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                         string op_name = CSharp.Operator.GetMetadataName (op_type);
 691                         MethodGroupExpr user_op = MethodLookup (ec.Compiler, ec.CurrentType, expr.Type, MemberKind.Operator, op_name, 0, expr.Location);
 692                         if (user_op == null)
 693                                 return null;
 694
 695                         Arguments args = new Arguments (1);
 696                         args.Add (new Argument (expr));
 697                         user_op = user_op.OverloadResolve (ec, ref args, false, expr.Location);
 698
 699                         if (user_op == null)
 700                                 return null;
 701
 702                         Expr = args [0].Expr;
 703                         return new UserOperatorCall (user_op, args, CreateExpressionTree, expr.Location);
 704                 }
 705
 706                 //
 707                 // Unary user type overload resolution
 708                 //
 709                 Expression ResolveUserType (ResolveContext ec, Expression expr)
 710                 {
 711                         Expression best_expr = ResolveUserOperator (ec, expr);
 712                         if (best_expr != null)
 713                                 return best_expr;
 714
 715                         TypeSpec[] predefined = predefined_operators [(int) Oper];
 716                         foreach (TypeSpec t in predefined) {
 717                                 Expression oper_expr = Convert.UserDefinedConversion (ec, expr, t, expr.Location, false, false);
 718                                 if (oper_expr == null)
 719                                         continue;
 720
 721                                 //
 722                                 // decimal type is predefined but has user-operators
 723                                 //
 724                                 if (oper_expr.Type == TypeManager.decimal_type)
 725                                         oper_expr = ResolveUserType (ec, oper_expr);
 726                                 else
 727                                         oper_expr = ResolvePrimitivePredefinedType (oper_expr);
 728
 729                                 if (oper_expr == null)
 730                                         continue;
 731
 732                                 if (best_expr == null) {
 733                                         best_expr = oper_expr;
 734                                         continue;
 735                                 }
 736
 737                                 int result = MethodGroupExpr.BetterTypeConversion (ec, best_expr.Type, t);
 738                                 if (result == 0) {
 739                                         ec.Report.Error (35, loc, "Operator `{0}' is ambiguous on an operand of type `{1}'",
 740                                                 OperName (Oper), TypeManager.CSharpName (expr.Type));
 741                                         break;
 742                                 }
 743
 744                                 if (result == 2)
 745                                         best_expr = oper_expr;
 746                         }
 747
 748                         if (best_expr == null)
 749                                 return null;
 750
 751                         //
 752                         // HACK: Decimal user-operator is included in standard operators
 753                         //
 754                         if (best_expr.Type == TypeManager.decimal_type)
 755                                 return best_expr;
 756
 757                         Expr = best_expr;
 758                         type = best_expr.Type;
 759                         return this;
 760                 }
 761
 762                 protected override void CloneTo (CloneContext clonectx, Expression t)
 763                 {
 764                         Unary target = (Unary) t;
 765
 766                         target.Expr = Expr.Clone (clonectx);
 767                 }
 768         }
 769
 770         //
 771         // Unary operators are turned into Indirection expressions
 772         // after semantic analysis (this is so we can take the address
 773         // of an indirection).
 774         //
 775         public class Indirection : Expression, IMemoryLocation, IAssignMethod, IFixedExpression {
 776                 Expression expr;
 777                 LocalTemporary temporary;
 778                 bool prepared;
 779
 780                 public Indirection (Expression expr, Location l)
 781                 {
 782                         this.expr = expr;
 783                         loc = l;
 784                 }
 785
 786                 public override Expression CreateExpressionTree (ResolveContext ec)
 787                 {
 788                         Error_PointerInsideExpressionTree (ec);
 789                         return null;
 790                 }
 791
 792                 protected override void CloneTo (CloneContext clonectx, Expression t)
 793                 {
 794                         Indirection target = (Indirection) t;
 795                         target.expr = expr.Clone (clonectx);
 796                 }
 797
 798                 public override void Emit (EmitContext ec)
 799                 {
 800                         if (!prepared)
 801                                 expr.Emit (ec);
 802
 803                         ec.EmitLoadFromPtr (Type);
 804                 }
 805
 806                 public void Emit (EmitContext ec, bool leave_copy)
 807                 {
 808                         Emit (ec);
 809                         if (leave_copy) {
 810                                 ec.Emit (OpCodes.Dup);
 811                                 temporary = new LocalTemporary (expr.Type);
 812                                 temporary.Store (ec);
 813                         }
 814                 }
 815
 816                 public void EmitAssign (EmitContext ec, Expression source, bool leave_copy, bool prepare_for_load)
 817                 {
 818                         prepared = prepare_for_load;
 819
 820                         expr.Emit (ec);
 821
 822                         if (prepare_for_load)
 823                                 ec.Emit (OpCodes.Dup);
 824
 825                         source.Emit (ec);
 826                         if (leave_copy) {
 827                                 ec.Emit (OpCodes.Dup);
 828                                 temporary = new LocalTemporary (expr.Type);
 829                                 temporary.Store (ec);
 830                         }
 831
 832                         ec.EmitStoreFromPtr (type);
 833
 834                         if (temporary != null) {
 835                                 temporary.Emit (ec);
 836                                 temporary.Release (ec);
 837                         }
 838                 }
 839
 840                 public void AddressOf (EmitContext ec, AddressOp Mode)
 841                 {
 842                         expr.Emit (ec);
 843                 }
 844
 845                 public override Expression DoResolveLValue (ResolveContext ec, Expression right_side)
 846                 {
 847                         return DoResolve (ec);
 848                 }
 849
 850                 protected override Expression DoResolve (ResolveContext ec)
 851                 {
 852                         expr = expr.Resolve (ec);
 853                         if (expr == null)
 854                                 return null;
 855
 856                         if (!ec.IsUnsafe)
 857                                 UnsafeError (ec, loc);
 858
 859                         if (!expr.Type.IsPointer) {
 860                                 ec.Report.Error (193, loc, "The * or -> operator must be applied to a pointer");
 861                                 return null;
 862                         }
 863
 864                         if (expr.Type == TypeManager.void_ptr_type) {
 865                                 ec.Report.Error (242, loc, "The operation in question is undefined on void pointers");
 866                                 return null;
 867                         }
 868
 869                         type = TypeManager.GetElementType (expr.Type);
 870                         eclass = ExprClass.Variable;
 871                         return this;
 872                 }
 873
 874                 public bool IsFixed {
 875                         get { return true; }
 876                 }
 877
 878                 public override string ToString ()
 879                 {
 880                         return "*(" + expr + ")";
 881                 }
 882         }
 883
 884         /// <summary>
 885         ///   Unary Mutator expressions (pre and post ++ and --)
 886         /// </summary>
 887         ///
 888         /// <remarks>
 889         ///   UnaryMutator implements ++ and -- expressions.   It derives from
 890         ///   ExpressionStatement becuase the pre/post increment/decrement
 891         ///   operators can be used in a statement context.
 892         ///
 893         /// FIXME: Idea, we could split this up in two classes, one simpler
 894         /// for the common case, and one with the extra fields for more complex
 895         /// classes (indexers require temporary access;  overloaded require method)
 896         ///
 897         /// </remarks>
 898         public class UnaryMutator : ExpressionStatement
 899         {
 900                 class DynamicPostMutator : Expression, IAssignMethod
 901                 {
 902                         LocalTemporary temp;
 903                         Expression expr;
 904
 905                         public DynamicPostMutator (Expression expr)
 906                         {
 907                                 this.expr = expr;
 908                                 this.type = expr.Type;
 909                                 this.loc = expr.Location;
 910                         }
 911
 912                         public override Expression CreateExpressionTree (ResolveContext ec)
 913                         {
 914                                 throw new NotImplementedException ("ET");
 915                         }
 916
 917                         protected override Expression DoResolve (ResolveContext rc)
 918                         {
 919                                 eclass = expr.eclass;
 920                                 return this;
 921                         }
 922
 923                         public override Expression DoResolveLValue (ResolveContext ec, Expression right_side)
 924                         {
 925                                 expr.DoResolveLValue (ec, right_side);
 926                                 return DoResolve (ec);
 927                         }
 928
 929                         public override void Emit (EmitContext ec)
 930                         {
 931                                 temp.Emit (ec);
 932                         }
 933
 934                         public void Emit (EmitContext ec, bool leave_copy)
 935                         {
 936                                 throw new NotImplementedException ();
 937                         }
 938
 939                         //
 940                         // Emits target assignment using unmodified source value
 941                         //
 942                         public void EmitAssign (EmitContext ec, Expression source, bool leave_copy, bool prepare_for_load)
 943                         {
 944                                 //
 945                                 // Allocate temporary variable to keep original value before it's modified
 946                                 //
 947                                 temp = new LocalTemporary (type);
 948                                 expr.Emit (ec);
 949                                 temp.Store (ec);
 950
 951                                 ((IAssignMethod) expr).EmitAssign (ec, source, false, prepare_for_load);
 952
 953                                 if (leave_copy)
 954                                         Emit (ec);
 955
 956                                 temp.Release (ec);
 957                                 temp = null;
 958                         }
 959                 }
 960
 961                 [Flags]
 962                 public enum Mode : byte {
 963                         IsIncrement    = 0,
 964                         IsDecrement    = 1,
 965                         IsPre          = 0,
 966                         IsPost         = 2,
 967
 968                         PreIncrement   = 0,
 969                         PreDecrement   = IsDecrement,
 970                         PostIncrement  = IsPost,
 971                         PostDecrement  = IsPost | IsDecrement
 972                 }
 973
 974                 Mode mode;
 975                 bool is_expr, recurse;
 976
 977                 Expression expr;
 978
 979                 // Holds the real operation
 980                 Expression operation;
 981
 982                 public UnaryMutator (Mode m, Expression e, Location loc)
 983                 {
 984                         mode = m;
 985                         this.loc = loc;
 986                         expr = e;
 987                 }
 988
 989                 public override Expression CreateExpressionTree (ResolveContext ec)
 990                 {
 991                         return new SimpleAssign (this, this).CreateExpressionTree (ec);
 992                 }
 993
 994                 protected override Expression DoResolve (ResolveContext ec)
 995                 {
 996                         expr = expr.Resolve (ec);
 997
 998                         if (expr == null)
 999                                 return null;
1000
1001                         if (expr.Type == InternalType.Dynamic) {
1002                                 //
1003                                 // Handle postfix unary operators using local
1004                                 // temporary variable
1005                                 //
1006                                 if ((mode & Mode.IsPost) != 0)
1007                                         expr = new DynamicPostMutator (expr);
1008
1009                                 Arguments args = new Arguments (1);
1010                                 args.Add (new Argument (expr));
1011                                 return new SimpleAssign (expr, new DynamicUnaryConversion (GetOperatorExpressionTypeName (), args, loc)).Resolve (ec);
1012                         }
1013
1014                         if (TypeManager.IsNullableType (expr.Type))
1015                                 return new Nullable.LiftedUnaryMutator (mode, expr, loc).Resolve (ec);
1016
1017                         eclass = ExprClass.Value;
1018                         type = expr.Type;
1019                         return ResolveOperator (ec);
1020                 }
1021
1022                 void EmitCode (EmitContext ec, bool is_expr)
1023                 {
1024                         recurse = true;
1025                         this.is_expr = is_expr;
1026                         ((IAssignMethod) expr).EmitAssign (ec, this, is_expr && (mode == Mode.PreIncrement || mode == Mode.PreDecrement), true);
1027                 }
1028
1029                 public override void Emit (EmitContext ec)
1030                 {
1031                         //
1032                         // We use recurse to allow ourselfs to be the source
1033                         // of an assignment. This little hack prevents us from
1034                         // having to allocate another expression
1035                         //
1036                         if (recurse) {
1037                                 ((IAssignMethod) expr).Emit (ec, is_expr && (mode == Mode.PostIncrement || mode == Mode.PostDecrement));
1038
1039                                 operation.Emit (ec);
1040
1041                                 recurse = false;
1042                                 return;
1043                         }
1044
1045                         EmitCode (ec, true);
1046                 }
1047
1048                 public override void EmitStatement (EmitContext ec)
1049                 {
1050                         EmitCode (ec, false);
1051                 }
1052
1053                 //
1054                 // Converts operator to System.Linq.Expressions.ExpressionType enum name
1055                 //
1056                 string GetOperatorExpressionTypeName ()
1057                 {
1058                         return IsDecrement ? "Decrement" : "Increment";
1059                 }
1060
1061                 bool IsDecrement {
1062                         get { return (mode & Mode.IsDecrement) != 0; }
1063                 }
1064
1065                 //
1066                 //   Returns whether an object of type `t' can be incremented
1067                 //   or decremented with add/sub (ie, basically whether we can
1068                 //   use pre-post incr-decr operations on it, but it is not a
1069                 //   System.Decimal, which we require operator overloading to catch)
1070                 //
1071                 static bool IsPredefinedOperator (TypeSpec t)
1072                 {
1073                         return (TypeManager.IsPrimitiveType (t) && t != TypeManager.bool_type) ||
1074                                 TypeManager.IsEnumType (t) ||
1075                                 t.IsPointer && t != TypeManager.void_ptr_type;
1076                 }
1077
1078 #if NET_4_0
1079                 public override SLE.Expression MakeExpression (BuilderContext ctx)
1080                 {
1081                         var target = ((RuntimeValueExpression) expr).MetaObject.Expression;
1082                         var source = SLE.Expression.Convert (operation.MakeExpression (ctx), target.Type);
1083                         return SLE.Expression.Assign (target, source);
1084                 }
1085 #endif
1086
1087                 protected override void CloneTo (CloneContext clonectx, Expression t)
1088                 {
1089                         UnaryMutator target = (UnaryMutator) t;
1090
1091                         target.expr = expr.Clone (clonectx);
1092                 }
1093
1094                 Expression ResolveOperator (ResolveContext ec)
1095                 {
1096                         if (expr is RuntimeValueExpression) {
1097                                 operation = expr;
1098                         } else {
1099                                 // Use itself at the top of the stack
1100                                 operation = new EmptyExpression (type);
1101                         }
1102
1103                         //
1104                         // The operand of the prefix/postfix increment decrement operators
1105                         // should be an expression that is classified as a variable,
1106                         // a property access or an indexer access
1107                         //
1108                         if (expr.eclass == ExprClass.Variable || expr.eclass == ExprClass.IndexerAccess || expr.eclass == ExprClass.PropertyAccess) {
1109                                 expr = expr.ResolveLValue (ec, expr);
1110                         } else {
1111                                 ec.Report.Error (1059, loc, "The operand of an increment or decrement operator must be a variable, property or indexer");
1112                         }
1113
1114                         //
1115                         // 1. Check predefined types
1116                         //
1117                         if (IsPredefinedOperator (type)) {
1118                                 // TODO: Move to IntConstant once I get rid of int32_type
1119                                 var one = new IntConstant (1, loc);
1120
1121                                 // TODO: Cache this based on type when using EmptyExpression in
1122                                 // context cache
1123                                 Binary.Operator op = IsDecrement ? Binary.Operator.Subtraction : Binary.Operator.Addition;
1124                                 operation = new Binary (op, operation, one, loc);
1125                                 operation = operation.Resolve (ec);
1126                                 if (operation != null && operation.Type != type)
1127                                         operation = Convert.ExplicitNumericConversion (operation, type);
1128
1129                                 return this;
1130                         }
1131
1132                         //
1133                         // Step 2: Perform Operator Overload location
1134                         //
1135                         string op_name;
1136
1137                         if (IsDecrement)
1138                                 op_name = Operator.GetMetadataName (Operator.OpType.Decrement);
1139                         else
1140                                 op_name = Operator.GetMetadataName (Operator.OpType.Increment);
1141
1142                         var mg = MethodLookup (ec.Compiler, ec.CurrentType, type, MemberKind.Operator, op_name, 0, loc);
1143
1144                         if (mg != null) {
1145                                 Arguments args = new Arguments (1);
1146                                 args.Add (new Argument (expr));
1147                                 mg = mg.OverloadResolve (ec, ref args, false, loc);
1148                                 if (mg == null)
1149                                         return null;
1150
1151                                 args[0].Expr = operation;
1152                                 operation = new UserOperatorCall (mg, args, null, loc);
1153                                 operation = Convert.ImplicitConversionRequired (ec, operation, type, loc);
1154                                 return this;
1155                         }
1156
1157                         string name = IsDecrement ?
1158                                 Operator.GetName (Operator.OpType.Decrement) :
1159                                 Operator.GetName (Operator.OpType.Increment);
1160
1161                         Unary.Error_OperatorCannotBeApplied (ec, loc, name, type);
1162                         return null;
1163                 }
1164         }
1165
1166         /// <summary>
1167         ///   Base class for the `Is' and `As' classes.
1168         /// </summary>
1169         ///
1170         /// <remarks>
1171         ///   FIXME: Split this in two, and we get to save the `Operator' Oper
1172         ///   size.
1173         /// </remarks>
1174         public abstract class Probe : Expression {
1175                 public Expression ProbeType;
1176                 protected Expression expr;
1177                 protected TypeExpr probe_type_expr;
1178
1179                 public Probe (Expression expr, Expression probe_type, Location l)
1180                 {
1181                         ProbeType = probe_type;
1182                         loc = l;
1183                         this.expr = expr;
1184                 }
1185
1186                 public Expression Expr {
1187                         get {
1188                                 return expr;
1189                         }
1190                 }
1191
1192                 protected override Expression DoResolve (ResolveContext ec)
1193                 {
1194                         probe_type_expr = ProbeType.ResolveAsTypeTerminal (ec, false);
1195                         if (probe_type_expr == null)
1196                                 return null;
1197
1198                         expr = expr.Resolve (ec);
1199                         if (expr == null)
1200                                 return null;
1201
1202                         if (probe_type_expr.Type.IsStatic) {
1203                                 ec.Report.Error (-244, loc, "The `{0}' operator cannot be applied to an operand of a static type",
1204                                         OperatorName);
1205                         }
1206
1207                         if (expr.Type.IsPointer || probe_type_expr.Type.IsPointer) {
1208                                 ec.Report.Error (244, loc, "The `{0}' operator cannot be applied to an operand of pointer type",
1209                                         OperatorName);
1210                                 return null;
1211                         }
1212
1213                         if (expr.Type == InternalType.AnonymousMethod) {
1214                                 ec.Report.Error (837, loc, "The `{0}' operator cannot be applied to a lambda expression or anonymous method",
1215                                         OperatorName);
1216                                 return null;
1217                         }
1218
1219                         return this;
1220                 }
1221
1222                 protected abstract string OperatorName { get; }
1223
1224                 protected override void CloneTo (CloneContext clonectx, Expression t)
1225                 {
1226                         Probe target = (Probe) t;
1227
1228                         target.expr = expr.Clone (clonectx);
1229                         target.ProbeType = ProbeType.Clone (clonectx);
1230                 }
1231
1232         }
1233
1234         /// <summary>
1235         ///   Implementation of the `is' operator.
1236         /// </summary>
1237         public class Is : Probe {
1238                 Nullable.Unwrap expr_unwrap;
1239
1240                 public Is (Expression expr, Expression probe_type, Location l)
1241                         : base (expr, probe_type, l)
1242                 {
1243                 }
1244
1245                 public override Expression CreateExpressionTree (ResolveContext ec)
1246                 {
1247                         Arguments args = Arguments.CreateForExpressionTree (ec, null,
1248                                 expr.CreateExpressionTree (ec),
1249                                 new TypeOf (probe_type_expr, loc));
1250
1251                         return CreateExpressionFactoryCall (ec, "TypeIs", args);
1252                 }
1253
1254                 public override void Emit (EmitContext ec)
1255                 {
1256                         if (expr_unwrap != null) {
1257                                 expr_unwrap.EmitCheck (ec);
1258                                 return;
1259                         }
1260
1261                         expr.Emit (ec);
1262                         ec.Emit (OpCodes.Isinst, probe_type_expr.Type);
1263                         ec.Emit (OpCodes.Ldnull);
1264                         ec.Emit (OpCodes.Cgt_Un);
1265                 }
1266
1267                 public override void EmitBranchable (EmitContext ec, Label target, bool on_true)
1268                 {
1269                         if (expr_unwrap != null) {
1270                                 expr_unwrap.EmitCheck (ec);
1271                         } else {
1272                                 expr.Emit (ec);
1273                                 ec.Emit (OpCodes.Isinst, probe_type_expr.Type);
1274                         }
1275                         ec.Emit (on_true ? OpCodes.Brtrue : OpCodes.Brfalse, target);
1276                 }
1277
1278                 Expression CreateConstantResult (ResolveContext ec, bool result)
1279                 {
1280                         if (result)
1281                                 ec.Report.Warning (183, 1, loc, "The given expression is always of the provided (`{0}') type",
1282                                         TypeManager.CSharpName (probe_type_expr.Type));
1283                         else
1284                                 ec.Report.Warning (184, 1, loc, "The given expression is never of the provided (`{0}') type",
1285                                         TypeManager.CSharpName (probe_type_expr.Type));
1286
1287                         return ReducedExpression.Create (new BoolConstant (result, loc).Resolve (ec), this);
1288                 }
1289
1290                 protected override Expression DoResolve (ResolveContext ec)
1291                 {
1292                         if (base.DoResolve (ec) == null)
1293                                 return null;
1294
1295                         TypeSpec d = expr.Type;
1296                         bool d_is_nullable = false;
1297
1298                         //
1299                         // If E is a method group or the null literal, or if the type of E is a reference
1300                         // type or a nullable type and the value of E is null, the result is false
1301                         //
1302                         if (expr.IsNull || expr.eclass == ExprClass.MethodGroup)
1303                                 return CreateConstantResult (ec, false);
1304
1305                         if (TypeManager.IsNullableType (d)) {
1306                                 var ut = Nullable.NullableInfo.GetUnderlyingType (d);
1307                                 if (!ut.IsGenericParameter) {
1308                                         d = ut;
1309                                         d_is_nullable = true;
1310                                 }
1311                         }
1312
1313                         type = TypeManager.bool_type;
1314                         eclass = ExprClass.Value;
1315                         TypeSpec t = probe_type_expr.Type;
1316                         bool t_is_nullable = false;
1317                         if (TypeManager.IsNullableType (t)) {
1318                                 var ut = Nullable.NullableInfo.GetUnderlyingType (t);
1319                                 if (!ut.IsGenericParameter) {
1320                                         t = ut;
1321                                         t_is_nullable = true;
1322                                 }
1323                         }
1324
1325                         if (TypeManager.IsStruct (t)) {
1326                                 if (d == t) {
1327                                         //
1328                                         // D and T are the same value types but D can be null
1329                                         //
1330                                         if (d_is_nullable && !t_is_nullable) {
1331                                                 expr_unwrap = Nullable.Unwrap.Create (expr, false);
1332                                                 return this;
1333                                         }
1334
1335                                         //
1336                                         // The result is true if D and T are the same value types
1337                                         //
1338                                         return CreateConstantResult (ec, true);
1339                                 }
1340
1341                                 var tp = d as TypeParameterSpec;
1342                                 if (tp != null)
1343                                         return ResolveGenericParameter (ec, t, tp);
1344
1345                                 //
1346                                 // An unboxing conversion exists
1347                                 //
1348                                 if (Convert.ExplicitReferenceConversionExists (d, t))
1349                                         return this;
1350                         } else {
1351                                 if (TypeManager.IsGenericParameter (t))
1352                                         return ResolveGenericParameter (ec, d, (TypeParameterSpec) t);
1353
1354                                 if (TypeManager.IsStruct (d)) {
1355                                         bool temp;
1356                                         if (Convert.ImplicitBoxingConversionExists (d, t, out temp))
1357                                                 return CreateConstantResult (ec, true);
1358                                 } else {
1359                                         if (TypeManager.IsGenericParameter (d))
1360                                                 return ResolveGenericParameter (ec, t, (TypeParameterSpec) d);
1361
1362                                         if (TypeManager.ContainsGenericParameters (d))
1363                                                 return this;
1364
1365                                         if (Convert.ImplicitReferenceConversionExists (expr, t) ||
1366                                                 Convert.ExplicitReferenceConversionExists (d, t)) {
1367                                                 return this;
1368                                         }
1369                                 }
1370                         }
1371
1372                         return CreateConstantResult (ec, false);
1373                 }
1374
1375                 Expression ResolveGenericParameter (ResolveContext ec, TypeSpec d, TypeParameterSpec t)
1376                 {
1377                         if (t.IsReferenceType) {
1378                                 if (TypeManager.IsStruct (d))
1379                                         return CreateConstantResult (ec, false);
1380                         }
1381
1382                         if (TypeManager.IsGenericParameter (expr.Type)) {
1383                                 if (t.IsValueType && expr.Type == t)
1384                                         return CreateConstantResult (ec, true);
1385
1386                                 expr = new BoxedCast (expr, d);
1387                         }
1388
1389                         return this;
1390                 }
1391
1392                 protected override string OperatorName {
1393                         get { return "is"; }
1394                 }
1395         }
1396
1397         /// <summary>
1398         ///   Implementation of the `as' operator.
1399         /// </summary>
1400         public class As : Probe {
1401                 bool do_isinst;
1402                 Expression resolved_type;
1403
1404                 public As (Expression expr, Expression probe_type, Location l)
1405                         : base (expr, probe_type, l)
1406                 {
1407                 }
1408
1409                 public override Expression CreateExpressionTree (ResolveContext ec)
1410                 {
1411                         Arguments args = Arguments.CreateForExpressionTree (ec, null,
1412                                 expr.CreateExpressionTree (ec),
1413                                 new TypeOf (probe_type_expr, loc));
1414
1415                         return CreateExpressionFactoryCall (ec, "TypeAs", args);
1416                 }
1417
1418                 public override void Emit (EmitContext ec)
1419                 {
1420                         expr.Emit (ec);
1421
1422                         if (do_isinst)
1423                                 ec.Emit (OpCodes.Isinst, type);
1424
1425                         if (TypeManager.IsGenericParameter (type) || TypeManager.IsNullableType (type))
1426                                 ec.Emit (OpCodes.Unbox_Any, type);
1427                 }
1428
1429                 protected override Expression DoResolve (ResolveContext ec)
1430                 {
1431                         if (resolved_type == null) {
1432                                 resolved_type = base.DoResolve (ec);
1433
1434                                 if (resolved_type == null)
1435                                         return null;
1436                         }
1437
1438                         type = probe_type_expr.Type;
1439                         eclass = ExprClass.Value;
1440                         TypeSpec etype = expr.Type;
1441
1442                         if (!TypeManager.IsReferenceType (type) && !TypeManager.IsNullableType (type)) {
1443                                 if (TypeManager.IsGenericParameter (type)) {
1444                                         ec.Report.Error (413, loc,
1445                                                 "The `as' operator cannot be used with a non-reference type parameter `{0}'. Consider adding `class' or a reference type constraint",
1446                                                 probe_type_expr.GetSignatureForError ());
1447                                 } else {
1448                                         ec.Report.Error (77, loc,
1449                                                 "The `as' operator cannot be used with a non-nullable value type `{0}'",
1450                                                 TypeManager.CSharpName (type));
1451                                 }
1452                                 return null;
1453                         }
1454
1455                         if (expr.IsNull && TypeManager.IsNullableType (type)) {
1456                                 return Nullable.LiftedNull.CreateFromExpression (ec, this);
1457                         }
1458
1459                         Expression e = Convert.ImplicitConversion (ec, expr, type, loc);
1460                         if (e != null){
1461                                 expr = e;
1462                                 do_isinst = false;
1463                                 return this;
1464                         }
1465
1466                         if (Convert.ExplicitReferenceConversionExists (etype, type)){
1467                                 if (TypeManager.IsGenericParameter (etype))
1468                                         expr = new BoxedCast (expr, etype);
1469
1470                                 do_isinst = true;
1471                                 return this;
1472                         }
1473
1474                         if (TypeManager.ContainsGenericParameters (etype) ||
1475                             TypeManager.ContainsGenericParameters (type)) {
1476                                 expr = new BoxedCast (expr, etype);
1477                                 do_isinst = true;
1478                                 return this;
1479                         }
1480
1481                         ec.Report.Error (39, loc, "Cannot convert type `{0}' to `{1}' via a built-in conversion",
1482                                 TypeManager.CSharpName (etype), TypeManager.CSharpName (type));
1483
1484                         return null;
1485                 }
1486
1487                 protected override string OperatorName {
1488                         get { return "as"; }
1489                 }
1490         }
1491
1492         /// <summary>
1493         ///   This represents a typecast in the source language.
1494         ///
1495         ///   FIXME: Cast expressions have an unusual set of parsing
1496         ///   rules, we need to figure those out.
1497         /// </summary>
1498         public class Cast : ShimExpression {
1499                 Expression target_type;
1500
1501                 public Cast (Expression cast_type, Expression expr)
1502                         : this (cast_type, expr, cast_type.Location)
1503                 {
1504                 }
1505
1506                 public Cast (Expression cast_type, Expression expr, Location loc)
1507                         : base (expr)
1508                 {
1509                         this.target_type = cast_type;
1510                         this.loc = loc;
1511                 }
1512
1513                 public Expression TargetType {
1514                         get { return target_type; }
1515                 }
1516
1517                 protected override Expression DoResolve (ResolveContext ec)
1518                 {
1519                         expr = expr.Resolve (ec);
1520                         if (expr == null)
1521                                 return null;
1522
1523                         TypeExpr target = target_type.ResolveAsTypeTerminal (ec, false);
1524                         if (target == null)
1525                                 return null;
1526
1527                         type = target.Type;
1528
1529                         if (type.IsStatic) {
1530                                 ec.Report.Error (716, loc, "Cannot convert to static type `{0}'", TypeManager.CSharpName (type));
1531                                 return null;
1532                         }
1533
1534                         eclass = ExprClass.Value;
1535
1536                         Constant c = expr as Constant;
1537                         if (c != null) {
1538                                 c = c.TryReduce (ec, type, loc);
1539                                 if (c != null)
1540                                         return c;
1541                         }
1542
1543                         if (type.IsPointer && !ec.IsUnsafe) {
1544                                 UnsafeError (ec, loc);
1545                         } else if (expr.Type == InternalType.Dynamic) {
1546                                 Arguments arg = new Arguments (1);
1547                                 arg.Add (new Argument (expr));
1548                                 return new DynamicConversion (type, CSharpBinderFlags.ConvertExplicit, arg, loc).Resolve (ec);
1549                         }
1550
1551                         expr = Convert.ExplicitConversion (ec, expr, type, loc);
1552                         return expr;
1553                 }
1554
1555                 protected override void CloneTo (CloneContext clonectx, Expression t)
1556                 {
1557                         Cast target = (Cast) t;
1558
1559                         target.target_type = target_type.Clone (clonectx);
1560                         target.expr = expr.Clone (clonectx);
1561                 }
1562         }
1563
1564         public class ImplicitCast : ShimExpression
1565         {
1566                 bool arrayAccess;
1567
1568                 public ImplicitCast (Expression expr, TypeSpec target, bool arrayAccess)
1569                         : base (expr)
1570                 {
1571                         this.loc = expr.Location;
1572                         this.type = target;
1573                         this.arrayAccess = arrayAccess;
1574                 }
1575
1576                 protected override Expression DoResolve (ResolveContext ec)
1577                 {
1578                         expr = expr.Resolve (ec);
1579                         if (expr == null)
1580                                 return null;
1581
1582                         if (arrayAccess)
1583                                 expr = ConvertExpressionToArrayIndex (ec, expr);
1584                         else
1585                                 expr = Convert.ImplicitConversionRequired (ec, expr, type, loc);
1586
1587                         return expr;
1588                 }
1589         }
1590
1591         //
1592         // C# 2.0 Default value expression
1593         //
1594         public class DefaultValueExpression : Expression
1595         {
1596                 Expression expr;
1597
1598                 public DefaultValueExpression (Expression expr, Location loc)
1599                 {
1600                         this.expr = expr;
1601                         this.loc = loc;
1602                 }
1603
1604                 public override Expression CreateExpressionTree (ResolveContext ec)
1605                 {
1606                         Arguments args = new Arguments (2);
1607                         args.Add (new Argument (this));
1608                         args.Add (new Argument (new TypeOf (new TypeExpression (type, loc), loc)));
1609                         return CreateExpressionFactoryCall (ec, "Constant", args);
1610                 }
1611
1612                 protected override Expression DoResolve (ResolveContext ec)
1613                 {
1614                         TypeExpr texpr = expr.ResolveAsTypeTerminal (ec, false);
1615                         if (texpr == null)
1616                                 return null;
1617
1618                         type = texpr.Type;
1619
1620                         if (type.IsStatic) {
1621                                 ec.Report.Error (-244, loc, "The `default value' operator cannot be applied to an operand of a static type");
1622                         }
1623
1624                         if (type.IsPointer)
1625                                 return new NullLiteral (Location).ConvertImplicitly (ec, type);
1626
1627                         if (TypeManager.IsReferenceType (type))
1628                                 return new NullConstant (type, loc);
1629
1630                         Constant c = New.Constantify (type);
1631                         if (c != null)
1632                                 return c.Resolve (ec);
1633
1634                         eclass = ExprClass.Variable;
1635                         return this;
1636                 }
1637
1638                 public override void Emit (EmitContext ec)
1639                 {
1640                         LocalTemporary temp_storage = new LocalTemporary(type);
1641
1642                         temp_storage.AddressOf(ec, AddressOp.LoadStore);
1643                         ec.Emit(OpCodes.Initobj, type);
1644                         temp_storage.Emit(ec);
1645                 }
1646
1647                 protected override void CloneTo (CloneContext clonectx, Expression t)
1648                 {
1649                         DefaultValueExpression target = (DefaultValueExpression) t;
1650
1651                         target.expr = expr.Clone (clonectx);
1652                 }
1653         }
1654
1655         /// <summary>
1656         ///   Binary operators
1657         /// </summary>
1658         public class Binary : Expression, IDynamicBinder
1659         {
1660                 protected class PredefinedOperator {
1661                         protected readonly TypeSpec left;
1662                         protected readonly TypeSpec right;
1663                         public readonly Operator OperatorsMask;
1664                         public TypeSpec ReturnType;
1665
1666                         public PredefinedOperator (TypeSpec ltype, TypeSpec rtype, Operator op_mask)
1667                                 : this (ltype, rtype, op_mask, ltype)
1668                         {
1669                         }
1670
1671                         public PredefinedOperator (TypeSpec type, Operator op_mask, TypeSpec return_type)
1672                                 : this (type, type, op_mask, return_type)
1673                         {
1674                         }
1675
1676                         public PredefinedOperator (TypeSpec type, Operator op_mask)
1677                                 : this (type, type, op_mask, type)
1678                         {
1679                         }
1680
1681                         public PredefinedOperator (TypeSpec ltype, TypeSpec rtype, Operator op_mask, TypeSpec return_type)
1682                         {
1683                                 if ((op_mask & Operator.ValuesOnlyMask) != 0)
1684                                         throw new InternalErrorException ("Only masked values can be used");
1685
1686                                 this.left = ltype;
1687                                 this.right = rtype;
1688                                 this.OperatorsMask = op_mask;
1689                                 this.ReturnType = return_type;
1690                         }
1691
1692                         public virtual Expression ConvertResult (ResolveContext ec, Binary b)
1693                         {
1694                                 b.type = ReturnType;
1695
1696                                 b.left = Convert.ImplicitConversion (ec, b.left, left, b.left.Location);
1697                                 b.right = Convert.ImplicitConversion (ec, b.right, right, b.right.Location);
1698
1699                                 //
1700                                 // A user operators does not support multiple user conversions, but decimal type
1701                                 // is considered to be predefined type therefore we apply predefined operators rules
1702                                 // and then look for decimal user-operator implementation
1703                                 //
1704                                 if (left == TypeManager.decimal_type)
1705                                         return b.ResolveUserOperator (ec, b.left.Type, b.right.Type);
1706
1707                                 var c = b.right as Constant;
1708                                 if (c != null) {
1709                                         if (c.IsDefaultValue && (b.oper == Operator.Addition || b.oper == Operator.BitwiseOr || b.oper == Operator.Subtraction))
1710                                                 return ReducedExpression.Create (b.left, b).Resolve (ec);
1711                                         if ((b.oper == Operator.Multiply || b.oper == Operator.Division) && c.IsOneInteger)
1712                                                 return ReducedExpression.Create (b.left, b).Resolve (ec);
1713                                         return b;
1714                                 }
1715
1716                                 c = b.left as Constant;
1717                                 if (c != null) {
1718                                         if (c.IsDefaultValue && (b.oper == Operator.Addition || b.oper == Operator.BitwiseOr))
1719                                                 return ReducedExpression.Create (b.right, b).Resolve (ec);
1720                                         if (b.oper == Operator.Multiply && c.IsOneInteger)
1721                                                 return ReducedExpression.Create (b.right, b).Resolve (ec);
1722                                         return b;
1723                                 }
1724
1725                                 return b;
1726                         }
1727
1728                         public bool IsPrimitiveApplicable (TypeSpec ltype, TypeSpec rtype)
1729                         {
1730                                 //
1731                                 // We are dealing with primitive types only
1732                                 //
1733                                 return left == ltype && ltype == rtype;
1734                         }
1735
1736                         public virtual bool IsApplicable (ResolveContext ec, Expression lexpr, Expression rexpr)
1737                         {
1738                                 if (TypeManager.IsEqual (left, lexpr.Type) &&
1739                                         TypeManager.IsEqual (right, rexpr.Type))
1740                                         return true;
1741
1742                                 return Convert.ImplicitConversionExists (ec, lexpr, left) &&
1743                                         Convert.ImplicitConversionExists (ec, rexpr, right);
1744                         }
1745
1746                         public PredefinedOperator ResolveBetterOperator (ResolveContext ec, PredefinedOperator best_operator)
1747                         {
1748                                 int result = 0;
1749                                 if (left != null && best_operator.left != null) {
1750                                         result = MethodGroupExpr.BetterTypeConversion (ec, best_operator.left, left);
1751                                 }
1752
1753                                 //
1754                                 // When second arguments are same as the first one, the result is same
1755                                 //
1756                                 if (right != null && (left != right || best_operator.left != best_operator.right)) {
1757                                         result |= MethodGroupExpr.BetterTypeConversion (ec, best_operator.right, right);
1758                                 }
1759
1760                                 if (result == 0 || result > 2)
1761                                         return null;
1762
1763                                 return result == 1 ? best_operator : this;
1764                         }
1765                 }
1766
1767                 class PredefinedStringOperator : PredefinedOperator {
1768                         public PredefinedStringOperator (TypeSpec type, Operator op_mask)
1769                                 : base (type, op_mask, type)
1770                         {
1771                                 ReturnType = TypeManager.string_type;
1772                         }
1773
1774                         public PredefinedStringOperator (TypeSpec ltype, TypeSpec rtype, Operator op_mask)
1775                                 : base (ltype, rtype, op_mask)
1776                         {
1777                                 ReturnType = TypeManager.string_type;
1778                         }
1779
1780                         public override Expression ConvertResult (ResolveContext ec, Binary b)
1781                         {
1782                                 //
1783                                 // Use original expression for nullable arguments
1784                                 //
1785                                 Nullable.Unwrap unwrap = b.left as Nullable.Unwrap;
1786                                 if (unwrap != null)
1787                                         b.left = unwrap.Original;
1788
1789                                 unwrap = b.right as Nullable.Unwrap;
1790                                 if (unwrap != null)
1791                                         b.right = unwrap.Original;
1792
1793                                 b.left = Convert.ImplicitConversion (ec, b.left, left, b.left.Location);
1794                                 b.right = Convert.ImplicitConversion (ec, b.right, right, b.right.Location);
1795
1796                                 //
1797                                 // Start a new concat expression using converted expression
1798                                 //
1799                                 return StringConcat.Create (ec, b.left, b.right, b.loc);
1800                         }
1801                 }
1802
1803                 class PredefinedShiftOperator : PredefinedOperator {
1804                         public PredefinedShiftOperator (TypeSpec ltype, Operator op_mask) :
1805                                 base (ltype, TypeManager.int32_type, op_mask)
1806                         {
1807                         }
1808
1809                         public override Expression ConvertResult (ResolveContext ec, Binary b)
1810                         {
1811                                 b.left = Convert.ImplicitConversion (ec, b.left, left, b.left.Location);
1812
1813                                 Expression expr_tree_expr = Convert.ImplicitConversion (ec, b.right, TypeManager.int32_type, b.right.Location);
1814
1815                                 int right_mask = left == TypeManager.int32_type || left == TypeManager.uint32_type ? 0x1f : 0x3f;
1816
1817                                 //
1818                                 // b = b.left >> b.right & (0x1f|0x3f)
1819                                 //
1820                                 b.right = new Binary (Operator.BitwiseAnd,
1821                                         b.right, new IntConstant (right_mask, b.right.Location), b.loc).Resolve (ec);
1822
1823                                 //
1824                                 // Expression tree representation does not use & mask
1825                                 //
1826                                 b.right = ReducedExpression.Create (b.right, expr_tree_expr).Resolve (ec);
1827                                 b.type = ReturnType;
1828
1829                                 //
1830                                 // Optimize shift by 0
1831                                 //
1832                                 var c = b.right as Constant;
1833                                 if (c != null && c.IsDefaultValue)
1834                                         return ReducedExpression.Create (b.left, b).Resolve (ec);
1835
1836                                 return b;
1837                         }
1838                 }
1839
1840                 class PredefinedPointerOperator : PredefinedOperator {
1841                         public PredefinedPointerOperator (TypeSpec ltype, TypeSpec rtype, Operator op_mask)
1842                                 : base (ltype, rtype, op_mask)
1843                         {
1844                         }
1845
1846                         public PredefinedPointerOperator (TypeSpec ltype, TypeSpec rtype, Operator op_mask, TypeSpec retType)
1847                                 : base (ltype, rtype, op_mask, retType)
1848                         {
1849                         }
1850
1851                         public PredefinedPointerOperator (TypeSpec type, Operator op_mask, TypeSpec return_type)
1852                                 : base (type, op_mask, return_type)
1853                         {
1854                         }
1855
1856                         public override bool IsApplicable (ResolveContext ec, Expression lexpr, Expression rexpr)
1857                         {
1858                                 if (left == null) {
1859                                         if (!lexpr.Type.IsPointer)
1860                                                 return false;
1861                                 } else {
1862                                         if (!Convert.ImplicitConversionExists (ec, lexpr, left))
1863                                                 return false;
1864                                 }
1865
1866                                 if (right == null) {
1867                                         if (!rexpr.Type.IsPointer)
1868                                                 return false;
1869                                 } else {
1870                                         if (!Convert.ImplicitConversionExists (ec, rexpr, right))
1871                                                 return false;
1872                                 }
1873
1874                                 return true;
1875                         }
1876
1877                         public override Expression ConvertResult (ResolveContext ec, Binary b)
1878                         {
1879                                 if (left != null) {
1880                                         b.left = EmptyCast.Create (b.left, left);
1881                                 } else if (right != null) {
1882                                         b.right = EmptyCast.Create (b.right, right);
1883                                 }
1884
1885                                 TypeSpec r_type = ReturnType;
1886                                 Expression left_arg, right_arg;
1887                                 if (r_type == null) {
1888                                         if (left == null) {
1889                                                 left_arg = b.left;
1890                                                 right_arg = b.right;
1891                                                 r_type = b.left.Type;
1892                                         } else {
1893                                                 left_arg = b.right;
1894                                                 right_arg = b.left;
1895                                                 r_type = b.right.Type;
1896                                         }
1897                                 } else {
1898                                         left_arg = b.left;
1899                                         right_arg = b.right;
1900                                 }
1901
1902                                 return new PointerArithmetic (b.oper, left_arg, right_arg, r_type, b.loc).Resolve (ec);
1903                         }
1904                 }
1905
1906                 [Flags]
1907                 public enum Operator {
1908                         Multiply        = 0 | ArithmeticMask,
1909                         Division        = 1 | ArithmeticMask,
1910                         Modulus         = 2 | ArithmeticMask,
1911                         Addition        = 3 | ArithmeticMask | AdditionMask,
1912                         Subtraction = 4 | ArithmeticMask | SubtractionMask,
1913
1914                         LeftShift       = 5 | ShiftMask,
1915                         RightShift      = 6 | ShiftMask,
1916
1917                         LessThan        = 7 | ComparisonMask | RelationalMask,
1918                         GreaterThan     = 8 | ComparisonMask | RelationalMask,
1919                         LessThanOrEqual         = 9 | ComparisonMask | RelationalMask,
1920                         GreaterThanOrEqual      = 10 | ComparisonMask | RelationalMask,
1921                         Equality        = 11 | ComparisonMask | EqualityMask,
1922                         Inequality      = 12 | ComparisonMask | EqualityMask,
1923
1924                         BitwiseAnd      = 13 | BitwiseMask,
1925                         ExclusiveOr     = 14 | BitwiseMask,
1926                         BitwiseOr       = 15 | BitwiseMask,
1927
1928                         LogicalAnd      = 16 | LogicalMask,
1929                         LogicalOr       = 17 | LogicalMask,
1930
1931                         //
1932                         // Operator masks
1933                         //
1934                         ValuesOnlyMask  = ArithmeticMask - 1,
1935                         ArithmeticMask  = 1 << 5,
1936                         ShiftMask               = 1 << 6,
1937                         ComparisonMask  = 1 << 7,
1938                         EqualityMask    = 1 << 8,
1939                         BitwiseMask             = 1 << 9,
1940                         LogicalMask             = 1 << 10,
1941                         AdditionMask    = 1 << 11,
1942                         SubtractionMask = 1 << 12,
1943                         RelationalMask  = 1 << 13
1944                 }
1945
1946                 readonly Operator oper;
1947                 protected Expression left, right;
1948                 readonly bool is_compound;
1949                 Expression enum_conversion;
1950
1951                 static PredefinedOperator[] standard_operators;
1952                 static PredefinedOperator[] pointer_operators;
1953
1954                 public Binary (Operator oper, Expression left, Expression right, bool isCompound, Location loc)
1955                         : this (oper, left, right, loc)
1956                 {
1957                         this.is_compound = isCompound;
1958                 }
1959
1960                 public Binary (Operator oper, Expression left, Expression right, Location loc)
1961                 {
1962                         this.oper = oper;
1963                         this.left = left;
1964                         this.right = right;
1965                         this.loc = loc;
1966                 }
1967
1968                 public Operator Oper {
1969                         get {
1970                                 return oper;
1971                         }
1972                 }
1973
1974                 /// <summary>
1975                 ///   Returns a stringified representation of the Operator
1976                 /// </summary>
1977                 string OperName (Operator oper)
1978                 {
1979                         string s;
1980                         switch (oper){
1981                         case Operator.Multiply:
1982                                 s = "*";
1983                                 break;
1984                         case Operator.Division:
1985                                 s = "/";
1986                                 break;
1987                         case Operator.Modulus:
1988                                 s = "%";
1989                                 break;
1990                         case Operator.Addition:
1991                                 s = "+";
1992                                 break;
1993                         case Operator.Subtraction:
1994                                 s = "-";
1995                                 break;
1996                         case Operator.LeftShift:
1997                                 s = "<<";
1998                                 break;
1999                         case Operator.RightShift:
2000                                 s = ">>";
2001                                 break;
2002                         case Operator.LessThan:
2003                                 s = "<";
2004                                 break;
2005                         case Operator.GreaterThan:
2006                                 s = ">";
2007                                 break;
2008                         case Operator.LessThanOrEqual:
2009                                 s = "<=";
2010                                 break;
2011                         case Operator.GreaterThanOrEqual:
2012                                 s = ">=";
2013                                 break;
2014                         case Operator.Equality:
2015                                 s = "==";
2016                                 break;
2017                         case Operator.Inequality:
2018                                 s = "!=";
2019                                 break;
2020                         case Operator.BitwiseAnd:
2021                                 s = "&";
2022                                 break;
2023                         case Operator.BitwiseOr:
2024                                 s = "|";
2025                                 break;
2026                         case Operator.ExclusiveOr:
2027                                 s = "^";
2028                                 break;
2029                         case Operator.LogicalOr:
2030                                 s = "||";
2031                                 break;
2032                         case Operator.LogicalAnd:
2033                                 s = "&&";
2034                                 break;
2035                         default:
2036                                 s = oper.ToString ();
2037                                 break;
2038                         }
2039
2040                         if (is_compound)
2041                                 return s + "=";
2042
2043                         return s;
2044                 }
2045
2046                 public static void Error_OperatorCannotBeApplied (ResolveContext ec, Expression left, Expression right, Operator oper, Location loc)
2047                 {
2048                         new Binary (oper, left, right, loc).Error_OperatorCannotBeApplied (ec, left, right);
2049                 }
2050
2051                 public static void Error_OperatorCannotBeApplied (ResolveContext ec, Expression left, Expression right, string oper, Location loc)
2052                 {
2053                         string l, r;
2054                         l = TypeManager.CSharpName (left.Type);
2055                         r = TypeManager.CSharpName (right.Type);
2056
2057                         ec.Report.Error (19, loc, "Operator `{0}' cannot be applied to operands of type `{1}' and `{2}'",
2058                                 oper, l, r);
2059                 }
2060
2061                 protected void Error_OperatorCannotBeApplied (ResolveContext ec, Expression left, Expression right)
2062                 {
2063                         Error_OperatorCannotBeApplied (ec, left, right, OperName (oper), loc);
2064                 }
2065
2066                 //
2067                 // Converts operator to System.Linq.Expressions.ExpressionType enum name
2068                 //
2069                 string GetOperatorExpressionTypeName ()
2070                 {
2071                         switch (oper) {
2072                         case Operator.Addition:
2073                                 return is_compound ? "AddAssign" : "Add";
2074                         case Operator.BitwiseAnd:
2075                                 return is_compound ? "AndAssign" : "And";
2076                         case Operator.BitwiseOr:
2077                                 return is_compound ? "OrAssign" : "Or";
2078                         case Operator.Division:
2079                                 return is_compound ? "DivideAssign" : "Divide";
2080                         case Operator.ExclusiveOr:
2081                                 return is_compound ? "ExclusiveOrAssign" : "ExclusiveOr";
2082                         case Operator.Equality:
2083                                 return "Equal";
2084                         case Operator.GreaterThan:
2085                                 return "GreaterThan";
2086                         case Operator.GreaterThanOrEqual:
2087                                 return "GreaterThanOrEqual";
2088                         case Operator.Inequality:
2089                                 return "NotEqual";
2090                         case Operator.LeftShift:
2091                                 return is_compound ? "LeftShiftAssign" : "LeftShift";
2092                         case Operator.LessThan:
2093                                 return "LessThan";
2094                         case Operator.LessThanOrEqual:
2095                                 return "LessThanOrEqual";
2096                         case Operator.LogicalAnd:
2097                                 return "And";
2098                         case Operator.LogicalOr:
2099                                 return "Or";
2100                         case Operator.Modulus:
2101                                 return is_compound ? "ModuloAssign" : "Modulo";
2102                         case Operator.Multiply:
2103                                 return is_compound ? "MultiplyAssign" : "Multiply";
2104                         case Operator.RightShift:
2105                                 return is_compound ? "RightShiftAssign" : "RightShift";
2106                         case Operator.Subtraction:
2107                                 return is_compound ? "SubtractAssign" : "Subtract";
2108                         default:
2109                                 throw new NotImplementedException ("Unknown expression type operator " + oper.ToString ());
2110                         }
2111                 }
2112
2113                 static string GetOperatorMetadataName (Operator op)
2114                 {
2115                         CSharp.Operator.OpType op_type;
2116                         switch (op) {
2117                         case Operator.Addition:
2118                                 op_type = CSharp.Operator.OpType.Addition; break;
2119                         case Operator.BitwiseAnd:
2120                                 op_type = CSharp.Operator.OpType.BitwiseAnd; break;
2121                         case Operator.BitwiseOr:
2122                                 op_type = CSharp.Operator.OpType.BitwiseOr; break;
2123                         case Operator.Division:
2124                                 op_type = CSharp.Operator.OpType.Division; break;
2125                         case Operator.Equality:
2126                                 op_type = CSharp.Operator.OpType.Equality; break;
2127                         case Operator.ExclusiveOr:
2128                                 op_type = CSharp.Operator.OpType.ExclusiveOr; break;
2129                         case Operator.GreaterThan:
2130                                 op_type = CSharp.Operator.OpType.GreaterThan; break;
2131                         case Operator.GreaterThanOrEqual:
2132                                 op_type = CSharp.Operator.OpType.GreaterThanOrEqual; break;
2133                         case Operator.Inequality:
2134                                 op_type = CSharp.Operator.OpType.Inequality; break;
2135                         case Operator.LeftShift:
2136                                 op_type = CSharp.Operator.OpType.LeftShift; break;
2137                         case Operator.LessThan:
2138                                 op_type = CSharp.Operator.OpType.LessThan; break;
2139                         case Operator.LessThanOrEqual:
2140                                 op_type = CSharp.Operator.OpType.LessThanOrEqual; break;
2141                         case Operator.Modulus:
2142                                 op_type = CSharp.Operator.OpType.Modulus; break;
2143                         case Operator.Multiply:
2144                                 op_type = CSharp.Operator.OpType.Multiply; break;
2145                         case Operator.RightShift:
2146                                 op_type = CSharp.Operator.OpType.RightShift; break;
2147                         case Operator.Subtraction:
2148                                 op_type = CSharp.Operator.OpType.Subtraction; break;
2149                         default:
2150                                 throw new InternalErrorException (op.ToString ());
2151                         }
2152
2153                         return CSharp.Operator.GetMetadataName (op_type);
2154                 }
2155
2156                 public static void EmitOperatorOpcode (EmitContext ec, Operator oper, TypeSpec l)
2157                 {
2158                         OpCode opcode;
2159
2160                         switch (oper){
2161                         case Operator.Multiply:
2162                                 if (ec.HasSet (EmitContext.Options.CheckedScope)) {
2163                                         if (l == TypeManager.int32_type || l == TypeManager.int64_type)
2164                                                 opcode = OpCodes.Mul_Ovf;
2165                                         else if (!IsFloat (l))
2166                                                 opcode = OpCodes.Mul_Ovf_Un;
2167                                         else
2168                                                 opcode = OpCodes.Mul;
2169                                 } else
2170                                         opcode = OpCodes.Mul;
2171
2172                                 break;
2173
2174                         case Operator.Division:
2175                                 if (IsUnsigned (l))
2176                                         opcode = OpCodes.Div_Un;
2177                                 else
2178                                         opcode = OpCodes.Div;
2179                                 break;
2180
2181                         case Operator.Modulus:
2182                                 if (IsUnsigned (l))
2183                                         opcode = OpCodes.Rem_Un;
2184                                 else
2185                                         opcode = OpCodes.Rem;
2186                                 break;
2187
2188                         case Operator.Addition:
2189                                 if (ec.HasSet (EmitContext.Options.CheckedScope)) {
2190                                         if (l == TypeManager.int32_type || l == TypeManager.int64_type)
2191                                                 opcode = OpCodes.Add_Ovf;
2192                                         else if (!IsFloat (l))
2193                                                 opcode = OpCodes.Add_Ovf_Un;
2194                                         else
2195                                                 opcode = OpCodes.Add;
2196                                 } else
2197                                         opcode = OpCodes.Add;
2198                                 break;
2199
2200                         case Operator.Subtraction:
2201                                 if (ec.HasSet (EmitContext.Options.CheckedScope)) {
2202                                         if (l == TypeManager.int32_type || l == TypeManager.int64_type)
2203                                                 opcode = OpCodes.Sub_Ovf;
2204                                         else if (!IsFloat (l))
2205                                                 opcode = OpCodes.Sub_Ovf_Un;
2206                                         else
2207                                                 opcode = OpCodes.Sub;
2208                                 } else
2209                                         opcode = OpCodes.Sub;
2210                                 break;
2211
2212                         case Operator.RightShift:
2213                                 if (IsUnsigned (l))
2214                                         opcode = OpCodes.Shr_Un;
2215                                 else
2216                                         opcode = OpCodes.Shr;
2217                                 break;
2218
2219                         case Operator.LeftShift:
2220                                 opcode = OpCodes.Shl;
2221                                 break;
2222
2223                         case Operator.Equality:
2224                                 opcode = OpCodes.Ceq;
2225                                 break;
2226
2227                         case Operator.Inequality:
2228                                 ec.Emit (OpCodes.Ceq);
2229                                 ec.Emit (OpCodes.Ldc_I4_0);
2230
2231                                 opcode = OpCodes.Ceq;
2232                                 break;
2233
2234                         case Operator.LessThan:
2235                                 if (IsUnsigned (l))
2236                                         opcode = OpCodes.Clt_Un;
2237                                 else
2238                                         opcode = OpCodes.Clt;
2239                                 break;
2240
2241                         case Operator.GreaterThan:
2242                                 if (IsUnsigned (l))
2243                                         opcode = OpCodes.Cgt_Un;
2244                                 else
2245                                         opcode = OpCodes.Cgt;
2246                                 break;
2247
2248                         case Operator.LessThanOrEqual:
2249                                 if (IsUnsigned (l) || IsFloat (l))
2250                                         ec.Emit (OpCodes.Cgt_Un);
2251                                 else
2252                                         ec.Emit (OpCodes.Cgt);
2253                                 ec.Emit (OpCodes.Ldc_I4_0);
2254
2255                                 opcode = OpCodes.Ceq;
2256                                 break;
2257
2258                         case Operator.GreaterThanOrEqual:
2259                                 if (IsUnsigned (l) || IsFloat (l))
2260                                         ec.Emit (OpCodes.Clt_Un);
2261                                 else
2262                                         ec.Emit (OpCodes.Clt);
2263
2264                                 ec.Emit (OpCodes.Ldc_I4_0);
2265
2266                                 opcode = OpCodes.Ceq;
2267                                 break;
2268
2269                         case Operator.BitwiseOr:
2270                                 opcode = OpCodes.Or;
2271                                 break;
2272
2273                         case Operator.BitwiseAnd:
2274                                 opcode = OpCodes.And;
2275                                 break;
2276
2277                         case Operator.ExclusiveOr:
2278                                 opcode = OpCodes.Xor;
2279                                 break;
2280
2281                         default:
2282                                 throw new InternalErrorException (oper.ToString ());
2283                         }
2284
2285                         ec.Emit (opcode);
2286                 }
2287
2288                 static bool IsUnsigned (TypeSpec t)
2289                 {
2290                         if (t.IsPointer)
2291                                 return true;
2292
2293                         return (t == TypeManager.uint32_type || t == TypeManager.uint64_type ||
2294                                 t == TypeManager.ushort_type || t == TypeManager.byte_type);
2295                 }
2296
2297                 static bool IsFloat (TypeSpec t)
2298                 {
2299                         return t == TypeManager.float_type || t == TypeManager.double_type;
2300                 }
2301
2302                 public static void Reset ()
2303                 {
2304                         pointer_operators = standard_operators = null;
2305                 }
2306
2307                 Expression ResolveOperator (ResolveContext ec)
2308                 {
2309                         TypeSpec l = left.Type;
2310                         TypeSpec r = right.Type;
2311                         Expression expr;
2312                         bool primitives_only = false;
2313
2314                         if (standard_operators == null)
2315                                 CreateStandardOperatorsTable ();
2316
2317                         //
2318                         // Handles predefined primitive types
2319                         //
2320                         if (TypeManager.IsPrimitiveType (l) && TypeManager.IsPrimitiveType (r)) {
2321                                 if ((oper & Operator.ShiftMask) == 0) {
2322                                         if (l != TypeManager.bool_type && !DoBinaryOperatorPromotion (ec))
2323                                                 return null;
2324
2325                                         primitives_only = true;
2326                                 }
2327                         } else {
2328                                 // Pointers
2329                                 if (l.IsPointer || r.IsPointer)
2330                                         return ResolveOperatorPointer (ec, l, r);
2331
2332                                 // Enums
2333                                 bool lenum = TypeManager.IsEnumType (l);
2334                                 bool renum = TypeManager.IsEnumType (r);
2335                                 if (lenum || renum) {
2336                                         expr = ResolveOperatorEnum (ec, lenum, renum, l, r);
2337
2338                                         // TODO: Can this be ambiguous
2339                                         if (expr != null)
2340                                                 return expr;
2341                                 }
2342
2343                                 // Delegates
2344                                 if ((oper == Operator.Addition || oper == Operator.Subtraction || (oper & Operator.EqualityMask) != 0) &&
2345                                          (TypeManager.IsDelegateType (l) || TypeManager.IsDelegateType (r))) {
2346
2347                                         expr = ResolveOperatorDelegate (ec, l, r);
2348
2349                                         // TODO: Can this be ambiguous
2350                                         if (expr != null)
2351                                                 return expr;
2352                                 }
2353
2354                                 // User operators
2355                                 expr = ResolveUserOperator (ec, l, r);
2356                                 if (expr != null)
2357                                         return expr;
2358
2359                                 // Predefined reference types equality
2360                                 if ((oper & Operator.EqualityMask) != 0) {
2361                                         expr = ResolveOperatorEqualityRerefence (ec, l, r);
2362                                         if (expr != null)
2363                                                 return expr;
2364                                 }
2365                         }
2366
2367                         return ResolveOperatorPredefined (ec, standard_operators, primitives_only, null);
2368                 }
2369
2370                 // at least one of 'left' or 'right' is an enumeration constant (EnumConstant or SideEffectConstant or ...)
2371                 // if 'left' is not an enumeration constant, create one from the type of 'right'
2372                 Constant EnumLiftUp (ResolveContext ec, Constant left, Constant right, Location loc)
2373                 {
2374                         switch (oper) {
2375                         case Operator.BitwiseOr:
2376                         case Operator.BitwiseAnd:
2377                         case Operator.ExclusiveOr:
2378                         case Operator.Equality:
2379                         case Operator.Inequality:
2380                         case Operator.LessThan:
2381                         case Operator.LessThanOrEqual:
2382                         case Operator.GreaterThan:
2383                         case Operator.GreaterThanOrEqual:
2384                                 if (TypeManager.IsEnumType (left.Type))
2385                                         return left;
2386
2387                                 if (left.IsZeroInteger)
2388                                         return left.TryReduce (ec, right.Type, loc);
2389
2390                                 break;
2391
2392                         case Operator.Addition:
2393                         case Operator.Subtraction:
2394                                 return left;
2395
2396                         case Operator.Multiply:
2397                         case Operator.Division:
2398                         case Operator.Modulus:
2399                         case Operator.LeftShift:
2400                         case Operator.RightShift:
2401                                 if (TypeManager.IsEnumType (right.Type) || TypeManager.IsEnumType (left.Type))
2402                                         break;
2403                                 return left;
2404                         }
2405                         Error_OperatorCannotBeApplied (ec, this.left, this.right);
2406                         return null;
2407                 }
2408
2409                 //
2410                 // The `|' operator used on types which were extended is dangerous
2411                 //
2412                 void CheckBitwiseOrOnSignExtended (ResolveContext ec)
2413                 {
2414                         OpcodeCast lcast = left as OpcodeCast;
2415                         if (lcast != null) {
2416                                 if (IsUnsigned (lcast.UnderlyingType))
2417                                         lcast = null;
2418                         }
2419
2420                         OpcodeCast rcast = right as OpcodeCast;
2421                         if (rcast != null) {
2422                                 if (IsUnsigned (rcast.UnderlyingType))
2423                                         rcast = null;
2424                         }
2425
2426                         if (lcast == null && rcast == null)
2427                                 return;
2428
2429                         // FIXME: consider constants
2430
2431                         ec.Report.Warning (675, 3, loc,
2432                                 "The operator `|' used on the sign-extended type `{0}'. Consider casting to a smaller unsigned type first",
2433                                 TypeManager.CSharpName (lcast != null ? lcast.UnderlyingType : rcast.UnderlyingType));
2434                 }
2435
2436                 static void CreatePointerOperatorsTable ()
2437                 {
2438                         var temp = new List<PredefinedPointerOperator> ();
2439
2440                         //
2441                         // Pointer arithmetic:
2442                         //
2443                         // T* operator + (T* x, int y);         T* operator - (T* x, int y);
2444                         // T* operator + (T* x, uint y);        T* operator - (T* x, uint y);
2445                         // T* operator + (T* x, long y);        T* operator - (T* x, long y);
2446                         // T* operator + (T* x, ulong y);       T* operator - (T* x, ulong y);
2447                         //
2448                         temp.Add (new PredefinedPointerOperator (null, TypeManager.int32_type, Operator.AdditionMask | Operator.SubtractionMask));
2449                         temp.Add (new PredefinedPointerOperator (null, TypeManager.uint32_type, Operator.AdditionMask | Operator.SubtractionMask));
2450                         temp.Add (new PredefinedPointerOperator (null, TypeManager.int64_type, Operator.AdditionMask | Operator.SubtractionMask));
2451                         temp.Add (new PredefinedPointerOperator (null, TypeManager.uint64_type, Operator.AdditionMask | Operator.SubtractionMask));
2452
2453                         //
2454                         // T* operator + (int y,   T* x);
2455                         // T* operator + (uint y,  T *x);
2456                         // T* operator + (long y,  T *x);
2457                         // T* operator + (ulong y, T *x);
2458                         //
2459                         temp.Add (new PredefinedPointerOperator (TypeManager.int32_type, null, Operator.AdditionMask, null));
2460                         temp.Add (new PredefinedPointerOperator (TypeManager.uint32_type, null, Operator.AdditionMask, null));
2461                         temp.Add (new PredefinedPointerOperator (TypeManager.int64_type, null, Operator.AdditionMask, null));
2462                         temp.Add (new PredefinedPointerOperator (TypeManager.uint64_type, null, Operator.AdditionMask, null));
2463
2464                         //
2465                         // long operator - (T* x, T *y)
2466                         //
2467                         temp.Add (new PredefinedPointerOperator (null, Operator.SubtractionMask, TypeManager.int64_type));
2468
2469                         pointer_operators = temp.ToArray ();
2470                 }
2471
2472                 static void CreateStandardOperatorsTable ()
2473                 {
2474                         var temp = new List<PredefinedOperator> ();
2475                         TypeSpec bool_type = TypeManager.bool_type;
2476
2477                         temp.Add (new PredefinedOperator (TypeManager.int32_type, Operator.ArithmeticMask | Operator.BitwiseMask));
2478                         temp.Add (new PredefinedOperator (TypeManager.uint32_type, Operator.ArithmeticMask | Operator.BitwiseMask));
2479                         temp.Add (new PredefinedOperator (TypeManager.int64_type, Operator.ArithmeticMask | Operator.BitwiseMask));
2480                         temp.Add (new PredefinedOperator (TypeManager.uint64_type, Operator.ArithmeticMask | Operator.BitwiseMask));
2481                         temp.Add (new PredefinedOperator (TypeManager.float_type, Operator.ArithmeticMask));
2482                         temp.Add (new PredefinedOperator (TypeManager.double_type, Operator.ArithmeticMask));
2483                         temp.Add (new PredefinedOperator (TypeManager.decimal_type, Operator.ArithmeticMask));
2484
2485                         temp.Add (new PredefinedOperator (TypeManager.int32_type, Operator.ComparisonMask, bool_type));
2486                         temp.Add (new PredefinedOperator (TypeManager.uint32_type, Operator.ComparisonMask, bool_type));
2487                         temp.Add (new PredefinedOperator (TypeManager.int64_type, Operator.ComparisonMask, bool_type));
2488                         temp.Add (new PredefinedOperator (TypeManager.uint64_type, Operator.ComparisonMask, bool_type));
2489                         temp.Add (new PredefinedOperator (TypeManager.float_type, Operator.ComparisonMask, bool_type));
2490                         temp.Add (new PredefinedOperator (TypeManager.double_type, Operator.ComparisonMask, bool_type));
2491                         temp.Add (new PredefinedOperator (TypeManager.decimal_type, Operator.ComparisonMask, bool_type));
2492
2493                         temp.Add (new PredefinedOperator (TypeManager.string_type, Operator.EqualityMask, bool_type));
2494
2495                         temp.Add (new PredefinedStringOperator (TypeManager.string_type, Operator.AdditionMask));
2496                         temp.Add (new PredefinedStringOperator (TypeManager.string_type, TypeManager.object_type, Operator.AdditionMask));
2497                         temp.Add (new PredefinedStringOperator (TypeManager.object_type, TypeManager.string_type, Operator.AdditionMask));
2498
2499                         temp.Add (new PredefinedOperator (bool_type,
2500                                 Operator.BitwiseMask | Operator.LogicalMask | Operator.EqualityMask, bool_type));
2501
2502                         temp.Add (new PredefinedShiftOperator (TypeManager.int32_type, Operator.ShiftMask));
2503                         temp.Add (new PredefinedShiftOperator (TypeManager.uint32_type, Operator.ShiftMask));
2504                         temp.Add (new PredefinedShiftOperator (TypeManager.int64_type, Operator.ShiftMask));
2505                         temp.Add (new PredefinedShiftOperator (TypeManager.uint64_type, Operator.ShiftMask));
2506
2507                         standard_operators = temp.ToArray ();
2508                 }
2509
2510                 //
2511                 // Rules used during binary numeric promotion
2512                 //
2513                 static bool DoNumericPromotion (ResolveContext rc, ref Expression prim_expr, ref Expression second_expr, TypeSpec type)
2514                 {
2515                         Expression temp;
2516                         TypeSpec etype;
2517
2518                         Constant c = prim_expr as Constant;
2519                         if (c != null) {
2520                                 temp = c.ConvertImplicitly (rc, type);
2521                                 if (temp != null) {
2522                                         prim_expr = temp;
2523                                         return true;
2524                                 }
2525                         }
2526
2527                         if (type == TypeManager.uint32_type) {
2528                                 etype = prim_expr.Type;
2529                                 if (etype == TypeManager.int32_type || etype == TypeManager.short_type || etype == TypeManager.sbyte_type) {
2530                                         type = TypeManager.int64_type;
2531
2532                                         if (type != second_expr.Type) {
2533                                                 c = second_expr as Constant;
2534                                                 if (c != null)
2535                                                         temp = c.ConvertImplicitly (rc, type);
2536                                                 else
2537                                                         temp = Convert.ImplicitNumericConversion (second_expr, type);
2538                                                 if (temp == null)
2539                                                         return false;
2540                                                 second_expr = temp;
2541                                         }
2542                                 }
2543                         } else if (type == TypeManager.uint64_type) {
2544                                 //
2545                                 // A compile-time error occurs if the other operand is of type sbyte, short, int, or long
2546                                 //
2547                                 if (type == TypeManager.int32_type || type == TypeManager.int64_type ||
2548                                         type == TypeManager.short_type || type == TypeManager.sbyte_type)
2549                                         return false;
2550                         }
2551
2552                         temp = Convert.ImplicitNumericConversion (prim_expr, type);
2553                         if (temp == null)
2554                                 return false;
2555
2556                         prim_expr = temp;
2557                         return true;
2558                 }
2559
2560                 //
2561                 // 7.2.6.2 Binary numeric promotions
2562                 //
2563                 public bool DoBinaryOperatorPromotion (ResolveContext ec)
2564                 {
2565                         TypeSpec ltype = left.Type;
2566                         TypeSpec rtype = right.Type;
2567                         Expression temp;
2568
2569                         foreach (TypeSpec t in ConstantFold.BinaryPromotionsTypes) {
2570                                 if (t == ltype)
2571                                         return t == rtype || DoNumericPromotion (ec, ref right, ref left, t);
2572
2573                                 if (t == rtype)
2574                                         return t == ltype || DoNumericPromotion (ec, ref left, ref right, t);
2575                         }
2576
2577                         TypeSpec int32 = TypeManager.int32_type;
2578                         if (ltype != int32) {
2579                                 Constant c = left as Constant;
2580                                 if (c != null)
2581                                         temp = c.ConvertImplicitly (ec, int32);
2582                                 else
2583                                         temp = Convert.ImplicitNumericConversion (left, int32);
2584
2585                                 if (temp == null)
2586                                         return false;
2587                                 left = temp;
2588                         }
2589
2590                         if (rtype != int32) {
2591                                 Constant c = right as Constant;
2592                                 if (c != null)
2593                                         temp = c.ConvertImplicitly (ec, int32);
2594                                 else
2595                                         temp = Convert.ImplicitNumericConversion (right, int32);
2596
2597                                 if (temp == null)
2598                                         return false;
2599                                 right = temp;
2600                         }
2601
2602                         return true;
2603                 }
2604
2605                 protected override Expression DoResolve (ResolveContext ec)
2606                 {
2607                         if (left == null)
2608                                 return null;
2609
2610                         if ((oper == Operator.Subtraction) && (left is ParenthesizedExpression)) {
2611                                 left = ((ParenthesizedExpression) left).Expr;
2612                                 left = left.Resolve (ec, ResolveFlags.VariableOrValue | ResolveFlags.Type);
2613                                 if (left == null)
2614                                         return null;
2615
2616                                 if (left.eclass == ExprClass.Type) {
2617                                         ec.Report.Error (75, loc, "To cast a negative value, you must enclose the value in parentheses");
2618                                         return null;
2619                                 }
2620                         } else
2621                                 left = left.Resolve (ec);
2622
2623                         if (left == null)
2624                                 return null;
2625
2626                         Constant lc = left as Constant;
2627
2628                         if (lc != null && lc.Type == TypeManager.bool_type &&
2629                                 ((oper == Operator.LogicalAnd && lc.IsDefaultValue) ||
2630                                  (oper == Operator.LogicalOr && !lc.IsDefaultValue))) {
2631
2632                                 // FIXME: resolve right expression as unreachable
2633                                 // right.Resolve (ec);
2634
2635                                 ec.Report.Warning (429, 4, loc, "Unreachable expression code detected");
2636                                 return left;
2637                         }
2638
2639                         right = right.Resolve (ec);
2640                         if (right == null)
2641                                 return null;
2642
2643                         eclass = ExprClass.Value;
2644                         Constant rc = right as Constant;
2645
2646                         // The conversion rules are ignored in enum context but why
2647                         if (!ec.HasSet (ResolveContext.Options.EnumScope) && lc != null && rc != null && (TypeManager.IsEnumType (left.Type) || TypeManager.IsEnumType (right.Type))) {
2648                                 lc = EnumLiftUp (ec, lc, rc, loc);
2649                                 if (lc != null)
2650                                         rc = EnumLiftUp (ec, rc, lc, loc);
2651                         }
2652
2653                         if (rc != null && lc != null) {
2654                                 int prev_e = ec.Report.Errors;
2655                                 Expression e = ConstantFold.BinaryFold (ec, oper, lc, rc, loc);
2656                                 if (e != null)
2657                                         e = e.Resolve (ec);
2658
2659                                 if (e != null || ec.Report.Errors != prev_e)
2660                                         return e;
2661                         }
2662
2663                         // Comparison warnings
2664                         if ((oper & Operator.ComparisonMask) != 0) {
2665                                 if (left.Equals (right)) {
2666                                         ec.Report.Warning (1718, 3, loc, "A comparison made to same variable. Did you mean to compare something else?");
2667                                 }
2668                                 CheckUselessComparison (ec, lc, right.Type);
2669                                 CheckUselessComparison (ec, rc, left.Type);
2670                         }
2671
2672                         if (left.Type == InternalType.Dynamic || right.Type == InternalType.Dynamic) {
2673                                 Arguments args = new Arguments (2);
2674                                 args.Add (new Argument (left));
2675                                 args.Add (new Argument (right));
2676                                 return new DynamicExpressionStatement (this, args, loc).Resolve (ec);
2677                         }
2678
2679                         if (RootContext.Version >= LanguageVersion.ISO_2 &&
2680                                 ((TypeManager.IsNullableType (left.Type) && (right is NullLiteral || TypeManager.IsNullableType (right.Type) || TypeManager.IsValueType (right.Type))) ||
2681                                 (TypeManager.IsValueType (left.Type) && right is NullLiteral) ||
2682                                 (TypeManager.IsNullableType (right.Type) && (left is NullLiteral || TypeManager.IsNullableType (left.Type) || TypeManager.IsValueType (left.Type))) ||
2683                                 (TypeManager.IsValueType (right.Type) && left is NullLiteral)))
2684                                 return new Nullable.LiftedBinaryOperator (oper, left, right, loc).Resolve (ec);
2685
2686                         return DoResolveCore (ec, left, right);
2687                 }
2688
2689                 protected Expression DoResolveCore (ResolveContext ec, Expression left_orig, Expression right_orig)
2690                 {
2691                         Expression expr = ResolveOperator (ec);
2692                         if (expr == null)
2693                                 Error_OperatorCannotBeApplied (ec, left_orig, right_orig);
2694
2695                         if (left == null || right == null)
2696                                 throw new InternalErrorException ("Invalid conversion");
2697
2698                         if (oper == Operator.BitwiseOr)
2699                                 CheckBitwiseOrOnSignExtended (ec);
2700
2701                         return expr;
2702                 }
2703
2704                 public override SLE.Expression MakeExpression (BuilderContext ctx)
2705                 {
2706                         var le = left.MakeExpression (ctx);
2707                         var re = right.MakeExpression (ctx);
2708                         bool is_checked = ctx.HasSet (BuilderContext.Options.CheckedScope);
2709
2710                         switch (oper) {
2711                         case Operator.Addition:
2712                                 return is_checked ? SLE.Expression.AddChecked (le, re) : SLE.Expression.Add (le, re);
2713                         case Operator.BitwiseAnd:
2714                                 return SLE.Expression.And (le, re);
2715                         case Operator.BitwiseOr:
2716                                 return SLE.Expression.Or (le, re);
2717                         case Operator.Division:
2718                                 return SLE.Expression.Divide (le, re);
2719                         case Operator.Equality:
2720                                 return SLE.Expression.Equal (le, re);
2721                         case Operator.ExclusiveOr:
2722                                 return SLE.Expression.ExclusiveOr (le, re);
2723                         case Operator.GreaterThan:
2724                                 return SLE.Expression.GreaterThan (le, re);
2725                         case Operator.GreaterThanOrEqual:
2726                                 return SLE.Expression.GreaterThanOrEqual (le, re);
2727                         case Operator.Inequality:
2728                                 return SLE.Expression.NotEqual (le, re);
2729                         case Operator.LeftShift:
2730                                 return SLE.Expression.LeftShift (le, re);
2731                         case Operator.LessThan:
2732                                 return SLE.Expression.LessThan (le, re);
2733                         case Operator.LessThanOrEqual:
2734                                 return SLE.Expression.LessThanOrEqual (le, re);
2735                         case Operator.LogicalAnd:
2736                                 return SLE.Expression.AndAlso (le, re);
2737                         case Operator.LogicalOr:
2738                                 return SLE.Expression.OrElse (le, re);
2739                         case Operator.Modulus:
2740                                 return SLE.Expression.Modulo (le, re);
2741                         case Operator.Multiply:
2742                                 return is_checked ? SLE.Expression.MultiplyChecked (le, re) : SLE.Expression.Multiply (le, re);
2743                         case Operator.RightShift:
2744                                 return SLE.Expression.RightShift (le, re);
2745                         case Operator.Subtraction:
2746                                 return is_checked ? SLE.Expression.SubtractChecked (le, re) : SLE.Expression.Subtract (le, re);
2747                         default:
2748                                 throw new NotImplementedException (oper.ToString ());
2749                         }
2750                 }
2751
2752                 //
2753                 // D operator + (D x, D y)
2754                 // D operator - (D x, D y)
2755                 // bool operator == (D x, D y)
2756                 // bool operator != (D x, D y)
2757                 //
2758                 Expression ResolveOperatorDelegate (ResolveContext ec, TypeSpec l, TypeSpec r)
2759                 {
2760                         bool is_equality = (oper & Operator.EqualityMask) != 0;
2761                         if (!TypeManager.IsEqual (l, r) && !TypeSpecComparer.Variant.IsEqual (r, l)) {
2762                                 Expression tmp;
2763                                 if (right.eclass == ExprClass.MethodGroup || (r == InternalType.AnonymousMethod && !is_equality)) {
2764                                         tmp = Convert.ImplicitConversionRequired (ec, right, l, loc);
2765                                         if (tmp == null)
2766                                                 return null;
2767                                         right = tmp;
2768                                         r = right.Type;
2769                                 } else if (left.eclass == ExprClass.MethodGroup || (l == InternalType.AnonymousMethod && !is_equality)) {
2770                                         tmp = Convert.ImplicitConversionRequired (ec, left, r, loc);
2771                                         if (tmp == null)
2772                                                 return null;
2773                                         left = tmp;
2774                                         l = left.Type;
2775                                 } else {
2776                                         return null;
2777                                 }
2778                         }
2779
2780                         //
2781                         // Resolve delegate equality as a user operator
2782                         //
2783                         if (is_equality)
2784                                 return ResolveUserOperator (ec, l, r);
2785
2786                         MethodSpec method;
2787                         Arguments args = new Arguments (2);
2788                         args.Add (new Argument (left));
2789                         args.Add (new Argument (right));
2790
2791                         if (oper == Operator.Addition) {
2792                                 if (TypeManager.delegate_combine_delegate_delegate == null) {
2793                                         TypeManager.delegate_combine_delegate_delegate = TypeManager.GetPredefinedMethod (
2794                                                 TypeManager.delegate_type, "Combine", loc, TypeManager.delegate_type, TypeManager.delegate_type);
2795                                 }
2796
2797                                 method = TypeManager.delegate_combine_delegate_delegate;
2798                         } else {
2799                                 if (TypeManager.delegate_remove_delegate_delegate == null) {
2800                                         TypeManager.delegate_remove_delegate_delegate = TypeManager.GetPredefinedMethod (
2801                                                 TypeManager.delegate_type, "Remove", loc, TypeManager.delegate_type, TypeManager.delegate_type);
2802                                 }
2803
2804                                 method = TypeManager.delegate_remove_delegate_delegate;
2805                         }
2806
2807                         if (method == null)
2808                                 return new EmptyExpression (TypeManager.decimal_type);
2809
2810                         MethodGroupExpr mg = new MethodGroupExpr (method, TypeManager.delegate_type, loc);
2811                         mg = mg.OverloadResolve (ec, ref args, false, loc);
2812
2813                         return new ClassCast (new UserOperatorCall (mg, args, CreateExpressionTree, loc), l);
2814                 }
2815
2816                 //
2817                 // Enumeration operators
2818                 //
2819                 Expression ResolveOperatorEnum (ResolveContext ec, bool lenum, bool renum, TypeSpec ltype, TypeSpec rtype)
2820                 {
2821                         //
2822                         // bool operator == (E x, E y);
2823                         // bool operator != (E x, E y);
2824                         // bool operator < (E x, E y);
2825                         // bool operator > (E x, E y);
2826                         // bool operator <= (E x, E y);
2827                         // bool operator >= (E x, E y);
2828                         //
2829                         // E operator & (E x, E y);
2830                         // E operator | (E x, E y);
2831                         // E operator ^ (E x, E y);
2832                         //
2833                         // U operator - (E e, E f)
2834                         // E operator - (E e, U x)
2835                         //
2836                         // E operator + (U x, E e)
2837                         // E operator + (E e, U x)
2838                         //
2839                         if (!((oper & (Operator.ComparisonMask | Operator.BitwiseMask)) != 0 ||
2840                                 (oper == Operator.Subtraction && lenum) ||
2841                                 (oper == Operator.Addition && (lenum != renum || type != null))))       // type != null for lifted null
2842                                 return null;
2843
2844                         Expression ltemp = left;
2845                         Expression rtemp = right;
2846                         TypeSpec underlying_type;
2847                         Expression expr;
2848
2849                         if ((oper & (Operator.ComparisonMask | Operator.BitwiseMask)) != 0) {
2850                                 if (renum) {
2851                                         expr = Convert.ImplicitConversion (ec, left, rtype, loc);
2852                                         if (expr != null) {
2853                                                 left = expr;
2854                                                 ltype = expr.Type;
2855                                         }
2856                                 } else if (lenum) {
2857                                         expr = Convert.ImplicitConversion (ec, right, ltype, loc);
2858                                         if (expr != null) {
2859                                                 right = expr;
2860                                                 rtype = expr.Type;
2861                                         }
2862                                 }
2863                         }
2864
2865                         if (TypeManager.IsEqual (ltype, rtype)) {
2866                                 underlying_type = EnumSpec.GetUnderlyingType (ltype);
2867
2868                                 if (left is Constant)
2869                                         left = ((Constant) left).ConvertExplicitly (false, underlying_type).Resolve (ec);
2870                                 else
2871                                         left = EmptyCast.Create (left, underlying_type);
2872
2873                                 if (right is Constant)
2874                                         right = ((Constant) right).ConvertExplicitly (false, underlying_type).Resolve (ec);
2875                                 else
2876                                         right = EmptyCast.Create (right, underlying_type);
2877                         } else if (lenum) {
2878                                 underlying_type = EnumSpec.GetUnderlyingType (ltype);
2879
2880                                 if (oper != Operator.Subtraction && oper != Operator.Addition) {
2881                                         Constant c = right as Constant;
2882                                         if (c == null || !c.IsDefaultValue)
2883                                                 return null;
2884                                 } else {
2885                                         if (!Convert.ImplicitStandardConversionExists (right, underlying_type))
2886                                                 return null;
2887
2888                                         right = Convert.ImplicitConversionStandard (ec, right, underlying_type, right.Location);
2889                                 }
2890
2891                                 if (left is Constant)
2892                                         left = ((Constant) left).ConvertExplicitly (false, underlying_type).Resolve (ec);
2893                                 else
2894                                         left = EmptyCast.Create (left, underlying_type);
2895
2896                         } else if (renum) {
2897                                 underlying_type = EnumSpec.GetUnderlyingType (rtype);
2898
2899                                 if (oper != Operator.Addition) {
2900                                         Constant c = left as Constant;
2901                                         if (c == null || !c.IsDefaultValue)
2902                                                 return null;
2903                                 } else {
2904                                         if (!Convert.ImplicitStandardConversionExists (left, underlying_type))
2905                                                 return null;
2906
2907                                         left = Convert.ImplicitConversionStandard (ec, left, underlying_type, left.Location);
2908                                 }
2909
2910                                 if (right is Constant)
2911                                         right = ((Constant) right).ConvertExplicitly (false, underlying_type).Resolve (ec);
2912                                 else
2913                                         right = EmptyCast.Create (right, underlying_type);
2914
2915                         } else {
2916                                 return null;
2917                         }
2918
2919                         //
2920                         // C# specification uses explicit cast syntax which means binary promotion
2921                         // should happen, however it seems that csc does not do that
2922                         //
2923                         if (!DoBinaryOperatorPromotion (ec)) {
2924                                 left = ltemp;
2925                                 right = rtemp;
2926                                 return null;
2927                         }
2928
2929                         TypeSpec res_type = null;
2930                         if ((oper & Operator.BitwiseMask) != 0 || oper == Operator.Subtraction || oper == Operator.Addition) {
2931                                 TypeSpec promoted_type = lenum ? left.Type : right.Type;
2932                                 enum_conversion = Convert.ExplicitNumericConversion (
2933                                         new EmptyExpression (promoted_type), underlying_type);
2934
2935                                 if (oper == Operator.Subtraction && renum && lenum)
2936                                         res_type = underlying_type;
2937                                 else if (oper == Operator.Addition && renum)
2938                                         res_type = rtype;
2939                                 else
2940                                         res_type = ltype;
2941                         }
2942
2943                         expr = ResolveOperatorPredefined (ec, standard_operators, true, res_type);
2944                         if (!is_compound || expr == null)
2945                                 return expr;
2946
2947                         //
2948                         // Section: 7.16.2
2949                         //
2950
2951                         //
2952                         // If the return type of the selected operator is implicitly convertible to the type of x
2953                         //
2954                         if (Convert.ImplicitConversionExists (ec, expr, ltype))
2955                                 return expr;
2956
2957                         //
2958                         // Otherwise, if the selected operator is a predefined operator, if the return type of the
2959                         // selected operator is explicitly convertible to the type of x, and if y is implicitly
2960                         // convertible to the type of x or the operator is a shift operator, then the operation
2961                         // is evaluated as x = (T)(x op y), where T is the type of x
2962                         //
2963                         expr = Convert.ExplicitConversion (ec, expr, ltype, loc);
2964                         if (expr == null)
2965                                 return null;
2966
2967                         if (Convert.ImplicitConversionExists (ec, ltemp, ltype))
2968                                 return expr;
2969
2970                         return null;
2971                 }
2972
2973                 //
2974                 // 7.9.6 Reference type equality operators
2975                 //
2976                 Binary ResolveOperatorEqualityRerefence (ResolveContext ec, TypeSpec l, TypeSpec r)
2977                 {
2978                         //
2979                         // operator != (object a, object b)
2980                         // operator == (object a, object b)
2981                         //
2982
2983                         // TODO: this method is almost equivalent to Convert.ImplicitReferenceConversion
2984
2985                         if (left.eclass == ExprClass.MethodGroup || right.eclass == ExprClass.MethodGroup)
2986                                 return null;
2987
2988                         type = TypeManager.bool_type;
2989
2990                         var lgen = l as TypeParameterSpec;
2991
2992                         if (l == r) {
2993                                 if (l is InternalType)
2994                                         return null;
2995
2996                                 if (lgen != null) {
2997                                         //
2998                                         // Only allow to compare same reference type parameter
2999                                         //
3000                                         if (TypeManager.IsReferenceType (l)) {
3001                                                 left = new BoxedCast (left, TypeManager.object_type);
3002                                                 right = new BoxedCast (right, TypeManager.object_type);
3003                                                 return this;
3004                                         }
3005
3006                                         return null;
3007                                 }
3008
3009                                 if (TypeManager.IsValueType (l))
3010                                         return null;
3011
3012                                 return this;
3013                         }
3014
3015                         var rgen = r as TypeParameterSpec;
3016
3017                         //
3018                         // a, Both operands are reference-type values or the value null
3019                         // b, One operand is a value of type T where T is a type-parameter and
3020                         // the other operand is the value null. Furthermore T does not have the
3021                         // value type constrain
3022                         //
3023                         if (left is NullLiteral || right is NullLiteral) {
3024                                 if (lgen != null) {
3025                                         if (lgen.HasSpecialStruct)
3026                                                 return null;
3027
3028                                         left = new BoxedCast (left, TypeManager.object_type);
3029                                         return this;
3030                                 }
3031
3032                                 if (rgen != null) {
3033                                         if (rgen.HasSpecialStruct)
3034                                                 return null;
3035
3036                                         right = new BoxedCast (right, TypeManager.object_type);
3037                                         return this;
3038                                 }
3039                         }
3040
3041                         //
3042                         // An interface is converted to the object before the
3043                         // standard conversion is applied. It's not clear from the
3044                         // standard but it looks like it works like that.
3045                         //
3046                         if (lgen != null) {
3047                                 if (!TypeManager.IsReferenceType (l))
3048                                         return null;
3049
3050                                 l = TypeManager.object_type;
3051                                 left = new BoxedCast (left, l);
3052                         } else if (l.IsInterface) {
3053                                 l = TypeManager.object_type;
3054                         } else if (TypeManager.IsStruct (l)) {
3055                                 return null;
3056                         }
3057
3058                         if (rgen != null) {
3059                                 if (!TypeManager.IsReferenceType (r))
3060                                         return null;
3061
3062                                 r = TypeManager.object_type;
3063                                 right = new BoxedCast (right, r);
3064                         } else if (r.IsInterface) {
3065                                 r = TypeManager.object_type;
3066                         } else if (TypeManager.IsStruct (r)) {
3067                                 return null;
3068                         }
3069
3070
3071                         const string ref_comparison = "Possible unintended reference comparison. " +
3072                                 "Consider casting the {0} side of the expression to `string' to compare the values";
3073
3074                         //
3075                         // A standard implicit conversion exists from the type of either
3076                         // operand to the type of the other operand
3077                         //
3078                         if (Convert.ImplicitReferenceConversionExists (left, r)) {
3079                                 if (l == TypeManager.string_type)
3080                                         ec.Report.Warning (253, 2, loc, ref_comparison, "right");
3081
3082                                 return this;
3083                         }
3084
3085                         if (Convert.ImplicitReferenceConversionExists (right, l)) {
3086                                 if (r == TypeManager.string_type)
3087                                         ec.Report.Warning (252, 2, loc, ref_comparison, "left");
3088
3089                                 return this;
3090                         }
3091
3092                         return null;
3093                 }
3094
3095
3096                 Expression ResolveOperatorPointer (ResolveContext ec, TypeSpec l, TypeSpec r)
3097                 {
3098                         //
3099                         // bool operator == (void* x, void* y);
3100                         // bool operator != (void* x, void* y);
3101                         // bool operator < (void* x, void* y);
3102                         // bool operator > (void* x, void* y);
3103                         // bool operator <= (void* x, void* y);
3104                         // bool operator >= (void* x, void* y);
3105                         //
3106                         if ((oper & Operator.ComparisonMask) != 0) {
3107                                 Expression temp;
3108                                 if (!l.IsPointer) {
3109                                         temp = Convert.ImplicitConversion (ec, left, r, left.Location);
3110                                         if (temp == null)
3111                                                 return null;
3112                                         left = temp;
3113                                 }
3114
3115                                 if (!r.IsPointer) {
3116                                         temp = Convert.ImplicitConversion (ec, right, l, right.Location);
3117                                         if (temp == null)
3118                                                 return null;
3119                                         right = temp;
3120                                 }
3121
3122                                 type = TypeManager.bool_type;
3123                                 return this;
3124                         }
3125
3126                         if (pointer_operators == null)
3127                                 CreatePointerOperatorsTable ();
3128
3129                         return ResolveOperatorPredefined (ec, pointer_operators, false, null);
3130                 }
3131
3132                 //
3133                 // Build-in operators method overloading
3134                 //
3135                 protected virtual Expression ResolveOperatorPredefined (ResolveContext ec, PredefinedOperator [] operators, bool primitives_only, TypeSpec enum_type)
3136                 {
3137                         PredefinedOperator best_operator = null;
3138                         TypeSpec l = left.Type;
3139                         TypeSpec r = right.Type;
3140                         Operator oper_mask = oper & ~Operator.ValuesOnlyMask;
3141
3142                         foreach (PredefinedOperator po in operators) {
3143                                 if ((po.OperatorsMask & oper_mask) == 0)
3144                                         continue;
3145
3146                                 if (primitives_only) {
3147                                         if (!po.IsPrimitiveApplicable (l, r))
3148                                                 continue;
3149                                 } else {
3150                                         if (!po.IsApplicable (ec, left, right))
3151                                                 continue;
3152                                 }
3153
3154                                 if (best_operator == null) {
3155                                         best_operator = po;
3156                                         if (primitives_only)
3157                                                 break;
3158
3159                                         continue;
3160                                 }
3161
3162                                 best_operator = po.ResolveBetterOperator (ec, best_operator);
3163
3164                                 if (best_operator == null) {
3165                                         ec.Report.Error (34, loc, "Operator `{0}' is ambiguous on operands of type `{1}' and `{2}'",
3166                                                 OperName (oper), TypeManager.CSharpName (l), TypeManager.CSharpName (r));
3167
3168                                         best_operator = po;
3169                                         break;
3170                                 }
3171                         }
3172
3173                         if (best_operator == null)
3174                                 return null;
3175
3176                         Expression expr = best_operator.ConvertResult (ec, this);
3177
3178                         //
3179                         // Optimize &/&& constant expressions with 0 value
3180                         //
3181                         if (oper == Operator.BitwiseAnd || oper == Operator.LogicalAnd) {
3182                                 Constant rc = right as Constant;
3183                                 Constant lc = left as Constant;
3184                                 if ((lc != null && lc.IsDefaultValue) || (rc != null && rc.IsDefaultValue)) {
3185                                         //
3186                                         // The result is a constant with side-effect
3187                                         //
3188                                         Constant side_effect = rc == null ?
3189                                                 new SideEffectConstant (lc, right, loc) :
3190                                                 new SideEffectConstant (rc, left, loc);
3191
3192                                         return ReducedExpression.Create (side_effect.Resolve (ec), expr);
3193                                 }
3194                         }
3195
3196                         if (enum_type == null)
3197                                 return expr;
3198
3199                         //
3200                         // HACK: required by enum_conversion
3201                         //
3202                         expr.Type = enum_type;
3203                         return EmptyCast.Create (expr, enum_type);
3204                 }
3205
3206                 //
3207                 // Performs user-operator overloading
3208                 //
3209                 protected virtual Expression ResolveUserOperator (ResolveContext ec, TypeSpec l, TypeSpec r)
3210                 {
3211                         Operator user_oper;
3212                         if (oper == Operator.LogicalAnd)
3213                                 user_oper = Operator.BitwiseAnd;
3214                         else if (oper == Operator.LogicalOr)
3215                                 user_oper = Operator.BitwiseOr;
3216                         else
3217                                 user_oper = oper;
3218
3219                         string op = GetOperatorMetadataName (user_oper);
3220
3221                         MethodGroupExpr left_operators = MethodLookup (ec.Compiler, ec.CurrentType, l, MemberKind.Operator, op, 0, loc);
3222                         MethodGroupExpr right_operators = null;
3223
3224                         if (!TypeManager.IsEqual (r, l)) {
3225                                 right_operators = MethodLookup (ec.Compiler, ec.CurrentType, r, MemberKind.Operator, op, 0, loc);
3226                                 if (right_operators == null && left_operators == null)
3227                                         return null;
3228                         } else if (left_operators == null) {
3229                                 return null;
3230                         }
3231
3232                         Arguments args = new Arguments (2);
3233                         Argument larg = new Argument (left);
3234                         args.Add (larg);
3235                         Argument rarg = new Argument (right);
3236                         args.Add (rarg);
3237
3238                         MethodGroupExpr union;
3239
3240                         //
3241                         // User-defined operator implementations always take precedence
3242                         // over predefined operator implementations
3243                         //
3244                         if (left_operators != null && right_operators != null) {
3245                                 if (IsPredefinedUserOperator (l, user_oper)) {
3246                                         union = right_operators.OverloadResolve (ec, ref args, true, loc);
3247                                         if (union == null)
3248                                                 union = left_operators;
3249                                 } else if (IsPredefinedUserOperator (r, user_oper)) {
3250                                         union = left_operators.OverloadResolve (ec, ref args, true, loc);
3251                                         if (union == null)
3252                                                 union = right_operators;
3253                                 } else {
3254                                         union = MethodGroupExpr.MakeUnionSet (left_operators, right_operators, loc);
3255                                 }
3256                         } else if (left_operators != null) {
3257                                 union = left_operators;
3258                         } else {
3259                                 union = right_operators;
3260                         }
3261
3262                         union = union.OverloadResolve (ec, ref args, true, loc);
3263                         if (union == null)
3264                                 return null;
3265
3266                         Expression oper_expr;
3267
3268                         // TODO: CreateExpressionTree is allocated every time
3269                         if (user_oper != oper) {
3270                                 oper_expr = new ConditionalLogicalOperator (union, args, CreateExpressionTree,
3271                                         oper == Operator.LogicalAnd, loc).Resolve (ec);
3272                         } else {
3273                                 oper_expr = new UserOperatorCall (union, args, CreateExpressionTree, loc);
3274
3275                                 //
3276                                 // This is used to check if a test 'x == null' can be optimized to a reference equals,
3277                                 // and not invoke user operator
3278                                 //
3279                                 if ((oper & Operator.EqualityMask) != 0) {
3280                                         if ((left is NullLiteral && IsBuildInEqualityOperator (r)) ||
3281                                                 (right is NullLiteral && IsBuildInEqualityOperator (l))) {
3282                                                 type = TypeManager.bool_type;
3283                                                 if (left is NullLiteral || right is NullLiteral)
3284                                                         oper_expr = ReducedExpression.Create (this, oper_expr);
3285                                         } else if (l != r) {
3286                                                 var mi = union.BestCandidate;
3287
3288                                                 //
3289                                                 // Two System.Delegate(s) are never equal
3290                                                 //
3291                                                 if (mi.DeclaringType == TypeManager.multicast_delegate_type)
3292                                                         return null;
3293                                         }
3294                                 }
3295                         }
3296
3297                         left = larg.Expr;
3298                         right = rarg.Expr;
3299                         return oper_expr;
3300                 }
3301
3302                 public override TypeExpr ResolveAsTypeTerminal (IMemberContext ec, bool silent)
3303                 {
3304                         return null;
3305                 }
3306
3307                 private void CheckUselessComparison (ResolveContext ec, Constant c, TypeSpec type)
3308                 {
3309                         if (c == null || !IsTypeIntegral (type)
3310                                 || c is StringConstant
3311                                 || c is BoolConstant
3312                                 || c is FloatConstant
3313                                 || c is DoubleConstant
3314                                 || c is DecimalConstant
3315                                 )
3316                                 return;
3317
3318                         long value = 0;
3319
3320                         if (c is ULongConstant) {
3321                                 ulong uvalue = ((ULongConstant) c).Value;
3322                                 if (uvalue > long.MaxValue) {
3323                                         if (type == TypeManager.byte_type ||
3324                                             type == TypeManager.sbyte_type ||
3325                                             type == TypeManager.short_type ||
3326                                             type == TypeManager.ushort_type ||
3327                                             type == TypeManager.int32_type ||
3328                                             type == TypeManager.uint32_type ||
3329                                             type == TypeManager.int64_type ||
3330                                                 type == TypeManager.char_type)
3331                                                 WarnUselessComparison (ec, type);
3332                                         return;
3333                                 }
3334                                 value = (long) uvalue;
3335                         }
3336                         else if (c is ByteConstant)
3337                                 value = ((ByteConstant) c).Value;
3338                         else if (c is SByteConstant)
3339                                 value = ((SByteConstant) c).Value;
3340                         else if (c is ShortConstant)
3341                                 value = ((ShortConstant) c).Value;
3342                         else if (c is UShortConstant)
3343                                 value = ((UShortConstant) c).Value;
3344                         else if (c is IntConstant)
3345                                 value = ((IntConstant) c).Value;
3346                         else if (c is UIntConstant)
3347                                 value = ((UIntConstant) c).Value;
3348                         else if (c is LongConstant)
3349                                 value = ((LongConstant) c).Value;
3350                         else if (c is CharConstant)
3351                                 value = ((CharConstant)c).Value;
3352
3353                         if (value == 0)
3354                                 return;
3355
3356                         if (IsValueOutOfRange (value, type))
3357                                 WarnUselessComparison (ec, type);
3358                 }
3359
3360                 static bool IsValueOutOfRange (long value, TypeSpec type)
3361                 {
3362                         if (IsTypeUnsigned (type) && value < 0)
3363                                 return true;
3364                         return type == TypeManager.sbyte_type && (value >= 0x80 || value < -0x80) ||
3365                                 type == TypeManager.byte_type && value >= 0x100 ||
3366                                 type == TypeManager.short_type && (value >= 0x8000 || value < -0x8000) ||
3367                                 type == TypeManager.ushort_type && value >= 0x10000 ||
3368                                 type == TypeManager.int32_type && (value >= 0x80000000 || value < -0x80000000) ||
3369                                 type == TypeManager.uint32_type && value >= 0x100000000;
3370                 }
3371
3372                 static bool IsBuildInEqualityOperator (TypeSpec t)
3373                 {
3374                         return t == TypeManager.object_type || t == TypeManager.string_type ||
3375                                 t == TypeManager.delegate_type || TypeManager.IsDelegateType (t);
3376                 }
3377
3378                 static bool IsPredefinedUserOperator (TypeSpec t, Operator op)
3379                 {
3380                         //
3381                         // Some predefined types have user operators
3382                         //
3383                         return (op & Operator.EqualityMask) != 0 && (t == TypeManager.string_type || t == TypeManager.decimal_type);
3384                 }
3385
3386                 private static bool IsTypeIntegral (TypeSpec type)
3387                 {
3388                         return type == TypeManager.uint64_type ||
3389                                 type == TypeManager.int64_type ||
3390                                 type == TypeManager.uint32_type ||
3391                                 type == TypeManager.int32_type ||
3392                                 type == TypeManager.ushort_type ||
3393                                 type == TypeManager.short_type ||
3394                                 type == TypeManager.sbyte_type ||
3395                                 type == TypeManager.byte_type ||
3396                                 type == TypeManager.char_type;
3397                 }
3398
3399                 private static bool IsTypeUnsigned (TypeSpec type)
3400                 {
3401                         return type == TypeManager.uint64_type ||
3402                                 type == TypeManager.uint32_type ||
3403                                 type == TypeManager.ushort_type ||
3404                                 type == TypeManager.byte_type ||
3405                                 type == TypeManager.char_type;
3406                 }
3407
3408                 private void WarnUselessComparison (ResolveContext ec, TypeSpec type)
3409                 {
3410                         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}'",
3411                                 TypeManager.CSharpName (type));
3412                 }
3413
3414                 /// <remarks>
3415                 ///   EmitBranchable is called from Statement.EmitBoolExpression in the
3416                 ///   context of a conditional bool expression.  This function will return
3417                 ///   false if it is was possible to use EmitBranchable, or true if it was.
3418                 ///
3419                 ///   The expression's code is generated, and we will generate a branch to `target'
3420                 ///   if the resulting expression value is equal to isTrue
3421                 /// </remarks>
3422                 public override void EmitBranchable (EmitContext ec, Label target, bool on_true)
3423                 {
3424                         //
3425                         // This is more complicated than it looks, but its just to avoid
3426                         // duplicated tests: basically, we allow ==, !=, >, <, >= and <=
3427                         // but on top of that we want for == and != to use a special path
3428                         // if we are comparing against null
3429                         //
3430                         if ((oper == Operator.Equality || oper == Operator.Inequality) && (left is Constant || right is Constant)) {
3431                                 bool my_on_true = oper == Operator.Inequality ? on_true : !on_true;
3432
3433                                 //
3434                                 // put the constant on the rhs, for simplicity
3435                                 //
3436                                 if (left is Constant) {
3437                                         Expression swap = right;
3438                                         right = left;
3439                                         left = swap;
3440                                 }
3441
3442                                 if (((Constant) right).IsZeroInteger) {
3443                                         left.EmitBranchable (ec, target, my_on_true);
3444                                         return;
3445                                 }
3446                                 if (right.Type == TypeManager.bool_type) {
3447                                         // right is a boolean, and it's not 'false' => it is 'true'
3448                                         left.EmitBranchable (ec, target, !my_on_true);
3449                                         return;
3450                                 }
3451
3452                         } else if (oper == Operator.LogicalAnd) {
3453
3454                                 if (on_true) {
3455                                         Label tests_end = ec.DefineLabel ();
3456
3457                                         left.EmitBranchable (ec, tests_end, false);
3458                                         right.EmitBranchable (ec, target, true);
3459                                         ec.MarkLabel (tests_end);
3460                                 } else {
3461                                         //
3462                                         // This optimizes code like this
3463                                         // if (true && i > 4)
3464                                         //
3465                                         if (!(left is Constant))
3466                                                 left.EmitBranchable (ec, target, false);
3467
3468                                         if (!(right is Constant))
3469                                                 right.EmitBranchable (ec, target, false);
3470                                 }
3471
3472                                 return;
3473
3474                         } else if (oper == Operator.LogicalOr){
3475                                 if (on_true) {
3476                                         left.EmitBranchable (ec, target, true);
3477                                         right.EmitBranchable (ec, target, true);
3478
3479                                 } else {
3480                                         Label tests_end = ec.DefineLabel ();
3481                                         left.EmitBranchable (ec, tests_end, true);
3482                                         right.EmitBranchable (ec, target, false);
3483                                         ec.MarkLabel (tests_end);
3484                                 }
3485
3486                                 return;
3487
3488                         } else if (!(oper == Operator.LessThan        || oper == Operator.GreaterThan ||
3489                                      oper == Operator.LessThanOrEqual || oper == Operator.GreaterThanOrEqual ||
3490                                      oper == Operator.Equality        || oper == Operator.Inequality)) {
3491                                 base.EmitBranchable (ec, target, on_true);
3492                                 return;
3493                         }
3494
3495                         left.Emit (ec);
3496                         right.Emit (ec);
3497
3498                         TypeSpec t = left.Type;
3499                         bool is_float = IsFloat (t);
3500                         bool is_unsigned = is_float || IsUnsigned (t);
3501
3502                         switch (oper){
3503                         case Operator.Equality:
3504                                 if (on_true)
3505                                         ec.Emit (OpCodes.Beq, target);
3506                                 else
3507                                         ec.Emit (OpCodes.Bne_Un, target);
3508                                 break;
3509
3510                         case Operator.Inequality:
3511                                 if (on_true)
3512                                         ec.Emit (OpCodes.Bne_Un, target);
3513                                 else
3514                                         ec.Emit (OpCodes.Beq, target);
3515                                 break;
3516
3517                         case Operator.LessThan:
3518                                 if (on_true)
3519                                         if (is_unsigned && !is_float)
3520                                                 ec.Emit (OpCodes.Blt_Un, target);
3521                                         else
3522                                                 ec.Emit (OpCodes.Blt, target);
3523                                 else
3524                                         if (is_unsigned)
3525                                                 ec.Emit (OpCodes.Bge_Un, target);
3526                                         else
3527                                                 ec.Emit (OpCodes.Bge, target);
3528                                 break;
3529
3530                         case Operator.GreaterThan:
3531                                 if (on_true)
3532                                         if (is_unsigned && !is_float)
3533                                                 ec.Emit (OpCodes.Bgt_Un, target);
3534                                         else
3535                                                 ec.Emit (OpCodes.Bgt, target);
3536                                 else
3537                                         if (is_unsigned)
3538                                                 ec.Emit (OpCodes.Ble_Un, target);
3539                                         else
3540                                                 ec.Emit (OpCodes.Ble, target);
3541                                 break;
3542
3543                         case Operator.LessThanOrEqual:
3544                                 if (on_true)
3545                                         if (is_unsigned && !is_float)
3546                                                 ec.Emit (OpCodes.Ble_Un, target);
3547                                         else
3548                                                 ec.Emit (OpCodes.Ble, target);
3549                                 else
3550                                         if (is_unsigned)
3551                                                 ec.Emit (OpCodes.Bgt_Un, target);
3552                                         else
3553                                                 ec.Emit (OpCodes.Bgt, target);
3554                                 break;
3555
3556
3557                         case Operator.GreaterThanOrEqual:
3558                                 if (on_true)
3559                                         if (is_unsigned && !is_float)
3560                                                 ec.Emit (OpCodes.Bge_Un, target);
3561                                         else
3562                                                 ec.Emit (OpCodes.Bge, target);
3563                                 else
3564                                         if (is_unsigned)
3565                                                 ec.Emit (OpCodes.Blt_Un, target);
3566                                         else
3567                                                 ec.Emit (OpCodes.Blt, target);
3568                                 break;
3569                         default:
3570                                 throw new InternalErrorException (oper.ToString ());
3571                         }
3572                 }
3573
3574                 public override void Emit (EmitContext ec)
3575                 {
3576                         EmitOperator (ec, left.Type);
3577                 }
3578
3579                 protected virtual void EmitOperator (EmitContext ec, TypeSpec l)
3580                 {
3581                         //
3582                         // Handle short-circuit operators differently
3583                         // than the rest
3584                         //
3585                         if ((oper & Operator.LogicalMask) != 0) {
3586                                 Label load_result = ec.DefineLabel ();
3587                                 Label end = ec.DefineLabel ();
3588
3589                                 bool is_or = oper == Operator.LogicalOr;
3590                                 left.EmitBranchable (ec, load_result, is_or);
3591                                 right.Emit (ec);
3592                                 ec.Emit (OpCodes.Br_S, end);
3593
3594                                 ec.MarkLabel (load_result);
3595                                 ec.Emit (is_or ? OpCodes.Ldc_I4_1 : OpCodes.Ldc_I4_0);
3596                                 ec.MarkLabel (end);
3597                                 return;
3598                         }
3599
3600                         //
3601                         // Optimize zero-based operations which cannot be optimized at expression level
3602                         //
3603                         if (oper == Operator.Subtraction) {
3604                                 var lc = left as IntegralConstant;
3605                                 if (lc != null && lc.IsDefaultValue) {
3606                                         right.Emit (ec);
3607                                         ec.Emit (OpCodes.Neg);
3608                                         return;
3609                                 }
3610                         }
3611
3612                         left.Emit (ec);
3613                         right.Emit (ec);
3614                         EmitOperatorOpcode (ec, oper, l);
3615
3616                         //
3617                         // Nullable enum could require underlying type cast and we cannot simply wrap binary
3618                         // expression because that would wrap lifted binary operation
3619                         //
3620                         if (enum_conversion != null)
3621                                 enum_conversion.Emit (ec);
3622                 }
3623
3624                 public override void EmitSideEffect (EmitContext ec)
3625                 {
3626                         if ((oper & Operator.LogicalMask) != 0 ||
3627                                 (ec.HasSet (EmitContext.Options.CheckedScope) && (oper == Operator.Multiply || oper == Operator.Addition || oper == Operator.Subtraction))) {
3628                                 base.EmitSideEffect (ec);
3629                         } else {
3630                                 left.EmitSideEffect (ec);
3631                                 right.EmitSideEffect (ec);
3632                         }
3633                 }
3634
3635                 protected override void CloneTo (CloneContext clonectx, Expression t)
3636                 {
3637                         Binary target = (Binary) t;
3638
3639                         target.left = left.Clone (clonectx);
3640                         target.right = right.Clone (clonectx);
3641                 }
3642
3643                 public Expression CreateCallSiteBinder (ResolveContext ec, Arguments args)
3644                 {
3645                         Arguments binder_args = new Arguments (4);
3646
3647                         MemberAccess sle = new MemberAccess (new MemberAccess (
3648                                 new QualifiedAliasMember (QualifiedAliasMember.GlobalAlias, "System", loc), "Linq", loc), "Expressions", loc);
3649
3650                         CSharpBinderFlags flags = 0;
3651                         if (ec.HasSet (ResolveContext.Options.CheckedScope))
3652                                 flags = CSharpBinderFlags.CheckedContext;
3653
3654                         if ((oper & Operator.LogicalMask) != 0)
3655                                 flags |= CSharpBinderFlags.BinaryOperationLogical;
3656
3657                         binder_args.Add (new Argument (new EnumConstant (new IntLiteral ((int) flags, loc), TypeManager.binder_flags)));
3658                         binder_args.Add (new Argument (new MemberAccess (new MemberAccess (sle, "ExpressionType", loc), GetOperatorExpressionTypeName (), loc)));
3659                         binder_args.Add (new Argument (new TypeOf (new TypeExpression (ec.CurrentType, loc), loc)));
3660                         binder_args.Add (new Argument (new ImplicitlyTypedArrayCreation ("[]", args.CreateDynamicBinderArguments (ec), loc)));
3661
3662                         return new Invocation (DynamicExpressionStatement.GetBinder ("BinaryOperation", loc), binder_args);
3663                 }
3664
3665                 public override Expression CreateExpressionTree (ResolveContext ec)
3666                 {
3667                         return CreateExpressionTree (ec, null);
3668                 }
3669
3670                 Expression CreateExpressionTree (ResolveContext ec, MethodGroupExpr method)
3671                 {
3672                         string method_name;
3673                         bool lift_arg = false;
3674
3675                         switch (oper) {
3676                         case Operator.Addition:
3677                                 if (method == null && ec.HasSet (ResolveContext.Options.CheckedScope) && !IsFloat (type))
3678                                         method_name = "AddChecked";
3679                                 else
3680                                         method_name = "Add";
3681                                 break;
3682                         case Operator.BitwiseAnd:
3683                                 method_name = "And";
3684                                 break;
3685                         case Operator.BitwiseOr:
3686                                 method_name = "Or";
3687                                 break;
3688                         case Operator.Division:
3689                                 method_name = "Divide";
3690                                 break;
3691                         case Operator.Equality:
3692                                 method_name = "Equal";
3693                                 lift_arg = true;
3694                                 break;
3695                         case Operator.ExclusiveOr:
3696                                 method_name = "ExclusiveOr";
3697                                 break;
3698                         case Operator.GreaterThan:
3699                                 method_name = "GreaterThan";
3700                                 lift_arg = true;
3701                                 break;
3702                         case Operator.GreaterThanOrEqual:
3703                                 method_name = "GreaterThanOrEqual";
3704                                 lift_arg = true;
3705                                 break;
3706                         case Operator.Inequality:
3707                                 method_name = "NotEqual";
3708                                 lift_arg = true;
3709                                 break;
3710                         case Operator.LeftShift:
3711                                 method_name = "LeftShift";
3712                                 break;
3713                         case Operator.LessThan:
3714                                 method_name = "LessThan";
3715                                 lift_arg = true;
3716                                 break;
3717                         case Operator.LessThanOrEqual:
3718                                 method_name = "LessThanOrEqual";
3719                                 lift_arg = true;
3720                                 break;
3721                         case Operator.LogicalAnd:
3722                                 method_name = "AndAlso";
3723                                 break;
3724                         case Operator.LogicalOr:
3725                                 method_name = "OrElse";
3726                                 break;
3727                         case Operator.Modulus:
3728                                 method_name = "Modulo";
3729                                 break;
3730                         case Operator.Multiply:
3731                                 if (method == null && ec.HasSet (ResolveContext.Options.CheckedScope) && !IsFloat (type))
3732                                         method_name = "MultiplyChecked";
3733                                 else
3734                                         method_name = "Multiply";
3735                                 break;
3736                         case Operator.RightShift:
3737                                 method_name = "RightShift";
3738                                 break;
3739                         case Operator.Subtraction:
3740                                 if (method == null && ec.HasSet (ResolveContext.Options.CheckedScope) && !IsFloat (type))
3741                                         method_name = "SubtractChecked";
3742                                 else
3743                                         method_name = "Subtract";
3744                                 break;
3745
3746                         default:
3747                                 throw new InternalErrorException ("Unknown expression tree binary operator " + oper);
3748                         }
3749
3750                         Arguments args = new Arguments (2);
3751                         args.Add (new Argument (left.CreateExpressionTree (ec)));
3752                         args.Add (new Argument (right.CreateExpressionTree (ec)));
3753                         if (method != null) {
3754                                 if (lift_arg)
3755                                         args.Add (new Argument (new BoolConstant (false, loc)));
3756
3757                                 args.Add (new Argument (method.CreateExpressionTree (ec)));
3758                         }
3759
3760                         return CreateExpressionFactoryCall (ec, method_name, args);
3761                 }
3762         }
3763
3764         //
3765         // Represents the operation a + b [+ c [+ d [+ ...]]], where a is a string
3766         // b, c, d... may be strings or objects.
3767         //
3768         public class StringConcat : Expression {
3769                 Arguments arguments;
3770
3771                 public StringConcat (Expression left, Expression right, Location loc)
3772                 {
3773                         this.loc = loc;
3774                         type = TypeManager.string_type;
3775                         eclass = ExprClass.Value;
3776
3777                         arguments = new Arguments (2);
3778                 }
3779
3780                 public static StringConcat Create (ResolveContext rc, Expression left, Expression right, Location loc)
3781                 {
3782                         if (left.eclass == ExprClass.Unresolved || right.eclass == ExprClass.Unresolved)
3783                                 throw new ArgumentException ();
3784
3785                         var s = new StringConcat (left, right, loc);
3786                         s.Append (rc, left);
3787                         s.Append (rc, right);
3788                         return s;
3789                 }
3790
3791                 public override Expression CreateExpressionTree (ResolveContext ec)
3792                 {
3793                         Argument arg = arguments [0];
3794                         return CreateExpressionAddCall (ec, arg, arg.CreateExpressionTree (ec), 1);
3795                 }
3796
3797                 //
3798                 // Creates nested calls tree from an array of arguments used for IL emit
3799                 //
3800                 Expression CreateExpressionAddCall (ResolveContext ec, Argument left, Expression left_etree, int pos)
3801                 {
3802                         Arguments concat_args = new Arguments (2);
3803                         Arguments add_args = new Arguments (3);
3804
3805                         concat_args.Add (left);
3806                         add_args.Add (new Argument (left_etree));
3807
3808                         concat_args.Add (arguments [pos]);
3809                         add_args.Add (new Argument (arguments [pos].CreateExpressionTree (ec)));
3810
3811                         MethodGroupExpr method = CreateConcatMemberExpression ().Resolve (ec) as MethodGroupExpr;
3812                         if (method == null)
3813                                 return null;
3814
3815                         method = method.OverloadResolve (ec, ref concat_args, false, loc);
3816                         if (method == null)
3817                                 return null;
3818
3819                         add_args.Add (new Argument (method.CreateExpressionTree (ec)));
3820
3821                         Expression expr = CreateExpressionFactoryCall (ec, "Add", add_args);
3822                         if (++pos == arguments.Count)
3823                                 return expr;
3824
3825                         left = new Argument (new EmptyExpression (method.BestCandidate.ReturnType));
3826                         return CreateExpressionAddCall (ec, left, expr, pos);
3827                 }
3828
3829                 protected override Expression DoResolve (ResolveContext ec)
3830                 {
3831                         return this;
3832                 }
3833
3834                 void Append (ResolveContext rc, Expression operand)
3835                 {
3836                         //
3837                         // Constant folding
3838                         //
3839                         StringConstant sc = operand as StringConstant;
3840                         if (sc != null) {
3841                                 if (arguments.Count != 0) {
3842                                         Argument last_argument = arguments [arguments.Count - 1];
3843                                         StringConstant last_expr_constant = last_argument.Expr as StringConstant;
3844                                         if (last_expr_constant != null) {
3845                                                 last_argument.Expr = new StringConstant (
3846                                                         last_expr_constant.Value + sc.Value, sc.Location).Resolve (rc);
3847                                                 return;
3848                                         }
3849                                 }
3850                         } else {
3851                                 //
3852                                 // Multiple (3+) concatenation are resolved as multiple StringConcat instances
3853                                 //
3854                                 StringConcat concat_oper = operand as StringConcat;
3855                                 if (concat_oper != null) {
3856                                         arguments.AddRange (concat_oper.arguments);
3857                                         return;
3858                                 }
3859                         }
3860
3861                         arguments.Add (new Argument (operand));
3862                 }
3863
3864                 Expression CreateConcatMemberExpression ()
3865                 {
3866                         return new MemberAccess (new MemberAccess (new QualifiedAliasMember ("global", "System", loc), "String", loc), "Concat", loc);
3867                 }
3868
3869                 public override void Emit (EmitContext ec)
3870                 {
3871                         Expression concat = new Invocation (CreateConcatMemberExpression (), arguments, true);
3872                         concat = concat.Resolve (new ResolveContext (ec.MemberContext));
3873                         if (concat != null)
3874                                 concat.Emit (ec);
3875                 }
3876
3877                 public override SLE.Expression MakeExpression (BuilderContext ctx)
3878                 {
3879                         if (arguments.Count != 2)
3880                                 throw new NotImplementedException ("arguments.Count != 2");
3881
3882                         var concat = typeof (string).GetMethod ("Concat", new[] { typeof (object), typeof (object) });
3883                         return SLE.Expression.Add (arguments[0].Expr.MakeExpression (ctx), arguments[1].Expr.MakeExpression (ctx), concat);
3884                 }
3885         }
3886
3887         //
3888         // User-defined conditional logical operator
3889         //
3890         public class ConditionalLogicalOperator : UserOperatorCall {
3891                 readonly bool is_and;
3892                 Expression oper;
3893
3894                 public ConditionalLogicalOperator (MethodGroupExpr oper_method, Arguments arguments,
3895                         ExpressionTreeExpression expr_tree, bool is_and, Location loc)
3896                         : base (oper_method, arguments, expr_tree, loc)
3897                 {
3898                         this.is_and = is_and;
3899                         eclass = ExprClass.Unresolved;
3900                 }
3901
3902                 protected override Expression DoResolve (ResolveContext ec)
3903                 {
3904                         var method = mg.BestCandidate;
3905                         type = method.ReturnType;
3906                         AParametersCollection pd = method.Parameters;
3907                         if (!TypeManager.IsEqual (type, type) || !TypeManager.IsEqual (type, pd.Types [0]) || !TypeManager.IsEqual (type, pd.Types [1])) {
3908                                 ec.Report.Error (217, loc,
3909                                         "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",
3910                                         TypeManager.CSharpSignature (method));
3911                                 return null;
3912                         }
3913
3914                         Expression left_dup = new EmptyExpression (type);
3915                         Expression op_true = GetOperatorTrue (ec, left_dup, loc);
3916                         Expression op_false = GetOperatorFalse (ec, left_dup, loc);
3917                         if (op_true == null || op_false == null) {
3918                                 ec.Report.Error (218, loc,
3919                                         "The type `{0}' must have operator `true' and operator `false' defined when `{1}' is used as a short circuit operator",
3920                                         TypeManager.CSharpName (type), TypeManager.CSharpSignature (method));
3921                                 return null;
3922                         }
3923
3924                         oper = is_and ? op_false : op_true;
3925                         eclass = ExprClass.Value;
3926                         return this;
3927                 }
3928
3929                 public override void Emit (EmitContext ec)
3930                 {
3931                         Label end_target = ec.DefineLabel ();
3932
3933                         //
3934                         // Emit and duplicate left argument
3935                         //
3936                         arguments [0].Expr.Emit (ec);
3937                         ec.Emit (OpCodes.Dup);
3938                         arguments.RemoveAt (0);
3939
3940                         oper.EmitBranchable (ec, end_target, true);
3941                         base.Emit (ec);
3942                         ec.MarkLabel (end_target);
3943                 }
3944         }
3945
3946         public class PointerArithmetic : Expression {
3947                 Expression left, right;
3948                 Binary.Operator op;
3949
3950                 //
3951                 // We assume that `l' is always a pointer
3952                 //
3953                 public PointerArithmetic (Binary.Operator op, Expression l, Expression r, TypeSpec t, Location loc)
3954                 {
3955                         type = t;
3956                         this.loc = loc;
3957                         left = l;
3958                         right = r;
3959                         this.op = op;
3960                 }
3961
3962                 public override Expression CreateExpressionTree (ResolveContext ec)
3963                 {
3964                         Error_PointerInsideExpressionTree (ec);
3965                         return null;
3966                 }
3967
3968                 protected override Expression DoResolve (ResolveContext ec)
3969                 {
3970                         eclass = ExprClass.Variable;
3971
3972                         if (left.Type == TypeManager.void_ptr_type) {
3973                                 ec.Report.Error (242, loc, "The operation in question is undefined on void pointers");
3974                                 return null;
3975                         }
3976
3977                         return this;
3978                 }
3979
3980                 public override void Emit (EmitContext ec)
3981                 {
3982                         TypeSpec op_type = left.Type;
3983
3984                         // It must be either array or fixed buffer
3985                         TypeSpec element;
3986                         if (TypeManager.HasElementType (op_type)) {
3987                                 element = TypeManager.GetElementType (op_type);
3988                         } else {
3989                                 FieldExpr fe = left as FieldExpr;
3990                                 if (fe != null)
3991                                         element = ((FixedFieldSpec) (fe.Spec)).ElementType;
3992                                 else
3993                                         element = op_type;
3994                         }
3995
3996                         int size = GetTypeSize (element);
3997                         TypeSpec rtype = right.Type;
3998
3999                         if ((op & Binary.Operator.SubtractionMask) != 0 && rtype.IsPointer){
4000                                 //
4001                                 // handle (pointer - pointer)
4002                                 //
4003                                 left.Emit (ec);
4004                                 right.Emit (ec);
4005                                 ec.Emit (OpCodes.Sub);
4006
4007                                 if (size != 1){
4008                                         if (size == 0)
4009                                                 ec.Emit (OpCodes.Sizeof, element);
4010                                         else
4011                                                 ec.EmitInt (size);
4012                                         ec.Emit (OpCodes.Div);
4013                                 }
4014                                 ec.Emit (OpCodes.Conv_I8);
4015                         } else {
4016                                 //
4017                                 // handle + and - on (pointer op int)
4018                                 //
4019                                 Constant left_const = left as Constant;
4020                                 if (left_const != null) {
4021                                         //
4022                                         // Optimize ((T*)null) pointer operations
4023                                         //
4024                                         if (left_const.IsDefaultValue) {
4025                                                 left = EmptyExpression.Null;
4026                                         } else {
4027                                                 left_const = null;
4028                                         }
4029                                 }
4030
4031                                 left.Emit (ec);
4032
4033                                 var right_const = right as Constant;
4034                                 if (right_const != null) {
4035                                         //
4036                                         // Optimize 0-based arithmetic
4037                                         //
4038                                         if (right_const.IsDefaultValue)
4039                                                 return;
4040
4041                                         if (size != 0)
4042                                                 right = new IntConstant (size, right.Location);
4043                                         else
4044                                                 right = new SizeOf (new TypeExpression (element, right.Location), right.Location);
4045
4046                                         // TODO: Should be the checks resolve context sensitive?
4047                                         ResolveContext rc = new ResolveContext (ec.MemberContext, ResolveContext.Options.UnsafeScope);
4048                                         right = new Binary (Binary.Operator.Multiply, right, right_const, loc).Resolve (rc);
4049                                         if (right == null)
4050                                                 return;
4051                                 }
4052
4053                                 right.Emit (ec);
4054                                 if (rtype == TypeManager.sbyte_type || rtype == TypeManager.byte_type ||
4055                                         rtype == TypeManager.short_type || rtype == TypeManager.ushort_type) {
4056                                         ec.Emit (OpCodes.Conv_I);
4057                                 } else if (rtype == TypeManager.uint32_type) {
4058                                         ec.Emit (OpCodes.Conv_U);
4059                                 }
4060
4061                                 if (right_const == null && size != 1){
4062                                         if (size == 0)
4063                                                 ec.Emit (OpCodes.Sizeof, element);
4064                                         else
4065                                                 ec.EmitInt (size);
4066                                         if (rtype == TypeManager.int64_type || rtype == TypeManager.uint64_type)
4067                                                 ec.Emit (OpCodes.Conv_I8);
4068
4069                                         Binary.EmitOperatorOpcode (ec, Binary.Operator.Multiply, rtype);
4070                                 }
4071
4072                                 if (left_const == null) {
4073                                         if (rtype == TypeManager.int64_type)
4074                                                 ec.Emit (OpCodes.Conv_I);
4075                                         else if (rtype == TypeManager.uint64_type)
4076                                                 ec.Emit (OpCodes.Conv_U);
4077
4078                                         Binary.EmitOperatorOpcode (ec, op, op_type);
4079                                 }
4080                         }
4081                 }
4082         }
4083
4084         //
4085         // A boolean-expression is an expression that yields a result
4086         // of type bool
4087         //
4088         public class BooleanExpression : ShimExpression
4089         {
4090                 public BooleanExpression (Expression expr)
4091                         : base (expr)
4092                 {
4093                         this.loc = expr.Location;
4094                 }
4095
4096                 public override Expression CreateExpressionTree (ResolveContext ec)
4097                 {
4098                         // TODO: We should emit IsTrue (v4) instead of direct user operator
4099                         // call but that would break csc compatibility
4100                         return base.CreateExpressionTree (ec);
4101                 }
4102
4103                 protected override Expression DoResolve (ResolveContext ec)
4104                 {
4105                         // A boolean-expression is required to be of a type
4106                         // that can be implicitly converted to bool or of
4107                         // a type that implements operator true
4108
4109                         expr = expr.Resolve (ec);
4110                         if (expr == null)
4111                                 return null;
4112
4113                         Assign ass = expr as Assign;
4114                         if (ass != null && ass.Source is Constant) {
4115                                 ec.Report.Warning (665, 3, loc,
4116                                         "Assignment in conditional expression is always constant. Did you mean to use `==' instead ?");
4117                         }
4118
4119                         if (expr.Type == TypeManager.bool_type)
4120                                 return expr;
4121
4122                         if (expr.Type == InternalType.Dynamic) {
4123                                 Arguments args = new Arguments (1);
4124                                 args.Add (new Argument (expr));
4125                                 return new DynamicUnaryConversion ("IsTrue", args, loc).Resolve (ec);
4126                         }
4127
4128                         type = TypeManager.bool_type;
4129                         Expression converted = Convert.ImplicitConversion (ec, expr, type, loc);
4130                         if (converted != null)
4131                                 return converted;
4132
4133                         //
4134                         // If no implicit conversion to bool exists, try using `operator true'
4135                         //
4136                         converted = GetOperatorTrue (ec, expr, loc);
4137                         if (converted == null) {
4138                                 expr.Error_ValueCannotBeConverted (ec, loc, type, false);
4139                                 return null;
4140                         }
4141
4142                         return converted;
4143                 }
4144         }
4145
4146         /// <summary>
4147         ///   Implements the ternary conditional operator (?:)
4148         /// </summary>
4149         public class Conditional : Expression {
4150                 Expression expr, true_expr, false_expr;
4151
4152                 public Conditional (BooleanExpression expr, Expression true_expr, Expression false_expr)
4153                 {
4154                         this.expr = expr;
4155                         this.true_expr = true_expr;
4156                         this.false_expr = false_expr;
4157                         this.loc = expr.Location;
4158                 }
4159
4160                 public Expression Expr {
4161                         get {
4162                                 return expr;
4163                         }
4164                 }
4165
4166                 public Expression TrueExpr {
4167                         get {
4168                                 return true_expr;
4169                         }
4170                 }
4171
4172                 public Expression FalseExpr {
4173                         get {
4174                                 return false_expr;
4175                         }
4176                 }
4177
4178                 public override Expression CreateExpressionTree (ResolveContext ec)
4179                 {
4180                         Arguments args = new Arguments (3);
4181                         args.Add (new Argument (expr.CreateExpressionTree (ec)));
4182                         args.Add (new Argument (true_expr.CreateExpressionTree (ec)));
4183                         args.Add (new Argument (false_expr.CreateExpressionTree (ec)));
4184                         return CreateExpressionFactoryCall (ec, "Condition", args);
4185                 }
4186
4187                 protected override Expression DoResolve (ResolveContext ec)
4188                 {
4189                         expr = expr.Resolve (ec);
4190                         true_expr = true_expr.Resolve (ec);
4191                         false_expr = false_expr.Resolve (ec);
4192
4193                         if (true_expr == null || false_expr == null || expr == null)
4194                                 return null;
4195
4196                         eclass = ExprClass.Value;
4197                         TypeSpec true_type = true_expr.Type;
4198                         TypeSpec false_type = false_expr.Type;
4199                         type = true_type;
4200
4201                         //
4202                         // First, if an implicit conversion exists from true_expr
4203                         // to false_expr, then the result type is of type false_expr.Type
4204                         //
4205                         if (!TypeManager.IsEqual (true_type, false_type)) {
4206                                 Expression conv = Convert.ImplicitConversion (ec, true_expr, false_type, loc);
4207                                 if (conv != null) {
4208                                         //
4209                                         // Check if both can convert implicitly to each other's type
4210                                         //
4211                                         if (Convert.ImplicitConversion (ec, false_expr, true_type, loc) != null) {
4212                                                 ec.Report.Error (172, true_expr.Location,
4213                                                         "Type of conditional expression cannot be determined as `{0}' and `{1}' convert implicitly to each other",
4214                                                         TypeManager.CSharpName (true_type), TypeManager.CSharpName (false_type));
4215                                                 return null;
4216                                         }
4217                                         type = false_type;
4218                                         true_expr = conv;
4219                                 } else if ((conv = Convert.ImplicitConversion (ec, false_expr, true_type, loc)) != null) {
4220                                         false_expr = conv;
4221                                 } else {
4222                                         ec.Report.Error (173, true_expr.Location,
4223                                                 "Type of conditional expression cannot be determined because there is no implicit conversion between `{0}' and `{1}'",
4224                                                 TypeManager.CSharpName (true_type), TypeManager.CSharpName (false_type));
4225                                         return null;
4226                                 }
4227                         }
4228
4229                         // Dead code optimalization
4230                         Constant c = expr as Constant;
4231                         if (c != null){
4232                                 bool is_false = c.IsDefaultValue;
4233                                 ec.Report.Warning (429, 4, is_false ? true_expr.Location : false_expr.Location, "Unreachable expression code detected");
4234                                 return ReducedExpression.Create (is_false ? false_expr : true_expr, this).Resolve (ec);
4235                         }
4236
4237                         return this;
4238                 }
4239
4240                 public override TypeExpr ResolveAsTypeTerminal (IMemberContext ec, bool silent)
4241                 {
4242                         return null;
4243                 }
4244
4245                 public override void Emit (EmitContext ec)
4246                 {
4247                         Label false_target = ec.DefineLabel ();
4248                         Label end_target = ec.DefineLabel ();
4249
4250                         expr.EmitBranchable (ec, false_target, false);
4251                         true_expr.Emit (ec);
4252
4253                         if (type.IsInterface) {
4254                                 LocalBuilder temp = ec.GetTemporaryLocal (type);
4255                                 ec.Emit (OpCodes.Stloc, temp);
4256                                 ec.Emit (OpCodes.Ldloc, temp);
4257                                 ec.FreeTemporaryLocal (temp, type);
4258                         }
4259
4260                         ec.Emit (OpCodes.Br, end_target);
4261                         ec.MarkLabel (false_target);
4262                         false_expr.Emit (ec);
4263                         ec.MarkLabel (end_target);
4264                 }
4265
4266                 protected override void CloneTo (CloneContext clonectx, Expression t)
4267                 {
4268                         Conditional target = (Conditional) t;
4269
4270                         target.expr = expr.Clone (clonectx);
4271                         target.true_expr = true_expr.Clone (clonectx);
4272                         target.false_expr = false_expr.Clone (clonectx);
4273                 }
4274         }
4275
4276         public abstract class VariableReference : Expression, IAssignMethod, IMemoryLocation, IVariableReference {
4277                 LocalTemporary temp;
4278
4279                 #region Abstract
4280                 public abstract HoistedVariable GetHoistedVariable (AnonymousExpression ae);
4281                 public abstract bool IsFixed { get; }
4282                 public abstract bool IsRef { get; }
4283                 public abstract string Name { get; }
4284                 public abstract void SetHasAddressTaken ();
4285
4286                 //
4287                 // Variable IL data, it has to be protected to encapsulate hoisted variables
4288                 //
4289                 protected abstract ILocalVariable Variable { get; }
4290
4291                 //
4292                 // Variable flow-analysis data
4293                 //
4294                 public abstract VariableInfo VariableInfo { get; }
4295                 #endregion
4296
4297                 public virtual void AddressOf (EmitContext ec, AddressOp mode)
4298                 {
4299                         HoistedVariable hv = GetHoistedVariable (ec);
4300                         if (hv != null) {
4301                                 hv.AddressOf (ec, mode);
4302                                 return;
4303                         }
4304
4305                         Variable.EmitAddressOf (ec);
4306                 }
4307
4308                 public HoistedVariable GetHoistedVariable (ResolveContext rc)
4309                 {
4310                         return GetHoistedVariable (rc.CurrentAnonymousMethod);
4311                 }
4312
4313                 public HoistedVariable GetHoistedVariable (EmitContext ec)
4314                 {
4315                         return GetHoistedVariable (ec.CurrentAnonymousMethod);
4316                 }
4317
4318                 public override string GetSignatureForError ()
4319                 {
4320                         return Name;
4321                 }
4322
4323                 public override void Emit (EmitContext ec)
4324                 {
4325                         Emit (ec, false);
4326                 }
4327
4328                 public override void EmitSideEffect (EmitContext ec)
4329                 {
4330                         // do nothing
4331                 }
4332
4333                 //
4334                 // This method is used by parameters that are references, that are
4335                 // being passed as references:  we only want to pass the pointer (that
4336                 // is already stored in the parameter, not the address of the pointer,
4337                 // and not the value of the variable).
4338                 //
4339                 public void EmitLoad (EmitContext ec)
4340                 {
4341                         Variable.Emit (ec);
4342                 }
4343
4344                 public void Emit (EmitContext ec, bool leave_copy)
4345                 {
4346                         Report.Debug (64, "VARIABLE EMIT", this, Variable, type, IsRef, loc);
4347
4348                         HoistedVariable hv = GetHoistedVariable (ec);
4349                         if (hv != null) {
4350                                 hv.Emit (ec, leave_copy);
4351                                 return;
4352                         }
4353
4354                         EmitLoad (ec);
4355
4356                         if (IsRef) {
4357                                 //
4358                                 // If we are a reference, we loaded on the stack a pointer
4359                                 // Now lets load the real value
4360                                 //
4361                                 ec.EmitLoadFromPtr (type);
4362                         }
4363
4364                         if (leave_copy) {
4365                                 ec.Emit (OpCodes.Dup);
4366
4367                                 if (IsRef) {
4368                                         temp = new LocalTemporary (Type);
4369                                         temp.Store (ec);
4370                                 }
4371                         }
4372                 }
4373
4374                 public void EmitAssign (EmitContext ec, Expression source, bool leave_copy,
4375                                         bool prepare_for_load)
4376                 {
4377                         HoistedVariable hv = GetHoistedVariable (ec);
4378                         if (hv != null) {
4379                                 hv.EmitAssign (ec, source, leave_copy, prepare_for_load);
4380                                 return;
4381                         }
4382
4383                         New n_source = source as New;
4384                         if (n_source != null) {
4385                                 if (!n_source.Emit (ec, this)) {
4386                                         if (leave_copy)
4387                                                 EmitLoad (ec);
4388                                         return;
4389                                 }
4390                         } else {
4391                                 if (IsRef)
4392                                         EmitLoad (ec);
4393
4394                                 source.Emit (ec);
4395                         }
4396
4397                         if (leave_copy) {
4398                                 ec.Emit (OpCodes.Dup);
4399                                 if (IsRef) {
4400                                         temp = new LocalTemporary (Type);
4401                                         temp.Store (ec);
4402                                 }
4403                         }
4404
4405                         if (IsRef)
4406                                 ec.EmitStoreFromPtr (type);
4407                         else
4408                                 Variable.EmitAssign (ec);
4409
4410                         if (temp != null) {
4411                                 temp.Emit (ec);
4412                                 temp.Release (ec);
4413                         }
4414                 }
4415
4416                 public bool IsHoisted {
4417                         get { return GetHoistedVariable ((AnonymousExpression) null) != null; }
4418                 }
4419         }
4420
4421         /// <summary>
4422         ///   Local variables
4423         /// </summary>
4424         public class LocalVariableReference : VariableReference {
4425                 readonly string name;
4426                 public Block Block;
4427                 public LocalInfo local_info;
4428                 bool is_readonly;
4429
4430                 public LocalVariableReference (Block block, string name, Location l)
4431                 {
4432                         Block = block;
4433                         this.name = name;
4434                         loc = l;
4435                 }
4436
4437                 //
4438                 // Setting `is_readonly' to false will allow you to create a writable
4439                 // reference to a read-only variable.  This is used by foreach and using.
4440                 //
4441                 public LocalVariableReference (Block block, string name, Location l,
4442                                                LocalInfo local_info, bool is_readonly)
4443                         : this (block, name, l)
4444                 {
4445                         this.local_info = local_info;
4446                         this.is_readonly = is_readonly;
4447                 }
4448
4449                 public override VariableInfo VariableInfo {
4450                         get { return local_info.VariableInfo; }
4451                 }
4452
4453                 public override HoistedVariable GetHoistedVariable (AnonymousExpression ae)
4454                 {
4455                         return local_info.HoistedVariant;
4456                 }
4457
4458                 //
4459                 // A local variable is always fixed
4460                 //
4461                 public override bool IsFixed {
4462                         get { return true; }
4463                 }
4464
4465                 public override bool IsRef {
4466                         get { return false; }
4467                 }
4468
4469                 public bool IsReadOnly {
4470                         get { return is_readonly; }
4471                 }
4472
4473                 public override string Name {
4474                         get { return name; }
4475                 }
4476
4477                 public bool VerifyAssigned (ResolveContext ec)
4478                 {
4479                         VariableInfo variable_info = local_info.VariableInfo;
4480                         return variable_info == null || variable_info.IsAssigned (ec, loc);
4481                 }
4482
4483                 void ResolveLocalInfo ()
4484                 {
4485                         if (local_info == null) {
4486                                 local_info = Block.GetLocalInfo (Name);
4487                                 type = local_info.VariableType;
4488                                 is_readonly = local_info.ReadOnly;
4489                         }
4490                 }
4491
4492                 public override void SetHasAddressTaken ()
4493                 {
4494                         local_info.AddressTaken = true;
4495                 }
4496
4497                 public override Expression CreateExpressionTree (ResolveContext ec)
4498                 {
4499                         HoistedVariable hv = GetHoistedVariable (ec);
4500                         if (hv != null)
4501                                 return hv.CreateExpressionTree ();
4502
4503                         Arguments arg = new Arguments (1);
4504                         arg.Add (new Argument (this));
4505                         return CreateExpressionFactoryCall (ec, "Constant", arg);
4506                 }
4507
4508                 Expression DoResolveBase (ResolveContext ec)
4509                 {
4510                         Expression e = Block.GetConstantExpression (Name);
4511                         if (e != null)
4512                                 return e.Resolve (ec);
4513
4514                         VerifyAssigned (ec);
4515
4516                         //
4517                         // If we are referencing a variable from the external block
4518                         // flag it for capturing
4519                         //
4520                         if (ec.MustCaptureVariable (local_info)) {
4521                                 if (local_info.AddressTaken)
4522                                         AnonymousMethodExpression.Error_AddressOfCapturedVar (ec, this, loc);
4523
4524                                 if (ec.IsVariableCapturingRequired) {
4525                                         AnonymousMethodStorey storey = local_info.Block.Explicit.CreateAnonymousMethodStorey (ec);
4526                                         storey.CaptureLocalVariable (ec, local_info);
4527                                 }
4528                         }
4529
4530                         eclass = ExprClass.Variable;
4531                         type = local_info.VariableType;
4532                         return this;
4533                 }
4534
4535                 protected override Expression DoResolve (ResolveContext ec)
4536                 {
4537                         ResolveLocalInfo ();
4538                         local_info.Used = true;
4539
4540                         if (type == null && local_info.Type is VarExpr) {
4541                             local_info.VariableType = TypeManager.object_type;
4542                                 Error_VariableIsUsedBeforeItIsDeclared (ec.Report, Name);
4543                             return null;
4544                         }
4545
4546                         return DoResolveBase (ec);
4547                 }
4548
4549                 public override Expression DoResolveLValue (ResolveContext ec, Expression right_side)
4550                 {
4551                         ResolveLocalInfo ();
4552
4553                         // is out param
4554                         if (right_side == EmptyExpression.OutAccess.Instance)
4555                                 local_info.Used = true;
4556
4557                         // Infer implicitly typed local variable
4558                         if (type == null) {
4559                                 VarExpr ve = local_info.Type as VarExpr;
4560                                 if (ve != null) {
4561                                         if (!ve.InferType (ec, right_side))
4562                                                 return null;
4563                                         type = local_info.VariableType = ve.Type;
4564                                 }
4565                         }
4566
4567                         if (is_readonly) {
4568                                 int code;
4569                                 string msg;
4570                                 if (right_side == EmptyExpression.OutAccess.Instance) {
4571                                         code = 1657; msg = "Cannot pass `{0}' as a ref or out argument because it is a `{1}'";
4572                                 } else if (right_side == EmptyExpression.LValueMemberAccess) {
4573                                         code = 1654; msg = "Cannot assign to members of `{0}' because it is a `{1}'";
4574                                 } else if (right_side == EmptyExpression.LValueMemberOutAccess) {
4575                                         code = 1655; msg = "Cannot pass members of `{0}' as ref or out arguments because it is a `{1}'";
4576                                 } else if (right_side == EmptyExpression.UnaryAddress) {
4577                                         code = 459; msg = "Cannot take the address of {1} `{0}'";
4578                                 } else {
4579                                         code = 1656; msg = "Cannot assign to `{0}' because it is a `{1}'";
4580                                 }
4581                                 ec.Report.Error (code, loc, msg, Name, local_info.GetReadOnlyContext ());
4582                         } else if (VariableInfo != null) {
4583                                 VariableInfo.SetAssigned (ec);
4584                         }
4585
4586                         return DoResolveBase (ec);
4587                 }
4588
4589                 public override int GetHashCode ()
4590                 {
4591                         return Name.GetHashCode ();
4592                 }
4593
4594                 public override bool Equals (object obj)
4595                 {
4596                         LocalVariableReference lvr = obj as LocalVariableReference;
4597                         if (lvr == null)
4598                                 return false;
4599
4600                         return Name == lvr.Name && Block == lvr.Block;
4601                 }
4602
4603                 protected override ILocalVariable Variable {
4604                         get { return local_info; }
4605                 }
4606
4607                 public override string ToString ()
4608                 {
4609                         return String.Format ("{0} ({1}:{2})", GetType (), Name, loc);
4610                 }
4611
4612                 protected override void CloneTo (CloneContext clonectx, Expression t)
4613                 {
4614                         LocalVariableReference target = (LocalVariableReference) t;
4615
4616                         target.Block = clonectx.LookupBlock (Block);
4617                         if (local_info != null)
4618                                 target.local_info = clonectx.LookupVariable (local_info);
4619                 }
4620         }
4621
4622         /// <summary>
4623         ///   This represents a reference to a parameter in the intermediate
4624         ///   representation.
4625         /// </summary>
4626         public class ParameterReference : VariableReference {
4627                 readonly ToplevelParameterInfo pi;
4628
4629                 public ParameterReference (ToplevelParameterInfo pi, Location loc)
4630                 {
4631                         this.pi = pi;
4632                         this.loc = loc;
4633                 }
4634
4635                 public override bool IsRef {
4636                         get { return (pi.Parameter.ModFlags & Parameter.Modifier.ISBYREF) != 0; }
4637                 }
4638
4639                 bool HasOutModifier {
4640                         get { return pi.Parameter.ModFlags == Parameter.Modifier.OUT; }
4641                 }
4642
4643                 public override HoistedVariable GetHoistedVariable (AnonymousExpression ae)
4644                 {
4645                         return pi.Parameter.HoistedVariant;
4646                 }
4647
4648                 //
4649                 // A ref or out parameter is classified as a moveable variable, even
4650                 // if the argument given for the parameter is a fixed variable
4651                 //
4652                 public override bool IsFixed {
4653                         get { return !IsRef; }
4654                 }
4655
4656                 public override string Name {
4657                         get { return Parameter.Name; }
4658                 }
4659
4660                 public Parameter Parameter {
4661                         get { return pi.Parameter; }
4662                 }
4663
4664                 public override VariableInfo VariableInfo {
4665                         get { return pi.VariableInfo; }
4666                 }
4667
4668                 protected override ILocalVariable Variable {
4669                         get { return Parameter; }
4670                 }
4671
4672                 public bool IsAssigned (ResolveContext ec, Location loc)
4673                 {
4674                         // HACK: Variables are not captured in probing mode
4675                         if (ec.IsInProbingMode)
4676                                 return true;
4677
4678                         if (!ec.DoFlowAnalysis || !HasOutModifier || ec.CurrentBranching.IsAssigned (VariableInfo))
4679                                 return true;
4680
4681                         ec.Report.Error (269, loc, "Use of unassigned out parameter `{0}'", Name);
4682                         return false;
4683                 }
4684
4685                 public override void SetHasAddressTaken ()
4686                 {
4687                         Parameter.HasAddressTaken = true;
4688                 }
4689
4690                 void SetAssigned (ResolveContext ec)
4691                 {
4692                         if (HasOutModifier && ec.DoFlowAnalysis)
4693                                 ec.CurrentBranching.SetAssigned (VariableInfo);
4694                 }
4695
4696                 bool DoResolveBase (ResolveContext ec)
4697                 {
4698                         type = pi.ParameterType;
4699                         eclass = ExprClass.Variable;
4700
4701                         AnonymousExpression am = ec.CurrentAnonymousMethod;
4702                         if (am == null)
4703                                 return true;
4704
4705                         Block b = ec.CurrentBlock;
4706                         while (b != null) {
4707                                 b = b.Toplevel;
4708                                 IParameterData[] p = b.Toplevel.Parameters.FixedParameters;
4709                                 for (int i = 0; i < p.Length; ++i) {
4710                                         if (p [i] != Parameter)
4711                                                 continue;
4712
4713                                         //
4714                                         // Don't capture local parameters
4715                                         //
4716                                         if (b == ec.CurrentBlock.Toplevel && !am.IsIterator)
4717                                                 return true;
4718
4719                                         if (IsRef) {
4720                                                 ec.Report.Error (1628, loc,
4721                                                         "Parameter `{0}' cannot be used inside `{1}' when using `ref' or `out' modifier",
4722                                                         Name, am.ContainerType);
4723                                         }
4724
4725                                         if (pi.Parameter.HasAddressTaken)
4726                                                 AnonymousMethodExpression.Error_AddressOfCapturedVar (ec, this, loc);
4727
4728                                         if (ec.IsVariableCapturingRequired && !b.Toplevel.IsExpressionTree) {
4729                                                 AnonymousMethodStorey storey = pi.Block.CreateAnonymousMethodStorey (ec);
4730                                                 storey.CaptureParameter (ec, this);
4731                                         }
4732
4733                                         return true;
4734                                 }
4735
4736                                 b = b.Parent;
4737                         }
4738
4739                         return true;
4740                 }
4741
4742                 public override int GetHashCode ()
4743                 {
4744                         return Name.GetHashCode ();
4745                 }
4746
4747                 public override bool Equals (object obj)
4748                 {
4749                         ParameterReference pr = obj as ParameterReference;
4750                         if (pr == null)
4751                                 return false;
4752
4753                         return Name == pr.Name;
4754                 }
4755
4756                 public override void AddressOf (EmitContext ec, AddressOp mode)
4757                 {
4758                         //
4759                         // ParameterReferences might already be a reference
4760                         //
4761                         if (IsRef) {
4762                                 EmitLoad (ec);
4763                                 return;
4764                         }
4765
4766                         base.AddressOf (ec, mode);
4767                 }
4768
4769                 protected override void CloneTo (CloneContext clonectx, Expression target)
4770                 {
4771                         // Nothing to clone
4772                 }
4773
4774                 public override Expression CreateExpressionTree (ResolveContext ec)
4775                 {
4776                         HoistedVariable hv = GetHoistedVariable (ec);
4777                         if (hv != null)
4778                                 return hv.CreateExpressionTree ();
4779
4780                         return Parameter.ExpressionTreeVariableReference ();
4781                 }
4782
4783                 //
4784                 // Notice that for ref/out parameters, the type exposed is not the
4785                 // same type exposed externally.
4786                 //
4787                 // for "ref int a":
4788                 //   externally we expose "int&"
4789                 //   here we expose       "int".
4790                 //
4791                 // We record this in "is_ref".  This means that the type system can treat
4792                 // the type as it is expected, but when we generate the code, we generate
4793                 // the alternate kind of code.
4794                 //
4795                 protected override Expression DoResolve (ResolveContext ec)
4796                 {
4797                         if (!DoResolveBase (ec))
4798                                 return null;
4799
4800                         // HACK: Variables are not captured in probing mode
4801                         if (ec.IsInProbingMode)
4802                                 return this;
4803
4804                         if (HasOutModifier && ec.DoFlowAnalysis &&
4805                             (!ec.OmitStructFlowAnalysis || !VariableInfo.TypeInfo.IsStruct) && !IsAssigned (ec, loc))
4806                                 return null;
4807
4808                         return this;
4809                 }
4810
4811                 override public Expression DoResolveLValue (ResolveContext ec, Expression right_side)
4812                 {
4813                         if (!DoResolveBase (ec))
4814                                 return null;
4815
4816                         // HACK: parameters are not captured when probing is on
4817                         if (!ec.IsInProbingMode)
4818                                 SetAssigned (ec);
4819
4820                         return this;
4821                 }
4822
4823                 static public void EmitLdArg (EmitContext ec, int x)
4824                 {
4825                         switch (x) {
4826                         case 0: ec.Emit (OpCodes.Ldarg_0); break;
4827                         case 1: ec.Emit (OpCodes.Ldarg_1); break;
4828                         case 2: ec.Emit (OpCodes.Ldarg_2); break;
4829                         case 3: ec.Emit (OpCodes.Ldarg_3); break;
4830                         default:
4831                                 if (x > byte.MaxValue)
4832                                         ec.Emit (OpCodes.Ldarg, x);
4833                                 else
4834                                         ec.Emit (OpCodes.Ldarg_S, (byte) x);
4835                                 break;
4836                         }
4837                 }
4838         }
4839
4840         /// <summary>
4841         ///   Invocation of methods or delegates.
4842         /// </summary>
4843         public class Invocation : ExpressionStatement
4844         {
4845                 protected Arguments arguments;
4846                 protected Expression expr;
4847                 protected MethodGroupExpr mg;
4848                 bool arguments_resolved;
4849
4850                 //
4851                 // arguments is an ArrayList, but we do not want to typecast,
4852                 // as it might be null.
4853                 //
4854                 public Invocation (Expression expr, Arguments arguments)
4855                 {
4856                         SimpleName sn = expr as SimpleName;
4857                         if (sn != null)
4858                                 this.expr = sn.GetMethodGroup ();
4859                         else
4860                                 this.expr = expr;
4861
4862                         this.arguments = arguments;
4863                         if (expr != null)
4864                                 loc = expr.Location;
4865                 }
4866
4867                 public Invocation (Expression expr, Arguments arguments, bool arguments_resolved)
4868                         : this (expr, arguments)
4869                 {
4870                         this.arguments_resolved = arguments_resolved;
4871                 }
4872
4873                 public override Expression CreateExpressionTree (ResolveContext ec)
4874                 {
4875                         Expression instance = mg.IsInstance ?
4876                                 mg.InstanceExpression.CreateExpressionTree (ec) :
4877                                 new NullLiteral (loc);
4878
4879                         var args = Arguments.CreateForExpressionTree (ec, arguments,
4880                                 instance,
4881                                 mg.CreateExpressionTree (ec));
4882
4883                         if (mg.IsBase)
4884                                 MemberExpr.Error_BaseAccessInExpressionTree (ec, loc);
4885
4886                         return CreateExpressionFactoryCall (ec, "Call", args);
4887                 }
4888
4889                 protected override Expression DoResolve (ResolveContext ec)
4890                 {
4891                         Expression member_expr = expr.Resolve (ec, ResolveFlags.VariableOrValue | ResolveFlags.MethodGroup);
4892                         if (member_expr == null)
4893                                 return null;
4894
4895                         //
4896                         // Next, evaluate all the expressions in the argument list
4897                         //
4898                         bool dynamic_arg = false;
4899                         if (arguments != null && !arguments_resolved)
4900                                 arguments.Resolve (ec, out dynamic_arg);
4901
4902                         TypeSpec expr_type = member_expr.Type;
4903                         mg = member_expr as MethodGroupExpr;
4904
4905                         bool dynamic_member = expr_type == InternalType.Dynamic;
4906
4907                         if (!dynamic_member) {
4908                                 Expression invoke = null;
4909
4910                                 if (mg == null) {
4911                                         if (expr_type != null && TypeManager.IsDelegateType (expr_type)) {
4912                                                 invoke = new DelegateInvocation (member_expr, arguments, loc);
4913                                                 invoke = invoke.Resolve (ec);
4914                                                 if (invoke == null || !dynamic_arg)
4915                                                         return invoke;
4916                                         } else {
4917                                                 MemberExpr me = member_expr as MemberExpr;
4918                                                 if (me == null) {
4919                                                         member_expr.Error_UnexpectedKind (ec, ResolveFlags.MethodGroup, loc);
4920                                                         return null;
4921                                                 }
4922
4923                                                 mg = ec.LookupExtensionMethod (me.Type, me.Name, -1, loc);
4924                                                 if (mg == null) {
4925                                                         ec.Report.Error (1955, loc, "The member `{0}' cannot be used as method or delegate",
4926                                                                 member_expr.GetSignatureForError ());
4927                                                         return null;
4928                                                 }
4929
4930                                                 ((ExtensionMethodGroupExpr) mg).ExtensionExpression = me.InstanceExpression;
4931                                         }
4932                                 }
4933
4934                                 if (invoke == null) {
4935                                         mg = DoResolveOverload (ec);
4936                                         if (mg == null)
4937                                                 return null;
4938                                 }
4939                         }
4940
4941                         if (dynamic_arg || dynamic_member)
4942                                 return DoResolveDynamic (ec, member_expr);
4943
4944                         var method = mg.BestCandidate;
4945                         if (method != null) {
4946                                 type = method.ReturnType;
4947                         }
4948
4949                         //
4950                         // Only base will allow this invocation to happen.
4951                         //
4952                         if (mg.IsBase && method.IsAbstract){
4953                                 Error_CannotCallAbstractBase (ec, TypeManager.CSharpSignature (method));
4954                                 return null;
4955                         }
4956
4957                         if (arguments == null && method.DeclaringType == TypeManager.object_type && method.Name == Destructor.MetadataName) {
4958                                 if (mg.IsBase)
4959                                         ec.Report.Error (250, loc, "Do not directly call your base class Finalize method. It is called automatically from your destructor");
4960                                 else
4961                                         ec.Report.Error (245, loc, "Destructors and object.Finalize cannot be called directly. Consider calling IDisposable.Dispose if available");
4962                                 return null;
4963                         }
4964
4965                         IsSpecialMethodInvocation (ec, method, loc);
4966
4967                         if (mg.InstanceExpression != null)
4968                                 mg.InstanceExpression.CheckMarshalByRefAccess (ec);
4969
4970                         eclass = ExprClass.Value;
4971                         return this;
4972                 }
4973
4974                 Expression DoResolveDynamic (ResolveContext ec, Expression memberExpr)
4975                 {
4976                         Arguments args;
4977                         DynamicMemberBinder dmb = memberExpr as DynamicMemberBinder;
4978                         if (dmb != null) {
4979                                 args = dmb.Arguments;
4980                                 if (arguments != null)
4981                                         args.AddRange (arguments);
4982                         } else if (mg == null) {
4983                                 if (arguments == null)
4984                                         args = new Arguments (1);
4985                                 else
4986                                         args = arguments;
4987
4988                                 args.Insert (0, new Argument (memberExpr));
4989                                 this.expr = null;
4990                         } else {
4991                                 if (mg.IsBase) {
4992                                         ec.Report.Error (1971, loc,
4993                                                 "The base call to method `{0}' cannot be dynamically dispatched. Consider casting the dynamic arguments or eliminating the base access",
4994                                                 mg.Name);
4995                                         return null;
4996                                 }
4997
4998                                 args = arguments;
4999
5000                                 if (mg.IsStatic != mg.IsInstance) {
5001                                         if (args == null)
5002                                                 args = new Arguments (1);
5003
5004                                         if (mg.IsStatic) {
5005                                                 args.Insert (0, new Argument (new TypeOf (new TypeExpression (mg.DeclaringType, loc), loc).Resolve (ec), Argument.AType.DynamicTypeName));
5006                                         } else {
5007                                                 MemberAccess ma = expr as MemberAccess;
5008                                                 if (ma != null)
5009                                                         args.Insert (0, new Argument (ma.Left.Resolve (ec)));
5010                                                 else
5011                                                         args.Insert (0, new Argument (new This (loc).Resolve (ec)));
5012                                         }
5013                                 }
5014                         }
5015
5016                         return new DynamicInvocation (expr as ATypeNameExpression, args, loc).Resolve (ec);
5017                 }
5018
5019                 protected virtual MethodGroupExpr DoResolveOverload (ResolveContext ec)
5020                 {
5021                         return mg.OverloadResolve (ec, ref arguments, false, loc);
5022                 }
5023
5024                 public static bool IsSpecialMethodInvocation (ResolveContext ec, MethodSpec method, Location loc)
5025                 {
5026                         if (!method.IsReservedMethod)
5027                                 return false;
5028
5029                         if (ec.HasSet (ResolveContext.Options.InvokeSpecialName))
5030                                 return false;
5031
5032                         ec.Report.SymbolRelatedToPreviousError (method);
5033                         ec.Report.Error (571, loc, "`{0}': cannot explicitly call operator or accessor",
5034                                 method.GetSignatureForError ());
5035
5036                         return true;
5037                 }
5038
5039                 static Type[] GetVarargsTypes (MethodSpec mb, Arguments arguments)
5040                 {
5041                         AParametersCollection pd = mb.Parameters;
5042
5043                         Argument a = arguments [pd.Count - 1];
5044                         Arglist list = (Arglist) a.Expr;
5045
5046                         return list.ArgumentTypes;
5047                 }
5048
5049                 /// <remarks>
5050                 ///   is_base tells whether we want to force the use of the `call'
5051                 ///   opcode instead of using callvirt.  Call is required to call
5052                 ///   a specific method, while callvirt will always use the most
5053                 ///   recent method in the vtable.
5054                 ///
5055                 ///   is_static tells whether this is an invocation on a static method
5056                 ///
5057                 ///   instance_expr is an expression that represents the instance
5058                 ///   it must be non-null if is_static is false.
5059                 ///
5060                 ///   method is the method to invoke.
5061                 ///
5062                 ///   Arguments is the list of arguments to pass to the method or constructor.
5063                 /// </remarks>
5064                 public static void EmitCall (EmitContext ec, bool is_base,
5065                                              Expression instance_expr,
5066                                              MethodSpec method, Arguments Arguments, Location loc)
5067                 {
5068                         EmitCall (ec, is_base, instance_expr, method, Arguments, loc, false, false);
5069                 }
5070
5071                 // `dup_args' leaves an extra copy of the arguments on the stack
5072                 // `omit_args' does not leave any arguments at all.
5073                 // So, basically, you could make one call with `dup_args' set to true,
5074                 // and then another with `omit_args' set to true, and the two calls
5075                 // would have the same set of arguments. However, each argument would
5076                 // only have been evaluated once.
5077                 public static void EmitCall (EmitContext ec, bool is_base,
5078                                              Expression instance_expr,
5079                                              MethodSpec method, Arguments Arguments, Location loc,
5080                                              bool dup_args, bool omit_args)
5081                 {
5082                         bool struct_call = false;
5083                         bool this_call = false;
5084                         LocalTemporary this_arg = null;
5085
5086                         TypeSpec decl_type = method.DeclaringType;
5087
5088                         // Speed up the check by not doing it on not allowed targets
5089                         if (method.ReturnType == TypeManager.void_type && method.IsConditionallyExcluded (loc))
5090                                 return;
5091
5092                         bool is_static = method.IsStatic;
5093                         if (!is_static){
5094                                 this_call = instance_expr is This;
5095                                 if (TypeManager.IsStruct (decl_type) || TypeManager.IsEnumType (decl_type))
5096                                         struct_call = true;
5097
5098                                 //
5099                                 // If this is ourselves, push "this"
5100                                 //
5101                                 if (!omit_args) {
5102                                         TypeSpec t = null;
5103                                         TypeSpec iexpr_type = instance_expr.Type;
5104
5105                                         //
5106                                         // Push the instance expression
5107                                         //
5108                                         if (TypeManager.IsValueType (iexpr_type) || TypeManager.IsGenericParameter (iexpr_type)) {
5109                                                 //
5110                                                 // Special case: calls to a function declared in a
5111                                                 // reference-type with a value-type argument need
5112                                                 // to have their value boxed.
5113                                                 if (TypeManager.IsStruct (decl_type) ||
5114                                                     TypeManager.IsGenericParameter (iexpr_type)) {
5115                                                         //
5116                                                         // If the expression implements IMemoryLocation, then
5117                                                         // we can optimize and use AddressOf on the
5118                                                         // return.
5119                                                         //
5120                                                         // If not we have to use some temporary storage for
5121                                                         // it.
5122                                                         if (instance_expr is IMemoryLocation) {
5123                                                                 ((IMemoryLocation)instance_expr).
5124                                                                         AddressOf (ec, AddressOp.LoadStore);
5125                                                         } else {
5126                                                                 LocalTemporary temp = new LocalTemporary (iexpr_type);
5127                                                                 instance_expr.Emit (ec);
5128                                                                 temp.Store (ec);
5129                                                                 temp.AddressOf (ec, AddressOp.Load);
5130                                                         }
5131
5132                                                         // avoid the overhead of doing this all the time.
5133                                                         if (dup_args)
5134                                                                 t = ReferenceContainer.MakeType (iexpr_type);
5135                                                 } else {
5136                                                         instance_expr.Emit (ec);
5137
5138                                                         // FIXME: should use instance_expr is IMemoryLocation + constraint.
5139                                                         // to help JIT to produce better code
5140                                                         ec.Emit (OpCodes.Box, instance_expr.Type);
5141                                                         t = TypeManager.object_type;
5142                                                 }
5143                                         } else {
5144                                                 instance_expr.Emit (ec);
5145                                                 t = instance_expr.Type;
5146                                         }
5147
5148                                         if (dup_args) {
5149                                                 ec.Emit (OpCodes.Dup);
5150                                                 if (Arguments != null && Arguments.Count != 0) {
5151                                                         this_arg = new LocalTemporary (t);
5152                                                         this_arg.Store (ec);
5153                                                 }
5154                                         }
5155                                 }
5156                         }
5157
5158                         if (!omit_args && Arguments != null)
5159                                 Arguments.Emit (ec, dup_args, this_arg);
5160
5161                         OpCode call_op;
5162                         if (is_static || struct_call || is_base || (this_call && !method.IsVirtual)) {
5163                                 call_op = OpCodes.Call;
5164                         } else {
5165                                 call_op = OpCodes.Callvirt;
5166
5167                                 if ((instance_expr != null) && (instance_expr.Type.IsGenericParameter))
5168                                         ec.Emit (OpCodes.Constrained, instance_expr.Type);
5169                         }
5170
5171                         if (method.Parameters.HasArglist) {
5172                                 Type[] varargs_types = GetVarargsTypes (method, Arguments);
5173                                 ec.Emit (call_op, method, varargs_types);
5174                                 return;
5175                         }
5176
5177                         //
5178                         // If you have:
5179                         // this.DoFoo ();
5180                         // and DoFoo is not virtual, you can omit the callvirt,
5181                         // because you don't need the null checking behavior.
5182                         //
5183                         ec.Emit (call_op, method);
5184                 }
5185
5186                 public override void Emit (EmitContext ec)
5187                 {
5188                         mg.EmitCall (ec, arguments);
5189                 }
5190
5191                 public override void EmitStatement (EmitContext ec)
5192                 {
5193                         Emit (ec);
5194
5195                         //
5196                         // Pop the return value if there is one
5197                         //
5198                         if (type != TypeManager.void_type)
5199                                 ec.Emit (OpCodes.Pop);
5200                 }
5201
5202                 protected override void CloneTo (CloneContext clonectx, Expression t)
5203                 {
5204                         Invocation target = (Invocation) t;
5205
5206                         if (arguments != null)
5207                                 target.arguments = arguments.Clone (clonectx);
5208
5209                         target.expr = expr.Clone (clonectx);
5210                 }
5211
5212                 public override SLE.Expression MakeExpression (BuilderContext ctx)
5213                 {
5214                         return MakeExpression (ctx, mg.InstanceExpression, (MethodSpec) mg, arguments);
5215                 }
5216
5217                 public static SLE.Expression MakeExpression (BuilderContext ctx, Expression instance, MethodSpec mi, Arguments args)
5218                 {
5219                         var instance_expr = instance == null ? null : instance.MakeExpression (ctx);
5220                         return SLE.Expression.Call (instance_expr, (MethodInfo) mi.GetMetaInfo (), Arguments.MakeExpression (args, ctx));
5221                 }
5222         }
5223
5224         /// <summary>
5225         ///    Implements the new expression
5226         /// </summary>
5227         public class New : ExpressionStatement, IMemoryLocation {
5228                 protected Arguments Arguments;
5229
5230                 //
5231                 // During bootstrap, it contains the RequestedType,
5232                 // but if `type' is not null, it *might* contain a NewDelegate
5233                 // (because of field multi-initialization)
5234                 //
5235                 protected Expression RequestedType;
5236
5237                 protected MethodGroupExpr method;
5238
5239                 public New (Expression requested_type, Arguments arguments, Location l)
5240                 {
5241                         RequestedType = requested_type;
5242                         Arguments = arguments;
5243                         loc = l;
5244                 }
5245
5246                 /// <summary>
5247                 /// Converts complex core type syntax like 'new int ()' to simple constant
5248                 /// </summary>
5249                 public static Constant Constantify (TypeSpec t)
5250                 {
5251                         if (t == TypeManager.int32_type)
5252                                 return new IntConstant (0, Location.Null);
5253                         if (t == TypeManager.uint32_type)
5254                                 return new UIntConstant (0, Location.Null);
5255                         if (t == TypeManager.int64_type)
5256                                 return new LongConstant (0, Location.Null);
5257                         if (t == TypeManager.uint64_type)
5258                                 return new ULongConstant (0, Location.Null);
5259                         if (t == TypeManager.float_type)
5260                                 return new FloatConstant (0, Location.Null);
5261                         if (t == TypeManager.double_type)
5262                                 return new DoubleConstant (0, Location.Null);
5263                         if (t == TypeManager.short_type)
5264                                 return new ShortConstant (0, Location.Null);
5265                         if (t == TypeManager.ushort_type)
5266                                 return new UShortConstant (0, Location.Null);
5267                         if (t == TypeManager.sbyte_type)
5268                                 return new SByteConstant (0, Location.Null);
5269                         if (t == TypeManager.byte_type)
5270                                 return new ByteConstant (0, Location.Null);
5271                         if (t == TypeManager.char_type)
5272                                 return new CharConstant ('\0', Location.Null);
5273                         if (t == TypeManager.bool_type)
5274                                 return new BoolConstant (false, Location.Null);
5275                         if (t == TypeManager.decimal_type)
5276                                 return new DecimalConstant (0, Location.Null);
5277                         if (TypeManager.IsEnumType (t))
5278                                 return new EnumConstant (Constantify (EnumSpec.GetUnderlyingType (t)), t);
5279                         if (TypeManager.IsNullableType (t))
5280                                 return Nullable.LiftedNull.Create (t, Location.Null);
5281
5282                         return null;
5283                 }
5284
5285                 //
5286                 // Checks whether the type is an interface that has the
5287                 // [ComImport, CoClass] attributes and must be treated
5288                 // specially
5289                 //
5290                 public Expression CheckComImport (ResolveContext ec)
5291                 {
5292                         if (!type.IsInterface)
5293                                 return null;
5294
5295                         //
5296                         // Turn the call into:
5297                         // (the-interface-stated) (new class-referenced-in-coclassattribute ())
5298                         //
5299                         var real_class = type.MemberDefinition.GetAttributeCoClass ();
5300                         if (real_class == null)
5301                                 return null;
5302
5303                         New proxy = new New (new TypeExpression (real_class, loc), Arguments, loc);
5304                         Cast cast = new Cast (new TypeExpression (type, loc), proxy, loc);
5305                         return cast.Resolve (ec);
5306                 }
5307
5308                 public override Expression CreateExpressionTree (ResolveContext ec)
5309                 {
5310                         Arguments args;
5311                         if (method == null) {
5312                                 args = new Arguments (1);
5313                                 args.Add (new Argument (new TypeOf (new TypeExpression (type, loc), loc)));
5314                         } else {
5315                                 args = Arguments.CreateForExpressionTree (ec,
5316                                         Arguments,
5317                                         method.CreateExpressionTree (ec));
5318                         }
5319
5320                         return CreateExpressionFactoryCall (ec, "New", args);
5321                 }
5322
5323                 protected override Expression DoResolve (ResolveContext ec)
5324                 {
5325                         //
5326                         // The New DoResolve might be called twice when initializing field
5327                         // expressions (see EmitFieldInitializers, the call to
5328                         // GetInitializerExpression will perform a resolve on the expression,
5329                         // and later the assign will trigger another resolution
5330                         //
5331                         // This leads to bugs (#37014)
5332                         //
5333                         if (type != null){
5334                                 if (RequestedType is NewDelegate)
5335                                         return RequestedType;
5336                                 return this;
5337                         }
5338
5339                         TypeExpr texpr = RequestedType.ResolveAsTypeTerminal (ec, false);
5340                         if (texpr == null)
5341                                 return null;
5342
5343                         type = texpr.Type;
5344
5345                         if (type.IsPointer) {
5346                                 ec.Report.Error (1919, loc, "Unsafe type `{0}' cannot be used in an object creation expression",
5347                                         TypeManager.CSharpName (type));
5348                                 return null;
5349                         }
5350
5351                         if (Arguments == null) {
5352                                 Constant c = Constantify (type);
5353                                 if (c != null)
5354                                         return ReducedExpression.Create (c.Resolve (ec), this);
5355                         }
5356
5357                         if (TypeManager.IsDelegateType (type)) {
5358                                 return (new NewDelegate (type, Arguments, loc)).Resolve (ec);
5359                         }
5360
5361                         var tparam = type as TypeParameterSpec;
5362                         if (tparam != null) {
5363                                 if (!tparam.HasSpecialConstructor && !tparam.HasSpecialStruct) {
5364                                         ec.Report.Error (304, loc,
5365                                                 "Cannot create an instance of the variable type `{0}' because it does not have the new() constraint",
5366                                                 TypeManager.CSharpName (type));
5367                                 }
5368
5369                                 if ((Arguments != null) && (Arguments.Count != 0)) {
5370                                         ec.Report.Error (417, loc,
5371                                                 "`{0}': cannot provide arguments when creating an instance of a variable type",
5372                                                 TypeManager.CSharpName (type));
5373                                 }
5374
5375                                 if (TypeManager.activator_create_instance == null) {
5376                                         TypeSpec activator_type = TypeManager.CoreLookupType (ec.Compiler, "System", "Activator", MemberKind.Class, true);
5377                                         if (activator_type != null) {
5378                                                 TypeManager.activator_create_instance = TypeManager.GetPredefinedMethod (
5379                                                         activator_type, MemberFilter.Method ("CreateInstance", 1, ParametersCompiled.EmptyReadOnlyParameters, null), loc);
5380                                         }
5381                                 }
5382
5383                                 eclass = ExprClass.Value;
5384                                 return this;
5385                         }
5386
5387                         if (type.IsStatic) {
5388                                 ec.Report.SymbolRelatedToPreviousError (type);
5389                                 ec.Report.Error (712, loc, "Cannot create an instance of the static class `{0}'", TypeManager.CSharpName (type));
5390                                 return null;
5391                         }
5392
5393                         if (type.IsInterface || type.IsAbstract){
5394                                 if (!TypeManager.IsGenericType (type)) {
5395                                         RequestedType = CheckComImport (ec);
5396                                         if (RequestedType != null)
5397                                                 return RequestedType;
5398                                 }
5399
5400                                 ec.Report.SymbolRelatedToPreviousError (type);
5401                                 ec.Report.Error (144, loc, "Cannot create an instance of the abstract class or interface `{0}'", TypeManager.CSharpName (type));
5402                                 return null;
5403                         }
5404
5405                         bool is_struct = TypeManager.IsStruct (type);
5406                         eclass = ExprClass.Value;
5407
5408                         //
5409                         // SRE returns a match for .ctor () on structs (the object constructor),
5410                         // so we have to manually ignore it.
5411                         //
5412                         if (is_struct && Arguments == null)
5413                                 return this;
5414
5415                         // For member-lookup, treat 'new Foo (bar)' as call to 'foo.ctor (bar)', where 'foo' is of type 'Foo'.
5416                         Expression ml = MemberLookupFinal (ec, type, type, ConstructorInfo.ConstructorName, 0,
5417                                 MemberKind.Constructor, BindingRestriction.AccessibleOnly | BindingRestriction.DeclaredOnly, loc);
5418
5419                         bool dynamic;
5420                         if (Arguments != null) {
5421                                 Arguments.Resolve (ec, out dynamic);
5422                         } else {
5423                                 dynamic = false;
5424                         }
5425
5426                         if (ml == null)
5427                                 return null;
5428
5429                         method = ml as MethodGroupExpr;
5430                         if (method == null) {
5431                                 ml.Error_UnexpectedKind (ec, ResolveFlags.MethodGroup, loc);
5432                                 return null;
5433                         }
5434
5435                         method = method.OverloadResolve (ec, ref Arguments, false, loc);
5436                         if (method == null)
5437                                 return null;
5438
5439                         if (dynamic) {
5440                                 Arguments.Insert (0, new Argument (new TypeOf (texpr, loc).Resolve (ec), Argument.AType.DynamicTypeName));
5441                                 return new DynamicConstructorBinder (type, Arguments, loc).Resolve (ec);
5442                         }
5443
5444                         return this;
5445                 }
5446
5447                 bool DoEmitTypeParameter (EmitContext ec)
5448                 {
5449                         var ctor_factory = TypeManager.activator_create_instance.MakeGenericMethod (type);
5450                         var tparam = (TypeParameterSpec) type;
5451
5452                         if (tparam.IsReferenceType) {
5453                                 ec.Emit (OpCodes.Call, ctor_factory);
5454                                 return true;
5455                         }
5456
5457                         // Allow DoEmit() to be called multiple times.
5458                         // We need to create a new LocalTemporary each time since
5459                         // you can't share LocalBuilders among ILGeneators.
5460                         LocalTemporary temp = new LocalTemporary (type);
5461
5462                         Label label_activator = ec.DefineLabel ();
5463                         Label label_end = ec.DefineLabel ();
5464
5465                         temp.AddressOf (ec, AddressOp.Store);
5466                         ec.Emit (OpCodes.Initobj, type);
5467
5468                         temp.Emit (ec);
5469                         ec.Emit (OpCodes.Box, type);
5470                         ec.Emit (OpCodes.Brfalse, label_activator);
5471
5472                         temp.AddressOf (ec, AddressOp.Store);
5473                         ec.Emit (OpCodes.Initobj, type);
5474                         temp.Emit (ec);
5475                         ec.Emit (OpCodes.Br_S, label_end);
5476
5477                         ec.MarkLabel (label_activator);
5478
5479                         ec.Emit (OpCodes.Call, ctor_factory);
5480                         ec.MarkLabel (label_end);
5481                         return true;
5482                 }
5483
5484                 //
5485                 // This Emit can be invoked in two contexts:
5486                 //    * As a mechanism that will leave a value on the stack (new object)
5487                 //    * As one that wont (init struct)
5488                 //
5489                 // If we are dealing with a ValueType, we have a few
5490                 // situations to deal with:
5491                 //
5492                 //    * The target is a ValueType, and we have been provided
5493                 //      the instance (this is easy, we are being assigned).
5494                 //
5495                 //    * The target of New is being passed as an argument,
5496                 //      to a boxing operation or a function that takes a
5497                 //      ValueType.
5498                 //
5499                 //      In this case, we need to create a temporary variable
5500                 //      that is the argument of New.
5501                 //
5502                 // Returns whether a value is left on the stack
5503                 //
5504                 // *** Implementation note ***
5505                 //
5506                 // To benefit from this optimization, each assignable expression
5507                 // has to manually cast to New and call this Emit.
5508                 //
5509                 // TODO: It's worth to implement it for arrays and fields
5510                 //
5511                 public virtual bool Emit (EmitContext ec, IMemoryLocation target)
5512                 {
5513                         bool is_value_type = TypeManager.IsValueType (type);
5514                         VariableReference vr = target as VariableReference;
5515
5516                         if (target != null && is_value_type && (vr != null || method == null)) {
5517                                 target.AddressOf (ec, AddressOp.Store);
5518                         } else if (vr != null && vr.IsRef) {
5519                                 vr.EmitLoad (ec);
5520                         }
5521
5522                         if (Arguments != null)
5523                                 Arguments.Emit (ec);
5524
5525                         if (is_value_type) {
5526                                 if (method == null) {
5527                                         ec.Emit (OpCodes.Initobj, type);
5528                                         return false;
5529                                 }
5530
5531                                 if (vr != null) {
5532                                         ec.Emit (OpCodes.Call, method.BestCandidate);
5533                                         return false;
5534                                 }
5535                         }
5536
5537                         if (type is TypeParameterSpec)
5538                                 return DoEmitTypeParameter (ec);
5539
5540                         ec.Emit (OpCodes.Newobj, method.BestCandidate);
5541                         return true;
5542                 }
5543
5544                 public override void Emit (EmitContext ec)
5545                 {
5546                         LocalTemporary v = null;
5547                         if (method == null && TypeManager.IsValueType (type)) {
5548                                 // TODO: Use temporary variable from pool
5549                                 v = new LocalTemporary (type);
5550                         }
5551
5552                         if (!Emit (ec, v))
5553                                 v.Emit (ec);
5554                 }
5555
5556                 public override void EmitStatement (EmitContext ec)
5557                 {
5558                         LocalTemporary v = null;
5559                         if (method == null && TypeManager.IsValueType (type)) {
5560                                 // TODO: Use temporary variable from pool
5561                                 v = new LocalTemporary (type);
5562                         }
5563
5564                         if (Emit (ec, v))
5565                                 ec.Emit (OpCodes.Pop);
5566                 }
5567
5568                 public virtual bool HasInitializer {
5569                         get {
5570                                 return false;
5571                         }
5572                 }
5573
5574                 public void AddressOf (EmitContext ec, AddressOp mode)
5575                 {
5576                         EmitAddressOf (ec, mode);
5577                 }
5578
5579                 protected virtual IMemoryLocation EmitAddressOf (EmitContext ec, AddressOp mode)
5580                 {
5581                         LocalTemporary value_target = new LocalTemporary (type);
5582
5583                         if (type is TypeParameterSpec) {
5584                                 DoEmitTypeParameter (ec);
5585                                 value_target.Store (ec);
5586                                 value_target.AddressOf (ec, mode);
5587                                 return value_target;
5588                         }
5589
5590                         if (!TypeManager.IsStruct (type)){
5591                                 //
5592                                 // We throw an exception.  So far, I believe we only need to support
5593                                 // value types:
5594                                 // foreach (int j in new StructType ())
5595                                 // see bug 42390
5596                                 //
5597                                 throw new Exception ("AddressOf should not be used for classes");
5598                         }
5599
5600                         value_target.AddressOf (ec, AddressOp.Store);
5601
5602                         if (method == null) {
5603                                 ec.Emit (OpCodes.Initobj, type);
5604                         } else {
5605                                 if (Arguments != null)
5606                                         Arguments.Emit (ec);
5607
5608                                 ec.Emit (OpCodes.Call, method.BestCandidate);
5609                         }
5610
5611                         value_target.AddressOf (ec, mode);
5612                         return value_target;
5613                 }
5614
5615                 protected override void CloneTo (CloneContext clonectx, Expression t)
5616                 {
5617                         New target = (New) t;
5618
5619                         target.RequestedType = RequestedType.Clone (clonectx);
5620                         if (Arguments != null){
5621                                 target.Arguments = Arguments.Clone (clonectx);
5622                         }
5623                 }
5624
5625                 public override SLE.Expression MakeExpression (BuilderContext ctx)
5626                 {
5627                         return SLE.Expression.New ((ConstructorInfo) method.BestCandidate.GetMetaInfo (), Arguments.MakeExpression (Arguments, ctx));
5628                 }
5629         }
5630
5631         public class ArrayInitializer : ShimExpression
5632         {
5633                 List<Expression> elements;
5634
5635                 public ArrayInitializer (List<Expression> init, Location loc)
5636                         : base (null)
5637                 {
5638                         elements = init;
5639                 }
5640
5641                 public ArrayInitializer (int count, Location loc)
5642                         : base (null)
5643                 {
5644                         elements = new List<Expression> (count);
5645                 }
5646
5647                 public ArrayInitializer (Location loc)
5648                         : this (4, loc)
5649                 {
5650                 }
5651
5652                 public void Add (Expression expr)
5653                 {
5654                         elements.Add (expr);
5655                 }
5656
5657                 protected override void CloneTo (CloneContext clonectx, Expression t)
5658                 {
5659                         var target = (ArrayInitializer) t;
5660
5661                         target.elements = new List<Expression> (elements.Count);
5662                         foreach (var element in elements)
5663                                 target.elements.Add (element.Clone (clonectx));
5664
5665                         base.CloneTo (clonectx, t);
5666                 }
5667
5668                 public int Count {
5669                         get { return elements.Count; }
5670                 }
5671
5672                 protected override Expression DoResolve (ResolveContext rc)
5673                 {
5674                         throw new NotImplementedException ();
5675                 }
5676
5677                 public Expression this [int index] {
5678                         get { return elements [index]; }
5679                 }
5680         }
5681
5682         /// <summary>
5683         ///   14.5.10.2: Represents an array creation expression.
5684         /// </summary>
5685         ///
5686         /// <remarks>
5687         ///   There are two possible scenarios here: one is an array creation
5688         ///   expression that specifies the dimensions and optionally the
5689         ///   initialization data and the other which does not need dimensions
5690         ///   specified but where initialization data is mandatory.
5691         /// </remarks>
5692         public class ArrayCreation : Expression
5693         {
5694                 FullNamedExpression requested_base_type;
5695                 ArrayInitializer initializers;
5696
5697                 //
5698                 // The list of Argument types.
5699                 // This is used to construct the `newarray' or constructor signature
5700                 //
5701                 protected List<Expression> arguments;
5702
5703                 protected TypeSpec array_element_type;
5704                 int num_arguments = 0;
5705                 protected int dimensions;
5706                 protected readonly string rank;
5707                 Expression first_emit;
5708                 LocalTemporary first_emit_temp;
5709
5710                 protected List<Expression> array_data;
5711
5712                 Dictionary<int, int> bounds;
5713
5714                 // The number of constants in array initializers
5715                 int const_initializers_count;
5716                 bool only_constant_initializers;
5717
5718                 public ArrayCreation (FullNamedExpression requested_base_type, List<Expression> exprs, string rank, ArrayInitializer initializers, Location l)
5719                 {
5720                         this.requested_base_type = requested_base_type;
5721                         this.initializers = initializers;
5722                         this.rank = rank;
5723                         loc = l;
5724
5725                         arguments = new List<Expression> (exprs);
5726                         num_arguments = arguments.Count;
5727                 }
5728
5729                 public ArrayCreation (FullNamedExpression requested_base_type, string rank, ArrayInitializer initializers, Location l)
5730                 {
5731                         this.requested_base_type = requested_base_type;
5732                         this.initializers = initializers;
5733                         this.rank = rank;
5734                         loc = l;
5735                 }
5736
5737                 protected override void Error_NegativeArrayIndex (ResolveContext ec, Location loc)
5738                 {
5739                         ec.Report.Error (248, loc, "Cannot create an array with a negative size");
5740                 }
5741
5742                 bool CheckIndices (ResolveContext ec, ArrayInitializer probe, int idx, bool specified_dims, int child_bounds)
5743                 {
5744                         if (initializers != null && bounds == null) {
5745                                 //
5746                                 // We use this to store all the date values in the order in which we
5747                                 // will need to store them in the byte blob later
5748                                 //
5749                                 array_data = new List<Expression> ();
5750                                 bounds = new Dictionary<int, int> ();
5751                         }
5752
5753                         if (specified_dims) {
5754                                 Expression a = arguments [idx];
5755                                 a = a.Resolve (ec);
5756                                 if (a == null)
5757                                         return false;
5758
5759                                 a = ConvertExpressionToArrayIndex (ec, a);
5760                                 if (a == null)
5761                                         return false;
5762
5763                                 arguments[idx] = a;
5764
5765                                 if (initializers != null) {
5766                                         Constant c = a as Constant;
5767                                         if (c == null && a is ArrayIndexCast)
5768                                                 c = ((ArrayIndexCast) a).Child as Constant;
5769
5770                                         if (c == null) {
5771                                                 ec.Report.Error (150, a.Location, "A constant value is expected");
5772                                                 return false;
5773                                         }
5774
5775                                         int value;
5776                                         try {
5777                                                 value = System.Convert.ToInt32 (c.GetValue ());
5778                                         } catch {
5779                                                 ec.Report.Error (150, a.Location, "A constant value is expected");
5780                                                 return false;
5781                                         }
5782
5783                                         // TODO: probe.Count does not fit ulong in
5784                                         if (value != probe.Count) {
5785                                                 ec.Report.Error (847, loc, "An array initializer of length `{0}' was expected", value.ToString ());
5786                                                 return false;
5787                                         }
5788
5789                                         bounds[idx] = value;
5790                                 }
5791                         }
5792
5793                         if (initializers == null)
5794                                 return true;
5795
5796                         only_constant_initializers = true;
5797                         for (int i = 0; i < probe.Count; ++i) {
5798                                 var o = probe [i];
5799                                 if (o is ArrayInitializer) {
5800                                         var sub_probe = o as ArrayInitializer;
5801                                         if (idx + 1 >= dimensions){
5802                                                 ec.Report.Error (623, loc, "Array initializers can only be used in a variable or field initializer. Try using a new expression instead");
5803                                                 return false;
5804                                         }
5805
5806                                         bool ret = CheckIndices (ec, sub_probe, idx + 1, specified_dims, child_bounds - 1);
5807                                         if (!ret)
5808                                                 return false;
5809                                 } else if (child_bounds > 1) {
5810                                         ec.Report.Error (846, o.Location, "A nested array initializer was expected");
5811                                 } else {
5812                                         Expression element = ResolveArrayElement (ec, o);
5813                                         if (element == null)
5814                                                 continue;
5815
5816                                         // Initializers with the default values can be ignored
5817                                         Constant c = element as Constant;
5818                                         if (c != null) {
5819                                                 if (!c.IsDefaultInitializer (array_element_type)) {
5820                                                         ++const_initializers_count;
5821                                                 }
5822                                         } else {
5823                                                 only_constant_initializers = false;
5824                                         }
5825
5826                                         array_data.Add (element);
5827                                 }
5828                         }
5829
5830                         return true;
5831                 }
5832
5833                 public override Expression CreateExpressionTree (ResolveContext ec)
5834                 {
5835                         Arguments args;
5836
5837                         if (array_data == null) {
5838                                 args = new Arguments (arguments.Count + 1);
5839                                 args.Add (new Argument (new TypeOf (new TypeExpression (array_element_type, loc), loc)));
5840                                 foreach (Expression a in arguments)
5841                                         args.Add (new Argument (a.CreateExpressionTree (ec)));
5842
5843                                 return CreateExpressionFactoryCall (ec, "NewArrayBounds", args);
5844                         }
5845
5846                         if (dimensions > 1) {
5847                                 ec.Report.Error (838, loc, "An expression tree cannot contain a multidimensional array initializer");
5848                                 return null;
5849                         }
5850
5851                         args = new Arguments (array_data == null ? 1 : array_data.Count + 1);
5852                         args.Add (new Argument (new TypeOf (new TypeExpression (array_element_type, loc), loc)));
5853                         if (array_data != null) {
5854                                 for (int i = 0; i < array_data.Count; ++i) {
5855                                         Expression e = array_data [i];
5856                                         args.Add (new Argument (e.CreateExpressionTree (ec)));
5857                                 }
5858                         }
5859
5860                         return CreateExpressionFactoryCall (ec, "NewArrayInit", args);
5861                 }
5862
5863                 public void UpdateIndices ()
5864                 {
5865                         int i = 0;
5866                         for (var probe = initializers; probe != null;) {
5867                                 if (probe.Count > 0 && probe [0] is ArrayInitializer) {
5868                                         Expression e = new IntConstant (probe.Count, Location.Null);
5869                                         arguments.Add (e);
5870
5871                                         bounds [i++] = probe.Count;
5872
5873                                         probe = (ArrayInitializer) probe[0];
5874
5875                                 } else {
5876                                         Expression e = new IntConstant (probe.Count, Location.Null);
5877                                         arguments.Add (e);
5878
5879                                         bounds [i++] = probe.Count;
5880                                         return;
5881                                 }
5882                         }
5883                 }
5884
5885                 protected virtual Expression ResolveArrayElement (ResolveContext ec, Expression element)
5886                 {
5887                         element = element.Resolve (ec);
5888                         if (element == null)
5889                                 return null;
5890
5891                         if (element is CompoundAssign.TargetExpression) {
5892                                 if (first_emit != null)
5893                                         throw new InternalErrorException ("Can only handle one mutator at a time");
5894                                 first_emit = element;
5895                                 element = first_emit_temp = new LocalTemporary (element.Type);
5896                         }
5897
5898                         return Convert.ImplicitConversionRequired (
5899                                 ec, element, array_element_type, loc);
5900                 }
5901
5902                 protected bool ResolveInitializers (ResolveContext ec)
5903                 {
5904                         if (arguments != null) {
5905                                 bool res = true;
5906                                 for (int i = 0; i < arguments.Count; ++i) {
5907                                         res &= CheckIndices (ec, initializers, i, true, dimensions);
5908                                         if (initializers != null)
5909                                                 break;
5910                                 }
5911
5912                                 return res;
5913                         }
5914
5915                         arguments = new List<Expression> ();
5916
5917                         if (!CheckIndices (ec, initializers, 0, false, dimensions))
5918                                 return false;
5919
5920                         UpdateIndices ();
5921
5922                         return true;
5923                 }
5924
5925                 //
5926                 // Resolved the type of the array
5927                 //
5928                 bool ResolveArrayType (ResolveContext ec)
5929                 {
5930                         if (requested_base_type is VarExpr) {
5931                                 ec.Report.Error (820, loc, "An implicitly typed local variable declarator cannot use an array initializer");
5932                                 return false;
5933                         }
5934
5935                         StringBuilder array_qualifier = new StringBuilder ();
5936
5937                         //
5938                         // `In the first form allocates an array instace of the type that results
5939                         // from deleting each of the individual expression from the expression list'
5940                         //
5941                         if (num_arguments > 0) {
5942                                 array_qualifier.Append ("[");
5943                                 for (int i = num_arguments-1; i > 0; i--)
5944                                         array_qualifier.Append (",");
5945                                 array_qualifier.Append ("]");
5946                         }
5947
5948                         array_qualifier.Append (rank);
5949
5950                         //
5951                         // Lookup the type
5952                         //
5953                         TypeExpr array_type_expr;
5954                         array_type_expr = new ComposedCast (requested_base_type, array_qualifier.ToString (), loc);
5955                         array_type_expr = array_type_expr.ResolveAsTypeTerminal (ec, false);
5956                         if (array_type_expr == null)
5957                                 return false;
5958
5959                         type = array_type_expr.Type;
5960                         var ac = type as ArrayContainer;
5961                         if (ac == null) {
5962                                 ec.Report.Error (622, loc, "Can only use array initializer expressions to assign to array types. Try using a new expression instead");
5963                                 return false;
5964                         }
5965
5966                         array_element_type = ac.Element;
5967                         dimensions = ac.Rank;
5968
5969                         return true;
5970                 }
5971
5972                 protected override Expression DoResolve (ResolveContext ec)
5973                 {
5974                         if (type != null)
5975                                 return this;
5976
5977                         if (!ResolveArrayType (ec))
5978                                 return null;
5979
5980                         //
5981                         // validate the initializers and fill in any missing bits
5982                         //
5983                         if (!ResolveInitializers (ec))
5984                                 return null;
5985
5986                         eclass = ExprClass.Value;
5987                         return this;
5988                 }
5989
5990                 byte [] MakeByteBlob ()
5991                 {
5992                         int factor;
5993                         byte [] data;
5994                         byte [] element;
5995                         int count = array_data.Count;
5996
5997                         TypeSpec element_type = array_element_type;
5998                         if (TypeManager.IsEnumType (element_type))
5999                                 element_type = EnumSpec.GetUnderlyingType (element_type);
6000
6001                         factor = GetTypeSize (element_type);
6002                         if (factor == 0)
6003                                 throw new Exception ("unrecognized type in MakeByteBlob: " + element_type);
6004
6005                         data = new byte [(count * factor + 3) & ~3];
6006                         int idx = 0;
6007
6008                         for (int i = 0; i < count; ++i) {
6009                                 object v = array_data [i];
6010
6011                                 if (v is EnumConstant)
6012                                         v = ((EnumConstant) v).Child;
6013
6014                                 if (v is Constant && !(v is StringConstant))
6015                                         v = ((Constant) v).GetValue ();
6016                                 else {
6017                                         idx += factor;
6018                                         continue;
6019                                 }
6020
6021                                 if (element_type == TypeManager.int64_type){
6022                                         if (!(v is Expression)){
6023                                                 long val = (long) v;
6024
6025                                                 for (int j = 0; j < factor; ++j) {
6026                                                         data [idx + j] = (byte) (val & 0xFF);
6027                                                         val = (val >> 8);
6028                                                 }
6029                                         }
6030                                 } else if (element_type == TypeManager.uint64_type){
6031                                         if (!(v is Expression)){
6032                                                 ulong val = (ulong) v;
6033
6034                                                 for (int j = 0; j < factor; ++j) {
6035                                                         data [idx + j] = (byte) (val & 0xFF);
6036                                                         val = (val >> 8);
6037                                                 }
6038                                         }
6039                                 } else if (element_type == TypeManager.float_type) {
6040                                         if (!(v is Expression)){
6041                                                 element = BitConverter.GetBytes ((float) v);
6042
6043                                                 for (int j = 0; j < factor; ++j)
6044                                                         data [idx + j] = element [j];
6045                                                 if (!BitConverter.IsLittleEndian)
6046                                                         System.Array.Reverse (data, idx, 4);
6047                                         }
6048                                 } else if (element_type == TypeManager.double_type) {
6049                                         if (!(v is Expression)){
6050                                                 element = BitConverter.GetBytes ((double) v);
6051
6052                                                 for (int j = 0; j < factor; ++j)
6053                                                         data [idx + j] = element [j];
6054
6055                                                 // FIXME: Handle the ARM float format.
6056                                                 if (!BitConverter.IsLittleEndian)
6057                                                         System.Array.Reverse (data, idx, 8);
6058                                         }
6059                                 } else if (element_type == TypeManager.char_type){
6060                                         if (!(v is Expression)){
6061                                                 int val = (int) ((char) v);
6062
6063                                                 data [idx] = (byte) (val & 0xff);
6064                                                 data [idx+1] = (byte) (val >> 8);
6065                                         }
6066                                 } else if (element_type == TypeManager.short_type){
6067                                         if (!(v is Expression)){
6068                                                 int val = (int) ((short) v);
6069
6070                                                 data [idx] = (byte) (val & 0xff);
6071                                                 data [idx+1] = (byte) (val >> 8);
6072                                         }
6073                                 } else if (element_type == TypeManager.ushort_type){
6074                                         if (!(v is Expression)){
6075                                                 int val = (int) ((ushort) v);
6076
6077                                                 data [idx] = (byte) (val & 0xff);
6078                                                 data [idx+1] = (byte) (val >> 8);
6079                                         }
6080                                 } else if (element_type == TypeManager.int32_type) {
6081                                         if (!(v is Expression)){
6082                                                 int val = (int) v;
6083
6084                                                 data [idx]   = (byte) (val & 0xff);
6085                                                 data [idx+1] = (byte) ((val >> 8) & 0xff);
6086                                                 data [idx+2] = (byte) ((val >> 16) & 0xff);
6087                                                 data [idx+3] = (byte) (val >> 24);
6088                                         }
6089                                 } else if (element_type == TypeManager.uint32_type) {
6090                                         if (!(v is Expression)){
6091                                                 uint val = (uint) v;
6092
6093                                                 data [idx]   = (byte) (val & 0xff);
6094                                                 data [idx+1] = (byte) ((val >> 8) & 0xff);
6095                                                 data [idx+2] = (byte) ((val >> 16) & 0xff);
6096                                                 data [idx+3] = (byte) (val >> 24);
6097                                         }
6098                                 } else if (element_type == TypeManager.sbyte_type) {
6099                                         if (!(v is Expression)){
6100                                                 sbyte val = (sbyte) v;
6101                                                 data [idx] = (byte) val;
6102                                         }
6103                                 } else if (element_type == TypeManager.byte_type) {
6104                                         if (!(v is Expression)){
6105                                                 byte val = (byte) v;
6106                                                 data [idx] = (byte) val;
6107                                         }
6108                                 } else if (element_type == TypeManager.bool_type) {
6109                                         if (!(v is Expression)){
6110                                                 bool val = (bool) v;
6111                                                 data [idx] = (byte) (val ? 1 : 0);
6112                                         }
6113                                 } else if (element_type == TypeManager.decimal_type){
6114                                         if (!(v is Expression)){
6115                                                 int [] bits = Decimal.GetBits ((decimal) v);
6116                                                 int p = idx;
6117
6118                                                 // FIXME: For some reason, this doesn't work on the MS runtime.
6119                                                 int [] nbits = new int [4];
6120                                                 nbits [0] = bits [3];
6121                                                 nbits [1] = bits [2];
6122                                                 nbits [2] = bits [0];
6123                                                 nbits [3] = bits [1];
6124
6125                                                 for (int j = 0; j < 4; j++){
6126                                                         data [p++] = (byte) (nbits [j] & 0xff);
6127                                                         data [p++] = (byte) ((nbits [j] >> 8) & 0xff);
6128                                                         data [p++] = (byte) ((nbits [j] >> 16) & 0xff);
6129                                                         data [p++] = (byte) (nbits [j] >> 24);
6130                                                 }
6131                                         }
6132                                 } else {
6133                                         throw new Exception ("Unrecognized type in MakeByteBlob: " + element_type);
6134                                 }
6135
6136                                 idx += factor;
6137                         }
6138
6139                         return data;
6140                 }
6141
6142 #if NET_4_0
6143                 public override SLE.Expression MakeExpression (BuilderContext ctx)
6144                 {
6145                         var initializers = new SLE.Expression [array_data.Count];
6146                         for (var i = 0; i < initializers.Length; i++) {
6147                                 if (array_data [i] == null)
6148                                         initializers [i] = SLE.Expression.Default (array_element_type.GetMetaInfo ());
6149                                 else
6150                                         initializers [i] = array_data [i].MakeExpression (ctx);
6151                         }
6152
6153                         return SLE.Expression.NewArrayInit (array_element_type.GetMetaInfo (), initializers);
6154                 }
6155 #endif
6156                 //
6157                 // Emits the initializers for the array
6158                 //
6159                 void EmitStaticInitializers (EmitContext ec)
6160                 {
6161                         // FIXME: This should go to Resolve !
6162                         if (TypeManager.void_initializearray_array_fieldhandle == null) {
6163                                 TypeManager.void_initializearray_array_fieldhandle = TypeManager.GetPredefinedMethod (
6164                                         TypeManager.runtime_helpers_type, "InitializeArray", loc,
6165                                         TypeManager.array_type, TypeManager.runtime_field_handle_type);
6166                                 if (TypeManager.void_initializearray_array_fieldhandle == null)
6167                                         return;
6168                         }
6169
6170                         //
6171                         // First, the static data
6172                         //
6173                         FieldBuilder fb;
6174
6175                         byte [] data = MakeByteBlob ();
6176
6177                         fb = RootContext.MakeStaticData (data);
6178
6179                         ec.Emit (OpCodes.Dup);
6180                         ec.Emit (OpCodes.Ldtoken, fb);
6181                         ec.Emit (OpCodes.Call, TypeManager.void_initializearray_array_fieldhandle);
6182                 }
6183
6184                 //
6185                 // Emits pieces of the array that can not be computed at compile
6186                 // time (variables and string locations).
6187                 //
6188                 // This always expect the top value on the stack to be the array
6189                 //
6190                 void EmitDynamicInitializers (EmitContext ec, bool emitConstants)
6191                 {
6192                         int dims = bounds.Count;
6193                         var current_pos = new int [dims];
6194
6195                         for (int i = 0; i < array_data.Count; i++){
6196
6197                                 Expression e = array_data [i];
6198                                 var c = e as Constant;
6199
6200                                 // Constant can be initialized via StaticInitializer
6201                                 if (c == null || (c != null && emitConstants && !c.IsDefaultInitializer (array_element_type))) {
6202                                         TypeSpec etype = e.Type;
6203
6204                                         ec.Emit (OpCodes.Dup);
6205
6206                                         for (int idx = 0; idx < dims; idx++)
6207                                                 ec.EmitInt (current_pos [idx]);
6208
6209                                         //
6210                                         // If we are dealing with a struct, get the
6211                                         // address of it, so we can store it.
6212                                         //
6213                                         if ((dims == 1) && TypeManager.IsStruct (etype) &&
6214                                             (!TypeManager.IsBuiltinOrEnum (etype) ||
6215                                              etype == TypeManager.decimal_type)) {
6216
6217                                                 ec.Emit (OpCodes.Ldelema, etype);
6218                                         }
6219
6220                                         e.Emit (ec);
6221
6222                                         ec.EmitArrayStore ((ArrayContainer) type);
6223                                 }
6224
6225                                 //
6226                                 // Advance counter
6227                                 //
6228                                 for (int j = dims - 1; j >= 0; j--){
6229                                         current_pos [j]++;
6230                                         if (current_pos [j] < bounds [j])
6231                                                 break;
6232                                         current_pos [j] = 0;
6233                                 }
6234                         }
6235                 }
6236
6237                 public override void Emit (EmitContext ec)
6238                 {
6239                         if (first_emit != null) {
6240                                 first_emit.Emit (ec);
6241                                 first_emit_temp.Store (ec);
6242                         }
6243
6244                         foreach (Expression e in arguments)
6245                                 e.Emit (ec);
6246
6247                         ec.EmitArrayNew ((ArrayContainer) type);
6248
6249                         if (initializers == null)
6250                                 return;
6251
6252                         // Emit static initializer for arrays which have contain more than 2 items and
6253                         // the static initializer will initialize at least 25% of array values.
6254                         // NOTE: const_initializers_count does not contain default constant values.
6255                         if (const_initializers_count > 2 && const_initializers_count * 4 > (array_data.Count) &&
6256                                 (TypeManager.IsPrimitiveType (array_element_type) || TypeManager.IsEnumType (array_element_type))) {
6257                                 EmitStaticInitializers (ec);
6258
6259                                 if (!only_constant_initializers)
6260                                         EmitDynamicInitializers (ec, false);
6261                         } else {
6262                                 EmitDynamicInitializers (ec, true);
6263                         }
6264
6265                         if (first_emit_temp != null)
6266                                 first_emit_temp.Release (ec);
6267                 }
6268
6269                 public override void EncodeAttributeValue (IMemberContext rc, AttributeEncoder enc, TypeSpec targetType)
6270                 {
6271                         // no multi dimensional or jagged arrays
6272                         if (arguments.Count != 1 || array_element_type.IsArray) {
6273                                 base.EncodeAttributeValue (rc, enc, targetType);
6274                                 return;
6275                         }
6276
6277                         // No array covariance, except for array -> object
6278                         if (type != targetType) {
6279                                 if (targetType != TypeManager.object_type) {
6280                                         base.EncodeAttributeValue (rc, enc, targetType);
6281                                         return;
6282                                 }
6283
6284                                 enc.Encode (type);
6285                         }
6286
6287                         // Single dimensional array of 0 size
6288                         if (array_data == null) {
6289                                 IntConstant ic = arguments[0] as IntConstant;
6290                                 if (ic == null || !ic.IsDefaultValue) {
6291                                         base.EncodeAttributeValue (rc, enc, targetType);
6292                                 } else {
6293                                         enc.Stream.Write (0);
6294                                 }
6295
6296                                 return;
6297                         }
6298
6299                         enc.Stream.Write ((int) array_data.Count);
6300                         foreach (var element in array_data) {
6301                                 element.EncodeAttributeValue (rc, enc, array_element_type);
6302                         }
6303                 }
6304
6305                 protected override void CloneTo (CloneContext clonectx, Expression t)
6306                 {
6307                         ArrayCreation target = (ArrayCreation) t;
6308
6309                         if (requested_base_type != null)
6310                                 target.requested_base_type = (FullNamedExpression)requested_base_type.Clone (clonectx);
6311
6312                         if (arguments != null){
6313                                 target.arguments = new List<Expression> (arguments.Count);
6314                                 foreach (Expression e in arguments)
6315                                         target.arguments.Add (e.Clone (clonectx));
6316                         }
6317
6318                         if (initializers != null)
6319                                 target.initializers = (ArrayInitializer) initializers.Clone (clonectx);
6320                 }
6321         }
6322
6323         //
6324         // Represents an implicitly typed array epxression
6325         //
6326         class ImplicitlyTypedArrayCreation : ArrayCreation
6327         {
6328                 public ImplicitlyTypedArrayCreation (string rank, ArrayInitializer initializers, Location loc)
6329                         : base (null, rank, initializers, loc)
6330                 {
6331                         if (rank.Length > 2) {
6332                                 while (rank [++dimensions] == ',');
6333                         } else {
6334                                 dimensions = 1;
6335                         }
6336                 }
6337
6338                 protected override Expression DoResolve (ResolveContext ec)
6339                 {
6340                         if (type != null)
6341                                 return this;
6342
6343                         if (!ResolveInitializers (ec))
6344                                 return null;
6345
6346                         if (array_element_type == null || array_element_type == TypeManager.null_type ||
6347                                 array_element_type == TypeManager.void_type || array_element_type == InternalType.AnonymousMethod ||
6348                                 array_element_type == InternalType.MethodGroup ||
6349                                 arguments.Count != dimensions) {
6350                                 Error_NoBestType (ec);
6351                                 return null;
6352                         }
6353
6354                         //
6355                         // At this point we found common base type for all initializer elements
6356                         // but we have to be sure that all static initializer elements are of
6357                         // same type
6358                         //
6359                         UnifyInitializerElement (ec);
6360
6361                         type = TypeManager.GetConstructedType (array_element_type, rank);
6362                         eclass = ExprClass.Value;
6363                         return this;
6364                 }
6365
6366                 void Error_NoBestType (ResolveContext ec)
6367                 {
6368                         ec.Report.Error (826, loc,
6369                                 "The type of an implicitly typed array cannot be inferred from the initializer. Try specifying array type explicitly");
6370                 }
6371
6372                 //
6373                 // Converts static initializer only
6374                 //
6375                 void UnifyInitializerElement (ResolveContext ec)
6376                 {
6377                         for (int i = 0; i < array_data.Count; ++i) {
6378                                 Expression e = (Expression)array_data[i];
6379                                 if (e != null)
6380                                         array_data [i] = Convert.ImplicitConversion (ec, e, array_element_type, Location.Null);
6381                         }
6382                 }
6383
6384                 protected override Expression ResolveArrayElement (ResolveContext ec, Expression element)
6385                 {
6386                         element = element.Resolve (ec);
6387                         if (element == null)
6388                                 return null;
6389
6390                         if (array_element_type == null) {
6391                                 if (element.Type != TypeManager.null_type)
6392                                         array_element_type = element.Type;
6393
6394                                 return element;
6395                         }
6396
6397                         if (Convert.ImplicitConversionExists (ec, element, array_element_type)) {
6398                                 return element;
6399                         }
6400
6401                         if (Convert.ImplicitConversionExists (ec, new TypeExpression (array_element_type, loc), element.Type)) {
6402                                 array_element_type = element.Type;
6403                                 return element;
6404                         }
6405
6406                         Error_NoBestType (ec);
6407                         return null;
6408                 }
6409         }
6410
6411         public sealed class CompilerGeneratedThis : This
6412         {
6413                 public static This Instance = new CompilerGeneratedThis ();
6414
6415                 private CompilerGeneratedThis ()
6416                         : base (Location.Null)
6417                 {
6418                 }
6419
6420                 public CompilerGeneratedThis (TypeSpec type, Location loc)
6421                         : base (loc)
6422                 {
6423                         this.type = type;
6424                 }
6425
6426                 protected override Expression DoResolve (ResolveContext ec)
6427                 {
6428                         eclass = ExprClass.Variable;
6429                         if (type == null)
6430                                 type = ec.CurrentType;
6431
6432                         is_struct = TypeManager.IsStruct (type);
6433                         return this;
6434                 }
6435
6436                 public override HoistedVariable GetHoistedVariable (AnonymousExpression ae)
6437                 {
6438                         return null;
6439                 }
6440         }
6441
6442         /// <summary>
6443         ///   Represents the `this' construct
6444         /// </summary>
6445
6446         public class This : VariableReference
6447         {
6448                 sealed class ThisVariable : ILocalVariable
6449                 {
6450                         public static readonly ILocalVariable Instance = new ThisVariable ();
6451
6452                         public void Emit (EmitContext ec)
6453                         {
6454                                 ec.Emit (OpCodes.Ldarg_0);
6455                         }
6456
6457                         public void EmitAssign (EmitContext ec)
6458                         {
6459                                 throw new InvalidOperationException ();
6460                         }
6461
6462                         public void EmitAddressOf (EmitContext ec)
6463                         {
6464                                 ec.Emit (OpCodes.Ldarg_0);
6465                         }
6466                 }
6467
6468                 Block block;
6469                 VariableInfo variable_info;
6470                 protected bool is_struct;
6471
6472                 public This (Block block, Location loc)
6473                 {
6474                         this.loc = loc;
6475                         this.block = block;
6476                 }
6477
6478                 public This (Location loc)
6479                 {
6480                         this.loc = loc;
6481                 }
6482
6483                 public override VariableInfo VariableInfo {
6484                         get { return variable_info; }
6485                 }
6486
6487                 public override bool IsFixed {
6488                         get { return false; }
6489                 }
6490
6491                 public override HoistedVariable GetHoistedVariable (AnonymousExpression ae)
6492                 {
6493                         if (ae == null)
6494                                 return null;
6495
6496                         AnonymousMethodStorey storey = ae.Storey;
6497                         while (storey != null) {
6498                                 AnonymousMethodStorey temp = storey.Parent as AnonymousMethodStorey;
6499                                 if (temp == null)
6500                                         return storey.HoistedThis;
6501
6502                                 storey = temp;
6503                         }
6504
6505                         return null;
6506                 }
6507
6508                 public override bool IsRef {
6509                         get { return is_struct; }
6510                 }
6511
6512                 protected override ILocalVariable Variable {
6513                         get { return ThisVariable.Instance; }
6514                 }
6515
6516                 public static bool IsThisAvailable (ResolveContext ec, bool ignoreAnonymous)
6517                 {
6518                         if (ec.IsStatic || ec.HasAny (ResolveContext.Options.FieldInitializerScope | ResolveContext.Options.BaseInitializer | ResolveContext.Options.ConstantScope))
6519                                 return false;
6520
6521                         if (ignoreAnonymous || ec.CurrentAnonymousMethod == null)
6522                                 return true;
6523
6524                         if (TypeManager.IsStruct (ec.CurrentType) && ec.CurrentIterator == null)
6525                                 return false;
6526
6527                         return true;
6528                 }
6529
6530                 public bool ResolveBase (ResolveContext ec)
6531                 {
6532                         eclass = ExprClass.Variable;
6533                         type = ec.CurrentType;
6534
6535                         if (!IsThisAvailable (ec, false)) {
6536                                 if (ec.IsStatic && !ec.HasSet (ResolveContext.Options.ConstantScope)) {
6537                                         ec.Report.Error (26, loc, "Keyword `this' is not valid in a static property, static method, or static field initializer");
6538                                 } else if (ec.CurrentAnonymousMethod != null) {
6539                                         ec.Report.Error (1673, loc,
6540                                                 "Anonymous methods inside structs cannot access instance members of `this'. " +
6541                                                 "Consider copying `this' to a local variable outside the anonymous method and using the local instead");
6542                                 } else {
6543                                         ec.Report.Error (27, loc, "Keyword `this' is not available in the current context");
6544                                 }
6545                         }
6546
6547                         is_struct = TypeManager.IsStruct (type);
6548
6549                         if (block != null) {
6550                                 if (block.Toplevel.ThisVariable != null)
6551                                         variable_info = block.Toplevel.ThisVariable.VariableInfo;
6552
6553                                 AnonymousExpression am = ec.CurrentAnonymousMethod;
6554                                 if (am != null && ec.IsVariableCapturingRequired) {
6555                                         am.SetHasThisAccess ();
6556                                 }
6557                         }
6558
6559                         return true;
6560                 }
6561
6562                 //
6563                 // Called from Invocation to check if the invocation is correct
6564                 //
6565                 public override void CheckMarshalByRefAccess (ResolveContext ec)
6566                 {
6567                         if ((variable_info != null) && !(TypeManager.IsStruct (type) && ec.OmitStructFlowAnalysis) &&
6568                             !variable_info.IsAssigned (ec)) {
6569                                 ec.Report.Error (188, loc,
6570                                         "The `this' object cannot be used before all of its fields are assigned to");
6571                                 variable_info.SetAssigned (ec);
6572                         }
6573                 }
6574
6575                 public override Expression CreateExpressionTree (ResolveContext ec)
6576                 {
6577                         Arguments args = new Arguments (1);
6578                         args.Add (new Argument (this));
6579
6580                         // Use typeless constant for ldarg.0 to save some
6581                         // space and avoid problems with anonymous stories
6582                         return CreateExpressionFactoryCall (ec, "Constant", args);
6583                 }
6584
6585                 protected override Expression DoResolve (ResolveContext ec)
6586                 {
6587                         ResolveBase (ec);
6588                         return this;
6589                 }
6590
6591                 override public Expression DoResolveLValue (ResolveContext ec, Expression right_side)
6592                 {
6593                         if (!ResolveBase (ec))
6594                                 return null;
6595
6596                         if (variable_info != null)
6597                                 variable_info.SetAssigned (ec);
6598
6599                         if (ec.CurrentType.IsClass){
6600                                 if (right_side == EmptyExpression.UnaryAddress)
6601                                         ec.Report.Error (459, loc, "Cannot take the address of `this' because it is read-only");
6602                                 else if (right_side == EmptyExpression.OutAccess.Instance)
6603                                         ec.Report.Error (1605, loc, "Cannot pass `this' as a ref or out argument because it is read-only");
6604                                 else
6605                                         ec.Report.Error (1604, loc, "Cannot assign to `this' because it is read-only");
6606                         }
6607
6608                         return this;
6609                 }
6610
6611                 public override int GetHashCode()
6612                 {
6613                         return block.GetHashCode ();
6614                 }
6615
6616                 public override string Name {
6617                         get { return "this"; }
6618                 }
6619
6620                 public override bool Equals (object obj)
6621                 {
6622                         This t = obj as This;
6623                         if (t == null)
6624                                 return false;
6625
6626                         return block == t.block;
6627                 }
6628
6629                 protected override void CloneTo (CloneContext clonectx, Expression t)
6630                 {
6631                         This target = (This) t;
6632
6633                         target.block = clonectx.LookupBlock (block);
6634                 }
6635
6636                 public override void SetHasAddressTaken ()
6637                 {
6638                         // Nothing
6639                 }
6640         }
6641
6642         /// <summary>
6643         ///   Represents the `__arglist' construct
6644         /// </summary>
6645         public class ArglistAccess : Expression
6646         {
6647                 public ArglistAccess (Location loc)
6648                 {
6649                         this.loc = loc;
6650                 }
6651
6652                 public override Expression CreateExpressionTree (ResolveContext ec)
6653                 {
6654                         throw new NotSupportedException ("ET");
6655                 }
6656
6657                 protected override Expression DoResolve (ResolveContext ec)
6658                 {
6659                         eclass = ExprClass.Variable;
6660                         type = TypeManager.runtime_argument_handle_type;
6661
6662                         if (ec.HasSet (ResolveContext.Options.FieldInitializerScope) || !ec.CurrentBlock.Toplevel.Parameters.HasArglist) {
6663                                 ec.Report.Error (190, loc,
6664                                         "The __arglist construct is valid only within a variable argument method");
6665                         }
6666
6667                         return this;
6668                 }
6669
6670                 public override void Emit (EmitContext ec)
6671                 {
6672                         ec.Emit (OpCodes.Arglist);
6673                 }
6674
6675                 protected override void CloneTo (CloneContext clonectx, Expression target)
6676                 {
6677                         // nothing.
6678                 }
6679         }
6680
6681         /// <summary>
6682         ///   Represents the `__arglist (....)' construct
6683         /// </summary>
6684         public class Arglist : Expression
6685         {
6686                 Arguments Arguments;
6687
6688                 public Arglist (Location loc)
6689                         : this (null, loc)
6690                 {
6691                 }
6692
6693                 public Arglist (Arguments args, Location l)
6694                 {
6695                         Arguments = args;
6696                         loc = l;
6697                 }
6698
6699                 public Type[] ArgumentTypes {
6700                     get {
6701                                 if (Arguments == null)
6702                                         return System.Type.EmptyTypes;
6703
6704                         var retval = new Type [Arguments.Count];
6705                         for (int i = 0; i < retval.Length; i++)
6706                                         retval[i] = Arguments[i].Expr.Type.GetMetaInfo ();
6707
6708                         return retval;
6709                     }
6710                 }
6711
6712                 public override Expression CreateExpressionTree (ResolveContext ec)
6713                 {
6714                         ec.Report.Error (1952, loc, "An expression tree cannot contain a method with variable arguments");
6715                         return null;
6716                 }
6717
6718                 protected override Expression DoResolve (ResolveContext ec)
6719                 {
6720                         eclass = ExprClass.Variable;
6721                         type = InternalType.Arglist;
6722                         if (Arguments != null) {
6723                                 bool dynamic;   // Can be ignored as there is always only 1 overload
6724                                 Arguments.Resolve (ec, out dynamic);
6725                         }
6726
6727                         return this;
6728                 }
6729
6730                 public override void Emit (EmitContext ec)
6731                 {
6732                         if (Arguments != null)
6733                                 Arguments.Emit (ec);
6734                 }
6735
6736                 protected override void CloneTo (CloneContext clonectx, Expression t)
6737                 {
6738                         Arglist target = (Arglist) t;
6739
6740                         if (Arguments != null)
6741                                 target.Arguments = Arguments.Clone (clonectx);
6742                 }
6743         }
6744
6745         /// <summary>
6746         ///   Implements the typeof operator
6747         /// </summary>
6748         public class TypeOf : Expression {
6749                 Expression QueriedType;
6750                 protected TypeSpec typearg;
6751
6752                 public TypeOf (Expression queried_type, Location l)
6753                 {
6754                         QueriedType = queried_type;
6755                         loc = l;
6756                 }
6757
6758                 public override Expression CreateExpressionTree (ResolveContext ec)
6759                 {
6760                         Arguments args = new Arguments (2);
6761                         args.Add (new Argument (this));
6762                         args.Add (new Argument (new TypeOf (new TypeExpression (type, loc), loc)));
6763                         return CreateExpressionFactoryCall (ec, "Constant", args);
6764                 }
6765
6766                 protected override Expression DoResolve (ResolveContext ec)
6767                 {
6768                         TypeExpr texpr = QueriedType.ResolveAsTypeTerminal (ec, false);
6769                         if (texpr == null)
6770                                 return null;
6771
6772                         typearg = texpr.Type;
6773
6774                         //
6775                         // Get generic type definition for unbounded type arguments
6776                         //
6777                         var tne = QueriedType as ATypeNameExpression;
6778                         if (tne != null && typearg.IsGeneric && !tne.HasTypeArguments)
6779                                 typearg = typearg.GetDefinition ();
6780
6781                         if (typearg == TypeManager.void_type) {
6782                                 ec.Report.Error (673, loc, "System.Void cannot be used from C#. Use typeof (void) to get the void type object");
6783                         } else if (typearg.IsPointer && !ec.IsUnsafe){
6784                                 UnsafeError (ec, loc);
6785                         } else if (texpr is DynamicTypeExpr) {
6786                                 ec.Report.Error (1962, QueriedType.Location,
6787                                         "The typeof operator cannot be used on the dynamic type");
6788                         }
6789
6790                         type = TypeManager.type_type;
6791
6792                         return DoResolveBase ();
6793                 }
6794
6795                 protected Expression DoResolveBase ()
6796                 {
6797                         if (TypeManager.system_type_get_type_from_handle == null) {
6798                                 TypeManager.system_type_get_type_from_handle = TypeManager.GetPredefinedMethod (
6799                                         TypeManager.type_type, "GetTypeFromHandle", loc, TypeManager.runtime_handle_type);
6800                         }
6801
6802                         // Even though what is returned is a type object, it's treated as a value by the compiler.
6803                         // In particular, 'typeof (Foo).X' is something totally different from 'Foo.X'.
6804                         eclass = ExprClass.Value;
6805                         return this;
6806                 }
6807
6808                 public override void EncodeAttributeValue (IMemberContext rc, AttributeEncoder enc, TypeSpec targetType)
6809                 {
6810                         // Target type is not System.Type therefore must be object
6811                         // and we need to use different encoding sequence
6812                         if (targetType != type)
6813                                 enc.Encode (type);
6814
6815 /*
6816                         var gi = typearg as InflatedTypeSpec;
6817                         if (gi != null) {
6818                                 // TODO: This has to be recursive, handle arrays, etc.
6819                                 // I could probably do it after CustomAttribute encoder rewrite
6820                                 foreach (var ta in gi.TypeArguments) {
6821                                         if (ta.IsGenericParameter) {
6822                                                 ec.Report.SymbolRelatedToPreviousError (typearg);
6823                                                 ec.Report.Error (416, loc, "`{0}': an attribute argument cannot use type parameters",
6824                                                                  TypeManager.CSharpName (typearg));
6825                                                 value = null;
6826                                                 return false;
6827                                         }
6828                                 }
6829                         }
6830  */
6831
6832                         if (!enc.EncodeTypeName (typearg)) {
6833                                 rc.Compiler.Report.SymbolRelatedToPreviousError (typearg);
6834                                 rc.Compiler.Report.Error (416, loc, "`{0}': an attribute argument cannot use type parameters",
6835                                         TypeManager.CSharpName (typearg));
6836                         }
6837                 }
6838
6839                 public override void Emit (EmitContext ec)
6840                 {
6841                         ec.Emit (OpCodes.Ldtoken, typearg);
6842                         ec.Emit (OpCodes.Call, TypeManager.system_type_get_type_from_handle);
6843                 }
6844
6845                 public TypeSpec TypeArgument {
6846                         get {
6847                                 return typearg;
6848                         }
6849                 }
6850
6851                 protected override void CloneTo (CloneContext clonectx, Expression t)
6852                 {
6853                         TypeOf target = (TypeOf) t;
6854                         if (QueriedType != null)
6855                                 target.QueriedType = QueriedType.Clone (clonectx);
6856                 }
6857         }
6858
6859         /// <summary>
6860         ///   Implements the `typeof (void)' operator
6861         /// </summary>
6862         public class TypeOfVoid : TypeOf {
6863                 public TypeOfVoid (Location l) : base (null, l)
6864                 {
6865                         loc = l;
6866                 }
6867
6868                 protected override Expression DoResolve (ResolveContext ec)
6869                 {
6870                         type = TypeManager.type_type;
6871                         typearg = TypeManager.void_type;
6872
6873                         return DoResolveBase ();
6874                 }
6875         }
6876
6877         class TypeOfMethod : TypeOfMember<MethodSpec>
6878         {
6879                 public TypeOfMethod (MethodSpec method, Location loc)
6880                         : base (method, loc)
6881                 {
6882                 }
6883
6884                 protected override Expression DoResolve (ResolveContext ec)
6885                 {
6886                         if (member.IsConstructor) {
6887                                 type = TypeManager.ctorinfo_type;
6888                                 if (type == null)
6889                                         type = TypeManager.ctorinfo_type = TypeManager.CoreLookupType (ec.Compiler, "System.Reflection", "ConstructorInfo", MemberKind.Class, true);
6890                         } else {
6891                                 type = TypeManager.methodinfo_type;
6892                                 if (type == null)
6893                                         type = TypeManager.methodinfo_type = TypeManager.CoreLookupType (ec.Compiler, "System.Reflection", "MethodInfo", MemberKind.Class, true);
6894                         }
6895
6896                         return base.DoResolve (ec);
6897                 }
6898
6899                 public override void Emit (EmitContext ec)
6900                 {
6901                         ec.Emit (OpCodes.Ldtoken, member);
6902
6903                         base.Emit (ec);
6904                         ec.Emit (OpCodes.Castclass, type);
6905                 }
6906
6907                 protected override string GetMethodName {
6908                         get { return "GetMethodFromHandle"; }
6909                 }
6910
6911                 protected override string RuntimeHandleName {
6912                         get { return "RuntimeMethodHandle"; }
6913                 }
6914
6915                 protected override MethodSpec TypeFromHandle {
6916                         get {
6917                                 return TypeManager.methodbase_get_type_from_handle;
6918                         }
6919                         set {
6920                                 TypeManager.methodbase_get_type_from_handle = value;
6921                         }
6922                 }
6923
6924                 protected override MethodSpec TypeFromHandleGeneric {
6925                         get {
6926                                 return TypeManager.methodbase_get_type_from_handle_generic;
6927                         }
6928                         set {
6929                                 TypeManager.methodbase_get_type_from_handle_generic = value;
6930                         }
6931                 }
6932
6933                 protected override string TypeName {
6934                         get { return "MethodBase"; }
6935                 }
6936         }
6937
6938         abstract class TypeOfMember<T> : Expression where T : MemberSpec
6939         {
6940                 protected readonly T member;
6941
6942                 protected TypeOfMember (T member, Location loc)
6943                 {
6944                         this.member = member;
6945                         this.loc = loc;
6946                 }
6947
6948                 public override Expression CreateExpressionTree (ResolveContext ec)
6949                 {
6950                         Arguments args = new Arguments (2);
6951                         args.Add (new Argument (this));
6952                         args.Add (new Argument (new TypeOf (new TypeExpression (type, loc), loc)));
6953                         return CreateExpressionFactoryCall (ec, "Constant", args);
6954                 }
6955
6956                 protected override Expression DoResolve (ResolveContext ec)
6957                 {
6958                         bool is_generic = member.DeclaringType.IsGenericOrParentIsGeneric;
6959                         var mi = is_generic ? TypeFromHandleGeneric : TypeFromHandle;
6960
6961                         if (mi == null) {
6962                                 TypeSpec t = TypeManager.CoreLookupType (ec.Compiler, "System.Reflection", TypeName, MemberKind.Class, true);
6963                                 TypeSpec handle_type = TypeManager.CoreLookupType (ec.Compiler, "System", RuntimeHandleName, MemberKind.Struct, true);
6964
6965                                 if (t == null || handle_type == null)
6966                                         return null;
6967
6968                                 mi = TypeManager.GetPredefinedMethod (t, GetMethodName, loc,
6969                                         is_generic ?
6970                                         new TypeSpec[] { handle_type, TypeManager.runtime_handle_type } :
6971                                         new TypeSpec[] { handle_type } );
6972
6973                                 if (is_generic)
6974                                         TypeFromHandleGeneric = mi;
6975                                 else
6976                                         TypeFromHandle = mi;
6977                         }
6978
6979                         eclass = ExprClass.Value;
6980                         return this;
6981                 }
6982
6983                 public override void Emit (EmitContext ec)
6984                 {
6985                         bool is_generic = member.DeclaringType.IsGenericOrParentIsGeneric;
6986                         MethodSpec mi;
6987                         if (is_generic) {
6988                                 mi = TypeFromHandleGeneric;
6989                                 ec.Emit (OpCodes.Ldtoken, member.DeclaringType);
6990                         } else {
6991                                 mi = TypeFromHandle;
6992                         }
6993
6994                         ec.Emit (OpCodes.Call, mi);
6995                 }
6996
6997                 protected abstract string GetMethodName { get; }
6998                 protected abstract string RuntimeHandleName { get; }
6999                 protected abstract MethodSpec TypeFromHandle { get; set; }
7000                 protected abstract MethodSpec TypeFromHandleGeneric { get; set; }
7001                 protected abstract string TypeName { get; }
7002         }
7003
7004         class TypeOfField : TypeOfMember<FieldSpec>
7005         {
7006                 public TypeOfField (FieldSpec field, Location loc)
7007                         : base (field, loc)
7008                 {
7009                 }
7010
7011                 protected override Expression DoResolve (ResolveContext ec)
7012                 {
7013                         if (TypeManager.fieldinfo_type == null)
7014                                 TypeManager.fieldinfo_type = TypeManager.CoreLookupType (ec.Compiler, "System.Reflection", TypeName, MemberKind.Class, true);
7015
7016                         type = TypeManager.fieldinfo_type;
7017                         return base.DoResolve (ec);
7018                 }
7019
7020                 public override void Emit (EmitContext ec)
7021                 {
7022                         ec.Emit (OpCodes.Ldtoken, member);
7023                         base.Emit (ec);
7024                 }
7025
7026                 protected override string GetMethodName {
7027                         get { return "GetFieldFromHandle"; }
7028                 }
7029
7030                 protected override string RuntimeHandleName {
7031                         get { return "RuntimeFieldHandle"; }
7032                 }
7033
7034                 protected override MethodSpec TypeFromHandle {
7035                         get {
7036                                 return TypeManager.fieldinfo_get_field_from_handle;
7037                         }
7038                         set {
7039                                 TypeManager.fieldinfo_get_field_from_handle = value;
7040                         }
7041                 }
7042
7043                 protected override MethodSpec TypeFromHandleGeneric {
7044                         get {
7045                                 return TypeManager.fieldinfo_get_field_from_handle_generic;
7046                         }
7047                         set {
7048                                 TypeManager.fieldinfo_get_field_from_handle_generic = value;
7049                         }
7050                 }
7051
7052                 protected override string TypeName {
7053                         get { return "FieldInfo"; }
7054                 }
7055         }
7056
7057         /// <summary>
7058         ///   Implements the sizeof expression
7059         /// </summary>
7060         public class SizeOf : Expression {
7061                 readonly Expression QueriedType;
7062                 TypeSpec type_queried;
7063
7064                 public SizeOf (Expression queried_type, Location l)
7065                 {
7066                         this.QueriedType = queried_type;
7067                         loc = l;
7068                 }
7069
7070                 public override Expression CreateExpressionTree (ResolveContext ec)
7071                 {
7072                         Error_PointerInsideExpressionTree (ec);
7073                         return null;
7074                 }
7075
7076                 protected override Expression DoResolve (ResolveContext ec)
7077                 {
7078                         TypeExpr texpr = QueriedType.ResolveAsTypeTerminal (ec, false);
7079                         if (texpr == null)
7080                                 return null;
7081
7082                         type_queried = texpr.Type;
7083                         if (TypeManager.IsEnumType (type_queried))
7084                                 type_queried = EnumSpec.GetUnderlyingType (type_queried);
7085
7086                         int size_of = GetTypeSize (type_queried);
7087                         if (size_of > 0) {
7088                                 return new IntConstant (size_of, loc).Resolve (ec);
7089                         }
7090
7091                         if (!TypeManager.VerifyUnmanaged (ec.Compiler, type_queried, loc)){
7092                                 return null;
7093                         }
7094
7095                         if (!ec.IsUnsafe) {
7096                                 ec.Report.Error (233, loc,
7097                                         "`{0}' does not have a predefined size, therefore sizeof can only be used in an unsafe context (consider using System.Runtime.InteropServices.Marshal.SizeOf)",
7098                                         TypeManager.CSharpName (type_queried));
7099                         }
7100
7101                         type = TypeManager.int32_type;
7102                         eclass = ExprClass.Value;
7103                         return this;
7104                 }
7105
7106                 public override void Emit (EmitContext ec)
7107                 {
7108                         ec.Emit (OpCodes.Sizeof, type_queried);
7109                 }
7110
7111                 protected override void CloneTo (CloneContext clonectx, Expression t)
7112                 {
7113                 }
7114         }
7115
7116         /// <summary>
7117         ///   Implements the qualified-alias-member (::) expression.
7118         /// </summary>
7119         public class QualifiedAliasMember : MemberAccess
7120         {
7121                 readonly string alias;
7122                 public static readonly string GlobalAlias = "global";
7123
7124                 public QualifiedAliasMember (string alias, string identifier, Location l)
7125                         : base (null, identifier, l)
7126                 {
7127                         this.alias = alias;
7128                 }
7129
7130                 public QualifiedAliasMember (string alias, string identifier, TypeArguments targs, Location l)
7131                         : base (null, identifier, targs, l)
7132                 {
7133                         this.alias = alias;
7134                 }
7135
7136                 public QualifiedAliasMember (string alias, string identifier, int arity, Location l)
7137                         : base (null, identifier, arity, l)
7138                 {
7139                         this.alias = alias;
7140                 }
7141
7142                 public override FullNamedExpression ResolveAsTypeStep (IMemberContext ec, bool silent)
7143                 {
7144                         if (alias == GlobalAlias) {
7145                                 expr = GlobalRootNamespace.Instance;
7146                                 return base.ResolveAsTypeStep (ec, silent);
7147                         }
7148
7149                         int errors = ec.Compiler.Report.Errors;
7150                         expr = ec.LookupNamespaceAlias (alias);
7151                         if (expr == null) {
7152                                 if (errors == ec.Compiler.Report.Errors)
7153                                         ec.Compiler.Report.Error (432, loc, "Alias `{0}' not found", alias);
7154                                 return null;
7155                         }
7156
7157                         FullNamedExpression fne = base.ResolveAsTypeStep (ec, silent);
7158                         if (fne == null)
7159                                 return null;
7160
7161                         if (expr.eclass == ExprClass.Type) {
7162                                 if (!silent) {
7163                                         ec.Compiler.Report.Error (431, loc,
7164                                                 "Alias `{0}' cannot be used with '::' since it denotes a type. Consider replacing '::' with '.'", alias);
7165                                 }
7166                                 return null;
7167                         }
7168
7169                         return fne;
7170                 }
7171
7172                 protected override Expression DoResolve (ResolveContext ec)
7173                 {
7174                         return ResolveAsTypeStep (ec, false);
7175                 }
7176
7177                 protected override void Error_IdentifierNotFound (IMemberContext rc, TypeSpec expr_type, string identifier)
7178                 {
7179                         rc.Compiler.Report.Error (687, loc,
7180                                 "A namespace alias qualifier `{0}' did not resolve to a namespace or a type",
7181                                 GetSignatureForError ());
7182                 }
7183
7184                 public override string GetSignatureForError ()
7185                 {
7186                         string name = Name;
7187                         if (targs != null) {
7188                                 name = Name + "<" + targs.GetSignatureForError () + ">";
7189                         }
7190
7191                         return alias + "::" + name;
7192                 }
7193
7194                 protected override void CloneTo (CloneContext clonectx, Expression t)
7195                 {
7196                         // Nothing
7197                 }
7198         }
7199
7200         /// <summary>
7201         ///   Implements the member access expression
7202         /// </summary>
7203         public class MemberAccess : ATypeNameExpression {
7204                 protected Expression expr;
7205
7206                 public MemberAccess (Expression expr, string id)
7207                         : base (id, expr.Location)
7208                 {
7209                         this.expr = expr;
7210                 }
7211
7212                 public MemberAccess (Expression expr, string identifier, Location loc)
7213                         : base (identifier, loc)
7214                 {
7215                         this.expr = expr;
7216                 }
7217
7218                 public MemberAccess (Expression expr, string identifier, TypeArguments args, Location loc)
7219                         : base (identifier, args, loc)
7220                 {
7221                         this.expr = expr;
7222                 }
7223
7224                 public MemberAccess (Expression expr, string identifier, int arity, Location loc)
7225                         : base (identifier, arity, loc)
7226                 {
7227                         this.expr = expr;
7228                 }
7229
7230                 Expression DoResolve (ResolveContext ec, Expression right_side)
7231                 {
7232                         if (type != null)
7233                                 throw new Exception ();
7234
7235                         //
7236                         // Resolve the expression with flow analysis turned off, we'll do the definite
7237                         // assignment checks later.  This is because we don't know yet what the expression
7238                         // will resolve to - it may resolve to a FieldExpr and in this case we must do the
7239                         // definite assignment check on the actual field and not on the whole struct.
7240                         //
7241
7242                         SimpleName original = expr as SimpleName;
7243                         Expression expr_resolved;
7244                         const ResolveFlags flags = ResolveFlags.VariableOrValue | ResolveFlags.Type;
7245
7246                         using (ec.Set (ResolveContext.Options.OmitStructFlowAnalysis)) {
7247                                 if (original != null) {
7248                                         expr_resolved = original.DoResolve (ec, true);
7249                                         if (expr_resolved != null) {
7250                                                 // Ugly, simulate skipped Resolve
7251                                                 if (expr_resolved is ConstantExpr) {
7252                                                         expr_resolved = expr_resolved.Resolve (ec);
7253                                                 } else if (expr_resolved is FieldExpr || expr_resolved is PropertyExpr) {
7254                                                         // nothing yet
7255                                                 } else if ((flags & expr_resolved.ExprClassToResolveFlags) == 0) {
7256                                                         expr_resolved.Error_UnexpectedKind (ec, flags, expr.Location);
7257                                                         expr_resolved = null;
7258                                                 }
7259                                         }
7260                                 } else {
7261                                         expr_resolved = expr.Resolve (ec, flags);
7262                                 }
7263                         }
7264
7265                         if (expr_resolved == null)
7266                                 return null;
7267
7268                         Namespace ns = expr_resolved as Namespace;
7269                         if (ns != null) {
7270                                 FullNamedExpression retval = ns.Lookup (ec.Compiler, Name, Arity, loc);
7271
7272                                 if (retval == null)
7273                                         ns.Error_NamespaceDoesNotExist (loc, Name, Arity, ec);
7274                                 else if (HasTypeArguments)
7275                                         retval = new GenericTypeExpr (retval.Type, targs, loc).ResolveAsTypeStep (ec, false);
7276
7277                                 return retval;
7278                         }
7279
7280                         TypeSpec expr_type = expr_resolved.Type;
7281                         if (expr_type == InternalType.Dynamic) {
7282                                 Arguments args = new Arguments (1);
7283                                 args.Add (new Argument (expr_resolved.Resolve (ec)));
7284                                 expr = new DynamicMemberBinder (Name, args, loc);
7285                                 if (right_side != null)
7286                                         return expr.DoResolveLValue (ec, right_side);
7287
7288                                 return expr.Resolve (ec);
7289                         }
7290
7291                         const MemberKind dot_kinds = MemberKind.Class | MemberKind.Struct | MemberKind.Delegate | MemberKind.Enum | MemberKind.Interface | MemberKind.TypeParameter;
7292                         if ((expr_type.Kind & dot_kinds) == 0 || expr_type == TypeManager.void_type) {
7293                                 Unary.Error_OperatorCannotBeApplied (ec, loc, ".", expr_type);
7294                                 return null;
7295                         }
7296
7297                         var arity = HasTypeArguments ? targs.Count : -1;
7298
7299                         var member_lookup = MemberLookup (ec.Compiler,
7300                                 ec.CurrentType, expr_type, expr_type, Name, arity, BindingRestriction.NoOverrides, loc);
7301
7302                         if (member_lookup == null) {
7303                                 expr = expr_resolved.Resolve (ec);
7304
7305                                 ExprClass expr_eclass = expr.eclass;
7306
7307                                 //
7308                                 // Extension methods are not allowed on all expression types
7309                                 //
7310                                 if (expr_eclass == ExprClass.Value || expr_eclass == ExprClass.Variable ||
7311                                         expr_eclass == ExprClass.IndexerAccess || expr_eclass == ExprClass.PropertyAccess ||
7312                                         expr_eclass == ExprClass.EventAccess) {
7313                                         ExtensionMethodGroupExpr ex_method_lookup = ec.LookupExtensionMethod (expr_type, Name, arity, loc);
7314                                         if (ex_method_lookup != null) {
7315                                                 ex_method_lookup.ExtensionExpression = expr;
7316
7317                                                 if (HasTypeArguments) {
7318                                                         if (!targs.Resolve (ec))
7319                                                                 return null;
7320
7321                                                         ex_method_lookup.SetTypeArguments (ec, targs);
7322                                                 }
7323
7324                                                 return ex_method_lookup.Resolve (ec);
7325                                         }
7326                                 }
7327
7328                                 member_lookup = Error_MemberLookupFailed (ec,
7329                                         ec.CurrentType, expr_type, expr_type, Name, arity, null,
7330                                         MemberKind.All, BindingRestriction.AccessibleOnly);
7331                                 if (member_lookup == null)
7332                                         return null;
7333                         }
7334
7335                         MemberExpr me;
7336                         TypeExpr texpr = member_lookup as TypeExpr;
7337                         if (texpr != null) {
7338                                 if (!(expr_resolved is TypeExpr)) {
7339                                         me = expr_resolved as MemberExpr;
7340                                         if (me == null || me.ProbeIdenticalTypeName (ec, expr_resolved, original) == expr_resolved) {
7341                                                 ec.Report.Error (572, loc, "`{0}': cannot reference a type through an expression; try `{1}' instead",
7342                                                         Name, member_lookup.GetSignatureForError ());
7343                                                 return null;
7344                                         }
7345                                 }
7346
7347                                 if (!texpr.CheckAccessLevel (ec.MemberContext)) {
7348                                         ec.Report.SymbolRelatedToPreviousError (member_lookup.Type);
7349                                         ErrorIsInaccesible (loc, TypeManager.CSharpName (member_lookup.Type), ec.Report);
7350                                         return null;
7351                                 }
7352
7353                                 if (HasTypeArguments) {
7354                                         var ct = new GenericTypeExpr (member_lookup.Type, targs, loc);
7355                                         return ct.ResolveAsTypeStep (ec, false);
7356                                 }
7357
7358                                 return member_lookup;
7359                         }
7360
7361                         me = (MemberExpr) member_lookup;
7362
7363                         if (original != null && me.IsStatic)
7364                                 expr_resolved = me.ProbeIdenticalTypeName (ec, expr_resolved, original);
7365
7366                         me = me.ResolveMemberAccess (ec, expr_resolved, original);
7367
7368                         if (HasTypeArguments) {
7369                                 if (!targs.Resolve (ec))
7370                                         return null;
7371
7372                                 me.SetTypeArguments (ec, targs);
7373                         }
7374
7375                         if (original != null && (!TypeManager.IsValueType (expr_type) || me is PropertyExpr)) {
7376                                 if (me.IsInstance) {
7377                                         LocalVariableReference var = expr_resolved as LocalVariableReference;
7378                                         if (var != null && !var.VerifyAssigned (ec))
7379                                                 return null;
7380                                 }
7381                         }
7382
7383                         // The following DoResolve/DoResolveLValue will do the definite assignment
7384                         // check.
7385
7386                         if (right_side != null)
7387                                 return me.DoResolveLValue (ec, right_side);
7388                         else
7389                                 return me.Resolve (ec);
7390                 }
7391
7392                 protected override Expression DoResolve (ResolveContext ec)
7393                 {
7394                         return DoResolve (ec, null);
7395                 }
7396
7397                 public override Expression DoResolveLValue (ResolveContext ec, Expression right_side)
7398                 {
7399                         return DoResolve (ec, right_side);
7400                 }
7401
7402                 public override FullNamedExpression ResolveAsTypeStep (IMemberContext ec, bool silent)
7403                 {
7404                         return ResolveNamespaceOrType (ec, silent);
7405                 }
7406
7407                 public FullNamedExpression ResolveNamespaceOrType (IMemberContext rc, bool silent)
7408                 {
7409                         FullNamedExpression expr_resolved = expr.ResolveAsTypeStep (rc, silent);
7410
7411                         if (expr_resolved == null)
7412                                 return null;
7413
7414                         Namespace ns = expr_resolved as Namespace;
7415                         if (ns != null) {
7416                                 FullNamedExpression retval = ns.Lookup (rc.Compiler, Name, Arity, loc);
7417
7418                                 if (retval == null) {
7419                                         if (!silent)
7420                                                 ns.Error_NamespaceDoesNotExist (loc, Name, Arity, rc);
7421                                 } else if (HasTypeArguments) {
7422                                         retval = new GenericTypeExpr (retval.Type, targs, loc).ResolveAsTypeStep (rc, silent);
7423                                 }
7424
7425                                 return retval;
7426                         }
7427
7428                         TypeExpr tnew_expr = expr_resolved.ResolveAsTypeTerminal (rc, false);
7429                         if (tnew_expr == null)
7430                                 return null;
7431
7432                         TypeSpec expr_type = tnew_expr.Type;
7433                         if (TypeManager.IsGenericParameter (expr_type)) {
7434                                 rc.Compiler.Report.Error (704, loc, "A nested type cannot be specified through a type parameter `{0}'",
7435                                         tnew_expr.GetSignatureForError ());
7436                                 return null;
7437                         }
7438
7439                         var nested = MemberCache.FindNestedType (expr_type, Name, Arity);
7440                         if (nested == null) {
7441                                 if (silent)
7442                                         return null;
7443
7444                                 Error_IdentifierNotFound (rc, expr_type, Name);
7445                                 return null;
7446                         }
7447
7448                         bool extra_check;
7449                         if (!IsMemberAccessible (rc.CurrentType ?? InternalType.FakeInternalType, nested, out extra_check)) {
7450                                 ErrorIsInaccesible (loc, nested.GetSignatureForError (), rc.Compiler.Report);
7451                         }
7452
7453                         TypeExpr texpr;
7454                         if (HasTypeArguments) {
7455                                 texpr = new GenericTypeExpr (nested, targs, loc);
7456                         } else {
7457                                 texpr = new TypeExpression (nested, loc);
7458                         }
7459
7460                         return texpr.ResolveAsTypeStep (rc, false);
7461                 }
7462
7463                 protected virtual void Error_IdentifierNotFound (IMemberContext rc, TypeSpec expr_type, string identifier)
7464                 {
7465                         var nested = MemberCache.FindNestedType (expr_type, Name, -System.Math.Max (1, Arity));
7466
7467                         if (nested != null) {
7468                                 Error_TypeArgumentsCannotBeUsed (rc.Compiler.Report, expr.Location, nested, Arity);
7469                                 return;
7470                         }
7471
7472                         var member_lookup = MemberLookup (rc.Compiler,
7473                                 rc.CurrentType, expr_type, expr_type, identifier, -1,
7474                                         MemberKind.All, BindingRestriction.None, loc);
7475
7476                         if (member_lookup == null) {
7477                                 rc.Compiler.Report.Error (426, loc, "The nested type `{0}' does not exist in the type `{1}'",
7478                                                   Name, expr_type.GetSignatureForError ());
7479                         } else {
7480                                 // TODO: Report.SymbolRelatedToPreviousError
7481                                 member_lookup.Error_UnexpectedKind (rc.Compiler.Report, null, "type", loc);
7482                         }
7483                 }
7484
7485                 protected override void Error_TypeDoesNotContainDefinition (ResolveContext ec, TypeSpec type, string name)
7486                 {
7487                         if (RootContext.Version > LanguageVersion.ISO_2 && !ec.Compiler.IsRuntimeBinder &&
7488                                 ((expr.eclass & (ExprClass.Value | ExprClass.Variable)) != 0)) {
7489                                 ec.Report.Error (1061, loc, "Type `{0}' does not contain a definition for `{1}' and no " +
7490                                         "extension method `{1}' of type `{0}' could be found " +
7491                                         "(are you missing a using directive or an assembly reference?)",
7492                                         TypeManager.CSharpName (type), name);
7493                                 return;
7494                         }
7495
7496                         base.Error_TypeDoesNotContainDefinition (ec, type, name);
7497                 }
7498
7499                 public override string GetSignatureForError ()
7500                 {
7501                         return expr.GetSignatureForError () + "." + base.GetSignatureForError ();
7502                 }
7503
7504                 public Expression Left {
7505                         get {
7506                                 return expr;
7507                         }
7508                 }
7509
7510                 protected override void CloneTo (CloneContext clonectx, Expression t)
7511                 {
7512                         MemberAccess target = (MemberAccess) t;
7513
7514                         target.expr = expr.Clone (clonectx);
7515                 }
7516         }
7517
7518         /// <summary>
7519         ///   Implements checked expressions
7520         /// </summary>
7521         public class CheckedExpr : Expression {
7522
7523                 public Expression Expr;
7524
7525                 public CheckedExpr (Expression e, Location l)
7526                 {
7527                         Expr = e;
7528                         loc = l;
7529                 }
7530
7531                 public override Expression CreateExpressionTree (ResolveContext ec)
7532                 {
7533                         using (ec.With (ResolveContext.Options.AllCheckStateFlags, true))
7534                                 return Expr.CreateExpressionTree (ec);
7535                 }
7536
7537                 protected override Expression DoResolve (ResolveContext ec)
7538                 {
7539                         using (ec.With (ResolveContext.Options.AllCheckStateFlags, true))
7540                                 Expr = Expr.Resolve (ec);
7541
7542                         if (Expr == null)
7543                                 return null;
7544
7545                         if (Expr is Constant || Expr is MethodGroupExpr || Expr is AnonymousMethodExpression || Expr is DefaultValueExpression)
7546                                 return Expr;
7547
7548                         eclass = Expr.eclass;
7549                         type = Expr.Type;
7550                         return this;
7551                 }
7552
7553                 public override void Emit (EmitContext ec)
7554                 {
7555                         using (ec.With (EmitContext.Options.AllCheckStateFlags, true))
7556                                 Expr.Emit (ec);
7557                 }
7558
7559                 public override void EmitBranchable (EmitContext ec, Label target, bool on_true)
7560                 {
7561                         using (ec.With (EmitContext.Options.AllCheckStateFlags, true))
7562                                 Expr.EmitBranchable (ec, target, on_true);
7563                 }
7564
7565                 public override SLE.Expression MakeExpression (BuilderContext ctx)
7566                 {
7567                         using (ctx.With (BuilderContext.Options.AllCheckStateFlags, true)) {
7568                                 return Expr.MakeExpression (ctx);
7569                         }
7570                 }
7571
7572                 protected override void CloneTo (CloneContext clonectx, Expression t)
7573                 {
7574                         CheckedExpr target = (CheckedExpr) t;
7575
7576                         target.Expr = Expr.Clone (clonectx);
7577                 }
7578         }
7579
7580         /// <summary>
7581         ///   Implements the unchecked expression
7582         /// </summary>
7583         public class UnCheckedExpr : Expression {
7584
7585                 public Expression Expr;
7586
7587                 public UnCheckedExpr (Expression e, Location l)
7588                 {
7589                         Expr = e;
7590                         loc = l;
7591                 }
7592
7593                 public override Expression CreateExpressionTree (ResolveContext ec)
7594                 {
7595                         using (ec.With (ResolveContext.Options.AllCheckStateFlags, false))
7596                                 return Expr.CreateExpressionTree (ec);
7597                 }
7598
7599                 protected override Expression DoResolve (ResolveContext ec)
7600                 {
7601                         using (ec.With (ResolveContext.Options.AllCheckStateFlags, false))
7602                                 Expr = Expr.Resolve (ec);
7603
7604                         if (Expr == null)
7605                                 return null;
7606
7607                         if (Expr is Constant || Expr is MethodGroupExpr || Expr is AnonymousMethodExpression || Expr is DefaultValueExpression)
7608                                 return Expr;
7609
7610                         eclass = Expr.eclass;
7611                         type = Expr.Type;
7612                         return this;
7613                 }
7614
7615                 public override void Emit (EmitContext ec)
7616                 {
7617                         using (ec.With (EmitContext.Options.AllCheckStateFlags, false))
7618                                 Expr.Emit (ec);
7619                 }
7620
7621                 public override void EmitBranchable (EmitContext ec, Label target, bool on_true)
7622                 {
7623                         using (ec.With (EmitContext.Options.AllCheckStateFlags, false))
7624                                 Expr.EmitBranchable (ec, target, on_true);
7625                 }
7626
7627                 protected override void CloneTo (CloneContext clonectx, Expression t)
7628                 {
7629                         UnCheckedExpr target = (UnCheckedExpr) t;
7630
7631                         target.Expr = Expr.Clone (clonectx);
7632                 }
7633         }
7634
7635         /// <summary>
7636         ///   An Element Access expression.
7637         ///
7638         ///   During semantic analysis these are transformed into
7639         ///   IndexerAccess, ArrayAccess or a PointerArithmetic.
7640         /// </summary>
7641         public class ElementAccess : Expression {
7642                 public Arguments Arguments;
7643                 public Expression Expr;
7644
7645                 public ElementAccess (Expression e, Arguments args)
7646                 {
7647                         Expr = e;
7648                         loc  = e.Location;
7649                         this.Arguments = args;
7650                 }
7651
7652                 public override Expression CreateExpressionTree (ResolveContext ec)
7653                 {
7654                         Arguments args = Arguments.CreateForExpressionTree (ec, Arguments,
7655                                 Expr.CreateExpressionTree (ec));
7656
7657                         return CreateExpressionFactoryCall (ec, "ArrayIndex", args);
7658                 }
7659
7660                 Expression MakePointerAccess (ResolveContext ec, TypeSpec t)
7661                 {
7662                         if (Arguments.Count != 1){
7663                                 ec.Report.Error (196, loc, "A pointer must be indexed by only one value");
7664                                 return null;
7665                         }
7666
7667                         if (Arguments [0] is NamedArgument)
7668                                 Error_NamedArgument ((NamedArgument) Arguments[0], ec.Report);
7669
7670                         Expression p = new PointerArithmetic (Binary.Operator.Addition, Expr, Arguments [0].Expr.Resolve (ec), t, loc);
7671                         return new Indirection (p, loc).Resolve (ec);
7672                 }
7673
7674                 protected override Expression DoResolve (ResolveContext ec)
7675                 {
7676                         Expr = Expr.Resolve (ec);
7677                         if (Expr == null)
7678                                 return null;
7679
7680                         //
7681                         // We perform some simple tests, and then to "split" the emit and store
7682                         // code we create an instance of a different class, and return that.
7683                         //
7684                         // I am experimenting with this pattern.
7685                         //
7686                         TypeSpec t = Expr.Type;
7687
7688                         if (t == TypeManager.array_type){
7689                                 ec.Report.Error (21, loc, "Cannot apply indexing with [] to an expression of type `System.Array'");
7690                                 return null;
7691                         }
7692
7693                         if (t.IsArray)
7694                                 return (new ArrayAccess (this, loc)).Resolve (ec);
7695                         if (t.IsPointer)
7696                                 return MakePointerAccess (ec, t);
7697
7698                         FieldExpr fe = Expr as FieldExpr;
7699                         if (fe != null) {
7700                                 var ff = fe.Spec as FixedFieldSpec;
7701                                 if (ff != null) {
7702                                         return MakePointerAccess (ec, ff.ElementType);
7703                                 }
7704                         }
7705                         return (new IndexerAccess (this, loc)).Resolve (ec);
7706                 }
7707
7708                 public override Expression DoResolveLValue (ResolveContext ec, Expression right_side)
7709                 {
7710                         Expr = Expr.Resolve (ec);
7711                         if (Expr == null)
7712                                 return null;
7713
7714                         type = Expr.Type;
7715                         if (type.IsArray)
7716                                 return (new ArrayAccess (this, loc)).DoResolveLValue (ec, right_side);
7717
7718                         if (type.IsPointer)
7719                                 return MakePointerAccess (ec, type);
7720
7721                         if (Expr.eclass != ExprClass.Variable && TypeManager.IsStruct (type))
7722                                 Error_CannotModifyIntermediateExpressionValue (ec);
7723
7724                         return (new IndexerAccess (this, loc)).DoResolveLValue (ec, right_side);
7725                 }
7726
7727                 public override void Emit (EmitContext ec)
7728                 {
7729                         throw new Exception ("Should never be reached");
7730                 }
7731
7732                 public static void Error_NamedArgument (NamedArgument na, Report Report)
7733                 {
7734                         Report.Error (1742, na.Location, "An element access expression cannot use named argument");
7735                 }
7736
7737                 public override string GetSignatureForError ()
7738                 {
7739                         return Expr.GetSignatureForError ();
7740                 }
7741
7742                 protected override void CloneTo (CloneContext clonectx, Expression t)
7743                 {
7744                         ElementAccess target = (ElementAccess) t;
7745
7746                         target.Expr = Expr.Clone (clonectx);
7747                         if (Arguments != null)
7748                                 target.Arguments = Arguments.Clone (clonectx);
7749                 }
7750         }
7751
7752         /// <summary>
7753         ///   Implements array access
7754         /// </summary>
7755         public class ArrayAccess : Expression, IDynamicAssign, IMemoryLocation {
7756                 //
7757                 // Points to our "data" repository
7758                 //
7759                 ElementAccess ea;
7760
7761                 LocalTemporary temp;
7762
7763                 bool prepared;
7764
7765                 public ArrayAccess (ElementAccess ea_data, Location l)
7766                 {
7767                         ea = ea_data;
7768                         loc = l;
7769                 }
7770
7771                 public override Expression CreateExpressionTree (ResolveContext ec)
7772                 {
7773                         return ea.CreateExpressionTree (ec);
7774                 }
7775
7776                 public override Expression DoResolveLValue (ResolveContext ec, Expression right_side)
7777                 {
7778                         return DoResolve (ec);
7779                 }
7780
7781                 protected override Expression DoResolve (ResolveContext ec)
7782                 {
7783                         // dynamic is used per argument in ConvertExpressionToArrayIndex case
7784                         bool dynamic;
7785                         ea.Arguments.Resolve (ec, out dynamic);
7786
7787                         TypeSpec t = ea.Expr.Type;
7788                         int rank = ea.Arguments.Count;
7789                         if (t.GetMetaInfo ().GetArrayRank () != rank) {
7790                                 ec.Report.Error (22, ea.Location, "Wrong number of indexes `{0}' inside [], expected `{1}'",
7791                                           ea.Arguments.Count.ToString (), t.GetMetaInfo ().GetArrayRank ().ToString ());
7792                                 return null;
7793                         }
7794
7795                         type = TypeManager.GetElementType (t);
7796                         if (type.IsPointer && !ec.IsUnsafe) {
7797                                 UnsafeError (ec, ea.Location);
7798                         }
7799
7800                         foreach (Argument a in ea.Arguments) {
7801                                 if (a is NamedArgument)
7802                                         ElementAccess.Error_NamedArgument ((NamedArgument) a, ec.Report);
7803
7804                                 a.Expr = ConvertExpressionToArrayIndex (ec, a.Expr);
7805                         }
7806
7807                         eclass = ExprClass.Variable;
7808
7809                         return this;
7810                 }
7811
7812                 protected override void Error_NegativeArrayIndex (ResolveContext ec, Location loc)
7813                 {
7814                         ec.Report.Warning (251, 2, loc, "Indexing an array with a negative index (array indices always start at zero)");
7815                 }
7816
7817                 //
7818                 // Load the array arguments into the stack.
7819                 //
7820                 void LoadArrayAndArguments (EmitContext ec)
7821                 {
7822                         ea.Expr.Emit (ec);
7823
7824                         for (int i = 0; i < ea.Arguments.Count; ++i) {
7825                                 ea.Arguments [i].Emit (ec);
7826                         }
7827                 }
7828
7829                 public void Emit (EmitContext ec, bool leave_copy)
7830                 {
7831                         var ac = ea.Expr.Type as ArrayContainer;
7832
7833                         if (prepared) {
7834                                 ec.EmitLoadFromPtr (type);
7835                         } else {
7836                                 LoadArrayAndArguments (ec);
7837                                 ec.EmitArrayLoad (ac);
7838                         }
7839
7840                         if (leave_copy) {
7841                                 ec.Emit (OpCodes.Dup);
7842                                 temp = new LocalTemporary (this.type);
7843                                 temp.Store (ec);
7844                         }
7845                 }
7846
7847                 public override void Emit (EmitContext ec)
7848                 {
7849                         Emit (ec, false);
7850                 }
7851
7852                 public void EmitAssign (EmitContext ec, Expression source, bool leave_copy, bool prepare_for_load)
7853                 {
7854                         var ac = (ArrayContainer) ea.Expr.Type;
7855                         TypeSpec t = source.Type;
7856                         prepared = prepare_for_load;
7857
7858                         if (prepared) {
7859                                 AddressOf (ec, AddressOp.LoadStore);
7860                                 ec.Emit (OpCodes.Dup);
7861                         } else {
7862                                 LoadArrayAndArguments (ec);
7863
7864                                 //
7865                                 // If we are dealing with a struct, get the
7866                                 // address of it, so we can store it.
7867                                 //
7868                                 // The stobj opcode used by value types will need
7869                                 // an address on the stack, not really an array/array
7870                                 // pair
7871                                 //
7872                                 if (ac.Rank == 1 && TypeManager.IsStruct (t) &&
7873                                         (!TypeManager.IsBuiltinOrEnum (t) ||
7874                                          t == TypeManager.decimal_type)) {
7875
7876                                         ec.Emit (OpCodes.Ldelema, t);
7877                                 }
7878                         }
7879
7880                         source.Emit (ec);
7881                         if (leave_copy) {
7882                                 ec.Emit (OpCodes.Dup);
7883                                 temp = new LocalTemporary (this.type);
7884                                 temp.Store (ec);
7885                         }
7886
7887                         if (prepared) {
7888                                 ec.EmitStoreFromPtr (t);
7889                         } else {
7890                                 ec.EmitArrayStore (ac);
7891                         }
7892
7893                         if (temp != null) {
7894                                 temp.Emit (ec);
7895                                 temp.Release (ec);
7896                         }
7897                 }
7898
7899                 public void EmitNew (EmitContext ec, New source, bool leave_copy)
7900                 {
7901                         if (!source.Emit (ec, this)) {
7902                                 if (leave_copy)
7903                                         throw new NotImplementedException ();
7904
7905                                 return;
7906                         }
7907
7908                         throw new NotImplementedException ();
7909                 }
7910
7911                 public void AddressOf (EmitContext ec, AddressOp mode)
7912                 {
7913                         var ac = (ArrayContainer) ea.Expr.Type;
7914
7915                         LoadArrayAndArguments (ec);
7916                         ec.EmitArrayAddress (ac);
7917                 }
7918
7919 #if NET_4_0
7920                 public SLE.Expression MakeAssignExpression (BuilderContext ctx)
7921                 {
7922                         return SLE.Expression.ArrayAccess (
7923                                 ea.Expr.MakeExpression (ctx),
7924                                 Arguments.MakeExpression (ea.Arguments, ctx));
7925                 }
7926 #endif
7927
7928                 public override SLE.Expression MakeExpression (BuilderContext ctx)
7929                 {
7930                         return SLE.Expression.ArrayIndex (
7931                                 ea.Expr.MakeExpression (ctx),
7932                                 Arguments.MakeExpression (ea.Arguments, ctx));
7933                 }
7934         }
7935
7936         /// <summary>
7937         ///   Expressions that represent an indexer call.
7938         /// </summary>
7939         public class IndexerAccess : Expression, IDynamicAssign
7940         {
7941                 class IndexerMethodGroupExpr : MethodGroupExpr
7942                 {
7943                         IEnumerable<IndexerSpec> candidates;
7944
7945                         public IndexerMethodGroupExpr (IEnumerable<IndexerSpec> indexers, Location loc)
7946                                 : base (FilterAccessors (indexers).ToList (), null, loc)
7947                         {
7948                                 candidates = indexers;
7949                         }
7950
7951                         public IndexerSpec BestIndexer ()
7952                         {
7953                                 return candidates.Where (l => l.Get == BestCandidate || l.Set == BestCandidate).First ();
7954                         }
7955
7956                         static IEnumerable<MemberSpec> FilterAccessors (IEnumerable<IndexerSpec> indexers)
7957                         {
7958                                 foreach (IndexerSpec i in indexers) {
7959                                         if (i.HasGet)
7960                                                 yield return i.Get;
7961                                         else
7962                                                 yield return i.Set;
7963                                 }
7964                         }
7965
7966                         protected override IList<MemberSpec> GetBaseTypeMethods (ResolveContext rc, TypeSpec type)
7967                         {
7968                                 candidates = GetIndexersForType (type);
7969                                 if (candidates == null)
7970                                         return null;
7971
7972                                 return FilterAccessors (candidates).ToList ();
7973                         }
7974
7975                         public override string Name {
7976                                 get {
7977                                         return "this";
7978                                 }
7979                         }
7980
7981                         protected override int GetApplicableParametersCount (MethodSpec method, AParametersCollection parameters)
7982                         {
7983                                 //
7984                                 // Here is the trick, decrease number of arguments by 1 when only
7985                                 // available property method is setter. This makes overload resolution
7986                                 // work correctly for indexers.
7987                                 //
7988
7989                                 if (method.Name [0] == 'g')
7990                                         return parameters.Count;
7991
7992                                 return parameters.Count - 1;
7993                         }
7994                 }
7995
7996                 //
7997                 // Points to our "data" repository
7998                 //
7999                 IndexerSpec spec;
8000                 bool is_base_indexer;
8001                 bool prepared;
8002                 LocalTemporary temp;
8003                 LocalTemporary prepared_value;
8004                 Expression set_expr;
8005
8006                 protected TypeSpec indexer_type;
8007                 protected TypeSpec current_type;
8008                 protected Expression instance_expr;
8009                 protected Arguments arguments;
8010
8011                 public IndexerAccess (ElementAccess ea, Location loc)
8012                         : this (ea.Expr, false, loc)
8013                 {
8014                         this.arguments = ea.Arguments;
8015                 }
8016
8017                 protected IndexerAccess (Expression instance_expr, bool is_base_indexer,
8018                                          Location loc)
8019                 {
8020                         this.instance_expr = instance_expr;
8021                         this.is_base_indexer = is_base_indexer;
8022                         this.loc = loc;
8023                 }
8024
8025                 static string GetAccessorName (bool isSet)
8026                 {
8027                         return isSet ? "set" : "get";
8028                 }
8029
8030                 public override Expression CreateExpressionTree (ResolveContext ec)
8031                 {
8032                         Arguments args = Arguments.CreateForExpressionTree (ec, arguments,
8033                                 instance_expr.CreateExpressionTree (ec),
8034                                 new TypeOfMethod (spec.Get, loc));
8035
8036                         return CreateExpressionFactoryCall (ec, "Call", args);
8037                 }
8038
8039                 static IEnumerable<IndexerSpec> GetIndexersForType (TypeSpec lookup_type)
8040                 {
8041                         return MemberCache.FindIndexers (lookup_type, BindingRestriction.AccessibleOnly | BindingRestriction.NoOverrides);
8042                 }
8043
8044                 protected virtual void CommonResolve (ResolveContext ec)
8045                 {
8046                         indexer_type = instance_expr.Type;
8047                         current_type = ec.CurrentType;
8048                 }
8049
8050                 protected override Expression DoResolve (ResolveContext ec)
8051                 {
8052                         return ResolveAccessor (ec, null);
8053                 }
8054
8055                 public override Expression DoResolveLValue (ResolveContext ec, Expression right_side)
8056                 {
8057                         if (right_side == EmptyExpression.OutAccess.Instance) {
8058                                 right_side.DoResolveLValue (ec, this);
8059                                 return null;
8060                         }
8061
8062                         // if the indexer returns a value type, and we try to set a field in it
8063                         if (right_side == EmptyExpression.LValueMemberAccess || right_side == EmptyExpression.LValueMemberOutAccess) {
8064                                 Error_CannotModifyIntermediateExpressionValue (ec);
8065                         }
8066
8067                         return ResolveAccessor (ec, right_side);
8068                 }
8069
8070                 Expression ResolveAccessor (ResolveContext ec, Expression right_side)
8071                 {
8072                         CommonResolve (ec);
8073
8074                         bool dynamic;
8075
8076                         arguments.Resolve (ec, out dynamic);
8077
8078                         if (indexer_type == InternalType.Dynamic) {
8079                                 dynamic = true;
8080                         } else {
8081                                 var ilist = GetIndexersForType (/*current_type,*/ indexer_type);
8082                                 if (ilist == null) {
8083                                         ec.Report.Error (21, loc, "Cannot apply indexing with [] to an expression of type `{0}'",
8084                                                           TypeManager.CSharpName (indexer_type));
8085                                         return null;
8086                                 }
8087
8088                                 var mg = new IndexerMethodGroupExpr (ilist, loc);
8089                                 mg.InstanceExpression = instance_expr;
8090                                 mg = mg.OverloadResolve (ec, ref arguments, false, loc) as IndexerMethodGroupExpr;
8091                                 if (mg == null)
8092                                         return null;
8093
8094                                 if (!dynamic)
8095                                         spec = mg.BestIndexer ();
8096                         }
8097
8098                         if (dynamic) {
8099                                 Arguments args = new Arguments (arguments.Count + 1);
8100                                 if (is_base_indexer) {
8101                                         ec.Report.Error (1972, loc, "The indexer base access cannot be dynamically dispatched. Consider casting the dynamic arguments or eliminating the base access");
8102                                 } else {
8103                                         args.Add (new Argument (instance_expr));
8104                                 }
8105                                 args.AddRange (arguments);
8106
8107                                 var expr = new DynamicIndexBinder (args, loc);
8108                                 if (right_side != null)
8109                                         return expr.ResolveLValue (ec, right_side);
8110
8111                                 return expr.Resolve (ec);
8112                         }
8113
8114                         type = spec.MemberType;
8115                         if (type.IsPointer && !ec.IsUnsafe)
8116                                 UnsafeError (ec, loc);
8117
8118                         MethodSpec accessor;
8119                         if (right_side == null) {
8120                                 accessor = spec.Get;
8121                         } else {
8122                                 accessor = spec.Set;
8123                                 if (!spec.HasSet && spec.HasGet) {
8124                                         ec.Report.SymbolRelatedToPreviousError (spec);
8125                                         ec.Report.Error (200, loc, "The read only property or indexer `{0}' cannot be assigned to",
8126                                                 spec.GetSignatureForError ());
8127                                         return null;
8128                                 }
8129
8130                                 set_expr = Convert.ImplicitConversion (ec, right_side, type, loc);
8131                         }
8132
8133                         if (accessor == null || accessor.Kind == MemberKind.FakeMethod) {
8134                                 ec.Report.SymbolRelatedToPreviousError (spec);
8135                                 ec.Report.Error (154, loc, "The property or indexer `{0}' cannot be used in this context because it lacks a `{1}' accessor",
8136                                         spec.GetSignatureForError (), GetAccessorName (right_side != null));
8137                                 return null;
8138                         }
8139
8140                         //
8141                         // Only base will allow this invocation to happen.
8142                         //
8143                         if (spec.IsAbstract && this is BaseIndexerAccess) {
8144                                 Error_CannotCallAbstractBase (ec, spec.GetSignatureForError ());
8145                         }
8146
8147                         bool must_do_cs1540_check;
8148                         if (!IsMemberAccessible (ec.CurrentType, accessor, out must_do_cs1540_check)) {
8149                                 if (spec.HasDifferentAccessibility) {
8150                                         ec.Report.SymbolRelatedToPreviousError (accessor);
8151                                         ec.Report.Error (271, loc, "The property or indexer `{0}' cannot be used in this context because a `{1}' accessor is inaccessible",
8152                                                 TypeManager.GetFullNameSignature (spec), GetAccessorName (right_side != null));
8153                                 } else {
8154                                         ec.Report.SymbolRelatedToPreviousError (spec);
8155                                         ErrorIsInaccesible (loc, TypeManager.GetFullNameSignature (spec), ec.Report);
8156                                 }
8157                         }
8158
8159                         instance_expr.CheckMarshalByRefAccess (ec);
8160
8161                         if (must_do_cs1540_check && (instance_expr != EmptyExpression.Null) &&
8162                             !TypeManager.IsInstantiationOfSameGenericType (instance_expr.Type, ec.CurrentType) &&
8163                             !TypeManager.IsNestedChildOf (ec.CurrentType, instance_expr.Type) &&
8164                             !TypeManager.IsSubclassOf (instance_expr.Type, ec.CurrentType)) {
8165                                 ec.Report.SymbolRelatedToPreviousError (accessor);
8166                                 Error_CannotAccessProtected (ec, loc, spec, instance_expr.Type, ec.CurrentType);
8167                                 return null;
8168                         }
8169
8170                         eclass = ExprClass.IndexerAccess;
8171                         return this;
8172                 }
8173
8174                 public override void Emit (EmitContext ec)
8175                 {
8176                         Emit (ec, false);
8177                 }
8178
8179                 public void Emit (EmitContext ec, bool leave_copy)
8180                 {
8181                         if (prepared) {
8182                                 prepared_value.Emit (ec);
8183                         } else {
8184                                 Invocation.EmitCall (ec, is_base_indexer, instance_expr, spec.Get,
8185                                         arguments, loc, false, false);
8186                         }
8187
8188                         if (leave_copy) {
8189                                 ec.Emit (OpCodes.Dup);
8190                                 temp = new LocalTemporary (Type);
8191                                 temp.Store (ec);
8192                         }
8193                 }
8194
8195                 //
8196                 // source is ignored, because we already have a copy of it from the
8197                 // LValue resolution and we have already constructed a pre-cached
8198                 // version of the arguments (ea.set_arguments);
8199                 //
8200                 public void EmitAssign (EmitContext ec, Expression source, bool leave_copy, bool prepare_for_load)
8201                 {
8202                         prepared = prepare_for_load;
8203                         Expression value = set_expr;
8204
8205                         if (prepared) {
8206                                 Invocation.EmitCall (ec, is_base_indexer, instance_expr, spec.Get,
8207                                         arguments, loc, true, false);
8208
8209                                 prepared_value = new LocalTemporary (type);
8210                                 prepared_value.Store (ec);
8211                                 source.Emit (ec);
8212                                 prepared_value.Release (ec);
8213
8214                                 if (leave_copy) {
8215                                         ec.Emit (OpCodes.Dup);
8216                                         temp = new LocalTemporary (Type);
8217                                         temp.Store (ec);
8218                                 }
8219                         } else if (leave_copy) {
8220                                 temp = new LocalTemporary (Type);
8221                                 source.Emit (ec);
8222                                 temp.Store (ec);
8223                                 value = temp;
8224                         }
8225
8226                         if (!prepared)
8227                                 arguments.Add (new Argument (value));
8228
8229                         Invocation.EmitCall (ec, is_base_indexer, instance_expr, spec.Set, arguments, loc, false, prepared);
8230
8231                         if (temp != null) {
8232                                 temp.Emit (ec);
8233                                 temp.Release (ec);
8234                         }
8235                 }
8236
8237                 public override string GetSignatureForError ()
8238                 {
8239                         return spec.GetSignatureForError ();
8240                 }
8241
8242 #if NET_4_0
8243                 public SLE.Expression MakeAssignExpression (BuilderContext ctx)
8244                 {
8245                         var value = new[] { set_expr.MakeExpression (ctx) };
8246                         var args = Arguments.MakeExpression (arguments, ctx).Concat (value);
8247
8248                         return SLE.Expression.Block (
8249                                         SLE.Expression.Call (instance_expr.MakeExpression (ctx), (MethodInfo) spec.Set.GetMetaInfo (), args),
8250                                         value [0]);
8251                 }
8252 #endif
8253
8254                 public override SLE.Expression MakeExpression (BuilderContext ctx)
8255                 {
8256                         var args = Arguments.MakeExpression (arguments, ctx);
8257                         return SLE.Expression.Call (instance_expr.MakeExpression (ctx), (MethodInfo) spec.Get.GetMetaInfo (), args);
8258                 }
8259
8260                 protected override void CloneTo (CloneContext clonectx, Expression t)
8261                 {
8262                         IndexerAccess target = (IndexerAccess) t;
8263
8264                         if (arguments != null)
8265                                 target.arguments = arguments.Clone (clonectx);
8266
8267                         if (instance_expr != null)
8268                                 target.instance_expr = instance_expr.Clone (clonectx);
8269                 }
8270         }
8271
8272         /// <summary>
8273         ///   The base operator for method names
8274         /// </summary>
8275         public class BaseAccess : Expression {
8276                 public readonly string Identifier;
8277                 TypeArguments args;
8278
8279                 public BaseAccess (string member, Location l)
8280                 {
8281                         this.Identifier = member;
8282                         loc = l;
8283                 }
8284
8285                 public BaseAccess (string member, TypeArguments args, Location l)
8286                         : this (member, l)
8287                 {
8288                         this.args = args;
8289                 }
8290
8291                 public override Expression CreateExpressionTree (ResolveContext ec)
8292                 {
8293                         throw new NotSupportedException ("ET");
8294                 }
8295
8296                 protected override Expression DoResolve (ResolveContext ec)
8297                 {
8298                         Expression c = CommonResolve (ec);
8299
8300                         if (c == null)
8301                                 return null;
8302
8303                         //
8304                         // MethodGroups use this opportunity to flag an error on lacking ()
8305                         //
8306                         if (!(c is MethodGroupExpr))
8307                                 return c.Resolve (ec);
8308                         return c;
8309                 }
8310
8311                 public override Expression DoResolveLValue (ResolveContext ec, Expression right_side)
8312                 {
8313                         Expression c = CommonResolve (ec);
8314
8315                         if (c == null)
8316                                 return null;
8317
8318                         //
8319                         // MethodGroups use this opportunity to flag an error on lacking ()
8320                         //
8321                         if (! (c is MethodGroupExpr))
8322                                 return c.DoResolveLValue (ec, right_side);
8323
8324                         return c;
8325                 }
8326
8327                 Expression CommonResolve (ResolveContext ec)
8328                 {
8329                         Expression member_lookup;
8330                         TypeSpec current_type = ec.CurrentType;
8331                         TypeSpec base_type = current_type.BaseType;
8332
8333                         if (!This.IsThisAvailable (ec, false)) {
8334                                 if (ec.IsStatic) {
8335                                         ec.Report.Error (1511, loc, "Keyword `base' is not available in a static method");
8336                                 } else {
8337                                         ec.Report.Error (1512, loc, "Keyword `base' is not available in the current context");
8338                                 }
8339                                 return null;
8340                         }
8341
8342                         var arity = args == null ? -1 : args.Count;
8343                         member_lookup = MemberLookup (ec.Compiler, ec.CurrentType, null, base_type, Identifier, arity,
8344                                                       MemberKind.All, BindingRestriction.AccessibleOnly, loc);
8345                         if (member_lookup == null) {
8346                                 Error_MemberLookupFailed (ec, ec.CurrentType, base_type, base_type, Identifier, arity,
8347                                         null, MemberKind.All, BindingRestriction.AccessibleOnly);
8348                                 return null;
8349                         }
8350
8351                         Expression left;
8352
8353                         if (ec.IsStatic)
8354                                 left = new TypeExpression (base_type, loc);
8355                         else
8356                                 left = ec.GetThis (loc);
8357
8358                         MemberExpr me = member_lookup as MemberExpr;
8359                         if (me == null){
8360                                 if (member_lookup is TypeExpression){
8361                                         ec.Report.Error (582, loc, "{0}: Can not reference a type through an expression, try `{1}' instead",
8362                                                          Identifier, member_lookup.GetSignatureForError ());
8363                                 } else {
8364                                         ec.Report.Error (582, loc, "{0}: Can not reference a {1} through an expression",
8365                                                          Identifier, member_lookup.ExprClassName);
8366                                 }
8367
8368                                 return null;
8369                         }
8370
8371                         me = me.ResolveMemberAccess (ec, left, null);
8372                         me.IsBase = true;
8373
8374                         if (args != null) {
8375                                 args.Resolve (ec);
8376                                 me.SetTypeArguments (ec, args);
8377                         }
8378
8379                         return me;
8380                 }
8381
8382                 public override void Emit (EmitContext ec)
8383                 {
8384                         throw new Exception ("Should never be called");
8385                 }
8386
8387                 protected override void CloneTo (CloneContext clonectx, Expression t)
8388                 {
8389                         BaseAccess target = (BaseAccess) t;
8390
8391                         if (args != null)
8392                                 target.args = args.Clone ();
8393                 }
8394         }
8395
8396         /// <summary>
8397         ///   The base indexer operator
8398         /// </summary>
8399         public class BaseIndexerAccess : IndexerAccess {
8400                 public BaseIndexerAccess (Arguments args, Location loc)
8401                         : base (null, true, loc)
8402                 {
8403                         this.arguments = args;
8404                 }
8405
8406                 protected override void CommonResolve (ResolveContext ec)
8407                 {
8408                         instance_expr = ec.GetThis (loc);
8409
8410                         current_type = ec.CurrentType.BaseType;
8411                         indexer_type = current_type;
8412                 }
8413
8414                 public override Expression CreateExpressionTree (ResolveContext ec)
8415                 {
8416                         MemberExpr.Error_BaseAccessInExpressionTree (ec, loc);
8417                         return base.CreateExpressionTree (ec);
8418                 }
8419         }
8420
8421         /// <summary>
8422         ///   This class exists solely to pass the Type around and to be a dummy
8423         ///   that can be passed to the conversion functions (this is used by
8424         ///   foreach implementation to typecast the object return value from
8425         ///   get_Current into the proper type.  All code has been generated and
8426         ///   we only care about the side effect conversions to be performed
8427         ///
8428         ///   This is also now used as a placeholder where a no-action expression
8429         ///   is needed (the `New' class).
8430         /// </summary>
8431         public class EmptyExpression : Expression {
8432                 public static readonly Expression Null = new EmptyExpression ();
8433
8434                 public class OutAccess : EmptyExpression
8435                 {
8436                         public static readonly OutAccess Instance = new OutAccess ();
8437
8438                         public override Expression DoResolveLValue (ResolveContext rc, Expression right_side)
8439                         {
8440                                 rc.Report.Error (206, right_side.Location,
8441                                         "A property, indexer or dynamic member access may not be passed as `ref' or `out' parameter");
8442
8443                                 return null;
8444                         }
8445                 }
8446
8447                 public static readonly EmptyExpression LValueMemberAccess = new EmptyExpression ();
8448                 public static readonly EmptyExpression LValueMemberOutAccess = new EmptyExpression ();
8449                 public static readonly EmptyExpression UnaryAddress = new EmptyExpression ();
8450
8451                 static EmptyExpression temp = new EmptyExpression ();
8452                 public static EmptyExpression Grab ()
8453                 {
8454                         EmptyExpression retval = temp == null ? new EmptyExpression () : temp;
8455                         temp = null;
8456                         return retval;
8457                 }
8458
8459                 public static void Release (EmptyExpression e)
8460                 {
8461                         temp = e;
8462                 }
8463
8464                 EmptyExpression ()
8465                 {
8466                         // FIXME: Don't set to object
8467                         type = TypeManager.object_type;
8468                         eclass = ExprClass.Value;
8469                         loc = Location.Null;
8470                 }
8471
8472                 public EmptyExpression (TypeSpec t)
8473                 {
8474                         type = t;
8475                         eclass = ExprClass.Value;
8476                         loc = Location.Null;
8477                 }
8478
8479                 public override Expression CreateExpressionTree (ResolveContext ec)
8480                 {
8481                         throw new NotSupportedException ("ET");
8482                 }
8483
8484                 protected override Expression DoResolve (ResolveContext ec)
8485                 {
8486                         return this;
8487                 }
8488
8489                 public override void Emit (EmitContext ec)
8490                 {
8491                         // nothing, as we only exist to not do anything.
8492                 }
8493
8494                 public override void EmitSideEffect (EmitContext ec)
8495                 {
8496                 }
8497
8498                 //
8499                 // This is just because we might want to reuse this bad boy
8500                 // instead of creating gazillions of EmptyExpressions.
8501                 // (CanImplicitConversion uses it)
8502                 //
8503                 public void SetType (TypeSpec t)
8504                 {
8505                         type = t;
8506                 }
8507         }
8508
8509         //
8510         // Empty statement expression
8511         //
8512         public sealed class EmptyExpressionStatement : ExpressionStatement
8513         {
8514                 public static readonly EmptyExpressionStatement Instance = new EmptyExpressionStatement ();
8515
8516                 private EmptyExpressionStatement ()
8517                 {
8518                         loc = Location.Null;
8519                 }
8520
8521                 public override Expression CreateExpressionTree (ResolveContext ec)
8522                 {
8523                         return null;
8524                 }
8525
8526                 public override void EmitStatement (EmitContext ec)
8527                 {
8528                         // Do nothing
8529                 }
8530
8531                 protected override Expression DoResolve (ResolveContext ec)
8532                 {
8533                         eclass = ExprClass.Value;
8534                         type = TypeManager.object_type;
8535                         return this;
8536                 }
8537
8538                 public override void Emit (EmitContext ec)
8539                 {
8540                         // Do nothing
8541                 }
8542         }
8543
8544         public class UserCast : Expression {
8545                 MethodSpec method;
8546                 Expression source;
8547
8548                 public UserCast (MethodSpec method, Expression source, Location l)
8549                 {
8550                         this.method = method;
8551                         this.source = source;
8552                         type = method.ReturnType;
8553                         loc = l;
8554                 }
8555
8556                 public Expression Source {
8557                         get {
8558                                 return source;
8559                         }
8560                 }
8561
8562                 public override Expression CreateExpressionTree (ResolveContext ec)
8563                 {
8564                         Arguments args = new Arguments (3);
8565                         args.Add (new Argument (source.CreateExpressionTree (ec)));
8566                         args.Add (new Argument (new TypeOf (new TypeExpression (type, loc), loc)));
8567                         args.Add (new Argument (new TypeOfMethod (method, loc)));
8568                         return CreateExpressionFactoryCall (ec, "Convert", args);
8569                 }
8570
8571                 protected override Expression DoResolve (ResolveContext ec)
8572                 {
8573                         ObsoleteAttribute oa = method.GetAttributeObsolete ();
8574                         if (oa != null)
8575                                 AttributeTester.Report_ObsoleteMessage (oa, GetSignatureForError (), loc, ec.Report);
8576
8577                         eclass = ExprClass.Value;
8578                         return this;
8579                 }
8580
8581                 public override void Emit (EmitContext ec)
8582                 {
8583                         source.Emit (ec);
8584                         ec.Emit (OpCodes.Call, method);
8585                 }
8586
8587                 public override string GetSignatureForError ()
8588                 {
8589                         return TypeManager.CSharpSignature (method);
8590                 }
8591
8592                 public override SLE.Expression MakeExpression (BuilderContext ctx)
8593                 {
8594                         return SLE.Expression.Convert (source.MakeExpression (ctx), type.GetMetaInfo (), (MethodInfo) method.GetMetaInfo ());
8595                 }
8596         }
8597
8598         // <summary>
8599         //   This class is used to "construct" the type during a typecast
8600         //   operation.  Since the Type.GetType class in .NET can parse
8601         //   the type specification, we just use this to construct the type
8602         //   one bit at a time.
8603         // </summary>
8604         public class ComposedCast : TypeExpr {
8605                 FullNamedExpression left;
8606                 string dim;
8607
8608                 public ComposedCast (FullNamedExpression left, string dim)
8609                         : this (left, dim, left.Location)
8610                 {
8611                 }
8612
8613                 public ComposedCast (FullNamedExpression left, string dim, Location l)
8614                 {
8615                         this.left = left;
8616                         this.dim = dim;
8617                         loc = l;
8618                 }
8619
8620                 protected override TypeExpr DoResolveAsTypeStep (IMemberContext ec)
8621                 {
8622                         TypeExpr lexpr = left.ResolveAsTypeTerminal (ec, false);
8623                         if (lexpr == null)
8624                                 return null;
8625
8626                         TypeSpec ltype = lexpr.Type;
8627                         if ((dim.Length > 0) && (dim [0] == '?')) {
8628                                 TypeExpr nullable = new Nullable.NullableType (lexpr, loc);
8629                                 if (dim.Length > 1)
8630                                         nullable = new ComposedCast (nullable, dim.Substring (1), loc);
8631                                 return nullable.ResolveAsTypeTerminal (ec, false);
8632                         }
8633
8634                         if (dim == "*" && !TypeManager.VerifyUnmanaged (ec.Compiler, ltype, loc))
8635                                 return null;
8636
8637                         if (dim.Length != 0 && dim [0] == '[') {
8638                                 if (TypeManager.IsSpecialType (ltype)) {
8639                                         ec.Compiler.Report.Error (611, loc, "Array elements cannot be of type `{0}'", TypeManager.CSharpName (ltype));
8640                                         return null;
8641                                 }
8642
8643                                 if (ltype.IsStatic) {
8644                                         ec.Compiler.Report.SymbolRelatedToPreviousError (ltype);
8645                                         ec.Compiler.Report.Error (719, loc, "Array elements cannot be of static type `{0}'",
8646                                                 TypeManager.CSharpName (ltype));
8647                                 }
8648                         }
8649
8650                         if (dim != "")
8651                                 type = TypeManager.GetConstructedType (ltype, dim);
8652                         else
8653                                 type = ltype;
8654
8655                         if (type == null)
8656                                 throw new InternalErrorException ("Couldn't create computed type " + ltype + dim);
8657
8658                         if (type.IsPointer && !ec.IsUnsafe){
8659                                 UnsafeError (ec.Compiler.Report, loc);
8660                         }
8661
8662                         eclass = ExprClass.Type;
8663                         return this;
8664                 }
8665
8666                 public override string GetSignatureForError ()
8667                 {
8668                         return left.GetSignatureForError () + dim;
8669                 }
8670         }
8671
8672         public class FixedBufferPtr : Expression {
8673                 Expression array;
8674
8675                 public FixedBufferPtr (Expression array, TypeSpec array_type, Location l)
8676                 {
8677                         this.array = array;
8678                         this.loc = l;
8679
8680                         type = PointerContainer.MakeType (array_type);
8681                         eclass = ExprClass.Value;
8682                 }
8683
8684                 public override Expression CreateExpressionTree (ResolveContext ec)
8685                 {
8686                         Error_PointerInsideExpressionTree (ec);
8687                         return null;
8688                 }
8689
8690                 public override void Emit(EmitContext ec)
8691                 {
8692                         array.Emit (ec);
8693                 }
8694
8695                 protected override Expression DoResolve (ResolveContext ec)
8696                 {
8697                         //
8698                         // We are born fully resolved
8699                         //
8700                         return this;
8701                 }
8702         }
8703
8704
8705         //
8706         // This class is used to represent the address of an array, used
8707         // only by the Fixed statement, this generates "&a [0]" construct
8708         // for fixed (char *pa = a)
8709         //
8710         public class ArrayPtr : FixedBufferPtr {
8711                 TypeSpec array_type;
8712
8713                 public ArrayPtr (Expression array, TypeSpec array_type, Location l):
8714                         base (array, array_type, l)
8715                 {
8716                         this.array_type = array_type;
8717                 }
8718
8719                 public override void Emit (EmitContext ec)
8720                 {
8721                         base.Emit (ec);
8722
8723                         ec.EmitInt (0);
8724                         ec.Emit (OpCodes.Ldelema, array_type);
8725                 }
8726         }
8727
8728         //
8729         // Encapsulates a conversion rules required for array indexes
8730         //
8731         public class ArrayIndexCast : TypeCast
8732         {
8733                 public ArrayIndexCast (Expression expr)
8734                         : base (expr, TypeManager.int32_type)
8735                 {
8736                         if (expr.Type == TypeManager.int32_type)
8737                                 throw new ArgumentException ("unnecessary array index conversion");
8738                 }
8739
8740                 public override Expression CreateExpressionTree (ResolveContext ec)
8741                 {
8742                         using (ec.Set (ResolveContext.Options.CheckedScope)) {
8743                                 return base.CreateExpressionTree (ec);
8744                         }
8745                 }
8746
8747                 public override void Emit (EmitContext ec)
8748                 {
8749                         child.Emit (ec);
8750
8751                         var expr_type = child.Type;
8752
8753                         if (expr_type == TypeManager.uint32_type)
8754                                 ec.Emit (OpCodes.Conv_U);
8755                         else if (expr_type == TypeManager.int64_type)
8756                                 ec.Emit (OpCodes.Conv_Ovf_I);
8757                         else if (expr_type == TypeManager.uint64_type)
8758                                 ec.Emit (OpCodes.Conv_Ovf_I_Un);
8759                         else
8760                                 throw new InternalErrorException ("Cannot emit cast to unknown array element type", type);
8761                 }
8762         }
8763
8764         //
8765         // Implements the `stackalloc' keyword
8766         //
8767         public class StackAlloc : Expression {
8768                 TypeSpec otype;
8769                 Expression t;
8770                 Expression count;
8771
8772                 public StackAlloc (Expression type, Expression count, Location l)
8773                 {
8774                         t = type;
8775                         this.count = count;
8776                         loc = l;
8777                 }
8778
8779                 public override Expression CreateExpressionTree (ResolveContext ec)
8780                 {
8781                         throw new NotSupportedException ("ET");
8782                 }
8783
8784                 protected override Expression DoResolve (ResolveContext ec)
8785                 {
8786                         count = count.Resolve (ec);
8787                         if (count == null)
8788                                 return null;
8789
8790                         if (count.Type != TypeManager.uint32_type){
8791                                 count = Convert.ImplicitConversionRequired (ec, count, TypeManager.int32_type, loc);
8792                                 if (count == null)
8793                                         return null;
8794                         }
8795
8796                         Constant c = count as Constant;
8797                         if (c != null && c.IsNegative) {
8798                                 ec.Report.Error (247, loc, "Cannot use a negative size with stackalloc");
8799                         }
8800
8801                         if (ec.HasAny (ResolveContext.Options.CatchScope | ResolveContext.Options.FinallyScope)) {
8802                                 ec.Report.Error (255, loc, "Cannot use stackalloc in finally or catch");
8803                         }
8804
8805                         TypeExpr texpr = t.ResolveAsTypeTerminal (ec, false);
8806                         if (texpr == null)
8807                                 return null;
8808
8809                         otype = texpr.Type;
8810
8811                         if (!TypeManager.VerifyUnmanaged (ec.Compiler, otype, loc))
8812                                 return null;
8813
8814                         type = PointerContainer.MakeType (otype);
8815                         eclass = ExprClass.Value;
8816
8817                         return this;
8818                 }
8819
8820                 public override void Emit (EmitContext ec)
8821                 {
8822                         int size = GetTypeSize (otype);
8823
8824                         count.Emit (ec);
8825
8826                         if (size == 0)
8827                                 ec.Emit (OpCodes.Sizeof, otype);
8828                         else
8829                                 ec.EmitInt (size);
8830
8831                         ec.Emit (OpCodes.Mul_Ovf_Un);
8832                         ec.Emit (OpCodes.Localloc);
8833                 }
8834
8835                 protected override void CloneTo (CloneContext clonectx, Expression t)
8836                 {
8837                         StackAlloc target = (StackAlloc) t;
8838                         target.count = count.Clone (clonectx);
8839                         target.t = t.Clone (clonectx);
8840                 }
8841         }
8842
8843         //
8844         // An object initializer expression
8845         //
8846         public class ElementInitializer : Assign
8847         {
8848                 public readonly string Name;
8849
8850                 public ElementInitializer (string name, Expression initializer, Location loc)
8851                         : base (null, initializer, loc)
8852                 {
8853                         this.Name = name;
8854                 }
8855
8856                 protected override void CloneTo (CloneContext clonectx, Expression t)
8857                 {
8858                         ElementInitializer target = (ElementInitializer) t;
8859                         target.source = source.Clone (clonectx);
8860                 }
8861
8862                 public override Expression CreateExpressionTree (ResolveContext ec)
8863                 {
8864                         Arguments args = new Arguments (2);
8865                         FieldExpr fe = target as FieldExpr;
8866                         if (fe != null)
8867                                 args.Add (new Argument (fe.CreateTypeOfExpression ()));
8868                         else
8869                                 args.Add (new Argument (((PropertyExpr)target).CreateSetterTypeOfExpression ()));
8870
8871                         args.Add (new Argument (source.CreateExpressionTree (ec)));
8872                         return CreateExpressionFactoryCall (ec,
8873                                 source is CollectionOrObjectInitializers ? "ListBind" : "Bind",
8874                                 args);
8875                 }
8876
8877                 protected override Expression DoResolve (ResolveContext ec)
8878                 {
8879                         if (source == null)
8880                                 return EmptyExpressionStatement.Instance;
8881
8882                         MemberExpr me = MemberLookupFinal (ec, ec.CurrentInitializerVariable.Type, ec.CurrentInitializerVariable.Type,
8883                                 Name, 0, MemberKind.Field | MemberKind.Property, BindingRestriction.AccessibleOnly | BindingRestriction.InstanceOnly, loc) as MemberExpr;
8884
8885                         if (me == null)
8886                                 return null;
8887
8888                         target = me;
8889                         me.InstanceExpression = ec.CurrentInitializerVariable;
8890
8891                         if (source is CollectionOrObjectInitializers) {
8892                                 Expression previous = ec.CurrentInitializerVariable;
8893                                 ec.CurrentInitializerVariable = target;
8894                                 source = source.Resolve (ec);
8895                                 ec.CurrentInitializerVariable = previous;
8896                                 if (source == null)
8897                                         return null;
8898
8899                                 eclass = source.eclass;
8900                                 type = source.Type;
8901                                 return this;
8902                         }
8903
8904                         Expression expr = base.DoResolve (ec);
8905                         if (expr == null)
8906                                 return null;
8907
8908                         //
8909                         // Ignore field initializers with default value
8910                         //
8911                         Constant c = source as Constant;
8912                         if (c != null && c.IsDefaultInitializer (type) && target.eclass == ExprClass.Variable)
8913                                 return EmptyExpressionStatement.Instance.Resolve (ec);
8914
8915                         return expr;
8916                 }
8917
8918                 protected override MemberExpr Error_MemberLookupFailed (ResolveContext ec, TypeSpec type, IList<MemberSpec> members)
8919                 {
8920                         var member = members.First ();
8921                         if (member.Kind != MemberKind.Property && member.Kind != MemberKind.Field)
8922                                 ec.Report.Error (1913, loc, "Member `{0}' cannot be initialized. An object " +
8923                                         "initializer may only be used for fields, or properties", TypeManager.GetFullNameSignature (member));
8924                         else
8925                                 ec.Report.Error (1914, loc, " Static field or property `{0}' cannot be assigned in an object initializer",
8926                                         TypeManager.GetFullNameSignature (member));
8927
8928                         return null;
8929                 }
8930
8931                 public override void EmitStatement (EmitContext ec)
8932                 {
8933                         if (source is CollectionOrObjectInitializers)
8934                                 source.Emit (ec);
8935                         else
8936                                 base.EmitStatement (ec);
8937                 }
8938         }
8939
8940         //
8941         // A collection initializer expression
8942         //
8943         class CollectionElementInitializer : Invocation
8944         {
8945                 public class ElementInitializerArgument : Argument
8946                 {
8947                         public ElementInitializerArgument (Expression e)
8948                                 : base (e)
8949                         {
8950                         }
8951                 }
8952
8953                 sealed class AddMemberAccess : MemberAccess
8954                 {
8955                         public AddMemberAccess (Expression expr, Location loc)
8956                                 : base (expr, "Add", loc)
8957                         {
8958                         }
8959
8960                         protected override void Error_TypeDoesNotContainDefinition (ResolveContext ec, TypeSpec type, string name)
8961                         {
8962                                 if (TypeManager.HasElementType (type))
8963                                         return;
8964
8965                                 base.Error_TypeDoesNotContainDefinition (ec, type, name);
8966                         }
8967                 }
8968
8969                 public CollectionElementInitializer (Expression argument)
8970                         : base (null, new Arguments (1))
8971                 {
8972                         base.arguments.Add (new ElementInitializerArgument (argument));
8973                         this.loc = argument.Location;
8974                 }
8975
8976                 public CollectionElementInitializer (List<Expression> arguments, Location loc)
8977                         : base (null, new Arguments (arguments.Count))
8978                 {
8979                         foreach (Expression e in arguments)
8980                                 base.arguments.Add (new ElementInitializerArgument (e));
8981
8982                         this.loc = loc;
8983                 }
8984
8985                 public override Expression CreateExpressionTree (ResolveContext ec)
8986                 {
8987                         Arguments args = new Arguments (2);
8988                         args.Add (new Argument (mg.CreateExpressionTree (ec)));
8989
8990                         var expr_initializers = new ArrayInitializer (arguments.Count, loc);
8991                         foreach (Argument a in arguments)
8992                                 expr_initializers.Add (a.CreateExpressionTree (ec));
8993
8994                         args.Add (new Argument (new ArrayCreation (
8995                                 CreateExpressionTypeExpression (ec, loc), "[]", expr_initializers, loc)));
8996                         return CreateExpressionFactoryCall (ec, "ElementInit", args);
8997                 }
8998
8999                 protected override void CloneTo (CloneContext clonectx, Expression t)
9000                 {
9001                         CollectionElementInitializer target = (CollectionElementInitializer) t;
9002                         if (arguments != null)
9003                                 target.arguments = arguments.Clone (clonectx);
9004                 }
9005
9006                 protected override Expression DoResolve (ResolveContext ec)
9007                 {
9008                         base.expr = new AddMemberAccess (ec.CurrentInitializerVariable, loc);
9009
9010                         return base.DoResolve (ec);
9011                 }
9012         }
9013
9014         //
9015         // A block of object or collection initializers
9016         //
9017         public class CollectionOrObjectInitializers : ExpressionStatement
9018         {
9019                 IList<Expression> initializers;
9020                 bool is_collection_initialization;
9021
9022                 public static readonly CollectionOrObjectInitializers Empty =
9023                         new CollectionOrObjectInitializers (Array.AsReadOnly (new Expression [0]), Location.Null);
9024
9025                 public CollectionOrObjectInitializers (IList<Expression> initializers, Location loc)
9026                 {
9027                         this.initializers = initializers;
9028                         this.loc = loc;
9029                 }
9030
9031                 public bool IsEmpty {
9032                         get {
9033                                 return initializers.Count == 0;
9034                         }
9035                 }
9036
9037                 public bool IsCollectionInitializer {
9038                         get {
9039                                 return is_collection_initialization;
9040                         }
9041                 }
9042
9043                 protected override void CloneTo (CloneContext clonectx, Expression target)
9044                 {
9045                         CollectionOrObjectInitializers t = (CollectionOrObjectInitializers) target;
9046
9047                         t.initializers = new List<Expression> (initializers.Count);
9048                         foreach (var e in initializers)
9049                                 t.initializers.Add (e.Clone (clonectx));
9050                 }
9051
9052                 public override Expression CreateExpressionTree (ResolveContext ec)
9053                 {
9054                         var expr_initializers = new ArrayInitializer (initializers.Count, loc);
9055                         foreach (Expression e in initializers) {
9056                                 Expression expr = e.CreateExpressionTree (ec);
9057                                 if (expr != null)
9058                                         expr_initializers.Add (expr);
9059                         }
9060
9061                         return new ImplicitlyTypedArrayCreation ("[]", expr_initializers, loc);
9062                 }
9063
9064                 protected override Expression DoResolve (ResolveContext ec)
9065                 {
9066                         List<string> element_names = null;
9067                         for (int i = 0; i < initializers.Count; ++i) {
9068                                 Expression initializer = (Expression) initializers [i];
9069                                 ElementInitializer element_initializer = initializer as ElementInitializer;
9070
9071                                 if (i == 0) {
9072                                         if (element_initializer != null) {
9073                                                 element_names = new List<string> (initializers.Count);
9074                                                 element_names.Add (element_initializer.Name);
9075                                         } else if (initializer is CompletingExpression){
9076                                                 initializer.Resolve (ec);
9077                                                 throw new InternalErrorException ("This line should never be reached");
9078                                         } else {
9079                                                 if (!ec.CurrentInitializerVariable.Type.ImplementsInterface (TypeManager.ienumerable_type)) {
9080                                                         ec.Report.Error (1922, loc, "A field or property `{0}' cannot be initialized with a collection " +
9081                                                                 "object initializer because type `{1}' does not implement `{2}' interface",
9082                                                                 ec.CurrentInitializerVariable.GetSignatureForError (),
9083                                                                 TypeManager.CSharpName (ec.CurrentInitializerVariable.Type),
9084                                                                 TypeManager.CSharpName (TypeManager.ienumerable_type));
9085                                                         return null;
9086                                                 }
9087                                                 is_collection_initialization = true;
9088                                         }
9089                                 } else {
9090                                         if (is_collection_initialization != (element_initializer == null)) {
9091                                                 ec.Report.Error (747, initializer.Location, "Inconsistent `{0}' member declaration",
9092                                                         is_collection_initialization ? "collection initializer" : "object initializer");
9093                                                 continue;
9094                                         }
9095
9096                                         if (!is_collection_initialization) {
9097                                                 if (element_names.Contains (element_initializer.Name)) {
9098                                                         ec.Report.Error (1912, element_initializer.Location,
9099                                                                 "An object initializer includes more than one member `{0}' initialization",
9100                                                                 element_initializer.Name);
9101                                                 } else {
9102                                                         element_names.Add (element_initializer.Name);
9103                                                 }
9104                                         }
9105                                 }
9106
9107                                 Expression e = initializer.Resolve (ec);
9108                                 if (e == EmptyExpressionStatement.Instance)
9109                                         initializers.RemoveAt (i--);
9110                                 else
9111                                         initializers [i] = e;
9112                         }
9113
9114                         type = ec.CurrentInitializerVariable.Type;
9115                         if (is_collection_initialization) {
9116                                 if (TypeManager.HasElementType (type)) {
9117                                         ec.Report.Error (1925, loc, "Cannot initialize object of type `{0}' with a collection initializer",
9118                                                 TypeManager.CSharpName (type));
9119                                 }
9120                         }
9121
9122                         eclass = ExprClass.Variable;
9123                         return this;
9124                 }
9125
9126                 public override void Emit (EmitContext ec)
9127                 {
9128                         EmitStatement (ec);
9129                 }
9130
9131                 public override void EmitStatement (EmitContext ec)
9132                 {
9133                         foreach (ExpressionStatement e in initializers)
9134                                 e.EmitStatement (ec);
9135                 }
9136         }
9137
9138         //
9139         // New expression with element/object initializers
9140         //
9141         public class NewInitialize : New
9142         {
9143                 //
9144                 // This class serves as a proxy for variable initializer target instances.
9145                 // A real variable is assigned later when we resolve left side of an
9146                 // assignment
9147                 //
9148                 sealed class InitializerTargetExpression : Expression, IMemoryLocation
9149                 {
9150                         NewInitialize new_instance;
9151
9152                         public InitializerTargetExpression (NewInitialize newInstance)
9153                         {
9154                                 this.type = newInstance.type;
9155                                 this.loc = newInstance.loc;
9156                                 this.eclass = newInstance.eclass;
9157                                 this.new_instance = newInstance;
9158                         }
9159
9160                         public override Expression CreateExpressionTree (ResolveContext ec)
9161                         {
9162                                 // Should not be reached
9163                                 throw new NotSupportedException ("ET");
9164                         }
9165
9166                         protected override Expression DoResolve (ResolveContext ec)
9167                         {
9168                                 return this;
9169                         }
9170
9171                         public override Expression DoResolveLValue (ResolveContext ec, Expression right_side)
9172                         {
9173                                 return this;
9174                         }
9175
9176                         public override void Emit (EmitContext ec)
9177                         {
9178                                 Expression e = (Expression) new_instance.instance;
9179                                 e.Emit (ec);
9180                         }
9181
9182                         #region IMemoryLocation Members
9183
9184                         public void AddressOf (EmitContext ec, AddressOp mode)
9185                         {
9186                                 new_instance.instance.AddressOf (ec, mode);
9187                         }
9188
9189                         #endregion
9190                 }
9191
9192                 CollectionOrObjectInitializers initializers;
9193                 IMemoryLocation instance;
9194
9195                 public NewInitialize (Expression requested_type, Arguments arguments, CollectionOrObjectInitializers initializers, Location l)
9196                         : base (requested_type, arguments, l)
9197                 {
9198                         this.initializers = initializers;
9199                 }
9200
9201                 protected override IMemoryLocation EmitAddressOf (EmitContext ec, AddressOp Mode)
9202                 {
9203                         instance = base.EmitAddressOf (ec, Mode);
9204
9205                         if (!initializers.IsEmpty)
9206                                 initializers.Emit (ec);
9207
9208                         return instance;
9209                 }
9210
9211                 protected override void CloneTo (CloneContext clonectx, Expression t)
9212                 {
9213                         base.CloneTo (clonectx, t);
9214
9215                         NewInitialize target = (NewInitialize) t;
9216                         target.initializers = (CollectionOrObjectInitializers) initializers.Clone (clonectx);
9217                 }
9218
9219                 public override Expression CreateExpressionTree (ResolveContext ec)
9220                 {
9221                         Arguments args = new Arguments (2);
9222                         args.Add (new Argument (base.CreateExpressionTree (ec)));
9223                         if (!initializers.IsEmpty)
9224                                 args.Add (new Argument (initializers.CreateExpressionTree (ec)));
9225
9226                         return CreateExpressionFactoryCall (ec,
9227                                 initializers.IsCollectionInitializer ? "ListInit" : "MemberInit",
9228                                 args);
9229                 }
9230
9231                 protected override Expression DoResolve (ResolveContext ec)
9232                 {
9233                         Expression e = base.DoResolve (ec);
9234                         if (type == null)
9235                                 return null;
9236
9237                         Expression previous = ec.CurrentInitializerVariable;
9238                         ec.CurrentInitializerVariable = new InitializerTargetExpression (this);
9239                         initializers.Resolve (ec);
9240                         ec.CurrentInitializerVariable = previous;
9241                         return e;
9242                 }
9243
9244                 public override bool Emit (EmitContext ec, IMemoryLocation target)
9245                 {
9246                         bool left_on_stack = base.Emit (ec, target);
9247
9248                         if (initializers.IsEmpty)
9249                                 return left_on_stack;
9250
9251                         LocalTemporary temp = target as LocalTemporary;
9252                         if (temp == null) {
9253                                 if (!left_on_stack) {
9254                                         VariableReference vr = target as VariableReference;
9255
9256                                         // FIXME: This still does not work correctly for pre-set variables
9257                                         if (vr != null && vr.IsRef)
9258                                                 target.AddressOf (ec, AddressOp.Load);
9259
9260                                         ((Expression) target).Emit (ec);
9261                                         left_on_stack = true;
9262                                 }
9263
9264                                 temp = new LocalTemporary (type);
9265                         }
9266
9267                         instance = temp;
9268                         if (left_on_stack)
9269                                 temp.Store (ec);
9270
9271                         initializers.Emit (ec);
9272
9273                         if (left_on_stack) {
9274                                 temp.Emit (ec);
9275                                 temp.Release (ec);
9276                         }
9277
9278                         return left_on_stack;
9279                 }
9280
9281                 public override bool HasInitializer {
9282                         get {
9283                                 return !initializers.IsEmpty;
9284                         }
9285                 }
9286         }
9287
9288         public class NewAnonymousType : New
9289         {
9290                 static readonly AnonymousTypeParameter[] EmptyParameters = new AnonymousTypeParameter[0];
9291
9292                 List<AnonymousTypeParameter> parameters;
9293                 readonly TypeContainer parent;
9294                 AnonymousTypeClass anonymous_type;
9295
9296                 public NewAnonymousType (List<AnonymousTypeParameter> parameters, TypeContainer parent, Location loc)
9297                          : base (null, null, loc)
9298                 {
9299                         this.parameters = parameters;
9300                         this.parent = parent;
9301                 }
9302
9303                 protected override void CloneTo (CloneContext clonectx, Expression target)
9304                 {
9305                         if (parameters == null)
9306                                 return;
9307
9308                         NewAnonymousType t = (NewAnonymousType) target;
9309                         t.parameters = new List<AnonymousTypeParameter> (parameters.Count);
9310                         foreach (AnonymousTypeParameter atp in parameters)
9311                                 t.parameters.Add ((AnonymousTypeParameter) atp.Clone (clonectx));
9312                 }
9313
9314                 AnonymousTypeClass CreateAnonymousType (ResolveContext ec, IList<AnonymousTypeParameter> parameters)
9315                 {
9316                         AnonymousTypeClass type = parent.Module.Compiled.GetAnonymousType (parameters);
9317                         if (type != null)
9318                                 return type;
9319
9320                         type = AnonymousTypeClass.Create (ec.Compiler, parent, parameters, loc);
9321                         if (type == null)
9322                                 return null;
9323
9324                         type.CreateType ();
9325                         type.DefineType ();
9326                         type.ResolveTypeParameters ();
9327                         type.Define ();
9328                         type.EmitType ();
9329                         if (ec.Report.Errors == 0)
9330                                 type.CloseType ();
9331
9332                         parent.Module.Compiled.AddAnonymousType (type);
9333                         return type;
9334                 }
9335
9336                 public override Expression CreateExpressionTree (ResolveContext ec)
9337                 {
9338                         if (parameters == null)
9339                                 return base.CreateExpressionTree (ec);
9340
9341                         var init = new ArrayInitializer (parameters.Count, loc);
9342                         foreach (Property p in anonymous_type.Properties)
9343                                 init.Add (new TypeOfMethod (MemberCache.GetMember (type, p.Get.Spec), loc));
9344
9345                         var ctor_args = new ArrayInitializer (Arguments.Count, loc);
9346                         foreach (Argument a in Arguments)
9347                                 ctor_args.Add (a.CreateExpressionTree (ec));
9348
9349                         Arguments args = new Arguments (3);
9350                         args.Add (new Argument (method.CreateExpressionTree (ec)));
9351                         args.Add (new Argument (new ArrayCreation (TypeManager.expression_type_expr, "[]", ctor_args, loc)));
9352                         args.Add (new Argument (new ImplicitlyTypedArrayCreation ("[]", init, loc)));
9353
9354                         return CreateExpressionFactoryCall (ec, "New", args);
9355                 }
9356
9357                 protected override Expression DoResolve (ResolveContext ec)
9358                 {
9359                         if (ec.HasSet (ResolveContext.Options.ConstantScope)) {
9360                                 ec.Report.Error (836, loc, "Anonymous types cannot be used in this expression");
9361                                 return null;
9362                         }
9363
9364                         if (parameters == null) {
9365                                 anonymous_type = CreateAnonymousType (ec, EmptyParameters);
9366                                 RequestedType = new TypeExpression (anonymous_type.Definition, loc);
9367                                 return base.DoResolve (ec);
9368                         }
9369
9370                         bool error = false;
9371                         Arguments = new Arguments (parameters.Count);
9372                         TypeExpression [] t_args = new TypeExpression [parameters.Count];
9373                         for (int i = 0; i < parameters.Count; ++i) {
9374                                 Expression e = ((AnonymousTypeParameter) parameters [i]).Resolve (ec);
9375                                 if (e == null) {
9376                                         error = true;
9377                                         continue;
9378                                 }
9379
9380                                 Arguments.Add (new Argument (e));
9381                                 t_args [i] = new TypeExpression (e.Type, e.Location);
9382                         }
9383
9384                         if (error)
9385                                 return null;
9386
9387                         anonymous_type = CreateAnonymousType (ec, parameters);
9388                         if (anonymous_type == null)
9389                                 return null;
9390
9391                         RequestedType = new GenericTypeExpr (anonymous_type.Definition, new TypeArguments (t_args), loc);
9392                         return base.DoResolve (ec);
9393                 }
9394         }
9395
9396         public class AnonymousTypeParameter : ShimExpression
9397         {
9398                 public readonly string Name;
9399
9400                 public AnonymousTypeParameter (Expression initializer, string name, Location loc)
9401                         : base (initializer)
9402                 {
9403                         this.Name = name;
9404                         this.loc = loc;
9405                 }
9406
9407                 public AnonymousTypeParameter (Parameter parameter)
9408                         : base (new SimpleName (parameter.Name, parameter.Location))
9409                 {
9410                         this.Name = parameter.Name;
9411                         this.loc = parameter.Location;
9412                 }
9413
9414                 public override bool Equals (object o)
9415                 {
9416                         AnonymousTypeParameter other = o as AnonymousTypeParameter;
9417                         return other != null && Name == other.Name;
9418                 }
9419
9420                 public override int GetHashCode ()
9421                 {
9422                         return Name.GetHashCode ();
9423                 }
9424
9425                 protected override Expression DoResolve (ResolveContext ec)
9426                 {
9427                         Expression e = expr.Resolve (ec);
9428                         if (e == null)
9429                                 return null;
9430
9431                         if (e.eclass == ExprClass.MethodGroup) {
9432                                 Error_InvalidInitializer (ec, e.ExprClassName);
9433                                 return null;
9434                         }
9435
9436                         type = e.Type;
9437                         if (type == TypeManager.void_type || type == TypeManager.null_type ||
9438                                 type == InternalType.AnonymousMethod || type.IsPointer) {
9439                                 Error_InvalidInitializer (ec, e.GetSignatureForError ());
9440                                 return null;
9441                         }
9442
9443                         return e;
9444                 }
9445
9446                 protected virtual void Error_InvalidInitializer (ResolveContext ec, string initializer)
9447                 {
9448                         ec.Report.Error (828, loc, "An anonymous type property `{0}' cannot be initialized with `{1}'",
9449                                 Name, initializer);
9450                 }
9451         }
9452 }