mcs/gmcs/expression.cs

   1 //
   2 // expression.cs: Expression representation for the IL tree.
   3 //
   4 // Author:
   5 //   Miguel de Icaza (miguel@ximian.com)
   6 //
   7 // (C) 2001, 2002, 2003 Ximian, Inc.
   8 // (C) 2003, 2004 Novell, Inc.
   9 //
  10 #define USE_OLD
  11
  12 namespace Mono.CSharp {
  13         using System;
  14         using System.Collections;
  15         using System.Reflection;
  16         using System.Reflection.Emit;
  17         using System.Text;
  18
  19         /// <summary>
  20         ///   This is just a helper class, it is generated by Unary, UnaryMutator
  21         ///   when an overloaded method has been found.  It just emits the code for a
  22         ///   static call.
  23         /// </summary>
  24         public class StaticCallExpr : ExpressionStatement {
  25                 ArrayList args;
  26                 MethodInfo mi;
  27
  28                 public StaticCallExpr (MethodInfo m, ArrayList a, Location l)
  29                 {
  30                         mi = m;
  31                         args = a;
  32
  33                         type = m.ReturnType;
  34                         eclass = ExprClass.Value;
  35                         loc = l;
  36                 }
  37
  38                 public override Expression DoResolve (EmitContext ec)
  39                 {
  40                         //
  41                         // We are born fully resolved
  42                         //
  43                         return this;
  44                 }
  45
  46                 public override void Emit (EmitContext ec)
  47                 {
  48                         if (args != null)
  49                                 Invocation.EmitArguments (ec, mi, args, false, null);
  50
  51                         ec.ig.Emit (OpCodes.Call, mi);
  52                         return;
  53                 }
  54
  55                 static public StaticCallExpr MakeSimpleCall (EmitContext ec, MethodGroupExpr mg,
  56                                                          Expression e, Location loc)
  57                 {
  58                         ArrayList args;
  59                         MethodBase method;
  60
  61                         args = new ArrayList (1);
  62                         Argument a = new Argument (e, Argument.AType.Expression);
  63
  64                         // We need to resolve the arguments before sending them in !
  65                         if (!a.Resolve (ec, loc))
  66                                 return null;
  67
  68                         args.Add (a);
  69                         method = Invocation.OverloadResolve (
  70                                 ec, (MethodGroupExpr) mg, args, false, loc);
  71
  72                         if (method == null)
  73                                 return null;
  74
  75                         return new StaticCallExpr ((MethodInfo) method, args, loc);
  76                 }
  77
  78                 public override void EmitStatement (EmitContext ec)
  79                 {
  80                         Emit (ec);
  81                         if (TypeManager.TypeToCoreType (type) != TypeManager.void_type)
  82                                 ec.ig.Emit (OpCodes.Pop);
  83                 }
  84
  85                 public MethodInfo Method {
  86                         get { return mi; }
  87                 }
  88         }
  89
  90         public class ParenthesizedExpression : Expression
  91         {
  92                 public Expression Expr;
  93
  94                 public ParenthesizedExpression (Expression expr, Location loc)
  95                 {
  96                         this.Expr = expr;
  97                         this.loc = loc;
  98                 }
  99
 100                 public override Expression DoResolve (EmitContext ec)
 101                 {
 102                         Expr = Expr.Resolve (ec);
 103                         return Expr;
 104                 }
 105
 106                 public override void Emit (EmitContext ec)
 107                 {
 108                         throw new Exception ("Should not happen");
 109                 }
 110         }
 111
 112         /// <summary>
 113         ///   Unary expressions.
 114         /// </summary>
 115         ///
 116         /// <remarks>
 117         ///   Unary implements unary expressions.   It derives from
 118         ///   ExpressionStatement becuase the pre/post increment/decrement
 119         ///   operators can be used in a statement context.
 120         /// </remarks>
 121         public class Unary : Expression {
 122                 public enum Operator : byte {
 123                         UnaryPlus, UnaryNegation, LogicalNot, OnesComplement,
 124                         Indirection, AddressOf,  TOP
 125                 }
 126
 127                 public Operator Oper;
 128                 public Expression Expr;
 129
 130                 public Unary (Operator op, Expression expr, Location loc)
 131                 {
 132                         this.Oper = op;
 133                         this.Expr = expr;
 134                         this.loc = loc;
 135                 }
 136
 137                 /// <summary>
 138                 ///   Returns a stringified representation of the Operator
 139                 /// </summary>
 140                 static public string OperName (Operator oper)
 141                 {
 142                         switch (oper){
 143                         case Operator.UnaryPlus:
 144                                 return "+";
 145                         case Operator.UnaryNegation:
 146                                 return "-";
 147                         case Operator.LogicalNot:
 148                                 return "!";
 149                         case Operator.OnesComplement:
 150                                 return "~";
 151                         case Operator.AddressOf:
 152                                 return "&";
 153                         case Operator.Indirection:
 154                                 return "*";
 155                         }
 156
 157                         return oper.ToString ();
 158                 }
 159
 160                 public static readonly string [] oper_names;
 161
 162                 static Unary ()
 163                 {
 164                         oper_names = new string [(int)Operator.TOP];
 165
 166                         oper_names [(int) Operator.UnaryPlus] = "op_UnaryPlus";
 167                         oper_names [(int) Operator.UnaryNegation] = "op_UnaryNegation";
 168                         oper_names [(int) Operator.LogicalNot] = "op_LogicalNot";
 169                         oper_names [(int) Operator.OnesComplement] = "op_OnesComplement";
 170                         oper_names [(int) Operator.Indirection] = "op_Indirection";
 171                         oper_names [(int) Operator.AddressOf] = "op_AddressOf";
 172                 }
 173
 174                 void Error23 (Type t)
 175                 {
 176                         Error (
 177                                 23, "Operator " + OperName (Oper) +
 178                                 " cannot be applied to operand of type `" +
 179                                 TypeManager.CSharpName (t) + "'");
 180                 }
 181
 182                 /// <remarks>
 183                 ///   The result has been already resolved:
 184                 ///
 185                 ///   FIXME: a minus constant -128 sbyte cant be turned into a
 186                 ///   constant byte.
 187                 /// </remarks>
 188                 static Expression TryReduceNegative (Constant expr)
 189                 {
 190                         Expression e = null;
 191
 192                         if (expr is IntConstant)
 193                                 e = new IntConstant (-((IntConstant) expr).Value);
 194                         else if (expr is UIntConstant){
 195                                 uint value = ((UIntConstant) expr).Value;
 196
 197                                 if (value < 2147483649)
 198                                         return new IntConstant (-(int)value);
 199                                 else
 200                                         e = new LongConstant (-value);
 201                         }
 202                         else if (expr is LongConstant)
 203                                 e = new LongConstant (-((LongConstant) expr).Value);
 204                         else if (expr is ULongConstant){
 205                                 ulong value = ((ULongConstant) expr).Value;
 206
 207                                 if (value < 9223372036854775809)
 208                                         return new LongConstant(-(long)value);
 209                         }
 210                         else if (expr is FloatConstant)
 211                                 e = new FloatConstant (-((FloatConstant) expr).Value);
 212                         else if (expr is DoubleConstant)
 213                                 e = new DoubleConstant (-((DoubleConstant) expr).Value);
 214                         else if (expr is DecimalConstant)
 215                                 e = new DecimalConstant (-((DecimalConstant) expr).Value);
 216                         else if (expr is ShortConstant)
 217                                 e = new IntConstant (-((ShortConstant) expr).Value);
 218                         else if (expr is UShortConstant)
 219                                 e = new IntConstant (-((UShortConstant) expr).Value);
 220                         else if (expr is SByteConstant)
 221                                 e = new IntConstant (-((SByteConstant) expr).Value);
 222                         else if (expr is ByteConstant)
 223                                 e = new IntConstant (-((ByteConstant) expr).Value);
 224                         return e;
 225                 }
 226
 227                 // <summary>
 228                 //   This routine will attempt to simplify the unary expression when the
 229                 //   argument is a constant.  The result is returned in `result' and the
 230                 //   function returns true or false depending on whether a reduction
 231                 //   was performed or not
 232                 // </summary>
 233                 bool Reduce (EmitContext ec, Constant e, out Expression result)
 234                 {
 235                         Type expr_type = e.Type;
 236
 237                         switch (Oper){
 238                         case Operator.UnaryPlus:
 239                                 result = e;
 240                                 return true;
 241
 242                         case Operator.UnaryNegation:
 243                                 result = TryReduceNegative (e);
 244                                 return result != null;
 245
 246                         case Operator.LogicalNot:
 247                                 if (expr_type != TypeManager.bool_type) {
 248                                         result = null;
 249                                         Error23 (expr_type);
 250                                         return false;
 251                                 }
 252
 253                                 BoolConstant b = (BoolConstant) e;
 254                                 result = new BoolConstant (!(b.Value));
 255                                 return true;
 256
 257                         case Operator.OnesComplement:
 258                                 if (!((expr_type == TypeManager.int32_type) ||
 259                                       (expr_type == TypeManager.uint32_type) ||
 260                                       (expr_type == TypeManager.int64_type) ||
 261                                       (expr_type == TypeManager.uint64_type) ||
 262                                       (expr_type.IsSubclassOf (TypeManager.enum_type)))){
 263
 264                                         result = null;
 265                                         if (Convert.ImplicitConversionExists (ec, e, TypeManager.int32_type)){
 266                                                 result = new Cast (new TypeExpression (TypeManager.int32_type, loc), e, loc);
 267                                                 result = result.Resolve (ec);
 268                                         } else if (Convert.ImplicitConversionExists (ec, e, TypeManager.uint32_type)){
 269                                                 result = new Cast (new TypeExpression (TypeManager.uint32_type, loc), e, loc);
 270                                                 result = result.Resolve (ec);
 271                                         } else if (Convert.ImplicitConversionExists (ec, e, TypeManager.int64_type)){
 272                                                 result = new Cast (new TypeExpression (TypeManager.int64_type, loc), e, loc);
 273                                                 result = result.Resolve (ec);
 274                                         } else if (Convert.ImplicitConversionExists (ec, e, TypeManager.uint64_type)){
 275                                                 result = new Cast (new TypeExpression (TypeManager.uint64_type, loc), e, loc);
 276                                                 result = result.Resolve (ec);
 277                                         }
 278
 279                                         if (result == null || !(result is Constant)){
 280                                                 result = null;
 281                                                 Error23 (expr_type);
 282                                                 return false;
 283                                         }
 284
 285                                         expr_type = result.Type;
 286                                         e = (Constant) result;
 287                                 }
 288
 289                                 if (e is EnumConstant){
 290                                         EnumConstant enum_constant = (EnumConstant) e;
 291                                         Expression reduced;
 292
 293                                         if (Reduce (ec, enum_constant.Child, out reduced)){
 294                                                 result = new EnumConstant ((Constant) reduced, enum_constant.Type);
 295                                                 return true;
 296                                         } else {
 297                                                 result = null;
 298                                                 return false;
 299                                         }
 300                                 }
 301
 302                                 if (expr_type == TypeManager.int32_type){
 303                                         result = new IntConstant (~ ((IntConstant) e).Value);
 304                                 } else if (expr_type == TypeManager.uint32_type){
 305                                         result = new UIntConstant (~ ((UIntConstant) e).Value);
 306                                 } else if (expr_type == TypeManager.int64_type){
 307                                         result = new LongConstant (~ ((LongConstant) e).Value);
 308                                 } else if (expr_type == TypeManager.uint64_type){
 309                                         result = new ULongConstant (~ ((ULongConstant) e).Value);
 310                                 } else {
 311                                         result = null;
 312                                         Error23 (expr_type);
 313                                         return false;
 314                                 }
 315                                 return true;
 316
 317                         case Operator.AddressOf:
 318                                 result = this;
 319                                 return false;
 320
 321                         case Operator.Indirection:
 322                                 result = this;
 323                                 return false;
 324                         }
 325                         throw new Exception ("Can not constant fold: " + Oper.ToString());
 326                 }
 327
 328                 Expression ResolveOperator (EmitContext ec)
 329                 {
 330                         //
 331                         // Step 1: Default operations on CLI native types.
 332                         //
 333
 334                         // Attempt to use a constant folding operation.
 335                         if (Expr is Constant){
 336                                 Expression result;
 337
 338                                 if (Reduce (ec, (Constant) Expr, out result))
 339                                         return result;
 340                         }
 341
 342                         //
 343                         // Step 2: Perform Operator Overload location
 344                         //
 345                         Type expr_type = Expr.Type;
 346                         Expression mg;
 347                         string op_name;
 348
 349                         op_name = oper_names [(int) Oper];
 350
 351                         mg = MemberLookup (ec, expr_type, op_name, MemberTypes.Method, AllBindingFlags, loc);
 352
 353                         if (mg != null) {
 354                                 Expression e = StaticCallExpr.MakeSimpleCall (
 355                                         ec, (MethodGroupExpr) mg, Expr, loc);
 356
 357                                 if (e == null){
 358                                         Error23 (expr_type);
 359                                         return null;
 360                                 }
 361
 362                                 return e;
 363                         }
 364
 365                         // Only perform numeric promotions on:
 366                         // +, -
 367
 368                         if (expr_type == null)
 369                                 return null;
 370
 371                         switch (Oper){
 372                         case Operator.LogicalNot:
 373                                 if (expr_type != TypeManager.bool_type) {
 374                                         Expr = ResolveBoolean (ec, Expr, loc);
 375                                         if (Expr == null){
 376                                                 Error23 (expr_type);
 377                                                 return null;
 378                                         }
 379                                 }
 380
 381                                 type = TypeManager.bool_type;
 382                                 return this;
 383
 384                         case Operator.OnesComplement:
 385                                 if (!((expr_type == TypeManager.int32_type) ||
 386                                       (expr_type == TypeManager.uint32_type) ||
 387                                       (expr_type == TypeManager.int64_type) ||
 388                                       (expr_type == TypeManager.uint64_type) ||
 389                                       (expr_type.IsSubclassOf (TypeManager.enum_type)))){
 390                                         Expression e;
 391
 392                                         e = Convert.ImplicitConversion (ec, Expr, TypeManager.int32_type, loc);
 393                                         if (e != null){
 394                                                 type = TypeManager.int32_type;
 395                                                 return this;
 396                                         }
 397                                         e = Convert.ImplicitConversion (ec, Expr, TypeManager.uint32_type, loc);
 398                                         if (e != null){
 399                                                 type = TypeManager.uint32_type;
 400                                                 return this;
 401                                         }
 402                                         e = Convert.ImplicitConversion (ec, Expr, TypeManager.int64_type, loc);
 403                                         if (e != null){
 404                                                 type = TypeManager.int64_type;
 405                                                 return this;
 406                                         }
 407                                         e = Convert.ImplicitConversion (ec, Expr, TypeManager.uint64_type, loc);
 408                                         if (e != null){
 409                                                 type = TypeManager.uint64_type;
 410                                                 return this;
 411                                         }
 412                                         Error23 (expr_type);
 413                                         return null;
 414                                 }
 415                                 type = expr_type;
 416                                 return this;
 417
 418                         case Operator.AddressOf:
 419                                 if (!ec.InUnsafe) {
 420                                         UnsafeError (loc);
 421                                         return null;
 422                                 }
 423
 424                                 if (!TypeManager.VerifyUnManaged (Expr.Type, loc)){
 425                                         return null;
 426                                 }
 427
 428                                 IVariable variable = Expr as IVariable;
 429                                 bool is_fixed = variable != null && variable.VerifyFixed (false);
 430
 431                                 if (!ec.InFixedInitializer && !is_fixed) {
 432                                         Error (212, "You can only take the address of an unfixed expression inside " +
 433                                                "of a fixed statement initializer");
 434                                         return null;
 435                                 }
 436
 437                                 if (ec.InFixedInitializer && is_fixed) {
 438                                         Error (213, "You can not fix an already fixed expression");
 439                                         return null;
 440                                 }
 441
 442                                 LocalVariableReference lr = Expr as LocalVariableReference;
 443                                 if (lr != null){
 444                                         if (lr.local_info.IsCaptured){
 445                                                 AnonymousMethod.Error_AddressOfCapturedVar (lr.Name, loc);
 446                                                 return null;
 447                                         }
 448                                         lr.local_info.AddressTaken = true;
 449                                         lr.local_info.Used = true;
 450                                 }
 451
 452                                 // According to the specs, a variable is considered definitely assigned if you take
 453                                 // its address.
 454                                 if ((variable != null) && (variable.VariableInfo != null))
 455                                         variable.VariableInfo.SetAssigned (ec);
 456
 457                                 type = TypeManager.GetPointerType (Expr.Type);
 458                                 return this;
 459
 460                         case Operator.Indirection:
 461                                 if (!ec.InUnsafe){
 462                                         UnsafeError (loc);
 463                                         return null;
 464                                 }
 465
 466                                 if (!expr_type.IsPointer){
 467                                         Error (193, "The * or -> operator can only be applied to pointers");
 468                                         return null;
 469                                 }
 470
 471                                 //
 472                                 // We create an Indirection expression, because
 473                                 // it can implement the IMemoryLocation.
 474                                 //
 475                                 return new Indirection (Expr, loc);
 476
 477                         case Operator.UnaryPlus:
 478                                 //
 479                                 // A plus in front of something is just a no-op, so return the child.
 480                                 //
 481                                 return Expr;
 482
 483                         case Operator.UnaryNegation:
 484                                 //
 485                                 // Deals with -literals
 486                                 // int     operator- (int x)
 487                                 // long    operator- (long x)
 488                                 // float   operator- (float f)
 489                                 // double  operator- (double d)
 490                                 // decimal operator- (decimal d)
 491                                 //
 492                                 Expression expr = null;
 493
 494                                 //
 495                                 // transform - - expr into expr
 496                                 //
 497                                 if (Expr is Unary){
 498                                         Unary unary = (Unary) Expr;
 499
 500                                         if (unary.Oper == Operator.UnaryNegation)
 501                                                 return unary.Expr;
 502                                 }
 503
 504                                 //
 505                                 // perform numeric promotions to int,
 506                                 // long, double.
 507                                 //
 508                                 //
 509                                 // The following is inneficient, because we call
 510                                 // ImplicitConversion too many times.
 511                                 //
 512                                 // It is also not clear if we should convert to Float
 513                                 // or Double initially.
 514                                 //
 515                                 if (expr_type == TypeManager.uint32_type){
 516                                         //
 517                                         // FIXME: handle exception to this rule that
 518                                         // permits the int value -2147483648 (-2^31) to
 519                                         // bt wrote as a decimal interger literal
 520                                         //
 521                                         type = TypeManager.int64_type;
 522                                         Expr = Convert.ImplicitConversion (ec, Expr, type, loc);
 523                                         return this;
 524                                 }
 525
 526                                 if (expr_type == TypeManager.uint64_type){
 527                                         //
 528                                         // FIXME: Handle exception of `long value'
 529                                         // -92233720368547758087 (-2^63) to be wrote as
 530                                         // decimal integer literal.
 531                                         //
 532                                         Error23 (expr_type);
 533                                         return null;
 534                                 }
 535
 536                                 if (expr_type == TypeManager.float_type){
 537                                         type = expr_type;
 538                                         return this;
 539                                 }
 540
 541                                 expr = Convert.ImplicitConversion (ec, Expr, TypeManager.int32_type, loc);
 542                                 if (expr != null){
 543                                         Expr = expr;
 544                                         type = expr.Type;
 545                                         return this;
 546                                 }
 547
 548                                 expr = Convert.ImplicitConversion (ec, Expr, TypeManager.int64_type, loc);
 549                                 if (expr != null){
 550                                         Expr = expr;
 551                                         type = expr.Type;
 552                                         return this;
 553                                 }
 554
 555                                 expr = Convert.ImplicitConversion (ec, Expr, TypeManager.double_type, loc);
 556                                 if (expr != null){
 557                                         Expr = expr;
 558                                         type = expr.Type;
 559                                         return this;
 560                                 }
 561
 562                                 Error23 (expr_type);
 563                                 return null;
 564                         }
 565
 566                         Error (187, "No such operator '" + OperName (Oper) + "' defined for type '" +
 567                                TypeManager.CSharpName (expr_type) + "'");
 568                         return null;
 569                 }
 570
 571                 public override Expression DoResolve (EmitContext ec)
 572                 {
 573                         if (Oper == Operator.AddressOf) {
 574                                 Expr = Expr.DoResolveLValue (ec, new EmptyExpression ());
 575
 576                                 if (Expr == null || Expr.eclass != ExprClass.Variable){
 577                                         Error (211, "Cannot take the address of non-variables");
 578                                         return null;
 579                                 }
 580                         }
 581                         else
 582                                 Expr = Expr.Resolve (ec);
 583
 584                         if (Expr == null)
 585                                 return null;
 586
 587                         if (TypeManager.IsNullableType (Expr.Type))
 588                                 return new Nullable.LiftedUnaryOperator (Oper, Expr, loc).Resolve (ec);
 589
 590                         eclass = ExprClass.Value;
 591                         return ResolveOperator (ec);
 592                 }
 593
 594                 public override Expression DoResolveLValue (EmitContext ec, Expression right)
 595                 {
 596                         if (Oper == Operator.Indirection)
 597                                 return DoResolve (ec);
 598
 599                         return null;
 600                 }
 601
 602                 public override void Emit (EmitContext ec)
 603                 {
 604                         ILGenerator ig = ec.ig;
 605
 606                         switch (Oper) {
 607                         case Operator.UnaryPlus:
 608                                 throw new Exception ("This should be caught by Resolve");
 609
 610                         case Operator.UnaryNegation:
 611                                 if (ec.CheckState) {
 612                                         ig.Emit (OpCodes.Ldc_I4_0);
 613                                         if (type == TypeManager.int64_type)
 614                                                 ig.Emit (OpCodes.Conv_U8);
 615                                         Expr.Emit (ec);
 616                                         ig.Emit (OpCodes.Sub_Ovf);
 617                                 } else {
 618                                 Expr.Emit (ec);
 619                                 ig.Emit (OpCodes.Neg);
 620                                 }
 621
 622                                 break;
 623
 624                         case Operator.LogicalNot:
 625                                 Expr.Emit (ec);
 626                                 ig.Emit (OpCodes.Ldc_I4_0);
 627                                 ig.Emit (OpCodes.Ceq);
 628                                 break;
 629
 630                         case Operator.OnesComplement:
 631                                 Expr.Emit (ec);
 632                                 ig.Emit (OpCodes.Not);
 633                                 break;
 634
 635                         case Operator.AddressOf:
 636                                 ((IMemoryLocation)Expr).AddressOf (ec, AddressOp.LoadStore);
 637                                 break;
 638
 639                         default:
 640                                 throw new Exception ("This should not happen: Operator = "
 641                                                      + Oper.ToString ());
 642                         }
 643                 }
 644
 645                 public override void EmitBranchable (EmitContext ec, Label target, bool onTrue)
 646                 {
 647                         if (Oper == Operator.LogicalNot)
 648                                 Expr.EmitBranchable (ec, target, !onTrue);
 649                         else
 650                                 base.EmitBranchable (ec, target, onTrue);
 651                 }
 652
 653                 public override string ToString ()
 654                 {
 655                         return "Unary (" + Oper + ", " + Expr + ")";
 656                 }
 657
 658         }
 659
 660         //
 661         // Unary operators are turned into Indirection expressions
 662         // after semantic analysis (this is so we can take the address
 663         // of an indirection).
 664         //
 665         public class Indirection : Expression, IMemoryLocation, IAssignMethod, IVariable {
 666                 Expression expr;
 667                 LocalTemporary temporary;
 668                 bool prepared;
 669
 670                 public Indirection (Expression expr, Location l)
 671                 {
 672                         this.expr = expr;
 673                         type = TypeManager.HasElementType (expr.Type) ? TypeManager.GetElementType (expr.Type) : expr.Type;
 674                         eclass = ExprClass.Variable;
 675                         loc = l;
 676                 }
 677
 678                 public override void Emit (EmitContext ec)
 679                 {
 680                         if (!prepared)
 681                                 expr.Emit (ec);
 682
 683                         LoadFromPtr (ec.ig, Type);
 684                 }
 685
 686                 public void Emit (EmitContext ec, bool leave_copy)
 687                 {
 688                         Emit (ec);
 689                         if (leave_copy) {
 690                                 ec.ig.Emit (OpCodes.Dup);
 691                                 temporary = new LocalTemporary (ec, expr.Type);
 692                                 temporary.Store (ec);
 693                         }
 694                 }
 695
 696                 public void EmitAssign (EmitContext ec, Expression source, bool leave_copy, bool prepare_for_load)
 697                 {
 698                         prepared = prepare_for_load;
 699
 700                         expr.Emit (ec);
 701
 702                         if (prepare_for_load)
 703                                 ec.ig.Emit (OpCodes.Dup);
 704
 705                         source.Emit (ec);
 706                         if (leave_copy) {
 707                                 ec.ig.Emit (OpCodes.Dup);
 708                                 temporary = new LocalTemporary (ec, expr.Type);
 709                                 temporary.Store (ec);
 710                         }
 711
 712                         StoreFromPtr (ec.ig, type);
 713
 714                         if (temporary != null)
 715                                 temporary.Emit (ec);
 716                 }
 717
 718                 public void AddressOf (EmitContext ec, AddressOp Mode)
 719                 {
 720                         expr.Emit (ec);
 721                 }
 722
 723                 public override Expression DoResolveLValue (EmitContext ec, Expression right_side)
 724                 {
 725                         return DoResolve (ec);
 726                 }
 727
 728                 public override Expression DoResolve (EmitContext ec)
 729                 {
 730                         //
 731                         // Born fully resolved
 732                         //
 733                         return this;
 734                 }
 735
 736                 public override string ToString ()
 737                 {
 738                         return "*(" + expr + ")";
 739                 }
 740
 741                 #region IVariable Members
 742
 743                 public VariableInfo VariableInfo {
 744                         get {
 745                                 return null;
 746                         }
 747                 }
 748
 749                 public bool VerifyFixed (bool is_expression)
 750                 {
 751                         return true;
 752                 }
 753
 754                 #endregion
 755         }
 756
 757         /// <summary>
 758         ///   Unary Mutator expressions (pre and post ++ and --)
 759         /// </summary>
 760         ///
 761         /// <remarks>
 762         ///   UnaryMutator implements ++ and -- expressions.   It derives from
 763         ///   ExpressionStatement becuase the pre/post increment/decrement
 764         ///   operators can be used in a statement context.
 765         ///
 766         /// FIXME: Idea, we could split this up in two classes, one simpler
 767         /// for the common case, and one with the extra fields for more complex
 768         /// classes (indexers require temporary access;  overloaded require method)
 769         ///
 770         /// </remarks>
 771         public class UnaryMutator : ExpressionStatement {
 772                 [Flags]
 773                 public enum Mode : byte {
 774                         IsIncrement    = 0,
 775                         IsDecrement    = 1,
 776                         IsPre          = 0,
 777                         IsPost         = 2,
 778
 779                         PreIncrement   = 0,
 780                         PreDecrement   = IsDecrement,
 781                         PostIncrement  = IsPost,
 782                         PostDecrement  = IsPost | IsDecrement
 783                 }
 784
 785                 Mode mode;
 786                 bool is_expr = false;
 787                 bool recurse = false;
 788
 789                 Expression expr;
 790
 791                 //
 792                 // This is expensive for the simplest case.
 793                 //
 794                 StaticCallExpr method;
 795
 796                 public UnaryMutator (Mode m, Expression e, Location l)
 797                 {
 798                         mode = m;
 799                         loc = l;
 800                         expr = e;
 801                 }
 802
 803                 static string OperName (Mode mode)
 804                 {
 805                         return (mode == Mode.PreIncrement || mode == Mode.PostIncrement) ?
 806                                 "++" : "--";
 807                 }
 808
 809                 /// <summary>
 810                 ///   Returns whether an object of type `t' can be incremented
 811                 ///   or decremented with add/sub (ie, basically whether we can
 812                 ///   use pre-post incr-decr operations on it, but it is not a
 813                 ///   System.Decimal, which we require operator overloading to catch)
 814                 /// </summary>
 815                 static bool IsIncrementableNumber (Type t)
 816                 {
 817                         return (t == TypeManager.sbyte_type) ||
 818                                 (t == TypeManager.byte_type) ||
 819                                 (t == TypeManager.short_type) ||
 820                                 (t == TypeManager.ushort_type) ||
 821                                 (t == TypeManager.int32_type) ||
 822                                 (t == TypeManager.uint32_type) ||
 823                                 (t == TypeManager.int64_type) ||
 824                                 (t == TypeManager.uint64_type) ||
 825                                 (t == TypeManager.char_type) ||
 826                                 (t.IsSubclassOf (TypeManager.enum_type)) ||
 827                                 (t == TypeManager.float_type) ||
 828                                 (t == TypeManager.double_type) ||
 829                                 (t.IsPointer && t != TypeManager.void_ptr_type);
 830                 }
 831
 832                 Expression ResolveOperator (EmitContext ec)
 833                 {
 834                         Type expr_type = expr.Type;
 835
 836                         //
 837                         // Step 1: Perform Operator Overload location
 838                         //
 839                         Expression mg;
 840                         string op_name;
 841
 842                         if (mode == Mode.PreIncrement || mode == Mode.PostIncrement)
 843                                 op_name = "op_Increment";
 844                         else
 845                                 op_name = "op_Decrement";
 846
 847                         mg = MemberLookup (ec, expr_type, op_name, MemberTypes.Method, AllBindingFlags, loc);
 848
 849                         if (mg != null) {
 850                                 method = StaticCallExpr.MakeSimpleCall (
 851                                         ec, (MethodGroupExpr) mg, expr, loc);
 852
 853                                 type = method.Type;
 854                         } else if (!IsIncrementableNumber (expr_type)) {
 855                                 Error (187, "No such operator '" + OperName (mode) + "' defined for type '" +
 856                                        TypeManager.CSharpName (expr_type) + "'");
 857                                    return null;
 858                         }
 859
 860                         //
 861                         // The operand of the prefix/postfix increment decrement operators
 862                         // should be an expression that is classified as a variable,
 863                         // a property access or an indexer access
 864                         //
 865                         type = expr_type;
 866                         if (expr.eclass == ExprClass.Variable){
 867                                 LocalVariableReference var = expr as LocalVariableReference;
 868                                 if ((var != null) && var.IsReadOnly) {
 869                                         Error (1604, "cannot assign to `" + var.Name + "' because it is readonly");
 870                                         return null;
 871                                 }
 872                         } else if (expr.eclass == ExprClass.IndexerAccess || expr.eclass == ExprClass.PropertyAccess){
 873                                 expr = expr.ResolveLValue (ec, this);
 874                                 if (expr == null)
 875                                         return null;
 876                         } else {
 877                                 expr.Error_UnexpectedKind ("variable, indexer or property access", loc);
 878                                 return null;
 879                         }
 880
 881                         return this;
 882                 }
 883
 884                 public override Expression DoResolve (EmitContext ec)
 885                 {
 886                         expr = expr.Resolve (ec);
 887
 888                         if (expr == null)
 889                                 return null;
 890
 891                         eclass = ExprClass.Value;
 892
 893                         if (TypeManager.IsNullableType (expr.Type))
 894                                 return new Nullable.LiftedUnaryMutator (mode, expr, loc).Resolve (ec);
 895
 896                         return ResolveOperator (ec);
 897                 }
 898
 899                 static int PtrTypeSize (Type t)
 900                 {
 901                         return GetTypeSize (TypeManager.GetElementType (t));
 902                 }
 903
 904                 //
 905                 // Loads the proper "1" into the stack based on the type, then it emits the
 906                 // opcode for the operation requested
 907                 //
 908                 void LoadOneAndEmitOp (EmitContext ec, Type t)
 909                 {
 910                         //
 911                         // Measure if getting the typecode and using that is more/less efficient
 912                         // that comparing types.  t.GetTypeCode() is an internal call.
 913                         //
 914                         ILGenerator ig = ec.ig;
 915
 916                         if (t == TypeManager.uint64_type || t == TypeManager.int64_type)
 917                                 LongConstant.EmitLong (ig, 1);
 918                         else if (t == TypeManager.double_type)
 919                                 ig.Emit (OpCodes.Ldc_R8, 1.0);
 920                         else if (t == TypeManager.float_type)
 921                                 ig.Emit (OpCodes.Ldc_R4, 1.0F);
 922                         else if (t.IsPointer){
 923                                 int n = PtrTypeSize (t);
 924
 925                                 if (n == 0)
 926                                         ig.Emit (OpCodes.Sizeof, t);
 927                                 else
 928                                         IntConstant.EmitInt (ig, n);
 929                         } else
 930                                 ig.Emit (OpCodes.Ldc_I4_1);
 931
 932                         //
 933                         // Now emit the operation
 934                         //
 935                         if (ec.CheckState){
 936                                 if (t == TypeManager.int32_type ||
 937                                     t == TypeManager.int64_type){
 938                                         if ((mode & Mode.IsDecrement) != 0)
 939                                                 ig.Emit (OpCodes.Sub_Ovf);
 940                                         else
 941                                                 ig.Emit (OpCodes.Add_Ovf);
 942                                 } else if (t == TypeManager.uint32_type ||
 943                                            t == TypeManager.uint64_type){
 944                                         if ((mode & Mode.IsDecrement) != 0)
 945                                                 ig.Emit (OpCodes.Sub_Ovf_Un);
 946                                         else
 947                                                 ig.Emit (OpCodes.Add_Ovf_Un);
 948                                 } else {
 949                                         if ((mode & Mode.IsDecrement) != 0)
 950                                                 ig.Emit (OpCodes.Sub_Ovf);
 951                                         else
 952                                                 ig.Emit (OpCodes.Add_Ovf);
 953                                 }
 954                         } else {
 955                                 if ((mode & Mode.IsDecrement) != 0)
 956                                         ig.Emit (OpCodes.Sub);
 957                                 else
 958                                         ig.Emit (OpCodes.Add);
 959                         }
 960
 961                         if (t == TypeManager.sbyte_type){
 962                                 if (ec.CheckState)
 963                                         ig.Emit (OpCodes.Conv_Ovf_I1);
 964                                 else
 965                                         ig.Emit (OpCodes.Conv_I1);
 966                         } else if (t == TypeManager.byte_type){
 967                                 if (ec.CheckState)
 968                                         ig.Emit (OpCodes.Conv_Ovf_U1);
 969                                 else
 970                                         ig.Emit (OpCodes.Conv_U1);
 971                         } else if (t == TypeManager.short_type){
 972                                 if (ec.CheckState)
 973                                         ig.Emit (OpCodes.Conv_Ovf_I2);
 974                                 else
 975                                         ig.Emit (OpCodes.Conv_I2);
 976                         } else if (t == TypeManager.ushort_type || t == TypeManager.char_type){
 977                                 if (ec.CheckState)
 978                                         ig.Emit (OpCodes.Conv_Ovf_U2);
 979                                 else
 980                                         ig.Emit (OpCodes.Conv_U2);
 981                         }
 982
 983                 }
 984
 985                 void EmitCode (EmitContext ec, bool is_expr)
 986                 {
 987                         recurse = true;
 988                         this.is_expr = is_expr;
 989                         ((IAssignMethod) expr).EmitAssign (ec, this, is_expr && (mode == Mode.PreIncrement || mode == Mode.PreDecrement), true);
 990                 }
 991
 992                 public override void Emit (EmitContext ec)
 993                 {
 994                         //
 995                         // We use recurse to allow ourselfs to be the source
 996                         // of an assignment. This little hack prevents us from
 997                         // having to allocate another expression
 998                         //
 999                         if (recurse) {
1000                                 ((IAssignMethod) expr).Emit (ec, is_expr && (mode == Mode.PostIncrement  || mode == Mode.PostDecrement));
1001                                 if (method == null)
1002                                         LoadOneAndEmitOp (ec, expr.Type);
1003                                 else
1004                                         ec.ig.Emit (OpCodes.Call, method.Method);
1005                                 recurse = false;
1006                                 return;
1007                         }
1008
1009                         EmitCode (ec, true);
1010                 }
1011
1012                 public override void EmitStatement (EmitContext ec)
1013                 {
1014                         EmitCode (ec, false);
1015                 }
1016         }
1017
1018         /// <summary>
1019         ///   Base class for the `Is' and `As' classes.
1020         /// </summary>
1021         ///
1022         /// <remarks>
1023         ///   FIXME: Split this in two, and we get to save the `Operator' Oper
1024         ///   size.
1025         /// </remarks>
1026         public abstract class Probe : Expression {
1027                 public Expression ProbeType;
1028                 protected Expression expr;
1029                 protected Type probe_type;
1030
1031                 public Probe (Expression expr, Expression probe_type, Location l)
1032                 {
1033                         ProbeType = probe_type;
1034                         loc = l;
1035                         this.expr = expr;
1036                 }
1037
1038                 public Expression Expr {
1039                         get {
1040                                 return expr;
1041                         }
1042                 }
1043
1044                 public override Expression DoResolve (EmitContext ec)
1045                 {
1046                         TypeExpr texpr = ProbeType.ResolveAsTypeTerminal (ec);
1047                         if (texpr == null)
1048                                 return null;
1049                         probe_type = texpr.Type;
1050
1051                         CheckObsoleteAttribute (probe_type);
1052
1053                         expr = expr.Resolve (ec);
1054                         if (expr == null)
1055                                 return null;
1056
1057                         if (expr.Type.IsPointer) {
1058                                 Report.Error (244, loc, "\"is\" or \"as\" are not valid on pointer types");
1059                                 return null;
1060                         }
1061                         return this;
1062                 }
1063         }
1064
1065         /// <summary>
1066         ///   Implementation of the `is' operator.
1067         /// </summary>
1068         public class Is : Probe {
1069                 public Is (Expression expr, Expression probe_type, Location l)
1070                         : base (expr, probe_type, l)
1071                 {
1072                 }
1073
1074                 enum Action {
1075                         AlwaysTrue, AlwaysNull, AlwaysFalse, LeaveOnStack, Probe
1076                 }
1077
1078                 Action action;
1079
1080                 public override void Emit (EmitContext ec)
1081                 {
1082                         ILGenerator ig = ec.ig;
1083
1084                         expr.Emit (ec);
1085
1086                         switch (action){
1087                         case Action.AlwaysFalse:
1088                                 ig.Emit (OpCodes.Pop);
1089                                 IntConstant.EmitInt (ig, 0);
1090                                 return;
1091                         case Action.AlwaysTrue:
1092                                 ig.Emit (OpCodes.Pop);
1093                                 IntConstant.EmitInt (ig, 1);
1094                                 return;
1095                         case Action.LeaveOnStack:
1096                                 // the `e != null' rule.
1097                                 ig.Emit (OpCodes.Ldnull);
1098                                 ig.Emit (OpCodes.Ceq);
1099                                 ig.Emit (OpCodes.Ldc_I4_0);
1100                                 ig.Emit (OpCodes.Ceq);
1101                                 return;
1102                         case Action.Probe:
1103                                 ig.Emit (OpCodes.Isinst, probe_type);
1104                                 ig.Emit (OpCodes.Ldnull);
1105                                 ig.Emit (OpCodes.Cgt_Un);
1106                                 return;
1107                         }
1108                         throw new Exception ("never reached");
1109                 }
1110
1111                 public override void EmitBranchable (EmitContext ec, Label target, bool onTrue)
1112                 {
1113                         ILGenerator ig = ec.ig;
1114
1115                         switch (action){
1116                         case Action.AlwaysFalse:
1117                                 if (! onTrue)
1118                                         ig.Emit (OpCodes.Br, target);
1119
1120                                 return;
1121                         case Action.AlwaysTrue:
1122                                 if (onTrue)
1123                                         ig.Emit (OpCodes.Br, target);
1124
1125                                 return;
1126                         case Action.LeaveOnStack:
1127                                 // the `e != null' rule.
1128                                 expr.Emit (ec);
1129                                 ig.Emit (onTrue ? OpCodes.Brtrue : OpCodes.Brfalse, target);
1130                                 return;
1131                         case Action.Probe:
1132                                 expr.Emit (ec);
1133                                 ig.Emit (OpCodes.Isinst, probe_type);
1134                                 ig.Emit (onTrue ? OpCodes.Brtrue : OpCodes.Brfalse, target);
1135                                 return;
1136                         }
1137                         throw new Exception ("never reached");
1138                 }
1139
1140                 public override Expression DoResolve (EmitContext ec)
1141                 {
1142                         Expression e = base.DoResolve (ec);
1143
1144                         if ((e == null) || (expr == null))
1145                                 return null;
1146
1147                         Type etype = expr.Type;
1148                         bool warning_always_matches = false;
1149                         bool warning_never_matches = false;
1150
1151                         type = TypeManager.bool_type;
1152                         eclass = ExprClass.Value;
1153
1154                         //
1155                         // First case, if at compile time, there is an implicit conversion
1156                         // then e != null (objects) or true (value types)
1157                         //
1158                         e = Convert.ImplicitConversionStandard (ec, expr, probe_type, loc);
1159                         if (e != null){
1160                                 expr = e;
1161                                 if (etype.IsValueType)
1162                                         action = Action.AlwaysTrue;
1163                                 else
1164                                         action = Action.LeaveOnStack;
1165
1166                                 warning_always_matches = true;
1167                         } else if (Convert.ExplicitReferenceConversionExists (etype, probe_type)){
1168                                 if (etype.IsGenericParameter)
1169                                         expr = new BoxedCast (expr, etype);
1170
1171                                 //
1172                                 // Second case: explicit reference convresion
1173                                 //
1174                                 if (expr is NullLiteral)
1175                                         action = Action.AlwaysFalse;
1176                                 else
1177                                         action = Action.Probe;
1178                         } else {
1179                                 action = Action.AlwaysFalse;
1180                                 warning_never_matches = true;
1181                         }
1182
1183                         if (warning_always_matches)
1184                                 Warning (183, "The given expression is always of the provided ('{0}') type", TypeManager.CSharpName (probe_type));
1185                         else if (warning_never_matches){
1186                                 if (!(probe_type.IsInterface || expr.Type.IsInterface))
1187                                         Warning (184, "The given expression is never of the provided ('{0}') type", TypeManager.CSharpName (probe_type));
1188                         }
1189
1190                         return this;
1191                 }
1192         }
1193
1194         /// <summary>
1195         ///   Implementation of the `as' operator.
1196         /// </summary>
1197         public class As : Probe {
1198                 public As (Expression expr, Expression probe_type, Location l)
1199                         : base (expr, probe_type, l)
1200                 {
1201                 }
1202
1203                 bool do_isinst = false;
1204
1205                 public override void Emit (EmitContext ec)
1206                 {
1207                         ILGenerator ig = ec.ig;
1208
1209                         expr.Emit (ec);
1210
1211                         if (do_isinst)
1212                                 ig.Emit (OpCodes.Isinst, probe_type);
1213                 }
1214
1215                 static void Error_CannotConvertType (Type source, Type target, Location loc)
1216                 {
1217                         Report.Error (
1218                                 39, loc, "as operator can not convert from `" +
1219                                 TypeManager.CSharpName (source) + "' to `" +
1220                                 TypeManager.CSharpName (target) + "'");
1221                 }
1222
1223                 public override Expression DoResolve (EmitContext ec)
1224                 {
1225                         Expression e = base.DoResolve (ec);
1226
1227                         if (e == null)
1228                                 return null;
1229
1230                         type = probe_type;
1231                         eclass = ExprClass.Value;
1232                         Type etype = expr.Type;
1233
1234                         if (TypeManager.IsValueType (probe_type)){
1235                                 Report.Error (77, loc, "The as operator should be used with a reference type only (" +
1236                                               TypeManager.CSharpName (probe_type) + " is a value type)");
1237                                 return null;
1238
1239                         }
1240
1241                         e = Convert.ImplicitConversion (ec, expr, probe_type, loc);
1242                         if (e != null){
1243                                 expr = e;
1244                                 do_isinst = false;
1245                                 return this;
1246                         }
1247
1248                         if (Convert.ExplicitReferenceConversionExists (etype, probe_type)){
1249                                 if (etype.IsGenericParameter)
1250                                         expr = new BoxedCast (expr, etype);
1251
1252                                 do_isinst = true;
1253                                 return this;
1254                         }
1255
1256                         Error_CannotConvertType (etype, probe_type, loc);
1257                         return null;
1258                 }
1259         }
1260
1261         /// <summary>
1262         ///   This represents a typecast in the source language.
1263         ///
1264         ///   FIXME: Cast expressions have an unusual set of parsing
1265         ///   rules, we need to figure those out.
1266         /// </summary>
1267         public class Cast : Expression {
1268                 Expression target_type;
1269                 Expression expr;
1270
1271                 public Cast (Expression cast_type, Expression expr, Location loc)
1272                 {
1273                         this.target_type = cast_type;
1274                         this.expr = expr;
1275                         this.loc = loc;
1276                 }
1277
1278                 public Expression TargetType {
1279                         get {
1280                                 return target_type;
1281                         }
1282                 }
1283
1284                 public Expression Expr {
1285                         get {
1286                                 return expr;
1287                         }
1288                         set {
1289                                 expr = value;
1290                         }
1291                 }
1292
1293                 bool CheckRange (EmitContext ec, long value, Type type, long min, long max)
1294                 {
1295                         if (!ec.ConstantCheckState)
1296                                 return true;
1297
1298                         if ((value < min) || (value > max)) {
1299                                 Error (221, "Constant value `" + value + "' cannot be converted " +
1300                                        "to a `" + TypeManager.CSharpName (type) + "' (use `unchecked' " +
1301                                        "syntax to override)");
1302                                 return false;
1303                         }
1304
1305                         return true;
1306                 }
1307
1308                 bool CheckRange (EmitContext ec, ulong value, Type type, ulong max)
1309                 {
1310                         if (!ec.ConstantCheckState)
1311                                 return true;
1312
1313                         if (value > max) {
1314                                 Error (221, "Constant value `" + value + "' cannot be converted " +
1315                                        "to a `" + TypeManager.CSharpName (type) + "' (use `unchecked' " +
1316                                        "syntax to override)");
1317                                 return false;
1318                         }
1319
1320                         return true;
1321                 }
1322
1323                 bool CheckUnsigned (EmitContext ec, long value, Type type)
1324                 {
1325                         if (!ec.ConstantCheckState)
1326                                 return true;
1327
1328                         if (value < 0) {
1329                                 Error (221, "Constant value `" + value + "' cannot be converted " +
1330                                        "to a `" + TypeManager.CSharpName (type) + "' (use `unchecked' " +
1331                                        "syntax to override)");
1332                                 return false;
1333                         }
1334
1335                         return true;
1336                 }
1337
1338                 /// <summary>
1339                 ///   Attempts to do a compile-time folding of a constant cast.
1340                 /// </summary>
1341                 Expression TryReduce (EmitContext ec, Type target_type)
1342                 {
1343                         Expression real_expr = expr;
1344                         if (real_expr is EnumConstant)
1345                                 real_expr = ((EnumConstant) real_expr).Child;
1346
1347                         if (real_expr is ByteConstant){
1348                                 byte v = ((ByteConstant) real_expr).Value;
1349
1350                                 if (target_type == TypeManager.sbyte_type) {
1351                                         if (!CheckRange (ec, v, target_type, SByte.MinValue, SByte.MaxValue))
1352                                                 return null;
1353                                         return new SByteConstant ((sbyte) v);
1354                                 }
1355                                 if (target_type == TypeManager.short_type)
1356                                         return new ShortConstant ((short) v);
1357                                 if (target_type == TypeManager.ushort_type)
1358                                         return new UShortConstant ((ushort) v);
1359                                 if (target_type == TypeManager.int32_type)
1360                                         return new IntConstant ((int) v);
1361                                 if (target_type == TypeManager.uint32_type)
1362                                         return new UIntConstant ((uint) v);
1363                                 if (target_type == TypeManager.int64_type)
1364                                         return new LongConstant ((long) v);
1365                                 if (target_type == TypeManager.uint64_type)
1366                                         return new ULongConstant ((ulong) v);
1367                                 if (target_type == TypeManager.float_type)
1368                                         return new FloatConstant ((float) v);
1369                                 if (target_type == TypeManager.double_type)
1370                                         return new DoubleConstant ((double) v);
1371                                 if (target_type == TypeManager.char_type)
1372                                         return new CharConstant ((char) v);
1373                                 if (target_type == TypeManager.decimal_type)
1374                                         return new DecimalConstant ((decimal) v);
1375                         }
1376                         if (real_expr is SByteConstant){
1377                                 sbyte v = ((SByteConstant) real_expr).Value;
1378
1379                                 if (target_type == TypeManager.byte_type) {
1380                                         if (!CheckUnsigned (ec, v, target_type))
1381                                                 return null;
1382                                         return new ByteConstant ((byte) v);
1383                                 }
1384                                 if (target_type == TypeManager.short_type)
1385                                         return new ShortConstant ((short) v);
1386                                 if (target_type == TypeManager.ushort_type) {
1387                                         if (!CheckUnsigned (ec, v, target_type))
1388                                                 return null;
1389                                         return new UShortConstant ((ushort) v);
1390                                 } if (target_type == TypeManager.int32_type)
1391                                         return new IntConstant ((int) v);
1392                                 if (target_type == TypeManager.uint32_type) {
1393                                         if (!CheckUnsigned (ec, v, target_type))
1394                                                 return null;
1395                                         return new UIntConstant ((uint) v);
1396                                 } if (target_type == TypeManager.int64_type)
1397                                         return new LongConstant ((long) v);
1398                                 if (target_type == TypeManager.uint64_type) {
1399                                         if (!CheckUnsigned (ec, v, target_type))
1400                                                 return null;
1401                                         return new ULongConstant ((ulong) v);
1402                                 }
1403                                 if (target_type == TypeManager.float_type)
1404                                         return new FloatConstant ((float) v);
1405                                 if (target_type == TypeManager.double_type)
1406                                         return new DoubleConstant ((double) v);
1407                                 if (target_type == TypeManager.char_type) {
1408                                         if (!CheckUnsigned (ec, v, target_type))
1409                                                 return null;
1410                                         return new CharConstant ((char) v);
1411                                 }
1412                                 if (target_type == TypeManager.decimal_type)
1413                                         return new DecimalConstant ((decimal) v);
1414                         }
1415                         if (real_expr is ShortConstant){
1416                                 short v = ((ShortConstant) real_expr).Value;
1417
1418                                 if (target_type == TypeManager.byte_type) {
1419                                         if (!CheckRange (ec, v, target_type, Byte.MinValue, Byte.MaxValue))
1420                                                 return null;
1421                                         return new ByteConstant ((byte) v);
1422                                 }
1423                                 if (target_type == TypeManager.sbyte_type) {
1424                                         if (!CheckRange (ec, v, target_type, SByte.MinValue, SByte.MaxValue))
1425                                                 return null;
1426                                         return new SByteConstant ((sbyte) v);
1427                                 }
1428                                 if (target_type == TypeManager.ushort_type) {
1429                                         if (!CheckUnsigned (ec, v, target_type))
1430                                                 return null;
1431                                         return new UShortConstant ((ushort) v);
1432                                 }
1433                                 if (target_type == TypeManager.int32_type)
1434                                         return new IntConstant ((int) v);
1435                                 if (target_type == TypeManager.uint32_type) {
1436                                         if (!CheckUnsigned (ec, v, target_type))
1437                                                 return null;
1438                                         return new UIntConstant ((uint) v);
1439                                 }
1440                                 if (target_type == TypeManager.int64_type)
1441                                         return new LongConstant ((long) v);
1442                                 if (target_type == TypeManager.uint64_type) {
1443                                         if (!CheckUnsigned (ec, v, target_type))
1444                                                 return null;
1445                                         return new ULongConstant ((ulong) v);
1446                                 }
1447                                 if (target_type == TypeManager.float_type)
1448                                         return new FloatConstant ((float) v);
1449                                 if (target_type == TypeManager.double_type)
1450                                         return new DoubleConstant ((double) v);
1451                                 if (target_type == TypeManager.char_type) {
1452                                         if (!CheckRange (ec, v, target_type, Char.MinValue, Char.MaxValue))
1453                                                 return null;
1454                                         return new CharConstant ((char) v);
1455                                 }
1456                                 if (target_type == TypeManager.decimal_type)
1457                                         return new DecimalConstant ((decimal) v);
1458                         }
1459                         if (real_expr is UShortConstant){
1460                                 ushort v = ((UShortConstant) real_expr).Value;
1461
1462                                 if (target_type == TypeManager.byte_type) {
1463                                         if (!CheckRange (ec, v, target_type, Byte.MinValue, Byte.MaxValue))
1464                                                 return null;
1465                                         return new ByteConstant ((byte) v);
1466                                 }
1467                                 if (target_type == TypeManager.sbyte_type) {
1468                                         if (!CheckRange (ec, v, target_type, SByte.MinValue, SByte.MaxValue))
1469                                                 return null;
1470                                         return new SByteConstant ((sbyte) v);
1471                                 }
1472                                 if (target_type == TypeManager.short_type) {
1473                                         if (!CheckRange (ec, v, target_type, Int16.MinValue, Int16.MaxValue))
1474                                                 return null;
1475                                         return new ShortConstant ((short) v);
1476                                 }
1477                                 if (target_type == TypeManager.int32_type)
1478                                         return new IntConstant ((int) v);
1479                                 if (target_type == TypeManager.uint32_type)
1480                                         return new UIntConstant ((uint) v);
1481                                 if (target_type == TypeManager.int64_type)
1482                                         return new LongConstant ((long) v);
1483                                 if (target_type == TypeManager.uint64_type)
1484                                         return new ULongConstant ((ulong) v);
1485                                 if (target_type == TypeManager.float_type)
1486                                         return new FloatConstant ((float) v);
1487                                 if (target_type == TypeManager.double_type)
1488                                         return new DoubleConstant ((double) v);
1489                                 if (target_type == TypeManager.char_type) {
1490                                         if (!CheckRange (ec, v, target_type, Char.MinValue, Char.MaxValue))
1491                                                 return null;
1492                                         return new CharConstant ((char) v);
1493                                 }
1494                                 if (target_type == TypeManager.decimal_type)
1495                                         return new DecimalConstant ((decimal) v);
1496                         }
1497                         if (real_expr is IntConstant){
1498                                 int v = ((IntConstant) real_expr).Value;
1499
1500                                 if (target_type == TypeManager.byte_type) {
1501                                         if (!CheckRange (ec, v, target_type, Byte.MinValue, Byte.MaxValue))
1502                                                 return null;
1503                                         return new ByteConstant ((byte) v);
1504                                 }
1505                                 if (target_type == TypeManager.sbyte_type) {
1506                                         if (!CheckRange (ec, v, target_type, SByte.MinValue, SByte.MaxValue))
1507                                                 return null;
1508                                         return new SByteConstant ((sbyte) v);
1509                                 }
1510                                 if (target_type == TypeManager.short_type) {
1511                                         if (!CheckRange (ec, v, target_type, Int16.MinValue, Int16.MaxValue))
1512                                                 return null;
1513                                         return new ShortConstant ((short) v);
1514                                 }
1515                                 if (target_type == TypeManager.ushort_type) {
1516                                         if (!CheckRange (ec, v, target_type, UInt16.MinValue, UInt16.MaxValue))
1517                                                 return null;
1518                                         return new UShortConstant ((ushort) v);
1519                                 }
1520                                 if (target_type == TypeManager.uint32_type) {
1521                                         if (!CheckRange (ec, v, target_type, Int32.MinValue, Int32.MaxValue))
1522                                                 return null;
1523                                         return new UIntConstant ((uint) v);
1524                                 }
1525                                 if (target_type == TypeManager.int64_type)
1526                                         return new LongConstant ((long) v);
1527                                 if (target_type == TypeManager.uint64_type) {
1528                                         if (!CheckUnsigned (ec, v, target_type))
1529                                                 return null;
1530                                         return new ULongConstant ((ulong) v);
1531                                 }
1532                                 if (target_type == TypeManager.float_type)
1533                                         return new FloatConstant ((float) v);
1534                                 if (target_type == TypeManager.double_type)
1535                                         return new DoubleConstant ((double) v);
1536                                 if (target_type == TypeManager.char_type) {
1537                                         if (!CheckRange (ec, v, target_type, Char.MinValue, Char.MaxValue))
1538                                                 return null;
1539                                         return new CharConstant ((char) v);
1540                                 }
1541                                 if (target_type == TypeManager.decimal_type)
1542                                         return new DecimalConstant ((decimal) v);
1543                         }
1544                         if (real_expr is UIntConstant){
1545                                 uint v = ((UIntConstant) real_expr).Value;
1546
1547                                 if (target_type == TypeManager.byte_type) {
1548                                         if (!CheckRange (ec, v, target_type, Char.MinValue, Char.MaxValue))
1549                                                 return null;
1550                                         return new ByteConstant ((byte) v);
1551                                 }
1552                                 if (target_type == TypeManager.sbyte_type) {
1553                                         if (!CheckRange (ec, v, target_type, SByte.MinValue, SByte.MaxValue))
1554                                                 return null;
1555                                         return new SByteConstant ((sbyte) v);
1556                                 }
1557                                 if (target_type == TypeManager.short_type) {
1558                                         if (!CheckRange (ec, v, target_type, Int16.MinValue, Int16.MaxValue))
1559                                                 return null;
1560                                         return new ShortConstant ((short) v);
1561                                 }
1562                                 if (target_type == TypeManager.ushort_type) {
1563                                         if (!CheckRange (ec, v, target_type, UInt16.MinValue, UInt16.MaxValue))
1564                                                 return null;
1565                                         return new UShortConstant ((ushort) v);
1566                                 }
1567                                 if (target_type == TypeManager.int32_type) {
1568                                         if (!CheckRange (ec, v, target_type, Int32.MinValue, Int32.MaxValue))
1569                                                 return null;
1570                                         return new IntConstant ((int) v);
1571                                 }
1572                                 if (target_type == TypeManager.int64_type)
1573                                         return new LongConstant ((long) v);
1574                                 if (target_type == TypeManager.uint64_type)
1575                                         return new ULongConstant ((ulong) v);
1576                                 if (target_type == TypeManager.float_type)
1577                                         return new FloatConstant ((float) v);
1578                                 if (target_type == TypeManager.double_type)
1579                                         return new DoubleConstant ((double) v);
1580                                 if (target_type == TypeManager.char_type) {
1581                                         if (!CheckRange (ec, v, target_type, Char.MinValue, Char.MaxValue))
1582                                                 return null;
1583                                         return new CharConstant ((char) v);
1584                                 }
1585                                 if (target_type == TypeManager.decimal_type)
1586                                         return new DecimalConstant ((decimal) v);
1587                         }
1588                         if (real_expr is LongConstant){
1589                                 long v = ((LongConstant) real_expr).Value;
1590
1591                                 if (target_type == TypeManager.byte_type) {
1592                                         if (!CheckRange (ec, v, target_type, Byte.MinValue, Byte.MaxValue))
1593                                                 return null;
1594                                         return new ByteConstant ((byte) v);
1595                                 }
1596                                 if (target_type == TypeManager.sbyte_type) {
1597                                         if (!CheckRange (ec, v, target_type, SByte.MinValue, SByte.MaxValue))
1598                                                 return null;
1599                                         return new SByteConstant ((sbyte) v);
1600                                 }
1601                                 if (target_type == TypeManager.short_type) {
1602                                         if (!CheckRange (ec, v, target_type, Int16.MinValue, Int16.MaxValue))
1603                                                 return null;
1604                                         return new ShortConstant ((short) v);
1605                                 }
1606                                 if (target_type == TypeManager.ushort_type) {
1607                                         if (!CheckRange (ec, v, target_type, UInt16.MinValue, UInt16.MaxValue))
1608                                                 return null;
1609                                         return new UShortConstant ((ushort) v);
1610                                 }
1611                                 if (target_type == TypeManager.int32_type) {
1612                                         if (!CheckRange (ec, v, target_type, Int32.MinValue, Int32.MaxValue))
1613                                                 return null;
1614                                         return new IntConstant ((int) v);
1615                                 }
1616                                 if (target_type == TypeManager.uint32_type) {
1617                                         if (!CheckRange (ec, v, target_type, UInt32.MinValue, UInt32.MaxValue))
1618                                                 return null;
1619                                         return new UIntConstant ((uint) v);
1620                                 }
1621                                 if (target_type == TypeManager.uint64_type) {
1622                                         if (!CheckUnsigned (ec, v, target_type))
1623                                                 return null;
1624                                         return new ULongConstant ((ulong) v);
1625                                 }
1626                                 if (target_type == TypeManager.float_type)
1627                                         return new FloatConstant ((float) v);
1628                                 if (target_type == TypeManager.double_type)
1629                                         return new DoubleConstant ((double) v);
1630                                 if (target_type == TypeManager.char_type) {
1631                                         if (!CheckRange (ec, v, target_type, Char.MinValue, Char.MaxValue))
1632                                                 return null;
1633                                         return new CharConstant ((char) v);
1634                                 }
1635                                 if (target_type == TypeManager.decimal_type)
1636                                         return new DecimalConstant ((decimal) v);
1637                         }
1638                         if (real_expr is ULongConstant){
1639                                 ulong v = ((ULongConstant) real_expr).Value;
1640
1641                                 if (target_type == TypeManager.byte_type) {
1642                                         if (!CheckRange (ec, v, target_type, Byte.MaxValue))
1643                                                 return null;
1644                                         return new ByteConstant ((byte) v);
1645                                 }
1646                                 if (target_type == TypeManager.sbyte_type) {
1647                                         if (!CheckRange (ec, v, target_type, (ulong) SByte.MaxValue))
1648                                                 return null;
1649                                         return new SByteConstant ((sbyte) v);
1650                                 }
1651                                 if (target_type == TypeManager.short_type) {
1652                                         if (!CheckRange (ec, v, target_type, (ulong) Int16.MaxValue))
1653                                                 return null;
1654                                         return new ShortConstant ((short) v);
1655                                 }
1656                                 if (target_type == TypeManager.ushort_type) {
1657                                         if (!CheckRange (ec, v, target_type, UInt16.MaxValue))
1658                                                 return null;
1659                                         return new UShortConstant ((ushort) v);
1660                                 }
1661                                 if (target_type == TypeManager.int32_type) {
1662                                         if (!CheckRange (ec, v, target_type, Int32.MaxValue))
1663                                                 return null;
1664                                         return new IntConstant ((int) v);
1665                                 }
1666                                 if (target_type == TypeManager.uint32_type) {
1667                                         if (!CheckRange (ec, v, target_type, UInt32.MaxValue))
1668                                                 return null;
1669                                         return new UIntConstant ((uint) v);
1670                                 }
1671                                 if (target_type == TypeManager.int64_type) {
1672                                         if (!CheckRange (ec, v, target_type, (ulong) Int64.MaxValue))
1673                                                 return null;
1674                                         return new LongConstant ((long) v);
1675                                 }
1676                                 if (target_type == TypeManager.float_type)
1677                                         return new FloatConstant ((float) v);
1678                                 if (target_type == TypeManager.double_type)
1679                                         return new DoubleConstant ((double) v);
1680                                 if (target_type == TypeManager.char_type) {
1681                                         if (!CheckRange (ec, v, target_type, Char.MaxValue))
1682                                                 return null;
1683                                         return new CharConstant ((char) v);
1684                                 }
1685                                 if (target_type == TypeManager.decimal_type)
1686                                         return new DecimalConstant ((decimal) v);
1687                         }
1688                         if (real_expr is FloatConstant){
1689                                 float v = ((FloatConstant) real_expr).Value;
1690
1691                                 if (target_type == TypeManager.byte_type)
1692                                         return new ByteConstant ((byte) v);
1693                                 if (target_type == TypeManager.sbyte_type)
1694                                         return new SByteConstant ((sbyte) v);
1695                                 if (target_type == TypeManager.short_type)
1696                                         return new ShortConstant ((short) v);
1697                                 if (target_type == TypeManager.ushort_type)
1698                                         return new UShortConstant ((ushort) v);
1699                                 if (target_type == TypeManager.int32_type)
1700                                         return new IntConstant ((int) v);
1701                                 if (target_type == TypeManager.uint32_type)
1702                                         return new UIntConstant ((uint) v);
1703                                 if (target_type == TypeManager.int64_type)
1704                                         return new LongConstant ((long) v);
1705                                 if (target_type == TypeManager.uint64_type)
1706                                         return new ULongConstant ((ulong) v);
1707                                 if (target_type == TypeManager.double_type)
1708                                         return new DoubleConstant ((double) v);
1709                                 if (target_type == TypeManager.char_type)
1710                                         return new CharConstant ((char) v);
1711                                 if (target_type == TypeManager.decimal_type)
1712                                         return new DecimalConstant ((decimal) v);
1713                         }
1714                         if (real_expr is DoubleConstant){
1715                                 double v = ((DoubleConstant) real_expr).Value;
1716
1717                                 if (target_type == TypeManager.byte_type){
1718                                         return new ByteConstant ((byte) v);
1719                                 } if (target_type == TypeManager.sbyte_type)
1720                                         return new SByteConstant ((sbyte) v);
1721                                 if (target_type == TypeManager.short_type)
1722                                         return new ShortConstant ((short) v);
1723                                 if (target_type == TypeManager.ushort_type)
1724                                         return new UShortConstant ((ushort) v);
1725                                 if (target_type == TypeManager.int32_type)
1726                                         return new IntConstant ((int) v);
1727                                 if (target_type == TypeManager.uint32_type)
1728                                         return new UIntConstant ((uint) v);
1729                                 if (target_type == TypeManager.int64_type)
1730                                         return new LongConstant ((long) v);
1731                                 if (target_type == TypeManager.uint64_type)
1732                                         return new ULongConstant ((ulong) v);
1733                                 if (target_type == TypeManager.float_type)
1734                                         return new FloatConstant ((float) v);
1735                                 if (target_type == TypeManager.char_type)
1736                                         return new CharConstant ((char) v);
1737                                 if (target_type == TypeManager.decimal_type)
1738                                         return new DecimalConstant ((decimal) v);
1739                         }
1740
1741                         if (real_expr is CharConstant){
1742                                 char v = ((CharConstant) real_expr).Value;
1743
1744                                 if (target_type == TypeManager.byte_type) {
1745                                         if (!CheckRange (ec, v, target_type, Byte.MinValue, Byte.MaxValue))
1746                                                 return null;
1747                                         return new ByteConstant ((byte) v);
1748                                 }
1749                                 if (target_type == TypeManager.sbyte_type) {
1750                                         if (!CheckRange (ec, v, target_type, SByte.MinValue, SByte.MaxValue))
1751                                                 return null;
1752                                         return new SByteConstant ((sbyte) v);
1753                                 }
1754                                 if (target_type == TypeManager.short_type) {
1755                                         if (!CheckRange (ec, v, target_type, Int16.MinValue, Int16.MaxValue))
1756                                                 return null;
1757                                         return new ShortConstant ((short) v);
1758                                 }
1759                                 if (target_type == TypeManager.int32_type)
1760                                         return new IntConstant ((int) v);
1761                                 if (target_type == TypeManager.uint32_type)
1762                                         return new UIntConstant ((uint) v);
1763                                 if (target_type == TypeManager.int64_type)
1764                                         return new LongConstant ((long) v);
1765                                 if (target_type == TypeManager.uint64_type)
1766                                         return new ULongConstant ((ulong) v);
1767                                 if (target_type == TypeManager.float_type)
1768                                         return new FloatConstant ((float) v);
1769                                 if (target_type == TypeManager.double_type)
1770                                         return new DoubleConstant ((double) v);
1771                                 if (target_type == TypeManager.char_type) {
1772                                         if (!CheckRange (ec, v, target_type, Char.MinValue, Char.MaxValue))
1773                                                 return null;
1774                                         return new CharConstant ((char) v);
1775                                 }
1776                                 if (target_type == TypeManager.decimal_type)
1777                                         return new DecimalConstant ((decimal) v);
1778                         }
1779
1780                         return null;
1781                 }
1782
1783                 public override Expression DoResolveLValue (EmitContext ec, Expression right_side)
1784                 {
1785                         expr = expr.DoResolveLValue (ec, right_side);
1786                         if (expr == null)
1787                                 return null;
1788
1789                         return ResolveRest (ec);
1790                 }
1791
1792                 public override Expression DoResolve (EmitContext ec)
1793                 {
1794                         expr = expr.Resolve (ec);
1795                         if (expr == null)
1796                                 return null;
1797
1798                         return ResolveRest (ec);
1799                 }
1800
1801                 Expression ResolveRest (EmitContext ec)
1802                 {
1803                         TypeExpr target = target_type.ResolveAsTypeTerminal (ec);
1804                         if (target == null)
1805                                 return null;
1806
1807                         type = target.Type;
1808
1809                         CheckObsoleteAttribute (type);
1810
1811                         if (type.IsAbstract && type.IsSealed) {
1812                                 Report.Error (716, loc, "Cannot convert to static type '{0}'", TypeManager.CSharpName (type));
1813                                 return null;
1814                         }
1815
1816                         eclass = ExprClass.Value;
1817
1818                         if (expr is Constant){
1819                                 Expression e = TryReduce (ec, type);
1820
1821                                 if (e != null)
1822                                         return e;
1823                         }
1824
1825                         if (type.IsPointer && !ec.InUnsafe) {
1826                                 UnsafeError (loc);
1827                                 return null;
1828                         }
1829                         expr = Convert.ExplicitConversion (ec, expr, type, loc);
1830                         return expr;
1831                 }
1832
1833                 public override void Emit (EmitContext ec)
1834                 {
1835                         //
1836                         // This one will never happen
1837                         //
1838                         throw new Exception ("Should not happen");
1839                 }
1840         }
1841
1842         /// <summary>
1843         ///   Binary operators
1844         /// </summary>
1845         public class Binary : Expression {
1846                 public enum Operator : byte {
1847                         Multiply, Division, Modulus,
1848                         Addition, Subtraction,
1849                         LeftShift, RightShift,
1850                         LessThan, GreaterThan, LessThanOrEqual, GreaterThanOrEqual,
1851                         Equality, Inequality,
1852                         BitwiseAnd,
1853                         ExclusiveOr,
1854                         BitwiseOr,
1855                         LogicalAnd,
1856                         LogicalOr,
1857                         TOP
1858                 }
1859
1860                 Operator oper;
1861                 Expression left, right;
1862
1863                 // This must be kept in sync with Operator!!!
1864                 public static readonly string [] oper_names;
1865
1866                 static Binary ()
1867                 {
1868                         oper_names = new string [(int) Operator.TOP];
1869
1870                         oper_names [(int) Operator.Multiply] = "op_Multiply";
1871                         oper_names [(int) Operator.Division] = "op_Division";
1872                         oper_names [(int) Operator.Modulus] = "op_Modulus";
1873                         oper_names [(int) Operator.Addition] = "op_Addition";
1874                         oper_names [(int) Operator.Subtraction] = "op_Subtraction";
1875                         oper_names [(int) Operator.LeftShift] = "op_LeftShift";
1876                         oper_names [(int) Operator.RightShift] = "op_RightShift";
1877                         oper_names [(int) Operator.LessThan] = "op_LessThan";
1878                         oper_names [(int) Operator.GreaterThan] = "op_GreaterThan";
1879                         oper_names [(int) Operator.LessThanOrEqual] = "op_LessThanOrEqual";
1880                         oper_names [(int) Operator.GreaterThanOrEqual] = "op_GreaterThanOrEqual";
1881                         oper_names [(int) Operator.Equality] = "op_Equality";
1882                         oper_names [(int) Operator.Inequality] = "op_Inequality";
1883                         oper_names [(int) Operator.BitwiseAnd] = "op_BitwiseAnd";
1884                         oper_names [(int) Operator.BitwiseOr] = "op_BitwiseOr";
1885                         oper_names [(int) Operator.ExclusiveOr] = "op_ExclusiveOr";
1886                         oper_names [(int) Operator.LogicalOr] = "op_LogicalOr";
1887                         oper_names [(int) Operator.LogicalAnd] = "op_LogicalAnd";
1888                 }
1889
1890                 public Binary (Operator oper, Expression left, Expression right, Location loc)
1891                 {
1892                         this.oper = oper;
1893                         this.left = left;
1894                         this.right = right;
1895                         this.loc = loc;
1896                 }
1897
1898                 public Operator Oper {
1899                         get {
1900                                 return oper;
1901                         }
1902                         set {
1903                                 oper = value;
1904                         }
1905                 }
1906
1907                 public Expression Left {
1908                         get {
1909                                 return left;
1910                         }
1911                         set {
1912                                 left = value;
1913                         }
1914                 }
1915
1916                 public Expression Right {
1917                         get {
1918                                 return right;
1919                         }
1920                         set {
1921                                 right = value;
1922                         }
1923                 }
1924
1925
1926                 /// <summary>
1927                 ///   Returns a stringified representation of the Operator
1928                 /// </summary>
1929                 static string OperName (Operator oper)
1930                 {
1931                         switch (oper){
1932                         case Operator.Multiply:
1933                                 return "*";
1934                         case Operator.Division:
1935                                 return "/";
1936                         case Operator.Modulus:
1937                                 return "%";
1938                         case Operator.Addition:
1939                                 return "+";
1940                         case Operator.Subtraction:
1941                                 return "-";
1942                         case Operator.LeftShift:
1943                                 return "<<";
1944                         case Operator.RightShift:
1945                                 return ">>";
1946                         case Operator.LessThan:
1947                                 return "<";
1948                         case Operator.GreaterThan:
1949                                 return ">";
1950                         case Operator.LessThanOrEqual:
1951                                 return "<=";
1952                         case Operator.GreaterThanOrEqual:
1953                                 return ">=";
1954                         case Operator.Equality:
1955                                 return "==";
1956                         case Operator.Inequality:
1957                                 return "!=";
1958                         case Operator.BitwiseAnd:
1959                                 return "&";
1960                         case Operator.BitwiseOr:
1961                                 return "|";
1962                         case Operator.ExclusiveOr:
1963                                 return "^";
1964                         case Operator.LogicalOr:
1965                                 return "||";
1966                         case Operator.LogicalAnd:
1967                                 return "&&";
1968                         }
1969
1970                         return oper.ToString ();
1971                 }
1972
1973                 public override string ToString ()
1974                 {
1975                         return "operator " + OperName (oper) + "(" + left.ToString () + ", " +
1976                                 right.ToString () + ")";
1977                 }
1978
1979                 Expression ForceConversion (EmitContext ec, Expression expr, Type target_type)
1980                 {
1981                         if (expr.Type == target_type)
1982                                 return expr;
1983
1984                         return Convert.ImplicitConversion (ec, expr, target_type, loc);
1985                 }
1986
1987                 public static void Error_OperatorAmbiguous (Location loc, Operator oper, Type l, Type r)
1988                 {
1989                         Report.Error (
1990                                 34, loc, "Operator `" + OperName (oper)
1991                                 + "' is ambiguous on operands of type `"
1992                                 + TypeManager.CSharpName (l) + "' "
1993                                 + "and `" + TypeManager.CSharpName (r)
1994                                 + "'");
1995                 }
1996
1997                 bool IsOfType (EmitContext ec, Type l, Type r, Type t, bool check_user_conversions)
1998                 {
1999                         if ((l == t) || (r == t))
2000                                 return true;
2001
2002                         if (!check_user_conversions)
2003                                 return false;
2004
2005                         if (Convert.ImplicitUserConversionExists (ec, l, t))
2006                                 return true;
2007                         else if (Convert.ImplicitUserConversionExists (ec, r, t))
2008                                 return true;
2009                         else
2010                                 return false;
2011                 }
2012
2013                 //
2014                 // Note that handling the case l == Decimal || r == Decimal
2015                 // is taken care of by the Step 1 Operator Overload resolution.
2016                 //
2017                 // If `check_user_conv' is true, we also check whether a user-defined conversion
2018                 // exists.  Note that we only need to do this if both arguments are of a user-defined
2019                 // type, otherwise ConvertImplict() already finds the user-defined conversion for us,
2020                 // so we don't explicitly check for performance reasons.
2021                 //
2022                 bool DoNumericPromotions (EmitContext ec, Type l, Type r, bool check_user_conv)
2023                 {
2024                         if (IsOfType (ec, l, r, TypeManager.double_type, check_user_conv)){
2025                                 //
2026                                 // If either operand is of type double, the other operand is
2027                                 // conveted to type double.
2028                                 //
2029                                 if (r != TypeManager.double_type)
2030                                         right = Convert.ImplicitConversion (ec, right, TypeManager.double_type, loc);
2031                                 if (l != TypeManager.double_type)
2032                                         left = Convert.ImplicitConversion (ec, left, TypeManager.double_type, loc);
2033
2034                                 type = TypeManager.double_type;
2035                         } else if (IsOfType (ec, l, r, TypeManager.float_type, check_user_conv)){
2036                                 //
2037                                 // if either operand is of type float, the other operand is
2038                                 // converted to type float.
2039                                 //
2040                                 if (r != TypeManager.double_type)
2041                                         right = Convert.ImplicitConversion (ec, right, TypeManager.float_type, loc);
2042                                 if (l != TypeManager.double_type)
2043                                         left = Convert.ImplicitConversion (ec, left, TypeManager.float_type, loc);
2044                                 type = TypeManager.float_type;
2045                         } else if (IsOfType (ec, l, r, TypeManager.uint64_type, check_user_conv)){
2046                                 Expression e;
2047                                 Type other;
2048                                 //
2049                                 // If either operand is of type ulong, the other operand is
2050                                 // converted to type ulong.  or an error ocurrs if the other
2051                                 // operand is of type sbyte, short, int or long
2052                                 //
2053                                 if (l == TypeManager.uint64_type){
2054                                         if (r != TypeManager.uint64_type){
2055                                                 if (right is IntConstant){
2056                                                         IntConstant ic = (IntConstant) right;
2057
2058                                                         e = Convert.TryImplicitIntConversion (l, ic);
2059                                                         if (e != null)
2060                                                                 right = e;
2061                                                 } else if (right is LongConstant){
2062                                                         long ll = ((LongConstant) right).Value;
2063
2064                                                         if (ll >= 0)
2065                                                                 right = new ULongConstant ((ulong) ll);
2066                                                 } else {
2067                                                         e = Convert.ImplicitNumericConversion (ec, right, l, loc);
2068                                                         if (e != null)
2069                                                                 right = e;
2070                                                 }
2071                                         }
2072                                         other = right.Type;
2073                                 } else {
2074                                         if (left is IntConstant){
2075                                                 e = Convert.TryImplicitIntConversion (r, (IntConstant) left);
2076                                                 if (e != null)
2077                                                         left = e;
2078                                         } else if (left is LongConstant){
2079                                                 long ll = ((LongConstant) left).Value;
2080
2081                                                 if (ll > 0)
2082                                                         left = new ULongConstant ((ulong) ll);
2083                                         } else {
2084                                                 e = Convert.ImplicitNumericConversion (ec, left, r, loc);
2085                                                 if (e != null)
2086                                                         left = e;
2087                                         }
2088                                         other = left.Type;
2089                                 }
2090
2091                                 if ((other == TypeManager.sbyte_type) ||
2092                                     (other == TypeManager.short_type) ||
2093                                     (other == TypeManager.int32_type) ||
2094                                     (other == TypeManager.int64_type))
2095                                         Error_OperatorAmbiguous (loc, oper, l, r);
2096                                 else {
2097                                         left = ForceConversion (ec, left, TypeManager.uint64_type);
2098                                         right = ForceConversion (ec, right, TypeManager.uint64_type);
2099                                 }
2100                                 type = TypeManager.uint64_type;
2101                         } else if (IsOfType (ec, l, r, TypeManager.int64_type, check_user_conv)){
2102                                 //
2103                                 // If either operand is of type long, the other operand is converted
2104                                 // to type long.
2105                                 //
2106                                 if (l != TypeManager.int64_type)
2107                                         left = Convert.ImplicitConversion (ec, left, TypeManager.int64_type, loc);
2108                                 if (r != TypeManager.int64_type)
2109                                         right = Convert.ImplicitConversion (ec, right, TypeManager.int64_type, loc);
2110
2111                                 type = TypeManager.int64_type;
2112                         } else if (IsOfType (ec, l, r, TypeManager.uint32_type, check_user_conv)){
2113                                 //
2114                                 // If either operand is of type uint, and the other
2115                                 // operand is of type sbyte, short or int, othe operands are
2116                                 // converted to type long (unless we have an int constant).
2117                                 //
2118                                 Type other = null;
2119
2120                                 if (l == TypeManager.uint32_type){
2121                                         if (right is IntConstant){
2122                                                 IntConstant ic = (IntConstant) right;
2123                                                 int val = ic.Value;
2124
2125                                                 if (val >= 0){
2126                                                         right = new UIntConstant ((uint) val);
2127                                                         type = l;
2128
2129                                                         return true;
2130                                                 }
2131                                         }
2132                                         other = r;
2133                                 } else if (r == TypeManager.uint32_type){
2134                                         if (left is IntConstant){
2135                                                 IntConstant ic = (IntConstant) left;
2136                                                 int val = ic.Value;
2137
2138                                                 if (val >= 0){
2139                                                         left = new UIntConstant ((uint) val);
2140                                                         type = r;
2141                                                         return true;
2142                                                 }
2143                                         }
2144
2145                                         other = l;
2146                                 }
2147
2148                                 if ((other == TypeManager.sbyte_type) ||
2149                                     (other == TypeManager.short_type) ||
2150                                     (other == TypeManager.int32_type)){
2151                                         left = ForceConversion (ec, left, TypeManager.int64_type);
2152                                         right = ForceConversion (ec, right, TypeManager.int64_type);
2153                                         type = TypeManager.int64_type;
2154                                 } else {
2155                                         //
2156                                         // if either operand is of type uint, the other
2157                                         // operand is converd to type uint
2158                                         //
2159                                         left = ForceConversion (ec, left, TypeManager.uint32_type);
2160                                         right = ForceConversion (ec, right, TypeManager.uint32_type);
2161                                         type = TypeManager.uint32_type;
2162                                 }
2163                         } else if (l == TypeManager.decimal_type || r == TypeManager.decimal_type){
2164                                 if (l != TypeManager.decimal_type)
2165                                         left = Convert.ImplicitConversion (ec, left, TypeManager.decimal_type, loc);
2166
2167                                 if (r != TypeManager.decimal_type)
2168                                         right = Convert.ImplicitConversion (ec, right, TypeManager.decimal_type, loc);
2169                                 type = TypeManager.decimal_type;
2170                         } else {
2171                                 left = ForceConversion (ec, left, TypeManager.int32_type);
2172                                 right = ForceConversion (ec, right, TypeManager.int32_type);
2173
2174                                 type = TypeManager.int32_type;
2175                         }
2176
2177                         return (left != null) && (right != null);
2178                 }
2179
2180                 static public void Error_OperatorCannotBeApplied (Location loc, string name, Type l, Type r)
2181                 {
2182                         Report.Error (19, loc,
2183                                "Operator " + name + " cannot be applied to operands of type `" +
2184                                TypeManager.CSharpName (l) + "' and `" +
2185                                TypeManager.CSharpName (r) + "'");
2186                 }
2187
2188                 void Error_OperatorCannotBeApplied ()
2189                 {
2190                         Error_OperatorCannotBeApplied (loc, OperName (oper), left.Type, right.Type);
2191                 }
2192
2193                 static bool is_unsigned (Type t)
2194                 {
2195                         return (t == TypeManager.uint32_type || t == TypeManager.uint64_type ||
2196                                 t == TypeManager.short_type || t == TypeManager.byte_type);
2197                 }
2198
2199                 static bool is_user_defined (Type t)
2200                 {
2201                         if (t.IsSubclassOf (TypeManager.value_type) &&
2202                             (!TypeManager.IsBuiltinType (t) || t == TypeManager.decimal_type))
2203                                 return true;
2204                         else
2205                                 return false;
2206                 }
2207
2208                 Expression Make32or64 (EmitContext ec, Expression e)
2209                 {
2210                         Type t= e.Type;
2211
2212                         if (t == TypeManager.int32_type || t == TypeManager.uint32_type ||
2213                             t == TypeManager.int64_type || t == TypeManager.uint64_type)
2214                                 return e;
2215                         Expression ee = Convert.ImplicitConversion (ec, e, TypeManager.int32_type, loc);
2216                         if (ee != null)
2217                                 return ee;
2218                         ee = Convert.ImplicitConversion (ec, e, TypeManager.uint32_type, loc);
2219                         if (ee != null)
2220                                 return ee;
2221                         ee = Convert.ImplicitConversion (ec, e, TypeManager.int64_type, loc);
2222                         if (ee != null)
2223                                 return ee;
2224                         ee = Convert.ImplicitConversion (ec, e, TypeManager.uint64_type, loc);
2225                         if (ee != null)
2226                                 return ee;
2227                         return null;
2228                 }
2229
2230                 Expression CheckShiftArguments (EmitContext ec)
2231                 {
2232                         Expression e;
2233
2234                         e = ForceConversion (ec, right, TypeManager.int32_type);
2235                         if (e == null){
2236                                 Error_OperatorCannotBeApplied ();
2237                                 return null;
2238                         }
2239                         right = e;
2240
2241                         if (((e = Convert.ImplicitConversion (ec, left, TypeManager.int32_type, loc)) != null) ||
2242                             ((e = Convert.ImplicitConversion (ec, left, TypeManager.uint32_type, loc)) != null) ||
2243                             ((e = Convert.ImplicitConversion (ec, left, TypeManager.int64_type, loc)) != null) ||
2244                             ((e = Convert.ImplicitConversion (ec, left, TypeManager.uint64_type, loc)) != null)){
2245                                 left = e;
2246                                 type = e.Type;
2247
2248                                 if (type == TypeManager.int32_type || type == TypeManager.uint32_type){
2249                                         right = new Binary (Binary.Operator.BitwiseAnd, right, new IntLiteral (31), loc);
2250                                         right = right.DoResolve (ec);
2251                                 } else {
2252                                         right = new Binary (Binary.Operator.BitwiseAnd, right, new IntLiteral (63), loc);
2253                                         right = right.DoResolve (ec);
2254                                 }
2255
2256                                 return this;
2257                         }
2258                         Error_OperatorCannotBeApplied ();
2259                         return null;
2260                 }
2261
2262                 Expression ResolveOperator (EmitContext ec)
2263                 {
2264                         Type l = left.Type;
2265                         Type r = right.Type;
2266
2267                         //
2268                         // Special cases: string or type parameter comapred to null
2269                         //
2270                         if (oper == Operator.Equality || oper == Operator.Inequality){
2271                                 if ((!TypeManager.IsValueType (l) && r == TypeManager.null_type) ||
2272                                     (!TypeManager.IsValueType (r) && l == TypeManager.null_type)) {
2273                                         Type = TypeManager.bool_type;
2274
2275                                         return this;
2276                                 }
2277
2278                                 if (l.IsGenericParameter && (right is NullLiteral)) {
2279                                         if (l.BaseType == TypeManager.value_type) {
2280                                                 Error_OperatorCannotBeApplied ();
2281                                                 return null;
2282                                         }
2283
2284                                         left = new BoxedCast (left);
2285                                         Type = TypeManager.bool_type;
2286                                         return this;
2287                                 }
2288
2289                                 if (r.IsGenericParameter && (left is NullLiteral)) {
2290                                         if (r.BaseType == TypeManager.value_type) {
2291                                                 Error_OperatorCannotBeApplied ();
2292                                                 return null;
2293                                         }
2294
2295                                         right = new BoxedCast (right);
2296                                         Type = TypeManager.bool_type;
2297                                         return this;
2298                                 }
2299
2300                                 // IntPtr equality
2301                                 if (l == TypeManager.intptr_type && r == TypeManager.intptr_type) {
2302                                         Type = TypeManager.bool_type;
2303
2304                                         return this;
2305                                 }
2306                         }
2307
2308                         //
2309                         // Do not perform operator overload resolution when both sides are
2310                         // built-in types
2311                         //
2312                         if (!(TypeManager.IsPrimitiveType (l) && TypeManager.IsPrimitiveType (r))){
2313                                 //
2314                                 // Step 1: Perform Operator Overload location
2315                                 //
2316                                 Expression left_expr, right_expr;
2317
2318                                 string op = oper_names [(int) oper];
2319
2320                                 MethodGroupExpr union;
2321                                 left_expr = MemberLookup (ec, l, op, MemberTypes.Method, AllBindingFlags, loc);
2322                                 if (r != l){
2323                                         right_expr = MemberLookup (
2324                                                 ec, r, op, MemberTypes.Method, AllBindingFlags, loc);
2325                                         union = Invocation.MakeUnionSet (left_expr, right_expr, loc);
2326                                 } else
2327                                         union = (MethodGroupExpr) left_expr;
2328
2329                                 if (union != null) {
2330                                         ArrayList args = new ArrayList (2);
2331                                         args.Add (new Argument (left, Argument.AType.Expression));
2332                                         args.Add (new Argument (right, Argument.AType.Expression));
2333
2334                                         MethodBase method = Invocation.OverloadResolve (
2335                                                 ec, union, args, true, Location.Null);
2336
2337                                         if (method != null) {
2338                                                 MethodInfo mi = (MethodInfo) method;
2339
2340                                                 return new BinaryMethod (mi.ReturnType, method, args);
2341                                         }
2342                                 }
2343                         }
2344
2345                         //
2346                         // Step 0: String concatenation (because overloading will get this wrong)
2347                         //
2348                         if (oper == Operator.Addition){
2349                                 //
2350                                 // If any of the arguments is a string, cast to string
2351                                 //
2352
2353                                 // Simple constant folding
2354                                 if (left is StringConstant && right is StringConstant)
2355                                         return new StringConstant (((StringConstant) left).Value + ((StringConstant) right).Value);
2356
2357                                 if (l == TypeManager.string_type || r == TypeManager.string_type) {
2358
2359                                         if (r == TypeManager.void_type || l == TypeManager.void_type) {
2360                                                 Error_OperatorCannotBeApplied ();
2361                                                 return null;
2362                                         }
2363
2364                                         // try to fold it in on the left
2365                                         if (left is StringConcat) {
2366
2367                                                 //
2368                                                 // We have to test here for not-null, since we can be doubly-resolved
2369                                                 // take care of not appending twice
2370                                                 //
2371                                                 if (type == null){
2372                                                         type = TypeManager.string_type;
2373                                                         ((StringConcat) left).Append (ec, right);
2374                                                         return left.Resolve (ec);
2375                                                 } else {
2376                                                         return left;
2377                                                 }
2378                                         }
2379
2380                                         // Otherwise, start a new concat expression
2381                                         return new StringConcat (ec, loc, left, right).Resolve (ec);
2382                                 }
2383
2384                                 //
2385                                 // Transform a + ( - b) into a - b
2386                                 //
2387                                 if (right is Unary){
2388                                         Unary right_unary = (Unary) right;
2389
2390                                         if (right_unary.Oper == Unary.Operator.UnaryNegation){
2391                                                 oper = Operator.Subtraction;
2392                                                 right = right_unary.Expr;
2393                                                 r = right.Type;
2394                                         }
2395                                 }
2396                         }
2397
2398                         if (oper == Operator.Equality || oper == Operator.Inequality){
2399                                 if (l == TypeManager.bool_type || r == TypeManager.bool_type){
2400                                         if (r != TypeManager.bool_type || l != TypeManager.bool_type){
2401                                                 Error_OperatorCannotBeApplied ();
2402                                                 return null;
2403                                         }
2404
2405                                         type = TypeManager.bool_type;
2406                                         return this;
2407                                 }
2408
2409                                 bool left_is_null = left is NullLiteral;
2410                                 bool right_is_null = right is NullLiteral;
2411                                 if (left_is_null || right_is_null) {
2412                                         if (oper == Operator.Equality)
2413                                                 return new BoolLiteral (left_is_null == right_is_null);
2414                                         else
2415                                                 return new BoolLiteral (left_is_null != right_is_null);
2416                                 }
2417
2418                                 //
2419                                 // operator != (object a, object b)
2420                                 // operator == (object a, object b)
2421                                 //
2422                                 // For this to be used, both arguments have to be reference-types.
2423                                 // Read the rationale on the spec (14.9.6)
2424                                 //
2425                                 // Also, if at compile time we know that the classes do not inherit
2426                                 // one from the other, then we catch the error there.
2427                                 //
2428                                 if (!(l.IsValueType || r.IsValueType)){
2429                                         type = TypeManager.bool_type;
2430
2431                                         if (l == r)
2432                                                 return this;
2433
2434                                         if (l.IsSubclassOf (r) || r.IsSubclassOf (l))
2435                                                 return this;
2436
2437                                         //
2438                                         // Also, a standard conversion must exist from either one
2439                                         //
2440                                         if (!(Convert.ImplicitStandardConversionExists (ec, left, r) ||
2441                                               Convert.ImplicitStandardConversionExists (ec, right, l))){
2442                                                 Error_OperatorCannotBeApplied ();
2443                                                 return null;
2444                                         }
2445                                         //
2446                                         // We are going to have to convert to an object to compare
2447                                         //
2448                                         if (l != TypeManager.object_type)
2449                                                 left = new EmptyCast (left, TypeManager.object_type);
2450                                         if (r != TypeManager.object_type)
2451                                                 right = new EmptyCast (right, TypeManager.object_type);
2452
2453                                         //
2454                                         // FIXME: CSC here catches errors cs254 and cs252
2455                                         //
2456                                         return this;
2457                                 }
2458
2459                                 //
2460                                 // One of them is a valuetype, but the other one is not.
2461                                 //
2462                                 if (!l.IsValueType || !r.IsValueType) {
2463                                         Error_OperatorCannotBeApplied ();
2464                                         return null;
2465                                 }
2466                         }
2467
2468                         // Only perform numeric promotions on:
2469                         // +, -, *, /, %, &, |, ^, ==, !=, <, >, <=, >=
2470                         //
2471                         if (oper == Operator.Addition || oper == Operator.Subtraction) {
2472                                 if (TypeManager.IsDelegateType (l)){
2473                                         if (((right.eclass == ExprClass.MethodGroup) ||
2474                                              (r == TypeManager.anonymous_method_type))){
2475                                                 if ((RootContext.Version != LanguageVersion.ISO_1)){
2476                                                         Expression tmp = Convert.ImplicitConversionRequired (ec, right, l, loc);
2477                                                         if (tmp == null)
2478                                                                 return null;
2479                                                         right = tmp;
2480                                                         r = right.Type;
2481                                                 }
2482                                         }
2483
2484                                         if (TypeManager.IsDelegateType (r)){
2485                                                 MethodInfo method;
2486                                                 ArrayList args = new ArrayList (2);
2487
2488                                                 args = new ArrayList (2);
2489                                                 args.Add (new Argument (left, Argument.AType.Expression));
2490                                                 args.Add (new Argument (right, Argument.AType.Expression));
2491
2492                                                 if (oper == Operator.Addition)
2493                                                         method = TypeManager.delegate_combine_delegate_delegate;
2494                                                 else
2495                                                         method = TypeManager.delegate_remove_delegate_delegate;
2496
2497                                                 if (!TypeManager.IsEqual (l, r)) {
2498                                                         Error_OperatorCannotBeApplied ();
2499                                                         return null;
2500                                                 }
2501
2502                                                 return new BinaryDelegate (l, method, args);
2503                                         }
2504                                 }
2505
2506                                 //
2507                                 // Pointer arithmetic:
2508                                 //
2509                                 // T* operator + (T* x, int y);
2510                                 // T* operator + (T* x, uint y);
2511                                 // T* operator + (T* x, long y);
2512                                 // T* operator + (T* x, ulong y);
2513                                 //
2514                                 // T* operator + (int y,   T* x);
2515                                 // T* operator + (uint y,  T *x);
2516                                 // T* operator + (long y,  T *x);
2517                                 // T* operator + (ulong y, T *x);
2518                                 //
2519                                 // T* operator - (T* x, int y);
2520                                 // T* operator - (T* x, uint y);
2521                                 // T* operator - (T* x, long y);
2522                                 // T* operator - (T* x, ulong y);
2523                                 //
2524                                 // long operator - (T* x, T *y)
2525                                 //
2526                                 if (l.IsPointer){
2527                                         if (r.IsPointer && oper == Operator.Subtraction){
2528                                                 if (r == l)
2529                                                         return new PointerArithmetic (
2530                                                                 false, left, right, TypeManager.int64_type,
2531                                                                 loc).Resolve (ec);
2532                                         } else {
2533                                                 Expression t = Make32or64 (ec, right);
2534                                                 if (t != null)
2535                                                         return new PointerArithmetic (oper == Operator.Addition, left, t, l, loc).Resolve (ec);
2536                                         }
2537                                 } else if (r.IsPointer && oper == Operator.Addition){
2538                                         Expression t = Make32or64 (ec, left);
2539                                         if (t != null)
2540                                                 return new PointerArithmetic (true, right, t, r, loc).Resolve (ec);
2541                                 }
2542                         }
2543
2544                         //
2545                         // Enumeration operators
2546                         //
2547                         bool lie = TypeManager.IsEnumType (l);
2548                         bool rie = TypeManager.IsEnumType (r);
2549                         if (lie || rie){
2550                                 Expression temp;
2551
2552                                 // U operator - (E e, E f)
2553                                 if (lie && rie){
2554                                         if (oper == Operator.Subtraction){
2555                                         if (l == r){
2556                                                 type = TypeManager.EnumToUnderlying (l);
2557                                                 return this;
2558                                         }
2559                                         Error_OperatorCannotBeApplied ();
2560                                         return null;
2561                                 }
2562                                 }
2563
2564                                 //
2565                                 // operator + (E e, U x)
2566                                 // operator - (E e, U x)
2567                                 //
2568                                 if (oper == Operator.Addition || oper == Operator.Subtraction){
2569                                         Type enum_type = lie ? l : r;
2570                                         Type other_type = lie ? r : l;
2571                                         Type underlying_type = TypeManager.EnumToUnderlying (enum_type);
2572
2573                                         if (underlying_type != other_type){
2574                                                 temp = Convert.ImplicitConversion (ec, lie ? right : left, underlying_type, loc);
2575                                                 if (temp != null){
2576                                                         if (lie)
2577                                                                 right = temp;
2578                                                         else
2579                                                                 left = temp;
2580                                                         type = enum_type;
2581                                                         return this;
2582                                                 }
2583
2584                                                 Error_OperatorCannotBeApplied ();
2585                                                 return null;
2586                                         }
2587
2588                                         type = enum_type;
2589                                         return this;
2590                                 }
2591
2592                                 if (!rie){
2593                                         temp = Convert.ImplicitConversion (ec, right, l, loc);
2594                                         if (temp != null)
2595                                                 right = temp;
2596                                         else {
2597                                                 Error_OperatorCannotBeApplied ();
2598                                                 return null;
2599                                         }
2600                                 } if (!lie){
2601                                         temp = Convert.ImplicitConversion (ec, left, r, loc);
2602                                         if (temp != null){
2603                                                 left = temp;
2604                                                 l = r;
2605                                         } else {
2606                                                 Error_OperatorCannotBeApplied ();
2607                                                 return null;
2608                                         }
2609                                 }
2610
2611                                 if (oper == Operator.Equality || oper == Operator.Inequality ||
2612                                     oper == Operator.LessThanOrEqual || oper == Operator.LessThan ||
2613                                     oper == Operator.GreaterThanOrEqual || oper == Operator.GreaterThan){
2614                                         if (left.Type != right.Type){
2615                                                 Error_OperatorCannotBeApplied ();
2616                                                 return null;
2617                                         }
2618                                         type = TypeManager.bool_type;
2619                                         return this;
2620                                 }
2621
2622                                 if (oper == Operator.BitwiseAnd ||
2623                                     oper == Operator.BitwiseOr ||
2624                                     oper == Operator.ExclusiveOr){
2625                                         if (left.Type != right.Type){
2626                                                 Error_OperatorCannotBeApplied ();
2627                                                 return null;
2628                                         }
2629                                         type = l;
2630                                         return this;
2631                                 }
2632                                 Error_OperatorCannotBeApplied ();
2633                                 return null;
2634                         }
2635
2636                         if (oper == Operator.LeftShift || oper == Operator.RightShift)
2637                                 return CheckShiftArguments (ec);
2638
2639                         if (oper == Operator.LogicalOr || oper == Operator.LogicalAnd){
2640                                 if (l == TypeManager.bool_type && r == TypeManager.bool_type) {
2641                                         type = TypeManager.bool_type;
2642                                         return this;
2643                                 }
2644
2645                                 if (l != r) {
2646                                         Error_OperatorCannotBeApplied ();
2647                                         return null;
2648                                 }
2649
2650                                 Expression e = new ConditionalLogicalOperator (
2651                                         oper == Operator.LogicalAnd, left, right, l, loc);
2652                                 return e.Resolve (ec);
2653                         }
2654
2655                         //
2656                         // operator & (bool x, bool y)
2657                         // operator | (bool x, bool y)
2658                         // operator ^ (bool x, bool y)
2659                         //
2660                         if (l == TypeManager.bool_type && r == TypeManager.bool_type){
2661                                 if (oper == Operator.BitwiseAnd ||
2662                                     oper == Operator.BitwiseOr ||
2663                                     oper == Operator.ExclusiveOr){
2664                                         type = l;
2665                                         return this;
2666                                 }
2667                         }
2668
2669                         //
2670                         // Pointer comparison
2671                         //
2672                         if (l.IsPointer && r.IsPointer){
2673                                 if (oper == Operator.Equality || oper == Operator.Inequality ||
2674                                     oper == Operator.LessThan || oper == Operator.LessThanOrEqual ||
2675                                     oper == Operator.GreaterThan || oper == Operator.GreaterThanOrEqual){
2676                                         type = TypeManager.bool_type;
2677                                         return this;
2678                                 }
2679                         }
2680
2681                         //
2682                         // This will leave left or right set to null if there is an error
2683                         //
2684                         bool check_user_conv = is_user_defined (l) && is_user_defined (r);
2685                         DoNumericPromotions (ec, l, r, check_user_conv);
2686                         if (left == null || right == null){
2687                                 Error_OperatorCannotBeApplied (loc, OperName (oper), l, r);
2688                                 return null;
2689                         }
2690
2691                         //
2692                         // reload our cached types if required
2693                         //
2694                         l = left.Type;
2695                         r = right.Type;
2696
2697                         if (oper == Operator.BitwiseAnd ||
2698                             oper == Operator.BitwiseOr ||
2699                             oper == Operator.ExclusiveOr){
2700                                 if (l == r){
2701                                         if (((l == TypeManager.int32_type) ||
2702                                              (l == TypeManager.uint32_type) ||
2703                                              (l == TypeManager.short_type) ||
2704                                              (l == TypeManager.ushort_type) ||
2705                                              (l == TypeManager.int64_type) ||
2706                                              (l == TypeManager.uint64_type))){
2707                                                 type = l;
2708                                         } else {
2709                                                 Error_OperatorCannotBeApplied ();
2710                                                 return null;
2711                                         }
2712                                 } else {
2713                                         Error_OperatorCannotBeApplied ();
2714                                         return null;
2715                                 }
2716                         }
2717
2718                         if (oper == Operator.Equality ||
2719                             oper == Operator.Inequality ||
2720                             oper == Operator.LessThanOrEqual ||
2721                             oper == Operator.LessThan ||
2722                             oper == Operator.GreaterThanOrEqual ||
2723                             oper == Operator.GreaterThan){
2724                                 type = TypeManager.bool_type;
2725                         }
2726
2727                         return this;
2728                 }
2729
2730                 public override Expression DoResolve (EmitContext ec)
2731                 {
2732                         if ((oper == Operator.Subtraction) && (left is ParenthesizedExpression)) {
2733                                 left = ((ParenthesizedExpression) left).Expr;
2734                                 left = left.Resolve (ec, ResolveFlags.VariableOrValue | ResolveFlags.Type);
2735                                 if (left == null)
2736                                         return null;
2737
2738                                 if (left.eclass == ExprClass.Type) {
2739                                         Error (75, "Casting a negative value needs to have the value in parentheses.");
2740                                         return null;
2741                                 }
2742                         } else
2743                                 left = left.Resolve (ec);
2744
2745                         if (left == null)
2746                                 return null;
2747
2748                         Constant lc = left as Constant;
2749                         if (lc != null && lc.Type == TypeManager.bool_type &&
2750                                 ((oper == Operator.LogicalAnd && (bool)lc.GetValue () == false) ||
2751                                  (oper == Operator.LogicalOr && (bool)lc.GetValue () == true))) {
2752
2753                                 // TODO: make a sense to resolve unreachable expression as we do for statement
2754                                 Report.Warning (429, 4, loc, "Unreachable expression code detected");
2755                                 return left;
2756                         }
2757
2758                         right = right.Resolve (ec);
2759                         if (right == null)
2760                                 return null;
2761
2762                         eclass = ExprClass.Value;
2763
2764                         Constant rc = right as Constant;
2765                         if (rc != null & lc != null){
2766                                 Expression e = ConstantFold.BinaryFold (
2767                                         ec, oper, lc, rc, loc);
2768                                         if (e != null)
2769                                                 return e;
2770                         }
2771
2772                         if (TypeManager.IsNullableType (left.Type) || TypeManager.IsNullableType (right.Type))
2773                                 return new Nullable.LiftedBinaryOperator (oper, left, right, loc).Resolve (ec);
2774
2775                         return ResolveOperator (ec);
2776                 }
2777
2778                 /// <remarks>
2779                 ///   EmitBranchable is called from Statement.EmitBoolExpression in the
2780                 ///   context of a conditional bool expression.  This function will return
2781                 ///   false if it is was possible to use EmitBranchable, or true if it was.
2782                 ///
2783                 ///   The expression's code is generated, and we will generate a branch to `target'
2784                 ///   if the resulting expression value is equal to isTrue
2785                 /// </remarks>
2786                 public override void EmitBranchable (EmitContext ec, Label target, bool onTrue)
2787                 {
2788                         ILGenerator ig = ec.ig;
2789
2790                         //
2791                         // This is more complicated than it looks, but its just to avoid
2792                         // duplicated tests: basically, we allow ==, !=, >, <, >= and <=
2793                         // but on top of that we want for == and != to use a special path
2794                         // if we are comparing against null
2795                         //
2796                         if ((oper == Operator.Equality || oper == Operator.Inequality) && (left is Constant || right is Constant)) {
2797                                 bool my_on_true = oper == Operator.Inequality ? onTrue : !onTrue;
2798
2799                                 //
2800                                 // put the constant on the rhs, for simplicity
2801                                 //
2802                                 if (left is Constant) {
2803                                         Expression swap = right;
2804                                         right = left;
2805                                         left = swap;
2806                                 }
2807
2808                                 if (((Constant) right).IsZeroInteger) {
2809                                         left.Emit (ec);
2810                                         if (my_on_true)
2811                                                 ig.Emit (OpCodes.Brtrue, target);
2812                                         else
2813                                                 ig.Emit (OpCodes.Brfalse, target);
2814
2815                                         return;
2816                                 } else if (right is BoolConstant){
2817                                         left.Emit (ec);
2818                                         if (my_on_true != ((BoolConstant) right).Value)
2819                                                 ig.Emit (OpCodes.Brtrue, target);
2820                                         else
2821                                                 ig.Emit (OpCodes.Brfalse, target);
2822
2823                                         return;
2824                                 }
2825
2826                         } else if (oper == Operator.LogicalAnd) {
2827
2828                                 if (onTrue) {
2829                                                 Label tests_end = ig.DefineLabel ();
2830
2831                                         left.EmitBranchable (ec, tests_end, false);
2832                                         right.EmitBranchable (ec, target, true);
2833                                                         ig.MarkLabel (tests_end);
2834                                         } else {
2835                                         left.EmitBranchable (ec, target, false);
2836                                         right.EmitBranchable (ec, target, false);
2837                                         }
2838
2839                                 return;
2840
2841                         } else if (oper == Operator.LogicalOr){
2842                                 if (onTrue) {
2843                                         left.EmitBranchable (ec, target, true);
2844                                         right.EmitBranchable (ec, target, true);
2845
2846                                         } else {
2847                                                 Label tests_end = ig.DefineLabel ();
2848                                         left.EmitBranchable (ec, tests_end, true);
2849                                         right.EmitBranchable (ec, target, false);
2850                                         ig.MarkLabel (tests_end);
2851                                 }
2852
2853                                 return;
2854
2855                         } else if (!(oper == Operator.LessThan        || oper == Operator.GreaterThan ||
2856                                      oper == Operator.LessThanOrEqual || oper == Operator.GreaterThanOrEqual ||
2857                                      oper == Operator.Equality        || oper == Operator.Inequality)) {
2858                                 base.EmitBranchable (ec, target, onTrue);
2859                                 return;
2860                                 }
2861
2862                         left.Emit (ec);
2863                         right.Emit (ec);
2864
2865                         Type t = left.Type;
2866                         bool isUnsigned = is_unsigned (t) || t == TypeManager.double_type || t == TypeManager.float_type;
2867
2868                         switch (oper){
2869                         case Operator.Equality:
2870                                 if (onTrue)
2871                                         ig.Emit (OpCodes.Beq, target);
2872                                 else
2873                                         ig.Emit (OpCodes.Bne_Un, target);
2874                                 break;
2875
2876                         case Operator.Inequality:
2877                                 if (onTrue)
2878                                         ig.Emit (OpCodes.Bne_Un, target);
2879                                 else
2880                                         ig.Emit (OpCodes.Beq, target);
2881                                 break;
2882
2883                         case Operator.LessThan:
2884                                 if (onTrue)
2885                                         if (isUnsigned)
2886                                                 ig.Emit (OpCodes.Blt_Un, target);
2887                                         else
2888                                                 ig.Emit (OpCodes.Blt, target);
2889                                 else
2890                                         if (isUnsigned)
2891                                                 ig.Emit (OpCodes.Bge_Un, target);
2892                                         else
2893                                                 ig.Emit (OpCodes.Bge, target);
2894                                 break;
2895
2896                         case Operator.GreaterThan:
2897                                 if (onTrue)
2898                                         if (isUnsigned)
2899                                                 ig.Emit (OpCodes.Bgt_Un, target);
2900                                         else
2901                                                 ig.Emit (OpCodes.Bgt, target);
2902                                 else
2903                                         if (isUnsigned)
2904                                                 ig.Emit (OpCodes.Ble_Un, target);
2905                                         else
2906                                                 ig.Emit (OpCodes.Ble, target);
2907                                 break;
2908
2909                         case Operator.LessThanOrEqual:
2910                                 if (onTrue)
2911                                         if (isUnsigned)
2912                                                 ig.Emit (OpCodes.Ble_Un, target);
2913                                         else
2914                                                 ig.Emit (OpCodes.Ble, target);
2915                                 else
2916                                         if (isUnsigned)
2917                                                 ig.Emit (OpCodes.Bgt_Un, target);
2918                                         else
2919                                                 ig.Emit (OpCodes.Bgt, target);
2920                                 break;
2921
2922
2923                         case Operator.GreaterThanOrEqual:
2924                                 if (onTrue)
2925                                         if (isUnsigned)
2926                                                 ig.Emit (OpCodes.Bge_Un, target);
2927                                         else
2928                                                 ig.Emit (OpCodes.Bge, target);
2929                                 else
2930                                         if (isUnsigned)
2931                                                 ig.Emit (OpCodes.Blt_Un, target);
2932                                         else
2933                                                 ig.Emit (OpCodes.Blt, target);
2934                                 break;
2935                         default:
2936                                 Console.WriteLine (oper);
2937                                 throw new Exception ("what is THAT");
2938                         }
2939                 }
2940
2941                 public override void Emit (EmitContext ec)
2942                 {
2943                         ILGenerator ig = ec.ig;
2944                         Type l = left.Type;
2945                         OpCode opcode;
2946
2947                         //
2948                         // Handle short-circuit operators differently
2949                         // than the rest
2950                         //
2951                         if (oper == Operator.LogicalAnd) {
2952                                 Label load_zero = ig.DefineLabel ();
2953                                 Label end = ig.DefineLabel ();
2954
2955                                 left.EmitBranchable (ec, load_zero, false);
2956                                                 right.Emit (ec);
2957                                                 ig.Emit (OpCodes.Br, end);
2958
2959                                 ig.MarkLabel (load_zero);
2960                                 ig.Emit (OpCodes.Ldc_I4_0);
2961                                 ig.MarkLabel (end);
2962                                 return;
2963                         } else if (oper == Operator.LogicalOr) {
2964                                 Label load_one = ig.DefineLabel ();
2965                                 Label end = ig.DefineLabel ();
2966
2967                                 left.EmitBranchable (ec, load_one, true);
2968                                                 right.Emit (ec);
2969                                                 ig.Emit (OpCodes.Br, end);
2970
2971                                 ig.MarkLabel (load_one);
2972                                 ig.Emit (OpCodes.Ldc_I4_1);
2973                                 ig.MarkLabel (end);
2974                                 return;
2975                         }
2976
2977                         left.Emit (ec);
2978                         right.Emit (ec);
2979
2980                         bool isUnsigned = is_unsigned (left.Type);
2981
2982                         switch (oper){
2983                         case Operator.Multiply:
2984                                 if (ec.CheckState){
2985                                         if (l == TypeManager.int32_type || l == TypeManager.int64_type)
2986                                                 opcode = OpCodes.Mul_Ovf;
2987                                         else if (isUnsigned)
2988                                                 opcode = OpCodes.Mul_Ovf_Un;
2989                                         else
2990                                                 opcode = OpCodes.Mul;
2991                                 } else
2992                                         opcode = OpCodes.Mul;
2993
2994                                 break;
2995
2996                         case Operator.Division:
2997                                 if (isUnsigned)
2998                                         opcode = OpCodes.Div_Un;
2999                                 else
3000                                         opcode = OpCodes.Div;
3001                                 break;
3002
3003                         case Operator.Modulus:
3004                                 if (isUnsigned)
3005                                         opcode = OpCodes.Rem_Un;
3006                                 else
3007                                         opcode = OpCodes.Rem;
3008                                 break;
3009
3010                         case Operator.Addition:
3011                                 if (ec.CheckState){
3012                                         if (l == TypeManager.int32_type || l == TypeManager.int64_type)
3013                                                 opcode = OpCodes.Add_Ovf;
3014                                         else if (isUnsigned)
3015                                                 opcode = OpCodes.Add_Ovf_Un;
3016                                         else
3017                                                 opcode = OpCodes.Add;
3018                                 } else
3019                                         opcode = OpCodes.Add;
3020                                 break;
3021
3022                         case Operator.Subtraction:
3023                                 if (ec.CheckState){
3024                                         if (l == TypeManager.int32_type || l == TypeManager.int64_type)
3025                                                 opcode = OpCodes.Sub_Ovf;
3026                                         else if (isUnsigned)
3027                                                 opcode = OpCodes.Sub_Ovf_Un;
3028                                         else
3029                                                 opcode = OpCodes.Sub;
3030                                 } else
3031                                         opcode = OpCodes.Sub;
3032                                 break;
3033
3034                         case Operator.RightShift:
3035                                 if (isUnsigned)
3036                                         opcode = OpCodes.Shr_Un;
3037                                 else
3038                                         opcode = OpCodes.Shr;
3039                                 break;
3040
3041                         case Operator.LeftShift:
3042                                 opcode = OpCodes.Shl;
3043                                 break;
3044
3045                         case Operator.Equality:
3046                                 opcode = OpCodes.Ceq;
3047                                 break;
3048
3049                         case Operator.Inequality:
3050                                 ig.Emit (OpCodes.Ceq);
3051                                 ig.Emit (OpCodes.Ldc_I4_0);
3052
3053                                 opcode = OpCodes.Ceq;
3054                                 break;
3055
3056                         case Operator.LessThan:
3057                                 if (isUnsigned)
3058                                         opcode = OpCodes.Clt_Un;
3059                                 else
3060                                         opcode = OpCodes.Clt;
3061                                 break;
3062
3063                         case Operator.GreaterThan:
3064                                 if (isUnsigned)
3065                                         opcode = OpCodes.Cgt_Un;
3066                                 else
3067                                         opcode = OpCodes.Cgt;
3068                                 break;
3069
3070                         case Operator.LessThanOrEqual:
3071                                 Type lt = left.Type;
3072
3073                                 if (isUnsigned || (lt == TypeManager.double_type || lt == TypeManager.float_type))
3074                                         ig.Emit (OpCodes.Cgt_Un);
3075                                 else
3076                                         ig.Emit (OpCodes.Cgt);
3077                                 ig.Emit (OpCodes.Ldc_I4_0);
3078
3079                                 opcode = OpCodes.Ceq;
3080                                 break;
3081
3082                         case Operator.GreaterThanOrEqual:
3083                                 Type le = left.Type;
3084
3085                                 if (isUnsigned || (le == TypeManager.double_type || le == TypeManager.float_type))
3086                                         ig.Emit (OpCodes.Clt_Un);
3087                                 else
3088                                         ig.Emit (OpCodes.Clt);
3089
3090                                 ig.Emit (OpCodes.Ldc_I4_0);
3091
3092                                 opcode = OpCodes.Ceq;
3093                                 break;
3094
3095                         case Operator.BitwiseOr:
3096                                 opcode = OpCodes.Or;
3097                                 break;
3098
3099                         case Operator.BitwiseAnd:
3100                                 opcode = OpCodes.And;
3101                                 break;
3102
3103                         case Operator.ExclusiveOr:
3104                                 opcode = OpCodes.Xor;
3105                                 break;
3106
3107                         default:
3108                                 throw new Exception ("This should not happen: Operator = "
3109                                                      + oper.ToString ());
3110                         }
3111
3112                         ig.Emit (opcode);
3113                 }
3114         }
3115
3116         //
3117         // Object created by Binary when the binary operator uses an method instead of being
3118         // a binary operation that maps to a CIL binary operation.
3119         //
3120         public class BinaryMethod : Expression {
3121                 public MethodBase method;
3122                 public ArrayList  Arguments;
3123
3124                 public BinaryMethod (Type t, MethodBase m, ArrayList args)
3125                 {
3126                         method = m;
3127                         Arguments = args;
3128                         type = t;
3129                         eclass = ExprClass.Value;
3130                 }
3131
3132                 public override Expression DoResolve (EmitContext ec)
3133                 {
3134                         return this;
3135                 }
3136
3137                 public override void Emit (EmitContext ec)
3138                 {
3139                         ILGenerator ig = ec.ig;
3140
3141                         if (Arguments != null)
3142                                 Invocation.EmitArguments (ec, method, Arguments, false, null);
3143
3144                         if (method is MethodInfo)
3145                                 ig.Emit (OpCodes.Call, (MethodInfo) method);
3146                         else
3147                                 ig.Emit (OpCodes.Call, (ConstructorInfo) method);
3148                 }
3149         }
3150
3151         //
3152         // Represents the operation a + b [+ c [+ d [+ ...]]], where a is a string
3153         // b, c, d... may be strings or objects.
3154         //
3155         public class StringConcat : Expression {
3156                 ArrayList operands;
3157                 bool invalid = false;
3158                 bool emit_conv_done = false;
3159                 //
3160                 // Are we also concating objects?
3161                 //
3162                 bool is_strings_only = true;
3163
3164                 public StringConcat (EmitContext ec, Location loc, Expression left, Expression right)
3165                 {
3166                         this.loc = loc;
3167                         type = TypeManager.string_type;
3168                         eclass = ExprClass.Value;
3169
3170                         operands = new ArrayList (2);
3171                         Append (ec, left);
3172                         Append (ec, right);
3173                 }
3174
3175                 public override Expression DoResolve (EmitContext ec)
3176                 {
3177                         if (invalid)
3178                                 return null;
3179
3180                         return this;
3181                 }
3182
3183                 public void Append (EmitContext ec, Expression operand)
3184                 {
3185                         //
3186                         // Constant folding
3187                         //
3188                         if (operand is StringConstant && operands.Count != 0) {
3189                                 StringConstant last_operand = operands [operands.Count - 1] as StringConstant;
3190                                 if (last_operand != null) {
3191                                         operands [operands.Count - 1] = new StringConstant (last_operand.Value + ((StringConstant) operand).Value);
3192                                         return;
3193                                 }
3194                         }
3195
3196                         //
3197                         // Conversion to object
3198                         //
3199                         if (operand.Type != TypeManager.string_type) {
3200                                 Expression no = Convert.ImplicitConversion (ec, operand, TypeManager.object_type, loc);
3201
3202                                 if (no == null) {
3203                                         Binary.Error_OperatorCannotBeApplied (loc, "+", TypeManager.string_type, operand.Type);
3204                                         invalid = true;
3205                                 }
3206                                 operand = no;
3207                         }
3208
3209                         operands.Add (operand);
3210                 }
3211
3212                 public override void Emit (EmitContext ec)
3213                 {
3214                         MethodInfo concat_method = null;
3215
3216                         //
3217                         // Do conversion to arguments; check for strings only
3218                         //
3219
3220                         // This can get called multiple times, so we have to deal with that.
3221                         if (!emit_conv_done) {
3222                                 emit_conv_done = true;
3223                         for (int i = 0; i < operands.Count; i ++) {
3224                                 Expression e = (Expression) operands [i];
3225                                 is_strings_only &= e.Type == TypeManager.string_type;
3226                         }
3227
3228                         for (int i = 0; i < operands.Count; i ++) {
3229                                 Expression e = (Expression) operands [i];
3230
3231                                 if (! is_strings_only && e.Type == TypeManager.string_type) {
3232                                         // need to make sure this is an object, because the EmitParams
3233                                         // method might look at the type of this expression, see it is a
3234                                         // string and emit a string [] when we want an object [];
3235
3236                                                 e = new EmptyCast (e, TypeManager.object_type);
3237                                 }
3238                                 operands [i] = new Argument (e, Argument.AType.Expression);
3239                         }
3240                         }
3241
3242                         //
3243                         // Find the right method
3244                         //
3245                         switch (operands.Count) {
3246                         case 1:
3247                                 //
3248                                 // This should not be possible, because simple constant folding
3249                                 // is taken care of in the Binary code.
3250                                 //
3251                                 throw new Exception ("how did you get here?");
3252
3253                         case 2:
3254                                 concat_method = is_strings_only ?
3255                                         TypeManager.string_concat_string_string :
3256                                         TypeManager.string_concat_object_object ;
3257                                 break;
3258                         case 3:
3259                                 concat_method = is_strings_only ?
3260                                         TypeManager.string_concat_string_string_string :
3261                                         TypeManager.string_concat_object_object_object ;
3262                                 break;
3263                         case 4:
3264                                 //
3265                                 // There is not a 4 param overlaod for object (the one that there is
3266                                 // is actually a varargs methods, and is only in corlib because it was
3267                                 // introduced there before.).
3268                                 //
3269                                 if (!is_strings_only)
3270                                         goto default;
3271
3272                                 concat_method = TypeManager.string_concat_string_string_string_string;
3273                                 break;
3274                         default:
3275                                 concat_method = is_strings_only ?
3276                                         TypeManager.string_concat_string_dot_dot_dot :
3277                                         TypeManager.string_concat_object_dot_dot_dot ;
3278                                 break;
3279                         }
3280
3281                         Invocation.EmitArguments (ec, concat_method, operands, false, null);
3282                         ec.ig.Emit (OpCodes.Call, concat_method);
3283                 }
3284         }
3285
3286         //
3287         // Object created with +/= on delegates
3288         //
3289         public class BinaryDelegate : Expression {
3290                 MethodInfo method;
3291                 ArrayList  args;
3292
3293                 public BinaryDelegate (Type t, MethodInfo mi, ArrayList args)
3294                 {
3295                         method = mi;
3296                         this.args = args;
3297                         type = t;
3298                         eclass = ExprClass.Value;
3299                 }
3300
3301                 public override Expression DoResolve (EmitContext ec)
3302                 {
3303                         return this;
3304                 }
3305
3306                 public override void Emit (EmitContext ec)
3307                 {
3308                         ILGenerator ig = ec.ig;
3309
3310                         Invocation.EmitArguments (ec, method, args, false, null);
3311
3312                         ig.Emit (OpCodes.Call, (MethodInfo) method);
3313                         ig.Emit (OpCodes.Castclass, type);
3314                 }
3315
3316                 public Expression Right {
3317                         get {
3318                                 Argument arg = (Argument) args [1];
3319                                 return arg.Expr;
3320                         }
3321                 }
3322
3323                 public bool IsAddition {
3324                         get {
3325                                 return method == TypeManager.delegate_combine_delegate_delegate;
3326                         }
3327                 }
3328         }
3329
3330         //
3331         // User-defined conditional logical operator
3332         public class ConditionalLogicalOperator : Expression {
3333                 Expression left, right;
3334                 bool is_and;
3335
3336                 public ConditionalLogicalOperator (bool is_and, Expression left, Expression right, Type t, Location loc)
3337                 {
3338                         type = t;
3339                         eclass = ExprClass.Value;
3340                         this.loc = loc;
3341                         this.left = left;
3342                         this.right = right;
3343                         this.is_and = is_and;
3344                 }
3345
3346                 protected void Error19 ()
3347                 {
3348                         Binary.Error_OperatorCannotBeApplied (loc, is_and ? "&&" : "||", type, type);
3349                 }
3350
3351                 protected void Error218 ()
3352                 {
3353                         Error (218, "The type ('" + TypeManager.CSharpName (type) + "') must contain " +
3354                                "declarations of operator true and operator false");
3355                 }
3356
3357                 Expression op_true, op_false, op;
3358                 LocalTemporary left_temp;
3359
3360                 public override Expression DoResolve (EmitContext ec)
3361                 {
3362                         MethodInfo method;
3363                         Expression operator_group;
3364
3365                         operator_group = MethodLookup (ec, type, is_and ? "op_BitwiseAnd" : "op_BitwiseOr", loc);
3366                         if (operator_group == null) {
3367                                 Error19 ();
3368                                 return null;
3369                         }
3370
3371                         left_temp = new LocalTemporary (ec, type);
3372
3373                         ArrayList arguments = new ArrayList ();
3374                         arguments.Add (new Argument (left_temp, Argument.AType.Expression));
3375                         arguments.Add (new Argument (right, Argument.AType.Expression));
3376                         method = Invocation.OverloadResolve (
3377                                 ec, (MethodGroupExpr) operator_group, arguments, false, loc)
3378                                 as MethodInfo;
3379                         if (method == null) {
3380                                 Error19 ();
3381                                 return null;
3382                         }
3383
3384                         if (method.ReturnType != type) {
3385                                 Report.Error (217, loc, "In order to be applicable as a short circuit operator a user-defined logical operator ('{0}') " +
3386                                                 "must have the same return type as the type of its 2 parameters", TypeManager.CSharpSignature (method));
3387                                 return null;
3388                         }
3389
3390                         op = new StaticCallExpr (method, arguments, loc);
3391
3392                         op_true = GetOperatorTrue (ec, left_temp, loc);
3393                         op_false = GetOperatorFalse (ec, left_temp, loc);
3394                         if ((op_true == null) || (op_false == null)) {
3395                                 Error218 ();
3396                                 return null;
3397                         }
3398
3399                         return this;
3400                 }
3401
3402                 public override void Emit (EmitContext ec)
3403                 {
3404                         ILGenerator ig = ec.ig;
3405                         Label false_target = ig.DefineLabel ();
3406                         Label end_target = ig.DefineLabel ();
3407
3408                         left.Emit (ec);
3409                         left_temp.Store (ec);
3410
3411                         (is_and ? op_false : op_true).EmitBranchable (ec, false_target, false);
3412                         left_temp.Emit (ec);
3413                         ig.Emit (OpCodes.Br, end_target);
3414                         ig.MarkLabel (false_target);
3415                         op.Emit (ec);
3416                         ig.MarkLabel (end_target);
3417                 }
3418         }
3419
3420         public class PointerArithmetic : Expression {
3421                 Expression left, right;
3422                 bool is_add;
3423
3424                 //
3425                 // We assume that `l' is always a pointer
3426                 //
3427                 public PointerArithmetic (bool is_addition, Expression l, Expression r, Type t, Location loc)
3428                 {
3429                         type = t;
3430                         this.loc = loc;
3431                         left = l;
3432                         right = r;
3433                         is_add = is_addition;
3434                 }
3435
3436                 public override Expression DoResolve (EmitContext ec)
3437                 {
3438                         eclass = ExprClass.Variable;
3439
3440                         if (left.Type == TypeManager.void_ptr_type) {
3441                                 Error (242, "The operation in question is undefined on void pointers");
3442                                 return null;
3443                         }
3444
3445                         return this;
3446                 }
3447
3448                 public override void Emit (EmitContext ec)
3449                 {
3450                         Type op_type = left.Type;
3451                         ILGenerator ig = ec.ig;
3452
3453                         // It must be either array or fixed buffer
3454                         Type element = TypeManager.HasElementType (op_type) ?
3455                                 element = TypeManager.GetElementType (op_type) :
3456                                 element = AttributeTester.GetFixedBuffer (((FieldExpr)left).FieldInfo).ElementType;
3457
3458                         int size = GetTypeSize (element);
3459                         Type rtype = right.Type;
3460
3461                         if (rtype.IsPointer){
3462                                 //
3463                                 // handle (pointer - pointer)
3464                                 //
3465                                 left.Emit (ec);
3466                                 right.Emit (ec);
3467                                 ig.Emit (OpCodes.Sub);
3468
3469                                 if (size != 1){
3470                                         if (size == 0)
3471                                                 ig.Emit (OpCodes.Sizeof, element);
3472                                         else
3473                                                 IntLiteral.EmitInt (ig, size);
3474                                         ig.Emit (OpCodes.Div);
3475                                 }
3476                                 ig.Emit (OpCodes.Conv_I8);
3477                         } else {
3478                                 //
3479                                 // handle + and - on (pointer op int)
3480                                 //
3481                                 left.Emit (ec);
3482                                 ig.Emit (OpCodes.Conv_I);
3483
3484                                 Constant right_const = right as Constant;
3485                                 if (right_const != null && size != 0) {
3486                                         Expression ex = ConstantFold.BinaryFold (ec, Binary.Operator.Multiply, new IntConstant (size), right_const, loc);
3487                                         if (ex == null)
3488                                                 return;
3489                                         ex.Emit (ec);
3490                                 } else {
3491                                         right.Emit (ec);
3492                                         if (size != 1){
3493                                                 if (size == 0)
3494                                                         ig.Emit (OpCodes.Sizeof, element);
3495                                                 else
3496                                                         IntLiteral.EmitInt (ig, size);
3497                                                 if (rtype == TypeManager.int64_type)
3498                                                         ig.Emit (OpCodes.Conv_I8);
3499                                                 else if (rtype == TypeManager.uint64_type)
3500                                                         ig.Emit (OpCodes.Conv_U8);
3501                                                 ig.Emit (OpCodes.Mul);
3502                                         }
3503                                 }
3504
3505                                 if (rtype == TypeManager.int64_type || rtype == TypeManager.uint64_type)
3506                                         ig.Emit (OpCodes.Conv_I);
3507
3508                                 if (is_add)
3509                                         ig.Emit (OpCodes.Add);
3510                                 else
3511                                         ig.Emit (OpCodes.Sub);
3512                         }
3513                 }
3514         }
3515
3516         /// <summary>
3517         ///   Implements the ternary conditional operator (?:)
3518         /// </summary>
3519         public class Conditional : Expression {
3520                 Expression expr, trueExpr, falseExpr;
3521
3522                 public Conditional (Expression expr, Expression trueExpr, Expression falseExpr, Location l)
3523                 {
3524                         this.expr = expr;
3525                         this.trueExpr = trueExpr;
3526                         this.falseExpr = falseExpr;
3527                         this.loc = l;
3528                 }
3529
3530                 public Expression Expr {
3531                         get {
3532                                 return expr;
3533                         }
3534                 }
3535
3536                 public Expression TrueExpr {
3537                         get {
3538                                 return trueExpr;
3539                         }
3540                 }
3541
3542                 public Expression FalseExpr {
3543                         get {
3544                                 return falseExpr;
3545                         }
3546                 }
3547
3548                 public override Expression DoResolve (EmitContext ec)
3549                 {
3550                         expr = expr.Resolve (ec);
3551
3552                         if (expr == null)
3553                                 return null;
3554
3555                         if (TypeManager.IsNullableType (expr.Type))
3556                                 return new Nullable.LiftedConditional (expr, trueExpr, falseExpr, loc).Resolve (ec);
3557
3558                         if (expr.Type != TypeManager.bool_type){
3559                                 expr = Expression.ResolveBoolean (
3560                                         ec, expr, loc);
3561
3562                                 if (expr == null)
3563                                         return null;
3564                         }
3565
3566                         trueExpr = trueExpr.Resolve (ec);
3567                         falseExpr = falseExpr.Resolve (ec);
3568
3569                         if (trueExpr == null || falseExpr == null)
3570                                 return null;
3571
3572                         eclass = ExprClass.Value;
3573                         if (trueExpr.Type == falseExpr.Type)
3574                                 type = trueExpr.Type;
3575                         else {
3576                                 Expression conv;
3577                                 Type true_type = trueExpr.Type;
3578                                 Type false_type = falseExpr.Type;
3579
3580                                 //
3581                                 // First, if an implicit conversion exists from trueExpr
3582                                 // to falseExpr, then the result type is of type falseExpr.Type
3583                                 //
3584                                 conv = Convert.ImplicitConversion (ec, trueExpr, false_type, loc);
3585                                 if (conv != null){
3586                                         //
3587                                         // Check if both can convert implicitl to each other's type
3588                                         //
3589                                         if (Convert.ImplicitConversion (ec, falseExpr, true_type, loc) != null){
3590                                                 Error (172,
3591                                                        "Can not compute type of conditional expression " +
3592                                                        "as `" + TypeManager.CSharpName (trueExpr.Type) +
3593                                                        "' and `" + TypeManager.CSharpName (falseExpr.Type) +
3594                                                        "' convert implicitly to each other");
3595                                                 return null;
3596                                         }
3597                                         type = false_type;
3598                                         trueExpr = conv;
3599                                 } else if ((conv = Convert.ImplicitConversion(ec, falseExpr, true_type,loc))!= null){
3600                                         type = true_type;
3601                                         falseExpr = conv;
3602                                 } else {
3603                                         Error (173, "The type of the conditional expression can " +
3604                                                "not be computed because there is no implicit conversion" +
3605                                                " from `" + TypeManager.CSharpName (trueExpr.Type) + "'" +
3606                                                " and `" + TypeManager.CSharpName (falseExpr.Type) + "'");
3607                                         return null;
3608                                 }
3609                         }
3610
3611                         // Dead code optimalization
3612                         if (expr is BoolConstant){
3613                                 BoolConstant bc = (BoolConstant) expr;
3614
3615                                 Report.Warning (429, 4, bc.Value ? falseExpr.Location : trueExpr.Location, "Unreachable expression code detected");
3616                                 return bc.Value ? trueExpr : falseExpr;
3617                         }
3618
3619                         return this;
3620                 }
3621
3622                 public override void Emit (EmitContext ec)
3623                 {
3624                         ILGenerator ig = ec.ig;
3625                         Label false_target = ig.DefineLabel ();
3626                         Label end_target = ig.DefineLabel ();
3627
3628                         expr.EmitBranchable (ec, false_target, false);
3629                         trueExpr.Emit (ec);
3630                         ig.Emit (OpCodes.Br, end_target);
3631                         ig.MarkLabel (false_target);
3632                         falseExpr.Emit (ec);
3633                         ig.MarkLabel (end_target);
3634                 }
3635
3636         }
3637
3638         /// <summary>
3639         ///   Local variables
3640         /// </summary>
3641         public class LocalVariableReference : Expression, IAssignMethod, IMemoryLocation, IVariable {
3642                 public readonly string Name;
3643                 public readonly Block Block;
3644                 public LocalInfo local_info;
3645                 bool is_readonly;
3646                 bool prepared;
3647                 LocalTemporary temp;
3648
3649                 public LocalVariableReference (Block block, string name, Location l)
3650                 {
3651                         Block = block;
3652                         Name = name;
3653                         loc = l;
3654                         eclass = ExprClass.Variable;
3655                 }
3656
3657                 //
3658                 // Setting `is_readonly' to false will allow you to create a writable
3659                 // reference to a read-only variable.  This is used by foreach and using.
3660                 //
3661                 public LocalVariableReference (Block block, string name, Location l,
3662                                                LocalInfo local_info, bool is_readonly)
3663                         : this (block, name, l)
3664                 {
3665                         this.local_info = local_info;
3666                         this.is_readonly = is_readonly;
3667                 }
3668
3669                 public VariableInfo VariableInfo {
3670                         get {
3671                                 return local_info.VariableInfo;
3672                         }
3673                 }
3674
3675                 public bool IsReadOnly {
3676                         get {
3677                                 return is_readonly;
3678                         }
3679                 }
3680
3681                 protected Expression DoResolveBase (EmitContext ec, Expression lvalue_right_side)
3682                 {
3683                         if (local_info == null) {
3684                                 local_info = Block.GetLocalInfo (Name);
3685
3686                                 // is out param
3687                                 if (lvalue_right_side == EmptyExpression.Null)
3688                                         local_info.Used = true;
3689
3690                                 is_readonly = local_info.ReadOnly;
3691                         }
3692
3693                         type = local_info.VariableType;
3694
3695                         VariableInfo variable_info = local_info.VariableInfo;
3696                         if (lvalue_right_side != null){
3697                                 if (is_readonly){
3698                                         Error (1604, "cannot assign to `" + Name + "' because it is readonly");
3699                                         return null;
3700                                 }
3701
3702                                 if (variable_info != null)
3703                                         variable_info.SetAssigned (ec);
3704                 }
3705
3706                         Expression e = Block.GetConstantExpression (Name);
3707                         if (e != null) {
3708                                 local_info.Used = true;
3709                                 eclass = ExprClass.Value;
3710                                 return e.Resolve (ec);
3711                         }
3712
3713                         if ((variable_info != null) && !variable_info.IsAssigned (ec, loc))
3714                                 return null;
3715
3716                         if (lvalue_right_side == null)
3717                                 local_info.Used = true;
3718
3719                         if (ec.CurrentAnonymousMethod != null){
3720                                 //
3721                                 // If we are referencing a variable from the external block
3722                                 // flag it for capturing
3723                                 //
3724                                 if (local_info.Block.Toplevel != ec.CurrentBlock.Toplevel){
3725                                         if (local_info.AddressTaken){
3726                                                 AnonymousMethod.Error_AddressOfCapturedVar (local_info.Name, loc);
3727                                                 return null;
3728                                         }
3729                                         ec.CaptureVariable (local_info);
3730                                 }
3731                         }
3732
3733                         return this;
3734                 }
3735
3736                 public override Expression DoResolve (EmitContext ec)
3737                 {
3738                         return DoResolveBase (ec, null);
3739                 }
3740
3741                 override public Expression DoResolveLValue (EmitContext ec, Expression right_side)
3742                 {
3743                         Expression ret = DoResolveBase (ec, right_side);
3744                         if (ret != null)
3745                                 CheckObsoleteAttribute (ret.Type);
3746
3747                         return ret;
3748                 }
3749
3750                 public bool VerifyFixed (bool is_expression)
3751                 {
3752                         return !is_expression || local_info.IsFixed;
3753                 }
3754
3755                 public override int GetHashCode()
3756                 {
3757                         return Name.GetHashCode ();
3758                 }
3759
3760                 public override bool Equals (object obj)
3761                 {
3762                         LocalVariableReference lvr = obj as LocalVariableReference;
3763                         if (lvr == null)
3764                                 return false;
3765
3766                         return Name == lvr.Name && Block == lvr.Block;
3767                 }
3768
3769                 public override void Emit (EmitContext ec)
3770                 {
3771                         ILGenerator ig = ec.ig;
3772
3773                         if (local_info.FieldBuilder == null){
3774                                 //
3775                                 // A local variable on the local CLR stack
3776                                 //
3777                         ig.Emit (OpCodes.Ldloc, local_info.LocalBuilder);
3778                         } else {
3779                                 //
3780                                 // A local variable captured by anonymous methods.
3781                                 //
3782                                 if (!prepared)
3783                                         ec.EmitCapturedVariableInstance (local_info);
3784
3785                                 ig.Emit (OpCodes.Ldfld, local_info.FieldBuilder);
3786                         }
3787                 }
3788
3789                 public void Emit (EmitContext ec, bool leave_copy)
3790                 {
3791                         Emit (ec);
3792                         if (leave_copy){
3793                                 ec.ig.Emit (OpCodes.Dup);
3794                                 if (local_info.FieldBuilder != null){
3795                                         temp = new LocalTemporary (ec, Type);
3796                                         temp.Store (ec);
3797                                 }
3798                         }
3799                 }
3800
3801                 public void EmitAssign (EmitContext ec, Expression source, bool leave_copy, bool prepare_for_load)
3802                 {
3803                         ILGenerator ig = ec.ig;
3804                         prepared = prepare_for_load;
3805
3806                         if (local_info.FieldBuilder == null){
3807                                 //
3808                                 // A local variable on the local CLR stack
3809                                 //
3810                                 if (local_info.LocalBuilder == null)
3811                                         throw new Exception ("This should not happen: both Field and Local are null");
3812
3813                         source.Emit (ec);
3814                         if (leave_copy)
3815                                 ec.ig.Emit (OpCodes.Dup);
3816                                 ig.Emit (OpCodes.Stloc, local_info.LocalBuilder);
3817                         } else {
3818                                 //
3819                                 // A local variable captured by anonymous methods or itereators.
3820                                 //
3821                                 ec.EmitCapturedVariableInstance (local_info);
3822
3823                                 if (prepare_for_load)
3824                                         ig.Emit (OpCodes.Dup);
3825                                 source.Emit (ec);
3826                                 if (leave_copy){
3827                                         ig.Emit (OpCodes.Dup);
3828                                         temp = new LocalTemporary (ec, Type);
3829                                         temp.Store (ec);
3830                                 }
3831                                 ig.Emit (OpCodes.Stfld, local_info.FieldBuilder);
3832                                 if (temp != null)
3833                                         temp.Emit (ec);
3834                         }
3835                 }
3836
3837                 public void AddressOf (EmitContext ec, AddressOp mode)
3838                 {
3839                         ILGenerator ig = ec.ig;
3840
3841                         if (local_info.FieldBuilder == null){
3842                                 //
3843                                 // A local variable on the local CLR stack
3844                                 //
3845                         ig.Emit (OpCodes.Ldloca, local_info.LocalBuilder);
3846                         } else {
3847                                 //
3848                                 // A local variable captured by anonymous methods or iterators
3849                                 //
3850                                 ec.EmitCapturedVariableInstance (local_info);
3851                                 ig.Emit (OpCodes.Ldflda, local_info.FieldBuilder);
3852                         }
3853                 }
3854
3855                 public override string ToString ()
3856                 {
3857                         return String.Format ("{0} ({1}:{2})", GetType (), Name, loc);
3858                 }
3859         }
3860
3861         /// <summary>
3862         ///   This represents a reference to a parameter in the intermediate
3863         ///   representation.
3864         /// </summary>
3865         public class ParameterReference : Expression, IAssignMethod, IMemoryLocation, IVariable {
3866                 Parameters pars;
3867                 String name;
3868                 int idx;
3869                 Block block;
3870                 VariableInfo vi;
3871                 public Parameter.Modifier mod;
3872                 public bool is_ref, is_out, prepared;
3873
3874                 public bool IsOut {
3875                         get {
3876                                 return is_out;
3877                         }
3878                 }
3879
3880                 public bool IsRef {
3881                         get {
3882                                 return is_ref;
3883                         }
3884                 }
3885
3886                 LocalTemporary temp;
3887
3888                 public ParameterReference (Parameters pars, Block block, int idx, string name, Location loc)
3889                 {
3890                         this.pars = pars;
3891                         this.block = block;
3892                         this.idx  = idx;
3893                         this.name = name;
3894                         this.loc = loc;
3895                         eclass = ExprClass.Variable;
3896                 }
3897
3898                 public VariableInfo VariableInfo {
3899                         get { return vi; }
3900                 }
3901
3902                 public bool VerifyFixed (bool is_expression)
3903                 {
3904                         return !is_expression || TypeManager.IsValueType (type);
3905                 }
3906
3907                 public bool IsAssigned (EmitContext ec, Location loc)
3908                 {
3909                         if (!ec.DoFlowAnalysis || !is_out || ec.CurrentBranching.IsAssigned (vi))
3910                                 return true;
3911
3912                         Report.Error (269, loc,
3913                                       "Use of unassigned out parameter '{0}'", name);
3914                         return false;
3915                 }
3916
3917                 public bool IsFieldAssigned (EmitContext ec, string field_name, Location loc)
3918                 {
3919                         if (!ec.DoFlowAnalysis || !is_out || ec.CurrentBranching.IsFieldAssigned (vi, field_name))
3920                                 return true;
3921
3922                         Report.Error (170, loc,
3923                                       "Use of possibly unassigned field `" + field_name + "'");
3924                         return false;
3925                 }
3926
3927                 public void SetAssigned (EmitContext ec)
3928                 {
3929                         if (is_out && ec.DoFlowAnalysis)
3930                                 ec.CurrentBranching.SetAssigned (vi);
3931                 }
3932
3933                 public void SetFieldAssigned (EmitContext ec, string field_name)
3934                 {
3935                         if (is_out && ec.DoFlowAnalysis)
3936                                 ec.CurrentBranching.SetFieldAssigned (vi, field_name);
3937                 }
3938
3939                 protected void DoResolveBase (EmitContext ec)
3940                 {
3941                         type = pars.GetParameterInfo (ec, idx, out mod);
3942                         is_ref = (mod & Parameter.Modifier.ISBYREF) != 0;
3943                         is_out = (mod & Parameter.Modifier.OUT) != 0;
3944                         eclass = ExprClass.Variable;
3945
3946                         if (is_out)
3947                                 vi = block.ParameterMap [idx];
3948
3949                         if (ec.CurrentAnonymousMethod != null){
3950                                 if (is_ref){
3951                                         Report.Error (1628, Location,
3952                                                       "Can not reference a ref or out parameter in an anonymous method");
3953                                         return;
3954                                 }
3955
3956                                 //
3957                                 // If we are referencing the parameter from the external block
3958                                 // flag it for capturing
3959                                 //
3960                                 //Console.WriteLine ("Is parameter `{0}' local? {1}", name, block.IsLocalParameter (name));
3961                                 if (!block.IsLocalParameter (name)){
3962                                         ec.CaptureParameter (name, type, idx);
3963                                 }
3964                         }
3965                 }
3966
3967                 public override int GetHashCode()
3968                 {
3969                         return name.GetHashCode ();
3970                 }
3971
3972                 public override bool Equals (object obj)
3973                 {
3974                         ParameterReference pr = obj as ParameterReference;
3975                         if (pr == null)
3976                                 return false;
3977
3978                         return name == pr.name && block == pr.block;
3979                 }
3980
3981                 //
3982                 // Notice that for ref/out parameters, the type exposed is not the
3983                 // same type exposed externally.
3984                 //
3985                 // for "ref int a":
3986                 //   externally we expose "int&"
3987                 //   here we expose       "int".
3988                 //
3989                 // We record this in "is_ref".  This means that the type system can treat
3990                 // the type as it is expected, but when we generate the code, we generate
3991                 // the alternate kind of code.
3992                 //
3993                 public override Expression DoResolve (EmitContext ec)
3994                 {
3995                         DoResolveBase (ec);
3996
3997                         if (is_out && ec.DoFlowAnalysis && !IsAssigned (ec, loc))
3998                                 return null;
3999
4000                         if (ec.RemapToProxy)
4001                                 return ec.RemapParameter (idx);
4002
4003                         return this;
4004                 }
4005
4006                 override public Expression DoResolveLValue (EmitContext ec, Expression right_side)
4007                 {
4008                         DoResolveBase (ec);
4009
4010                         SetAssigned (ec);
4011
4012                         if (ec.RemapToProxy)
4013                                 return ec.RemapParameterLValue (idx, right_side);
4014
4015                         return this;
4016                 }
4017
4018                 static public void EmitLdArg (ILGenerator ig, int x)
4019                 {
4020                         if (x <= 255){
4021                                 switch (x){
4022                                 case 0: ig.Emit (OpCodes.Ldarg_0); break;
4023                                 case 1: ig.Emit (OpCodes.Ldarg_1); break;
4024                                 case 2: ig.Emit (OpCodes.Ldarg_2); break;
4025                                 case 3: ig.Emit (OpCodes.Ldarg_3); break;
4026                                 default: ig.Emit (OpCodes.Ldarg_S, (byte) x); break;
4027                                 }
4028                         } else
4029                                 ig.Emit (OpCodes.Ldarg, x);
4030                 }
4031
4032                 //
4033                 // This method is used by parameters that are references, that are
4034                 // being passed as references:  we only want to pass the pointer (that
4035                 // is already stored in the parameter, not the address of the pointer,
4036                 // and not the value of the variable).
4037                 //
4038                 public void EmitLoad (EmitContext ec)
4039                 {
4040                         ILGenerator ig = ec.ig;
4041                         int arg_idx = idx;
4042
4043                         if (!ec.MethodIsStatic)
4044                                 arg_idx++;
4045
4046
4047                         EmitLdArg (ig, arg_idx);
4048
4049                         //
4050                         // FIXME: Review for anonymous methods
4051                         //
4052                 }
4053
4054                 public override void Emit (EmitContext ec)
4055                 {
4056                         if (ec.HaveCaptureInfo && ec.IsParameterCaptured (name)){
4057                                 ec.EmitParameter (name);
4058                                 return;
4059                         }
4060
4061                         Emit (ec, false);
4062                 }
4063
4064                 public void Emit (EmitContext ec, bool leave_copy)
4065                 {
4066                         ILGenerator ig = ec.ig;
4067                         int arg_idx = idx;
4068
4069                         if (!ec.MethodIsStatic)
4070                                 arg_idx++;
4071
4072                         EmitLdArg (ig, arg_idx);
4073
4074                         if (is_ref) {
4075                                 if (prepared)
4076                                         ec.ig.Emit (OpCodes.Dup);
4077
4078                                 //
4079                                 // If we are a reference, we loaded on the stack a pointer
4080                                 // Now lets load the real value
4081                                 //
4082                                 LoadFromPtr (ig, type);
4083                         }
4084
4085                         if (leave_copy) {
4086                                 ec.ig.Emit (OpCodes.Dup);
4087
4088                                 if (is_ref) {
4089                                         temp = new LocalTemporary (ec, type);
4090                                         temp.Store (ec);
4091                                 }
4092                         }
4093                 }
4094
4095                 public void EmitAssign (EmitContext ec, Expression source, bool leave_copy, bool prepare_for_load)
4096                 {
4097                         if (ec.HaveCaptureInfo && ec.IsParameterCaptured (name)){
4098                                 ec.EmitAssignParameter (name, source, leave_copy, prepare_for_load);
4099                                 return;
4100                         }
4101
4102                         ILGenerator ig = ec.ig;
4103                         int arg_idx = idx;
4104
4105                         prepared = prepare_for_load;
4106
4107                         if (!ec.MethodIsStatic)
4108                                 arg_idx++;
4109
4110                         if (is_ref && !prepared)
4111                                 EmitLdArg (ig, arg_idx);
4112
4113                         source.Emit (ec);
4114
4115                         if (leave_copy)
4116                                 ec.ig.Emit (OpCodes.Dup);
4117
4118                         if (is_ref) {
4119                                 if (leave_copy) {
4120                                         temp = new LocalTemporary (ec, type);
4121                                         temp.Store (ec);
4122                                 }
4123
4124                                 StoreFromPtr (ig, type);
4125
4126                                 if (temp != null)
4127                                         temp.Emit (ec);
4128                         } else {
4129                                 if (arg_idx <= 255)
4130                                         ig.Emit (OpCodes.Starg_S, (byte) arg_idx);
4131                                 else
4132                                         ig.Emit (OpCodes.Starg, arg_idx);
4133                         }
4134                 }
4135
4136                 public void AddressOf (EmitContext ec, AddressOp mode)
4137                 {
4138                         if (ec.HaveCaptureInfo && ec.IsParameterCaptured (name)){
4139                                 ec.EmitAddressOfParameter (name);
4140                                 return;
4141                         }
4142
4143                         int arg_idx = idx;
4144
4145                         if (!ec.MethodIsStatic)
4146                                 arg_idx++;
4147
4148                         if (is_ref){
4149                                 if (arg_idx <= 255)
4150                                         ec.ig.Emit (OpCodes.Ldarg_S, (byte) arg_idx);
4151                                 else
4152                                         ec.ig.Emit (OpCodes.Ldarg, arg_idx);
4153                         } else {
4154                                 if (arg_idx <= 255)
4155                                         ec.ig.Emit (OpCodes.Ldarga_S, (byte) arg_idx);
4156                                 else
4157                                         ec.ig.Emit (OpCodes.Ldarga, arg_idx);
4158                         }
4159                 }
4160
4161         }
4162
4163         /// <summary>
4164         ///   Used for arguments to New(), Invocation()
4165         /// </summary>
4166         public class Argument {
4167                 public enum AType : byte {
4168                         Expression,
4169                         Ref,
4170                         Out,
4171                         ArgList
4172                 };
4173
4174                 public readonly AType ArgType;
4175                 public Expression Expr;
4176
4177                 public Argument (Expression expr, AType type)
4178                 {
4179                         this.Expr = expr;
4180                         this.ArgType = type;
4181                 }
4182
4183                 public Argument (Expression expr)
4184                 {
4185                         this.Expr = expr;
4186                         this.ArgType = AType.Expression;
4187                 }
4188
4189                 public Type Type {
4190                         get {
4191                                 if (ArgType == AType.Ref || ArgType == AType.Out)
4192                                         return TypeManager.GetReferenceType (Expr.Type);
4193                                 else
4194                                         return Expr.Type;
4195                         }
4196                 }
4197
4198                 public Parameter.Modifier GetParameterModifier ()
4199                 {
4200                         switch (ArgType) {
4201                         case AType.Out:
4202                                 return Parameter.Modifier.OUT | Parameter.Modifier.ISBYREF;
4203
4204                         case AType.Ref:
4205                                 return Parameter.Modifier.REF | Parameter.Modifier.ISBYREF;
4206
4207                         default:
4208                                 return Parameter.Modifier.NONE;
4209                         }
4210                 }
4211
4212                 public static string FullDesc (Argument a)
4213                 {
4214                         if (a.ArgType == AType.ArgList)
4215                                 return "__arglist";
4216
4217                         return (a.ArgType == AType.Ref ? "ref " :
4218                                 (a.ArgType == AType.Out ? "out " : "")) +
4219                                 TypeManager.CSharpName (a.Expr.Type);
4220                 }
4221
4222                 public bool ResolveMethodGroup (EmitContext ec, Location loc)
4223                 {
4224                         SimpleName sn = Expr as SimpleName;
4225                         if (sn != null)
4226                                 Expr = sn.GetMethodGroup ();
4227
4228                         // FIXME: csc doesn't report any error if you try to use `ref' or
4229                         //        `out' in a delegate creation expression.
4230                         Expr = Expr.Resolve (ec, ResolveFlags.VariableOrValue | ResolveFlags.MethodGroup);
4231                         if (Expr == null)
4232                                 return false;
4233
4234                         return true;
4235                 }
4236
4237                 void Error_LValueRequired (Location loc)
4238                 {
4239                         Report.Error (1510, loc, "An lvalue is required as an argument to out or ref");
4240                 }
4241
4242                 public bool Resolve (EmitContext ec, Location loc)
4243                 {
4244                         if (ArgType == AType.Ref) {
4245                                 Expr = Expr.Resolve (ec);
4246                                 if (Expr == null)
4247                                         return false;
4248
4249                                 if (!ec.IsConstructor) {
4250                                         FieldExpr fe = Expr as FieldExpr;
4251                                         if (fe != null && fe.FieldInfo.IsInitOnly) {
4252                                                 if (fe.FieldInfo.IsStatic)
4253                                                         Report.Error (199, loc, "A static readonly field cannot be passed ref or out (except in a static constructor)");
4254                                                 else
4255                                                         Report.Error (192, loc, "A readonly field cannot be passed ref or out (except in a constructor)");
4256                                                 return false;
4257                                         }
4258                                 }
4259                                 Expr = Expr.DoResolveLValue (ec, Expr);
4260                                 if (Expr == null)
4261                                         Error_LValueRequired (loc);
4262                         } else if (ArgType == AType.Out) {
4263                                 Expr = Expr.DoResolveLValue (ec, EmptyExpression.Null);
4264                                 if (Expr == null)
4265                                         Error_LValueRequired (loc);
4266                         }
4267                         else
4268                                 Expr = Expr.Resolve (ec);
4269
4270                         if (Expr == null)
4271                                 return false;
4272
4273                         if (ArgType == AType.Expression)
4274                                 return true;
4275                         else {
4276                                 //
4277                                 // Catch errors where fields of a MarshalByRefObject are passed as ref or out
4278                                 // This is only allowed for `this'
4279                                 //
4280                                 FieldExpr fe = Expr as FieldExpr;
4281                                 if (fe != null && !fe.IsStatic){
4282                                         Expression instance = fe.InstanceExpression;
4283
4284                                         if (instance.GetType () != typeof (This)){
4285                                                 if (fe.InstanceExpression.Type.IsSubclassOf (TypeManager.mbr_type)){
4286                                                         Report.SymbolRelatedToPreviousError (fe.InstanceExpression.Type);
4287                                                         Report.Error (197, loc, "Cannot pass '{0}' as ref or out or take its address because it is a member of a marshal-by-reference class",
4288                                                                 fe.Name);
4289                                                         return false;
4290                                                 }
4291                                         }
4292                                 }
4293                         }
4294
4295                         if (Expr.eclass != ExprClass.Variable){
4296                                 //
4297                                 // We just probe to match the CSC output
4298                                 //
4299                                 if (Expr.eclass == ExprClass.PropertyAccess ||
4300                                     Expr.eclass == ExprClass.IndexerAccess){
4301                                         Report.Error (
4302                                                 206, loc,
4303                                                 "A property or indexer can not be passed as an out or ref " +
4304                                                 "parameter");
4305                                 } else {
4306                                         Error_LValueRequired (loc);
4307                                 }
4308                                 return false;
4309                         }
4310
4311                         return true;
4312                 }
4313
4314                 public void Emit (EmitContext ec)
4315                 {
4316                         //
4317                         // Ref and Out parameters need to have their addresses taken.
4318                         //
4319                         // ParameterReferences might already be references, so we want
4320                         // to pass just the value
4321                         //
4322                         if (ArgType == AType.Ref || ArgType == AType.Out){
4323                                 AddressOp mode = AddressOp.Store;
4324
4325                                 if (ArgType == AType.Ref)
4326                                         mode |= AddressOp.Load;
4327
4328                                 if (Expr is ParameterReference){
4329                                         ParameterReference pr = (ParameterReference) Expr;
4330
4331                                         if (pr.IsRef)
4332                                                 pr.EmitLoad (ec);
4333                                         else {
4334
4335                                                 pr.AddressOf (ec, mode);
4336                                         }
4337                                 } else {
4338                                         if (Expr is IMemoryLocation)
4339                                                ((IMemoryLocation) Expr).AddressOf (ec, mode);
4340                                         else {
4341                                                 Report.Error (
4342                                                         1510, Expr.Location,
4343                                                         "An lvalue is required as an argument to out or ref");
4344                                                 return;
4345                                         }
4346                                 }
4347                         } else
4348                                 Expr.Emit (ec);
4349                 }
4350         }
4351
4352         /// <summary>
4353         ///   Invocation of methods or delegates.
4354         /// </summary>
4355         public class Invocation : ExpressionStatement {
4356                 public readonly ArrayList Arguments;
4357
4358                 Expression expr;
4359                 MethodBase method = null;
4360
4361                 //
4362                 // arguments is an ArrayList, but we do not want to typecast,
4363                 // as it might be null.
4364                 //
4365                 // FIXME: only allow expr to be a method invocation or a
4366                 // delegate invocation (7.5.5)
4367                 //
4368                 public Invocation (Expression expr, ArrayList arguments, Location l)
4369                 {
4370                         this.expr = expr;
4371                         Arguments = arguments;
4372                         loc = l;
4373                 }
4374
4375                 public Expression Expr {
4376                         get {
4377                                 return expr;
4378                         }
4379                 }
4380
4381                 /// <summary>
4382                 ///   Determines "better conversion" as specified in 7.4.2.3
4383                 ///
4384                 ///    Returns : p    if a->p is better,
4385                 ///              q    if a->q is better,
4386                 ///              null if neither is better
4387                 /// </summary>
4388                 static Type BetterConversion (EmitContext ec, Argument a, Type p, Type q, Location loc)
4389                 {
4390                         Type argument_type = TypeManager.TypeToCoreType (a.Type);
4391                         Expression argument_expr = a.Expr;
4392
4393                         // p = TypeManager.TypeToCoreType (p);
4394                         // q = TypeManager.TypeToCoreType (q);
4395
4396                         if (argument_type == null)
4397                                 throw new Exception ("Expression of type " + a.Expr +
4398                                                      " does not resolve its type");
4399
4400                         if (p == null || q == null)
4401                                 throw new InternalErrorException ("BetterConversion Got a null conversion");
4402
4403                         if (p == q)
4404                                 return null;
4405
4406                         if (argument_expr is NullLiteral) {
4407                         //
4408                                 // If the argument is null and one of the types to compare is 'object' and
4409                                 // the other is a reference type, we prefer the other.
4410                         //
4411                                 // This follows from the usual rules:
4412                                 //   * There is an implicit conversion from 'null' to type 'object'
4413                                 //   * There is an implicit conversion from 'null' to any reference type
4414                                 //   * There is an implicit conversion from any reference type to type 'object'
4415                                 //   * There is no implicit conversion from type 'object' to other reference types
4416                                 //  => Conversion of 'null' to a reference type is better than conversion to 'object'
4417                                 //
4418                                 //  FIXME: This probably isn't necessary, since the type of a NullLiteral is the
4419                                 //         null type. I think it used to be 'object' and thus needed a special
4420                                 //         case to avoid the immediately following two checks.
4421                                 //
4422                                 if (!p.IsValueType && q == TypeManager.object_type)
4423                                         return p;
4424                                 if (!q.IsValueType && p == TypeManager.object_type)
4425                                         return q;
4426                         }
4427
4428                         if (argument_type == p)
4429                                 return p;
4430
4431                         if (argument_type == q)
4432                                 return q;
4433
4434                         Expression p_tmp = new EmptyExpression (p);
4435                         Expression q_tmp = new EmptyExpression (q);
4436
4437                         bool p_to_q = Convert.ImplicitConversionExists (ec, p_tmp, q);
4438                         bool q_to_p = Convert.ImplicitConversionExists (ec, q_tmp, p);
4439
4440                         if (p_to_q && !q_to_p)
4441                                 return p;
4442
4443                         if (q_to_p && !p_to_q)
4444                                 return q;
4445
4446                         if (p == TypeManager.sbyte_type)
4447                                 if (q == TypeManager.byte_type || q == TypeManager.ushort_type ||
4448                                     q == TypeManager.uint32_type || q == TypeManager.uint64_type)
4449                                         return p;
4450                         if (q == TypeManager.sbyte_type)
4451                                 if (p == TypeManager.byte_type || p == TypeManager.ushort_type ||
4452                                     p == TypeManager.uint32_type || p == TypeManager.uint64_type)
4453                                         return q;
4454
4455                         if (p == TypeManager.short_type)
4456                                 if (q == TypeManager.ushort_type || q == TypeManager.uint32_type ||
4457                                     q == TypeManager.uint64_type)
4458                                         return p;
4459
4460                         if (q == TypeManager.short_type)
4461                                 if (p == TypeManager.ushort_type || p == TypeManager.uint32_type ||
4462                                     p == TypeManager.uint64_type)
4463                                         return q;
4464
4465                         if (p == TypeManager.int32_type)
4466                                 if (q == TypeManager.uint32_type || q == TypeManager.uint64_type)
4467                                         return p;
4468
4469                         if (q == TypeManager.int32_type)
4470                                 if (p == TypeManager.uint32_type || p == TypeManager.uint64_type)
4471                                         return q;
4472
4473                         if (p == TypeManager.int64_type)
4474                                 if (q == TypeManager.uint64_type)
4475                                         return p;
4476                         if (q == TypeManager.int64_type)
4477                                 if (p == TypeManager.uint64_type)
4478                                         return q;
4479
4480                         return null;
4481                 }
4482
4483                 /// <summary>
4484                 ///   Determines "Better function" between candidate
4485                 ///   and the current best match
4486                 /// </summary>
4487                 /// <remarks>
4488                 ///    Returns a boolean indicating :
4489                 ///     false if candidate ain't better
4490                 ///     true  if candidate is better than the current best match
4491                 /// </remarks>
4492                 static bool BetterFunction (EmitContext ec, ArrayList args, int argument_count,
4493                                            MethodBase candidate, bool candidate_params,
4494                                            MethodBase best, bool best_params, Location loc)
4495                 {
4496                         ParameterData candidate_pd = TypeManager.GetParameterData (candidate);
4497                         ParameterData best_pd = TypeManager.GetParameterData (best);
4498
4499                         bool better_at_least_one = false;
4500                         bool same = true;
4501                         for (int j = 0; j < argument_count; ++j) {
4502                                 Argument a = (Argument) args [j];
4503
4504                                 Type ct = TypeManager.TypeToCoreType (candidate_pd.ParameterType (j));
4505                                 Type bt = TypeManager.TypeToCoreType (best_pd.ParameterType (j));
4506
4507                                 if (candidate_pd.ParameterModifier (j) == Parameter.Modifier.PARAMS)
4508                                         if (candidate_params)
4509                                                 ct = TypeManager.GetElementType (ct);
4510
4511                                 if (best_pd.ParameterModifier (j) == Parameter.Modifier.PARAMS)
4512                                         if (best_params)
4513                                                 bt = TypeManager.GetElementType (bt);
4514
4515                                 if (ct.Equals (bt))
4516                                         continue;
4517
4518                                 same = false;
4519                                 Type better = BetterConversion (ec, a, ct, bt, loc);
4520                                 // for each argument, the conversion to 'ct' should be no worse than
4521                                 // the conversion to 'bt'.
4522                                 if (better == bt)
4523                                         return false;
4524
4525                                 // for at least one argument, the conversion to 'ct' should be better than
4526                                 // the conversion to 'bt'.
4527                                 if (better == ct)
4528                                         better_at_least_one = true;
4529                         }
4530
4531                         if (better_at_least_one)
4532                                 return true;
4533
4534                         if (!same)
4535                                 return false;
4536
4537                         //
4538                         // If two methods have equal parameter types, but
4539                         // only one of them is generic, the non-generic one wins.
4540                         //
4541                         if (TypeManager.IsGenericMethod (best) && !TypeManager.IsGenericMethod (candidate))
4542                                 return true;
4543                         else if (!TypeManager.IsGenericMethod (best) && TypeManager.IsGenericMethod (candidate))
4544                                 return false;
4545
4546                         //
4547                         // Note that this is not just an optimization.  This handles the case
4548                         // This handles the case
4549                         //
4550                         //   Add (float f1, float f2, float f3);
4551                         //   Add (params decimal [] foo);
4552                         //
4553                         // The call Add (3, 4, 5) should be ambiguous.  Without this check, the
4554                         // first candidate would've chosen as better.
4555                         //
4556                         //
4557                         // This handles the following cases:
4558                         //
4559                         //   Trim () is better than Trim (params char[] chars)
4560                         //   Concat (string s1, string s2, string s3) is better than
4561                         //     Concat (string s1, params string [] srest)
4562                         //
4563                         return !candidate_params && best_params;
4564                 }
4565
4566                 static bool IsOverride (MethodBase cand_method, MethodBase base_method)
4567                 {
4568                         if (!IsAncestralType (base_method.DeclaringType, cand_method.DeclaringType))
4569                                 return false;
4570
4571                         ParameterData cand_pd = TypeManager.GetParameterData (cand_method);
4572                         ParameterData base_pd = TypeManager.GetParameterData (base_method);
4573
4574                         if (cand_pd.Count != base_pd.Count)
4575                                 return false;
4576
4577                         for (int j = 0; j < cand_pd.Count; ++j) {
4578                                 Parameter.Modifier cm = cand_pd.ParameterModifier (j);
4579                                 Parameter.Modifier bm = base_pd.ParameterModifier (j);
4580                                 Type ct = TypeManager.TypeToCoreType (cand_pd.ParameterType (j));
4581                                 Type bt = TypeManager.TypeToCoreType (base_pd.ParameterType (j));
4582
4583                                 if (cm != bm || ct != bt)
4584                                         return false;
4585                         }
4586
4587                         return true;
4588                 }
4589
4590                 public static string FullMethodDesc (MethodBase mb)
4591                 {
4592                         string ret_type = "";
4593
4594                         if (mb == null)
4595                                 return "";
4596
4597                         if (mb is MethodInfo)
4598                                 ret_type = TypeManager.CSharpName (((MethodInfo) mb).ReturnType);
4599
4600                         StringBuilder sb = new StringBuilder (ret_type);
4601                         sb.Append (" ");
4602                         sb.Append (mb.ReflectedType.ToString ());
4603                         sb.Append (".");
4604                         sb.Append (mb.Name);
4605
4606                         ParameterData pd = TypeManager.GetParameterData (mb);
4607
4608                         int count = pd.Count;
4609                         sb.Append (" (");
4610
4611                         for (int i = count; i > 0; ) {
4612                                 i--;
4613
4614                                 sb.Append (pd.ParameterDesc (count - i - 1));
4615                                 if (i != 0)
4616                                         sb.Append (", ");
4617                         }
4618
4619                         sb.Append (")");
4620                         return sb.ToString ();
4621                 }
4622
4623                 public static MethodGroupExpr MakeUnionSet (Expression mg1, Expression mg2, Location loc)
4624                 {
4625                         MemberInfo [] miset;
4626                         MethodGroupExpr union;
4627
4628                         if (mg1 == null) {
4629                                 if (mg2 == null)
4630                                         return null;
4631                                 return (MethodGroupExpr) mg2;
4632                         } else {
4633                                 if (mg2 == null)
4634                                         return (MethodGroupExpr) mg1;
4635                         }
4636
4637                         MethodGroupExpr left_set = null, right_set = null;
4638                         int length1 = 0, length2 = 0;
4639
4640                         left_set = (MethodGroupExpr) mg1;
4641                         length1 = left_set.Methods.Length;
4642
4643                         right_set = (MethodGroupExpr) mg2;
4644                         length2 = right_set.Methods.Length;
4645
4646                         ArrayList common = new ArrayList ();
4647
4648                         foreach (MethodBase r in right_set.Methods){
4649                                 if (TypeManager.ArrayContainsMethod (left_set.Methods, r))
4650                                         common.Add (r);
4651                         }
4652
4653                         miset = new MemberInfo [length1 + length2 - common.Count];
4654                         left_set.Methods.CopyTo (miset, 0);
4655
4656                         int k = length1;
4657
4658                         foreach (MethodBase r in right_set.Methods) {
4659                                 if (!common.Contains (r))
4660                                         miset [k++] = r;
4661                         }
4662
4663                         union = new MethodGroupExpr (miset, loc);
4664
4665                         return union;
4666                 }
4667
4668                 public static bool IsParamsMethodApplicable (EmitContext ec, MethodGroupExpr me,
4669                                                              ArrayList arguments, int arg_count,
4670                                                              ref MethodBase candidate)
4671                 {
4672                         return IsParamsMethodApplicable (
4673                                 ec, me, arguments, arg_count, false, ref candidate) ||
4674                                 IsParamsMethodApplicable (
4675                                         ec, me, arguments, arg_count, true, ref candidate);
4676
4677
4678                 }
4679
4680                 static bool IsParamsMethodApplicable (EmitContext ec, MethodGroupExpr me,
4681                                                       ArrayList arguments, int arg_count,
4682                                                       bool do_varargs, ref MethodBase candidate)
4683                 {
4684                         if (!me.HasTypeArguments &&
4685                             !TypeManager.InferParamsTypeArguments (ec, arguments, ref candidate))
4686                                 return false;
4687
4688                         return IsParamsMethodApplicable (
4689                                 ec, arguments, arg_count, candidate, do_varargs);
4690                 }
4691
4692                 /// <summary>
4693                 ///   Determines if the candidate method, if a params method, is applicable
4694                 ///   in its expanded form to the given set of arguments
4695                 /// </summary>
4696                 static bool IsParamsMethodApplicable (EmitContext ec, ArrayList arguments,
4697                                                       int arg_count, MethodBase candidate,
4698                                                       bool do_varargs)
4699                 {
4700                         ParameterData pd = TypeManager.GetParameterData (candidate);
4701
4702                         int pd_count = pd.Count;
4703
4704                         if (pd_count == 0)
4705                                 return false;
4706
4707                         int count = pd_count - 1;
4708                         if (do_varargs) {
4709                                 if (pd.ParameterModifier (count) != Parameter.Modifier.ARGLIST)
4710                                         return false;
4711                                 if (pd_count != arg_count)
4712                                         return false;
4713                         } else {
4714                                 if (pd.ParameterModifier (count) != Parameter.Modifier.PARAMS)
4715                                 return false;
4716                         }
4717
4718                         if (count > arg_count)
4719                                 return false;
4720
4721                         if (pd_count == 1 && arg_count == 0)
4722                                 return true;
4723
4724                         //
4725                         // If we have come this far, the case which
4726                         // remains is when the number of parameters is
4727                         // less than or equal to the argument count.
4728                         //
4729                         for (int i = 0; i < count; ++i) {
4730
4731                                 Argument a = (Argument) arguments [i];
4732
4733                                 Parameter.Modifier a_mod = a.GetParameterModifier () &
4734                                         (unchecked (~(Parameter.Modifier.OUT | Parameter.Modifier.REF)));
4735                                 Parameter.Modifier p_mod = pd.ParameterModifier (i) &
4736                                         (unchecked (~(Parameter.Modifier.OUT | Parameter.Modifier.REF)));
4737
4738                                 if (a_mod == p_mod) {
4739
4740                                         if (a_mod == Parameter.Modifier.NONE)
4741                                                 if (!Convert.ImplicitConversionExists (ec,
4742                                                                                        a.Expr,
4743                                                                                        pd.ParameterType (i)))
4744                                                         return false;
4745
4746                                         if ((a_mod & Parameter.Modifier.ISBYREF) != 0) {
4747                                                 Type pt = pd.ParameterType (i);
4748
4749                                                 if (!pt.IsByRef)
4750                                                         pt = TypeManager.GetReferenceType (pt);
4751
4752                                                 if (pt != a.Type)
4753                                                         return false;
4754                                         }
4755                                 } else
4756                                         return false;
4757
4758                         }
4759
4760                         if (do_varargs) {
4761                                 Argument a = (Argument) arguments [count];
4762                                 if (!(a.Expr is Arglist))
4763                                         return false;
4764
4765                                 return true;
4766                         }
4767
4768                         Type element_type = TypeManager.GetElementType (pd.ParameterType (pd_count - 1));
4769
4770                         for (int i = pd_count - 1; i < arg_count; i++) {
4771                                 Argument a = (Argument) arguments [i];
4772
4773                                 if (!Convert.ImplicitConversionExists (ec, a.Expr, element_type))
4774                                         return false;
4775                         }
4776
4777                         return true;
4778                 }
4779
4780                 public static bool IsApplicable (EmitContext ec, MethodGroupExpr me,
4781                                                  ArrayList arguments, int arg_count,
4782                                                  ref MethodBase candidate)
4783                 {
4784                         if (!me.HasTypeArguments &&
4785                             !TypeManager.InferTypeArguments (ec, arguments, ref candidate))
4786                                 return false;
4787
4788                         return IsApplicable (ec, arguments, arg_count, candidate);
4789                 }
4790
4791                 /// <summary>
4792                 ///   Determines if the candidate method is applicable (section 14.4.2.1)
4793                 ///   to the given set of arguments
4794                 /// </summary>
4795                 static bool IsApplicable (EmitContext ec, ArrayList arguments, int arg_count,
4796                                           MethodBase candidate)
4797                 {
4798                         ParameterData pd = TypeManager.GetParameterData (candidate);
4799
4800                         if (arg_count != pd.Count)
4801                                 return false;
4802
4803                         for (int i = arg_count; i > 0; ) {
4804                                 i--;
4805
4806                                 Argument a = (Argument) arguments [i];
4807
4808                                 Parameter.Modifier a_mod = a.GetParameterModifier () &
4809                                         unchecked (~(Parameter.Modifier.OUT | Parameter.Modifier.REF));
4810                                 Parameter.Modifier p_mod = pd.ParameterModifier (i) &
4811                                         unchecked (~(Parameter.Modifier.OUT | Parameter.Modifier.REF));
4812
4813
4814                                 if (a_mod == p_mod ||
4815                                     (a_mod == Parameter.Modifier.NONE && p_mod == Parameter.Modifier.PARAMS)) {
4816                                         if (a_mod == Parameter.Modifier.NONE) {
4817                                                 if (!Convert.ImplicitConversionExists (ec,
4818                                                                                        a.Expr,
4819                                                                                        pd.ParameterType (i)))
4820                                                         return false;
4821                                         }
4822
4823                                         if ((a_mod & Parameter.Modifier.ISBYREF) != 0) {
4824                                                 Type pt = pd.ParameterType (i);
4825
4826                                                 if (!pt.IsByRef)
4827                                                         pt = TypeManager.GetReferenceType (pt);
4828
4829                                                 if (pt != a.Type)
4830                                                         return false;
4831                                         }
4832                                 } else
4833                                         return false;
4834                         }
4835
4836                         return true;
4837                 }
4838
4839                 static private bool IsAncestralType (Type first_type, Type second_type)
4840                 {
4841                         return first_type != second_type &&
4842                                 (second_type.IsSubclassOf (first_type) ||
4843                                  TypeManager.ImplementsInterface (second_type, first_type));
4844                 }
4845
4846                 /// <summary>
4847                 ///   Find the Applicable Function Members (7.4.2.1)
4848                 ///
4849                 ///   me: Method Group expression with the members to select.
4850                 ///       it might contain constructors or methods (or anything
4851                 ///       that maps to a method).
4852                 ///
4853                 ///   Arguments: ArrayList containing resolved Argument objects.
4854                 ///
4855                 ///   loc: The location if we want an error to be reported, or a Null
4856                 ///        location for "probing" purposes.
4857                 ///
4858                 ///   Returns: The MethodBase (either a ConstructorInfo or a MethodInfo)
4859                 ///            that is the best match of me on Arguments.
4860                 ///
4861                 /// </summary>
4862                 public static MethodBase OverloadResolve (EmitContext ec, MethodGroupExpr me,
4863                                                           ArrayList Arguments, bool may_fail,
4864                                                           Location loc)
4865                 {
4866                         MethodBase method = null;
4867                         bool method_params = false;
4868                         Type applicable_type = null;
4869                         int arg_count = 0;
4870                         ArrayList candidates = new ArrayList (2);
4871                         ArrayList candidate_overrides = null;
4872
4873                         //
4874                         // Used to keep a map between the candidate
4875                         // and whether it is being considered in its
4876                         // normal or expanded form
4877                         //
4878                         // false is normal form, true is expanded form
4879                         //
4880                         Hashtable candidate_to_form = null;
4881
4882                         if (Arguments != null)
4883                                 arg_count = Arguments.Count;
4884
4885                         if ((me.Name == "Invoke") &&
4886                             TypeManager.IsDelegateType (me.DeclaringType)) {
4887                                 Error_InvokeOnDelegate (loc);
4888                                 return null;
4889                         }
4890
4891                         MethodBase[] methods = me.Methods;
4892
4893                         //
4894                         // First we construct the set of applicable methods
4895                         //
4896                         bool is_sorted = true;
4897                         for (int i = 0; i < methods.Length; i++){
4898                                 Type decl_type = methods [i].DeclaringType;
4899
4900                                 //
4901                                 // If we have already found an applicable method
4902                                 // we eliminate all base types (Section 14.5.5.1)
4903                                 //
4904                                 if ((applicable_type != null) &&
4905                                     IsAncestralType (decl_type, applicable_type))
4906                                         continue;
4907
4908                                 //
4909                                 // Methods marked 'override' don't take part in 'applicable_type'
4910                                 // computation, nor in the actual overload resolution.
4911                                 // However, they still need to be emitted instead of a base virtual method.
4912                                 // We avoid doing the 'applicable' test here, since it'll anyway be applied
4913                                 // to the base virtual function, and IsOverride is much faster than IsApplicable.
4914                                 //
4915                                 if (!me.IsBase &&
4916                                     methods [i].IsVirtual &&
4917                                     (methods [i].Attributes & MethodAttributes.NewSlot) == 0) {
4918                                         if (candidate_overrides == null)
4919                                                 candidate_overrides = new ArrayList ();
4920                                         candidate_overrides.Add (methods [i]);
4921                                         continue;
4922                                 }
4923
4924                                 //
4925                                 // Check if candidate is applicable (section 14.4.2.1)
4926                                 //   Is candidate applicable in normal form?
4927                                 //
4928                                 bool is_applicable = IsApplicable (
4929                                         ec, me, Arguments, arg_count, ref methods [i]);
4930
4931                                 if (!is_applicable &&
4932                                     (IsParamsMethodApplicable (
4933                                             ec, me, Arguments, arg_count, ref methods [i]))) {
4934                                         MethodBase candidate = methods [i];
4935                                         if (candidate_to_form == null)
4936                                                 candidate_to_form = new PtrHashtable ();
4937                                         candidate_to_form [candidate] = candidate;
4938                                         // Candidate is applicable in expanded form
4939                                         is_applicable = true;
4940                                 }
4941
4942                                 if (!is_applicable)
4943                                         continue;
4944
4945                                 candidates.Add (methods [i]);
4946
4947                                 if (applicable_type == null)
4948                                         applicable_type = decl_type;
4949                                 else if (applicable_type != decl_type) {
4950                                         is_sorted = false;
4951                                         if (IsAncestralType (applicable_type, decl_type))
4952                                                 applicable_type = decl_type;
4953                                 }
4954                         }
4955
4956                         int candidate_top = candidates.Count;
4957
4958                         if (applicable_type == null) {
4959                                 //
4960                                 // Okay so we have failed to find anything so we
4961                                 // return by providing info about the closest match
4962                                 //
4963                                 for (int i = 0; i < methods.Length; ++i) {
4964                                         MethodBase c = (MethodBase) methods [i];
4965                                         ParameterData pd = TypeManager.GetParameterData (c);
4966
4967                                         if (pd.Count != arg_count)
4968                                                 continue;
4969
4970                                         if (!TypeManager.InferTypeArguments (ec, Arguments, ref c))
4971                                                 continue;
4972
4973                                         VerifyArgumentsCompat (ec, Arguments, arg_count,
4974                                                                c, false, null, may_fail, loc);
4975                                         break;
4976                                 }
4977
4978                                 if (!may_fail) {
4979                                         string report_name = me.Name;
4980                                         if (report_name == ".ctor")
4981                                                 report_name = me.DeclaringType.ToString ();
4982
4983                                         for (int i = 0; i < methods.Length; ++i) {
4984                                                 MethodBase c = methods [i];
4985                                                 ParameterData pd = TypeManager.GetParameterData (c);
4986
4987                                                 if (pd.Count != arg_count)
4988                                                         continue;
4989
4990                                                 if (TypeManager.InferTypeArguments (ec, Arguments, ref c))
4991                                                         continue;
4992
4993                                                 Report.Error (
4994                                                         411, loc, "The type arguments for " +
4995                                                         "method `{0}' cannot be infered from " +
4996                                                         "the usage. Try specifying the type " +
4997                                                         "arguments explicitly.", report_name);
4998                                                 return null;
4999                                         }
5000
5001                                         Error_WrongNumArguments (
5002                                                 loc, report_name, arg_count);
5003                                         return null;
5004                                 }
5005
5006                                 return null;
5007                         }
5008
5009                         if (!is_sorted) {
5010                                 //
5011                                 // At this point, applicable_type is _one_ of the most derived types
5012                                 // in the set of types containing the methods in this MethodGroup.
5013                                 // Filter the candidates so that they only contain methods from the
5014                                 // most derived types.
5015                                 //
5016
5017                                 int finalized = 0; // Number of finalized candidates
5018
5019                                 do {
5020                                         // Invariant: applicable_type is a most derived type
5021
5022                                         // We'll try to complete Section 14.5.5.1 for 'applicable_type' by
5023                                         // eliminating all it's base types.  At the same time, we'll also move
5024                                         // every unrelated type to the end of the array, and pick the next
5025                                         // 'applicable_type'.
5026
5027                                         Type next_applicable_type = null;
5028                                         int j = finalized; // where to put the next finalized candidate
5029                                         int k = finalized; // where to put the next undiscarded candidate
5030                                         for (int i = finalized; i < candidate_top; ++i) {
5031                                                 MethodBase candidate = (MethodBase) candidates [i];
5032                                                 Type decl_type = candidate.DeclaringType;
5033
5034                                                 if (decl_type == applicable_type) {
5035                                                         candidates [k++] = candidates [j];
5036                                                         candidates [j++] = candidates [i];
5037                                                         continue;
5038                                                 }
5039
5040                                                 if (IsAncestralType (decl_type, applicable_type))
5041                                                         continue;
5042
5043                                                 if (next_applicable_type != null &&
5044                                                     IsAncestralType (decl_type, next_applicable_type))
5045                                                         continue;
5046
5047                                                 candidates [k++] = candidates [i];
5048
5049                                                 if (next_applicable_type == null ||
5050                                                     IsAncestralType (next_applicable_type, decl_type))
5051                                                         next_applicable_type = decl_type;
5052                                         }
5053
5054                                         applicable_type = next_applicable_type;
5055                                         finalized = j;
5056                                         candidate_top = k;
5057                                 } while (applicable_type != null);
5058                         }
5059
5060                         //
5061                         // Now we actually find the best method
5062                         //
5063
5064                         method = (MethodBase) candidates [0];
5065                         method_params = candidate_to_form != null && candidate_to_form.Contains (method);
5066                         for (int ix = 1; ix < candidate_top; ix++){
5067                                 MethodBase candidate = (MethodBase) candidates [ix];
5068
5069                                 if (candidate == method)
5070                                         continue;
5071
5072                                 bool cand_params = candidate_to_form != null && candidate_to_form.Contains (candidate);
5073
5074                                 if (BetterFunction (ec, Arguments, arg_count,
5075                                                     candidate, cand_params,
5076                                                     method, method_params, loc)) {
5077                                         method = candidate;
5078                                         method_params = cand_params;
5079                                 }
5080                         }
5081
5082                         //
5083                         // Now check that there are no ambiguities i.e the selected method
5084                         // should be better than all the others
5085                         //
5086                         bool ambiguous = false;
5087                         for (int ix = 0; ix < candidate_top; ix++){
5088                                 MethodBase candidate = (MethodBase) candidates [ix];
5089
5090                                 if (candidate == method)
5091                                         continue;
5092
5093                                 bool cand_params = candidate_to_form != null && candidate_to_form.Contains (candidate);
5094                                 if (!BetterFunction (ec, Arguments, arg_count,
5095                                                     method, method_params,
5096                                                     candidate, cand_params,
5097                                                      loc)) {
5098                                         Report.SymbolRelatedToPreviousError (candidate);
5099                                         ambiguous = true;
5100                                 }
5101                         }
5102
5103                         if (ambiguous) {
5104                                 Report.SymbolRelatedToPreviousError (method);
5105                                 Report.Error (121, loc, "Ambiguous call when selecting function due to implicit casts");
5106                                 return null;
5107                         }
5108
5109                         //
5110                         // If the method is a virtual function, pick an override closer to the LHS type.
5111                         //
5112                         if (!me.IsBase && method.IsVirtual) {
5113                                 if ((method.Attributes & MethodAttributes.NewSlot) != MethodAttributes.NewSlot)
5114                                         throw new InternalErrorException (
5115                                                 "Should not happen.  An 'override' method took part in overload resolution: " + method);
5116
5117                                 if (candidate_overrides != null)
5118                                         foreach (MethodBase candidate in candidate_overrides) {
5119                                                 if (IsOverride (candidate, method))
5120                                                         method = candidate;
5121                                         }
5122                         }
5123
5124                         //
5125                         // And now check if the arguments are all
5126                         // compatible, perform conversions if
5127                         // necessary etc. and return if everything is
5128                         // all right
5129                         //
5130                         if (!VerifyArgumentsCompat (ec, Arguments, arg_count, method,
5131                                                     method_params, null, may_fail, loc))
5132                                 return null;
5133
5134                         if (method != null) {
5135                                 IMethodData data = TypeManager.GetMethod (method);
5136                                 if (data != null)
5137                                         data.SetMemberIsUsed ();
5138                         }
5139                         return method;
5140                 }
5141
5142                 static void Error_WrongNumArguments (Location loc, String name, int arg_count)
5143                 {
5144                         if (name == "Finalize" && arg_count == 0) {
5145                                 Report.Error (245, loc, "Destructors and object.Finalize cannot be called directly. Consider calling IDisposable.Dispose if available");
5146                         }
5147                         else {
5148                                 Report.Error (1501, loc,
5149                                         "No overload for method `" + name + "' takes `" +
5150                                         arg_count + "' arguments");
5151                         }
5152                 }
5153
5154                 static void Error_InvokeOnDelegate (Location loc)
5155                 {
5156                         Report.Error (1533, loc,
5157                                       "Invoke cannot be called directly on a delegate");
5158                 }
5159
5160                 static void Error_InvalidArguments (Location loc, int idx, MethodBase method,
5161                                                     Type delegate_type, string arg_sig, string par_desc)
5162                 {
5163                         if (delegate_type == null)
5164                                 Report.Error (1502, loc,
5165                                               "The best overloaded match for method '" +
5166                                               FullMethodDesc (method) +
5167                                               "' has some invalid arguments");
5168                         else
5169                                 Report.Error (1594, loc,
5170                                               "Delegate '" + delegate_type.ToString () +
5171                                               "' has some invalid arguments.");
5172                         Report.Error (1503, loc,
5173                                       String.Format ("Argument {0}: Cannot convert from '{1}' to '{2}'",
5174                                                      idx, arg_sig, par_desc));
5175                 }
5176
5177                 public static bool VerifyArgumentsCompat (EmitContext ec, ArrayList Arguments,
5178                                                           int arg_count, MethodBase method,
5179                                                           bool chose_params_expanded,
5180                                                           Type delegate_type, bool may_fail,
5181                                                           Location loc)
5182                 {
5183                         ParameterData pd = TypeManager.GetParameterData (method);
5184                         int pd_count = pd.Count;
5185
5186                         for (int j = 0; j < arg_count; j++) {
5187                                 Argument a = (Argument) Arguments [j];
5188                                 Expression a_expr = a.Expr;
5189                                 Type parameter_type = pd.ParameterType (j);
5190                                 Parameter.Modifier pm = pd.ParameterModifier (j);
5191
5192                                 if (pm == Parameter.Modifier.PARAMS){
5193                                         if ((pm & ~Parameter.Modifier.PARAMS) != a.GetParameterModifier ()) {
5194                                                 if (!may_fail)
5195                                                         Error_InvalidArguments (
5196                                                                 loc, j, method, delegate_type,
5197                                                                 Argument.FullDesc (a), pd.ParameterDesc (j));
5198                                                 return false;
5199                                         }
5200
5201                                         if (chose_params_expanded)
5202                                                 parameter_type = TypeManager.GetElementType (parameter_type);
5203                                 } else if (pm == Parameter.Modifier.ARGLIST){
5204                                         continue;
5205                                 } else {
5206                                         //
5207                                         // Check modifiers
5208                                         //
5209                                         if (pd.ParameterModifier (j) != a.GetParameterModifier ()){
5210                                                 if (!may_fail)
5211                                                         Error_InvalidArguments (
5212                                                                 loc, j, method, delegate_type,
5213                                                                 Argument.FullDesc (a), pd.ParameterDesc (j));
5214                                                 return false;
5215                                         }
5216                                 }
5217
5218                                 //
5219                                 // Check Type
5220                                 //
5221                                 if (!TypeManager.IsEqual (a.Type, parameter_type)){
5222                                         Expression conv;
5223
5224                                         conv = Convert.ImplicitConversion (ec, a_expr, parameter_type, loc);
5225
5226                                         if (conv == null) {
5227                                                 if (!may_fail)
5228                                                         Error_InvalidArguments (
5229                                                                 loc, j, method, delegate_type,
5230                                                                 Argument.FullDesc (a), pd.ParameterDesc (j));
5231                                                 return false;
5232                                         }
5233
5234                                         //
5235                                         // Update the argument with the implicit conversion
5236                                         //
5237                                         if (a_expr != conv)
5238                                                 a.Expr = conv;
5239                                 }
5240
5241                                 if (parameter_type.IsPointer){
5242                                         if (!ec.InUnsafe){
5243                                                 UnsafeError (loc);
5244                                                 return false;
5245                                         }
5246                                 }
5247
5248                                 Parameter.Modifier a_mod = a.GetParameterModifier () &
5249                                         unchecked (~(Parameter.Modifier.OUT | Parameter.Modifier.REF));
5250                                 Parameter.Modifier p_mod = pd.ParameterModifier (j) &
5251                                         unchecked (~(Parameter.Modifier.OUT | Parameter.Modifier.REF));
5252
5253                                 if (a_mod != p_mod &&
5254                                     pd.ParameterModifier (pd_count - 1) != Parameter.Modifier.PARAMS) {
5255                                         if (!may_fail) {
5256                                                 Report.Error (1502, loc,
5257                                                        "The best overloaded match for method '" + FullMethodDesc (method)+
5258                                                        "' has some invalid arguments");
5259                                                 Report.Error (1503, loc,
5260                                                        "Argument " + (j+1) +
5261                                                        ": Cannot convert from '" + Argument.FullDesc (a)
5262                                                        + "' to '" + pd.ParameterDesc (j) + "'");
5263                                         }
5264
5265                                         return false;
5266                                 }
5267                         }
5268
5269                         return true;
5270                 }
5271
5272                 public override Expression DoResolve (EmitContext ec)
5273                 {
5274                         //
5275                         // First, resolve the expression that is used to
5276                         // trigger the invocation
5277                         //
5278                         SimpleName sn = expr as SimpleName;
5279                         if (sn != null)
5280                                 expr = sn.GetMethodGroup ();
5281
5282                         expr = expr.Resolve (ec, ResolveFlags.VariableOrValue | ResolveFlags.MethodGroup);
5283                         if (expr == null)
5284                                 return null;
5285
5286                         if (!(expr is MethodGroupExpr)) {
5287                                 Type expr_type = expr.Type;
5288
5289                                 if (expr_type != null){
5290                                         bool IsDelegate = TypeManager.IsDelegateType (expr_type);
5291                                         if (IsDelegate)
5292                                                 return (new DelegateInvocation (
5293                                                         this.expr, Arguments, loc)).Resolve (ec);
5294                                 }
5295                         }
5296
5297                         if (!(expr is MethodGroupExpr)){
5298                                 expr.Error_UnexpectedKind (ResolveFlags.MethodGroup, loc);
5299                                 return null;
5300                         }
5301
5302                         //
5303                         // Next, evaluate all the expressions in the argument list
5304                         //
5305                         if (Arguments != null){
5306                                 foreach (Argument a in Arguments){
5307                                         if (!a.Resolve (ec, loc))
5308                                                 return null;
5309                                 }
5310                         }
5311
5312                         MethodGroupExpr mg = (MethodGroupExpr) expr;
5313                         method = OverloadResolve (ec, mg, Arguments, false, loc);
5314
5315                         if (method == null)
5316                                 return null;
5317
5318                         MethodInfo mi = method as MethodInfo;
5319                         if (mi != null) {
5320                                 type = TypeManager.TypeToCoreType (mi.ReturnType);
5321                                 Expression iexpr = mg.InstanceExpression;
5322                                 if (mi.IsStatic) {
5323                                         if (iexpr == null ||
5324                                             iexpr is This || iexpr is EmptyExpression ||
5325                                             mg.IdenticalTypeName) {
5326                                                 mg.InstanceExpression = null;
5327                                         } else {
5328                                                 MemberExpr.error176 (loc, mi.Name);
5329                                                 return null;
5330                                         }
5331                                 } else {
5332                                         if (iexpr == null || iexpr is EmptyExpression) {
5333                                                 SimpleName.Error_ObjectRefRequired (ec, loc, mi.Name);
5334                                                 return null;
5335                                         }
5336                                 }
5337                         }
5338
5339                         if (type.IsPointer){
5340                                 if (!ec.InUnsafe){
5341                                         UnsafeError (loc);
5342                                         return null;
5343                                 }
5344                         }
5345
5346                         //
5347                         // Only base will allow this invocation to happen.
5348                         //
5349                         if (mg.IsBase && method.IsAbstract){
5350                                 Report.Error (205, loc, "Cannot call an abstract base member: " +
5351                                               FullMethodDesc (method));
5352                                 return null;
5353                         }
5354
5355                         if (method.Name == "Finalize" && Arguments == null) {
5356                                 Report.Error (250, loc, "Do not directly call your base class Finalize method. It is called automatically from your destructor");
5357                                 return null;
5358                         }
5359
5360                         if ((method.Attributes & MethodAttributes.SpecialName) != 0){
5361                                 if (TypeManager.LookupDeclSpace (method.DeclaringType) != null || TypeManager.IsSpecialMethod (method)) {
5362                                         Report.Error (571, loc, TypeManager.CSharpSignature (method) + ": can not call operator or accessor");
5363                                         return null;
5364                                 }
5365                         }
5366
5367                         if (mg.InstanceExpression != null)
5368                                 mg.InstanceExpression.CheckMarshallByRefAccess (ec.ContainerType);
5369
5370                         eclass = ExprClass.Value;
5371                         return this;
5372                 }
5373
5374                 // <summary>
5375                 //   Emits the list of arguments as an array
5376                 // </summary>
5377                 static void EmitParams (EmitContext ec, int idx, ArrayList arguments)
5378                 {
5379                         ILGenerator ig = ec.ig;
5380                         int count = arguments.Count - idx;
5381                         Argument a = (Argument) arguments [idx];
5382                         Type t = a.Expr.Type;
5383
5384                         IntConstant.EmitInt (ig, count);
5385                         ig.Emit (OpCodes.Newarr, TypeManager.TypeToCoreType (t));
5386
5387                         int top = arguments.Count;
5388                         for (int j = idx; j < top; j++){
5389                                 a = (Argument) arguments [j];
5390
5391                                 ig.Emit (OpCodes.Dup);
5392                                 IntConstant.EmitInt (ig, j - idx);
5393
5394                                 bool is_stobj, has_type_arg;
5395                                 OpCode op = ArrayAccess.GetStoreOpcode (t, out is_stobj, out has_type_arg);
5396                                 if (is_stobj)
5397                                         ig.Emit (OpCodes.Ldelema, t);
5398
5399                                 a.Emit (ec);
5400
5401                                 if (has_type_arg)
5402                                         ig.Emit (op, t);
5403                                 else
5404                                         ig.Emit (op);
5405                         }
5406                 }
5407
5408                 /// <summary>
5409                 ///   Emits a list of resolved Arguments that are in the arguments
5410                 ///   ArrayList.
5411                 ///
5412                 ///   The MethodBase argument might be null if the
5413                 ///   emission of the arguments is known not to contain
5414                 ///   a `params' field (for example in constructors or other routines
5415                 ///   that keep their arguments in this structure)
5416                 ///
5417                 ///   if `dup_args' is true, a copy of the arguments will be left
5418                 ///   on the stack. If `dup_args' is true, you can specify `this_arg'
5419                 ///   which will be duplicated before any other args. Only EmitCall
5420                 ///   should be using this interface.
5421                 /// </summary>
5422                 public static void EmitArguments (EmitContext ec, MethodBase mb, ArrayList arguments, bool dup_args, LocalTemporary this_arg)
5423                 {
5424                         ParameterData pd;
5425                         if (mb != null)
5426                                 pd = TypeManager.GetParameterData (mb);
5427                         else
5428                                 pd = null;
5429
5430                         LocalTemporary [] temps = null;
5431
5432                         if (dup_args)
5433                                 temps = new LocalTemporary [arguments.Count];
5434
5435                         //
5436                         // If we are calling a params method with no arguments, special case it
5437                         //
5438                         if (arguments == null){
5439                                 if (pd != null && pd.Count > 0 &&
5440                                     pd.ParameterModifier (0) == Parameter.Modifier.PARAMS){
5441                                         ILGenerator ig = ec.ig;
5442
5443                                         IntConstant.EmitInt (ig, 0);
5444                                         ig.Emit (OpCodes.Newarr, TypeManager.GetElementType (pd.ParameterType (0)));
5445                                 }
5446
5447                                 return;
5448                         }
5449
5450                         int top = arguments.Count;
5451
5452                         for (int i = 0; i < top; i++){
5453                                 Argument a = (Argument) arguments [i];
5454
5455                                 if (pd != null){
5456                                         if (pd.ParameterModifier (i) == Parameter.Modifier.PARAMS){
5457                                                 //
5458                                                 // Special case if we are passing the same data as the
5459                                                 // params argument, do not put it in an array.
5460                                                 //
5461                                                 if (pd.ParameterType (i) == a.Type)
5462                                                         a.Emit (ec);
5463                                                 else
5464                                                         EmitParams (ec, i, arguments);
5465                                                 return;
5466                                         }
5467                                 }
5468
5469                                 a.Emit (ec);
5470                                 if (dup_args) {
5471                                         ec.ig.Emit (OpCodes.Dup);
5472                                         (temps [i] = new LocalTemporary (ec, a.Type)).Store (ec);
5473                                 }
5474                         }
5475
5476                         if (dup_args) {
5477                                 if (this_arg != null)
5478                                         this_arg.Emit (ec);
5479
5480                                 for (int i = 0; i < top; i ++)
5481                                         temps [i].Emit (ec);
5482                         }
5483
5484                         if (pd != null && pd.Count > top &&
5485                             pd.ParameterModifier (top) == Parameter.Modifier.PARAMS){
5486                                 ILGenerator ig = ec.ig;
5487
5488                                 IntConstant.EmitInt (ig, 0);
5489                                 ig.Emit (OpCodes.Newarr, TypeManager.GetElementType (pd.ParameterType (top)));
5490                         }
5491                 }
5492
5493                 static Type[] GetVarargsTypes (EmitContext ec, MethodBase mb,
5494                                                ArrayList arguments)
5495                 {
5496                         ParameterData pd = TypeManager.GetParameterData (mb);
5497
5498                         if (arguments == null)
5499                                 return new Type [0];
5500
5501                         Argument a = (Argument) arguments [pd.Count - 1];
5502                         Arglist list = (Arglist) a.Expr;
5503
5504                         return list.ArgumentTypes;
5505                 }
5506
5507                 /// <summary>
5508                 /// This checks the ConditionalAttribute on the method
5509                 /// </summary>
5510                 static bool IsMethodExcluded (MethodBase method, EmitContext ec)
5511                 {
5512                         if (method.IsConstructor)
5513                                 return false;
5514
5515                         IMethodData md = TypeManager.GetMethod (method);
5516                         if (md != null)
5517                                 return md.IsExcluded (ec);
5518
5519                         // For some methods (generated by delegate class) GetMethod returns null
5520                         // because they are not included in builder_to_method table
5521                         if (method.DeclaringType is TypeBuilder)
5522                                 return false;
5523
5524                         return AttributeTester.IsConditionalMethodExcluded (method);
5525                 }
5526
5527                 /// <remarks>
5528                 ///   is_base tells whether we want to force the use of the `call'
5529                 ///   opcode instead of using callvirt.  Call is required to call
5530                 ///   a specific method, while callvirt will always use the most
5531                 ///   recent method in the vtable.
5532                 ///
5533                 ///   is_static tells whether this is an invocation on a static method
5534                 ///
5535                 ///   instance_expr is an expression that represents the instance
5536                 ///   it must be non-null if is_static is false.
5537                 ///
5538                 ///   method is the method to invoke.
5539                 ///
5540                 ///   Arguments is the list of arguments to pass to the method or constructor.
5541                 /// </remarks>
5542                 public static void EmitCall (EmitContext ec, bool is_base,
5543                                              bool is_static, Expression instance_expr,
5544                                              MethodBase method, ArrayList Arguments, Location loc)
5545                 {
5546                         EmitCall (ec, is_base, is_static, instance_expr, method, Arguments, loc, false, false);
5547                 }
5548
5549                 // `dup_args' leaves an extra copy of the arguments on the stack
5550                 // `omit_args' does not leave any arguments at all.
5551                 // So, basically, you could make one call with `dup_args' set to true,
5552                 // and then another with `omit_args' set to true, and the two calls
5553                 // would have the same set of arguments. However, each argument would
5554                 // only have been evaluated once.
5555                 public static void EmitCall (EmitContext ec, bool is_base,
5556                                              bool is_static, Expression instance_expr,
5557                                              MethodBase method, ArrayList Arguments, Location loc,
5558                                              bool dup_args, bool omit_args)
5559                 {
5560                         ILGenerator ig = ec.ig;
5561                         bool struct_call = false;
5562                         bool this_call = false;
5563                         LocalTemporary this_arg = null;
5564
5565                         Type decl_type = method.DeclaringType;
5566
5567                         if (!RootContext.StdLib) {
5568                                 // Replace any calls to the system's System.Array type with calls to
5569                                 // the newly created one.
5570                                 if (method == TypeManager.system_int_array_get_length)
5571                                         method = TypeManager.int_array_get_length;
5572                                 else if (method == TypeManager.system_int_array_get_rank)
5573                                         method = TypeManager.int_array_get_rank;
5574                                 else if (method == TypeManager.system_object_array_clone)
5575                                         method = TypeManager.object_array_clone;
5576                                 else if (method == TypeManager.system_int_array_get_length_int)
5577                                         method = TypeManager.int_array_get_length_int;
5578                                 else if (method == TypeManager.system_int_array_get_lower_bound_int)
5579                                         method = TypeManager.int_array_get_lower_bound_int;
5580                                 else if (method == TypeManager.system_int_array_get_upper_bound_int)
5581                                         method = TypeManager.int_array_get_upper_bound_int;
5582                                 else if (method == TypeManager.system_void_array_copyto_array_int)
5583                                         method = TypeManager.void_array_copyto_array_int;
5584                         }
5585
5586                         if (ec.TestObsoleteMethodUsage) {
5587                                 //
5588                                 // This checks ObsoleteAttribute on the method and on the declaring type
5589                                 //
5590                                 ObsoleteAttribute oa = AttributeTester.GetMethodObsoleteAttribute (method);
5591                                 if (oa != null)
5592                                         AttributeTester.Report_ObsoleteMessage (oa, TypeManager.CSharpSignature (method), loc);
5593
5594                                 oa = AttributeTester.GetObsoleteAttribute (method.DeclaringType);
5595                                 if (oa != null) {
5596                                         AttributeTester.Report_ObsoleteMessage (oa, method.DeclaringType.FullName, loc);
5597                                 }
5598                         }
5599
5600                         if (IsMethodExcluded (method, ec))
5601                                 return;
5602
5603                         if (!is_static){
5604                                 this_call = instance_expr == null;
5605                                 if (decl_type.IsValueType || (!this_call && instance_expr.Type.IsValueType))
5606                                         struct_call = true;
5607
5608                                 //
5609                                 // If this is ourselves, push "this"
5610                                 //
5611                                 if (!omit_args) {
5612                                         Type t = null;
5613                                         if (this_call) {
5614                                                 ig.Emit (OpCodes.Ldarg_0);
5615                                                 t = decl_type;
5616                                         } else {
5617                                                 Type iexpr_type = instance_expr.Type;
5618
5619                                                 //
5620                                                 // Push the instance expression
5621                                                 //
5622                                                 if (TypeManager.IsValueType (iexpr_type)) {
5623                                                         //
5624                                                         // Special case: calls to a function declared in a
5625                                                         // reference-type with a value-type argument need
5626                                                         // to have their value boxed.
5627                                                         if (decl_type.IsValueType ||
5628                                                             iexpr_type.IsGenericParameter) {
5629                                                                 //
5630                                                                 // If the expression implements IMemoryLocation, then
5631                                                                 // we can optimize and use AddressOf on the
5632                                                                 // return.
5633                                                                 //
5634                                                                 // If not we have to use some temporary storage for
5635                                                                 // it.
5636                                                                 if (instance_expr is IMemoryLocation) {
5637                                                                         ((IMemoryLocation)instance_expr).
5638                                                                                 AddressOf (ec, AddressOp.LoadStore);
5639                                                                 } else {
5640                                                                         LocalTemporary temp = new LocalTemporary (ec, iexpr_type);
5641                                                                         instance_expr.Emit (ec);
5642                                                                         temp.Store (ec);
5643                                                                         temp.AddressOf (ec, AddressOp.Load);
5644                                                                 }
5645
5646                                                                 // avoid the overhead of doing this all the time.
5647                                                                 if (dup_args)
5648                                                                         t = TypeManager.GetReferenceType (iexpr_type);
5649                                                         } else {
5650                                                                 instance_expr.Emit (ec);
5651                                                                 ig.Emit (OpCodes.Box, instance_expr.Type);
5652                                                                 t = TypeManager.object_type;
5653                                                         }
5654                                                 } else {
5655                                                         instance_expr.Emit (ec);
5656                                                         t = instance_expr.Type;
5657                                                 }
5658                                         }
5659
5660                                         if (dup_args) {
5661                                                 this_arg = new LocalTemporary (ec, t);
5662                                                 ig.Emit (OpCodes.Dup);
5663                                                 this_arg.Store (ec);
5664                                         }
5665                                 }
5666                         }
5667
5668                         if (!omit_args)
5669                                 EmitArguments (ec, method, Arguments, dup_args, this_arg);
5670
5671                         if ((instance_expr != null) && (instance_expr.Type.IsGenericParameter))
5672                                 ig.Emit (OpCodes.Constrained, instance_expr.Type);
5673
5674                         OpCode call_op;
5675                         if (is_static || struct_call || is_base || (this_call && !method.IsVirtual))
5676                                 call_op = OpCodes.Call;
5677                         else
5678                                 call_op = OpCodes.Callvirt;
5679
5680                         if ((method.CallingConvention & CallingConventions.VarArgs) != 0) {
5681                                 Type[] varargs_types = GetVarargsTypes (ec, method, Arguments);
5682                                 ig.EmitCall (call_op, (MethodInfo) method, varargs_types);
5683                                 return;
5684                         }
5685
5686                         //
5687                         // If you have:
5688                         // this.DoFoo ();
5689                         // and DoFoo is not virtual, you can omit the callvirt,
5690                         // because you don't need the null checking behavior.
5691                         //
5692                         if (method is MethodInfo)
5693                                 ig.Emit (call_op, (MethodInfo) method);
5694                         else
5695                                 ig.Emit (call_op, (ConstructorInfo) method);
5696                 }
5697
5698                 public override void Emit (EmitContext ec)
5699                 {
5700                         MethodGroupExpr mg = (MethodGroupExpr) this.expr;
5701
5702                         EmitCall (ec, mg.IsBase, method.IsStatic, mg.InstanceExpression, method, Arguments, loc);
5703                 }
5704
5705                 public override void EmitStatement (EmitContext ec)
5706                 {
5707                         Emit (ec);
5708
5709                         //
5710                         // Pop the return value if there is one
5711                         //
5712                         if (method is MethodInfo){
5713                                 Type ret = ((MethodInfo)method).ReturnType;
5714                                 if (TypeManager.TypeToCoreType (ret) != TypeManager.void_type)
5715                                         ec.ig.Emit (OpCodes.Pop);
5716                         }
5717                 }
5718         }
5719
5720         public class InvocationOrCast : ExpressionStatement
5721         {
5722                 Expression expr;
5723                 Expression argument;
5724
5725                 public InvocationOrCast (Expression expr, Expression argument, Location loc)
5726                 {
5727                         this.expr = expr;
5728                         this.argument = argument;
5729                         this.loc = loc;
5730                 }
5731
5732                 public override Expression DoResolve (EmitContext ec)
5733                 {
5734                         //
5735                         // First try to resolve it as a cast.
5736                         //
5737                         TypeExpr te = expr.ResolveAsTypeStep (ec) as TypeExpr;
5738                         if ((te != null) && (te.eclass == ExprClass.Type)) {
5739                                 Cast cast = new Cast (te, argument, loc);
5740                                 return cast.Resolve (ec);
5741                         }
5742
5743                         //
5744                         // This can either be a type or a delegate invocation.
5745                         // Let's just resolve it and see what we'll get.
5746                         //
5747                         expr = expr.Resolve (ec, ResolveFlags.Type | ResolveFlags.VariableOrValue);
5748                         if (expr == null)
5749                                 return null;
5750
5751                         //
5752                         // Ok, so it's a Cast.
5753                         //
5754                         if (expr.eclass == ExprClass.Type) {
5755                                 Cast cast = new Cast (new TypeExpression (expr.Type, loc), argument, loc);
5756                                 return cast.Resolve (ec);
5757                         }
5758
5759                         //
5760                         // It's a delegate invocation.
5761                         //
5762                         if (!TypeManager.IsDelegateType (expr.Type)) {
5763                                 Error (149, "Method name expected");
5764                                 return null;
5765                         }
5766
5767                         ArrayList args = new ArrayList ();
5768                         args.Add (new Argument (argument, Argument.AType.Expression));
5769                         DelegateInvocation invocation = new DelegateInvocation (expr, args, loc);
5770                         return invocation.Resolve (ec);
5771                 }
5772
5773                 void error201 ()
5774                 {
5775                         Error (201, "Only assignment, call, increment, decrement and new object " +
5776                                "expressions can be used as a statement");
5777                 }
5778
5779                 public override ExpressionStatement ResolveStatement (EmitContext ec)
5780                 {
5781                         //
5782                         // First try to resolve it as a cast.
5783                         //
5784                         TypeExpr te = expr.ResolveAsTypeStep (ec) as TypeExpr;
5785                         if ((te != null) && (te.eclass == ExprClass.Type)) {
5786                                 error201 ();
5787                                 return null;
5788                         }
5789
5790                         //
5791                         // This can either be a type or a delegate invocation.
5792                         // Let's just resolve it and see what we'll get.
5793                         //
5794                         expr = expr.Resolve (ec, ResolveFlags.Type | ResolveFlags.VariableOrValue);
5795                         if ((expr == null) || (expr.eclass == ExprClass.Type)) {
5796                                 error201 ();
5797                                 return null;
5798                         }
5799
5800                         //
5801                         // It's a delegate invocation.
5802                         //
5803                         if (!TypeManager.IsDelegateType (expr.Type)) {
5804                                 Error (149, "Method name expected");
5805                                 return null;
5806                         }
5807
5808                         ArrayList args = new ArrayList ();
5809                         args.Add (new Argument (argument, Argument.AType.Expression));
5810                         DelegateInvocation invocation = new DelegateInvocation (expr, args, loc);
5811                         return invocation.ResolveStatement (ec);
5812                 }
5813
5814                 public override void Emit (EmitContext ec)
5815                 {
5816                         throw new Exception ("Cannot happen");
5817                 }
5818
5819                 public override void EmitStatement (EmitContext ec)
5820                 {
5821                         throw new Exception ("Cannot happen");
5822                 }
5823         }
5824
5825         //
5826         // This class is used to "disable" the code generation for the
5827         // temporary variable when initializing value types.
5828         //
5829         class EmptyAddressOf : EmptyExpression, IMemoryLocation {
5830                 public void AddressOf (EmitContext ec, AddressOp Mode)
5831                 {
5832                         // nothing
5833                 }
5834         }
5835
5836         /// <summary>
5837         ///    Implements the new expression
5838         /// </summary>
5839         public class New : ExpressionStatement, IMemoryLocation {
5840                 public readonly ArrayList Arguments;
5841
5842                 //
5843                 // During bootstrap, it contains the RequestedType,
5844                 // but if `type' is not null, it *might* contain a NewDelegate
5845                 // (because of field multi-initialization)
5846                 //
5847                 public Expression RequestedType;
5848
5849                 MethodBase method = null;
5850
5851                 //
5852                 // If set, the new expression is for a value_target, and
5853                 // we will not leave anything on the stack.
5854                 //
5855                 Expression value_target;
5856                 bool value_target_set = false;
5857                 bool is_type_parameter = false;
5858
5859                 public New (Expression requested_type, ArrayList arguments, Location l)
5860                 {
5861                         RequestedType = requested_type;
5862                         Arguments = arguments;
5863                         loc = l;
5864                 }
5865
5866                 public bool SetValueTypeVariable (Expression value)
5867                 {
5868                         value_target = value;
5869                         value_target_set = true;
5870                         if (!(value_target is IMemoryLocation)){
5871                                 Error_UnexpectedKind ("variable", loc);
5872                                 return false;
5873                         }
5874                         return true;
5875                 }
5876
5877                 //
5878                 // This function is used to disable the following code sequence for
5879                 // value type initialization:
5880                 //
5881                 // AddressOf (temporary)
5882                 // Construct/Init
5883                 // LoadTemporary
5884                 //
5885                 // Instead the provide will have provided us with the address on the
5886                 // stack to store the results.
5887                 //
5888                 static Expression MyEmptyExpression;
5889
5890                 public void DisableTemporaryValueType ()
5891                 {
5892                         if (MyEmptyExpression == null)
5893                                 MyEmptyExpression = new EmptyAddressOf ();
5894
5895                         //
5896                         // To enable this, look into:
5897                         // test-34 and test-89 and self bootstrapping.
5898                         //
5899                         // For instance, we can avoid a copy by using `newobj'
5900                         // instead of Call + Push-temp on value types.
5901 //                      value_target = MyEmptyExpression;
5902                 }
5903
5904
5905                 /// <summary>
5906                 /// Converts complex core type syntax like 'new int ()' to simple constant
5907                 /// </summary>
5908                 Expression Constantify (Type t)
5909                 {
5910                         if (t == TypeManager.int32_type)
5911                                 return new IntConstant (0);
5912                         if (t == TypeManager.uint32_type)
5913                                 return new UIntConstant (0);
5914                         if (t == TypeManager.int64_type)
5915                                 return new LongConstant (0);
5916                         if (t == TypeManager.uint64_type)
5917                                 return new ULongConstant (0);
5918                         if (t == TypeManager.float_type)
5919                                 return new FloatConstant (0);
5920                         if (t == TypeManager.double_type)
5921                                 return new DoubleConstant (0);
5922                         if (t == TypeManager.short_type)
5923                                 return new ShortConstant (0);
5924                         if (t == TypeManager.ushort_type)
5925                                 return new UShortConstant (0);
5926                         if (t == TypeManager.sbyte_type)
5927                                 return new SByteConstant (0);
5928                         if (t == TypeManager.byte_type)
5929                                 return new ByteConstant (0);
5930                         if (t == TypeManager.char_type)
5931                                 return new CharConstant ('\0');
5932                         if (t == TypeManager.bool_type)
5933                                 return new BoolConstant (false);
5934                         if (t == TypeManager.decimal_type)
5935                                 return new DecimalConstant (0);
5936
5937                         return null;
5938                 }
5939
5940                 public override Expression DoResolve (EmitContext ec)
5941                 {
5942                         //
5943                         // The New DoResolve might be called twice when initializing field
5944                         // expressions (see EmitFieldInitializers, the call to
5945                         // GetInitializerExpression will perform a resolve on the expression,
5946                         // and later the assign will trigger another resolution
5947                         //
5948                         // This leads to bugs (#37014)
5949                         //
5950                         if (type != null){
5951                                 if (RequestedType is NewDelegate)
5952                                         return RequestedType;
5953                                 return this;
5954                         }
5955
5956                         TypeExpr texpr = RequestedType.ResolveAsTypeTerminal (ec);
5957                         if (texpr == null)
5958                                 return null;
5959
5960                         if (Arguments == null) {
5961                                 Expression c = Constantify (type);
5962                                 if (c != null)
5963                                         return c;
5964                         }
5965
5966                         type = texpr.Type;
5967                         if (type == null)
5968                                 return null;
5969
5970                         CheckObsoleteAttribute (type);
5971
5972                         bool IsDelegate = TypeManager.IsDelegateType (type);
5973
5974                         if (IsDelegate){
5975                                 RequestedType = (new NewDelegate (type, Arguments, loc)).Resolve (ec);
5976                                 if (RequestedType != null)
5977                                         if (!(RequestedType is DelegateCreation))
5978                                                 throw new Exception ("NewDelegate.Resolve returned a non NewDelegate: " + RequestedType.GetType ());
5979                                 return RequestedType;
5980                         }
5981
5982                         if (type.IsGenericParameter) {
5983                                 if (!TypeManager.HasConstructorConstraint (type)) {
5984                                         Error (304, String.Format (
5985                                                        "Cannot create an instance of the " +
5986                                                        "variable type '{0}' because it " +
5987                                                        "doesn't have the new() constraint",
5988                                                        type));
5989                                         return null;
5990                                 }
5991
5992                                 if ((Arguments != null) && (Arguments.Count != 0)) {
5993                                         Error (417, String.Format (
5994                                                        "`{0}': cannot provide arguments " +
5995                                                        "when creating an instance of a " +
5996                                                        "variable type.", type));
5997                                         return null;
5998                                 }
5999
6000                                 is_type_parameter = true;
6001                                 eclass = ExprClass.Value;
6002                                 return this;
6003                         }
6004
6005                         if (type.IsInterface || type.IsAbstract){
6006                                 Error (144, "It is not possible to create instances of interfaces or abstract classes");
6007                                 return null;
6008                         }
6009
6010                         if (type.IsAbstract && type.IsSealed) {
6011                                 Report.Error (712, loc, "Cannot create an instance of the static class '{0}'", TypeManager.CSharpName (type));
6012                                 return null;
6013                         }
6014
6015                         bool is_struct = type.IsValueType;
6016                         eclass = ExprClass.Value;
6017
6018                         //
6019                         // SRE returns a match for .ctor () on structs (the object constructor),
6020                         // so we have to manually ignore it.
6021                         //
6022                         if (is_struct && Arguments == null)
6023                                 return this;
6024
6025                         Expression ml;
6026                         ml = MemberLookupFinal (ec, type, type, ".ctor",
6027                                                 // For member-lookup, treat 'new Foo (bar)' as call to 'foo.ctor (bar)', where 'foo' is of type 'Foo'.
6028                                                 MemberTypes.Constructor,
6029                                                 AllBindingFlags | BindingFlags.DeclaredOnly, loc);
6030
6031                         if (ml == null)
6032                                 return null;
6033
6034                         if (! (ml is MethodGroupExpr)){
6035                                 if (!is_struct){
6036                                         ml.Error_UnexpectedKind ("method group", loc);
6037                                         return null;
6038                                 }
6039                         }
6040
6041                         if (ml != null) {
6042                                 if (Arguments != null){
6043                                         foreach (Argument a in Arguments){
6044                                                 if (!a.Resolve (ec, loc))
6045                                                         return null;
6046                                         }
6047                                 }
6048
6049                                 method = Invocation.OverloadResolve (
6050                                         ec, (MethodGroupExpr) ml, Arguments, true, loc);
6051
6052                         }
6053
6054                         if (method == null) {
6055                                 if (almostMatchedMembers.Count != 0) {
6056                                         MemberLookupFailed (ec, type, type, ".ctor", null, true, loc);
6057                                         return null;
6058                                 }
6059
6060                                 if (!is_struct || Arguments.Count > 0) {
6061                                         Error (1501, String.Format (
6062                                             "New invocation: Can not find a constructor in `{0}' for this argument list",
6063                                             TypeManager.CSharpName (type)));
6064                                         return null;
6065                                 }
6066                         }
6067
6068                         return this;
6069                 }
6070
6071                 bool DoEmitTypeParameter (EmitContext ec)
6072                 {
6073                         ILGenerator ig = ec.ig;
6074
6075                         ig.Emit (OpCodes.Ldtoken, type);
6076                         ig.Emit (OpCodes.Call, TypeManager.system_type_get_type_from_handle);
6077                         ig.Emit (OpCodes.Call, TypeManager.activator_create_instance);
6078                         ig.Emit (OpCodes.Unbox_Any, type);
6079
6080                         return true;
6081                 }
6082
6083                 //
6084                 // This DoEmit can be invoked in two contexts:
6085                 //    * As a mechanism that will leave a value on the stack (new object)
6086                 //    * As one that wont (init struct)
6087                 //
6088                 // You can control whether a value is required on the stack by passing
6089                 // need_value_on_stack.  The code *might* leave a value on the stack
6090                 // so it must be popped manually
6091                 //
6092                 // If we are dealing with a ValueType, we have a few
6093                 // situations to deal with:
6094                 //
6095                 //    * The target is a ValueType, and we have been provided
6096                 //      the instance (this is easy, we are being assigned).
6097                 //
6098                 //    * The target of New is being passed as an argument,
6099                 //      to a boxing operation or a function that takes a
6100                 //      ValueType.
6101                 //
6102                 //      In this case, we need to create a temporary variable
6103                 //      that is the argument of New.
6104                 //
6105                 // Returns whether a value is left on the stack
6106                 //
6107                 bool DoEmit (EmitContext ec, bool need_value_on_stack)
6108                 {
6109                         bool is_value_type = TypeManager.IsValueType (type);
6110                         ILGenerator ig = ec.ig;
6111
6112                         if (is_value_type){
6113                                 IMemoryLocation ml;
6114
6115                                 // Allow DoEmit() to be called multiple times.
6116                                 // We need to create a new LocalTemporary each time since
6117                                 // you can't share LocalBuilders among ILGeneators.
6118                                 if (!value_target_set)
6119                                         value_target = new LocalTemporary (ec, type);
6120
6121                                 ml = (IMemoryLocation) value_target;
6122                                 ml.AddressOf (ec, AddressOp.Store);
6123                         }
6124
6125                         if (method != null)
6126                                 Invocation.EmitArguments (ec, method, Arguments, false, null);
6127
6128                         if (is_value_type){
6129                                 if (method == null)
6130                                         ig.Emit (OpCodes.Initobj, type);
6131                                 else
6132                                         ig.Emit (OpCodes.Call, (ConstructorInfo) method);
6133                                 if (need_value_on_stack){
6134                                         value_target.Emit (ec);
6135                                         return true;
6136                                 }
6137                                 return false;
6138                         } else {
6139                                 ig.Emit (OpCodes.Newobj, (ConstructorInfo) method);
6140                                 return true;
6141                         }
6142                 }
6143
6144                 public override void Emit (EmitContext ec)
6145                 {
6146                         if (is_type_parameter)
6147                                 DoEmitTypeParameter (ec);
6148                         else
6149                                 DoEmit (ec, true);
6150                 }
6151
6152                 public override void EmitStatement (EmitContext ec)
6153                 {
6154                         if (is_type_parameter)
6155                                 throw new InvalidOperationException ();
6156
6157                         if (DoEmit (ec, false))
6158                                 ec.ig.Emit (OpCodes.Pop);
6159                 }
6160
6161                 public void AddressOf (EmitContext ec, AddressOp Mode)
6162                 {
6163                         if (is_type_parameter)
6164                                 throw new InvalidOperationException ();
6165
6166                         if (!type.IsValueType){
6167                                 //
6168                                 // We throw an exception.  So far, I believe we only need to support
6169                                 // value types:
6170                                 // foreach (int j in new StructType ())
6171                                 // see bug 42390
6172                                 //
6173                                 throw new Exception ("AddressOf should not be used for classes");
6174                         }
6175
6176                         if (!value_target_set)
6177                                 value_target = new LocalTemporary (ec, type);
6178
6179                         IMemoryLocation ml = (IMemoryLocation) value_target;
6180                         ml.AddressOf (ec, AddressOp.Store);
6181                         if (method != null)
6182                                 Invocation.EmitArguments (ec, method, Arguments, false, null);
6183
6184                         if (method == null)
6185                                 ec.ig.Emit (OpCodes.Initobj, type);
6186                         else
6187                                 ec.ig.Emit (OpCodes.Call, (ConstructorInfo) method);
6188
6189                         ((IMemoryLocation) value_target).AddressOf (ec, Mode);
6190                 }
6191         }
6192
6193         /// <summary>
6194         ///   14.5.10.2: Represents an array creation expression.
6195         /// </summary>
6196         ///
6197         /// <remarks>
6198         ///   There are two possible scenarios here: one is an array creation
6199         ///   expression that specifies the dimensions and optionally the
6200         ///   initialization data and the other which does not need dimensions
6201         ///   specified but where initialization data is mandatory.
6202         /// </remarks>
6203         public class ArrayCreation : Expression {
6204                 Expression requested_base_type;
6205                 ArrayList initializers;
6206
6207                 //
6208                 // The list of Argument types.
6209                 // This is used to construct the `newarray' or constructor signature
6210                 //
6211                 ArrayList arguments;
6212
6213                 //
6214                 // Method used to create the array object.
6215                 //
6216                 MethodBase new_method = null;
6217
6218                 Type array_element_type;
6219                 Type underlying_type;
6220                 bool is_one_dimensional = false;
6221                 bool is_builtin_type = false;
6222                 bool expect_initializers = false;
6223                 int num_arguments = 0;
6224                 int dimensions = 0;
6225                 string rank;
6226
6227                 ArrayList array_data;
6228
6229                 Hashtable bounds;
6230
6231                 //
6232                 // The number of array initializers that we can handle
6233                 // via the InitializeArray method - through EmitStaticInitializers
6234                 //
6235                 int num_automatic_initializers;
6236
6237                 const int max_automatic_initializers = 6;
6238
6239                 public ArrayCreation (Expression requested_base_type, ArrayList exprs, string rank, ArrayList initializers, Location l)
6240                 {
6241                         this.requested_base_type = requested_base_type;
6242                         this.initializers = initializers;
6243                         this.rank = rank;
6244                         loc = l;
6245
6246                         arguments = new ArrayList ();
6247
6248                         foreach (Expression e in exprs) {
6249                                 arguments.Add (new Argument (e, Argument.AType.Expression));
6250                                 num_arguments++;
6251                         }
6252                 }
6253
6254                 public ArrayCreation (Expression requested_base_type, string rank, ArrayList initializers, Location l)
6255                 {
6256                         this.requested_base_type = requested_base_type;
6257                         this.initializers = initializers;
6258                         this.rank = rank;
6259                         loc = l;
6260
6261                         //this.rank = rank.Substring (0, rank.LastIndexOf ('['));
6262                         //
6263                         //string tmp = rank.Substring (rank.LastIndexOf ('['));
6264                         //
6265                         //dimensions = tmp.Length - 1;
6266                         expect_initializers = true;
6267                 }
6268
6269                 public Expression FormArrayType (Expression base_type, int idx_count, string rank)
6270                 {
6271                         StringBuilder sb = new StringBuilder (rank);
6272
6273                         sb.Append ("[");
6274                         for (int i = 1; i < idx_count; i++)
6275                                 sb.Append (",");
6276
6277                         sb.Append ("]");
6278
6279                         return new ComposedCast (base_type, sb.ToString (), loc);
6280                 }
6281
6282                 void Error_IncorrectArrayInitializer ()
6283                 {
6284                         Error (178, "Incorrectly structured array initializer");
6285                 }
6286
6287                 public bool CheckIndices (EmitContext ec, ArrayList probe, int idx, bool specified_dims)
6288                 {
6289                         if (specified_dims) {
6290                                 Argument a = (Argument) arguments [idx];
6291
6292                                 if (!a.Resolve (ec, loc))
6293                                         return false;
6294
6295                                 if (!(a.Expr is Constant)) {
6296                                         Error (150, "A constant value is expected");
6297                                         return false;
6298                                 }
6299
6300                                 int value = (int) ((Constant) a.Expr).GetValue ();
6301
6302                                 if (value != probe.Count) {
6303                                         Error_IncorrectArrayInitializer ();
6304                                         return false;
6305                                 }
6306
6307                                 bounds [idx] = value;
6308                         }
6309
6310                         int child_bounds = -1;
6311                         for (int i = 0; i < probe.Count; ++i) {
6312                                 object o = probe [i];
6313                                 if (o is ArrayList) {
6314                                         ArrayList sub_probe = o as ArrayList;
6315                                         int current_bounds = sub_probe.Count;
6316
6317                                         if (child_bounds == -1)
6318                                                 child_bounds = current_bounds;
6319
6320                                         else if (child_bounds != current_bounds){
6321                                                 Error_IncorrectArrayInitializer ();
6322                                                 return false;
6323                                         }
6324                                         if (specified_dims && (idx + 1 >= arguments.Count)){
6325                                                 Error (623, "Array initializers can only be used in a variable or field initializer, try using the new expression");
6326                                                 return false;
6327                                         }
6328
6329                                         bool ret = CheckIndices (ec, sub_probe, idx + 1, specified_dims);
6330                                         if (!ret)
6331                                                 return false;
6332                                 } else {
6333                                         if (child_bounds != -1){
6334                                                 Error_IncorrectArrayInitializer ();
6335                                                 return false;
6336                                         }
6337
6338                                         Expression tmp = (Expression) o;
6339                                         tmp = tmp.Resolve (ec);
6340                                         probe [i] = tmp;
6341                                         if (tmp == null)
6342                                                 return false;
6343
6344                                         // Console.WriteLine ("I got: " + tmp);
6345                                         // Handle initialization from vars, fields etc.
6346
6347                                         Expression conv = Convert.ImplicitConversionRequired (
6348                                                 ec, tmp, underlying_type, loc);
6349
6350                                         if (conv == null)
6351                                                 return false;
6352
6353                                         if (conv is StringConstant || conv is DecimalConstant || conv is NullCast) {
6354                                                 // These are subclasses of Constant that can appear as elements of an
6355                                                 // array that cannot be statically initialized (with num_automatic_initializers
6356                                                 // > max_automatic_initializers), so num_automatic_initializers should be left as zero.
6357                                                 array_data.Add (conv);
6358                                         } else if (conv is Constant) {
6359                                                 // These are the types of Constant that can appear in arrays that can be
6360                                                 // statically allocated.
6361                                                 array_data.Add (conv);
6362                                                 num_automatic_initializers++;
6363                                         } else
6364                                                 array_data.Add (conv);
6365                                 }
6366                         }
6367
6368                         return true;
6369                 }
6370
6371                 public void UpdateIndices (EmitContext ec)
6372                 {
6373                         int i = 0;
6374                         for (ArrayList probe = initializers; probe != null;) {
6375                                 if (probe.Count > 0 && probe [0] is ArrayList) {
6376                                         Expression e = new IntConstant (probe.Count);
6377                                         arguments.Add (new Argument (e, Argument.AType.Expression));
6378
6379                                         bounds [i++] =  probe.Count;
6380
6381                                         probe = (ArrayList) probe [0];
6382
6383                                 } else {
6384                                         Expression e = new IntConstant (probe.Count);
6385                                         arguments.Add (new Argument (e, Argument.AType.Expression));
6386
6387                                         bounds [i++] = probe.Count;
6388                                         probe = null;
6389                                 }
6390                         }
6391
6392                 }
6393
6394                 public bool ValidateInitializers (EmitContext ec, Type array_type)
6395                 {
6396                         if (initializers == null) {
6397                                 if (expect_initializers)
6398                                         return false;
6399                                 else
6400                                         return true;
6401                         }
6402
6403                         if (underlying_type == null)
6404                                 return false;
6405
6406                         //
6407                         // We use this to store all the date values in the order in which we
6408                         // will need to store them in the byte blob later
6409                         //
6410                         array_data = new ArrayList ();
6411                         bounds = new Hashtable ();
6412
6413                         bool ret;
6414
6415                         if (arguments != null) {
6416                                 ret = CheckIndices (ec, initializers, 0, true);
6417                                 return ret;
6418                         } else {
6419                                 arguments = new ArrayList ();
6420
6421                                 ret = CheckIndices (ec, initializers, 0, false);
6422
6423                                 if (!ret)
6424                                         return false;
6425
6426                                 UpdateIndices (ec);
6427
6428                                 if (arguments.Count != dimensions) {
6429                                         Error_IncorrectArrayInitializer ();
6430                                         return false;
6431                                 }
6432
6433                                 return ret;
6434                         }
6435                 }
6436
6437                 //
6438                 // Creates the type of the array
6439                 //
6440                 bool LookupType (EmitContext ec)
6441                 {
6442                         StringBuilder array_qualifier = new StringBuilder (rank);
6443
6444                         //
6445                         // `In the first form allocates an array instace of the type that results
6446                         // from deleting each of the individual expression from the expression list'
6447                         //
6448                         if (num_arguments > 0) {
6449                                 array_qualifier.Append ("[");
6450                                 for (int i = num_arguments-1; i > 0; i--)
6451                                         array_qualifier.Append (",");
6452                                 array_qualifier.Append ("]");
6453                         }
6454
6455                         //
6456                         // Lookup the type
6457                         //
6458                         TypeExpr array_type_expr;
6459                         array_type_expr = new ComposedCast (requested_base_type, array_qualifier.ToString (), loc);
6460                         array_type_expr = array_type_expr.ResolveAsTypeTerminal (ec);
6461                         if (array_type_expr == null)
6462                                 return false;
6463
6464                         type = array_type_expr.Type;
6465
6466                         if (!type.IsArray) {
6467                                 Error (622, "Can only use array initializer expressions to assign to array types. Try using a new expression instead.");
6468                                 return false;
6469                         }
6470                         underlying_type = TypeManager.GetElementType (type);
6471                         dimensions = type.GetArrayRank ();
6472
6473                         return true;
6474                 }
6475
6476                 public override Expression DoResolve (EmitContext ec)
6477                 {
6478                         int arg_count;
6479
6480                         if (!LookupType (ec))
6481                                 return null;
6482
6483                         //
6484                         // First step is to validate the initializers and fill
6485                         // in any missing bits
6486                         //
6487                         if (!ValidateInitializers (ec, type))
6488                                 return null;
6489
6490                         if (arguments == null)
6491                                 arg_count = 0;
6492                         else {
6493                                 arg_count = arguments.Count;
6494                                 foreach (Argument a in arguments){
6495                                         if (!a.Resolve (ec, loc))
6496                                                 return null;
6497
6498                                         Expression real_arg = ExpressionToArrayArgument (ec, a.Expr, loc);
6499                                         if (real_arg == null)
6500                                                 return null;
6501
6502                                         a.Expr = real_arg;
6503                                 }
6504                         }
6505
6506                         array_element_type = TypeManager.GetElementType (type);
6507
6508                         if (array_element_type.IsAbstract && array_element_type.IsSealed) {
6509                                 Report.Error (719, loc, "'{0}': array elements cannot be of static type", TypeManager.CSharpName (array_element_type));
6510                                 return null;
6511                         }
6512
6513                         if (arg_count == 1) {
6514                                 is_one_dimensional = true;
6515                                 eclass = ExprClass.Value;
6516                                 return this;
6517                         }
6518
6519                         is_builtin_type = TypeManager.IsBuiltinType (type);
6520
6521                         if (is_builtin_type) {
6522                                 Expression ml;
6523
6524                                 ml = MemberLookup (ec, type, ".ctor", MemberTypes.Constructor,
6525                                                    AllBindingFlags, loc);
6526
6527                                 if (!(ml is MethodGroupExpr)) {
6528                                         ml.Error_UnexpectedKind ("method group", loc);
6529                                         return null;
6530                                 }
6531
6532                                 if (ml == null) {
6533                                         Error (-6, "New invocation: Can not find a constructor for " +
6534                                                       "this argument list");
6535                                         return null;
6536                                 }
6537
6538                                 new_method = Invocation.OverloadResolve (
6539                                         ec, (MethodGroupExpr) ml, arguments, false, loc);
6540
6541                                 if (new_method == null) {
6542                                         Error (-6, "New invocation: Can not find a constructor for " +
6543                                                       "this argument list");
6544                                         return null;
6545                                 }
6546
6547                                 eclass = ExprClass.Value;
6548                                 return this;
6549                         } else {
6550                                 ModuleBuilder mb = CodeGen.Module.Builder;
6551                                 ArrayList args = new ArrayList ();
6552
6553                                 if (arguments != null) {
6554                                         for (int i = 0; i < arg_count; i++)
6555                                                 args.Add (TypeManager.int32_type);
6556                                 }
6557
6558                                 Type [] arg_types = null;
6559
6560                                 if (args.Count > 0)
6561                                         arg_types = new Type [args.Count];
6562
6563                                 args.CopyTo (arg_types, 0);
6564
6565                                 new_method = mb.GetArrayMethod (type, ".ctor", CallingConventions.HasThis, null,
6566                                                             arg_types);
6567
6568                                 if (new_method == null) {
6569                                         Error (-6, "New invocation: Can not find a constructor for " +
6570                                                       "this argument list");
6571                                         return null;
6572                                 }
6573
6574                                 eclass = ExprClass.Value;
6575                                 return this;
6576                         }
6577                 }
6578
6579                 public static byte [] MakeByteBlob (ArrayList array_data, Type underlying_type, Location loc)
6580                 {
6581                         int factor;
6582                         byte [] data;
6583                         byte [] element;
6584                         int count = array_data.Count;
6585
6586                         if (underlying_type.IsEnum)
6587                                 underlying_type = TypeManager.EnumToUnderlying (underlying_type);
6588
6589                         factor = GetTypeSize (underlying_type);
6590                         if (factor == 0)
6591                                 throw new Exception ("unrecognized type in MakeByteBlob: " + underlying_type);
6592
6593                         data = new byte [(count * factor + 4) & ~3];
6594                         int idx = 0;
6595
6596                         for (int i = 0; i < count; ++i) {
6597                                 object v = array_data [i];
6598
6599                                 if (v is EnumConstant)
6600                                         v = ((EnumConstant) v).Child;
6601
6602                                 if (v is Constant && !(v is StringConstant))
6603                                         v = ((Constant) v).GetValue ();
6604                                 else {
6605                                         idx += factor;
6606                                         continue;
6607                                 }
6608
6609                                 if (underlying_type == TypeManager.int64_type){
6610                                         if (!(v is Expression)){
6611                                                 long val = (long) v;
6612
6613                                                 for (int j = 0; j < factor; ++j) {
6614                                                         data [idx + j] = (byte) (val & 0xFF);
6615                                                         val = (val >> 8);
6616                                                 }
6617                                         }
6618                                 } else if (underlying_type == TypeManager.uint64_type){
6619                                         if (!(v is Expression)){
6620                                                 ulong val = (ulong) v;
6621
6622                                                 for (int j = 0; j < factor; ++j) {
6623                                                         data [idx + j] = (byte) (val & 0xFF);
6624                                                         val = (val >> 8);
6625                                                 }
6626                                         }
6627                                 } else if (underlying_type == TypeManager.float_type) {
6628                                         if (!(v is Expression)){
6629                                                 element = BitConverter.GetBytes ((float) v);
6630
6631                                                 for (int j = 0; j < factor; ++j)
6632                                                         data [idx + j] = element [j];
6633                                         }
6634                                 } else if (underlying_type == TypeManager.double_type) {
6635                                         if (!(v is Expression)){
6636                                                 element = BitConverter.GetBytes ((double) v);
6637
6638                                                 for (int j = 0; j < factor; ++j)
6639                                                         data [idx + j] = element [j];
6640                                         }
6641                                 } else if (underlying_type == TypeManager.char_type){
6642                                         if (!(v is Expression)){
6643                                                 int val = (int) ((char) v);
6644
6645                                                 data [idx] = (byte) (val & 0xff);
6646                                                 data [idx+1] = (byte) (val >> 8);
6647                                         }
6648                                 } else if (underlying_type == TypeManager.short_type){
6649                                         if (!(v is Expression)){
6650                                                 int val = (int) ((short) v);
6651
6652                                                 data [idx] = (byte) (val & 0xff);
6653                                                 data [idx+1] = (byte) (val >> 8);
6654                                         }
6655                                 } else if (underlying_type == TypeManager.ushort_type){
6656                                         if (!(v is Expression)){
6657                                                 int val = (int) ((ushort) v);
6658
6659                                                 data [idx] = (byte) (val & 0xff);
6660                                                 data [idx+1] = (byte) (val >> 8);
6661                                         }
6662                                 } else if (underlying_type == TypeManager.int32_type) {
6663                                         if (!(v is Expression)){
6664                                                 int val = (int) v;
6665
6666                                                 data [idx]   = (byte) (val & 0xff);
6667                                                 data [idx+1] = (byte) ((val >> 8) & 0xff);
6668                                                 data [idx+2] = (byte) ((val >> 16) & 0xff);
6669                                                 data [idx+3] = (byte) (val >> 24);
6670                                         }
6671                                 } else if (underlying_type == TypeManager.uint32_type) {
6672                                         if (!(v is Expression)){
6673                                                 uint val = (uint) v;
6674
6675                                                 data [idx]   = (byte) (val & 0xff);
6676                                                 data [idx+1] = (byte) ((val >> 8) & 0xff);
6677                                                 data [idx+2] = (byte) ((val >> 16) & 0xff);
6678                                                 data [idx+3] = (byte) (val >> 24);
6679                                         }
6680                                 } else if (underlying_type == TypeManager.sbyte_type) {
6681                                         if (!(v is Expression)){
6682                                                 sbyte val = (sbyte) v;
6683                                                 data [idx] = (byte) val;
6684                                         }
6685                                 } else if (underlying_type == TypeManager.byte_type) {
6686                                         if (!(v is Expression)){
6687                                                 byte val = (byte) v;
6688                                                 data [idx] = (byte) val;
6689                                         }
6690                                 } else if (underlying_type == TypeManager.bool_type) {
6691                                         if (!(v is Expression)){
6692                                                 bool val = (bool) v;
6693                                                 data [idx] = (byte) (val ? 1 : 0);
6694                                         }
6695                                 } else if (underlying_type == TypeManager.decimal_type){
6696                                         if (!(v is Expression)){
6697                                                 int [] bits = Decimal.GetBits ((decimal) v);
6698                                                 int p = idx;
6699
6700                                                 // FIXME: For some reason, this doesn't work on the MS runtime.
6701                                                 int [] nbits = new int [4];
6702                                                 nbits [0] = bits [3];
6703                                                 nbits [1] = bits [2];
6704                                                 nbits [2] = bits [0];
6705                                                 nbits [3] = bits [1];
6706
6707                                                 for (int j = 0; j < 4; j++){
6708                                                         data [p++] = (byte) (nbits [j] & 0xff);
6709                                                         data [p++] = (byte) ((nbits [j] >> 8) & 0xff);
6710                                                         data [p++] = (byte) ((nbits [j] >> 16) & 0xff);
6711                                                         data [p++] = (byte) (nbits [j] >> 24);
6712                                                 }
6713                                         }
6714                                 } else
6715                                         throw new Exception ("Unrecognized type in MakeByteBlob: " + underlying_type);
6716
6717                                 idx += factor;
6718                         }
6719
6720                         return data;
6721                 }
6722
6723                 //
6724                 // Emits the initializers for the array
6725                 //
6726                 void EmitStaticInitializers (EmitContext ec)
6727                 {
6728                         //
6729                         // First, the static data
6730                         //
6731                         FieldBuilder fb;
6732                         ILGenerator ig = ec.ig;
6733
6734                         byte [] data = MakeByteBlob (array_data, underlying_type, loc);
6735
6736                         fb = RootContext.MakeStaticData (data);
6737
6738                         ig.Emit (OpCodes.Dup);
6739                         ig.Emit (OpCodes.Ldtoken, fb);
6740                         ig.Emit (OpCodes.Call,
6741                                  TypeManager.void_initializearray_array_fieldhandle);
6742                 }
6743
6744                 //
6745                 // Emits pieces of the array that can not be computed at compile
6746                 // time (variables and string locations).
6747                 //
6748                 // This always expect the top value on the stack to be the array
6749                 //
6750                 void EmitDynamicInitializers (EmitContext ec)
6751                 {
6752                         ILGenerator ig = ec.ig;
6753                         int dims = bounds.Count;
6754                         int [] current_pos = new int [dims];
6755                         int top = array_data.Count;
6756
6757                         MethodInfo set = null;
6758
6759                         if (dims != 1){
6760                                 Type [] args;
6761                                 ModuleBuilder mb = null;
6762                                 mb = CodeGen.Module.Builder;
6763                                 args = new Type [dims + 1];
6764
6765                                 int j;
6766                                 for (j = 0; j < dims; j++)
6767                                         args [j] = TypeManager.int32_type;
6768
6769                                 args [j] = array_element_type;
6770
6771                                 set = mb.GetArrayMethod (
6772                                         type, "Set",
6773                                         CallingConventions.HasThis | CallingConventions.Standard,
6774                                         TypeManager.void_type, args);
6775                         }
6776
6777                         for (int i = 0; i < top; i++){
6778
6779                                 Expression e = null;
6780
6781                                 if (array_data [i] is Expression)
6782                                         e = (Expression) array_data [i];
6783
6784                                 if (e != null) {
6785                                         //
6786                                         // Basically we do this for string literals and
6787                                         // other non-literal expressions
6788                                         //
6789                                         if (e is EnumConstant){
6790                                                 e = ((EnumConstant) e).Child;
6791                                         }
6792
6793                                         if (e is StringConstant || e is DecimalConstant || !(e is Constant) ||
6794                                             num_automatic_initializers <= max_automatic_initializers) {
6795                                                 Type etype = e.Type;
6796
6797                                                 ig.Emit (OpCodes.Dup);
6798
6799                                                 for (int idx = 0; idx < dims; idx++)
6800                                                         IntConstant.EmitInt (ig, current_pos [idx]);
6801
6802                                                 //
6803                                                 // If we are dealing with a struct, get the
6804                                                 // address of it, so we can store it.
6805                                                 //
6806                                                 if ((dims == 1) && etype.IsValueType &&
6807                                                     (!TypeManager.IsBuiltinOrEnum (etype) ||
6808                                                      etype == TypeManager.decimal_type)) {
6809                                                         if (e is New){
6810                                                                 New n = (New) e;
6811
6812                                                                 //
6813                                                                 // Let new know that we are providing
6814                                                                 // the address where to store the results
6815                                                                 //
6816                                                                 n.DisableTemporaryValueType ();
6817                                                         }
6818
6819                                                         ig.Emit (OpCodes.Ldelema, etype);
6820                                                 }
6821
6822                                                 e.Emit (ec);
6823
6824                                                 if (dims == 1) {
6825                                                         bool is_stobj, has_type_arg;
6826                                                         OpCode op = ArrayAccess.GetStoreOpcode (
6827                                                                 etype, out is_stobj,
6828                                                                 out has_type_arg);
6829                                                         if (is_stobj)
6830                                                                 ig.Emit (OpCodes.Stobj, etype);
6831                                                         else if (has_type_arg)
6832                                                                 ig.Emit (op, etype);
6833                                                         else
6834                                                                 ig.Emit (op);
6835                                                 } else
6836                                                         ig.Emit (OpCodes.Call, set);
6837                                         }
6838                                 }
6839
6840                                 //
6841                                 // Advance counter
6842                                 //
6843                                 for (int j = dims - 1; j >= 0; j--){
6844                                         current_pos [j]++;
6845                                         if (current_pos [j] < (int) bounds [j])
6846                                                 break;
6847                                         current_pos [j] = 0;
6848                                 }
6849                         }
6850                 }
6851
6852                 void EmitArrayArguments (EmitContext ec)
6853                 {
6854                         ILGenerator ig = ec.ig;
6855
6856                         foreach (Argument a in arguments) {
6857                                 Type atype = a.Type;
6858                                 a.Emit (ec);
6859
6860                                 if (atype == TypeManager.uint64_type)
6861                                         ig.Emit (OpCodes.Conv_Ovf_U4);
6862                                 else if (atype == TypeManager.int64_type)
6863                                         ig.Emit (OpCodes.Conv_Ovf_I4);
6864                         }
6865                 }
6866
6867                 public override void Emit (EmitContext ec)
6868                 {
6869                         ILGenerator ig = ec.ig;
6870
6871                         EmitArrayArguments (ec);
6872                         if (is_one_dimensional)
6873                                 ig.Emit (OpCodes.Newarr, array_element_type);
6874                         else {
6875                                 if (is_builtin_type)
6876                                         ig.Emit (OpCodes.Newobj, (ConstructorInfo) new_method);
6877                                 else
6878                                         ig.Emit (OpCodes.Newobj, (MethodInfo) new_method);
6879                         }
6880
6881                         if (initializers != null){
6882                                 //
6883                                 // FIXME: Set this variable correctly.
6884                                 //
6885                                 bool dynamic_initializers = true;
6886
6887                                 // This will never be true for array types that cannot be statically
6888                                 // initialized. num_automatic_initializers will always be zero.  See
6889                                 // CheckIndices.
6890                                         if (num_automatic_initializers > max_automatic_initializers)
6891                                                 EmitStaticInitializers (ec);
6892
6893                                 if (dynamic_initializers)
6894                                         EmitDynamicInitializers (ec);
6895                         }
6896                 }
6897
6898                 public object EncodeAsAttribute ()
6899                 {
6900                         if (!is_one_dimensional){
6901                                 Report.Error (-211, Location, "attribute can not encode multi-dimensional arrays");
6902                                 return null;
6903                         }
6904
6905                         if (array_data == null){
6906                                 Report.Error (-212, Location, "array should be initialized when passing it to an attribute");
6907                                 return null;
6908                         }
6909
6910                         object [] ret = new object [array_data.Count];
6911                         int i = 0;
6912                         foreach (Expression e in array_data){
6913                                 object v;
6914
6915                                 if (e is NullLiteral)
6916                                         v = null;
6917                                 else {
6918                                         if (!Attribute.GetAttributeArgumentExpression (e, Location, array_element_type, out v))
6919                                                 return null;
6920                                 }
6921                                 ret [i++] = v;
6922                         }
6923                         return ret;
6924                 }
6925         }
6926
6927         /// <summary>
6928         ///   Represents the `this' construct
6929         /// </summary>
6930         public class This : Expression, IAssignMethod, IMemoryLocation, IVariable {
6931
6932                 Block block;
6933                 VariableInfo variable_info;
6934
6935                 public This (Block block, Location loc)
6936                 {
6937                         this.loc = loc;
6938                         this.block = block;
6939                 }
6940
6941                 public This (Location loc)
6942                 {
6943                         this.loc = loc;
6944                 }
6945
6946                 public VariableInfo VariableInfo {
6947                         get { return variable_info; }
6948                 }
6949
6950                 public bool VerifyFixed (bool is_expression)
6951                 {
6952                         if ((variable_info == null) || (variable_info.LocalInfo == null))
6953                                 return false;
6954                         else
6955                                 return variable_info.LocalInfo.IsFixed;
6956                 }
6957
6958                 public bool ResolveBase (EmitContext ec)
6959                 {
6960                         eclass = ExprClass.Variable;
6961
6962                         if (ec.TypeContainer.CurrentType != null)
6963                                 type = ec.TypeContainer.CurrentType;
6964                         else
6965                                 type = ec.ContainerType;
6966
6967                         if (ec.IsStatic) {
6968                                 Error (26, "Keyword this not valid in static code");
6969                                 return false;
6970                         }
6971
6972                         if ((block != null) && (block.ThisVariable != null))
6973                                 variable_info = block.ThisVariable.VariableInfo;
6974
6975                         if (ec.CurrentAnonymousMethod != null)
6976                                 ec.CaptureThis ();
6977
6978                         return true;
6979                 }
6980
6981                 public override Expression DoResolve (EmitContext ec)
6982                 {
6983                         if (!ResolveBase (ec))
6984                                 return null;
6985
6986                         if ((variable_info != null) && !variable_info.IsAssigned (ec)) {
6987                                 Error (188, "The this object cannot be used before all " +
6988                                        "of its fields are assigned to");
6989                                 variable_info.SetAssigned (ec);
6990                                 return this;
6991                         }
6992
6993                         if (ec.IsFieldInitializer) {
6994                                 Error (27, "Keyword `this' can't be used outside a constructor, " +
6995                                        "a method or a property.");
6996                                 return null;
6997                         }
6998
6999                         return this;
7000                 }
7001
7002                 override public Expression DoResolveLValue (EmitContext ec, Expression right_side)
7003                 {
7004                         if (!ResolveBase (ec))
7005                                 return null;
7006
7007                         if (variable_info != null)
7008                                 variable_info.SetAssigned (ec);
7009
7010                         if (ec.TypeContainer is Class){
7011                                 Error (1604, "Cannot assign to 'this' because it is read-only");
7012                                 return null;
7013                         }
7014
7015                         return this;
7016                 }
7017
7018                 public void Emit (EmitContext ec, bool leave_copy)
7019                 {
7020                         Emit (ec);
7021                         if (leave_copy)
7022                                 ec.ig.Emit (OpCodes.Dup);
7023                 }
7024
7025                 public void EmitAssign (EmitContext ec, Expression source, bool leave_copy, bool prepare_for_load)
7026                 {
7027                         ILGenerator ig = ec.ig;
7028
7029                         if (ec.TypeContainer is Struct){
7030                                 ec.EmitThis ();
7031                                 source.Emit (ec);
7032                                 if (leave_copy)
7033                                         ec.ig.Emit (OpCodes.Dup);
7034                                 ig.Emit (OpCodes.Stobj, type);
7035                         } else {
7036                                 throw new Exception ("how did you get here");
7037                         }
7038                 }
7039
7040                 public override void Emit (EmitContext ec)
7041                 {
7042                         ILGenerator ig = ec.ig;
7043
7044                         ec.EmitThis ();
7045                         if (ec.TypeContainer is Struct)
7046                                 ig.Emit (OpCodes.Ldobj, type);
7047                 }
7048
7049                 public override int GetHashCode()
7050                 {
7051                         return block.GetHashCode ();
7052                 }
7053
7054                 public override bool Equals (object obj)
7055                 {
7056                         This t = obj as This;
7057                         if (t == null)
7058                                 return false;
7059
7060                         return block == t.block;
7061                 }
7062
7063                 public void AddressOf (EmitContext ec, AddressOp mode)
7064                 {
7065                         ec.EmitThis ();
7066
7067                         // FIMXE
7068                         // FIGURE OUT WHY LDARG_S does not work
7069                         //
7070                         // consider: struct X { int val; int P { set { val = value; }}}
7071                         //
7072                         // Yes, this looks very bad. Look at `NOTAS' for
7073                         // an explanation.
7074                         // ec.ig.Emit (OpCodes.Ldarga_S, (byte) 0);
7075                 }
7076         }
7077
7078         /// <summary>
7079         ///   Represents the `__arglist' construct
7080         /// </summary>
7081         public class ArglistAccess : Expression
7082         {
7083                 public ArglistAccess (Location loc)
7084                 {
7085                         this.loc = loc;
7086                 }
7087
7088                 public bool ResolveBase (EmitContext ec)
7089                 {
7090                         eclass = ExprClass.Variable;
7091                         type = TypeManager.runtime_argument_handle_type;
7092                         return true;
7093                 }
7094
7095                 public override Expression DoResolve (EmitContext ec)
7096                 {
7097                         if (!ResolveBase (ec))
7098                                 return null;
7099
7100                         if (ec.IsFieldInitializer || !ec.CurrentBlock.HasVarargs) {
7101                                 Error (190, "The __arglist construct is valid only within " +
7102                                        "a variable argument method.");
7103                                 return null;
7104                         }
7105
7106                         return this;
7107                 }
7108
7109                 public override void Emit (EmitContext ec)
7110                 {
7111                         ec.ig.Emit (OpCodes.Arglist);
7112                 }
7113         }
7114
7115         /// <summary>
7116         ///   Represents the `__arglist (....)' construct
7117         /// </summary>
7118         public class Arglist : Expression
7119         {
7120                 public readonly Argument[] Arguments;
7121
7122                 public Arglist (Argument[] args, Location l)
7123                 {
7124                         Arguments = args;
7125                         loc = l;
7126                 }
7127
7128                 public Type[] ArgumentTypes {
7129                         get {
7130                                 Type[] retval = new Type [Arguments.Length];
7131                                 for (int i = 0; i < Arguments.Length; i++)
7132                                         retval [i] = Arguments [i].Type;
7133                                 return retval;
7134                         }
7135                 }
7136
7137                 public override Expression DoResolve (EmitContext ec)
7138                 {
7139                         eclass = ExprClass.Variable;
7140                         type = TypeManager.runtime_argument_handle_type;
7141
7142                         foreach (Argument arg in Arguments) {
7143                                 if (!arg.Resolve (ec, loc))
7144                                         return null;
7145                         }
7146
7147                         return this;
7148                 }
7149
7150                 public override void Emit (EmitContext ec)
7151                 {
7152                         foreach (Argument arg in Arguments)
7153                                 arg.Emit (ec);
7154                 }
7155         }
7156
7157         //
7158         // This produces the value that renders an instance, used by the iterators code
7159         //
7160         public class ProxyInstance : Expression, IMemoryLocation  {
7161                 public override Expression DoResolve (EmitContext ec)
7162                 {
7163                         eclass = ExprClass.Variable;
7164                         type = ec.ContainerType;
7165                         return this;
7166                 }
7167
7168                 public override void Emit (EmitContext ec)
7169                 {
7170                         ec.ig.Emit (OpCodes.Ldarg_0);
7171
7172                 }
7173
7174                 public void AddressOf (EmitContext ec, AddressOp mode)
7175                 {
7176                         ec.ig.Emit (OpCodes.Ldarg_0);
7177                 }
7178         }
7179
7180         /// <summary>
7181         ///   Implements the typeof operator
7182         /// </summary>
7183         public class TypeOf : Expression {
7184                 public Expression QueriedType;
7185                 protected Type typearg;
7186
7187                 public TypeOf (Expression queried_type, Location l)
7188                 {
7189                         QueriedType = queried_type;
7190                         loc = l;
7191                 }
7192
7193                 public override Expression DoResolve (EmitContext ec)
7194                 {
7195                         TypeExpr texpr = QueriedType.ResolveAsTypeTerminal (ec);
7196                         if (texpr == null)
7197                                 return null;
7198
7199                         typearg = texpr.Type;
7200
7201                         if (typearg == TypeManager.void_type) {
7202                                 Error (673, "System.Void cannot be used from C# - " +
7203                                        "use typeof (void) to get the void type object");
7204                                 return null;
7205                         }
7206
7207                         if (typearg.IsPointer && !ec.InUnsafe){
7208                                 UnsafeError (loc);
7209                                 return null;
7210                         }
7211                         CheckObsoleteAttribute (typearg);
7212
7213                         type = TypeManager.type_type;
7214                         eclass = ExprClass.Type;
7215                         return this;
7216                 }
7217
7218                 public override void Emit (EmitContext ec)
7219                 {
7220                         ec.ig.Emit (OpCodes.Ldtoken, typearg);
7221                         ec.ig.Emit (OpCodes.Call, TypeManager.system_type_get_type_from_handle);
7222                 }
7223
7224                 public Type TypeArg {
7225                         get { return typearg; }
7226                 }
7227         }
7228
7229         /// <summary>
7230         ///   Implements the `typeof (void)' operator
7231         /// </summary>
7232         public class TypeOfVoid : TypeOf {
7233                 public TypeOfVoid (Location l) : base (null, l)
7234                 {
7235                         loc = l;
7236                 }
7237
7238                 public override Expression DoResolve (EmitContext ec)
7239                 {
7240                         type = TypeManager.type_type;
7241                         typearg = TypeManager.void_type;
7242                         eclass = ExprClass.Type;
7243                         return this;
7244                 }
7245         }
7246
7247         /// <summary>
7248         ///   Implements the sizeof expression
7249         /// </summary>
7250         public class SizeOf : Expression {
7251                 public Expression QueriedType;
7252                 Type type_queried;
7253
7254                 public SizeOf (Expression queried_type, Location l)
7255                 {
7256                         this.QueriedType = queried_type;
7257                         loc = l;
7258                 }
7259
7260                 public override Expression DoResolve (EmitContext ec)
7261                 {
7262                         TypeExpr texpr = QueriedType.ResolveAsTypeTerminal (ec);
7263                         if (texpr == null)
7264                                 return null;
7265
7266                         if (texpr is TypeParameterExpr){
7267                                 ((TypeParameterExpr)texpr).Error_CannotUseAsUnmanagedType (loc);
7268                                 return null;
7269                         }
7270
7271                         type_queried = texpr.Type;
7272
7273                         int size_of = GetTypeSize (type_queried);
7274                         if (size_of > 0) {
7275                                 return new IntConstant (size_of);
7276                         }
7277
7278                         if (!ec.InUnsafe) {
7279                                 Report.Error (233, loc, "'{0}' does not have a predefined size, therefore sizeof can only be used in an unsafe context (consider using System.Runtime.InteropServices.Marshal.SizeOf)",
7280                                          TypeManager.CSharpName (type_queried));
7281                                 return null;
7282                         }
7283
7284                         CheckObsoleteAttribute (type_queried);
7285
7286                         if (!TypeManager.IsUnmanagedType (type_queried)){
7287                                 Report.Error (208, loc, "Cannot take the size of an unmanaged type (" + TypeManager.CSharpName (type_queried) + ")");
7288                                 return null;
7289                         }
7290
7291                         type = TypeManager.int32_type;
7292                         eclass = ExprClass.Value;
7293                         return this;
7294                 }
7295
7296                 public override void Emit (EmitContext ec)
7297                 {
7298                         int size = GetTypeSize (type_queried);
7299
7300                         if (size == 0)
7301                                 ec.ig.Emit (OpCodes.Sizeof, type_queried);
7302                         else
7303                                 IntConstant.EmitInt (ec.ig, size);
7304                 }
7305         }
7306
7307         /// <summary>
7308         ///   Implements the member access expression
7309         /// </summary>
7310         public class MemberAccess : Expression {
7311                 public string Identifier;
7312                 protected Expression expr;
7313                 protected TypeArguments args;
7314
7315                 public MemberAccess (Expression expr, string id, Location l)
7316                 {
7317                         this.expr = expr;
7318                         Identifier = id;
7319                         loc = l;
7320                 }
7321
7322                 public MemberAccess (Expression expr, string id, TypeArguments args,
7323                                      Location l)
7324                         : this (expr, id, l)
7325                 {
7326                         this.args = args;
7327                 }
7328
7329                 public Expression Expr {
7330                         get {
7331                                 return expr;
7332                         }
7333                 }
7334
7335                 public virtual Expression DoResolve (EmitContext ec, Expression right_side,
7336                                                      ResolveFlags flags)
7337                 {
7338                         if (type != null)
7339                                 throw new Exception ();
7340
7341                         //
7342                         // Resolve the expression with flow analysis turned off, we'll do the definite
7343                         // assignment checks later.  This is because we don't know yet what the expression
7344                         // will resolve to - it may resolve to a FieldExpr and in this case we must do the
7345                         // definite assignment check on the actual field and not on the whole struct.
7346                         //
7347
7348                         SimpleName original = expr as SimpleName;
7349                         expr = expr.Resolve (ec, flags | ResolveFlags.Intermediate | ResolveFlags.DisableFlowAnalysis);
7350                         if (expr == null)
7351                                 return null;
7352
7353                         if (expr is Namespace) {
7354                                 Namespace ns = (Namespace) expr;
7355                                 string lookup_id = MemberName.MakeName (Identifier, args);
7356                                 FullNamedExpression retval = ns.Lookup (ec.DeclSpace, lookup_id, loc);
7357                                 if ((retval != null) && (args != null))
7358                                         retval = new ConstructedType (retval, args, loc).ResolveAsTypeStep (ec);
7359                                 if (retval == null)
7360                                         Report.Error (234, loc, "The type or namespace name `{0}' could not be found in namespace `{1}'", Identifier, ns.FullName);
7361                                 return retval;
7362                         }
7363
7364                         //
7365                         // TODO: I mailed Ravi about this, and apparently we can get rid
7366                         // of this and put it in the right place.
7367                         //
7368                         // Handle enums here when they are in transit.
7369                         // Note that we cannot afford to hit MemberLookup in this case because
7370                         // it will fail to find any members at all
7371                         //
7372
7373                         Type expr_type;
7374                         if (expr is TypeExpr){
7375                                 expr_type = expr.Type;
7376
7377                                 if (!ec.DeclSpace.CheckAccessLevel (expr_type)){
7378                                         Report.Error (122, loc, "'{0}' is inaccessible due to its protection level", expr_type);
7379                                         return null;
7380                                 }
7381
7382                                 if (expr_type == TypeManager.enum_type || expr_type.IsSubclassOf (TypeManager.enum_type)){
7383                                         Enum en = TypeManager.LookupEnum (expr_type);
7384
7385                                         if (en != null) {
7386                                                 object value = en.LookupEnumValue (Identifier, loc);
7387
7388                                                 if (value != null){
7389                                                         MemberCore mc = en.GetDefinition (Identifier);
7390                                                         ObsoleteAttribute oa = mc.GetObsoleteAttribute (en);
7391                                                         if (oa != null) {
7392                                                                 AttributeTester.Report_ObsoleteMessage (oa, mc.GetSignatureForError (), Location);
7393                                                         }
7394                                                         oa = en.GetObsoleteAttribute (en);
7395                                                         if (oa != null) {
7396                                                                 AttributeTester.Report_ObsoleteMessage (oa, en.GetSignatureForError (), Location);
7397                                                         }
7398
7399                                                         Constant c = Constantify (value, en.UnderlyingType);
7400                                                         return new EnumConstant (c, expr_type);
7401                                                 }
7402                                         } else {
7403                                                 CheckObsoleteAttribute (expr_type);
7404
7405                                                 FieldInfo fi = expr_type.GetField (Identifier);
7406                                                 if (fi != null) {
7407                                                         ObsoleteAttribute oa = AttributeTester.GetMemberObsoleteAttribute (fi);
7408                                                         if (oa != null)
7409                                                                 AttributeTester.Report_ObsoleteMessage (oa, TypeManager.GetFullNameSignature (fi), Location);
7410                                                 }
7411                                         }
7412                                 }
7413                         } else
7414                                 expr_type = expr.Type;
7415
7416                         if (expr_type.IsPointer){
7417                                 Error (23, "The `.' operator can not be applied to pointer operands (" +
7418                                        TypeManager.CSharpName (expr_type) + ")");
7419                                 return null;
7420                         }
7421
7422                         Expression member_lookup;
7423                         member_lookup = MemberLookup (
7424                                 ec, expr_type, expr_type, Identifier, loc);
7425                         if ((member_lookup == null) && (args != null)) {
7426                                 string lookup_id = MemberName.MakeName (Identifier, args);
7427                                 member_lookup = MemberLookup (
7428                                         ec, expr_type, expr_type, lookup_id, loc);
7429                         }
7430                         if (member_lookup == null) {
7431                                 MemberLookupFailed (
7432                                         ec, expr_type, expr_type, Identifier, null, false, loc);
7433                                 return null;
7434                         }
7435
7436                         if (member_lookup is TypeExpr) {
7437                                 if (!(expr is TypeExpr) &&
7438                                     (original == null || !original.IdenticalNameAndTypeName (ec, expr, loc))) {
7439                                         Error (572, "Can't reference type `" + Identifier + "' through an expression; try `" +
7440                                                member_lookup.Type + "' instead");
7441                                         return null;
7442                                 }
7443
7444                                 return member_lookup;
7445                         }
7446
7447                         MemberExpr me = (MemberExpr) member_lookup;
7448                         member_lookup = me.ResolveMemberAccess (ec, expr, loc, original);
7449                         if (member_lookup == null)
7450                                 return null;
7451
7452                         if (args != null) {
7453                                 MethodGroupExpr mg = member_lookup as MethodGroupExpr;
7454                                 if (mg == null)
7455                                         throw new InternalErrorException ();
7456
7457                                 return mg.ResolveGeneric (ec, args);
7458                         }
7459
7460                         // The following DoResolve/DoResolveLValue will do the definite assignment
7461                         // check.
7462
7463                         if (right_side != null)
7464                                 member_lookup = member_lookup.DoResolveLValue (ec, right_side);
7465                         else
7466                                 member_lookup = member_lookup.DoResolve (ec);
7467
7468                         return member_lookup;
7469                 }
7470
7471                 public override Expression DoResolve (EmitContext ec)
7472                 {
7473                         return DoResolve (ec, null, ResolveFlags.VariableOrValue | ResolveFlags.Type);
7474                 }
7475
7476                 public override Expression DoResolveLValue (EmitContext ec, Expression right_side)
7477                 {
7478                         return DoResolve (ec, right_side, ResolveFlags.VariableOrValue | ResolveFlags.Type);
7479                 }
7480
7481                 public override FullNamedExpression ResolveAsTypeStep (EmitContext ec)
7482                 {
7483                         return ResolveNamespaceOrType (ec, false);
7484                 }
7485
7486                 public FullNamedExpression ResolveNamespaceOrType (EmitContext ec, bool silent)
7487                 {
7488                         FullNamedExpression new_expr = expr.ResolveAsTypeStep (ec);
7489
7490                         if (new_expr == null)
7491                                 return null;
7492
7493                         string lookup_id = MemberName.MakeName (Identifier, args);
7494
7495                         if (new_expr is Namespace) {
7496                                 Namespace ns = (Namespace) new_expr;
7497                                 FullNamedExpression retval = ns.Lookup (ec.DeclSpace, lookup_id, loc);
7498                                 if ((retval != null) && (args != null))
7499                                         retval = new ConstructedType (retval, args, loc).ResolveAsTypeStep (ec);
7500                                 if (!silent && retval == null)
7501                                         Report.Error (234, loc, "The type or namespace name `{0}' could not be found in namespace `{1}'", Identifier, ns.FullName);
7502                                 return retval;
7503                         }
7504
7505                         TypeExpr tnew_expr = new_expr.ResolveAsTypeTerminal (ec);
7506                         if (tnew_expr == null)
7507                                 return null;
7508
7509                         Type expr_type = tnew_expr.Type;
7510
7511                         if (expr_type.IsPointer){
7512                                 Error (23, "The `.' operator can not be applied to pointer operands (" +
7513                                        TypeManager.CSharpName (expr_type) + ")");
7514                                 return null;
7515                         }
7516
7517                         Expression member_lookup = MemberLookup (ec, expr_type, expr_type, lookup_id, loc);
7518                         if (member_lookup == null) {
7519                                 int errors = Report.Errors;
7520                                 MemberLookupFailed (ec, expr_type, expr_type, lookup_id, null, false, loc);
7521
7522                                 if (!silent && errors == Report.Errors)
7523                                         Report.Error (234, loc, "The type name `{0}' could not be found in type `{1}'",
7524                                                       lookup_id, new_expr.FullName);
7525                                 return null;
7526                         }
7527
7528                         if (!(member_lookup is TypeExpr)) {
7529                                 Report.Error (118, loc, "'{0}.{1}' denotes a '{2}', where a type was expected",
7530                                               new_expr.FullName, lookup_id, member_lookup.ExprClassName ());
7531                                 return null;
7532                         }
7533
7534                         TypeExpr texpr = member_lookup.ResolveAsTypeTerminal (ec);
7535                         if (texpr == null)
7536                                 return null;
7537
7538                         TypeArguments the_args = args;
7539                         if (TypeManager.HasGenericArguments (expr_type)) {
7540                                 Type[] decl_args = TypeManager.GetTypeArguments (expr_type);
7541
7542                                 TypeArguments new_args = new TypeArguments (loc);
7543                                 foreach (Type decl in decl_args)
7544                                         new_args.Add (new TypeExpression (decl, loc));
7545
7546                                 if (args != null)
7547                                         new_args.Add (args);
7548
7549                                 the_args = new_args;
7550                         }
7551
7552                         if (the_args != null) {
7553                                 ConstructedType ctype = new ConstructedType (texpr.Type, the_args, loc);
7554                                 return ctype.ResolveAsTypeStep (ec);
7555                         }
7556
7557                         return texpr;
7558                 }
7559
7560                 public override void Emit (EmitContext ec)
7561                 {
7562                         throw new Exception ("Should not happen");
7563                 }
7564
7565                 public override string ToString ()
7566                 {
7567                         return expr + "." + MemberName.MakeName (Identifier, args);
7568                 }
7569         }
7570
7571         /// <summary>
7572         ///   Implements checked expressions
7573         /// </summary>
7574         public class CheckedExpr : Expression {
7575
7576                 public Expression Expr;
7577
7578                 public CheckedExpr (Expression e, Location l)
7579                 {
7580                         Expr = e;
7581                         loc = l;
7582                 }
7583
7584                 public override Expression DoResolve (EmitContext ec)
7585                 {
7586                         bool last_check = ec.CheckState;
7587                         bool last_const_check = ec.ConstantCheckState;
7588
7589                         ec.CheckState = true;
7590                         ec.ConstantCheckState = true;
7591                         Expr = Expr.Resolve (ec);
7592                         ec.CheckState = last_check;
7593                         ec.ConstantCheckState = last_const_check;
7594
7595                         if (Expr == null)
7596                                 return null;
7597
7598                         if (Expr is Constant)
7599                                 return Expr;
7600
7601                         eclass = Expr.eclass;
7602                         type = Expr.Type;
7603                         return this;
7604                 }
7605
7606                 public override void Emit (EmitContext ec)
7607                 {
7608                         bool last_check = ec.CheckState;
7609                         bool last_const_check = ec.ConstantCheckState;
7610
7611                         ec.CheckState = true;
7612                         ec.ConstantCheckState = true;
7613                         Expr.Emit (ec);
7614                         ec.CheckState = last_check;
7615                         ec.ConstantCheckState = last_const_check;
7616                 }
7617
7618         }
7619
7620         /// <summary>
7621         ///   Implements the unchecked expression
7622         /// </summary>
7623         public class UnCheckedExpr : Expression {
7624
7625                 public Expression Expr;
7626
7627                 public UnCheckedExpr (Expression e, Location l)
7628                 {
7629                         Expr = e;
7630                         loc = l;
7631                 }
7632
7633                 public override Expression DoResolve (EmitContext ec)
7634                 {
7635                         bool last_check = ec.CheckState;
7636                         bool last_const_check = ec.ConstantCheckState;
7637
7638                         ec.CheckState = false;
7639                         ec.ConstantCheckState = false;
7640                         Expr = Expr.Resolve (ec);
7641                         ec.CheckState = last_check;
7642                         ec.ConstantCheckState = last_const_check;
7643
7644                         if (Expr == null)
7645                                 return null;
7646
7647                         if (Expr is Constant)
7648                                 return Expr;
7649
7650                         eclass = Expr.eclass;
7651                         type = Expr.Type;
7652                         return this;
7653                 }
7654
7655                 public override void Emit (EmitContext ec)
7656                 {
7657                         bool last_check = ec.CheckState;
7658                         bool last_const_check = ec.ConstantCheckState;
7659
7660                         ec.CheckState = false;
7661                         ec.ConstantCheckState = false;
7662                         Expr.Emit (ec);
7663                         ec.CheckState = last_check;
7664                         ec.ConstantCheckState = last_const_check;
7665                 }
7666
7667         }
7668
7669         /// <summary>
7670         ///   An Element Access expression.
7671         ///
7672         ///   During semantic analysis these are transformed into
7673         ///   IndexerAccess, ArrayAccess or a PointerArithmetic.
7674         /// </summary>
7675         public class ElementAccess : Expression {
7676                 public ArrayList  Arguments;
7677                 public Expression Expr;
7678
7679                 public ElementAccess (Expression e, ArrayList e_list, Location l)
7680                 {
7681                         Expr = e;
7682
7683                         loc  = l;
7684
7685                         if (e_list == null)
7686                                 return;
7687
7688                         Arguments = new ArrayList ();
7689                         foreach (Expression tmp in e_list)
7690                                 Arguments.Add (new Argument (tmp, Argument.AType.Expression));
7691
7692                 }
7693
7694                 bool CommonResolve (EmitContext ec)
7695                 {
7696                         Expr = Expr.Resolve (ec);
7697
7698                         if (Expr == null)
7699                                 return false;
7700
7701                         if (Arguments == null)
7702                                 return false;
7703
7704                         foreach (Argument a in Arguments){
7705                                 if (!a.Resolve (ec, loc))
7706                                         return false;
7707                         }
7708
7709                         return true;
7710                 }
7711
7712                 Expression MakePointerAccess (EmitContext ec, Type t)
7713                 {
7714                         if (t == TypeManager.void_ptr_type){
7715                                 Error (242, "The array index operation is not valid for void pointers");
7716                                 return null;
7717                         }
7718                         if (Arguments.Count != 1){
7719                                 Error (196, "A pointer must be indexed by a single value");
7720                                 return null;
7721                         }
7722                         Expression p;
7723
7724                         p = new PointerArithmetic (true, Expr, ((Argument)Arguments [0]).Expr, t, loc).Resolve (ec);
7725                         if (p == null)
7726                                 return null;
7727                         return new Indirection (p, loc).Resolve (ec);
7728                 }
7729
7730                 public override Expression DoResolve (EmitContext ec)
7731                 {
7732                         if (!CommonResolve (ec))
7733                                 return null;
7734
7735                         //
7736                         // We perform some simple tests, and then to "split" the emit and store
7737                         // code we create an instance of a different class, and return that.
7738                         //
7739                         // I am experimenting with this pattern.
7740                         //
7741                         Type t = Expr.Type;
7742
7743                         if (t == TypeManager.array_type){
7744                                 Report.Error (21, loc, "Cannot use indexer on System.Array");
7745                                 return null;
7746                         }
7747
7748                         if (t.IsArray)
7749                                 return (new ArrayAccess (this, loc)).Resolve (ec);
7750                         if (t.IsPointer)
7751                                 return MakePointerAccess (ec, Expr.Type);
7752
7753                         FieldExpr fe = Expr as FieldExpr;
7754                         if (fe != null) {
7755                                 IFixedBuffer ff = AttributeTester.GetFixedBuffer (fe.FieldInfo);
7756                                 if (ff != null) {
7757                                         return MakePointerAccess (ec, ff.ElementType);
7758                                 }
7759                         }
7760                         return (new IndexerAccess (this, loc)).Resolve (ec);
7761                 }
7762
7763                 public override Expression DoResolveLValue (EmitContext ec, Expression right_side)
7764                 {
7765                         if (!CommonResolve (ec))
7766                                 return null;
7767
7768                         Type t = Expr.Type;
7769                         if (t.IsArray)
7770                                 return (new ArrayAccess (this, loc)).ResolveLValue (ec, right_side);
7771
7772                         if (t.IsPointer)
7773                                 return MakePointerAccess (ec, Expr.Type);
7774
7775                         FieldExpr fe = Expr as FieldExpr;
7776                         if (fe != null) {
7777                                 IFixedBuffer ff = AttributeTester.GetFixedBuffer (fe.FieldInfo);
7778                                 if (ff != null) {
7779                                         if (!(fe.InstanceExpression is LocalVariableReference) &&
7780                                                 !(fe.InstanceExpression is This)) {
7781                                                 Error (1708, "Fixed buffers can only be accessed through locals or fields");
7782                                                 return null;
7783                                         }
7784 // TODO: not sure whether it is correct
7785 //                                      if (!ec.InFixedInitializer) {
7786 //                                              Error (1666, "You cannot use fixed sized buffers contained in unfixed expressions. Try using the fixed statement");
7787 //                                              return null;
7788 //                                      }
7789                                         return MakePointerAccess (ec, ff.ElementType);
7790                                 }
7791                         }
7792                         return (new IndexerAccess (this, loc)).ResolveLValue (ec, right_side);
7793                 }
7794
7795                 public override void Emit (EmitContext ec)
7796                 {
7797                         throw new Exception ("Should never be reached");
7798                 }
7799         }
7800
7801         /// <summary>
7802         ///   Implements array access
7803         /// </summary>
7804         public class ArrayAccess : Expression, IAssignMethod, IMemoryLocation {
7805                 //
7806                 // Points to our "data" repository
7807                 //
7808                 ElementAccess ea;
7809
7810                 LocalTemporary temp;
7811                 bool prepared;
7812
7813                 public ArrayAccess (ElementAccess ea_data, Location l)
7814                 {
7815                         ea = ea_data;
7816                         eclass = ExprClass.Variable;
7817                         loc = l;
7818                 }
7819
7820                 public override Expression DoResolveLValue (EmitContext ec, Expression right_side)
7821                 {
7822                         return DoResolve (ec);
7823                 }
7824
7825                 public override Expression DoResolve (EmitContext ec)
7826                 {
7827 #if false
7828                         ExprClass eclass = ea.Expr.eclass;
7829
7830                         // As long as the type is valid
7831                         if (!(eclass == ExprClass.Variable || eclass == ExprClass.PropertyAccess ||
7832                               eclass == ExprClass.Value)) {
7833                                 ea.Expr.Error_UnexpectedKind ("variable or value");
7834                                 return null;
7835                         }
7836 #endif
7837
7838                         Type t = ea.Expr.Type;
7839                         if (t.GetArrayRank () != ea.Arguments.Count){
7840                                 ea.Error (22,
7841                                           "Incorrect number of indexes for array " +
7842                                           " expected: " + t.GetArrayRank () + " got: " +
7843                                           ea.Arguments.Count);
7844                                 return null;
7845                         }
7846
7847                         type = TypeManager.GetElementType (t);
7848                         if (type.IsPointer && !ec.InUnsafe){
7849                                 UnsafeError (ea.Location);
7850                                 return null;
7851                         }
7852
7853                         foreach (Argument a in ea.Arguments){
7854                                 Type argtype = a.Type;
7855
7856                                 if (argtype == TypeManager.int32_type ||
7857                                     argtype == TypeManager.uint32_type ||
7858                                     argtype == TypeManager.int64_type ||
7859                                     argtype == TypeManager.uint64_type) {
7860                                         Constant c = a.Expr as Constant;
7861                                         if (c != null && c.IsNegative) {
7862                                                 Report.Warning (251, 2, a.Expr.Location, "Indexing an array with a negative index (array indices always start at zero)");
7863                                         }
7864                                         continue;
7865                                 }
7866
7867                                 //
7868                                 // Mhm.  This is strage, because the Argument.Type is not the same as
7869                                 // Argument.Expr.Type: the value changes depending on the ref/out setting.
7870                                 //
7871                                 // Wonder if I will run into trouble for this.
7872                                 //
7873                                 a.Expr = ExpressionToArrayArgument (ec, a.Expr, ea.Location);
7874                                 if (a.Expr == null)
7875                                         return null;
7876                         }
7877
7878                         eclass = ExprClass.Variable;
7879
7880                         return this;
7881                 }
7882
7883                 /// <summary>
7884                 ///    Emits the right opcode to load an object of Type `t'
7885                 ///    from an array of T
7886                 /// </summary>
7887                 static public void EmitLoadOpcode (ILGenerator ig, Type type)
7888                 {
7889                         if (type == TypeManager.byte_type || type == TypeManager.bool_type)
7890                                 ig.Emit (OpCodes.Ldelem_U1);
7891                         else if (type == TypeManager.sbyte_type)
7892                                 ig.Emit (OpCodes.Ldelem_I1);
7893                         else if (type == TypeManager.short_type)
7894                                 ig.Emit (OpCodes.Ldelem_I2);
7895                         else if (type == TypeManager.ushort_type || type == TypeManager.char_type)
7896                                 ig.Emit (OpCodes.Ldelem_U2);
7897                         else if (type == TypeManager.int32_type)
7898                                 ig.Emit (OpCodes.Ldelem_I4);
7899                         else if (type == TypeManager.uint32_type)
7900                                 ig.Emit (OpCodes.Ldelem_U4);
7901                         else if (type == TypeManager.uint64_type)
7902                                 ig.Emit (OpCodes.Ldelem_I8);
7903                         else if (type == TypeManager.int64_type)
7904                                 ig.Emit (OpCodes.Ldelem_I8);
7905                         else if (type == TypeManager.float_type)
7906                                 ig.Emit (OpCodes.Ldelem_R4);
7907                         else if (type == TypeManager.double_type)
7908                                 ig.Emit (OpCodes.Ldelem_R8);
7909                         else if (type == TypeManager.intptr_type)
7910                                 ig.Emit (OpCodes.Ldelem_I);
7911                         else if (TypeManager.IsEnumType (type)){
7912                                 EmitLoadOpcode (ig, TypeManager.EnumToUnderlying (type));
7913                         } else if (type.IsValueType){
7914                                 ig.Emit (OpCodes.Ldelema, type);
7915                                 ig.Emit (OpCodes.Ldobj, type);
7916                         } else if (type.IsGenericParameter)
7917                                 ig.Emit (OpCodes.Ldelem_Any, type);
7918                         else
7919                                 ig.Emit (OpCodes.Ldelem_Ref);
7920                 }
7921
7922                 /// <summary>
7923                 ///    Returns the right opcode to store an object of Type `t'
7924                 ///    from an array of T.
7925                 /// </summary>
7926                 static public OpCode GetStoreOpcode (Type t, out bool is_stobj, out bool has_type_arg)
7927                 {
7928                         //Console.WriteLine (new System.Diagnostics.StackTrace ());
7929                         has_type_arg = false; is_stobj = false;
7930                         t = TypeManager.TypeToCoreType (t);
7931                         if (TypeManager.IsEnumType (t))
7932                                 t = TypeManager.EnumToUnderlying (t);
7933                         if (t == TypeManager.byte_type || t == TypeManager.sbyte_type ||
7934                             t == TypeManager.bool_type)
7935                                 return OpCodes.Stelem_I1;
7936                         else if (t == TypeManager.short_type || t == TypeManager.ushort_type ||
7937                                  t == TypeManager.char_type)
7938                                 return OpCodes.Stelem_I2;
7939                         else if (t == TypeManager.int32_type || t == TypeManager.uint32_type)
7940                                 return OpCodes.Stelem_I4;
7941                         else if (t == TypeManager.int64_type || t == TypeManager.uint64_type)
7942                                 return OpCodes.Stelem_I8;
7943                         else if (t == TypeManager.float_type)
7944                                 return OpCodes.Stelem_R4;
7945                         else if (t == TypeManager.double_type)
7946                                 return OpCodes.Stelem_R8;
7947                         else if (t == TypeManager.intptr_type) {
7948                                 has_type_arg = true;
7949                                 is_stobj = true;
7950                                 return OpCodes.Stobj;
7951                         } else if (t.IsValueType) {
7952                                 has_type_arg = true;
7953                                 is_stobj = true;
7954                                 return OpCodes.Stobj;
7955                         } else if (t.IsGenericParameter) {
7956                                 has_type_arg = true;
7957                                 return OpCodes.Stelem_Any;
7958                         } else
7959                                 return OpCodes.Stelem_Ref;
7960                 }
7961
7962                 MethodInfo FetchGetMethod ()
7963                 {
7964                         ModuleBuilder mb = CodeGen.Module.Builder;
7965                         int arg_count = ea.Arguments.Count;
7966                         Type [] args = new Type [arg_count];
7967                         MethodInfo get;
7968
7969                         for (int i = 0; i < arg_count; i++){
7970                                 //args [i++] = a.Type;
7971                                 args [i] = TypeManager.int32_type;
7972                         }
7973
7974                         get = mb.GetArrayMethod (
7975                                 ea.Expr.Type, "Get",
7976                                 CallingConventions.HasThis |
7977                                 CallingConventions.Standard,
7978                                 type, args);
7979                         return get;
7980                 }
7981
7982
7983                 MethodInfo FetchAddressMethod ()
7984                 {
7985                         ModuleBuilder mb = CodeGen.Module.Builder;
7986                         int arg_count = ea.Arguments.Count;
7987                         Type [] args = new Type [arg_count];
7988                         MethodInfo address;
7989                         Type ret_type;
7990
7991                         ret_type = TypeManager.GetReferenceType (type);
7992
7993                         for (int i = 0; i < arg_count; i++){
7994                                 //args [i++] = a.Type;
7995                                 args [i] = TypeManager.int32_type;
7996                         }
7997
7998                         address = mb.GetArrayMethod (
7999                                 ea.Expr.Type, "Address",
8000                                 CallingConventions.HasThis |
8001                                 CallingConventions.Standard,
8002                                 ret_type, args);
8003
8004                         return address;
8005                 }
8006
8007                 //
8008                 // Load the array arguments into the stack.
8009                 //
8010                 // If we have been requested to cache the values (cached_locations array
8011                 // initialized), then load the arguments the first time and store them
8012                 // in locals.  otherwise load from local variables.
8013                 //
8014                 void LoadArrayAndArguments (EmitContext ec)
8015                 {
8016                         ILGenerator ig = ec.ig;
8017
8018                         ea.Expr.Emit (ec);
8019                         foreach (Argument a in ea.Arguments){
8020                                 Type argtype = a.Expr.Type;
8021
8022                                 a.Expr.Emit (ec);
8023
8024                                 if (argtype == TypeManager.int64_type)
8025                                         ig.Emit (OpCodes.Conv_Ovf_I);
8026                                 else if (argtype == TypeManager.uint64_type)
8027                                         ig.Emit (OpCodes.Conv_Ovf_I_Un);
8028                         }
8029                 }
8030
8031                 public void Emit (EmitContext ec, bool leave_copy)
8032                 {
8033                         int rank = ea.Expr.Type.GetArrayRank ();
8034                         ILGenerator ig = ec.ig;
8035
8036                         if (!prepared) {
8037                                 LoadArrayAndArguments (ec);
8038
8039                                 if (rank == 1)
8040                                         EmitLoadOpcode (ig, type);
8041                                 else {
8042                                         MethodInfo method;
8043
8044                                         method = FetchGetMethod ();
8045                                         ig.Emit (OpCodes.Call, method);
8046                                 }
8047                         } else
8048                                 LoadFromPtr (ec.ig, this.type);
8049
8050                         if (leave_copy) {
8051                                 ec.ig.Emit (OpCodes.Dup);
8052                                 temp = new LocalTemporary (ec, this.type);
8053                                 temp.Store (ec);
8054                         }
8055                 }
8056
8057                 public override void Emit (EmitContext ec)
8058                 {
8059                         Emit (ec, false);
8060                 }
8061
8062                 public void EmitAssign (EmitContext ec, Expression source, bool leave_copy, bool prepare_for_load)
8063                 {
8064                         int rank = ea.Expr.Type.GetArrayRank ();
8065                         ILGenerator ig = ec.ig;
8066                         Type t = source.Type;
8067                         prepared = prepare_for_load;
8068
8069                         if (prepare_for_load) {
8070                                 AddressOf (ec, AddressOp.LoadStore);
8071                                 ec.ig.Emit (OpCodes.Dup);
8072                                 source.Emit (ec);
8073                                 if (leave_copy) {
8074                                         ec.ig.Emit (OpCodes.Dup);
8075                                         temp = new LocalTemporary (ec, this.type);
8076                                         temp.Store (ec);
8077                                 }
8078                                 StoreFromPtr (ec.ig, t);
8079
8080                                 if (temp != null)
8081                                         temp.Emit (ec);
8082
8083                                 return;
8084                         }
8085
8086                         LoadArrayAndArguments (ec);
8087
8088                         if (rank == 1) {
8089                                 bool is_stobj, has_type_arg;
8090                                 OpCode op = GetStoreOpcode (t, out is_stobj, out has_type_arg);
8091
8092                                 //
8093                                 // The stobj opcode used by value types will need
8094                                 // an address on the stack, not really an array/array
8095                                 // pair
8096                                 //
8097                                 if (is_stobj)
8098                                         ig.Emit (OpCodes.Ldelema, t);
8099
8100                                 source.Emit (ec);
8101                                 if (leave_copy) {
8102                                         ec.ig.Emit (OpCodes.Dup);
8103                                         temp = new LocalTemporary (ec, this.type);
8104                                         temp.Store (ec);
8105                                 }
8106
8107                                 if (is_stobj)
8108                                         ig.Emit (OpCodes.Stobj, t);
8109                                 else if (has_type_arg)
8110                                         ig.Emit (op, t);
8111                                 else
8112                                         ig.Emit (op);
8113                         } else {
8114                                 ModuleBuilder mb = CodeGen.Module.Builder;
8115                                 int arg_count = ea.Arguments.Count;
8116                                 Type [] args = new Type [arg_count + 1];
8117                                 MethodInfo set;
8118
8119                                 source.Emit (ec);
8120                                 if (leave_copy) {
8121                                         ec.ig.Emit (OpCodes.Dup);
8122                                         temp = new LocalTemporary (ec, this.type);
8123                                         temp.Store (ec);
8124                                 }
8125
8126                                 for (int i = 0; i < arg_count; i++){
8127                                         //args [i++] = a.Type;
8128                                         args [i] = TypeManager.int32_type;
8129                                 }
8130
8131                                 args [arg_count] = type;
8132
8133                                 set = mb.GetArrayMethod (
8134                                         ea.Expr.Type, "Set",
8135                                         CallingConventions.HasThis |
8136                                         CallingConventions.Standard,
8137                                         TypeManager.void_type, args);
8138
8139                                 ig.Emit (OpCodes.Call, set);
8140                         }
8141
8142                         if (temp != null)
8143                                 temp.Emit (ec);
8144                 }
8145
8146                 public void AddressOf (EmitContext ec, AddressOp mode)
8147                 {
8148                         int rank = ea.Expr.Type.GetArrayRank ();
8149                         ILGenerator ig = ec.ig;
8150
8151                         LoadArrayAndArguments (ec);
8152
8153                         if (rank == 1){
8154                                 ig.Emit (OpCodes.Ldelema, type);
8155                         } else {
8156                                 MethodInfo address = FetchAddressMethod ();
8157                                 ig.Emit (OpCodes.Call, address);
8158                         }
8159                 }
8160         }
8161
8162
8163         class Indexers {
8164                 public ArrayList Properties;
8165                 static Hashtable map;
8166
8167                 public struct Indexer {
8168                         public readonly Type Type;
8169                         public readonly MethodInfo Getter, Setter;
8170
8171                         public Indexer (Type type, MethodInfo get, MethodInfo set)
8172                         {
8173                                 this.Type = type;
8174                                 this.Getter = get;
8175                                 this.Setter = set;
8176                         }
8177                 }
8178
8179                 static Indexers ()
8180                 {
8181                         map = new Hashtable ();
8182                 }
8183
8184                 Indexers ()
8185                 {
8186                         Properties = new ArrayList ();
8187                 }
8188
8189                 void Append (MemberInfo [] mi)
8190                 {
8191                         foreach (PropertyInfo property in mi){
8192                                 MethodInfo get, set;
8193
8194                                 get = property.GetGetMethod (true);
8195                                 set = property.GetSetMethod (true);
8196                                 Properties.Add (new Indexer (property.PropertyType, get, set));
8197                         }
8198                 }
8199
8200                 static private MemberInfo [] GetIndexersForTypeOrInterface (Type caller_type, Type lookup_type)
8201                 {
8202                         string p_name = TypeManager.IndexerPropertyName (lookup_type);
8203
8204                         MemberInfo [] mi = TypeManager.MemberLookup (
8205                                 caller_type, caller_type, lookup_type, MemberTypes.Property,
8206                                 BindingFlags.Public | BindingFlags.Instance |
8207                                 BindingFlags.DeclaredOnly, p_name, null);
8208
8209                         if (mi == null || mi.Length == 0)
8210                                 return null;
8211
8212                         return mi;
8213                 }
8214
8215                 static public Indexers GetIndexersForType (Type caller_type, Type lookup_type, Location loc)
8216                 {
8217                         Indexers ix = (Indexers) map [lookup_type];
8218
8219                         if (ix != null)
8220                                 return ix;
8221
8222                         Type copy = lookup_type;
8223                         while (copy != TypeManager.object_type && copy != null){
8224                                 MemberInfo [] mi = GetIndexersForTypeOrInterface (caller_type, copy);
8225
8226                                 if (mi != null){
8227                                         if (ix == null)
8228                                                 ix = new Indexers ();
8229
8230                                         ix.Append (mi);
8231                                 }
8232
8233                                 copy = copy.BaseType;
8234                         }
8235
8236                         if (!lookup_type.IsInterface)
8237                                 return ix;
8238
8239                         Type [] ifaces = TypeManager.GetInterfaces (lookup_type);
8240                         if (ifaces != null) {
8241                                 foreach (Type itype in ifaces) {
8242                                         MemberInfo [] mi = GetIndexersForTypeOrInterface (caller_type, itype);
8243                                         if (mi != null){
8244                                                 if (ix == null)
8245                                                         ix = new Indexers ();
8246
8247                                                 ix.Append (mi);
8248                                         }
8249                                 }
8250                         }
8251
8252                         return ix;
8253                 }
8254         }
8255
8256         /// <summary>
8257         ///   Expressions that represent an indexer call.
8258         /// </summary>
8259         public class IndexerAccess : Expression, IAssignMethod {
8260                 //
8261                 // Points to our "data" repository
8262                 //
8263                 MethodInfo get, set;
8264                 ArrayList set_arguments;
8265                 bool is_base_indexer;
8266
8267                 protected Type indexer_type;
8268                 protected Type current_type;
8269                 protected Expression instance_expr;
8270                 protected ArrayList arguments;
8271
8272                 public IndexerAccess (ElementAccess ea, Location loc)
8273                         : this (ea.Expr, false, loc)
8274                 {
8275                         this.arguments = ea.Arguments;
8276                 }
8277
8278                 protected IndexerAccess (Expression instance_expr, bool is_base_indexer,
8279                                          Location loc)
8280                 {
8281                         this.instance_expr = instance_expr;
8282                         this.is_base_indexer = is_base_indexer;
8283                         this.eclass = ExprClass.Value;
8284                         this.loc = loc;
8285                 }
8286
8287                 protected virtual bool CommonResolve (EmitContext ec)
8288                 {
8289                         indexer_type = instance_expr.Type;
8290                         current_type = ec.ContainerType;
8291
8292                         return true;
8293                 }
8294
8295                 public override Expression DoResolve (EmitContext ec)
8296                 {
8297                         ArrayList AllGetters = new ArrayList();
8298                         if (!CommonResolve (ec))
8299                                 return null;
8300
8301                         //
8302                         // Step 1: Query for all `Item' *properties*.  Notice
8303                         // that the actual methods are pointed from here.
8304                         //
8305                         // This is a group of properties, piles of them.
8306
8307                         bool found_any = false, found_any_getters = false;
8308                         Type lookup_type = indexer_type;
8309
8310                         Indexers ilist;
8311                         ilist = Indexers.GetIndexersForType (current_type, lookup_type, loc);
8312                         if (ilist != null) {
8313                                 found_any = true;
8314                                 if (ilist.Properties != null) {
8315                                         foreach (Indexers.Indexer ix in ilist.Properties) {
8316                                                 if (ix.Getter != null)
8317                                                         AllGetters.Add(ix.Getter);
8318                                         }
8319                                 }
8320                         }
8321
8322                         if (AllGetters.Count > 0) {
8323                                 found_any_getters = true;
8324                                 get = (MethodInfo) Invocation.OverloadResolve (
8325                                         ec, new MethodGroupExpr (AllGetters, loc),
8326                                         arguments, false, loc);
8327                         }
8328
8329                         if (!found_any) {
8330                                 Report.Error (21, loc,
8331                                               "Type `" + TypeManager.CSharpName (indexer_type) +
8332                                               "' does not have any indexers defined");
8333                                 return null;
8334                         }
8335
8336                         if (!found_any_getters) {
8337                                 Error (154, "indexer can not be used in this context, because " +
8338                                        "it lacks a `get' accessor");
8339                                 return null;
8340                         }
8341
8342                         if (get == null) {
8343                                 Error (1501, "No Overload for method `this' takes `" +
8344                                        arguments.Count + "' arguments");
8345                                 return null;
8346                         }
8347
8348                         //
8349                         // Only base will allow this invocation to happen.
8350                         //
8351                         if (get.IsAbstract && this is BaseIndexerAccess){
8352                                 Report.Error (205, loc, "Cannot call an abstract base indexer: " + Invocation.FullMethodDesc (get));
8353                                 return null;
8354                         }
8355
8356                         type = get.ReturnType;
8357                         if (type.IsPointer && !ec.InUnsafe){
8358                                 UnsafeError (loc);
8359                                 return null;
8360                         }
8361
8362                         instance_expr.CheckMarshallByRefAccess (ec.ContainerType);
8363
8364                         eclass = ExprClass.IndexerAccess;
8365                         return this;
8366                 }
8367
8368                 public override Expression DoResolveLValue (EmitContext ec, Expression right_side)
8369                 {
8370                         ArrayList AllSetters = new ArrayList();
8371                         if (!CommonResolve (ec))
8372                                 return null;
8373
8374                         bool found_any = false, found_any_setters = false;
8375
8376                         Indexers ilist = Indexers.GetIndexersForType (current_type, indexer_type, loc);
8377                         if (ilist != null) {
8378                                 found_any = true;
8379                                 if (ilist.Properties != null) {
8380                                         foreach (Indexers.Indexer ix in ilist.Properties) {
8381                                                 if (ix.Setter != null)
8382                                                         AllSetters.Add(ix.Setter);
8383                                         }
8384                                 }
8385                         }
8386                         if (AllSetters.Count > 0) {
8387                                 found_any_setters = true;
8388                                 set_arguments = (ArrayList) arguments.Clone ();
8389                                 set_arguments.Add (new Argument (right_side, Argument.AType.Expression));
8390                                 set = (MethodInfo) Invocation.OverloadResolve (
8391                                         ec, new MethodGroupExpr (AllSetters, loc),
8392                                         set_arguments, false, loc);
8393                         }
8394
8395                         if (!found_any) {
8396                                 Report.Error (21, loc,
8397                                               "Type `" + TypeManager.CSharpName (indexer_type) +
8398                                               "' does not have any indexers defined");
8399                                 return null;
8400                         }
8401
8402                         if (!found_any_setters) {
8403                                 Error (154, "indexer can not be used in this context, because " +
8404                                        "it lacks a `set' accessor");
8405                                 return null;
8406                         }
8407
8408                         if (set == null) {
8409                                 Error (1501, "No Overload for method `this' takes `" +
8410                                        arguments.Count + "' arguments");
8411                                 return null;
8412                         }
8413
8414                         //
8415                         // Only base will allow this invocation to happen.
8416                         //
8417                         if (set.IsAbstract && this is BaseIndexerAccess){
8418                                 Report.Error (205, loc, "Cannot call an abstract base indexer: " + Invocation.FullMethodDesc (set));
8419                                 return null;
8420                         }
8421
8422                         //
8423                         // Now look for the actual match in the list of indexers to set our "return" type
8424                         //
8425                         type = TypeManager.void_type;   // default value
8426                         foreach (Indexers.Indexer ix in ilist.Properties){
8427                                 if (ix.Setter == set){
8428                                         type = ix.Type;
8429                                         break;
8430                                 }
8431                         }
8432
8433                         instance_expr.CheckMarshallByRefAccess (ec.ContainerType);
8434
8435                         eclass = ExprClass.IndexerAccess;
8436                         return this;
8437                 }
8438
8439                 bool prepared = false;
8440                 LocalTemporary temp;
8441
8442                 public void Emit (EmitContext ec, bool leave_copy)
8443                 {
8444                         Invocation.EmitCall (ec, is_base_indexer, false, instance_expr, get, arguments, loc, prepared, false);
8445                         if (leave_copy) {
8446                                 ec.ig.Emit (OpCodes.Dup);
8447                                 temp = new LocalTemporary (ec, Type);
8448                                 temp.Store (ec);
8449                         }
8450                 }
8451
8452                 //
8453                 // source is ignored, because we already have a copy of it from the
8454                 // LValue resolution and we have already constructed a pre-cached
8455                 // version of the arguments (ea.set_arguments);
8456                 //
8457                 public void EmitAssign (EmitContext ec, Expression source, bool leave_copy, bool prepare_for_load)
8458                 {
8459                         prepared = prepare_for_load;
8460                         Argument a = (Argument) set_arguments [set_arguments.Count - 1];
8461
8462                         if (prepared) {
8463                                 source.Emit (ec);
8464                                 if (leave_copy) {
8465                                         ec.ig.Emit (OpCodes.Dup);
8466                                         temp = new LocalTemporary (ec, Type);
8467                                         temp.Store (ec);
8468                                 }
8469                         } else if (leave_copy) {
8470                                 temp = new LocalTemporary (ec, Type);
8471                                 source.Emit (ec);
8472                                 temp.Store (ec);
8473                                 a.Expr = temp;
8474                         }
8475
8476                         Invocation.EmitCall (ec, is_base_indexer, false, instance_expr, set, set_arguments, loc, false, prepared);
8477
8478                         if (temp != null)
8479                                 temp.Emit (ec);
8480                 }
8481
8482
8483                 public override void Emit (EmitContext ec)
8484                 {
8485                         Emit (ec, false);
8486                 }
8487         }
8488
8489         /// <summary>
8490         ///   The base operator for method names
8491         /// </summary>
8492         public class BaseAccess : Expression {
8493                 string member;
8494
8495                 public BaseAccess (string member, Location l)
8496                 {
8497                         this.member = member;
8498                         loc = l;
8499                 }
8500
8501                 public override Expression DoResolve (EmitContext ec)
8502                 {
8503                         Expression c = CommonResolve (ec);
8504
8505                         if (c == null)
8506                                 return null;
8507
8508                         //
8509                         // MethodGroups use this opportunity to flag an error on lacking ()
8510                         //
8511                         if (!(c is MethodGroupExpr))
8512                                 return c.Resolve (ec);
8513                         return c;
8514                 }
8515
8516                 public override Expression DoResolveLValue (EmitContext ec, Expression right_side)
8517                 {
8518                         Expression c = CommonResolve (ec);
8519
8520                         if (c == null)
8521                                 return null;
8522
8523                         //
8524                         // MethodGroups use this opportunity to flag an error on lacking ()
8525                         //
8526                         if (! (c is MethodGroupExpr))
8527                                 return c.DoResolveLValue (ec, right_side);
8528
8529                         return c;
8530                 }
8531
8532                 Expression CommonResolve (EmitContext ec)
8533                 {
8534                         Expression member_lookup;
8535                         Type current_type = ec.ContainerType;
8536                         Type base_type = current_type.BaseType;
8537
8538                         if (ec.IsStatic){
8539                                 Error (1511, "Keyword base is not allowed in static method");
8540                                 return null;
8541                         }
8542
8543                         if (ec.IsFieldInitializer){
8544                                 Error (1512, "Keyword base is not available in the current context");
8545                                 return null;
8546                         }
8547
8548                         member_lookup = MemberLookup (ec, ec.ContainerType, null, base_type,
8549                                                       member, AllMemberTypes, AllBindingFlags,
8550                                                       loc);
8551                         if (member_lookup == null) {
8552                                 MemberLookupFailed (ec, base_type, base_type, member, null, true, loc);
8553                                 return null;
8554                         }
8555
8556                         Expression left;
8557
8558                         if (ec.IsStatic)
8559                                 left = new TypeExpression (base_type, loc);
8560                         else
8561                                 left = ec.GetThis (loc);
8562
8563                         MemberExpr me = (MemberExpr) member_lookup;
8564
8565                         Expression e = me.ResolveMemberAccess (ec, left, loc, null);
8566
8567                         if (e is PropertyExpr) {
8568                                 PropertyExpr pe = (PropertyExpr) e;
8569
8570                                 pe.IsBase = true;
8571                         }
8572
8573                         if (e is MethodGroupExpr)
8574                                 ((MethodGroupExpr) e).IsBase = true;
8575
8576                         return e;
8577                 }
8578
8579                 public override void Emit (EmitContext ec)
8580                 {
8581                         throw new Exception ("Should never be called");
8582                 }
8583         }
8584
8585         /// <summary>
8586         ///   The base indexer operator
8587         /// </summary>
8588         public class BaseIndexerAccess : IndexerAccess {
8589                 public BaseIndexerAccess (ArrayList args, Location loc)
8590                         : base (null, true, loc)
8591                 {
8592                         arguments = new ArrayList ();
8593                         foreach (Expression tmp in args)
8594                                 arguments.Add (new Argument (tmp, Argument.AType.Expression));
8595                 }
8596
8597                 protected override bool CommonResolve (EmitContext ec)
8598                 {
8599                         instance_expr = ec.GetThis (loc);
8600
8601                         current_type = ec.ContainerType.BaseType;
8602                         indexer_type = current_type;
8603
8604                         foreach (Argument a in arguments){
8605                                 if (!a.Resolve (ec, loc))
8606                                         return false;
8607                         }
8608
8609                         return true;
8610                 }
8611         }
8612
8613         /// <summary>
8614         ///   This class exists solely to pass the Type around and to be a dummy
8615         ///   that can be passed to the conversion functions (this is used by
8616         ///   foreach implementation to typecast the object return value from
8617         ///   get_Current into the proper type.  All code has been generated and
8618         ///   we only care about the side effect conversions to be performed
8619         ///
8620         ///   This is also now used as a placeholder where a no-action expression
8621         ///   is needed (the `New' class).
8622         /// </summary>
8623         public class EmptyExpression : Expression {
8624                 public static readonly EmptyExpression Null = new EmptyExpression ();
8625
8626                 // TODO: should be protected
8627                 public EmptyExpression ()
8628                 {
8629                         type = TypeManager.object_type;
8630                         eclass = ExprClass.Value;
8631                         loc = Location.Null;
8632                 }
8633
8634                 public EmptyExpression (Type t)
8635                 {
8636                         type = t;
8637                         eclass = ExprClass.Value;
8638                         loc = Location.Null;
8639                 }
8640
8641                 public override Expression DoResolve (EmitContext ec)
8642                 {
8643                         return this;
8644                 }
8645
8646                 public override void Emit (EmitContext ec)
8647                 {
8648                         // nothing, as we only exist to not do anything.
8649                 }
8650
8651                 //
8652                 // This is just because we might want to reuse this bad boy
8653                 // instead of creating gazillions of EmptyExpressions.
8654                 // (CanImplicitConversion uses it)
8655                 //
8656                 public void SetType (Type t)
8657                 {
8658                         type = t;
8659                 }
8660         }
8661
8662         public class UserCast : Expression {
8663                 MethodBase method;
8664                 Expression source;
8665
8666                 public UserCast (MethodInfo method, Expression source, Location l)
8667                 {
8668                         this.method = method;
8669                         this.source = source;
8670                         type = method.ReturnType;
8671                         eclass = ExprClass.Value;
8672                         loc = l;
8673                 }
8674
8675                 public Expression Source {
8676                         get {
8677                                 return source;
8678                         }
8679                 }
8680
8681                 public override Expression DoResolve (EmitContext ec)
8682                 {
8683                         //
8684                         // We are born fully resolved
8685                         //
8686                         return this;
8687                 }
8688
8689                 public override void Emit (EmitContext ec)
8690                 {
8691                         ILGenerator ig = ec.ig;
8692
8693                         source.Emit (ec);
8694
8695                         if (method is MethodInfo)
8696                                 ig.Emit (OpCodes.Call, (MethodInfo) method);
8697                         else
8698                                 ig.Emit (OpCodes.Call, (ConstructorInfo) method);
8699
8700                 }
8701         }
8702
8703         // <summary>
8704         //   This class is used to "construct" the type during a typecast
8705         //   operation.  Since the Type.GetType class in .NET can parse
8706         //   the type specification, we just use this to construct the type
8707         //   one bit at a time.
8708         // </summary>
8709         public class ComposedCast : TypeExpr {
8710                 Expression left;
8711                 string dim;
8712
8713                 public ComposedCast (Expression left, string dim, Location l)
8714                 {
8715                         this.left = left;
8716                         this.dim = dim;
8717                         loc = l;
8718                 }
8719
8720                 protected override TypeExpr DoResolveAsTypeStep (EmitContext ec)
8721                 {
8722                         TypeExpr lexpr = left.ResolveAsTypeTerminal (ec);
8723                         if (lexpr == null)
8724                                 return null;
8725
8726                         Type ltype = lexpr.Type;
8727
8728                         if ((ltype == TypeManager.void_type) && (dim != "*")) {
8729                                 Report.Error (1547, Location,
8730                                               "Keyword 'void' cannot be used in this context");
8731                                 return null;
8732                         }
8733
8734                         if ((dim.Length > 0) && (dim [0] == '?')) {
8735                                 TypeExpr nullable = new NullableType (left, loc);
8736                                 if (dim.Length > 1)
8737                                         nullable = new ComposedCast (nullable, dim.Substring (1), loc);
8738                                 return nullable.ResolveAsTypeTerminal (ec);
8739                         }
8740
8741                         if (dim == "*" && !TypeManager.IsUnmanagedType (ltype)) {
8742                                 Report.Error (208, loc, "Cannot declare a pointer to a managed type ('{0}')", ltype);
8743                                 return null;
8744                         }
8745
8746                         if (dim != "")
8747                                 type = TypeManager.GetConstructedType (ltype, dim);
8748                         else
8749                                 type = ltype;
8750
8751                         if (type == null) {
8752                                 throw new InternalErrorException ("Couldn't create computed type " + ltype + dim);
8753                         }
8754
8755                         if (!ec.InUnsafe && type.IsPointer){
8756                                 UnsafeError (loc);
8757                                 return null;
8758                         }
8759
8760                         if (type.IsArray && (type.GetElementType () == TypeManager.arg_iterator_type ||
8761                                 type.GetElementType () == TypeManager.typed_reference_type)) {
8762                                 Report.Error (611, loc, "Array elements cannot be of type '{0}'", TypeManager.CSharpName (type.GetElementType ()));
8763                                 return null;
8764                         }
8765
8766                         eclass = ExprClass.Type;
8767                         return this;
8768                 }
8769
8770                 public override string Name {
8771                         get {
8772                                 return left + dim;
8773                         }
8774                 }
8775
8776                 public override string FullName {
8777                         get {
8778                                 return type.FullName;
8779                         }
8780                 }
8781         }
8782
8783         public class FixedBufferPtr: Expression {
8784                 Expression array;
8785
8786                 public FixedBufferPtr (Expression array, Type array_type, Location l)
8787                 {
8788                         this.array = array;
8789                         this.loc = l;
8790
8791                         type = TypeManager.GetPointerType (array_type);
8792                         eclass = ExprClass.Value;
8793                 }
8794
8795                 public override void Emit(EmitContext ec)
8796                 {
8797                         array.Emit (ec);
8798                 }
8799
8800                 public override Expression DoResolve (EmitContext ec)
8801                 {
8802                         //
8803                         // We are born fully resolved
8804                         //
8805                         return this;
8806                 }
8807         }
8808
8809
8810         //
8811         // This class is used to represent the address of an array, used
8812         // only by the Fixed statement, this generates "&a [0]" construct
8813         // for fixed (char *pa = a)
8814         //
8815         public class ArrayPtr : FixedBufferPtr {
8816                 Type array_type;
8817
8818                 public ArrayPtr (Expression array, Type array_type, Location l):
8819                         base (array, array_type, l)
8820                 {
8821                         this.array_type = array_type;
8822                 }
8823
8824                 public override void Emit (EmitContext ec)
8825                 {
8826                         base.Emit (ec);
8827
8828                         ILGenerator ig = ec.ig;
8829                         IntLiteral.EmitInt (ig, 0);
8830                         ig.Emit (OpCodes.Ldelema, array_type);
8831                 }
8832         }
8833
8834         //
8835         // Used by the fixed statement
8836         //
8837         public class StringPtr : Expression {
8838                 LocalBuilder b;
8839
8840                 public StringPtr (LocalBuilder b, Location l)
8841                 {
8842                         this.b = b;
8843                         eclass = ExprClass.Value;
8844                         type = TypeManager.char_ptr_type;
8845                         loc = l;
8846                 }
8847
8848                 public override Expression DoResolve (EmitContext ec)
8849                 {
8850                         // This should never be invoked, we are born in fully
8851                         // initialized state.
8852
8853                         return this;
8854                 }
8855
8856                 public override void Emit (EmitContext ec)
8857                 {
8858                         ILGenerator ig = ec.ig;
8859
8860                         ig.Emit (OpCodes.Ldloc, b);
8861                         ig.Emit (OpCodes.Conv_I);
8862                         ig.Emit (OpCodes.Call, TypeManager.int_get_offset_to_string_data);
8863                         ig.Emit (OpCodes.Add);
8864                 }
8865         }
8866
8867         //
8868         // Implements the `stackalloc' keyword
8869         //
8870         public class StackAlloc : Expression {
8871                 Type otype;
8872                 Expression t;
8873                 Expression count;
8874
8875                 public StackAlloc (Expression type, Expression count, Location l)
8876                 {
8877                         t = type;
8878                         this.count = count;
8879                         loc = l;
8880                 }
8881
8882                 public override Expression DoResolve (EmitContext ec)
8883                 {
8884                         count = count.Resolve (ec);
8885                         if (count == null)
8886                                 return null;
8887
8888                         if (count.Type != TypeManager.int32_type){
8889                                 count = Convert.ImplicitConversionRequired (ec, count, TypeManager.int32_type, loc);
8890                                 if (count == null)
8891                                         return null;
8892                         }
8893
8894                         Constant c = count as Constant;
8895                         if (c != null && c.IsNegative) {
8896                                 Report.Error (247, loc, "Cannot use a negative size with stackalloc");
8897                                 return null;
8898                         }
8899
8900                         if (ec.CurrentBranching.InCatch () ||
8901                             ec.CurrentBranching.InFinally (true)) {
8902                                 Error (255,
8903                                               "stackalloc can not be used in a catch or finally block");
8904                                 return null;
8905                         }
8906
8907                         TypeExpr texpr = t.ResolveAsTypeTerminal (ec);
8908                         if (texpr == null)
8909                                 return null;
8910
8911                         otype = texpr.Type;
8912
8913                         if (!TypeManager.VerifyUnManaged (otype, loc))
8914                                 return null;
8915
8916                         type = TypeManager.GetPointerType (otype);
8917                         eclass = ExprClass.Value;
8918
8919                         return this;
8920                 }
8921
8922                 public override void Emit (EmitContext ec)
8923                 {
8924                         int size = GetTypeSize (otype);
8925                         ILGenerator ig = ec.ig;
8926
8927                         if (size == 0)
8928                                 ig.Emit (OpCodes.Sizeof, otype);
8929                         else
8930                                 IntConstant.EmitInt (ig, size);
8931                         count.Emit (ec);
8932                         ig.Emit (OpCodes.Mul);
8933                         ig.Emit (OpCodes.Localloc);
8934                 }
8935         }
8936 }