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         /// <summary>
3133         ///   Used for arguments to New(), Invocation()
3134         /// </summary>
3135         public class Argument {
3136                 public enum AType : byte {
3137                         Expression,
3138                         Ref,
3139                         Out
3140                 };
3141
3142                 public readonly AType ArgType;
3143                 public Expression Expr;
3144
3145                 public Argument (Expression expr, AType type)
3146                 {
3147                         this.Expr = expr;
3148                         this.ArgType = type;
3149                 }
3150
3151                 public Type Type {
3152                         get {
3153                                 if (ArgType == AType.Ref || ArgType == AType.Out)
3154                                         return TypeManager.LookupType (Expr.Type.ToString () + "&");
3155                                 else
3156                                         return Expr.Type;
3157                         }
3158                 }
3159
3160                 public Parameter.Modifier GetParameterModifier ()
3161                 {
3162                         switch (ArgType) {
3163                         case AType.Out:
3164                                 return Parameter.Modifier.OUT | Parameter.Modifier.ISBYREF;
3165
3166                         case AType.Ref:
3167                                 return Parameter.Modifier.REF | Parameter.Modifier.ISBYREF;
3168
3169                         default:
3170                                 return Parameter.Modifier.NONE;
3171                         }
3172                 }
3173
3174                 public static string FullDesc (Argument a)
3175                 {
3176                         return (a.ArgType == AType.Ref ? "ref " :
3177                                 (a.ArgType == AType.Out ? "out " : "")) +
3178                                 TypeManager.CSharpName (a.Expr.Type);
3179                 }
3180
3181                 public bool ResolveMethodGroup (EmitContext ec, Location loc)
3182                 {
3183                         // FIXME: csc doesn't report any error if you try to use `ref' or
3184                         //        `out' in a delegate creation expression.
3185                         Expr = Expr.Resolve (ec, ResolveFlags.VariableOrValue | ResolveFlags.MethodGroup);
3186                         if (Expr == null)
3187                                 return false;
3188
3189                         return true;
3190                 }
3191
3192                 public bool Resolve (EmitContext ec, Location loc)
3193                 {
3194                         if (ArgType == AType.Ref) {
3195                                 Expr = Expr.Resolve (ec);
3196                                 if (Expr == null)
3197                                         return false;
3198
3199                                 Expr = Expr.ResolveLValue (ec, Expr);
3200                         } else if (ArgType == AType.Out)
3201                                 Expr = Expr.ResolveLValue (ec, new EmptyExpression ());
3202                         else
3203                                 Expr = Expr.Resolve (ec);
3204
3205                         if (Expr == null)
3206                                 return false;
3207
3208                         if (ArgType == AType.Expression)
3209                                 return true;
3210
3211                         if (Expr.eclass != ExprClass.Variable){
3212                                 //
3213                                 // We just probe to match the CSC output
3214                                 //
3215                                 if (Expr.eclass == ExprClass.PropertyAccess ||
3216                                     Expr.eclass == ExprClass.IndexerAccess){
3217                                         Report.Error (
3218                                                 206, loc,
3219                                                 "A property or indexer can not be passed as an out or ref " +
3220                                                 "parameter");
3221                                 } else {
3222                                         Report.Error (
3223                                                 1510, loc,
3224                                                 "An lvalue is required as an argument to out or ref");
3225                                 }
3226                                 return false;
3227                         }
3228
3229                         return true;
3230                 }
3231
3232                 public void Emit (EmitContext ec)
3233                 {
3234                         //
3235                         // Ref and Out parameters need to have their addresses taken.
3236                         //
3237                         // ParameterReferences might already be references, so we want
3238                         // to pass just the value
3239                         //
3240                         if (ArgType == AType.Ref || ArgType == AType.Out){
3241                                 AddressOp mode = AddressOp.Store;
3242
3243                                 if (ArgType == AType.Ref)
3244                                         mode |= AddressOp.Load;
3245
3246                                 if (Expr is ParameterReference){
3247                                         ParameterReference pr = (ParameterReference) Expr;
3248
3249                                         if (pr.is_ref)
3250                                                 pr.EmitLoad (ec);
3251                                         else {
3252
3253                                                 pr.AddressOf (ec, mode);
3254                                         }
3255                                 } else
3256                                         ((IMemoryLocation)Expr).AddressOf (ec, mode);
3257                         } else
3258                                 Expr.Emit (ec);
3259                 }
3260         }
3261
3262         /// <summary>
3263         ///   Invocation of methods or delegates.
3264         /// </summary>
3265         public class Invocation : ExpressionStatement {
3266                 public ArrayList Arguments;
3267
3268                 Expression expr;
3269                 MethodBase method = null;
3270                 bool is_base;
3271
3272                 static Hashtable method_parameter_cache;
3273
3274                 static Invocation ()
3275                 {
3276                         method_parameter_cache = new PtrHashtable ();
3277                 }
3278
3279                 //
3280                 // arguments is an ArrayList, but we do not want to typecast,
3281                 // as it might be null.
3282                 //
3283                 // FIXME: only allow expr to be a method invocation or a
3284                 // delegate invocation (7.5.5)
3285                 //
3286                 public Invocation (Expression expr, ArrayList arguments, Location l)
3287                 {
3288                         this.expr = expr;
3289                         Arguments = arguments;
3290                         loc = l;
3291                 }
3292
3293                 public Expression Expr {
3294                         get {
3295                                 return expr;
3296                         }
3297                 }
3298
3299                 /// <summary>
3300                 ///   Returns the Parameters (a ParameterData interface) for the
3301                 ///   Method `mb'
3302                 /// </summary>
3303                 public static ParameterData GetParameterData (MethodBase mb)
3304                 {
3305                         object pd = method_parameter_cache [mb];
3306                         object ip;
3307
3308                         if (pd != null)
3309                                 return (ParameterData) pd;
3310
3311
3312                         ip = TypeManager.LookupParametersByBuilder (mb);
3313                         if (ip != null){
3314                                 method_parameter_cache [mb] = ip;
3315
3316                                 return (ParameterData) ip;
3317                         } else {
3318                                 ParameterInfo [] pi = mb.GetParameters ();
3319                                 ReflectionParameters rp = new ReflectionParameters (pi);
3320                                 method_parameter_cache [mb] = rp;
3321
3322                                 return (ParameterData) rp;
3323                         }
3324                 }
3325
3326                 /// <summary>
3327                 ///  Determines "better conversion" as specified in 7.4.2.3
3328                 ///  Returns : 1 if a->p is better
3329                 ///            0 if a->q or neither is better
3330                 /// </summary>
3331                 static int BetterConversion (EmitContext ec, Argument a, Type p, Type q, Location loc)
3332                 {
3333                         Type argument_type = a.Type;
3334                         Expression argument_expr = a.Expr;
3335
3336                         if (argument_type == null)
3337                                 throw new Exception ("Expression of type " + a.Expr + " does not resolve its type");
3338
3339                         //
3340                         // This is a special case since csc behaves this way. I can't find
3341                         // it anywhere in the spec but oh well ...
3342                         //
3343                         if (argument_expr is NullLiteral && p == TypeManager.string_type && q == TypeManager.object_type)
3344                                 return 1;
3345                         else if (argument_expr is NullLiteral && p == TypeManager.object_type && q == TypeManager.string_type)
3346                                 return 0;
3347
3348                         if (p == q)
3349                                 return 0;
3350
3351                         if (argument_type == p)
3352                                 return 1;
3353
3354                         if (argument_type == q)
3355                                 return 0;
3356
3357                         //
3358                         // Now probe whether an implicit constant expression conversion
3359                         // can be used.
3360                         //
3361                         // An implicit constant expression conversion permits the following
3362                         // conversions:
3363                         //
3364                         //    * A constant-expression of type `int' can be converted to type
3365                         //      sbyte, byute, short, ushort, uint, ulong provided the value of
3366                         //      of the expression is withing the range of the destination type.
3367                         //
3368                         //    * A constant-expression of type long can be converted to type
3369                         //      ulong, provided the value of the constant expression is not negative
3370                         //
3371                         // FIXME: Note that this assumes that constant folding has
3372                         // taken place.  We dont do constant folding yet.
3373                         //
3374
3375                         if (argument_expr is IntConstant){
3376                                 IntConstant ei = (IntConstant) argument_expr;
3377                                 int value = ei.Value;
3378
3379                                 if (p == TypeManager.sbyte_type){
3380                                         if (value >= SByte.MinValue && value <= SByte.MaxValue)
3381                                                 return 1;
3382                                 } else if (p == TypeManager.byte_type){
3383                                         if (Byte.MinValue >= 0 && value <= Byte.MaxValue)
3384                                                 return 1;
3385                                 } else if (p == TypeManager.short_type){
3386                                         if (value >= Int16.MinValue && value <= Int16.MaxValue)
3387                                                 return 1;
3388                                 } else if (p == TypeManager.ushort_type){
3389                                         if (value >= UInt16.MinValue && value <= UInt16.MaxValue)
3390                                                 return 1;
3391                                 } else if (p == TypeManager.uint32_type){
3392                                         //
3393                                         // we can optimize this case: a positive int32
3394                                         // always fits on a uint32
3395                                         //
3396                                         if (value >= 0)
3397                                                 return 1;
3398                                 } else if (p == TypeManager.uint64_type){
3399                                         //
3400                                         // we can optimize this case: a positive int32
3401                                         // always fits on a uint64
3402                                         //
3403                                         if (value >= 0)
3404                                                 return 1;
3405                                 }
3406                         } else if (argument_type == TypeManager.int64_type && argument_expr is LongConstant){
3407                                 LongConstant lc = (LongConstant) argument_expr;
3408
3409                                 if (p == TypeManager.uint64_type){
3410                                         if (lc.Value > 0)
3411                                                 return 1;
3412                                 }
3413                         }
3414
3415                         if (q == null) {
3416                                 Expression tmp = ConvertImplicit (ec, argument_expr, p, loc);
3417
3418                                 if (tmp != null)
3419                                         return 1;
3420                                 else
3421                                         return 0;
3422                         }
3423
3424                         Expression p_tmp = new EmptyExpression (p);
3425                         Expression q_tmp = new EmptyExpression (q);
3426
3427                         if (StandardConversionExists (p_tmp, q) == true &&
3428                             StandardConversionExists (q_tmp, p) == false)
3429                                 return 1;
3430
3431                         if (p == TypeManager.sbyte_type)
3432                                 if (q == TypeManager.byte_type || q == TypeManager.ushort_type ||
3433                                     q == TypeManager.uint32_type || q == TypeManager.uint64_type)
3434                                         return 1;
3435
3436                         if (p == TypeManager.short_type)
3437                                 if (q == TypeManager.ushort_type || q == TypeManager.uint32_type ||
3438                                     q == TypeManager.uint64_type)
3439                                         return 1;
3440
3441                         if (p == TypeManager.int32_type)
3442                                 if (q == TypeManager.uint32_type || q == TypeManager.uint64_type)
3443                                         return 1;
3444
3445                         if (p == TypeManager.int64_type)
3446                                 if (q == TypeManager.uint64_type)
3447                                         return 1;
3448
3449                         return 0;
3450                 }
3451
3452                 /// <summary>
3453                 ///  Determines "Better function"
3454                 /// </summary>
3455                 /// <remarks>
3456                 ///    and returns an integer indicating :
3457                 ///    0 if candidate ain't better
3458                 ///    1 if candidate is better than the current best match
3459                 /// </remarks>
3460                 static int BetterFunction (EmitContext ec, ArrayList args,
3461                                            MethodBase candidate, MethodBase best,
3462                                            bool expanded_form, Location loc)
3463                 {
3464                         ParameterData candidate_pd = GetParameterData (candidate);
3465                         ParameterData best_pd;
3466                         int argument_count;
3467
3468                         if (args == null)
3469                                 argument_count = 0;
3470                         else
3471                                 argument_count = args.Count;
3472
3473                         int cand_count = candidate_pd.Count;
3474
3475                         if (cand_count == 0 && argument_count == 0)
3476                                 return 1;
3477
3478                         if (candidate_pd.ParameterModifier (cand_count - 1) != Parameter.Modifier.PARAMS)
3479                                 if (cand_count != argument_count)
3480                                         return 0;
3481
3482                         if (best == null) {
3483                                 int x = 0;
3484
3485                                 if (argument_count == 0 && cand_count == 1 &&
3486                                     candidate_pd.ParameterModifier (cand_count - 1) == Parameter.Modifier.PARAMS)
3487                                         return 1;
3488
3489                                 for (int j = argument_count; j > 0;) {
3490                                         j--;
3491
3492                                         Argument a = (Argument) args [j];
3493                                         Type t = candidate_pd.ParameterType (j);
3494
3495                                         if (candidate_pd.ParameterModifier (j) == Parameter.Modifier.PARAMS)
3496                                                 if (expanded_form)
3497                                                         t = t.GetElementType ();
3498
3499                                         x = BetterConversion (ec, a, t, null, loc);
3500
3501                                         if (x <= 0)
3502                                                 break;
3503                                 }
3504
3505                                 if (x > 0)
3506                                         return 1;
3507                                 else
3508                                         return 0;
3509                         }
3510
3511                         best_pd = GetParameterData (best);
3512
3513                         int rating1 = 0, rating2 = 0;
3514
3515                         for (int j = 0; j < argument_count; ++j) {
3516                                 int x, y;
3517
3518                                 Argument a = (Argument) args [j];
3519
3520                                 Type ct = candidate_pd.ParameterType (j);
3521                                 Type bt = best_pd.ParameterType (j);
3522
3523                                 if (candidate_pd.ParameterModifier (j) == Parameter.Modifier.PARAMS)
3524                                         if (expanded_form)
3525                                                 ct = ct.GetElementType ();
3526
3527                                 if (best_pd.ParameterModifier (j) == Parameter.Modifier.PARAMS)
3528                                         if (expanded_form)
3529                                                 bt = bt.GetElementType ();
3530
3531                                 x = BetterConversion (ec, a, ct, bt, loc);
3532                                 y = BetterConversion (ec, a, bt, ct, loc);
3533
3534                                 if (x < y)
3535                                         return 0;
3536
3537                                 rating1 += x;
3538                                 rating2 += y;
3539                         }
3540
3541                         if (rating1 > rating2)
3542                                 return 1;
3543                         else
3544                                 return 0;
3545                 }
3546
3547                 public static string FullMethodDesc (MethodBase mb)
3548                 {
3549                         string ret_type = "";
3550
3551                         if (mb is MethodInfo)
3552                                 ret_type = TypeManager.CSharpName (((MethodInfo) mb).ReturnType) + " ";
3553
3554                         StringBuilder sb = new StringBuilder (ret_type + mb.Name);
3555                         ParameterData pd = GetParameterData (mb);
3556
3557                         int count = pd.Count;
3558                         sb.Append (" (");
3559
3560                         for (int i = count; i > 0; ) {
3561                                 i--;
3562
3563                                 sb.Append (pd.ParameterDesc (count - i - 1));
3564                                 if (i != 0)
3565                                         sb.Append (", ");
3566                         }
3567
3568                         sb.Append (")");
3569                         return sb.ToString ();
3570                 }
3571
3572                 public static MethodGroupExpr MakeUnionSet (Expression mg1, Expression mg2, Location loc)
3573                 {
3574                         MemberInfo [] miset;
3575                         MethodGroupExpr union;
3576
3577                         if (mg1 == null){
3578                                 if (mg2 == null)
3579                                         return null;
3580                                 return (MethodGroupExpr) mg2;
3581                         } else {
3582                                 if (mg2 == null)
3583                                         return (MethodGroupExpr) mg1;
3584                         }
3585
3586                         MethodGroupExpr left_set = null, right_set = null;
3587                         int length1 = 0, length2 = 0;
3588
3589                         left_set = (MethodGroupExpr) mg1;
3590                         length1 = left_set.Methods.Length;
3591
3592                         right_set = (MethodGroupExpr) mg2;
3593                         length2 = right_set.Methods.Length;
3594
3595                         ArrayList common = new ArrayList ();
3596
3597                         foreach (MethodBase l in left_set.Methods){
3598                                 foreach (MethodBase r in right_set.Methods){
3599                                         if (l != r)
3600                                                 continue;
3601                                         common.Add (r);
3602                                         break;
3603                                 }
3604                         }
3605
3606                         miset = new MemberInfo [length1 + length2 - common.Count];
3607                         left_set.Methods.CopyTo (miset, 0);
3608
3609                         int k = length1;
3610
3611                         foreach (MemberInfo mi in right_set.Methods){
3612                                 if (!common.Contains (mi))
3613                                         miset [k++] = mi;
3614                         }
3615
3616                         union = new MethodGroupExpr (miset, loc);
3617
3618                         return union;
3619                 }
3620
3621                 /// <summary>
3622                 ///  Determines is the candidate method, if a params method, is applicable
3623                 ///  in its expanded form to the given set of arguments
3624                 /// </summary>
3625                 static bool IsParamsMethodApplicable (EmitContext ec, ArrayList arguments, MethodBase candidate)
3626                 {
3627                         int arg_count;
3628
3629                         if (arguments == null)
3630                                 arg_count = 0;
3631                         else
3632                                 arg_count = arguments.Count;
3633
3634                         ParameterData pd = GetParameterData (candidate);
3635
3636                         int pd_count = pd.Count;
3637
3638                         if (pd_count == 0)
3639                                 return false;
3640
3641                         if (pd.ParameterModifier (pd_count - 1) != Parameter.Modifier.PARAMS)
3642                                 return false;
3643
3644                         if (pd_count - 1 > arg_count)
3645                                 return false;
3646
3647                         if (pd_count == 1 && arg_count == 0)
3648                                 return true;
3649
3650                         //
3651                         // If we have come this far, the case which remains is when the number of parameters
3652                         // is less than or equal to the argument count.
3653                         //
3654                         for (int i = 0; i < pd_count - 1; ++i) {
3655
3656                                 Argument a = (Argument) arguments [i];
3657
3658                                 Parameter.Modifier a_mod = a.GetParameterModifier () &
3659                                         ~(Parameter.Modifier.OUT | Parameter.Modifier.REF);
3660                                 Parameter.Modifier p_mod = pd.ParameterModifier (i) &
3661                                         ~(Parameter.Modifier.OUT | Parameter.Modifier.REF);
3662
3663                                 if (a_mod == p_mod) {
3664
3665                                         if (a_mod == Parameter.Modifier.NONE)
3666                                                 if (!ImplicitConversionExists (ec, a.Expr, pd.ParameterType (i)))
3667                                                         return false;
3668
3669                                         if ((a_mod & Parameter.Modifier.ISBYREF) != 0) {
3670                                                 Type pt = pd.ParameterType (i);
3671
3672                                                 if (!pt.IsByRef)
3673                                                         pt = TypeManager.LookupType (pt.FullName + "&");
3674
3675                                                 if (pt != a.Type)
3676                                                         return false;
3677                                         }
3678                                 } else
3679                                         return false;
3680
3681                         }
3682
3683                         Type element_type = pd.ParameterType (pd_count - 1).GetElementType ();
3684
3685                         for (int i = pd_count - 1; i < arg_count; i++) {
3686                                 Argument a = (Argument) arguments [i];
3687
3688                                 if (!StandardConversionExists (a.Expr, element_type))
3689                                         return false;
3690                         }
3691
3692                         return true;
3693                 }
3694
3695                 /// <summary>
3696                 ///  Determines if the candidate method is applicable (section 14.4.2.1)
3697                 ///  to the given set of arguments
3698                 /// </summary>
3699                 static bool IsApplicable (EmitContext ec, ArrayList arguments, MethodBase candidate)
3700                 {
3701                         int arg_count;
3702
3703                         if (arguments == null)
3704                                 arg_count = 0;
3705                         else
3706                                 arg_count = arguments.Count;
3707
3708                         ParameterData pd = GetParameterData (candidate);
3709
3710                         int pd_count = pd.Count;
3711
3712                         if (arg_count != pd.Count)
3713                                 return false;
3714
3715                         for (int i = arg_count; i > 0; ) {
3716                                 i--;
3717
3718                                 Argument a = (Argument) arguments [i];
3719
3720                                 Parameter.Modifier a_mod = a.GetParameterModifier () &
3721                                         ~(Parameter.Modifier.OUT | Parameter.Modifier.REF);
3722                                 Parameter.Modifier p_mod = pd.ParameterModifier (i) &
3723                                         ~(Parameter.Modifier.OUT | Parameter.Modifier.REF);
3724
3725                                 if (a_mod == p_mod ||
3726                                     (a_mod == Parameter.Modifier.NONE && p_mod == Parameter.Modifier.PARAMS)) {
3727                                         if (a_mod == Parameter.Modifier.NONE)
3728                                                 if (!ImplicitConversionExists (ec, a.Expr, pd.ParameterType (i)))
3729                                                         return false;
3730
3731                                         if ((a_mod & Parameter.Modifier.ISBYREF) != 0) {
3732                                                 Type pt = pd.ParameterType (i);
3733
3734                                                 if (!pt.IsByRef)
3735                                                         pt = TypeManager.LookupType (pt.FullName + "&");
3736
3737                                                 if (pt != a.Type)
3738                                                         return false;
3739                                         }
3740                                 } else
3741                                         return false;
3742                         }
3743
3744                         return true;
3745                 }
3746
3747
3748
3749                 /// <summary>
3750                 ///   Find the Applicable Function Members (7.4.2.1)
3751                 ///
3752                 ///   me: Method Group expression with the members to select.
3753                 ///       it might contain constructors or methods (or anything
3754                 ///       that maps to a method).
3755                 ///
3756                 ///   Arguments: ArrayList containing resolved Argument objects.
3757                 ///
3758                 ///   loc: The location if we want an error to be reported, or a Null
3759                 ///        location for "probing" purposes.
3760                 ///
3761                 ///   Returns: The MethodBase (either a ConstructorInfo or a MethodInfo)
3762                 ///            that is the best match of me on Arguments.
3763                 ///
3764                 /// </summary>
3765                 public static MethodBase OverloadResolve (EmitContext ec, MethodGroupExpr me,
3766                                                           ArrayList Arguments, Location loc)
3767                 {
3768                         ArrayList afm = new ArrayList ();
3769                         MethodBase method = null;
3770                         Type current_type = null;
3771                         int argument_count;
3772                         ArrayList candidates = new ArrayList ();
3773
3774
3775                         foreach (MethodBase candidate in me.Methods){
3776                                 int x;
3777
3778                                 // If we're going one level higher in the class hierarchy, abort if
3779                                 // we already found an applicable method.
3780                                 if (candidate.DeclaringType != current_type) {
3781                                         current_type = candidate.DeclaringType;
3782                                         if (method != null)
3783                                                 break;
3784                                 }
3785
3786                                 // Check if candidate is applicable (section 14.4.2.1)
3787                                 if (!IsApplicable (ec, Arguments, candidate))
3788                                         continue;
3789
3790                                 candidates.Add (candidate);
3791                                 x = BetterFunction (ec, Arguments, candidate, method, false, loc);
3792
3793                                 if (x == 0)
3794                                         continue;
3795
3796                                 method = candidate;
3797                         }
3798
3799                         if (Arguments == null)
3800                                 argument_count = 0;
3801                         else
3802                                 argument_count = Arguments.Count;
3803
3804                         //
3805                         // Now we see if we can find params functions, applicable in their expanded form
3806                         // since if they were applicable in their normal form, they would have been selected
3807                         // above anyways
3808                         //
3809                         bool chose_params_expanded = false;
3810
3811                         if (method == null) {
3812                                 candidates = new ArrayList ();
3813                                 foreach (MethodBase candidate in me.Methods){
3814                                         if (!IsParamsMethodApplicable (ec, Arguments, candidate))
3815                                                 continue;
3816
3817                                         candidates.Add (candidate);
3818
3819                                         int x = BetterFunction (ec, Arguments, candidate, method, true, loc);
3820                                         if (x == 0)
3821                                                 continue;
3822
3823                                         method = candidate;
3824                                         chose_params_expanded = true;
3825                                 }
3826                         }
3827
3828                         if (method == null) {
3829                                 //
3830                                 // Okay so we have failed to find anything so we
3831                                 // return by providing info about the closest match
3832                                 //
3833                                 for (int i = 0; i < me.Methods.Length; ++i) {
3834
3835                                         MethodBase c = (MethodBase) me.Methods [i];
3836                                         ParameterData pd = GetParameterData (c);
3837
3838                                         if (pd.Count != argument_count)
3839                                                 continue;
3840
3841                                         VerifyArgumentsCompat (ec, Arguments, argument_count, c, false,
3842                                                                null, loc);
3843                                 }
3844
3845                                 return null;
3846                         }
3847
3848                         //
3849                         // Now check that there are no ambiguities i.e the selected method
3850                         // should be better than all the others
3851                         //
3852
3853                         foreach (MethodBase candidate in candidates){
3854                                 if (candidate == method)
3855                                         continue;
3856
3857                                 //
3858                                 // If a normal method is applicable in the sense that it has the same
3859                                 // number of arguments, then the expanded params method is never applicable
3860                                 // so we debar the params method.
3861                                 //
3862                                 if (IsParamsMethodApplicable (ec, Arguments, candidate) &&
3863                                     IsApplicable (ec, Arguments, method))
3864                                         continue;
3865
3866                                 int x = BetterFunction (ec, Arguments, method, candidate,
3867                                                         chose_params_expanded, loc);
3868
3869                                 if (x != 1) {
3870                                         Report.Error (
3871                                                 121, loc,
3872                                                 "Ambiguous call when selecting function due to implicit casts");
3873                                         return null;
3874                                 }
3875                         }
3876
3877                         //
3878                         // And now check if the arguments are all compatible, perform conversions
3879                         // if necessary etc. and return if everything is all right
3880                         //
3881
3882                         if (VerifyArgumentsCompat (ec, Arguments, argument_count, method,
3883                                                    chose_params_expanded, null, loc))
3884                                 return method;
3885                         else
3886                                 return null;
3887                 }
3888
3889                 public static bool VerifyArgumentsCompat (EmitContext ec, ArrayList Arguments,
3890                         int argument_count,
3891                         MethodBase method,
3892                         bool chose_params_expanded,
3893                         Type delegate_type,
3894                         Location loc)
3895                 {
3896                         return (VerifyArgumentsCompat (ec, Arguments, argument_count,
3897                                 method, chose_params_expanded, delegate_type, loc, null));
3898                 }
3899
3900                 public static bool VerifyArgumentsCompat (EmitContext ec, ArrayList Arguments,
3901                                                           int argument_count,
3902                                                           MethodBase method,
3903                                                           bool chose_params_expanded,
3904                                                           Type delegate_type,
3905                                                           Location loc,
3906                                                           string InvokingProperty)
3907                 {
3908                         ParameterData pd = GetParameterData (method);
3909                         int pd_count = pd.Count;
3910
3911                         for (int j = 0; j < argument_count; j++) {
3912                                 Argument a = (Argument) Arguments [j];
3913                                 Expression a_expr = a.Expr;
3914                                 Type parameter_type = pd.ParameterType (j);
3915
3916                                 if (pd.ParameterModifier (j) == Parameter.Modifier.PARAMS &&
3917                                     chose_params_expanded)
3918                                         parameter_type = TypeManager.TypeToCoreType (parameter_type.GetElementType ());
3919
3920                                 if (a.Type != parameter_type){
3921                                         Expression conv;
3922
3923                                         conv = ConvertImplicit (ec, a_expr, parameter_type, loc);
3924
3925                                         if (conv == null) {
3926                                                 if (!Location.IsNull (loc)) {
3927                                                         if (delegate_type == null)
3928                                                                 if (InvokingProperty == null)
3929                                                                         Report.Error (1502, loc,
3930                                                                                 "The best overloaded match for method '" +
3931                                                                                 FullMethodDesc (method) +
3932                                                                                 "' has some invalid arguments");
3933                                                                 else
3934                                                                         Report.Error (1502, loc,
3935                                                                                 "Property '" +
3936                                                                                 InvokingProperty +
3937                                                                                 "' has some invalid arguments");
3938                                                         else
3939                                                                 Report.Error (1594, loc,
3940                                                                               "Delegate '" + delegate_type.ToString () +
3941                                                                               "' has some invalid arguments.");
3942                                                         Report.Error (1503, loc,
3943                                                          "Argument " + (j+1) +
3944                                                          ": Cannot convert from '" + Argument.FullDesc (a)
3945                                                          + "' to '" + pd.ParameterDesc (j) + "'");
3946                                                 }
3947
3948                                                 return false;
3949                                         }
3950
3951                                         //
3952                                         // Update the argument with the implicit conversion
3953                                         //
3954                                         if (a_expr != conv)
3955                                                 a.Expr = conv;
3956                                 }
3957
3958                                 Parameter.Modifier a_mod = a.GetParameterModifier () &
3959                                         ~(Parameter.Modifier.OUT | Parameter.Modifier.REF);
3960                                 Parameter.Modifier p_mod = pd.ParameterModifier (j) &
3961                                         ~(Parameter.Modifier.OUT | Parameter.Modifier.REF);
3962
3963
3964                                 if (a_mod != p_mod &&
3965                                     pd.ParameterModifier (pd_count - 1) != Parameter.Modifier.PARAMS) {
3966                                         if (!Location.IsNull (loc)) {
3967                                                 Report.Error (1502, loc,
3968                                                        "The best overloaded match for method '" + FullMethodDesc (method)+
3969                                                        "' has some invalid arguments");
3970                                                 Report.Error (1503, loc,
3971                                                        "Argument " + (j+1) +
3972                                                        ": Cannot convert from '" + Argument.FullDesc (a)
3973                                                        + "' to '" + pd.ParameterDesc (j) + "'");
3974                                         }
3975
3976                                         return false;
3977                                 }
3978                         }
3979
3980                         return true;
3981                 }
3982
3983                 public override Expression DoResolve (EmitContext ec)
3984                 {
3985                         //
3986                         // First, resolve the expression that is used to
3987                         // trigger the invocation
3988                         //
3989                         Expression expr_to_return = null;
3990
3991                         if (expr is BaseAccess)
3992                                 is_base = true;
3993
3994                         expr = expr.Resolve (ec, ResolveFlags.VariableOrValue | ResolveFlags.MethodGroup);
3995                         if (expr == null)
3996                                 return null;
3997
3998                         if (!(expr is MethodGroupExpr))
3999                         {
4000                                 Type expr_type = expr.Type;
4001
4002                                 if (expr_type != null)
4003                                 {
4004                                         bool IsDelegate = TypeManager.IsDelegateType (expr_type);
4005                                         if (IsDelegate)
4006                                                 return (new DelegateInvocation (
4007                                                         this.expr, Arguments, loc)).Resolve (ec);
4008                                 }
4009                         }
4010                         /*
4011                         if (!(expr is MethodGroupExpr)){
4012                                 expr.Error118 (ResolveFlags.MethodGroup);
4013                                 return null;
4014                         }
4015                         */
4016                         //
4017                         // Next, evaluate all the expressions in the argument list
4018                         //
4019                         if (Arguments != null)
4020                         {
4021                                 foreach (Argument a in Arguments)
4022                                 {
4023                                         if (!a.Resolve (ec, loc))
4024                                                 return null;
4025                                 }
4026                         }
4027
4028                         if (expr is MethodGroupExpr)
4029                         {
4030                                 MethodGroupExpr mg = (MethodGroupExpr) expr;
4031                                 method = OverloadResolve (ec, mg, Arguments, loc);
4032
4033                                 if (method == null)
4034                                 {
4035                                         Error (-6,
4036                                                 "Could not find any applicable function for this argument list");
4037                                         return null;
4038                                 }
4039
4040                                 MethodInfo mi = method as MethodInfo;
4041                                 if (mi != null)
4042                                 {
4043                                         type = TypeManager.TypeToCoreType (mi.ReturnType);
4044                                         if (!mi.IsStatic && !mg.IsExplicitImpl && (mg.InstanceExpression == null))
4045                                                 SimpleName.Error_ObjectRefRequired (ec, loc, mi.Name);
4046                                 }
4047
4048                                 if (type.IsPointer)
4049                                 {
4050                                         if (!ec.InUnsafe)
4051                                         {
4052                                                 UnsafeError (loc);
4053                                                 return null;
4054                                         }
4055                                 }
4056                                 eclass = ExprClass.Value;
4057                                 expr_to_return = this;
4058                         }
4059
4060                         if (expr is PropertyExpr)
4061                         {
4062                                 PropertyExpr pe = ((PropertyExpr) expr);
4063                                 pe.PropertyArgs = (ArrayList) Arguments.Clone();
4064                                 Arguments.Clear();
4065                                 Arguments = new ArrayList();
4066                                 MethodBase mi = pe.PropertyInfo.GetGetMethod(true);
4067
4068                                 if(VerifyArgumentsCompat (ec, pe.PropertyArgs,
4069                                         pe.PropertyArgs.Count, mi, false, null, loc, pe.Name)) \r
4070                                 {
4071
4072                                         expr_to_return = pe.DoResolve (ec);
4073                                         expr_to_return.eclass = ExprClass.PropertyAccess;
4074                                 }
4075                         }
4076
4077                         return expr_to_return;
4078                 }
4079
4080                 // <summary>
4081                 //   Emits the list of arguments as an array
4082                 // </summary>
4083                 static void EmitParams (EmitContext ec, int idx, ArrayList arguments)
4084                 {
4085                         ILGenerator ig = ec.ig;
4086                         int count = arguments.Count - idx;
4087                         Argument a = (Argument) arguments [idx];
4088                         Type t = a.Expr.Type;
4089                         string array_type = t.FullName + "[]";
4090                         LocalBuilder array;
4091
4092                         array = ig.DeclareLocal (TypeManager.LookupType (array_type));
4093                         IntConstant.EmitInt (ig, count);
4094                         ig.Emit (OpCodes.Newarr, TypeManager.TypeToCoreType (t));
4095                         ig.Emit (OpCodes.Stloc, array);
4096
4097                         int top = arguments.Count;
4098                         for (int j = idx; j < top; j++){
4099                                 a = (Argument) arguments [j];
4100
4101                                 ig.Emit (OpCodes.Ldloc, array);
4102                                 IntConstant.EmitInt (ig, j - idx);
4103                                 a.Emit (ec);
4104
4105                                 ArrayAccess.EmitStoreOpcode (ig, t);
4106                         }
4107                         ig.Emit (OpCodes.Ldloc, array);
4108                 }
4109
4110                 /// <summary>
4111                 ///   Emits a list of resolved Arguments that are in the arguments
4112                 ///   ArrayList.
4113                 ///
4114                 ///   The MethodBase argument might be null if the
4115                 ///   emission of the arguments is known not to contain
4116                 ///   a `params' field (for example in constructors or other routines
4117                 ///   that keep their arguments in this structure)
4118                 /// </summary>
4119                 public static void EmitArguments (EmitContext ec, MethodBase mb, ArrayList arguments)
4120                 {
4121                         ParameterData pd;
4122                         if (mb != null)
4123                                 pd = GetParameterData (mb);
4124                         else
4125                                 pd = null;
4126
4127                         //
4128                         // If we are calling a params method with no arguments, special case it
4129                         //
4130                         if (arguments == null){
4131                                 if (pd != null && pd.Count > 0 &&
4132                                     pd.ParameterModifier (0) == Parameter.Modifier.PARAMS){
4133                                         ILGenerator ig = ec.ig;
4134
4135                                         IntConstant.EmitInt (ig, 0);
4136                                         ig.Emit (OpCodes.Newarr, pd.ParameterType (0).GetElementType ());
4137                                 }
4138
4139                                 return;
4140                         }
4141
4142                         int top = arguments.Count;
4143
4144                         for (int i = 0; i < top; i++){
4145                                 Argument a = (Argument) arguments [i];
4146
4147                                 if (pd != null){
4148                                         if (pd.ParameterModifier (i) == Parameter.Modifier.PARAMS){
4149                                                 //
4150                                                 // Special case if we are passing the same data as the
4151                                                 // params argument, do not put it in an array.
4152                                                 //
4153                                                 if (pd.ParameterType (i) == a.Type)
4154                                                         a.Emit (ec);
4155                                                 else
4156                                                         EmitParams (ec, i, arguments);
4157                                                 return;
4158                                         }
4159                                 }
4160
4161                                 a.Emit (ec);
4162                         }
4163
4164                         if (pd != null && pd.Count > top &&
4165                             pd.ParameterModifier (top) == Parameter.Modifier.PARAMS){
4166                                 ILGenerator ig = ec.ig;
4167
4168                                 IntConstant.EmitInt (ig, 0);
4169                                 ig.Emit (OpCodes.Newarr, pd.ParameterType (top).GetElementType ());
4170                         }
4171                 }
4172
4173                 /// <remarks>
4174                 ///   is_base tells whether we want to force the use of the `call'
4175                 ///   opcode instead of using callvirt.  Call is required to call
4176                 ///   a specific method, while callvirt will always use the most
4177                 ///   recent method in the vtable.
4178                 ///
4179                 ///   is_static tells whether this is an invocation on a static method
4180                 ///
4181                 ///   instance_expr is an expression that represents the instance
4182                 ///   it must be non-null if is_static is false.
4183                 ///
4184                 ///   method is the method to invoke.
4185                 ///
4186                 ///   Arguments is the list of arguments to pass to the method or constructor.
4187                 /// </remarks>
4188                 public static void EmitCall (EmitContext ec, bool is_base,
4189                                              bool is_static, Expression instance_expr,
4190                                              MethodBase method, ArrayList Arguments, Location loc)
4191                 {
4192                         EmitCall (ec, is_base, is_static, instance_expr, method, Arguments, null, loc);
4193                 }
4194
4195                 public static void EmitCall (EmitContext ec, bool is_base,
4196                         bool is_static, Expression instance_expr,
4197                         MethodBase method, ArrayList Arguments, ArrayList prop_args, Location loc)
4198                 {
4199                         ILGenerator ig = ec.ig;
4200                         bool struct_call = false;
4201
4202                         Type decl_type = method.DeclaringType;
4203
4204                         if (!RootContext.StdLib) \r
4205                         {
4206                                 // Replace any calls to the system's System.Array type with calls to
4207                                 // the newly created one.
4208                                 if (method == TypeManager.system_int_array_get_length)
4209                                         method = TypeManager.int_array_get_length;
4210                                 else if (method == TypeManager.system_int_array_get_rank)
4211                                         method = TypeManager.int_array_get_rank;
4212                                 else if (method == TypeManager.system_object_array_clone)
4213                                         method = TypeManager.object_array_clone;
4214                                 else if (method == TypeManager.system_int_array_get_length_int)
4215                                         method = TypeManager.int_array_get_length_int;
4216                                 else if (method == TypeManager.system_int_array_get_lower_bound_int)
4217                                         method = TypeManager.int_array_get_lower_bound_int;
4218                                 else if (method == TypeManager.system_int_array_get_upper_bound_int)
4219                                         method = TypeManager.int_array_get_upper_bound_int;
4220                                 else if (method == TypeManager.system_void_array_copyto_array_int)
4221                                         method = TypeManager.void_array_copyto_array_int;
4222                         }
4223
4224                         //
4225                         // This checks the `ConditionalAttribute' on the method, and the
4226                         // ObsoleteAttribute
4227                         //
4228                         TypeManager.MethodFlags flags = TypeManager.GetMethodFlags (method, loc);
4229                         if ((flags & TypeManager.MethodFlags.IsObsoleteError) != 0)
4230                                 return;
4231                         if ((flags & TypeManager.MethodFlags.ShouldIgnore) != 0)
4232                                 return;
4233
4234                         if (!is_static)\r
4235                         {
4236                                 if (decl_type.IsValueType)
4237                                         struct_call = true;
4238                                 //
4239                                 // If this is ourselves, push "this"
4240                                 //
4241                                 if (instance_expr == null)\r
4242                                 {
4243                                         ig.Emit (OpCodes.Ldarg_0);
4244                                 } \r
4245                                 else \r
4246                                 {
4247                                         //
4248                                         // Push the instance expression
4249                                         //
4250                                         if (instance_expr.Type.IsValueType)\r
4251                                         {
4252                                                 //
4253                                                 // Special case: calls to a function declared in a
4254                                                 // reference-type with a value-type argument need
4255                                                 // to have their value boxed.
4256
4257                                                 struct_call = true;
4258                                                 if (decl_type.IsValueType)\r
4259                                                 {
4260                                                         //
4261                                                         // If the expression implements IMemoryLocation, then
4262                                                         // we can optimize and use AddressOf on the
4263                                                         // return.
4264                                                         //
4265                                                         // If not we have to use some temporary storage for
4266                                                         // it.
4267                                                         if (instance_expr is IMemoryLocation)\r
4268                                                         {
4269                                                                 ((IMemoryLocation)instance_expr).
4270                                                                         AddressOf (ec, AddressOp.LoadStore);
4271                                                         }
4272                                                         else \r
4273                                                         {
4274                                                                 Type t = instance_expr.Type;
4275
4276                                                                 instance_expr.Emit (ec);
4277                                                                 LocalBuilder temp = ig.DeclareLocal (t);
4278                                                                 ig.Emit (OpCodes.Stloc, temp);
4279                                                                 ig.Emit (OpCodes.Ldloca, temp);
4280                                                         }
4281                                                 } \r
4282                                                 else \r
4283                                                 {
4284                                                         instance_expr.Emit (ec);
4285                                                         ig.Emit (OpCodes.Box, instance_expr.Type);
4286                                                 }
4287                                         } \r
4288                                         else
4289                                                 instance_expr.Emit (ec);
4290                                 }
4291                         }
4292
4293                         if (prop_args != null && prop_args.Count > 0)\r
4294                         {
4295                                 if (Arguments == null)
4296                                         Arguments = new ArrayList();
4297
4298                                 for (int i = prop_args.Count-1; i >=0 ; i--) \r
4299                                 {
4300                                         Arguments.Insert (0,prop_args[i]);
4301                                 }
4302
4303                         }
4304
4305                         EmitArguments (ec, method, Arguments);\r
4306 \r
4307                         if (is_static || struct_call || is_base)\r
4308                         {
4309                                 if (method is MethodInfo) \r
4310                                 {
4311                                         ig.Emit (OpCodes.Call, (MethodInfo) method);
4312                                 } \r
4313                                 else
4314                                         ig.Emit (OpCodes.Call, (ConstructorInfo) method);
4315                         } \r
4316                         else \r
4317                         {
4318                                 if (method is MethodInfo)
4319                                         ig.Emit (OpCodes.Callvirt, (MethodInfo) method);
4320                                 else
4321                                         ig.Emit (OpCodes.Callvirt, (ConstructorInfo) method);
4322                         }
4323                 }
4324
4325                 static void EmitPropertyArgs (EmitContext ec, ArrayList prop_args)
4326                 {
4327                         int top = prop_args.Count;
4328
4329                         for (int i = 0; i < top; i++)\r
4330                         {
4331                                 Argument a = (Argument) prop_args [i];
4332                                 a.Emit (ec);
4333                         }
4334                 }
4335
4336                 public override void Emit (EmitContext ec)
4337                 {
4338                         MethodGroupExpr mg = (MethodGroupExpr) this.expr;
4339
4340                         EmitCall (
4341                                 ec, is_base, method.IsStatic, mg.InstanceExpression, method, Arguments, loc);
4342                 }
4343
4344                 public override void EmitStatement (EmitContext ec)
4345                 {
4346                         Emit (ec);
4347
4348                         //
4349                         // Pop the return value if there is one
4350                         //
4351                         if (method is MethodInfo){
4352                                 Type ret = ((MethodInfo)method).ReturnType;
4353                                 if (TypeManager.TypeToCoreType (ret) != TypeManager.void_type)
4354                                         ec.ig.Emit (OpCodes.Pop);
4355                         }
4356                 }
4357         }
4358
4359         //
4360         // This class is used to "disable" the code generation for the
4361         // temporary variable when initializing value types.
4362         //
4363         class EmptyAddressOf : EmptyExpression, IMemoryLocation {
4364                 public void AddressOf (EmitContext ec, AddressOp Mode)
4365                 {
4366                         // nothing
4367                 }
4368         }
4369
4370         /// <summary>
4371         ///    Implements the new expression
4372         /// </summary>
4373         public class New : ExpressionStatement {
4374                 public readonly ArrayList Arguments;
4375                 public readonly Expression RequestedType;
4376
4377                 MethodBase method = null;
4378
4379                 //
4380                 // If set, the new expression is for a value_target, and
4381                 // we will not leave anything on the stack.
4382                 //
4383                 Expression value_target;
4384                 bool value_target_set = false;
4385
4386                 public New (Expression requested_type, ArrayList arguments, Location l)
4387                 {
4388                         RequestedType = requested_type;
4389                         Arguments = arguments;
4390                         loc = l;
4391                 }
4392
4393                 public Expression ValueTypeVariable {
4394                         get {
4395                                 return value_target;
4396                         }
4397
4398                         set {
4399                                 value_target = value;
4400                                 value_target_set = true;
4401                         }
4402                 }
4403
4404                 //
4405                 // This function is used to disable the following code sequence for
4406                 // value type initialization:
4407                 //
4408                 // AddressOf (temporary)
4409                 // Construct/Init
4410                 // LoadTemporary
4411                 //
4412                 // Instead the provide will have provided us with the address on the
4413                 // stack to store the results.
4414                 //
4415                 static Expression MyEmptyExpression;
4416
4417                 public void DisableTemporaryValueType ()
4418                 {
4419                         if (MyEmptyExpression == null)
4420                                 MyEmptyExpression = new EmptyAddressOf ();
4421
4422                         //
4423                         // To enable this, look into:
4424                         // test-34 and test-89 and self bootstrapping.
4425                         //
4426                         // For instance, we can avoid a copy by using `newobj'
4427                         // instead of Call + Push-temp on value types.
4428 //                      value_target = MyEmptyExpression;
4429                 }
4430
4431                 public override Expression DoResolve (EmitContext ec)
4432                 {
4433                         type = ec.DeclSpace.ResolveType (RequestedType, false, loc);
4434
4435                         if (type == null)
4436                                 return null;
4437
4438                         bool IsDelegate = TypeManager.IsDelegateType (type);
4439
4440                         if (IsDelegate)
4441                                 return (new NewDelegate (type, Arguments, loc)).Resolve (ec);
4442
4443                         if (type.IsInterface || type.IsAbstract){
4444                                 Error (
4445                                         144, "It is not possible to create instances of interfaces " +
4446                                         "or abstract classes");
4447                                 return null;
4448                         }
4449
4450                         bool is_struct = false;
4451                         is_struct = type.IsValueType;
4452                         eclass = ExprClass.Value;
4453
4454                         //
4455                         // SRE returns a match for .ctor () on structs (the object constructor),
4456                         // so we have to manually ignore it.
4457                         //
4458                         if (is_struct && Arguments == null)
4459                                 return this;
4460
4461                         Expression ml;
4462                         ml = MemberLookupFinal (ec, type, ".ctor",
4463                                                 MemberTypes.Constructor,
4464                                                 AllBindingFlags | BindingFlags.DeclaredOnly, loc);
4465
4466                         if (ml == null)
4467                                 return null;
4468
4469                         if (! (ml is MethodGroupExpr)){
4470                                 if (!is_struct){
4471                                         ml.Error118 ("method group");
4472                                         return null;
4473                                 }
4474                         }
4475
4476                         if (ml != null) {
4477                                 if (Arguments != null){
4478                                         foreach (Argument a in Arguments){
4479                                                 if (!a.Resolve (ec, loc))
4480                                                         return null;
4481                                         }
4482                                 }
4483
4484                                 method = Invocation.OverloadResolve (ec, (MethodGroupExpr) ml,
4485                                                                      Arguments, loc);
4486
4487                         }
4488
4489                         if (method == null) {
4490                                 if (!is_struct || Arguments.Count > 0) {
4491                                         Error (1501,
4492                                                "New invocation: Can not find a constructor for " +
4493                                                "this argument list");
4494                                         return null;
4495                                 }
4496                         }
4497                         return this;
4498                 }
4499
4500                 //
4501                 // This DoEmit can be invoked in two contexts:
4502                 //    * As a mechanism that will leave a value on the stack (new object)
4503                 //    * As one that wont (init struct)
4504                 //
4505                 // You can control whether a value is required on the stack by passing
4506                 // need_value_on_stack.  The code *might* leave a value on the stack
4507                 // so it must be popped manually
4508                 //
4509                 // If we are dealing with a ValueType, we have a few
4510                 // situations to deal with:
4511                 //
4512                 //    * The target is a ValueType, and we have been provided
4513                 //      the instance (this is easy, we are being assigned).
4514                 //
4515                 //    * The target of New is being passed as an argument,
4516                 //      to a boxing operation or a function that takes a
4517                 //      ValueType.
4518                 //
4519                 //      In this case, we need to create a temporary variable
4520                 //      that is the argument of New.
4521                 //
4522                 // Returns whether a value is left on the stack
4523                 //
4524                 bool DoEmit (EmitContext ec, bool need_value_on_stack)
4525                 {
4526                         bool is_value_type = type.IsValueType;
4527                         ILGenerator ig = ec.ig;
4528
4529                         if (is_value_type){
4530                                 IMemoryLocation ml;
4531
4532                                 // Allow DoEmit() to be called multiple times.
4533                                 // We need to create a new LocalTemporary each time since
4534                                 // you can't share LocalBuilders among ILGeneators.
4535                                 if (!value_target_set)
4536                                         value_target = new LocalTemporary (ec, type);
4537
4538                                 ml = (IMemoryLocation) value_target;
4539                                 ml.AddressOf (ec, AddressOp.Store);
4540                         }
4541
4542                         if (method != null)
4543                                 Invocation.EmitArguments (ec, method, Arguments);
4544
4545                         if (is_value_type){
4546                                 if (method == null)
4547                                         ig.Emit (OpCodes.Initobj, type);
4548                                 else
4549                                         ig.Emit (OpCodes.Call, (ConstructorInfo) method);
4550                                 if (need_value_on_stack){
4551                                         value_target.Emit (ec);
4552                                         return true;
4553                                 }
4554                                 return false;
4555                         } else {
4556                                 ig.Emit (OpCodes.Newobj, (ConstructorInfo) method);
4557                                 return true;
4558                         }
4559                 }
4560
4561                 public override void Emit (EmitContext ec)
4562                 {
4563                         DoEmit (ec, true);
4564                 }
4565
4566                 public override void EmitStatement (EmitContext ec)
4567                 {
4568                         if (DoEmit (ec, false))
4569                                 ec.ig.Emit (OpCodes.Pop);
4570                 }
4571         }
4572
4573         /// <summary>
4574         ///   14.5.10.2: Represents an array creation expression.
4575         /// </summary>
4576         ///
4577         /// <remarks>
4578         ///   There are two possible scenarios here: one is an array creation
4579         ///   expression that specifies the dimensions and optionally the
4580         ///   initialization data and the other which does not need dimensions
4581         ///   specified but where initialization data is mandatory.
4582         /// </remarks>
4583         public class ArrayCreation : ExpressionStatement {
4584                 Expression requested_base_type;
4585                 ArrayList initializers;
4586
4587                 //
4588                 // The list of Argument types.
4589                 // This is used to construct the `newarray' or constructor signature
4590                 //
4591                 ArrayList arguments;
4592
4593                 //
4594                 // Method used to create the array object.
4595                 //
4596                 MethodBase new_method = null;
4597
4598                 Type array_element_type;
4599                 Type underlying_type;
4600                 bool is_one_dimensional = false;
4601                 bool is_builtin_type = false;
4602                 bool expect_initializers = false;
4603                 int num_arguments = 0;
4604                 int dimensions = 0;
4605                 string rank;
4606
4607                 ArrayList array_data;
4608
4609                 Hashtable bounds;
4610
4611                 //
4612                 // The number of array initializers that we can handle
4613                 // via the InitializeArray method - through EmitStaticInitializers
4614                 //
4615                 int num_automatic_initializers;
4616
4617                 public ArrayCreation (Expression requested_base_type, ArrayList exprs, string rank, ArrayList initializers, Location l)
4618                 {
4619                         this.requested_base_type = requested_base_type;
4620                         this.initializers = initializers;
4621                         this.rank = rank;
4622                         loc = l;
4623
4624                         arguments = new ArrayList ();
4625
4626                         foreach (Expression e in exprs) {
4627                                 arguments.Add (new Argument (e, Argument.AType.Expression));
4628                                 num_arguments++;
4629                         }
4630                 }
4631
4632                 public ArrayCreation (Expression requested_base_type, string rank, ArrayList initializers, Location l)
4633                 {
4634                         this.requested_base_type = requested_base_type;
4635                         this.initializers = initializers;
4636                         this.rank = rank;
4637                         loc = l;
4638
4639                         //this.rank = rank.Substring (0, rank.LastIndexOf ("["));
4640                         //
4641                         //string tmp = rank.Substring (rank.LastIndexOf ("["));
4642                         //
4643                         //dimensions = tmp.Length - 1;
4644                         expect_initializers = true;
4645                 }
4646
4647                 public Expression FormArrayType (Expression base_type, int idx_count, string rank)
4648                 {
4649                         StringBuilder sb = new StringBuilder (rank);
4650
4651                         sb.Append ("[");
4652                         for (int i = 1; i < idx_count; i++)
4653                                 sb.Append (",");
4654
4655                         sb.Append ("]");
4656
4657                         return new ComposedCast (base_type, sb.ToString (), loc);
4658                 }
4659
4660                 void Error_IncorrectArrayInitializer ()
4661                 {
4662                         Error (178, "Incorrectly structured array initializer");
4663                 }
4664
4665                 public bool CheckIndices (EmitContext ec, ArrayList probe, int idx, bool specified_dims)
4666                 {
4667                         if (specified_dims) {
4668                                 Argument a = (Argument) arguments [idx];
4669
4670                                 if (!a.Resolve (ec, loc))
4671                                         return false;
4672
4673                                 if (!(a.Expr is Constant)) {
4674                                         Error (150, "A constant value is expected");
4675                                         return false;
4676                                 }
4677
4678                                 int value = (int) ((Constant) a.Expr).GetValue ();
4679
4680                                 if (value != probe.Count) {
4681                                         Error_IncorrectArrayInitializer ();
4682                                         return false;
4683                                 }
4684
4685                                 bounds [idx] = value;
4686                         }
4687
4688                         int child_bounds = -1;
4689                         foreach (object o in probe) {
4690                                 if (o is ArrayList) {
4691                                         int current_bounds = ((ArrayList) o).Count;
4692
4693                                         if (child_bounds == -1)
4694                                                 child_bounds = current_bounds;
4695
4696                                         else if (child_bounds != current_bounds){
4697                                                 Error_IncorrectArrayInitializer ();
4698                                                 return false;
4699                                         }
4700                                         bool ret = CheckIndices (ec, (ArrayList) o, idx + 1, specified_dims);
4701                                         if (!ret)
4702                                                 return false;
4703                                 } else {
4704                                         if (child_bounds != -1){
4705                                                 Error_IncorrectArrayInitializer ();
4706                                                 return false;
4707                                         }
4708
4709                                         Expression tmp = (Expression) o;
4710                                         tmp = tmp.Resolve (ec);
4711                                         if (tmp == null)
4712                                                 continue;
4713
4714                                         // Console.WriteLine ("I got: " + tmp);
4715                                         // Handle initialization from vars, fields etc.
4716
4717                                         Expression conv = ConvertImplicitRequired (
4718                                                 ec, tmp, underlying_type, loc);
4719
4720                                         if (conv == null)
4721                                                 return false;
4722
4723                                         if (conv is StringConstant)
4724                                                 array_data.Add (conv);
4725                                         else if (conv is Constant) {
4726                                                 array_data.Add (conv);
4727                                                 num_automatic_initializers++;
4728                                         } else
4729                                                 array_data.Add (conv);
4730                                 }
4731                         }
4732
4733                         return true;
4734                 }
4735
4736                 public void UpdateIndices (EmitContext ec)
4737                 {
4738                         int i = 0;
4739                         for (ArrayList probe = initializers; probe != null;) {
4740                                 if (probe.Count > 0 && probe [0] is ArrayList) {
4741                                         Expression e = new IntConstant (probe.Count);
4742                                         arguments.Add (new Argument (e, Argument.AType.Expression));
4743
4744                                         bounds [i++] =  probe.Count;
4745
4746                                         probe = (ArrayList) probe [0];
4747
4748                                 } else {
4749                                         Expression e = new IntConstant (probe.Count);
4750                                         arguments.Add (new Argument (e, Argument.AType.Expression));
4751
4752                                         bounds [i++] = probe.Count;
4753                                         probe = null;
4754                                 }
4755                         }
4756
4757                 }
4758
4759                 public bool ValidateInitializers (EmitContext ec, Type array_type)
4760                 {
4761                         if (initializers == null) {
4762                                 if (expect_initializers)
4763                                         return false;
4764                                 else
4765                                         return true;
4766                         }
4767
4768                         if (underlying_type == null)
4769                                 return false;
4770
4771                         //
4772                         // We use this to store all the date values in the order in which we
4773                         // will need to store them in the byte blob later
4774                         //
4775                         array_data = new ArrayList ();
4776                         bounds = new Hashtable ();
4777
4778                         bool ret;
4779
4780                         if (arguments != null) {
4781                                 ret = CheckIndices (ec, initializers, 0, true);
4782                                 return ret;
4783                         } else {
4784                                 arguments = new ArrayList ();
4785
4786                                 ret = CheckIndices (ec, initializers, 0, false);
4787
4788                                 if (!ret)
4789                                         return false;
4790
4791                                 UpdateIndices (ec);
4792
4793                                 if (arguments.Count != dimensions) {
4794                                         Error_IncorrectArrayInitializer ();
4795                                         return false;
4796                                 }
4797
4798                                 return ret;
4799                         }
4800                 }
4801
4802                 void Error_NegativeArrayIndex ()
4803                 {
4804                         Error (284, "Can not create array with a negative size");
4805                 }
4806
4807                 //
4808                 // Converts `source' to an int, uint, long or ulong.
4809                 //
4810                 Expression ExpressionToArrayArgument (EmitContext ec, Expression source)
4811                 {
4812                         Expression target;
4813
4814                         bool old_checked = ec.CheckState;
4815                         ec.CheckState = true;
4816
4817                         target = ConvertImplicit (ec, source, TypeManager.int32_type, loc);
4818                         if (target == null){
4819                                 target = ConvertImplicit (ec, source, TypeManager.uint32_type, loc);
4820                                 if (target == null){
4821                                         target = ConvertImplicit (ec, source, TypeManager.int64_type, loc);
4822                                         if (target == null){
4823                                                 target = ConvertImplicit (ec, source, TypeManager.uint64_type, loc);
4824                                                 if (target == null)
4825                                                         Expression.Error_CannotConvertImplicit (loc, source.Type, TypeManager.int32_type);
4826                                         }
4827                                 }
4828                         }
4829                         ec.CheckState = old_checked;
4830
4831                         //
4832                         // Only positive constants are allowed at compile time
4833                         //
4834                         if (target is Constant){
4835                                 if (target is IntConstant){
4836                                         if (((IntConstant) target).Value < 0){
4837                                                 Error_NegativeArrayIndex ();
4838                                                 return null;
4839                                         }
4840                                 }
4841
4842                                 if (target is LongConstant){
4843                                         if (((LongConstant) target).Value < 0){
4844                                                 Error_NegativeArrayIndex ();
4845                                                 return null;
4846                                         }
4847                                 }
4848
4849                         }
4850
4851                         return target;
4852                 }
4853
4854                 //
4855                 // Creates the type of the array
4856                 //
4857                 bool LookupType (EmitContext ec)
4858                 {
4859                         StringBuilder array_qualifier = new StringBuilder (rank);
4860
4861                         //
4862                         // `In the first form allocates an array instace of the type that results
4863                         // from deleting each of the individual expression from the expression list'
4864                         //
4865                         if (num_arguments > 0) {
4866                                 array_qualifier.Append ("[");
4867                                 for (int i = num_arguments-1; i > 0; i--)
4868                                         array_qualifier.Append (",");
4869                                 array_qualifier.Append ("]");
4870                         }
4871
4872                         //
4873                         // Lookup the type
4874                         //
4875                         Expression array_type_expr;
4876                         array_type_expr = new ComposedCast (requested_base_type, array_qualifier.ToString (), loc);
4877                         type = ec.DeclSpace.ResolveType (array_type_expr, false, loc);
4878
4879                         if (type == null)
4880                                 return false;
4881
4882                         underlying_type = type;
4883                         if (underlying_type.IsArray)
4884                                 underlying_type = TypeManager.TypeToCoreType (underlying_type.GetElementType ());
4885                         dimensions = type.GetArrayRank ();
4886
4887                         return true;
4888                 }
4889
4890                 public override Expression DoResolve (EmitContext ec)
4891                 {
4892                         int arg_count;
4893
4894                         if (!LookupType (ec))
4895                                 return null;
4896
4897                         //
4898                         // First step is to validate the initializers and fill
4899                         // in any missing bits
4900                         //
4901                         if (!ValidateInitializers (ec, type))
4902                                 return null;
4903
4904                         if (arguments == null)
4905                                 arg_count = 0;
4906                         else {
4907                                 arg_count = arguments.Count;
4908                                 foreach (Argument a in arguments){
4909                                         if (!a.Resolve (ec, loc))
4910                                                 return null;
4911
4912                                         Expression real_arg = ExpressionToArrayArgument (ec, a.Expr, loc);
4913                                         if (real_arg == null)
4914                                                 return null;
4915
4916                                         a.Expr = real_arg;
4917                                 }
4918                         }
4919
4920                         array_element_type = TypeManager.TypeToCoreType (type.GetElementType ());
4921
4922                         if (arg_count == 1) {
4923                                 is_one_dimensional = true;
4924                                 eclass = ExprClass.Value;
4925                                 return this;
4926                         }
4927
4928                         is_builtin_type = TypeManager.IsBuiltinType (type);
4929
4930                         if (is_builtin_type) {
4931                                 Expression ml;
4932
4933                                 ml = MemberLookup (ec, type, ".ctor", MemberTypes.Constructor,
4934                                                    AllBindingFlags, loc);
4935
4936                                 if (!(ml is MethodGroupExpr)) {
4937                                         ml.Error118 ("method group");
4938                                         return null;
4939                                 }
4940
4941                                 if (ml == null) {
4942                                         Error (-6, "New invocation: Can not find a constructor for " +
4943                                                       "this argument list");
4944                                         return null;
4945                                 }
4946
4947                                 new_method = Invocation.OverloadResolve (ec, (MethodGroupExpr) ml, arguments, loc);
4948
4949                                 if (new_method == null) {
4950                                         Error (-6, "New invocation: Can not find a constructor for " +
4951                                                       "this argument list");
4952                                         return null;
4953                                 }
4954
4955                                 eclass = ExprClass.Value;
4956                                 return this;
4957                         } else {
4958                                 ModuleBuilder mb = CodeGen.ModuleBuilder;
4959                                 ArrayList args = new ArrayList ();
4960
4961                                 if (arguments != null) {
4962                                         for (int i = 0; i < arg_count; i++)
4963                                                 args.Add (TypeManager.int32_type);
4964                                 }
4965
4966                                 Type [] arg_types = null;
4967
4968                                 if (args.Count > 0)
4969                                         arg_types = new Type [args.Count];
4970
4971                                 args.CopyTo (arg_types, 0);
4972
4973                                 new_method = mb.GetArrayMethod (type, ".ctor", CallingConventions.HasThis, null,
4974                                                             arg_types);
4975
4976                                 if (new_method == null) {
4977                                         Error (-6, "New invocation: Can not find a constructor for " +
4978                                                       "this argument list");
4979                                         return null;
4980                                 }
4981
4982                                 eclass = ExprClass.Value;
4983                                 return this;
4984                         }
4985                 }
4986
4987                 public static byte [] MakeByteBlob (ArrayList array_data, Type underlying_type, Location loc)
4988                 {
4989                         int factor;
4990                         byte [] data;
4991                         byte [] element;
4992                         int count = array_data.Count;
4993
4994                         if (underlying_type.IsEnum)
4995                                 underlying_type = TypeManager.EnumToUnderlying (underlying_type);
4996
4997                         factor = GetTypeSize (underlying_type);
4998                         if (factor == 0)
4999                                 throw new Exception ("unrecognized type in MakeByteBlob: " + underlying_type);
5000
5001                         data = new byte [(count * factor + 4) & ~3];
5002                         int idx = 0;
5003
5004                         for (int i = 0; i < count; ++i) {
5005                                 object v = array_data [i];
5006
5007                                 if (v is EnumConstant)
5008                                         v = ((EnumConstant) v).Child;
5009
5010                                 if (v is Constant && !(v is StringConstant))
5011                                         v = ((Constant) v).GetValue ();
5012                                 else {
5013                                         idx += factor;
5014                                         continue;
5015                                 }
5016
5017                                 if (underlying_type == TypeManager.int64_type){
5018                                         if (!(v is Expression)){
5019                                                 long val = (long) v;
5020
5021                                                 for (int j = 0; j < factor; ++j) {
5022                                                         data [idx + j] = (byte) (val & 0xFF);
5023                                                         val = (val >> 8);
5024                                                 }
5025                                         }
5026                                 } else if (underlying_type == TypeManager.uint64_type){
5027                                         if (!(v is Expression)){
5028                                                 ulong val = (ulong) v;
5029
5030                                                 for (int j = 0; j < factor; ++j) {
5031                                                         data [idx + j] = (byte) (val & 0xFF);
5032                                                         val = (val >> 8);
5033                                                 }
5034                                         }
5035                                 } else if (underlying_type == TypeManager.float_type) {
5036                                         if (!(v is Expression)){
5037                                                 element = BitConverter.GetBytes ((float) v);
5038
5039                                                 for (int j = 0; j < factor; ++j)
5040                                                         data [idx + j] = element [j];
5041                                         }
5042                                 } else if (underlying_type == TypeManager.double_type) {
5043                                         if (!(v is Expression)){
5044                                                 element = BitConverter.GetBytes ((double) v);
5045
5046                                                 for (int j = 0; j < factor; ++j)
5047                                                         data [idx + j] = element [j];
5048                                         }
5049                                 } else if (underlying_type == TypeManager.char_type){
5050                                         if (!(v is Expression)){
5051                                                 int val = (int) ((char) v);
5052
5053                                                 data [idx] = (byte) (val & 0xff);
5054                                                 data [idx+1] = (byte) (val >> 8);
5055                                         }
5056                                 } else if (underlying_type == TypeManager.short_type){
5057                                         if (!(v is Expression)){
5058                                                 int val = (int) ((short) v);
5059
5060                                                 data [idx] = (byte) (val & 0xff);
5061                                                 data [idx+1] = (byte) (val >> 8);
5062                                         }
5063                                 } else if (underlying_type == TypeManager.ushort_type){
5064                                         if (!(v is Expression)){
5065                                                 int val = (int) ((ushort) v);
5066
5067                                                 data [idx] = (byte) (val & 0xff);
5068                                                 data [idx+1] = (byte) (val >> 8);
5069                                         }
5070                                 } else if (underlying_type == TypeManager.int32_type) {
5071                                         if (!(v is Expression)){
5072                                                 int val = (int) v;
5073
5074                                                 data [idx]   = (byte) (val & 0xff);
5075                                                 data [idx+1] = (byte) ((val >> 8) & 0xff);
5076                                                 data [idx+2] = (byte) ((val >> 16) & 0xff);
5077                                                 data [idx+3] = (byte) (val >> 24);
5078                                         }
5079                                 } else if (underlying_type == TypeManager.uint32_type) {
5080                                         if (!(v is Expression)){
5081                                                 uint val = (uint) v;
5082
5083                                                 data [idx]   = (byte) (val & 0xff);
5084                                                 data [idx+1] = (byte) ((val >> 8) & 0xff);
5085                                                 data [idx+2] = (byte) ((val >> 16) & 0xff);
5086                                                 data [idx+3] = (byte) (val >> 24);
5087                                         }
5088                                 } else if (underlying_type == TypeManager.sbyte_type) {
5089                                         if (!(v is Expression)){
5090                                                 sbyte val = (sbyte) v;
5091                                                 data [idx] = (byte) val;
5092                                         }
5093                                 } else if (underlying_type == TypeManager.byte_type) {
5094                                         if (!(v is Expression)){
5095                                                 byte val = (byte) v;
5096                                                 data [idx] = (byte) val;
5097                                         }
5098                                 } else if (underlying_type == TypeManager.bool_type) {
5099                                         if (!(v is Expression)){
5100                                                 bool val = (bool) v;
5101                                                 data [idx] = (byte) (val ? 1 : 0);
5102                                         }
5103                                 } else if (underlying_type == TypeManager.decimal_type){
5104                                         if (!(v is Expression)){
5105                                                 int [] bits = Decimal.GetBits ((decimal) v);
5106                                                 int p = idx;
5107
5108                                                 for (int j = 0; j < 4; j++){
5109                                                         data [p++] = (byte) (bits [j] & 0xff);
5110                                                         data [p++] = (byte) ((bits [j] >> 8) & 0xff);
5111                                                         data [p++] = (byte) ((bits [j] >> 16) & 0xff);
5112                                                         data [p++] = (byte) (bits [j] >> 24);
5113                                                 }
5114                                         }
5115                                 } else
5116                                         throw new Exception ("Unrecognized type in MakeByteBlob: " + underlying_type);
5117
5118                                 idx += factor;
5119                         }
5120
5121                         return data;
5122                 }
5123
5124                 //
5125                 // Emits the initializers for the array
5126                 //
5127                 void EmitStaticInitializers (EmitContext ec, bool is_expression)
5128                 {
5129                         //
5130                         // First, the static data
5131                         //
5132                         FieldBuilder fb;
5133                         ILGenerator ig = ec.ig;
5134
5135                         byte [] data = MakeByteBlob (array_data, underlying_type, loc);
5136
5137                         fb = RootContext.MakeStaticData (data);
5138
5139                         if (is_expression)
5140                                 ig.Emit (OpCodes.Dup);
5141                         ig.Emit (OpCodes.Ldtoken, fb);
5142                         ig.Emit (OpCodes.Call,
5143                                  TypeManager.void_initializearray_array_fieldhandle);
5144                 }
5145
5146                 //
5147                 // Emits pieces of the array that can not be computed at compile
5148                 // time (variables and string locations).
5149                 //
5150                 // This always expect the top value on the stack to be the array
5151                 //
5152                 void EmitDynamicInitializers (EmitContext ec, bool is_expression)
5153                 {
5154                         ILGenerator ig = ec.ig;
5155                         int dims = bounds.Count;
5156                         int [] current_pos = new int [dims];
5157                         int top = array_data.Count;
5158                         LocalBuilder temp = ig.DeclareLocal (type);
5159
5160                         ig.Emit (OpCodes.Stloc, temp);
5161
5162                         MethodInfo set = null;
5163
5164                         if (dims != 1){
5165                                 Type [] args;
5166                                 ModuleBuilder mb = null;
5167                                 mb = CodeGen.ModuleBuilder;
5168                                 args = new Type [dims + 1];
5169
5170                                 int j;
5171                                 for (j = 0; j < dims; j++)
5172                                         args [j] = TypeManager.int32_type;
5173
5174                                 args [j] = array_element_type;
5175
5176                                 set = mb.GetArrayMethod (
5177                                         type, "Set",
5178                                         CallingConventions.HasThis | CallingConventions.Standard,
5179                                         TypeManager.void_type, args);
5180                         }
5181
5182                         for (int i = 0; i < top; i++){
5183
5184                                 Expression e = null;
5185
5186                                 if (array_data [i] is Expression)
5187                                         e = (Expression) array_data [i];
5188
5189                                 if (e != null) {
5190                                         //
5191                                         // Basically we do this for string literals and
5192                                         // other non-literal expressions
5193                                         //
5194                                         if (e is StringConstant || !(e is Constant) ||
5195                                             num_automatic_initializers <= 2) {
5196                                                 Type etype = e.Type;
5197
5198                                                 ig.Emit (OpCodes.Ldloc, temp);
5199
5200                                                 for (int idx = 0; idx < dims; idx++)
5201                                                         IntConstant.EmitInt (ig, current_pos [idx]);
5202
5203                                                 //
5204                                                 // If we are dealing with a struct, get the
5205                                                 // address of it, so we can store it.
5206                                                 //
5207                                                 if ((dims == 1) &&
5208                                                     etype.IsSubclassOf (TypeManager.value_type) &&
5209                                                     (!TypeManager.IsBuiltinType (etype) ||
5210                                                      etype == TypeManager.decimal_type)) {
5211                                                         if (e is New){
5212                                                                 New n = (New) e;
5213
5214                                                                 //
5215                                                                 // Let new know that we are providing
5216                                                                 // the address where to store the results
5217                                                                 //
5218                                                                 n.DisableTemporaryValueType ();
5219                                                         }
5220
5221                                                         ig.Emit (OpCodes.Ldelema, etype);
5222                                                 }
5223
5224                                                 e.Emit (ec);
5225
5226                                                 if (dims == 1)
5227                                                         ArrayAccess.EmitStoreOpcode (ig, array_element_type);
5228                                                 else
5229                                                         ig.Emit (OpCodes.Call, set);
5230                                         }
5231                                 }
5232
5233                                 //
5234                                 // Advance counter
5235                                 //
5236                                 for (int j = dims - 1; j >= 0; j--){
5237                                         current_pos [j]++;
5238                                         if (current_pos [j] < (int) bounds [j])
5239                                                 break;
5240                                         current_pos [j] = 0;
5241                                 }
5242                         }
5243
5244                         if (is_expression)
5245                                 ig.Emit (OpCodes.Ldloc, temp);
5246                 }
5247
5248                 void EmitArrayArguments (EmitContext ec)
5249                 {
5250                         ILGenerator ig = ec.ig;
5251
5252                         foreach (Argument a in arguments) {
5253                                 Type atype = a.Type;
5254                                 a.Emit (ec);
5255
5256                                 if (atype == TypeManager.uint64_type)
5257                                         ig.Emit (OpCodes.Conv_Ovf_U4);
5258                                 else if (atype == TypeManager.int64_type)
5259                                         ig.Emit (OpCodes.Conv_Ovf_I4);
5260                         }
5261                 }
5262
5263                 void DoEmit (EmitContext ec, bool is_statement)
5264                 {
5265                         ILGenerator ig = ec.ig;
5266
5267                         EmitArrayArguments (ec);
5268                         if (is_one_dimensional)
5269                                 ig.Emit (OpCodes.Newarr, array_element_type);
5270                         else {
5271                                 if (is_builtin_type)
5272                                         ig.Emit (OpCodes.Newobj, (ConstructorInfo) new_method);
5273                                 else
5274                                         ig.Emit (OpCodes.Newobj, (MethodInfo) new_method);
5275                         }
5276
5277                         if (initializers != null){
5278                                 //
5279                                 // FIXME: Set this variable correctly.
5280                                 //
5281                                 bool dynamic_initializers = true;
5282
5283                                 if (underlying_type != TypeManager.string_type &&
5284                                     underlying_type != TypeManager.object_type) {
5285                                         if (num_automatic_initializers > 2)
5286                                                 EmitStaticInitializers (ec, dynamic_initializers || !is_statement);
5287                                 }
5288
5289                                 if (dynamic_initializers)
5290                                         EmitDynamicInitializers (ec, !is_statement);
5291                         }
5292                 }
5293
5294                 public override void Emit (EmitContext ec)
5295                 {
5296                         DoEmit (ec, false);
5297                 }
5298
5299                 public override void EmitStatement (EmitContext ec)
5300                 {
5301                         DoEmit (ec, true);
5302                 }
5303
5304         }
5305
5306         /// <summary>
5307         ///   Represents the `this' construct
5308         /// </summary>
5309         public class This : Expression, IAssignMethod, IMemoryLocation, IVariable {
5310
5311                 Block block;
5312                 VariableInfo vi;
5313
5314                 public This (Block block, Location loc)
5315                 {
5316                         this.loc = loc;
5317                         this.block = block;
5318                 }
5319
5320                 public This (Location loc)
5321                 {
5322                         this.loc = loc;
5323                 }
5324
5325                 public bool IsAssigned (EmitContext ec, Location loc)
5326                 {
5327                         if (vi == null)
5328                                 return true;
5329
5330                         return vi.IsAssigned (ec, loc);
5331                 }
5332
5333                 public bool IsFieldAssigned (EmitContext ec, string field_name, Location loc)
5334                 {
5335                         if (vi == null)
5336                                 return true;
5337
5338                         return vi.IsFieldAssigned (ec, field_name, loc);
5339                 }
5340
5341                 public void SetAssigned (EmitContext ec)
5342                 {
5343                         if (vi != null)
5344                                 vi.SetAssigned (ec);
5345                 }
5346
5347                 public void SetFieldAssigned (EmitContext ec, string field_name)
5348                 {
5349                         if (vi != null)
5350                                 vi.SetFieldAssigned (ec, field_name);
5351                 }
5352
5353                 public override Expression DoResolve (EmitContext ec)
5354                 {
5355                         eclass = ExprClass.Variable;
5356                         type = ec.ContainerType;
5357
5358                         if (ec.IsStatic){
5359                                 Error (26, "Keyword this not valid in static code");
5360                                 return null;
5361                         }
5362
5363                         if (block != null)
5364                                 vi = block.ThisVariable;
5365
5366                         return this;
5367                 }
5368
5369                 override public Expression DoResolveLValue (EmitContext ec, Expression right_side)
5370                 {
5371                         DoResolve (ec);
5372
5373                         VariableInfo vi = ec.CurrentBlock.ThisVariable;
5374                         if (vi != null)
5375                                 vi.SetAssigned (ec);
5376
5377                         if (ec.TypeContainer is Class){
5378                                 Error (1604, "Cannot assign to `this'");
5379                                 return null;
5380                         }
5381
5382                         return this;
5383                 }
5384
5385                 public override void Emit (EmitContext ec)
5386                 {
5387                         ILGenerator ig = ec.ig;
5388
5389                         ig.Emit (OpCodes.Ldarg_0);
5390                         if (ec.TypeContainer is Struct)
5391                                 ig.Emit (OpCodes.Ldobj, type);
5392                 }
5393
5394                 public void EmitAssign (EmitContext ec, Expression source)
5395                 {
5396                         ILGenerator ig = ec.ig;
5397
5398                         if (ec.TypeContainer is Struct){
5399                                 ig.Emit (OpCodes.Ldarg_0);
5400                                 source.Emit (ec);
5401                                 ig.Emit (OpCodes.Stobj, type);
5402                         } else {
5403                                 source.Emit (ec);
5404                                 ig.Emit (OpCodes.Starg, 0);
5405                         }
5406                 }
5407
5408                 public void AddressOf (EmitContext ec, AddressOp mode)
5409                 {
5410                         ec.ig.Emit (OpCodes.Ldarg_0);
5411
5412                         // FIMXE
5413                         // FIGURE OUT WHY LDARG_S does not work
5414                         //
5415                         // consider: struct X { int val; int P { set { val = value; }}}
5416                         //
5417                         // Yes, this looks very bad. Look at `NOTAS' for
5418                         // an explanation.
5419                         // ec.ig.Emit (OpCodes.Ldarga_S, (byte) 0);
5420                 }
5421         }
5422
5423         /// <summary>
5424         ///   Implements the typeof operator
5425         /// </summary>
5426         public class TypeOf : Expression {
5427                 public readonly Expression QueriedType;
5428                 Type typearg;
5429
5430                 public TypeOf (Expression queried_type, Location l)
5431                 {
5432                         QueriedType = queried_type;
5433                         loc = l;
5434                 }
5435
5436                 public override Expression DoResolve (EmitContext ec)
5437                 {
5438                         typearg = ec.DeclSpace.ResolveType (QueriedType, false, loc);
5439
5440                         if (typearg == null)
5441                                 return null;
5442
5443                         type = TypeManager.type_type;
5444                         eclass = ExprClass.Type;
5445                         return this;
5446                 }
5447
5448                 public override void Emit (EmitContext ec)
5449                 {
5450                         ec.ig.Emit (OpCodes.Ldtoken, typearg);
5451                         ec.ig.Emit (OpCodes.Call, TypeManager.system_type_get_type_from_handle);
5452                 }
5453
5454                 public Type TypeArg {
5455                         get { return typearg; }
5456                 }
5457         }
5458
5459         /// <summary>
5460         ///   Implements the sizeof expression
5461         /// </summary>
5462         public class SizeOf : Expression {
5463                 public readonly Expression QueriedType;
5464                 Type type_queried;
5465
5466                 public SizeOf (Expression queried_type, Location l)
5467                 {
5468                         this.QueriedType = queried_type;
5469                         loc = l;
5470                 }
5471
5472                 public override Expression DoResolve (EmitContext ec)
5473                 {
5474                         if (!ec.InUnsafe) {
5475                                 Error (233, "Sizeof may only be used in an unsafe context " +
5476                                        "(consider using System.Runtime.InteropServices.Marshal.Sizeof");
5477                                 return null;
5478                         }
5479
5480                         type_queried = ec.DeclSpace.ResolveType (QueriedType, false, loc);
5481                         if (type_queried == null)
5482                                 return null;
5483
5484                         if (!TypeManager.IsUnmanagedType (type_queried)){
5485                                 Report.Error (208, "Cannot take the size of an unmanaged type (" + TypeManager.CSharpName (type_queried) + ")");
5486                                 return null;
5487                         }
5488
5489                         type = TypeManager.int32_type;
5490                         eclass = ExprClass.Value;
5491                         return this;
5492                 }
5493
5494                 public override void Emit (EmitContext ec)
5495                 {
5496                         int size = GetTypeSize (type_queried);
5497
5498                         if (size == 0)
5499                                 ec.ig.Emit (OpCodes.Sizeof, type_queried);
5500                         else
5501                                 IntConstant.EmitInt (ec.ig, size);
5502                 }
5503         }
5504
5505         /// <summary>
5506         ///   Implements the member access expression
5507         /// </summary>
5508         public class MemberAccess : Expression, ITypeExpression {
5509                 public readonly string Identifier;
5510                 Expression expr;
5511                 Expression member_lookup;
5512
5513                 public MemberAccess (Expression expr, string id, Location l)
5514                 {
5515                         this.expr = expr;
5516                         Identifier = id;
5517                         loc = l;
5518                 }
5519
5520                 public Expression Expr {
5521                         get {
5522                                 return expr;
5523                         }
5524                 }
5525
5526                 static void error176 (Location loc, string name)
5527                 {
5528                         Report.Error (176, loc, "Static member `" +
5529                                       name + "' cannot be accessed " +
5530                                       "with an instance reference, qualify with a " +
5531                                       "type name instead");
5532                 }
5533
5534                 static bool IdenticalNameAndTypeName (EmitContext ec, Expression left_original, Location loc)
5535                 {
5536                         if (left_original == null)
5537                                 return false;
5538
5539                         if (!(left_original is SimpleName))
5540                                 return false;
5541
5542                         SimpleName sn = (SimpleName) left_original;
5543
5544                         Type t = RootContext.LookupType (ec.DeclSpace, sn.Name, true, loc);
5545                         if (t != null)
5546                                 return true;
5547
5548                         return false;
5549                 }
5550
5551                 public static Expression ResolveMemberAccess (EmitContext ec, Expression member_lookup,
5552                                                               Expression left, Location loc,
5553                                                               Expression left_original)
5554                 {
5555                         bool left_is_type, left_is_explicit;
5556
5557                         // If `left' is null, then we're called from SimpleNameResolve and this is
5558                         // a member in the currently defining class.
5559                         if (left == null) {
5560                                 left_is_type = ec.IsStatic || ec.IsFieldInitializer;
5561                                 left_is_explicit = false;
5562
5563                                 // Implicitly default to `this' unless we're static.
5564                                 if (!ec.IsStatic && !ec.IsFieldInitializer && !ec.InEnumContext)
5565                                         left = ec.This;
5566                         } else {
5567                                 left_is_type = left is TypeExpr;
5568                                 left_is_explicit = true;
5569                         }
5570
5571                         if (member_lookup is FieldExpr){
5572                                 FieldExpr fe = (FieldExpr) member_lookup;
5573                                 FieldInfo fi = fe.FieldInfo;
5574                                 Type decl_type = fi.DeclaringType;
5575
5576                                 if (fi is FieldBuilder) {
5577                                         Const c = TypeManager.LookupConstant ((FieldBuilder) fi);
5578
5579                                         if (c != null) {
5580                                                 object o = c.LookupConstantValue (ec);
5581                                                 object real_value = ((Constant) c.Expr).GetValue ();
5582
5583                                                 return Constantify (real_value, fi.FieldType);
5584                                         }
5585                                 }
5586
5587                                 if (fi.IsLiteral) {
5588                                         Type t = fi.FieldType;
5589
5590                                         object o;
5591
5592                                         if (fi is FieldBuilder)
5593                                                 o = TypeManager.GetValue ((FieldBuilder) fi);
5594                                         else
5595                                                 o = fi.GetValue (fi);
5596
5597                                         if (decl_type.IsSubclassOf (TypeManager.enum_type)) {
5598                                                 if (left_is_explicit && !left_is_type &&
5599                                                     !IdenticalNameAndTypeName (ec, left_original, loc)) {
5600                                                         error176 (loc, fe.FieldInfo.Name);
5601                                                         return null;
5602                                                 }
5603
5604                                                 Expression enum_member = MemberLookup (
5605                                                         ec, decl_type, "value__", MemberTypes.Field,
5606                                                         AllBindingFlags, loc);
5607
5608                                                 Enum en = TypeManager.LookupEnum (decl_type);
5609
5610                                                 Constant c;
5611                                                 if (en != null)
5612                                                         c = Constantify (o, en.UnderlyingType);
5613                                                 else
5614                                                         c = Constantify (o, enum_member.Type);
5615
5616                                                 return new EnumConstant (c, decl_type);
5617                                         }
5618
5619                                         Expression exp = Constantify (o, t);
5620
5621                                         if (left_is_explicit && !left_is_type) {
5622                                                 error176 (loc, fe.FieldInfo.Name);
5623                                                 return null;
5624                                         }
5625
5626                                         return exp;
5627                                 }
5628
5629                                 if (fi.FieldType.IsPointer && !ec.InUnsafe){
5630                                         UnsafeError (loc);
5631                                         return null;
5632                                 }
5633                         }
5634
5635                         if (member_lookup is EventExpr) {
5636
5637                                 EventExpr ee = (EventExpr) member_lookup;
5638
5639                                 //
5640                                 // If the event is local to this class, we transform ourselves into
5641                                 // a FieldExpr
5642                                 //
5643
5644                                 if (ee.EventInfo.DeclaringType == ec.ContainerType) {
5645                                         MemberInfo mi = GetFieldFromEvent (ee);
5646
5647                                         if (mi == null) {
5648                                                 //
5649                                                 // If this happens, then we have an event with its own
5650                                                 // accessors and private field etc so there's no need
5651                                                 // to transform ourselves : we should instead flag an error
5652                                                 //
5653                                                 Assign.error70 (ee.EventInfo, loc);
5654                                                 return null;
5655                                         }
5656
5657                                         Expression ml = ExprClassFromMemberInfo (ec, mi, loc);
5658
5659                                         if (ml == null) {
5660                                                 Report.Error (-200, loc, "Internal error!!");
5661                                                 return null;
5662                                         }
5663
5664                                         return ResolveMemberAccess (ec, ml, left, loc, left_original);
5665                                 }
5666                         }
5667
5668                         if (member_lookup is IMemberExpr) {
5669                                 IMemberExpr me = (IMemberExpr) member_lookup;
5670
5671                                 if (left_is_type){
5672                                         MethodGroupExpr mg = me as MethodGroupExpr;
5673                                         if ((mg != null) && left_is_explicit && left.Type.IsInterface)
5674                                                 mg.IsExplicitImpl = left_is_explicit;
5675
5676                                         if (!me.IsStatic){
5677                                                 if (IdenticalNameAndTypeName (ec, left_original, loc))
5678                                                         return member_lookup;
5679
5680                                                 SimpleName.Error_ObjectRefRequired (ec, loc, me.Name);
5681                                                 return null;
5682                                         }
5683
5684                                 } else {
5685                                         if (!me.IsInstance){
5686                                                 if (IdenticalNameAndTypeName (ec, left_original, loc))
5687                                                         return member_lookup;
5688
5689                                                 if (left_is_explicit) {
5690                                                         error176 (loc, me.Name);
5691                                                         return null;
5692                                                 }
5693                                         }
5694
5695                                         //
5696                                         // Since we can not check for instance objects in SimpleName,
5697                                         // becaue of the rule that allows types and variables to share
5698                                         // the name (as long as they can be de-ambiguated later, see
5699                                         // IdenticalNameAndTypeName), we have to check whether left
5700                                         // is an instance variable in a static context
5701                                         //
5702                                         // However, if the left-hand value is explicitly given, then
5703                                         // it is already our instance expression, so we aren't in
5704                                         // static context.
5705                                         //
5706
5707                                         if (ec.IsStatic && !left_is_explicit && left is IMemberExpr){
5708                                                 IMemberExpr mexp = (IMemberExpr) left;
5709
5710                                                 if (!mexp.IsStatic){
5711                                                         SimpleName.Error_ObjectRefRequired (ec, loc, mexp.Name);
5712                                                         return null;
5713                                                 }
5714                                         }
5715
5716                                         me.InstanceExpression = left;
5717                                 }
5718
5719                                 return member_lookup;
5720                         }
5721
5722                         if (member_lookup is TypeExpr){
5723                                 member_lookup.Resolve (ec, ResolveFlags.Type);
5724                                 return member_lookup;
5725                         }
5726
5727                         Console.WriteLine ("Left is: " + left);
5728                         Report.Error (-100, loc, "Support for [" + member_lookup + "] is not present yet");
5729                         Environment.Exit (0);
5730                         return null;
5731                 }
5732
5733                 public Expression DoResolve (EmitContext ec, Expression right_side, ResolveFlags flags)
5734                 {
5735                         if (type != null)
5736                                 throw new Exception ();
5737                         //
5738                         // Resolve the expression with flow analysis turned off, we'll do the definite
5739                         // assignment checks later.  This is because we don't know yet what the expression
5740                         // will resolve to - it may resolve to a FieldExpr and in this case we must do the
5741                         // definite assignment check on the actual field and not on the whole struct.
5742                         //
5743
5744                         Expression original = expr;
5745                         expr = expr.Resolve (ec, flags | ResolveFlags.DisableFlowAnalysis);
5746
5747                         if (expr == null)
5748                                 return null;
5749
5750                         if (expr is SimpleName){
5751                                 SimpleName child_expr = (SimpleName) expr;
5752
5753                                 Expression new_expr = new SimpleName (child_expr.Name + "." + Identifier, loc);
5754
5755                                 return new_expr.Resolve (ec, flags);
5756                         }
5757
5758                         //
5759                         // TODO: I mailed Ravi about this, and apparently we can get rid
5760                         // of this and put it in the right place.
5761                         //
5762                         // Handle enums here when they are in transit.
5763                         // Note that we cannot afford to hit MemberLookup in this case because
5764                         // it will fail to find any members at all
5765                         //
5766
5767                         int errors = Report.Errors;
5768
5769                         Type expr_type = expr.Type;
5770                         if ((expr is TypeExpr) && (expr_type.IsSubclassOf (TypeManager.enum_type))){
5771
5772                                 Enum en = TypeManager.LookupEnum (expr_type);
5773
5774                                 if (en != null) {
5775                                         object value = en.LookupEnumValue (ec, Identifier, loc);
5776
5777                                         if (value != null){
5778                                                 Constant c = Constantify (value, en.UnderlyingType);
5779                                                 return new EnumConstant (c, expr_type);
5780                                         }
5781                                 }
5782                         }
5783
5784                         if (expr_type.IsPointer){
5785                                 Error (23, "The `.' operator can not be applied to pointer operands (" +
5786                                        TypeManager.CSharpName (expr_type) + ")");
5787                                 return null;
5788                         }
5789
5790                         member_lookup = MemberLookup (ec, expr_type, Identifier, loc);
5791
5792                         if (member_lookup == null){
5793                                 // Error has already been reported.
5794                                 if (errors < Report.Errors)
5795                                         return null;
5796
5797                                 //
5798                                 // Try looking the member up from the same type, if we find
5799                                 // it, we know that the error was due to limited visibility
5800                                 //
5801                                 object lookup = TypeManager.MemberLookup (
5802                                         expr_type, expr_type, AllMemberTypes, AllBindingFlags |
5803                                         BindingFlags.NonPublic, Identifier);
5804                                 if (lookup == null)
5805                                         Error (117, "`" + expr_type + "' does not contain a " +
5806                                                "definition for `" + Identifier + "'");
5807                                 else if ((expr_type != ec.ContainerType) &&
5808                                          ec.ContainerType.IsSubclassOf (expr_type)){
5809
5810                                         // Although a derived class can access protected members of
5811                                         // its base class it cannot do so through an instance of the
5812                                         // base class (CS1540).  If the expr_type is a parent of the
5813                                         // ec.ContainerType and the lookup succeeds with the latter one,
5814                                         // then we are in this situation.
5815
5816                                         lookup = TypeManager.MemberLookup (
5817                                                 ec.ContainerType, ec.ContainerType, AllMemberTypes,
5818                                                 AllBindingFlags, Identifier);
5819
5820                                         if (lookup != null)
5821                                                 Error (1540, "Cannot access protected member `" +
5822                                                        expr_type + "." + Identifier + "' " +
5823                                                        "via a qualifier of type `" +
5824                                                        TypeManager.CSharpName (expr_type) + "'; the " +
5825                                                        "qualifier must be of type `" +
5826                                                        TypeManager.CSharpName (ec.ContainerType) + "' " +
5827                                                        "(or derived from it)");
5828                                         else
5829                                                 Error (122, "`" + expr_type + "." + Identifier + "' " +
5830                                                        "is inaccessible because of its protection level");
5831                                 } else
5832                                         Error (122, "`" + expr_type + "." + Identifier + "' " +
5833                                                "is inaccessible because of its protection level");
5834
5835                                 return null;
5836                         }
5837
5838                         if (member_lookup is TypeExpr){
5839                                 member_lookup.Resolve (ec, ResolveFlags.Type);
5840                                 return member_lookup;
5841                         } else if ((flags & ResolveFlags.MaskExprClass) == ResolveFlags.Type)
5842                                 return null;
5843
5844                         member_lookup = ResolveMemberAccess (ec, member_lookup, expr, loc, original);
5845                         if (member_lookup == null)
5846                                 return null;
5847
5848                         // The following DoResolve/DoResolveLValue will do the definite assignment
5849                         // check.
5850
5851                         if (right_side != null)
5852                                 member_lookup = member_lookup.DoResolveLValue (ec, right_side);
5853                         else
5854                                 member_lookup = member_lookup.DoResolve (ec);
5855
5856                         return member_lookup;
5857                 }
5858
5859                 public override Expression DoResolve (EmitContext ec)
5860                 {
5861                         return DoResolve (ec, null, ResolveFlags.VariableOrValue |
5862                                           ResolveFlags.SimpleName | ResolveFlags.Type);
5863                 }
5864
5865                 public override Expression DoResolveLValue (EmitContext ec, Expression right_side)
5866                 {
5867                         return DoResolve (ec, right_side, ResolveFlags.VariableOrValue |
5868                                           ResolveFlags.SimpleName | ResolveFlags.Type);
5869                 }
5870
5871                 public Expression DoResolveType (EmitContext ec)
5872                 {
5873                         return DoResolve (ec, null, ResolveFlags.Type);
5874                 }
5875
5876                 public override void Emit (EmitContext ec)
5877                 {
5878                         throw new Exception ("Should not happen");
5879                 }
5880
5881                 public override string ToString ()
5882                 {
5883                         return expr + "." + Identifier;
5884                 }
5885         }
5886
5887         /// <summary>
5888         ///   Implements checked expressions
5889         /// </summary>
5890         public class CheckedExpr : Expression {
5891
5892                 public Expression Expr;
5893
5894                 public CheckedExpr (Expression e, Location l)
5895                 {
5896                         Expr = e;
5897                         loc = l;
5898                 }
5899
5900                 public override Expression DoResolve (EmitContext ec)
5901                 {
5902                         bool last_const_check = ec.ConstantCheckState;
5903
5904                         ec.ConstantCheckState = true;
5905                         Expr = Expr.Resolve (ec);
5906                         ec.ConstantCheckState = last_const_check;
5907
5908                         if (Expr == null)
5909                                 return null;
5910
5911                         if (Expr is Constant)
5912                                 return Expr;
5913
5914                         eclass = Expr.eclass;
5915                         type = Expr.Type;
5916                         return this;
5917                 }
5918
5919                 public override void Emit (EmitContext ec)
5920                 {
5921                         bool last_check = ec.CheckState;
5922                         bool last_const_check = ec.ConstantCheckState;
5923
5924                         ec.CheckState = true;
5925                         ec.ConstantCheckState = true;
5926                         Expr.Emit (ec);
5927                         ec.CheckState = last_check;
5928                         ec.ConstantCheckState = last_const_check;
5929                 }
5930
5931         }
5932
5933         /// <summary>
5934         ///   Implements the unchecked expression
5935         /// </summary>
5936         public class UnCheckedExpr : Expression {
5937
5938                 public Expression Expr;
5939
5940                 public UnCheckedExpr (Expression e, Location l)
5941                 {
5942                         Expr = e;
5943                         loc = l;
5944                 }
5945
5946                 public override Expression DoResolve (EmitContext ec)
5947                 {
5948                         bool last_const_check = ec.ConstantCheckState;
5949
5950                         ec.ConstantCheckState = false;
5951                         Expr = Expr.Resolve (ec);
5952                         ec.ConstantCheckState = last_const_check;
5953
5954                         if (Expr == null)
5955                                 return null;
5956
5957                         if (Expr is Constant)
5958                                 return Expr;
5959
5960                         eclass = Expr.eclass;
5961                         type = Expr.Type;
5962                         return this;
5963                 }
5964
5965                 public override void Emit (EmitContext ec)
5966                 {
5967                         bool last_check = ec.CheckState;
5968                         bool last_const_check = ec.ConstantCheckState;
5969
5970                         ec.CheckState = false;
5971                         ec.ConstantCheckState = false;
5972                         Expr.Emit (ec);
5973                         ec.CheckState = last_check;
5974                         ec.ConstantCheckState = last_const_check;
5975                 }
5976
5977         }
5978
5979         /// <summary>
5980         ///   An Element Access expression.
5981         ///
5982         ///   During semantic analysis these are transformed into
5983         ///   IndexerAccess or ArrayAccess
5984         /// </summary>
5985         public class ElementAccess : Expression {
5986                 public ArrayList  Arguments;
5987                 public Expression Expr;
5988
5989                 public ElementAccess (Expression e, ArrayList e_list, Location l)
5990                 {
5991                         Expr = e;
5992
5993                         loc  = l;
5994
5995                         if (e_list == null)
5996                                 return;
5997
5998                         Arguments = new ArrayList ();
5999                         foreach (Expression tmp in e_list)
6000                                 Arguments.Add (new Argument (tmp, Argument.AType.Expression));
6001
6002                 }
6003
6004                 bool CommonResolve (EmitContext ec)
6005                 {
6006                         Expr = Expr.Resolve (ec);
6007
6008                         if (Expr == null)
6009                                 return false;
6010
6011                         if (Arguments == null)
6012                                 return false;
6013
6014                         foreach (Argument a in Arguments){
6015                                 if (!a.Resolve (ec, loc))
6016                                         return false;
6017                         }
6018
6019                         return true;
6020                 }
6021
6022                 Expression MakePointerAccess ()
6023                 {
6024                         Type t = Expr.Type;
6025
6026                         if (t == TypeManager.void_ptr_type){
6027                                 Error (
6028                                         242,
6029                                         "The array index operation is not valid for void pointers");
6030                                 return null;
6031                         }
6032                         if (Arguments.Count != 1){
6033                                 Error (
6034                                         196,
6035                                         "A pointer must be indexed by a single value");
6036                                 return null;
6037                         }
6038                         Expression p = new PointerArithmetic (true, Expr, ((Argument)Arguments [0]).Expr,
6039                                                               t, loc);
6040                         return new Indirection (p, loc);
6041                 }
6042
6043                 public override Expression DoResolve (EmitContext ec)
6044                 {
6045                         if (!CommonResolve (ec))
6046                                 return null;
6047
6048                         //
6049                         // We perform some simple tests, and then to "split" the emit and store
6050                         // code we create an instance of a different class, and return that.
6051                         //
6052                         // I am experimenting with this pattern.
6053                         //
6054                         Type t = Expr.Type;
6055
6056                         if (t.IsArray)
6057                                 return (new ArrayAccess (this, loc)).Resolve (ec);
6058                         else if (t.IsPointer)
6059                                 return MakePointerAccess ();
6060                         else
6061                                 return (new IndexerAccess (this, loc)).Resolve (ec);
6062                 }
6063
6064                 public override Expression DoResolveLValue (EmitContext ec, Expression right_side)
6065                 {
6066                         if (!CommonResolve (ec))
6067                                 return null;
6068
6069                         Type t = Expr.Type;
6070                         if (t.IsArray)
6071                                 return (new ArrayAccess (this, loc)).ResolveLValue (ec, right_side);
6072                         else if (t.IsPointer)
6073                                 return MakePointerAccess ();
6074                         else
6075                                 return (new IndexerAccess (this, loc)).ResolveLValue (ec, right_side);
6076                 }
6077
6078                 public override void Emit (EmitContext ec)
6079                 {
6080                         throw new Exception ("Should never be reached");
6081                 }
6082         }
6083
6084         /// <summary>
6085         ///   Implements array access
6086         /// </summary>
6087         public class ArrayAccess : Expression, IAssignMethod, IMemoryLocation {
6088                 //
6089                 // Points to our "data" repository
6090                 //
6091                 ElementAccess ea;
6092
6093                 LocalTemporary [] cached_locations;
6094
6095                 public ArrayAccess (ElementAccess ea_data, Location l)
6096                 {
6097                         ea = ea_data;
6098                         eclass = ExprClass.Variable;
6099                         loc = l;
6100                 }
6101
6102                 public override Expression DoResolve (EmitContext ec)
6103                 {
6104                         ExprClass eclass = ea.Expr.eclass;
6105
6106 #if false
6107                         // As long as the type is valid
6108                         if (!(eclass == ExprClass.Variable || eclass == ExprClass.PropertyAccess ||
6109                               eclass == ExprClass.Value)) {
6110                                 ea.Expr.Error118 ("variable or value");
6111                                 return null;
6112                         }
6113 #endif
6114
6115                         Type t = ea.Expr.Type;
6116                         if (t.GetArrayRank () != ea.Arguments.Count){
6117                                 ea.Error (22,
6118                                           "Incorrect number of indexes for array " +
6119                                           " expected: " + t.GetArrayRank () + " got: " +
6120                                           ea.Arguments.Count);
6121                                 return null;
6122                         }
6123                         type = TypeManager.TypeToCoreType (t.GetElementType ());
6124                         if (type.IsPointer && !ec.InUnsafe){
6125                                 UnsafeError (ea.Location);
6126                                 return null;
6127                         }
6128
6129                         foreach (Argument a in ea.Arguments){
6130                                 Type argtype = a.Type;
6131
6132                                 if (argtype == TypeManager.int32_type ||
6133                                     argtype == TypeManager.uint32_type ||
6134                                     argtype == TypeManager.int64_type ||
6135                                     argtype == TypeManager.uint64_type)
6136                                         continue;
6137
6138                                 //
6139                                 // Mhm.  This is strage, because the Argument.Type is not the same as
6140                                 // Argument.Expr.Type: the value changes depending on the ref/out setting.
6141                                 //
6142                                 // Wonder if I will run into trouble for this.
6143                                 //
6144                                 a.Expr = ExpressionToArrayArgument (ec, a.Expr, ea.Location);
6145                                 if (a.Expr == null)
6146                                         return null;
6147                         }
6148
6149                         eclass = ExprClass.Variable;
6150
6151                         return this;
6152                 }
6153
6154                 /// <summary>
6155                 ///    Emits the right opcode to load an object of Type `t'
6156                 ///    from an array of T
6157                 /// </summary>
6158                 static public void EmitLoadOpcode (ILGenerator ig, Type type)
6159                 {
6160                         if (type == TypeManager.byte_type || type == TypeManager.bool_type)
6161                                 ig.Emit (OpCodes.Ldelem_U1);
6162                         else if (type == TypeManager.sbyte_type)
6163                                 ig.Emit (OpCodes.Ldelem_I1);
6164                         else if (type == TypeManager.short_type)
6165                                 ig.Emit (OpCodes.Ldelem_I2);
6166                         else if (type == TypeManager.ushort_type || type == TypeManager.char_type)
6167                                 ig.Emit (OpCodes.Ldelem_U2);
6168                         else if (type == TypeManager.int32_type)
6169                                 ig.Emit (OpCodes.Ldelem_I4);
6170                         else if (type == TypeManager.uint32_type)
6171                                 ig.Emit (OpCodes.Ldelem_U4);
6172                         else if (type == TypeManager.uint64_type)
6173                                 ig.Emit (OpCodes.Ldelem_I8);
6174                         else if (type == TypeManager.int64_type)
6175                                 ig.Emit (OpCodes.Ldelem_I8);
6176                         else if (type == TypeManager.float_type)
6177                                 ig.Emit (OpCodes.Ldelem_R4);
6178                         else if (type == TypeManager.double_type)
6179                                 ig.Emit (OpCodes.Ldelem_R8);
6180                         else if (type == TypeManager.intptr_type)
6181                                 ig.Emit (OpCodes.Ldelem_I);
6182                         else if (type.IsValueType){
6183                                 ig.Emit (OpCodes.Ldelema, type);
6184                                 ig.Emit (OpCodes.Ldobj, type);
6185                         } else
6186                                 ig.Emit (OpCodes.Ldelem_Ref);
6187                 }
6188
6189                 /// <summary>
6190                 ///    Emits the right opcode to store an object of Type `t'
6191                 ///    from an array of T.
6192                 /// </summary>
6193                 static public void EmitStoreOpcode (ILGenerator ig, Type t)
6194                 {
6195                         t = TypeManager.TypeToCoreType (t);
6196                         if (TypeManager.IsEnumType (t) && t != TypeManager.enum_type)
6197                                 t = TypeManager.EnumToUnderlying (t);
6198                         if (t == TypeManager.byte_type || t == TypeManager.sbyte_type ||
6199                             t == TypeManager.bool_type)
6200                                 ig.Emit (OpCodes.Stelem_I1);
6201                         else if (t == TypeManager.short_type || t == TypeManager.ushort_type || t == TypeManager.char_type)
6202                                 ig.Emit (OpCodes.Stelem_I2);
6203                         else if (t == TypeManager.int32_type || t == TypeManager.uint32_type)
6204                                 ig.Emit (OpCodes.Stelem_I4);
6205                         else if (t == TypeManager.int64_type || t == TypeManager.uint64_type)
6206                                 ig.Emit (OpCodes.Stelem_I8);
6207                         else if (t == TypeManager.float_type)
6208                                 ig.Emit (OpCodes.Stelem_R4);
6209                         else if (t == TypeManager.double_type)
6210                                 ig.Emit (OpCodes.Stelem_R8);
6211                         else if (t == TypeManager.intptr_type)
6212                                 ig.Emit (OpCodes.Stelem_I);
6213                         else if (t.IsValueType){
6214                                 ig.Emit (OpCodes.Stobj, t);
6215                         } else
6216                                 ig.Emit (OpCodes.Stelem_Ref);
6217                 }
6218
6219                 MethodInfo FetchGetMethod ()
6220                 {
6221                         ModuleBuilder mb = CodeGen.ModuleBuilder;
6222                         int arg_count = ea.Arguments.Count;
6223                         Type [] args = new Type [arg_count];
6224                         MethodInfo get;
6225
6226                         for (int i = 0; i < arg_count; i++){
6227                                 //args [i++] = a.Type;
6228                                 args [i] = TypeManager.int32_type;
6229                         }
6230
6231                         get = mb.GetArrayMethod (
6232                                 ea.Expr.Type, "Get",
6233                                 CallingConventions.HasThis |
6234                                 CallingConventions.Standard,
6235                                 type, args);
6236                         return get;
6237                 }
6238
6239
6240                 MethodInfo FetchAddressMethod ()
6241                 {
6242                         ModuleBuilder mb = CodeGen.ModuleBuilder;
6243                         int arg_count = ea.Arguments.Count;
6244                         Type [] args = new Type [arg_count];
6245                         MethodInfo address;
6246                         string ptr_type_name;
6247                         Type ret_type;
6248
6249                         ptr_type_name = type.FullName + "&";
6250                         ret_type = Type.GetType (ptr_type_name);
6251
6252                         //
6253                         // It is a type defined by the source code we are compiling
6254                         //
6255                         if (ret_type == null){
6256                                 ret_type = mb.GetType (ptr_type_name);
6257                         }
6258
6259                         for (int i = 0; i < arg_count; i++){
6260                                 //args [i++] = a.Type;
6261                                 args [i] = TypeManager.int32_type;
6262                         }
6263
6264                         address = mb.GetArrayMethod (
6265                                 ea.Expr.Type, "Address",
6266                                 CallingConventions.HasThis |
6267                                 CallingConventions.Standard,
6268                                 ret_type, args);
6269
6270                         return address;
6271                 }
6272
6273                 //
6274                 // Load the array arguments into the stack.
6275                 //
6276                 // If we have been requested to cache the values (cached_locations array
6277                 // initialized), then load the arguments the first time and store them
6278                 // in locals.  otherwise load from local variables.
6279                 //
6280                 void LoadArrayAndArguments (EmitContext ec)
6281                 {
6282                         ILGenerator ig = ec.ig;
6283
6284                         if (cached_locations == null){
6285                                 ea.Expr.Emit (ec);
6286                                 foreach (Argument a in ea.Arguments){
6287                                         Type argtype = a.Expr.Type;
6288
6289                                         a.Expr.Emit (ec);
6290
6291                                         if (argtype == TypeManager.int64_type)
6292                                                 ig.Emit (OpCodes.Conv_Ovf_I);
6293                                         else if (argtype == TypeManager.uint64_type)
6294                                                 ig.Emit (OpCodes.Conv_Ovf_I_Un);
6295                                 }
6296                                 return;
6297                         }
6298
6299                         if (cached_locations [0] == null){
6300                                 cached_locations [0] = new LocalTemporary (ec, ea.Expr.Type);
6301                                 ea.Expr.Emit (ec);
6302                                 ig.Emit (OpCodes.Dup);
6303                                 cached_locations [0].Store (ec);
6304
6305                                 int j = 1;
6306
6307                                 foreach (Argument a in ea.Arguments){
6308                                         Type argtype = a.Expr.Type;
6309
6310                                         cached_locations [j] = new LocalTemporary (ec, TypeManager.intptr_type /* a.Expr.Type */);
6311                                         a.Expr.Emit (ec);
6312                                         if (argtype == TypeManager.int64_type)
6313                                                 ig.Emit (OpCodes.Conv_Ovf_I);
6314                                         else if (argtype == TypeManager.uint64_type)
6315                                                 ig.Emit (OpCodes.Conv_Ovf_I_Un);
6316
6317                                         ig.Emit (OpCodes.Dup);
6318                                         cached_locations [j].Store (ec);
6319                                         j++;
6320                                 }
6321                                 return;
6322                         }
6323
6324                         foreach (LocalTemporary lt in cached_locations)
6325                                 lt.Emit (ec);
6326                 }
6327
6328                 public new void CacheTemporaries (EmitContext ec)
6329                 {
6330                         cached_locations = new LocalTemporary [ea.Arguments.Count + 1];
6331                 }
6332
6333                 public override void Emit (EmitContext ec)
6334                 {
6335                         int rank = ea.Expr.Type.GetArrayRank ();
6336                         ILGenerator ig = ec.ig;
6337
6338                         LoadArrayAndArguments (ec);
6339
6340                         if (rank == 1)
6341                                 EmitLoadOpcode (ig, type);
6342                         else {
6343                                 MethodInfo method;
6344
6345                                 method = FetchGetMethod ();
6346                                 ig.Emit (OpCodes.Call, method);
6347                         }
6348                 }
6349
6350                 public void EmitAssign (EmitContext ec, Expression source)
6351                 {
6352                         int rank = ea.Expr.Type.GetArrayRank ();
6353                         ILGenerator ig = ec.ig;
6354                         Type t = source.Type;
6355
6356                         LoadArrayAndArguments (ec);
6357
6358                         //
6359                         // The stobj opcode used by value types will need
6360                         // an address on the stack, not really an array/array
6361                         // pair
6362                         //
6363                         if (rank == 1){
6364                                 if (t == TypeManager.enum_type || t == TypeManager.decimal_type ||
6365                                     (t.IsSubclassOf (TypeManager.value_type) && !TypeManager.IsEnumType (t) && !TypeManager.IsBuiltinType (t)))
6366                                         ig.Emit (OpCodes.Ldelema, t);
6367                         }
6368
6369                         source.Emit (ec);
6370
6371                         if (rank == 1)
6372                                 EmitStoreOpcode (ig, t);
6373                         else {
6374                                 ModuleBuilder mb = CodeGen.ModuleBuilder;
6375                                 int arg_count = ea.Arguments.Count;
6376                                 Type [] args = new Type [arg_count + 1];
6377                                 MethodInfo set;
6378
6379                                 for (int i = 0; i < arg_count; i++){
6380                                         //args [i++] = a.Type;
6381                                         args [i] = TypeManager.int32_type;
6382                                 }
6383
6384                                 args [arg_count] = type;
6385
6386                                 set = mb.GetArrayMethod (
6387                                         ea.Expr.Type, "Set",
6388                                         CallingConventions.HasThis |
6389                                         CallingConventions.Standard,
6390                                         TypeManager.void_type, args);
6391
6392                                 ig.Emit (OpCodes.Call, set);
6393                         }
6394                 }
6395
6396                 public void AddressOf (EmitContext ec, AddressOp mode)
6397                 {
6398                         int rank = ea.Expr.Type.GetArrayRank ();
6399                         ILGenerator ig = ec.ig;
6400
6401                         LoadArrayAndArguments (ec);
6402
6403                         if (rank == 1){
6404                                 ig.Emit (OpCodes.Ldelema, type);
6405                         } else {
6406                                 MethodInfo address = FetchAddressMethod ();
6407                                 ig.Emit (OpCodes.Call, address);
6408                         }
6409                 }
6410         }
6411
6412
6413         class Indexers {
6414                 public ArrayList getters, setters;
6415                 static Hashtable map;
6416
6417                 static Indexers ()
6418                 {
6419                         map = new Hashtable ();
6420                 }
6421
6422                 Indexers (MemberInfo [] mi)
6423                 {
6424                         foreach (PropertyInfo property in mi){
6425                                 MethodInfo get, set;
6426
6427                                 get = property.GetGetMethod (true);
6428                                 if (get != null){
6429                                         if (getters == null)
6430                                                 getters = new ArrayList ();
6431
6432                                         getters.Add (get);
6433                                 }
6434
6435                                 set = property.GetSetMethod (true);
6436                                 if (set != null){
6437                                         if (setters == null)
6438                                                 setters = new ArrayList ();
6439                                         setters.Add (set);
6440                                 }
6441                         }
6442                 }
6443
6444                 static private Indexers GetIndexersForTypeOrInterface (Type caller_type, Type lookup_type)
6445                 {
6446                         Indexers ix = (Indexers) map [lookup_type];
6447
6448                         if (ix != null)
6449                                 return ix;
6450
6451                         string p_name = TypeManager.IndexerPropertyName (lookup_type);
6452
6453                         MemberInfo [] mi = TypeManager.MemberLookup (
6454                                 caller_type, lookup_type, MemberTypes.Property,
6455                                 BindingFlags.Public | BindingFlags.Instance, p_name);
6456
6457                         if (mi == null || mi.Length == 0)
6458                                 return null;
6459
6460                         ix = new Indexers (mi);
6461                         map [lookup_type] = ix;
6462
6463                         return ix;
6464                 }
6465
6466                 static public Indexers GetIndexersForType (Type caller_type, Type lookup_type, Location loc)
6467                 {
6468                         Indexers ix = (Indexers) map [lookup_type];
6469
6470                         if (ix != null)
6471                                 return ix;
6472
6473                         ix = GetIndexersForTypeOrInterface (caller_type, lookup_type);
6474                         if (ix != null)
6475                                 return ix;
6476
6477                         Type [] ifaces = TypeManager.GetInterfaces (lookup_type);
6478                         if (ifaces != null) {
6479                                 foreach (Type itype in ifaces) {
6480                                         ix = GetIndexersForTypeOrInterface (caller_type, itype);
6481                                         if (ix != null)
6482                                                 return ix;
6483                                 }
6484                         }
6485
6486                         Report.Error (21, loc,
6487                                       "Type `" + TypeManager.CSharpName (lookup_type) +
6488                                       "' does not have any indexers defined");
6489                         return null;
6490                 }
6491         }
6492
6493         /// <summary>
6494         ///   Expressions that represent an indexer call.
6495         /// </summary>
6496         public class IndexerAccess : Expression, IAssignMethod {
6497                 //
6498                 // Points to our "data" repository
6499                 //
6500                 MethodInfo get, set;
6501                 Indexers ilist;
6502                 ArrayList set_arguments;
6503                 bool is_base_indexer;
6504
6505                 protected Type indexer_type;
6506                 protected Type current_type;
6507                 protected Expression instance_expr;
6508                 protected ArrayList arguments;
6509
6510                 public IndexerAccess (ElementAccess ea, Location loc)
6511                         : this (ea.Expr, false, loc)
6512                 {
6513                         this.arguments = ea.Arguments;
6514                 }
6515
6516                 protected IndexerAccess (Expression instance_expr, bool is_base_indexer,
6517                                          Location loc)
6518                 {
6519                         this.instance_expr = instance_expr;
6520                         this.is_base_indexer = is_base_indexer;
6521                         this.eclass = ExprClass.Value;
6522                         this.loc = loc;
6523                 }
6524
6525                 protected virtual bool CommonResolve (EmitContext ec)
6526                 {
6527                         indexer_type = instance_expr.Type;
6528                         current_type = ec.ContainerType;
6529
6530                         return true;
6531                 }
6532
6533                 public override Expression DoResolve (EmitContext ec)
6534                 {
6535                         if (!CommonResolve (ec))
6536                                 return null;
6537
6538                         //
6539                         // Step 1: Query for all `Item' *properties*.  Notice
6540                         // that the actual methods are pointed from here.
6541                         //
6542                         // This is a group of properties, piles of them.
6543
6544                         if (ilist == null)
6545                                 ilist = Indexers.GetIndexersForType (
6546                                         current_type, indexer_type, loc);
6547
6548                         //
6549                         // Step 2: find the proper match
6550                         //
6551                         if (ilist != null && ilist.getters != null && ilist.getters.Count > 0)
6552                                 get = (MethodInfo) Invocation.OverloadResolve (
6553                                         ec, new MethodGroupExpr (ilist.getters, loc), arguments, loc);
6554
6555                         if (get == null){
6556                                 Error (154, "indexer can not be used in this context, because " +
6557                                        "it lacks a `get' accessor");
6558                                 return null;
6559                         }
6560
6561                         type = get.ReturnType;
6562                         if (type.IsPointer && !ec.InUnsafe){
6563                                 UnsafeError (loc);
6564                                 return null;
6565                         }
6566
6567                         eclass = ExprClass.IndexerAccess;
6568                         return this;
6569                 }
6570
6571                 public override Expression DoResolveLValue (EmitContext ec, Expression right_side)
6572                 {
6573                         if (!CommonResolve (ec))
6574                                 return null;
6575
6576                         Type right_type = right_side.Type;
6577
6578                         if (ilist == null)
6579                                 ilist = Indexers.GetIndexersForType (
6580                                         current_type, indexer_type, loc);
6581
6582                         if (ilist != null && ilist.setters != null && ilist.setters.Count > 0){
6583                                 set_arguments = (ArrayList) arguments.Clone ();
6584                                 set_arguments.Add (new Argument (right_side, Argument.AType.Expression));
6585
6586                                 set = (MethodInfo) Invocation.OverloadResolve (
6587                                         ec, new MethodGroupExpr (ilist.setters, loc), set_arguments, loc);
6588                         }
6589
6590                         if (set == null){
6591                                 Error (200, "indexer X.this [" + TypeManager.CSharpName (right_type) +
6592                                        "] lacks a `set' accessor");
6593                                 return null;
6594                         }
6595
6596                         type = TypeManager.void_type;
6597                         eclass = ExprClass.IndexerAccess;
6598                         return this;
6599                 }
6600
6601                 public override void Emit (EmitContext ec)
6602                 {
6603                         Invocation.EmitCall (ec, false, false, instance_expr, get, arguments, loc);
6604                 }
6605
6606                 //
6607                 // source is ignored, because we already have a copy of it from the
6608                 // LValue resolution and we have already constructed a pre-cached
6609                 // version of the arguments (ea.set_arguments);
6610                 //
6611                 public void EmitAssign (EmitContext ec, Expression source)
6612                 {
6613                         Invocation.EmitCall (ec, false, false, instance_expr, set, set_arguments, loc);
6614                 }
6615         }
6616
6617         /// <summary>
6618         ///   The base operator for method names
6619         /// </summary>
6620         public class BaseAccess : Expression {
6621                 string member;
6622
6623                 public BaseAccess (string member, Location l)
6624                 {
6625                         this.member = member;
6626                         loc = l;
6627                 }
6628
6629                 public override Expression DoResolve (EmitContext ec)
6630                 {
6631                         Expression member_lookup;
6632                         Type current_type = ec.ContainerType;
6633                         Type base_type = current_type.BaseType;
6634                         Expression e;
6635
6636                         if (ec.IsStatic){
6637                                 Error (1511,
6638                                               "Keyword base is not allowed in static method");
6639                                 return null;
6640                         }
6641
6642                         member_lookup = MemberLookup (ec, base_type, base_type, member,
6643                                                       AllMemberTypes, AllBindingFlags, loc);
6644                         if (member_lookup == null) {
6645                                 Error (117,
6646                                               TypeManager.CSharpName (base_type) + " does not " +
6647                                               "contain a definition for `" + member + "'");
6648                                 return null;
6649                         }
6650
6651                         Expression left;
6652
6653                         if (ec.IsStatic)
6654                                 left = new TypeExpr (base_type, loc);
6655                         else
6656                                 left = ec.This;
6657
6658                         e = MemberAccess.ResolveMemberAccess (ec, member_lookup, left, loc, null);
6659
6660                         if (e is PropertyExpr){
6661                                 PropertyExpr pe = (PropertyExpr) e;
6662
6663                                 pe.IsBase = true;
6664                         }
6665
6666                         return e;
6667                 }
6668
6669                 public override void Emit (EmitContext ec)
6670                 {
6671                         throw new Exception ("Should never be called");
6672                 }
6673         }
6674
6675         /// <summary>
6676         ///   The base indexer operator
6677         /// </summary>
6678         public class BaseIndexerAccess : IndexerAccess {
6679                 public BaseIndexerAccess (ArrayList args, Location loc)
6680                         : base (null, true, loc)
6681                 {
6682                         arguments = new ArrayList ();
6683                         foreach (Expression tmp in args)
6684                                 arguments.Add (new Argument (tmp, Argument.AType.Expression));
6685                 }
6686
6687                 protected override bool CommonResolve (EmitContext ec)
6688                 {
6689                         instance_expr = ec.This;
6690
6691                         current_type = ec.ContainerType.BaseType;
6692                         indexer_type = current_type;
6693
6694                         foreach (Argument a in arguments){
6695                                 if (!a.Resolve (ec, loc))
6696                                         return false;
6697                         }
6698
6699                         return true;
6700                 }
6701         }
6702
6703         /// <summary>
6704         ///   This class exists solely to pass the Type around and to be a dummy
6705         ///   that can be passed to the conversion functions (this is used by
6706         ///   foreach implementation to typecast the object return value from
6707         ///   get_Current into the proper type.  All code has been generated and
6708         ///   we only care about the side effect conversions to be performed
6709         ///
6710         ///   This is also now used as a placeholder where a no-action expression
6711         ///   is needed (the `New' class).
6712         /// </summary>
6713         public class EmptyExpression : Expression {
6714                 public EmptyExpression ()
6715                 {
6716                         type = TypeManager.object_type;
6717                         eclass = ExprClass.Value;
6718                         loc = Location.Null;
6719                 }
6720
6721                 public EmptyExpression (Type t)
6722                 {
6723                         type = t;
6724                         eclass = ExprClass.Value;
6725                         loc = Location.Null;
6726                 }
6727
6728                 public override Expression DoResolve (EmitContext ec)
6729                 {
6730                         return this;
6731                 }
6732
6733                 public override void Emit (EmitContext ec)
6734                 {
6735                         // nothing, as we only exist to not do anything.
6736                 }
6737
6738                 //
6739                 // This is just because we might want to reuse this bad boy
6740                 // instead of creating gazillions of EmptyExpressions.
6741                 // (CanConvertImplicit uses it)
6742                 //
6743                 public void SetType (Type t)
6744                 {
6745                         type = t;
6746                 }
6747         }
6748
6749         public class UserCast : Expression {
6750                 MethodBase method;
6751                 Expression source;
6752
6753                 public UserCast (MethodInfo method, Expression source, Location l)
6754                 {
6755                         this.method = method;
6756                         this.source = source;
6757                         type = method.ReturnType;
6758                         eclass = ExprClass.Value;
6759                         loc = l;
6760                 }
6761
6762                 public override Expression DoResolve (EmitContext ec)
6763                 {
6764                         //
6765                         // We are born fully resolved
6766                         //
6767                         return this;
6768                 }
6769
6770                 public override void Emit (EmitContext ec)
6771                 {
6772                         ILGenerator ig = ec.ig;
6773
6774                         source.Emit (ec);
6775
6776                         if (method is MethodInfo)
6777                                 ig.Emit (OpCodes.Call, (MethodInfo) method);
6778                         else
6779                                 ig.Emit (OpCodes.Call, (ConstructorInfo) method);
6780
6781                 }
6782         }
6783
6784         // <summary>
6785         //   This class is used to "construct" the type during a typecast
6786         //   operation.  Since the Type.GetType class in .NET can parse
6787         //   the type specification, we just use this to construct the type
6788         //   one bit at a time.
6789         // </summary>
6790         public class ComposedCast : Expression, ITypeExpression {
6791                 Expression left;
6792                 string dim;
6793
6794                 public ComposedCast (Expression left, string dim, Location l)
6795                 {
6796                         this.left = left;
6797                         this.dim = dim;
6798                         loc = l;
6799                 }
6800
6801                 public Expression DoResolveType (EmitContext ec)
6802                 {
6803                         Type ltype = ec.DeclSpace.ResolveType (left, false, loc);
6804                         if (ltype == null)
6805                                 return null;
6806
6807                         //
6808                         // ltype.Fullname is already fully qualified, so we can skip
6809                         // a lot of probes, and go directly to TypeManager.LookupType
6810                         //
6811                         string cname = ltype.FullName + dim;
6812                         type = TypeManager.LookupTypeDirect (cname);
6813                         if (type == null){
6814                                 //
6815                                 // For arrays of enumerations we are having a problem
6816                                 // with the direct lookup.  Need to investigate.
6817                                 //
6818                                 // For now, fall back to the full lookup in that case.
6819                                 //
6820                                 type = RootContext.LookupType (
6821                                         ec.DeclSpace, cname, false, loc);
6822
6823                                 if (type == null)
6824                                         return null;
6825                         }
6826
6827                         if (!ec.ResolvingTypeTree){
6828                                 //
6829                                 // If the above flag is set, this is being invoked from the ResolveType function.
6830                                 // Upper layers take care of the type validity in this context.
6831                                 //
6832                         if (!ec.InUnsafe && type.IsPointer){
6833                                 UnsafeError (loc);
6834                                 return null;
6835                         }
6836                         }
6837
6838                         eclass = ExprClass.Type;
6839                         return this;
6840                 }
6841
6842                 public override Expression DoResolve (EmitContext ec)
6843                 {
6844                         return DoResolveType (ec);
6845                 }
6846
6847                 public override void Emit (EmitContext ec)
6848                 {
6849                         throw new Exception ("This should never be called");
6850                 }
6851
6852                 public override string ToString ()
6853                 {
6854                         return left + dim;
6855                 }
6856         }
6857
6858         //
6859         // This class is used to represent the address of an array, used
6860         // only by the Fixed statement, this is like the C "&a [0]" construct.
6861         //
6862         public class ArrayPtr : Expression {
6863                 Expression array;
6864
6865                 public ArrayPtr (Expression array, Location l)
6866                 {
6867                         Type array_type = array.Type.GetElementType ();
6868
6869                         this.array = array;
6870
6871                         string array_ptr_type_name = array_type.FullName + "*";
6872
6873                         type = Type.GetType (array_ptr_type_name);
6874                         if (type == null){
6875                                 ModuleBuilder mb = CodeGen.ModuleBuilder;
6876
6877                                 type = mb.GetType (array_ptr_type_name);
6878                         }
6879
6880                         eclass = ExprClass.Value;
6881                         loc = l;
6882                 }
6883
6884                 public override void Emit (EmitContext ec)
6885                 {
6886                         ILGenerator ig = ec.ig;
6887
6888                         array.Emit (ec);
6889                         IntLiteral.EmitInt (ig, 0);
6890                         ig.Emit (OpCodes.Ldelema, array.Type.GetElementType ());
6891                 }
6892
6893                 public override Expression DoResolve (EmitContext ec)
6894                 {
6895                         //
6896                         // We are born fully resolved
6897                         //
6898                         return this;
6899                 }
6900         }
6901
6902         //
6903         // Used by the fixed statement
6904         //
6905         public class StringPtr : Expression {
6906                 LocalBuilder b;
6907
6908                 public StringPtr (LocalBuilder b, Location l)
6909                 {
6910                         this.b = b;
6911                         eclass = ExprClass.Value;
6912                         type = TypeManager.char_ptr_type;
6913                         loc = l;
6914                 }
6915
6916                 public override Expression DoResolve (EmitContext ec)
6917                 {
6918                         // This should never be invoked, we are born in fully
6919                         // initialized state.
6920
6921                         return this;
6922                 }
6923
6924                 public override void Emit (EmitContext ec)
6925                 {
6926                         ILGenerator ig = ec.ig;
6927
6928                         ig.Emit (OpCodes.Ldloc, b);
6929                         ig.Emit (OpCodes.Conv_I);
6930                         ig.Emit (OpCodes.Call, TypeManager.int_get_offset_to_string_data);
6931                         ig.Emit (OpCodes.Add);
6932                 }
6933         }
6934
6935         //
6936         // Implements the `stackalloc' keyword
6937         //
6938         public class StackAlloc : Expression {
6939                 Type otype;
6940                 Expression t;
6941                 Expression count;
6942
6943                 public StackAlloc (Expression type, Expression count, Location l)
6944                 {
6945                         t = type;
6946                         this.count = count;
6947                         loc = l;
6948                 }
6949
6950                 public override Expression DoResolve (EmitContext ec)
6951                 {
6952                         count = count.Resolve (ec);
6953                         if (count == null)
6954                                 return null;
6955
6956                         if (count.Type != TypeManager.int32_type){
6957                                 count = ConvertImplicitRequired (ec, count, TypeManager.int32_type, loc);
6958                                 if (count == null)
6959                                         return null;
6960                         }
6961
6962                         if (ec.InCatch || ec.InFinally){
6963                                 Error (255,
6964                                               "stackalloc can not be used in a catch or finally block");
6965                                 return null;
6966                         }
6967
6968                         otype = ec.DeclSpace.ResolveType (t, false, loc);
6969
6970                         if (otype == null)
6971                                 return null;
6972
6973                         if (!TypeManager.VerifyUnManaged (otype, loc))
6974                                 return null;
6975
6976                         string ptr_name = otype.FullName + "*";
6977                         type = Type.GetType (ptr_name);
6978                         if (type == null){
6979                                 ModuleBuilder mb = CodeGen.ModuleBuilder;
6980
6981                                 type = mb.GetType (ptr_name);
6982                         }
6983                         eclass = ExprClass.Value;
6984
6985                         return this;
6986                 }
6987
6988                 public override void Emit (EmitContext ec)
6989                 {
6990                         int size = GetTypeSize (otype);
6991                         ILGenerator ig = ec.ig;
6992
6993                         if (size == 0)
6994                                 ig.Emit (OpCodes.Sizeof, otype);
6995                         else
6996                                 IntConstant.EmitInt (ig, size);
6997                         count.Emit (ec);
6998                         ig.Emit (OpCodes.Mul);
6999                         ig.Emit (OpCodes.Localloc);
7000                 }
7001         }
7002 }