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                         //
4015                         // Next, evaluate all the expressions in the argument list
4016                         //
4017                         if (Arguments != null)
4018                         {
4019                                 foreach (Argument a in Arguments)
4020                                 {
4021                                         if ((a.ArgType == Argument.AType.NoArg) && (!(expr is MethodGroupExpr)))
4022                                                 Report.Error (999, "This item cannot have empty arguments");
4023
4024                                         if (!a.Resolve (ec, loc))
4025                                                 return null;
4026                                 }
4027                         }
4028
4029                         if (expr is MethodGroupExpr)
4030                         {
4031                                 MethodGroupExpr mg = (MethodGroupExpr) expr;
4032                                 method = OverloadResolve (ec, mg, ref Arguments, loc);
4033
4034                                 if (method == null)
4035                                 {
4036                                         Error (-6,
4037                                                 "Could not find any applicable function for this argument list");
4038                                         return null;
4039                                 }
4040
4041                                 if ((method as MethodInfo) != null)
4042                                 {
4043                                         MethodInfo mi = method as MethodInfo;
4044                                         type = TypeManager.TypeToCoreType (mi.ReturnType);
4045                                         if (!mi.IsStatic && !mg.IsExplicitImpl && (mg.InstanceExpression == null))
4046                                                 SimpleName.Error_ObjectRefRequired (ec, loc, mi.Name);
4047                                 }
4048
4049                                 if ((method as ConstructorInfo) != null)
4050                                 {
4051                                         ConstructorInfo ci = method as ConstructorInfo;
4052                                         type = TypeManager.void_type;
4053                                         if (!ci.IsStatic && !mg.IsExplicitImpl && (mg.InstanceExpression == null))
4054                                                 SimpleName.Error_ObjectRefRequired (ec, loc, ci.Name);
4055                                 }
4056
4057                                 if (type.IsPointer)
4058                                 {
4059                                         if (!ec.InUnsafe)
4060                                         {
4061                                                 UnsafeError (loc);
4062                                                 return null;
4063                                         }
4064                                 }
4065                                 eclass = ExprClass.Value;
4066                                 expr_to_return = this;
4067                         }
4068
4069                         if (expr is PropertyExpr)
4070                         {
4071                                 PropertyExpr pe = ((PropertyExpr) expr);
4072                                 pe.PropertyArgs = (ArrayList) Arguments.Clone();
4073                                 Arguments.Clear();
4074                                 Arguments = new ArrayList();
4075                                 MethodBase mi = pe.PropertyInfo.GetGetMethod(true);
4076
4077                                 if(VerifyArgumentsCompat (ec, pe.PropertyArgs,
4078                                         pe.PropertyArgs.Count, mi, false, null, loc, pe.Name))
4079                                 {
4080
4081                                         expr_to_return = pe.DoResolve (ec);
4082                                         expr_to_return.eclass = ExprClass.PropertyAccess;
4083                                 }
4084                         }
4085
4086                         if (expr is FieldExpr || expr is LocalVariableReference) {
4087                                 // If we are here, expr must be an ArrayAccess
4088                                 // FIXME: we should check dimensions, etc.
4089                                 ArrayList idxs = new ArrayList();
4090                                 foreach (Argument a in Arguments)
4091                                 {
4092                                         idxs.Add (a.Expr);
4093                                 }
4094                                 ElementAccess ea = new ElementAccess (expr, idxs, expr.Location);
4095                                 ArrayAccess aa = new ArrayAccess (ea, expr.Location);
4096                                 expr_to_return = aa.DoResolve(ec);
4097                                 expr_to_return.eclass = ExprClass.Variable;
4098                         }
4099
4100                         return expr_to_return;
4101                 }
4102
4103                 // <summary>
4104                 //   Emits the list of arguments as an array
4105                 // </summary>
4106                 static void EmitParams (EmitContext ec, int idx, ArrayList arguments)
4107                 {
4108                         ILGenerator ig = ec.ig;
4109                         int count = arguments.Count - idx;
4110                         Argument a = (Argument) arguments [idx];
4111                         Type t = a.Expr.Type;
4112                         string array_type = t.FullName + "[]";
4113                         LocalBuilder array;
4114
4115                         array = ig.DeclareLocal (TypeManager.LookupType (array_type));
4116                         IntConstant.EmitInt (ig, count);
4117                         ig.Emit (OpCodes.Newarr, TypeManager.TypeToCoreType (t));
4118                         ig.Emit (OpCodes.Stloc, array);
4119
4120                         int top = arguments.Count;
4121                         for (int j = idx; j < top; j++){
4122                                 a = (Argument) arguments [j];
4123
4124                                 ig.Emit (OpCodes.Ldloc, array);
4125                                 IntConstant.EmitInt (ig, j - idx);
4126                                 a.Emit (ec);
4127
4128                                 ArrayAccess.EmitStoreOpcode (ig, t);
4129                         }
4130                         ig.Emit (OpCodes.Ldloc, array);
4131                 }
4132
4133                 /// <summary>
4134                 ///   Emits a list of resolved Arguments that are in the arguments
4135                 ///   ArrayList.
4136                 ///
4137                 ///   The MethodBase argument might be null if the
4138                 ///   emission of the arguments is known not to contain
4139                 ///   a `params' field (for example in constructors or other routines
4140                 ///   that keep their arguments in this structure)
4141                 /// </summary>
4142                 public static void EmitArguments (EmitContext ec, MethodBase mb, ArrayList arguments)
4143                 {
4144                         ParameterData pd;
4145                         if (mb != null)
4146                                 pd = GetParameterData (mb);
4147                         else
4148                                 pd = null;
4149
4150                         //
4151                         // If we are calling a params method with no arguments, special case it
4152                         //
4153                         if (arguments == null){
4154                                 if (pd != null && pd.Count > 0 &&
4155                                     pd.ParameterModifier (0) == Parameter.Modifier.PARAMS){
4156                                         ILGenerator ig = ec.ig;
4157
4158                                         IntConstant.EmitInt (ig, 0);
4159                                         ig.Emit (OpCodes.Newarr, pd.ParameterType (0).GetElementType ());
4160                                 }
4161                                 return;
4162                         }
4163
4164                         int top = arguments.Count;
4165
4166                         for (int i = 0; i < top; i++){
4167                                 Argument a = (Argument) arguments [i];
4168
4169                                 if (pd != null){
4170                                         if (pd.ParameterModifier (i) == Parameter.Modifier.PARAMS){
4171                                                 //
4172                                                 // Special case if we are passing the same data as the
4173                                                 // params argument, do not put it in an array.
4174                                                 //
4175                                                 if (pd.ParameterType (i) == a.Type)
4176                                                         a.Emit (ec);
4177                                                 else
4178                                                         EmitParams (ec, i, arguments);
4179                                                 return;
4180                                         }
4181                                 }
4182
4183                                 a.Emit (ec);
4184                         }
4185
4186                         if (pd != null && pd.Count > top &&
4187                             pd.ParameterModifier (top) == Parameter.Modifier.PARAMS){
4188                                 ILGenerator ig = ec.ig;
4189
4190                                 IntConstant.EmitInt (ig, 0);
4191                                 ig.Emit (OpCodes.Newarr, pd.ParameterType (top).GetElementType ());
4192                         }
4193                 }
4194
4195                 /// <remarks>
4196                 ///   is_base tells whether we want to force the use of the `call'
4197                 ///   opcode instead of using callvirt.  Call is required to call
4198                 ///   a specific method, while callvirt will always use the most
4199                 ///   recent method in the vtable.
4200                 ///
4201                 ///   is_static tells whether this is an invocation on a static method
4202                 ///
4203                 ///   instance_expr is an expression that represents the instance
4204                 ///   it must be non-null if is_static is false.
4205                 ///
4206                 ///   method is the method to invoke.
4207                 ///
4208                 ///   Arguments is the list of arguments to pass to the method or constructor.
4209                 /// </remarks>
4210                 public static void EmitCall (EmitContext ec, bool is_base,
4211                                              bool is_static, Expression instance_expr,
4212                                              MethodBase method, ArrayList Arguments, Location loc)
4213                 {
4214                         EmitCall (ec, is_base, is_static, instance_expr, method, Arguments, null, loc);
4215                 }
4216
4217                 public static void EmitCall (EmitContext ec, bool is_base,
4218                         bool is_static, Expression instance_expr,
4219                         MethodBase method, ArrayList Arguments, ArrayList prop_args, Location loc)
4220                 {
4221                         ILGenerator ig = ec.ig;
4222                         bool struct_call = false;
4223
4224                         Type decl_type = method.DeclaringType;
4225
4226                         if (!RootContext.StdLib)
4227                         {
4228                                 // Replace any calls to the system's System.Array type with calls to
4229                                 // the newly created one.
4230                                 if (method == TypeManager.system_int_array_get_length)
4231                                         method = TypeManager.int_array_get_length;
4232                                 else if (method == TypeManager.system_int_array_get_rank)
4233                                         method = TypeManager.int_array_get_rank;
4234                                 else if (method == TypeManager.system_object_array_clone)
4235                                         method = TypeManager.object_array_clone;
4236                                 else if (method == TypeManager.system_int_array_get_length_int)
4237                                         method = TypeManager.int_array_get_length_int;
4238                                 else if (method == TypeManager.system_int_array_get_lower_bound_int)
4239                                         method = TypeManager.int_array_get_lower_bound_int;
4240                                 else if (method == TypeManager.system_int_array_get_upper_bound_int)
4241                                         method = TypeManager.int_array_get_upper_bound_int;
4242                                 else if (method == TypeManager.system_void_array_copyto_array_int)
4243                                         method = TypeManager.void_array_copyto_array_int;
4244                         }
4245
4246                         //
4247                         // This checks the `ConditionalAttribute' on the method, and the
4248                         // ObsoleteAttribute
4249                         //
4250                         TypeManager.MethodFlags flags = TypeManager.GetMethodFlags (method, loc);
4251                         if ((flags & TypeManager.MethodFlags.IsObsoleteError) != 0)
4252                                 return;
4253                         if ((flags & TypeManager.MethodFlags.ShouldIgnore) != 0)
4254                                 return;
4255
4256                         if (!is_static)
4257                         {
4258                                 if (decl_type.IsValueType)
4259                                         struct_call = true;
4260                                 //
4261                                 // If this is ourselves, push "this"
4262                                 //
4263                                 if (instance_expr == null)
4264                                 {
4265                                         ig.Emit (OpCodes.Ldarg_0);
4266                                 }
4267                                 else
4268                                 {
4269                                         //
4270                                         // Push the instance expression
4271                                         //
4272                                         if (instance_expr.Type.IsValueType)
4273                                         {
4274                                                 //
4275                                                 // Special case: calls to a function declared in a
4276                                                 // reference-type with a value-type argument need
4277                                                 // to have their value boxed.
4278
4279                                                 struct_call = true;
4280                                                 if (decl_type.IsValueType)
4281                                                 {
4282                                                         //
4283                                                         // If the expression implements IMemoryLocation, then
4284                                                         // we can optimize and use AddressOf on the
4285                                                         // return.
4286                                                         //
4287                                                         // If not we have to use some temporary storage for
4288                                                         // it.
4289                                                         if (instance_expr is IMemoryLocation)
4290                                                         {
4291                                                                 ((IMemoryLocation)instance_expr).
4292                                                                         AddressOf (ec, AddressOp.LoadStore);
4293                                                         }
4294                                                         else
4295                                                         {
4296                                                                 Type t = instance_expr.Type;
4297
4298                                                                 instance_expr.Emit (ec);
4299                                                                 LocalBuilder temp = ig.DeclareLocal (t);
4300                                                                 ig.Emit (OpCodes.Stloc, temp);
4301                                                                 ig.Emit (OpCodes.Ldloca, temp);
4302                                                         }
4303                                                 }
4304                                                 else
4305                                                 {
4306                                                         instance_expr.Emit (ec);
4307                                                         ig.Emit (OpCodes.Box, instance_expr.Type);
4308                                                 }
4309                                         }
4310                                         else
4311                                                 instance_expr.Emit (ec);
4312                                 }
4313                         }
4314
4315                         if (prop_args != null && prop_args.Count > 0)
4316                         {
4317                                 if (Arguments == null)
4318                                         Arguments = new ArrayList();
4319
4320                                 for (int i = prop_args.Count-1; i >=0 ; i--)
4321                                 {
4322                                         Arguments.Insert (0,prop_args[i]);
4323                                 }
4324
4325                         }
4326
4327                         EmitArguments (ec, method, Arguments);
4328
4329                         if (is_static || struct_call || is_base)
4330                         {
4331                                 if (method is MethodInfo)
4332                                 {
4333                                         ig.Emit (OpCodes.Call, (MethodInfo) method);
4334                                 }
4335                                 else
4336                                         ig.Emit (OpCodes.Call, (ConstructorInfo) method);
4337                         }
4338                         else
4339                         {
4340                                 if (method is MethodInfo)
4341                                         ig.Emit (OpCodes.Callvirt, (MethodInfo) method);
4342                                 else
4343                                         ig.Emit (OpCodes.Callvirt, (ConstructorInfo) method);
4344                         }
4345                 }
4346
4347                 static void EmitPropertyArgs (EmitContext ec, ArrayList prop_args)
4348                 {
4349                         int top = prop_args.Count;
4350
4351                         for (int i = 0; i < top; i++)
4352                         {
4353                                 Argument a = (Argument) prop_args [i];
4354                                 a.Emit (ec);
4355                         }
4356                 }
4357
4358                 public override void Emit (EmitContext ec)
4359                 {
4360                         MethodGroupExpr mg = (MethodGroupExpr) this.expr;
4361
4362                         EmitCall (
4363                                 ec, is_base, method.IsStatic, mg.InstanceExpression, method, Arguments, loc);
4364                 }
4365
4366                 public override void EmitStatement (EmitContext ec)
4367                 {
4368                         Emit (ec);
4369
4370                         //
4371                         // Pop the return value if there is one
4372                         //
4373                         if (method is MethodInfo){
4374                                 Type ret = ((MethodInfo)method).ReturnType;
4375                                 if (TypeManager.TypeToCoreType (ret) != TypeManager.void_type)
4376                                         ec.ig.Emit (OpCodes.Pop);
4377                         }
4378                 }
4379         }
4380
4381         //
4382         // This class is used to "disable" the code generation for the
4383         // temporary variable when initializing value types.
4384         //
4385         class EmptyAddressOf : EmptyExpression, IMemoryLocation {
4386                 public void AddressOf (EmitContext ec, AddressOp Mode)
4387                 {
4388                         // nothing
4389                 }
4390         }
4391
4392         /// <summary>
4393         ///    Implements the new expression
4394         /// </summary>
4395         public class New : ExpressionStatement {
4396                 public readonly ArrayList Arguments;
4397                 public readonly Expression RequestedType;
4398
4399                 MethodBase method = null;
4400
4401                 //
4402                 // If set, the new expression is for a value_target, and
4403                 // we will not leave anything on the stack.
4404                 //
4405                 Expression value_target;
4406                 bool value_target_set = false;
4407
4408                 public New (Expression requested_type, ArrayList arguments, Location l)
4409                 {
4410                         RequestedType = requested_type;
4411                         Arguments = arguments;
4412                         loc = l;
4413                 }
4414
4415                 public Expression ValueTypeVariable {
4416                         get {
4417                                 return value_target;
4418                         }
4419
4420                         set {
4421                                 value_target = value;
4422                                 value_target_set = true;
4423                         }
4424                 }
4425
4426                 //
4427                 // This function is used to disable the following code sequence for
4428                 // value type initialization:
4429                 //
4430                 // AddressOf (temporary)
4431                 // Construct/Init
4432                 // LoadTemporary
4433                 //
4434                 // Instead the provide will have provided us with the address on the
4435                 // stack to store the results.
4436                 //
4437                 static Expression MyEmptyExpression;
4438
4439                 public void DisableTemporaryValueType ()
4440                 {
4441                         if (MyEmptyExpression == null)
4442                                 MyEmptyExpression = new EmptyAddressOf ();
4443
4444                         //
4445                         // To enable this, look into:
4446                         // test-34 and test-89 and self bootstrapping.
4447                         //
4448                         // For instance, we can avoid a copy by using `newobj'
4449                         // instead of Call + Push-temp on value types.
4450 //                      value_target = MyEmptyExpression;
4451                 }
4452
4453                 public override Expression DoResolve (EmitContext ec)
4454                 {
4455                         type = ec.DeclSpace.ResolveType (RequestedType, false, loc);
4456
4457                         if (type == null)
4458                                 return null;
4459
4460                         bool IsDelegate = TypeManager.IsDelegateType (type);
4461
4462                         if (IsDelegate)
4463                                 return (new NewDelegate (type, Arguments, loc)).Resolve (ec);
4464
4465                         if (type.IsInterface || type.IsAbstract){
4466                                 Error (
4467                                         144, "It is not possible to create instances of interfaces " +
4468                                         "or abstract classes");
4469                                 return null;
4470                         }
4471
4472                         bool is_struct = false;
4473                         is_struct = type.IsValueType;
4474                         eclass = ExprClass.Value;
4475
4476                         //
4477                         // SRE returns a match for .ctor () on structs (the object constructor),
4478                         // so we have to manually ignore it.
4479                         //
4480                         if (is_struct && Arguments == null)
4481                                 return this;
4482
4483                         Expression ml;
4484                         ml = MemberLookupFinal (ec, type, ".ctor",
4485                                                 MemberTypes.Constructor,
4486                                                 AllBindingFlags | BindingFlags.Public, loc);
4487
4488                         if (ml == null)
4489                                 return null;
4490
4491                         if (! (ml is MethodGroupExpr)){
4492                                 if (!is_struct){
4493                                         ml.Error118 ("method group");
4494                                         return null;
4495                                 }
4496                         }
4497
4498                         if (ml != null) {
4499                                 if (Arguments != null){
4500                                         foreach (Argument a in Arguments){
4501                                                 if (!a.Resolve (ec, loc))
4502                                                         return null;
4503                                         }
4504                                 }
4505
4506                                 method = Invocation.OverloadResolve (ec, (MethodGroupExpr) ml,
4507                                                                      Arguments, loc);
4508
4509                         }
4510
4511                         if (method == null) {
4512                                 if (!is_struct || Arguments.Count > 0) {
4513                                         Error (1501,
4514                                                "New invocation: Can not find a constructor for " +
4515                                                "this argument list");
4516                                         return null;
4517                                 }
4518                         }
4519                         return this;
4520                 }
4521
4522                 //
4523                 // This DoEmit can be invoked in two contexts:
4524                 //    * As a mechanism that will leave a value on the stack (new object)
4525                 //    * As one that wont (init struct)
4526                 //
4527                 // You can control whether a value is required on the stack by passing
4528                 // need_value_on_stack.  The code *might* leave a value on the stack
4529                 // so it must be popped manually
4530                 //
4531                 // If we are dealing with a ValueType, we have a few
4532                 // situations to deal with:
4533                 //
4534                 //    * The target is a ValueType, and we have been provided
4535                 //      the instance (this is easy, we are being assigned).
4536                 //
4537                 //    * The target of New is being passed as an argument,
4538                 //      to a boxing operation or a function that takes a
4539                 //      ValueType.
4540                 //
4541                 //      In this case, we need to create a temporary variable
4542                 //      that is the argument of New.
4543                 //
4544                 // Returns whether a value is left on the stack
4545                 //
4546                 bool DoEmit (EmitContext ec, bool need_value_on_stack)
4547                 {
4548                         bool is_value_type = type.IsValueType;
4549                         ILGenerator ig = ec.ig;
4550
4551                         if (is_value_type){
4552                                 IMemoryLocation ml;
4553
4554                                 // Allow DoEmit() to be called multiple times.
4555                                 // We need to create a new LocalTemporary each time since
4556                                 // you can't share LocalBuilders among ILGeneators.
4557                                 if (!value_target_set)
4558                                         value_target = new LocalTemporary (ec, type);
4559
4560                                 ml = (IMemoryLocation) value_target;
4561                                 ml.AddressOf (ec, AddressOp.Store);
4562                         }
4563
4564                         if (method != null)
4565                                 Invocation.EmitArguments (ec, method, Arguments);
4566
4567                         if (is_value_type){
4568                                 if (method == null)
4569                                         ig.Emit (OpCodes.Initobj, type);
4570                                 else
4571                                         ig.Emit (OpCodes.Call, (ConstructorInfo) method);
4572                                 if (need_value_on_stack){
4573                                         value_target.Emit (ec);
4574                                         return true;
4575                                 }
4576                                 return false;
4577                         } else {
4578                                 ig.Emit (OpCodes.Newobj, (ConstructorInfo) method);
4579                                 return true;
4580                         }
4581                 }
4582
4583                 public override void Emit (EmitContext ec)
4584                 {
4585                         DoEmit (ec, true);
4586                 }
4587
4588                 public override void EmitStatement (EmitContext ec)
4589                 {
4590                         if (DoEmit (ec, false))
4591                                 ec.ig.Emit (OpCodes.Pop);
4592                 }
4593         }
4594
4595         /// <summary>
4596         ///   14.5.10.2: Represents an array creation expression.
4597         /// </summary>
4598         ///
4599         /// <remarks>
4600         ///   There are two possible scenarios here: one is an array creation
4601         ///   expression that specifies the dimensions and optionally the
4602         ///   initialization data and the other which does not need dimensions
4603         ///   specified but where initialization data is mandatory.
4604         /// </remarks>
4605         public class ArrayCreation : ExpressionStatement {
4606                 Expression requested_base_type;
4607                 ArrayList initializers;
4608
4609                 //
4610                 // The list of Argument types.
4611                 // This is used to construct the `newarray' or constructor signature
4612                 //
4613                 ArrayList arguments;
4614
4615                 //
4616                 // Method used to create the array object.
4617                 //
4618                 MethodBase new_method = null;
4619
4620                 Type array_element_type;
4621                 Type underlying_type;
4622                 bool is_one_dimensional = false;
4623                 bool is_builtin_type = false;
4624                 bool expect_initializers = false;
4625                 int num_arguments = 0;
4626                 int dimensions = 0;
4627                 string rank;
4628
4629                 ArrayList array_data;
4630
4631                 Hashtable bounds;
4632
4633                 //
4634                 // The number of array initializers that we can handle
4635                 // via the InitializeArray method - through EmitStaticInitializers
4636                 //
4637                 int num_automatic_initializers;
4638
4639                 public ArrayCreation (Expression requested_base_type, ArrayList exprs, string rank, ArrayList initializers, Location l)
4640                 {
4641                         this.requested_base_type = requested_base_type;
4642                         this.initializers = initializers;
4643                         this.rank = rank;
4644                         loc = l;
4645
4646                         arguments = new ArrayList ();
4647
4648                         foreach (Expression e in exprs) {
4649                                 arguments.Add (new Argument (e, Argument.AType.Expression));
4650                                 num_arguments++;
4651                         }
4652                 }
4653
4654                 public ArrayCreation (Expression requested_base_type, string rank, ArrayList initializers, Location l)
4655                 {
4656                         this.requested_base_type = requested_base_type;
4657                         this.initializers = initializers;
4658                         this.rank = rank;
4659                         loc = l;
4660
4661                         //this.rank = rank.Substring (0, rank.LastIndexOf ("["));
4662                         //
4663                         //string tmp = rank.Substring (rank.LastIndexOf ("["));
4664                         //
4665                         //dimensions = tmp.Length - 1;
4666                         expect_initializers = true;
4667                 }
4668
4669                 public Expression FormArrayType (Expression base_type, int idx_count, string rank)
4670                 {
4671                         StringBuilder sb = new StringBuilder (rank);
4672
4673                         sb.Append ("[");
4674                         for (int i = 1; i < idx_count; i++)
4675                                 sb.Append (",");
4676
4677                         sb.Append ("]");
4678
4679                         return new ComposedCast (base_type, sb.ToString (), loc);
4680                 }
4681
4682                 void Error_IncorrectArrayInitializer ()
4683                 {
4684                         Error (178, "Incorrectly structured array initializer");
4685                 }
4686
4687                 public bool CheckIndices (EmitContext ec, ArrayList probe, int idx, bool specified_dims)
4688                 {
4689                         if (specified_dims) {
4690                                 Console.WriteLine  ("specified_dims");
4691                                 Argument a = (Argument) arguments [idx];
4692
4693                                 if (!a.Resolve (ec, loc))
4694                                         return false;
4695
4696                                 if (!(a.Expr is Constant)) {
4697                                         Error (150, "A constant value is expected");
4698                                         return false;
4699                                 }
4700
4701                                 int value = (int) ((Constant) a.Expr).GetValue ();
4702
4703                                 if (value != probe.Count) {
4704                                         Error_IncorrectArrayInitializer ();
4705                                         return false;
4706                                 }
4707
4708                                 bounds [idx] = value;
4709                         }
4710
4711                         int child_bounds = -1;
4712                         foreach (object o in probe) {
4713                                 if (o is ArrayList) {
4714                                         int current_bounds = ((ArrayList) o).Count;
4715
4716                                         if (child_bounds == -1)
4717                                                 child_bounds = current_bounds;
4718
4719                                         else if (child_bounds != current_bounds){
4720                                                 Error_IncorrectArrayInitializer ();
4721                                                 return false;
4722                                         }
4723                                         bool ret = CheckIndices (ec, (ArrayList) o, idx + 1, specified_dims);
4724                                         if (!ret)
4725                                                 return false;
4726                                 } else {
4727                                         if (child_bounds != -1){
4728                                                 Error_IncorrectArrayInitializer ();
4729                                                 return false;
4730                                         }
4731
4732                                         Expression tmp = (Expression) o;
4733                                         tmp = tmp.Resolve (ec);
4734                                         if (tmp == null)
4735                                                 continue;
4736
4737                                         // Console.WriteLine ("I got: " + tmp);
4738                                         // Handle initialization from vars, fields etc.
4739
4740                                         Expression conv = ConvertImplicitRequired (
4741                                                 ec, tmp, underlying_type, loc);
4742
4743                                         if (conv == null)
4744                                                 return false;
4745
4746                                         if (conv is StringConstant)
4747                                                 array_data.Add (conv);
4748                                         else if (conv is Constant) {
4749                                                 array_data.Add (conv);
4750                                                 num_automatic_initializers++;
4751                                         } else
4752                                                 array_data.Add (conv);
4753                                 }
4754                         }
4755
4756                         return true;
4757                 }
4758
4759                 public void UpdateIndices (EmitContext ec)
4760                 {
4761                         int i = 0;
4762                         for (ArrayList probe = initializers; probe != null;) {
4763                                 if (probe.Count > 0 && probe [0] is ArrayList) {
4764                                         Expression e = new IntConstant (probe.Count);
4765                                         arguments.Add (new Argument (e, Argument.AType.Expression));
4766
4767                                         bounds [i++] =  probe.Count;
4768
4769                                         probe = (ArrayList) probe [0];
4770
4771                                 } else {
4772                                         Expression e = new IntConstant (probe.Count);
4773                                         arguments.Add (new Argument (e, Argument.AType.Expression));
4774
4775                                         bounds [i++] = probe.Count;
4776                                         probe = null;
4777                                 }
4778                         }
4779
4780                 }
4781
4782                 public bool ValidateInitializers (EmitContext ec, Type array_type)
4783                 {
4784                         if (initializers == null) {
4785                                 if (expect_initializers)
4786                                         return false;
4787                                 else
4788                                         return true;
4789                         }
4790
4791                         if (underlying_type == null)
4792                                 return false;
4793
4794                         //
4795                         // We use this to store all the date values in the order in which we
4796                         // will need to store them in the byte blob later
4797                         //
4798                         array_data = new ArrayList ();
4799                         bounds = new Hashtable ();
4800
4801                         bool ret;
4802
4803                         if (arguments != null) {
4804                                 ret = CheckIndices (ec, initializers, 0, true);
4805                                 return ret;
4806                         } else {
4807                                 arguments = new ArrayList ();
4808
4809                                 ret = CheckIndices (ec, initializers, 0, false);
4810
4811                                 if (!ret)
4812                                         return false;
4813
4814                                 UpdateIndices (ec);
4815
4816                                 if (arguments.Count != dimensions) {
4817                                         Error_IncorrectArrayInitializer ();
4818                                         return false;
4819                                 }
4820
4821                                 return ret;
4822                         }
4823                 }
4824
4825                 void Error_NegativeArrayIndex ()
4826                 {
4827                         Error (284, "Can not create array with a negative size");
4828                 }
4829
4830                 //
4831                 // Converts `source' to an int, uint, long or ulong.
4832                 //
4833                 Expression ExpressionToArrayArgument (EmitContext ec, Expression source)
4834                 {
4835                         Expression target;
4836
4837                         bool old_checked = ec.CheckState;
4838                         ec.CheckState = true;
4839
4840                         target = ConvertImplicit (ec, source, TypeManager.int32_type, loc);
4841                         if (target == null){
4842                                 target = ConvertImplicit (ec, source, TypeManager.uint32_type, loc);
4843                                 if (target == null){
4844                                         target = ConvertImplicit (ec, source, TypeManager.int64_type, loc);
4845                                         if (target == null){
4846                                                 target = ConvertImplicit (ec, source, TypeManager.uint64_type, loc);
4847                                                 if (target == null)
4848                                                         Expression.Error_CannotConvertImplicit (loc, source.Type, TypeManager.int32_type);
4849                                         }
4850                                 }
4851                         }
4852                         ec.CheckState = old_checked;
4853
4854                         //
4855                         // Only positive constants are allowed at compile time
4856                         //
4857                         if (target is Constant){
4858                                 if (target is IntConstant){
4859                                         if (((IntConstant) target).Value < 0){
4860                                                 Error_NegativeArrayIndex ();
4861                                                 return null;
4862                                         }
4863                                 }
4864
4865                                 if (target is LongConstant){
4866                                         if (((LongConstant) target).Value < 0){
4867                                                 Error_NegativeArrayIndex ();
4868                                                 return null;
4869                                         }
4870                                 }
4871
4872                         }
4873
4874                         return target;
4875                 }
4876
4877                 //
4878                 // Creates the type of the array
4879                 //
4880                 bool LookupType (EmitContext ec)
4881                 {
4882                         StringBuilder array_qualifier = new StringBuilder (rank);
4883
4884                         //
4885                         // `In the first form allocates an array instace of the type that results
4886                         // from deleting each of the individual expression from the expression list'
4887                         //
4888                         if (num_arguments > 0) {
4889                                 array_qualifier.Append ("[");
4890                                 for (int i = num_arguments-1; i > 0; i--)
4891                                         array_qualifier.Append (",");
4892                                 array_qualifier.Append ("]");
4893                         }
4894
4895                         //
4896                         // Lookup the type
4897                         //
4898                         Expression array_type_expr;
4899                         array_type_expr = new ComposedCast (requested_base_type, array_qualifier.ToString (), loc);
4900                         type = ec.DeclSpace.ResolveType (array_type_expr, false, loc);
4901
4902                         if (type == null)
4903                                 return false;
4904
4905                         underlying_type = type;
4906                         if (underlying_type.IsArray)
4907                                 underlying_type = TypeManager.TypeToCoreType (underlying_type.GetElementType ());
4908                         dimensions = type.GetArrayRank ();
4909
4910                         return true;
4911                 }
4912
4913                 public override Expression DoResolve (EmitContext ec)
4914                 {
4915                         int arg_count;
4916
4917                         if (!LookupType (ec))
4918                                 return null;
4919
4920                         //
4921                         // First step is to validate the initializers and fill
4922                         // in any missing bits
4923                         //
4924                         if (!ValidateInitializers (ec, type))
4925                                 return null;
4926
4927                         if (arguments == null)
4928                                 arg_count = 0;
4929                         else {
4930                                 arg_count = arguments.Count;
4931                                 foreach (Argument a in arguments){
4932                                         if (!a.Resolve (ec, loc))
4933                                                 return null;
4934
4935                                         Expression real_arg = ExpressionToArrayArgument (ec, a.Expr, loc);
4936                                         if (real_arg == null)
4937                                                 return null;
4938
4939                                         a.Expr = real_arg;
4940                                 }
4941                         }
4942
4943                         array_element_type = TypeManager.TypeToCoreType (type.GetElementType ());
4944
4945                         if (arg_count == 1) {
4946                                 is_one_dimensional = true;
4947                                 eclass = ExprClass.Value;
4948                                 return this;
4949                         }
4950
4951                         is_builtin_type = TypeManager.IsBuiltinType (type);
4952
4953                         if (is_builtin_type) {
4954                                 Expression ml;
4955
4956                                 ml = MemberLookup (ec, type, ".ctor", MemberTypes.Constructor,
4957                                                    AllBindingFlags, loc);
4958
4959                                 if (!(ml is MethodGroupExpr)) {
4960                                         ml.Error118 ("method group");
4961                                         return null;
4962                                 }
4963
4964                                 if (ml == null) {
4965                                         Error (-6, "New invocation: Can not find a constructor for " +
4966                                                       "this argument list");
4967                                         return null;
4968                                 }
4969
4970                                 new_method = Invocation.OverloadResolve (ec, (MethodGroupExpr) ml, arguments, loc);
4971
4972                                 if (new_method == null) {
4973                                         Error (-6, "New invocation: Can not find a constructor for " +
4974                                                       "this argument list");
4975                                         return null;
4976                                 }
4977
4978                                 eclass = ExprClass.Value;
4979                                 return this;
4980                         } else {
4981                                 ModuleBuilder mb = CodeGen.ModuleBuilder;
4982                                 ArrayList args = new ArrayList ();
4983
4984                                 if (arguments != null) {
4985                                         for (int i = 0; i < arg_count; i++)
4986                                                 args.Add (TypeManager.int32_type);
4987                                 }
4988
4989                                 Type [] arg_types = null;
4990
4991                                 if (args.Count > 0)
4992                                         arg_types = new Type [args.Count];
4993
4994                                 args.CopyTo (arg_types, 0);
4995
4996                                 new_method = mb.GetArrayMethod (type, ".ctor", CallingConventions.HasThis, null,
4997                                                             arg_types);
4998
4999                                 if (new_method == null) {
5000                                         Error (-6, "New invocation: Can not find a constructor for " +
5001                                                       "this argument list");
5002                                         return null;
5003                                 }
5004
5005                                 eclass = ExprClass.Value;
5006                                 return this;
5007                         }
5008                 }
5009
5010                 public static byte [] MakeByteBlob (ArrayList array_data, Type underlying_type, Location loc)
5011                 {
5012                         int factor;
5013                         byte [] data;
5014                         byte [] element;
5015                         int count = array_data.Count;
5016
5017                         if (underlying_type.IsEnum)
5018                                 underlying_type = TypeManager.EnumToUnderlying (underlying_type);
5019
5020                         factor = GetTypeSize (underlying_type);
5021                         if (factor == 0)
5022                                 throw new Exception ("unrecognized type in MakeByteBlob: " + underlying_type);
5023
5024                         data = new byte [(count * factor + 4) & ~3];
5025                         int idx = 0;
5026
5027                         for (int i = 0; i < count; ++i) {
5028                                 object v = array_data [i];
5029
5030                                 if (v is EnumConstant)
5031                                         v = ((EnumConstant) v).Child;
5032
5033                                 if (v is Constant && !(v is StringConstant))
5034                                         v = ((Constant) v).GetValue ();
5035                                 else {
5036                                         idx += factor;
5037                                         continue;
5038                                 }
5039
5040                                 if (underlying_type == TypeManager.int64_type){
5041                                         if (!(v is Expression)){
5042                                                 long val = (long) v;
5043
5044                                                 for (int j = 0; j < factor; ++j) {
5045                                                         data [idx + j] = (byte) (val & 0xFF);
5046                                                         val = (val >> 8);
5047                                                 }
5048                                         }
5049                                 } else if (underlying_type == TypeManager.uint64_type){
5050                                         if (!(v is Expression)){
5051                                                 ulong val = (ulong) v;
5052
5053                                                 for (int j = 0; j < factor; ++j) {
5054                                                         data [idx + j] = (byte) (val & 0xFF);
5055                                                         val = (val >> 8);
5056                                                 }
5057                                         }
5058                                 } else if (underlying_type == TypeManager.float_type) {
5059                                         if (!(v is Expression)){
5060                                                 element = BitConverter.GetBytes ((float) v);
5061
5062                                                 for (int j = 0; j < factor; ++j)
5063                                                         data [idx + j] = element [j];
5064                                         }
5065                                 } else if (underlying_type == TypeManager.double_type) {
5066                                         if (!(v is Expression)){
5067                                                 element = BitConverter.GetBytes ((double) v);
5068
5069                                                 for (int j = 0; j < factor; ++j)
5070                                                         data [idx + j] = element [j];
5071                                         }
5072                                 } else if (underlying_type == TypeManager.char_type){
5073                                         if (!(v is Expression)){
5074                                                 int val = (int) ((char) v);
5075
5076                                                 data [idx] = (byte) (val & 0xff);
5077                                                 data [idx+1] = (byte) (val >> 8);
5078                                         }
5079                                 } else if (underlying_type == TypeManager.short_type){
5080                                         if (!(v is Expression)){
5081                                                 int val = (int) ((short) v);
5082
5083                                                 data [idx] = (byte) (val & 0xff);
5084                                                 data [idx+1] = (byte) (val >> 8);
5085                                         }
5086                                 } else if (underlying_type == TypeManager.ushort_type){
5087                                         if (!(v is Expression)){
5088                                                 int val = (int) ((ushort) v);
5089
5090                                                 data [idx] = (byte) (val & 0xff);
5091                                                 data [idx+1] = (byte) (val >> 8);
5092                                         }
5093                                 } else if (underlying_type == TypeManager.int32_type) {
5094                                         if (!(v is Expression)){
5095                                                 int val = (int) v;
5096
5097                                                 data [idx]   = (byte) (val & 0xff);
5098                                                 data [idx+1] = (byte) ((val >> 8) & 0xff);
5099                                                 data [idx+2] = (byte) ((val >> 16) & 0xff);
5100                                                 data [idx+3] = (byte) (val >> 24);
5101                                         }
5102                                 } else if (underlying_type == TypeManager.uint32_type) {
5103                                         if (!(v is Expression)){
5104                                                 uint val = (uint) v;
5105
5106                                                 data [idx]   = (byte) (val & 0xff);
5107                                                 data [idx+1] = (byte) ((val >> 8) & 0xff);
5108                                                 data [idx+2] = (byte) ((val >> 16) & 0xff);
5109                                                 data [idx+3] = (byte) (val >> 24);
5110                                         }
5111                                 } else if (underlying_type == TypeManager.sbyte_type) {
5112                                         if (!(v is Expression)){
5113                                                 sbyte val = (sbyte) v;
5114                                                 data [idx] = (byte) val;
5115                                         }
5116                                 } else if (underlying_type == TypeManager.byte_type) {
5117                                         if (!(v is Expression)){
5118                                                 byte val = (byte) v;
5119                                                 data [idx] = (byte) val;
5120                                         }
5121                                 } else if (underlying_type == TypeManager.bool_type) {
5122                                         if (!(v is Expression)){
5123                                                 bool val = (bool) v;
5124                                                 data [idx] = (byte) (val ? 1 : 0);
5125                                         }
5126                                 } else if (underlying_type == TypeManager.decimal_type){
5127                                         if (!(v is Expression)){
5128                                                 int [] bits = Decimal.GetBits ((decimal) v);
5129                                                 int p = idx;
5130
5131                                                 for (int j = 0; j < 4; j++){
5132                                                         data [p++] = (byte) (bits [j] & 0xff);
5133                                                         data [p++] = (byte) ((bits [j] >> 8) & 0xff);
5134                                                         data [p++] = (byte) ((bits [j] >> 16) & 0xff);
5135                                                         data [p++] = (byte) (bits [j] >> 24);
5136                                                 }
5137                                         }
5138                                 } else
5139                                         throw new Exception ("Unrecognized type in MakeByteBlob: " + underlying_type);
5140
5141                                 idx += factor;
5142                         }
5143
5144                         return data;
5145                 }
5146
5147                 //
5148                 // Emits the initializers for the array
5149                 //
5150                 void EmitStaticInitializers (EmitContext ec, bool is_expression)
5151                 {
5152                         //
5153                         // First, the static data
5154                         //
5155                         FieldBuilder fb;
5156                         ILGenerator ig = ec.ig;
5157
5158                         byte [] data = MakeByteBlob (array_data, underlying_type, loc);
5159
5160                         fb = RootContext.MakeStaticData (data);
5161
5162                         if (is_expression)
5163                                 ig.Emit (OpCodes.Dup);
5164                         ig.Emit (OpCodes.Ldtoken, fb);
5165                         ig.Emit (OpCodes.Call,
5166                                  TypeManager.void_initializearray_array_fieldhandle);
5167                 }
5168
5169                 //
5170                 // Emits pieces of the array that can not be computed at compile
5171                 // time (variables and string locations).
5172                 //
5173                 // This always expect the top value on the stack to be the array
5174                 //
5175                 void EmitDynamicInitializers (EmitContext ec, bool is_expression)
5176                 {
5177                         ILGenerator ig = ec.ig;
5178                         int dims = bounds.Count;
5179                         int [] current_pos = new int [dims];
5180                         int top = array_data.Count;
5181                         LocalBuilder temp = ig.DeclareLocal (type);
5182
5183                         ig.Emit (OpCodes.Stloc, temp);
5184
5185                         MethodInfo set = null;
5186
5187                         if (dims != 1){
5188                                 Type [] args;
5189                                 ModuleBuilder mb = null;
5190                                 mb = CodeGen.ModuleBuilder;
5191                                 args = new Type [dims + 1];
5192
5193                                 int j;
5194                                 for (j = 0; j < dims; j++)
5195                                         args [j] = TypeManager.int32_type;
5196
5197                                 args [j] = array_element_type;
5198
5199                                 set = mb.GetArrayMethod (
5200                                         type, "Set",
5201                                         CallingConventions.HasThis | CallingConventions.Standard,
5202                                         TypeManager.void_type, args);
5203                         }
5204
5205                         for (int i = 0; i < top; i++){
5206
5207                                 Expression e = null;
5208
5209                                 if (array_data [i] is Expression)
5210                                         e = (Expression) array_data [i];
5211
5212                                 if (e != null) {
5213                                         //
5214                                         // Basically we do this for string literals and
5215                                         // other non-literal expressions
5216                                         //
5217                                         if (e is StringConstant || !(e is Constant) ||
5218                                             num_automatic_initializers <= 2) {
5219                                                 Type etype = e.Type;
5220
5221                                                 ig.Emit (OpCodes.Ldloc, temp);
5222
5223                                                 for (int idx = 0; idx < dims; idx++)
5224                                                         IntConstant.EmitInt (ig, current_pos [idx]);
5225
5226                                                 //
5227                                                 // If we are dealing with a struct, get the
5228                                                 // address of it, so we can store it.
5229                                                 //
5230                                                 if ((dims == 1) &&
5231                                                     etype.IsSubclassOf (TypeManager.value_type) &&
5232                                                     (!TypeManager.IsBuiltinType (etype) ||
5233                                                      etype == TypeManager.decimal_type)) {
5234                                                         if (e is New){
5235                                                                 New n = (New) e;
5236
5237                                                                 //
5238                                                                 // Let new know that we are providing
5239                                                                 // the address where to store the results
5240                                                                 //
5241                                                                 n.DisableTemporaryValueType ();
5242                                                         }
5243
5244                                                         ig.Emit (OpCodes.Ldelema, etype);
5245                                                 }
5246
5247                                                 e.Emit (ec);
5248
5249                                                 if (dims == 1)
5250                                                         ArrayAccess.EmitStoreOpcode (ig, array_element_type);
5251                                                 else
5252                                                         ig.Emit (OpCodes.Call, set);
5253                                         }
5254                                 }
5255
5256                                 //
5257                                 // Advance counter
5258                                 //
5259                                 for (int j = dims - 1; j >= 0; j--){
5260                                         current_pos [j]++;
5261                                         if (current_pos [j] < (int) bounds [j])
5262                                                 break;
5263                                         current_pos [j] = 0;
5264                                 }
5265                         }
5266
5267                         if (is_expression)
5268                                 ig.Emit (OpCodes.Ldloc, temp);
5269                 }
5270
5271                 void EmitArrayArguments (EmitContext ec)
5272                 {
5273                         ILGenerator ig = ec.ig;
5274
5275                         foreach (Argument a in arguments) {
5276                                 Type atype = a.Type;
5277                                 a.Emit (ec);
5278
5279                                 if (atype == TypeManager.uint64_type)
5280                                         ig.Emit (OpCodes.Conv_Ovf_U4);
5281                                 else if (atype == TypeManager.int64_type)
5282                                         ig.Emit (OpCodes.Conv_Ovf_I4);
5283                         }
5284                 }
5285
5286                 void DoEmit (EmitContext ec, bool is_statement)
5287                 {
5288                         ILGenerator ig = ec.ig;
5289
5290                         EmitArrayArguments (ec);
5291                         if (is_one_dimensional)
5292                                 ig.Emit (OpCodes.Newarr, array_element_type);
5293                         else {
5294                                 if (is_builtin_type)
5295                                         ig.Emit (OpCodes.Newobj, (ConstructorInfo) new_method);
5296                                 else
5297                                         ig.Emit (OpCodes.Newobj, (MethodInfo) new_method);
5298                         }
5299
5300                         if (initializers != null){
5301                                 //
5302                                 // FIXME: Set this variable correctly.
5303                                 //
5304                                 bool dynamic_initializers = true;
5305
5306                                 if (underlying_type != TypeManager.string_type &&
5307                                     underlying_type != TypeManager.object_type) {
5308                                         if (num_automatic_initializers > 2)
5309                                                 EmitStaticInitializers (ec, dynamic_initializers || !is_statement);
5310                                 }
5311
5312                                 if (dynamic_initializers)
5313                                         EmitDynamicInitializers (ec, !is_statement);
5314                         }
5315                 }
5316
5317                 public override void Emit (EmitContext ec)
5318                 {
5319                         DoEmit (ec, false);
5320                 }
5321
5322                 public override void EmitStatement (EmitContext ec)
5323                 {
5324                         DoEmit (ec, true);
5325                 }
5326
5327         }
5328
5329         /// <summary>
5330         ///   Represents the `this' construct
5331         /// </summary>
5332         public class This : Expression, IAssignMethod, IMemoryLocation, IVariable {
5333
5334                 Block block;
5335                 VariableInfo vi;
5336
5337                 public This (Block block, Location loc)
5338                 {
5339                         this.loc = loc;
5340                         this.block = block;
5341                 }
5342
5343                 public This (Location loc)
5344                 {
5345                         this.loc = loc;
5346                 }
5347
5348                 public bool IsAssigned (EmitContext ec, Location loc)
5349                 {
5350                         if (vi == null)
5351                                 return true;
5352
5353                         return vi.IsAssigned (ec, loc);
5354                 }
5355
5356                 public bool IsFieldAssigned (EmitContext ec, string field_name, Location loc)
5357                 {
5358                         if (vi == null)
5359                                 return true;
5360
5361                         return vi.IsFieldAssigned (ec, field_name, loc);
5362                 }
5363
5364                 public void SetAssigned (EmitContext ec)
5365                 {
5366                         if (vi != null)
5367                                 vi.SetAssigned (ec);
5368                 }
5369
5370                 public void SetFieldAssigned (EmitContext ec, string field_name)
5371                 {
5372                         if (vi != null)
5373                                 vi.SetFieldAssigned (ec, field_name);
5374                 }
5375
5376                 public override Expression DoResolve (EmitContext ec)
5377                 {
5378                         eclass = ExprClass.Variable;
5379                         type = ec.ContainerType;
5380
5381                         if (ec.IsStatic){
5382                                 Error (26, "Keyword this not valid in static code");
5383                                 return null;
5384                         }
5385
5386                         if (block != null)
5387                                 vi = block.ThisVariable;
5388
5389                         return this;
5390                 }
5391
5392                 override public Expression DoResolveLValue (EmitContext ec, Expression right_side)
5393                 {
5394                         DoResolve (ec);
5395
5396                         VariableInfo vi = ec.CurrentBlock.ThisVariable;
5397                         if (vi != null)
5398                                 vi.SetAssigned (ec);
5399
5400                         if (ec.TypeContainer is Class){
5401                                 Error (1604, "Cannot assign to `this'");
5402                                 return null;
5403                         }
5404
5405                         return this;
5406                 }
5407
5408                 public override void Emit (EmitContext ec)
5409                 {
5410                         ILGenerator ig = ec.ig;
5411
5412                         ig.Emit (OpCodes.Ldarg_0);
5413                         if (ec.TypeContainer is Struct)
5414                                 ig.Emit (OpCodes.Ldobj, type);
5415                 }
5416
5417                 public void EmitAssign (EmitContext ec, Expression source)
5418                 {
5419                         ILGenerator ig = ec.ig;
5420
5421                         if (ec.TypeContainer is Struct){
5422                                 ig.Emit (OpCodes.Ldarg_0);
5423                                 source.Emit (ec);
5424                                 ig.Emit (OpCodes.Stobj, type);
5425                         } else {
5426                                 source.Emit (ec);
5427                                 ig.Emit (OpCodes.Starg, 0);
5428                         }
5429                 }
5430
5431                 public void AddressOf (EmitContext ec, AddressOp mode)
5432                 {
5433                         ec.ig.Emit (OpCodes.Ldarg_0);
5434
5435                         // FIMXE
5436                         // FIGURE OUT WHY LDARG_S does not work
5437                         //
5438                         // consider: struct X { int val; int P { set { val = value; }}}
5439                         //
5440                         // Yes, this looks very bad. Look at `NOTAS' for
5441                         // an explanation.
5442                         // ec.ig.Emit (OpCodes.Ldarga_S, (byte) 0);
5443                 }
5444         }
5445
5446         /// <summary>
5447         ///   Implements the typeof operator
5448         /// </summary>
5449         public class TypeOf : Expression {
5450                 public readonly Expression QueriedType;
5451                 Type typearg;
5452
5453                 public TypeOf (Expression queried_type, Location l)
5454                 {
5455                         QueriedType = queried_type;
5456                         loc = l;
5457                 }
5458
5459                 public override Expression DoResolve (EmitContext ec)
5460                 {
5461                         typearg = ec.DeclSpace.ResolveType (QueriedType, false, loc);
5462
5463                         if (typearg == null)
5464                                 return null;
5465
5466                         type = TypeManager.type_type;
5467                         eclass = ExprClass.Type;
5468                         return this;
5469                 }
5470
5471                 public override void Emit (EmitContext ec)
5472                 {
5473                         ec.ig.Emit (OpCodes.Ldtoken, typearg);
5474                         ec.ig.Emit (OpCodes.Call, TypeManager.system_type_get_type_from_handle);
5475                 }
5476
5477                 public Type TypeArg {
5478                         get { return typearg; }
5479                 }
5480         }
5481
5482         /// <summary>
5483         ///   Implements the sizeof expression
5484         /// </summary>
5485         public class SizeOf : Expression {
5486                 public readonly Expression QueriedType;
5487                 Type type_queried;
5488
5489                 public SizeOf (Expression queried_type, Location l)
5490                 {
5491                         this.QueriedType = queried_type;
5492                         loc = l;
5493                 }
5494
5495                 public override Expression DoResolve (EmitContext ec)
5496                 {
5497                         if (!ec.InUnsafe) {
5498                                 Error (233, "Sizeof may only be used in an unsafe context " +
5499                                        "(consider using System.Runtime.InteropServices.Marshal.Sizeof");
5500                                 return null;
5501                         }
5502
5503                         type_queried = ec.DeclSpace.ResolveType (QueriedType, false, loc);
5504                         if (type_queried == null)
5505                                 return null;
5506
5507                         if (!TypeManager.IsUnmanagedType (type_queried)){
5508                                 Report.Error (208, "Cannot take the size of an unmanaged type (" + TypeManager.CSharpName (type_queried) + ")");
5509                                 return null;
5510                         }
5511
5512                         type = TypeManager.int32_type;
5513                         eclass = ExprClass.Value;
5514                         return this;
5515                 }
5516
5517                 public override void Emit (EmitContext ec)
5518                 {
5519                         int size = GetTypeSize (type_queried);
5520
5521                         if (size == 0)
5522                                 ec.ig.Emit (OpCodes.Sizeof, type_queried);
5523                         else
5524                                 IntConstant.EmitInt (ec.ig, size);
5525                 }
5526         }
5527
5528         /// <summary>
5529         ///   Implements the member access expression
5530         /// </summary>
5531         public class MemberAccess : Expression, ITypeExpression {
5532                 public readonly string Identifier;
5533                 Expression expr;
5534                 Expression member_lookup;
5535
5536                 public MemberAccess (Expression expr, string id, Location l)
5537                 {
5538                         this.expr = expr;
5539                         Identifier = id;
5540                         loc = l;
5541                 }
5542
5543                 public Expression Expr {
5544                         get {
5545                                 return expr;
5546                         }
5547                 }
5548
5549                 static void error176 (Location loc, string name)
5550                 {
5551                         Report.Error (176, loc, "Static member `" +
5552                                       name + "' cannot be accessed " +
5553                                       "with an instance reference, qualify with a " +
5554                                       "type name instead");
5555                 }
5556
5557                 static bool IdenticalNameAndTypeName (EmitContext ec, Expression left_original, Location loc)
5558                 {
5559                         if (left_original == null)
5560                                 return false;
5561
5562                         if (!(left_original is SimpleName))
5563                                 return false;
5564
5565                         SimpleName sn = (SimpleName) left_original;
5566
5567                         Type t = RootContext.LookupType (ec.DeclSpace, sn.Name, true, loc);
5568                         if (t != null)
5569                                 return true;
5570
5571                         return false;
5572                 }
5573
5574                 public static Expression ResolveMemberAccess (EmitContext ec, Expression member_lookup,
5575                                                               Expression left, Location loc,
5576                                                               Expression left_original)
5577                 {
5578                         bool left_is_type, left_is_explicit;
5579
5580                         // If `left' is null, then we're called from SimpleNameResolve and this is
5581                         // a member in the currently defining class.
5582                         if (left == null) {
5583                                 left_is_type = ec.IsStatic || ec.IsFieldInitializer;
5584                                 left_is_explicit = false;
5585
5586                                 // Implicitly default to `this' unless we're static.
5587                                 if (!ec.IsStatic && !ec.IsFieldInitializer && !ec.InEnumContext)
5588                                         left = ec.This;
5589                         } else {
5590                                 left_is_type = left is TypeExpr;
5591                                 left_is_explicit = true;
5592                         }
5593
5594                         if (member_lookup is FieldExpr){
5595                                 FieldExpr fe = (FieldExpr) member_lookup;
5596                                 FieldInfo fi = fe.FieldInfo;
5597                                 Type decl_type = fi.DeclaringType;
5598
5599                                 if (fi is FieldBuilder) {
5600                                         Const c = TypeManager.LookupConstant ((FieldBuilder) fi);
5601
5602                                         if (c != null) {
5603                                                 object o = c.LookupConstantValue (ec);
5604                                                 object real_value = ((Constant) c.Expr).GetValue ();
5605
5606                                                 return Constantify (real_value, fi.FieldType);
5607                                         }
5608                                 }
5609
5610                                 if (fi.IsLiteral) {
5611                                         Type t = fi.FieldType;
5612
5613                                         object o;
5614
5615                                         if (fi is FieldBuilder)
5616                                                 o = TypeManager.GetValue ((FieldBuilder) fi);
5617                                         else
5618                                                 o = fi.GetValue (fi);
5619
5620                                         if (decl_type.IsSubclassOf (TypeManager.enum_type)) {
5621                                                 if (left_is_explicit && !left_is_type &&
5622                                                     !IdenticalNameAndTypeName (ec, left_original, loc)) {
5623                                                         error176 (loc, fe.FieldInfo.Name);
5624                                                         return null;
5625                                                 }
5626
5627                                                 Expression enum_member = MemberLookup (
5628                                                         ec, decl_type, "value__", MemberTypes.Field,
5629                                                         AllBindingFlags, loc);
5630
5631                                                 Enum en = TypeManager.LookupEnum (decl_type);
5632
5633                                                 Constant c;
5634                                                 if (en != null)
5635                                                         c = Constantify (o, en.UnderlyingType);
5636                                                 else
5637                                                         c = Constantify (o, enum_member.Type);
5638
5639                                                 return new EnumConstant (c, decl_type);
5640                                         }
5641
5642                                         Expression exp = Constantify (o, t);
5643
5644                                         if (left_is_explicit && !left_is_type) {
5645                                                 error176 (loc, fe.FieldInfo.Name);
5646                                                 return null;
5647                                         }
5648
5649                                         return exp;
5650                                 }
5651
5652                                 if (fi.FieldType.IsPointer && !ec.InUnsafe){
5653                                         UnsafeError (loc);
5654                                         return null;
5655                                 }
5656                         }
5657
5658                         if (member_lookup is EventExpr) {
5659
5660                                 EventExpr ee = (EventExpr) member_lookup;
5661
5662                                 //
5663                                 // If the event is local to this class, we transform ourselves into
5664                                 // a FieldExpr
5665                                 //
5666
5667                                 if (ee.EventInfo.DeclaringType == ec.ContainerType) {
5668                                         MemberInfo mi = GetFieldFromEvent (ee);
5669
5670                                         if (mi == null) {
5671                                                 //
5672                                                 // If this happens, then we have an event with its own
5673                                                 // accessors and private field etc so there's no need
5674                                                 // to transform ourselves : we should instead flag an error
5675                                                 //
5676                                                 Assign.error70 (ee.EventInfo, loc);
5677                                                 return null;
5678                                         }
5679
5680                                         Expression ml = ExprClassFromMemberInfo (ec, mi, loc);
5681
5682                                         if (ml == null) {
5683                                                 Report.Error (-200, loc, "Internal error!!");
5684                                                 return null;
5685                                         }
5686
5687                                         return ResolveMemberAccess (ec, ml, left, loc, left_original);
5688                                 }
5689                         }
5690
5691                         if (member_lookup is IMemberExpr) {
5692                                 IMemberExpr me = (IMemberExpr) member_lookup;
5693
5694                                 if (left_is_type){
5695                                         MethodGroupExpr mg = me as MethodGroupExpr;
5696                                         if ((mg != null) && left_is_explicit && left.Type.IsInterface)
5697                                                 mg.IsExplicitImpl = left_is_explicit;
5698
5699                                         if (!me.IsStatic){
5700                                                 if (IdenticalNameAndTypeName (ec, left_original, loc))
5701                                                         return member_lookup;
5702
5703                                                 SimpleName.Error_ObjectRefRequired (ec, loc, me.Name);
5704                                                 return null;
5705                                         }
5706
5707                                 } else {
5708                                         if (!me.IsInstance){
5709                                                 if (IdenticalNameAndTypeName (ec, left_original, loc))
5710                                                         return member_lookup;
5711
5712                                                 if (left_is_explicit) {
5713                                                         error176 (loc, me.Name);
5714                                                         return null;
5715                                                 }
5716                                         }
5717
5718                                         //
5719                                         // Since we can not check for instance objects in SimpleName,
5720                                         // becaue of the rule that allows types and variables to share
5721                                         // the name (as long as they can be de-ambiguated later, see
5722                                         // IdenticalNameAndTypeName), we have to check whether left
5723                                         // is an instance variable in a static context
5724                                         //
5725                                         // However, if the left-hand value is explicitly given, then
5726                                         // it is already our instance expression, so we aren't in
5727                                         // static context.
5728                                         //
5729
5730                                         if (ec.IsStatic && !left_is_explicit && left is IMemberExpr){
5731                                                 IMemberExpr mexp = (IMemberExpr) left;
5732
5733                                                 if (!mexp.IsStatic){
5734                                                         SimpleName.Error_ObjectRefRequired (ec, loc, mexp.Name);
5735                                                         return null;
5736                                                 }
5737                                         }
5738
5739                                         me.InstanceExpression = left;
5740                                 }
5741
5742                                 return member_lookup;
5743                         }
5744
5745                         if (member_lookup is TypeExpr){
5746                                 member_lookup.Resolve (ec, ResolveFlags.Type);
5747                                 return member_lookup;
5748                         }
5749
5750                         Console.WriteLine ("Left is: " + left);
5751                         Report.Error (-100, loc, "Support for [" + member_lookup + "] is not present yet");
5752                         Environment.Exit (0);
5753                         return null;
5754                 }
5755
5756                 public Expression DoResolve (EmitContext ec, Expression right_side, ResolveFlags flags)
5757                 {
5758                         if (type != null)
5759                                 throw new Exception ();
5760                         //
5761                         // Resolve the expression with flow analysis turned off, we'll do the definite
5762                         // assignment checks later.  This is because we don't know yet what the expression
5763                         // will resolve to - it may resolve to a FieldExpr and in this case we must do the
5764                         // definite assignment check on the actual field and not on the whole struct.
5765                         //
5766
5767                         Expression original = expr;
5768                         expr = expr.Resolve (ec, flags | ResolveFlags.DisableFlowAnalysis);
5769
5770                         if (expr == null)
5771                                 return null;
5772
5773                         if (expr is SimpleName){
5774                                 SimpleName child_expr = (SimpleName) expr;
5775
5776                                 Expression new_expr = new SimpleName (child_expr.Name + "." + Identifier, loc);
5777
5778                                 return new_expr.Resolve (ec, flags);
5779                         }
5780
5781                         //
5782                         // TODO: I mailed Ravi about this, and apparently we can get rid
5783                         // of this and put it in the right place.
5784                         //
5785                         // Handle enums here when they are in transit.
5786                         // Note that we cannot afford to hit MemberLookup in this case because
5787                         // it will fail to find any members at all
5788                         //
5789
5790                         int errors = Report.Errors;
5791
5792                         Type expr_type = expr.Type;
5793                         if ((expr is TypeExpr) && (expr_type.IsSubclassOf (TypeManager.enum_type))){
5794
5795                                 Enum en = TypeManager.LookupEnum (expr_type);
5796
5797                                 if (en != null) {
5798                                         object value = en.LookupEnumValue (ec, Identifier, loc);
5799
5800                                         if (value != null){
5801                                                 Constant c = Constantify (value, en.UnderlyingType);
5802                                                 return new EnumConstant (c, expr_type);
5803                                         }
5804                                 }
5805                         }
5806
5807                         if (expr_type.IsPointer){
5808                                 Error (23, "The `.' operator can not be applied to pointer operands (" +
5809                                        TypeManager.CSharpName (expr_type) + ")");
5810                                 return null;
5811                         }
5812
5813                         member_lookup = MemberLookup (ec, expr_type, Identifier, loc);
5814
5815                         if (member_lookup == null){
5816                                 // Error has already been reported.
5817                                 if (errors < Report.Errors)
5818                                         return null;
5819
5820                                 //
5821                                 // Try looking the member up from the same type, if we find
5822                                 // it, we know that the error was due to limited visibility
5823                                 //
5824                                 object lookup = TypeManager.MemberLookup (
5825                                         expr_type, expr_type, AllMemberTypes, AllBindingFlags |
5826                                         BindingFlags.NonPublic, Identifier);
5827                                 if (lookup == null)
5828                                         Error (117, "`" + expr_type + "' does not contain a " +
5829                                                "definition for `" + Identifier + "'");
5830                                 else if ((expr_type != ec.ContainerType) &&
5831                                          ec.ContainerType.IsSubclassOf (expr_type)){
5832
5833                                         // Although a derived class can access protected members of
5834                                         // its base class it cannot do so through an instance of the
5835                                         // base class (CS1540).  If the expr_type is a parent of the
5836                                         // ec.ContainerType and the lookup succeeds with the latter one,
5837                                         // then we are in this situation.
5838
5839                                         lookup = TypeManager.MemberLookup (
5840                                                 ec.ContainerType, ec.ContainerType, AllMemberTypes,
5841                                                 AllBindingFlags, Identifier);
5842
5843                                         if (lookup != null)
5844                                                 Error (1540, "Cannot access protected member `" +
5845                                                        expr_type + "." + Identifier + "' " +
5846                                                        "via a qualifier of type `" +
5847                                                        TypeManager.CSharpName (expr_type) + "'; the " +
5848                                                        "qualifier must be of type `" +
5849                                                        TypeManager.CSharpName (ec.ContainerType) + "' " +
5850                                                        "(or derived from it)");
5851                                         else
5852                                                 Error (122, "`" + expr_type + "." + Identifier + "' " +
5853                                                        "is inaccessible because of its protection level");
5854                                 } else
5855                                         Error (122, "`" + expr_type + "." + Identifier + "' " +
5856                                                "is inaccessible because of its protection level");
5857
5858                                 return null;
5859                         }
5860
5861                         if (member_lookup is TypeExpr){
5862                                 member_lookup.Resolve (ec, ResolveFlags.Type);
5863                                 return member_lookup;
5864                         } else if ((flags & ResolveFlags.MaskExprClass) == ResolveFlags.Type)
5865                                 return null;
5866
5867                         member_lookup = ResolveMemberAccess (ec, member_lookup, expr, loc, original);
5868                         if (member_lookup == null)
5869                                 return null;
5870
5871                         // The following DoResolve/DoResolveLValue will do the definite assignment
5872                         // check.
5873
5874                         if (right_side != null)
5875                                 member_lookup = member_lookup.DoResolveLValue (ec, right_side);
5876                         else
5877                                 member_lookup = member_lookup.DoResolve (ec);
5878
5879                         return member_lookup;
5880                 }
5881
5882                 public override Expression DoResolve (EmitContext ec)
5883                 {
5884                         return DoResolve (ec, null, ResolveFlags.VariableOrValue |
5885                                           ResolveFlags.SimpleName | ResolveFlags.Type);
5886                 }
5887
5888                 public override Expression DoResolveLValue (EmitContext ec, Expression right_side)
5889                 {
5890                         return DoResolve (ec, right_side, ResolveFlags.VariableOrValue |
5891                                           ResolveFlags.SimpleName | ResolveFlags.Type);
5892                 }
5893
5894                 public Expression DoResolveType (EmitContext ec)
5895                 {
5896                         return DoResolve (ec, null, ResolveFlags.Type);
5897                 }
5898
5899                 public override void Emit (EmitContext ec)
5900                 {
5901                         throw new Exception ("Should not happen");
5902                 }
5903
5904                 public override string ToString ()
5905                 {
5906                         return expr + "." + Identifier;
5907                 }
5908         }
5909
5910         /// <summary>
5911         ///   Implements checked expressions
5912         /// </summary>
5913         public class CheckedExpr : Expression {
5914
5915                 public Expression Expr;
5916
5917                 public CheckedExpr (Expression e, Location l)
5918                 {
5919                         Expr = e;
5920                         loc = l;
5921                 }
5922
5923                 public override Expression DoResolve (EmitContext ec)
5924                 {
5925                         bool last_const_check = ec.ConstantCheckState;
5926
5927                         ec.ConstantCheckState = true;
5928                         Expr = Expr.Resolve (ec);
5929                         ec.ConstantCheckState = last_const_check;
5930
5931                         if (Expr == null)
5932                                 return null;
5933
5934                         if (Expr is Constant)
5935                                 return Expr;
5936
5937                         eclass = Expr.eclass;
5938                         type = Expr.Type;
5939                         return this;
5940                 }
5941
5942                 public override void Emit (EmitContext ec)
5943                 {
5944                         bool last_check = ec.CheckState;
5945                         bool last_const_check = ec.ConstantCheckState;
5946
5947                         ec.CheckState = true;
5948                         ec.ConstantCheckState = true;
5949                         Expr.Emit (ec);
5950                         ec.CheckState = last_check;
5951                         ec.ConstantCheckState = last_const_check;
5952                 }
5953
5954         }
5955
5956         /// <summary>
5957         ///   Implements the unchecked expression
5958         /// </summary>
5959         public class UnCheckedExpr : Expression {
5960
5961                 public Expression Expr;
5962
5963                 public UnCheckedExpr (Expression e, Location l)
5964                 {
5965                         Expr = e;
5966                         loc = l;
5967                 }
5968
5969                 public override Expression DoResolve (EmitContext ec)
5970                 {
5971                         bool last_const_check = ec.ConstantCheckState;
5972
5973                         ec.ConstantCheckState = false;
5974                         Expr = Expr.Resolve (ec);
5975                         ec.ConstantCheckState = last_const_check;
5976
5977                         if (Expr == null)
5978                                 return null;
5979
5980                         if (Expr is Constant)
5981                                 return Expr;
5982
5983                         eclass = Expr.eclass;
5984                         type = Expr.Type;
5985                         return this;
5986                 }
5987
5988                 public override void Emit (EmitContext ec)
5989                 {
5990                         bool last_check = ec.CheckState;
5991                         bool last_const_check = ec.ConstantCheckState;
5992
5993                         ec.CheckState = false;
5994                         ec.ConstantCheckState = false;
5995                         Expr.Emit (ec);
5996                         ec.CheckState = last_check;
5997                         ec.ConstantCheckState = last_const_check;
5998                 }
5999
6000         }
6001
6002         /// <summary>
6003         ///   An Element Access expression.
6004         ///
6005         ///   During semantic analysis these are transformed into
6006         ///   IndexerAccess or ArrayAccess
6007         /// </summary>
6008         public class ElementAccess : Expression {
6009                 public ArrayList  Arguments;
6010                 public Expression Expr;
6011
6012                 public ElementAccess (Expression e, ArrayList e_list, Location l)
6013                 {
6014                         Expr = e;
6015
6016                         loc  = l;
6017
6018                         if (e_list == null)
6019                                 return;
6020
6021                         Arguments = new ArrayList ();
6022                         foreach (Expression tmp in e_list)
6023                                 Arguments.Add (new Argument (tmp, Argument.AType.Expression));
6024
6025                 }
6026
6027                 bool CommonResolve (EmitContext ec)
6028                 {
6029                         Expr = Expr.Resolve (ec);
6030
6031                         if (Expr == null)
6032                                 return false;
6033
6034                         if (Arguments == null)
6035                                 return false;
6036
6037                         foreach (Argument a in Arguments){
6038                                 if (!a.Resolve (ec, loc))
6039                                         return false;
6040                         }
6041
6042                         return true;
6043                 }
6044
6045                 Expression MakePointerAccess ()
6046                 {
6047                         Type t = Expr.Type;
6048
6049                         if (t == TypeManager.void_ptr_type){
6050                                 Error (
6051                                         242,
6052                                         "The array index operation is not valid for void pointers");
6053                                 return null;
6054                         }
6055                         if (Arguments.Count != 1){
6056                                 Error (
6057                                         196,
6058                                         "A pointer must be indexed by a single value");
6059                                 return null;
6060                         }
6061                         Expression p = new PointerArithmetic (true, Expr, ((Argument)Arguments [0]).Expr,
6062                                                               t, loc);
6063                         return new Indirection (p, loc);
6064                 }
6065
6066                 public override Expression DoResolve (EmitContext ec)
6067                 {
6068                         if (!CommonResolve (ec))
6069                                 return null;
6070
6071                         //
6072                         // We perform some simple tests, and then to "split" the emit and store
6073                         // code we create an instance of a different class, and return that.
6074                         //
6075                         // I am experimenting with this pattern.
6076                         //
6077                         Type t = Expr.Type;
6078
6079                         if (t.IsArray)
6080                                 return (new ArrayAccess (this, loc)).Resolve (ec);
6081                         else if (t.IsPointer)
6082                                 return MakePointerAccess ();
6083                         else
6084                                 return (new IndexerAccess (this, loc)).Resolve (ec);
6085                 }
6086
6087                 public override Expression DoResolveLValue (EmitContext ec, Expression right_side)
6088                 {
6089                         if (!CommonResolve (ec))
6090                                 return null;
6091
6092                         Type t = Expr.Type;
6093                         if (t.IsArray)
6094                                 return (new ArrayAccess (this, loc)).ResolveLValue (ec, right_side);
6095                         else if (t.IsPointer)
6096                                 return MakePointerAccess ();
6097                         else
6098                                 return (new IndexerAccess (this, loc)).ResolveLValue (ec, right_side);
6099                 }
6100
6101                 public override void Emit (EmitContext ec)
6102                 {
6103                         throw new Exception ("Should never be reached");
6104                 }
6105         }
6106
6107         /// <summary>
6108         ///   Implements array access
6109         /// </summary>
6110         public class ArrayAccess : Expression, IAssignMethod, IMemoryLocation {
6111                 //
6112                 // Points to our "data" repository
6113                 //
6114                 ElementAccess ea;
6115
6116                 LocalTemporary [] cached_locations;
6117
6118                 public ArrayAccess (ElementAccess ea_data, Location l)
6119                 {
6120                         ea = ea_data;
6121                         eclass = ExprClass.Variable;
6122                         loc = l;
6123                 }
6124
6125                 public override Expression DoResolve (EmitContext ec)
6126                 {
6127                         ExprClass eclass = ea.Expr.eclass;
6128
6129 #if false
6130                         // As long as the type is valid
6131                         if (!(eclass == ExprClass.Variable || eclass == ExprClass.PropertyAccess ||
6132                               eclass == ExprClass.Value)) {
6133                                 ea.Expr.Error118 ("variable or value");
6134                                 return null;
6135                         }
6136 #endif
6137
6138                         Type t = ea.Expr.Type;
6139                         if (t.GetArrayRank () != ea.Arguments.Count){
6140                                 ea.Error (22,
6141                                           "Incorrect number of indexes for array " +
6142                                           " expected: " + t.GetArrayRank () + " got: " +
6143                                           ea.Arguments.Count);
6144                                 return null;
6145                         }
6146                         type = TypeManager.TypeToCoreType (t.GetElementType ());
6147                         if (type.IsPointer && !ec.InUnsafe){
6148                                 UnsafeError (ea.Location);
6149                                 return null;
6150                         }
6151
6152                         foreach (Argument a in ea.Arguments){
6153                                 Type argtype = a.Type;
6154
6155                                 if (argtype == TypeManager.int32_type ||
6156                                     argtype == TypeManager.uint32_type ||
6157                                     argtype == TypeManager.int64_type ||
6158                                     argtype == TypeManager.uint64_type)
6159                                         continue;
6160
6161                                 //
6162                                 // Mhm.  This is strage, because the Argument.Type is not the same as
6163                                 // Argument.Expr.Type: the value changes depending on the ref/out setting.
6164                                 //
6165                                 // Wonder if I will run into trouble for this.
6166                                 //
6167                                 a.Expr = ExpressionToArrayArgument (ec, a.Expr, ea.Location);
6168                                 if (a.Expr == null)
6169                                         return null;
6170                         }
6171
6172                         eclass = ExprClass.Variable;
6173
6174                         return this;
6175                 }
6176
6177                 /// <summary>
6178                 ///    Emits the right opcode to load an object of Type `t'
6179                 ///    from an array of T
6180                 /// </summary>
6181                 static public void EmitLoadOpcode (ILGenerator ig, Type type)
6182                 {
6183                         if (type == TypeManager.byte_type || type == TypeManager.bool_type)
6184                                 ig.Emit (OpCodes.Ldelem_U1);
6185                         else if (type == TypeManager.sbyte_type)
6186                                 ig.Emit (OpCodes.Ldelem_I1);
6187                         else if (type == TypeManager.short_type)
6188                                 ig.Emit (OpCodes.Ldelem_I2);
6189                         else if (type == TypeManager.ushort_type || type == TypeManager.char_type)
6190                                 ig.Emit (OpCodes.Ldelem_U2);
6191                         else if (type == TypeManager.int32_type)
6192                                 ig.Emit (OpCodes.Ldelem_I4);
6193                         else if (type == TypeManager.uint32_type)
6194                                 ig.Emit (OpCodes.Ldelem_U4);
6195                         else if (type == TypeManager.uint64_type)
6196                                 ig.Emit (OpCodes.Ldelem_I8);
6197                         else if (type == TypeManager.int64_type)
6198                                 ig.Emit (OpCodes.Ldelem_I8);
6199                         else if (type == TypeManager.float_type)
6200                                 ig.Emit (OpCodes.Ldelem_R4);
6201                         else if (type == TypeManager.double_type)
6202                                 ig.Emit (OpCodes.Ldelem_R8);
6203                         else if (type == TypeManager.intptr_type)
6204                                 ig.Emit (OpCodes.Ldelem_I);
6205                         else if (type.IsValueType){
6206                                 ig.Emit (OpCodes.Ldelema, type);
6207                                 ig.Emit (OpCodes.Ldobj, type);
6208                         } else
6209                                 ig.Emit (OpCodes.Ldelem_Ref);
6210                 }
6211
6212                 /// <summary>
6213                 ///    Emits the right opcode to store an object of Type `t'
6214                 ///    from an array of T.
6215                 /// </summary>
6216                 static public void EmitStoreOpcode (ILGenerator ig, Type t)
6217                 {
6218                         t = TypeManager.TypeToCoreType (t);
6219                         if (TypeManager.IsEnumType (t) && t != TypeManager.enum_type)
6220                                 t = TypeManager.EnumToUnderlying (t);
6221                         if (t == TypeManager.byte_type || t == TypeManager.sbyte_type ||
6222                             t == TypeManager.bool_type)
6223                                 ig.Emit (OpCodes.Stelem_I1);
6224                         else if (t == TypeManager.short_type || t == TypeManager.ushort_type || t == TypeManager.char_type)
6225                                 ig.Emit (OpCodes.Stelem_I2);
6226                         else if (t == TypeManager.int32_type || t == TypeManager.uint32_type)
6227                                 ig.Emit (OpCodes.Stelem_I4);
6228                         else if (t == TypeManager.int64_type || t == TypeManager.uint64_type)
6229                                 ig.Emit (OpCodes.Stelem_I8);
6230                         else if (t == TypeManager.float_type)
6231                                 ig.Emit (OpCodes.Stelem_R4);
6232                         else if (t == TypeManager.double_type)
6233                                 ig.Emit (OpCodes.Stelem_R8);
6234                         else if (t == TypeManager.intptr_type)
6235                                 ig.Emit (OpCodes.Stelem_I);
6236                         else if (t.IsValueType){
6237                                 ig.Emit (OpCodes.Stobj, t);
6238                         } else
6239                                 ig.Emit (OpCodes.Stelem_Ref);
6240                 }
6241
6242                 MethodInfo FetchGetMethod ()
6243                 {
6244                         ModuleBuilder mb = CodeGen.ModuleBuilder;
6245                         int arg_count = ea.Arguments.Count;
6246                         Type [] args = new Type [arg_count];
6247                         MethodInfo get;
6248
6249                         for (int i = 0; i < arg_count; i++){
6250                                 //args [i++] = a.Type;
6251                                 args [i] = TypeManager.int32_type;
6252                         }
6253
6254                         get = mb.GetArrayMethod (
6255                                 ea.Expr.Type, "Get",
6256                                 CallingConventions.HasThis |
6257                                 CallingConventions.Standard,
6258                                 type, args);
6259                         return get;
6260                 }
6261
6262
6263                 MethodInfo FetchAddressMethod ()
6264                 {
6265                         ModuleBuilder mb = CodeGen.ModuleBuilder;
6266                         int arg_count = ea.Arguments.Count;
6267                         Type [] args = new Type [arg_count];
6268                         MethodInfo address;
6269                         string ptr_type_name;
6270                         Type ret_type;
6271
6272                         ptr_type_name = type.FullName + "&";
6273                         ret_type = Type.GetType (ptr_type_name);
6274
6275                         //
6276                         // It is a type defined by the source code we are compiling
6277                         //
6278                         if (ret_type == null){
6279                                 ret_type = mb.GetType (ptr_type_name);
6280                         }
6281
6282                         for (int i = 0; i < arg_count; i++){
6283                                 //args [i++] = a.Type;
6284                                 args [i] = TypeManager.int32_type;
6285                         }
6286
6287                         address = mb.GetArrayMethod (
6288                                 ea.Expr.Type, "Address",
6289                                 CallingConventions.HasThis |
6290                                 CallingConventions.Standard,
6291                                 ret_type, args);
6292
6293                         return address;
6294                 }
6295
6296                 //
6297                 // Load the array arguments into the stack.
6298                 //
6299                 // If we have been requested to cache the values (cached_locations array
6300                 // initialized), then load the arguments the first time and store them
6301                 // in locals.  otherwise load from local variables.
6302                 //
6303                 void LoadArrayAndArguments (EmitContext ec)
6304                 {
6305                         ILGenerator ig = ec.ig;
6306
6307                         if (cached_locations == null){
6308                                 ea.Expr.Emit (ec);
6309                                 foreach (Argument a in ea.Arguments){
6310                                         Type argtype = a.Expr.Type;
6311
6312                                         a.Expr.Emit (ec);
6313
6314                                         if (argtype == TypeManager.int64_type)
6315                                                 ig.Emit (OpCodes.Conv_Ovf_I);
6316                                         else if (argtype == TypeManager.uint64_type)
6317                                                 ig.Emit (OpCodes.Conv_Ovf_I_Un);
6318                                 }
6319                                 return;
6320                         }
6321
6322                         if (cached_locations [0] == null){
6323                                 cached_locations [0] = new LocalTemporary (ec, ea.Expr.Type);
6324                                 ea.Expr.Emit (ec);
6325                                 ig.Emit (OpCodes.Dup);
6326                                 cached_locations [0].Store (ec);
6327
6328                                 int j = 1;
6329
6330                                 foreach (Argument a in ea.Arguments){
6331                                         Type argtype = a.Expr.Type;
6332
6333                                         cached_locations [j] = new LocalTemporary (ec, TypeManager.intptr_type /* a.Expr.Type */);
6334                                         a.Expr.Emit (ec);
6335                                         if (argtype == TypeManager.int64_type)
6336                                                 ig.Emit (OpCodes.Conv_Ovf_I);
6337                                         else if (argtype == TypeManager.uint64_type)
6338                                                 ig.Emit (OpCodes.Conv_Ovf_I_Un);
6339
6340                                         ig.Emit (OpCodes.Dup);
6341                                         cached_locations [j].Store (ec);
6342                                         j++;
6343                                 }
6344                                 return;
6345                         }
6346
6347                         foreach (LocalTemporary lt in cached_locations)
6348                                 lt.Emit (ec);
6349                 }
6350
6351                 public new void CacheTemporaries (EmitContext ec)
6352                 {
6353                         cached_locations = new LocalTemporary [ea.Arguments.Count + 1];
6354                 }
6355
6356                 public override void Emit (EmitContext ec)
6357                 {
6358                         int rank = ea.Expr.Type.GetArrayRank ();
6359                         ILGenerator ig = ec.ig;
6360
6361                         LoadArrayAndArguments (ec);
6362
6363                         if (rank == 1)
6364                                 EmitLoadOpcode (ig, type);
6365                         else {
6366                                 MethodInfo method;
6367
6368                                 method = FetchGetMethod ();
6369                                 ig.Emit (OpCodes.Call, method);
6370                         }
6371                 }
6372
6373                 public void EmitAssign (EmitContext ec, Expression source)
6374                 {
6375                         int rank = ea.Expr.Type.GetArrayRank ();
6376                         ILGenerator ig = ec.ig;
6377                         Type t = source.Type;
6378
6379                         LoadArrayAndArguments (ec);
6380
6381                         //
6382                         // The stobj opcode used by value types will need
6383                         // an address on the stack, not really an array/array
6384                         // pair
6385                         //
6386                         if (rank == 1){
6387                                 if (t == TypeManager.enum_type || t == TypeManager.decimal_type ||
6388                                     (t.IsSubclassOf (TypeManager.value_type) && !TypeManager.IsEnumType (t) && !TypeManager.IsBuiltinType (t)))
6389                                         ig.Emit (OpCodes.Ldelema, t);
6390                         }
6391
6392                         source.Emit (ec);
6393
6394                         if (rank == 1)
6395                                 EmitStoreOpcode (ig, t);
6396                         else {
6397                                 ModuleBuilder mb = CodeGen.ModuleBuilder;
6398                                 int arg_count = ea.Arguments.Count;
6399                                 Type [] args = new Type [arg_count + 1];
6400                                 MethodInfo set;
6401
6402                                 for (int i = 0; i < arg_count; i++){
6403                                         //args [i++] = a.Type;
6404                                         args [i] = TypeManager.int32_type;
6405                                 }
6406
6407                                 args [arg_count] = type;
6408
6409                                 set = mb.GetArrayMethod (
6410                                         ea.Expr.Type, "Set",
6411                                         CallingConventions.HasThis |
6412                                         CallingConventions.Standard,
6413                                         TypeManager.void_type, args);
6414
6415                                 ig.Emit (OpCodes.Call, set);
6416                         }
6417                 }
6418
6419                 public void AddressOf (EmitContext ec, AddressOp mode)
6420                 {
6421                         int rank = ea.Expr.Type.GetArrayRank ();
6422                         ILGenerator ig = ec.ig;
6423
6424                         LoadArrayAndArguments (ec);
6425
6426                         if (rank == 1){
6427                                 ig.Emit (OpCodes.Ldelema, type);
6428                         } else {
6429                                 MethodInfo address = FetchAddressMethod ();
6430                                 ig.Emit (OpCodes.Call, address);
6431                         }
6432                 }
6433         }
6434
6435
6436         class Indexers {
6437                 public ArrayList getters, setters;
6438                 static Hashtable map;
6439
6440                 static Indexers ()
6441                 {
6442                         map = new Hashtable ();
6443                 }
6444
6445                 Indexers (MemberInfo [] mi)
6446                 {
6447                         foreach (PropertyInfo property in mi){
6448                                 MethodInfo get, set;
6449
6450                                 get = property.GetGetMethod (true);
6451                                 if (get != null){
6452                                         if (getters == null)
6453                                                 getters = new ArrayList ();
6454
6455                                         getters.Add (get);
6456                                 }
6457
6458                                 set = property.GetSetMethod (true);
6459                                 if (set != null){
6460                                         if (setters == null)
6461                                                 setters = new ArrayList ();
6462                                         setters.Add (set);
6463                                 }
6464                         }
6465                 }
6466
6467                 static private Indexers GetIndexersForTypeOrInterface (Type caller_type, Type lookup_type)
6468                 {
6469                         Indexers ix = (Indexers) map [lookup_type];
6470
6471                         if (ix != null)
6472                                 return ix;
6473
6474                         string p_name = TypeManager.IndexerPropertyName (lookup_type);
6475
6476                         MemberInfo [] mi = TypeManager.MemberLookup (
6477                                 caller_type, lookup_type, MemberTypes.Property,
6478                                 BindingFlags.Public | BindingFlags.Instance, p_name);
6479
6480                         if (mi == null || mi.Length == 0)
6481                                 return null;
6482
6483                         ix = new Indexers (mi);
6484                         map [lookup_type] = ix;
6485
6486                         return ix;
6487                 }
6488
6489                 static public Indexers GetIndexersForType (Type caller_type, Type lookup_type, Location loc)
6490                 {
6491                         Indexers ix = (Indexers) map [lookup_type];
6492
6493                         if (ix != null)
6494                                 return ix;
6495
6496                         ix = GetIndexersForTypeOrInterface (caller_type, lookup_type);
6497                         if (ix != null)
6498                                 return ix;
6499
6500                         Type [] ifaces = TypeManager.GetInterfaces (lookup_type);
6501                         if (ifaces != null) {
6502                                 foreach (Type itype in ifaces) {
6503                                         ix = GetIndexersForTypeOrInterface (caller_type, itype);
6504                                         if (ix != null)
6505                                                 return ix;
6506                                 }
6507                         }
6508
6509                         Report.Error (21, loc,
6510                                       "Type `" + TypeManager.CSharpName (lookup_type) +
6511                                       "' does not have any indexers defined");
6512                         return null;
6513                 }
6514         }
6515
6516         /// <summary>
6517         ///   Expressions that represent an indexer call.
6518         /// </summary>
6519         public class IndexerAccess : Expression, IAssignMethod {
6520                 //
6521                 // Points to our "data" repository
6522                 //
6523                 MethodInfo get, set;
6524                 Indexers ilist;
6525                 ArrayList set_arguments;
6526                 bool is_base_indexer;
6527
6528                 protected Type indexer_type;
6529                 protected Type current_type;
6530                 protected Expression instance_expr;
6531                 protected ArrayList arguments;
6532
6533                 public IndexerAccess (ElementAccess ea, Location loc)
6534                         : this (ea.Expr, false, loc)
6535                 {
6536                         this.arguments = ea.Arguments;
6537                 }
6538
6539                 protected IndexerAccess (Expression instance_expr, bool is_base_indexer,
6540                                          Location loc)
6541                 {
6542                         this.instance_expr = instance_expr;
6543                         this.is_base_indexer = is_base_indexer;
6544                         this.eclass = ExprClass.Value;
6545                         this.loc = loc;
6546                 }
6547
6548                 protected virtual bool CommonResolve (EmitContext ec)
6549                 {
6550                         indexer_type = instance_expr.Type;
6551                         current_type = ec.ContainerType;
6552
6553                         return true;
6554                 }
6555
6556                 public override Expression DoResolve (EmitContext ec)
6557                 {
6558                         if (!CommonResolve (ec))
6559                                 return null;
6560
6561                         //
6562                         // Step 1: Query for all `Item' *properties*.  Notice
6563                         // that the actual methods are pointed from here.
6564                         //
6565                         // This is a group of properties, piles of them.
6566
6567                         if (ilist == null)
6568                                 ilist = Indexers.GetIndexersForType (
6569                                         current_type, indexer_type, loc);
6570
6571                         //
6572                         // Step 2: find the proper match
6573                         //
6574                         if (ilist != null && ilist.getters != null && ilist.getters.Count > 0)
6575                                 get = (MethodInfo) Invocation.OverloadResolve (
6576                                         ec, new MethodGroupExpr (ilist.getters, loc), arguments, loc);
6577
6578                         if (get == null){
6579                                 Error (154, "indexer can not be used in this context, because " +
6580                                        "it lacks a `get' accessor");
6581                                 return null;
6582                         }
6583
6584                         type = get.ReturnType;
6585                         if (type.IsPointer && !ec.InUnsafe){
6586                                 UnsafeError (loc);
6587                                 return null;
6588                         }
6589
6590                         eclass = ExprClass.IndexerAccess;
6591                         return this;
6592                 }
6593
6594                 public override Expression DoResolveLValue (EmitContext ec, Expression right_side)
6595                 {
6596                         if (!CommonResolve (ec))
6597                                 return null;
6598
6599                         Type right_type = right_side.Type;
6600
6601                         if (ilist == null)
6602                                 ilist = Indexers.GetIndexersForType (
6603                                         current_type, indexer_type, loc);
6604
6605                         if (ilist != null && ilist.setters != null && ilist.setters.Count > 0){
6606                                 set_arguments = (ArrayList) arguments.Clone ();
6607                                 set_arguments.Add (new Argument (right_side, Argument.AType.Expression));
6608
6609                                 set = (MethodInfo) Invocation.OverloadResolve (
6610                                         ec, new MethodGroupExpr (ilist.setters, loc), set_arguments, loc);
6611                         }
6612
6613                         if (set == null){
6614                                 Error (200, "indexer X.this [" + TypeManager.CSharpName (right_type) +
6615                                        "] lacks a `set' accessor");
6616                                 return null;
6617                         }
6618
6619                         type = TypeManager.void_type;
6620                         eclass = ExprClass.IndexerAccess;
6621                         return this;
6622                 }
6623
6624                 public override void Emit (EmitContext ec)
6625                 {
6626                         Invocation.EmitCall (ec, false, false, instance_expr, get, arguments, loc);
6627                 }
6628
6629                 //
6630                 // source is ignored, because we already have a copy of it from the
6631                 // LValue resolution and we have already constructed a pre-cached
6632                 // version of the arguments (ea.set_arguments);
6633                 //
6634                 public void EmitAssign (EmitContext ec, Expression source)
6635                 {
6636                         Invocation.EmitCall (ec, false, false, instance_expr, set, set_arguments, loc);
6637                 }
6638         }
6639
6640         /// <summary>
6641         ///   The base operator for method names
6642         /// </summary>
6643         public class BaseAccess : Expression {
6644                 string member;
6645
6646                 public BaseAccess (string member, Location l)
6647                 {
6648                         this.member = member;
6649                         loc = l;
6650                 }
6651
6652                 public override Expression DoResolve (EmitContext ec)
6653                 {
6654                         Expression member_lookup;
6655                         Type current_type = ec.ContainerType;
6656                         Type base_type = current_type.BaseType;
6657                         Expression e;
6658
6659                         if (ec.IsStatic){
6660                                 Error (1511, "Keyword MyBase is not allowed in static method");
6661                                 return null;
6662                         }
6663
6664                         if (member == "New")
6665                                 member = ".ctor";
6666
6667                         member_lookup = MemberLookup (ec, base_type, base_type, member,
6668                                                       AllMemberTypes, AllBindingFlags, loc);
6669
6670                         if (member_lookup == null) {
6671                                 Error (117,
6672                                               TypeManager.CSharpName (base_type) + " does not " +
6673                                               "contain a definition for `" + member + "'");
6674                                 return null;
6675                         }
6676
6677                         Expression left;
6678
6679                         if (ec.IsStatic)
6680                                 left = new TypeExpr (base_type, loc);
6681                         else
6682                                 left = ec.This;
6683
6684                         e = MemberAccess.ResolveMemberAccess (ec, member_lookup, left, loc, null);
6685
6686                         if (e is PropertyExpr){
6687                                 PropertyExpr pe = (PropertyExpr) e;
6688
6689                                 pe.IsBase = true;
6690                         }
6691
6692                         return e;
6693                 }
6694
6695                 public override void Emit (EmitContext ec)
6696                 {
6697                         throw new Exception ("Should never be called");
6698                 }
6699         }
6700
6701         /// <summary>
6702         ///   The base indexer operator
6703         /// </summary>
6704         public class BaseIndexerAccess : IndexerAccess {
6705                 public BaseIndexerAccess (ArrayList args, Location loc)
6706                         : base (null, true, loc)
6707                 {
6708                         arguments = new ArrayList ();
6709                         foreach (Expression tmp in args)
6710                                 arguments.Add (new Argument (tmp, Argument.AType.Expression));
6711                 }
6712
6713                 protected override bool CommonResolve (EmitContext ec)
6714                 {
6715                         instance_expr = ec.This;
6716
6717                         current_type = ec.ContainerType.BaseType;
6718                         indexer_type = current_type;
6719
6720                         foreach (Argument a in arguments){
6721                                 if (!a.Resolve (ec, loc))
6722                                         return false;
6723                         }
6724
6725                         return true;
6726                 }
6727         }
6728
6729         /// <summary>
6730         ///   This class exists solely to pass the Type around and to be a dummy
6731         ///   that can be passed to the conversion functions (this is used by
6732         ///   foreach implementation to typecast the object return value from
6733         ///   get_Current into the proper type.  All code has been generated and
6734         ///   we only care about the side effect conversions to be performed
6735         ///
6736         ///   This is also now used as a placeholder where a no-action expression
6737         ///   is needed (the `New' class).
6738         /// </summary>
6739         public class EmptyExpression : Expression {
6740                 public EmptyExpression ()
6741                 {
6742                         type = TypeManager.object_type;
6743                         eclass = ExprClass.Value;
6744                         loc = Location.Null;
6745                 }
6746
6747                 public EmptyExpression (Type t)
6748                 {
6749                         type = t;
6750                         eclass = ExprClass.Value;
6751                         loc = Location.Null;
6752                 }
6753
6754                 public override Expression DoResolve (EmitContext ec)
6755                 {
6756                         return this;
6757                 }
6758
6759                 public override void Emit (EmitContext ec)
6760                 {
6761                         // nothing, as we only exist to not do anything.
6762                 }
6763
6764                 //
6765                 // This is just because we might want to reuse this bad boy
6766                 // instead of creating gazillions of EmptyExpressions.
6767                 // (CanConvertImplicit uses it)
6768                 //
6769                 public void SetType (Type t)
6770                 {
6771                         type = t;
6772                 }
6773         }
6774
6775         public class UserCast : Expression {
6776                 MethodBase method;
6777                 Expression source;
6778
6779                 public UserCast (MethodInfo method, Expression source, Location l)
6780                 {
6781                         this.method = method;
6782                         this.source = source;
6783                         type = method.ReturnType;
6784                         eclass = ExprClass.Value;
6785                         loc = l;
6786                 }
6787
6788                 public override Expression DoResolve (EmitContext ec)
6789                 {
6790                         //
6791                         // We are born fully resolved
6792                         //
6793                         return this;
6794                 }
6795
6796                 public override void Emit (EmitContext ec)
6797                 {
6798                         ILGenerator ig = ec.ig;
6799
6800                         source.Emit (ec);
6801
6802                         if (method is MethodInfo)
6803                                 ig.Emit (OpCodes.Call, (MethodInfo) method);
6804                         else
6805                                 ig.Emit (OpCodes.Call, (ConstructorInfo) method);
6806
6807                 }
6808         }
6809
6810         // <summary>
6811         //   This class is used to "construct" the type during a typecast
6812         //   operation.  Since the Type.GetType class in .NET can parse
6813         //   the type specification, we just use this to construct the type
6814         //   one bit at a time.
6815         // </summary>
6816         public class ComposedCast : Expression, ITypeExpression {
6817                 Expression left;
6818                 string dim;
6819
6820                 public ComposedCast (Expression left, string dim, Location l)
6821                 {
6822                         this.left = left;
6823                         this.dim = dim;
6824                         loc = l;
6825                 }
6826
6827                 public Expression DoResolveType (EmitContext ec)
6828                 {
6829                         Type ltype = ec.DeclSpace.ResolveType (left, false, loc);
6830                         if (ltype == null)
6831                                 return null;
6832
6833                         //
6834                         // ltype.Fullname is already fully qualified, so we can skip
6835                         // a lot of probes, and go directly to TypeManager.LookupType
6836                         //
6837                         string cname = ltype.FullName + dim;
6838                         type = TypeManager.LookupTypeDirect (cname);
6839                         if (type == null){
6840                                 //
6841                                 // For arrays of enumerations we are having a problem
6842                                 // with the direct lookup.  Need to investigate.
6843                                 //
6844                                 // For now, fall back to the full lookup in that case.
6845                                 //
6846                                 type = RootContext.LookupType (
6847                                         ec.DeclSpace, cname, false, loc);
6848
6849                                 if (type == null)
6850                                         return null;
6851                         }
6852
6853                         if (!ec.ResolvingTypeTree){
6854                                 //
6855                                 // If the above flag is set, this is being invoked from the ResolveType function.
6856                                 // Upper layers take care of the type validity in this context.
6857                                 //
6858                         if (!ec.InUnsafe && type.IsPointer){
6859                                 UnsafeError (loc);
6860                                 return null;
6861                         }
6862                         }
6863
6864                         eclass = ExprClass.Type;
6865                         return this;
6866                 }
6867
6868                 public override Expression DoResolve (EmitContext ec)
6869                 {
6870                         return DoResolveType (ec);
6871                 }
6872
6873                 public override void Emit (EmitContext ec)
6874                 {
6875                         throw new Exception ("This should never be called");
6876                 }
6877
6878                 public override string ToString ()
6879                 {
6880                         return left + dim;
6881                 }
6882         }
6883
6884         //
6885         // This class is used to represent the address of an array, used
6886         // only by the Fixed statement, this is like the C "&a [0]" construct.
6887         //
6888         public class ArrayPtr : Expression {
6889                 Expression array;
6890
6891                 public ArrayPtr (Expression array, Location l)
6892                 {
6893                         Type array_type = array.Type.GetElementType ();
6894
6895                         this.array = array;
6896
6897                         string array_ptr_type_name = array_type.FullName + "*";
6898
6899                         type = Type.GetType (array_ptr_type_name);
6900                         if (type == null){
6901                                 ModuleBuilder mb = CodeGen.ModuleBuilder;
6902
6903                                 type = mb.GetType (array_ptr_type_name);
6904                         }
6905
6906                         eclass = ExprClass.Value;
6907                         loc = l;
6908                 }
6909
6910                 public override void Emit (EmitContext ec)
6911                 {
6912                         ILGenerator ig = ec.ig;
6913
6914                         array.Emit (ec);
6915                         IntLiteral.EmitInt (ig, 0);
6916                         ig.Emit (OpCodes.Ldelema, array.Type.GetElementType ());
6917                 }
6918
6919                 public override Expression DoResolve (EmitContext ec)
6920                 {
6921                         //
6922                         // We are born fully resolved
6923                         //
6924                         return this;
6925                 }
6926         }
6927
6928         //
6929         // Used by the fixed statement
6930         //
6931         public class StringPtr : Expression {
6932                 LocalBuilder b;
6933
6934                 public StringPtr (LocalBuilder b, Location l)
6935                 {
6936                         this.b = b;
6937                         eclass = ExprClass.Value;
6938                         type = TypeManager.char_ptr_type;
6939                         loc = l;
6940                 }
6941
6942                 public override Expression DoResolve (EmitContext ec)
6943                 {
6944                         // This should never be invoked, we are born in fully
6945                         // initialized state.
6946
6947                         return this;
6948                 }
6949
6950                 public override void Emit (EmitContext ec)
6951                 {
6952                         ILGenerator ig = ec.ig;
6953
6954                         ig.Emit (OpCodes.Ldloc, b);
6955                         ig.Emit (OpCodes.Conv_I);
6956                         ig.Emit (OpCodes.Call, TypeManager.int_get_offset_to_string_data);
6957                         ig.Emit (OpCodes.Add);
6958                 }
6959         }
6960
6961         //
6962         // Implements the `stackalloc' keyword
6963         //
6964         public class StackAlloc : Expression {
6965                 Type otype;
6966                 Expression t;
6967                 Expression count;
6968
6969                 public StackAlloc (Expression type, Expression count, Location l)
6970                 {
6971                         t = type;
6972                         this.count = count;
6973                         loc = l;
6974                 }
6975
6976                 public override Expression DoResolve (EmitContext ec)
6977                 {
6978                         count = count.Resolve (ec);
6979                         if (count == null)
6980                                 return null;
6981
6982                         if (count.Type != TypeManager.int32_type){
6983                                 count = ConvertImplicitRequired (ec, count, TypeManager.int32_type, loc);
6984                                 if (count == null)
6985                                         return null;
6986                         }
6987
6988                         if (ec.InCatch || ec.InFinally){
6989                                 Error (255,
6990                                               "stackalloc can not be used in a catch or finally block");
6991                                 return null;
6992                         }
6993
6994                         otype = ec.DeclSpace.ResolveType (t, false, loc);
6995
6996                         if (otype == null)
6997                                 return null;
6998
6999                         if (!TypeManager.VerifyUnManaged (otype, loc))
7000                                 return null;
7001
7002                         string ptr_name = otype.FullName + "*";
7003                         type = Type.GetType (ptr_name);
7004                         if (type == null){
7005                                 ModuleBuilder mb = CodeGen.ModuleBuilder;
7006
7007                                 type = mb.GetType (ptr_name);
7008                         }
7009                         eclass = ExprClass.Value;
7010
7011                         return this;
7012                 }
7013
7014                 public override void Emit (EmitContext ec)
7015                 {
7016                         int size = GetTypeSize (otype);
7017                         ILGenerator ig = ec.ig;
7018
7019                         if (size == 0)
7020                                 ig.Emit (OpCodes.Sizeof, otype);
7021                         else
7022                                 IntConstant.EmitInt (ig, size);
7023                         count.Emit (ec);
7024                         ig.Emit (OpCodes.Mul);
7025                         ig.Emit (OpCodes.Localloc);
7026                 }
7027         }
7028 }