mcs/mbas/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 Ximian, Inc.
   8 //
   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                 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);
  50
  51                         ec.ig.Emit (OpCodes.Call, mi);
  52                         return;
  53                 }
  54
  55                 static public Expression MakeSimpleCall (EmitContext ec, MethodGroupExpr mg,
  56                                                          Expression e, Location loc)
  57                 {
  58                         ArrayList args;
  59                         MethodBase method;
  60
  61                         args = new ArrayList (1);
  62                         args.Add (new Argument (e, Argument.AType.Expression));
  63                         method = Invocation.OverloadResolve (ec, (MethodGroupExpr) mg, args, loc);
  64
  65                         if (method == null)
  66                                 return null;
  67
  68                         return new StaticCallExpr ((MethodInfo) method, args, loc);
  69                 }
  70
  71                 public override void EmitStatement (EmitContext ec)
  72                 {
  73                         Emit (ec);
  74                         if (TypeManager.TypeToCoreType (type) != TypeManager.void_type)
  75                                 ec.ig.Emit (OpCodes.Pop);
  76                 }
  77         }
  78
  79         /// <summary>
  80         ///   Unary expressions.
  81         /// </summary>
  82         ///
  83         /// <remarks>
  84         ///   Unary implements unary expressions.   It derives from
  85         ///   ExpressionStatement becuase the pre/post increment/decrement
  86         ///   operators can be used in a statement context.
  87         /// </remarks>
  88         public class Unary : Expression {
  89                 public enum Operator : byte {
  90                         UnaryPlus, UnaryNegation, LogicalNot, OnesComplement,
  91                         Indirection, AddressOf,  TOP
  92                 }
  93
  94                 public Operator Oper;
  95                 public Expression Expr;
  96
  97                 public Unary (Operator op, Expression expr, Location loc)
  98                 {
  99                         this.Oper = op;
 100                         this.Expr = expr;
 101                         this.loc = loc;
 102                 }
 103
 104                 /// <summary>
 105                 ///   Returns a stringified representation of the Operator
 106                 /// </summary>
 107                 static public string OperName (Operator oper)
 108                 {
 109                         switch (oper){
 110                         case Operator.UnaryPlus:
 111                                 return "+";
 112                         case Operator.UnaryNegation:
 113                                 return "-";
 114                         case Operator.LogicalNot:
 115                                 return "!";
 116                         case Operator.OnesComplement:
 117                                 return "~";
 118                         case Operator.AddressOf:
 119                                 return "&";
 120                         case Operator.Indirection:
 121                                 return "*";
 122                         }
 123
 124                         return oper.ToString ();
 125                 }
 126
 127                 static string [] oper_names;
 128
 129                 static Unary ()
 130                 {
 131                         oper_names = new string [(int)Operator.TOP];
 132
 133                         oper_names [(int) Operator.UnaryPlus] = "op_UnaryPlus";
 134                         oper_names [(int) Operator.UnaryNegation] = "op_UnaryNegation";
 135                         oper_names [(int) Operator.LogicalNot] = "op_LogicalNot";
 136                         oper_names [(int) Operator.OnesComplement] = "op_OnesComplement";
 137                         oper_names [(int) Operator.Indirection] = "op_Indirection";
 138                         oper_names [(int) Operator.AddressOf] = "op_AddressOf";
 139                 }
 140
 141                 void Error23 (Type t)
 142                 {
 143                         Error (
 144                                 23, "Operator " + OperName (Oper) +
 145                                 " cannot be applied to operand of type `" +
 146                                 TypeManager.CSharpName (t) + "'");
 147                 }
 148
 149                 /// <remarks>
 150                 ///   The result has been already resolved:
 151                 ///
 152                 ///   FIXME: a minus constant -128 sbyte cant be turned into a
 153                 ///   constant byte.
 154                 /// </remarks>
 155                 static Expression TryReduceNegative (Constant expr)
 156                 {
 157                         Expression e = null;
 158
 159                         if (expr is IntConstant)
 160                                 e = new IntConstant (-((IntConstant) expr).Value);
 161                         else if (expr is UIntConstant){
 162                                 uint value = ((UIntConstant) expr).Value;
 163
 164                                 if (value < 2147483649)
 165                                         return new IntConstant (-(int)value);
 166                                 else
 167                                         e = new LongConstant (value);
 168                         }
 169                         else if (expr is LongConstant)
 170                                 e = new LongConstant (-((LongConstant) expr).Value);
 171                         else if (expr is ULongConstant){
 172                                 ulong value = ((ULongConstant) expr).Value;
 173
 174                                 if (value < 9223372036854775809)
 175                                         return new LongConstant(-(long)value);
 176                         }
 177                         else if (expr is FloatConstant)
 178                                 e = new FloatConstant (-((FloatConstant) expr).Value);
 179                         else if (expr is DoubleConstant)
 180                                 e = new DoubleConstant (-((DoubleConstant) expr).Value);
 181                         else if (expr is DecimalConstant)
 182                                 e = new DecimalConstant (-((DecimalConstant) expr).Value);
 183                         else if (expr is ShortConstant)
 184                                 e = new IntConstant (-((ShortConstant) expr).Value);
 185                         else if (expr is UShortConstant)
 186                                 e = new IntConstant (-((UShortConstant) expr).Value);
 187                         return e;
 188                 }
 189
 190                 // <summary>
 191                 //   This routine will attempt to simplify the unary expression when the
 192                 //   argument is a constant.  The result is returned in `result' and the
 193                 //   function returns true or false depending on whether a reduction
 194                 //   was performed or not
 195                 // </summary>
 196                 bool Reduce (EmitContext ec, Constant e, out Expression result)
 197                 {
 198                         Type expr_type = e.Type;
 199
 200                         switch (Oper){
 201                         case Operator.UnaryPlus:
 202                                 result = e;
 203                                 return true;
 204
 205                         case Operator.UnaryNegation:
 206                                 result = TryReduceNegative (e);
 207                                 return true;
 208
 209                         case Operator.LogicalNot:
 210                                 if (expr_type != TypeManager.bool_type) {
 211                                         result = null;
 212                                         Error23 (expr_type);
 213                                         return false;
 214                                 }
 215
 216                                 BoolConstant b = (BoolConstant) e;
 217                                 result = new BoolConstant (!(b.Value));
 218                                 return true;
 219
 220                         case Operator.OnesComplement:
 221                                 if (!((expr_type == TypeManager.int32_type) ||
 222                                       (expr_type == TypeManager.uint32_type) ||
 223                                       (expr_type == TypeManager.int64_type) ||
 224                                       (expr_type == TypeManager.uint64_type) ||
 225                                       (expr_type.IsSubclassOf (TypeManager.enum_type)))){
 226                                         result = null;
 227                                         Error23 (expr_type);
 228                                         return false;
 229                                 }
 230
 231                                 if (e is EnumConstant){
 232                                         EnumConstant enum_constant = (EnumConstant) e;
 233                                         Expression reduced;
 234
 235                                         if (Reduce (ec, enum_constant.Child, out reduced)){
 236                                                 result = new EnumConstant ((Constant) reduced, enum_constant.Type);
 237                                                 return true;
 238                                         } else {
 239                                                 result = null;
 240                                                 return false;
 241                                         }
 242                                 }
 243
 244                                 if (expr_type == TypeManager.int32_type){
 245                                         result = new IntConstant (~ ((IntConstant) e).Value);
 246                                 } else if (expr_type == TypeManager.uint32_type){
 247                                         result = new UIntConstant (~ ((UIntConstant) e).Value);
 248                                 } else if (expr_type == TypeManager.int64_type){
 249                                         result = new LongConstant (~ ((LongConstant) e).Value);
 250                                 } else if (expr_type == TypeManager.uint64_type){
 251                                         result = new ULongConstant (~ ((ULongConstant) e).Value);
 252                                 } else {
 253                                         result = null;
 254                                         Error23 (expr_type);
 255                                         return false;
 256                                 }
 257                                 return true;
 258
 259                         case Operator.AddressOf:
 260                                 result = this;
 261                                 return false;
 262
 263                         case Operator.Indirection:
 264                                 result = this;
 265                                 return false;
 266                         }
 267                         throw new Exception ("Can not constant fold: " + Oper.ToString());
 268                 }
 269
 270                 Expression ResolveOperator (EmitContext ec)
 271                 {
 272                         Type expr_type = Expr.Type;
 273
 274                         //
 275                         // Step 1: Perform Operator Overload location
 276                         //
 277                         Expression mg;
 278                         string op_name;
 279
 280                         op_name = oper_names [(int) Oper];
 281
 282                         mg = MemberLookup (ec, expr_type, op_name, MemberTypes.Method, AllBindingFlags, loc);
 283
 284                         if (mg != null) {
 285                                 Expression e = StaticCallExpr.MakeSimpleCall (
 286                                         ec, (MethodGroupExpr) mg, Expr, loc);
 287
 288                                 if (e == null){
 289                                         Error23 (expr_type);
 290                                         return null;
 291                                 }
 292
 293                                 return e;
 294                         }
 295
 296                         // Only perform numeric promotions on:
 297                         // +, -
 298
 299                         if (expr_type == null)
 300                                 return null;
 301
 302                         //
 303                         // Step 2: Default operations on CLI native types.
 304                         //
 305
 306                         // Attempt to use a constant folding operation.
 307                         if (Expr is Constant){
 308                                 Expression result;
 309
 310                                 if (Reduce (ec, (Constant) Expr, out result))
 311                                         return result;
 312                         }
 313
 314                         switch (Oper){
 315                         case Operator.LogicalNot:
 316                                 if (expr_type != TypeManager.bool_type) {
 317                                         Error23 (Expr.Type);
 318                                         return null;
 319                                 }
 320
 321                                 type = TypeManager.bool_type;
 322                                 return this;
 323
 324                         case Operator.OnesComplement:
 325                                 if (!((expr_type == TypeManager.int32_type) ||
 326                                       (expr_type == TypeManager.uint32_type) ||
 327                                       (expr_type == TypeManager.int64_type) ||
 328                                       (expr_type == TypeManager.uint64_type) ||
 329                                       (expr_type.IsSubclassOf (TypeManager.enum_type)))){
 330                                         Expression e;
 331
 332                                         e = ConvertImplicit (ec, Expr, TypeManager.int32_type, loc);
 333                                         if (e != null){
 334                                                 type = TypeManager.int32_type;
 335                                                 return this;
 336                                         }
 337                                         e = ConvertImplicit (ec, Expr, TypeManager.uint32_type, loc);
 338                                         if (e != null){
 339                                                 type = TypeManager.uint32_type;
 340                                                 return this;
 341                                         }
 342                                         e = ConvertImplicit (ec, Expr, TypeManager.int64_type, loc);
 343                                         if (e != null){
 344                                                 type = TypeManager.int64_type;
 345                                                 return this;
 346                                         }
 347                                         e = ConvertImplicit (ec, Expr, TypeManager.uint64_type, loc);
 348                                         if (e != null){
 349                                                 type = TypeManager.uint64_type;
 350                                                 return this;
 351                                         }
 352                                         Error23 (expr_type);
 353                                         return null;
 354                                 }
 355                                 type = expr_type;
 356                                 return this;
 357
 358                         case Operator.AddressOf:
 359                                 if (Expr.eclass != ExprClass.Variable){
 360                                         Error (211, "Cannot take the address of non-variables");
 361                                         return null;
 362                                 }
 363
 364                                 if (!ec.InUnsafe) {
 365                                         UnsafeError (loc);
 366                                         return null;
 367                                 }
 368
 369                                 if (!TypeManager.VerifyUnManaged (Expr.Type, loc)){
 370                                         return null;
 371                                 }
 372
 373                                 string ptr_type_name = Expr.Type.FullName + "*";
 374                                 type = TypeManager.LookupType (ptr_type_name);
 375
 376                                 return this;
 377
 378                         case Operator.Indirection:
 379                                 if (!ec.InUnsafe){
 380                                         UnsafeError (loc);
 381                                         return null;
 382                                 }
 383
 384                                 if (!expr_type.IsPointer){
 385                                         Error (
 386                                                 193,
 387                                                 "The * or -> operator can only be applied to pointers");
 388                                         return null;
 389                                 }
 390
 391                                 //
 392                                 // We create an Indirection expression, because
 393                                 // it can implement the IMemoryLocation.
 394                                 //
 395                                 return new Indirection (Expr, loc);
 396
 397                         case Operator.UnaryPlus:
 398                                 //
 399                                 // A plus in front of something is just a no-op, so return the child.
 400                                 //
 401                                 return Expr;
 402
 403                         case Operator.UnaryNegation:
 404                                 //
 405                                 // Deals with -literals
 406                                 // int     operator- (int x)
 407                                 // long    operator- (long x)
 408                                 // float   operator- (float f)
 409                                 // double  operator- (double d)
 410                                 // decimal operator- (decimal d)
 411                                 //
 412                                 Expression expr = null;
 413
 414                                 //
 415                                 // transform - - expr into expr
 416                                 //
 417                                 if (Expr is Unary){
 418                                         Unary unary = (Unary) Expr;
 419
 420                                         if (unary.Oper == Operator.UnaryNegation)
 421                                                 return unary.Expr;
 422                                 }
 423
 424                                 //
 425                                 // perform numeric promotions to int,
 426                                 // long, double.
 427                                 //
 428                                 //
 429                                 // The following is inneficient, because we call
 430                                 // ConvertImplicit too many times.
 431                                 //
 432                                 // It is also not clear if we should convert to Float
 433                                 // or Double initially.
 434                                 //
 435                                 if (expr_type == TypeManager.uint32_type){
 436                                         //
 437                                         // FIXME: handle exception to this rule that
 438                                         // permits the int value -2147483648 (-2^31) to
 439                                         // bt wrote as a decimal interger literal
 440                                         //
 441                                         type = TypeManager.int64_type;
 442                                         Expr = ConvertImplicit (ec, Expr, type, loc);
 443                                         return this;
 444                                 }
 445
 446                                 if (expr_type == TypeManager.uint64_type){
 447                                         //
 448                                         // FIXME: Handle exception of `long value'
 449                                         // -92233720368547758087 (-2^63) to be wrote as
 450                                         // decimal integer literal.
 451                                         //
 452                                         Error23 (expr_type);
 453                                         return null;
 454                                 }
 455
 456                                 if (expr_type == TypeManager.float_type){
 457                                         type = expr_type;
 458                                         return this;
 459                                 }
 460
 461                                 expr = ConvertImplicit (ec, Expr, TypeManager.int32_type, loc);
 462                                 if (expr != null){
 463                                         Expr = expr;
 464                                         type = expr.Type;
 465                                         return this;
 466                                 }
 467
 468                                 expr = ConvertImplicit (ec, Expr, TypeManager.int64_type, loc);
 469                                 if (expr != null){
 470                                         Expr = expr;
 471                                         type = expr.Type;
 472                                         return this;
 473                                 }
 474
 475                                 expr = ConvertImplicit (ec, Expr, TypeManager.double_type, loc);
 476                                 if (expr != null){
 477                                         Expr = expr;
 478                                         type = expr.Type;
 479                                         return this;
 480                                 }
 481
 482                                 Error23 (expr_type);
 483                                 return null;
 484                         }
 485
 486                         Error (187, "No such operator '" + OperName (Oper) + "' defined for type '" +
 487                                TypeManager.CSharpName (expr_type) + "'");
 488                         return null;
 489                 }
 490
 491                 public override Expression DoResolve (EmitContext ec)
 492                 {
 493                         if (Oper == Operator.AddressOf)
 494                                 Expr = Expr.ResolveLValue (ec, new EmptyExpression ());
 495                         else
 496                                 Expr = Expr.Resolve (ec);
 497
 498                         if (Expr == null)
 499                                 return null;
 500
 501                         eclass = ExprClass.Value;
 502                         return ResolveOperator (ec);
 503                 }
 504
 505                 public override void Emit (EmitContext ec)
 506                 {
 507                         ILGenerator ig = ec.ig;
 508                         Type expr_type = Expr.Type;
 509
 510                         switch (Oper) {
 511                         case Operator.UnaryPlus:
 512                                 throw new Exception ("This should be caught by Resolve");
 513
 514                         case Operator.UnaryNegation:
 515                                 Expr.Emit (ec);
 516                                 ig.Emit (OpCodes.Neg);
 517                                 break;
 518
 519                         case Operator.LogicalNot:
 520                                 Expr.Emit (ec);
 521                                 ig.Emit (OpCodes.Ldc_I4_0);
 522                                 ig.Emit (OpCodes.Ceq);
 523                                 break;
 524
 525                         case Operator.OnesComplement:
 526                                 Expr.Emit (ec);
 527                                 ig.Emit (OpCodes.Not);
 528                                 break;
 529
 530                         case Operator.AddressOf:
 531                                 ((IMemoryLocation)Expr).AddressOf (ec, AddressOp.LoadStore);
 532                                 break;
 533
 534                         default:
 535                                 throw new Exception ("This should not happen: Operator = "
 536                                                      + Oper.ToString ());
 537                         }
 538                 }
 539
 540                 /// <summary>
 541                 ///   This will emit the child expression for `ec' avoiding the logical
 542                 ///   not.  The parent will take care of changing brfalse/brtrue
 543                 /// </summary>
 544                 public void EmitLogicalNot (EmitContext ec)
 545                 {
 546                         if (Oper != Operator.LogicalNot)
 547                                 throw new Exception ("EmitLogicalNot can only be called with !expr");
 548
 549                         Expr.Emit (ec);
 550                 }
 551
 552                 public override string ToString ()
 553                 {
 554                         return "Unary (" + Oper + ", " + Expr + ")";
 555                 }
 556
 557         }
 558
 559         //
 560         // Unary operators are turned into Indirection expressions
 561         // after semantic analysis (this is so we can take the address
 562         // of an indirection).
 563         //
 564         public class Indirection : Expression, IMemoryLocation, IAssignMethod {
 565                 Expression expr;
 566                 LocalTemporary temporary;
 567                 bool have_temporary;
 568
 569                 public Indirection (Expression expr, Location l)
 570                 {
 571                         this.expr = expr;
 572                         this.type = TypeManager.TypeToCoreType (expr.Type.GetElementType ());
 573                         eclass = ExprClass.Variable;
 574                         loc = l;
 575                 }
 576
 577                 void LoadExprValue (EmitContext ec)
 578                 {
 579                 }
 580
 581                 public override void Emit (EmitContext ec)
 582                 {
 583                         ILGenerator ig = ec.ig;
 584
 585                         if (temporary != null){
 586                                 if (have_temporary){
 587                                         temporary.Emit (ec);
 588                                         return;
 589                                 }
 590                                 expr.Emit (ec);
 591                                 ec.ig.Emit (OpCodes.Dup);
 592                                 temporary.Store (ec);
 593                                 have_temporary = true;
 594                         } else
 595                                 expr.Emit (ec);
 596
 597                         LoadFromPtr (ig, Type);
 598                 }
 599
 600                 public void EmitAssign (EmitContext ec, Expression source)
 601                 {
 602                         if (temporary != null){
 603                                 if (have_temporary){
 604                                         temporary.Emit (ec);
 605                                         return;
 606                                 }
 607                                 expr.Emit (ec);
 608                                 ec.ig.Emit (OpCodes.Dup);
 609                                 temporary.Store (ec);
 610                                 have_temporary = true;
 611                         } else
 612                                 expr.Emit (ec);
 613
 614                         source.Emit (ec);
 615                         StoreFromPtr (ec.ig, type);
 616                 }
 617
 618                 public void AddressOf (EmitContext ec, AddressOp Mode)
 619                 {
 620                         if (temporary != null){
 621                                 if (have_temporary){
 622                                         temporary.Emit (ec);
 623                                         return;
 624                                 }
 625                                 expr.Emit (ec);
 626                                 ec.ig.Emit (OpCodes.Dup);
 627                                 temporary.Store (ec);
 628                                 have_temporary = true;
 629                         } else
 630                                 expr.Emit (ec);
 631                 }
 632
 633                 public override Expression DoResolve (EmitContext ec)
 634                 {
 635                         //
 636                         // Born fully resolved
 637                         //
 638                         return this;
 639                 }
 640
 641                 public new void CacheTemporaries (EmitContext ec)
 642                 {
 643                         temporary = new LocalTemporary (ec, type);
 644                 }
 645         }
 646
 647         /// <summary>
 648         ///   Unary Mutator expressions (pre and post ++ and --)
 649         /// </summary>
 650         ///
 651         /// <remarks>
 652         ///   UnaryMutator implements ++ and -- expressions.   It derives from
 653         ///   ExpressionStatement becuase the pre/post increment/decrement
 654         ///   operators can be used in a statement context.
 655         ///
 656         /// FIXME: Idea, we could split this up in two classes, one simpler
 657         /// for the common case, and one with the extra fields for more complex
 658         /// classes (indexers require temporary access;  overloaded require method)
 659         ///
 660         /// Maybe we should have classes PreIncrement, PostIncrement, PreDecrement,
 661         /// PostDecrement, that way we could save the `Mode' byte as well.
 662         /// </remarks>
 663         public class UnaryMutator : ExpressionStatement {
 664                 public enum Mode : byte {
 665                         PreIncrement, PreDecrement, PostIncrement, PostDecrement
 666                 }
 667
 668                 Mode mode;
 669                 Expression expr;
 670                 LocalTemporary temp_storage;
 671
 672                 //
 673                 // This is expensive for the simplest case.
 674                 //
 675                 Expression method;
 676
 677                 public UnaryMutator (Mode m, Expression e, Location l)
 678                 {
 679                         mode = m;
 680                         loc = l;
 681                         expr = e;
 682                 }
 683
 684                 static string OperName (Mode mode)
 685                 {
 686                         return (mode == Mode.PreIncrement || mode == Mode.PostIncrement) ?
 687                                 "++" : "--";
 688                 }
 689
 690                 void Error23 (Type t)
 691                 {
 692                         Error (
 693                                 23, "Operator " + OperName (mode) +
 694                                 " cannot be applied to operand of type `" +
 695                                 TypeManager.CSharpName (t) + "'");
 696                 }
 697
 698                 /// <summary>
 699                 ///   Returns whether an object of type `t' can be incremented
 700                 ///   or decremented with add/sub (ie, basically whether we can
 701                 ///   use pre-post incr-decr operations on it, but it is not a
 702                 ///   System.Decimal, which we require operator overloading to catch)
 703                 /// </summary>
 704                 static bool IsIncrementableNumber (Type t)
 705                 {
 706                         return (t == TypeManager.sbyte_type) ||
 707                                 (t == TypeManager.byte_type) ||
 708                                 (t == TypeManager.short_type) ||
 709                                 (t == TypeManager.ushort_type) ||
 710                                 (t == TypeManager.int32_type) ||
 711                                 (t == TypeManager.uint32_type) ||
 712                                 (t == TypeManager.int64_type) ||
 713                                 (t == TypeManager.uint64_type) ||
 714                                 (t == TypeManager.char_type) ||
 715                                 (t.IsSubclassOf (TypeManager.enum_type)) ||
 716                                 (t == TypeManager.float_type) ||
 717                                 (t == TypeManager.double_type) ||
 718                                 (t.IsPointer && t != TypeManager.void_ptr_type);
 719                 }
 720
 721                 Expression ResolveOperator (EmitContext ec)
 722                 {
 723                         Type expr_type = expr.Type;
 724
 725                         //
 726                         // Step 1: Perform Operator Overload location
 727                         //
 728                         Expression mg;
 729                         string op_name;
 730
 731                         if (mode == Mode.PreIncrement || mode == Mode.PostIncrement)
 732                                 op_name = "op_Increment";
 733                         else
 734                                 op_name = "op_Decrement";
 735
 736                         mg = MemberLookup (ec, expr_type, op_name, MemberTypes.Method, AllBindingFlags, loc);
 737
 738                         if (mg == null && expr_type.BaseType != null)
 739                                 mg = MemberLookup (ec, expr_type.BaseType, op_name,
 740                                                    MemberTypes.Method, AllBindingFlags, loc);
 741
 742                         if (mg != null) {
 743                                 method = StaticCallExpr.MakeSimpleCall (
 744                                         ec, (MethodGroupExpr) mg, expr, loc);
 745
 746                                 type = method.Type;
 747                                 return this;
 748                         }
 749
 750                         //
 751                         // The operand of the prefix/postfix increment decrement operators
 752                         // should be an expression that is classified as a variable,
 753                         // a property access or an indexer access
 754                         //
 755                         type = expr_type;
 756                         if (expr.eclass == ExprClass.Variable){
 757                                 if (IsIncrementableNumber (expr_type) ||
 758                                     expr_type == TypeManager.decimal_type){
 759                                         return this;
 760                                 }
 761                         } else if (expr.eclass == ExprClass.IndexerAccess){
 762                                 IndexerAccess ia = (IndexerAccess) expr;
 763
 764                                 temp_storage = new LocalTemporary (ec, expr.Type);
 765
 766                                 expr = ia.ResolveLValue (ec, temp_storage);
 767                                 if (expr == null)
 768                                         return null;
 769
 770                                 return this;
 771                         } else if (expr.eclass == ExprClass.PropertyAccess){
 772                                 PropertyExpr pe = (PropertyExpr) expr;
 773
 774                                 if (pe.VerifyAssignable ())
 775                                         return this;
 776
 777                                 return null;
 778                         } else {
 779                                 expr.Error118 ("variable, indexer or property access");
 780                                 return null;
 781                         }
 782
 783                         Error (187, "No such operator '" + OperName (mode) + "' defined for type '" +
 784                                TypeManager.CSharpName (expr_type) + "'");
 785                         return null;
 786                 }
 787
 788                 public override Expression DoResolve (EmitContext ec)
 789                 {
 790                         expr = expr.Resolve (ec);
 791
 792                         if (expr == null)
 793                                 return null;
 794
 795                         eclass = ExprClass.Value;
 796                         return ResolveOperator (ec);
 797                 }
 798
 799                 static int PtrTypeSize (Type t)
 800                 {
 801                         return GetTypeSize (t.GetElementType ());
 802                 }
 803
 804                 //
 805                 // Loads the proper "1" into the stack based on the type
 806                 //
 807                 static void LoadOne (ILGenerator ig, Type t)
 808                 {
 809                         if (t == TypeManager.uint64_type || t == TypeManager.int64_type)
 810                                 ig.Emit (OpCodes.Ldc_I8, 1L);
 811                         else if (t == TypeManager.double_type)
 812                                 ig.Emit (OpCodes.Ldc_R8, 1.0);
 813                         else if (t == TypeManager.float_type)
 814                                 ig.Emit (OpCodes.Ldc_R4, 1.0F);
 815                         else if (t.IsPointer){
 816                                 int n = PtrTypeSize (t);
 817
 818                                 if (n == 0)
 819                                         ig.Emit (OpCodes.Sizeof, t);
 820                                 else
 821                                         IntConstant.EmitInt (ig, n);
 822                         } else
 823                                 ig.Emit (OpCodes.Ldc_I4_1);
 824                 }
 825
 826
 827                 //
 828                 // FIXME: We need some way of avoiding the use of temp_storage
 829                 // for some types of storage (parameters, local variables,
 830                 // static fields) and single-dimension array access.
 831                 //
 832                 void EmitCode (EmitContext ec, bool is_expr)
 833                 {
 834                         ILGenerator ig = ec.ig;
 835                         IAssignMethod ia = (IAssignMethod) expr;
 836                         Type expr_type = expr.Type;
 837
 838                         if (temp_storage == null)
 839                                 temp_storage = new LocalTemporary (ec, expr_type);
 840
 841                         ia.CacheTemporaries (ec);
 842                         ig.Emit (OpCodes.Nop);
 843                         switch (mode){
 844                         case Mode.PreIncrement:
 845                         case Mode.PreDecrement:
 846                                 if (method == null){
 847                                         expr.Emit (ec);
 848
 849                                         LoadOne (ig, expr_type);
 850
 851                                         //
 852                                         // Select the opcode based on the check state (then the type)
 853                                         // and the actual operation
 854                                         //
 855                                         if (ec.CheckState){
 856                                                 if (expr_type == TypeManager.int32_type ||
 857                                                     expr_type == TypeManager.int64_type){
 858                                                         if (mode == Mode.PreDecrement)
 859                                                                 ig.Emit (OpCodes.Sub_Ovf);
 860                                                         else
 861                                                                 ig.Emit (OpCodes.Add_Ovf);
 862                                                 } else if (expr_type == TypeManager.uint32_type ||
 863                                                            expr_type == TypeManager.uint64_type){
 864                                                         if (mode == Mode.PreDecrement)
 865                                                                 ig.Emit (OpCodes.Sub_Ovf_Un);
 866                                                         else
 867                                                                 ig.Emit (OpCodes.Add_Ovf_Un);
 868                                                 } else {
 869                                                         if (mode == Mode.PreDecrement)
 870                                                                 ig.Emit (OpCodes.Sub_Ovf);
 871                                                         else
 872                                                                 ig.Emit (OpCodes.Add_Ovf);
 873                                                 }
 874                                         } else {
 875                                                 if (mode == Mode.PreDecrement)
 876                                                         ig.Emit (OpCodes.Sub);
 877                                                 else
 878                                                         ig.Emit (OpCodes.Add);
 879                                         }
 880                                 } else
 881                                         method.Emit (ec);
 882
 883                                 temp_storage.Store (ec);
 884                                 ia.EmitAssign (ec, temp_storage);
 885                                 if (is_expr)
 886                                         temp_storage.Emit (ec);
 887                                 break;
 888
 889                         case Mode.PostIncrement:
 890                         case Mode.PostDecrement:
 891                                 if (is_expr)
 892                                         expr.Emit (ec);
 893
 894                                 if (method == null){
 895                                         if (!is_expr)
 896                                                 expr.Emit (ec);
 897                                         else
 898                                                 ig.Emit (OpCodes.Dup);
 899
 900                                         LoadOne (ig, expr_type);
 901
 902                                         if (ec.CheckState){
 903                                                 if (expr_type == TypeManager.int32_type ||
 904                                                     expr_type == TypeManager.int64_type){
 905                                                         if (mode == Mode.PostDecrement)
 906                                                                 ig.Emit (OpCodes.Sub_Ovf);
 907                                                         else
 908                                                                 ig.Emit (OpCodes.Add_Ovf);
 909                                                 } else if (expr_type == TypeManager.uint32_type ||
 910                                                            expr_type == TypeManager.uint64_type){
 911                                                         if (mode == Mode.PostDecrement)
 912                                                                 ig.Emit (OpCodes.Sub_Ovf_Un);
 913                                                         else
 914                                                                 ig.Emit (OpCodes.Add_Ovf_Un);
 915                                                 } else {
 916                                                         if (mode == Mode.PostDecrement)
 917                                                                 ig.Emit (OpCodes.Sub_Ovf);
 918                                                         else
 919                                                                 ig.Emit (OpCodes.Add_Ovf);
 920                                                 }
 921                                         } else {
 922                                                 if (mode == Mode.PostDecrement)
 923                                                         ig.Emit (OpCodes.Sub);
 924                                                 else
 925                                                         ig.Emit (OpCodes.Add);
 926                                         }
 927                                 } else {
 928                                         method.Emit (ec);
 929                                 }
 930
 931                                 temp_storage.Store (ec);
 932                                 ia.EmitAssign (ec, temp_storage);
 933                                 break;
 934                         }
 935                 }
 936
 937                 public override void Emit (EmitContext ec)
 938                 {
 939                         EmitCode (ec, true);
 940
 941                 }
 942
 943                 public override void EmitStatement (EmitContext ec)
 944                 {
 945                         EmitCode (ec, false);
 946                 }
 947
 948         }
 949
 950         /// <summary>
 951         ///   Base class for the `Is' and `As' classes.
 952         /// </summary>
 953         ///
 954         /// <remarks>
 955         ///   FIXME: Split this in two, and we get to save the `Operator' Oper
 956         ///   size.
 957         /// </remarks>
 958         public abstract class Probe : Expression {
 959                 public readonly Expression ProbeType;
 960                 protected Expression expr;
 961                 protected Type probe_type;
 962
 963                 public Probe (Expression expr, Expression probe_type, Location l)
 964                 {
 965                         ProbeType = probe_type;
 966                         loc = l;
 967                         this.expr = expr;
 968                 }
 969
 970                 public Expression Expr {
 971                         get {
 972                                 return expr;
 973                         }
 974                 }
 975
 976                 public override Expression DoResolve (EmitContext ec)
 977                 {
 978                         probe_type = ec.DeclSpace.ResolveType (ProbeType, false, loc);
 979
 980                         if (probe_type == null)
 981                                 return null;
 982
 983                         expr = expr.Resolve (ec);
 984
 985                         return this;
 986                 }
 987         }
 988
 989         /// <summary>
 990         ///   Implementation of the `is' operator.
 991         /// </summary>
 992         public class Is : Probe {
 993                 public Is (Expression expr, Expression probe_type, Location l)
 994                         : base (expr, probe_type, l)
 995                 {
 996                 }
 997
 998                 enum Action {
 999                         AlwaysTrue, AlwaysNull, AlwaysFalse, LeaveOnStack, Probe
1000                 }
1001
1002                 Action action;
1003
1004                 public override void Emit (EmitContext ec)
1005                 {
1006                         ILGenerator ig = ec.ig;
1007
1008                         expr.Emit (ec);
1009
1010                         switch (action){
1011                         case Action.AlwaysFalse:
1012                                 ig.Emit (OpCodes.Pop);
1013                                 IntConstant.EmitInt (ig, 0);
1014                                 return;
1015                         case Action.AlwaysTrue:
1016                                 ig.Emit (OpCodes.Pop);
1017                                 ig.Emit (OpCodes.Nop);
1018                                 IntConstant.EmitInt (ig, 1);
1019                                 return;
1020                         case Action.LeaveOnStack:
1021                                 // the `e != null' rule.
1022                                 return;
1023                         case Action.Probe:
1024                                 ig.Emit (OpCodes.Isinst, probe_type);
1025                                 ig.Emit (OpCodes.Ldnull);
1026                                 ig.Emit (OpCodes.Cgt_Un);
1027                                 return;
1028                         }
1029                         throw new Exception ("never reached");
1030                 }
1031
1032                 public override Expression DoResolve (EmitContext ec)
1033                 {
1034                         Expression e = base.DoResolve (ec);
1035
1036                         if ((e == null) || (expr == null))
1037                                 return null;
1038
1039                         Type etype = expr.Type;
1040                         bool warning_always_matches = false;
1041                         bool warning_never_matches = false;
1042
1043                         type = TypeManager.bool_type;
1044                         eclass = ExprClass.Value;
1045
1046                         //
1047                         // First case, if at compile time, there is an implicit conversion
1048                         // then e != null (objects) or true (value types)
1049                         //
1050                         e = ConvertImplicitStandard (ec, expr, probe_type, loc);
1051                         if (e != null){
1052                                 expr = e;
1053                                 if (etype.IsValueType)
1054                                         action = Action.AlwaysTrue;
1055                                 else
1056                                         action = Action.LeaveOnStack;
1057
1058                                 warning_always_matches = true;
1059                         } else if (ExplicitReferenceConversionExists (etype, probe_type)){
1060                                 //
1061                                 // Second case: explicit reference convresion
1062                                 //
1063                                 if (expr is NullLiteral)
1064                                         action = Action.AlwaysFalse;
1065                                 else
1066                                         action = Action.Probe;
1067                         } else {
1068                                 action = Action.AlwaysFalse;
1069                                 warning_never_matches = true;
1070                         }
1071
1072                         if (RootContext.WarningLevel >= 1){
1073                                 if (warning_always_matches)
1074                                         Warning (
1075                                                 183,
1076                                                 "The expression is always of type `" +
1077                                                 TypeManager.CSharpName (probe_type) + "'");
1078                                 else if (warning_never_matches){
1079                                         if (!(probe_type.IsInterface || expr.Type.IsInterface))
1080                                                 Warning (
1081                                                         184,
1082                                                         "The expression is never of type `" +
1083                                                         TypeManager.CSharpName (probe_type) + "'");
1084                                 }
1085                         }
1086
1087                         return this;
1088                 }
1089         }
1090
1091         /// <summary>
1092         ///   Implementation of the `as' operator.
1093         /// </summary>
1094         public class As : Probe {
1095                 public As (Expression expr, Expression probe_type, Location l)
1096                         : base (expr, probe_type, l)
1097                 {
1098                 }
1099
1100                 bool do_isinst = false;
1101
1102                 public override void Emit (EmitContext ec)
1103                 {
1104                         ILGenerator ig = ec.ig;
1105
1106                         expr.Emit (ec);
1107
1108                         if (do_isinst)
1109                                 ig.Emit (OpCodes.Isinst, probe_type);
1110                 }
1111
1112                 static void Error_CannotConvertType (Type source, Type target, Location loc)
1113                 {
1114                         Report.Error (
1115                                 39, loc, "as operator can not convert from `" +
1116                                 TypeManager.CSharpName (source) + "' to `" +
1117                                 TypeManager.CSharpName (target) + "'");
1118                 }
1119
1120                 public override Expression DoResolve (EmitContext ec)
1121                 {
1122                         Expression e = base.DoResolve (ec);
1123
1124                         if (e == null)
1125                                 return null;
1126
1127                         type = probe_type;
1128                         eclass = ExprClass.Value;
1129                         Type etype = expr.Type;
1130
1131                         if (TypeManager.IsValueType (probe_type)){
1132                                 Report.Error (77, loc, "The as operator should be used with a reference type only (" +
1133                                               TypeManager.CSharpName (probe_type) + " is a value type");
1134                                 return null;
1135
1136                         }
1137
1138                         e = ConvertImplicit (ec, expr, probe_type, loc);
1139                         if (e != null){
1140                                 expr = e;
1141                                 do_isinst = false;
1142                                 return this;
1143                         }
1144
1145                         if (ExplicitReferenceConversionExists (etype, probe_type)){
1146                                 do_isinst = true;
1147                                 return this;
1148                         }
1149
1150                         Error_CannotConvertType (etype, probe_type, loc);
1151                         return null;
1152                 }
1153         }
1154
1155         /// <summary>
1156         ///   This represents a typecast in the source language.
1157         ///
1158         ///   FIXME: Cast expressions have an unusual set of parsing
1159         ///   rules, we need to figure those out.
1160         /// </summary>
1161         public class Cast : Expression {
1162                 Expression target_type;
1163                 Expression expr;
1164
1165                 public Cast (Expression cast_type, Expression expr, Location loc)
1166                 {
1167                         this.target_type = cast_type;
1168                         this.expr = expr;
1169                         this.loc = loc;
1170                 }
1171
1172                 public Expression TargetType {
1173                         get {
1174                                 return target_type;
1175                         }
1176                 }
1177
1178                 public Expression Expr {
1179                         get {
1180                                 return expr;
1181                         }
1182                         set {
1183                                 expr = value;
1184                         }
1185                 }
1186
1187                 /// <summary>
1188                 ///   Attempts to do a compile-time folding of a constant cast.
1189                 /// </summary>
1190                 Expression TryReduce (EmitContext ec, Type target_type)
1191                 {
1192                         if (expr is ByteConstant){
1193                                 byte v = ((ByteConstant) expr).Value;
1194
1195                                 if (target_type == TypeManager.sbyte_type)
1196                                         return new SByteConstant ((sbyte) v);
1197                                 if (target_type == TypeManager.short_type)
1198                                         return new ShortConstant ((short) v);
1199                                 if (target_type == TypeManager.ushort_type)
1200                                         return new UShortConstant ((ushort) v);
1201                                 if (target_type == TypeManager.int32_type)
1202                                         return new IntConstant ((int) v);
1203                                 if (target_type == TypeManager.uint32_type)
1204                                         return new UIntConstant ((uint) v);
1205                                 if (target_type == TypeManager.int64_type)
1206                                         return new LongConstant ((long) v);
1207                                 if (target_type == TypeManager.uint64_type)
1208                                         return new ULongConstant ((ulong) v);
1209                                 if (target_type == TypeManager.float_type)
1210                                         return new FloatConstant ((float) v);
1211                                 if (target_type == TypeManager.double_type)
1212                                         return new DoubleConstant ((double) v);
1213                                 if (target_type == TypeManager.char_type)
1214                                         return new CharConstant ((char) v);
1215                                 if (target_type == TypeManager.decimal_type)
1216                                         return new DecimalConstant ((decimal) v);
1217                         }
1218                         if (expr is SByteConstant){
1219                                 sbyte v = ((SByteConstant) expr).Value;
1220
1221                                 if (target_type == TypeManager.byte_type)
1222                                         return new ByteConstant ((byte) v);
1223                                 if (target_type == TypeManager.short_type)
1224                                         return new ShortConstant ((short) v);
1225                                 if (target_type == TypeManager.ushort_type)
1226                                         return new UShortConstant ((ushort) v);
1227                                 if (target_type == TypeManager.int32_type)
1228                                         return new IntConstant ((int) v);
1229                                 if (target_type == TypeManager.uint32_type)
1230                                         return new UIntConstant ((uint) v);
1231                                 if (target_type == TypeManager.int64_type)
1232                                         return new LongConstant ((long) v);
1233                                 if (target_type == TypeManager.uint64_type)
1234                                         return new ULongConstant ((ulong) v);
1235                                 if (target_type == TypeManager.float_type)
1236                                         return new FloatConstant ((float) v);
1237                                 if (target_type == TypeManager.double_type)
1238                                         return new DoubleConstant ((double) v);
1239                                 if (target_type == TypeManager.char_type)
1240                                         return new CharConstant ((char) v);
1241                                 if (target_type == TypeManager.decimal_type)
1242                                         return new DecimalConstant ((decimal) v);
1243                         }
1244                         if (expr is ShortConstant){
1245                                 short v = ((ShortConstant) expr).Value;
1246
1247                                 if (target_type == TypeManager.byte_type)
1248                                         return new ByteConstant ((byte) v);
1249                                 if (target_type == TypeManager.sbyte_type)
1250                                         return new SByteConstant ((sbyte) v);
1251                                 if (target_type == TypeManager.ushort_type)
1252                                         return new UShortConstant ((ushort) v);
1253                                 if (target_type == TypeManager.int32_type)
1254                                         return new IntConstant ((int) v);
1255                                 if (target_type == TypeManager.uint32_type)
1256                                         return new UIntConstant ((uint) v);
1257                                 if (target_type == TypeManager.int64_type)
1258                                         return new LongConstant ((long) v);
1259                                 if (target_type == TypeManager.uint64_type)
1260                                         return new ULongConstant ((ulong) v);
1261                                 if (target_type == TypeManager.float_type)
1262                                         return new FloatConstant ((float) v);
1263                                 if (target_type == TypeManager.double_type)
1264                                         return new DoubleConstant ((double) v);
1265                                 if (target_type == TypeManager.char_type)
1266                                         return new CharConstant ((char) v);
1267                                 if (target_type == TypeManager.decimal_type)
1268                                         return new DecimalConstant ((decimal) v);
1269                         }
1270                         if (expr is UShortConstant){
1271                                 ushort v = ((UShortConstant) expr).Value;
1272
1273                                 if (target_type == TypeManager.byte_type)
1274                                         return new ByteConstant ((byte) v);
1275                                 if (target_type == TypeManager.sbyte_type)
1276                                         return new SByteConstant ((sbyte) v);
1277                                 if (target_type == TypeManager.short_type)
1278                                         return new ShortConstant ((short) v);
1279                                 if (target_type == TypeManager.int32_type)
1280                                         return new IntConstant ((int) v);
1281                                 if (target_type == TypeManager.uint32_type)
1282                                         return new UIntConstant ((uint) v);
1283                                 if (target_type == TypeManager.int64_type)
1284                                         return new LongConstant ((long) v);
1285                                 if (target_type == TypeManager.uint64_type)
1286                                         return new ULongConstant ((ulong) v);
1287                                 if (target_type == TypeManager.float_type)
1288                                         return new FloatConstant ((float) v);
1289                                 if (target_type == TypeManager.double_type)
1290                                         return new DoubleConstant ((double) v);
1291                                 if (target_type == TypeManager.char_type)
1292                                         return new CharConstant ((char) v);
1293                                 if (target_type == TypeManager.decimal_type)
1294                                         return new DecimalConstant ((decimal) v);
1295                         }
1296                         if (expr is IntConstant){
1297                                 int v = ((IntConstant) expr).Value;
1298
1299                                 if (target_type == TypeManager.byte_type)
1300                                         return new ByteConstant ((byte) v);
1301                                 if (target_type == TypeManager.sbyte_type)
1302                                         return new SByteConstant ((sbyte) v);
1303                                 if (target_type == TypeManager.short_type)
1304                                         return new ShortConstant ((short) v);
1305                                 if (target_type == TypeManager.ushort_type)
1306                                         return new UShortConstant ((ushort) v);
1307                                 if (target_type == TypeManager.uint32_type)
1308                                         return new UIntConstant ((uint) v);
1309                                 if (target_type == TypeManager.int64_type)
1310                                         return new LongConstant ((long) v);
1311                                 if (target_type == TypeManager.uint64_type)
1312                                         return new ULongConstant ((ulong) v);
1313                                 if (target_type == TypeManager.float_type)
1314                                         return new FloatConstant ((float) v);
1315                                 if (target_type == TypeManager.double_type)
1316                                         return new DoubleConstant ((double) v);
1317                                 if (target_type == TypeManager.char_type)
1318                                         return new CharConstant ((char) v);
1319                                 if (target_type == TypeManager.decimal_type)
1320                                         return new DecimalConstant ((decimal) v);
1321                         }
1322                         if (expr is UIntConstant){
1323                                 uint v = ((UIntConstant) expr).Value;
1324
1325                                 if (target_type == TypeManager.byte_type)
1326                                         return new ByteConstant ((byte) v);
1327                                 if (target_type == TypeManager.sbyte_type)
1328                                         return new SByteConstant ((sbyte) v);
1329                                 if (target_type == TypeManager.short_type)
1330                                         return new ShortConstant ((short) v);
1331                                 if (target_type == TypeManager.ushort_type)
1332                                         return new UShortConstant ((ushort) v);
1333                                 if (target_type == TypeManager.int32_type)
1334                                         return new IntConstant ((int) v);
1335                                 if (target_type == TypeManager.int64_type)
1336                                         return new LongConstant ((long) v);
1337                                 if (target_type == TypeManager.uint64_type)
1338                                         return new ULongConstant ((ulong) v);
1339                                 if (target_type == TypeManager.float_type)
1340                                         return new FloatConstant ((float) v);
1341                                 if (target_type == TypeManager.double_type)
1342                                         return new DoubleConstant ((double) v);
1343                                 if (target_type == TypeManager.char_type)
1344                                         return new CharConstant ((char) v);
1345                                 if (target_type == TypeManager.decimal_type)
1346                                         return new DecimalConstant ((decimal) v);
1347                         }
1348                         if (expr is LongConstant){
1349                                 long v = ((LongConstant) expr).Value;
1350
1351                                 if (target_type == TypeManager.byte_type)
1352                                         return new ByteConstant ((byte) v);
1353                                 if (target_type == TypeManager.sbyte_type)
1354                                         return new SByteConstant ((sbyte) v);
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.uint64_type)
1364                                         return new ULongConstant ((ulong) v);
1365                                 if (target_type == TypeManager.float_type)
1366                                         return new FloatConstant ((float) v);
1367                                 if (target_type == TypeManager.double_type)
1368                                         return new DoubleConstant ((double) v);
1369                                 if (target_type == TypeManager.char_type)
1370                                         return new CharConstant ((char) v);
1371                                 if (target_type == TypeManager.decimal_type)
1372                                         return new DecimalConstant ((decimal) v);
1373                         }
1374                         if (expr is ULongConstant){
1375                                 ulong v = ((ULongConstant) expr).Value;
1376
1377                                 if (target_type == TypeManager.byte_type)
1378                                         return new ByteConstant ((byte) v);
1379                                 if (target_type == TypeManager.sbyte_type)
1380                                         return new SByteConstant ((sbyte) v);
1381                                 if (target_type == TypeManager.short_type)
1382                                         return new ShortConstant ((short) v);
1383                                 if (target_type == TypeManager.ushort_type)
1384                                         return new UShortConstant ((ushort) v);
1385                                 if (target_type == TypeManager.int32_type)
1386                                         return new IntConstant ((int) v);
1387                                 if (target_type == TypeManager.uint32_type)
1388                                         return new UIntConstant ((uint) v);
1389                                 if (target_type == TypeManager.int64_type)
1390                                         return new LongConstant ((long) v);
1391                                 if (target_type == TypeManager.float_type)
1392                                         return new FloatConstant ((float) v);
1393                                 if (target_type == TypeManager.double_type)
1394                                         return new DoubleConstant ((double) v);
1395                                 if (target_type == TypeManager.char_type)
1396                                         return new CharConstant ((char) v);
1397                                 if (target_type == TypeManager.decimal_type)
1398                                         return new DecimalConstant ((decimal) v);
1399                         }
1400                         if (expr is FloatConstant){
1401                                 float v = ((FloatConstant) expr).Value;
1402
1403                                 if (target_type == TypeManager.byte_type)
1404                                         return new ByteConstant ((byte) v);
1405                                 if (target_type == TypeManager.sbyte_type)
1406                                         return new SByteConstant ((sbyte) v);
1407                                 if (target_type == TypeManager.short_type)
1408                                         return new ShortConstant ((short) v);
1409                                 if (target_type == TypeManager.ushort_type)
1410                                         return new UShortConstant ((ushort) v);
1411                                 if (target_type == TypeManager.int32_type)
1412                                         return new IntConstant ((int) v);
1413                                 if (target_type == TypeManager.uint32_type)
1414                                         return new UIntConstant ((uint) v);
1415                                 if (target_type == TypeManager.int64_type)
1416                                         return new LongConstant ((long) v);
1417                                 if (target_type == TypeManager.uint64_type)
1418                                         return new ULongConstant ((ulong) v);
1419                                 if (target_type == TypeManager.double_type)
1420                                         return new DoubleConstant ((double) v);
1421                                 if (target_type == TypeManager.char_type)
1422                                         return new CharConstant ((char) v);
1423                                 if (target_type == TypeManager.decimal_type)
1424                                         return new DecimalConstant ((decimal) v);
1425                         }
1426                         if (expr is DoubleConstant){
1427                                 double v = ((DoubleConstant) expr).Value;
1428
1429                                 if (target_type == TypeManager.byte_type)
1430                                         return new ByteConstant ((byte) v);
1431                                 if (target_type == TypeManager.sbyte_type)
1432                                         return new SByteConstant ((sbyte) v);
1433                                 if (target_type == TypeManager.short_type)
1434                                         return new ShortConstant ((short) v);
1435                                 if (target_type == TypeManager.ushort_type)
1436                                         return new UShortConstant ((ushort) v);
1437                                 if (target_type == TypeManager.int32_type)
1438                                         return new IntConstant ((int) v);
1439                                 if (target_type == TypeManager.uint32_type)
1440                                         return new UIntConstant ((uint) v);
1441                                 if (target_type == TypeManager.int64_type)
1442                                         return new LongConstant ((long) v);
1443                                 if (target_type == TypeManager.uint64_type)
1444                                         return new ULongConstant ((ulong) v);
1445                                 if (target_type == TypeManager.float_type)
1446                                         return new FloatConstant ((float) v);
1447                                 if (target_type == TypeManager.char_type)
1448                                         return new CharConstant ((char) v);
1449                                 if (target_type == TypeManager.decimal_type)
1450                                         return new DecimalConstant ((decimal) v);
1451                         }
1452
1453                         return null;
1454                 }
1455
1456                 public override Expression DoResolve (EmitContext ec)
1457                 {
1458                         expr = expr.Resolve (ec);
1459                         if (expr == null)
1460                                 return null;
1461
1462                         int errors = Report.Errors;
1463
1464                         type = ec.DeclSpace.ResolveType (target_type, false, Location);
1465
1466                         if (type == null)
1467                                 return null;
1468
1469                         eclass = ExprClass.Value;
1470
1471                         if (expr is Constant){
1472                                 Expression e = TryReduce (ec, type);
1473
1474                                 if (e != null)
1475                                         return e;
1476                         }
1477
1478                         expr = ConvertExplicit (ec, expr, type, loc);
1479                         return expr;
1480                 }
1481
1482                 public override void Emit (EmitContext ec)
1483                 {
1484                         //
1485                         // This one will never happen
1486                         //
1487                         throw new Exception ("Should not happen");
1488                 }
1489         }
1490
1491         /// <summary>
1492         ///   Binary operators
1493         /// </summary>
1494         public class Binary : Expression {
1495                 public enum Operator : byte {
1496                         Multiply, Division, Modulus,
1497                         Addition, Subtraction,
1498                         LeftShift, RightShift,
1499                         LessThan, GreaterThan, LessThanOrEqual, GreaterThanOrEqual,
1500                         Equality, Inequality,
1501                         BitwiseAnd,
1502                         ExclusiveOr,
1503                         BitwiseOr,
1504                         LogicalAnd,
1505                         LogicalOr,
1506                         TOP
1507                 }
1508
1509                 Operator oper;
1510                 Expression left, right;
1511
1512                 //
1513                 // After resolution, method might contain the operator overload
1514                 // method.
1515                 //
1516                 protected MethodBase method;
1517                 ArrayList  Arguments;
1518
1519                 bool DelegateOperation;
1520
1521                 // This must be kept in sync with Operator!!!
1522                 static string [] oper_names;
1523
1524                 static Binary ()
1525                 {
1526                         oper_names = new string [(int) Operator.TOP];
1527
1528                         oper_names [(int) Operator.Multiply] = "op_Multiply";
1529                         oper_names [(int) Operator.Division] = "op_Division";
1530                         oper_names [(int) Operator.Modulus] = "op_Modulus";
1531                         oper_names [(int) Operator.Addition] = "op_Addition";
1532                         oper_names [(int) Operator.Subtraction] = "op_Subtraction";
1533                         oper_names [(int) Operator.LeftShift] = "op_LeftShift";
1534                         oper_names [(int) Operator.RightShift] = "op_RightShift";
1535                         oper_names [(int) Operator.LessThan] = "op_LessThan";
1536                         oper_names [(int) Operator.GreaterThan] = "op_GreaterThan";
1537                         oper_names [(int) Operator.LessThanOrEqual] = "op_LessThanOrEqual";
1538                         oper_names [(int) Operator.GreaterThanOrEqual] = "op_GreaterThanOrEqual";
1539                         oper_names [(int) Operator.Equality] = "op_Equality";
1540                         oper_names [(int) Operator.Inequality] = "op_Inequality";
1541                         oper_names [(int) Operator.BitwiseAnd] = "op_BitwiseAnd";
1542                         oper_names [(int) Operator.BitwiseOr] = "op_BitwiseOr";
1543                         oper_names [(int) Operator.ExclusiveOr] = "op_ExclusiveOr";
1544                         oper_names [(int) Operator.LogicalOr] = "op_LogicalOr";
1545                         oper_names [(int) Operator.LogicalAnd] = "op_LogicalAnd";
1546                 }
1547
1548                 public Binary (Operator oper, Expression left, Expression right, Location loc)
1549                 {
1550                         this.oper = oper;
1551                         this.left = left;
1552                         this.right = right;
1553                         this.loc = loc;
1554                 }
1555
1556                 public Operator Oper {
1557                         get {
1558                                 return oper;
1559                         }
1560                         set {
1561                                 oper = value;
1562                         }
1563                 }
1564
1565                 public Expression Left {
1566                         get {
1567                                 return left;
1568                         }
1569                         set {
1570                                 left = value;
1571                         }
1572                 }
1573
1574                 public Expression Right {
1575                         get {
1576                                 return right;
1577                         }
1578                         set {
1579                                 right = value;
1580                         }
1581                 }
1582
1583
1584                 /// <summary>
1585                 ///   Returns a stringified representation of the Operator
1586                 /// </summary>
1587                 static string OperName (Operator oper)
1588                 {
1589                         switch (oper){
1590                         case Operator.Multiply:
1591                                 return "*";
1592                         case Operator.Division:
1593                                 return "/";
1594                         case Operator.Modulus:
1595                                 return "%";
1596                         case Operator.Addition:
1597                                 return "+";
1598                         case Operator.Subtraction:
1599                                 return "-";
1600                         case Operator.LeftShift:
1601                                 return "<<";
1602                         case Operator.RightShift:
1603                                 return ">>";
1604                         case Operator.LessThan:
1605                                 return "<";
1606                         case Operator.GreaterThan:
1607                                 return ">";
1608                         case Operator.LessThanOrEqual:
1609                                 return "<=";
1610                         case Operator.GreaterThanOrEqual:
1611                                 return ">=";
1612                         case Operator.Equality:
1613                                 return "==";
1614                         case Operator.Inequality:
1615                                 return "!=";
1616                         case Operator.BitwiseAnd:
1617                                 return "&";
1618                         case Operator.BitwiseOr:
1619                                 return "|";
1620                         case Operator.ExclusiveOr:
1621                                 return "^";
1622                         case Operator.LogicalOr:
1623                                 return "||";
1624                         case Operator.LogicalAnd:
1625                                 return "&&";
1626                         }
1627
1628                         return oper.ToString ();
1629                 }
1630
1631                 public override string ToString ()
1632                 {
1633                         return "operator " + OperName (oper) + "(" + left.ToString () + ", " +
1634                                 right.ToString () + ")";
1635                 }
1636
1637                 Expression ForceConversion (EmitContext ec, Expression expr, Type target_type)
1638                 {
1639                         if (expr.Type == target_type)
1640                                 return expr;
1641
1642                         return ConvertImplicit (ec, expr, target_type, new Location (-1));
1643                 }
1644
1645                 public static void Error_OperatorAmbiguous (Location loc, Operator oper, Type l, Type r)
1646                 {
1647                         Report.Error (
1648                                 34, loc, "Operator `" + OperName (oper)
1649                                 + "' is ambiguous on operands of type `"
1650                                 + TypeManager.CSharpName (l) + "' "
1651                                 + "and `" + TypeManager.CSharpName (r)
1652                                 + "'");
1653                 }
1654
1655                 //
1656                 // Note that handling the case l == Decimal || r == Decimal
1657                 // is taken care of by the Step 1 Operator Overload resolution.
1658                 //
1659                 bool DoNumericPromotions (EmitContext ec, Type l, Type r)
1660                 {
1661                         if (l == TypeManager.double_type || r == TypeManager.double_type){
1662                                 //
1663                                 // If either operand is of type double, the other operand is
1664                                 // conveted to type double.
1665                                 //
1666                                 if (r != TypeManager.double_type)
1667                                         right = ConvertImplicit (ec, right, TypeManager.double_type, loc);
1668                                 if (l != TypeManager.double_type)
1669                                         left = ConvertImplicit (ec, left, TypeManager.double_type, loc);
1670
1671                                 type = TypeManager.double_type;
1672                         } else if (l == TypeManager.float_type || r == TypeManager.float_type){
1673                                 //
1674                                 // if either operand is of type float, the other operand is
1675                                 // converted to type float.
1676                                 //
1677                                 if (r != TypeManager.double_type)
1678                                         right = ConvertImplicit (ec, right, TypeManager.float_type, loc);
1679                                 if (l != TypeManager.double_type)
1680                                         left = ConvertImplicit (ec, left, TypeManager.float_type, loc);
1681                                 type = TypeManager.float_type;
1682                         } else if (l == TypeManager.uint64_type || r == TypeManager.uint64_type){
1683                                 Expression e;
1684                                 Type other;
1685                                 //
1686                                 // If either operand is of type ulong, the other operand is
1687                                 // converted to type ulong.  or an error ocurrs if the other
1688                                 // operand is of type sbyte, short, int or long
1689                                 //
1690                                 if (l == TypeManager.uint64_type){
1691                                         if (r != TypeManager.uint64_type){
1692                                                 if (right is IntConstant){
1693                                                         IntConstant ic = (IntConstant) right;
1694
1695                                                         e = TryImplicitIntConversion (l, ic);
1696                                                         if (e != null)
1697                                                                 right = e;
1698                                                 } else if (right is LongConstant){
1699                                                         long ll = ((LongConstant) right).Value;
1700
1701                                                         if (ll > 0)
1702                                                                 right = new ULongConstant ((ulong) ll);
1703                                                 } else {
1704                                                         e = ImplicitNumericConversion (ec, right, l, loc);
1705                                                         if (e != null)
1706                                                                 right = e;
1707                                                 }
1708                                         }
1709                                         other = right.Type;
1710                                 } else {
1711                                         if (left is IntConstant){
1712                                                 e = TryImplicitIntConversion (r, (IntConstant) left);
1713                                                 if (e != null)
1714                                                         left = e;
1715                                         } else if (left is LongConstant){
1716                                                 long ll = ((LongConstant) left).Value;
1717
1718                                                 if (ll > 0)
1719                                                         left = new ULongConstant ((ulong) ll);
1720                                         } else {
1721                                                 e = ImplicitNumericConversion (ec, left, r, loc);
1722                                                 if (e != null)
1723                                                         left = e;
1724                                         }
1725                                         other = left.Type;
1726                                 }
1727
1728                                 if ((other == TypeManager.sbyte_type) ||
1729                                     (other == TypeManager.short_type) ||
1730                                     (other == TypeManager.int32_type) ||
1731                                     (other == TypeManager.int64_type))
1732                                         Error_OperatorAmbiguous (loc, oper, l, r);
1733                                 type = TypeManager.uint64_type;
1734                         } else if (l == TypeManager.int64_type || r == TypeManager.int64_type){
1735                                 //
1736                                 // If either operand is of type long, the other operand is converted
1737                                 // to type long.
1738                                 //
1739                                 if (l != TypeManager.int64_type)
1740                                         left = ConvertImplicit (ec, left, TypeManager.int64_type, loc);
1741                                 if (r != TypeManager.int64_type)
1742                                         right = ConvertImplicit (ec, right, TypeManager.int64_type, loc);
1743
1744                                 type = TypeManager.int64_type;
1745                         } else if (l == TypeManager.uint32_type || r == TypeManager.uint32_type){
1746                                 //
1747                                 // If either operand is of type uint, and the other
1748                                 // operand is of type sbyte, short or int, othe operands are
1749                                 // converted to type long.
1750                                 //
1751                                 Type other = null;
1752
1753                                 if (l == TypeManager.uint32_type){
1754                                         if (right is IntConstant){
1755                                                 IntConstant ic = (IntConstant) right;
1756                                                 int val = ic.Value;
1757
1758                                                 if (val >= 0)
1759                                                         right = new UIntConstant ((uint) val);
1760
1761                                                 type = l;
1762                                                 return true;
1763                                         }
1764                                         other = r;
1765                                 }
1766                                 else if (r == TypeManager.uint32_type){
1767                                         if (left is IntConstant){
1768                                                 IntConstant ic = (IntConstant) left;
1769                                                 int val = ic.Value;
1770
1771                                                 if (val >= 0)
1772                                                         left = new UIntConstant ((uint) val);
1773
1774                                                 type = r;
1775                                                 return true;
1776                                         }
1777
1778                                         other = l;
1779                                 }
1780
1781                                 if ((other == TypeManager.sbyte_type) ||
1782                                     (other == TypeManager.short_type) ||
1783                                     (other == TypeManager.int32_type)){
1784                                         left = ForceConversion (ec, left, TypeManager.int64_type);
1785                                         right = ForceConversion (ec, right, TypeManager.int64_type);
1786                                         type = TypeManager.int64_type;
1787                                 } else {
1788                                         //
1789                                         // if either operand is of type uint, the other
1790                                         // operand is converd to type uint
1791                                         //
1792                                         left = ForceConversion (ec, left, TypeManager.uint32_type);
1793                                         right = ForceConversion (ec, right, TypeManager.uint32_type);
1794                                         type = TypeManager.uint32_type;
1795                                 }
1796                         } else if (l == TypeManager.decimal_type || r == TypeManager.decimal_type){
1797                                 if (l != TypeManager.decimal_type)
1798                                         left = ConvertImplicit (ec, left, TypeManager.decimal_type, loc);
1799
1800                                 if (r != TypeManager.decimal_type)
1801                                         right = ConvertImplicit (ec, right, TypeManager.decimal_type, loc);
1802                                 type = TypeManager.decimal_type;
1803                         } else {
1804                                 left = ForceConversion (ec, left, TypeManager.int32_type);
1805                                 right = ForceConversion (ec, right, TypeManager.int32_type);
1806
1807                                 type = TypeManager.int32_type;
1808                         }
1809
1810                         return (left != null) && (right != null);
1811                 }
1812
1813                 static public void Error_OperatorCannotBeApplied (Location loc, string name, Type l, Type r)
1814                 {
1815                         Report.Error (19, loc,
1816                                "Operator " + name + " cannot be applied to operands of type `" +
1817                                TypeManager.CSharpName (l) + "' and `" +
1818                                TypeManager.CSharpName (r) + "'");
1819                 }
1820
1821                 void Error_OperatorCannotBeApplied ()
1822                 {
1823                         Error_OperatorCannotBeApplied (loc, OperName (oper), left.Type, right.Type);
1824                 }
1825
1826                 static bool is_32_or_64 (Type t)
1827                 {
1828                         return (t == TypeManager.int32_type || t == TypeManager.uint32_type ||
1829                                 t == TypeManager.int64_type || t == TypeManager.uint64_type);
1830                 }
1831
1832                 static bool is_unsigned (Type t)
1833                 {
1834                         return (t == TypeManager.uint32_type || t == TypeManager.uint64_type ||
1835                                 t == TypeManager.short_type || t == TypeManager.byte_type);
1836                 }
1837
1838                 Expression CheckShiftArguments (EmitContext ec)
1839                 {
1840                         Expression e;
1841                         Type l = left.Type;
1842                         Type r = right.Type;
1843
1844                         e = ForceConversion (ec, right, TypeManager.int32_type);
1845                         if (e == null){
1846                                 Error_OperatorCannotBeApplied ();
1847                                 return null;
1848                         }
1849                         right = e;
1850
1851                         if (((e = ConvertImplicit (ec, left, TypeManager.int32_type, loc)) != null) ||
1852                             ((e = ConvertImplicit (ec, left, TypeManager.uint32_type, loc)) != null) ||
1853                             ((e = ConvertImplicit (ec, left, TypeManager.int64_type, loc)) != null) ||
1854                             ((e = ConvertImplicit (ec, left, TypeManager.uint64_type, loc)) != null)){
1855                                 left = e;
1856                                 type = e.Type;
1857
1858                                 return this;
1859                         }
1860                         Error_OperatorCannotBeApplied ();
1861                         return null;
1862                 }
1863
1864                 Expression ResolveOperator (EmitContext ec)
1865                 {
1866                         Type l = left.Type;
1867                         Type r = right.Type;
1868
1869                         bool overload_failed = false;
1870
1871                         //
1872                         // Step 1: Perform Operator Overload location
1873                         //
1874                         Expression left_expr, right_expr;
1875
1876                         string op = oper_names [(int) oper];
1877
1878                         MethodGroupExpr union;
1879                         left_expr = MemberLookup (ec, l, op, MemberTypes.Method, AllBindingFlags, loc);
1880                         if (r != l){
1881                                 right_expr = MemberLookup (
1882                                         ec, r, op, MemberTypes.Method, AllBindingFlags, loc);
1883                                 union = Invocation.MakeUnionSet (left_expr, right_expr, loc);
1884                         } else
1885                                 union = (MethodGroupExpr) left_expr;
1886
1887                         if (union != null) {
1888                                 Arguments = new ArrayList ();
1889                                 Arguments.Add (new Argument (left, Argument.AType.Expression));
1890                                 Arguments.Add (new Argument (right, Argument.AType.Expression));
1891
1892                                 method = Invocation.OverloadResolve (ec, union, Arguments, Location.Null);
1893                                 if (method != null) {
1894                                         MethodInfo mi = (MethodInfo) method;
1895
1896                                         type = mi.ReturnType;
1897                                         return this;
1898                                 } else {
1899                                         overload_failed = true;
1900                                 }
1901                         }
1902
1903                         //
1904                         // Step 2: Default operations on CLI native types.
1905                         //
1906
1907                         //
1908                         // Step 0: String concatenation (because overloading will get this wrong)
1909                         //
1910                         if (oper == Operator.Addition){
1911                                 //
1912                                 // If any of the arguments is a string, cast to string
1913                                 //
1914
1915                                 if (l == TypeManager.string_type){
1916
1917                                         if (r == TypeManager.void_type) {
1918                                                 Error_OperatorCannotBeApplied ();
1919                                                 return null;
1920                                         }
1921
1922                                         if (r == TypeManager.string_type){
1923                                                 if (left is Constant && right is Constant){
1924                                                         StringConstant ls = (StringConstant) left;
1925                                                         StringConstant rs = (StringConstant) right;
1926
1927                                                         return new StringConstant (
1928                                                                 ls.Value + rs.Value);
1929                                                 }
1930
1931                                                 // string + string
1932                                                 method = TypeManager.string_concat_string_string;
1933                                         } else {
1934                                                 // string + object
1935                                                 method = TypeManager.string_concat_object_object;
1936                                                 right = ConvertImplicit (ec, right,
1937                                                                          TypeManager.object_type, loc);
1938                                                 if (right == null){
1939                                                         Error_OperatorCannotBeApplied (loc, OperName (oper), l, r);
1940                                                         return null;
1941                                                 }
1942                                         }
1943                                         type = TypeManager.string_type;
1944
1945                                         Arguments = new ArrayList ();
1946                                         Arguments.Add (new Argument (left, Argument.AType.Expression));
1947                                         Arguments.Add (new Argument (right, Argument.AType.Expression));
1948
1949                                         return this;
1950
1951                                 } else if (r == TypeManager.string_type){
1952                                         // object + string
1953
1954                                         if (l == TypeManager.void_type) {
1955                                                 Error_OperatorCannotBeApplied ();
1956                                                 return null;
1957                                         }
1958
1959                                         method = TypeManager.string_concat_object_object;
1960                                         left = ConvertImplicit (ec, left, TypeManager.object_type, loc);
1961                                         if (left == null){
1962                                                 Error_OperatorCannotBeApplied (loc, OperName (oper), l, r);
1963                                                 return null;
1964                                         }
1965                                         Arguments = new ArrayList ();
1966                                         Arguments.Add (new Argument (left, Argument.AType.Expression));
1967                                         Arguments.Add (new Argument (right, Argument.AType.Expression));
1968
1969                                         type = TypeManager.string_type;
1970
1971                                         return this;
1972                                 }
1973
1974                                 //
1975                                 // Transform a + ( - b) into a - b
1976                                 //
1977                                 if (right is Unary){
1978                                         Unary right_unary = (Unary) right;
1979
1980                                         if (right_unary.Oper == Unary.Operator.UnaryNegation){
1981                                                 oper = Operator.Subtraction;
1982                                                 right = right_unary.Expr;
1983                                                 r = right.Type;
1984                                         }
1985                                 }
1986                         }
1987
1988                         if (oper == Operator.Equality || oper == Operator.Inequality){
1989                                 if (l == TypeManager.bool_type || r == TypeManager.bool_type){
1990                                         if (r != TypeManager.bool_type || l != TypeManager.bool_type){
1991                                                 Error_OperatorCannotBeApplied ();
1992                                                 return null;
1993                                         }
1994
1995                                         type = TypeManager.bool_type;
1996                                         return this;
1997                                 }
1998
1999                                 //
2000                                 // operator != (object a, object b)
2001                                 // operator == (object a, object b)
2002                                 //
2003                                 // For this to be used, both arguments have to be reference-types.
2004                                 // Read the rationale on the spec (14.9.6)
2005                                 //
2006                                 // Also, if at compile time we know that the classes do not inherit
2007                                 // one from the other, then we catch the error there.
2008                                 //
2009                                 if (!(l.IsValueType || r.IsValueType)){
2010                                         type = TypeManager.bool_type;
2011
2012                                         if (l == r)
2013                                                 return this;
2014
2015                                         if (l.IsSubclassOf (r) || r.IsSubclassOf (l))
2016                                                 return this;
2017
2018                                         //
2019                                         // Also, a standard conversion must exist from either one
2020                                         //
2021                                         if (!(StandardConversionExists (left, r) ||
2022                                               StandardConversionExists (right, l))){
2023                                                 Error_OperatorCannotBeApplied ();
2024                                                 return null;
2025                                         }
2026                                         //
2027                                         // We are going to have to convert to an object to compare
2028                                         //
2029                                         if (l != TypeManager.object_type)
2030                                                 left = new EmptyCast (left, TypeManager.object_type);
2031                                         if (r != TypeManager.object_type)
2032                                                 right = new EmptyCast (right, TypeManager.object_type);
2033
2034                                         //
2035                                         // FIXME: CSC here catches errors cs254 and cs252
2036                                         //
2037                                         return this;
2038                                 }
2039
2040                                 //
2041                                 // One of them is a valuetype, but the other one is not.
2042                                 //
2043                                 if (!l.IsValueType || !r.IsValueType) {
2044                                         Error_OperatorCannotBeApplied ();
2045                                         return null;
2046                                 }
2047                         }
2048
2049                         // Only perform numeric promotions on:
2050                         // +, -, *, /, %, &, |, ^, ==, !=, <, >, <=, >=
2051                         //
2052                         if (oper == Operator.Addition || oper == Operator.Subtraction) {
2053                                 if (l.IsSubclassOf (TypeManager.delegate_type) &&
2054                                     r.IsSubclassOf (TypeManager.delegate_type)) {
2055
2056                                         Arguments = new ArrayList ();
2057                                         Arguments.Add (new Argument (left, Argument.AType.Expression));
2058                                         Arguments.Add (new Argument (right, Argument.AType.Expression));
2059
2060                                         if (oper == Operator.Addition)
2061                                                 method = TypeManager.delegate_combine_delegate_delegate;
2062                                         else
2063                                                 method = TypeManager.delegate_remove_delegate_delegate;
2064
2065                                         if (l != r) {
2066                                                 Error_OperatorCannotBeApplied ();
2067                                                 return null;
2068                                         }
2069
2070                                         DelegateOperation = true;
2071                                         type = l;
2072                                         return this;
2073                                 }
2074
2075                                 //
2076                                 // Pointer arithmetic:
2077                                 //
2078                                 // T* operator + (T* x, int y);
2079                                 // T* operator + (T* x, uint y);
2080                                 // T* operator + (T* x, long y);
2081                                 // T* operator + (T* x, ulong y);
2082                                 //
2083                                 // T* operator + (int y,   T* x);
2084                                 // T* operator + (uint y,  T *x);
2085                                 // T* operator + (long y,  T *x);
2086                                 // T* operator + (ulong y, T *x);
2087                                 //
2088                                 // T* operator - (T* x, int y);
2089                                 // T* operator - (T* x, uint y);
2090                                 // T* operator - (T* x, long y);
2091                                 // T* operator - (T* x, ulong y);
2092                                 //
2093                                 // long operator - (T* x, T *y)
2094                                 //
2095                                 if (l.IsPointer){
2096                                         if (r.IsPointer && oper == Operator.Subtraction){
2097                                                 if (r == l)
2098                                                         return new PointerArithmetic (
2099                                                                 false, left, right, TypeManager.int64_type,
2100                                                                 loc);
2101                                         } else if (is_32_or_64 (r))
2102                                                 return new PointerArithmetic (
2103                                                         oper == Operator.Addition, left, right, l, loc);
2104                                 } else if (r.IsPointer && is_32_or_64 (l) && oper == Operator.Addition)
2105                                         return new PointerArithmetic (
2106                                                 true, right, left, r, loc);
2107                         }
2108
2109                         //
2110                         // Enumeration operators
2111                         //
2112                         bool lie = TypeManager.IsEnumType (l);
2113                         bool rie = TypeManager.IsEnumType (r);
2114                         if (lie || rie){
2115                                 Expression temp;
2116
2117                                 // U operator - (E e, E f)
2118                                 if (lie && rie && oper == Operator.Subtraction){
2119                                         if (l == r){
2120                                                 type = TypeManager.EnumToUnderlying (l);
2121                                                 return this;
2122                                         }
2123                                         Error_OperatorCannotBeApplied ();
2124                                         return null;
2125                                 }
2126
2127                                 //
2128                                 // operator + (E e, U x)
2129                                 // operator - (E e, U x)
2130                                 //
2131                                 if (oper == Operator.Addition || oper == Operator.Subtraction){
2132                                         Type enum_type = lie ? l : r;
2133                                         Type other_type = lie ? r : l;
2134                                         Type underlying_type = TypeManager.EnumToUnderlying (enum_type);
2135 ;
2136
2137                                         if (underlying_type != other_type){
2138                                                 Error_OperatorCannotBeApplied ();
2139                                                 return null;
2140                                         }
2141
2142                                         type = enum_type;
2143                                         return this;
2144                                 }
2145
2146                                 if (!rie){
2147                                         temp = ConvertImplicit (ec, right, l, loc);
2148                                         if (temp != null)
2149                                                 right = temp;
2150                                         else {
2151                                                 Error_OperatorCannotBeApplied ();
2152                                                 return null;
2153                                         }
2154                                 } if (!lie){
2155                                         temp = ConvertImplicit (ec, left, r, loc);
2156                                         if (temp != null){
2157                                                 left = temp;
2158                                                 l = r;
2159                                         } else {
2160                                                 Error_OperatorCannotBeApplied ();
2161                                                 return null;
2162                                         }
2163                                 }
2164
2165                                 if (oper == Operator.Equality || oper == Operator.Inequality ||
2166                                     oper == Operator.LessThanOrEqual || oper == Operator.LessThan ||
2167                                     oper == Operator.GreaterThanOrEqual || oper == Operator.GreaterThan){
2168                                         type = TypeManager.bool_type;
2169                                         return this;
2170                                 }
2171
2172                                 if (oper == Operator.BitwiseAnd ||
2173                                     oper == Operator.BitwiseOr ||
2174                                     oper == Operator.ExclusiveOr){
2175                                         type = l;
2176                                         return this;
2177                                 }
2178                                 Error_OperatorCannotBeApplied ();
2179                                 return null;
2180                         }
2181
2182                         if (oper == Operator.LeftShift || oper == Operator.RightShift)
2183                                 return CheckShiftArguments (ec);
2184
2185                         if (oper == Operator.LogicalOr || oper == Operator.LogicalAnd){
2186                                 if (l != TypeManager.bool_type || r != TypeManager.bool_type){
2187                                         Error_OperatorCannotBeApplied ();
2188                                         return null;
2189                                 }
2190
2191                                 type = TypeManager.bool_type;
2192                                 return this;
2193                         }
2194
2195                         //
2196                         // operator & (bool x, bool y)
2197                         // operator | (bool x, bool y)
2198                         // operator ^ (bool x, bool y)
2199                         //
2200                         if (l == TypeManager.bool_type && r == TypeManager.bool_type){
2201                                 if (oper == Operator.BitwiseAnd ||
2202                                     oper == Operator.BitwiseOr ||
2203                                     oper == Operator.ExclusiveOr){
2204                                         type = l;
2205                                         return this;
2206                                 }
2207                         }
2208
2209                         //
2210                         // Pointer comparison
2211                         //
2212                         if (l.IsPointer && r.IsPointer){
2213                                 if (oper == Operator.Equality || oper == Operator.Inequality ||
2214                                     oper == Operator.LessThan || oper == Operator.LessThanOrEqual ||
2215                                     oper == Operator.GreaterThan || oper == Operator.GreaterThanOrEqual){
2216                                         type = TypeManager.bool_type;
2217                                         return this;
2218                                 }
2219                         }
2220
2221                         //
2222                         // We are dealing with numbers
2223                         //
2224                         if (overload_failed){
2225                                 Error_OperatorCannotBeApplied ();
2226                                 return null;
2227                         }
2228
2229                         //
2230                         // This will leave left or right set to null if there is an error
2231                         //
2232                         DoNumericPromotions (ec, l, r);
2233                         if (left == null || right == null){
2234                                 Error_OperatorCannotBeApplied (loc, OperName (oper), l, r);
2235                                 return null;
2236                         }
2237
2238                         //
2239                         // reload our cached types if required
2240                         //
2241                         l = left.Type;
2242                         r = right.Type;
2243
2244                         if (oper == Operator.BitwiseAnd ||
2245                             oper == Operator.BitwiseOr ||
2246                             oper == Operator.ExclusiveOr){
2247                                 if (l == r){
2248                                         if (!((l == TypeManager.int32_type) ||
2249                                               (l == TypeManager.uint32_type) ||
2250                                               (l == TypeManager.int64_type) ||
2251                                               (l == TypeManager.uint64_type)))
2252                                                 type = l;
2253                                 } else {
2254                                         Error_OperatorCannotBeApplied ();
2255                                         return null;
2256                                 }
2257                         }
2258
2259                         if (oper == Operator.Equality ||
2260                             oper == Operator.Inequality ||
2261                             oper == Operator.LessThanOrEqual ||
2262                             oper == Operator.LessThan ||
2263                             oper == Operator.GreaterThanOrEqual ||
2264                             oper == Operator.GreaterThan){
2265                                 type = TypeManager.bool_type;
2266                         }
2267
2268                         return this;
2269                 }
2270
2271                 public override Expression DoResolve (EmitContext ec)
2272                 {
2273                         left = left.Resolve (ec);
2274                         right = right.Resolve (ec);
2275
2276                         if (left == null || right == null)
2277                                 return null;
2278
2279                         if (left.Type == null)
2280                                 throw new Exception (
2281                                         "Resolve returned non null, but did not set the type! (" +
2282                                         left + ") at Line: " + loc.Row);
2283                         if (right.Type == null)
2284                                 throw new Exception (
2285                                         "Resolve returned non null, but did not set the type! (" +
2286                                         right + ") at Line: "+ loc.Row);
2287
2288                         eclass = ExprClass.Value;
2289
2290                         if (left is Constant && right is Constant){
2291                                 Expression e = ConstantFold.BinaryFold (
2292                                         ec, oper, (Constant) left, (Constant) right, loc);
2293                                 if (e != null)
2294                                         return e;
2295                         }
2296
2297                         return ResolveOperator (ec);
2298                 }
2299
2300                 /// <remarks>
2301                 ///   EmitBranchable is called from Statement.EmitBoolExpression in the
2302                 ///   context of a conditional bool expression.  This function will return
2303                 ///   false if it is was possible to use EmitBranchable, or true if it was.
2304                 ///
2305                 ///   The expression's code is generated, and we will generate a branch to `target'
2306                 ///   if the resulting expression value is equal to isTrue
2307                 /// </remarks>
2308                 public bool EmitBranchable (EmitContext ec, Label target, bool onTrue)
2309                 {
2310                         if (method != null)
2311                                 return false;
2312
2313                         ILGenerator ig = ec.ig;
2314
2315                         //
2316                         // This is more complicated than it looks, but its just to avoid
2317                         // duplicated tests: basically, we allow ==, !=, >, <, >= and <=
2318                         // but on top of that we want for == and != to use a special path
2319                         // if we are comparing against null
2320                         //
2321                         if (oper == Operator.Equality || oper == Operator.Inequality){
2322                                 bool my_on_true = oper == Operator.Inequality ? onTrue : !onTrue;
2323
2324                                 if (left is NullLiteral){
2325                                         right.Emit (ec);
2326                                         if (my_on_true)
2327                                                 ig.Emit (OpCodes.Brtrue, target);
2328                                         else
2329                                                 ig.Emit (OpCodes.Brfalse, target);
2330                                         return true;
2331                                 } else if (right is NullLiteral){
2332                                         left.Emit (ec);
2333                                         if (my_on_true)
2334                                                 ig.Emit (OpCodes.Brtrue, target);
2335                                         else
2336                                                 ig.Emit (OpCodes.Brfalse, target);
2337                                         return true;
2338                                 }
2339                         } else if (!(oper == Operator.LessThan ||
2340                                       oper == Operator.GreaterThan ||
2341                                       oper == Operator.LessThanOrEqual ||
2342                                       oper == Operator.GreaterThanOrEqual))
2343                                 return false;
2344
2345
2346
2347                         left.Emit (ec);
2348                         right.Emit (ec);
2349
2350                         bool isUnsigned = is_unsigned (left.Type);
2351
2352                         switch (oper){
2353                         case Operator.Equality:
2354                                 if (onTrue)
2355                                         ig.Emit (OpCodes.Beq, target);
2356                                 else
2357                                         ig.Emit (OpCodes.Bne_Un, target);
2358                                 break;
2359
2360                         case Operator.Inequality:
2361                                 if (onTrue)
2362                                         ig.Emit (OpCodes.Bne_Un, target);
2363                                 else
2364                                         ig.Emit (OpCodes.Beq, target);
2365                                 break;
2366
2367                         case Operator.LessThan:
2368                                 if (onTrue)
2369                                         if (isUnsigned)
2370                                                 ig.Emit (OpCodes.Blt_Un, target);
2371                                         else
2372                                                 ig.Emit (OpCodes.Blt, target);
2373                                 else
2374                                         if (isUnsigned)
2375                                                 ig.Emit (OpCodes.Bge_Un, target);
2376                                         else
2377                                                 ig.Emit (OpCodes.Bge, target);
2378                                 break;
2379
2380                         case Operator.GreaterThan:
2381                                 if (onTrue)
2382                                         if (isUnsigned)
2383                                                 ig.Emit (OpCodes.Bgt_Un, target);
2384                                         else
2385                                                 ig.Emit (OpCodes.Bgt, target);
2386                                 else
2387                                         if (isUnsigned)
2388                                                 ig.Emit (OpCodes.Ble_Un, target);
2389                                         else
2390                                                 ig.Emit (OpCodes.Ble, target);
2391                                 break;
2392
2393                         case Operator.LessThanOrEqual:
2394                                 if (onTrue)
2395                                         if (isUnsigned)
2396                                                 ig.Emit (OpCodes.Ble_Un, target);
2397                                         else
2398                                                 ig.Emit (OpCodes.Ble, target);
2399                                 else
2400                                         if (isUnsigned)
2401                                                 ig.Emit (OpCodes.Bgt_Un, target);
2402                                         else
2403                                                 ig.Emit (OpCodes.Bgt, target);
2404                                 break;
2405
2406
2407                         case Operator.GreaterThanOrEqual:
2408                                 if (onTrue)
2409                                         if (isUnsigned)
2410                                                 ig.Emit (OpCodes.Bge_Un, target);
2411                                         else
2412                                                 ig.Emit (OpCodes.Bge, target);
2413                                 else
2414                                         if (isUnsigned)
2415                                                 ig.Emit (OpCodes.Blt_Un, target);
2416                                         else
2417                                                 ig.Emit (OpCodes.Blt, target);
2418                                 break;
2419
2420                         default:
2421                                 return false;
2422                         }
2423
2424                         return true;
2425                 }
2426
2427                 public override void Emit (EmitContext ec)
2428                 {
2429                         ILGenerator ig = ec.ig;
2430                         Type l = left.Type;
2431                         Type r = right.Type;
2432                         OpCode opcode;
2433
2434                         if (method != null) {
2435
2436                                 // Note that operators are static anyway
2437
2438                                 if (Arguments != null)
2439                                         Invocation.EmitArguments (ec, method, Arguments);
2440
2441                                 if (method is MethodInfo)
2442                                         ig.Emit (OpCodes.Call, (MethodInfo) method);
2443                                 else
2444                                         ig.Emit (OpCodes.Call, (ConstructorInfo) method);
2445
2446                                 if (DelegateOperation)
2447                                         ig.Emit (OpCodes.Castclass, type);
2448
2449                                 return;
2450                         }
2451
2452                         //
2453                         // Handle short-circuit operators differently
2454                         // than the rest
2455                         //
2456                         if (oper == Operator.LogicalAnd){
2457                                 Label load_zero = ig.DefineLabel ();
2458                                 Label end = ig.DefineLabel ();
2459
2460                                 left.Emit (ec);
2461                                 ig.Emit (OpCodes.Brfalse, load_zero);
2462                                 right.Emit (ec);
2463                                 ig.Emit (OpCodes.Br, end);
2464                                 ig.MarkLabel (load_zero);
2465                                 ig.Emit (OpCodes.Ldc_I4_0);
2466                                 ig.MarkLabel (end);
2467                                 return;
2468                         } else if (oper == Operator.LogicalOr){
2469                                 Label load_one = ig.DefineLabel ();
2470                                 Label end = ig.DefineLabel ();
2471
2472                                 left.Emit (ec);
2473                                 ig.Emit (OpCodes.Brtrue, load_one);
2474                                 right.Emit (ec);
2475                                 ig.Emit (OpCodes.Br, end);
2476                                 ig.MarkLabel (load_one);
2477                                 ig.Emit (OpCodes.Ldc_I4_1);
2478                                 ig.MarkLabel (end);
2479                                 return;
2480                         }
2481
2482                         left.Emit (ec);
2483                         right.Emit (ec);
2484
2485                         switch (oper){
2486                         case Operator.Multiply:
2487                                 if (ec.CheckState){
2488                                         if (l == TypeManager.int32_type || l == TypeManager.int64_type)
2489                                                 opcode = OpCodes.Mul_Ovf;
2490                                         else if (l==TypeManager.uint32_type || l==TypeManager.uint64_type)
2491                                                 opcode = OpCodes.Mul_Ovf_Un;
2492                                         else
2493                                                 opcode = OpCodes.Mul;
2494                                 } else
2495                                         opcode = OpCodes.Mul;
2496
2497                                 break;
2498
2499                         case Operator.Division:
2500                                 if (l == TypeManager.uint32_type || l == TypeManager.uint64_type)
2501                                         opcode = OpCodes.Div_Un;
2502                                 else
2503                                         opcode = OpCodes.Div;
2504                                 break;
2505
2506                         case Operator.Modulus:
2507                                 if (l == TypeManager.uint32_type || l == TypeManager.uint64_type)
2508                                         opcode = OpCodes.Rem_Un;
2509                                 else
2510                                         opcode = OpCodes.Rem;
2511                                 break;
2512
2513                         case Operator.Addition:
2514                                 if (ec.CheckState){
2515                                         if (l == TypeManager.int32_type || l == TypeManager.int64_type)
2516                                                 opcode = OpCodes.Add_Ovf;
2517                                         else if (l==TypeManager.uint32_type || l==TypeManager.uint64_type)
2518                                                 opcode = OpCodes.Add_Ovf_Un;
2519                                         else
2520                                                 opcode = OpCodes.Add;
2521                                 } else
2522                                         opcode = OpCodes.Add;
2523                                 break;
2524
2525                         case Operator.Subtraction:
2526                                 if (ec.CheckState){
2527                                         if (l == TypeManager.int32_type || l == TypeManager.int64_type)
2528                                                 opcode = OpCodes.Sub_Ovf;
2529                                         else if (l==TypeManager.uint32_type || l==TypeManager.uint64_type)
2530                                                 opcode = OpCodes.Sub_Ovf_Un;
2531                                         else
2532                                                 opcode = OpCodes.Sub;
2533                                 } else
2534                                         opcode = OpCodes.Sub;
2535                                 break;
2536
2537                         case Operator.RightShift:
2538                                 if (l == TypeManager.uint32_type || l == TypeManager.uint64_type)
2539                                         opcode = OpCodes.Shr_Un;
2540                                 else
2541                                         opcode = OpCodes.Shr;
2542                                 break;
2543
2544                         case Operator.LeftShift:
2545                                 opcode = OpCodes.Shl;
2546                                 break;
2547
2548                         case Operator.Equality:
2549                                 opcode = OpCodes.Ceq;
2550                                 break;
2551
2552                         case Operator.Inequality:
2553                                 ec.ig.Emit (OpCodes.Ceq);
2554                                 ec.ig.Emit (OpCodes.Ldc_I4_0);
2555
2556                                 opcode = OpCodes.Ceq;
2557                                 break;
2558
2559                         case Operator.LessThan:
2560                                 opcode = OpCodes.Clt;
2561                                 break;
2562
2563                         case Operator.GreaterThan:
2564                                 opcode = OpCodes.Cgt;
2565                                 break;
2566
2567                         case Operator.LessThanOrEqual:
2568                                 ec.ig.Emit (OpCodes.Cgt);
2569                                 ec.ig.Emit (OpCodes.Ldc_I4_0);
2570
2571                                 opcode = OpCodes.Ceq;
2572                                 break;
2573
2574                         case Operator.GreaterThanOrEqual:
2575                                 ec.ig.Emit (OpCodes.Clt);
2576                                 ec.ig.Emit (OpCodes.Ldc_I4_1);
2577
2578                                 opcode = OpCodes.Sub;
2579                                 break;
2580
2581                         case Operator.BitwiseOr:
2582                                 opcode = OpCodes.Or;
2583                                 break;
2584
2585                         case Operator.BitwiseAnd:
2586                                 opcode = OpCodes.And;
2587                                 break;
2588
2589                         case Operator.ExclusiveOr:
2590                                 opcode = OpCodes.Xor;
2591                                 break;
2592
2593                         default:
2594                                 throw new Exception ("This should not happen: Operator = "
2595                                                      + oper.ToString ());
2596                         }
2597
2598                         ig.Emit (opcode);
2599                 }
2600
2601                 public bool IsBuiltinOperator {
2602                         get {
2603                                 return method == null;
2604                         }
2605                 }
2606         }
2607
2608         public class PointerArithmetic : Expression {
2609                 Expression left, right;
2610                 bool is_add;
2611
2612                 //
2613                 // We assume that `l' is always a pointer
2614                 //
2615                 public PointerArithmetic (bool is_addition, Expression l, Expression r, Type t,
2616                                           Location loc)
2617                 {
2618                         type = t;
2619                         eclass = ExprClass.Variable;
2620                         this.loc = loc;
2621                         left = l;
2622                         right = r;
2623                         is_add = is_addition;
2624                 }
2625
2626                 public override Expression DoResolve (EmitContext ec)
2627                 {
2628                         //
2629                         // We are born fully resolved
2630                         //
2631                         return this;
2632                 }
2633
2634                 public override void Emit (EmitContext ec)
2635                 {
2636                         Type op_type = left.Type;
2637                         ILGenerator ig = ec.ig;
2638                         int size = GetTypeSize (op_type.GetElementType ());
2639
2640                         if (right.Type.IsPointer){
2641                                 //
2642                                 // handle (pointer - pointer)
2643                                 //
2644                                 left.Emit (ec);
2645                                 right.Emit (ec);
2646                                 ig.Emit (OpCodes.Sub);
2647
2648                                 if (size != 1){
2649                                         if (size == 0)
2650                                                 ig.Emit (OpCodes.Sizeof, op_type);
2651                                         else
2652                                                 IntLiteral.EmitInt (ig, size);
2653                                         ig.Emit (OpCodes.Div);
2654                                 }
2655                                 ig.Emit (OpCodes.Conv_I8);
2656                         } else {
2657                                 //
2658                                 // handle + and - on (pointer op int)
2659                                 //
2660                                 left.Emit (ec);
2661                                 ig.Emit (OpCodes.Conv_I);
2662                                 right.Emit (ec);
2663                                 if (size != 1){
2664                                         if (size == 0)
2665                                                 ig.Emit (OpCodes.Sizeof, op_type);
2666                                         else
2667                                                 IntLiteral.EmitInt (ig, size);
2668                                         ig.Emit (OpCodes.Mul);
2669                                 }
2670                                 if (is_add)
2671                                         ig.Emit (OpCodes.Add);
2672                                 else
2673                                         ig.Emit (OpCodes.Sub);
2674                         }
2675                 }
2676         }
2677
2678         /// <summary>
2679         ///   Implements the ternary conditional operator (?:)
2680         /// </summary>
2681         public class Conditional : Expression {
2682                 Expression expr, trueExpr, falseExpr;
2683
2684                 public Conditional (Expression expr, Expression trueExpr, Expression falseExpr, Location l)
2685                 {
2686                         this.expr = expr;
2687                         this.trueExpr = trueExpr;
2688                         this.falseExpr = falseExpr;
2689                         this.loc = l;
2690                 }
2691
2692                 public Expression Expr {
2693                         get {
2694                                 return expr;
2695                         }
2696                 }
2697
2698                 public Expression TrueExpr {
2699                         get {
2700                                 return trueExpr;
2701                         }
2702                 }
2703
2704                 public Expression FalseExpr {
2705                         get {
2706                                 return falseExpr;
2707                         }
2708                 }
2709
2710                 public override Expression DoResolve (EmitContext ec)
2711                 {
2712                         expr = expr.Resolve (ec);
2713
2714                         if (expr == null)
2715                                 return null;
2716
2717                         if (expr.Type != TypeManager.bool_type)
2718                                 expr = Expression.ConvertImplicitRequired (
2719                                         ec, expr, TypeManager.bool_type, loc);
2720
2721                         trueExpr = trueExpr.Resolve (ec);
2722                         falseExpr = falseExpr.Resolve (ec);
2723
2724                         if (trueExpr == null || falseExpr == null)
2725                                 return null;
2726
2727                         eclass = ExprClass.Value;
2728                         if (trueExpr.Type == falseExpr.Type)
2729                                 type = trueExpr.Type;
2730                         else {
2731                                 Expression conv;
2732                                 Type true_type = trueExpr.Type;
2733                                 Type false_type = falseExpr.Type;
2734
2735                                 if (trueExpr is NullLiteral){
2736                                         type = false_type;
2737                                         return this;
2738                                 } else if (falseExpr is NullLiteral){
2739                                         type = true_type;
2740                                         return this;
2741                                 }
2742
2743                                 //
2744                                 // First, if an implicit conversion exists from trueExpr
2745                                 // to falseExpr, then the result type is of type falseExpr.Type
2746                                 //
2747                                 conv = ConvertImplicit (ec, trueExpr, false_type, loc);
2748                                 if (conv != null){
2749                                         //
2750                                         // Check if both can convert implicitl to each other's type
2751                                         //
2752                                         if (ConvertImplicit (ec, falseExpr, true_type, loc) != null){
2753                                                 Error (172,
2754                                                        "Can not compute type of conditional expression " +
2755                                                        "as `" + TypeManager.CSharpName (trueExpr.Type) +
2756                                                        "' and `" + TypeManager.CSharpName (falseExpr.Type) +
2757                                                        "' convert implicitly to each other");
2758                                                 return null;
2759                                         }
2760                                         type = false_type;
2761                                         trueExpr = conv;
2762                                 } else if ((conv = ConvertImplicit(ec, falseExpr, true_type,loc))!= null){
2763                                         type = true_type;
2764                                         falseExpr = conv;
2765                                 } else {
2766                                         Error (173, "The type of the conditional expression can " +
2767                                                "not be computed because there is no implicit conversion" +
2768                                                " from `" + TypeManager.CSharpName (trueExpr.Type) + "'" +
2769                                                " and `" + TypeManager.CSharpName (falseExpr.Type) + "'");
2770                                         return null;
2771                                 }
2772                         }
2773
2774                         if (expr is BoolConstant){
2775                                 BoolConstant bc = (BoolConstant) expr;
2776
2777                                 if (bc.Value)
2778                                         return trueExpr;
2779                                 else
2780                                         return falseExpr;
2781                         }
2782
2783                         return this;
2784                 }
2785
2786                 public override void Emit (EmitContext ec)
2787                 {
2788                         ILGenerator ig = ec.ig;
2789                         Label false_target = ig.DefineLabel ();
2790                         Label end_target = ig.DefineLabel ();
2791
2792                         Statement.EmitBoolExpression (ec, expr, false_target, false);
2793                         trueExpr.Emit (ec);
2794                         ig.Emit (OpCodes.Br, end_target);
2795                         ig.MarkLabel (false_target);
2796                         falseExpr.Emit (ec);
2797                         ig.MarkLabel (end_target);
2798                 }
2799
2800         }
2801
2802         /// <summary>
2803         ///   Local variables
2804         /// </summary>
2805         public class LocalVariableReference : Expression, IAssignMethod, IMemoryLocation, IVariable {
2806                 public readonly string Name;
2807                 public readonly Block Block;
2808                 VariableInfo variable_info;
2809                 bool is_readonly;
2810
2811                 public LocalVariableReference (Block block, string name, Location l)
2812                 {
2813                         Block = block;
2814                         Name = name;
2815                         loc = l;
2816                         eclass = ExprClass.Variable;
2817                 }
2818
2819                 // Setting `is_readonly' to false will allow you to create a writable
2820                 // reference to a read-only variable.  This is used by foreach and using.
2821                 public LocalVariableReference (Block block, string name, Location l,
2822                                                VariableInfo variable_info, bool is_readonly)
2823                         : this (block, name, l)
2824                 {
2825                         this.variable_info = variable_info;
2826                         this.is_readonly = is_readonly;
2827                 }
2828
2829                 public VariableInfo VariableInfo {
2830                         get {
2831                                 if (variable_info == null) {
2832                                         variable_info = Block.GetVariableInfo (Name);
2833                                         is_readonly = variable_info.ReadOnly;
2834                                 }
2835                                 return variable_info;
2836                         }
2837                 }
2838
2839                 public bool IsAssigned (EmitContext ec, Location loc)
2840                 {
2841                         return VariableInfo.IsAssigned (ec, loc);
2842                 }
2843
2844                 public bool IsFieldAssigned (EmitContext ec, string name, Location loc)
2845                 {
2846                         return VariableInfo.IsFieldAssigned (ec, name, loc);
2847                 }
2848
2849                 public void SetAssigned (EmitContext ec)
2850                 {
2851                         VariableInfo.SetAssigned (ec);
2852                 }
2853
2854                 public void SetFieldAssigned (EmitContext ec, string name)
2855                 {
2856                         VariableInfo.SetFieldAssigned (ec, name);
2857                 }
2858
2859                 public bool IsReadOnly {
2860                         get {
2861                                 if (variable_info == null) {
2862                                         variable_info = Block.GetVariableInfo (Name);
2863                                         is_readonly = variable_info.ReadOnly;
2864                                 }
2865                                 return is_readonly;
2866                         }
2867                 }
2868
2869                 public override Expression DoResolve (EmitContext ec)
2870                 {
2871                         VariableInfo vi = VariableInfo;
2872
2873                         if (Block.IsConstant (Name)) {
2874                                 Expression e = Block.GetConstantExpression (Name);
2875
2876                                 vi.Used = true;
2877                                 return e;
2878                         }
2879
2880                         if (ec.DoFlowAnalysis && !IsAssigned (ec, loc))
2881                                 return null;
2882
2883                         type = vi.VariableType;
2884                         return this;
2885                 }
2886
2887                 override public Expression DoResolveLValue (EmitContext ec, Expression right_side)
2888                 {
2889                         VariableInfo vi = VariableInfo;
2890
2891                         if (ec.DoFlowAnalysis)
2892                                 ec.SetVariableAssigned (vi);
2893
2894                         Expression e = DoResolve (ec);
2895
2896                         if (e == null)
2897                                 return null;
2898
2899                         if (is_readonly){
2900                                 Error (1604, "cannot assign to `" + Name + "' because it is readonly");
2901                                 return null;
2902                         }
2903
2904                         return this;
2905                 }
2906
2907                 public override void Emit (EmitContext ec)
2908                 {
2909                         VariableInfo vi = VariableInfo;
2910                         ILGenerator ig = ec.ig;
2911
2912                         ig.Emit (OpCodes.Ldloc, vi.LocalBuilder);
2913                         vi.Used = true;
2914                 }
2915
2916                 public void EmitAssign (EmitContext ec, Expression source)
2917                 {
2918                         ILGenerator ig = ec.ig;
2919                         VariableInfo vi = VariableInfo;
2920
2921                         vi.Assigned = true;
2922
2923                         source.Emit (ec);
2924
2925                         ig.Emit (OpCodes.Stloc, vi.LocalBuilder);
2926                 }
2927
2928                 public void AddressOf (EmitContext ec, AddressOp mode)
2929                 {
2930                         VariableInfo vi = VariableInfo;
2931
2932                         ec.ig.Emit (OpCodes.Ldloca, vi.LocalBuilder);
2933                 }
2934         }
2935
2936         /// <summary>
2937         ///   This represents a reference to a parameter in the intermediate
2938         ///   representation.
2939         /// </summary>
2940         public class ParameterReference : Expression, IAssignMethod, IMemoryLocation, IVariable {
2941                 Parameters pars;
2942                 String name;
2943                 int idx;
2944                 public Parameter.Modifier mod;
2945                 public bool is_ref, is_out;
2946
2947                 public ParameterReference (Parameters pars, int idx, string name, Location loc)
2948                 {
2949                         this.pars = pars;
2950                         this.idx  = idx;
2951                         this.name = name;
2952                         this.loc = loc;
2953                         eclass = ExprClass.Variable;
2954                 }
2955
2956                 public bool IsAssigned (EmitContext ec, Location loc)
2957                 {
2958                         if (!is_out || !ec.DoFlowAnalysis)
2959                                 return true;
2960
2961                         if (!ec.CurrentBranching.IsParameterAssigned (idx)) {
2962                                 Report.Error (165, loc,
2963                                               "Use of unassigned local variable `" + name + "'");
2964                                 return false;
2965                         }
2966
2967                         return true;
2968                 }
2969
2970                 public bool IsFieldAssigned (EmitContext ec, string field_name, Location loc)
2971                 {
2972                         if (!is_out || !ec.DoFlowAnalysis)
2973                                 return true;
2974
2975                         if (ec.CurrentBranching.IsParameterAssigned (idx))
2976                                 return true;
2977
2978                         if (!ec.CurrentBranching.IsParameterAssigned (idx, field_name)) {
2979                                 Report.Error (170, loc,
2980                                               "Use of possibly unassigned field `" + field_name + "'");
2981                                 return false;
2982                         }
2983
2984                         return true;
2985                 }
2986
2987                 public void SetAssigned (EmitContext ec)
2988                 {
2989                         if (is_out && ec.DoFlowAnalysis)
2990                                 ec.CurrentBranching.SetParameterAssigned (idx);
2991                 }
2992
2993                 public void SetFieldAssigned (EmitContext ec, string field_name)
2994                 {
2995                         if (is_out && ec.DoFlowAnalysis)
2996                                 ec.CurrentBranching.SetParameterAssigned (idx, field_name);
2997                 }
2998
2999                 //
3000                 // Notice that for ref/out parameters, the type exposed is not the
3001                 // same type exposed externally.
3002                 //
3003                 // for "ref int a":
3004                 //   externally we expose "int&"
3005                 //   here we expose       "int".
3006                 //
3007                 // We record this in "is_ref".  This means that the type system can treat
3008                 // the type as it is expected, but when we generate the code, we generate
3009                 // the alternate kind of code.
3010                 //
3011                 public override Expression DoResolve (EmitContext ec)
3012                 {
3013                         type = pars.GetParameterInfo (ec.DeclSpace, idx, out mod);
3014                         is_ref = (mod & Parameter.Modifier.ISBYREF) != 0;
3015                         is_out = (mod & Parameter.Modifier.OUT) != 0;
3016                         eclass = ExprClass.Variable;
3017
3018                         if (is_out && ec.DoFlowAnalysis && !IsAssigned (ec, loc))
3019                                 return null;
3020
3021                         return this;
3022                 }
3023
3024                 override public Expression DoResolveLValue (EmitContext ec, Expression right_side)
3025                 {
3026                         type = pars.GetParameterInfo (ec.DeclSpace, idx, out mod);
3027                         is_ref = (mod & Parameter.Modifier.ISBYREF) != 0;
3028                         is_out = (mod & Parameter.Modifier.OUT) != 0;
3029                         eclass = ExprClass.Variable;
3030
3031                         if (is_out && ec.DoFlowAnalysis)
3032                                 ec.SetParameterAssigned (idx);
3033
3034                         return this;
3035                 }
3036
3037                 static void EmitLdArg (ILGenerator ig, int x)
3038                 {
3039                         if (x <= 255){
3040                                 switch (x){
3041                                 case 0: ig.Emit (OpCodes.Ldarg_0); break;
3042                                 case 1: ig.Emit (OpCodes.Ldarg_1); break;
3043                                 case 2: ig.Emit (OpCodes.Ldarg_2); break;
3044                                 case 3: ig.Emit (OpCodes.Ldarg_3); break;
3045                                 default: ig.Emit (OpCodes.Ldarg_S, (byte) x); break;
3046                                 }
3047                         } else
3048                                 ig.Emit (OpCodes.Ldarg, x);
3049                 }
3050
3051                 //
3052                 // This method is used by parameters that are references, that are
3053                 // being passed as references:  we only want to pass the pointer (that
3054                 // is already stored in the parameter, not the address of the pointer,
3055                 // and not the value of the variable).
3056                 //
3057                 public void EmitLoad (EmitContext ec)
3058                 {
3059                         ILGenerator ig = ec.ig;
3060                         int arg_idx = idx;
3061
3062                         if (!ec.IsStatic)
3063                                 arg_idx++;
3064
3065                         EmitLdArg (ig, arg_idx);
3066                 }
3067
3068                 public override void Emit (EmitContext ec)
3069                 {
3070                         ILGenerator ig = ec.ig;
3071                         int arg_idx = idx;
3072
3073                         if (!ec.IsStatic)
3074                                 arg_idx++;
3075
3076                         EmitLdArg (ig, arg_idx);
3077
3078                         if (!is_ref)
3079                                 return;
3080
3081                         //
3082                         // If we are a reference, we loaded on the stack a pointer
3083                         // Now lets load the real value
3084                         //
3085                         LoadFromPtr (ig, type);
3086                 }
3087
3088                 public void EmitAssign (EmitContext ec, Expression source)
3089                 {
3090                         ILGenerator ig = ec.ig;
3091                         int arg_idx = idx;
3092
3093                         if (!ec.IsStatic)
3094                                 arg_idx++;
3095
3096                         if (is_ref)
3097                                 EmitLdArg (ig, arg_idx);
3098
3099                         source.Emit (ec);
3100
3101                         if (is_ref)
3102                                 StoreFromPtr (ig, type);
3103                         else {
3104                                 if (arg_idx <= 255)
3105                                         ig.Emit (OpCodes.Starg_S, (byte) arg_idx);
3106                                 else
3107                                         ig.Emit (OpCodes.Starg, arg_idx);
3108                         }
3109                 }
3110
3111                 public void AddressOf (EmitContext ec, AddressOp mode)
3112                 {
3113                         int arg_idx = idx;
3114
3115                         if (!ec.IsStatic)
3116                                 arg_idx++;
3117
3118                         if (is_ref){
3119                                 if (arg_idx <= 255)
3120                                         ec.ig.Emit (OpCodes.Ldarg_S, (byte) arg_idx);
3121                                 else
3122                                         ec.ig.Emit (OpCodes.Ldarg, arg_idx);
3123                         } else {
3124                                 if (arg_idx <= 255)
3125                                         ec.ig.Emit (OpCodes.Ldarga_S, (byte) arg_idx);
3126                                 else
3127                                         ec.ig.Emit (OpCodes.Ldarga, arg_idx);
3128                         }
3129                 }
3130         }
3131
3132
3133         /// <summary>
3134         ///   Invocation of methods or delegates.
3135         /// </summary>
3136         public class Invocation : ExpressionStatement {
3137                 public ArrayList Arguments;
3138
3139                 Expression expr;
3140                 MethodBase method = null;
3141                 bool is_base;
3142
3143                 static Hashtable method_parameter_cache;
3144                 static MemberFilter CompareName;
3145
3146                 static Invocation ()
3147                 {
3148                         method_parameter_cache = new PtrHashtable ();
3149                 }
3150
3151                 //
3152                 // arguments is an ArrayList, but we do not want to typecast,
3153                 // as it might be null.
3154                 //
3155                 // FIXME: only allow expr to be a method invocation or a
3156                 // delegate invocation (7.5.5)
3157                 //
3158                 public Invocation (Expression expr, ArrayList arguments, Location l)
3159                 {
3160                         this.expr = expr;
3161                         Arguments = arguments;
3162                         loc = l;
3163                         CompareName = new MemberFilter (compare_name_filter);
3164                 }
3165
3166                 public Expression Expr {
3167                         get {
3168                                 return expr;
3169                         }
3170                 }
3171
3172                 /// <summary>
3173                 ///   Returns the Parameters (a ParameterData interface) for the
3174                 ///   Method `mb'
3175                 /// </summary>
3176                 public static ParameterData GetParameterData (MethodBase mb)
3177                 {
3178                         object pd = method_parameter_cache [mb];
3179                         object ip;
3180
3181                         if (pd != null)
3182                                 return (ParameterData) pd;
3183
3184
3185                         ip = TypeManager.LookupParametersByBuilder (mb);
3186                         if (ip != null){
3187                                 method_parameter_cache [mb] = ip;
3188
3189                                 return (ParameterData) ip;
3190                         } else {
3191                                 ParameterInfo [] pi = mb.GetParameters ();
3192                                 ReflectionParameters rp = new ReflectionParameters (pi);
3193                                 method_parameter_cache [mb] = rp;
3194
3195                                 return (ParameterData) rp;
3196                         }
3197                 }
3198
3199                 /// <summary>
3200                 ///  Determines "better conversion" as specified in 7.4.2.3
3201                 ///  Returns : 1 if a->p is better
3202                 ///            0 if a->q or neither is better
3203                 /// </summary>
3204                 static int BetterConversion (EmitContext ec, Argument a, Type p, Type q, Location loc)
3205                 {
3206                         Type argument_type = a.Type;
3207                         Expression argument_expr = a.Expr;
3208
3209                         if (argument_type == null)
3210                                 throw new Exception ("Expression of type " + a.Expr + " does not resolve its type");
3211
3212                         //
3213                         // This is a special case since csc behaves this way. I can't find
3214                         // it anywhere in the spec but oh well ...
3215                         //
3216                         if (argument_expr is NullLiteral && p == TypeManager.string_type && q == TypeManager.object_type)
3217                                 return 1;
3218                         else if (argument_expr is NullLiteral && p == TypeManager.object_type && q == TypeManager.string_type)
3219                                 return 0;
3220
3221                         if (p == q)
3222                                 return 0;
3223
3224                         if (argument_type == p)
3225                                 return 1;
3226
3227                         if (argument_type == q)
3228                                 return 0;
3229
3230                         //
3231                         // Now probe whether an implicit constant expression conversion
3232                         // can be used.
3233                         //
3234                         // An implicit constant expression conversion permits the following
3235                         // conversions:
3236                         //
3237                         //    * A constant-expression of type `int' can be converted to type
3238                         //      sbyte, byute, short, ushort, uint, ulong provided the value of
3239                         //      of the expression is withing the range of the destination type.
3240                         //
3241                         //    * A constant-expression of type long can be converted to type
3242                         //      ulong, provided the value of the constant expression is not negative
3243                         //
3244                         // FIXME: Note that this assumes that constant folding has
3245                         // taken place.  We dont do constant folding yet.
3246                         //
3247
3248                         if (argument_expr is IntConstant){
3249                                 IntConstant ei = (IntConstant) argument_expr;
3250                                 int value = ei.Value;
3251
3252                                 if (p == TypeManager.sbyte_type){
3253                                         if (value >= SByte.MinValue && value <= SByte.MaxValue)
3254                                                 return 1;
3255                                 } else if (p == TypeManager.byte_type){
3256                                         if (Byte.MinValue >= 0 && value <= Byte.MaxValue)
3257                                                 return 1;
3258                                 } else if (p == TypeManager.short_type){
3259                                         if (value >= Int16.MinValue && value <= Int16.MaxValue)
3260                                                 return 1;
3261                                 } else if (p == TypeManager.ushort_type){
3262                                         if (value >= UInt16.MinValue && value <= UInt16.MaxValue)
3263                                                 return 1;
3264                                 } else if (p == TypeManager.uint32_type){
3265                                         //
3266                                         // we can optimize this case: a positive int32
3267                                         // always fits on a uint32
3268                                         //
3269                                         if (value >= 0)
3270                                                 return 1;
3271                                 } else if (p == TypeManager.uint64_type){
3272                                         //
3273                                         // we can optimize this case: a positive int32
3274                                         // always fits on a uint64
3275                                         //
3276                                         if (value >= 0)
3277                                                 return 1;
3278                                 }
3279                         } else if (argument_type == TypeManager.int64_type && argument_expr is LongConstant){
3280                                 LongConstant lc = (LongConstant) argument_expr;
3281
3282                                 if (p == TypeManager.uint64_type){
3283                                         if (lc.Value > 0)
3284                                                 return 1;
3285                                 }
3286                         }
3287
3288                         if (q == null) {
3289                                 Expression tmp = ConvertImplicit (ec, argument_expr, p, loc);
3290
3291                                 if (tmp != null)
3292                                         return 1;
3293                                 else
3294                                         return 0;
3295                         }
3296
3297                         Expression p_tmp = new EmptyExpression (p);
3298                         Expression q_tmp = new EmptyExpression (q);
3299
3300                         if (StandardConversionExists (p_tmp, q) == true &&
3301                             StandardConversionExists (q_tmp, p) == false)
3302                                 return 1;
3303
3304                         if (p == TypeManager.sbyte_type)
3305                                 if (q == TypeManager.byte_type || q == TypeManager.ushort_type ||
3306                                     q == TypeManager.uint32_type || q == TypeManager.uint64_type)
3307                                         return 1;
3308
3309                         if (p == TypeManager.short_type)
3310                                 if (q == TypeManager.ushort_type || q == TypeManager.uint32_type ||
3311                                     q == TypeManager.uint64_type)
3312                                         return 1;
3313
3314                         if (p == TypeManager.int32_type)
3315                                 if (q == TypeManager.uint32_type || q == TypeManager.uint64_type)
3316                                         return 1;
3317
3318                         if (p == TypeManager.int64_type)
3319                                 if (q == TypeManager.uint64_type)
3320                                         return 1;
3321
3322                         return 0;
3323                 }
3324
3325                 /// <summary>
3326                 ///  Determines "Better function"
3327                 /// </summary>
3328                 /// <remarks>
3329                 ///    and returns an integer indicating :
3330                 ///    0 if candidate ain't better
3331                 ///    1 if candidate is better than the current best match
3332                 /// </remarks>
3333                 static int BetterFunction (EmitContext ec, ArrayList args,
3334                                            MethodBase candidate, MethodBase best,
3335                                            bool expanded_form, Location loc)
3336                 {
3337                         ParameterData candidate_pd = GetParameterData (candidate);
3338                         ParameterData best_pd;
3339                         int argument_count;
3340
3341                         if (args == null)
3342                                 argument_count = 0;
3343                         else
3344                                 argument_count = args.Count;
3345
3346                         int cand_count = candidate_pd.Count;
3347
3348                         if (cand_count == 0 && argument_count == 0)
3349                                 return 1;
3350
3351                         if (candidate_pd.ParameterModifier (cand_count - 1) != Parameter.Modifier.PARAMS)
3352                                 if (cand_count != argument_count)
3353                                         return 0;
3354
3355                         if (best == null) {
3356                                 int x = 0;
3357
3358                                 if (argument_count == 0 && cand_count == 1 &&
3359                                     candidate_pd.ParameterModifier (cand_count - 1) == Parameter.Modifier.PARAMS)
3360                                         return 1;
3361
3362                                 for (int j = argument_count; j > 0;) {
3363                                         j--;
3364
3365                                         Argument a = (Argument) args [j];
3366                                         Type t = candidate_pd.ParameterType (j);
3367
3368                                         if (candidate_pd.ParameterModifier (j) == Parameter.Modifier.PARAMS)
3369                                                 if (expanded_form)
3370                                                         t = t.GetElementType ();
3371
3372                                         x = BetterConversion (ec, a, t, null, loc);
3373
3374                                         if (x <= 0)
3375                                                 break;
3376                                 }
3377
3378                                 if (x > 0)
3379                                         return 1;
3380                                 else
3381                                         return 0;
3382                         }
3383
3384                         best_pd = GetParameterData (best);
3385
3386                         int rating1 = 0, rating2 = 0;
3387
3388                         for (int j = 0; j < argument_count; ++j) {
3389                                 int x, y;
3390
3391                                 Argument a = (Argument) args [j];
3392
3393                                 Type ct = candidate_pd.ParameterType (j);
3394                                 Type bt = best_pd.ParameterType (j);
3395
3396                                 if (candidate_pd.ParameterModifier (j) == Parameter.Modifier.PARAMS)
3397                                         if (expanded_form)
3398                                                 ct = ct.GetElementType ();
3399
3400                                 if (best_pd.ParameterModifier (j) == Parameter.Modifier.PARAMS)
3401                                         if (expanded_form)
3402                                                 bt = bt.GetElementType ();
3403
3404                                 x = BetterConversion (ec, a, ct, bt, loc);
3405                                 y = BetterConversion (ec, a, bt, ct, loc);
3406
3407                                 if (x < y)
3408                                         return 0;
3409
3410                                 rating1 += x;
3411                                 rating2 += y;
3412                         }
3413
3414                         if (rating1 > rating2)
3415                                 return 1;
3416                         else
3417                                 return 0;
3418                 }
3419
3420                 public static string FullMethodDesc (MethodBase mb)
3421                 {
3422                         string ret_type = "";
3423
3424                         if (mb is MethodInfo)
3425                                 ret_type = TypeManager.CSharpName (((MethodInfo) mb).ReturnType) + " ";
3426
3427                         StringBuilder sb = new StringBuilder (ret_type + mb.Name);
3428                         ParameterData pd = GetParameterData (mb);
3429
3430                         int count = pd.Count;
3431                         sb.Append (" (");
3432
3433                         for (int i = count; i > 0; ) {
3434                                 i--;
3435
3436                                 sb.Append (pd.ParameterDesc (count - i - 1));
3437                                 if (i != 0)
3438                                         sb.Append (", ");
3439                         }
3440
3441                         sb.Append (")");
3442                         return sb.ToString ();
3443                 }
3444
3445                 public static MethodGroupExpr MakeUnionSet (Expression mg1, Expression mg2, Location loc)
3446                 {
3447                         MemberInfo [] miset;
3448                         MethodGroupExpr union;
3449
3450                         if (mg1 == null){
3451                                 if (mg2 == null)
3452                                         return null;
3453                                 return (MethodGroupExpr) mg2;
3454                         } else {
3455                                 if (mg2 == null)
3456                                         return (MethodGroupExpr) mg1;
3457                         }
3458
3459                         MethodGroupExpr left_set = null, right_set = null;
3460                         int length1 = 0, length2 = 0;
3461
3462                         left_set = (MethodGroupExpr) mg1;
3463                         length1 = left_set.Methods.Length;
3464
3465                         right_set = (MethodGroupExpr) mg2;
3466                         length2 = right_set.Methods.Length;
3467
3468                         ArrayList common = new ArrayList ();
3469
3470                         foreach (MethodBase l in left_set.Methods){
3471                                 foreach (MethodBase r in right_set.Methods){
3472                                         if (l != r)
3473                                                 continue;
3474                                         common.Add (r);
3475                                         break;
3476                                 }
3477                         }
3478
3479                         miset = new MemberInfo [length1 + length2 - common.Count];
3480                         left_set.Methods.CopyTo (miset, 0);
3481
3482                         int k = length1;
3483
3484                         foreach (MemberInfo mi in right_set.Methods){
3485                                 if (!common.Contains (mi))
3486                                         miset [k++] = mi;
3487                         }
3488
3489                         union = new MethodGroupExpr (miset, loc);
3490
3491                         return union;
3492                 }
3493
3494                 /// <summary>
3495                 ///  Determines is the candidate method, if a params method, is applicable
3496                 ///  in its expanded form to the given set of arguments
3497                 /// </summary>
3498                 static bool IsParamsMethodApplicable (EmitContext ec, ArrayList arguments, MethodBase candidate)
3499                 {
3500                         int arg_count;
3501
3502                         if (arguments == null)
3503                                 arg_count = 0;
3504                         else
3505                                 arg_count = arguments.Count;
3506
3507                         ParameterData pd = GetParameterData (candidate);
3508
3509                         int pd_count = pd.Count;
3510
3511                         if (pd_count == 0)
3512                                 return false;
3513
3514                         if (pd.ParameterModifier (pd_count - 1) != Parameter.Modifier.PARAMS)
3515                                 return false;
3516
3517                         if (pd_count - 1 > arg_count)
3518                                 return false;
3519
3520                         if (pd_count == 1 && arg_count == 0)
3521                                 return true;
3522
3523                         //
3524                         // If we have come this far, the case which remains is when the number of parameters
3525                         // is less than or equal to the argument count.
3526                         //
3527                         for (int i = 0; i < pd_count - 1; ++i) {
3528
3529                                 Argument a = (Argument) arguments [i];
3530
3531                                 Parameter.Modifier a_mod = a.GetParameterModifier () &
3532                                         ~(Parameter.Modifier.OUT | Parameter.Modifier.REF);
3533                                 Parameter.Modifier p_mod = pd.ParameterModifier (i) &
3534                                         ~(Parameter.Modifier.OUT | Parameter.Modifier.REF);
3535
3536                                 if (a_mod == p_mod) {
3537
3538                                         if (a_mod == Parameter.Modifier.NONE)
3539                                                 if (!ImplicitConversionExists (ec, a.Expr, pd.ParameterType (i)))
3540                                                         return false;
3541
3542                                         if ((a_mod & Parameter.Modifier.ISBYREF) != 0) {
3543                                                 Type pt = pd.ParameterType (i);
3544
3545                                                 if (!pt.IsByRef)
3546                                                         pt = TypeManager.LookupType (pt.FullName + "&");
3547
3548                                                 if (pt != a.Type)
3549                                                         return false;
3550                                         }
3551                                 } else
3552                                         return false;
3553
3554                         }
3555
3556                         Type element_type = pd.ParameterType (pd_count - 1).GetElementType ();
3557
3558                         for (int i = pd_count - 1; i < arg_count; i++) {
3559                                 Argument a = (Argument) arguments [i];
3560
3561                                 if (!StandardConversionExists (a.Expr, element_type))
3562                                         return false;
3563                         }
3564
3565                         return true;
3566                 }
3567
3568                 static bool CheckParameterAgainstArgument (EmitContext ec, ParameterData pd, int i, Argument a, Type ptype)
3569                 {
3570                         Parameter.Modifier a_mod = a.GetParameterModifier () &
3571                                 ~(Parameter.Modifier.OUT | Parameter.Modifier.REF);
3572                         Parameter.Modifier p_mod = pd.ParameterModifier (i) &
3573                                 ~(Parameter.Modifier.OUT | Parameter.Modifier.REF);
3574
3575                         if (a_mod == p_mod || (a_mod == Parameter.Modifier.NONE && p_mod == Parameter.Modifier.PARAMS)) {
3576                                 if (a_mod == Parameter.Modifier.NONE)
3577                                         if (!ImplicitConversionExists (ec, a.Expr, ptype))
3578                                                 return false;
3579
3580                                 if ((a_mod & Parameter.Modifier.ISBYREF) != 0) {
3581                                         Type pt = pd.ParameterType (i);
3582
3583                                         if (!pt.IsByRef)
3584                                                 pt = TypeManager.LookupType (pt.FullName + "&");
3585
3586                                         if (pt != a.Type)
3587                                                 return false;
3588                                 }
3589                         } else
3590                                 return false;
3591
3592                         return true;
3593                 }
3594
3595                 /// <summary>
3596                 ///  Determines if the candidate method is applicable (section 14.4.2.1)
3597                 ///  to the given set of arguments
3598                 /// </summary>
3599                 static bool IsApplicable (EmitContext ec, ref ArrayList arguments, MethodBase candidate)
3600                 {
3601                         int arg_count, ps_count, po_count;
3602                         Type param_type;
3603
3604                         if (arguments == null)
3605                                 arg_count = 0;
3606                         else
3607                                 arg_count = arguments.Count;
3608
3609                         ParameterData pd = GetParameterData (candidate);
3610                         Parameters ps = GetFullParameters (candidate);
3611
3612                         if (ps == null) {
3613                                 ps_count = 0;
3614                                 po_count = 0;
3615                         }
3616                         else
3617                         {
3618                                 ps_count = ps.CountStandardParams();
3619                                 po_count = ps.CountOptionalParams();
3620                         }
3621                         int pd_count = pd.Count;
3622
3623                         // Validate argument count
3624                         if (po_count == 0) {
3625                                 if (arg_count != pd.Count)
3626                                         return false;
3627                         }
3628                         else
3629                         {
3630                                 if ((arg_count < ps_count) || (arg_count > pd_count))
3631                                         return false;
3632                         }
3633
3634                         if (arg_count > 0) {
3635                                 for (int i = arg_count; i > 0 ; ) {
3636                                         i--;
3637
3638                                         Argument a = (Argument) arguments [i];
3639                                         if (a.ArgType == Argument.AType.NoArg)
3640                                         {
3641                                                 Parameter p = (Parameter) ps.FixedParameters[i];
3642                                                 a = new Argument (p.ParameterInitializer, Argument.AType.Expression);
3643                                                 param_type = p.ParameterInitializer.Type;
3644                                         }
3645                                         else
3646                                         {
3647                                                 param_type = pd.ParameterType (i);
3648                                                 if (ps != null) {
3649                                                         Parameter p = (Parameter) ps.FixedParameters[i];
3650
3651                                                         if ((p.ModFlags & Parameter.Modifier.REF) != 0)
3652                                                         {
3653                                                                 a = new Argument (a.Expr, Argument.AType.Ref);
3654                                                                 if (!a.Resolve(ec,Location.Null))
3655                                                                         return false;
3656                                                         }
3657                                                 }
3658                                         }
3659
3660                                         if (!CheckParameterAgainstArgument (ec, pd, i, a, param_type))
3661                                                 return (false);
3662                                 }
3663                         }
3664                         else
3665                         {
3666                                 // If we have no arguments AND the first parameter is optional
3667                                 // we must check for a candidate (the loop above wouldn't)
3668                                 if (po_count > 0) {
3669                                         ArrayList arglist = new ArrayList();
3670
3671                                         // Since we got so far, there's no need to check if
3672                                         // arguments are optional; we simply retrieve
3673                                         // parameter default values and build a brand-new
3674                                         // argument list.
3675
3676                                         for (int i = 0; i < ps.FixedParameters.Length; i++) {
3677                                                 Parameter p = ps.FixedParameters[i];
3678                                                 Argument a = new Argument (p.ParameterInitializer, Argument.AType.Expression);
3679                                                 a.Resolve(ec, Location.Null);
3680                                                 arglist.Add (a);
3681                                         }
3682                                         arguments = arglist;
3683                                         return true;
3684                                 }
3685                         }
3686                         // We've found a candidate, so we exchange the dummy NoArg arguments
3687                         // with new arguments containing the default value for that parameter
3688                         ArrayList newarglist = new ArrayList();
3689                         for (int i = 0; i < arg_count; i++) {
3690                                 Argument a = (Argument) arguments [i];
3691                                 Parameter p = null;
3692
3693                                 if (ps != null)
3694                                         p = (Parameter) ps.FixedParameters[i];
3695
3696                                 if (a.ArgType == Argument.AType.NoArg){
3697                                         a = new Argument (p.ParameterInitializer, Argument.AType.Expression);
3698                                         a.Resolve(ec, Location.Null);
3699                                 }
3700
3701                                 if ((p != null) && ((p.ModFlags & Parameter.Modifier.REF) != 0))
3702                                 {
3703                                         a.ArgType = Argument.AType.Ref;
3704                                         a.Resolve(ec, Location.Null);
3705                                 }
3706                                 newarglist.Add(a);
3707                                 int n = pd_count - arg_count;
3708                                 if (n > 0)
3709                                 {
3710                                         for (int x = 0; x < n; x++)
3711                                         {
3712                                                 Parameter op = (Parameter) ps.FixedParameters[x + arg_count];
3713                                                 Argument b = new Argument (op.ParameterInitializer, Argument.AType.Expression);
3714                                                 b.Resolve(ec, Location.Null);
3715                                                 newarglist.Add (b);
3716                                         }
3717                                 }
3718                         }
3719                         arguments = newarglist;
3720                         return true;
3721                 }
3722
3723                 static bool compare_name_filter (MemberInfo m, object filterCriteria)
3724                 {
3725                         return (m.Name == ((string) filterCriteria));
3726                 }
3727
3728                 static Parameters GetFullParameters (MethodBase mb)
3729                 {
3730                         TypeContainer tc = TypeManager.LookupTypeContainer (mb.DeclaringType);
3731                         InternalParameters ip = TypeManager.LookupParametersByBuilder(mb);
3732
3733                         return (ip != null) ? ip.Parameters : null;
3734                 }
3735
3736                 // We need an overload for OverloadResolve because Invocation.DoResolve
3737                 // must pass Arguments by reference, since a later call to IsApplicable
3738                 // can change the argument list if optional parameters are defined
3739                 // in the method declaration
3740                 public static MethodBase OverloadResolve (EmitContext ec, MethodGroupExpr me,
3741                                                           ArrayList Arguments, Location loc)
3742                 {
3743                         ArrayList a = Arguments;
3744                         return OverloadResolve (ec, me, ref a, loc);
3745                 }
3746
3747                 /// <summary>
3748                 ///   Find the Applicable Function Members (7.4.2.1)
3749                 ///
3750                 ///   me: Method Group expression with the members to select.
3751                 ///       it might contain constructors or methods (or anything
3752                 ///       that maps to a method).
3753                 ///
3754                 ///   Arguments: ArrayList containing resolved Argument objects.
3755                 ///
3756                 ///   loc: The location if we want an error to be reported, or a Null
3757                 ///        location for "probing" purposes.
3758                 ///
3759                 ///   Returns: The MethodBase (either a ConstructorInfo or a MethodInfo)
3760                 ///            that is the best match of me on Arguments.
3761                 ///
3762                 /// </summary>
3763                 public static MethodBase OverloadResolve (EmitContext ec, MethodGroupExpr me,
3764                                                           ref ArrayList Arguments, Location loc)
3765                 {
3766                         ArrayList afm = new ArrayList ();
3767                         MethodBase method = null;
3768                         Type current_type = null;
3769                         int argument_count;
3770                         ArrayList candidates = new ArrayList ();
3771
3772                         foreach (MethodBase candidate in me.Methods){
3773                                 int x;
3774
3775                                 // If we're going one level higher in the class hierarchy, abort if
3776                                 // we already found an applicable method.
3777                                 if (candidate.DeclaringType != current_type) {
3778                                         current_type = candidate.DeclaringType;
3779                                         if (method != null)
3780                                                 break;
3781                                 }
3782
3783                                 // Check if candidate is applicable (section 14.4.2.1)
3784                                 if (!IsApplicable (ec, ref Arguments, candidate))
3785                                         continue;
3786
3787                                 candidates.Add (candidate);
3788                                 x = BetterFunction (ec, Arguments, candidate, method, false, loc);
3789
3790                                 if (x == 0)
3791                                         continue;
3792
3793                                 method = candidate;
3794                         }
3795
3796                         if (Arguments == null)
3797                                 argument_count = 0;
3798                         else
3799                                 argument_count = Arguments.Count;
3800
3801
3802                         //
3803                         // Now we see if we can find params functions, applicable in their expanded form
3804                         // since if they were applicable in their normal form, they would have been selected
3805                         // above anyways
3806                         //
3807                         bool chose_params_expanded = false;
3808
3809                         if (method == null) {
3810                                 candidates = new ArrayList ();
3811                                 foreach (MethodBase candidate in me.Methods){
3812                                         if (!IsParamsMethodApplicable (ec, Arguments, candidate))
3813                                                 continue;
3814
3815                                         candidates.Add (candidate);
3816
3817                                         int x = BetterFunction (ec, Arguments, candidate, method, true, loc);
3818                                         if (x == 0)
3819                                                 continue;
3820
3821                                         method = candidate;
3822                                         chose_params_expanded = true;
3823                                 }
3824                         }
3825
3826                         if (method == null) {
3827                                 //
3828                                 // Okay so we have failed to find anything so we
3829                                 // return by providing info about the closest match
3830                                 //
3831                                 for (int i = 0; i < me.Methods.Length; ++i) {
3832
3833                                         MethodBase c = (MethodBase) me.Methods [i];
3834                                         ParameterData pd = GetParameterData (c);
3835
3836                                         if (pd.Count != argument_count)
3837                                                 continue;
3838
3839                                         VerifyArgumentsCompat (ec, Arguments, argument_count, c, false,
3840                                                                null, loc);
3841                                 }
3842
3843                                 return null;
3844                         }
3845
3846                         //
3847                         // Now check that there are no ambiguities i.e the selected method
3848                         // should be better than all the others
3849                         //
3850
3851                         foreach (MethodBase candidate in candidates){
3852                                 if (candidate == method)
3853                                         continue;
3854
3855                                 //
3856                                 // If a normal method is applicable in the sense that it has the same
3857                                 // number of arguments, then the expanded params method is never applicable
3858                                 // so we debar the params method.
3859                                 //
3860                                 if (IsParamsMethodApplicable (ec, Arguments, candidate) &&
3861                                     IsApplicable (ec, ref Arguments, method))
3862                                         continue;
3863
3864                                 int x = BetterFunction (ec, Arguments, method, candidate,
3865                                                         chose_params_expanded, loc);
3866
3867                                 if (x != 1) {
3868                                         Report.Error (
3869                                                 121, loc,
3870                                                 "Ambiguous call when selecting function due to implicit casts");
3871                                         return null;
3872                                 }
3873                         }
3874
3875                         //
3876                         // And now check if the arguments are all compatible, perform conversions
3877                         // if necessary etc. and return if everything is all right
3878                         //
3879                         if (VerifyArgumentsCompat (ec, Arguments, argument_count, method,
3880                                                    chose_params_expanded, null, loc))
3881                                 return method;
3882                         else
3883                                 return null;
3884                 }
3885
3886                 public static bool VerifyArgumentsCompat (EmitContext ec, ArrayList Arguments,
3887                         int argument_count,
3888                         MethodBase method,
3889                         bool chose_params_expanded,
3890                         Type delegate_type,
3891                         Location loc)
3892                 {
3893                         return (VerifyArgumentsCompat (ec, Arguments, argument_count,
3894                                 method, chose_params_expanded, delegate_type, loc, null));
3895                 }
3896
3897                 public static bool VerifyArgumentsCompat (EmitContext ec,
3898                                                           ArrayList Arguments,
3899                                                           int argument_count,
3900                                                           MethodBase method,
3901                                                           bool chose_params_expanded,
3902                                                           Type delegate_type,
3903                                                           Location loc,
3904                                                           string InvokingProperty)
3905                 {
3906                         ParameterData pd = GetParameterData (method);
3907                         int pd_count = pd.Count;
3908
3909                         for (int j = 0; j < argument_count; j++) {
3910                                 Argument a = (Argument) Arguments [j];
3911                                 Expression a_expr = a.Expr;
3912                                 Type parameter_type = pd.ParameterType (j);
3913
3914                                 if (pd.ParameterModifier (j) == Parameter.Modifier.PARAMS &&
3915                                     chose_params_expanded)
3916                                         parameter_type = TypeManager.TypeToCoreType (parameter_type.GetElementType ());
3917
3918                                 if (a.Type != parameter_type){
3919                                         Expression conv;
3920
3921                                         conv = ConvertImplicit (ec, a_expr, parameter_type, loc);
3922
3923                                         if (conv == null) {
3924                                                 if (!Location.IsNull (loc)) {
3925                                                         if (delegate_type == null)
3926                                                                 if (InvokingProperty == null)
3927                                                                         Report.Error (1502, loc,
3928                                                                                 "The best overloaded match for method '" +
3929                                                                                 FullMethodDesc (method) +
3930                                                                                 "' has some invalid arguments");
3931                                                                 else
3932                                                                         Report.Error (1502, loc,
3933                                                                                 "Property '" +
3934                                                                                 InvokingProperty +
3935                                                                                 "' has some invalid arguments");
3936                                                         else
3937                                                                 Report.Error (1594, loc,
3938                                                                               "Delegate '" + delegate_type.ToString () +
3939                                                                               "' has some invalid arguments.");
3940                                                         Report.Error (1503, loc,
3941                                                          "Argument " + (j+1) +
3942                                                          ": Cannot convert from '" + Argument.FullDesc (a)
3943                                                          + "' to '" + pd.ParameterDesc (j) + "'");
3944                                                 }
3945
3946                                                 return false;
3947                                         }
3948
3949                                         //
3950                                         // Update the argument with the implicit conversion
3951                                         //
3952                                         if (a_expr != conv)
3953                                                 a.Expr = conv;
3954                                 }
3955
3956                                 Parameter.Modifier a_mod = a.GetParameterModifier () &
3957                                         ~(Parameter.Modifier.OUT | Parameter.Modifier.REF);
3958                                 Parameter.Modifier p_mod = pd.ParameterModifier (j) &
3959                                         ~(Parameter.Modifier.OUT | Parameter.Modifier.REF);
3960
3961
3962                                 if (a_mod != p_mod &&
3963                                     pd.ParameterModifier (pd_count - 1) != Parameter.Modifier.PARAMS) {
3964                                         if (!Location.IsNull (loc)) {
3965                                                 Report.Error (1502, loc,
3966                                                        "The best overloaded match for method '" + FullMethodDesc (method)+
3967                                                        "' has some invalid arguments");
3968                                                 Report.Error (1503, loc,
3969                                                        "Argument " + (j+1) +
3970                                                        ": Cannot convert from '" + Argument.FullDesc (a)
3971                                                        + "' to '" + pd.ParameterDesc (j) + "'");
3972                                         }
3973
3974                                         return false;
3975                                 }
3976                         }
3977
3978                         return true;
3979                 }
3980
3981                 public override Expression DoResolve (EmitContext ec)
3982                 {
3983                         //
3984                         // First, resolve the expression that is used to
3985                         // trigger the invocation
3986                         //
3987                         Expression expr_to_return = null;
3988
3989                         if (expr is BaseAccess)
3990                                 is_base = true;
3991
3992                         expr = expr.Resolve (ec, ResolveFlags.VariableOrValue | ResolveFlags.MethodGroup);
3993                         if (expr == null)
3994                                 return null;
3995
3996                         if (expr is Invocation) {
3997                                 // FIXME Calls which return an Array are not resolved (here or in the grammar)
3998                                 expr = expr.Resolve(ec);
3999                         }
4000
4001                         if (!(expr is MethodGroupExpr))
4002                         {
4003                                 Type expr_type = expr.Type;
4004
4005                                 if (expr_type != null)
4006                                 {
4007                                         bool IsDelegate = TypeManager.IsDelegateType (expr_type);
4008                                         if (IsDelegate)
4009                                                 return (new DelegateInvocation (
4010                                                         this.expr, Arguments, loc)).Resolve (ec);
4011                                 }
4012                         }
4013                         /*
4014                         if (!(expr is MethodGroupExpr)){
4015                                 expr.Error118 (ResolveFlags.MethodGroup);
4016                                 return null;
4017                         }
4018                         */
4019
4020                         //
4021                         // Next, evaluate all the expressions in the argument list
4022                         //
4023                         if (Arguments != null)
4024                         {
4025                                 foreach (Argument a in Arguments)
4026                                 {
4027                                         if ((a.ArgType == Argument.AType.NoArg) && (!(expr is MethodGroupExpr)))
4028                                                 Report.Error (999, "This item cannot have empty arguments");
4029
4030                                         if (!a.Resolve (ec, loc))
4031                                                 return null;
4032                                 }
4033                         }
4034
4035                         if (expr is MethodGroupExpr)
4036                         {
4037                                 MethodGroupExpr mg = (MethodGroupExpr) expr;
4038                                 method = OverloadResolve (ec, mg, ref Arguments, loc);
4039
4040                                 if (method == null)
4041                                 {
4042                                         Error (-6,
4043                                                 "Could not find any applicable function for this argument list");
4044                                         return null;
4045                                 }
4046
4047                                 MethodInfo mi = method as MethodInfo;
4048                                 if (mi != null)
4049                                 {
4050                                         type = TypeManager.TypeToCoreType (mi.ReturnType);
4051                                         if (!mi.IsStatic && !mg.IsExplicitImpl && (mg.InstanceExpression == null))
4052                                                 SimpleName.Error_ObjectRefRequired (ec, loc, mi.Name);
4053                                 }
4054
4055                                 if (type.IsPointer)
4056                                 {
4057                                         if (!ec.InUnsafe)
4058                                         {
4059                                                 UnsafeError (loc);
4060                                                 return null;
4061                                         }
4062                                 }
4063                                 eclass = ExprClass.Value;
4064                                 expr_to_return = this;
4065                         }
4066
4067                         if (expr is PropertyExpr)
4068                         {
4069                                 PropertyExpr pe = ((PropertyExpr) expr);
4070                                 pe.PropertyArgs = (ArrayList) Arguments.Clone();
4071                                 Arguments.Clear();
4072                                 Arguments = new ArrayList();
4073                                 MethodBase mi = pe.PropertyInfo.GetGetMethod(true);
4074
4075                                 if(VerifyArgumentsCompat (ec, pe.PropertyArgs,
4076                                         pe.PropertyArgs.Count, mi, false, null, loc, pe.Name))
4077                                 {
4078
4079                                         expr_to_return = pe.DoResolve (ec);
4080                                         expr_to_return.eclass = ExprClass.PropertyAccess;
4081                                 }
4082                         }
4083
4084                         if (expr is FieldExpr || expr is LocalVariableReference) {
4085                                 // If we are here, expr must be an ArrayAccess
4086                                 // FIXME: we should check dimensions, etc.
4087                                 ArrayList idxs = new ArrayList();
4088                                 foreach (Argument a in Arguments)
4089                                 {
4090                                         idxs.Add (a.Expr);
4091                                 }
4092                                 ElementAccess ea = new ElementAccess (expr, idxs, expr.Location);
4093                                 ArrayAccess aa = new ArrayAccess (ea, expr.Location);
4094                                 expr_to_return = aa.DoResolve(ec);
4095                                 expr_to_return.eclass = ExprClass.Variable;
4096                         }
4097
4098                         return expr_to_return;
4099                 }
4100
4101                 // <summary>
4102                 //   Emits the list of arguments as an array
4103                 // </summary>
4104                 static void EmitParams (EmitContext ec, int idx, ArrayList arguments)
4105                 {
4106                         ILGenerator ig = ec.ig;
4107                         int count = arguments.Count - idx;
4108                         Argument a = (Argument) arguments [idx];
4109                         Type t = a.Expr.Type;
4110                         string array_type = t.FullName + "[]";
4111                         LocalBuilder array;
4112
4113                         array = ig.DeclareLocal (TypeManager.LookupType (array_type));
4114                         IntConstant.EmitInt (ig, count);
4115                         ig.Emit (OpCodes.Newarr, TypeManager.TypeToCoreType (t));
4116                         ig.Emit (OpCodes.Stloc, array);
4117
4118                         int top = arguments.Count;
4119                         for (int j = idx; j < top; j++){
4120                                 a = (Argument) arguments [j];
4121
4122                                 ig.Emit (OpCodes.Ldloc, array);
4123                                 IntConstant.EmitInt (ig, j - idx);
4124                                 a.Emit (ec);
4125
4126                                 ArrayAccess.EmitStoreOpcode (ig, t);
4127                         }
4128                         ig.Emit (OpCodes.Ldloc, array);
4129                 }
4130
4131                 /// <summary>
4132                 ///   Emits a list of resolved Arguments that are in the arguments
4133                 ///   ArrayList.
4134                 ///
4135                 ///   The MethodBase argument might be null if the
4136                 ///   emission of the arguments is known not to contain
4137                 ///   a `params' field (for example in constructors or other routines
4138                 ///   that keep their arguments in this structure)
4139                 /// </summary>
4140                 public static void EmitArguments (EmitContext ec, MethodBase mb, ArrayList arguments)
4141                 {
4142                         ParameterData pd;
4143                         if (mb != null)
4144                                 pd = GetParameterData (mb);
4145                         else
4146                                 pd = null;
4147
4148                         //
4149                         // If we are calling a params method with no arguments, special case it
4150                         //
4151                         if (arguments == null){
4152                                 if (pd != null && pd.Count > 0 &&
4153                                     pd.ParameterModifier (0) == Parameter.Modifier.PARAMS){
4154                                         ILGenerator ig = ec.ig;
4155
4156                                         IntConstant.EmitInt (ig, 0);
4157                                         ig.Emit (OpCodes.Newarr, pd.ParameterType (0).GetElementType ());
4158                                 }
4159                                 return;
4160                         }
4161
4162                         int top = arguments.Count;
4163
4164                         for (int i = 0; i < top; i++){
4165                                 Argument a = (Argument) arguments [i];
4166
4167                                 if (pd != null){
4168                                         if (pd.ParameterModifier (i) == Parameter.Modifier.PARAMS){
4169                                                 //
4170                                                 // Special case if we are passing the same data as the
4171                                                 // params argument, do not put it in an array.
4172                                                 //
4173                                                 if (pd.ParameterType (i) == a.Type)
4174                                                         a.Emit (ec);
4175                                                 else
4176                                                         EmitParams (ec, i, arguments);
4177                                                 return;
4178                                         }
4179                                 }
4180
4181                                 a.Emit (ec);
4182                         }
4183
4184                         if (pd != null && pd.Count > top &&
4185                             pd.ParameterModifier (top) == Parameter.Modifier.PARAMS){
4186                                 ILGenerator ig = ec.ig;
4187
4188                                 IntConstant.EmitInt (ig, 0);
4189                                 ig.Emit (OpCodes.Newarr, pd.ParameterType (top).GetElementType ());
4190                         }
4191                 }
4192
4193                 /// <remarks>
4194                 ///   is_base tells whether we want to force the use of the `call'
4195                 ///   opcode instead of using callvirt.  Call is required to call
4196                 ///   a specific method, while callvirt will always use the most
4197                 ///   recent method in the vtable.
4198                 ///
4199                 ///   is_static tells whether this is an invocation on a static method
4200                 ///
4201                 ///   instance_expr is an expression that represents the instance
4202                 ///   it must be non-null if is_static is false.
4203                 ///
4204                 ///   method is the method to invoke.
4205                 ///
4206                 ///   Arguments is the list of arguments to pass to the method or constructor.
4207                 /// </remarks>
4208                 public static void EmitCall (EmitContext ec, bool is_base,
4209                                              bool is_static, Expression instance_expr,
4210                                              MethodBase method, ArrayList Arguments, Location loc)
4211                 {
4212                         EmitCall (ec, is_base, is_static, instance_expr, method, Arguments, null, loc);
4213                 }
4214
4215                 public static void EmitCall (EmitContext ec, bool is_base,
4216                         bool is_static, Expression instance_expr,
4217                         MethodBase method, ArrayList Arguments, ArrayList prop_args, Location loc)
4218                 {
4219                         ILGenerator ig = ec.ig;
4220                         bool struct_call = false;
4221
4222                         Type decl_type = method.DeclaringType;
4223
4224                         if (!RootContext.StdLib)
4225                         {
4226                                 // Replace any calls to the system's System.Array type with calls to
4227                                 // the newly created one.
4228                                 if (method == TypeManager.system_int_array_get_length)
4229                                         method = TypeManager.int_array_get_length;
4230                                 else if (method == TypeManager.system_int_array_get_rank)
4231                                         method = TypeManager.int_array_get_rank;
4232                                 else if (method == TypeManager.system_object_array_clone)
4233                                         method = TypeManager.object_array_clone;
4234                                 else if (method == TypeManager.system_int_array_get_length_int)
4235                                         method = TypeManager.int_array_get_length_int;
4236                                 else if (method == TypeManager.system_int_array_get_lower_bound_int)
4237                                         method = TypeManager.int_array_get_lower_bound_int;
4238                                 else if (method == TypeManager.system_int_array_get_upper_bound_int)
4239                                         method = TypeManager.int_array_get_upper_bound_int;
4240                                 else if (method == TypeManager.system_void_array_copyto_array_int)
4241                                         method = TypeManager.void_array_copyto_array_int;
4242                         }
4243
4244                         //
4245                         // This checks the `ConditionalAttribute' on the method, and the
4246                         // ObsoleteAttribute
4247                         //
4248                         TypeManager.MethodFlags flags = TypeManager.GetMethodFlags (method, loc);
4249                         if ((flags & TypeManager.MethodFlags.IsObsoleteError) != 0)
4250                                 return;
4251                         if ((flags & TypeManager.MethodFlags.ShouldIgnore) != 0)
4252                                 return;
4253
4254                         if (!is_static)
4255                         {
4256                                 if (decl_type.IsValueType)
4257                                         struct_call = true;
4258                                 //
4259                                 // If this is ourselves, push "this"
4260                                 //
4261                                 if (instance_expr == null)
4262                                 {
4263                                         ig.Emit (OpCodes.Ldarg_0);
4264                                 }
4265                                 else
4266                                 {
4267                                         //
4268                                         // Push the instance expression
4269                                         //
4270                                         if (instance_expr.Type.IsValueType)
4271                                         {
4272                                                 //
4273                                                 // Special case: calls to a function declared in a
4274                                                 // reference-type with a value-type argument need
4275                                                 // to have their value boxed.
4276
4277                                                 struct_call = true;
4278                                                 if (decl_type.IsValueType)
4279                                                 {
4280                                                         //
4281                                                         // If the expression implements IMemoryLocation, then
4282                                                         // we can optimize and use AddressOf on the
4283                                                         // return.
4284                                                         //
4285                                                         // If not we have to use some temporary storage for
4286                                                         // it.
4287                                                         if (instance_expr is IMemoryLocation)
4288                                                         {
4289                                                                 ((IMemoryLocation)instance_expr).
4290                                                                         AddressOf (ec, AddressOp.LoadStore);
4291                                                         }
4292                                                         else
4293                                                         {
4294                                                                 Type t = instance_expr.Type;
4295
4296                                                                 instance_expr.Emit (ec);
4297                                                                 LocalBuilder temp = ig.DeclareLocal (t);
4298                                                                 ig.Emit (OpCodes.Stloc, temp);
4299                                                                 ig.Emit (OpCodes.Ldloca, temp);
4300                                                         }
4301                                                 }
4302                                                 else
4303                                                 {
4304                                                         instance_expr.Emit (ec);
4305                                                         ig.Emit (OpCodes.Box, instance_expr.Type);
4306                                                 }
4307                                         }
4308                                         else
4309                                                 instance_expr.Emit (ec);
4310                                 }
4311                         }
4312
4313                         if (prop_args != null && prop_args.Count > 0)
4314                         {
4315                                 if (Arguments == null)
4316                                         Arguments = new ArrayList();
4317
4318                                 for (int i = prop_args.Count-1; i >=0 ; i--)
4319                                 {
4320                                         Arguments.Insert (0,prop_args[i]);
4321                                 }
4322
4323                         }
4324
4325                         EmitArguments (ec, method, Arguments);
4326
4327                         if (is_static || struct_call || is_base)
4328                         {
4329                                 if (method is MethodInfo)
4330                                 {
4331                                         ig.Emit (OpCodes.Call, (MethodInfo) method);
4332                                 }
4333                                 else
4334                                         ig.Emit (OpCodes.Call, (ConstructorInfo) method);
4335                         }
4336                         else
4337                         {
4338                                 if (method is MethodInfo)
4339                                         ig.Emit (OpCodes.Callvirt, (MethodInfo) method);
4340                                 else
4341                                         ig.Emit (OpCodes.Callvirt, (ConstructorInfo) method);
4342                         }
4343                 }
4344
4345                 static void EmitPropertyArgs (EmitContext ec, ArrayList prop_args)
4346                 {
4347                         int top = prop_args.Count;
4348
4349                         for (int i = 0; i < top; i++)
4350                         {
4351                                 Argument a = (Argument) prop_args [i];
4352                                 a.Emit (ec);
4353                         }
4354                 }
4355
4356                 public override void Emit (EmitContext ec)
4357                 {
4358                         MethodGroupExpr mg = (MethodGroupExpr) this.expr;
4359
4360                         EmitCall (
4361                                 ec, is_base, method.IsStatic, mg.InstanceExpression, method, Arguments, loc);
4362                 }
4363
4364                 public override void EmitStatement (EmitContext ec)
4365                 {
4366                         Emit (ec);
4367
4368                         //
4369                         // Pop the return value if there is one
4370                         //
4371                         if (method is MethodInfo){
4372                                 Type ret = ((MethodInfo)method).ReturnType;
4373                                 if (TypeManager.TypeToCoreType (ret) != TypeManager.void_type)
4374                                         ec.ig.Emit (OpCodes.Pop);
4375                         }
4376                 }
4377         }
4378
4379         //
4380         // This class is used to "disable" the code generation for the
4381         // temporary variable when initializing value types.
4382         //
4383         class EmptyAddressOf : EmptyExpression, IMemoryLocation {
4384                 public void AddressOf (EmitContext ec, AddressOp Mode)
4385                 {
4386                         // nothing
4387                 }
4388         }
4389
4390         /// <summary>
4391         ///    Implements the new expression
4392         /// </summary>
4393         public class New : ExpressionStatement {
4394                 public readonly ArrayList Arguments;
4395                 public readonly Expression RequestedType;
4396
4397                 MethodBase method = null;
4398
4399                 //
4400                 // If set, the new expression is for a value_target, and
4401                 // we will not leave anything on the stack.
4402                 //
4403                 Expression value_target;
4404                 bool value_target_set = false;
4405
4406                 public New (Expression requested_type, ArrayList arguments, Location l)
4407                 {
4408                         RequestedType = requested_type;
4409                         Arguments = arguments;
4410                         loc = l;
4411                 }
4412
4413                 public Expression ValueTypeVariable {
4414                         get {
4415                                 return value_target;
4416                         }
4417
4418                         set {
4419                                 value_target = value;
4420                                 value_target_set = true;
4421                         }
4422                 }
4423
4424                 //
4425                 // This function is used to disable the following code sequence for
4426                 // value type initialization:
4427                 //
4428                 // AddressOf (temporary)
4429                 // Construct/Init
4430                 // LoadTemporary
4431                 //
4432                 // Instead the provide will have provided us with the address on the
4433                 // stack to store the results.
4434                 //
4435                 static Expression MyEmptyExpression;
4436
4437                 public void DisableTemporaryValueType ()
4438                 {
4439                         if (MyEmptyExpression == null)
4440                                 MyEmptyExpression = new EmptyAddressOf ();
4441
4442                         //
4443                         // To enable this, look into:
4444                         // test-34 and test-89 and self bootstrapping.
4445                         //
4446                         // For instance, we can avoid a copy by using `newobj'
4447                         // instead of Call + Push-temp on value types.
4448 //                      value_target = MyEmptyExpression;
4449                 }
4450
4451                 public override Expression DoResolve (EmitContext ec)
4452                 {
4453                         type = ec.DeclSpace.ResolveType (RequestedType, false, loc);
4454
4455                         if (type == null)
4456                                 return null;
4457
4458                         bool IsDelegate = TypeManager.IsDelegateType (type);
4459
4460                         if (IsDelegate)
4461                                 return (new NewDelegate (type, Arguments, loc)).Resolve (ec);
4462
4463                         if (type.IsInterface || type.IsAbstract){
4464                                 Error (
4465                                         144, "It is not possible to create instances of interfaces " +
4466                                         "or abstract classes");
4467                                 return null;
4468                         }
4469
4470                         bool is_struct = false;
4471                         is_struct = type.IsValueType;
4472                         eclass = ExprClass.Value;
4473
4474                         //
4475                         // SRE returns a match for .ctor () on structs (the object constructor),
4476                         // so we have to manually ignore it.
4477                         //
4478                         if (is_struct && Arguments == null)
4479                                 return this;
4480
4481                         Expression ml;
4482                         ml = MemberLookupFinal (ec, type, ".ctor",
4483                                                 MemberTypes.Constructor,
4484                                                 AllBindingFlags | BindingFlags.Public, loc);
4485
4486                         if (ml == null)
4487                                 return null;
4488
4489                         if (! (ml is MethodGroupExpr)){
4490                                 if (!is_struct){
4491                                         ml.Error118 ("method group");
4492                                         return null;
4493                                 }
4494                         }
4495
4496                         if (ml != null) {
4497                                 if (Arguments != null){
4498                                         foreach (Argument a in Arguments){
4499                                                 if (!a.Resolve (ec, loc))
4500                                                         return null;
4501                                         }
4502                                 }
4503
4504                                 method = Invocation.OverloadResolve (ec, (MethodGroupExpr) ml,
4505                                                                      Arguments, loc);
4506
4507                         }
4508
4509                         if (method == null) {
4510                                 if (!is_struct || Arguments.Count > 0) {
4511                                         Error (1501,
4512                                                "New invocation: Can not find a constructor for " +
4513                                                "this argument list");
4514                                         return null;
4515                                 }
4516                         }
4517                         return this;
4518                 }
4519
4520                 //
4521                 // This DoEmit can be invoked in two contexts:
4522                 //    * As a mechanism that will leave a value on the stack (new object)
4523                 //    * As one that wont (init struct)
4524                 //
4525                 // You can control whether a value is required on the stack by passing
4526                 // need_value_on_stack.  The code *might* leave a value on the stack
4527                 // so it must be popped manually
4528                 //
4529                 // If we are dealing with a ValueType, we have a few
4530                 // situations to deal with:
4531                 //
4532                 //    * The target is a ValueType, and we have been provided
4533                 //      the instance (this is easy, we are being assigned).
4534                 //
4535                 //    * The target of New is being passed as an argument,
4536                 //      to a boxing operation or a function that takes a
4537                 //      ValueType.
4538                 //
4539                 //      In this case, we need to create a temporary variable
4540                 //      that is the argument of New.
4541                 //
4542                 // Returns whether a value is left on the stack
4543                 //
4544                 bool DoEmit (EmitContext ec, bool need_value_on_stack)
4545                 {
4546                         bool is_value_type = type.IsValueType;
4547                         ILGenerator ig = ec.ig;
4548
4549                         if (is_value_type){
4550                                 IMemoryLocation ml;
4551
4552                                 // Allow DoEmit() to be called multiple times.
4553                                 // We need to create a new LocalTemporary each time since
4554                                 // you can't share LocalBuilders among ILGeneators.
4555                                 if (!value_target_set)
4556                                         value_target = new LocalTemporary (ec, type);
4557
4558                                 ml = (IMemoryLocation) value_target;
4559                                 ml.AddressOf (ec, AddressOp.Store);
4560                         }
4561
4562                         if (method != null)
4563                                 Invocation.EmitArguments (ec, method, Arguments);
4564
4565                         if (is_value_type){
4566                                 if (method == null)
4567                                         ig.Emit (OpCodes.Initobj, type);
4568                                 else
4569                                         ig.Emit (OpCodes.Call, (ConstructorInfo) method);
4570                                 if (need_value_on_stack){
4571                                         value_target.Emit (ec);
4572                                         return true;
4573                                 }
4574                                 return false;
4575                         } else {
4576                                 ig.Emit (OpCodes.Newobj, (ConstructorInfo) method);
4577                                 return true;
4578                         }
4579                 }
4580
4581                 public override void Emit (EmitContext ec)
4582                 {
4583                         DoEmit (ec, true);
4584                 }
4585
4586                 public override void EmitStatement (EmitContext ec)
4587                 {
4588                         if (DoEmit (ec, false))
4589                                 ec.ig.Emit (OpCodes.Pop);
4590                 }
4591         }
4592
4593         /// <summary>
4594         ///   14.5.10.2: Represents an array creation expression.
4595         /// </summary>
4596         ///
4597         /// <remarks>
4598         ///   There are two possible scenarios here: one is an array creation
4599         ///   expression that specifies the dimensions and optionally the
4600         ///   initialization data and the other which does not need dimensions
4601         ///   specified but where initialization data is mandatory.
4602         /// </remarks>
4603         public class ArrayCreation : ExpressionStatement {
4604                 Expression requested_base_type;
4605                 ArrayList initializers;
4606
4607                 //
4608                 // The list of Argument types.
4609                 // This is used to construct the `newarray' or constructor signature
4610                 //
4611                 ArrayList arguments;
4612
4613                 //
4614                 // Method used to create the array object.
4615                 //
4616                 MethodBase new_method = null;
4617
4618                 Type array_element_type;
4619                 Type underlying_type;
4620                 bool is_one_dimensional = false;
4621                 bool is_builtin_type = false;
4622                 bool expect_initializers = false;
4623                 int num_arguments = 0;
4624                 int dimensions = 0;
4625                 string rank;
4626
4627                 ArrayList array_data;
4628
4629                 Hashtable bounds;
4630
4631                 //
4632                 // The number of array initializers that we can handle
4633                 // via the InitializeArray method - through EmitStaticInitializers
4634                 //
4635                 int num_automatic_initializers;
4636
4637                 public ArrayCreation (Expression requested_base_type, ArrayList exprs, string rank, ArrayList initializers, Location l)
4638                 {
4639                         this.requested_base_type = requested_base_type;
4640                         this.initializers = initializers;
4641                         this.rank = rank;
4642                         loc = l;
4643
4644                         arguments = new ArrayList ();
4645
4646                         foreach (Expression e in exprs) {
4647                                 arguments.Add (new Argument (e, Argument.AType.Expression));
4648                                 num_arguments++;
4649                         }
4650                 }
4651
4652                 public ArrayCreation (Expression requested_base_type, string rank, ArrayList initializers, Location l)
4653                 {
4654                         this.requested_base_type = requested_base_type;
4655                         this.initializers = initializers;
4656                         this.rank = rank;
4657                         loc = l;
4658
4659                         //this.rank = rank.Substring (0, rank.LastIndexOf ("["));
4660                         //
4661                         //string tmp = rank.Substring (rank.LastIndexOf ("["));
4662                         //
4663                         //dimensions = tmp.Length - 1;
4664                         expect_initializers = true;
4665                 }
4666
4667                 public Expression FormArrayType (Expression base_type, int idx_count, string rank)
4668                 {
4669                         StringBuilder sb = new StringBuilder (rank);
4670
4671                         sb.Append ("[");
4672                         for (int i = 1; i < idx_count; i++)
4673                                 sb.Append (",");
4674
4675                         sb.Append ("]");
4676
4677                         return new ComposedCast (base_type, sb.ToString (), loc);
4678                 }
4679
4680                 void Error_IncorrectArrayInitializer ()
4681                 {
4682                         Error (178, "Incorrectly structured array initializer");
4683                 }
4684
4685                 public bool CheckIndices (EmitContext ec, ArrayList probe, int idx, bool specified_dims)
4686                 {
4687                         if (specified_dims) {
4688                                 Console.WriteLine  ("specified_dims");
4689                                 Argument a = (Argument) arguments [idx];
4690
4691                                 if (!a.Resolve (ec, loc))
4692                                         return false;
4693
4694                                 if (!(a.Expr is Constant)) {
4695                                         Error (150, "A constant value is expected");
4696                                         return false;
4697                                 }
4698
4699                                 int value = (int) ((Constant) a.Expr).GetValue ();
4700
4701                                 if (value != probe.Count) {
4702                                         Error_IncorrectArrayInitializer ();
4703                                         return false;
4704                                 }
4705
4706                                 bounds [idx] = value;
4707                         }
4708
4709                         int child_bounds = -1;
4710                         foreach (object o in probe) {
4711                                 if (o is ArrayList) {
4712                                         int current_bounds = ((ArrayList) o).Count;
4713
4714                                         if (child_bounds == -1)
4715                                                 child_bounds = current_bounds;
4716
4717                                         else if (child_bounds != current_bounds){
4718                                                 Error_IncorrectArrayInitializer ();
4719                                                 return false;
4720                                         }
4721                                         bool ret = CheckIndices (ec, (ArrayList) o, idx + 1, specified_dims);
4722                                         if (!ret)
4723                                                 return false;
4724                                 } else {
4725                                         if (child_bounds != -1){
4726                                                 Error_IncorrectArrayInitializer ();
4727                                                 return false;
4728                                         }
4729
4730                                         Expression tmp = (Expression) o;
4731                                         tmp = tmp.Resolve (ec);
4732                                         if (tmp == null)
4733                                                 continue;
4734
4735                                         // Console.WriteLine ("I got: " + tmp);
4736                                         // Handle initialization from vars, fields etc.
4737
4738                                         Expression conv = ConvertImplicitRequired (
4739                                                 ec, tmp, underlying_type, loc);
4740
4741                                         if (conv == null)
4742                                                 return false;
4743
4744                                         if (conv is StringConstant)
4745                                                 array_data.Add (conv);
4746                                         else if (conv is Constant) {
4747                                                 array_data.Add (conv);
4748                                                 num_automatic_initializers++;
4749                                         } else
4750                                                 array_data.Add (conv);
4751                                 }
4752                         }
4753
4754                         return true;
4755                 }
4756
4757                 public void UpdateIndices (EmitContext ec)
4758                 {
4759                         int i = 0;
4760                         for (ArrayList probe = initializers; probe != null;) {
4761                                 if (probe.Count > 0 && probe [0] is ArrayList) {
4762                                         Expression e = new IntConstant (probe.Count);
4763                                         arguments.Add (new Argument (e, Argument.AType.Expression));
4764
4765                                         bounds [i++] =  probe.Count;
4766
4767                                         probe = (ArrayList) probe [0];
4768
4769                                 } else {
4770                                         Expression e = new IntConstant (probe.Count);
4771                                         arguments.Add (new Argument (e, Argument.AType.Expression));
4772
4773                                         bounds [i++] = probe.Count;
4774                                         probe = null;
4775                                 }
4776                         }
4777
4778                 }
4779
4780                 public bool ValidateInitializers (EmitContext ec, Type array_type)
4781                 {
4782                         if (initializers == null) {
4783                                 if (expect_initializers)
4784                                         return false;
4785                                 else
4786                                         return true;
4787                         }
4788
4789                         if (underlying_type == null)
4790                                 return false;
4791
4792                         //
4793                         // We use this to store all the date values in the order in which we
4794                         // will need to store them in the byte blob later
4795                         //
4796                         array_data = new ArrayList ();
4797                         bounds = new Hashtable ();
4798
4799                         bool ret;
4800
4801                         if (arguments != null) {
4802                                 ret = CheckIndices (ec, initializers, 0, true);
4803                                 return ret;
4804                         } else {
4805                                 arguments = new ArrayList ();
4806
4807                                 ret = CheckIndices (ec, initializers, 0, false);
4808
4809                                 if (!ret)
4810                                         return false;
4811
4812                                 UpdateIndices (ec);
4813
4814                                 if (arguments.Count != dimensions) {
4815                                         Error_IncorrectArrayInitializer ();
4816                                         return false;
4817                                 }
4818
4819                                 return ret;
4820                         }
4821                 }
4822
4823                 void Error_NegativeArrayIndex ()
4824                 {
4825                         Error (284, "Can not create array with a negative size");
4826                 }
4827
4828                 //
4829                 // Converts `source' to an int, uint, long or ulong.
4830                 //
4831                 Expression ExpressionToArrayArgument (EmitContext ec, Expression source)
4832                 {
4833                         Expression target;
4834
4835                         bool old_checked = ec.CheckState;
4836                         ec.CheckState = true;
4837
4838                         target = ConvertImplicit (ec, source, TypeManager.int32_type, loc);
4839                         if (target == null){
4840                                 target = ConvertImplicit (ec, source, TypeManager.uint32_type, loc);
4841                                 if (target == null){
4842                                         target = ConvertImplicit (ec, source, TypeManager.int64_type, loc);
4843                                         if (target == null){
4844                                                 target = ConvertImplicit (ec, source, TypeManager.uint64_type, loc);
4845                                                 if (target == null)
4846                                                         Expression.Error_CannotConvertImplicit (loc, source.Type, TypeManager.int32_type);
4847                                         }
4848                                 }
4849                         }
4850                         ec.CheckState = old_checked;
4851
4852                         //
4853                         // Only positive constants are allowed at compile time
4854                         //
4855                         if (target is Constant){
4856                                 if (target is IntConstant){
4857                                         if (((IntConstant) target).Value < 0){
4858                                                 Error_NegativeArrayIndex ();
4859                                                 return null;
4860                                         }
4861                                 }
4862
4863                                 if (target is LongConstant){
4864                                         if (((LongConstant) target).Value < 0){
4865                                                 Error_NegativeArrayIndex ();
4866                                                 return null;
4867                                         }
4868                                 }
4869
4870                         }
4871
4872                         return target;
4873                 }
4874
4875                 //
4876                 // Creates the type of the array
4877                 //
4878                 bool LookupType (EmitContext ec)
4879                 {
4880                         StringBuilder array_qualifier = new StringBuilder (rank);
4881
4882                         //
4883                         // `In the first form allocates an array instace of the type that results
4884                         // from deleting each of the individual expression from the expression list'
4885                         //
4886                         if (num_arguments > 0) {
4887                                 array_qualifier.Append ("[");
4888                                 for (int i = num_arguments-1; i > 0; i--)
4889                                         array_qualifier.Append (",");
4890                                 array_qualifier.Append ("]");
4891                         }
4892
4893                         //
4894                         // Lookup the type
4895                         //
4896                         Expression array_type_expr;
4897                         array_type_expr = new ComposedCast (requested_base_type, array_qualifier.ToString (), loc);
4898                         type = ec.DeclSpace.ResolveType (array_type_expr, false, loc);
4899
4900                         if (type == null)
4901                                 return false;
4902
4903                         underlying_type = type;
4904                         if (underlying_type.IsArray)
4905                                 underlying_type = TypeManager.TypeToCoreType (underlying_type.GetElementType ());
4906                         dimensions = type.GetArrayRank ();
4907
4908                         return true;
4909                 }
4910
4911                 public override Expression DoResolve (EmitContext ec)
4912                 {
4913                         int arg_count;
4914
4915                         if (!LookupType (ec))
4916                                 return null;
4917
4918                         //
4919                         // First step is to validate the initializers and fill
4920                         // in any missing bits
4921                         //
4922                         if (!ValidateInitializers (ec, type))
4923                                 return null;
4924
4925                         if (arguments == null)
4926                                 arg_count = 0;
4927                         else {
4928                                 arg_count = arguments.Count;
4929                                 foreach (Argument a in arguments){
4930                                         if (!a.Resolve (ec, loc))
4931                                                 return null;
4932
4933                                         Expression real_arg = ExpressionToArrayArgument (ec, a.Expr, loc);
4934                                         if (real_arg == null)
4935                                                 return null;
4936
4937                                         a.Expr = real_arg;
4938                                 }
4939                         }
4940
4941                         array_element_type = TypeManager.TypeToCoreType (type.GetElementType ());
4942
4943                         if (arg_count == 1) {
4944                                 is_one_dimensional = true;
4945                                 eclass = ExprClass.Value;
4946                                 return this;
4947                         }
4948
4949                         is_builtin_type = TypeManager.IsBuiltinType (type);
4950
4951                         if (is_builtin_type) {
4952                                 Expression ml;
4953
4954                                 ml = MemberLookup (ec, type, ".ctor", MemberTypes.Constructor,
4955                                                    AllBindingFlags, loc);
4956
4957                                 if (!(ml is MethodGroupExpr)) {
4958                                         ml.Error118 ("method group");
4959                                         return null;
4960                                 }
4961
4962                                 if (ml == null) {
4963                                         Error (-6, "New invocation: Can not find a constructor for " +
4964                                                       "this argument list");
4965                                         return null;
4966                                 }
4967
4968                                 new_method = Invocation.OverloadResolve (ec, (MethodGroupExpr) ml, arguments, loc);
4969
4970                                 if (new_method == null) {
4971                                         Error (-6, "New invocation: Can not find a constructor for " +
4972                                                       "this argument list");
4973                                         return null;
4974                                 }
4975
4976                                 eclass = ExprClass.Value;
4977                                 return this;
4978                         } else {
4979                                 ModuleBuilder mb = CodeGen.ModuleBuilder;
4980                                 ArrayList args = new ArrayList ();
4981
4982                                 if (arguments != null) {
4983                                         for (int i = 0; i < arg_count; i++)
4984                                                 args.Add (TypeManager.int32_type);
4985                                 }
4986
4987                                 Type [] arg_types = null;
4988
4989                                 if (args.Count > 0)
4990                                         arg_types = new Type [args.Count];
4991
4992                                 args.CopyTo (arg_types, 0);
4993
4994                                 new_method = mb.GetArrayMethod (type, ".ctor", CallingConventions.HasThis, null,
4995                                                             arg_types);
4996
4997                                 if (new_method == null) {
4998                                         Error (-6, "New invocation: Can not find a constructor for " +
4999                                                       "this argument list");
5000                                         return null;
5001                                 }
5002
5003                                 eclass = ExprClass.Value;
5004                                 return this;
5005                         }
5006                 }
5007
5008                 public static byte [] MakeByteBlob (ArrayList array_data, Type underlying_type, Location loc)
5009                 {
5010                         int factor;
5011                         byte [] data;
5012                         byte [] element;
5013                         int count = array_data.Count;
5014
5015                         if (underlying_type.IsEnum)
5016                                 underlying_type = TypeManager.EnumToUnderlying (underlying_type);
5017
5018                         factor = GetTypeSize (underlying_type);
5019                         if (factor == 0)
5020                                 throw new Exception ("unrecognized type in MakeByteBlob: " + underlying_type);
5021
5022                         data = new byte [(count * factor + 4) & ~3];
5023                         int idx = 0;
5024
5025                         for (int i = 0; i < count; ++i) {
5026                                 object v = array_data [i];
5027
5028                                 if (v is EnumConstant)
5029                                         v = ((EnumConstant) v).Child;
5030
5031                                 if (v is Constant && !(v is StringConstant))
5032                                         v = ((Constant) v).GetValue ();
5033                                 else {
5034                                         idx += factor;
5035                                         continue;
5036                                 }
5037
5038                                 if (underlying_type == TypeManager.int64_type){
5039                                         if (!(v is Expression)){
5040                                                 long val = (long) v;
5041
5042                                                 for (int j = 0; j < factor; ++j) {
5043                                                         data [idx + j] = (byte) (val & 0xFF);
5044                                                         val = (val >> 8);
5045                                                 }
5046                                         }
5047                                 } else if (underlying_type == TypeManager.uint64_type){
5048                                         if (!(v is Expression)){
5049                                                 ulong val = (ulong) v;
5050
5051                                                 for (int j = 0; j < factor; ++j) {
5052                                                         data [idx + j] = (byte) (val & 0xFF);
5053                                                         val = (val >> 8);
5054                                                 }
5055                                         }
5056                                 } else if (underlying_type == TypeManager.float_type) {
5057                                         if (!(v is Expression)){
5058                                                 element = BitConverter.GetBytes ((float) v);
5059
5060                                                 for (int j = 0; j < factor; ++j)
5061                                                         data [idx + j] = element [j];
5062                                         }
5063                                 } else if (underlying_type == TypeManager.double_type) {
5064                                         if (!(v is Expression)){
5065                                                 element = BitConverter.GetBytes ((double) v);
5066
5067                                                 for (int j = 0; j < factor; ++j)
5068                                                         data [idx + j] = element [j];
5069                                         }
5070                                 } else if (underlying_type == TypeManager.char_type){
5071                                         if (!(v is Expression)){
5072                                                 int val = (int) ((char) v);
5073
5074                                                 data [idx] = (byte) (val & 0xff);
5075                                                 data [idx+1] = (byte) (val >> 8);
5076                                         }
5077                                 } else if (underlying_type == TypeManager.short_type){
5078                                         if (!(v is Expression)){
5079                                                 int val = (int) ((short) v);
5080
5081                                                 data [idx] = (byte) (val & 0xff);
5082                                                 data [idx+1] = (byte) (val >> 8);
5083                                         }
5084                                 } else if (underlying_type == TypeManager.ushort_type){
5085                                         if (!(v is Expression)){
5086                                                 int val = (int) ((ushort) v);
5087
5088                                                 data [idx] = (byte) (val & 0xff);
5089                                                 data [idx+1] = (byte) (val >> 8);
5090                                         }
5091                                 } else if (underlying_type == TypeManager.int32_type) {
5092                                         if (!(v is Expression)){
5093                                                 int val = (int) v;
5094
5095                                                 data [idx]   = (byte) (val & 0xff);
5096                                                 data [idx+1] = (byte) ((val >> 8) & 0xff);
5097                                                 data [idx+2] = (byte) ((val >> 16) & 0xff);
5098                                                 data [idx+3] = (byte) (val >> 24);
5099                                         }
5100                                 } else if (underlying_type == TypeManager.uint32_type) {
5101                                         if (!(v is Expression)){
5102                                                 uint val = (uint) v;
5103
5104                                                 data [idx]   = (byte) (val & 0xff);
5105                                                 data [idx+1] = (byte) ((val >> 8) & 0xff);
5106                                                 data [idx+2] = (byte) ((val >> 16) & 0xff);
5107                                                 data [idx+3] = (byte) (val >> 24);
5108                                         }
5109                                 } else if (underlying_type == TypeManager.sbyte_type) {
5110                                         if (!(v is Expression)){
5111                                                 sbyte val = (sbyte) v;
5112                                                 data [idx] = (byte) val;
5113                                         }
5114                                 } else if (underlying_type == TypeManager.byte_type) {
5115                                         if (!(v is Expression)){
5116                                                 byte val = (byte) v;
5117                                                 data [idx] = (byte) val;
5118                                         }
5119                                 } else if (underlying_type == TypeManager.bool_type) {
5120                                         if (!(v is Expression)){
5121                                                 bool val = (bool) v;
5122                                                 data [idx] = (byte) (val ? 1 : 0);
5123                                         }
5124                                 } else if (underlying_type == TypeManager.decimal_type){
5125                                         if (!(v is Expression)){
5126                                                 int [] bits = Decimal.GetBits ((decimal) v);
5127                                                 int p = idx;
5128
5129                                                 for (int j = 0; j < 4; j++){
5130                                                         data [p++] = (byte) (bits [j] & 0xff);
5131                                                         data [p++] = (byte) ((bits [j] >> 8) & 0xff);
5132                                                         data [p++] = (byte) ((bits [j] >> 16) & 0xff);
5133                                                         data [p++] = (byte) (bits [j] >> 24);
5134                                                 }
5135                                         }
5136                                 } else
5137                                         throw new Exception ("Unrecognized type in MakeByteBlob: " + underlying_type);
5138
5139                                 idx += factor;
5140                         }
5141
5142                         return data;
5143                 }
5144
5145                 //
5146                 // Emits the initializers for the array
5147                 //
5148                 void EmitStaticInitializers (EmitContext ec, bool is_expression)
5149                 {
5150                         //
5151                         // First, the static data
5152                         //
5153                         FieldBuilder fb;
5154                         ILGenerator ig = ec.ig;
5155
5156                         byte [] data = MakeByteBlob (array_data, underlying_type, loc);
5157
5158                         fb = RootContext.MakeStaticData (data);
5159
5160                         if (is_expression)
5161                                 ig.Emit (OpCodes.Dup);
5162                         ig.Emit (OpCodes.Ldtoken, fb);
5163                         ig.Emit (OpCodes.Call,
5164                                  TypeManager.void_initializearray_array_fieldhandle);
5165                 }
5166
5167                 //
5168                 // Emits pieces of the array that can not be computed at compile
5169                 // time (variables and string locations).
5170                 //
5171                 // This always expect the top value on the stack to be the array
5172                 //
5173                 void EmitDynamicInitializers (EmitContext ec, bool is_expression)
5174                 {
5175                         ILGenerator ig = ec.ig;
5176                         int dims = bounds.Count;
5177                         int [] current_pos = new int [dims];
5178                         int top = array_data.Count;
5179                         LocalBuilder temp = ig.DeclareLocal (type);
5180
5181                         ig.Emit (OpCodes.Stloc, temp);
5182
5183                         MethodInfo set = null;
5184
5185                         if (dims != 1){
5186                                 Type [] args;
5187                                 ModuleBuilder mb = null;
5188                                 mb = CodeGen.ModuleBuilder;
5189                                 args = new Type [dims + 1];
5190
5191                                 int j;
5192                                 for (j = 0; j < dims; j++)
5193                                         args [j] = TypeManager.int32_type;
5194
5195                                 args [j] = array_element_type;
5196
5197                                 set = mb.GetArrayMethod (
5198                                         type, "Set",
5199                                         CallingConventions.HasThis | CallingConventions.Standard,
5200                                         TypeManager.void_type, args);
5201                         }
5202
5203                         for (int i = 0; i < top; i++){
5204
5205                                 Expression e = null;
5206
5207                                 if (array_data [i] is Expression)
5208                                         e = (Expression) array_data [i];
5209
5210                                 if (e != null) {
5211                                         //
5212                                         // Basically we do this for string literals and
5213                                         // other non-literal expressions
5214                                         //
5215                                         if (e is StringConstant || !(e is Constant) ||
5216                                             num_automatic_initializers <= 2) {
5217                                                 Type etype = e.Type;
5218
5219                                                 ig.Emit (OpCodes.Ldloc, temp);
5220
5221                                                 for (int idx = 0; idx < dims; idx++)
5222                                                         IntConstant.EmitInt (ig, current_pos [idx]);
5223
5224                                                 //
5225                                                 // If we are dealing with a struct, get the
5226                                                 // address of it, so we can store it.
5227                                                 //
5228                                                 if ((dims == 1) &&
5229                                                     etype.IsSubclassOf (TypeManager.value_type) &&
5230                                                     (!TypeManager.IsBuiltinType (etype) ||
5231                                                      etype == TypeManager.decimal_type)) {
5232                                                         if (e is New){
5233                                                                 New n = (New) e;
5234
5235                                                                 //
5236                                                                 // Let new know that we are providing
5237                                                                 // the address where to store the results
5238                                                                 //
5239                                                                 n.DisableTemporaryValueType ();
5240                                                         }
5241
5242                                                         ig.Emit (OpCodes.Ldelema, etype);
5243                                                 }
5244
5245                                                 e.Emit (ec);
5246
5247                                                 if (dims == 1)
5248                                                         ArrayAccess.EmitStoreOpcode (ig, array_element_type);
5249                                                 else
5250                                                         ig.Emit (OpCodes.Call, set);
5251                                         }
5252                                 }
5253
5254                                 //
5255                                 // Advance counter
5256                                 //
5257                                 for (int j = dims - 1; j >= 0; j--){
5258                                         current_pos [j]++;
5259                                         if (current_pos [j] < (int) bounds [j])
5260                                                 break;
5261                                         current_pos [j] = 0;
5262                                 }
5263                         }
5264
5265                         if (is_expression)
5266                                 ig.Emit (OpCodes.Ldloc, temp);
5267                 }
5268
5269                 void EmitArrayArguments (EmitContext ec)
5270                 {
5271                         ILGenerator ig = ec.ig;
5272
5273                         foreach (Argument a in arguments) {
5274                                 Type atype = a.Type;
5275                                 a.Emit (ec);
5276
5277                                 if (atype == TypeManager.uint64_type)
5278                                         ig.Emit (OpCodes.Conv_Ovf_U4);
5279                                 else if (atype == TypeManager.int64_type)
5280                                         ig.Emit (OpCodes.Conv_Ovf_I4);
5281                         }
5282                 }
5283
5284                 void DoEmit (EmitContext ec, bool is_statement)
5285                 {
5286                         ILGenerator ig = ec.ig;
5287
5288                         EmitArrayArguments (ec);
5289                         if (is_one_dimensional)
5290                                 ig.Emit (OpCodes.Newarr, array_element_type);
5291                         else {
5292                                 if (is_builtin_type)
5293                                         ig.Emit (OpCodes.Newobj, (ConstructorInfo) new_method);
5294                                 else
5295                                         ig.Emit (OpCodes.Newobj, (MethodInfo) new_method);
5296                         }
5297
5298                         if (initializers != null){
5299                                 //
5300                                 // FIXME: Set this variable correctly.
5301                                 //
5302                                 bool dynamic_initializers = true;
5303
5304                                 if (underlying_type != TypeManager.string_type &&
5305                                     underlying_type != TypeManager.object_type) {
5306                                         if (num_automatic_initializers > 2)
5307                                                 EmitStaticInitializers (ec, dynamic_initializers || !is_statement);
5308                                 }
5309
5310                                 if (dynamic_initializers)
5311                                         EmitDynamicInitializers (ec, !is_statement);
5312                         }
5313                 }
5314
5315                 public override void Emit (EmitContext ec)
5316                 {
5317                         DoEmit (ec, false);
5318                 }
5319
5320                 public override void EmitStatement (EmitContext ec)
5321                 {
5322                         DoEmit (ec, true);
5323                 }
5324
5325         }
5326
5327         /// <summary>
5328         ///   Represents the `this' construct
5329         /// </summary>
5330         public class This : Expression, IAssignMethod, IMemoryLocation, IVariable {
5331
5332                 Block block;
5333                 VariableInfo vi;
5334
5335                 public This (Block block, Location loc)
5336                 {
5337                         this.loc = loc;
5338                         this.block = block;
5339                 }
5340
5341                 public This (Location loc)
5342                 {
5343                         this.loc = loc;
5344                 }
5345
5346                 public bool IsAssigned (EmitContext ec, Location loc)
5347                 {
5348                         if (vi == null)
5349                                 return true;
5350
5351                         return vi.IsAssigned (ec, loc);
5352                 }
5353
5354                 public bool IsFieldAssigned (EmitContext ec, string field_name, Location loc)
5355                 {
5356                         if (vi == null)
5357                                 return true;
5358
5359                         return vi.IsFieldAssigned (ec, field_name, loc);
5360                 }
5361
5362                 public void SetAssigned (EmitContext ec)
5363                 {
5364                         if (vi != null)
5365                                 vi.SetAssigned (ec);
5366                 }
5367
5368                 public void SetFieldAssigned (EmitContext ec, string field_name)
5369                 {
5370                         if (vi != null)
5371                                 vi.SetFieldAssigned (ec, field_name);
5372                 }
5373
5374                 public override Expression DoResolve (EmitContext ec)
5375                 {
5376                         eclass = ExprClass.Variable;
5377                         type = ec.ContainerType;
5378
5379                         if (ec.IsStatic){
5380                                 Error (26, "Keyword this not valid in static code");
5381                                 return null;
5382                         }
5383
5384                         if (block != null)
5385                                 vi = block.ThisVariable;
5386
5387                         return this;
5388                 }
5389
5390                 override public Expression DoResolveLValue (EmitContext ec, Expression right_side)
5391                 {
5392                         DoResolve (ec);
5393
5394                         VariableInfo vi = ec.CurrentBlock.ThisVariable;
5395                         if (vi != null)
5396                                 vi.SetAssigned (ec);
5397
5398                         if (ec.TypeContainer is Class){
5399                                 Error (1604, "Cannot assign to `this'");
5400                                 return null;
5401                         }
5402
5403                         return this;
5404                 }
5405
5406                 public override void Emit (EmitContext ec)
5407                 {
5408                         ILGenerator ig = ec.ig;
5409
5410                         ig.Emit (OpCodes.Ldarg_0);
5411                         if (ec.TypeContainer is Struct)
5412                                 ig.Emit (OpCodes.Ldobj, type);
5413                 }
5414
5415                 public void EmitAssign (EmitContext ec, Expression source)
5416                 {
5417                         ILGenerator ig = ec.ig;
5418
5419                         if (ec.TypeContainer is Struct){
5420                                 ig.Emit (OpCodes.Ldarg_0);
5421                                 source.Emit (ec);
5422                                 ig.Emit (OpCodes.Stobj, type);
5423                         } else {
5424                                 source.Emit (ec);
5425                                 ig.Emit (OpCodes.Starg, 0);
5426                         }
5427                 }
5428
5429                 public void AddressOf (EmitContext ec, AddressOp mode)
5430                 {
5431                         ec.ig.Emit (OpCodes.Ldarg_0);
5432
5433                         // FIMXE
5434                         // FIGURE OUT WHY LDARG_S does not work
5435                         //
5436                         // consider: struct X { int val; int P { set { val = value; }}}
5437                         //
5438                         // Yes, this looks very bad. Look at `NOTAS' for
5439                         // an explanation.
5440                         // ec.ig.Emit (OpCodes.Ldarga_S, (byte) 0);
5441                 }
5442         }
5443
5444         /// <summary>
5445         ///   Implements the typeof operator
5446         /// </summary>
5447         public class TypeOf : Expression {
5448                 public readonly Expression QueriedType;
5449                 Type typearg;
5450
5451                 public TypeOf (Expression queried_type, Location l)
5452                 {
5453                         QueriedType = queried_type;
5454                         loc = l;
5455                 }
5456
5457                 public override Expression DoResolve (EmitContext ec)
5458                 {
5459                         typearg = ec.DeclSpace.ResolveType (QueriedType, false, loc);
5460
5461                         if (typearg == null)
5462                                 return null;
5463
5464                         type = TypeManager.type_type;
5465                         eclass = ExprClass.Type;
5466                         return this;
5467                 }
5468
5469                 public override void Emit (EmitContext ec)
5470                 {
5471                         ec.ig.Emit (OpCodes.Ldtoken, typearg);
5472                         ec.ig.Emit (OpCodes.Call, TypeManager.system_type_get_type_from_handle);
5473                 }
5474
5475                 public Type TypeArg {
5476                         get { return typearg; }
5477                 }
5478         }
5479
5480         /// <summary>
5481         ///   Implements the sizeof expression
5482         /// </summary>
5483         public class SizeOf : Expression {
5484                 public readonly Expression QueriedType;
5485                 Type type_queried;
5486
5487                 public SizeOf (Expression queried_type, Location l)
5488                 {
5489                         this.QueriedType = queried_type;
5490                         loc = l;
5491                 }
5492
5493                 public override Expression DoResolve (EmitContext ec)
5494                 {
5495                         if (!ec.InUnsafe) {
5496                                 Error (233, "Sizeof may only be used in an unsafe context " +
5497                                        "(consider using System.Runtime.InteropServices.Marshal.Sizeof");
5498                                 return null;
5499                         }
5500
5501                         type_queried = ec.DeclSpace.ResolveType (QueriedType, false, loc);
5502                         if (type_queried == null)
5503                                 return null;
5504
5505                         if (!TypeManager.IsUnmanagedType (type_queried)){
5506                                 Report.Error (208, "Cannot take the size of an unmanaged type (" + TypeManager.CSharpName (type_queried) + ")");
5507                                 return null;
5508                         }
5509
5510                         type = TypeManager.int32_type;
5511                         eclass = ExprClass.Value;
5512                         return this;
5513                 }
5514
5515                 public override void Emit (EmitContext ec)
5516                 {
5517                         int size = GetTypeSize (type_queried);
5518
5519                         if (size == 0)
5520                                 ec.ig.Emit (OpCodes.Sizeof, type_queried);
5521                         else
5522                                 IntConstant.EmitInt (ec.ig, size);
5523                 }
5524         }
5525
5526         /// <summary>
5527         ///   Implements the member access expression
5528         /// </summary>
5529         public class MemberAccess : Expression, ITypeExpression {
5530                 public readonly string Identifier;
5531                 Expression expr;
5532                 Expression member_lookup;
5533
5534                 public MemberAccess (Expression expr, string id, Location l)
5535                 {
5536                         this.expr = expr;
5537                         Identifier = id;
5538                         loc = l;
5539                 }
5540
5541                 public Expression Expr {
5542                         get {
5543                                 return expr;
5544                         }
5545                 }
5546
5547                 static void error176 (Location loc, string name)
5548                 {
5549                         Report.Error (176, loc, "Static member `" +
5550                                       name + "' cannot be accessed " +
5551                                       "with an instance reference, qualify with a " +
5552                                       "type name instead");
5553                 }
5554
5555                 static bool IdenticalNameAndTypeName (EmitContext ec, Expression left_original, Location loc)
5556                 {
5557                         if (left_original == null)
5558                                 return false;
5559
5560                         if (!(left_original is SimpleName))
5561                                 return false;
5562
5563                         SimpleName sn = (SimpleName) left_original;
5564
5565                         Type t = RootContext.LookupType (ec.DeclSpace, sn.Name, true, loc);
5566                         if (t != null)
5567                                 return true;
5568
5569                         return false;
5570                 }
5571
5572                 public static Expression ResolveMemberAccess (EmitContext ec, Expression member_lookup,
5573                                                               Expression left, Location loc,
5574                                                               Expression left_original)
5575                 {
5576                         bool left_is_type, left_is_explicit;
5577
5578                         // If `left' is null, then we're called from SimpleNameResolve and this is
5579                         // a member in the currently defining class.
5580                         if (left == null) {
5581                                 left_is_type = ec.IsStatic || ec.IsFieldInitializer;
5582                                 left_is_explicit = false;
5583
5584                                 // Implicitly default to `this' unless we're static.
5585                                 if (!ec.IsStatic && !ec.IsFieldInitializer && !ec.InEnumContext)
5586                                         left = ec.This;
5587                         } else {
5588                                 left_is_type = left is TypeExpr;
5589                                 left_is_explicit = true;
5590                         }
5591
5592                         if (member_lookup is FieldExpr){
5593                                 FieldExpr fe = (FieldExpr) member_lookup;
5594                                 FieldInfo fi = fe.FieldInfo;
5595                                 Type decl_type = fi.DeclaringType;
5596
5597                                 if (fi is FieldBuilder) {
5598                                         Const c = TypeManager.LookupConstant ((FieldBuilder) fi);
5599
5600                                         if (c != null) {
5601                                                 object o = c.LookupConstantValue (ec);
5602                                                 object real_value = ((Constant) c.Expr).GetValue ();
5603
5604                                                 return Constantify (real_value, fi.FieldType);
5605                                         }
5606                                 }
5607
5608                                 if (fi.IsLiteral) {
5609                                         Type t = fi.FieldType;
5610
5611                                         object o;
5612
5613                                         if (fi is FieldBuilder)
5614                                                 o = TypeManager.GetValue ((FieldBuilder) fi);
5615                                         else
5616                                                 o = fi.GetValue (fi);
5617
5618                                         if (decl_type.IsSubclassOf (TypeManager.enum_type)) {
5619                                                 if (left_is_explicit && !left_is_type &&
5620                                                     !IdenticalNameAndTypeName (ec, left_original, loc)) {
5621                                                         error176 (loc, fe.FieldInfo.Name);
5622                                                         return null;
5623                                                 }
5624
5625                                                 Expression enum_member = MemberLookup (
5626                                                         ec, decl_type, "value__", MemberTypes.Field,
5627                                                         AllBindingFlags, loc);
5628
5629                                                 Enum en = TypeManager.LookupEnum (decl_type);
5630
5631                                                 Constant c;
5632                                                 if (en != null)
5633                                                         c = Constantify (o, en.UnderlyingType);
5634                                                 else
5635                                                         c = Constantify (o, enum_member.Type);
5636
5637                                                 return new EnumConstant (c, decl_type);
5638                                         }
5639
5640                                         Expression exp = Constantify (o, t);
5641
5642                                         if (left_is_explicit && !left_is_type) {
5643                                                 error176 (loc, fe.FieldInfo.Name);
5644                                                 return null;
5645                                         }
5646
5647                                         return exp;
5648                                 }
5649
5650                                 if (fi.FieldType.IsPointer && !ec.InUnsafe){
5651                                         UnsafeError (loc);
5652                                         return null;
5653                                 }
5654                         }
5655
5656                         if (member_lookup is EventExpr) {
5657
5658                                 EventExpr ee = (EventExpr) member_lookup;
5659
5660                                 //
5661                                 // If the event is local to this class, we transform ourselves into
5662                                 // a FieldExpr
5663                                 //
5664
5665                                 if (ee.EventInfo.DeclaringType == ec.ContainerType) {
5666                                         MemberInfo mi = GetFieldFromEvent (ee);
5667
5668                                         if (mi == null) {
5669                                                 //
5670                                                 // If this happens, then we have an event with its own
5671                                                 // accessors and private field etc so there's no need
5672                                                 // to transform ourselves : we should instead flag an error
5673                                                 //
5674                                                 Assign.error70 (ee.EventInfo, loc);
5675                                                 return null;
5676                                         }
5677
5678                                         Expression ml = ExprClassFromMemberInfo (ec, mi, loc);
5679
5680                                         if (ml == null) {
5681                                                 Report.Error (-200, loc, "Internal error!!");
5682                                                 return null;
5683                                         }
5684
5685                                         return ResolveMemberAccess (ec, ml, left, loc, left_original);
5686                                 }
5687                         }
5688
5689                         if (member_lookup is IMemberExpr) {
5690                                 IMemberExpr me = (IMemberExpr) member_lookup;
5691
5692                                 if (left_is_type){
5693                                         MethodGroupExpr mg = me as MethodGroupExpr;
5694                                         if ((mg != null) && left_is_explicit && left.Type.IsInterface)
5695                                                 mg.IsExplicitImpl = left_is_explicit;
5696
5697                                         if (!me.IsStatic){
5698                                                 if (IdenticalNameAndTypeName (ec, left_original, loc))
5699                                                         return member_lookup;
5700
5701                                                 SimpleName.Error_ObjectRefRequired (ec, loc, me.Name);
5702                                                 return null;
5703                                         }
5704
5705                                 } else {
5706                                         if (!me.IsInstance){
5707                                                 if (IdenticalNameAndTypeName (ec, left_original, loc))
5708                                                         return member_lookup;
5709
5710                                                 if (left_is_explicit) {
5711                                                         error176 (loc, me.Name);
5712                                                         return null;
5713                                                 }
5714                                         }
5715
5716                                         //
5717                                         // Since we can not check for instance objects in SimpleName,
5718                                         // becaue of the rule that allows types and variables to share
5719                                         // the name (as long as they can be de-ambiguated later, see
5720                                         // IdenticalNameAndTypeName), we have to check whether left
5721                                         // is an instance variable in a static context
5722                                         //
5723                                         // However, if the left-hand value is explicitly given, then
5724                                         // it is already our instance expression, so we aren't in
5725                                         // static context.
5726                                         //
5727
5728                                         if (ec.IsStatic && !left_is_explicit && left is IMemberExpr){
5729                                                 IMemberExpr mexp = (IMemberExpr) left;
5730
5731                                                 if (!mexp.IsStatic){
5732                                                         SimpleName.Error_ObjectRefRequired (ec, loc, mexp.Name);
5733                                                         return null;
5734                                                 }
5735                                         }
5736
5737                                         me.InstanceExpression = left;
5738                                 }
5739
5740                                 return member_lookup;
5741                         }
5742
5743                         if (member_lookup is TypeExpr){
5744                                 member_lookup.Resolve (ec, ResolveFlags.Type);
5745                                 return member_lookup;
5746                         }
5747
5748                         Console.WriteLine ("Left is: " + left);
5749                         Report.Error (-100, loc, "Support for [" + member_lookup + "] is not present yet");
5750                         Environment.Exit (0);
5751                         return null;
5752                 }
5753
5754                 public Expression DoResolve (EmitContext ec, Expression right_side, ResolveFlags flags)
5755                 {
5756                         if (type != null)
5757                                 throw new Exception ();
5758                         //
5759                         // Resolve the expression with flow analysis turned off, we'll do the definite
5760                         // assignment checks later.  This is because we don't know yet what the expression
5761                         // will resolve to - it may resolve to a FieldExpr and in this case we must do the
5762                         // definite assignment check on the actual field and not on the whole struct.
5763                         //
5764
5765                         Expression original = expr;
5766                         expr = expr.Resolve (ec, flags | ResolveFlags.DisableFlowAnalysis);
5767
5768                         if (expr == null)
5769                                 return null;
5770
5771                         if (expr is SimpleName){
5772                                 SimpleName child_expr = (SimpleName) expr;
5773
5774                                 Expression new_expr = new SimpleName (child_expr.Name + "." + Identifier, loc);
5775
5776                                 return new_expr.Resolve (ec, flags);
5777                         }
5778
5779                         //
5780                         // TODO: I mailed Ravi about this, and apparently we can get rid
5781                         // of this and put it in the right place.
5782                         //
5783                         // Handle enums here when they are in transit.
5784                         // Note that we cannot afford to hit MemberLookup in this case because
5785                         // it will fail to find any members at all
5786                         //
5787
5788                         int errors = Report.Errors;
5789
5790                         Type expr_type = expr.Type;
5791                         if ((expr is TypeExpr) && (expr_type.IsSubclassOf (TypeManager.enum_type))){
5792
5793                                 Enum en = TypeManager.LookupEnum (expr_type);
5794
5795                                 if (en != null) {
5796                                         object value = en.LookupEnumValue (ec, Identifier, loc);
5797
5798                                         if (value != null){
5799                                                 Constant c = Constantify (value, en.UnderlyingType);
5800                                                 return new EnumConstant (c, expr_type);
5801                                         }
5802                                 }
5803                         }
5804
5805                         if (expr_type.IsPointer){
5806                                 Error (23, "The `.' operator can not be applied to pointer operands (" +
5807                                        TypeManager.CSharpName (expr_type) + ")");
5808                                 return null;
5809                         }
5810
5811                         member_lookup = MemberLookup (ec, expr_type, Identifier, loc);
5812
5813                         if (member_lookup == null){
5814                                 // Error has already been reported.
5815                                 if (errors < Report.Errors)
5816                                         return null;
5817
5818                                 //
5819                                 // Try looking the member up from the same type, if we find
5820                                 // it, we know that the error was due to limited visibility
5821                                 //
5822                                 object lookup = TypeManager.MemberLookup (
5823                                         expr_type, expr_type, AllMemberTypes, AllBindingFlags |
5824                                         BindingFlags.NonPublic, Identifier);
5825                                 if (lookup == null)
5826                                         Error (117, "`" + expr_type + "' does not contain a " +
5827                                                "definition for `" + Identifier + "'");
5828                                 else if ((expr_type != ec.ContainerType) &&
5829                                          ec.ContainerType.IsSubclassOf (expr_type)){
5830
5831                                         // Although a derived class can access protected members of
5832                                         // its base class it cannot do so through an instance of the
5833                                         // base class (CS1540).  If the expr_type is a parent of the
5834                                         // ec.ContainerType and the lookup succeeds with the latter one,
5835                                         // then we are in this situation.
5836
5837                                         lookup = TypeManager.MemberLookup (
5838                                                 ec.ContainerType, ec.ContainerType, AllMemberTypes,
5839                                                 AllBindingFlags, Identifier);
5840
5841                                         if (lookup != null)
5842                                                 Error (1540, "Cannot access protected member `" +
5843                                                        expr_type + "." + Identifier + "' " +
5844                                                        "via a qualifier of type `" +
5845                                                        TypeManager.CSharpName (expr_type) + "'; the " +
5846                                                        "qualifier must be of type `" +
5847                                                        TypeManager.CSharpName (ec.ContainerType) + "' " +
5848                                                        "(or derived from it)");
5849                                         else
5850                                                 Error (122, "`" + expr_type + "." + Identifier + "' " +
5851                                                        "is inaccessible because of its protection level");
5852                                 } else
5853                                         Error (122, "`" + expr_type + "." + Identifier + "' " +
5854                                                "is inaccessible because of its protection level");
5855
5856                                 return null;
5857                         }
5858
5859                         if (member_lookup is TypeExpr){
5860                                 member_lookup.Resolve (ec, ResolveFlags.Type);
5861                                 return member_lookup;
5862                         } else if ((flags & ResolveFlags.MaskExprClass) == ResolveFlags.Type)
5863                                 return null;
5864
5865                         member_lookup = ResolveMemberAccess (ec, member_lookup, expr, loc, original);
5866                         if (member_lookup == null)
5867                                 return null;
5868
5869                         // The following DoResolve/DoResolveLValue will do the definite assignment
5870                         // check.
5871
5872                         if (right_side != null)
5873                                 member_lookup = member_lookup.DoResolveLValue (ec, right_side);
5874                         else
5875                                 member_lookup = member_lookup.DoResolve (ec);
5876
5877                         return member_lookup;
5878                 }
5879
5880                 public override Expression DoResolve (EmitContext ec)
5881                 {
5882                         return DoResolve (ec, null, ResolveFlags.VariableOrValue |
5883                                           ResolveFlags.SimpleName | ResolveFlags.Type);
5884                 }
5885
5886                 public override Expression DoResolveLValue (EmitContext ec, Expression right_side)
5887                 {
5888                         return DoResolve (ec, right_side, ResolveFlags.VariableOrValue |
5889                                           ResolveFlags.SimpleName | ResolveFlags.Type);
5890                 }
5891
5892                 public Expression DoResolveType (EmitContext ec)
5893                 {
5894                         return DoResolve (ec, null, ResolveFlags.Type);
5895                 }
5896
5897                 public override void Emit (EmitContext ec)
5898                 {
5899                         throw new Exception ("Should not happen");
5900                 }
5901
5902                 public override string ToString ()
5903                 {
5904                         return expr + "." + Identifier;
5905                 }
5906         }
5907
5908         /// <summary>
5909         ///   Implements checked expressions
5910         /// </summary>
5911         public class CheckedExpr : Expression {
5912
5913                 public Expression Expr;
5914
5915                 public CheckedExpr (Expression e, Location l)
5916                 {
5917                         Expr = e;
5918                         loc = l;
5919                 }
5920
5921                 public override Expression DoResolve (EmitContext ec)
5922                 {
5923                         bool last_const_check = ec.ConstantCheckState;
5924
5925                         ec.ConstantCheckState = true;
5926                         Expr = Expr.Resolve (ec);
5927                         ec.ConstantCheckState = last_const_check;
5928
5929                         if (Expr == null)
5930                                 return null;
5931
5932                         if (Expr is Constant)
5933                                 return Expr;
5934
5935                         eclass = Expr.eclass;
5936                         type = Expr.Type;
5937                         return this;
5938                 }
5939
5940                 public override void Emit (EmitContext ec)
5941                 {
5942                         bool last_check = ec.CheckState;
5943                         bool last_const_check = ec.ConstantCheckState;
5944
5945                         ec.CheckState = true;
5946                         ec.ConstantCheckState = true;
5947                         Expr.Emit (ec);
5948                         ec.CheckState = last_check;
5949                         ec.ConstantCheckState = last_const_check;
5950                 }
5951
5952         }
5953
5954         /// <summary>
5955         ///   Implements the unchecked expression
5956         /// </summary>
5957         public class UnCheckedExpr : Expression {
5958
5959                 public Expression Expr;
5960
5961                 public UnCheckedExpr (Expression e, Location l)
5962                 {
5963                         Expr = e;
5964                         loc = l;
5965                 }
5966
5967                 public override Expression DoResolve (EmitContext ec)
5968                 {
5969                         bool last_const_check = ec.ConstantCheckState;
5970
5971                         ec.ConstantCheckState = false;
5972                         Expr = Expr.Resolve (ec);
5973                         ec.ConstantCheckState = last_const_check;
5974
5975                         if (Expr == null)
5976                                 return null;
5977
5978                         if (Expr is Constant)
5979                                 return Expr;
5980
5981                         eclass = Expr.eclass;
5982                         type = Expr.Type;
5983                         return this;
5984                 }
5985
5986                 public override void Emit (EmitContext ec)
5987                 {
5988                         bool last_check = ec.CheckState;
5989                         bool last_const_check = ec.ConstantCheckState;
5990
5991                         ec.CheckState = false;
5992                         ec.ConstantCheckState = false;
5993                         Expr.Emit (ec);
5994                         ec.CheckState = last_check;
5995                         ec.ConstantCheckState = last_const_check;
5996                 }
5997
5998         }
5999
6000         /// <summary>
6001         ///   An Element Access expression.
6002         ///
6003         ///   During semantic analysis these are transformed into
6004         ///   IndexerAccess or ArrayAccess
6005         /// </summary>
6006         public class ElementAccess : Expression {
6007                 public ArrayList  Arguments;
6008                 public Expression Expr;
6009
6010                 public ElementAccess (Expression e, ArrayList e_list, Location l)
6011                 {
6012                         Expr = e;
6013
6014                         loc  = l;
6015
6016                         if (e_list == null)
6017                                 return;
6018
6019                         Arguments = new ArrayList ();
6020                         foreach (Expression tmp in e_list)
6021                                 Arguments.Add (new Argument (tmp, Argument.AType.Expression));
6022
6023                 }
6024
6025                 bool CommonResolve (EmitContext ec)
6026                 {
6027                         Expr = Expr.Resolve (ec);
6028
6029                         if (Expr == null)
6030                                 return false;
6031
6032                         if (Arguments == null)
6033                                 return false;
6034
6035                         foreach (Argument a in Arguments){
6036                                 if (!a.Resolve (ec, loc))
6037                                         return false;
6038                         }
6039
6040                         return true;
6041                 }
6042
6043                 Expression MakePointerAccess ()
6044                 {
6045                         Type t = Expr.Type;
6046
6047                         if (t == TypeManager.void_ptr_type){
6048                                 Error (
6049                                         242,
6050                                         "The array index operation is not valid for void pointers");
6051                                 return null;
6052                         }
6053                         if (Arguments.Count != 1){
6054                                 Error (
6055                                         196,
6056                                         "A pointer must be indexed by a single value");
6057                                 return null;
6058                         }
6059                         Expression p = new PointerArithmetic (true, Expr, ((Argument)Arguments [0]).Expr,
6060                                                               t, loc);
6061                         return new Indirection (p, loc);
6062                 }
6063
6064                 public override Expression DoResolve (EmitContext ec)
6065                 {
6066                         if (!CommonResolve (ec))
6067                                 return null;
6068
6069                         //
6070                         // We perform some simple tests, and then to "split" the emit and store
6071                         // code we create an instance of a different class, and return that.
6072                         //
6073                         // I am experimenting with this pattern.
6074                         //
6075                         Type t = Expr.Type;
6076
6077                         if (t.IsArray)
6078                                 return (new ArrayAccess (this, loc)).Resolve (ec);
6079                         else if (t.IsPointer)
6080                                 return MakePointerAccess ();
6081                         else
6082                                 return (new IndexerAccess (this, loc)).Resolve (ec);
6083                 }
6084
6085                 public override Expression DoResolveLValue (EmitContext ec, Expression right_side)
6086                 {
6087                         if (!CommonResolve (ec))
6088                                 return null;
6089
6090                         Type t = Expr.Type;
6091                         if (t.IsArray)
6092                                 return (new ArrayAccess (this, loc)).ResolveLValue (ec, right_side);
6093                         else if (t.IsPointer)
6094                                 return MakePointerAccess ();
6095                         else
6096                                 return (new IndexerAccess (this, loc)).ResolveLValue (ec, right_side);
6097                 }
6098
6099                 public override void Emit (EmitContext ec)
6100                 {
6101                         throw new Exception ("Should never be reached");
6102                 }
6103         }
6104
6105         /// <summary>
6106         ///   Implements array access
6107         /// </summary>
6108         public class ArrayAccess : Expression, IAssignMethod, IMemoryLocation {
6109                 //
6110                 // Points to our "data" repository
6111                 //
6112                 ElementAccess ea;
6113
6114                 LocalTemporary [] cached_locations;
6115
6116                 public ArrayAccess (ElementAccess ea_data, Location l)
6117                 {
6118                         ea = ea_data;
6119                         eclass = ExprClass.Variable;
6120                         loc = l;
6121                 }
6122
6123                 public override Expression DoResolve (EmitContext ec)
6124                 {
6125                         ExprClass eclass = ea.Expr.eclass;
6126
6127 #if false
6128                         // As long as the type is valid
6129                         if (!(eclass == ExprClass.Variable || eclass == ExprClass.PropertyAccess ||
6130                               eclass == ExprClass.Value)) {
6131                                 ea.Expr.Error118 ("variable or value");
6132                                 return null;
6133                         }
6134 #endif
6135
6136                         Type t = ea.Expr.Type;
6137                         if (t.GetArrayRank () != ea.Arguments.Count){
6138                                 ea.Error (22,
6139                                           "Incorrect number of indexes for array " +
6140                                           " expected: " + t.GetArrayRank () + " got: " +
6141                                           ea.Arguments.Count);
6142                                 return null;
6143                         }
6144                         type = TypeManager.TypeToCoreType (t.GetElementType ());
6145                         if (type.IsPointer && !ec.InUnsafe){
6146                                 UnsafeError (ea.Location);
6147                                 return null;
6148                         }
6149
6150                         foreach (Argument a in ea.Arguments){
6151                                 Type argtype = a.Type;
6152
6153                                 if (argtype == TypeManager.int32_type ||
6154                                     argtype == TypeManager.uint32_type ||
6155                                     argtype == TypeManager.int64_type ||
6156                                     argtype == TypeManager.uint64_type)
6157                                         continue;
6158
6159                                 //
6160                                 // Mhm.  This is strage, because the Argument.Type is not the same as
6161                                 // Argument.Expr.Type: the value changes depending on the ref/out setting.
6162                                 //
6163                                 // Wonder if I will run into trouble for this.
6164                                 //
6165                                 a.Expr = ExpressionToArrayArgument (ec, a.Expr, ea.Location);
6166                                 if (a.Expr == null)
6167                                         return null;
6168                         }
6169
6170                         eclass = ExprClass.Variable;
6171
6172                         return this;
6173                 }
6174
6175                 /// <summary>
6176                 ///    Emits the right opcode to load an object of Type `t'
6177                 ///    from an array of T
6178                 /// </summary>
6179                 static public void EmitLoadOpcode (ILGenerator ig, Type type)
6180                 {
6181                         if (type == TypeManager.byte_type || type == TypeManager.bool_type)
6182                                 ig.Emit (OpCodes.Ldelem_U1);
6183                         else if (type == TypeManager.sbyte_type)
6184                                 ig.Emit (OpCodes.Ldelem_I1);
6185                         else if (type == TypeManager.short_type)
6186                                 ig.Emit (OpCodes.Ldelem_I2);
6187                         else if (type == TypeManager.ushort_type || type == TypeManager.char_type)
6188                                 ig.Emit (OpCodes.Ldelem_U2);
6189                         else if (type == TypeManager.int32_type)
6190                                 ig.Emit (OpCodes.Ldelem_I4);
6191                         else if (type == TypeManager.uint32_type)
6192                                 ig.Emit (OpCodes.Ldelem_U4);
6193                         else if (type == TypeManager.uint64_type)
6194                                 ig.Emit (OpCodes.Ldelem_I8);
6195                         else if (type == TypeManager.int64_type)
6196                                 ig.Emit (OpCodes.Ldelem_I8);
6197                         else if (type == TypeManager.float_type)
6198                                 ig.Emit (OpCodes.Ldelem_R4);
6199                         else if (type == TypeManager.double_type)
6200                                 ig.Emit (OpCodes.Ldelem_R8);
6201                         else if (type == TypeManager.intptr_type)
6202                                 ig.Emit (OpCodes.Ldelem_I);
6203                         else if (type.IsValueType){
6204                                 ig.Emit (OpCodes.Ldelema, type);
6205                                 ig.Emit (OpCodes.Ldobj, type);
6206                         } else
6207                                 ig.Emit (OpCodes.Ldelem_Ref);
6208                 }
6209
6210                 /// <summary>
6211                 ///    Emits the right opcode to store an object of Type `t'
6212                 ///    from an array of T.
6213                 /// </summary>
6214                 static public void EmitStoreOpcode (ILGenerator ig, Type t)
6215                 {
6216                         t = TypeManager.TypeToCoreType (t);
6217                         if (TypeManager.IsEnumType (t) && t != TypeManager.enum_type)
6218                                 t = TypeManager.EnumToUnderlying (t);
6219                         if (t == TypeManager.byte_type || t == TypeManager.sbyte_type ||
6220                             t == TypeManager.bool_type)
6221                                 ig.Emit (OpCodes.Stelem_I1);
6222                         else if (t == TypeManager.short_type || t == TypeManager.ushort_type || t == TypeManager.char_type)
6223                                 ig.Emit (OpCodes.Stelem_I2);
6224                         else if (t == TypeManager.int32_type || t == TypeManager.uint32_type)
6225                                 ig.Emit (OpCodes.Stelem_I4);
6226                         else if (t == TypeManager.int64_type || t == TypeManager.uint64_type)
6227                                 ig.Emit (OpCodes.Stelem_I8);
6228                         else if (t == TypeManager.float_type)
6229                                 ig.Emit (OpCodes.Stelem_R4);
6230                         else if (t == TypeManager.double_type)
6231                                 ig.Emit (OpCodes.Stelem_R8);
6232                         else if (t == TypeManager.intptr_type)
6233                                 ig.Emit (OpCodes.Stelem_I);
6234                         else if (t.IsValueType){
6235                                 ig.Emit (OpCodes.Stobj, t);
6236                         } else
6237                                 ig.Emit (OpCodes.Stelem_Ref);
6238                 }
6239
6240                 MethodInfo FetchGetMethod ()
6241                 {
6242                         ModuleBuilder mb = CodeGen.ModuleBuilder;
6243                         int arg_count = ea.Arguments.Count;
6244                         Type [] args = new Type [arg_count];
6245                         MethodInfo get;
6246
6247                         for (int i = 0; i < arg_count; i++){
6248                                 //args [i++] = a.Type;
6249                                 args [i] = TypeManager.int32_type;
6250                         }
6251
6252                         get = mb.GetArrayMethod (
6253                                 ea.Expr.Type, "Get",
6254                                 CallingConventions.HasThis |
6255                                 CallingConventions.Standard,
6256                                 type, args);
6257                         return get;
6258                 }
6259
6260
6261                 MethodInfo FetchAddressMethod ()
6262                 {
6263                         ModuleBuilder mb = CodeGen.ModuleBuilder;
6264                         int arg_count = ea.Arguments.Count;
6265                         Type [] args = new Type [arg_count];
6266                         MethodInfo address;
6267                         string ptr_type_name;
6268                         Type ret_type;
6269
6270                         ptr_type_name = type.FullName + "&";
6271                         ret_type = Type.GetType (ptr_type_name);
6272
6273                         //
6274                         // It is a type defined by the source code we are compiling
6275                         //
6276                         if (ret_type == null){
6277                                 ret_type = mb.GetType (ptr_type_name);
6278                         }
6279
6280                         for (int i = 0; i < arg_count; i++){
6281                                 //args [i++] = a.Type;
6282                                 args [i] = TypeManager.int32_type;
6283                         }
6284
6285                         address = mb.GetArrayMethod (
6286                                 ea.Expr.Type, "Address",
6287                                 CallingConventions.HasThis |
6288                                 CallingConventions.Standard,
6289                                 ret_type, args);
6290
6291                         return address;
6292                 }
6293
6294                 //
6295                 // Load the array arguments into the stack.
6296                 //
6297                 // If we have been requested to cache the values (cached_locations array
6298                 // initialized), then load the arguments the first time and store them
6299                 // in locals.  otherwise load from local variables.
6300                 //
6301                 void LoadArrayAndArguments (EmitContext ec)
6302                 {
6303                         ILGenerator ig = ec.ig;
6304
6305                         if (cached_locations == null){
6306                                 ea.Expr.Emit (ec);
6307                                 foreach (Argument a in ea.Arguments){
6308                                         Type argtype = a.Expr.Type;
6309
6310                                         a.Expr.Emit (ec);
6311
6312                                         if (argtype == TypeManager.int64_type)
6313                                                 ig.Emit (OpCodes.Conv_Ovf_I);
6314                                         else if (argtype == TypeManager.uint64_type)
6315                                                 ig.Emit (OpCodes.Conv_Ovf_I_Un);
6316                                 }
6317                                 return;
6318                         }
6319
6320                         if (cached_locations [0] == null){
6321                                 cached_locations [0] = new LocalTemporary (ec, ea.Expr.Type);
6322                                 ea.Expr.Emit (ec);
6323                                 ig.Emit (OpCodes.Dup);
6324                                 cached_locations [0].Store (ec);
6325
6326                                 int j = 1;
6327
6328                                 foreach (Argument a in ea.Arguments){
6329                                         Type argtype = a.Expr.Type;
6330
6331                                         cached_locations [j] = new LocalTemporary (ec, TypeManager.intptr_type /* a.Expr.Type */);
6332                                         a.Expr.Emit (ec);
6333                                         if (argtype == TypeManager.int64_type)
6334                                                 ig.Emit (OpCodes.Conv_Ovf_I);
6335                                         else if (argtype == TypeManager.uint64_type)
6336                                                 ig.Emit (OpCodes.Conv_Ovf_I_Un);
6337
6338                                         ig.Emit (OpCodes.Dup);
6339                                         cached_locations [j].Store (ec);
6340                                         j++;
6341                                 }
6342                                 return;
6343                         }
6344
6345                         foreach (LocalTemporary lt in cached_locations)
6346                                 lt.Emit (ec);
6347                 }
6348
6349                 public new void CacheTemporaries (EmitContext ec)
6350                 {
6351                         cached_locations = new LocalTemporary [ea.Arguments.Count + 1];
6352                 }
6353
6354                 public override void Emit (EmitContext ec)
6355                 {
6356                         int rank = ea.Expr.Type.GetArrayRank ();
6357                         ILGenerator ig = ec.ig;
6358
6359                         LoadArrayAndArguments (ec);
6360
6361                         if (rank == 1)
6362                                 EmitLoadOpcode (ig, type);
6363                         else {
6364                                 MethodInfo method;
6365
6366                                 method = FetchGetMethod ();
6367                                 ig.Emit (OpCodes.Call, method);
6368                         }
6369                 }
6370
6371                 public void EmitAssign (EmitContext ec, Expression source)
6372                 {
6373                         int rank = ea.Expr.Type.GetArrayRank ();
6374                         ILGenerator ig = ec.ig;
6375                         Type t = source.Type;
6376
6377                         LoadArrayAndArguments (ec);
6378
6379                         //
6380                         // The stobj opcode used by value types will need
6381                         // an address on the stack, not really an array/array
6382                         // pair
6383                         //
6384                         if (rank == 1){
6385                                 if (t == TypeManager.enum_type || t == TypeManager.decimal_type ||
6386                                     (t.IsSubclassOf (TypeManager.value_type) && !TypeManager.IsEnumType (t) && !TypeManager.IsBuiltinType (t)))
6387                                         ig.Emit (OpCodes.Ldelema, t);
6388                         }
6389
6390                         source.Emit (ec);
6391
6392                         if (rank == 1)
6393                                 EmitStoreOpcode (ig, t);
6394                         else {
6395                                 ModuleBuilder mb = CodeGen.ModuleBuilder;
6396                                 int arg_count = ea.Arguments.Count;
6397                                 Type [] args = new Type [arg_count + 1];
6398                                 MethodInfo set;
6399
6400                                 for (int i = 0; i < arg_count; i++){
6401                                         //args [i++] = a.Type;
6402                                         args [i] = TypeManager.int32_type;
6403                                 }
6404
6405                                 args [arg_count] = type;
6406
6407                                 set = mb.GetArrayMethod (
6408                                         ea.Expr.Type, "Set",
6409                                         CallingConventions.HasThis |
6410                                         CallingConventions.Standard,
6411                                         TypeManager.void_type, args);
6412
6413                                 ig.Emit (OpCodes.Call, set);
6414                         }
6415                 }
6416
6417                 public void AddressOf (EmitContext ec, AddressOp mode)
6418                 {
6419                         int rank = ea.Expr.Type.GetArrayRank ();
6420                         ILGenerator ig = ec.ig;
6421
6422                         LoadArrayAndArguments (ec);
6423
6424                         if (rank == 1){
6425                                 ig.Emit (OpCodes.Ldelema, type);
6426                         } else {
6427                                 MethodInfo address = FetchAddressMethod ();
6428                                 ig.Emit (OpCodes.Call, address);
6429                         }
6430                 }
6431         }
6432
6433
6434         class Indexers {
6435                 public ArrayList getters, setters;
6436                 static Hashtable map;
6437
6438                 static Indexers ()
6439                 {
6440                         map = new Hashtable ();
6441                 }
6442
6443                 Indexers (MemberInfo [] mi)
6444                 {
6445                         foreach (PropertyInfo property in mi){
6446                                 MethodInfo get, set;
6447
6448                                 get = property.GetGetMethod (true);
6449                                 if (get != null){
6450                                         if (getters == null)
6451                                                 getters = new ArrayList ();
6452
6453                                         getters.Add (get);
6454                                 }
6455
6456                                 set = property.GetSetMethod (true);
6457                                 if (set != null){
6458                                         if (setters == null)
6459                                                 setters = new ArrayList ();
6460                                         setters.Add (set);
6461                                 }
6462                         }
6463                 }
6464
6465                 static private Indexers GetIndexersForTypeOrInterface (Type caller_type, Type lookup_type)
6466                 {
6467                         Indexers ix = (Indexers) map [lookup_type];
6468
6469                         if (ix != null)
6470                                 return ix;
6471
6472                         string p_name = TypeManager.IndexerPropertyName (lookup_type);
6473
6474                         MemberInfo [] mi = TypeManager.MemberLookup (
6475                                 caller_type, lookup_type, MemberTypes.Property,
6476                                 BindingFlags.Public | BindingFlags.Instance, p_name);
6477
6478                         if (mi == null || mi.Length == 0)
6479                                 return null;
6480
6481                         ix = new Indexers (mi);
6482                         map [lookup_type] = ix;
6483
6484                         return ix;
6485                 }
6486
6487                 static public Indexers GetIndexersForType (Type caller_type, Type lookup_type, Location loc)
6488                 {
6489                         Indexers ix = (Indexers) map [lookup_type];
6490
6491                         if (ix != null)
6492                                 return ix;
6493
6494                         ix = GetIndexersForTypeOrInterface (caller_type, lookup_type);
6495                         if (ix != null)
6496                                 return ix;
6497
6498                         Type [] ifaces = TypeManager.GetInterfaces (lookup_type);
6499                         if (ifaces != null) {
6500                                 foreach (Type itype in ifaces) {
6501                                         ix = GetIndexersForTypeOrInterface (caller_type, itype);
6502                                         if (ix != null)
6503                                                 return ix;
6504                                 }
6505                         }
6506
6507                         Report.Error (21, loc,
6508                                       "Type `" + TypeManager.CSharpName (lookup_type) +
6509                                       "' does not have any indexers defined");
6510                         return null;
6511                 }
6512         }
6513
6514         /// <summary>
6515         ///   Expressions that represent an indexer call.
6516         /// </summary>
6517         public class IndexerAccess : Expression, IAssignMethod {
6518                 //
6519                 // Points to our "data" repository
6520                 //
6521                 MethodInfo get, set;
6522                 Indexers ilist;
6523                 ArrayList set_arguments;
6524                 bool is_base_indexer;
6525
6526                 protected Type indexer_type;
6527                 protected Type current_type;
6528                 protected Expression instance_expr;
6529                 protected ArrayList arguments;
6530
6531                 public IndexerAccess (ElementAccess ea, Location loc)
6532                         : this (ea.Expr, false, loc)
6533                 {
6534                         this.arguments = ea.Arguments;
6535                 }
6536
6537                 protected IndexerAccess (Expression instance_expr, bool is_base_indexer,
6538                                          Location loc)
6539                 {
6540                         this.instance_expr = instance_expr;
6541                         this.is_base_indexer = is_base_indexer;
6542                         this.eclass = ExprClass.Value;
6543                         this.loc = loc;
6544                 }
6545
6546                 protected virtual bool CommonResolve (EmitContext ec)
6547                 {
6548                         indexer_type = instance_expr.Type;
6549                         current_type = ec.ContainerType;
6550
6551                         return true;
6552                 }
6553
6554                 public override Expression DoResolve (EmitContext ec)
6555                 {
6556                         if (!CommonResolve (ec))
6557                                 return null;
6558
6559                         //
6560                         // Step 1: Query for all `Item' *properties*.  Notice
6561                         // that the actual methods are pointed from here.
6562                         //
6563                         // This is a group of properties, piles of them.
6564
6565                         if (ilist == null)
6566                                 ilist = Indexers.GetIndexersForType (
6567                                         current_type, indexer_type, loc);
6568
6569                         //
6570                         // Step 2: find the proper match
6571                         //
6572                         if (ilist != null && ilist.getters != null && ilist.getters.Count > 0)
6573                                 get = (MethodInfo) Invocation.OverloadResolve (
6574                                         ec, new MethodGroupExpr (ilist.getters, loc), arguments, loc);
6575
6576                         if (get == null){
6577                                 Error (154, "indexer can not be used in this context, because " +
6578                                        "it lacks a `get' accessor");
6579                                 return null;
6580                         }
6581
6582                         type = get.ReturnType;
6583                         if (type.IsPointer && !ec.InUnsafe){
6584                                 UnsafeError (loc);
6585                                 return null;
6586                         }
6587
6588                         eclass = ExprClass.IndexerAccess;
6589                         return this;
6590                 }
6591
6592                 public override Expression DoResolveLValue (EmitContext ec, Expression right_side)
6593                 {
6594                         if (!CommonResolve (ec))
6595                                 return null;
6596
6597                         Type right_type = right_side.Type;
6598
6599                         if (ilist == null)
6600                                 ilist = Indexers.GetIndexersForType (
6601                                         current_type, indexer_type, loc);
6602
6603                         if (ilist != null && ilist.setters != null && ilist.setters.Count > 0){
6604                                 set_arguments = (ArrayList) arguments.Clone ();
6605                                 set_arguments.Add (new Argument (right_side, Argument.AType.Expression));
6606
6607                                 set = (MethodInfo) Invocation.OverloadResolve (
6608                                         ec, new MethodGroupExpr (ilist.setters, loc), set_arguments, loc);
6609                         }
6610
6611                         if (set == null){
6612                                 Error (200, "indexer X.this [" + TypeManager.CSharpName (right_type) +
6613                                        "] lacks a `set' accessor");
6614                                 return null;
6615                         }
6616
6617                         type = TypeManager.void_type;
6618                         eclass = ExprClass.IndexerAccess;
6619                         return this;
6620                 }
6621
6622                 public override void Emit (EmitContext ec)
6623                 {
6624                         Invocation.EmitCall (ec, false, false, instance_expr, get, arguments, loc);
6625                 }
6626
6627                 //
6628                 // source is ignored, because we already have a copy of it from the
6629                 // LValue resolution and we have already constructed a pre-cached
6630                 // version of the arguments (ea.set_arguments);
6631                 //
6632                 public void EmitAssign (EmitContext ec, Expression source)
6633                 {
6634                         Invocation.EmitCall (ec, false, false, instance_expr, set, set_arguments, loc);
6635                 }
6636         }
6637
6638         /// <summary>
6639         ///   The base operator for method names
6640         /// </summary>
6641         public class BaseAccess : Expression {
6642                 string member;
6643
6644                 public BaseAccess (string member, Location l)
6645                 {
6646                         this.member = member;
6647                         loc = l;
6648                 }
6649
6650                 public override Expression DoResolve (EmitContext ec)
6651                 {
6652                         Expression member_lookup;
6653                         Type current_type = ec.ContainerType;
6654                         Type base_type = current_type.BaseType;
6655                         Expression e;
6656
6657                         if (ec.IsStatic){
6658                                 Error (1511, "Keyword base is not allowed in static method");
6659                                 return null;
6660                         }
6661
6662                         member_lookup = MemberLookup (ec, base_type, base_type, member,
6663                                                       AllMemberTypes, AllBindingFlags, loc);
6664                         if (member_lookup == null) {
6665                                 Error (117,
6666                                               TypeManager.CSharpName (base_type) + " does not " +
6667                                               "contain a definition for `" + member + "'");
6668                                 return null;
6669                         }
6670
6671                         Expression left;
6672
6673                         if (ec.IsStatic)
6674                                 left = new TypeExpr (base_type, loc);
6675                         else
6676                                 left = ec.This;
6677
6678                         e = MemberAccess.ResolveMemberAccess (ec, member_lookup, left, loc, null);
6679
6680                         if (e is PropertyExpr){
6681                                 PropertyExpr pe = (PropertyExpr) e;
6682
6683                                 pe.IsBase = true;
6684                         }
6685
6686                         return e;
6687                 }
6688
6689                 public override void Emit (EmitContext ec)
6690                 {
6691                         throw new Exception ("Should never be called");
6692                 }
6693         }
6694
6695         /// <summary>
6696         ///   The base indexer operator
6697         /// </summary>
6698         public class BaseIndexerAccess : IndexerAccess {
6699                 public BaseIndexerAccess (ArrayList args, Location loc)
6700                         : base (null, true, loc)
6701                 {
6702                         arguments = new ArrayList ();
6703                         foreach (Expression tmp in args)
6704                                 arguments.Add (new Argument (tmp, Argument.AType.Expression));
6705                 }
6706
6707                 protected override bool CommonResolve (EmitContext ec)
6708                 {
6709                         instance_expr = ec.This;
6710
6711                         current_type = ec.ContainerType.BaseType;
6712                         indexer_type = current_type;
6713
6714                         foreach (Argument a in arguments){
6715                                 if (!a.Resolve (ec, loc))
6716                                         return false;
6717                         }
6718
6719                         return true;
6720                 }
6721         }
6722
6723         /// <summary>
6724         ///   This class exists solely to pass the Type around and to be a dummy
6725         ///   that can be passed to the conversion functions (this is used by
6726         ///   foreach implementation to typecast the object return value from
6727         ///   get_Current into the proper type.  All code has been generated and
6728         ///   we only care about the side effect conversions to be performed
6729         ///
6730         ///   This is also now used as a placeholder where a no-action expression
6731         ///   is needed (the `New' class).
6732         /// </summary>
6733         public class EmptyExpression : Expression {
6734                 public EmptyExpression ()
6735                 {
6736                         type = TypeManager.object_type;
6737                         eclass = ExprClass.Value;
6738                         loc = Location.Null;
6739                 }
6740
6741                 public EmptyExpression (Type t)
6742                 {
6743                         type = t;
6744                         eclass = ExprClass.Value;
6745                         loc = Location.Null;
6746                 }
6747
6748                 public override Expression DoResolve (EmitContext ec)
6749                 {
6750                         return this;
6751                 }
6752
6753                 public override void Emit (EmitContext ec)
6754                 {
6755                         // nothing, as we only exist to not do anything.
6756                 }
6757
6758                 //
6759                 // This is just because we might want to reuse this bad boy
6760                 // instead of creating gazillions of EmptyExpressions.
6761                 // (CanConvertImplicit uses it)
6762                 //
6763                 public void SetType (Type t)
6764                 {
6765                         type = t;
6766                 }
6767         }
6768
6769         public class UserCast : Expression {
6770                 MethodBase method;
6771                 Expression source;
6772
6773                 public UserCast (MethodInfo method, Expression source, Location l)
6774                 {
6775                         this.method = method;
6776                         this.source = source;
6777                         type = method.ReturnType;
6778                         eclass = ExprClass.Value;
6779                         loc = l;
6780                 }
6781
6782                 public override Expression DoResolve (EmitContext ec)
6783                 {
6784                         //
6785                         // We are born fully resolved
6786                         //
6787                         return this;
6788                 }
6789
6790                 public override void Emit (EmitContext ec)
6791                 {
6792                         ILGenerator ig = ec.ig;
6793
6794                         source.Emit (ec);
6795
6796                         if (method is MethodInfo)
6797                                 ig.Emit (OpCodes.Call, (MethodInfo) method);
6798                         else
6799                                 ig.Emit (OpCodes.Call, (ConstructorInfo) method);
6800
6801                 }
6802         }
6803
6804         // <summary>
6805         //   This class is used to "construct" the type during a typecast
6806         //   operation.  Since the Type.GetType class in .NET can parse
6807         //   the type specification, we just use this to construct the type
6808         //   one bit at a time.
6809         // </summary>
6810         public class ComposedCast : Expression, ITypeExpression {
6811                 Expression left;
6812                 string dim;
6813
6814                 public ComposedCast (Expression left, string dim, Location l)
6815                 {
6816                         this.left = left;
6817                         this.dim = dim;
6818                         loc = l;
6819                 }
6820
6821                 public Expression DoResolveType (EmitContext ec)
6822                 {
6823                         Type ltype = ec.DeclSpace.ResolveType (left, false, loc);
6824                         if (ltype == null)
6825                                 return null;
6826
6827                         //
6828                         // ltype.Fullname is already fully qualified, so we can skip
6829                         // a lot of probes, and go directly to TypeManager.LookupType
6830                         //
6831                         string cname = ltype.FullName + dim;
6832                         type = TypeManager.LookupTypeDirect (cname);
6833                         if (type == null){
6834                                 //
6835                                 // For arrays of enumerations we are having a problem
6836                                 // with the direct lookup.  Need to investigate.
6837                                 //
6838                                 // For now, fall back to the full lookup in that case.
6839                                 //
6840                                 type = RootContext.LookupType (
6841                                         ec.DeclSpace, cname, false, loc);
6842
6843                                 if (type == null)
6844                                         return null;
6845                         }
6846
6847                         if (!ec.ResolvingTypeTree){
6848                                 //
6849                                 // If the above flag is set, this is being invoked from the ResolveType function.
6850                                 // Upper layers take care of the type validity in this context.
6851                                 //
6852                         if (!ec.InUnsafe && type.IsPointer){
6853                                 UnsafeError (loc);
6854                                 return null;
6855                         }
6856                         }
6857
6858                         eclass = ExprClass.Type;
6859                         return this;
6860                 }
6861
6862                 public override Expression DoResolve (EmitContext ec)
6863                 {
6864                         return DoResolveType (ec);
6865                 }
6866
6867                 public override void Emit (EmitContext ec)
6868                 {
6869                         throw new Exception ("This should never be called");
6870                 }
6871
6872                 public override string ToString ()
6873                 {
6874                         return left + dim;
6875                 }
6876         }
6877
6878         //
6879         // This class is used to represent the address of an array, used
6880         // only by the Fixed statement, this is like the C "&a [0]" construct.
6881         //
6882         public class ArrayPtr : Expression {
6883                 Expression array;
6884
6885                 public ArrayPtr (Expression array, Location l)
6886                 {
6887                         Type array_type = array.Type.GetElementType ();
6888
6889                         this.array = array;
6890
6891                         string array_ptr_type_name = array_type.FullName + "*";
6892
6893                         type = Type.GetType (array_ptr_type_name);
6894                         if (type == null){
6895                                 ModuleBuilder mb = CodeGen.ModuleBuilder;
6896
6897                                 type = mb.GetType (array_ptr_type_name);
6898                         }
6899
6900                         eclass = ExprClass.Value;
6901                         loc = l;
6902                 }
6903
6904                 public override void Emit (EmitContext ec)
6905                 {
6906                         ILGenerator ig = ec.ig;
6907
6908                         array.Emit (ec);
6909                         IntLiteral.EmitInt (ig, 0);
6910                         ig.Emit (OpCodes.Ldelema, array.Type.GetElementType ());
6911                 }
6912
6913                 public override Expression DoResolve (EmitContext ec)
6914                 {
6915                         //
6916                         // We are born fully resolved
6917                         //
6918                         return this;
6919                 }
6920         }
6921
6922         //
6923         // Used by the fixed statement
6924         //
6925         public class StringPtr : Expression {
6926                 LocalBuilder b;
6927
6928                 public StringPtr (LocalBuilder b, Location l)
6929                 {
6930                         this.b = b;
6931                         eclass = ExprClass.Value;
6932                         type = TypeManager.char_ptr_type;
6933                         loc = l;
6934                 }
6935
6936                 public override Expression DoResolve (EmitContext ec)
6937                 {
6938                         // This should never be invoked, we are born in fully
6939                         // initialized state.
6940
6941                         return this;
6942                 }
6943
6944                 public override void Emit (EmitContext ec)
6945                 {
6946                         ILGenerator ig = ec.ig;
6947
6948                         ig.Emit (OpCodes.Ldloc, b);
6949                         ig.Emit (OpCodes.Conv_I);
6950                         ig.Emit (OpCodes.Call, TypeManager.int_get_offset_to_string_data);
6951                         ig.Emit (OpCodes.Add);
6952                 }
6953         }
6954
6955         //
6956         // Implements the `stackalloc' keyword
6957         //
6958         public class StackAlloc : Expression {
6959                 Type otype;
6960                 Expression t;
6961                 Expression count;
6962
6963                 public StackAlloc (Expression type, Expression count, Location l)
6964                 {
6965                         t = type;
6966                         this.count = count;
6967                         loc = l;
6968                 }
6969
6970                 public override Expression DoResolve (EmitContext ec)
6971                 {
6972                         count = count.Resolve (ec);
6973                         if (count == null)
6974                                 return null;
6975
6976                         if (count.Type != TypeManager.int32_type){
6977                                 count = ConvertImplicitRequired (ec, count, TypeManager.int32_type, loc);
6978                                 if (count == null)
6979                                         return null;
6980                         }
6981
6982                         if (ec.InCatch || ec.InFinally){
6983                                 Error (255,
6984                                               "stackalloc can not be used in a catch or finally block");
6985                                 return null;
6986                         }
6987
6988                         otype = ec.DeclSpace.ResolveType (t, false, loc);
6989
6990                         if (otype == null)
6991                                 return null;
6992
6993                         if (!TypeManager.VerifyUnManaged (otype, loc))
6994                                 return null;
6995
6996                         string ptr_name = otype.FullName + "*";
6997                         type = Type.GetType (ptr_name);
6998                         if (type == null){
6999                                 ModuleBuilder mb = CodeGen.ModuleBuilder;
7000
7001                                 type = mb.GetType (ptr_name);
7002                         }
7003                         eclass = ExprClass.Value;
7004
7005                         return this;
7006                 }
7007
7008                 public override void Emit (EmitContext ec)
7009                 {
7010                         int size = GetTypeSize (otype);
7011                         ILGenerator ig = ec.ig;
7012
7013                         if (size == 0)
7014                                 ig.Emit (OpCodes.Sizeof, otype);
7015                         else
7016                                 IntConstant.EmitInt (ig, size);
7017                         count.Emit (ec);
7018                         ig.Emit (OpCodes.Mul);
7019                         ig.Emit (OpCodes.Localloc);
7020                 }
7021         }
7022 }