038                         int idx = 0;
6039
6040                         for (int i = 0; i < count; ++i) {
6041                                 object v = array_data [i];
6042
6043                                 if (v is EnumConstant)
6044                                         v = ((EnumConstant) v).Child;
6045
6046                                 if (v is Constant && !(v is StringConstant))
6047                                         v = ((Constant) v).GetValue ();
6048                                 else {
6049                                         idx += factor;
6050                                         continue;
6051                                 }
6052
6053                                 if (element_type == TypeManager.int64_type){
6054                                         if (!(v is Expression)){
6055                                                 long val = (long) v;
6056
6057                                                 for (int j = 0; j < factor; ++j) {
6058                                                         data [idx + j] = (byte) (val & 0xFF);
6059                                                         val = (val >> 8);
6060                                                 }
6061                                         }
6062                                 } else if (element_type == TypeManager.uint64_type){
6063                                         if (!(v is Expression)){
6064                                                 ulong val = (ulong) v;
6065
6066                                                 for (int j = 0; j < factor; ++j) {
6067                                                         data [idx + j] = (byte) (val & 0xFF);
6068                                                         val = (val >> 8);
6069                                                 }
6070                                         }
6071                                 } else if (element_type == TypeManager.float_type) {
6072                                         if (!(v is Expression)){
6073                                                 element = BitConverter.GetBytes ((float) v);
6074
6075                                                 for (int j = 0; j < factor; ++j)
6076                                                         data [idx + j] = element [j];
6077                                                 if (!BitConverter.IsLittleEndian)
6078                                                         System.Array.Reverse (data, idx, 4);
6079                                         }
6080                                 } else if (element_type == TypeManager.double_type) {
6081                                         if (!(v is Expression)){
6082                                                 element = BitConverter.GetBytes ((double) v);
6083
6084                                                 for (int j = 0; j < factor; ++j)
6085                                                         data [idx + j] = element [j];
6086
6087                                                 // FIXME: Handle the ARM float format.
6088                                                 if (!BitConverter.IsLittleEndian)
6089                                                         System.Array.Reverse (data, idx, 8);
6090                                         }
6091                                 } else if (element_type == TypeManager.char_type){
6092                                         if (!(v is Expression)){
6093                                                 int val = (int) ((char) v);
6094
6095                                                 data [idx] = (byte) (val & 0xff);
6096                                                 data [idx+1] = (byte) (val >> 8);
6097                                         }
6098                                 } else if (element_type == TypeManager.short_type){
6099                                         if (!(v is Expression)){
6100                                                 int val = (int) ((short) v);
6101
6102                                                 data [idx] = (byte) (val & 0xff);
6103                                                 data [idx+1] = (byte) (val >> 8);
6104                                         }
6105                                 } else if (element_type == TypeManager.ushort_type){
6106                                         if (!(v is Expression)){
6107                                                 int val = (int) ((ushort) v);
6108
6109                                                 data [idx] = (byte) (val & 0xff);
6110                                                 data [idx+1] = (byte) (val >> 8);
6111                                         }
6112                                 } else if (element_type == TypeManager.int32_type) {
6113                                         if (!(v is Expression)){
6114                                                 int val = (int) v;
6115
6116                                                 data [idx]   = (byte) (val & 0xff);
6117                                                 data [idx+1] = (byte) ((val >> 8) & 0xff);
6118                                                 data [idx+2] = (byte) ((val >> 16) & 0xff);
6119                                                 data [idx+3] = (byte) (val >> 24);
6120                                         }
6121                                 } else if (element_type == TypeManager.uint32_type) {
6122                                         if (!(v is Expression)){
6123                                                 uint val = (uint) v;
6124
6125                                                 data [idx]   = (byte) (val & 0xff);
6126                                                 data [idx+1] = (byte) ((val >> 8) & 0xff);
6127                                                 data [idx+2] = (byte) ((val >> 16) & 0xff);
6128                                                 data [idx+3] = (byte) (val >> 24);
6129                                         }
6130                                 } else if (element_type == TypeManager.sbyte_type) {
6131                                         if (!(v is Expression)){
6132                                                 sbyte val = (sbyte) v;
6133                                                 data [idx] = (byte) val;
6134                                         }
6135                                 } else if (element_type == TypeManager.byte_type) {
6136                                         if (!(v is Expression)){
6137                                                 byte val = (byte) v;
6138                                                 data [idx] = (byte) val;
6139                                         }
6140                                 } else if (element_type == TypeManager.bool_type) {
6141                                         if (!(v is Expression)){
6142                                                 bool val = (bool) v;
6143                                                 data [idx] = (byte) (val ? 1 : 0);
6144                                         }
6145                                 } else if (element_type == TypeManager.decimal_type){
6146                                         if (!(v is Expression)){
6147                                                 int [] bits = Decimal.GetBits ((decimal) v);
6148                                                 int p = idx;
6149
6150                                                 // FIXME: For some reason, this doesn't work on the MS runtime.
6151                                                 int [] nbits = new int [4];
6152                                                 nbits [0] = bits [3];
6153                                                 nbits [1] = bits [2];
6154                                                 nbits [2] = bits [0];
6155                                                 nbits [3] = bits [1];
6156
6157                                                 for (int j = 0; j < 4; j++){
6158                                                         data [p++] = (byte) (nbits [j] & 0xff);
6159                                                         data [p++] = (byte) ((nbits [j] >> 8) & 0xff);
6160                                                         data [p++] = (byte) ((nbits [j] >> 16) & 0xff);
6161                                                         data [p++] = (byte) (nbits [j] >> 24);
6162                                                 }
6163                                         }
6164                                 } else {
6165                                         throw new Exception ("Unrecognized type in MakeByteBlob: " + element_type);
6166                                 }
6167
6168                                 idx += factor;
6169                         }
6170
6171                         return data;
6172                 }
6173
6174 #if NET_4_0
6175                 public override SLE.Expression MakeExpression (BuilderContext ctx)
6176                 {
6177                         var initializers = new SLE.Expression [array_data.Count];
6178                         for (var i = 0; i < initializers.Length; i++) {
6179                                 if (array_data [i] == null)
6180                                         initializers [i] = SLE.Expression.Default (array_element_type.GetMetaInfo ());
6181                                 else
6182                                         initializers [i] = array_data [i].MakeExpression (ctx);
6183                         }
6184
6185                         return SLE.Expression.NewArrayInit (array_element_type.GetMetaInfo (), initializers);
6186                 }
6187 #endif
6188                 //
6189                 // Emits the initializers for the array
6190                 //
6191                 void EmitStaticInitializers (EmitContext ec)
6192                 {
6193                         // FIXME: This should go to Resolve !
6194                         if (TypeManager.void_initializearray_array_fieldhandle == null) {
6195                                 TypeManager.void_initializearray_array_fieldhandle = TypeManager.GetPredefinedMethod (
6196                                         TypeManager.runtime_helpers_type, "InitializeArray", loc,
6197                                         TypeManager.array_type, TypeManager.runtime_field_handle_type);
6198                                 if (TypeManager.void_initializearray_array_fieldhandle == null)
6199                                         return;
6200                         }
6201
6202                         //
6203                         // First, the static data
6204                         //
6205                         FieldBuilder fb;
6206
6207                         byte [] data = MakeByteBlob ();
6208
6209                         fb = RootContext.MakeStaticData (data);
6210
6211                         ec.Emit (OpCodes.Dup);
6212                         ec.Emit (OpCodes.Ldtoken, fb);
6213                         ec.Emit (OpCodes.Call, TypeManager.void_initializearray_array_fieldhandle);
6214                 }
6215
6216                 //
6217                 // Emits pieces of the array that can not be computed at compile
6218                 // time (variables and string locations).
6219                 //
6220                 // This always expect the top value on the stack to be the array
6221                 //
6222                 void EmitDynamicInitializers (EmitContext ec, bool emitConstants)
6223                 {
6224                         int dims = bounds.Count;
6225                         var current_pos = new int [dims];
6226
6227                         for (int i = 0; i < array_data.Count; i++){
6228
6229                                 Expression e = array_data [i];
6230                                 var c = e as Constant;
6231
6232                                 // Constant can be initialized via StaticInitializer
6233                                 if (c == null || (c != null && emitConstants && !c.IsDefaultInitializer (array_element_type))) {
6234                                         TypeSpec etype = e.Type;
6235
6236                                         ec.Emit (OpCodes.Dup);
6237
6238                                         for (int idx = 0; idx < dims; idx++)
6239                                                 ec.EmitInt (current_pos [idx]);
6240
6241                                         //
6242                                         // If we are dealing with a struct, get the
6243                                         // address of it, so we can store it.
6244                                         //
6245                                         if ((dims == 1) && TypeManager.IsStruct (etype) &&
6246                                             (!TypeManager.IsBuiltinOrEnum (etype) ||
6247                                              etype == TypeManager.decimal_type)) {
6248
6249                                                 ec.Emit (OpCodes.Ldelema, etype);
6250                                         }
6251
6252                                         e.Emit (ec);
6253
6254                                         ec.EmitArrayStore ((ArrayContainer) type);
6255                                 }
6256
6257                                 //
6258                                 // Advance counter
6259                                 //
6260                                 for (int j = dims - 1; j >= 0; j--){
6261                                         current_pos [j]++;
6262                                         if (current_pos [j] < bounds [j])
6263                                                 break;
6264                                         current_pos [j] = 0;
6265                                 }
6266                         }
6267                 }
6268
6269                 public override void Emit (EmitContext ec)
6270                 {
6271                         if (first_emit != null) {
6272                                 first_emit.Emit (ec);
6273                                 first_emit_temp.Store (ec);
6274                         }
6275
6276                         foreach (Expression e in arguments)
6277                                 e.Emit (ec);
6278
6279                         ec.EmitArrayNew ((ArrayContainer) type);
6280
6281                         if (initializers == null)
6282                                 return;
6283
6284                         // Emit static initializer for arrays which have contain more than 2 items and
6285                         // the static initializer will initialize at least 25% of array values.
6286                         // NOTE: const_initializers_count does not contain default constant values.
6287                         if (const_initializers_count > 2 && const_initializers_count * 4 > (array_data.Count) &&
6288                                 (TypeManager.IsPrimitiveType (array_element_type) || TypeManager.IsEnumType (array_element_type))) {
6289                                 EmitStaticInitializers (ec);
6290
6291                                 if (!only_constant_initializers)
6292                                         EmitDynamicInitializers (ec, false);
6293                         } else {
6294                                 EmitDynamicInitializers (ec, true);
6295                         }
6296
6297                         if (first_emit_temp != null)
6298                                 first_emit_temp.Release (ec);
6299                 }
6300
6301                 public override void EncodeAttributeValue (IMemberContext rc, AttributeEncoder enc, TypeSpec targetType)
6302                 {
6303                         // no multi dimensional or jagged arrays
6304                         if (arguments.Count != 1 || array_element_type.IsArray) {
6305                                 base.EncodeAttributeValue (rc, enc, targetType);
6306                                 return;
6307                         }
6308
6309                         // No array covariance, except for array -> object
6310                         if (type != targetType) {
6311                                 if (targetType != TypeManager.object_type) {
6312                                         base.EncodeAttributeValue (rc, enc, targetType);
6313                                         return;
6314                                 }
6315
6316                                 enc.Encode (type);
6317                         }
6318
6319                         // Single dimensional array of 0 size
6320                         if (array_data == null) {
6321                                 IntConstant ic = arguments[0] as IntConstant;
6322                                 if (ic == null || !ic.IsDefaultValue) {
6323                                         base.EncodeAttributeValue (rc, enc, targetType);
6324                                 } else {
6325                                         enc.Stream.Write (0);
6326                                 }
6327
6328                                 return;
6329                         }
6330
6331                         enc.Stream.Write ((int) array_data.Count);
6332                         foreach (var element in array_data) {
6333                                 element.EncodeAttributeValue (rc, enc, array_element_type);
6334                         }
6335                 }
6336
6337                 protected override void CloneTo (CloneContext clonectx, Expression t)
6338                 {
6339                         ArrayCreation target = (ArrayCreation) t;
6340
6341                         if (requested_base_type != null)
6342                                 target.requested_base_type = (FullNamedExpression)requested_base_type.Clone (clonectx);
6343
6344                         if (arguments != null){
6345                                 target.arguments = new List<Expression> (arguments.Count);
6346                                 foreach (Expression e in arguments)
6347                                         target.arguments.Add (e.Clone (clonectx));
6348                         }
6349
6350                         if (initializers != null)
6351                                 target.initializers = (ArrayInitializer) initializers.Clone (clonectx);
6352                 }
6353         }
6354
6355         //
6356         // Represents an implicitly typed array epxression
6357         //
6358         class ImplicitlyTypedArrayCreation : ArrayCreation
6359         {
6360                 public ImplicitlyTypedArrayCreation (ComposedTypeSpecifier rank, ArrayInitializer initializers, Location loc)
6361                         : base (null, rank, initializers, loc)
6362                 {
6363                 }
6364
6365                 public ImplicitlyTypedArrayCreation (ArrayInitializer initializers, Location loc)
6366                         : base (null, initializers, loc)
6367                 {
6368                 }
6369
6370                 protected override Expression DoResolve (ResolveContext ec)
6371                 {
6372                         if (type != null)
6373                                 return this;
6374
6375                         dimensions = rank.Dimension;
6376
6377                         if (!ResolveInitializers (ec))
6378                                 return null;
6379
6380                         if (array_element_type == null || array_element_type == TypeManager.null_type ||
6381                                 array_element_type == TypeManager.void_type || array_element_type == InternalType.AnonymousMethod ||
6382                                 array_element_type == InternalType.MethodGroup ||
6383                                 arguments.Count != rank.Dimension) {
6384                                 Error_NoBestType (ec);
6385                                 return null;
6386                         }
6387
6388                         //
6389                         // At this point we found common base type for all initializer elements
6390                         // but we have to be sure that all static initializer elements are of
6391                         // same type
6392                         //
6393                         UnifyInitializerElement (ec);
6394
6395                         type = ArrayContainer.MakeType (array_element_type, dimensions);
6396                         eclass = ExprClass.Value;
6397                         return this;
6398                 }
6399
6400                 void Error_NoBestType (ResolveContext ec)
6401                 {
6402                         ec.Report.Error (826, loc,
6403                                 "The type of an implicitly typed array cannot be inferred from the initializer. Try specifying array type explicitly");
6404                 }
6405
6406                 //
6407                 // Converts static initializer only
6408                 //
6409                 void UnifyInitializerElement (ResolveContext ec)
6410                 {
6411                         for (int i = 0; i < array_data.Count; ++i) {
6412                                 Expression e = (Expression)array_data[i];
6413                                 if (e != null)
6414                                         array_data [i] = Convert.ImplicitConversion (ec, e, array_element_type, Location.Null);
6415                         }
6416                 }
6417
6418                 protected override Expression ResolveArrayElement (ResolveContext ec, Expression element)
6419                 {
6420                         element = element.Resolve (ec);
6421                         if (element == null)
6422                                 return null;
6423
6424                         if (array_element_type == null) {
6425                                 if (element.Type != TypeManager.null_type)
6426                                         array_element_type = element.Type;
6427
6428                                 return element;
6429                         }
6430
6431                         if (Convert.ImplicitConversionExists (ec, element, array_element_type)) {
6432                                 return element;
6433                         }
6434
6435                         if (Convert.ImplicitConversionExists (ec, new TypeExpression (array_element_type, loc), element.Type)) {
6436                                 array_element_type = element.Type;
6437                                 return element;
6438                         }
6439
6440                         Error_NoBestType (ec);
6441                         return null;
6442                 }
6443         }
6444
6445         public sealed class CompilerGeneratedThis : This
6446         {
6447                 public static This Instance = new CompilerGeneratedThis ();
6448
6449                 private CompilerGeneratedThis ()
6450                         : base (Location.Null)
6451                 {
6452                 }
6453
6454                 public CompilerGeneratedThis (TypeSpec type, Location loc)
6455                         : base (loc)
6456                 {
6457                         this.type = type;
6458                 }
6459
6460                 protected override Expression DoResolve (ResolveContext ec)
6461                 {
6462                         eclass = ExprClass.Variable;
6463                         if (type == null)
6464                                 type = ec.CurrentType;
6465
6466                         return this;
6467                 }
6468
6469                 public override HoistedVariable GetHoistedVariable (AnonymousExpression ae)
6470                 {
6471                         return null;
6472                 }
6473         }
6474
6475         /// <summary>
6476         ///   Represents the `this' construct
6477         /// </summary>
6478
6479         public class This : VariableReference
6480         {
6481                 sealed class ThisVariable : ILocalVariable
6482                 {
6483                         public static readonly ILocalVariable Instance = new ThisVariable ();
6484
6485                         public void Emit (EmitContext ec)
6486                         {
6487                                 ec.Emit (OpCodes.Ldarg_0);
6488                         }
6489
6490                         public void EmitAssign (EmitContext ec)
6491                         {
6492                                 throw new InvalidOperationException ();
6493                         }
6494
6495                         public void EmitAddressOf (EmitContext ec)
6496                         {
6497                                 ec.Emit (OpCodes.Ldarg_0);
6498                         }
6499                 }
6500
6501                 VariableInfo variable_info;
6502
6503                 public This (Location loc)
6504                 {
6505                         this.loc = loc;
6506                 }
6507
6508                 public override VariableInfo VariableInfo {
6509                         get { return variable_info; }
6510                 }
6511
6512                 public override bool IsFixed {
6513                         get { return false; }
6514                 }
6515
6516                 public override HoistedVariable GetHoistedVariable (AnonymousExpression ae)
6517                 {
6518                         if (ae == null)
6519                                 return null;
6520
6521                         AnonymousMethodStorey storey = ae.Storey;
6522                         while (storey != null) {
6523                                 AnonymousMethodStorey temp = storey.Parent as AnonymousMethodStorey;
6524                                 if (temp == null)
6525                                         return storey.HoistedThis;
6526
6527                                 storey = temp;
6528                         }
6529
6530                         return null;
6531                 }
6532
6533                 public override bool IsRef {
6534                         get { return type.IsStruct; }
6535                 }
6536
6537                 protected override ILocalVariable Variable {
6538                         get { return ThisVariable.Instance; }
6539                 }
6540
6541                 public static bool IsThisAvailable (ResolveContext ec, bool ignoreAnonymous)
6542                 {
6543                         if (ec.IsStatic || ec.HasAny (ResolveContext.Options.FieldInitializerScope | ResolveContext.Options.BaseInitializer | ResolveContext.Options.ConstantScope))
6544                                 return false;
6545
6546                         if (ignoreAnonymous || ec.CurrentAnonymousMethod == null)
6547                                 return true;
6548
6549                         if (TypeManager.IsStruct (ec.CurrentType) && ec.CurrentIterator == null)
6550                                 return false;
6551
6552                         return true;
6553                 }
6554
6555                 public bool ResolveBase (ResolveContext ec)
6556                 {
6557                         eclass = ExprClass.Variable;
6558                         type = ec.CurrentType;
6559
6560                         if (!IsThisAvailable (ec, false)) {
6561                                 if (ec.IsStatic && !ec.HasSet (ResolveContext.Options.ConstantScope)) {
6562                                         ec.Report.Error (26, loc, "Keyword `this' is not valid in a static property, static method, or static field initializer");
6563                                 } else if (ec.CurrentAnonymousMethod != null) {
6564                                         ec.Report.Error (1673, loc,
6565                                                 "Anonymous methods inside structs cannot access instance members of `this'. " +
6566                                                 "Consider copying `this' to a local variable outside the anonymous method and using the local instead");
6567                                 } else {
6568                                         ec.Report.Error (27, loc, "Keyword `this' is not available in the current context");
6569                                 }
6570                         }
6571
6572                         var block = ec.CurrentBlock;
6573                         if (block != null) {
6574                                 if (block.Toplevel.ThisVariable != null)
6575                                         variable_info = block.Toplevel.ThisVariable.VariableInfo;
6576
6577                                 AnonymousExpression am = ec.CurrentAnonymousMethod;
6578                                 if (am != null && ec.IsVariableCapturingRequired) {
6579                                         am.SetHasThisAccess ();
6580                                 }
6581                         }
6582
6583                         return true;
6584                 }
6585
6586                 //
6587                 // Called from Invocation to check if the invocation is correct
6588                 //
6589                 public override void CheckMarshalByRefAccess (ResolveContext ec)
6590                 {
6591                         if ((variable_info != null) && !(TypeManager.IsStruct (type) && ec.OmitStructFlowAnalysis) &&
6592                             !variable_info.IsAssigned (ec)) {
6593                                 ec.Report.Error (188, loc,
6594                                         "The `this' object cannot be used before all of its fields are assigned to");
6595                                 variable_info.SetAssigned (ec);
6596                         }
6597                 }
6598
6599                 public override Expression CreateExpressionTree (ResolveContext ec)
6600                 {
6601                         Arguments args = new Arguments (1);
6602                         args.Add (new Argument (this));
6603
6604                         // Use typeless constant for ldarg.0 to save some
6605                         // space and avoid problems with anonymous stories
6606                         return CreateExpressionFactoryCall (ec, "Constant", args);
6607                 }
6608
6609                 protected override Expression DoResolve (ResolveContext ec)
6610                 {
6611                         ResolveBase (ec);
6612                         return this;
6613                 }
6614
6615                 override public Expression DoResolveLValue (ResolveContext ec, Expression right_side)
6616                 {
6617                         if (!ResolveBase (ec))
6618                                 return null;
6619
6620                         if (variable_info != null)
6621                                 variable_info.SetAssigned (ec);
6622
6623                         if (ec.CurrentType.IsClass){
6624                                 if (right_side == EmptyExpression.UnaryAddress)
6625                                         ec.Report.Error (459, loc, "Cannot take the address of `this' because it is read-only");
6626                                 else if (right_side == EmptyExpression.OutAccess.Instance)
6627                                         ec.Report.Error (1605, loc, "Cannot pass `this' as a ref or out argument because it is read-only");
6628                                 else
6629                                         ec.Report.Error (1604, loc, "Cannot assign to `this' because it is read-only");
6630                         }
6631
6632                         return this;
6633                 }
6634
6635                 public override int GetHashCode()
6636                 {
6637                         throw new NotImplementedException ();
6638                 }
6639
6640                 public override string Name {
6641                         get { return "this"; }
6642                 }
6643
6644                 public override bool Equals (object obj)
6645                 {
6646                         This t = obj as This;
6647                         if (t == null)
6648                                 return false;
6649
6650                         return true;
6651                 }
6652
6653                 protected override void CloneTo (CloneContext clonectx, Expression t)
6654                 {
6655                         // Nothing
6656                 }
6657
6658                 public override void SetHasAddressTaken ()
6659                 {
6660                         // Nothing
6661                 }
6662         }
6663
6664         /// <summary>
6665         ///   Represents the `__arglist' construct
6666         /// </summary>
6667         public class ArglistAccess : Expression
6668         {
6669                 public ArglistAccess (Location loc)
6670                 {
6671                         this.loc = loc;
6672                 }
6673
6674                 public override Expression CreateExpressionTree (ResolveContext ec)
6675                 {
6676                         throw new NotSupportedException ("ET");
6677                 }
6678
6679                 protected override Expression DoResolve (ResolveContext ec)
6680                 {
6681                         eclass = ExprClass.Variable;
6682                         type = TypeManager.runtime_argument_handle_type;
6683
6684                         if (ec.HasSet (ResolveContext.Options.FieldInitializerScope) || !ec.CurrentBlock.Toplevel.Parameters.HasArglist) {
6685                                 ec.Report.Error (190, loc,
6686                                         "The __arglist construct is valid only within a variable argument method");
6687                         }
6688
6689                         return this;
6690                 }
6691
6692                 public override void Emit (EmitContext ec)
6693                 {
6694                         ec.Emit (OpCodes.Arglist);
6695                 }
6696
6697                 protected override void CloneTo (CloneContext clonectx, Expression target)
6698                 {
6699                         // nothing.
6700                 }
6701         }
6702
6703         /// <summary>
6704         ///   Represents the `__arglist (....)' construct
6705         /// </summary>
6706         public class Arglist : Expression
6707         {
6708                 Arguments Arguments;
6709
6710                 public Arglist (Location loc)
6711                         : this (null, loc)
6712                 {
6713                 }
6714
6715                 public Arglist (Arguments args, Location l)
6716                 {
6717                         Arguments = args;
6718                         loc = l;
6719                 }
6720
6721                 public Type[] ArgumentTypes {
6722                     get {
6723                                 if (Arguments == null)
6724                                         return System.Type.EmptyTypes;
6725
6726                         var retval = new Type [Arguments.Count];
6727                         for (int i = 0; i < retval.Length; i++)
6728                                         retval[i] = Arguments[i].Expr.Type.GetMetaInfo ();
6729
6730                         return retval;
6731                     }
6732                 }
6733
6734                 public override Expression CreateExpressionTree (ResolveContext ec)
6735                 {
6736                         ec.Report.Error (1952, loc, "An expression tree cannot contain a method with variable arguments");
6737                         return null;
6738                 }
6739
6740                 protected override Expression DoResolve (ResolveContext ec)
6741                 {
6742                         eclass = ExprClass.Variable;
6743                         type = InternalType.Arglist;
6744                         if (Arguments != null) {
6745                                 bool dynamic;   // Can be ignored as there is always only 1 overload
6746                                 Arguments.Resolve (ec, out dynamic);
6747                         }
6748
6749                         return this;
6750                 }
6751
6752                 public override void Emit (EmitContext ec)
6753                 {
6754                         if (Arguments != null)
6755                                 Arguments.Emit (ec);
6756                 }
6757
6758                 protected override void CloneTo (CloneContext clonectx, Expression t)
6759                 {
6760                         Arglist target = (Arglist) t;
6761
6762                         if (Arguments != null)
6763                                 target.Arguments = Arguments.Clone (clonectx);
6764                 }
6765         }
6766
6767         /// <summary>
6768         ///   Implements the typeof operator
6769         /// </summary>
6770         public class TypeOf : Expression {
6771                 FullNamedExpression QueriedType;
6772                 TypeSpec typearg;
6773
6774                 public TypeOf (FullNamedExpression queried_type, Location l)
6775                 {
6776                         QueriedType = queried_type;
6777                         loc = l;
6778                 }
6779
6780                 #region Properties
6781                 public TypeSpec TypeArgument {
6782                         get {
6783                                 return typearg;
6784                         }
6785                 }
6786
6787                 public FullNamedExpression TypeExpression {
6788                         get {
6789                                 return QueriedType;
6790                         }
6791                 }
6792
6793                 #endregion
6794
6795                 public override Expression CreateExpressionTree (ResolveContext ec)
6796                 {
6797                         Arguments args = new Arguments (2);
6798                         args.Add (new Argument (this));
6799                         args.Add (new Argument (new TypeOf (new TypeExpression (type, loc), loc)));
6800                         return CreateExpressionFactoryCall (ec, "Constant", args);
6801                 }
6802
6803                 protected override Expression DoResolve (ResolveContext ec)
6804                 {
6805                         TypeExpr texpr = QueriedType.ResolveAsTypeTerminal (ec, false);
6806                         if (texpr == null)
6807                                 return null;
6808
6809                         typearg = texpr.Type;
6810
6811                         if (typearg == TypeManager.void_type && !(QueriedType is TypeExpression)) {
6812                                 ec.Report.Error (673, loc, "System.Void cannot be used from C#. Use typeof (void) to get the void type object");
6813                         } else if (typearg.IsPointer && !ec.IsUnsafe){
6814                                 UnsafeError (ec, loc);
6815                         } else if (texpr is DynamicTypeExpr) {
6816                                 ec.Report.Error (1962, QueriedType.Location,
6817                                         "The typeof operator cannot be used on the dynamic type");
6818                         }
6819
6820                         type = TypeManager.type_type;
6821
6822                         return DoResolveBase ();
6823                 }
6824
6825                 protected Expression DoResolveBase ()
6826                 {
6827                         if (TypeManager.system_type_get_type_from_handle == null) {
6828                                 TypeManager.system_type_get_type_from_handle = TypeManager.GetPredefinedMethod (
6829                                         TypeManager.type_type, "GetTypeFromHandle", loc, TypeManager.runtime_handle_type);
6830                         }
6831
6832                         // Even though what is returned is a type object, it's treated as a value by the compiler.
6833                         // In particular, 'typeof (Foo).X' is something totally different from 'Foo.X'.
6834                         eclass = ExprClass.Value;
6835                         return this;
6836                 }
6837
6838                 static bool ContainsTypeParameter (TypeSpec type)
6839                 {
6840                         if (type.Kind == MemberKind.TypeParameter)
6841                                 return true;
6842
6843                         var element_container = type as ElementTypeSpec;
6844                         if (element_container != null)
6845                                 return ContainsTypeParameter (element_container.Element);
6846
6847                         foreach (var t in type.TypeArguments) {
6848                                 if (ContainsTypeParameter (t)) {
6849                                         return true;
6850                                 }
6851                         }
6852
6853                         return false;
6854                 }
6855
6856                 public override void EncodeAttributeValue (IMemberContext rc, AttributeEncoder enc, TypeSpec targetType)
6857                 {
6858                         // Target type is not System.Type therefore must be object
6859                         // and we need to use different encoding sequence
6860                         if (targetType != type)
6861                                 enc.Encode (type);
6862
6863                         if (ContainsTypeParameter (typearg)) {
6864                                 rc.Compiler.Report.Error (416, loc, "`{0}': an attribute argument cannot use type parameters",
6865                                         TypeManager.CSharpName (typearg));
6866                                 return;
6867                         }
6868
6869                         enc.EncodeTypeName (typearg);
6870                 }
6871
6872                 public override void Emit (EmitContext ec)
6873                 {
6874                         ec.Emit (OpCodes.Ldtoken, typearg);
6875                         ec.Emit (OpCodes.Call, TypeManager.system_type_get_type_from_handle);
6876                 }
6877
6878                 protected override void CloneTo (CloneContext clonectx, Expression t)
6879                 {
6880                         TypeOf target = (TypeOf) t;
6881                         if (QueriedType != null)
6882                                 target.QueriedType = (FullNamedExpression) QueriedType.Clone (clonectx);
6883                 }
6884         }
6885
6886         class TypeOfMethod : TypeOfMember<MethodSpec>
6887         {
6888                 public TypeOfMethod (MethodSpec method, Location loc)
6889                         : base (method, loc)
6890                 {
6891                 }
6892
6893                 protected override Expression DoResolve (ResolveContext ec)
6894                 {
6895                         if (member.IsConstructor) {
6896                                 type = TypeManager.ctorinfo_type;
6897                                 if (type == null)
6898                                         type = TypeManager.ctorinfo_type = TypeManager.CoreLookupType (ec.Compiler, "System.Reflection", "ConstructorInfo", MemberKind.Class, true);
6899                         } else {
6900                                 type = TypeManager.methodinfo_type;
6901                                 if (type == null)
6902                                         type = TypeManager.methodinfo_type = TypeManager.CoreLookupType (ec.Compiler, "System.Reflection", "MethodInfo", MemberKind.Class, true);
6903                         }
6904
6905                         return base.DoResolve (ec);
6906                 }
6907
6908                 public override void Emit (EmitContext ec)
6909                 {
6910                         ec.Emit (OpCodes.Ldtoken, member);
6911
6912                         base.Emit (ec);
6913                         ec.Emit (OpCodes.Castclass, type);
6914                 }
6915
6916                 protected override string GetMethodName {
6917                         get { return "GetMethodFromHandle"; }
6918                 }
6919
6920                 protected override string RuntimeHandleName {
6921                         get { return "RuntimeMethodHandle"; }
6922                 }
6923
6924                 protected override MethodSpec TypeFromHandle {
6925                         get {
6926                                 return TypeManager.methodbase_get_type_from_handle;
6927                         }
6928                         set {
6929                                 TypeManager.methodbase_get_type_from_handle = value;
6930                         }
6931                 }
6932
6933                 protected override MethodSpec TypeFromHandleGeneric {
6934                         get {
6935                                 return TypeManager.methodbase_get_type_from_handle_generic;
6936                         }
6937                         set {
6938                                 TypeManager.methodbase_get_type_from_handle_generic = value;
6939                         }
6940                 }
6941
6942                 protected override string TypeName {
6943                         get { return "MethodBase"; }
6944                 }
6945         }
6946
6947         abstract class TypeOfMember<T> : Expression where T : MemberSpec
6948         {
6949                 protected readonly T member;
6950
6951                 protected TypeOfMember (T member, Location loc)
6952                 {
6953                         this.member = member;
6954                         this.loc = loc;
6955                 }
6956
6957                 public override Expression CreateExpressionTree (ResolveContext ec)
6958                 {
6959                         Arguments args = new Arguments (2);
6960                         args.Add (new Argument (this));
6961                         args.Add (new Argument (new TypeOf (new TypeExpression (type, loc), loc)));
6962                         return CreateExpressionFactoryCall (ec, "Constant", args);
6963                 }
6964
6965                 protected override Expression DoResolve (ResolveContext ec)
6966                 {
6967                         bool is_generic = member.DeclaringType.IsGenericOrParentIsGeneric;
6968                         var mi = is_generic ? TypeFromHandleGeneric : TypeFromHandle;
6969
6970                         if (mi == null) {
6971                                 TypeSpec t = TypeManager.CoreLookupType (ec.Compiler, "System.Reflection", TypeName, MemberKind.Class, true);
6972                                 TypeSpec handle_type = TypeManager.CoreLookupType (ec.Compiler, "System", RuntimeHandleName, MemberKind.Struct, true);
6973
6974                                 if (t == null || handle_type == null)
6975                                         return null;
6976
6977                                 mi = TypeManager.GetPredefinedMethod (t, GetMethodName, loc,
6978                                         is_generic ?
6979                                         new TypeSpec[] { handle_type, TypeManager.runtime_handle_type } :
6980                                         new TypeSpec[] { handle_type } );
6981
6982                                 if (is_generic)
6983                                         TypeFromHandleGeneric = mi;
6984                                 else
6985                                         TypeFromHandle = mi;
6986                         }
6987
6988                         eclass = ExprClass.Value;
6989                         return this;
6990                 }
6991
6992                 public override void Emit (EmitContext ec)
6993                 {
6994                         bool is_generic = member.DeclaringType.IsGenericOrParentIsGeneric;
6995                         MethodSpec mi;
6996                         if (is_generic) {
6997                                 mi = TypeFromHandleGeneric;
6998                                 ec.Emit (OpCodes.Ldtoken, member.DeclaringType);
6999                         } else {
7000                                 mi = TypeFromHandle;
7001                         }
7002
7003                         ec.Emit (OpCodes.Call, mi);
7004                 }
7005
7006                 protected abstract string GetMethodName { get; }
7007                 protected abstract string RuntimeHandleName { get; }
7008                 protected abstract MethodSpec TypeFromHandle { get; set; }
7009                 protected abstract MethodSpec TypeFromHandleGeneric { get; set; }
7010                 protected abstract string TypeName { get; }
7011         }
7012
7013         class TypeOfField : TypeOfMember<FieldSpec>
7014         {
7015                 public TypeOfField (FieldSpec field, Location loc)
7016                         : base (field, loc)
7017                 {
7018                 }
7019
7020                 protected override Expression DoResolve (ResolveContext ec)
7021                 {
7022                         if (TypeManager.fieldinfo_type == null)
7023                                 TypeManager.fieldinfo_type = TypeManager.CoreLookupType (ec.Compiler, "System.Reflection", TypeName, MemberKind.Class, true);
7024
7025                         type = TypeManager.fieldinfo_type;
7026                         return base.DoResolve (ec);
7027                 }
7028
7029                 public override void Emit (EmitContext ec)
7030                 {
7031                         ec.Emit (OpCodes.Ldtoken, member);
7032                         base.Emit (ec);
7033                 }
7034
7035                 protected override string GetMethodName {
7036                         get { return "GetFieldFromHandle"; }
7037                 }
7038
7039                 protected override string RuntimeHandleName {
7040                         get { return "RuntimeFieldHandle"; }
7041                 }
7042
7043                 protected override MethodSpec TypeFromHandle {
7044                         get {
7045                                 return TypeManager.fieldinfo_get_field_from_handle;
7046                         }
7047                         set {
7048                                 TypeManager.fieldinfo_get_field_from_handle = value;
7049                         }
7050                 }
7051
7052                 protected override MethodSpec TypeFromHandleGeneric {
7053                         get {
7054                                 return TypeManager.fieldinfo_get_field_from_handle_generic;
7055                         }
7056                         set {
7057                                 TypeManager.fieldinfo_get_field_from_handle_generic = value;
7058                         }
7059                 }
7060
7061                 protected override string TypeName {
7062                         get { return "FieldInfo"; }
7063                 }
7064         }
7065
7066         /// <summary>
7067         ///   Implements the sizeof expression
7068         /// </summary>
7069         public class SizeOf : Expression {
7070                 readonly Expression QueriedType;
7071                 TypeSpec type_queried;
7072
7073                 public SizeOf (Expression queried_type, Location l)
7074                 {
7075                         this.QueriedType = queried_type;
7076                         loc = l;
7077                 }
7078
7079                 public override Expression CreateExpressionTree (ResolveContext ec)
7080                 {
7081                         Error_PointerInsideExpressionTree (ec);
7082                         return null;
7083                 }
7084
7085                 protected override Expression DoResolve (ResolveContext ec)
7086                 {
7087                         TypeExpr texpr = QueriedType.ResolveAsTypeTerminal (ec, false);
7088                         if (texpr == null)
7089                                 return null;
7090
7091                         type_queried = texpr.Type;
7092                         if (TypeManager.IsEnumType (type_queried))
7093                                 type_queried = EnumSpec.GetUnderlyingType (type_queried);
7094
7095                         int size_of = GetTypeSize (type_queried);
7096                         if (size_of > 0) {
7097                                 return new IntConstant (size_of, loc).Resolve (ec);
7098                         }
7099
7100                         if (!TypeManager.VerifyUnmanaged (ec.Compiler, type_queried, loc)){
7101                                 return null;
7102                         }
7103
7104                         if (!ec.IsUnsafe) {
7105                                 ec.Report.Error (233, loc,
7106                                         "`{0}' does not have a predefined size, therefore sizeof can only be used in an unsafe context (consider using System.Runtime.InteropServices.Marshal.SizeOf)",
7107                                         TypeManager.CSharpName (type_queried));
7108                         }
7109
7110                         type = TypeManager.int32_type;
7111                         eclass = ExprClass.Value;
7112                         return this;
7113                 }
7114
7115                 public override void Emit (EmitContext ec)
7116                 {
7117                         ec.Emit (OpCodes.Sizeof, type_queried);
7118                 }
7119
7120                 protected override void CloneTo (CloneContext clonectx, Expression t)
7121                 {
7122                 }
7123         }
7124
7125         /// <summary>
7126         ///   Implements the qualified-alias-member (::) expression.
7127         /// </summary>
7128         public class QualifiedAliasMember : MemberAccess
7129         {
7130                 readonly string alias;
7131                 public static readonly string GlobalAlias = "global";
7132
7133                 public QualifiedAliasMember (string alias, string identifier, Location l)
7134                         : base (null, identifier, l)
7135                 {
7136                         this.alias = alias;
7137                 }
7138
7139                 public QualifiedAliasMember (string alias, string identifier, TypeArguments targs, Location l)
7140                         : base (null, identifier, targs, l)
7141                 {
7142                         this.alias = alias;
7143                 }
7144
7145                 public QualifiedAliasMember (string alias, string identifier, int arity, Location l)
7146                         : base (null, identifier, arity, l)
7147                 {
7148                         this.alias = alias;
7149                 }
7150
7151                 public override FullNamedExpression ResolveAsTypeStep (IMemberContext ec, bool silent)
7152                 {
7153                         if (alias == GlobalAlias) {
7154                                 expr = GlobalRootNamespace.Instance;
7155                                 return base.ResolveAsTypeStep (ec, silent);
7156                         }
7157
7158                         int errors = ec.Compiler.Report.Errors;
7159                         expr = ec.LookupNamespaceAlias (alias);
7160                         if (expr == null) {
7161                                 if (errors == ec.Compiler.Report.Errors)
7162                                         ec.Compiler.Report.Error (432, loc, "Alias `{0}' not found", alias);
7163                                 return null;
7164                         }
7165
7166                         FullNamedExpression fne = base.ResolveAsTypeStep (ec, silent);
7167                         if (fne == null)
7168                                 return null;
7169
7170                         if (expr.eclass == ExprClass.Type) {
7171                                 if (!silent) {
7172                                         ec.Compiler.Report.Error (431, loc,
7173                                                 "Alias `{0}' cannot be used with '::' since it denotes a type. Consider replacing '::' with '.'", alias);
7174                                 }
7175                                 return null;
7176                         }
7177
7178                         return fne;
7179                 }
7180
7181                 protected override Expression DoResolve (ResolveContext ec)
7182                 {
7183                         return ResolveAsTypeStep (ec, false);
7184                 }
7185
7186                 protected override void Error_IdentifierNotFound (IMemberContext rc, TypeSpec expr_type, string identifier)
7187                 {
7188                         rc.Compiler.Report.Error (687, loc,
7189                                 "A namespace alias qualifier `{0}' did not resolve to a namespace or a type",
7190                                 GetSignatureForError ());
7191                 }
7192
7193                 public override string GetSignatureForError ()
7194                 {
7195                         string name = Name;
7196                         if (targs != null) {
7197                                 name = Name + "<" + targs.GetSignatureForError () + ">";
7198                         }
7199
7200                         return alias + "::" + name;
7201                 }
7202
7203                 protected override void CloneTo (CloneContext clonectx, Expression t)
7204                 {
7205                         // Nothing
7206                 }
7207         }
7208
7209         /// <summary>
7210         ///   Implements the member access expression
7211         /// </summary>
7212         public class MemberAccess : ATypeNameExpression {
7213                 protected Expression expr;
7214
7215                 public MemberAccess (Expression expr, string id)
7216                         : base (id, expr.Location)
7217                 {
7218                         this.expr = expr;
7219                 }
7220
7221                 public MemberAccess (Expression expr, string identifier, Location loc)
7222                         : base (identifier, loc)
7223                 {
7224                         this.expr = expr;
7225                 }
7226
7227                 public MemberAccess (Expression expr, string identifier, TypeArguments args, Location loc)
7228                         : base (identifier, args, loc)
7229                 {
7230                         this.expr = expr;
7231                 }
7232
7233                 public MemberAccess (Expression expr, string identifier, int arity, Location loc)
7234                         : base (identifier, arity, loc)
7235                 {
7236                         this.expr = expr;
7237                 }
7238
7239                 Expression DoResolve (ResolveContext ec, Expression right_side)
7240                 {
7241                         if (type != null)
7242                                 throw new Exception ();
7243
7244                         //
7245                         // Resolve the expression with flow analysis turned off, we'll do the definite
7246                         // assignment checks later.  This is because we don't know yet what the expression
7247                         // will resolve to - it may resolve to a FieldExpr and in this case we must do the
7248                         // definite assignment check on the actual field and not on the whole struct.
7249                         //
7250
7251                         SimpleName original = expr as SimpleName;
7252                         Expression expr_resolved;
7253                         const ResolveFlags flags = ResolveFlags.VariableOrValue | ResolveFlags.Type;
7254
7255                         using (ec.Set (ResolveContext.Options.OmitStructFlowAnalysis)) {
7256                                 if (original != null) {
7257                                         expr_resolved = original.DoResolve (ec, true);
7258                                         if (expr_resolved != null) {
7259                                                 // Ugly, simulate skipped Resolve
7260                                                 if (expr_resolved is ConstantExpr) {
7261                                                         expr_resolved = expr_resolved.Resolve (ec);
7262                                                 } else if (expr_resolved is FieldExpr || expr_resolved is PropertyExpr) {
7263                                                         // nothing yet
7264                                                 } else if ((flags & expr_resolved.ExprClassToResolveFlags) == 0) {
7265                                                         expr_resolved.Error_UnexpectedKind (ec, flags, expr.Location);
7266                                                         expr_resolved = null;
7267                                                 }
7268                                         }
7269                                 } else {
7270                                         expr_resolved = expr.Resolve (ec, flags);
7271                                 }
7272                         }
7273
7274                         if (expr_resolved == null)
7275                                 return null;
7276
7277                         Namespace ns = expr_resolved as Namespace;
7278                         if (ns != null) {
7279                                 FullNamedExpression retval = ns.Lookup (ec.Compiler, Name, Arity, loc);
7280
7281                                 if (retval == null)
7282                                         ns.Error_NamespaceDoesNotExist (loc, Name, Arity, ec);
7283                                 else if (HasTypeArguments)
7284                                         retval = new GenericTypeExpr (retval.Type, targs, loc).ResolveAsTypeStep (ec, false);
7285
7286                                 expr = expr_resolved;
7287                                 return retval;
7288                         }
7289
7290                         TypeSpec expr_type = expr_resolved.Type;
7291                         if (expr_type == InternalType.Dynamic) {
7292                                 Arguments args = new Arguments (1);
7293                                 args.Add (new Argument (expr_resolved.Resolve (ec)));
7294                                 expr = new DynamicMemberBinder (Name, args, loc);
7295                                 if (right_side != null)
7296                                         return expr.DoResolveLValue (ec, right_side);
7297
7298                                 return expr.Resolve (ec);
7299                         }
7300
7301
7302                         const MemberKind dot_kinds = MemberKind.Class | MemberKind.Struct | MemberKind.Delegate | MemberKind.Enum |
7303                                 MemberKind.Interface | MemberKind.TypeParameter | MemberKind.ArrayType;
7304
7305                         if ((expr_type.Kind & dot_kinds) == 0 || expr_type == TypeManager.void_type) {
7306                                 Unary.Error_OperatorCannotBeApplied (ec, loc, ".", expr_type);
7307                                 return null;
7308                         }
7309
7310                         var arity = HasTypeArguments ? targs.Count : -1;
7311
7312                         var member_lookup = MemberLookup (ec.Compiler,
7313                                 ec.CurrentType, expr_type, expr_type, Name, arity, BindingRestriction.DefaultMemberLookup, loc);
7314
7315                         if (member_lookup == null) {
7316                                 expr = expr_resolved.Resolve (ec);
7317
7318                                 ExprClass expr_eclass = expr.eclass;
7319
7320                                 //
7321                                 // Extension methods are not allowed on all expression types
7322                                 //
7323                                 if (expr_eclass == ExprClass.Value || expr_eclass == ExprClass.Variable ||
7324                                         expr_eclass == ExprClass.IndexerAccess || expr_eclass == ExprClass.PropertyAccess ||
7325                                         expr_eclass == ExprClass.EventAccess) {
7326                                         ExtensionMethodGroupExpr ex_method_lookup = ec.LookupExtensionMethod (expr_type, Name, arity, loc);
7327                                         if (ex_method_lookup != null) {
7328                                                 ex_method_lookup.ExtensionExpression = expr;
7329
7330                                                 if (HasTypeArguments) {
7331                                                         if (!targs.Resolve (ec))
7332                                                                 return null;
7333
7334                                                         ex_method_lookup.SetTypeArguments (ec, targs);
7335                                                 }
7336
7337                                                 return ex_method_lookup.Resolve (ec);
7338                                         }
7339                                 }
7340
7341                                 member_lookup = Error_MemberLookupFailed (ec,
7342                                         ec.CurrentType, expr_type, expr_type, Name, arity, null,
7343                                         MemberKind.All, BindingRestriction.AccessibleOnly);
7344                                 if (member_lookup == null)
7345                                         return null;
7346                         }
7347
7348                         expr = expr_resolved;
7349
7350                         MemberExpr me;
7351                         TypeExpr texpr = member_lookup as TypeExpr;
7352                         if (texpr != null) {
7353                                 if (!(expr_resolved is TypeExpr)) {
7354                                         me = expr_resolved as MemberExpr;
7355                                         if (me == null || me.ProbeIdenticalTypeName (ec, expr_resolved, original) == expr_resolved) {
7356                                                 ec.Report.Error (572, loc, "`{0}': cannot reference a type through an expression; try `{1}' instead",
7357                                                         Name, member_lookup.GetSignatureForError ());
7358                                                 return null;
7359                                         }
7360                                 }
7361
7362                                 if (!texpr.CheckAccessLevel (ec.MemberContext)) {
7363                                         ec.Report.SymbolRelatedToPreviousError (member_lookup.Type);
7364                                         ErrorIsInaccesible (loc, TypeManager.CSharpName (member_lookup.Type), ec.Report);
7365                                         return null;
7366                                 }
7367
7368                                 if (HasTypeArguments) {
7369                                         var ct = new GenericTypeExpr (member_lookup.Type, targs, loc);
7370                                         return ct.ResolveAsTypeStep (ec, false);
7371                                 }
7372
7373                                 return member_lookup;
7374                         }
7375
7376                         me = (MemberExpr) member_lookup;
7377
7378                         if (original != null && me.IsStatic)
7379                                 expr_resolved = me.ProbeIdenticalTypeName (ec, expr_resolved, original);
7380
7381                         me = me.ResolveMemberAccess (ec, expr_resolved, original);
7382
7383                         if (HasTypeArguments) {
7384                                 if (!targs.Resolve (ec))
7385                                         return null;
7386
7387                                 me.SetTypeArguments (ec, targs);
7388                         }
7389
7390                         if (original != null && (!TypeManager.IsValueType (expr_type) || me is PropertyExpr)) {
7391                                 if (me.IsInstance) {
7392                                         LocalVariableReference var = expr_resolved as LocalVariableReference;
7393                                         if (var != null && !var.VerifyAssigned (ec))
7394                                                 return null;
7395                                 }
7396                         }
7397
7398                         // The following DoResolve/DoResolveLValue will do the definite assignment
7399                         // check.
7400
7401                         if (right_side != null)
7402                                 return me.DoResolveLValue (ec, right_side);
7403                         else
7404                                 return me.Resolve (ec);
7405                 }
7406
7407                 protected override Expression DoResolve (ResolveContext ec)
7408                 {
7409                         return DoResolve (ec, null);
7410                 }
7411
7412                 public override Expression DoResolveLValue (ResolveContext ec, Expression right_side)
7413                 {
7414                         return DoResolve (ec, right_side);
7415                 }
7416
7417                 public override FullNamedExpression ResolveAsTypeStep (IMemberContext ec, bool silent)
7418                 {
7419                         return ResolveNamespaceOrType (ec, silent);
7420                 }
7421
7422                 public FullNamedExpression ResolveNamespaceOrType (IMemberContext rc, bool silent)
7423                 {
7424                         FullNamedExpression expr_resolved = expr.ResolveAsTypeStep (rc, silent);
7425
7426                         if (expr_resolved == null)
7427                                 return null;
7428
7429                         Namespace ns = expr_resolved as Namespace;
7430                         if (ns != null) {
7431                                 FullNamedExpression retval = ns.Lookup (rc.Compiler, Name, Arity, loc);
7432
7433                                 if (retval == null) {
7434                                         if (!silent)
7435                                                 ns.Error_NamespaceDoesNotExist (loc, Name, Arity, rc);
7436                                 } else if (HasTypeArguments) {
7437                                         retval = new GenericTypeExpr (retval.Type, targs, loc).ResolveAsTypeStep (rc, silent);
7438                                 }
7439
7440                                 return retval;
7441                         }
7442
7443                         TypeExpr tnew_expr = expr_resolved.ResolveAsTypeTerminal (rc, false);
7444                         if (tnew_expr == null)
7445                                 return null;
7446
7447                         TypeSpec expr_type = tnew_expr.Type;
7448                         if (TypeManager.IsGenericParameter (expr_type)) {
7449                                 rc.Compiler.Report.Error (704, loc, "A nested type cannot be specified through a type parameter `{0}'",
7450                                         tnew_expr.GetSignatureForError ());
7451                                 return null;
7452                         }
7453
7454                         var nested = MemberCache.FindNestedType (expr_type, Name, Arity);
7455                         if (nested == null) {
7456                                 if (silent)
7457                                         return null;
7458
7459                                 Error_IdentifierNotFound (rc, expr_type, Name);
7460                                 return null;
7461                         }
7462
7463                         bool extra_check;
7464                         if (!IsMemberAccessible (rc.CurrentType ?? InternalType.FakeInternalType, nested, out extra_check)) {
7465                                 ErrorIsInaccesible (loc, nested.GetSignatureForError (), rc.Compiler.Report);
7466                         }
7467
7468                         TypeExpr texpr;
7469                         if (HasTypeArguments) {
7470                                 texpr = new GenericTypeExpr (nested, targs, loc);
7471                         } else {
7472                                 texpr = new TypeExpression (nested, loc);
7473                         }
7474
7475                         return texpr.ResolveAsTypeStep (rc, false);
7476                 }
7477
7478                 protected virtual void Error_IdentifierNotFound (IMemberContext rc, TypeSpec expr_type, string identifier)
7479                 {
7480                         var nested = MemberCache.FindNestedType (expr_type, Name, -System.Math.Max (1, Arity));
7481
7482                         if (nested != null) {
7483                                 Error_TypeArgumentsCannotBeUsed (rc.Compiler.Report, expr.Location, nested, Arity);
7484                                 return;
7485                         }
7486
7487                         var member_lookup = MemberLookup (rc.Compiler,
7488                                 rc.CurrentType, expr_type, expr_type, identifier, -1,
7489                                         MemberKind.All, BindingRestriction.None, loc);
7490
7491                         if (member_lookup == null) {
7492                                 rc.Compiler.Report.Error (426, loc, "The nested type `{0}' does not exist in the type `{1}'",
7493                                                   Name, expr_type.GetSignatureForError ());
7494                         } else {
7495                                 // TODO: Report.SymbolRelatedToPreviousError
7496                                 member_lookup.Error_UnexpectedKind (rc.Compiler.Report, null, "type", loc);
7497                         }
7498                 }
7499
7500                 protected override void Error_TypeDoesNotContainDefinition (ResolveContext ec, TypeSpec type, string name)
7501                 {
7502                         if (RootContext.Version > LanguageVersion.ISO_2 && !ec.Compiler.IsRuntimeBinder &&
7503                                 ((expr.eclass & (ExprClass.Value | ExprClass.Variable)) != 0)) {
7504                                 ec.Report.Error (1061, loc, "Type `{0}' does not contain a definition for `{1}' and no " +
7505                                         "extension method `{1}' of type `{0}' could be found " +
7506                                         "(are you missing a using directive or an assembly reference?)",
7507                                         TypeManager.CSharpName (type), name);
7508                                 return;
7509                         }
7510
7511                         base.Error_TypeDoesNotContainDefinition (ec, type, name);
7512                 }
7513
7514                 public override string GetSignatureForError ()
7515                 {
7516                         return expr.GetSignatureForError () + "." + base.GetSignatureForError ();
7517                 }
7518
7519                 public Expression Left {
7520                         get {
7521                                 return expr;
7522                         }
7523                 }
7524
7525                 protected override void CloneTo (CloneContext clonectx, Expression t)
7526                 {
7527                         MemberAccess target = (MemberAccess) t;
7528
7529                         target.expr = expr.Clone (clonectx);
7530                 }
7531         }
7532
7533         /// <summary>
7534         ///   Implements checked expressions
7535         /// </summary>
7536         public class CheckedExpr : Expression {
7537
7538                 public Expression Expr;
7539
7540                 public CheckedExpr (Expression e, Location l)
7541                 {
7542                         Expr = e;
7543                         loc = l;
7544                 }
7545
7546                 public override Expression CreateExpressionTree (ResolveContext ec)
7547                 {
7548                         using (ec.With (ResolveContext.Options.AllCheckStateFlags, true))
7549                                 return Expr.CreateExpressionTree (ec);
7550                 }
7551
7552                 protected override Expression DoResolve (ResolveContext ec)
7553                 {
7554                         using (ec.With (ResolveContext.Options.AllCheckStateFlags, true))
7555                                 Expr = Expr.Resolve (ec);
7556
7557                         if (Expr == null)
7558                                 return null;
7559
7560                         if (Expr is Constant || Expr is MethodGroupExpr || Expr is AnonymousMethodExpression || Expr is DefaultValueExpression)
7561                                 return Expr;
7562
7563                         eclass = Expr.eclass;
7564                         type = Expr.Type;
7565                         return this;
7566                 }
7567
7568                 public override void Emit (EmitContext ec)
7569                 {
7570                         using (ec.With (EmitContext.Options.AllCheckStateFlags, true))
7571                                 Expr.Emit (ec);
7572                 }
7573
7574                 public override void EmitBranchable (EmitContext ec, Label target, bool on_true)
7575                 {
7576                         using (ec.With (EmitContext.Options.AllCheckStateFlags, true))
7577                                 Expr.EmitBranchable (ec, target, on_true);
7578                 }
7579
7580                 public override SLE.Expression MakeExpression (BuilderContext ctx)
7581                 {
7582                         using (ctx.With (BuilderContext.Options.AllCheckStateFlags, true)) {
7583                                 return Expr.MakeExpression (ctx);
7584                         }
7585                 }
7586
7587                 protected override void CloneTo (CloneContext clonectx, Expression t)
7588                 {
7589                         CheckedExpr target = (CheckedExpr) t;
7590
7591                         target.Expr = Expr.Clone (clonectx);
7592                 }
7593         }
7594
7595         /// <summary>
7596         ///   Implements the unchecked expression
7597         /// </summary>
7598         public class UnCheckedExpr : Expression {
7599
7600                 public Expression Expr;
7601
7602                 public UnCheckedExpr (Expression e, Location l)
7603                 {
7604                         Expr = e;
7605                         loc = l;
7606                 }
7607
7608                 public override Expression CreateExpressionTree (ResolveContext ec)
7609                 {
7610                         using (ec.With (ResolveContext.Options.AllCheckStateFlags, false))
7611                                 return Expr.CreateExpressionTree (ec);
7612                 }
7613
7614                 protected override Expression DoResolve (ResolveContext ec)
7615                 {
7616                         using (ec.With (ResolveContext.Options.AllCheckStateFlags, false))
7617                                 Expr = Expr.Resolve (ec);
7618
7619                         if (Expr == null)
7620                                 return null;
7621
7622                         if (Expr is Constant || Expr is MethodGroupExpr || Expr is AnonymousMethodExpression || Expr is DefaultValueExpression)
7623                                 return Expr;
7624
7625                         eclass = Expr.eclass;
7626                         type = Expr.Type;
7627                         return this;
7628                 }
7629
7630                 public override void Emit (EmitContext ec)
7631                 {
7632                         using (ec.With (EmitContext.Options.AllCheckStateFlags, false))
7633                                 Expr.Emit (ec);
7634                 }
7635
7636                 public override void EmitBranchable (EmitContext ec, Label target, bool on_true)
7637                 {
7638                         using (ec.With (EmitContext.Options.AllCheckStateFlags, false))
7639                                 Expr.EmitBranchable (ec, target, on_true);
7640                 }
7641
7642                 protected override void CloneTo (CloneContext clonectx, Expression t)
7643                 {
7644                         UnCheckedExpr target = (UnCheckedExpr) t;
7645
7646                         target.Expr = Expr.Clone (clonectx);
7647                 }
7648         }
7649
7650         /// <summary>
7651         ///   An Element Access expression.
7652         ///
7653         ///   During semantic analysis these are transformed into
7654         ///   IndexerAccess, ArrayAccess or a PointerArithmetic.
7655         /// </summary>
7656         public class ElementAccess : Expression {
7657                 public Arguments Arguments;
7658                 public Expression Expr;
7659
7660                 public ElementAccess (Expression e, Arguments args, Location loc)
7661                 {
7662                         Expr = e;
7663                         this.loc = loc;
7664                         this.Arguments = args;
7665                 }
7666
7667                 public override Expression CreateExpressionTree (ResolveContext ec)
7668                 {
7669                         Arguments args = Arguments.CreateForExpressionTree (ec, Arguments,
7670                                 Expr.CreateExpressionTree (ec));
7671
7672                         return CreateExpressionFactoryCall (ec, "ArrayIndex", args);
7673                 }
7674
7675                 Expression MakePointerAccess (ResolveContext ec, TypeSpec t)
7676                 {
7677                         if (Arguments.Count != 1){
7678                                 ec.Report.Error (196, loc, "A pointer must be indexed by only one value");
7679                                 return null;
7680                         }
7681
7682                         if (Arguments [0] is NamedArgument)
7683                                 Error_NamedArgument ((NamedArgument) Arguments[0], ec.Report);
7684
7685                         Expression p = new PointerArithmetic (Binary.Operator.Addition, Expr, Arguments [0].Expr.Resolve (ec), t, loc);
7686                         return new Indirection (p, loc).Resolve (ec);
7687                 }
7688
7689                 protected override Expression DoResolve (ResolveContext ec)
7690                 {
7691                         Expr = Expr.Resolve (ec);
7692                         if (Expr == null)
7693                                 return null;
7694
7695                         //
7696                         // We perform some simple tests, and then to "split" the emit and store
7697                         // code we create an instance of a different class, and return that.
7698                         //
7699                         // I am experimenting with this pattern.
7700                         //
7701                         TypeSpec t = Expr.Type;
7702
7703                         if (t == TypeManager.array_type){
7704                                 ec.Report.Error (21, loc, "Cannot apply indexing with [] to an expression of type `System.Array'");
7705                                 return null;
7706                         }
7707
7708                         if (t.IsArray)
7709                                 return (new ArrayAccess (this, loc)).Resolve (ec);
7710                         if (t.IsPointer)
7711                                 return MakePointerAccess (ec, t);
7712
7713                         FieldExpr fe = Expr as FieldExpr;
7714                         if (fe != null) {
7715                                 var ff = fe.Spec as FixedFieldSpec;
7716                                 if (ff != null) {
7717                                         return MakePointerAccess (ec, ff.ElementType);
7718                                 }
7719                         }
7720                         return (new IndexerAccess (this, loc)).Resolve (ec);
7721                 }
7722
7723                 public override Expression DoResolveLValue (ResolveContext ec, Expression right_side)
7724                 {
7725                         Expr = Expr.Resolve (ec);
7726                         if (Expr == null)
7727                                 return null;
7728
7729                         type = Expr.Type;
7730                         if (type.IsArray)
7731                                 return (new ArrayAccess (this, loc)).DoResolveLValue (ec, right_side);
7732
7733                         if (type.IsPointer)
7734                                 return MakePointerAccess (ec, type);
7735
7736                         if (Expr.eclass != ExprClass.Variable && TypeManager.IsStruct (type))
7737                                 Error_CannotModifyIntermediateExpressionValue (ec);
7738
7739                         return (new IndexerAccess (this, loc)).DoResolveLValue (ec, right_side);
7740                 }
7741
7742                 public override void Emit (EmitContext ec)
7743                 {
7744                         throw new Exception ("Should never be reached");
7745                 }
7746
7747                 public static void Error_NamedArgument (NamedArgument na, Report Report)
7748                 {
7749                         Report.Error (1742, na.Location, "An element access expression cannot use named argument");
7750                 }
7751
7752                 public override string GetSignatureForError ()
7753                 {
7754                         return Expr.GetSignatureForError ();
7755                 }
7756
7757                 protected override void CloneTo (CloneContext clonectx, Expression t)
7758                 {
7759                         ElementAccess target = (ElementAccess) t;
7760
7761                         target.Expr = Expr.Clone (clonectx);
7762                         if (Arguments != null)
7763                                 target.Arguments = Arguments.Clone (clonectx);
7764                 }
7765         }
7766
7767         /// <summary>
7768         ///   Implements array access
7769         /// </summary>
7770         public class ArrayAccess : Expression, IDynamicAssign, IMemoryLocation {
7771                 //
7772                 // Points to our "data" repository
7773                 //
7774                 ElementAccess ea;
7775
7776                 LocalTemporary temp;
7777
7778                 bool prepared;
7779
7780                 public ArrayAccess (ElementAccess ea_data, Location l)
7781                 {
7782                         ea = ea_data;
7783                         loc = l;
7784                 }
7785
7786                 public override Expression CreateExpressionTree (ResolveContext ec)
7787                 {
7788                         return ea.CreateExpressionTree (ec);
7789                 }
7790
7791                 public override Expression DoResolveLValue (ResolveContext ec, Expression right_side)
7792                 {
7793                         return DoResolve (ec);
7794                 }
7795
7796                 protected override Expression DoResolve (ResolveContext ec)
7797                 {
7798                         // dynamic is used per argument in ConvertExpressionToArrayIndex case
7799                         bool dynamic;
7800                         ea.Arguments.Resolve (ec, out dynamic);
7801
7802                         var ac = ea.Expr.Type as ArrayContainer;
7803                         int rank = ea.Arguments.Count;
7804                         if (ac.Rank != rank) {
7805                                 ec.Report.Error (22, ea.Location, "Wrong number of indexes `{0}' inside [], expected `{1}'",
7806                                           rank.ToString (), ac.Rank.ToString ());
7807                                 return null;
7808                         }
7809
7810                         type = ac.Element;
7811                         if (type.IsPointer && !ec.IsUnsafe) {
7812                                 UnsafeError (ec, ea.Location);
7813                         }
7814
7815                         foreach (Argument a in ea.Arguments) {
7816                                 if (a is NamedArgument)
7817                                         ElementAccess.Error_NamedArgument ((NamedArgument) a, ec.Report);
7818
7819                                 a.Expr = ConvertExpressionToArrayIndex (ec, a.Expr);
7820                         }
7821
7822                         eclass = ExprClass.Variable;
7823
7824                         return this;
7825                 }
7826
7827                 protected override void Error_NegativeArrayIndex (ResolveContext ec, Location loc)
7828                 {
7829                         ec.Report.Warning (251, 2, loc, "Indexing an array with a negative index (array indices always start at zero)");
7830                 }
7831
7832                 //
7833                 // Load the array arguments into the stack.
7834                 //
7835                 void LoadArrayAndArguments (EmitContext ec)
7836                 {
7837                         ea.Expr.Emit (ec);
7838
7839                         for (int i = 0; i < ea.Arguments.Count; ++i) {
7840                                 ea.Arguments [i].Emit (ec);
7841                         }
7842                 }
7843
7844                 public void Emit (EmitContext ec, bool leave_copy)
7845                 {
7846                         var ac = ea.Expr.Type as ArrayContainer;
7847
7848                         if (prepared) {
7849                                 ec.EmitLoadFromPtr (type);
7850                         } else {
7851                                 LoadArrayAndArguments (ec);
7852                                 ec.EmitArrayLoad (ac);
7853                         }
7854
7855                         if (leave_copy) {
7856                                 ec.Emit (OpCodes.Dup);
7857                                 temp = new LocalTemporary (this.type);
7858                                 temp.Store (ec);
7859                         }
7860                 }
7861
7862                 public override void Emit (EmitContext ec)
7863                 {
7864                         Emit (ec, false);
7865                 }
7866
7867                 public void EmitAssign (EmitContext ec, Expression source, bool leave_copy, bool prepare_for_load)
7868                 {
7869                         var ac = (ArrayContainer) ea.Expr.Type;
7870                         TypeSpec t = source.Type;
7871                         prepared = prepare_for_load;
7872
7873                         if (prepared) {
7874                                 AddressOf (ec, AddressOp.LoadStore);
7875                                 ec.Emit (OpCodes.Dup);
7876                         } else {
7877                                 LoadArrayAndArguments (ec);
7878
7879                                 //
7880                                 // If we are dealing with a struct, get the
7881                                 // address of it, so we can store it.
7882                                 //
7883                                 // The stobj opcode used by value types will need
7884                                 // an address on the stack, not really an array/array
7885                                 // pair
7886                                 //
7887                                 if (ac.Rank == 1 && TypeManager.IsStruct (t) &&
7888                                         (!TypeManager.IsBuiltinOrEnum (t) ||
7889                                          t == TypeManager.decimal_type)) {
7890
7891                                         ec.Emit (OpCodes.Ldelema, t);
7892                                 }
7893                         }
7894
7895                         source.Emit (ec);
7896                         if (leave_copy) {
7897                                 ec.Emit (OpCodes.Dup);
7898                                 temp = new LocalTemporary (this.type);
7899                                 temp.Store (ec);
7900                         }
7901
7902                         if (prepared) {
7903                                 ec.EmitStoreFromPtr (t);
7904                         } else {
7905                                 ec.EmitArrayStore (ac);
7906                         }
7907
7908                         if (temp != null) {
7909                                 temp.Emit (ec);
7910                                 temp.Release (ec);
7911                         }
7912                 }
7913
7914                 public void EmitNew (EmitContext ec, New source, bool leave_copy)
7915                 {
7916                         if (!source.Emit (ec, this)) {
7917                                 if (leave_copy)
7918                                         throw new NotImplementedException ();
7919
7920                                 return;
7921                         }
7922
7923                         throw new NotImplementedException ();
7924                 }
7925
7926                 public void AddressOf (EmitContext ec, AddressOp mode)
7927                 {
7928                         var ac = (ArrayContainer) ea.Expr.Type;
7929
7930                         LoadArrayAndArguments (ec);
7931                         ec.EmitArrayAddress (ac);
7932                 }
7933
7934 #if NET_4_0
7935                 public SLE.Expression MakeAssignExpression (BuilderContext ctx)
7936                 {
7937                         return SLE.Expression.ArrayAccess (
7938                                 ea.Expr.MakeExpression (ctx),
7939                                 Arguments.MakeExpression (ea.Arguments, ctx));
7940                 }
7941 #endif
7942
7943                 public override SLE.Expression MakeExpression (BuilderContext ctx)
7944                 {
7945                         return SLE.Expression.ArrayIndex (
7946                                 ea.Expr.MakeExpression (ctx),
7947                                 Arguments.MakeExpression (ea.Arguments, ctx));
7948                 }
7949         }
7950
7951         /// <summary>
7952         ///   Expressions that represent an indexer call.
7953         /// </summary>
7954         class IndexerAccess : Expression, IDynamicAssign
7955         {
7956                 class IndexerMethodGroupExpr : MethodGroupExpr
7957                 {
7958                         IEnumerable<IndexerSpec> candidates;
7959
7960                         public IndexerMethodGroupExpr (IEnumerable<IndexerSpec> indexers, Location loc)
7961                                 : base (FilterAccessors (indexers).ToList (), null, loc)
7962                         {
7963                                 candidates = indexers;
7964                         }
7965
7966                         public IndexerSpec BestIndexer ()
7967                         {
7968                                 return MemberCache.FindIndexers (BestCandidate.DeclaringType, BindingRestriction.None).
7969                                         Where (l =>
7970                                                 (l.HasGet && l.Get.MemberDefinition == BestCandidate.MemberDefinition) ||
7971                                                 (l.HasSet && l.Set.MemberDefinition == BestCandidate.MemberDefinition)).First ();
7972                         }
7973
7974                         static IEnumerable<MemberSpec> FilterAccessors (IEnumerable<IndexerSpec> indexers)
7975                         {
7976                                 foreach (IndexerSpec i in indexers) {
7977                                         if (i.HasGet)
7978                                                 yield return i.Get;
7979                                         else
7980                                                 yield return i.Set;
7981                                 }
7982                         }
7983
7984                         protected override IList<MemberSpec> GetBaseTypeMethods (ResolveContext rc, TypeSpec type)
7985                         {
7986                                 candidates = GetIndexersForType (type);
7987                                 if (candidates == null)
7988                                         return null;
7989
7990                                 return FilterAccessors (candidates).ToList ();
7991                         }
7992
7993                         public override string Name {
7994                                 get {
7995                                         return "this";
7996                                 }
7997                         }
7998
7999                         protected override int GetApplicableParametersCount (MethodSpec method, AParametersCollection parameters)
8000                         {
8001                                 //
8002                                 // Here is the trick, decrease number of arguments by 1 when only
8003                                 // available property method is setter. This makes overload resolution
8004                                 // work correctly for indexers.
8005                                 //
8006
8007                                 if (method.Name [0] == 'g')
8008                                         return parameters.Count;
8009
8010                                 return parameters.Count - 1;
8011                         }
8012                 }
8013
8014                 //
8015                 // Points to our "data" repository
8016                 //
8017                 IndexerSpec spec;
8018                 bool prepared;
8019                 LocalTemporary temp;
8020                 LocalTemporary prepared_value;
8021                 Expression set_expr;
8022
8023                 protected TypeSpec indexer_type;
8024                 protected Expression instance_expr;
8025                 protected Arguments arguments;
8026
8027                 public IndexerAccess (ElementAccess ea, Location loc)
8028                 {
8029                         this.instance_expr = ea.Expr;
8030                         this.arguments = ea.Arguments;
8031                         this.loc = loc;
8032                 }
8033
8034                 static string GetAccessorName (bool isSet)
8035                 {
8036                         return isSet ? "set" : "get";
8037                 }
8038
8039                 public override Expression CreateExpressionTree (ResolveContext ec)
8040                 {
8041                         Arguments args = Arguments.CreateForExpressionTree (ec, arguments,
8042                                 instance_expr.CreateExpressionTree (ec),
8043                                 new TypeOfMethod (spec.Get, loc));
8044
8045                         return CreateExpressionFactoryCall (ec, "Call", args);
8046                 }
8047
8048                 static IEnumerable<IndexerSpec> GetIndexersForType (TypeSpec lookup_type)
8049                 {
8050                         return MemberCache.FindIndexers (lookup_type, BindingRestriction.AccessibleOnly | BindingRestriction.DefaultMemberLookup);
8051                 }
8052
8053                 protected override Expression DoResolve (ResolveContext ec)
8054                 {
8055                         return ResolveAccessor (ec, null);
8056                 }
8057
8058                 public override Expression DoResolveLValue (ResolveContext ec, Expression right_side)
8059                 {
8060                         if (right_side == EmptyExpression.OutAccess.Instance) {
8061                                 right_side.DoResolveLValue (ec, this);
8062                                 return null;
8063                         }
8064
8065                         // if the indexer returns a value type, and we try to set a field in it
8066                         if (right_side == EmptyExpression.LValueMemberAccess || right_side == EmptyExpression.LValueMemberOutAccess) {
8067                                 Error_CannotModifyIntermediateExpressionValue (ec);
8068                         }
8069
8070                         return ResolveAccessor (ec, right_side);
8071                 }
8072
8073                 Expression ResolveAccessor (ResolveContext ec, Expression right_side)
8074                 {
8075                         indexer_type = instance_expr.Type;
8076
8077                         bool dynamic;
8078                         arguments.Resolve (ec, out dynamic);
8079
8080                         if (indexer_type == InternalType.Dynamic) {
8081                                 dynamic = true;
8082                         } else {
8083                                 var ilist = GetIndexersForType (indexer_type);
8084                                 if (ilist == null) {
8085                                         ec.Report.Error (21, loc, "Cannot apply indexing with [] to an expression of type `{0}'",
8086                                                           TypeManager.CSharpName (indexer_type));
8087                                         return null;
8088                                 }
8089
8090                                 var mg = new IndexerMethodGroupExpr (ilist, loc) {
8091                                         InstanceExpression = instance_expr
8092                                 };
8093
8094                                 mg = mg.OverloadResolve (ec, ref arguments, false, loc) as IndexerMethodGroupExpr;
8095                                 if (mg == null)
8096                                         return null;
8097
8098                                 if (!dynamic)
8099                                         spec = mg.BestIndexer ();
8100                         }
8101
8102                         if (dynamic) {
8103                                 Arguments args = new Arguments (arguments.Count + 1);
8104                                 if (instance_expr is BaseThis) {
8105                                         ec.Report.Error (1972, loc, "The indexer base access cannot be dynamically dispatched. Consider casting the dynamic arguments or eliminating the base access");
8106                                 } else {
8107                                         args.Add (new Argument (instance_expr));
8108                                 }
8109                                 args.AddRange (arguments);
8110
8111                                 var expr = new DynamicIndexBinder (args, loc);
8112                                 if (right_side != null)
8113                                         return expr.ResolveLValue (ec, right_side);
8114
8115                                 return expr.Resolve (ec);
8116                         }
8117
8118                         type = spec.MemberType;
8119                         if (type.IsPointer && !ec.IsUnsafe)
8120                                 UnsafeError (ec, loc);
8121
8122                         MethodSpec accessor;
8123                         if (right_side == null) {
8124                                 accessor = spec.Get;
8125                         } else {
8126                                 accessor = spec.Set;
8127                                 if (!spec.HasSet && spec.HasGet) {
8128                                         ec.Report.SymbolRelatedToPreviousError (spec);
8129                                         ec.Report.Error (200, loc, "The read only property or indexer `{0}' cannot be assigned to",
8130                                                 spec.GetSignatureForError ());
8131                                         return null;
8132                                 }
8133
8134                                 set_expr = Convert.ImplicitConversion (ec, right_side, type, loc);
8135                         }
8136
8137                         if (accessor == null) {
8138                                 ec.Report.SymbolRelatedToPreviousError (spec);
8139                                 ec.Report.Error (154, loc, "The property or indexer `{0}' cannot be used in this context because it lacks a `{1}' accessor",
8140                                         spec.GetSignatureForError (), GetAccessorName (right_side != null));
8141                                 return null;
8142                         }
8143
8144                         //
8145                         // Only base will allow this invocation to happen.
8146                         //
8147                         if (spec.IsAbstract && instance_expr is BaseThis) {
8148                                 Error_CannotCallAbstractBase (ec, spec.GetSignatureForError ());
8149                         }
8150
8151                         bool must_do_cs1540_check;
8152                         if (!IsMemberAccessible (ec.CurrentType, accessor, out must_do_cs1540_check)) {
8153                                 if (spec.HasDifferentAccessibility) {
8154                                         ec.Report.SymbolRelatedToPreviousError (accessor);
8155                                         ec.Report.Error (271, loc, "The property or indexer `{0}' cannot be used in this context because a `{1}' accessor is inaccessible",
8156                                                 TypeManager.GetFullNameSignature (spec), GetAccessorName (right_side != null));
8157                                 } else {
8158                                         ec.Report.SymbolRelatedToPreviousError (spec);
8159                                         ErrorIsInaccesible (loc, TypeManager.GetFullNameSignature (spec), ec.Report);
8160                                 }
8161                         }
8162
8163                         instance_expr.CheckMarshalByRefAccess (ec);
8164
8165                         if (must_do_cs1540_check && (instance_expr != EmptyExpression.Null) &&
8166                                 !(instance_expr is BaseThis) &&
8167                             !TypeManager.IsInstantiationOfSameGenericType (instance_expr.Type, ec.CurrentType) &&
8168                             !TypeManager.IsNestedChildOf (ec.CurrentType, instance_expr.Type) &&
8169                             !TypeManager.IsSubclassOf (instance_expr.Type, ec.CurrentType)) {
8170                                 ec.Report.SymbolRelatedToPreviousError (accessor);
8171                                 Error_CannotAccessProtected (ec, loc, spec, instance_expr.Type, ec.CurrentType);
8172                                 return null;
8173                         }
8174
8175                         eclass = ExprClass.IndexerAccess;
8176                         return this;
8177                 }
8178
8179                 public override void Emit (EmitContext ec)
8180                 {
8181                         Emit (ec, false);
8182                 }
8183
8184                 public void Emit (EmitContext ec, bool leave_copy)
8185                 {
8186                         if (prepared) {
8187                                 prepared_value.Emit (ec);
8188                         } else {
8189                                 Invocation.EmitCall (ec, instance_expr, spec.Get,
8190                                         arguments, loc, false, false);
8191                         }
8192
8193                         if (leave_copy) {
8194                                 ec.Emit (OpCodes.Dup);
8195                                 temp = new LocalTemporary (Type);
8196                                 temp.Store (ec);
8197                         }
8198                 }
8199
8200                 //
8201                 // source is ignored, because we already have a copy of it from the
8202                 // LValue resolution and we have already constructed a pre-cached
8203                 // version of the arguments (ea.set_arguments);
8204                 //
8205                 public void EmitAssign (EmitContext ec, Expression source, bool leave_copy, bool prepare_for_load)
8206                 {
8207                         prepared = prepare_for_load;
8208                         Expression value = set_expr;
8209
8210                         if (prepared) {
8211                                 Invocation.EmitCall (ec, instance_expr, spec.Get,
8212                                         arguments, loc, true, false);
8213
8214                                 prepared_value = new LocalTemporary (type);
8215                                 prepared_value.Store (ec);
8216                                 source.Emit (ec);
8217                                 prepared_value.Release (ec);
8218
8219                                 if (leave_copy) {
8220                                         ec.Emit (OpCodes.Dup);
8221                                         temp = new LocalTemporary (Type);
8222                                         temp.Store (ec);
8223                                 }
8224                         } else if (leave_copy) {
8225                                 temp = new LocalTemporary (Type);
8226                                 source.Emit (ec);
8227                                 temp.Store (ec);
8228                                 value = temp;
8229                         }
8230
8231                         if (!prepared)
8232                                 arguments.Add (new Argument (value));
8233
8234                         Invocation.EmitCall (ec, instance_expr, spec.Set, arguments, loc, false, prepared);
8235
8236                         if (temp != null) {
8237                                 temp.Emit (ec);
8238                                 temp.Release (ec);
8239                         }
8240                 }
8241
8242                 public override string GetSignatureForError ()
8243                 {
8244                         return spec.GetSignatureForError ();
8245                 }
8246
8247 #if NET_4_0
8248                 public SLE.Expression MakeAssignExpression (BuilderContext ctx)
8249                 {
8250                         var value = new[] { set_expr.MakeExpression (ctx) };
8251                         var args = Arguments.MakeExpression (arguments, ctx).Concat (value);
8252
8253                         return SLE.Expression.Block (
8254                                         SLE.Expression.Call (instance_expr.MakeExpression (ctx), (MethodInfo) spec.Set.GetMetaInfo (), args),
8255                                         value [0]);
8256                 }
8257 #endif
8258
8259                 public override SLE.Expression MakeExpression (BuilderContext ctx)
8260                 {
8261                         var args = Arguments.MakeExpression (arguments, ctx);
8262                         return SLE.Expression.Call (instance_expr.MakeExpression (ctx), (MethodInfo) spec.Get.GetMetaInfo (), args);
8263                 }
8264
8265                 protected override void CloneTo (CloneContext clonectx, Expression t)
8266                 {
8267                         IndexerAccess target = (IndexerAccess) t;
8268
8269                         if (arguments != null)
8270                                 target.arguments = arguments.Clone (clonectx);
8271
8272                         if (instance_expr != null)
8273                                 target.instance_expr = instance_expr.Clone (clonectx);
8274                 }
8275         }
8276
8277         //
8278         // A base access expression
8279         //
8280         public class BaseThis : Expression
8281         {
8282                 public BaseThis (Location loc)
8283                 {
8284                         this.loc = loc;
8285                 }
8286
8287                 public BaseThis (TypeSpec type, Location loc)
8288                 {
8289                         this.type = type;
8290                         eclass = ExprClass.Variable;
8291                         this.loc = loc;
8292                 }
8293
8294                 public override Expression CreateExpressionTree (ResolveContext ec)
8295                 {
8296                         ec.Report.Error (831, loc, "An expression tree may not contain a base access");
8297
8298                         Arguments args = new Arguments (1);
8299                         args.Add (new Argument (this));
8300                         return CreateExpressionFactoryCall (ec, "Constant", args);
8301                 }
8302
8303                 protected override Expression DoResolve (ResolveContext rc)
8304                 {
8305                         type = rc.CurrentType.BaseType;
8306
8307                         if (!This.IsThisAvailable (rc, false)) {
8308                                 if (rc.IsStatic) {
8309                                         rc.Report.Error (1511, loc, "Keyword `base' is not available in a static method");
8310                                 } else {
8311                                         rc.Report.Error (1512, loc, "Keyword `base' is not available in the current context");
8312                                 }
8313                         }
8314
8315                         eclass = ExprClass.Variable;
8316                         return this;
8317                 }
8318
8319                 public override void Emit (EmitContext ec)
8320                 {
8321                         ec.Emit (OpCodes.Ldarg_0);
8322
8323                         if (ec.CurrentType.IsStruct) {
8324                                 ec.Emit (OpCodes.Ldobj, ec.CurrentType);
8325                                 ec.Emit (OpCodes.Box, ec.CurrentType);
8326                         }
8327                 }
8328         }
8329
8330         /// <summary>
8331         ///   This class exists solely to pass the Type around and to be a dummy
8332         ///   that can be passed to the conversion functions (this is used by
8333         ///   foreach implementation to typecast the object return value from
8334         ///   get_Current into the proper type.  All code has been generated and
8335         ///   we only care about the side effect conversions to be performed
8336         ///
8337         ///   This is also now used as a placeholder where a no-action expression
8338         ///   is needed (the `New' class).
8339         /// </summary>
8340         public class EmptyExpression : Expression {
8341                 public static readonly Expression Null = new EmptyExpression ();
8342
8343                 public class OutAccess : EmptyExpression
8344                 {
8345                         public static readonly OutAccess Instance = new OutAccess ();
8346
8347                         public override Expression DoResolveLValue (ResolveContext rc, Expression right_side)
8348                         {
8349                                 rc.Report.Error (206, right_side.Location,
8350                                         "A property, indexer or dynamic member access may not be passed as `ref' or `out' parameter");
8351
8352                                 return null;
8353                         }
8354                 }
8355
8356                 public static readonly EmptyExpression LValueMemberAccess = new EmptyExpression ();
8357                 public static readonly EmptyExpression LValueMemberOutAccess = new EmptyExpression ();
8358                 public static readonly EmptyExpression UnaryAddress = new EmptyExpression ();
8359
8360                 static EmptyExpression temp = new EmptyExpression ();
8361                 public static EmptyExpression Grab ()
8362                 {
8363                         EmptyExpression retval = temp == null ? new EmptyExpression () : temp;
8364                         temp = null;
8365                         return retval;
8366                 }
8367
8368                 public static void Release (EmptyExpression e)
8369                 {
8370                         temp = e;
8371                 }
8372
8373                 EmptyExpression ()
8374                 {
8375                         // FIXME: Don't set to object
8376                         type = TypeManager.object_type;
8377                         eclass = ExprClass.Value;
8378                         loc = Location.Null;
8379                 }
8380
8381                 public EmptyExpression (TypeSpec t)
8382                 {
8383                         type = t;
8384                         eclass = ExprClass.Value;
8385                         loc = Location.Null;
8386                 }
8387
8388                 public override Expression CreateExpressionTree (ResolveContext ec)
8389                 {
8390                         throw new NotSupportedException ("ET");
8391                 }
8392
8393                 protected override Expression DoResolve (ResolveContext ec)
8394                 {
8395                         return this;
8396                 }
8397
8398                 public override void Emit (EmitContext ec)
8399                 {
8400                         // nothing, as we only exist to not do anything.
8401                 }
8402
8403                 public override void EmitSideEffect (EmitContext ec)
8404                 {
8405                 }
8406
8407                 //
8408                 // This is just because we might want to reuse this bad boy
8409                 // instead of creating gazillions of EmptyExpressions.
8410                 // (CanImplicitConversion uses it)
8411                 //
8412                 public void SetType (TypeSpec t)
8413                 {
8414                         type = t;
8415                 }
8416         }
8417
8418         //
8419         // Empty statement expression
8420         //
8421         public sealed class EmptyExpressionStatement : ExpressionStatement
8422         {
8423                 public static readonly EmptyExpressionStatement Instance = new EmptyExpressionStatement ();
8424
8425                 private EmptyExpressionStatement ()
8426                 {
8427                         loc = Location.Null;
8428                 }
8429
8430                 public override Expression CreateExpressionTree (ResolveContext ec)
8431                 {
8432                         return null;
8433                 }
8434
8435                 public override void EmitStatement (EmitContext ec)
8436                 {
8437                         // Do nothing
8438                 }
8439
8440                 protected override Expression DoResolve (ResolveContext ec)
8441                 {
8442                         eclass = ExprClass.Value;
8443                         type = TypeManager.object_type;
8444                         return this;
8445                 }
8446
8447                 public override void Emit (EmitContext ec)
8448                 {
8449                         // Do nothing
8450                 }
8451         }
8452
8453         public class UserCast : Expression {
8454                 MethodSpec method;
8455                 Expression source;
8456
8457                 public UserCast (MethodSpec method, Expression source, Location l)
8458                 {
8459                         this.method = method;
8460                         this.source = source;
8461                         type = method.ReturnType;
8462                         loc = l;
8463                 }
8464
8465                 public Expression Source {
8466                         get {
8467                                 return source;
8468                         }
8469                 }
8470
8471                 public override Expression CreateExpressionTree (ResolveContext ec)
8472                 {
8473                         Arguments args = new Arguments (3);
8474                         args.Add (new Argument (source.CreateExpressionTree (ec)));
8475                         args.Add (new Argument (new TypeOf (new TypeExpression (type, loc), loc)));
8476                         args.Add (new Argument (new TypeOfMethod (method, loc)));
8477                         return CreateExpressionFactoryCall (ec, "Convert", args);
8478                 }
8479
8480                 protected override Expression DoResolve (ResolveContext ec)
8481                 {
8482                         ObsoleteAttribute oa = method.GetAttributeObsolete ();
8483                         if (oa != null)
8484                                 AttributeTester.Report_ObsoleteMessage (oa, GetSignatureForError (), loc, ec.Report);
8485
8486                         eclass = ExprClass.Value;
8487                         return this;
8488                 }
8489
8490                 public override void Emit (EmitContext ec)
8491                 {
8492                         source.Emit (ec);
8493                         ec.Emit (OpCodes.Call, method);
8494                 }
8495
8496                 public override string GetSignatureForError ()
8497                 {
8498                         return TypeManager.CSharpSignature (method);
8499                 }
8500
8501                 public override SLE.Expression MakeExpression (BuilderContext ctx)
8502                 {
8503                         return SLE.Expression.Convert (source.MakeExpression (ctx), type.GetMetaInfo (), (MethodInfo) method.GetMetaInfo ());
8504                 }
8505         }
8506
8507         //
8508         // Holds additional type specifiers like ?, *, []
8509         //
8510         public class ComposedTypeSpecifier
8511         {
8512                 public static readonly ComposedTypeSpecifier SingleDimension = new ComposedTypeSpecifier (1, Location.Null);
8513
8514                 public readonly int Dimension;
8515                 public readonly Location Location;
8516
8517                 public ComposedTypeSpecifier (int specifier, Location loc)
8518                 {
8519                         this.Dimension = specifier;
8520                         this.Location = loc;
8521                 }
8522
8523                 #region Properties
8524                 public bool IsNullable {
8525                         get {
8526                                 return Dimension == -1;
8527                         }
8528                 }
8529
8530                 public bool IsPointer {
8531                         get {
8532                                 return Dimension == -2;
8533                         }
8534                 }
8535
8536                 public ComposedTypeSpecifier Next { get; set; }
8537
8538                 #endregion
8539
8540                 public static ComposedTypeSpecifier CreateArrayDimension (int dimension, Location loc)
8541                 {
8542                         return new ComposedTypeSpecifier (dimension, loc);
8543                 }
8544
8545                 public static ComposedTypeSpecifier CreateNullable (Location loc)
8546                 {
8547                         return new ComposedTypeSpecifier (-1, loc);
8548                 }
8549
8550                 public static ComposedTypeSpecifier CreatePointer (Location loc)
8551                 {
8552                         return new ComposedTypeSpecifier (-2, loc);
8553                 }
8554
8555                 public string GetSignatureForError ()
8556                 {
8557                         string s =
8558                                 IsPointer ? "*" :
8559                                 IsNullable ? "?" :
8560                                 ArrayContainer.GetPostfixSignature (Dimension);
8561
8562                         return Next != null ? s + Next.GetSignatureForError () : s;
8563                 }
8564         }
8565
8566         // <summary>
8567         //   This class is used to "construct" the type during a typecast
8568         //   operation.  Since the Type.GetType class in .NET can parse
8569         //   the type specification, we just use this to construct the type
8570         //   one bit at a time.
8571         // </summary>
8572         public class ComposedCast : TypeExpr {
8573                 FullNamedExpression left;
8574                 ComposedTypeSpecifier spec;
8575
8576                 public ComposedCast (FullNamedExpression left, ComposedTypeSpecifier spec)
8577                 {
8578                         if (spec == null)
8579                                 throw new ArgumentNullException ("spec");
8580
8581                         this.left = left;
8582                         this.spec = spec;
8583                         this.loc = spec.Location;
8584                 }
8585
8586                 protected override TypeExpr DoResolveAsTypeStep (IMemberContext ec)
8587                 {
8588                         TypeExpr lexpr = left.ResolveAsTypeTerminal (ec, false);
8589                         if (lexpr == null)
8590                                 return null;
8591
8592                         type = lexpr.Type;
8593                         eclass = ExprClass.Type;
8594
8595                         var single_spec = spec;
8596
8597                         if (single_spec.IsNullable) {
8598                                 lexpr = new Nullable.NullableType (lexpr, loc);
8599                                 lexpr = lexpr.ResolveAsTypeTerminal (ec, false);
8600                                 if (lexpr != null)
8601                                         type = lexpr.Type;
8602
8603                                 single_spec = single_spec.Next;
8604                         } else if (single_spec.IsPointer) {
8605                                 if (!TypeManager.VerifyUnmanaged (ec.Compiler, type, loc))
8606                                         return null;
8607
8608                                 if (!ec.IsUnsafe) {
8609                                         UnsafeError (ec.Compiler.Report, loc);
8610                                 }
8611
8612                                 type = PointerContainer.MakeType (type);
8613                                 single_spec = single_spec.Next;
8614                         }
8615
8616                         if (single_spec != null && single_spec.Dimension > 0) {
8617                                 if (TypeManager.IsSpecialType (type)) {
8618                                         ec.Compiler.Report.Error (611, loc, "Array elements cannot be of type `{0}'", type.GetSignatureForError ());
8619                                 } else if (type.IsStatic) {
8620                                         ec.Compiler.Report.SymbolRelatedToPreviousError (type);
8621                                         ec.Compiler.Report.Error (719, loc, "Array elements cannot be of static type `{0}'",
8622                                                 type.GetSignatureForError ());
8623                                 } else {
8624                                         MakeArray (single_spec);
8625                                 }
8626                         }
8627
8628                         return this;
8629                 }
8630
8631                 void MakeArray (ComposedTypeSpecifier spec)
8632                 {
8633                         if (spec.Next != null)
8634                                 MakeArray (spec.Next);
8635
8636                         type = ArrayContainer.MakeType (type, spec.Dimension);
8637                 }
8638
8639                 public override string GetSignatureForError ()
8640                 {
8641                         return left.GetSignatureForError () + spec.GetSignatureForError ();
8642                 }
8643         }
8644
8645         public class FixedBufferPtr : Expression {
8646                 Expression array;
8647
8648                 public FixedBufferPtr (Expression array, TypeSpec array_type, Location l)
8649                 {
8650                         this.array = array;
8651                         this.loc = l;
8652
8653                         type = PointerContainer.MakeType (array_type);
8654                         eclass = ExprClass.Value;
8655                 }
8656
8657                 public override Expression CreateExpressionTree (ResolveContext ec)
8658                 {
8659                         Error_PointerInsideExpressionTree (ec);
8660                         return null;
8661                 }
8662
8663                 public override void Emit(EmitContext ec)
8664                 {
8665                         array.Emit (ec);
8666                 }
8667
8668                 protected override Expression DoResolve (ResolveContext ec)
8669                 {
8670                         //
8671                         // We are born fully resolved
8672                         //
8673                         return this;
8674                 }
8675         }
8676
8677
8678         //
8679         // This class is used to represent the address of an array, used
8680         // only by the Fixed statement, this generates "&a [0]" construct
8681         // for fixed (char *pa = a)
8682         //
8683         public class ArrayPtr : FixedBufferPtr {
8684                 TypeSpec array_type;
8685
8686                 public ArrayPtr (Expression array, TypeSpec array_type, Location l):
8687                         base (array, array_type, l)
8688                 {
8689                         this.array_type = array_type;
8690                 }
8691
8692                 public override void Emit (EmitContext ec)
8693                 {
8694                         base.Emit (ec);
8695
8696                         ec.EmitInt (0);
8697                         ec.Emit (OpCodes.Ldelema, array_type);
8698                 }
8699         }
8700
8701         //
8702         // Encapsulates a conversion rules required for array indexes
8703         //
8704         public class ArrayIndexCast : TypeCast
8705         {
8706                 public ArrayIndexCast (Expression expr)
8707                         : base (expr, TypeManager.int32_type)
8708                 {
8709                         if (expr.Type == TypeManager.int32_type)
8710                                 throw new ArgumentException ("unnecessary array index conversion");
8711                 }
8712
8713                 public override Expression CreateExpressionTree (ResolveContext ec)
8714                 {
8715                         using (ec.Set (ResolveContext.Options.CheckedScope)) {
8716                                 return base.CreateExpressionTree (ec);
8717                         }
8718                 }
8719
8720                 public override void Emit (EmitContext ec)
8721                 {
8722                         child.Emit (ec);
8723
8724                         var expr_type = child.Type;
8725
8726                         if (expr_type == TypeManager.uint32_type)
8727                                 ec.Emit (OpCodes.Conv_U);
8728                         else if (expr_type == TypeManager.int64_type)
8729                                 ec.Emit (OpCodes.Conv_Ovf_I);
8730                         else if (expr_type == TypeManager.uint64_type)
8731                                 ec.Emit (OpCodes.Conv_Ovf_I_Un);
8732                         else
8733                                 throw new InternalErrorException ("Cannot emit cast to unknown array element type", type);
8734                 }
8735         }
8736
8737         //
8738         // Implements the `stackalloc' keyword
8739         //
8740         public class StackAlloc : Expression {
8741                 TypeSpec otype;
8742                 Expression t;
8743                 Expression count;
8744
8745                 public StackAlloc (Expression type, Expression count, Location l)
8746                 {
8747                         t = type;
8748                         this.count = count;
8749                         loc = l;
8750                 }
8751
8752                 public override Expression CreateExpressionTree (ResolveContext ec)
8753                 {
8754                         throw new NotSupportedException ("ET");
8755                 }
8756
8757                 protected override Expression DoResolve (ResolveContext ec)
8758                 {
8759                         count = count.Resolve (ec);
8760                         if (count == null)
8761                                 return null;
8762
8763                         if (count.Type != TypeManager.uint32_type){
8764                                 count = Convert.ImplicitConversionRequired (ec, count, TypeManager.int32_type, loc);
8765                                 if (count == null)
8766                                         return null;
8767                         }
8768
8769                         Constant c = count as Constant;
8770                         if (c != null && c.IsNegative) {
8771                                 ec.Report.Error (247, loc, "Cannot use a negative size with stackalloc");
8772                         }
8773
8774                         if (ec.HasAny (ResolveContext.Options.CatchScope | ResolveContext.Options.FinallyScope)) {
8775                                 ec.Report.Error (255, loc, "Cannot use stackalloc in finally or catch");
8776                         }
8777
8778                         TypeExpr texpr = t.ResolveAsTypeTerminal (ec, false);
8779                         if (texpr == null)
8780                                 return null;
8781
8782                         otype = texpr.Type;
8783
8784                         if (!TypeManager.VerifyUnmanaged (ec.Compiler, otype, loc))
8785                                 return null;
8786
8787                         type = PointerContainer.MakeType (otype);
8788                         eclass = ExprClass.Value;
8789
8790                         return this;
8791                 }
8792
8793                 public override void Emit (EmitContext ec)
8794                 {
8795                         int size = GetTypeSize (otype);
8796
8797                         count.Emit (ec);
8798
8799                         if (size == 0)
8800                                 ec.Emit (OpCodes.Sizeof, otype);
8801                         else
8802                                 ec.EmitInt (size);
8803
8804                         ec.Emit (OpCodes.Mul_Ovf_Un);
8805                         ec.Emit (OpCodes.Localloc);
8806                 }
8807
8808                 protected override void CloneTo (CloneContext clonectx, Expression t)
8809                 {
8810                         StackAlloc target = (StackAlloc) t;
8811                         target.count = count.Clone (clonectx);
8812                         target.t = t.Clone (clonectx);
8813                 }
8814         }
8815
8816         //
8817         // An object initializer expression
8818         //
8819         public class ElementInitializer : Assign
8820         {
8821                 public readonly string Name;
8822
8823                 public ElementInitializer (string name, Expression initializer, Location loc)
8824                         : base (null, initializer, loc)
8825                 {
8826                         this.Name = name;
8827                 }
8828
8829                 protected override void CloneTo (CloneContext clonectx, Expression t)
8830                 {
8831                         ElementInitializer target = (ElementInitializer) t;
8832                         target.source = source.Clone (clonectx);
8833                 }
8834
8835                 public override Expression CreateExpressionTree (ResolveContext ec)
8836                 {
8837                         Arguments args = new Arguments (2);
8838                         FieldExpr fe = target as FieldExpr;
8839                         if (fe != null)
8840                                 args.Add (new Argument (fe.CreateTypeOfExpression ()));
8841                         else
8842                                 args.Add (new Argument (((PropertyExpr)target).CreateSetterTypeOfExpression ()));
8843
8844                         args.Add (new Argument (source.CreateExpressionTree (ec)));
8845                         return CreateExpressionFactoryCall (ec,
8846                                 source is CollectionOrObjectInitializers ? "ListBind" : "Bind",
8847                                 args);
8848                 }
8849
8850                 protected override Expression DoResolve (ResolveContext ec)
8851                 {
8852                         if (source == null)
8853                                 return EmptyExpressionStatement.Instance;
8854
8855                         MemberExpr me = MemberLookupFinal (ec, ec.CurrentInitializerVariable.Type, ec.CurrentInitializerVariable.Type,
8856                                 Name, 0, MemberKind.Field | MemberKind.Property, BindingRestriction.AccessibleOnly | BindingRestriction.InstanceOnly | BindingRestriction.DefaultMemberLookup, loc) as MemberExpr;
8857
8858                         if (me == null)
8859                                 return null;
8860
8861                         target = me;
8862                         me.InstanceExpression = ec.CurrentInitializerVariable;
8863
8864                         if (source is CollectionOrObjectInitializers) {
8865                                 Expression previous = ec.CurrentInitializerVariable;
8866                                 ec.CurrentInitializerVariable = target;
8867                                 source = source.Resolve (ec);
8868                                 ec.CurrentInitializerVariable = previous;
8869                                 if (source == null)
8870                                         return null;
8871
8872                                 eclass = source.eclass;
8873                                 type = source.Type;
8874                                 return this;
8875                         }
8876
8877                         return base.DoResolve (ec);
8878                 }
8879
8880                 protected override MemberExpr Error_MemberLookupFailed (ResolveContext ec, TypeSpec type, IList<MemberSpec> members)
8881                 {
8882                         var member = members.First ();
8883                         if (member.Kind != MemberKind.Property && member.Kind != MemberKind.Field)
8884                                 ec.Report.Error (1913, loc, "Member `{0}' cannot be initialized. An object " +
8885                                         "initializer may only be used for fields, or properties", TypeManager.GetFullNameSignature (member));
8886                         else
8887                                 ec.Report.Error (1914, loc, " Static field or property `{0}' cannot be assigned in an object initializer",
8888                                         TypeManager.GetFullNameSignature (member));
8889
8890                         return null;
8891                 }
8892
8893                 public override void EmitStatement (EmitContext ec)
8894                 {
8895                         if (source is CollectionOrObjectInitializers)
8896                                 source.Emit (ec);
8897                         else
8898                                 base.EmitStatement (ec);
8899                 }
8900         }
8901
8902         //
8903         // A collection initializer expression
8904         //
8905         class CollectionElementInitializer : Invocation
8906         {
8907                 public class ElementInitializerArgument : Argument
8908                 {
8909                         public ElementInitializerArgument (Expression e)
8910                                 : base (e)
8911                         {
8912                         }
8913                 }
8914
8915                 sealed class AddMemberAccess : MemberAccess
8916                 {
8917                         public AddMemberAccess (Expression expr, Location loc)
8918                                 : base (expr, "Add", loc)
8919                         {
8920                         }
8921
8922                         protected override void Error_TypeDoesNotContainDefinition (ResolveContext ec, TypeSpec type, string name)
8923                         {
8924                                 if (TypeManager.HasElementType (type))
8925                                         return;
8926
8927                                 base.Error_TypeDoesNotContainDefinition (ec, type, name);
8928                         }
8929                 }
8930
8931                 public CollectionElementInitializer (Expression argument)
8932                         : base (null, new Arguments (1))
8933                 {
8934                         base.arguments.Add (new ElementInitializerArgument (argument));
8935                         this.loc = argument.Location;
8936                 }
8937
8938                 public CollectionElementInitializer (List<Expression> arguments, Location loc)
8939                         : base (null, new Arguments (arguments.Count))
8940                 {
8941                         foreach (Expression e in arguments)
8942                                 base.arguments.Add (new ElementInitializerArgument (e));
8943
8944                         this.loc = loc;
8945                 }
8946
8947                 public override Expression CreateExpressionTree (ResolveContext ec)
8948                 {
8949                         Arguments args = new Arguments (2);
8950                         args.Add (new Argument (mg.CreateExpressionTree (ec)));
8951
8952                         var expr_initializers = new ArrayInitializer (arguments.Count, loc);
8953                         foreach (Argument a in arguments)
8954                                 expr_initializers.Add (a.CreateExpressionTree (ec));
8955
8956                         args.Add (new Argument (new ArrayCreation (
8957                                 CreateExpressionTypeExpression (ec, loc), expr_initializers, loc)));
8958                         return CreateExpressionFactoryCall (ec, "ElementInit", args);
8959                 }
8960
8961                 protected override void CloneTo (CloneContext clonectx, Expression t)
8962                 {
8963                         CollectionElementInitializer target = (CollectionElementInitializer) t;
8964                         if (arguments != null)
8965                                 target.arguments = arguments.Clone (clonectx);
8966                 }
8967
8968                 protected override Expression DoResolve (ResolveContext ec)
8969                 {
8970                         base.expr = new AddMemberAccess (ec.CurrentInitializerVariable, loc);
8971
8972                         return base.DoResolve (ec);
8973                 }
8974         }
8975
8976         //
8977         // A block of object or collection initializers
8978         //
8979         public class CollectionOrObjectInitializers : ExpressionStatement
8980         {
8981                 IList<Expression> initializers;
8982                 bool is_collection_initialization;
8983
8984                 public static readonly CollectionOrObjectInitializers Empty =
8985                         new CollectionOrObjectInitializers (Array.AsReadOnly (new Expression [0]), Location.Null);
8986
8987                 public CollectionOrObjectInitializers (IList<Expression> initializers, Location loc)
8988                 {
8989                         this.initializers = initializers;
8990                         this.loc = loc;
8991                 }
8992
8993                 public bool IsEmpty {
8994                         get {
8995                                 return initializers.Count == 0;
8996                         }
8997                 }
8998
8999                 public bool IsCollectionInitializer {
9000                         get {
9001                                 return is_collection_initialization;
9002                         }
9003                 }
9004
9005                 protected override void CloneTo (CloneContext clonectx, Expression target)
9006                 {
9007                         CollectionOrObjectInitializers t = (CollectionOrObjectInitializers) target;
9008
9009                         t.initializers = new List<Expression> (initializers.Count);
9010                         foreach (var e in initializers)
9011                                 t.initializers.Add (e.Clone (clonectx));
9012                 }
9013
9014                 public override Expression CreateExpressionTree (ResolveContext ec)
9015                 {
9016                         var expr_initializers = new ArrayInitializer (initializers.Count, loc);
9017                         foreach (Expression e in initializers) {
9018                                 Expression expr = e.CreateExpressionTree (ec);
9019                                 if (expr != null)
9020                                         expr_initializers.Add (expr);
9021                         }
9022
9023                         return new ImplicitlyTypedArrayCreation (expr_initializers, loc);
9024                 }
9025
9026                 protected override Expression DoResolve (ResolveContext ec)
9027                 {
9028                         List<string> element_names = null;
9029                         for (int i = 0; i < initializers.Count; ++i) {
9030                                 Expression initializer = initializers [i];
9031                                 ElementInitializer element_initializer = initializer as ElementInitializer;
9032
9033                                 if (i == 0) {
9034                                         if (element_initializer != null) {
9035                                                 element_names = new List<string> (initializers.Count);
9036                                                 element_names.Add (element_initializer.Name);
9037                                         } else if (initializer is CompletingExpression){
9038                                                 initializer.Resolve (ec);
9039                                                 throw new InternalErrorException ("This line should never be reached");
9040                                         } else {
9041                                                 if (!ec.CurrentInitializerVariable.Type.ImplementsInterface (TypeManager.ienumerable_type)) {
9042                                                         ec.Report.Error (1922, loc, "A field or property `{0}' cannot be initialized with a collection " +
9043                                                                 "object initializer because type `{1}' does not implement `{2}' interface",
9044                                                                 ec.CurrentInitializerVariable.GetSignatureForError (),
9045                                                                 TypeManager.CSharpName (ec.CurrentInitializerVariable.Type),
9046                                                                 TypeManager.CSharpName (TypeManager.ienumerable_type));
9047                                                         return null;
9048                                                 }
9049                                                 is_collection_initialization = true;
9050                                         }
9051                                 } else {
9052                                         if (is_collection_initialization != (element_initializer == null)) {
9053                                                 ec.Report.Error (747, initializer.Location, "Inconsistent `{0}' member declaration",
9054                                                         is_collection_initialization ? "collection initializer" : "object initializer");
9055                                                 continue;
9056                                         }
9057
9058                                         if (!is_collection_initialization) {
9059                                                 if (element_names.Contains (element_initializer.Name)) {
9060                                                         ec.Report.Error (1912, element_initializer.Location,
9061                                                                 "An object initializer includes more than one member `{0}' initialization",
9062                                                                 element_initializer.Name);
9063                                                 } else {
9064                                                         element_names.Add (element_initializer.Name);
9065                                                 }
9066                                         }
9067                                 }
9068
9069                                 Expression e = initializer.Resolve (ec);
9070                                 if (e == EmptyExpressionStatement.Instance)
9071                                         initializers.RemoveAt (i--);
9072                                 else
9073                                         initializers [i] = e;
9074                         }
9075
9076                         type = ec.CurrentInitializerVariable.Type;
9077                         if (is_collection_initialization) {
9078                                 if (TypeManager.HasElementType (type)) {
9079                                         ec.Report.Error (1925, loc, "Cannot initialize object of type `{0}' with a collection initializer",
9080                                                 TypeManager.CSharpName (type));
9081                                 }
9082                         }
9083
9084                         eclass = ExprClass.Variable;
9085                         return this;
9086                 }
9087
9088                 public override void Emit (EmitContext ec)
9089                 {
9090                         EmitStatement (ec);
9091                 }
9092
9093                 public override void EmitStatement (EmitContext ec)
9094                 {
9095                         foreach (ExpressionStatement e in initializers)
9096                                 e.EmitStatement (ec);
9097                 }
9098         }
9099
9100         //
9101         // New expression with element/object initializers
9102         //
9103         public class NewInitialize : New
9104         {
9105                 //
9106                 // This class serves as a proxy for variable initializer target instances.
9107                 // A real variable is assigned later when we resolve left side of an
9108                 // assignment
9109                 //
9110                 sealed class InitializerTargetExpression : Expression, IMemoryLocation
9111                 {
9112                         NewInitialize new_instance;
9113
9114                         public InitializerTargetExpression (NewInitialize newInstance)
9115                         {
9116                                 this.type = newInstance.type;
9117                                 this.loc = newInstance.loc;
9118                                 this.eclass = newInstance.eclass;
9119                                 this.new_instance = newInstance;
9120                         }
9121
9122                         public override Expression CreateExpressionTree (ResolveContext ec)
9123                         {
9124                                 // Should not be reached
9125                                 throw new NotSupportedException ("ET");
9126                         }
9127
9128                         protected override Expression DoResolve (ResolveContext ec)
9129                         {
9130                                 return this;
9131                         }
9132
9133                         public override Expression DoResolveLValue (ResolveContext ec, Expression right_side)
9134                         {
9135                                 return this;
9136                         }
9137
9138                         public override void Emit (EmitContext ec)
9139                         {
9140                                 Expression e = (Expression) new_instance.instance;
9141                                 e.Emit (ec);
9142                         }
9143
9144                         #region IMemoryLocation Members
9145
9146                         public void AddressOf (EmitContext ec, AddressOp mode)
9147                         {
9148                                 new_instance.instance.AddressOf (ec, mode);
9149                         }
9150
9151                         #endregion
9152                 }
9153
9154                 CollectionOrObjectInitializers initializers;
9155                 IMemoryLocation instance;
9156
9157                 public NewInitialize (FullNamedExpression requested_type, Arguments arguments, CollectionOrObjectInitializers initializers, Location l)
9158                         : base (requested_type, arguments, l)
9159                 {
9160                         this.initializers = initializers;
9161                 }
9162
9163                 protected override IMemoryLocation EmitAddressOf (EmitContext ec, AddressOp Mode)
9164                 {
9165                         instance = base.EmitAddressOf (ec, Mode);
9166
9167                         if (!initializers.IsEmpty)
9168                                 initializers.Emit (ec);
9169
9170                         return instance;
9171                 }
9172
9173                 protected override void CloneTo (CloneContext clonectx, Expression t)
9174                 {
9175                         base.CloneTo (clonectx, t);
9176
9177                         NewInitialize target = (NewInitialize) t;
9178                         target.initializers = (CollectionOrObjectInitializers) initializers.Clone (clonectx);
9179                 }
9180
9181                 public override Expression CreateExpressionTree (ResolveContext ec)
9182                 {
9183                         Arguments args = new Arguments (2);
9184                         args.Add (new Argument (base.CreateExpressionTree (ec)));
9185                         if (!initializers.IsEmpty)
9186                                 args.Add (new Argument (initializers.CreateExpressionTree (ec)));
9187
9188                         return CreateExpressionFactoryCall (ec,
9189                                 initializers.IsCollectionInitializer ? "ListInit" : "MemberInit",
9190                                 args);
9191                 }
9192
9193                 protected override Expression DoResolve (ResolveContext ec)
9194                 {
9195                         Expression e = base.DoResolve (ec);
9196                         if (type == null)
9197                                 return null;
9198
9199                         Expression previous = ec.CurrentInitializerVariable;
9200                         ec.CurrentInitializerVariable = new InitializerTargetExpression (this);
9201                         initializers.Resolve (ec);
9202                         ec.CurrentInitializerVariable = previous;
9203                         return e;
9204                 }
9205
9206                 public override bool Emit (EmitContext ec, IMemoryLocation target)
9207                 {
9208                         bool left_on_stack = base.Emit (ec, target);
9209
9210                         if (initializers.IsEmpty)
9211                                 return left_on_stack;
9212
9213                         LocalTemporary temp = target as LocalTemporary;
9214                         if (temp == null) {
9215                                 if (!left_on_stack) {
9216                                         VariableReference vr = target as VariableReference;
9217
9218                                         // FIXME: This still does not work correctly for pre-set variables
9219                                         if (vr != null && vr.IsRef)
9220                                                 target.AddressOf (ec, AddressOp.Load);
9221
9222                                         ((Expression) target).Emit (ec);
9223                                         left_on_stack = true;
9224                                 }
9225
9226                                 temp = new LocalTemporary (type);
9227                         }
9228
9229                         instance = temp;
9230                         if (left_on_stack)
9231                                 temp.Store (ec);
9232
9233                         initializers.Emit (ec);
9234
9235                         if (left_on_stack) {
9236                                 temp.Emit (ec);
9237                                 temp.Release (ec);
9238                         }
9239
9240                         return left_on_stack;
9241                 }
9242
9243                 public override bool HasInitializer {
9244                         get {
9245                                 return !initializers.IsEmpty;
9246                         }
9247                 }
9248         }
9249
9250         public class NewAnonymousType : New
9251         {
9252                 static readonly AnonymousTypeParameter[] EmptyParameters = new AnonymousTypeParameter[0];
9253
9254                 List<AnonymousTypeParameter> parameters;
9255                 readonly TypeContainer parent;
9256                 AnonymousTypeClass anonymous_type;
9257
9258                 public NewAnonymousType (List<AnonymousTypeParameter> parameters, TypeContainer parent, Location loc)
9259                          : base (null, null, loc)
9260                 {
9261                         this.parameters = parameters;
9262                         this.parent = parent;
9263                 }
9264
9265                 protected override void CloneTo (CloneContext clonectx, Expression target)
9266                 {
9267                         if (parameters == null)
9268                                 return;
9269
9270                         NewAnonymousType t = (NewAnonymousType) target;
9271                         t.parameters = new List<AnonymousTypeParameter> (parameters.Count);
9272                         foreach (AnonymousTypeParameter atp in parameters)
9273                                 t.parameters.Add ((AnonymousTypeParameter) atp.Clone (clonectx));
9274                 }
9275
9276                 AnonymousTypeClass CreateAnonymousType (ResolveContext ec, IList<AnonymousTypeParameter> parameters)
9277                 {
9278                         AnonymousTypeClass type = parent.Module.Compiled.GetAnonymousType (parameters);
9279                         if (type != null)
9280                                 return type;
9281
9282                         type = AnonymousTypeClass.Create (ec.Compiler, parent, parameters, loc);
9283                         if (type == null)
9284                                 return null;
9285
9286                         type.CreateType ();
9287                         type.DefineType ();
9288                         type.ResolveTypeParameters ();
9289                         type.Define ();
9290                         type.EmitType ();
9291                         if (ec.Report.Errors == 0)
9292                                 type.CloseType ();
9293
9294                         parent.Module.Compiled.AddAnonymousType (type);
9295                         return type;
9296                 }
9297
9298                 public override Expression CreateExpressionTree (ResolveContext ec)
9299                 {
9300                         if (parameters == null)
9301                                 return base.CreateExpressionTree (ec);
9302
9303                         var init = new ArrayInitializer (parameters.Count, loc);
9304                         foreach (Property p in anonymous_type.Properties)
9305                                 init.Add (new TypeOfMethod (MemberCache.GetMember (type, p.Get.Spec), loc));
9306
9307                         var ctor_args = new ArrayInitializer (Arguments.Count, loc);
9308                         foreach (Argument a in Arguments)
9309                                 ctor_args.Add (a.CreateExpressionTree (ec));
9310
9311                         Arguments args = new Arguments (3);
9312                         args.Add (new Argument (method.CreateExpressionTree (ec)));
9313                         args.Add (new Argument (new ArrayCreation (TypeManager.expression_type_expr, ctor_args, loc)));
9314                         args.Add (new Argument (new ImplicitlyTypedArrayCreation (init, loc)));
9315
9316                         return CreateExpressionFactoryCall (ec, "New", args);
9317                 }
9318
9319                 protected override Expression DoResolve (ResolveContext ec)
9320                 {
9321                         if (ec.HasSet (ResolveContext.Options.ConstantScope)) {
9322                                 ec.Report.Error (836, loc, "Anonymous types cannot be used in this expression");
9323                                 return null;
9324                         }
9325
9326                         if (parameters == null) {
9327                                 anonymous_type = CreateAnonymousType (ec, EmptyParameters);
9328                                 RequestedType = new TypeExpression (anonymous_type.Definition, loc);
9329                                 return base.DoResolve (ec);
9330                         }
9331
9332                         bool error = false;
9333                         Arguments = new Arguments (parameters.Count);
9334                         TypeExpression [] t_args = new TypeExpression [parameters.Count];
9335                         for (int i = 0; i < parameters.Count; ++i) {
9336                                 Expression e = ((AnonymousTypeParameter) parameters [i]).Resolve (ec);
9337                                 if (e == null) {
9338                                         error = true;
9339                                         continue;
9340                                 }
9341
9342                                 Arguments.Add (new Argument (e));
9343                                 t_args [i] = new TypeExpression (e.Type, e.Location);
9344                         }
9345
9346                         if (error)
9347                                 return null;
9348
9349                         anonymous_type = CreateAnonymousType (ec, parameters);
9350                         if (anonymous_type == null)
9351                                 return null;
9352
9353                         RequestedType = new GenericTypeExpr (anonymous_type.Definition, new TypeArguments (t_args), loc);
9354                         return base.DoResolve (ec);
9355                 }
9356         }
9357
9358         public class AnonymousTypeParameter : ShimExpression
9359         {
9360                 public readonly string Name;
9361
9362                 public AnonymousTypeParameter (Expression initializer, string name, Location loc)
9363                         : base (initializer)
9364                 {
9365                         this.Name = name;
9366                         this.loc = loc;
9367                 }
9368
9369                 public AnonymousTypeParameter (Parameter parameter)
9370                         : base (new SimpleName (parameter.Name, parameter.Location))
9371                 {
9372                         this.Name = parameter.Name;
9373                         this.loc = parameter.Location;
9374                 }
9375
9376                 public override bool Equals (object o)
9377                 {
9378                         AnonymousTypeParameter other = o as AnonymousTypeParameter;
9379                         return other != null && Name == other.Name;
9380                 }
9381
9382                 public override int GetHashCode ()
9383                 {
9384                         return Name.GetHashCode ();
9385                 }
9386
9387                 protected override Expression DoResolve (ResolveContext ec)
9388                 {
9389                         Expression e = expr.Resolve (ec);
9390                         if (e == null)
9391                                 return null;
9392
9393                         if (e.eclass == ExprClass.MethodGroup) {
9394                                 Error_InvalidInitializer (ec, e.ExprClassName);
9395                                 return null;
9396                         }
9397
9398                         type = e.Type;
9399                         if (type == TypeManager.void_type || type == TypeManager.null_type ||
9400                                 type == InternalType.AnonymousMethod || type.IsPointer) {
9401                                 Error_InvalidInitializer (ec, e.GetSignatureForError ());
9402                                 return null;
9403                         }
9404
9405                         return e;
9406                 }
9407
9408                 protected virtual void Error_InvalidInitializer (ResolveContext ec, string initializer)
9409                 {
9410                         ec.Report.Error (828, loc, "An anonymous type property `{0}' cannot be initialized with `{1}'",
9411                                 Name, initializer);
9412                 }
9413         }
9414 }