mcs/gmcs/expression.cs

   1 //
   2 // expression.cs: Expression representation for the IL tree.
   3 //
   4 // Author:
   5 //   Miguel de Icaza (miguel@ximian.com)
   6 //
   7 // (C) 2001, 2002, 2003 Ximian, Inc.
   8 // (C) 2003, 2004 Novell, Inc.
   9 //
  10 #define USE_OLD
  11
  12 namespace Mono.CSharp {
  13         using System;
  14         using System.Collections;
  15         using System.Reflection;
  16         using System.Reflection.Emit;
  17         using System.Text;
  18
  19         /// <summary>
  20         ///   This is just a helper class, it is generated by Unary, UnaryMutator
  21         ///   when an overloaded method has been found.  It just emits the code for a
  22         ///   static call.
  23         /// </summary>
  24         public class StaticCallExpr : ExpressionStatement {
  25                 ArrayList args;
  26                 MethodInfo mi;
  27
  28                 public StaticCallExpr (MethodInfo m, ArrayList a, Location l)
  29                 {
  30                         mi = m;
  31                         args = a;
  32
  33                         type = m.ReturnType;
  34                         eclass = ExprClass.Value;
  35                         loc = l;
  36                 }
  37
  38                 public override Expression DoResolve (EmitContext ec)
  39                 {
  40                         //
  41                         // We are born fully resolved
  42                         //
  43                         return this;
  44                 }
  45
  46                 public override void Emit (EmitContext ec)
  47                 {
  48                         if (args != null)
  49                                 Invocation.EmitArguments (ec, mi, args, false, null);
  50
  51                         ec.ig.Emit (OpCodes.Call, mi);
  52                         return;
  53                 }
  54
  55                 static public StaticCallExpr MakeSimpleCall (EmitContext ec, MethodGroupExpr mg,
  56                                                          Expression e, Location loc)
  57                 {
  58                         ArrayList args;
  59                         MethodBase method;
  60
  61                         args = new ArrayList (1);
  62                         Argument a = new Argument (e, Argument.AType.Expression);
  63
  64                         // We need to resolve the arguments before sending them in !
  65                         if (!a.Resolve (ec, loc))
  66                                 return null;
  67
  68                         args.Add (a);
  69                         method = Invocation.OverloadResolve (
  70                                 ec, (MethodGroupExpr) mg, args, false, loc);
  71
  72                         if (method == null)
  73                                 return null;
  74
  75                         return new StaticCallExpr ((MethodInfo) method, args, loc);
  76                 }
  77
  78                 public override void EmitStatement (EmitContext ec)
  79                 {
  80                         Emit (ec);
  81                         if (TypeManager.TypeToCoreType (type) != TypeManager.void_type)
  82                                 ec.ig.Emit (OpCodes.Pop);
  83                 }
  84
  85                 public MethodInfo Method {
  86                         get { return mi; }
  87                 }
  88         }
  89
  90         public class ParenthesizedExpression : Expression
  91         {
  92                 public Expression Expr;
  93
  94                 public ParenthesizedExpression (Expression expr, Location loc)
  95                 {
  96                         this.Expr = expr;
  97                         this.loc = loc;
  98                 }
  99
 100                 public override Expression DoResolve (EmitContext ec)
 101                 {
 102                         Expr = Expr.Resolve (ec);
 103                         return Expr;
 104                 }
 105
 106                 public override void Emit (EmitContext ec)
 107                 {
 108                         throw new Exception ("Should not happen");
 109                 }
 110         }
 111
 112         /// <summary>
 113         ///   Unary expressions.
 114         /// </summary>
 115         ///
 116         /// <remarks>
 117         ///   Unary implements unary expressions.   It derives from
 118         ///   ExpressionStatement becuase the pre/post increment/decrement
 119         ///   operators can be used in a statement context.
 120         /// </remarks>
 121         public class Unary : Expression {
 122                 public enum Operator : byte {
 123                         UnaryPlus, UnaryNegation, LogicalNot, OnesComplement,
 124                         Indirection, AddressOf,  TOP
 125                 }
 126
 127                 public Operator Oper;
 128                 public Expression Expr;
 129
 130                 public Unary (Operator op, Expression expr, Location loc)
 131                 {
 132                         this.Oper = op;
 133                         this.Expr = expr;
 134                         this.loc = loc;
 135                 }
 136
 137                 /// <summary>
 138                 ///   Returns a stringified representation of the Operator
 139                 /// </summary>
 140                 static public string OperName (Operator oper)
 141                 {
 142                         switch (oper){
 143                         case Operator.UnaryPlus:
 144                                 return "+";
 145                         case Operator.UnaryNegation:
 146                                 return "-";
 147                         case Operator.LogicalNot:
 148                                 return "!";
 149                         case Operator.OnesComplement:
 150                                 return "~";
 151                         case Operator.AddressOf:
 152                                 return "&";
 153                         case Operator.Indirection:
 154                                 return "*";
 155                         }
 156
 157                         return oper.ToString ();
 158                 }
 159
 160                 public static readonly string [] oper_names;
 161
 162                 static Unary ()
 163                 {
 164                         oper_names = new string [(int)Operator.TOP];
 165
 166                         oper_names [(int) Operator.UnaryPlus] = "op_UnaryPlus";
 167                         oper_names [(int) Operator.UnaryNegation] = "op_UnaryNegation";
 168                         oper_names [(int) Operator.LogicalNot] = "op_LogicalNot";
 169                         oper_names [(int) Operator.OnesComplement] = "op_OnesComplement";
 170                         oper_names [(int) Operator.Indirection] = "op_Indirection";
 171                         oper_names [(int) Operator.AddressOf] = "op_AddressOf";
 172                 }
 173
 174                 void Error23 (Type t)
 175                 {
 176                         Error (
 177                                 23, "Operator " + OperName (Oper) +
 178                                 " cannot be applied to operand of type `" +
 179                                 TypeManager.CSharpName (t) + "'");
 180                 }
 181
 182                 /// <remarks>
 183                 ///   The result has been already resolved:
 184                 ///
 185                 ///   FIXME: a minus constant -128 sbyte cant be turned into a
 186                 ///   constant byte.
 187                 /// </remarks>
 188                 static Expression TryReduceNegative (Constant expr)
 189                 {
 190                         Expression e = null;
 191
 192                         if (expr is IntConstant)
 193                                 e = new IntConstant (-((IntConstant) expr).Value);
 194                         else if (expr is UIntConstant){
 195                                 uint value = ((UIntConstant) expr).Value;
 196
 197                                 if (value < 2147483649)
 198                                         return new IntConstant (-(int)value);
 199                                 else
 200                                         e = new LongConstant (-value);
 201                         }
 202                         else if (expr is LongConstant)
 203                                 e = new LongConstant (-((LongConstant) expr).Value);
 204                         else if (expr is ULongConstant){
 205                                 ulong value = ((ULongConstant) expr).Value;
 206
 207                                 if (value < 9223372036854775809)
 208                                         return new LongConstant(-(long)value);
 209                         }
 210                         else if (expr is FloatConstant)
 211                                 e = new FloatConstant (-((FloatConstant) expr).Value);
 212                         else if (expr is DoubleConstant)
 213                                 e = new DoubleConstant (-((DoubleConstant) expr).Value);
 214                         else if (expr is DecimalConstant)
 215                                 e = new DecimalConstant (-((DecimalConstant) expr).Value);
 216                         else if (expr is ShortConstant)
 217                                 e = new IntConstant (-((ShortConstant) expr).Value);
 218                         else if (expr is UShortConstant)
 219                                 e = new IntConstant (-((UShortConstant) expr).Value);
 220                         else if (expr is SByteConstant)
 221                                 e = new IntConstant (-((SByteConstant) expr).Value);
 222                         else if (expr is ByteConstant)
 223                                 e = new IntConstant (-((ByteConstant) expr).Value);
 224                         return e;
 225                 }
 226
 227                 // <summary>
 228                 //   This routine will attempt to simplify the unary expression when the
 229                 //   argument is a constant.  The result is returned in `result' and the
 230                 //   function returns true or false depending on whether a reduction
 231                 //   was performed or not
 232                 // </summary>
 233                 bool Reduce (EmitContext ec, Constant e, out Expression result)
 234                 {
 235                         Type expr_type = e.Type;
 236
 237                         switch (Oper){
 238                         case Operator.UnaryPlus:
 239                                 result = e;
 240                                 return true;
 241
 242                         case Operator.UnaryNegation:
 243                                 result = TryReduceNegative (e);
 244                                 return result != null;
 245
 246                         case Operator.LogicalNot:
 247                                 if (expr_type != TypeManager.bool_type) {
 248                                         result = null;
 249                                         Error23 (expr_type);
 250                                         return false;
 251                                 }
 252
 253                                 BoolConstant b = (BoolConstant) e;
 254                                 result = new BoolConstant (!(b.Value));
 255                                 return true;
 256
 257                         case Operator.OnesComplement:
 258                                 if (!((expr_type == TypeManager.int32_type) ||
 259                                       (expr_type == TypeManager.uint32_type) ||
 260                                       (expr_type == TypeManager.int64_type) ||
 261                                       (expr_type == TypeManager.uint64_type) ||
 262                                       (expr_type.IsSubclassOf (TypeManager.enum_type)))){
 263
 264                                         result = null;
 265                                         if (Convert.ImplicitConversionExists (ec, e, TypeManager.int32_type)){
 266                                                 result = new Cast (new TypeExpression (TypeManager.int32_type, loc), e, loc);
 267                                                 result = result.Resolve (ec);
 268                                         } else if (Convert.ImplicitConversionExists (ec, e, TypeManager.uint32_type)){
 269                                                 result = new Cast (new TypeExpression (TypeManager.uint32_type, loc), e, loc);
 270                                                 result = result.Resolve (ec);
 271                                         } else if (Convert.ImplicitConversionExists (ec, e, TypeManager.int64_type)){
 272                                                 result = new Cast (new TypeExpression (TypeManager.int64_type, loc), e, loc);
 273                                                 result = result.Resolve (ec);
 274                                         } else if (Convert.ImplicitConversionExists (ec, e, TypeManager.uint64_type)){
 275                                                 result = new Cast (new TypeExpression (TypeManager.uint64_type, loc), e, loc);
 276                                                 result = result.Resolve (ec);
 277                                         }
 278
 279                                         if (result == null || !(result is Constant)){
 280                                                 result = null;
 281                                                 Error23 (expr_type);
 282                                                 return false;
 283                                         }
 284
 285                                         expr_type = result.Type;
 286                                         e = (Constant) result;
 287                                 }
 288
 289                                 if (e is EnumConstant){
 290                                         EnumConstant enum_constant = (EnumConstant) e;
 291                                         Expression reduced;
 292
 293                                         if (Reduce (ec, enum_constant.Child, out reduced)){
 294                                                 result = new EnumConstant ((Constant) reduced, enum_constant.Type);
 295                                                 return true;
 296                                         } else {
 297                                                 result = null;
 298                                                 return false;
 299                                         }
 300                                 }
 301
 302                                 if (expr_type == TypeManager.int32_type){
 303                                         result = new IntConstant (~ ((IntConstant) e).Value);
 304                                 } else if (expr_type == TypeManager.uint32_type){
 305                                         result = new UIntConstant (~ ((UIntConstant) e).Value);
 306                                 } else if (expr_type == TypeManager.int64_type){
 307                                         result = new LongConstant (~ ((LongConstant) e).Value);
 308                                 } else if (expr_type == TypeManager.uint64_type){
 309                                         result = new ULongConstant (~ ((ULongConstant) e).Value);
 310                                 } else {
 311                                         result = null;
 312                                         Error23 (expr_type);
 313                                         return false;
 314                                 }
 315                                 return true;
 316
 317                         case Operator.AddressOf:
 318                                 result = this;
 319                                 return false;
 320
 321                         case Operator.Indirection:
 322                                 result = this;
 323                                 return false;
 324                         }
 325                         throw new Exception ("Can not constant fold: " + Oper.ToString());
 326                 }
 327
 328                 Expression ResolveOperator (EmitContext ec)
 329                 {
 330                         //
 331                         // Step 1: Default operations on CLI native types.
 332                         //
 333
 334                         // Attempt to use a constant folding operation.
 335                         if (Expr is Constant){
 336                                 Expression result;
 337
 338                                 if (Reduce (ec, (Constant) Expr, out result))
 339                                         return result;
 340                         }
 341
 342                         //
 343                         // Step 2: Perform Operator Overload location
 344                         //
 345                         Type expr_type = Expr.Type;
 346                         Expression mg;
 347                         string op_name;
 348
 349                         op_name = oper_names [(int) Oper];
 350
 351                         mg = MemberLookup (ec, expr_type, op_name, MemberTypes.Method, AllBindingFlags, loc);
 352
 353                         if (mg != null) {
 354                                 Expression e = StaticCallExpr.MakeSimpleCall (
 355                                         ec, (MethodGroupExpr) mg, Expr, loc);
 356
 357                                 if (e == null){
 358                                         Error23 (expr_type);
 359                                         return null;
 360                                 }
 361
 362                                 return e;
 363                         }
 364
 365                         // Only perform numeric promotions on:
 366                         // +, -
 367
 368                         if (expr_type == null)
 369                                 return null;
 370
 371                         switch (Oper){
 372                         case Operator.LogicalNot:
 373                                 if (expr_type != TypeManager.bool_type) {
 374                                         Expr = ResolveBoolean (ec, Expr, loc);
 375                                         if (Expr == null){
 376                                                 Error23 (expr_type);
 377                                                 return null;
 378                                         }
 379                                 }
 380
 381                                 type = TypeManager.bool_type;
 382                                 return this;
 383
 384                         case Operator.OnesComplement:
 385                                 if (!((expr_type == TypeManager.int32_type) ||
 386                                       (expr_type == TypeManager.uint32_type) ||
 387                                       (expr_type == TypeManager.int64_type) ||
 388                                       (expr_type == TypeManager.uint64_type) ||
 389                                       (expr_type.IsSubclassOf (TypeManager.enum_type)))){
 390                                         Expression e;
 391
 392                                         e = Convert.ImplicitConversion (ec, Expr, TypeManager.int32_type, loc);
 393                                         if (e != null){
 394                                                 type = TypeManager.int32_type;
 395                                                 return this;
 396                                         }
 397                                         e = Convert.ImplicitConversion (ec, Expr, TypeManager.uint32_type, loc);
 398                                         if (e != null){
 399                                                 type = TypeManager.uint32_type;
 400                                                 return this;
 401                                         }
 402                                         e = Convert.ImplicitConversion (ec, Expr, TypeManager.int64_type, loc);
 403                                         if (e != null){
 404                                                 type = TypeManager.int64_type;
 405                                                 return this;
 406                                         }
 407                                         e = Convert.ImplicitConversion (ec, Expr, TypeManager.uint64_type, loc);
 408                                         if (e != null){
 409                                                 type = TypeManager.uint64_type;
 410                                                 return this;
 411                                         }
 412                                         Error23 (expr_type);
 413                                         return null;
 414                                 }
 415                                 type = expr_type;
 416                                 return this;
 417
 418                         case Operator.AddressOf:
 419                                 if (Expr.eclass != ExprClass.Variable){
 420                                         Error (211, "Cannot take the address of non-variables");
 421                                         return null;
 422                                 }
 423
 424                                 if (!ec.InUnsafe) {
 425                                         UnsafeError (loc);
 426                                         return null;
 427                                 }
 428
 429                                 if (!TypeManager.VerifyUnManaged (Expr.Type, loc)){
 430                                         return null;
 431                                 }
 432
 433                                 IVariable variable = Expr as IVariable;
 434                                 bool is_fixed = variable != null && variable.VerifyFixed (false);
 435
 436                                 if (!ec.InFixedInitializer && !is_fixed) {
 437                                         Error (212, "You can only take the address of an unfixed expression inside " +
 438                                                "of a fixed statement initializer");
 439                                         return null;
 440                                 }
 441
 442                                 if (ec.InFixedInitializer && is_fixed) {
 443                                         Error (213, "You can not fix an already fixed expression");
 444                                         return null;
 445                                 }
 446
 447                                 LocalVariableReference lr = Expr as LocalVariableReference;
 448                                 if (lr != null){
 449                                         if (lr.local_info.IsCaptured){
 450                                                 AnonymousMethod.Error_AddressOfCapturedVar (lr.Name, loc);
 451                                                 return null;
 452                                         }
 453                                         lr.local_info.AddressTaken = true;
 454                                         lr.local_info.Used = true;
 455                                 }
 456
 457                                 // According to the specs, a variable is considered definitely assigned if you take
 458                                 // its address.
 459                                 if ((variable != null) && (variable.VariableInfo != null))
 460                                         variable.VariableInfo.SetAssigned (ec);
 461
 462                                 type = TypeManager.GetPointerType (Expr.Type);
 463                                 return this;
 464
 465                         case Operator.Indirection:
 466                                 if (!ec.InUnsafe){
 467                                         UnsafeError (loc);
 468                                         return null;
 469                                 }
 470
 471                                 if (!expr_type.IsPointer){
 472                                         Error (193, "The * or -> operator can only be applied to pointers");
 473                                         return null;
 474                                 }
 475
 476                                 //
 477                                 // We create an Indirection expression, because
 478                                 // it can implement the IMemoryLocation.
 479                                 //
 480                                 return new Indirection (Expr, loc);
 481
 482                         case Operator.UnaryPlus:
 483                                 //
 484                                 // A plus in front of something is just a no-op, so return the child.
 485                                 //
 486                                 return Expr;
 487
 488                         case Operator.UnaryNegation:
 489                                 //
 490                                 // Deals with -literals
 491                                 // int     operator- (int x)
 492                                 // long    operator- (long x)
 493                                 // float   operator- (float f)
 494                                 // double  operator- (double d)
 495                                 // decimal operator- (decimal d)
 496                                 //
 497                                 Expression expr = null;
 498
 499                                 //
 500                                 // transform - - expr into expr
 501                                 //
 502                                 if (Expr is Unary){
 503                                         Unary unary = (Unary) Expr;
 504
 505                                         if (unary.Oper == Operator.UnaryNegation)
 506                                                 return unary.Expr;
 507                                 }
 508
 509                                 //
 510                                 // perform numeric promotions to int,
 511                                 // long, double.
 512                                 //
 513                                 //
 514                                 // The following is inneficient, because we call
 515                                 // ImplicitConversion too many times.
 516                                 //
 517                                 // It is also not clear if we should convert to Float
 518                                 // or Double initially.
 519                                 //
 520                                 if (expr_type == TypeManager.uint32_type){
 521                                         //
 522                                         // FIXME: handle exception to this rule that
 523                                         // permits the int value -2147483648 (-2^31) to
 524                                         // bt wrote as a decimal interger literal
 525                                         //
 526                                         type = TypeManager.int64_type;
 527                                         Expr = Convert.ImplicitConversion (ec, Expr, type, loc);
 528                                         return this;
 529                                 }
 530
 531                                 if (expr_type == TypeManager.uint64_type){
 532                                         //
 533                                         // FIXME: Handle exception of `long value'
 534                                         // -92233720368547758087 (-2^63) to be wrote as
 535                                         // decimal integer literal.
 536                                         //
 537                                         Error23 (expr_type);
 538                                         return null;
 539                                 }
 540
 541                                 if (expr_type == TypeManager.float_type){
 542                                         type = expr_type;
 543                                         return this;
 544                                 }
 545
 546                                 expr = Convert.ImplicitConversion (ec, Expr, TypeManager.int32_type, loc);
 547                                 if (expr != null){
 548                                         Expr = expr;
 549                                         type = expr.Type;
 550                                         return this;
 551                                 }
 552
 553                                 expr = Convert.ImplicitConversion (ec, Expr, TypeManager.int64_type, loc);
 554                                 if (expr != null){
 555                                         Expr = expr;
 556                                         type = expr.Type;
 557                                         return this;
 558                                 }
 559
 560                                 expr = Convert.ImplicitConversion (ec, Expr, TypeManager.double_type, loc);
 561                                 if (expr != null){
 562                                         Expr = expr;
 563                                         type = expr.Type;
 564                                         return this;
 565                                 }
 566
 567                                 Error23 (expr_type);
 568                                 return null;
 569                         }
 570
 571                         Error (187, "No such operator '" + OperName (Oper) + "' defined for type '" +
 572                                TypeManager.CSharpName (expr_type) + "'");
 573                         return null;
 574                 }
 575
 576                 public override Expression DoResolve (EmitContext ec)
 577                 {
 578                         if (Oper == Operator.AddressOf)
 579                                 Expr = Expr.ResolveLValue (ec, new EmptyExpression ());
 580                         else
 581                                 Expr = Expr.Resolve (ec);
 582
 583                         if (Expr == null)
 584                                 return null;
 585
 586                         if (TypeManager.IsNullableType (Expr.Type))
 587                                 return new Nullable.LiftedUnaryOperator (Oper, Expr, loc).Resolve (ec);
 588
 589                         eclass = ExprClass.Value;
 590                         return ResolveOperator (ec);
 591                 }
 592
 593                 public override Expression DoResolveLValue (EmitContext ec, Expression right)
 594                 {
 595                         if (Oper == Operator.Indirection)
 596                                 return base.DoResolveLValue (ec, right);
 597
 598                         Error (131, "The left-hand side of an assignment must be a " +
 599                                "variable, property or indexer");
 600                         return null;
 601                 }
 602
 603                 public override void Emit (EmitContext ec)
 604                 {
 605                         ILGenerator ig = ec.ig;
 606
 607                         switch (Oper) {
 608                         case Operator.UnaryPlus:
 609                                 throw new Exception ("This should be caught by Resolve");
 610
 611                         case Operator.UnaryNegation:
 612                                 if (ec.CheckState) {
 613                                         ig.Emit (OpCodes.Ldc_I4_0);
 614                                         if (type == TypeManager.int64_type)
 615                                                 ig.Emit (OpCodes.Conv_U8);
 616                                         Expr.Emit (ec);
 617                                         ig.Emit (OpCodes.Sub_Ovf);
 618                                 } else {
 619                                 Expr.Emit (ec);
 620                                 ig.Emit (OpCodes.Neg);
 621                                 }
 622
 623                                 break;
 624
 625                         case Operator.LogicalNot:
 626                                 Expr.Emit (ec);
 627                                 ig.Emit (OpCodes.Ldc_I4_0);
 628                                 ig.Emit (OpCodes.Ceq);
 629                                 break;
 630
 631                         case Operator.OnesComplement:
 632                                 Expr.Emit (ec);
 633                                 ig.Emit (OpCodes.Not);
 634                                 break;
 635
 636                         case Operator.AddressOf:
 637                                 ((IMemoryLocation)Expr).AddressOf (ec, AddressOp.LoadStore);
 638                                 break;
 639
 640                         default:
 641                                 throw new Exception ("This should not happen: Operator = "
 642                                                      + Oper.ToString ());
 643                         }
 644                 }
 645
 646                 public override void EmitBranchable (EmitContext ec, Label target, bool onTrue)
 647                 {
 648                         if (Oper == Operator.LogicalNot)
 649                                 Expr.EmitBranchable (ec, target, !onTrue);
 650                         else
 651                                 base.EmitBranchable (ec, target, onTrue);
 652                 }
 653
 654                 public override string ToString ()
 655                 {
 656                         return "Unary (" + Oper + ", " + Expr + ")";
 657                 }
 658
 659         }
 660
 661         //
 662         // Unary operators are turned into Indirection expressions
 663         // after semantic analysis (this is so we can take the address
 664         // of an indirection).
 665         //
 666         public class Indirection : Expression, IMemoryLocation, IAssignMethod, IVariable {
 667                 Expression expr;
 668                 LocalTemporary temporary;
 669                 bool prepared;
 670
 671                 public Indirection (Expression expr, Location l)
 672                 {
 673                         this.expr = expr;
 674                         type = TypeManager.HasElementType (expr.Type) ? TypeManager.GetElementType (expr.Type) : expr.Type;
 675                         eclass = ExprClass.Variable;
 676                         loc = l;
 677                 }
 678
 679                 void LoadExprValue (EmitContext ec)
 680                 {
 681                 }
 682
 683                 public override void Emit (EmitContext ec)
 684                 {
 685                         if (!prepared)
 686                                 expr.Emit (ec);
 687
 688                         LoadFromPtr (ec.ig, Type);
 689                 }
 690
 691                 public void Emit (EmitContext ec, bool leave_copy)
 692                 {
 693                         Emit (ec);
 694                         if (leave_copy) {
 695                                 ec.ig.Emit (OpCodes.Dup);
 696                                 temporary = new LocalTemporary (ec, expr.Type);
 697                                 temporary.Store (ec);
 698                         }
 699                 }
 700
 701                 public void EmitAssign (EmitContext ec, Expression source, bool leave_copy, bool prepare_for_load)
 702                 {
 703                         prepared = prepare_for_load;
 704
 705                         expr.Emit (ec);
 706
 707                         if (prepare_for_load)
 708                                 ec.ig.Emit (OpCodes.Dup);
 709
 710                         source.Emit (ec);
 711                         if (leave_copy) {
 712                                 ec.ig.Emit (OpCodes.Dup);
 713                                 temporary = new LocalTemporary (ec, expr.Type);
 714                                 temporary.Store (ec);
 715                         }
 716
 717                         StoreFromPtr (ec.ig, type);
 718
 719                         if (temporary != null)
 720                                 temporary.Emit (ec);
 721                 }
 722
 723                 public void AddressOf (EmitContext ec, AddressOp Mode)
 724                 {
 725                         expr.Emit (ec);
 726                 }
 727
 728                 public override Expression DoResolve (EmitContext ec)
 729                 {
 730                         //
 731                         // Born fully resolved
 732                         //
 733                         return this;
 734                 }
 735
 736                 public override string ToString ()
 737                 {
 738                         return "*(" + expr + ")";
 739                 }
 740
 741                 #region IVariable Members
 742
 743                 public VariableInfo VariableInfo {
 744                         get {
 745                                 return null;
 746                         }
 747                 }
 748
 749                 public bool VerifyFixed (bool is_expression)
 750                 {
 751                         return true;
 752                 }
 753
 754                 #endregion
 755         }
 756
 757         /// <summary>
 758         ///   Unary Mutator expressions (pre and post ++ and --)
 759         /// </summary>
 760         ///
 761         /// <remarks>
 762         ///   UnaryMutator implements ++ and -- expressions.   It derives from
 763         ///   ExpressionStatement becuase the pre/post increment/decrement
 764         ///   operators can be used in a statement context.
 765         ///
 766         /// FIXME: Idea, we could split this up in two classes, one simpler
 767         /// for the common case, and one with the extra fields for more complex
 768         /// classes (indexers require temporary access;  overloaded require method)
 769         ///
 770         /// </remarks>
 771         public class UnaryMutator : ExpressionStatement {
 772                 [Flags]
 773                 public enum Mode : byte {
 774                         IsIncrement    = 0,
 775                         IsDecrement    = 1,
 776                         IsPre          = 0,
 777                         IsPost         = 2,
 778
 779                         PreIncrement   = 0,
 780                         PreDecrement   = IsDecrement,
 781                         PostIncrement  = IsPost,
 782                         PostDecrement  = IsPost | IsDecrement
 783                 }
 784
 785                 Mode mode;
 786                 bool is_expr = false;
 787                 bool recurse = false;
 788
 789                 Expression expr;
 790
 791                 //
 792                 // This is expensive for the simplest case.
 793                 //
 794                 StaticCallExpr method;
 795
 796                 public UnaryMutator (Mode m, Expression e, Location l)
 797                 {
 798                         mode = m;
 799                         loc = l;
 800                         expr = e;
 801                 }
 802
 803                 static string OperName (Mode mode)
 804                 {
 805                         return (mode == Mode.PreIncrement || mode == Mode.PostIncrement) ?
 806                                 "++" : "--";
 807                 }
 808
 809                 void Error23 (Type t)
 810                 {
 811                         Error (
 812                                 23, "Operator " + OperName (mode) +
 813                                 " cannot be applied to operand of type `" +
 814                                 TypeManager.CSharpName (t) + "'");
 815                 }
 816
 817                 /// <summary>
 818                 ///   Returns whether an object of type `t' can be incremented
 819                 ///   or decremented with add/sub (ie, basically whether we can
 820                 ///   use pre-post incr-decr operations on it, but it is not a
 821                 ///   System.Decimal, which we require operator overloading to catch)
 822                 /// </summary>
 823                 static bool IsIncrementableNumber (Type t)
 824                 {
 825                         return (t == TypeManager.sbyte_type) ||
 826                                 (t == TypeManager.byte_type) ||
 827                                 (t == TypeManager.short_type) ||
 828                                 (t == TypeManager.ushort_type) ||
 829                                 (t == TypeManager.int32_type) ||
 830                                 (t == TypeManager.uint32_type) ||
 831                                 (t == TypeManager.int64_type) ||
 832                                 (t == TypeManager.uint64_type) ||
 833                                 (t == TypeManager.char_type) ||
 834                                 (t.IsSubclassOf (TypeManager.enum_type)) ||
 835                                 (t == TypeManager.float_type) ||
 836                                 (t == TypeManager.double_type) ||
 837                                 (t.IsPointer && t != TypeManager.void_ptr_type);
 838                 }
 839
 840                 Expression ResolveOperator (EmitContext ec)
 841                 {
 842                         Type expr_type = expr.Type;
 843
 844                         //
 845                         // Step 1: Perform Operator Overload location
 846                         //
 847                         Expression mg;
 848                         string op_name;
 849
 850                         if (mode == Mode.PreIncrement || mode == Mode.PostIncrement)
 851                                 op_name = "op_Increment";
 852                         else
 853                                 op_name = "op_Decrement";
 854
 855                         mg = MemberLookup (ec, expr_type, op_name, MemberTypes.Method, AllBindingFlags, loc);
 856
 857                         if (mg == null && expr_type.BaseType != null)
 858                                 mg = MemberLookup (ec, expr_type.BaseType, op_name,
 859                                                    MemberTypes.Method, AllBindingFlags, loc);
 860
 861                         if (mg != null) {
 862                                 method = StaticCallExpr.MakeSimpleCall (
 863                                         ec, (MethodGroupExpr) mg, expr, loc);
 864
 865                                 type = method.Type;
 866                                 return this;
 867                         }
 868
 869                         //
 870                         // The operand of the prefix/postfix increment decrement operators
 871                         // should be an expression that is classified as a variable,
 872                         // a property access or an indexer access
 873                         //
 874                         type = expr_type;
 875                         if (expr.eclass == ExprClass.Variable){
 876                                 LocalVariableReference var = expr as LocalVariableReference;
 877                                 if ((var != null) && var.IsReadOnly)
 878                                         Error (1604, "cannot assign to `" + var.Name + "' because it is readonly");
 879                                 if (IsIncrementableNumber (expr_type) ||
 880                                     expr_type == TypeManager.decimal_type){
 881                                         return this;
 882                                 }
 883                         } else if (expr.eclass == ExprClass.IndexerAccess){
 884                                 IndexerAccess ia = (IndexerAccess) expr;
 885
 886                                 expr = ia.ResolveLValue (ec, this);
 887                                 if (expr == null)
 888                                         return null;
 889
 890                                 return this;
 891                         } else if (expr.eclass == ExprClass.PropertyAccess){
 892                                 PropertyExpr pe = (PropertyExpr) expr;
 893
 894                                 if (pe.VerifyAssignable ())
 895                                         return this;
 896
 897                                 return null;
 898                         } else {
 899                                 expr.Error_UnexpectedKind ("variable, indexer or property access", loc);
 900                                 return null;
 901                         }
 902
 903                         Error (187, "No such operator '" + OperName (mode) + "' defined for type '" +
 904                                TypeManager.CSharpName (expr_type) + "'");
 905                         return null;
 906                 }
 907
 908                 public override Expression DoResolve (EmitContext ec)
 909                 {
 910                         expr = expr.Resolve (ec);
 911
 912                         if (expr == null)
 913                                 return null;
 914
 915                         eclass = ExprClass.Value;
 916
 917                         if (TypeManager.IsNullableType (expr.Type))
 918                                 return new Nullable.LiftedUnaryMutator (mode, expr, loc).Resolve (ec);
 919
 920                         return ResolveOperator (ec);
 921                 }
 922
 923                 static int PtrTypeSize (Type t)
 924                 {
 925                         return GetTypeSize (TypeManager.GetElementType (t));
 926                 }
 927
 928                 //
 929                 // Loads the proper "1" into the stack based on the type, then it emits the
 930                 // opcode for the operation requested
 931                 //
 932                 void LoadOneAndEmitOp (EmitContext ec, Type t)
 933                 {
 934                         //
 935                         // Measure if getting the typecode and using that is more/less efficient
 936                         // that comparing types.  t.GetTypeCode() is an internal call.
 937                         //
 938                         ILGenerator ig = ec.ig;
 939
 940                         if (t == TypeManager.uint64_type || t == TypeManager.int64_type)
 941                                 LongConstant.EmitLong (ig, 1);
 942                         else if (t == TypeManager.double_type)
 943                                 ig.Emit (OpCodes.Ldc_R8, 1.0);
 944                         else if (t == TypeManager.float_type)
 945                                 ig.Emit (OpCodes.Ldc_R4, 1.0F);
 946                         else if (t.IsPointer){
 947                                 int n = PtrTypeSize (t);
 948
 949                                 if (n == 0)
 950                                         ig.Emit (OpCodes.Sizeof, t);
 951                                 else
 952                                         IntConstant.EmitInt (ig, n);
 953                         } else
 954                                 ig.Emit (OpCodes.Ldc_I4_1);
 955
 956                         //
 957                         // Now emit the operation
 958                         //
 959                         if (ec.CheckState){
 960                                 if (t == TypeManager.int32_type ||
 961                                     t == TypeManager.int64_type){
 962                                         if ((mode & Mode.IsDecrement) != 0)
 963                                                 ig.Emit (OpCodes.Sub_Ovf);
 964                                         else
 965                                                 ig.Emit (OpCodes.Add_Ovf);
 966                                 } else if (t == TypeManager.uint32_type ||
 967                                            t == TypeManager.uint64_type){
 968                                         if ((mode & Mode.IsDecrement) != 0)
 969                                                 ig.Emit (OpCodes.Sub_Ovf_Un);
 970                                         else
 971                                                 ig.Emit (OpCodes.Add_Ovf_Un);
 972                                 } else {
 973                                         if ((mode & Mode.IsDecrement) != 0)
 974                                                 ig.Emit (OpCodes.Sub_Ovf);
 975                                         else
 976                                                 ig.Emit (OpCodes.Add_Ovf);
 977                                 }
 978                         } else {
 979                                 if ((mode & Mode.IsDecrement) != 0)
 980                                         ig.Emit (OpCodes.Sub);
 981                                 else
 982                                         ig.Emit (OpCodes.Add);
 983                         }
 984
 985                         if (t == TypeManager.sbyte_type){
 986                                 if (ec.CheckState)
 987                                         ig.Emit (OpCodes.Conv_Ovf_I1);
 988                                 else
 989                                         ig.Emit (OpCodes.Conv_I1);
 990                         } else if (t == TypeManager.byte_type){
 991                                 if (ec.CheckState)
 992                                         ig.Emit (OpCodes.Conv_Ovf_U1);
 993                                 else
 994                                         ig.Emit (OpCodes.Conv_U1);
 995                         } else if (t == TypeManager.short_type){
 996                                 if (ec.CheckState)
 997                                         ig.Emit (OpCodes.Conv_Ovf_I2);
 998                                 else
 999                                         ig.Emit (OpCodes.Conv_I2);
1000                         } else if (t == TypeManager.ushort_type || t == TypeManager.char_type){
1001                                 if (ec.CheckState)
1002                                         ig.Emit (OpCodes.Conv_Ovf_U2);
1003                                 else
1004                                         ig.Emit (OpCodes.Conv_U2);
1005                         }
1006
1007                 }
1008
1009                 void EmitCode (EmitContext ec, bool is_expr)
1010                 {
1011                         recurse = true;
1012                         this.is_expr = is_expr;
1013                         ((IAssignMethod) expr).EmitAssign (ec, this, is_expr && (mode == Mode.PreIncrement || mode == Mode.PreDecrement), true);
1014                 }
1015
1016                 public override void Emit (EmitContext ec)
1017                 {
1018                         //
1019                         // We use recurse to allow ourselfs to be the source
1020                         // of an assignment. This little hack prevents us from
1021                         // having to allocate another expression
1022                         //
1023                         if (recurse) {
1024                                 ((IAssignMethod) expr).Emit (ec, is_expr && (mode == Mode.PostIncrement  || mode == Mode.PostDecrement));
1025                                 if (method == null)
1026                                         LoadOneAndEmitOp (ec, expr.Type);
1027                                 else
1028                                         ec.ig.Emit (OpCodes.Call, method.Method);
1029                                 recurse = false;
1030                                 return;
1031                         }
1032
1033                         EmitCode (ec, true);
1034                 }
1035
1036                 public override void EmitStatement (EmitContext ec)
1037                 {
1038                         EmitCode (ec, false);
1039                 }
1040         }
1041
1042         /// <summary>
1043         ///   Base class for the `Is' and `As' classes.
1044         /// </summary>
1045         ///
1046         /// <remarks>
1047         ///   FIXME: Split this in two, and we get to save the `Operator' Oper
1048         ///   size.
1049         /// </remarks>
1050         public abstract class Probe : Expression {
1051                 public Expression ProbeType;
1052                 protected Expression expr;
1053                 protected Type probe_type;
1054
1055                 public Probe (Expression expr, Expression probe_type, Location l)
1056                 {
1057                         ProbeType = probe_type;
1058                         loc = l;
1059                         this.expr = expr;
1060                 }
1061
1062                 public Expression Expr {
1063                         get {
1064                                 return expr;
1065                         }
1066                 }
1067
1068                 public override Expression DoResolve (EmitContext ec)
1069                 {
1070                         TypeExpr texpr = ProbeType.ResolveAsTypeTerminal (ec);
1071                         if (texpr == null)
1072                                 return null;
1073                         probe_type = texpr.Type;
1074
1075                         CheckObsoleteAttribute (probe_type);
1076
1077                         expr = expr.Resolve (ec);
1078                         if (expr == null)
1079                                 return null;
1080
1081                         if (expr.Type.IsPointer) {
1082                                 Report.Error (244, loc, "\"is\" or \"as\" are not valid on pointer types");
1083                                 return null;
1084                         }
1085                         return this;
1086                 }
1087         }
1088
1089         /// <summary>
1090         ///   Implementation of the `is' operator.
1091         /// </summary>
1092         public class Is : Probe {
1093                 public Is (Expression expr, Expression probe_type, Location l)
1094                         : base (expr, probe_type, l)
1095                 {
1096                 }
1097
1098                 enum Action {
1099                         AlwaysTrue, AlwaysNull, AlwaysFalse, LeaveOnStack, Probe
1100                 }
1101
1102                 Action action;
1103
1104                 public override void Emit (EmitContext ec)
1105                 {
1106                         ILGenerator ig = ec.ig;
1107
1108                         expr.Emit (ec);
1109
1110                         switch (action){
1111                         case Action.AlwaysFalse:
1112                                 ig.Emit (OpCodes.Pop);
1113                                 IntConstant.EmitInt (ig, 0);
1114                                 return;
1115                         case Action.AlwaysTrue:
1116                                 ig.Emit (OpCodes.Pop);
1117                                 IntConstant.EmitInt (ig, 1);
1118                                 return;
1119                         case Action.LeaveOnStack:
1120                                 // the `e != null' rule.
1121                                 ig.Emit (OpCodes.Ldnull);
1122                                 ig.Emit (OpCodes.Ceq);
1123                                 ig.Emit (OpCodes.Ldc_I4_0);
1124                                 ig.Emit (OpCodes.Ceq);
1125                                 return;
1126                         case Action.Probe:
1127                                 ig.Emit (OpCodes.Isinst, probe_type);
1128                                 ig.Emit (OpCodes.Ldnull);
1129                                 ig.Emit (OpCodes.Cgt_Un);
1130                                 return;
1131                         }
1132                         throw new Exception ("never reached");
1133                 }
1134
1135                 public override void EmitBranchable (EmitContext ec, Label target, bool onTrue)
1136                 {
1137                         ILGenerator ig = ec.ig;
1138
1139                         switch (action){
1140                         case Action.AlwaysFalse:
1141                                 if (! onTrue)
1142                                         ig.Emit (OpCodes.Br, target);
1143
1144                                 return;
1145                         case Action.AlwaysTrue:
1146                                 if (onTrue)
1147                                         ig.Emit (OpCodes.Br, target);
1148
1149                                 return;
1150                         case Action.LeaveOnStack:
1151                                 // the `e != null' rule.
1152                                 expr.Emit (ec);
1153                                 ig.Emit (onTrue ? OpCodes.Brtrue : OpCodes.Brfalse, target);
1154                                 return;
1155                         case Action.Probe:
1156                                 expr.Emit (ec);
1157                                 ig.Emit (OpCodes.Isinst, probe_type);
1158                                 ig.Emit (onTrue ? OpCodes.Brtrue : OpCodes.Brfalse, target);
1159                                 return;
1160                         }
1161                         throw new Exception ("never reached");
1162                 }
1163
1164                 public override Expression DoResolve (EmitContext ec)
1165                 {
1166                         Expression e = base.DoResolve (ec);
1167
1168                         if ((e == null) || (expr == null))
1169                                 return null;
1170
1171                         Type etype = expr.Type;
1172                         bool warning_always_matches = false;
1173                         bool warning_never_matches = false;
1174
1175                         type = TypeManager.bool_type;
1176                         eclass = ExprClass.Value;
1177
1178                         //
1179                         // First case, if at compile time, there is an implicit conversion
1180                         // then e != null (objects) or true (value types)
1181                         //
1182                         e = Convert.ImplicitConversionStandard (ec, expr, probe_type, loc);
1183                         if (e != null){
1184                                 expr = e;
1185                                 if (etype.IsValueType)
1186                                         action = Action.AlwaysTrue;
1187                                 else
1188                                         action = Action.LeaveOnStack;
1189
1190                                 warning_always_matches = true;
1191                         } else if (Convert.ExplicitReferenceConversionExists (etype, probe_type)){
1192                                 if (etype.IsGenericParameter)
1193                                         expr = new BoxedCast (expr, etype);
1194
1195                                 //
1196                                 // Second case: explicit reference convresion
1197                                 //
1198                                 if (expr is NullLiteral)
1199                                         action = Action.AlwaysFalse;
1200                                 else
1201                                         action = Action.Probe;
1202                         } else {
1203                                 action = Action.AlwaysFalse;
1204                                 warning_never_matches = true;
1205                         }
1206
1207                         if (warning_always_matches)
1208                                 Warning (183, "The given expression is always of the provided ('{0}') type", TypeManager.CSharpName (probe_type));
1209                         else if (warning_never_matches){
1210                                 if (!(probe_type.IsInterface || expr.Type.IsInterface))
1211                                         Warning (184, "The given expression is never of the provided ('{0}') type", TypeManager.CSharpName (probe_type));
1212                         }
1213
1214                         return this;
1215                 }
1216         }
1217
1218         /// <summary>
1219         ///   Implementation of the `as' operator.
1220         /// </summary>
1221         public class As : Probe {
1222                 public As (Expression expr, Expression probe_type, Location l)
1223                         : base (expr, probe_type, l)
1224                 {
1225                 }
1226
1227                 bool do_isinst = false;
1228
1229                 public override void Emit (EmitContext ec)
1230                 {
1231                         ILGenerator ig = ec.ig;
1232
1233                         expr.Emit (ec);
1234
1235                         if (do_isinst)
1236                                 ig.Emit (OpCodes.Isinst, probe_type);
1237                 }
1238
1239                 static void Error_CannotConvertType (Type source, Type target, Location loc)
1240                 {
1241                         Report.Error (
1242                                 39, loc, "as operator can not convert from `" +
1243                                 TypeManager.CSharpName (source) + "' to `" +
1244                                 TypeManager.CSharpName (target) + "'");
1245                 }
1246
1247                 public override Expression DoResolve (EmitContext ec)
1248                 {
1249                         Expression e = base.DoResolve (ec);
1250
1251                         if (e == null)
1252                                 return null;
1253
1254                         type = probe_type;
1255                         eclass = ExprClass.Value;
1256                         Type etype = expr.Type;
1257
1258                         if (TypeManager.IsValueType (probe_type)){
1259                                 Report.Error (77, loc, "The as operator should be used with a reference type only (" +
1260                                               TypeManager.CSharpName (probe_type) + " is a value type)");
1261                                 return null;
1262
1263                         }
1264
1265                         e = Convert.ImplicitConversion (ec, expr, probe_type, loc);
1266                         if (e != null){
1267                                 expr = e;
1268                                 do_isinst = false;
1269                                 return this;
1270                         }
1271
1272                         if (Convert.ExplicitReferenceConversionExists (etype, probe_type)){
1273                                 if (etype.IsGenericParameter)
1274                                         expr = new BoxedCast (expr, etype);
1275
1276                                 do_isinst = true;
1277                                 return this;
1278                         }
1279
1280                         Error_CannotConvertType (etype, probe_type, loc);
1281                         return null;
1282                 }
1283         }
1284
1285         /// <summary>
1286         ///   This represents a typecast in the source language.
1287         ///
1288         ///   FIXME: Cast expressions have an unusual set of parsing
1289         ///   rules, we need to figure those out.
1290         /// </summary>
1291         public class Cast : Expression {
1292                 Expression target_type;
1293                 Expression expr;
1294
1295                 public Cast (Expression cast_type, Expression expr, Location loc)
1296                 {
1297                         this.target_type = cast_type;
1298                         this.expr = expr;
1299                         this.loc = loc;
1300                 }
1301
1302                 public Expression TargetType {
1303                         get {
1304                                 return target_type;
1305                         }
1306                 }
1307
1308                 public Expression Expr {
1309                         get {
1310                                 return expr;
1311                         }
1312                         set {
1313                                 expr = value;
1314                         }
1315                 }
1316
1317                 bool CheckRange (EmitContext ec, long value, Type type, long min, long max)
1318                 {
1319                         if (!ec.ConstantCheckState)
1320                                 return true;
1321
1322                         if ((value < min) || (value > max)) {
1323                                 Error (221, "Constant value `" + value + "' cannot be converted " +
1324                                        "to a `" + TypeManager.CSharpName (type) + "' (use `unchecked' " +
1325                                        "syntax to override)");
1326                                 return false;
1327                         }
1328
1329                         return true;
1330                 }
1331
1332                 bool CheckRange (EmitContext ec, ulong value, Type type, ulong max)
1333                 {
1334                         if (!ec.ConstantCheckState)
1335                                 return true;
1336
1337                         if (value > max) {
1338                                 Error (221, "Constant value `" + value + "' cannot be converted " +
1339                                        "to a `" + TypeManager.CSharpName (type) + "' (use `unchecked' " +
1340                                        "syntax to override)");
1341                                 return false;
1342                         }
1343
1344                         return true;
1345                 }
1346
1347                 bool CheckUnsigned (EmitContext ec, long value, Type type)
1348                 {
1349                         if (!ec.ConstantCheckState)
1350                                 return true;
1351
1352                         if (value < 0) {
1353                                 Error (221, "Constant value `" + value + "' cannot be converted " +
1354                                        "to a `" + TypeManager.CSharpName (type) + "' (use `unchecked' " +
1355                                        "syntax to override)");
1356                                 return false;
1357                         }
1358
1359                         return true;
1360                 }
1361
1362                 /// <summary>
1363                 ///   Attempts to do a compile-time folding of a constant cast.
1364                 /// </summary>
1365                 Expression TryReduce (EmitContext ec, Type target_type)
1366                 {
1367                         Expression real_expr = expr;
1368                         if (real_expr is EnumConstant)
1369                                 real_expr = ((EnumConstant) real_expr).Child;
1370
1371                         if (real_expr is ByteConstant){
1372                                 byte v = ((ByteConstant) real_expr).Value;
1373
1374                                 if (target_type == TypeManager.sbyte_type) {
1375                                         if (!CheckRange (ec, v, target_type, SByte.MinValue, SByte.MaxValue))
1376                                                 return null;
1377                                         return new SByteConstant ((sbyte) v);
1378                                 }
1379                                 if (target_type == TypeManager.short_type)
1380                                         return new ShortConstant ((short) v);
1381                                 if (target_type == TypeManager.ushort_type)
1382                                         return new UShortConstant ((ushort) v);
1383                                 if (target_type == TypeManager.int32_type)
1384                                         return new IntConstant ((int) v);
1385                                 if (target_type == TypeManager.uint32_type)
1386                                         return new UIntConstant ((uint) v);
1387                                 if (target_type == TypeManager.int64_type)
1388                                         return new LongConstant ((long) v);
1389                                 if (target_type == TypeManager.uint64_type)
1390                                         return new ULongConstant ((ulong) 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 (real_expr is SByteConstant){
1401                                 sbyte v = ((SByteConstant) real_expr).Value;
1402
1403                                 if (target_type == TypeManager.byte_type) {
1404                                         if (!CheckUnsigned (ec, v, target_type))
1405                                                 return null;
1406                                         return new ByteConstant ((byte) v);
1407                                 }
1408                                 if (target_type == TypeManager.short_type)
1409                                         return new ShortConstant ((short) v);
1410                                 if (target_type == TypeManager.ushort_type) {
1411                                         if (!CheckUnsigned (ec, v, target_type))
1412                                                 return null;
1413                                         return new UShortConstant ((ushort) v);
1414                                 } if (target_type == TypeManager.int32_type)
1415                                         return new IntConstant ((int) v);
1416                                 if (target_type == TypeManager.uint32_type) {
1417                                         if (!CheckUnsigned (ec, v, target_type))
1418                                                 return null;
1419                                         return new UIntConstant ((uint) v);
1420                                 } if (target_type == TypeManager.int64_type)
1421                                         return new LongConstant ((long) v);
1422                                 if (target_type == TypeManager.uint64_type) {
1423                                         if (!CheckUnsigned (ec, v, target_type))
1424                                                 return null;
1425                                         return new ULongConstant ((ulong) v);
1426                                 }
1427                                 if (target_type == TypeManager.float_type)
1428                                         return new FloatConstant ((float) v);
1429                                 if (target_type == TypeManager.double_type)
1430                                         return new DoubleConstant ((double) v);
1431                                 if (target_type == TypeManager.char_type) {
1432                                         if (!CheckUnsigned (ec, v, target_type))
1433                                                 return null;
1434                                         return new CharConstant ((char) v);
1435                                 }
1436                                 if (target_type == TypeManager.decimal_type)
1437                                         return new DecimalConstant ((decimal) v);
1438                         }
1439                         if (real_expr is ShortConstant){
1440                                 short v = ((ShortConstant) real_expr).Value;
1441
1442                                 if (target_type == TypeManager.byte_type) {
1443                                         if (!CheckRange (ec, v, target_type, Byte.MinValue, Byte.MaxValue))
1444                                                 return null;
1445                                         return new ByteConstant ((byte) v);
1446                                 }
1447                                 if (target_type == TypeManager.sbyte_type) {
1448                                         if (!CheckRange (ec, v, target_type, SByte.MinValue, SByte.MaxValue))
1449                                                 return null;
1450                                         return new SByteConstant ((sbyte) v);
1451                                 }
1452                                 if (target_type == TypeManager.ushort_type) {
1453                                         if (!CheckUnsigned (ec, v, target_type))
1454                                                 return null;
1455                                         return new UShortConstant ((ushort) v);
1456                                 }
1457                                 if (target_type == TypeManager.int32_type)
1458                                         return new IntConstant ((int) v);
1459                                 if (target_type == TypeManager.uint32_type) {
1460                                         if (!CheckUnsigned (ec, v, target_type))
1461                                                 return null;
1462                                         return new UIntConstant ((uint) v);
1463                                 }
1464                                 if (target_type == TypeManager.int64_type)
1465                                         return new LongConstant ((long) v);
1466                                 if (target_type == TypeManager.uint64_type) {
1467                                         if (!CheckUnsigned (ec, v, target_type))
1468                                                 return null;
1469                                         return new ULongConstant ((ulong) v);
1470                                 }
1471                                 if (target_type == TypeManager.float_type)
1472                                         return new FloatConstant ((float) v);
1473                                 if (target_type == TypeManager.double_type)
1474                                         return new DoubleConstant ((double) v);
1475                                 if (target_type == TypeManager.char_type) {
1476                                         if (!CheckRange (ec, v, target_type, Char.MinValue, Char.MaxValue))
1477                                                 return null;
1478                                         return new CharConstant ((char) v);
1479                                 }
1480                                 if (target_type == TypeManager.decimal_type)
1481                                         return new DecimalConstant ((decimal) v);
1482                         }
1483                         if (real_expr is UShortConstant){
1484                                 ushort v = ((UShortConstant) real_expr).Value;
1485
1486                                 if (target_type == TypeManager.byte_type) {
1487                                         if (!CheckRange (ec, v, target_type, Byte.MinValue, Byte.MaxValue))
1488                                                 return null;
1489                                         return new ByteConstant ((byte) v);
1490                                 }
1491                                 if (target_type == TypeManager.sbyte_type) {
1492                                         if (!CheckRange (ec, v, target_type, SByte.MinValue, SByte.MaxValue))
1493                                                 return null;
1494                                         return new SByteConstant ((sbyte) v);
1495                                 }
1496                                 if (target_type == TypeManager.short_type) {
1497                                         if (!CheckRange (ec, v, target_type, Int16.MinValue, Int16.MaxValue))
1498                                                 return null;
1499                                         return new ShortConstant ((short) v);
1500                                 }
1501                                 if (target_type == TypeManager.int32_type)
1502                                         return new IntConstant ((int) v);
1503                                 if (target_type == TypeManager.uint32_type)
1504                                         return new UIntConstant ((uint) v);
1505                                 if (target_type == TypeManager.int64_type)
1506                                         return new LongConstant ((long) v);
1507                                 if (target_type == TypeManager.uint64_type)
1508                                         return new ULongConstant ((ulong) v);
1509                                 if (target_type == TypeManager.float_type)
1510                                         return new FloatConstant ((float) v);
1511                                 if (target_type == TypeManager.double_type)
1512                                         return new DoubleConstant ((double) v);
1513                                 if (target_type == TypeManager.char_type) {
1514                                         if (!CheckRange (ec, v, target_type, Char.MinValue, Char.MaxValue))
1515                                                 return null;
1516                                         return new CharConstant ((char) v);
1517                                 }
1518                                 if (target_type == TypeManager.decimal_type)
1519                                         return new DecimalConstant ((decimal) v);
1520                         }
1521                         if (real_expr is IntConstant){
1522                                 int v = ((IntConstant) real_expr).Value;
1523
1524                                 if (target_type == TypeManager.byte_type) {
1525                                         if (!CheckRange (ec, v, target_type, Byte.MinValue, Byte.MaxValue))
1526                                                 return null;
1527                                         return new ByteConstant ((byte) v);
1528                                 }
1529                                 if (target_type == TypeManager.sbyte_type) {
1530                                         if (!CheckRange (ec, v, target_type, SByte.MinValue, SByte.MaxValue))
1531                                                 return null;
1532                                         return new SByteConstant ((sbyte) v);
1533                                 }
1534                                 if (target_type == TypeManager.short_type) {
1535                                         if (!CheckRange (ec, v, target_type, Int16.MinValue, Int16.MaxValue))
1536                                                 return null;
1537                                         return new ShortConstant ((short) v);
1538                                 }
1539                                 if (target_type == TypeManager.ushort_type) {
1540                                         if (!CheckRange (ec, v, target_type, UInt16.MinValue, UInt16.MaxValue))
1541                                                 return null;
1542                                         return new UShortConstant ((ushort) v);
1543                                 }
1544                                 if (target_type == TypeManager.uint32_type) {
1545                                         if (!CheckRange (ec, v, target_type, Int32.MinValue, Int32.MaxValue))
1546                                                 return null;
1547                                         return new UIntConstant ((uint) v);
1548                                 }
1549                                 if (target_type == TypeManager.int64_type)
1550                                         return new LongConstant ((long) v);
1551                                 if (target_type == TypeManager.uint64_type) {
1552                                         if (!CheckUnsigned (ec, v, target_type))
1553                                                 return null;
1554                                         return new ULongConstant ((ulong) v);
1555                                 }
1556                                 if (target_type == TypeManager.float_type)
1557                                         return new FloatConstant ((float) v);
1558                                 if (target_type == TypeManager.double_type)
1559                                         return new DoubleConstant ((double) v);
1560                                 if (target_type == TypeManager.char_type) {
1561                                         if (!CheckRange (ec, v, target_type, Char.MinValue, Char.MaxValue))
1562                                                 return null;
1563                                         return new CharConstant ((char) v);
1564                                 }
1565                                 if (target_type == TypeManager.decimal_type)
1566                                         return new DecimalConstant ((decimal) v);
1567                         }
1568                         if (real_expr is UIntConstant){
1569                                 uint v = ((UIntConstant) real_expr).Value;
1570
1571                                 if (target_type == TypeManager.byte_type) {
1572                                         if (!CheckRange (ec, v, target_type, Char.MinValue, Char.MaxValue))
1573                                                 return null;
1574                                         return new ByteConstant ((byte) v);
1575                                 }
1576                                 if (target_type == TypeManager.sbyte_type) {
1577                                         if (!CheckRange (ec, v, target_type, SByte.MinValue, SByte.MaxValue))
1578                                                 return null;
1579                                         return new SByteConstant ((sbyte) v);
1580                                 }
1581                                 if (target_type == TypeManager.short_type) {
1582                                         if (!CheckRange (ec, v, target_type, Int16.MinValue, Int16.MaxValue))
1583                                                 return null;
1584                                         return new ShortConstant ((short) v);
1585                                 }
1586                                 if (target_type == TypeManager.ushort_type) {
1587                                         if (!CheckRange (ec, v, target_type, UInt16.MinValue, UInt16.MaxValue))
1588                                                 return null;
1589                                         return new UShortConstant ((ushort) v);
1590                                 }
1591                                 if (target_type == TypeManager.int32_type) {
1592                                         if (!CheckRange (ec, v, target_type, Int32.MinValue, Int32.MaxValue))
1593                                                 return null;
1594                                         return new IntConstant ((int) v);
1595                                 }
1596                                 if (target_type == TypeManager.int64_type)
1597                                         return new LongConstant ((long) v);
1598                                 if (target_type == TypeManager.uint64_type)
1599                                         return new ULongConstant ((ulong) v);
1600                                 if (target_type == TypeManager.float_type)
1601                                         return new FloatConstant ((float) v);
1602                                 if (target_type == TypeManager.double_type)
1603                                         return new DoubleConstant ((double) v);
1604                                 if (target_type == TypeManager.char_type) {
1605                                         if (!CheckRange (ec, v, target_type, Char.MinValue, Char.MaxValue))
1606                                                 return null;
1607                                         return new CharConstant ((char) v);
1608                                 }
1609                                 if (target_type == TypeManager.decimal_type)
1610                                         return new DecimalConstant ((decimal) v);
1611                         }
1612                         if (real_expr is LongConstant){
1613                                 long v = ((LongConstant) real_expr).Value;
1614
1615                                 if (target_type == TypeManager.byte_type) {
1616                                         if (!CheckRange (ec, v, target_type, Byte.MinValue, Byte.MaxValue))
1617                                                 return null;
1618                                         return new ByteConstant ((byte) v);
1619                                 }
1620                                 if (target_type == TypeManager.sbyte_type) {
1621                                         if (!CheckRange (ec, v, target_type, SByte.MinValue, SByte.MaxValue))
1622                                                 return null;
1623                                         return new SByteConstant ((sbyte) v);
1624                                 }
1625                                 if (target_type == TypeManager.short_type) {
1626                                         if (!CheckRange (ec, v, target_type, Int16.MinValue, Int16.MaxValue))
1627                                                 return null;
1628                                         return new ShortConstant ((short) v);
1629                                 }
1630                                 if (target_type == TypeManager.ushort_type) {
1631                                         if (!CheckRange (ec, v, target_type, UInt16.MinValue, UInt16.MaxValue))
1632                                                 return null;
1633                                         return new UShortConstant ((ushort) v);
1634                                 }
1635                                 if (target_type == TypeManager.int32_type) {
1636                                         if (!CheckRange (ec, v, target_type, Int32.MinValue, Int32.MaxValue))
1637                                                 return null;
1638                                         return new IntConstant ((int) v);
1639                                 }
1640                                 if (target_type == TypeManager.uint32_type) {
1641                                         if (!CheckRange (ec, v, target_type, UInt32.MinValue, UInt32.MaxValue))
1642                                                 return null;
1643                                         return new UIntConstant ((uint) v);
1644                                 }
1645                                 if (target_type == TypeManager.uint64_type) {
1646                                         if (!CheckUnsigned (ec, v, target_type))
1647                                                 return null;
1648                                         return new ULongConstant ((ulong) v);
1649                                 }
1650                                 if (target_type == TypeManager.float_type)
1651                                         return new FloatConstant ((float) v);
1652                                 if (target_type == TypeManager.double_type)
1653                                         return new DoubleConstant ((double) v);
1654                                 if (target_type == TypeManager.char_type) {
1655                                         if (!CheckRange (ec, v, target_type, Char.MinValue, Char.MaxValue))
1656                                                 return null;
1657                                         return new CharConstant ((char) v);
1658                                 }
1659                                 if (target_type == TypeManager.decimal_type)
1660                                         return new DecimalConstant ((decimal) v);
1661                         }
1662                         if (real_expr is ULongConstant){
1663                                 ulong v = ((ULongConstant) real_expr).Value;
1664
1665                                 if (target_type == TypeManager.byte_type) {
1666                                         if (!CheckRange (ec, v, target_type, Byte.MaxValue))
1667                                                 return null;
1668                                         return new ByteConstant ((byte) v);
1669                                 }
1670                                 if (target_type == TypeManager.sbyte_type) {
1671                                         if (!CheckRange (ec, v, target_type, (ulong) SByte.MaxValue))
1672                                                 return null;
1673                                         return new SByteConstant ((sbyte) v);
1674                                 }
1675                                 if (target_type == TypeManager.short_type) {
1676                                         if (!CheckRange (ec, v, target_type, (ulong) Int16.MaxValue))
1677                                                 return null;
1678                                         return new ShortConstant ((short) v);
1679                                 }
1680                                 if (target_type == TypeManager.ushort_type) {
1681                                         if (!CheckRange (ec, v, target_type, UInt16.MaxValue))
1682                                                 return null;
1683                                         return new UShortConstant ((ushort) v);
1684                                 }
1685                                 if (target_type == TypeManager.int32_type) {
1686                                         if (!CheckRange (ec, v, target_type, Int32.MaxValue))
1687                                                 return null;
1688                                         return new IntConstant ((int) v);
1689                                 }
1690                                 if (target_type == TypeManager.uint32_type) {
1691                                         if (!CheckRange (ec, v, target_type, UInt32.MaxValue))
1692                                                 return null;
1693                                         return new UIntConstant ((uint) v);
1694                                 }
1695                                 if (target_type == TypeManager.int64_type) {
1696                                         if (!CheckRange (ec, v, target_type, (ulong) Int64.MaxValue))
1697                                                 return null;
1698                                         return new LongConstant ((long) v);
1699                                 }
1700                                 if (target_type == TypeManager.float_type)
1701                                         return new FloatConstant ((float) v);
1702                                 if (target_type == TypeManager.double_type)
1703                                         return new DoubleConstant ((double) v);
1704                                 if (target_type == TypeManager.char_type) {
1705                                         if (!CheckRange (ec, v, target_type, Char.MaxValue))
1706                                                 return null;
1707                                         return new CharConstant ((char) v);
1708                                 }
1709                                 if (target_type == TypeManager.decimal_type)
1710                                         return new DecimalConstant ((decimal) v);
1711                         }
1712                         if (real_expr is FloatConstant){
1713                                 float v = ((FloatConstant) real_expr).Value;
1714
1715                                 if (target_type == TypeManager.byte_type)
1716                                         return new ByteConstant ((byte) v);
1717                                 if (target_type == TypeManager.sbyte_type)
1718                                         return new SByteConstant ((sbyte) v);
1719                                 if (target_type == TypeManager.short_type)
1720                                         return new ShortConstant ((short) v);
1721                                 if (target_type == TypeManager.ushort_type)
1722                                         return new UShortConstant ((ushort) v);
1723                                 if (target_type == TypeManager.int32_type)
1724                                         return new IntConstant ((int) v);
1725                                 if (target_type == TypeManager.uint32_type)
1726                                         return new UIntConstant ((uint) v);
1727                                 if (target_type == TypeManager.int64_type)
1728                                         return new LongConstant ((long) v);
1729                                 if (target_type == TypeManager.uint64_type)
1730                                         return new ULongConstant ((ulong) v);
1731                                 if (target_type == TypeManager.double_type)
1732                                         return new DoubleConstant ((double) v);
1733                                 if (target_type == TypeManager.char_type)
1734                                         return new CharConstant ((char) v);
1735                                 if (target_type == TypeManager.decimal_type)
1736                                         return new DecimalConstant ((decimal) v);
1737                         }
1738                         if (real_expr is DoubleConstant){
1739                                 double v = ((DoubleConstant) real_expr).Value;
1740
1741                                 if (target_type == TypeManager.byte_type){
1742                                         return new ByteConstant ((byte) v);
1743                                 } if (target_type == TypeManager.sbyte_type)
1744                                         return new SByteConstant ((sbyte) v);
1745                                 if (target_type == TypeManager.short_type)
1746                                         return new ShortConstant ((short) v);
1747                                 if (target_type == TypeManager.ushort_type)
1748                                         return new UShortConstant ((ushort) v);
1749                                 if (target_type == TypeManager.int32_type)
1750                                         return new IntConstant ((int) v);
1751                                 if (target_type == TypeManager.uint32_type)
1752                                         return new UIntConstant ((uint) v);
1753                                 if (target_type == TypeManager.int64_type)
1754                                         return new LongConstant ((long) v);
1755                                 if (target_type == TypeManager.uint64_type)
1756                                         return new ULongConstant ((ulong) v);
1757                                 if (target_type == TypeManager.float_type)
1758                                         return new FloatConstant ((float) v);
1759                                 if (target_type == TypeManager.char_type)
1760                                         return new CharConstant ((char) v);
1761                                 if (target_type == TypeManager.decimal_type)
1762                                         return new DecimalConstant ((decimal) v);
1763                         }
1764
1765                         if (real_expr is CharConstant){
1766                                 char v = ((CharConstant) real_expr).Value;
1767
1768                                 if (target_type == TypeManager.byte_type) {
1769                                         if (!CheckRange (ec, v, target_type, Byte.MinValue, Byte.MaxValue))
1770                                                 return null;
1771                                         return new ByteConstant ((byte) v);
1772                                 }
1773                                 if (target_type == TypeManager.sbyte_type) {
1774                                         if (!CheckRange (ec, v, target_type, SByte.MinValue, SByte.MaxValue))
1775                                                 return null;
1776                                         return new SByteConstant ((sbyte) v);
1777                                 }
1778                                 if (target_type == TypeManager.short_type) {
1779                                         if (!CheckRange (ec, v, target_type, Int16.MinValue, Int16.MaxValue))
1780                                                 return null;
1781                                         return new ShortConstant ((short) v);
1782                                 }
1783                                 if (target_type == TypeManager.int32_type)
1784                                         return new IntConstant ((int) v);
1785                                 if (target_type == TypeManager.uint32_type)
1786                                         return new UIntConstant ((uint) v);
1787                                 if (target_type == TypeManager.int64_type)
1788                                         return new LongConstant ((long) v);
1789                                 if (target_type == TypeManager.uint64_type)
1790                                         return new ULongConstant ((ulong) v);
1791                                 if (target_type == TypeManager.float_type)
1792                                         return new FloatConstant ((float) v);
1793                                 if (target_type == TypeManager.double_type)
1794                                         return new DoubleConstant ((double) v);
1795                                 if (target_type == TypeManager.char_type) {
1796                                         if (!CheckRange (ec, v, target_type, Char.MinValue, Char.MaxValue))
1797                                                 return null;
1798                                         return new CharConstant ((char) v);
1799                                 }
1800                                 if (target_type == TypeManager.decimal_type)
1801                                         return new DecimalConstant ((decimal) v);
1802                         }
1803
1804                         return null;
1805                 }
1806
1807                 public override Expression DoResolveLValue (EmitContext ec, Expression right_side)
1808                 {
1809                         expr = expr.DoResolveLValue (ec, right_side);
1810                         if (expr == null)
1811                                 return null;
1812
1813                         return ResolveRest (ec);
1814                 }
1815
1816                 public override Expression DoResolve (EmitContext ec)
1817                 {
1818                         expr = expr.Resolve (ec);
1819                         if (expr == null)
1820                                 return null;
1821
1822                         return ResolveRest (ec);
1823                 }
1824
1825                 Expression ResolveRest (EmitContext ec)
1826                 {
1827                         TypeExpr target = target_type.ResolveAsTypeTerminal (ec);
1828                         if (target == null)
1829                                 return null;
1830
1831                         type = target.Type;
1832
1833                         CheckObsoleteAttribute (type);
1834
1835                         if (type.IsAbstract && type.IsSealed) {
1836                                 Report.Error (716, loc, "Cannot convert to static type '{0}'", TypeManager.CSharpName (type));
1837                                 return null;
1838                         }
1839
1840                         eclass = ExprClass.Value;
1841
1842                         if (expr is Constant){
1843                                 Expression e = TryReduce (ec, type);
1844
1845                                 if (e != null)
1846                                         return e;
1847                         }
1848
1849                         if (type.IsPointer && !ec.InUnsafe) {
1850                                 UnsafeError (loc);
1851                                 return null;
1852                         }
1853                         expr = Convert.ExplicitConversion (ec, expr, type, loc);
1854                         return expr;
1855                 }
1856
1857                 public override void Emit (EmitContext ec)
1858                 {
1859                         //
1860                         // This one will never happen
1861                         //
1862                         throw new Exception ("Should not happen");
1863                 }
1864         }
1865
1866         /// <summary>
1867         ///   Binary operators
1868         /// </summary>
1869         public class Binary : Expression {
1870                 public enum Operator : byte {
1871                         Multiply, Division, Modulus,
1872                         Addition, Subtraction,
1873                         LeftShift, RightShift,
1874                         LessThan, GreaterThan, LessThanOrEqual, GreaterThanOrEqual,
1875                         Equality, Inequality,
1876                         BitwiseAnd,
1877                         ExclusiveOr,
1878                         BitwiseOr,
1879                         LogicalAnd,
1880                         LogicalOr,
1881                         TOP
1882                 }
1883
1884                 Operator oper;
1885                 Expression left, right;
1886
1887                 // This must be kept in sync with Operator!!!
1888                 public static readonly string [] oper_names;
1889
1890                 static Binary ()
1891                 {
1892                         oper_names = new string [(int) Operator.TOP];
1893
1894                         oper_names [(int) Operator.Multiply] = "op_Multiply";
1895                         oper_names [(int) Operator.Division] = "op_Division";
1896                         oper_names [(int) Operator.Modulus] = "op_Modulus";
1897                         oper_names [(int) Operator.Addition] = "op_Addition";
1898                         oper_names [(int) Operator.Subtraction] = "op_Subtraction";
1899                         oper_names [(int) Operator.LeftShift] = "op_LeftShift";
1900                         oper_names [(int) Operator.RightShift] = "op_RightShift";
1901                         oper_names [(int) Operator.LessThan] = "op_LessThan";
1902                         oper_names [(int) Operator.GreaterThan] = "op_GreaterThan";
1903                         oper_names [(int) Operator.LessThanOrEqual] = "op_LessThanOrEqual";
1904                         oper_names [(int) Operator.GreaterThanOrEqual] = "op_GreaterThanOrEqual";
1905                         oper_names [(int) Operator.Equality] = "op_Equality";
1906                         oper_names [(int) Operator.Inequality] = "op_Inequality";
1907                         oper_names [(int) Operator.BitwiseAnd] = "op_BitwiseAnd";
1908                         oper_names [(int) Operator.BitwiseOr] = "op_BitwiseOr";
1909                         oper_names [(int) Operator.ExclusiveOr] = "op_ExclusiveOr";
1910                         oper_names [(int) Operator.LogicalOr] = "op_LogicalOr";
1911                         oper_names [(int) Operator.LogicalAnd] = "op_LogicalAnd";
1912                 }
1913
1914                 public Binary (Operator oper, Expression left, Expression right, Location loc)
1915                 {
1916                         this.oper = oper;
1917                         this.left = left;
1918                         this.right = right;
1919                         this.loc = loc;
1920                 }
1921
1922                 public Operator Oper {
1923                         get {
1924                                 return oper;
1925                         }
1926                         set {
1927                                 oper = value;
1928                         }
1929                 }
1930
1931                 public Expression Left {
1932                         get {
1933                                 return left;
1934                         }
1935                         set {
1936                                 left = value;
1937                         }
1938                 }
1939
1940                 public Expression Right {
1941                         get {
1942                                 return right;
1943                         }
1944                         set {
1945                                 right = value;
1946                         }
1947                 }
1948
1949
1950                 /// <summary>
1951                 ///   Returns a stringified representation of the Operator
1952                 /// </summary>
1953                 static string OperName (Operator oper)
1954                 {
1955                         switch (oper){
1956                         case Operator.Multiply:
1957                                 return "*";
1958                         case Operator.Division:
1959                                 return "/";
1960                         case Operator.Modulus:
1961                                 return "%";
1962                         case Operator.Addition:
1963                                 return "+";
1964                         case Operator.Subtraction:
1965                                 return "-";
1966                         case Operator.LeftShift:
1967                                 return "<<";
1968                         case Operator.RightShift:
1969                                 return ">>";
1970                         case Operator.LessThan:
1971                                 return "<";
1972                         case Operator.GreaterThan:
1973                                 return ">";
1974                         case Operator.LessThanOrEqual:
1975                                 return "<=";
1976                         case Operator.GreaterThanOrEqual:
1977                                 return ">=";
1978                         case Operator.Equality:
1979                                 return "==";
1980                         case Operator.Inequality:
1981                                 return "!=";
1982                         case Operator.BitwiseAnd:
1983                                 return "&";
1984                         case Operator.BitwiseOr:
1985                                 return "|";
1986                         case Operator.ExclusiveOr:
1987                                 return "^";
1988                         case Operator.LogicalOr:
1989                                 return "||";
1990                         case Operator.LogicalAnd:
1991                                 return "&&";
1992                         }
1993
1994                         return oper.ToString ();
1995                 }
1996
1997                 public override string ToString ()
1998                 {
1999                         return "operator " + OperName (oper) + "(" + left.ToString () + ", " +
2000                                 right.ToString () + ")";
2001                 }
2002
2003                 Expression ForceConversion (EmitContext ec, Expression expr, Type target_type)
2004                 {
2005                         if (expr.Type == target_type)
2006                                 return expr;
2007
2008                         return Convert.ImplicitConversion (ec, expr, target_type, loc);
2009                 }
2010
2011                 public static void Error_OperatorAmbiguous (Location loc, Operator oper, Type l, Type r)
2012                 {
2013                         Report.Error (
2014                                 34, loc, "Operator `" + OperName (oper)
2015                                 + "' is ambiguous on operands of type `"
2016                                 + TypeManager.CSharpName (l) + "' "
2017                                 + "and `" + TypeManager.CSharpName (r)
2018                                 + "'");
2019                 }
2020
2021                 bool IsOfType (EmitContext ec, Type l, Type r, Type t, bool check_user_conversions)
2022                 {
2023                         if ((l == t) || (r == t))
2024                                 return true;
2025
2026                         if (!check_user_conversions)
2027                                 return false;
2028
2029                         if (Convert.ImplicitUserConversionExists (ec, l, t))
2030                                 return true;
2031                         else if (Convert.ImplicitUserConversionExists (ec, r, t))
2032                                 return true;
2033                         else
2034                                 return false;
2035                 }
2036
2037                 //
2038                 // Note that handling the case l == Decimal || r == Decimal
2039                 // is taken care of by the Step 1 Operator Overload resolution.
2040                 //
2041                 // If `check_user_conv' is true, we also check whether a user-defined conversion
2042                 // exists.  Note that we only need to do this if both arguments are of a user-defined
2043                 // type, otherwise ConvertImplict() already finds the user-defined conversion for us,
2044                 // so we don't explicitly check for performance reasons.
2045                 //
2046                 bool DoNumericPromotions (EmitContext ec, Type l, Type r, bool check_user_conv)
2047                 {
2048                         if (IsOfType (ec, l, r, TypeManager.double_type, check_user_conv)){
2049                                 //
2050                                 // If either operand is of type double, the other operand is
2051                                 // conveted to type double.
2052                                 //
2053                                 if (r != TypeManager.double_type)
2054                                         right = Convert.ImplicitConversion (ec, right, TypeManager.double_type, loc);
2055                                 if (l != TypeManager.double_type)
2056                                         left = Convert.ImplicitConversion (ec, left, TypeManager.double_type, loc);
2057
2058                                 type = TypeManager.double_type;
2059                         } else if (IsOfType (ec, l, r, TypeManager.float_type, check_user_conv)){
2060                                 //
2061                                 // if either operand is of type float, the other operand is
2062                                 // converted to type float.
2063                                 //
2064                                 if (r != TypeManager.double_type)
2065                                         right = Convert.ImplicitConversion (ec, right, TypeManager.float_type, loc);
2066                                 if (l != TypeManager.double_type)
2067                                         left = Convert.ImplicitConversion (ec, left, TypeManager.float_type, loc);
2068                                 type = TypeManager.float_type;
2069                         } else if (IsOfType (ec, l, r, TypeManager.uint64_type, check_user_conv)){
2070                                 Expression e;
2071                                 Type other;
2072                                 //
2073                                 // If either operand is of type ulong, the other operand is
2074                                 // converted to type ulong.  or an error ocurrs if the other
2075                                 // operand is of type sbyte, short, int or long
2076                                 //
2077                                 if (l == TypeManager.uint64_type){
2078                                         if (r != TypeManager.uint64_type){
2079                                                 if (right is IntConstant){
2080                                                         IntConstant ic = (IntConstant) right;
2081
2082                                                         e = Convert.TryImplicitIntConversion (l, ic);
2083                                                         if (e != null)
2084                                                                 right = e;
2085                                                 } else if (right is LongConstant){
2086                                                         long ll = ((LongConstant) right).Value;
2087
2088                                                         if (ll >= 0)
2089                                                                 right = new ULongConstant ((ulong) ll);
2090                                                 } else {
2091                                                         e = Convert.ImplicitNumericConversion (ec, right, l, loc);
2092                                                         if (e != null)
2093                                                                 right = e;
2094                                                 }
2095                                         }
2096                                         other = right.Type;
2097                                 } else {
2098                                         if (left is IntConstant){
2099                                                 e = Convert.TryImplicitIntConversion (r, (IntConstant) left);
2100                                                 if (e != null)
2101                                                         left = e;
2102                                         } else if (left is LongConstant){
2103                                                 long ll = ((LongConstant) left).Value;
2104
2105                                                 if (ll > 0)
2106                                                         left = new ULongConstant ((ulong) ll);
2107                                         } else {
2108                                                 e = Convert.ImplicitNumericConversion (ec, left, r, loc);
2109                                                 if (e != null)
2110                                                         left = e;
2111                                         }
2112                                         other = left.Type;
2113                                 }
2114
2115                                 if ((other == TypeManager.sbyte_type) ||
2116                                     (other == TypeManager.short_type) ||
2117                                     (other == TypeManager.int32_type) ||
2118                                     (other == TypeManager.int64_type))
2119                                         Error_OperatorAmbiguous (loc, oper, l, r);
2120                                 else {
2121                                         left = ForceConversion (ec, left, TypeManager.uint64_type);
2122                                         right = ForceConversion (ec, right, TypeManager.uint64_type);
2123                                 }
2124                                 type = TypeManager.uint64_type;
2125                         } else if (IsOfType (ec, l, r, TypeManager.int64_type, check_user_conv)){
2126                                 //
2127                                 // If either operand is of type long, the other operand is converted
2128                                 // to type long.
2129                                 //
2130                                 if (l != TypeManager.int64_type)
2131                                         left = Convert.ImplicitConversion (ec, left, TypeManager.int64_type, loc);
2132                                 if (r != TypeManager.int64_type)
2133                                         right = Convert.ImplicitConversion (ec, right, TypeManager.int64_type, loc);
2134
2135                                 type = TypeManager.int64_type;
2136                         } else if (IsOfType (ec, l, r, TypeManager.uint32_type, check_user_conv)){
2137                                 //
2138                                 // If either operand is of type uint, and the other
2139                                 // operand is of type sbyte, short or int, othe operands are
2140                                 // converted to type long (unless we have an int constant).
2141                                 //
2142                                 Type other = null;
2143
2144                                 if (l == TypeManager.uint32_type){
2145                                         if (right is IntConstant){
2146                                                 IntConstant ic = (IntConstant) right;
2147                                                 int val = ic.Value;
2148
2149                                                 if (val >= 0){
2150                                                         right = new UIntConstant ((uint) val);
2151                                                         type = l;
2152
2153                                                         return true;
2154                                                 }
2155                                         }
2156                                         other = r;
2157                                 } else if (r == TypeManager.uint32_type){
2158                                         if (left is IntConstant){
2159                                                 IntConstant ic = (IntConstant) left;
2160                                                 int val = ic.Value;
2161
2162                                                 if (val >= 0){
2163                                                         left = new UIntConstant ((uint) val);
2164                                                         type = r;
2165                                                         return true;
2166                                                 }
2167                                         }
2168
2169                                         other = l;
2170                                 }
2171
2172                                 if ((other == TypeManager.sbyte_type) ||
2173                                     (other == TypeManager.short_type) ||
2174                                     (other == TypeManager.int32_type)){
2175                                         left = ForceConversion (ec, left, TypeManager.int64_type);
2176                                         right = ForceConversion (ec, right, TypeManager.int64_type);
2177                                         type = TypeManager.int64_type;
2178                                 } else {
2179                                         //
2180                                         // if either operand is of type uint, the other
2181                                         // operand is converd to type uint
2182                                         //
2183                                         left = ForceConversion (ec, left, TypeManager.uint32_type);
2184                                         right = ForceConversion (ec, right, TypeManager.uint32_type);
2185                                         type = TypeManager.uint32_type;
2186                                 }
2187                         } else if (l == TypeManager.decimal_type || r == TypeManager.decimal_type){
2188                                 if (l != TypeManager.decimal_type)
2189                                         left = Convert.ImplicitConversion (ec, left, TypeManager.decimal_type, loc);
2190
2191                                 if (r != TypeManager.decimal_type)
2192                                         right = Convert.ImplicitConversion (ec, right, TypeManager.decimal_type, loc);
2193                                 type = TypeManager.decimal_type;
2194                         } else {
2195                                 left = ForceConversion (ec, left, TypeManager.int32_type);
2196                                 right = ForceConversion (ec, right, TypeManager.int32_type);
2197
2198                                 type = TypeManager.int32_type;
2199                         }
2200
2201                         return (left != null) && (right != null);
2202                 }
2203
2204                 static public void Error_OperatorCannotBeApplied (Location loc, string name, Type l, Type r)
2205                 {
2206                         Report.Error (19, loc,
2207                                "Operator " + name + " cannot be applied to operands of type `" +
2208                                TypeManager.CSharpName (l) + "' and `" +
2209                                TypeManager.CSharpName (r) + "'");
2210                 }
2211
2212                 void Error_OperatorCannotBeApplied ()
2213                 {
2214                         Error_OperatorCannotBeApplied (loc, OperName (oper), left.Type, right.Type);
2215                 }
2216
2217                 static bool is_unsigned (Type t)
2218                 {
2219                         return (t == TypeManager.uint32_type || t == TypeManager.uint64_type ||
2220                                 t == TypeManager.short_type || t == TypeManager.byte_type);
2221                 }
2222
2223                 static bool is_user_defined (Type t)
2224                 {
2225                         if (t.IsSubclassOf (TypeManager.value_type) &&
2226                             (!TypeManager.IsBuiltinType (t) || t == TypeManager.decimal_type))
2227                                 return true;
2228                         else
2229                                 return false;
2230                 }
2231
2232                 Expression Make32or64 (EmitContext ec, Expression e)
2233                 {
2234                         Type t= e.Type;
2235
2236                         if (t == TypeManager.int32_type || t == TypeManager.uint32_type ||
2237                             t == TypeManager.int64_type || t == TypeManager.uint64_type)
2238                                 return e;
2239                         Expression ee = Convert.ImplicitConversion (ec, e, TypeManager.int32_type, loc);
2240                         if (ee != null)
2241                                 return ee;
2242                         ee = Convert.ImplicitConversion (ec, e, TypeManager.uint32_type, loc);
2243                         if (ee != null)
2244                                 return ee;
2245                         ee = Convert.ImplicitConversion (ec, e, TypeManager.int64_type, loc);
2246                         if (ee != null)
2247                                 return ee;
2248                         ee = Convert.ImplicitConversion (ec, e, TypeManager.uint64_type, loc);
2249                         if (ee != null)
2250                                 return ee;
2251                         return null;
2252                 }
2253
2254                 Expression CheckShiftArguments (EmitContext ec)
2255                 {
2256                         Expression e;
2257
2258                         e = ForceConversion (ec, right, TypeManager.int32_type);
2259                         if (e == null){
2260                                 Error_OperatorCannotBeApplied ();
2261                                 return null;
2262                         }
2263                         right = e;
2264
2265                         if (((e = Convert.ImplicitConversion (ec, left, TypeManager.int32_type, loc)) != null) ||
2266                             ((e = Convert.ImplicitConversion (ec, left, TypeManager.uint32_type, loc)) != null) ||
2267                             ((e = Convert.ImplicitConversion (ec, left, TypeManager.int64_type, loc)) != null) ||
2268                             ((e = Convert.ImplicitConversion (ec, left, TypeManager.uint64_type, loc)) != null)){
2269                                 left = e;
2270                                 type = e.Type;
2271
2272                                 if (type == TypeManager.int32_type || type == TypeManager.uint32_type){
2273                                         right = new Binary (Binary.Operator.BitwiseAnd, right, new IntLiteral (31), loc);
2274                                         right = right.DoResolve (ec);
2275                                 } else {
2276                                         right = new Binary (Binary.Operator.BitwiseAnd, right, new IntLiteral (63), loc);
2277                                         right = right.DoResolve (ec);
2278                                 }
2279
2280                                 return this;
2281                         }
2282                         Error_OperatorCannotBeApplied ();
2283                         return null;
2284                 }
2285
2286                 Expression ResolveOperator (EmitContext ec)
2287                 {
2288                         Type l = left.Type;
2289                         Type r = right.Type;
2290
2291                         //
2292                         // Special cases: string or type parameter comapred to null
2293                         //
2294                         if (oper == Operator.Equality || oper == Operator.Inequality){
2295                                 if ((!TypeManager.IsValueType (l) && r == TypeManager.null_type) ||
2296                                     (!TypeManager.IsValueType (r) && l == TypeManager.null_type)) {
2297                                         Type = TypeManager.bool_type;
2298
2299                                         return this;
2300                                 }
2301
2302                                 if (l.IsGenericParameter && (right is NullLiteral)) {
2303                                         if (l.BaseType == TypeManager.value_type) {
2304                                                 Error_OperatorCannotBeApplied ();
2305                                                 return null;
2306                                         }
2307
2308                                         left = new BoxedCast (left);
2309                                         Type = TypeManager.bool_type;
2310                                         return this;
2311                                 }
2312
2313                                 if (r.IsGenericParameter && (left is NullLiteral)) {
2314                                         if (r.BaseType == TypeManager.value_type) {
2315                                                 Error_OperatorCannotBeApplied ();
2316                                                 return null;
2317                                         }
2318
2319                                         right = new BoxedCast (right);
2320                                         Type = TypeManager.bool_type;
2321                                         return this;
2322                                 }
2323
2324                                 // IntPtr equality
2325                                 if (l == TypeManager.intptr_type && r == TypeManager.intptr_type) {
2326                                         Type = TypeManager.bool_type;
2327
2328                                         return this;
2329                                 }
2330                         }
2331
2332                         //
2333                         // Do not perform operator overload resolution when both sides are
2334                         // built-in types
2335                         //
2336                         if (!(TypeManager.IsCLRType (l) && TypeManager.IsCLRType (r))){
2337                                 //
2338                                 // Step 1: Perform Operator Overload location
2339                                 //
2340                                 Expression left_expr, right_expr;
2341
2342                                 string op = oper_names [(int) oper];
2343
2344                                 MethodGroupExpr union;
2345                                 left_expr = MemberLookup (ec, l, op, MemberTypes.Method, AllBindingFlags, loc);
2346                                 if (r != l){
2347                                         right_expr = MemberLookup (
2348                                                 ec, r, op, MemberTypes.Method, AllBindingFlags, loc);
2349                                         union = Invocation.MakeUnionSet (left_expr, right_expr, loc);
2350                                 } else
2351                                         union = (MethodGroupExpr) left_expr;
2352
2353                                 if (union != null) {
2354                                         ArrayList args = new ArrayList (2);
2355                                         args.Add (new Argument (left, Argument.AType.Expression));
2356                                         args.Add (new Argument (right, Argument.AType.Expression));
2357
2358                                         MethodBase method = Invocation.OverloadResolve (
2359                                                 ec, union, args, true, Location.Null);
2360
2361                                         if (method != null) {
2362                                                 MethodInfo mi = (MethodInfo) method;
2363
2364                                                 return new BinaryMethod (mi.ReturnType, method, args);
2365                                         }
2366                                 }
2367                         }
2368
2369                         //
2370                         // Step 0: String concatenation (because overloading will get this wrong)
2371                         //
2372                         if (oper == Operator.Addition){
2373                                 //
2374                                 // If any of the arguments is a string, cast to string
2375                                 //
2376
2377                                 // Simple constant folding
2378                                 if (left is StringConstant && right is StringConstant)
2379                                         return new StringConstant (((StringConstant) left).Value + ((StringConstant) right).Value);
2380
2381                                 if (l == TypeManager.string_type || r == TypeManager.string_type) {
2382
2383                                         if (r == TypeManager.void_type || l == TypeManager.void_type) {
2384                                                 Error_OperatorCannotBeApplied ();
2385                                                 return null;
2386                                         }
2387
2388                                         // try to fold it in on the left
2389                                         if (left is StringConcat) {
2390
2391                                                 //
2392                                                 // We have to test here for not-null, since we can be doubly-resolved
2393                                                 // take care of not appending twice
2394                                                 //
2395                                                 if (type == null){
2396                                                         type = TypeManager.string_type;
2397                                                         ((StringConcat) left).Append (ec, right);
2398                                                         return left.Resolve (ec);
2399                                                 } else {
2400                                                         return left;
2401                                                 }
2402                                         }
2403
2404                                         // Otherwise, start a new concat expression
2405                                         return new StringConcat (ec, loc, left, right).Resolve (ec);
2406                                 }
2407
2408                                 //
2409                                 // Transform a + ( - b) into a - b
2410                                 //
2411                                 if (right is Unary){
2412                                         Unary right_unary = (Unary) right;
2413
2414                                         if (right_unary.Oper == Unary.Operator.UnaryNegation){
2415                                                 oper = Operator.Subtraction;
2416                                                 right = right_unary.Expr;
2417                                                 r = right.Type;
2418                                         }
2419                                 }
2420                         }
2421
2422                         if (oper == Operator.Equality || oper == Operator.Inequality){
2423                                 if (l == TypeManager.bool_type || r == TypeManager.bool_type){
2424                                         if (r != TypeManager.bool_type || l != TypeManager.bool_type){
2425                                                 Error_OperatorCannotBeApplied ();
2426                                                 return null;
2427                                         }
2428
2429                                         type = TypeManager.bool_type;
2430                                         return this;
2431                                 }
2432
2433                                 bool left_is_null = left is NullLiteral;
2434                                 bool right_is_null = right is NullLiteral;
2435                                 if (left_is_null || right_is_null) {
2436                                         if (oper == Operator.Equality)
2437                                                 return new BoolLiteral (left_is_null == right_is_null);
2438                                         else
2439                                                 return new BoolLiteral (left_is_null != right_is_null);
2440                                 }
2441
2442                                 //
2443                                 // operator != (object a, object b)
2444                                 // operator == (object a, object b)
2445                                 //
2446                                 // For this to be used, both arguments have to be reference-types.
2447                                 // Read the rationale on the spec (14.9.6)
2448                                 //
2449                                 // Also, if at compile time we know that the classes do not inherit
2450                                 // one from the other, then we catch the error there.
2451                                 //
2452                                 if (!(l.IsValueType || r.IsValueType)){
2453                                         type = TypeManager.bool_type;
2454
2455                                         if (l == r)
2456                                                 return this;
2457
2458                                         if (l.IsSubclassOf (r) || r.IsSubclassOf (l))
2459                                                 return this;
2460
2461                                         //
2462                                         // Also, a standard conversion must exist from either one
2463                                         //
2464                                         if (!(Convert.ImplicitStandardConversionExists (ec, left, r) ||
2465                                               Convert.ImplicitStandardConversionExists (ec, right, l))){
2466                                                 Error_OperatorCannotBeApplied ();
2467                                                 return null;
2468                                         }
2469                                         //
2470                                         // We are going to have to convert to an object to compare
2471                                         //
2472                                         if (l != TypeManager.object_type)
2473                                                 left = new EmptyCast (left, TypeManager.object_type);
2474                                         if (r != TypeManager.object_type)
2475                                                 right = new EmptyCast (right, TypeManager.object_type);
2476
2477                                         //
2478                                         // FIXME: CSC here catches errors cs254 and cs252
2479                                         //
2480                                         return this;
2481                                 }
2482
2483                                 //
2484                                 // One of them is a valuetype, but the other one is not.
2485                                 //
2486                                 if (!l.IsValueType || !r.IsValueType) {
2487                                         Error_OperatorCannotBeApplied ();
2488                                         return null;
2489                                 }
2490                         }
2491
2492                         // Only perform numeric promotions on:
2493                         // +, -, *, /, %, &, |, ^, ==, !=, <, >, <=, >=
2494                         //
2495                         if (oper == Operator.Addition || oper == Operator.Subtraction) {
2496                                 if (TypeManager.IsDelegateType (l)){
2497                                         if (((right.eclass == ExprClass.MethodGroup) ||
2498                                              (r == TypeManager.anonymous_method_type))){
2499                                                 if ((RootContext.Version != LanguageVersion.ISO_1)){
2500                                                         Expression tmp = Convert.ImplicitConversionRequired (ec, right, l, loc);
2501                                                         if (tmp == null)
2502                                                                 return null;
2503                                                         right = tmp;
2504                                                         r = right.Type;
2505                                                 }
2506                                         }
2507
2508                                         if (TypeManager.IsDelegateType (r)){
2509                                                 MethodInfo method;
2510                                                 ArrayList args = new ArrayList (2);
2511
2512                                                 args = new ArrayList (2);
2513                                                 args.Add (new Argument (left, Argument.AType.Expression));
2514                                                 args.Add (new Argument (right, Argument.AType.Expression));
2515
2516                                                 if (oper == Operator.Addition)
2517                                                         method = TypeManager.delegate_combine_delegate_delegate;
2518                                                 else
2519                                                         method = TypeManager.delegate_remove_delegate_delegate;
2520
2521                                                 if (!TypeManager.IsEqual (l, r)) {
2522                                                         Error_OperatorCannotBeApplied ();
2523                                                         return null;
2524                                                 }
2525
2526                                                 return new BinaryDelegate (l, method, args);
2527                                         }
2528                                 }
2529
2530                                 //
2531                                 // Pointer arithmetic:
2532                                 //
2533                                 // T* operator + (T* x, int y);
2534                                 // T* operator + (T* x, uint y);
2535                                 // T* operator + (T* x, long y);
2536                                 // T* operator + (T* x, ulong y);
2537                                 //
2538                                 // T* operator + (int y,   T* x);
2539                                 // T* operator + (uint y,  T *x);
2540                                 // T* operator + (long y,  T *x);
2541                                 // T* operator + (ulong y, T *x);
2542                                 //
2543                                 // T* operator - (T* x, int y);
2544                                 // T* operator - (T* x, uint y);
2545                                 // T* operator - (T* x, long y);
2546                                 // T* operator - (T* x, ulong y);
2547                                 //
2548                                 // long operator - (T* x, T *y)
2549                                 //
2550                                 if (l.IsPointer){
2551                                         if (r.IsPointer && oper == Operator.Subtraction){
2552                                                 if (r == l)
2553                                                         return new PointerArithmetic (
2554                                                                 false, left, right, TypeManager.int64_type,
2555                                                                 loc).Resolve (ec);
2556                                         } else {
2557                                                 Expression t = Make32or64 (ec, right);
2558                                                 if (t != null)
2559                                                         return new PointerArithmetic (oper == Operator.Addition, left, t, l, loc).Resolve (ec);
2560                                         }
2561                                 } else if (r.IsPointer && oper == Operator.Addition){
2562                                         Expression t = Make32or64 (ec, left);
2563                                         if (t != null)
2564                                                 return new PointerArithmetic (true, right, t, r, loc).Resolve (ec);
2565                                 }
2566                         }
2567
2568                         //
2569                         // Enumeration operators
2570                         //
2571                         bool lie = TypeManager.IsEnumType (l);
2572                         bool rie = TypeManager.IsEnumType (r);
2573                         if (lie || rie){
2574                                 Expression temp;
2575
2576                                 // U operator - (E e, E f)
2577                                 if (lie && rie){
2578                                         if (oper == Operator.Subtraction){
2579                                         if (l == r){
2580                                                 type = TypeManager.EnumToUnderlying (l);
2581                                                 return this;
2582                                         }
2583                                         Error_OperatorCannotBeApplied ();
2584                                         return null;
2585                                 }
2586                                 }
2587
2588                                 //
2589                                 // operator + (E e, U x)
2590                                 // operator - (E e, U x)
2591                                 //
2592                                 if (oper == Operator.Addition || oper == Operator.Subtraction){
2593                                         Type enum_type = lie ? l : r;
2594                                         Type other_type = lie ? r : l;
2595                                         Type underlying_type = TypeManager.EnumToUnderlying (enum_type);
2596
2597                                         if (underlying_type != other_type){
2598                                                 temp = Convert.ImplicitConversion (ec, lie ? right : left, underlying_type, loc);
2599                                                 if (temp != null){
2600                                                         if (lie)
2601                                                                 right = temp;
2602                                                         else
2603                                                                 left = temp;
2604                                                         type = enum_type;
2605                                                         return this;
2606                                                 }
2607
2608                                                 Error_OperatorCannotBeApplied ();
2609                                                 return null;
2610                                         }
2611
2612                                         type = enum_type;
2613                                         return this;
2614                                 }
2615
2616                                 if (!rie){
2617                                         temp = Convert.ImplicitConversion (ec, right, l, loc);
2618                                         if (temp != null)
2619                                                 right = temp;
2620                                         else {
2621                                                 Error_OperatorCannotBeApplied ();
2622                                                 return null;
2623                                         }
2624                                 } if (!lie){
2625                                         temp = Convert.ImplicitConversion (ec, left, r, loc);
2626                                         if (temp != null){
2627                                                 left = temp;
2628                                                 l = r;
2629                                         } else {
2630                                                 Error_OperatorCannotBeApplied ();
2631                                                 return null;
2632                                         }
2633                                 }
2634
2635                                 if (oper == Operator.Equality || oper == Operator.Inequality ||
2636                                     oper == Operator.LessThanOrEqual || oper == Operator.LessThan ||
2637                                     oper == Operator.GreaterThanOrEqual || oper == Operator.GreaterThan){
2638                                         if (left.Type != right.Type){
2639                                                 Error_OperatorCannotBeApplied ();
2640                                                 return null;
2641                                         }
2642                                         type = TypeManager.bool_type;
2643                                         return this;
2644                                 }
2645
2646                                 if (oper == Operator.BitwiseAnd ||
2647                                     oper == Operator.BitwiseOr ||
2648                                     oper == Operator.ExclusiveOr){
2649                                         type = l;
2650                                         return this;
2651                                 }
2652                                 Error_OperatorCannotBeApplied ();
2653                                 return null;
2654                         }
2655
2656                         if (oper == Operator.LeftShift || oper == Operator.RightShift)
2657                                 return CheckShiftArguments (ec);
2658
2659                         if (oper == Operator.LogicalOr || oper == Operator.LogicalAnd){
2660                                 if (l == TypeManager.bool_type && r == TypeManager.bool_type) {
2661                                         type = TypeManager.bool_type;
2662                                         return this;
2663                                 }
2664
2665                                 if (l != r) {
2666                                         Error_OperatorCannotBeApplied ();
2667                                         return null;
2668                                 }
2669
2670                                 Expression e = new ConditionalLogicalOperator (
2671                                         oper == Operator.LogicalAnd, left, right, l, loc);
2672                                 return e.Resolve (ec);
2673                         }
2674
2675                         //
2676                         // operator & (bool x, bool y)
2677                         // operator | (bool x, bool y)
2678                         // operator ^ (bool x, bool y)
2679                         //
2680                         if (l == TypeManager.bool_type && r == TypeManager.bool_type){
2681                                 if (oper == Operator.BitwiseAnd ||
2682                                     oper == Operator.BitwiseOr ||
2683                                     oper == Operator.ExclusiveOr){
2684                                         type = l;
2685                                         return this;
2686                                 }
2687                         }
2688
2689                         //
2690                         // Pointer comparison
2691                         //
2692                         if (l.IsPointer && r.IsPointer){
2693                                 if (oper == Operator.Equality || oper == Operator.Inequality ||
2694                                     oper == Operator.LessThan || oper == Operator.LessThanOrEqual ||
2695                                     oper == Operator.GreaterThan || oper == Operator.GreaterThanOrEqual){
2696                                         type = TypeManager.bool_type;
2697                                         return this;
2698                                 }
2699                         }
2700
2701                         //
2702                         // This will leave left or right set to null if there is an error
2703                         //
2704                         bool check_user_conv = is_user_defined (l) && is_user_defined (r);
2705                         DoNumericPromotions (ec, l, r, check_user_conv);
2706                         if (left == null || right == null){
2707                                 Error_OperatorCannotBeApplied (loc, OperName (oper), l, r);
2708                                 return null;
2709                         }
2710
2711                         //
2712                         // reload our cached types if required
2713                         //
2714                         l = left.Type;
2715                         r = right.Type;
2716
2717                         if (oper == Operator.BitwiseAnd ||
2718                             oper == Operator.BitwiseOr ||
2719                             oper == Operator.ExclusiveOr){
2720                                 if (l == r){
2721                                         if (((l == TypeManager.int32_type) ||
2722                                              (l == TypeManager.uint32_type) ||
2723                                              (l == TypeManager.short_type) ||
2724                                              (l == TypeManager.ushort_type) ||
2725                                              (l == TypeManager.int64_type) ||
2726                                              (l == TypeManager.uint64_type))){
2727                                                 type = l;
2728                                         } else {
2729                                                 Error_OperatorCannotBeApplied ();
2730                                                 return null;
2731                                         }
2732                                 } else {
2733                                         Error_OperatorCannotBeApplied ();
2734                                         return null;
2735                                 }
2736                         }
2737
2738                         if (oper == Operator.Equality ||
2739                             oper == Operator.Inequality ||
2740                             oper == Operator.LessThanOrEqual ||
2741                             oper == Operator.LessThan ||
2742                             oper == Operator.GreaterThanOrEqual ||
2743                             oper == Operator.GreaterThan){
2744                                 type = TypeManager.bool_type;
2745                         }
2746
2747                         return this;
2748                 }
2749
2750                 public override Expression DoResolve (EmitContext ec)
2751                 {
2752                         if ((oper == Operator.Subtraction) && (left is ParenthesizedExpression)) {
2753                                 left = ((ParenthesizedExpression) left).Expr;
2754                                 left = left.Resolve (ec, ResolveFlags.VariableOrValue | ResolveFlags.Type);
2755                                 if (left == null)
2756                                         return null;
2757
2758                                 if (left.eclass == ExprClass.Type) {
2759                                         Error (75, "Casting a negative value needs to have the value in parentheses.");
2760                                         return null;
2761                                 }
2762                         } else
2763                                 left = left.Resolve (ec);
2764
2765                         if (left == null)
2766                                 return null;
2767
2768                         Constant lc = left as Constant;
2769                         if (lc != null && lc.Type == TypeManager.bool_type &&
2770                                 ((oper == Operator.LogicalAnd && (bool)lc.GetValue () == false) ||
2771                                  (oper == Operator.LogicalOr && (bool)lc.GetValue () == true))) {
2772
2773                                 // TODO: make a sense to resolve unreachable expression as we do for statement
2774                                 Report.Warning (429, 4, loc, "Unreachable expression code detected");
2775                                 return left;
2776                         }
2777
2778                         right = right.Resolve (ec);
2779                         if (right == null)
2780                                 return null;
2781
2782                         eclass = ExprClass.Value;
2783
2784                         Constant rc = right as Constant;
2785                         if (rc != null & lc != null){
2786                                 Expression e = ConstantFold.BinaryFold (
2787                                         ec, oper, lc, rc, loc);
2788                                         if (e != null)
2789                                                 return e;
2790                         }
2791
2792                         if (TypeManager.IsNullableType (left.Type) || TypeManager.IsNullableType (right.Type))
2793                                 return new Nullable.LiftedBinaryOperator (oper, left, right, loc).Resolve (ec);
2794
2795                         return ResolveOperator (ec);
2796                 }
2797
2798                 /// <remarks>
2799                 ///   EmitBranchable is called from Statement.EmitBoolExpression in the
2800                 ///   context of a conditional bool expression.  This function will return
2801                 ///   false if it is was possible to use EmitBranchable, or true if it was.
2802                 ///
2803                 ///   The expression's code is generated, and we will generate a branch to `target'
2804                 ///   if the resulting expression value is equal to isTrue
2805                 /// </remarks>
2806                 public override void EmitBranchable (EmitContext ec, Label target, bool onTrue)
2807                 {
2808                         ILGenerator ig = ec.ig;
2809
2810                         //
2811                         // This is more complicated than it looks, but its just to avoid
2812                         // duplicated tests: basically, we allow ==, !=, >, <, >= and <=
2813                         // but on top of that we want for == and != to use a special path
2814                         // if we are comparing against null
2815                         //
2816                         if ((oper == Operator.Equality || oper == Operator.Inequality) && (left is Constant || right is Constant)) {
2817                                 bool my_on_true = oper == Operator.Inequality ? onTrue : !onTrue;
2818
2819                                 //
2820                                 // put the constant on the rhs, for simplicity
2821                                 //
2822                                 if (left is Constant) {
2823                                         Expression swap = right;
2824                                         right = left;
2825                                         left = swap;
2826                                 }
2827
2828                                 if (((Constant) right).IsZeroInteger) {
2829                                         left.Emit (ec);
2830                                         if (my_on_true)
2831                                                 ig.Emit (OpCodes.Brtrue, target);
2832                                         else
2833                                                 ig.Emit (OpCodes.Brfalse, target);
2834
2835                                         return;
2836                                 } else if (right is BoolConstant){
2837                                         left.Emit (ec);
2838                                         if (my_on_true != ((BoolConstant) right).Value)
2839                                                 ig.Emit (OpCodes.Brtrue, target);
2840                                         else
2841                                                 ig.Emit (OpCodes.Brfalse, target);
2842
2843                                         return;
2844                                 }
2845
2846                         } else if (oper == Operator.LogicalAnd) {
2847
2848                                 if (onTrue) {
2849                                                 Label tests_end = ig.DefineLabel ();
2850
2851                                         left.EmitBranchable (ec, tests_end, false);
2852                                         right.EmitBranchable (ec, target, true);
2853                                                         ig.MarkLabel (tests_end);
2854                                         } else {
2855                                         left.EmitBranchable (ec, target, false);
2856                                         right.EmitBranchable (ec, target, false);
2857                                         }
2858
2859                                 return;
2860
2861                         } else if (oper == Operator.LogicalOr){
2862                                 if (onTrue) {
2863                                         left.EmitBranchable (ec, target, true);
2864                                         right.EmitBranchable (ec, target, true);
2865
2866                                         } else {
2867                                                 Label tests_end = ig.DefineLabel ();
2868                                         left.EmitBranchable (ec, tests_end, true);
2869                                         right.EmitBranchable (ec, target, false);
2870                                         ig.MarkLabel (tests_end);
2871                                 }
2872
2873                                 return;
2874
2875                         } else if (!(oper == Operator.LessThan        || oper == Operator.GreaterThan ||
2876                                      oper == Operator.LessThanOrEqual || oper == Operator.GreaterThanOrEqual ||
2877                                      oper == Operator.Equality        || oper == Operator.Inequality)) {
2878                                 base.EmitBranchable (ec, target, onTrue);
2879                                 return;
2880                                 }
2881
2882                         left.Emit (ec);
2883                         right.Emit (ec);
2884
2885                         Type t = left.Type;
2886                         bool isUnsigned = is_unsigned (t) || t == TypeManager.double_type || t == TypeManager.float_type;
2887
2888                         switch (oper){
2889                         case Operator.Equality:
2890                                 if (onTrue)
2891                                         ig.Emit (OpCodes.Beq, target);
2892                                 else
2893                                         ig.Emit (OpCodes.Bne_Un, target);
2894                                 break;
2895
2896                         case Operator.Inequality:
2897                                 if (onTrue)
2898                                         ig.Emit (OpCodes.Bne_Un, target);
2899                                 else
2900                                         ig.Emit (OpCodes.Beq, target);
2901                                 break;
2902
2903                         case Operator.LessThan:
2904                                 if (onTrue)
2905                                         if (isUnsigned)
2906                                                 ig.Emit (OpCodes.Blt_Un, target);
2907                                         else
2908                                                 ig.Emit (OpCodes.Blt, target);
2909                                 else
2910                                         if (isUnsigned)
2911                                                 ig.Emit (OpCodes.Bge_Un, target);
2912                                         else
2913                                                 ig.Emit (OpCodes.Bge, target);
2914                                 break;
2915
2916                         case Operator.GreaterThan:
2917                                 if (onTrue)
2918                                         if (isUnsigned)
2919                                                 ig.Emit (OpCodes.Bgt_Un, target);
2920                                         else
2921                                                 ig.Emit (OpCodes.Bgt, target);
2922                                 else
2923                                         if (isUnsigned)
2924                                                 ig.Emit (OpCodes.Ble_Un, target);
2925                                         else
2926                                                 ig.Emit (OpCodes.Ble, target);
2927                                 break;
2928
2929                         case Operator.LessThanOrEqual:
2930                                 if (onTrue)
2931                                         if (isUnsigned)
2932                                                 ig.Emit (OpCodes.Ble_Un, target);
2933                                         else
2934                                                 ig.Emit (OpCodes.Ble, target);
2935                                 else
2936                                         if (isUnsigned)
2937                                                 ig.Emit (OpCodes.Bgt_Un, target);
2938                                         else
2939                                                 ig.Emit (OpCodes.Bgt, target);
2940                                 break;
2941
2942
2943                         case Operator.GreaterThanOrEqual:
2944                                 if (onTrue)
2945                                         if (isUnsigned)
2946                                                 ig.Emit (OpCodes.Bge_Un, target);
2947                                         else
2948                                                 ig.Emit (OpCodes.Bge, target);
2949                                 else
2950                                         if (isUnsigned)
2951                                                 ig.Emit (OpCodes.Blt_Un, target);
2952                                         else
2953                                                 ig.Emit (OpCodes.Blt, target);
2954                                 break;
2955                         default:
2956                                 Console.WriteLine (oper);
2957                                 throw new Exception ("what is THAT");
2958                         }
2959                 }
2960
2961                 public override void Emit (EmitContext ec)
2962                 {
2963                         ILGenerator ig = ec.ig;
2964                         Type l = left.Type;
2965                         OpCode opcode;
2966
2967                         //
2968                         // Handle short-circuit operators differently
2969                         // than the rest
2970                         //
2971                         if (oper == Operator.LogicalAnd) {
2972                                 Label load_zero = ig.DefineLabel ();
2973                                 Label end = ig.DefineLabel ();
2974
2975                                 left.EmitBranchable (ec, load_zero, false);
2976                                                 right.Emit (ec);
2977                                                 ig.Emit (OpCodes.Br, end);
2978
2979                                 ig.MarkLabel (load_zero);
2980                                 ig.Emit (OpCodes.Ldc_I4_0);
2981                                 ig.MarkLabel (end);
2982                                 return;
2983                         } else if (oper == Operator.LogicalOr) {
2984                                 Label load_one = ig.DefineLabel ();
2985                                 Label end = ig.DefineLabel ();
2986
2987                                 left.EmitBranchable (ec, load_one, true);
2988                                                 right.Emit (ec);
2989                                                 ig.Emit (OpCodes.Br, end);
2990
2991                                 ig.MarkLabel (load_one);
2992                                 ig.Emit (OpCodes.Ldc_I4_1);
2993                                 ig.MarkLabel (end);
2994                                 return;
2995                         }
2996
2997                         left.Emit (ec);
2998                         right.Emit (ec);
2999
3000                         bool isUnsigned = is_unsigned (left.Type);
3001
3002                         switch (oper){
3003                         case Operator.Multiply:
3004                                 if (ec.CheckState){
3005                                         if (l == TypeManager.int32_type || l == TypeManager.int64_type)
3006                                                 opcode = OpCodes.Mul_Ovf;
3007                                         else if (isUnsigned)
3008                                                 opcode = OpCodes.Mul_Ovf_Un;
3009                                         else
3010                                                 opcode = OpCodes.Mul;
3011                                 } else
3012                                         opcode = OpCodes.Mul;
3013
3014                                 break;
3015
3016                         case Operator.Division:
3017                                 if (isUnsigned)
3018                                         opcode = OpCodes.Div_Un;
3019                                 else
3020                                         opcode = OpCodes.Div;
3021                                 break;
3022
3023                         case Operator.Modulus:
3024                                 if (isUnsigned)
3025                                         opcode = OpCodes.Rem_Un;
3026                                 else
3027                                         opcode = OpCodes.Rem;
3028                                 break;
3029
3030                         case Operator.Addition:
3031                                 if (ec.CheckState){
3032                                         if (l == TypeManager.int32_type || l == TypeManager.int64_type)
3033                                                 opcode = OpCodes.Add_Ovf;
3034                                         else if (isUnsigned)
3035                                                 opcode = OpCodes.Add_Ovf_Un;
3036                                         else
3037                                                 opcode = OpCodes.Add;
3038                                 } else
3039                                         opcode = OpCodes.Add;
3040                                 break;
3041
3042                         case Operator.Subtraction:
3043                                 if (ec.CheckState){
3044                                         if (l == TypeManager.int32_type || l == TypeManager.int64_type)
3045                                                 opcode = OpCodes.Sub_Ovf;
3046                                         else if (isUnsigned)
3047                                                 opcode = OpCodes.Sub_Ovf_Un;
3048                                         else
3049                                                 opcode = OpCodes.Sub;
3050                                 } else
3051                                         opcode = OpCodes.Sub;
3052                                 break;
3053
3054                         case Operator.RightShift:
3055                                 if (isUnsigned)
3056                                         opcode = OpCodes.Shr_Un;
3057                                 else
3058                                         opcode = OpCodes.Shr;
3059                                 break;
3060
3061                         case Operator.LeftShift:
3062                                 opcode = OpCodes.Shl;
3063                                 break;
3064
3065                         case Operator.Equality:
3066                                 opcode = OpCodes.Ceq;
3067                                 break;
3068
3069                         case Operator.Inequality:
3070                                 ig.Emit (OpCodes.Ceq);
3071                                 ig.Emit (OpCodes.Ldc_I4_0);
3072
3073                                 opcode = OpCodes.Ceq;
3074                                 break;
3075
3076                         case Operator.LessThan:
3077                                 if (isUnsigned)
3078                                         opcode = OpCodes.Clt_Un;
3079                                 else
3080                                         opcode = OpCodes.Clt;
3081                                 break;
3082
3083                         case Operator.GreaterThan:
3084                                 if (isUnsigned)
3085                                         opcode = OpCodes.Cgt_Un;
3086                                 else
3087                                         opcode = OpCodes.Cgt;
3088                                 break;
3089
3090                         case Operator.LessThanOrEqual:
3091                                 Type lt = left.Type;
3092
3093                                 if (isUnsigned || (lt == TypeManager.double_type || lt == TypeManager.float_type))
3094                                         ig.Emit (OpCodes.Cgt_Un);
3095                                 else
3096                                         ig.Emit (OpCodes.Cgt);
3097                                 ig.Emit (OpCodes.Ldc_I4_0);
3098
3099                                 opcode = OpCodes.Ceq;
3100                                 break;
3101
3102                         case Operator.GreaterThanOrEqual:
3103                                 Type le = left.Type;
3104
3105                                 if (isUnsigned || (le == TypeManager.double_type || le == TypeManager.float_type))
3106                                         ig.Emit (OpCodes.Clt_Un);
3107                                 else
3108                                         ig.Emit (OpCodes.Clt);
3109
3110                                 ig.Emit (OpCodes.Ldc_I4_0);
3111
3112                                 opcode = OpCodes.Ceq;
3113                                 break;
3114
3115                         case Operator.BitwiseOr:
3116                                 opcode = OpCodes.Or;
3117                                 break;
3118
3119                         case Operator.BitwiseAnd:
3120                                 opcode = OpCodes.And;
3121                                 break;
3122
3123                         case Operator.ExclusiveOr:
3124                                 opcode = OpCodes.Xor;
3125                                 break;
3126
3127                         default:
3128                                 throw new Exception ("This should not happen: Operator = "
3129                                                      + oper.ToString ());
3130                         }
3131
3132                         ig.Emit (opcode);
3133                 }
3134         }
3135
3136         //
3137         // Object created by Binary when the binary operator uses an method instead of being
3138         // a binary operation that maps to a CIL binary operation.
3139         //
3140         public class BinaryMethod : Expression {
3141                 public MethodBase method;
3142                 public ArrayList  Arguments;
3143
3144                 public BinaryMethod (Type t, MethodBase m, ArrayList args)
3145                 {
3146                         method = m;
3147                         Arguments = args;
3148                         type = t;
3149                         eclass = ExprClass.Value;
3150                 }
3151
3152                 public override Expression DoResolve (EmitContext ec)
3153                 {
3154                         return this;
3155                 }
3156
3157                 public override void Emit (EmitContext ec)
3158                 {
3159                         ILGenerator ig = ec.ig;
3160
3161                         if (Arguments != null)
3162                                 Invocation.EmitArguments (ec, method, Arguments, false, null);
3163
3164                         if (method is MethodInfo)
3165                                 ig.Emit (OpCodes.Call, (MethodInfo) method);
3166                         else
3167                                 ig.Emit (OpCodes.Call, (ConstructorInfo) method);
3168                 }
3169         }
3170
3171         //
3172         // Represents the operation a + b [+ c [+ d [+ ...]]], where a is a string
3173         // b, c, d... may be strings or objects.
3174         //
3175         public class StringConcat : Expression {
3176                 ArrayList operands;
3177                 bool invalid = false;
3178                 bool emit_conv_done = false;
3179                 //
3180                 // Are we also concating objects?
3181                 //
3182                 bool is_strings_only = true;
3183
3184                 public StringConcat (EmitContext ec, Location loc, Expression left, Expression right)
3185                 {
3186                         this.loc = loc;
3187                         type = TypeManager.string_type;
3188                         eclass = ExprClass.Value;
3189
3190                         operands = new ArrayList (2);
3191                         Append (ec, left);
3192                         Append (ec, right);
3193                 }
3194
3195                 public override Expression DoResolve (EmitContext ec)
3196                 {
3197                         if (invalid)
3198                                 return null;
3199
3200                         return this;
3201                 }
3202
3203                 public void Append (EmitContext ec, Expression operand)
3204                 {
3205                         //
3206                         // Constant folding
3207                         //
3208                         if (operand is StringConstant && operands.Count != 0) {
3209                                 StringConstant last_operand = operands [operands.Count - 1] as StringConstant;
3210                                 if (last_operand != null) {
3211                                         operands [operands.Count - 1] = new StringConstant (last_operand.Value + ((StringConstant) operand).Value);
3212                                         return;
3213                                 }
3214                         }
3215
3216                         //
3217                         // Conversion to object
3218                         //
3219                         if (operand.Type != TypeManager.string_type) {
3220                                 Expression no = Convert.ImplicitConversion (ec, operand, TypeManager.object_type, loc);
3221
3222                                 if (no == null) {
3223                                         Binary.Error_OperatorCannotBeApplied (loc, "+", TypeManager.string_type, operand.Type);
3224                                         invalid = true;
3225                                 }
3226                                 operand = no;
3227                         }
3228
3229                         operands.Add (operand);
3230                 }
3231
3232                 public override void Emit (EmitContext ec)
3233                 {
3234                         MethodInfo concat_method = null;
3235
3236                         //
3237                         // Do conversion to arguments; check for strings only
3238                         //
3239
3240                         // This can get called multiple times, so we have to deal with that.
3241                         if (!emit_conv_done) {
3242                                 emit_conv_done = true;
3243                         for (int i = 0; i < operands.Count; i ++) {
3244                                 Expression e = (Expression) operands [i];
3245                                 is_strings_only &= e.Type == TypeManager.string_type;
3246                         }
3247
3248                         for (int i = 0; i < operands.Count; i ++) {
3249                                 Expression e = (Expression) operands [i];
3250
3251                                 if (! is_strings_only && e.Type == TypeManager.string_type) {
3252                                         // need to make sure this is an object, because the EmitParams
3253                                         // method might look at the type of this expression, see it is a
3254                                         // string and emit a string [] when we want an object [];
3255
3256                                                 e = new EmptyCast (e, TypeManager.object_type);
3257                                 }
3258                                 operands [i] = new Argument (e, Argument.AType.Expression);
3259                         }
3260                         }
3261
3262                         //
3263                         // Find the right method
3264                         //
3265                         switch (operands.Count) {
3266                         case 1:
3267                                 //
3268                                 // This should not be possible, because simple constant folding
3269                                 // is taken care of in the Binary code.
3270                                 //
3271                                 throw new Exception ("how did you get here?");
3272
3273                         case 2:
3274                                 concat_method = is_strings_only ?
3275                                         TypeManager.string_concat_string_string :
3276                                         TypeManager.string_concat_object_object ;
3277                                 break;
3278                         case 3:
3279                                 concat_method = is_strings_only ?
3280                                         TypeManager.string_concat_string_string_string :
3281                                         TypeManager.string_concat_object_object_object ;
3282                                 break;
3283                         case 4:
3284                                 //
3285                                 // There is not a 4 param overlaod for object (the one that there is
3286                                 // is actually a varargs methods, and is only in corlib because it was
3287                                 // introduced there before.).
3288                                 //
3289                                 if (!is_strings_only)
3290                                         goto default;
3291
3292                                 concat_method = TypeManager.string_concat_string_string_string_string;
3293                                 break;
3294                         default:
3295                                 concat_method = is_strings_only ?
3296                                         TypeManager.string_concat_string_dot_dot_dot :
3297                                         TypeManager.string_concat_object_dot_dot_dot ;
3298                                 break;
3299                         }
3300
3301                         Invocation.EmitArguments (ec, concat_method, operands, false, null);
3302                         ec.ig.Emit (OpCodes.Call, concat_method);
3303                 }
3304         }
3305
3306         //
3307         // Object created with +/= on delegates
3308         //
3309         public class BinaryDelegate : Expression {
3310                 MethodInfo method;
3311                 ArrayList  args;
3312
3313                 public BinaryDelegate (Type t, MethodInfo mi, ArrayList args)
3314                 {
3315                         method = mi;
3316                         this.args = args;
3317                         type = t;
3318                         eclass = ExprClass.Value;
3319                 }
3320
3321                 public override Expression DoResolve (EmitContext ec)
3322                 {
3323                         return this;
3324                 }
3325
3326                 public override void Emit (EmitContext ec)
3327                 {
3328                         ILGenerator ig = ec.ig;
3329
3330                         Invocation.EmitArguments (ec, method, args, false, null);
3331
3332                         ig.Emit (OpCodes.Call, (MethodInfo) method);
3333                         ig.Emit (OpCodes.Castclass, type);
3334                 }
3335
3336                 public Expression Right {
3337                         get {
3338                                 Argument arg = (Argument) args [1];
3339                                 return arg.Expr;
3340                         }
3341                 }
3342
3343                 public bool IsAddition {
3344                         get {
3345                                 return method == TypeManager.delegate_combine_delegate_delegate;
3346                         }
3347                 }
3348         }
3349
3350         //
3351         // User-defined conditional logical operator
3352         public class ConditionalLogicalOperator : Expression {
3353                 Expression left, right;
3354                 bool is_and;
3355
3356                 public ConditionalLogicalOperator (bool is_and, Expression left, Expression right, Type t, Location loc)
3357                 {
3358                         type = t;
3359                         eclass = ExprClass.Value;
3360                         this.loc = loc;
3361                         this.left = left;
3362                         this.right = right;
3363                         this.is_and = is_and;
3364                 }
3365
3366                 protected void Error19 ()
3367                 {
3368                         Binary.Error_OperatorCannotBeApplied (loc, is_and ? "&&" : "||", type, type);
3369                 }
3370
3371                 protected void Error218 ()
3372                 {
3373                         Error (218, "The type ('" + TypeManager.CSharpName (type) + "') must contain " +
3374                                "declarations of operator true and operator false");
3375                 }
3376
3377                 Expression op_true, op_false, op;
3378                 LocalTemporary left_temp;
3379
3380                 public override Expression DoResolve (EmitContext ec)
3381                 {
3382                         MethodInfo method;
3383                         Expression operator_group;
3384
3385                         operator_group = MethodLookup (ec, type, is_and ? "op_BitwiseAnd" : "op_BitwiseOr", loc);
3386                         if (operator_group == null) {
3387                                 Error19 ();
3388                                 return null;
3389                         }
3390
3391                         left_temp = new LocalTemporary (ec, type);
3392
3393                         ArrayList arguments = new ArrayList ();
3394                         arguments.Add (new Argument (left_temp, Argument.AType.Expression));
3395                         arguments.Add (new Argument (right, Argument.AType.Expression));
3396                         method = Invocation.OverloadResolve (
3397                                 ec, (MethodGroupExpr) operator_group, arguments, false, loc)
3398                                 as MethodInfo;
3399                         if ((method == null) || (method.ReturnType != type)) {
3400                                 Error19 ();
3401                                 return null;
3402                         }
3403
3404                         op = new StaticCallExpr (method, arguments, loc);
3405
3406                         op_true = GetOperatorTrue (ec, left_temp, loc);
3407                         op_false = GetOperatorFalse (ec, left_temp, loc);
3408                         if ((op_true == null) || (op_false == null)) {
3409                                 Error218 ();
3410                                 return null;
3411                         }
3412
3413                         return this;
3414                 }
3415
3416                 public override void Emit (EmitContext ec)
3417                 {
3418                         ILGenerator ig = ec.ig;
3419                         Label false_target = ig.DefineLabel ();
3420                         Label end_target = ig.DefineLabel ();
3421
3422                         left.Emit (ec);
3423                         left_temp.Store (ec);
3424
3425                         (is_and ? op_false : op_true).EmitBranchable (ec, false_target, false);
3426                         left_temp.Emit (ec);
3427                         ig.Emit (OpCodes.Br, end_target);
3428                         ig.MarkLabel (false_target);
3429                         op.Emit (ec);
3430                         ig.MarkLabel (end_target);
3431                 }
3432         }
3433
3434         public class PointerArithmetic : Expression {
3435                 Expression left, right;
3436                 bool is_add;
3437
3438                 //
3439                 // We assume that `l' is always a pointer
3440                 //
3441                 public PointerArithmetic (bool is_addition, Expression l, Expression r, Type t, Location loc)
3442                 {
3443                         type = t;
3444                         this.loc = loc;
3445                         left = l;
3446                         right = r;
3447                         is_add = is_addition;
3448                 }
3449
3450                 public override Expression DoResolve (EmitContext ec)
3451                 {
3452                         eclass = ExprClass.Variable;
3453
3454                         if (left.Type == TypeManager.void_ptr_type) {
3455                                 Error (242, "The operation in question is undefined on void pointers");
3456                                 return null;
3457                         }
3458
3459                         return this;
3460                 }
3461
3462                 public override void Emit (EmitContext ec)
3463                 {
3464                         Type op_type = left.Type;
3465                         ILGenerator ig = ec.ig;
3466
3467                         // It must be either array or fixed buffer
3468                         Type element = TypeManager.HasElementType (op_type) ?
3469                                 element = TypeManager.GetElementType (op_type) :
3470                                 element = AttributeTester.GetFixedBuffer (((FieldExpr)left).FieldInfo).ElementType;
3471
3472                         int size = GetTypeSize (element);
3473                         Type rtype = right.Type;
3474
3475                         if (rtype.IsPointer){
3476                                 //
3477                                 // handle (pointer - pointer)
3478                                 //
3479                                 left.Emit (ec);
3480                                 right.Emit (ec);
3481                                 ig.Emit (OpCodes.Sub);
3482
3483                                 if (size != 1){
3484                                         if (size == 0)
3485                                                 ig.Emit (OpCodes.Sizeof, element);
3486                                         else
3487                                                 IntLiteral.EmitInt (ig, size);
3488                                         ig.Emit (OpCodes.Div);
3489                                 }
3490                                 ig.Emit (OpCodes.Conv_I8);
3491                         } else {
3492                                 //
3493                                 // handle + and - on (pointer op int)
3494                                 //
3495                                 left.Emit (ec);
3496                                 ig.Emit (OpCodes.Conv_I);
3497
3498                                 Constant right_const = right as Constant;
3499                                 if (right_const != null && size != 0) {
3500                                         Expression ex = ConstantFold.BinaryFold (ec, Binary.Operator.Multiply, new IntConstant (size), right_const, loc);
3501                                         if (ex == null)
3502                                                 return;
3503                                         ex.Emit (ec);
3504                                 } else {
3505                                         right.Emit (ec);
3506                                         if (size != 1){
3507                                                 if (size == 0)
3508                                                         ig.Emit (OpCodes.Sizeof, element);
3509                                                 else
3510                                                         IntLiteral.EmitInt (ig, size);
3511                                                 if (rtype == TypeManager.int64_type)
3512                                                         ig.Emit (OpCodes.Conv_I8);
3513                                                 else if (rtype == TypeManager.uint64_type)
3514                                                         ig.Emit (OpCodes.Conv_U8);
3515                                                 ig.Emit (OpCodes.Mul);
3516                                         }
3517                                 }
3518
3519                                 if (rtype == TypeManager.int64_type || rtype == TypeManager.uint64_type)
3520                                         ig.Emit (OpCodes.Conv_I);
3521
3522                                 if (is_add)
3523                                         ig.Emit (OpCodes.Add);
3524                                 else
3525                                         ig.Emit (OpCodes.Sub);
3526                         }
3527                 }
3528         }
3529
3530         /// <summary>
3531         ///   Implements the ternary conditional operator (?:)
3532         /// </summary>
3533         public class Conditional : Expression {
3534                 Expression expr, trueExpr, falseExpr;
3535
3536                 public Conditional (Expression expr, Expression trueExpr, Expression falseExpr, Location l)
3537                 {
3538                         this.expr = expr;
3539                         this.trueExpr = trueExpr;
3540                         this.falseExpr = falseExpr;
3541                         this.loc = l;
3542                 }
3543
3544                 public Expression Expr {
3545                         get {
3546                                 return expr;
3547                         }
3548                 }
3549
3550                 public Expression TrueExpr {
3551                         get {
3552                                 return trueExpr;
3553                         }
3554                 }
3555
3556                 public Expression FalseExpr {
3557                         get {
3558                                 return falseExpr;
3559                         }
3560                 }
3561
3562                 public override Expression DoResolve (EmitContext ec)
3563                 {
3564                         expr = expr.Resolve (ec);
3565
3566                         if (expr == null)
3567                                 return null;
3568
3569                         if (TypeManager.IsNullableType (expr.Type))
3570                                 return new Nullable.LiftedConditional (expr, trueExpr, falseExpr, loc).Resolve (ec);
3571
3572                         if (expr.Type != TypeManager.bool_type){
3573                                 expr = Expression.ResolveBoolean (
3574                                         ec, expr, loc);
3575
3576                                 if (expr == null)
3577                                         return null;
3578                         }
3579
3580                         trueExpr = trueExpr.Resolve (ec);
3581                         falseExpr = falseExpr.Resolve (ec);
3582
3583                         if (trueExpr == null || falseExpr == null)
3584                                 return null;
3585
3586                         eclass = ExprClass.Value;
3587                         if (trueExpr.Type == falseExpr.Type)
3588                                 type = trueExpr.Type;
3589                         else {
3590                                 Expression conv;
3591                                 Type true_type = trueExpr.Type;
3592                                 Type false_type = falseExpr.Type;
3593
3594                                 //
3595                                 // First, if an implicit conversion exists from trueExpr
3596                                 // to falseExpr, then the result type is of type falseExpr.Type
3597                                 //
3598                                 conv = Convert.ImplicitConversion (ec, trueExpr, false_type, loc);
3599                                 if (conv != null){
3600                                         //
3601                                         // Check if both can convert implicitl to each other's type
3602                                         //
3603                                         if (Convert.ImplicitConversion (ec, falseExpr, true_type, loc) != null){
3604                                                 Error (172,
3605                                                        "Can not compute type of conditional expression " +
3606                                                        "as `" + TypeManager.CSharpName (trueExpr.Type) +
3607                                                        "' and `" + TypeManager.CSharpName (falseExpr.Type) +
3608                                                        "' convert implicitly to each other");
3609                                                 return null;
3610                                         }
3611                                         type = false_type;
3612                                         trueExpr = conv;
3613                                 } else if ((conv = Convert.ImplicitConversion(ec, falseExpr, true_type,loc))!= null){
3614                                         type = true_type;
3615                                         falseExpr = conv;
3616                                 } else {
3617                                         Error (173, "The type of the conditional expression can " +
3618                                                "not be computed because there is no implicit conversion" +
3619                                                " from `" + TypeManager.CSharpName (trueExpr.Type) + "'" +
3620                                                " and `" + TypeManager.CSharpName (falseExpr.Type) + "'");
3621                                         return null;
3622                                 }
3623                         }
3624
3625                         // Dead code optimalization
3626                         if (expr is BoolConstant){
3627                                 BoolConstant bc = (BoolConstant) expr;
3628
3629                                 Report.Warning (429, 4, bc.Value ? falseExpr.Location : trueExpr.Location, "Unreachable expression code detected");
3630                                 return bc.Value ? trueExpr : falseExpr;
3631                         }
3632
3633                         return this;
3634                 }
3635
3636                 public override void Emit (EmitContext ec)
3637                 {
3638                         ILGenerator ig = ec.ig;
3639                         Label false_target = ig.DefineLabel ();
3640                         Label end_target = ig.DefineLabel ();
3641
3642                         expr.EmitBranchable (ec, false_target, false);
3643                         trueExpr.Emit (ec);
3644                         ig.Emit (OpCodes.Br, end_target);
3645                         ig.MarkLabel (false_target);
3646                         falseExpr.Emit (ec);
3647                         ig.MarkLabel (end_target);
3648                 }
3649
3650         }
3651
3652         /// <summary>
3653         ///   Local variables
3654         /// </summary>
3655         public class LocalVariableReference : Expression, IAssignMethod, IMemoryLocation, IVariable {
3656                 public readonly string Name;
3657                 public readonly Block Block;
3658                 public LocalInfo local_info;
3659                 bool is_readonly;
3660                 bool prepared;
3661                 LocalTemporary temp;
3662
3663                 public LocalVariableReference (Block block, string name, Location l)
3664                 {
3665                         Block = block;
3666                         Name = name;
3667                         loc = l;
3668                         eclass = ExprClass.Variable;
3669                 }
3670
3671                 //
3672                 // Setting `is_readonly' to false will allow you to create a writable
3673                 // reference to a read-only variable.  This is used by foreach and using.
3674                 //
3675                 public LocalVariableReference (Block block, string name, Location l,
3676                                                LocalInfo local_info, bool is_readonly)
3677                         : this (block, name, l)
3678                 {
3679                         this.local_info = local_info;
3680                         this.is_readonly = is_readonly;
3681                 }
3682
3683                 public VariableInfo VariableInfo {
3684                         get {
3685                                 return local_info.VariableInfo;
3686                         }
3687                 }
3688
3689                 public bool IsReadOnly {
3690                         get {
3691                                 return is_readonly;
3692                         }
3693                 }
3694
3695                 protected Expression DoResolveBase (EmitContext ec, Expression lvalue_right_side)
3696                 {
3697                         if (local_info == null) {
3698                                 local_info = Block.GetLocalInfo (Name);
3699
3700                                 // is out param
3701                                 if (lvalue_right_side == EmptyExpression.Null)
3702                                         local_info.Used = true;
3703
3704                                 is_readonly = local_info.ReadOnly;
3705                         }
3706
3707                         type = local_info.VariableType;
3708
3709                         VariableInfo variable_info = local_info.VariableInfo;
3710                         if (lvalue_right_side != null){
3711                                 if (is_readonly){
3712                                         Error (1604, "cannot assign to `" + Name + "' because it is readonly");
3713                                         return null;
3714                                 }
3715
3716                                 if (variable_info != null)
3717                                         variable_info.SetAssigned (ec);
3718                 }
3719
3720                         Expression e = Block.GetConstantExpression (Name);
3721                         if (e != null) {
3722                                 local_info.Used = true;
3723                                 eclass = ExprClass.Value;
3724                                 return e.Resolve (ec);
3725                         }
3726
3727                         if ((variable_info != null) && !variable_info.IsAssigned (ec, loc))
3728                                 return null;
3729
3730                         if (lvalue_right_side == null)
3731                                 local_info.Used = true;
3732
3733                         if (ec.CurrentAnonymousMethod != null){
3734                                 //
3735                                 // If we are referencing a variable from the external block
3736                                 // flag it for capturing
3737                                 //
3738                                 if (local_info.Block.Toplevel != ec.CurrentBlock.Toplevel){
3739                                         if (local_info.AddressTaken){
3740                                                 AnonymousMethod.Error_AddressOfCapturedVar (local_info.Name, loc);
3741                                                 return null;
3742                                         }
3743                                         ec.CaptureVariable (local_info);
3744                                 }
3745                         }
3746
3747                         return this;
3748                 }
3749
3750                 public override Expression DoResolve (EmitContext ec)
3751                 {
3752                         return DoResolveBase (ec, null);
3753                 }
3754
3755                 override public Expression DoResolveLValue (EmitContext ec, Expression right_side)
3756                 {
3757                         Expression ret = DoResolveBase (ec, right_side);
3758                         if (ret != null)
3759                                 CheckObsoleteAttribute (ret.Type);
3760
3761                         return ret;
3762                 }
3763
3764                 public bool VerifyFixed (bool is_expression)
3765                 {
3766                         return !is_expression || local_info.IsFixed;
3767                 }
3768
3769                 public override void Emit (EmitContext ec)
3770                 {
3771                         ILGenerator ig = ec.ig;
3772
3773                         if (local_info.FieldBuilder == null){
3774                                 //
3775                                 // A local variable on the local CLR stack
3776                                 //
3777                         ig.Emit (OpCodes.Ldloc, local_info.LocalBuilder);
3778                         } else {
3779                                 //
3780                                 // A local variable captured by anonymous methods.
3781                                 //
3782                                 if (!prepared)
3783                                         ec.EmitCapturedVariableInstance (local_info);
3784
3785                                 ig.Emit (OpCodes.Ldfld, local_info.FieldBuilder);
3786                         }
3787                 }
3788
3789                 public void Emit (EmitContext ec, bool leave_copy)
3790                 {
3791                         Emit (ec);
3792                         if (leave_copy){
3793                                 ec.ig.Emit (OpCodes.Dup);
3794                                 if (local_info.FieldBuilder != null){
3795                                         temp = new LocalTemporary (ec, Type);
3796                                         temp.Store (ec);
3797                                 }
3798                         }
3799                 }
3800
3801                 public void EmitAssign (EmitContext ec, Expression source, bool leave_copy, bool prepare_for_load)
3802                 {
3803                         ILGenerator ig = ec.ig;
3804                         prepared = prepare_for_load;
3805
3806                         if (local_info.FieldBuilder == null){
3807                                 //
3808                                 // A local variable on the local CLR stack
3809                                 //
3810                                 if (local_info.LocalBuilder == null)
3811                                         throw new Exception ("This should not happen: both Field and Local are null");
3812
3813                         source.Emit (ec);
3814                         if (leave_copy)
3815                                 ec.ig.Emit (OpCodes.Dup);
3816                                 ig.Emit (OpCodes.Stloc, local_info.LocalBuilder);
3817                         } else {
3818                                 //
3819                                 // A local variable captured by anonymous methods or itereators.
3820                                 //
3821                                 ec.EmitCapturedVariableInstance (local_info);
3822
3823                                 if (prepare_for_load)
3824                                         ig.Emit (OpCodes.Dup);
3825                                 source.Emit (ec);
3826                                 if (leave_copy){
3827                                         ig.Emit (OpCodes.Dup);
3828                                         temp = new LocalTemporary (ec, Type);
3829                                         temp.Store (ec);
3830                                 }
3831                                 ig.Emit (OpCodes.Stfld, local_info.FieldBuilder);
3832                                 if (temp != null)
3833                                         temp.Emit (ec);
3834                         }
3835                 }
3836
3837                 public void AddressOf (EmitContext ec, AddressOp mode)
3838                 {
3839                         ILGenerator ig = ec.ig;
3840
3841                         if (local_info.FieldBuilder == null){
3842                                 //
3843                                 // A local variable on the local CLR stack
3844                                 //
3845                         ig.Emit (OpCodes.Ldloca, local_info.LocalBuilder);
3846                         } else {
3847                                 //
3848                                 // A local variable captured by anonymous methods or iterators
3849                                 //
3850                                 ec.EmitCapturedVariableInstance (local_info);
3851                                 ig.Emit (OpCodes.Ldflda, local_info.FieldBuilder);
3852                         }
3853                 }
3854
3855                 public override string ToString ()
3856                 {
3857                         return String.Format ("{0} ({1}:{2})", GetType (), Name, loc);
3858                 }
3859         }
3860
3861         /// <summary>
3862         ///   This represents a reference to a parameter in the intermediate
3863         ///   representation.
3864         /// </summary>
3865         public class ParameterReference : Expression, IAssignMethod, IMemoryLocation, IVariable {
3866                 Parameters pars;
3867                 String name;
3868                 int idx;
3869                 Block block;
3870                 VariableInfo vi;
3871                 public Parameter.Modifier mod;
3872                 public bool is_ref, is_out, prepared;
3873
3874                 public bool IsOut {
3875                         get {
3876                                 return is_out;
3877                         }
3878                 }
3879
3880                 public bool IsRef {
3881                         get {
3882                                 return is_ref;
3883                         }
3884                 }
3885
3886                 LocalTemporary temp;
3887
3888                 public ParameterReference (Parameters pars, Block block, int idx, string name, Location loc)
3889                 {
3890                         this.pars = pars;
3891                         this.block = block;
3892                         this.idx  = idx;
3893                         this.name = name;
3894                         this.loc = loc;
3895                         eclass = ExprClass.Variable;
3896                 }
3897
3898                 public VariableInfo VariableInfo {
3899                         get { return vi; }
3900                 }
3901
3902                 public bool VerifyFixed (bool is_expression)
3903                 {
3904                         return !is_expression || TypeManager.IsValueType (type);
3905                 }
3906
3907                 public bool IsAssigned (EmitContext ec, Location loc)
3908                 {
3909                         if (!ec.DoFlowAnalysis || !is_out || ec.CurrentBranching.IsAssigned (vi))
3910                                 return true;
3911
3912                         Report.Error (165, loc,
3913                                       "Use of unassigned parameter `" + name + "'");
3914                         return false;
3915                 }
3916
3917                 public bool IsFieldAssigned (EmitContext ec, string field_name, Location loc)
3918                 {
3919                         if (!ec.DoFlowAnalysis || !is_out || ec.CurrentBranching.IsFieldAssigned (vi, field_name))
3920                                 return true;
3921
3922                         Report.Error (170, loc,
3923                                       "Use of possibly unassigned field `" + field_name + "'");
3924                         return false;
3925                 }
3926
3927                 public void SetAssigned (EmitContext ec)
3928                 {
3929                         if (is_out && ec.DoFlowAnalysis)
3930                                 ec.CurrentBranching.SetAssigned (vi);
3931                 }
3932
3933                 public void SetFieldAssigned (EmitContext ec, string field_name)
3934                 {
3935                         if (is_out && ec.DoFlowAnalysis)
3936                                 ec.CurrentBranching.SetFieldAssigned (vi, field_name);
3937                 }
3938
3939                 protected void DoResolveBase (EmitContext ec)
3940                 {
3941                         type = pars.GetParameterInfo (ec, idx, out mod);
3942                         is_ref = (mod & Parameter.Modifier.ISBYREF) != 0;
3943                         is_out = (mod & Parameter.Modifier.OUT) != 0;
3944                         eclass = ExprClass.Variable;
3945
3946                         if (is_out)
3947                                 vi = block.ParameterMap [idx];
3948
3949                         if (ec.CurrentAnonymousMethod != null){
3950                                 if (is_ref){
3951                                         Report.Error (1628, Location,
3952                                                       "Can not reference a ref or out parameter in an anonymous method");
3953                                         return;
3954                                 }
3955
3956                                 //
3957                                 // If we are referencing the parameter from the external block
3958                                 // flag it for capturing
3959                                 //
3960                                 //Console.WriteLine ("Is parameter `{0}' local? {1}", name, block.IsLocalParameter (name));
3961                                 if (!block.IsLocalParameter (name)){
3962                                         ec.CaptureParameter (name, type, idx);
3963                                 }
3964                         }
3965                 }
3966
3967                 //
3968                 // Notice that for ref/out parameters, the type exposed is not the
3969                 // same type exposed externally.
3970                 //
3971                 // for "ref int a":
3972                 //   externally we expose "int&"
3973                 //   here we expose       "int".
3974                 //
3975                 // We record this in "is_ref".  This means that the type system can treat
3976                 // the type as it is expected, but when we generate the code, we generate
3977                 // the alternate kind of code.
3978                 //
3979                 public override Expression DoResolve (EmitContext ec)
3980                 {
3981                         DoResolveBase (ec);
3982
3983                         if (is_out && ec.DoFlowAnalysis && !IsAssigned (ec, loc))
3984                                 return null;
3985
3986                         if (ec.RemapToProxy)
3987                                 return ec.RemapParameter (idx);
3988
3989                         return this;
3990                 }
3991
3992                 override public Expression DoResolveLValue (EmitContext ec, Expression right_side)
3993                 {
3994                         DoResolveBase (ec);
3995
3996                         SetAssigned (ec);
3997
3998                         if (ec.RemapToProxy)
3999                                 return ec.RemapParameterLValue (idx, right_side);
4000
4001                         return this;
4002                 }
4003
4004                 static public void EmitLdArg (ILGenerator ig, int x)
4005                 {
4006                         if (x <= 255){
4007                                 switch (x){
4008                                 case 0: ig.Emit (OpCodes.Ldarg_0); break;
4009                                 case 1: ig.Emit (OpCodes.Ldarg_1); break;
4010                                 case 2: ig.Emit (OpCodes.Ldarg_2); break;
4011                                 case 3: ig.Emit (OpCodes.Ldarg_3); break;
4012                                 default: ig.Emit (OpCodes.Ldarg_S, (byte) x); break;
4013                                 }
4014                         } else
4015                                 ig.Emit (OpCodes.Ldarg, x);
4016                 }
4017
4018                 //
4019                 // This method is used by parameters that are references, that are
4020                 // being passed as references:  we only want to pass the pointer (that
4021                 // is already stored in the parameter, not the address of the pointer,
4022                 // and not the value of the variable).
4023                 //
4024                 public void EmitLoad (EmitContext ec)
4025                 {
4026                         ILGenerator ig = ec.ig;
4027                         int arg_idx = idx;
4028
4029                         if (!ec.IsStatic)
4030                                 arg_idx++;
4031
4032                         EmitLdArg (ig, arg_idx);
4033
4034                         //
4035                         // FIXME: Review for anonymous methods
4036                         //
4037                 }
4038
4039                 public override void Emit (EmitContext ec)
4040                 {
4041                         if (ec.HaveCaptureInfo && ec.IsParameterCaptured (name)){
4042                                 ec.EmitParameter (name);
4043                                 return;
4044                         }
4045
4046                         Emit (ec, false);
4047                 }
4048
4049                 public void Emit (EmitContext ec, bool leave_copy)
4050                 {
4051                         ILGenerator ig = ec.ig;
4052                         int arg_idx = idx;
4053
4054                         if (!ec.IsStatic)
4055                                 arg_idx++;
4056
4057                         EmitLdArg (ig, arg_idx);
4058
4059                         if (is_ref) {
4060                                 if (prepared)
4061                                         ec.ig.Emit (OpCodes.Dup);
4062
4063                                 //
4064                                 // If we are a reference, we loaded on the stack a pointer
4065                                 // Now lets load the real value
4066                                 //
4067                                 LoadFromPtr (ig, type);
4068                         }
4069
4070                         if (leave_copy) {
4071                                 ec.ig.Emit (OpCodes.Dup);
4072
4073                                 if (is_ref) {
4074                                         temp = new LocalTemporary (ec, type);
4075                                         temp.Store (ec);
4076                                 }
4077                         }
4078                 }
4079
4080                 public void EmitAssign (EmitContext ec, Expression source, bool leave_copy, bool prepare_for_load)
4081                 {
4082                         if (ec.HaveCaptureInfo && ec.IsParameterCaptured (name)){
4083                                 ec.EmitAssignParameter (name, source, leave_copy, prepare_for_load);
4084                                 return;
4085                         }
4086
4087                         ILGenerator ig = ec.ig;
4088                         int arg_idx = idx;
4089
4090                         prepared = prepare_for_load;
4091
4092                         if (!ec.IsStatic)
4093                                 arg_idx++;
4094
4095                         if (is_ref && !prepared)
4096                                 EmitLdArg (ig, arg_idx);
4097
4098                         source.Emit (ec);
4099
4100                         if (leave_copy)
4101                                 ec.ig.Emit (OpCodes.Dup);
4102
4103                         if (is_ref) {
4104                                 if (leave_copy) {
4105                                         temp = new LocalTemporary (ec, type);
4106                                         temp.Store (ec);
4107                                 }
4108
4109                                 StoreFromPtr (ig, type);
4110
4111                                 if (temp != null)
4112                                         temp.Emit (ec);
4113                         } else {
4114                                 if (arg_idx <= 255)
4115                                         ig.Emit (OpCodes.Starg_S, (byte) arg_idx);
4116                                 else
4117                                         ig.Emit (OpCodes.Starg, arg_idx);
4118                         }
4119                 }
4120
4121                 public void AddressOf (EmitContext ec, AddressOp mode)
4122                 {
4123                         if (ec.HaveCaptureInfo && ec.IsParameterCaptured (name)){
4124                                 ec.EmitAddressOfParameter (name);
4125                                 return;
4126                         }
4127
4128                         int arg_idx = idx;
4129
4130                         if (!ec.IsStatic)
4131                                 arg_idx++;
4132
4133                         if (is_ref){
4134                                 if (arg_idx <= 255)
4135                                         ec.ig.Emit (OpCodes.Ldarg_S, (byte) arg_idx);
4136                                 else
4137                                         ec.ig.Emit (OpCodes.Ldarg, arg_idx);
4138                         } else {
4139                                 if (arg_idx <= 255)
4140                                         ec.ig.Emit (OpCodes.Ldarga_S, (byte) arg_idx);
4141                                 else
4142                                         ec.ig.Emit (OpCodes.Ldarga, arg_idx);
4143                         }
4144                 }
4145
4146         }
4147
4148         /// <summary>
4149         ///   Used for arguments to New(), Invocation()
4150         /// </summary>
4151         public class Argument {
4152                 public enum AType : byte {
4153                         Expression,
4154                         Ref,
4155                         Out,
4156                         ArgList
4157                 };
4158
4159                 public readonly AType ArgType;
4160                 public Expression Expr;
4161
4162                 public Argument (Expression expr, AType type)
4163                 {
4164                         this.Expr = expr;
4165                         this.ArgType = type;
4166                 }
4167
4168                 public Argument (Expression expr)
4169                 {
4170                         this.Expr = expr;
4171                         this.ArgType = AType.Expression;
4172                 }
4173
4174                 public Type Type {
4175                         get {
4176                                 if (ArgType == AType.Ref || ArgType == AType.Out)
4177                                         return TypeManager.GetReferenceType (Expr.Type);
4178                                 else
4179                                         return Expr.Type;
4180                         }
4181                 }
4182
4183                 public Parameter.Modifier GetParameterModifier ()
4184                 {
4185                         switch (ArgType) {
4186                         case AType.Out:
4187                                 return Parameter.Modifier.OUT | Parameter.Modifier.ISBYREF;
4188
4189                         case AType.Ref:
4190                                 return Parameter.Modifier.REF | Parameter.Modifier.ISBYREF;
4191
4192                         default:
4193                                 return Parameter.Modifier.NONE;
4194                         }
4195                 }
4196
4197                 public static string FullDesc (Argument a)
4198                 {
4199                         if (a.ArgType == AType.ArgList)
4200                                 return "__arglist";
4201
4202                         return (a.ArgType == AType.Ref ? "ref " :
4203                                 (a.ArgType == AType.Out ? "out " : "")) +
4204                                 TypeManager.CSharpName (a.Expr.Type);
4205                 }
4206
4207                 public bool ResolveMethodGroup (EmitContext ec, Location loc)
4208                 {
4209                         ConstructedType ctype = Expr as ConstructedType;
4210                         if (ctype != null)
4211                                 Expr = ctype.GetSimpleName (ec);
4212
4213                         // FIXME: csc doesn't report any error if you try to use `ref' or
4214                         //        `out' in a delegate creation expression.
4215                         Expr = Expr.Resolve (ec, ResolveFlags.VariableOrValue | ResolveFlags.MethodGroup);
4216                         if (Expr == null)
4217                                 return false;
4218
4219                         return true;
4220                 }
4221
4222                 public bool Resolve (EmitContext ec, Location loc)
4223                 {
4224                         if (ArgType == AType.Ref) {
4225                                 Expr = Expr.Resolve (ec);
4226                                 if (Expr == null)
4227                                         return false;
4228
4229                                 if (!ec.IsConstructor) {
4230                                         FieldExpr fe = Expr as FieldExpr;
4231                                         if (fe != null && fe.FieldInfo.IsInitOnly) {
4232                                                 if (fe.FieldInfo.IsStatic)
4233                                                         Report.Error (199, loc, "A static readonly field cannot be passed ref or out (except in a static constructor)");
4234                                                 else
4235                                                         Report.Error (192, loc, "A readonly field cannot be passed ref or out (except in a constructor)");
4236                                                 return false;
4237                                         }
4238                                 }
4239                                 Expr = Expr.ResolveLValue (ec, Expr);
4240                         } else if (ArgType == AType.Out)
4241                                 Expr = Expr.ResolveLValue (ec, EmptyExpression.Null);
4242                         else
4243                                 Expr = Expr.Resolve (ec);
4244
4245                         if (Expr == null)
4246                                 return false;
4247
4248                         if (ArgType == AType.Expression)
4249                                 return true;
4250                         else {
4251                                 //
4252                                 // Catch errors where fields of a MarshalByRefObject are passed as ref or out
4253                                 // This is only allowed for `this'
4254                                 //
4255                                 FieldExpr fe = Expr as FieldExpr;
4256                                 if (fe != null && !fe.IsStatic){
4257                                         Expression instance = fe.InstanceExpression;
4258
4259                                         if (instance.GetType () != typeof (This)){
4260                                                 if (fe.InstanceExpression.Type.IsSubclassOf (TypeManager.mbr_type)){
4261                                                         Report.SymbolRelatedToPreviousError (fe.InstanceExpression.Type);
4262                                                         Report.Error (197, loc, "Cannot pass '{0}' as ref or out or take its address because it is a member of a marshal-by-reference class",
4263                                                                 fe.Name);
4264                                                         return false;
4265                                                 }
4266                                         }
4267                                 }
4268                         }
4269
4270                         if (Expr.eclass != ExprClass.Variable){
4271                                 //
4272                                 // We just probe to match the CSC output
4273                                 //
4274                                 if (Expr.eclass == ExprClass.PropertyAccess ||
4275                                     Expr.eclass == ExprClass.IndexerAccess){
4276                                         Report.Error (
4277                                                 206, loc,
4278                                                 "A property or indexer can not be passed as an out or ref " +
4279                                                 "parameter");
4280                                 } else {
4281                                         Report.Error (
4282                                                 1510, loc,
4283                                                 "An lvalue is required as an argument to out or ref");
4284                                 }
4285                                 return false;
4286                         }
4287
4288                         return true;
4289                 }
4290
4291                 public void Emit (EmitContext ec)
4292                 {
4293                         //
4294                         // Ref and Out parameters need to have their addresses taken.
4295                         //
4296                         // ParameterReferences might already be references, so we want
4297                         // to pass just the value
4298                         //
4299                         if (ArgType == AType.Ref || ArgType == AType.Out){
4300                                 AddressOp mode = AddressOp.Store;
4301
4302                                 if (ArgType == AType.Ref)
4303                                         mode |= AddressOp.Load;
4304
4305                                 if (Expr is ParameterReference){
4306                                         ParameterReference pr = (ParameterReference) Expr;
4307
4308                                         if (pr.IsRef)
4309                                                 pr.EmitLoad (ec);
4310                                         else {
4311
4312                                                 pr.AddressOf (ec, mode);
4313                                         }
4314                                 } else {
4315                                         if (Expr is IMemoryLocation)
4316                                                ((IMemoryLocation) Expr).AddressOf (ec, mode);
4317                                         else {
4318                                                 Report.Error (
4319                                                         1510, Expr.Location,
4320                                                         "An lvalue is required as an argument to out or ref");
4321                                                 return;
4322                                         }
4323                                 }
4324                         } else
4325                                 Expr.Emit (ec);
4326                 }
4327         }
4328
4329         /// <summary>
4330         ///   Invocation of methods or delegates.
4331         /// </summary>
4332         public class Invocation : ExpressionStatement {
4333                 public readonly ArrayList Arguments;
4334
4335                 Expression expr;
4336                 MethodBase method = null;
4337
4338                 //
4339                 // arguments is an ArrayList, but we do not want to typecast,
4340                 // as it might be null.
4341                 //
4342                 // FIXME: only allow expr to be a method invocation or a
4343                 // delegate invocation (7.5.5)
4344                 //
4345                 public Invocation (Expression expr, ArrayList arguments, Location l)
4346                 {
4347                         this.expr = expr;
4348                         Arguments = arguments;
4349                         loc = l;
4350                 }
4351
4352                 public Expression Expr {
4353                         get {
4354                                 return expr;
4355                         }
4356                 }
4357
4358                 /// <summary>
4359                 ///   Determines "better conversion" as specified in 7.4.2.3
4360                 ///
4361                 ///    Returns : p    if a->p is better,
4362                 ///              q    if a->q is better,
4363                 ///              null if neither is better
4364                 /// </summary>
4365                 static Type BetterConversion (EmitContext ec, Argument a, Type p, Type q, Location loc)
4366                 {
4367                         Type argument_type = TypeManager.TypeToCoreType (a.Type);
4368                         Expression argument_expr = a.Expr;
4369
4370                         // p = TypeManager.TypeToCoreType (p);
4371                         // q = TypeManager.TypeToCoreType (q);
4372
4373                         if (argument_type == null)
4374                                 throw new Exception ("Expression of type " + a.Expr +
4375                                                      " does not resolve its type");
4376
4377                         if (p == null || q == null)
4378                                 throw new InternalErrorException ("BetterConversion Got a null conversion");
4379
4380                         if (p == q)
4381                                 return null;
4382
4383                         if (argument_expr is NullLiteral) {
4384                         //
4385                                 // If the argument is null and one of the types to compare is 'object' and
4386                                 // the other is a reference type, we prefer the other.
4387                         //
4388                                 // This follows from the usual rules:
4389                                 //   * There is an implicit conversion from 'null' to type 'object'
4390                                 //   * There is an implicit conversion from 'null' to any reference type
4391                                 //   * There is an implicit conversion from any reference type to type 'object'
4392                                 //   * There is no implicit conversion from type 'object' to other reference types
4393                                 //  => Conversion of 'null' to a reference type is better than conversion to 'object'
4394                                 //
4395                                 //  FIXME: This probably isn't necessary, since the type of a NullLiteral is the
4396                                 //         null type. I think it used to be 'object' and thus needed a special
4397                                 //         case to avoid the immediately following two checks.
4398                                 //
4399                                 if (!p.IsValueType && q == TypeManager.object_type)
4400                                         return p;
4401                                 if (!q.IsValueType && p == TypeManager.object_type)
4402                                         return q;
4403                         }
4404
4405                         if (argument_type == p)
4406                                 return p;
4407
4408                         if (argument_type == q)
4409                                 return q;
4410
4411                         Expression p_tmp = new EmptyExpression (p);
4412                         Expression q_tmp = new EmptyExpression (q);
4413
4414                         bool p_to_q = Convert.ImplicitConversionExists (ec, p_tmp, q);
4415                         bool q_to_p = Convert.ImplicitConversionExists (ec, q_tmp, p);
4416
4417                         if (p_to_q && !q_to_p)
4418                                 return p;
4419
4420                         if (q_to_p && !p_to_q)
4421                                 return q;
4422
4423                         if (p == TypeManager.sbyte_type)
4424                                 if (q == TypeManager.byte_type || q == TypeManager.ushort_type ||
4425                                     q == TypeManager.uint32_type || q == TypeManager.uint64_type)
4426                                         return p;
4427                         if (q == TypeManager.sbyte_type)
4428                                 if (p == TypeManager.byte_type || p == TypeManager.ushort_type ||
4429                                     p == TypeManager.uint32_type || p == TypeManager.uint64_type)
4430                                         return q;
4431
4432                         if (p == TypeManager.short_type)
4433                                 if (q == TypeManager.ushort_type || q == TypeManager.uint32_type ||
4434                                     q == TypeManager.uint64_type)
4435                                         return p;
4436
4437                         if (q == TypeManager.short_type)
4438                                 if (p == TypeManager.ushort_type || p == TypeManager.uint32_type ||
4439                                     p == TypeManager.uint64_type)
4440                                         return q;
4441
4442                         if (p == TypeManager.int32_type)
4443                                 if (q == TypeManager.uint32_type || q == TypeManager.uint64_type)
4444                                         return p;
4445
4446                         if (q == TypeManager.int32_type)
4447                                 if (p == TypeManager.uint32_type || p == TypeManager.uint64_type)
4448                                         return q;
4449
4450                         if (p == TypeManager.int64_type)
4451                                 if (q == TypeManager.uint64_type)
4452                                         return p;
4453                         if (q == TypeManager.int64_type)
4454                                 if (p == TypeManager.uint64_type)
4455                                         return q;
4456
4457                         return null;
4458                 }
4459
4460                 /// <summary>
4461                 ///   Determines "Better function" between candidate
4462                 ///   and the current best match
4463                 /// </summary>
4464                 /// <remarks>
4465                 ///    Returns a boolean indicating :
4466                 ///     false if candidate ain't better
4467                 ///     true  if candidate is better than the current best match
4468                 /// </remarks>
4469                 static bool BetterFunction (EmitContext ec, ArrayList args, int argument_count,
4470                                            MethodBase candidate, bool candidate_params,
4471                                            MethodBase best, bool best_params, Location loc)
4472                 {
4473                         ParameterData candidate_pd = TypeManager.GetParameterData (candidate);
4474                         ParameterData best_pd = TypeManager.GetParameterData (best);
4475
4476                         bool better_at_least_one = false;
4477                         bool same = true;
4478                         for (int j = 0; j < argument_count; ++j) {
4479                                 Argument a = (Argument) args [j];
4480
4481                                 Type ct = TypeManager.TypeToCoreType (candidate_pd.ParameterType (j));
4482                                 Type bt = TypeManager.TypeToCoreType (best_pd.ParameterType (j));
4483
4484                                 if (candidate_pd.ParameterModifier (j) == Parameter.Modifier.PARAMS)
4485                                         if (candidate_params)
4486                                                 ct = TypeManager.GetElementType (ct);
4487
4488                                 if (best_pd.ParameterModifier (j) == Parameter.Modifier.PARAMS)
4489                                         if (best_params)
4490                                                 bt = TypeManager.GetElementType (bt);
4491
4492                                 if (ct.Equals (bt))
4493                                         continue;
4494
4495                                 same = false;
4496                                 Type better = BetterConversion (ec, a, ct, bt, loc);
4497                                 // for each argument, the conversion to 'ct' should be no worse than
4498                                 // the conversion to 'bt'.
4499                                 if (better == bt)
4500                                         return false;
4501
4502                                 // for at least one argument, the conversion to 'ct' should be better than
4503                                 // the conversion to 'bt'.
4504                                 if (better == ct)
4505                                         better_at_least_one = true;
4506                         }
4507
4508                         if (better_at_least_one)
4509                                 return true;
4510
4511                         if (!same)
4512                                 return false;
4513
4514                         //
4515                         // If two methods have equal parameter types, but
4516                         // only one of them is generic, the non-generic one wins.
4517                         //
4518                         if (TypeManager.IsGenericMethod (best) && !TypeManager.IsGenericMethod (candidate))
4519                                 return true;
4520                         else if (!TypeManager.IsGenericMethod (best) && TypeManager.IsGenericMethod (candidate))
4521                                 return false;
4522
4523                         //
4524                         // Note that this is not just an optimization.  This handles the case
4525                         //
4526                         //   Add (float f1, float f2, float f3);
4527                         //   Add (params decimal [] foo);
4528                         //
4529                         // The call Add (3, 4, 5) should be ambiguous.  Without this check, the
4530                         // first candidate would've chosen as better.
4531                         //
4532                         if (candidate_params == best_params) {
4533                                 //
4534                                 // We need to handle the case of a virtual function and its override.
4535                                 // The override is ignored during 'applicable_type' calculation.  However,
4536                                 // it should be chosen over the base virtual function, especially when handling
4537                                 // value types.
4538                                 //
4539                                 return IsAncestralType (best.DeclaringType, candidate.DeclaringType);
4540                         }
4541
4542                         //
4543                         // This handles the following cases:
4544                         //
4545                         //   Trim () is better than Trim (params char[] chars)
4546                         //   Concat (string s1, string s2, string s3) is better than
4547                         //     Concat (string s1, params string [] srest)
4548                         //
4549                         return !candidate_params && best_params;
4550                 }
4551
4552                 public static string FullMethodDesc (MethodBase mb)
4553                 {
4554                         string ret_type = "";
4555
4556                         if (mb == null)
4557                                 return "";
4558
4559                         if (mb is MethodInfo)
4560                                 ret_type = TypeManager.CSharpName (((MethodInfo) mb).ReturnType);
4561
4562                         StringBuilder sb = new StringBuilder (ret_type);
4563                         sb.Append (" ");
4564                         sb.Append (mb.ReflectedType.ToString ());
4565                         sb.Append (".");
4566                         sb.Append (mb.Name);
4567
4568                         ParameterData pd = TypeManager.GetParameterData (mb);
4569
4570                         int count = pd.Count;
4571                         sb.Append (" (");
4572
4573                         for (int i = count; i > 0; ) {
4574                                 i--;
4575
4576                                 sb.Append (pd.ParameterDesc (count - i - 1));
4577                                 if (i != 0)
4578                                         sb.Append (", ");
4579                         }
4580
4581                         sb.Append (")");
4582                         return sb.ToString ();
4583                 }
4584
4585                 public static MethodGroupExpr MakeUnionSet (Expression mg1, Expression mg2, Location loc)
4586                 {
4587                         MemberInfo [] miset;
4588                         MethodGroupExpr union;
4589
4590                         if (mg1 == null) {
4591                                 if (mg2 == null)
4592                                         return null;
4593                                 return (MethodGroupExpr) mg2;
4594                         } else {
4595                                 if (mg2 == null)
4596                                         return (MethodGroupExpr) mg1;
4597                         }
4598
4599                         MethodGroupExpr left_set = null, right_set = null;
4600                         int length1 = 0, length2 = 0;
4601
4602                         left_set = (MethodGroupExpr) mg1;
4603                         length1 = left_set.Methods.Length;
4604
4605                         right_set = (MethodGroupExpr) mg2;
4606                         length2 = right_set.Methods.Length;
4607
4608                         ArrayList common = new ArrayList ();
4609
4610                         foreach (MethodBase r in right_set.Methods){
4611                                 if (TypeManager.ArrayContainsMethod (left_set.Methods, r))
4612                                         common.Add (r);
4613                         }
4614
4615                         miset = new MemberInfo [length1 + length2 - common.Count];
4616                         left_set.Methods.CopyTo (miset, 0);
4617
4618                         int k = length1;
4619
4620                         foreach (MethodBase r in right_set.Methods) {
4621                                 if (!common.Contains (r))
4622                                         miset [k++] = r;
4623                         }
4624
4625                         union = new MethodGroupExpr (miset, loc);
4626
4627                         return union;
4628                 }
4629
4630                 static bool IsParamsMethodApplicable (EmitContext ec, MethodGroupExpr me,
4631                                                       ArrayList arguments, int arg_count,
4632                                                       ref MethodBase candidate)
4633                 {
4634                         return IsParamsMethodApplicable (
4635                                 ec, me, arguments, arg_count, false, ref candidate) ||
4636                                 IsParamsMethodApplicable (
4637                                         ec, me, arguments, arg_count, true, ref candidate);
4638
4639
4640                 }
4641
4642                 static bool IsParamsMethodApplicable (EmitContext ec, MethodGroupExpr me,
4643                                                       ArrayList arguments, int arg_count,
4644                                                       bool do_varargs, ref MethodBase candidate)
4645                 {
4646                         if (!me.HasTypeArguments &&
4647                             !TypeManager.InferParamsTypeArguments (ec, arguments, ref candidate))
4648                                 return false;
4649
4650                         return IsParamsMethodApplicable (
4651                                 ec, arguments, arg_count, candidate, do_varargs);
4652                 }
4653
4654                 /// <summary>
4655                 ///   Determines if the candidate method, if a params method, is applicable
4656                 ///   in its expanded form to the given set of arguments
4657                 /// </summary>
4658                 static bool IsParamsMethodApplicable (EmitContext ec, ArrayList arguments,
4659                                                       int arg_count, MethodBase candidate,
4660                                                       bool do_varargs)
4661                 {
4662                         ParameterData pd = TypeManager.GetParameterData (candidate);
4663
4664                         int pd_count = pd.Count;
4665
4666                         if (pd_count == 0)
4667                                 return false;
4668
4669                         int count = pd_count - 1;
4670                         if (do_varargs) {
4671                                 if (pd.ParameterModifier (count) != Parameter.Modifier.ARGLIST)
4672                                         return false;
4673                                 if (pd_count != arg_count)
4674                                         return false;
4675                         } else {
4676                                 if (pd.ParameterModifier (count) != Parameter.Modifier.PARAMS)
4677                                 return false;
4678                         }
4679
4680                         if (count > arg_count)
4681                                 return false;
4682
4683                         if (pd_count == 1 && arg_count == 0)
4684                                 return true;
4685
4686                         //
4687                         // If we have come this far, the case which
4688                         // remains is when the number of parameters is
4689                         // less than or equal to the argument count.
4690                         //
4691                         for (int i = 0; i < count; ++i) {
4692
4693                                 Argument a = (Argument) arguments [i];
4694
4695                                 Parameter.Modifier a_mod = a.GetParameterModifier () &
4696                                         (unchecked (~(Parameter.Modifier.OUT | Parameter.Modifier.REF)));
4697                                 Parameter.Modifier p_mod = pd.ParameterModifier (i) &
4698                                         (unchecked (~(Parameter.Modifier.OUT | Parameter.Modifier.REF)));
4699
4700                                 if (a_mod == p_mod) {
4701
4702                                         if (a_mod == Parameter.Modifier.NONE)
4703                                                 if (!Convert.ImplicitConversionExists (ec,
4704                                                                                        a.Expr,
4705                                                                                        pd.ParameterType (i)))
4706                                                         return false;
4707
4708                                         if ((a_mod & Parameter.Modifier.ISBYREF) != 0) {
4709                                                 Type pt = pd.ParameterType (i);
4710
4711                                                 if (!pt.IsByRef)
4712                                                         pt = TypeManager.GetReferenceType (pt);
4713
4714                                                 if (pt != a.Type)
4715                                                         return false;
4716                                         }
4717                                 } else
4718                                         return false;
4719
4720                         }
4721
4722                         if (do_varargs) {
4723                                 Argument a = (Argument) arguments [count];
4724                                 if (!(a.Expr is Arglist))
4725                                         return false;
4726
4727                                 return true;
4728                         }
4729
4730                         Type element_type = TypeManager.GetElementType (pd.ParameterType (pd_count - 1));
4731
4732                         for (int i = pd_count - 1; i < arg_count; i++) {
4733                                 Argument a = (Argument) arguments [i];
4734
4735                                 if (!Convert.ImplicitConversionExists (ec, a.Expr, element_type))
4736                                         return false;
4737                         }
4738
4739                         return true;
4740                 }
4741
4742                 static bool IsApplicable (EmitContext ec, MethodGroupExpr me,
4743                                           ArrayList arguments, int arg_count,
4744                                           ref MethodBase candidate)
4745                 {
4746                         if (!me.HasTypeArguments &&
4747                             !TypeManager.InferTypeArguments (ec, arguments, ref candidate))
4748                                 return false;
4749
4750                         return IsApplicable (ec, arguments, arg_count, candidate);
4751                 }
4752
4753                 /// <summary>
4754                 ///   Determines if the candidate method is applicable (section 14.4.2.1)
4755                 ///   to the given set of arguments
4756                 /// </summary>
4757                 static bool IsApplicable (EmitContext ec, ArrayList arguments, int arg_count,
4758                                           MethodBase candidate)
4759                 {
4760                         ParameterData pd = TypeManager.GetParameterData (candidate);
4761
4762                         if (arg_count != pd.Count)
4763                                 return false;
4764
4765                         for (int i = arg_count; i > 0; ) {
4766                                 i--;
4767
4768                                 Argument a = (Argument) arguments [i];
4769
4770                                 Parameter.Modifier a_mod = a.GetParameterModifier () &
4771                                         unchecked (~(Parameter.Modifier.OUT | Parameter.Modifier.REF));
4772                                 Parameter.Modifier p_mod = pd.ParameterModifier (i) &
4773                                         unchecked (~(Parameter.Modifier.OUT | Parameter.Modifier.REF));
4774
4775
4776                                 if (a_mod == p_mod ||
4777                                     (a_mod == Parameter.Modifier.NONE && p_mod == Parameter.Modifier.PARAMS)) {
4778                                         if (a_mod == Parameter.Modifier.NONE) {
4779                                                 if (!Convert.ImplicitConversionExists (ec,
4780                                                                                        a.Expr,
4781                                                                                        pd.ParameterType (i)))
4782                                                         return false;
4783                                         }
4784
4785                                         if ((a_mod & Parameter.Modifier.ISBYREF) != 0) {
4786                                                 Type pt = pd.ParameterType (i);
4787
4788                                                 if (!pt.IsByRef)
4789                                                         pt = TypeManager.GetReferenceType (pt);
4790
4791                                                 if (pt != a.Type)
4792                                                         return false;
4793                                         }
4794                                 } else
4795                                         return false;
4796                         }
4797
4798                         return true;
4799                 }
4800
4801                 static private bool IsAncestralType (Type first_type, Type second_type)
4802                 {
4803                         return first_type != second_type &&
4804                                 (second_type.IsSubclassOf (first_type) ||
4805                                  TypeManager.ImplementsInterface (second_type, first_type));
4806                 }
4807
4808                 /// <summary>
4809                 ///   Find the Applicable Function Members (7.4.2.1)
4810                 ///
4811                 ///   me: Method Group expression with the members to select.
4812                 ///       it might contain constructors or methods (or anything
4813                 ///       that maps to a method).
4814                 ///
4815                 ///   Arguments: ArrayList containing resolved Argument objects.
4816                 ///
4817                 ///   loc: The location if we want an error to be reported, or a Null
4818                 ///        location for "probing" purposes.
4819                 ///
4820                 ///   Returns: The MethodBase (either a ConstructorInfo or a MethodInfo)
4821                 ///            that is the best match of me on Arguments.
4822                 ///
4823                 /// </summary>
4824                 public static MethodBase OverloadResolve (EmitContext ec, MethodGroupExpr me,
4825                                                           ArrayList Arguments, bool may_fail,
4826                                                           Location loc)
4827                 {
4828                         MethodBase method = null;
4829                         bool method_params = false;
4830                         Type applicable_type = null;
4831                         int arg_count = 0;
4832                         ArrayList candidates = new ArrayList ();
4833
4834                         //
4835                         // Used to keep a map between the candidate
4836                         // and whether it is being considered in its
4837                         // normal or expanded form
4838                         //
4839                         // false is normal form, true is expanded form
4840                         //
4841                         Hashtable candidate_to_form = null;
4842
4843                         if (Arguments != null)
4844                                 arg_count = Arguments.Count;
4845
4846                         if ((me.Name == "Invoke") &&
4847                             TypeManager.IsDelegateType (me.DeclaringType)) {
4848                                 Error_InvokeOnDelegate (loc);
4849                                 return null;
4850                         }
4851
4852                         MethodBase[] methods = me.Methods;
4853
4854                         //
4855                         // First we construct the set of applicable methods
4856                         //
4857                         bool is_sorted = true;
4858                         for (int i = 0; i < methods.Length; i++){
4859                                 Type decl_type = methods [i].DeclaringType;
4860
4861                                 //
4862                                 // If we have already found an applicable method
4863                                 // we eliminate all base types (Section 14.5.5.1)
4864                                 //
4865                                 if ((applicable_type != null) &&
4866                                     IsAncestralType (decl_type, applicable_type))
4867                                         continue;
4868
4869                                 //
4870                                 // Check if candidate is applicable (section 14.4.2.1)
4871                                 //   Is candidate applicable in normal form?
4872                                 //
4873                                 bool is_applicable = IsApplicable (
4874                                         ec, me, Arguments, arg_count, ref methods [i]);
4875
4876                                 if (!is_applicable &&
4877                                     (IsParamsMethodApplicable (
4878                                             ec, me, Arguments, arg_count, ref methods [i]))) {
4879                                         MethodBase candidate = methods [i];
4880                                         if (candidate_to_form == null)
4881                                                 candidate_to_form = new PtrHashtable ();
4882                                         candidate_to_form [candidate] = candidate;
4883                                         // Candidate is applicable in expanded form
4884                                         is_applicable = true;
4885                                 }
4886
4887                                 if (!is_applicable)
4888                                         continue;
4889
4890                                 candidates.Add (methods [i]);
4891
4892                                 //
4893                                 // Methods marked 'override' don't take part in 'applicable_type'
4894                                 // computation.
4895                                 //
4896                                 if (!me.IsBase &&
4897                                     methods [i].IsVirtual &&
4898                                     (methods [i].Attributes & MethodAttributes.NewSlot) == 0)
4899                                         continue;
4900
4901                                 if (applicable_type == null)
4902                                         applicable_type = decl_type;
4903                                 else if (applicable_type != decl_type) {
4904                                         is_sorted = false;
4905                                         if (IsAncestralType (applicable_type, decl_type))
4906                                                 applicable_type = decl_type;
4907                                 }
4908                         }
4909
4910                         int candidate_top = candidates.Count;
4911
4912                         if (applicable_type == null) {
4913                                 //
4914                                 // Okay so we have failed to find anything so we
4915                                 // return by providing info about the closest match
4916                                 //
4917                                 for (int i = 0; i < methods.Length; ++i) {
4918                                         MethodBase c = (MethodBase) methods [i];
4919                                         ParameterData pd = TypeManager.GetParameterData (c);
4920
4921                                         if (pd.Count != arg_count)
4922                                                 continue;
4923
4924                                         if (!TypeManager.InferTypeArguments (ec, Arguments, ref c))
4925                                                 continue;
4926
4927                                         VerifyArgumentsCompat (ec, Arguments, arg_count,
4928                                                                c, false, null, may_fail, loc);
4929                                         break;
4930                                 }
4931
4932                                 if (!may_fail) {
4933                                         string report_name = me.Name;
4934                                         if (report_name == ".ctor")
4935                                                 report_name = me.DeclaringType.ToString ();
4936
4937                                         for (int i = 0; i < methods.Length; ++i) {
4938                                                 MethodBase c = methods [i];
4939                                                 ParameterData pd = TypeManager.GetParameterData (c);
4940
4941                                                 if (pd.Count != arg_count)
4942                                                         continue;
4943
4944                                                 if (TypeManager.InferTypeArguments (ec, Arguments, ref c))
4945                                                         continue;
4946
4947                                                 Report.Error (
4948                                                         411, loc, "The type arguments for " +
4949                                                         "method `{0}' cannot be infered from " +
4950                                                         "the usage. Try specifying the type " +
4951                                                         "arguments explicitly.", report_name);
4952                                                 return null;
4953                                         }
4954
4955                                         Error_WrongNumArguments (
4956                                                 loc, report_name, arg_count);
4957                                         return null;
4958                                 }
4959
4960                                 return null;
4961                         }
4962
4963                         if (!is_sorted) {
4964                                 //
4965                                 // At this point, applicable_type is _one_ of the most derived types
4966                                 // in the set of types containing the methods in this MethodGroup.
4967                                 // Filter the candidates so that they only contain methods from the
4968                                 // most derived types.
4969                                 //
4970
4971                                 int finalized = 0; // Number of finalized candidates
4972
4973                                 do {
4974                                         // Invariant: applicable_type is a most derived type
4975
4976                                         // We'll try to complete Section 14.5.5.1 for 'applicable_type' by
4977                                         // eliminating all it's base types.  At the same time, we'll also move
4978                                         // every unrelated type to the end of the array, and pick the next
4979                                         // 'applicable_type'.
4980
4981                                         Type next_applicable_type = null;
4982                                         int j = finalized; // where to put the next finalized candidate
4983                                         int k = finalized; // where to put the next undiscarded candidate
4984                                         for (int i = finalized; i < candidate_top; ++i) {
4985                                                 MethodBase candidate = (MethodBase) candidates [i];
4986                                                 Type decl_type = candidate.DeclaringType;
4987
4988                                                 if (decl_type == applicable_type) {
4989                                                         candidates [k++] = candidates [j];
4990                                                         candidates [j++] = candidates [i];
4991                                                         continue;
4992                                                 }
4993
4994                                                 if (IsAncestralType (decl_type, applicable_type))
4995                                                         continue;
4996
4997                                                 if (next_applicable_type != null &&
4998                                                     IsAncestralType (decl_type, next_applicable_type))
4999                                                         continue;
5000
5001                                                 candidates [k++] = candidates [i];
5002
5003 #if false
5004                                                 //
5005                                                 // Methods marked 'override' don't take part in 'applicable_type'
5006                                                 // computation.
5007                                                 //
5008                                                 if (!me.IsBase &&
5009                                                     candidate.IsVirtual &&
5010                                                     (candidate.Attributes & MethodAttributes.NewSlot) == 0)
5011                                                         continue;
5012 #endif
5013
5014                                                 if (next_applicable_type == null ||
5015                                                     IsAncestralType (next_applicable_type, decl_type))
5016                                                         next_applicable_type = decl_type;
5017                                         }
5018
5019                                         applicable_type = next_applicable_type;
5020                                         finalized = j;
5021                                         candidate_top = k;
5022                                 } while (applicable_type != null);
5023                         }
5024
5025                         //
5026                         // Now we actually find the best method
5027                         //
5028
5029                         method = (MethodBase) candidates [0];
5030                         method_params = candidate_to_form != null && candidate_to_form.Contains (method);
5031                         for (int ix = 1; ix < candidate_top; ix++){
5032                                 MethodBase candidate = (MethodBase) candidates [ix];
5033
5034                                 if (candidate == method)
5035                                         continue;
5036
5037                                 bool cand_params = candidate_to_form != null && candidate_to_form.Contains (candidate);
5038
5039                                 if (BetterFunction (ec, Arguments, arg_count,
5040                                                     candidate, cand_params,
5041                                                     method, method_params, loc)) {
5042                                         method = candidate;
5043                                         method_params = cand_params;
5044                                 }
5045                         }
5046
5047                         //
5048                         // Now check that there are no ambiguities i.e the selected method
5049                         // should be better than all the others
5050                         //
5051                         bool ambiguous = false;
5052                         for (int ix = 0; ix < candidate_top; ix++){
5053                                 MethodBase candidate = (MethodBase) candidates [ix];
5054
5055                                 if (candidate == method)
5056                                         continue;
5057
5058                                 bool cand_params = candidate_to_form != null && candidate_to_form.Contains (candidate);
5059                                 if (!BetterFunction (ec, Arguments, arg_count,
5060                                                     method, method_params,
5061                                                     candidate, cand_params,
5062                                                      loc)) {
5063                                         Report.SymbolRelatedToPreviousError (candidate);
5064                                         ambiguous = true;
5065                                 }
5066                         }
5067
5068                         if (ambiguous) {
5069                                 Report.SymbolRelatedToPreviousError (method);
5070                                 Report.Error (121, loc, "Ambiguous call when selecting function due to implicit casts");
5071                                 return null;
5072                         }
5073
5074                         //
5075                         // And now check if the arguments are all
5076                         // compatible, perform conversions if
5077                         // necessary etc. and return if everything is
5078                         // all right
5079                         //
5080                         if (!VerifyArgumentsCompat (ec, Arguments, arg_count, method,
5081                                                     method_params, null, may_fail, loc))
5082                                 return null;
5083
5084                         return method;
5085                 }
5086
5087                 static void Error_WrongNumArguments (Location loc, String name, int arg_count)
5088                 {
5089                         Report.Error (1501, loc,
5090                                       "No overload for method `" + name + "' takes `" +
5091                                       arg_count + "' arguments");
5092                 }
5093
5094                 static void Error_InvokeOnDelegate (Location loc)
5095                 {
5096                         Report.Error (1533, loc,
5097                                       "Invoke cannot be called directly on a delegate");
5098                 }
5099
5100                 static void Error_InvalidArguments (Location loc, int idx, MethodBase method,
5101                                                     Type delegate_type, string arg_sig, string par_desc)
5102                 {
5103                         if (delegate_type == null)
5104                                 Report.Error (1502, loc,
5105                                               "The best overloaded match for method '" +
5106                                               FullMethodDesc (method) +
5107                                               "' has some invalid arguments");
5108                         else
5109                                 Report.Error (1594, loc,
5110                                               "Delegate '" + delegate_type.ToString () +
5111                                               "' has some invalid arguments.");
5112                         Report.Error (1503, loc,
5113                                       String.Format ("Argument {0}: Cannot convert from '{1}' to '{2}'",
5114                                                      idx, arg_sig, par_desc));
5115                 }
5116
5117                 public static bool VerifyArgumentsCompat (EmitContext ec, ArrayList Arguments,
5118                                                           int arg_count, MethodBase method,
5119                                                           bool chose_params_expanded,
5120                                                           Type delegate_type, bool may_fail,
5121                                                           Location loc)
5122                 {
5123                         ParameterData pd = TypeManager.GetParameterData (method);
5124                         int pd_count = pd.Count;
5125
5126                         for (int j = 0; j < arg_count; j++) {
5127                                 Argument a = (Argument) Arguments [j];
5128                                 Expression a_expr = a.Expr;
5129                                 Type parameter_type = pd.ParameterType (j);
5130                                 Parameter.Modifier pm = pd.ParameterModifier (j);
5131
5132                                 if (pm == Parameter.Modifier.PARAMS){
5133                                         if ((pm & ~Parameter.Modifier.PARAMS) != a.GetParameterModifier ()) {
5134                                                 if (!may_fail)
5135                                                         Error_InvalidArguments (
5136                                                                 loc, j, method, delegate_type,
5137                                                                 Argument.FullDesc (a), pd.ParameterDesc (j));
5138                                                 return false;
5139                                         }
5140
5141                                         if (chose_params_expanded)
5142                                                 parameter_type = TypeManager.GetElementType (parameter_type);
5143                                 } else if (pm == Parameter.Modifier.ARGLIST){
5144                                         continue;
5145                                 } else {
5146                                         //
5147                                         // Check modifiers
5148                                         //
5149                                         if (pd.ParameterModifier (j) != a.GetParameterModifier ()){
5150                                                 if (!may_fail)
5151                                                         Error_InvalidArguments (
5152                                                                 loc, j, method, delegate_type,
5153                                                                 Argument.FullDesc (a), pd.ParameterDesc (j));
5154                                                 return false;
5155                                         }
5156                                 }
5157
5158                                 //
5159                                 // Check Type
5160                                 //
5161                                 if (!TypeManager.IsEqual (a.Type, parameter_type)){
5162                                         Expression conv;
5163
5164                                         conv = Convert.ImplicitConversion (ec, a_expr, parameter_type, loc);
5165
5166                                         if (conv == null) {
5167                                                 if (!may_fail)
5168                                                         Error_InvalidArguments (
5169                                                                 loc, j, method, delegate_type,
5170                                                                 Argument.FullDesc (a), pd.ParameterDesc (j));
5171                                                 return false;
5172                                         }
5173
5174                                         //
5175                                         // Update the argument with the implicit conversion
5176                                         //
5177                                         if (a_expr != conv)
5178                                                 a.Expr = conv;
5179                                 }
5180
5181                                 if (parameter_type.IsPointer){
5182                                         if (!ec.InUnsafe){
5183                                                 UnsafeError (loc);
5184                                                 return false;
5185                                         }
5186                                 }
5187
5188                                 Parameter.Modifier a_mod = a.GetParameterModifier () &
5189                                         unchecked (~(Parameter.Modifier.OUT | Parameter.Modifier.REF));
5190                                 Parameter.Modifier p_mod = pd.ParameterModifier (j) &
5191                                         unchecked (~(Parameter.Modifier.OUT | Parameter.Modifier.REF));
5192
5193                                 if (a_mod != p_mod &&
5194                                     pd.ParameterModifier (pd_count - 1) != Parameter.Modifier.PARAMS) {
5195                                         if (!may_fail) {
5196                                                 Report.Error (1502, loc,
5197                                                        "The best overloaded match for method '" + FullMethodDesc (method)+
5198                                                        "' has some invalid arguments");
5199                                                 Report.Error (1503, loc,
5200                                                        "Argument " + (j+1) +
5201                                                        ": Cannot convert from '" + Argument.FullDesc (a)
5202                                                        + "' to '" + pd.ParameterDesc (j) + "'");
5203                                         }
5204
5205                                         return false;
5206                                 }
5207                         }
5208
5209                         return true;
5210                 }
5211
5212                 public override Expression DoResolve (EmitContext ec)
5213                 {
5214                         //
5215                         // First, resolve the expression that is used to
5216                         // trigger the invocation
5217                         //
5218                         if (expr is ConstructedType)
5219                                 expr = ((ConstructedType) expr).GetSimpleName (ec);
5220
5221                         expr = expr.Resolve (ec, ResolveFlags.VariableOrValue | ResolveFlags.MethodGroup);
5222                         if (expr == null)
5223                                 return null;
5224
5225                         if (!(expr is MethodGroupExpr)) {
5226                                 Type expr_type = expr.Type;
5227
5228                                 if (expr_type != null){
5229                                         bool IsDelegate = TypeManager.IsDelegateType (expr_type);
5230                                         if (IsDelegate)
5231                                                 return (new DelegateInvocation (
5232                                                         this.expr, Arguments, loc)).Resolve (ec);
5233                                 }
5234                         }
5235
5236                         if (!(expr is MethodGroupExpr)){
5237                                 expr.Error_UnexpectedKind (ResolveFlags.MethodGroup, loc);
5238                                 return null;
5239                         }
5240
5241                         //
5242                         // Next, evaluate all the expressions in the argument list
5243                         //
5244                         if (Arguments != null){
5245                                 foreach (Argument a in Arguments){
5246                                         if (!a.Resolve (ec, loc))
5247                                                 return null;
5248                                 }
5249                         }
5250
5251                         MethodGroupExpr mg = (MethodGroupExpr) expr;
5252                         method = OverloadResolve (ec, mg, Arguments, false, loc);
5253
5254                         if (method == null)
5255                                 return null;
5256
5257                         MethodInfo mi = method as MethodInfo;
5258                         if (mi != null) {
5259                                 type = TypeManager.TypeToCoreType (mi.ReturnType);
5260                                 if (!mi.IsStatic && !mg.IsExplicitImpl && (mg.InstanceExpression == null)) {
5261                                         SimpleName.Error_ObjectRefRequired (ec, loc, mi.Name);
5262                                         return null;
5263                                 }
5264
5265                                 Expression iexpr = mg.InstanceExpression;
5266                                 if (mi.IsStatic && (iexpr != null) && !(iexpr is This)) {
5267                                         if (mg.IdenticalTypeName)
5268                                                 mg.InstanceExpression = null;
5269                                         else {
5270                                                 MemberAccess.error176 (loc, mi.Name);
5271                                                 return null;
5272                                         }
5273                                 }
5274                         }
5275
5276                         if (type.IsPointer){
5277                                 if (!ec.InUnsafe){
5278                                         UnsafeError (loc);
5279                                         return null;
5280                                 }
5281                         }
5282
5283                         //
5284                         // Only base will allow this invocation to happen.
5285                         //
5286                         if (mg.IsBase && method.IsAbstract){
5287                                 Report.Error (205, loc, "Cannot call an abstract base member: " +
5288                                               FullMethodDesc (method));
5289                                 return null;
5290                         }
5291
5292                         if (method.Name == "Finalize" && Arguments == null) {
5293                                 if (mg.IsBase)
5294                                         Report.Error (250, loc, "Do not directly call your base class Finalize method. It is called automatically from your destructor");
5295                                 else
5296                                         Report.Error (245, loc, "Destructors and object.Finalize cannot be called directly. Consider calling IDisposable.Dispose if available");
5297                                 return null;
5298                         }
5299
5300                         if ((method.Attributes & MethodAttributes.SpecialName) != 0){
5301                                 if (TypeManager.LookupDeclSpace (method.DeclaringType) != null || TypeManager.IsSpecialMethod (method)) {
5302                                         Report.Error (571, loc, TypeManager.CSharpSignature (method) + ": can not call operator or accessor");
5303                                         return null;
5304                                 }
5305                         }
5306
5307                         if (mg.InstanceExpression != null)
5308                                 mg.InstanceExpression.CheckMarshallByRefAccess (ec.ContainerType);
5309
5310                         eclass = ExprClass.Value;
5311                         return this;
5312                 }
5313
5314                 // <summary>
5315                 //   Emits the list of arguments as an array
5316                 // </summary>
5317                 static void EmitParams (EmitContext ec, int idx, ArrayList arguments)
5318                 {
5319                         ILGenerator ig = ec.ig;
5320                         int count = arguments.Count - idx;
5321                         Argument a = (Argument) arguments [idx];
5322                         Type t = a.Expr.Type;
5323
5324                         IntConstant.EmitInt (ig, count);
5325                         ig.Emit (OpCodes.Newarr, TypeManager.TypeToCoreType (t));
5326
5327                         int top = arguments.Count;
5328                         for (int j = idx; j < top; j++){
5329                                 a = (Argument) arguments [j];
5330
5331                                 ig.Emit (OpCodes.Dup);
5332                                 IntConstant.EmitInt (ig, j - idx);
5333
5334                                 bool is_stobj, has_type_arg;
5335                                 OpCode op = ArrayAccess.GetStoreOpcode (t, out is_stobj, out has_type_arg);
5336                                 if (is_stobj)
5337                                         ig.Emit (OpCodes.Ldelema, t);
5338
5339                                 a.Emit (ec);
5340
5341                                 if (has_type_arg)
5342                                         ig.Emit (op, t);
5343                                 else
5344                                         ig.Emit (op);
5345                         }
5346                 }
5347
5348                 /// <summary>
5349                 ///   Emits a list of resolved Arguments that are in the arguments
5350                 ///   ArrayList.
5351                 ///
5352                 ///   The MethodBase argument might be null if the
5353                 ///   emission of the arguments is known not to contain
5354                 ///   a `params' field (for example in constructors or other routines
5355                 ///   that keep their arguments in this structure)
5356                 ///
5357                 ///   if `dup_args' is true, a copy of the arguments will be left
5358                 ///   on the stack. If `dup_args' is true, you can specify `this_arg'
5359                 ///   which will be duplicated before any other args. Only EmitCall
5360                 ///   should be using this interface.
5361                 /// </summary>
5362                 public static void EmitArguments (EmitContext ec, MethodBase mb, ArrayList arguments, bool dup_args, LocalTemporary this_arg)
5363                 {
5364                         ParameterData pd;
5365                         if (mb != null)
5366                                 pd = TypeManager.GetParameterData (mb);
5367                         else
5368                                 pd = null;
5369
5370                         LocalTemporary [] temps = null;
5371
5372                         if (dup_args)
5373                                 temps = new LocalTemporary [arguments.Count];
5374
5375                         //
5376                         // If we are calling a params method with no arguments, special case it
5377                         //
5378                         if (arguments == null){
5379                                 if (pd != null && pd.Count > 0 &&
5380                                     pd.ParameterModifier (0) == Parameter.Modifier.PARAMS){
5381                                         ILGenerator ig = ec.ig;
5382
5383                                         IntConstant.EmitInt (ig, 0);
5384                                         ig.Emit (OpCodes.Newarr, TypeManager.GetElementType (pd.ParameterType (0)));
5385                                 }
5386
5387                                 return;
5388                         }
5389
5390                         int top = arguments.Count;
5391
5392                         for (int i = 0; i < top; i++){
5393                                 Argument a = (Argument) arguments [i];
5394
5395                                 if (pd != null){
5396                                         if (pd.ParameterModifier (i) == Parameter.Modifier.PARAMS){
5397                                                 //
5398                                                 // Special case if we are passing the same data as the
5399                                                 // params argument, do not put it in an array.
5400                                                 //
5401                                                 if (pd.ParameterType (i) == a.Type)
5402                                                         a.Emit (ec);
5403                                                 else
5404                                                         EmitParams (ec, i, arguments);
5405                                                 return;
5406                                         }
5407                                 }
5408
5409                                 a.Emit (ec);
5410                                 if (dup_args) {
5411                                         ec.ig.Emit (OpCodes.Dup);
5412                                         (temps [i] = new LocalTemporary (ec, a.Type)).Store (ec);
5413                                 }
5414                         }
5415
5416                         if (dup_args) {
5417                                 if (this_arg != null)
5418                                         this_arg.Emit (ec);
5419
5420                                 for (int i = 0; i < top; i ++)
5421                                         temps [i].Emit (ec);
5422                         }
5423
5424                         if (pd != null && pd.Count > top &&
5425                             pd.ParameterModifier (top) == Parameter.Modifier.PARAMS){
5426                                 ILGenerator ig = ec.ig;
5427
5428                                 IntConstant.EmitInt (ig, 0);
5429                                 ig.Emit (OpCodes.Newarr, TypeManager.GetElementType (pd.ParameterType (top)));
5430                         }
5431                 }
5432
5433                 static Type[] GetVarargsTypes (EmitContext ec, MethodBase mb,
5434                                                ArrayList arguments)
5435                 {
5436                         ParameterData pd = TypeManager.GetParameterData (mb);
5437
5438                         if (arguments == null)
5439                                 return new Type [0];
5440
5441                         Argument a = (Argument) arguments [pd.Count - 1];
5442                         Arglist list = (Arglist) a.Expr;
5443
5444                         return list.ArgumentTypes;
5445                 }
5446
5447                 /// <summary>
5448                 /// This checks the ConditionalAttribute on the method
5449                 /// </summary>
5450                 static bool IsMethodExcluded (MethodBase method, EmitContext ec)
5451                 {
5452                         if (method.IsConstructor)
5453                                 return false;
5454
5455                         IMethodData md = TypeManager.GetMethod (method);
5456                         if (md != null)
5457                                 return md.IsExcluded (ec);
5458
5459                         // For some methods (generated by delegate class) GetMethod returns null
5460                         // because they are not included in builder_to_method table
5461                         if (method.DeclaringType is TypeBuilder)
5462                                 return false;
5463
5464                         return AttributeTester.IsConditionalMethodExcluded (method);
5465                 }
5466
5467                 /// <remarks>
5468                 ///   is_base tells whether we want to force the use of the `call'
5469                 ///   opcode instead of using callvirt.  Call is required to call
5470                 ///   a specific method, while callvirt will always use the most
5471                 ///   recent method in the vtable.
5472                 ///
5473                 ///   is_static tells whether this is an invocation on a static method
5474                 ///
5475                 ///   instance_expr is an expression that represents the instance
5476                 ///   it must be non-null if is_static is false.
5477                 ///
5478                 ///   method is the method to invoke.
5479                 ///
5480                 ///   Arguments is the list of arguments to pass to the method or constructor.
5481                 /// </remarks>
5482                 public static void EmitCall (EmitContext ec, bool is_base,
5483                                              bool is_static, Expression instance_expr,
5484                                              MethodBase method, ArrayList Arguments, Location loc)
5485                 {
5486                         EmitCall (ec, is_base, is_static, instance_expr, method, Arguments, loc, false, false);
5487                 }
5488
5489                 // `dup_args' leaves an extra copy of the arguments on the stack
5490                 // `omit_args' does not leave any arguments at all.
5491                 // So, basically, you could make one call with `dup_args' set to true,
5492                 // and then another with `omit_args' set to true, and the two calls
5493                 // would have the same set of arguments. However, each argument would
5494                 // only have been evaluated once.
5495                 public static void EmitCall (EmitContext ec, bool is_base,
5496                                              bool is_static, Expression instance_expr,
5497                                              MethodBase method, ArrayList Arguments, Location loc,
5498                                              bool dup_args, bool omit_args)
5499                 {
5500                         ILGenerator ig = ec.ig;
5501                         bool struct_call = false;
5502                         bool this_call = false;
5503                         LocalTemporary this_arg = null;
5504
5505                         Type decl_type = method.DeclaringType;
5506
5507                         if (!RootContext.StdLib) {
5508                                 // Replace any calls to the system's System.Array type with calls to
5509                                 // the newly created one.
5510                                 if (method == TypeManager.system_int_array_get_length)
5511                                         method = TypeManager.int_array_get_length;
5512                                 else if (method == TypeManager.system_int_array_get_rank)
5513                                         method = TypeManager.int_array_get_rank;
5514                                 else if (method == TypeManager.system_object_array_clone)
5515                                         method = TypeManager.object_array_clone;
5516                                 else if (method == TypeManager.system_int_array_get_length_int)
5517                                         method = TypeManager.int_array_get_length_int;
5518                                 else if (method == TypeManager.system_int_array_get_lower_bound_int)
5519                                         method = TypeManager.int_array_get_lower_bound_int;
5520                                 else if (method == TypeManager.system_int_array_get_upper_bound_int)
5521                                         method = TypeManager.int_array_get_upper_bound_int;
5522                                 else if (method == TypeManager.system_void_array_copyto_array_int)
5523                                         method = TypeManager.void_array_copyto_array_int;
5524                         }
5525
5526                         if (ec.TestObsoleteMethodUsage) {
5527                                 //
5528                                 // This checks ObsoleteAttribute on the method and on the declaring type
5529                                 //
5530                                 ObsoleteAttribute oa = AttributeTester.GetMethodObsoleteAttribute (method);
5531                                 if (oa != null)
5532                                         AttributeTester.Report_ObsoleteMessage (oa, TypeManager.CSharpSignature (method), loc);
5533
5534                                 oa = AttributeTester.GetObsoleteAttribute (method.DeclaringType);
5535                                 if (oa != null) {
5536                                         AttributeTester.Report_ObsoleteMessage (oa, method.DeclaringType.FullName, loc);
5537                                 }
5538                         }
5539
5540                         if (IsMethodExcluded (method, ec))
5541                                 return;
5542
5543                         if (!is_static){
5544                                 this_call = instance_expr == null;
5545                                 if (decl_type.IsValueType || (!this_call && instance_expr.Type.IsValueType))
5546                                         struct_call = true;
5547
5548                                 //
5549                                 // If this is ourselves, push "this"
5550                                 //
5551                                 if (!omit_args) {
5552                                         Type t = null;
5553                                         if (this_call) {
5554                                                 ig.Emit (OpCodes.Ldarg_0);
5555                                                 t = decl_type;
5556                                         } else {
5557                                                 Type iexpr_type = instance_expr.Type;
5558
5559                                                 //
5560                                                 // Push the instance expression
5561                                                 //
5562                                                 if (TypeManager.IsValueType (iexpr_type)) {
5563                                                         //
5564                                                         // Special case: calls to a function declared in a
5565                                                         // reference-type with a value-type argument need
5566                                                         // to have their value boxed.
5567                                                         if (decl_type.IsValueType ||
5568                                                             iexpr_type.IsGenericParameter) {
5569                                                                 //
5570                                                                 // If the expression implements IMemoryLocation, then
5571                                                                 // we can optimize and use AddressOf on the
5572                                                                 // return.
5573                                                                 //
5574                                                                 // If not we have to use some temporary storage for
5575                                                                 // it.
5576                                                                 if (instance_expr is IMemoryLocation) {
5577                                                                         ((IMemoryLocation)instance_expr).
5578                                                                                 AddressOf (ec, AddressOp.LoadStore);
5579                                                                 } else {
5580                                                                         LocalTemporary temp = new LocalTemporary (ec, iexpr_type);
5581                                                                         instance_expr.Emit (ec);
5582                                                                         temp.Store (ec);
5583                                                                         temp.AddressOf (ec, AddressOp.Load);
5584                                                                 }
5585
5586                                                                 // avoid the overhead of doing this all the time.
5587                                                                 if (dup_args)
5588                                                                         t = TypeManager.GetReferenceType (iexpr_type);
5589                                                         } else {
5590                                                                 instance_expr.Emit (ec);
5591                                                                 ig.Emit (OpCodes.Box, instance_expr.Type);
5592                                                                 t = TypeManager.object_type;
5593                                                         }
5594                                                 } else {
5595                                                         instance_expr.Emit (ec);
5596                                                         t = instance_expr.Type;
5597                                                 }
5598                                         }
5599
5600                                         if (dup_args) {
5601                                                 this_arg = new LocalTemporary (ec, t);
5602                                                 ig.Emit (OpCodes.Dup);
5603                                                 this_arg.Store (ec);
5604                                         }
5605                                 }
5606                         }
5607
5608                         if (!omit_args)
5609                                 EmitArguments (ec, method, Arguments, dup_args, this_arg);
5610
5611                         if ((instance_expr != null) && (instance_expr.Type.IsGenericParameter))
5612                                 ig.Emit (OpCodes.Constrained, instance_expr.Type);
5613
5614                         OpCode call_op;
5615                         if (is_static || struct_call || is_base || (this_call && !method.IsVirtual))
5616                                 call_op = OpCodes.Call;
5617                         else
5618                                 call_op = OpCodes.Callvirt;
5619
5620                         if ((method.CallingConvention & CallingConventions.VarArgs) != 0) {
5621                                 Type[] varargs_types = GetVarargsTypes (ec, method, Arguments);
5622                                 ig.EmitCall (call_op, (MethodInfo) method, varargs_types);
5623                                 return;
5624                         }
5625
5626                         //
5627                         // If you have:
5628                         // this.DoFoo ();
5629                         // and DoFoo is not virtual, you can omit the callvirt,
5630                         // because you don't need the null checking behavior.
5631                         //
5632                         if (method is MethodInfo)
5633                                 ig.Emit (call_op, (MethodInfo) method);
5634                         else
5635                                 ig.Emit (call_op, (ConstructorInfo) method);
5636                 }
5637
5638                 public override void Emit (EmitContext ec)
5639                 {
5640                         MethodGroupExpr mg = (MethodGroupExpr) this.expr;
5641
5642                         EmitCall (ec, mg.IsBase, method.IsStatic, mg.InstanceExpression, method, Arguments, loc);
5643                 }
5644
5645                 public override void EmitStatement (EmitContext ec)
5646                 {
5647                         Emit (ec);
5648
5649                         //
5650                         // Pop the return value if there is one
5651                         //
5652                         if (method is MethodInfo){
5653                                 Type ret = ((MethodInfo)method).ReturnType;
5654                                 if (TypeManager.TypeToCoreType (ret) != TypeManager.void_type)
5655                                         ec.ig.Emit (OpCodes.Pop);
5656                         }
5657                 }
5658         }
5659
5660         public class InvocationOrCast : ExpressionStatement
5661         {
5662                 Expression expr;
5663                 Expression argument;
5664
5665                 public InvocationOrCast (Expression expr, Expression argument, Location loc)
5666                 {
5667                         this.expr = expr;
5668                         this.argument = argument;
5669                         this.loc = loc;
5670                 }
5671
5672                 public override Expression DoResolve (EmitContext ec)
5673                 {
5674                         //
5675                         // First try to resolve it as a cast.
5676                         //
5677                         TypeExpr te = expr.ResolveAsTypeStep (ec) as TypeExpr;
5678                         if ((te != null) && (te.eclass == ExprClass.Type)) {
5679                                 Cast cast = new Cast (te, argument, loc);
5680                                 return cast.Resolve (ec);
5681                         }
5682
5683                         //
5684                         // This can either be a type or a delegate invocation.
5685                         // Let's just resolve it and see what we'll get.
5686                         //
5687                         expr = expr.Resolve (ec, ResolveFlags.Type | ResolveFlags.VariableOrValue);
5688                         if (expr == null)
5689                                 return null;
5690
5691                         //
5692                         // Ok, so it's a Cast.
5693                         //
5694                         if (expr.eclass == ExprClass.Type) {
5695                                 Cast cast = new Cast (new TypeExpression (expr.Type, loc), argument, loc);
5696                                 return cast.Resolve (ec);
5697                         }
5698
5699                         //
5700                         // It's a delegate invocation.
5701                         //
5702                         if (!TypeManager.IsDelegateType (expr.Type)) {
5703                                 Error (149, "Method name expected");
5704                                 return null;
5705                         }
5706
5707                         ArrayList args = new ArrayList ();
5708                         args.Add (new Argument (argument, Argument.AType.Expression));
5709                         DelegateInvocation invocation = new DelegateInvocation (expr, args, loc);
5710                         return invocation.Resolve (ec);
5711                 }
5712
5713                 void error201 ()
5714                 {
5715                         Error (201, "Only assignment, call, increment, decrement and new object " +
5716                                "expressions can be used as a statement");
5717                 }
5718
5719                 public override ExpressionStatement ResolveStatement (EmitContext ec)
5720                 {
5721                         //
5722                         // First try to resolve it as a cast.
5723                         //
5724                         TypeExpr te = expr.ResolveAsTypeStep (ec) as TypeExpr;
5725                         if ((te != null) && (te.eclass == ExprClass.Type)) {
5726                                 error201 ();
5727                                 return null;
5728                         }
5729
5730                         //
5731                         // This can either be a type or a delegate invocation.
5732                         // Let's just resolve it and see what we'll get.
5733                         //
5734                         expr = expr.Resolve (ec, ResolveFlags.Type | ResolveFlags.VariableOrValue);
5735                         if ((expr == null) || (expr.eclass == ExprClass.Type)) {
5736                                 error201 ();
5737                                 return null;
5738                         }
5739
5740                         //
5741                         // It's a delegate invocation.
5742                         //
5743                         if (!TypeManager.IsDelegateType (expr.Type)) {
5744                                 Error (149, "Method name expected");
5745                                 return null;
5746                         }
5747
5748                         ArrayList args = new ArrayList ();
5749                         args.Add (new Argument (argument, Argument.AType.Expression));
5750                         DelegateInvocation invocation = new DelegateInvocation (expr, args, loc);
5751                         return invocation.ResolveStatement (ec);
5752                 }
5753
5754                 public override void Emit (EmitContext ec)
5755                 {
5756                         throw new Exception ("Cannot happen");
5757                 }
5758
5759                 public override void EmitStatement (EmitContext ec)
5760                 {
5761                         throw new Exception ("Cannot happen");
5762                 }
5763         }
5764
5765         //
5766         // This class is used to "disable" the code generation for the
5767         // temporary variable when initializing value types.
5768         //
5769         class EmptyAddressOf : EmptyExpression, IMemoryLocation {
5770                 public void AddressOf (EmitContext ec, AddressOp Mode)
5771                 {
5772                         // nothing
5773                 }
5774         }
5775
5776         /// <summary>
5777         ///    Implements the new expression
5778         /// </summary>
5779         public class New : ExpressionStatement, IMemoryLocation {
5780                 public readonly ArrayList Arguments;
5781
5782                 //
5783                 // During bootstrap, it contains the RequestedType,
5784                 // but if `type' is not null, it *might* contain a NewDelegate
5785                 // (because of field multi-initialization)
5786                 //
5787                 public Expression RequestedType;
5788
5789                 MethodBase method = null;
5790
5791                 //
5792                 // If set, the new expression is for a value_target, and
5793                 // we will not leave anything on the stack.
5794                 //
5795                 Expression value_target;
5796                 bool value_target_set = false;
5797                 bool is_type_parameter = false;
5798
5799                 public New (Expression requested_type, ArrayList arguments, Location l)
5800                 {
5801                         RequestedType = requested_type;
5802                         Arguments = arguments;
5803                         loc = l;
5804                 }
5805
5806                 public bool SetValueTypeVariable (Expression value)
5807                 {
5808                         value_target = value;
5809                         value_target_set = true;
5810                         if (!(value_target is IMemoryLocation)){
5811                                 Error_UnexpectedKind ("variable", loc);
5812                                 return false;
5813                         }
5814                         return true;
5815                 }
5816
5817                 //
5818                 // This function is used to disable the following code sequence for
5819                 // value type initialization:
5820                 //
5821                 // AddressOf (temporary)
5822                 // Construct/Init
5823                 // LoadTemporary
5824                 //
5825                 // Instead the provide will have provided us with the address on the
5826                 // stack to store the results.
5827                 //
5828                 static Expression MyEmptyExpression;
5829
5830                 public void DisableTemporaryValueType ()
5831                 {
5832                         if (MyEmptyExpression == null)
5833                                 MyEmptyExpression = new EmptyAddressOf ();
5834
5835                         //
5836                         // To enable this, look into:
5837                         // test-34 and test-89 and self bootstrapping.
5838                         //
5839                         // For instance, we can avoid a copy by using `newobj'
5840                         // instead of Call + Push-temp on value types.
5841 //                      value_target = MyEmptyExpression;
5842                 }
5843
5844                 public override Expression DoResolve (EmitContext ec)
5845                 {
5846                         //
5847                         // The New DoResolve might be called twice when initializing field
5848                         // expressions (see EmitFieldInitializers, the call to
5849                         // GetInitializerExpression will perform a resolve on the expression,
5850                         // and later the assign will trigger another resolution
5851                         //
5852                         // This leads to bugs (#37014)
5853                         //
5854                         if (type != null){
5855                                 if (RequestedType is NewDelegate)
5856                                         return RequestedType;
5857                                 return this;
5858                         }
5859
5860                         TypeExpr texpr = RequestedType.ResolveAsTypeTerminal (ec);
5861                         if (texpr == null)
5862                                 return null;
5863
5864                         type = texpr.Type;
5865                         if (type == null)
5866                                 return null;
5867
5868                         CheckObsoleteAttribute (type);
5869
5870                         bool IsDelegate = TypeManager.IsDelegateType (type);
5871
5872                         if (IsDelegate){
5873                                 RequestedType = (new NewDelegate (type, Arguments, loc)).Resolve (ec);
5874                                 if (RequestedType != null)
5875                                         if (!(RequestedType is DelegateCreation))
5876                                                 throw new Exception ("NewDelegate.Resolve returned a non NewDelegate: " + RequestedType.GetType ());
5877                                 return RequestedType;
5878                         }
5879
5880                         if (type.IsGenericParameter) {
5881                                 if (!TypeManager.HasConstructorConstraint (type)) {
5882                                         Error (304, String.Format (
5883                                                        "Cannot create an instance of the " +
5884                                                        "variable type '{0}' because it " +
5885                                                        "doesn't have the new() constraint",
5886                                                        type));
5887                                         return null;
5888                                 }
5889
5890                                 if ((Arguments != null) && (Arguments.Count != 0)) {
5891                                         Error (417, String.Format (
5892                                                        "`{0}': cannot provide arguments " +
5893                                                        "when creating an instance of a " +
5894                                                        "variable type.", type));
5895                                         return null;
5896                                 }
5897
5898                                 is_type_parameter = true;
5899                                 eclass = ExprClass.Value;
5900                                 return this;
5901                         }
5902
5903                         if (type.IsInterface || type.IsAbstract){
5904                                 Error (144, "It is not possible to create instances of interfaces or abstract classes");
5905                                 return null;
5906                         }
5907
5908                         if (type.IsAbstract && type.IsSealed) {
5909                                 Report.Error (712, loc, "Cannot create an instance of the static class '{0}'", TypeManager.CSharpName (type));
5910                                 return null;
5911                         }
5912
5913                         bool is_struct = type.IsValueType;
5914                         eclass = ExprClass.Value;
5915
5916                         //
5917                         // SRE returns a match for .ctor () on structs (the object constructor),
5918                         // so we have to manually ignore it.
5919                         //
5920                         if (is_struct && Arguments == null)
5921                                 return this;
5922
5923                         Expression ml;
5924                         ml = MemberLookupFinal (ec, type, type, ".ctor",
5925                                                 // For member-lookup, treat 'new Foo (bar)' as call to 'foo.ctor (bar)', where 'foo' is of type 'Foo'.
5926                                                 MemberTypes.Constructor,
5927                                                 AllBindingFlags | BindingFlags.DeclaredOnly, loc);
5928
5929                         if (ml == null)
5930                                 return null;
5931
5932                         if (! (ml is MethodGroupExpr)){
5933                                 if (!is_struct){
5934                                         ml.Error_UnexpectedKind ("method group", loc);
5935                                         return null;
5936                                 }
5937                         }
5938
5939                         if (ml != null) {
5940                                 if (Arguments != null){
5941                                         foreach (Argument a in Arguments){
5942                                                 if (!a.Resolve (ec, loc))
5943                                                         return null;
5944                                         }
5945                                 }
5946
5947                                 method = Invocation.OverloadResolve (
5948                                         ec, (MethodGroupExpr) ml, Arguments, true, loc);
5949
5950                         }
5951
5952                         if (method == null) {
5953                                 if (almostMatchedMembers.Count != 0) {
5954                                         MemberLookupFailed (ec, type, type, ".ctor", null, loc);
5955                                         return null;
5956                                 }
5957
5958                                 if (!is_struct || Arguments.Count > 0) {
5959                                         Error (1501, String.Format (
5960                                             "New invocation: Can not find a constructor in `{0}' for this argument list",
5961                                             TypeManager.CSharpName (type)));
5962                                         return null;
5963                                 }
5964                         }
5965
5966                         return this;
5967                 }
5968
5969                 bool DoEmitTypeParameter (EmitContext ec)
5970                 {
5971                         ILGenerator ig = ec.ig;
5972
5973                         ig.Emit (OpCodes.Ldtoken, type);
5974                         ig.Emit (OpCodes.Call, TypeManager.system_type_get_type_from_handle);
5975                         ig.Emit (OpCodes.Call, TypeManager.activator_create_instance);
5976                         ig.Emit (OpCodes.Unbox_Any, type);
5977
5978                         return true;
5979                 }
5980
5981                 //
5982                 // This DoEmit can be invoked in two contexts:
5983                 //    * As a mechanism that will leave a value on the stack (new object)
5984                 //    * As one that wont (init struct)
5985                 //
5986                 // You can control whether a value is required on the stack by passing
5987                 // need_value_on_stack.  The code *might* leave a value on the stack
5988                 // so it must be popped manually
5989                 //
5990                 // If we are dealing with a ValueType, we have a few
5991                 // situations to deal with:
5992                 //
5993                 //    * The target is a ValueType, and we have been provided
5994                 //      the instance (this is easy, we are being assigned).
5995                 //
5996                 //    * The target of New is being passed as an argument,
5997                 //      to a boxing operation or a function that takes a
5998                 //      ValueType.
5999                 //
6000                 //      In this case, we need to create a temporary variable
6001                 //      that is the argument of New.
6002                 //
6003                 // Returns whether a value is left on the stack
6004                 //
6005                 bool DoEmit (EmitContext ec, bool need_value_on_stack)
6006                 {
6007                         bool is_value_type = TypeManager.IsValueType (type);
6008                         ILGenerator ig = ec.ig;
6009
6010                         if (is_value_type){
6011                                 IMemoryLocation ml;
6012
6013                                 // Allow DoEmit() to be called multiple times.
6014                                 // We need to create a new LocalTemporary each time since
6015                                 // you can't share LocalBuilders among ILGeneators.
6016                                 if (!value_target_set)
6017                                         value_target = new LocalTemporary (ec, type);
6018
6019                                 ml = (IMemoryLocation) value_target;
6020                                 ml.AddressOf (ec, AddressOp.Store);
6021                         }
6022
6023                         if (method != null)
6024                                 Invocation.EmitArguments (ec, method, Arguments, false, null);
6025
6026                         if (is_value_type){
6027                                 if (method == null)
6028                                         ig.Emit (OpCodes.Initobj, type);
6029                                 else
6030                                         ig.Emit (OpCodes.Call, (ConstructorInfo) method);
6031                                 if (need_value_on_stack){
6032                                         value_target.Emit (ec);
6033                                         return true;
6034                                 }
6035                                 return false;
6036                         } else {
6037                                 ig.Emit (OpCodes.Newobj, (ConstructorInfo) method);
6038                                 return true;
6039                         }
6040                 }
6041
6042                 public override void Emit (EmitContext ec)
6043                 {
6044                         if (is_type_parameter)
6045                                 DoEmitTypeParameter (ec);
6046                         else
6047                                 DoEmit (ec, true);
6048                 }
6049
6050                 public override void EmitStatement (EmitContext ec)
6051                 {
6052                         if (is_type_parameter)
6053                                 throw new InvalidOperationException ();
6054
6055                         if (DoEmit (ec, false))
6056                                 ec.ig.Emit (OpCodes.Pop);
6057                 }
6058
6059                 public void AddressOf (EmitContext ec, AddressOp Mode)
6060                 {
6061                         if (is_type_parameter)
6062                                 throw new InvalidOperationException ();
6063
6064                         if (!type.IsValueType){
6065                                 //
6066                                 // We throw an exception.  So far, I believe we only need to support
6067                                 // value types:
6068                                 // foreach (int j in new StructType ())
6069                                 // see bug 42390
6070                                 //
6071                                 throw new Exception ("AddressOf should not be used for classes");
6072                         }
6073
6074                         if (!value_target_set)
6075                                 value_target = new LocalTemporary (ec, type);
6076
6077                         IMemoryLocation ml = (IMemoryLocation) value_target;
6078                         ml.AddressOf (ec, AddressOp.Store);
6079                         if (method != null)
6080                                 Invocation.EmitArguments (ec, method, Arguments, false, null);
6081
6082                         if (method == null)
6083                                 ec.ig.Emit (OpCodes.Initobj, type);
6084                         else
6085                                 ec.ig.Emit (OpCodes.Call, (ConstructorInfo) method);
6086
6087                         ((IMemoryLocation) value_target).AddressOf (ec, Mode);
6088                 }
6089         }
6090
6091         /// <summary>
6092         ///   14.5.10.2: Represents an array creation expression.
6093         /// </summary>
6094         ///
6095         /// <remarks>
6096         ///   There are two possible scenarios here: one is an array creation
6097         ///   expression that specifies the dimensions and optionally the
6098         ///   initialization data and the other which does not need dimensions
6099         ///   specified but where initialization data is mandatory.
6100         /// </remarks>
6101         public class ArrayCreation : Expression {
6102                 Expression requested_base_type;
6103                 ArrayList initializers;
6104
6105                 //
6106                 // The list of Argument types.
6107                 // This is used to construct the `newarray' or constructor signature
6108                 //
6109                 ArrayList arguments;
6110
6111                 //
6112                 // Method used to create the array object.
6113                 //
6114                 MethodBase new_method = null;
6115
6116                 Type array_element_type;
6117                 Type underlying_type;
6118                 bool is_one_dimensional = false;
6119                 bool is_builtin_type = false;
6120                 bool expect_initializers = false;
6121                 int num_arguments = 0;
6122                 int dimensions = 0;
6123                 string rank;
6124
6125                 ArrayList array_data;
6126
6127                 Hashtable bounds;
6128
6129                 //
6130                 // The number of array initializers that we can handle
6131                 // via the InitializeArray method - through EmitStaticInitializers
6132                 //
6133                 int num_automatic_initializers;
6134
6135                 const int max_automatic_initializers = 6;
6136
6137                 public ArrayCreation (Expression requested_base_type, ArrayList exprs, string rank, ArrayList initializers, Location l)
6138                 {
6139                         this.requested_base_type = requested_base_type;
6140                         this.initializers = initializers;
6141                         this.rank = rank;
6142                         loc = l;
6143
6144                         arguments = new ArrayList ();
6145
6146                         foreach (Expression e in exprs) {
6147                                 arguments.Add (new Argument (e, Argument.AType.Expression));
6148                                 num_arguments++;
6149                         }
6150                 }
6151
6152                 public ArrayCreation (Expression requested_base_type, string rank, ArrayList initializers, Location l)
6153                 {
6154                         this.requested_base_type = requested_base_type;
6155                         this.initializers = initializers;
6156                         this.rank = rank;
6157                         loc = l;
6158
6159                         //this.rank = rank.Substring (0, rank.LastIndexOf ('['));
6160                         //
6161                         //string tmp = rank.Substring (rank.LastIndexOf ('['));
6162                         //
6163                         //dimensions = tmp.Length - 1;
6164                         expect_initializers = true;
6165                 }
6166
6167                 public Expression FormArrayType (Expression base_type, int idx_count, string rank)
6168                 {
6169                         StringBuilder sb = new StringBuilder (rank);
6170
6171                         sb.Append ("[");
6172                         for (int i = 1; i < idx_count; i++)
6173                                 sb.Append (",");
6174
6175                         sb.Append ("]");
6176
6177                         return new ComposedCast (base_type, sb.ToString (), loc);
6178                 }
6179
6180                 void Error_IncorrectArrayInitializer ()
6181                 {
6182                         Error (178, "Incorrectly structured array initializer");
6183                 }
6184
6185                 public bool CheckIndices (EmitContext ec, ArrayList probe, int idx, bool specified_dims)
6186                 {
6187                         if (specified_dims) {
6188                                 Argument a = (Argument) arguments [idx];
6189
6190                                 if (!a.Resolve (ec, loc))
6191                                         return false;
6192
6193                                 if (!(a.Expr is Constant)) {
6194                                         Error (150, "A constant value is expected");
6195                                         return false;
6196                                 }
6197
6198                                 int value = (int) ((Constant) a.Expr).GetValue ();
6199
6200                                 if (value != probe.Count) {
6201                                         Error_IncorrectArrayInitializer ();
6202                                         return false;
6203                                 }
6204
6205                                 bounds [idx] = value;
6206                         }
6207
6208                         int child_bounds = -1;
6209                         foreach (object o in probe) {
6210                                 if (o is ArrayList) {
6211                                         int current_bounds = ((ArrayList) o).Count;
6212
6213                                         if (child_bounds == -1)
6214                                                 child_bounds = current_bounds;
6215
6216                                         else if (child_bounds != current_bounds){
6217                                                 Error_IncorrectArrayInitializer ();
6218                                                 return false;
6219                                         }
6220                                         if (specified_dims && (idx + 1 >= arguments.Count)){
6221                                                 Error (623, "Array initializers can only be used in a variable or field initializer, try using the new expression");
6222                                                 return false;
6223                                         }
6224
6225                                         bool ret = CheckIndices (ec, (ArrayList) o, idx + 1, specified_dims);
6226                                         if (!ret)
6227                                                 return false;
6228                                 } else {
6229                                         if (child_bounds != -1){
6230                                                 Error_IncorrectArrayInitializer ();
6231                                                 return false;
6232                                         }
6233
6234                                         Expression tmp = (Expression) o;
6235                                         tmp = tmp.Resolve (ec);
6236                                         if (tmp == null)
6237                                                 return false;
6238
6239                                         // Console.WriteLine ("I got: " + tmp);
6240                                         // Handle initialization from vars, fields etc.
6241
6242                                         Expression conv = Convert.ImplicitConversionRequired (
6243                                                 ec, tmp, underlying_type, loc);
6244
6245                                         if (conv == null)
6246                                                 return false;
6247
6248                                         if (conv is StringConstant || conv is DecimalConstant || conv is NullCast) {
6249                                                 // These are subclasses of Constant that can appear as elements of an
6250                                                 // array that cannot be statically initialized (with num_automatic_initializers
6251                                                 // > max_automatic_initializers), so num_automatic_initializers should be left as zero.
6252                                                 array_data.Add (conv);
6253                                         } else if (conv is Constant) {
6254                                                 // These are the types of Constant that can appear in arrays that can be
6255                                                 // statically allocated.
6256                                                 array_data.Add (conv);
6257                                                 num_automatic_initializers++;
6258                                         } else
6259                                                 array_data.Add (conv);
6260                                 }
6261                         }
6262
6263                         return true;
6264                 }
6265
6266                 public void UpdateIndices (EmitContext ec)
6267                 {
6268                         int i = 0;
6269                         for (ArrayList probe = initializers; probe != null;) {
6270                                 if (probe.Count > 0 && probe [0] is ArrayList) {
6271                                         Expression e = new IntConstant (probe.Count);
6272                                         arguments.Add (new Argument (e, Argument.AType.Expression));
6273
6274                                         bounds [i++] =  probe.Count;
6275
6276                                         probe = (ArrayList) probe [0];
6277
6278                                 } else {
6279                                         Expression e = new IntConstant (probe.Count);
6280                                         arguments.Add (new Argument (e, Argument.AType.Expression));
6281
6282                                         bounds [i++] = probe.Count;
6283                                         probe = null;
6284                                 }
6285                         }
6286
6287                 }
6288
6289                 public bool ValidateInitializers (EmitContext ec, Type array_type)
6290                 {
6291                         if (initializers == null) {
6292                                 if (expect_initializers)
6293                                         return false;
6294                                 else
6295                                         return true;
6296                         }
6297
6298                         if (underlying_type == null)
6299                                 return false;
6300
6301                         //
6302                         // We use this to store all the date values in the order in which we
6303                         // will need to store them in the byte blob later
6304                         //
6305                         array_data = new ArrayList ();
6306                         bounds = new Hashtable ();
6307
6308                         bool ret;
6309
6310                         if (arguments != null) {
6311                                 ret = CheckIndices (ec, initializers, 0, true);
6312                                 return ret;
6313                         } else {
6314                                 arguments = new ArrayList ();
6315
6316                                 ret = CheckIndices (ec, initializers, 0, false);
6317
6318                                 if (!ret)
6319                                         return false;
6320
6321                                 UpdateIndices (ec);
6322
6323                                 if (arguments.Count != dimensions) {
6324                                         Error_IncorrectArrayInitializer ();
6325                                         return false;
6326                                 }
6327
6328                                 return ret;
6329                         }
6330                 }
6331
6332                 //
6333                 // Converts `source' to an int, uint, long or ulong.
6334                 //
6335                 Expression ExpressionToArrayArgument (EmitContext ec, Expression source)
6336                 {
6337                         Expression target;
6338
6339                         bool old_checked = ec.CheckState;
6340                         ec.CheckState = true;
6341
6342                         target = Convert.ImplicitConversion (ec, source, TypeManager.int32_type, loc);
6343                         if (target == null){
6344                                 target = Convert.ImplicitConversion (ec, source, TypeManager.uint32_type, loc);
6345                                 if (target == null){
6346                                         target = Convert.ImplicitConversion (ec, source, TypeManager.int64_type, loc);
6347                                         if (target == null){
6348                                                 target = Convert.ImplicitConversion (ec, source, TypeManager.uint64_type, loc);
6349                                                 if (target == null)
6350                                                         Convert.Error_CannotImplicitConversion (loc, source.Type, TypeManager.int32_type);
6351                                         }
6352                                 }
6353                         }
6354                         ec.CheckState = old_checked;
6355
6356                         //
6357                         // Only positive constants are allowed at compile time
6358                         //
6359                         if (target is Constant){
6360                                 if (target is IntConstant){
6361                                         if (((IntConstant) target).Value < 0){
6362                                                 Expression.Error_NegativeArrayIndex (loc);
6363                                                 return null;
6364                                         }
6365                                 }
6366
6367                                 if (target is LongConstant){
6368                                         if (((LongConstant) target).Value < 0){
6369                                                 Expression.Error_NegativeArrayIndex (loc);
6370                                                 return null;
6371                                         }
6372                                 }
6373
6374                         }
6375
6376                         return target;
6377                 }
6378
6379                 //
6380                 // Creates the type of the array
6381                 //
6382                 bool LookupType (EmitContext ec)
6383                 {
6384                         StringBuilder array_qualifier = new StringBuilder (rank);
6385
6386                         //
6387                         // `In the first form allocates an array instace of the type that results
6388                         // from deleting each of the individual expression from the expression list'
6389                         //
6390                         if (num_arguments > 0) {
6391                                 array_qualifier.Append ("[");
6392                                 for (int i = num_arguments-1; i > 0; i--)
6393                                         array_qualifier.Append (",");
6394                                 array_qualifier.Append ("]");
6395                         }
6396
6397                         //
6398                         // Lookup the type
6399                         //
6400                         TypeExpr array_type_expr;
6401                         array_type_expr = new ComposedCast (requested_base_type, array_qualifier.ToString (), loc);
6402                         array_type_expr = array_type_expr.ResolveAsTypeTerminal (ec);
6403                         if (array_type_expr == null)
6404                                 return false;
6405
6406                         type = array_type_expr.Type;
6407
6408                         if (!type.IsArray) {
6409                                 Error (622, "Can only use array initializer expressions to assign to array types. Try using a new expression instead.");
6410                                 return false;
6411                         }
6412                         underlying_type = TypeManager.GetElementType (type);
6413                         dimensions = type.GetArrayRank ();
6414
6415                         return true;
6416                 }
6417
6418                 public override Expression DoResolve (EmitContext ec)
6419                 {
6420                         int arg_count;
6421
6422                         if (!LookupType (ec))
6423                                 return null;
6424
6425                         //
6426                         // First step is to validate the initializers and fill
6427                         // in any missing bits
6428                         //
6429                         if (!ValidateInitializers (ec, type))
6430                                 return null;
6431
6432                         if (arguments == null)
6433                                 arg_count = 0;
6434                         else {
6435                                 arg_count = arguments.Count;
6436                                 foreach (Argument a in arguments){
6437                                         if (!a.Resolve (ec, loc))
6438                                                 return null;
6439
6440                                         Expression real_arg = ExpressionToArrayArgument (ec, a.Expr, loc);
6441                                         if (real_arg == null)
6442                                                 return null;
6443
6444                                         a.Expr = real_arg;
6445                                 }
6446                         }
6447
6448                         array_element_type = TypeManager.GetElementType (type);
6449
6450                         if (array_element_type.IsAbstract && array_element_type.IsSealed) {
6451                                 Report.Error (719, loc, "'{0}': array elements cannot be of static type", TypeManager.CSharpName (array_element_type));
6452                                 return null;
6453                         }
6454
6455                         if (arg_count == 1) {
6456                                 is_one_dimensional = true;
6457                                 eclass = ExprClass.Value;
6458                                 return this;
6459                         }
6460
6461                         is_builtin_type = TypeManager.IsBuiltinType (type);
6462
6463                         if (is_builtin_type) {
6464                                 Expression ml;
6465
6466                                 ml = MemberLookup (ec, type, ".ctor", MemberTypes.Constructor,
6467                                                    AllBindingFlags, loc);
6468
6469                                 if (!(ml is MethodGroupExpr)) {
6470                                         ml.Error_UnexpectedKind ("method group", loc);
6471                                         return null;
6472                                 }
6473
6474                                 if (ml == null) {
6475                                         Error (-6, "New invocation: Can not find a constructor for " +
6476                                                       "this argument list");
6477                                         return null;
6478                                 }
6479
6480                                 new_method = Invocation.OverloadResolve (
6481                                         ec, (MethodGroupExpr) ml, arguments, false, loc);
6482
6483                                 if (new_method == null) {
6484                                         Error (-6, "New invocation: Can not find a constructor for " +
6485                                                       "this argument list");
6486                                         return null;
6487                                 }
6488
6489                                 eclass = ExprClass.Value;
6490                                 return this;
6491                         } else {
6492                                 ModuleBuilder mb = CodeGen.Module.Builder;
6493                                 ArrayList args = new ArrayList ();
6494
6495                                 if (arguments != null) {
6496                                         for (int i = 0; i < arg_count; i++)
6497                                                 args.Add (TypeManager.int32_type);
6498                                 }
6499
6500                                 Type [] arg_types = null;
6501
6502                                 if (args.Count > 0)
6503                                         arg_types = new Type [args.Count];
6504
6505                                 args.CopyTo (arg_types, 0);
6506
6507                                 new_method = mb.GetArrayMethod (type, ".ctor", CallingConventions.HasThis, null,
6508                                                             arg_types);
6509
6510                                 if (new_method == null) {
6511                                         Error (-6, "New invocation: Can not find a constructor for " +
6512                                                       "this argument list");
6513                                         return null;
6514                                 }
6515
6516                                 eclass = ExprClass.Value;
6517                                 return this;
6518                         }
6519                 }
6520
6521                 public static byte [] MakeByteBlob (ArrayList array_data, Type underlying_type, Location loc)
6522                 {
6523                         int factor;
6524                         byte [] data;
6525                         byte [] element;
6526                         int count = array_data.Count;
6527
6528                         if (underlying_type.IsEnum)
6529                                 underlying_type = TypeManager.EnumToUnderlying (underlying_type);
6530
6531                         factor = GetTypeSize (underlying_type);
6532                         if (factor == 0)
6533                                 throw new Exception ("unrecognized type in MakeByteBlob: " + underlying_type);
6534
6535                         data = new byte [(count * factor + 4) & ~3];
6536                         int idx = 0;
6537
6538                         for (int i = 0; i < count; ++i) {
6539                                 object v = array_data [i];
6540
6541                                 if (v is EnumConstant)
6542                                         v = ((EnumConstant) v).Child;
6543
6544                                 if (v is Constant && !(v is StringConstant))
6545                                         v = ((Constant) v).GetValue ();
6546                                 else {
6547                                         idx += factor;
6548                                         continue;
6549                                 }
6550
6551                                 if (underlying_type == TypeManager.int64_type){
6552                                         if (!(v is Expression)){
6553                                                 long val = (long) v;
6554
6555                                                 for (int j = 0; j < factor; ++j) {
6556                                                         data [idx + j] = (byte) (val & 0xFF);
6557                                                         val = (val >> 8);
6558                                                 }
6559                                         }
6560                                 } else if (underlying_type == TypeManager.uint64_type){
6561                                         if (!(v is Expression)){
6562                                                 ulong val = (ulong) v;
6563
6564                                                 for (int j = 0; j < factor; ++j) {
6565                                                         data [idx + j] = (byte) (val & 0xFF);
6566                                                         val = (val >> 8);
6567                                                 }
6568                                         }
6569                                 } else if (underlying_type == TypeManager.float_type) {
6570                                         if (!(v is Expression)){
6571                                                 element = BitConverter.GetBytes ((float) v);
6572
6573                                                 for (int j = 0; j < factor; ++j)
6574                                                         data [idx + j] = element [j];
6575                                         }
6576                                 } else if (underlying_type == TypeManager.double_type) {
6577                                         if (!(v is Expression)){
6578                                                 element = BitConverter.GetBytes ((double) v);
6579
6580                                                 for (int j = 0; j < factor; ++j)
6581                                                         data [idx + j] = element [j];
6582                                         }
6583                                 } else if (underlying_type == TypeManager.char_type){
6584                                         if (!(v is Expression)){
6585                                                 int val = (int) ((char) v);
6586
6587                                                 data [idx] = (byte) (val & 0xff);
6588                                                 data [idx+1] = (byte) (val >> 8);
6589                                         }
6590                                 } else if (underlying_type == TypeManager.short_type){
6591                                         if (!(v is Expression)){
6592                                                 int val = (int) ((short) v);
6593
6594                                                 data [idx] = (byte) (val & 0xff);
6595                                                 data [idx+1] = (byte) (val >> 8);
6596                                         }
6597                                 } else if (underlying_type == TypeManager.ushort_type){
6598                                         if (!(v is Expression)){
6599                                                 int val = (int) ((ushort) v);
6600
6601                                                 data [idx] = (byte) (val & 0xff);
6602                                                 data [idx+1] = (byte) (val >> 8);
6603                                         }
6604                                 } else if (underlying_type == TypeManager.int32_type) {
6605                                         if (!(v is Expression)){
6606                                                 int val = (int) v;
6607
6608                                                 data [idx]   = (byte) (val & 0xff);
6609                                                 data [idx+1] = (byte) ((val >> 8) & 0xff);
6610                                                 data [idx+2] = (byte) ((val >> 16) & 0xff);
6611                                                 data [idx+3] = (byte) (val >> 24);
6612                                         }
6613                                 } else if (underlying_type == TypeManager.uint32_type) {
6614                                         if (!(v is Expression)){
6615                                                 uint val = (uint) v;
6616
6617                                                 data [idx]   = (byte) (val & 0xff);
6618                                                 data [idx+1] = (byte) ((val >> 8) & 0xff);
6619                                                 data [idx+2] = (byte) ((val >> 16) & 0xff);
6620                                                 data [idx+3] = (byte) (val >> 24);
6621                                         }
6622                                 } else if (underlying_type == TypeManager.sbyte_type) {
6623                                         if (!(v is Expression)){
6624                                                 sbyte val = (sbyte) v;
6625                                                 data [idx] = (byte) val;
6626                                         }
6627                                 } else if (underlying_type == TypeManager.byte_type) {
6628                                         if (!(v is Expression)){
6629                                                 byte val = (byte) v;
6630                                                 data [idx] = (byte) val;
6631                                         }
6632                                 } else if (underlying_type == TypeManager.bool_type) {
6633                                         if (!(v is Expression)){
6634                                                 bool val = (bool) v;
6635                                                 data [idx] = (byte) (val ? 1 : 0);
6636                                         }
6637                                 } else if (underlying_type == TypeManager.decimal_type){
6638                                         if (!(v is Expression)){
6639                                                 int [] bits = Decimal.GetBits ((decimal) v);
6640                                                 int p = idx;
6641
6642                                                 // FIXME: For some reason, this doesn't work on the MS runtime.
6643                                                 int [] nbits = new int [4];
6644                                                 nbits [0] = bits [3];
6645                                                 nbits [1] = bits [2];
6646                                                 nbits [2] = bits [0];
6647                                                 nbits [3] = bits [1];
6648
6649                                                 for (int j = 0; j < 4; j++){
6650                                                         data [p++] = (byte) (nbits [j] & 0xff);
6651                                                         data [p++] = (byte) ((nbits [j] >> 8) & 0xff);
6652                                                         data [p++] = (byte) ((nbits [j] >> 16) & 0xff);
6653                                                         data [p++] = (byte) (nbits [j] >> 24);
6654                                                 }
6655                                         }
6656                                 } else
6657                                         throw new Exception ("Unrecognized type in MakeByteBlob: " + underlying_type);
6658
6659                                 idx += factor;
6660                         }
6661
6662                         return data;
6663                 }
6664
6665                 //
6666                 // Emits the initializers for the array
6667                 //
6668                 void EmitStaticInitializers (EmitContext ec)
6669                 {
6670                         //
6671                         // First, the static data
6672                         //
6673                         FieldBuilder fb;
6674                         ILGenerator ig = ec.ig;
6675
6676                         byte [] data = MakeByteBlob (array_data, underlying_type, loc);
6677
6678                         fb = RootContext.MakeStaticData (data);
6679
6680                         ig.Emit (OpCodes.Dup);
6681                         ig.Emit (OpCodes.Ldtoken, fb);
6682                         ig.Emit (OpCodes.Call,
6683                                  TypeManager.void_initializearray_array_fieldhandle);
6684                 }
6685
6686                 //
6687                 // Emits pieces of the array that can not be computed at compile
6688                 // time (variables and string locations).
6689                 //
6690                 // This always expect the top value on the stack to be the array
6691                 //
6692                 void EmitDynamicInitializers (EmitContext ec)
6693                 {
6694                         ILGenerator ig = ec.ig;
6695                         int dims = bounds.Count;
6696                         int [] current_pos = new int [dims];
6697                         int top = array_data.Count;
6698
6699                         MethodInfo set = null;
6700
6701                         if (dims != 1){
6702                                 Type [] args;
6703                                 ModuleBuilder mb = null;
6704                                 mb = CodeGen.Module.Builder;
6705                                 args = new Type [dims + 1];
6706
6707                                 int j;
6708                                 for (j = 0; j < dims; j++)
6709                                         args [j] = TypeManager.int32_type;
6710
6711                                 args [j] = array_element_type;
6712
6713                                 set = mb.GetArrayMethod (
6714                                         type, "Set",
6715                                         CallingConventions.HasThis | CallingConventions.Standard,
6716                                         TypeManager.void_type, args);
6717                         }
6718
6719                         for (int i = 0; i < top; i++){
6720
6721                                 Expression e = null;
6722
6723                                 if (array_data [i] is Expression)
6724                                         e = (Expression) array_data [i];
6725
6726                                 if (e != null) {
6727                                         //
6728                                         // Basically we do this for string literals and
6729                                         // other non-literal expressions
6730                                         //
6731                                         if (e is EnumConstant){
6732                                                 e = ((EnumConstant) e).Child;
6733                                         }
6734
6735                                         if (e is StringConstant || e is DecimalConstant || !(e is Constant) ||
6736                                             num_automatic_initializers <= max_automatic_initializers) {
6737                                                 Type etype = e.Type;
6738
6739                                                 ig.Emit (OpCodes.Dup);
6740
6741                                                 for (int idx = 0; idx < dims; idx++)
6742                                                         IntConstant.EmitInt (ig, current_pos [idx]);
6743
6744                                                 //
6745                                                 // If we are dealing with a struct, get the
6746                                                 // address of it, so we can store it.
6747                                                 //
6748                                                 if ((dims == 1) && etype.IsValueType &&
6749                                                     (!TypeManager.IsBuiltinOrEnum (etype) ||
6750                                                      etype == TypeManager.decimal_type)) {
6751                                                         if (e is New){
6752                                                                 New n = (New) e;
6753
6754                                                                 //
6755                                                                 // Let new know that we are providing
6756                                                                 // the address where to store the results
6757                                                                 //
6758                                                                 n.DisableTemporaryValueType ();
6759                                                         }
6760
6761                                                         ig.Emit (OpCodes.Ldelema, etype);
6762                                                 }
6763
6764                                                 e.Emit (ec);
6765
6766                                                 if (dims == 1) {
6767                                                         bool is_stobj, has_type_arg;
6768                                                         OpCode op = ArrayAccess.GetStoreOpcode (
6769                                                                 etype, out is_stobj,
6770                                                                 out has_type_arg);
6771                                                         if (is_stobj)
6772                                                                 ig.Emit (OpCodes.Stobj, etype);
6773                                                         else if (has_type_arg)
6774                                                                 ig.Emit (op, etype);
6775                                                         else
6776                                                                 ig.Emit (op);
6777                                                 } else
6778                                                         ig.Emit (OpCodes.Call, set);
6779                                         }
6780                                 }
6781
6782                                 //
6783                                 // Advance counter
6784                                 //
6785                                 for (int j = dims - 1; j >= 0; j--){
6786                                         current_pos [j]++;
6787                                         if (current_pos [j] < (int) bounds [j])
6788                                                 break;
6789                                         current_pos [j] = 0;
6790                                 }
6791                         }
6792                 }
6793
6794                 void EmitArrayArguments (EmitContext ec)
6795                 {
6796                         ILGenerator ig = ec.ig;
6797
6798                         foreach (Argument a in arguments) {
6799                                 Type atype = a.Type;
6800                                 a.Emit (ec);
6801
6802                                 if (atype == TypeManager.uint64_type)
6803                                         ig.Emit (OpCodes.Conv_Ovf_U4);
6804                                 else if (atype == TypeManager.int64_type)
6805                                         ig.Emit (OpCodes.Conv_Ovf_I4);
6806                         }
6807                 }
6808
6809                 public override void Emit (EmitContext ec)
6810                 {
6811                         ILGenerator ig = ec.ig;
6812
6813                         EmitArrayArguments (ec);
6814                         if (is_one_dimensional)
6815                                 ig.Emit (OpCodes.Newarr, array_element_type);
6816                         else {
6817                                 if (is_builtin_type)
6818                                         ig.Emit (OpCodes.Newobj, (ConstructorInfo) new_method);
6819                                 else
6820                                         ig.Emit (OpCodes.Newobj, (MethodInfo) new_method);
6821                         }
6822
6823                         if (initializers != null){
6824                                 //
6825                                 // FIXME: Set this variable correctly.
6826                                 //
6827                                 bool dynamic_initializers = true;
6828
6829                                 // This will never be true for array types that cannot be statically
6830                                 // initialized. num_automatic_initializers will always be zero.  See
6831                                 // CheckIndices.
6832                                         if (num_automatic_initializers > max_automatic_initializers)
6833                                                 EmitStaticInitializers (ec);
6834
6835                                 if (dynamic_initializers)
6836                                         EmitDynamicInitializers (ec);
6837                         }
6838                 }
6839
6840                 public object EncodeAsAttribute ()
6841                 {
6842                         if (!is_one_dimensional){
6843                                 Report.Error (-211, Location, "attribute can not encode multi-dimensional arrays");
6844                                 return null;
6845                         }
6846
6847                         if (array_data == null){
6848                                 Report.Error (-212, Location, "array should be initialized when passing it to an attribute");
6849                                 return null;
6850                         }
6851
6852                         object [] ret = new object [array_data.Count];
6853                         int i = 0;
6854                         foreach (Expression e in array_data){
6855                                 object v;
6856
6857                                 if (e is NullLiteral)
6858                                         v = null;
6859                                 else {
6860                                         if (!Attribute.GetAttributeArgumentExpression (e, Location, array_element_type, out v))
6861                                                 return null;
6862                                 }
6863                                 ret [i++] = v;
6864                         }
6865                         return ret;
6866                 }
6867         }
6868
6869         /// <summary>
6870         ///   Represents the `this' construct
6871         /// </summary>
6872         public class This : Expression, IAssignMethod, IMemoryLocation, IVariable {
6873
6874                 Block block;
6875                 VariableInfo variable_info;
6876
6877                 public This (Block block, Location loc)
6878                 {
6879                         this.loc = loc;
6880                         this.block = block;
6881                 }
6882
6883                 public This (Location loc)
6884                 {
6885                         this.loc = loc;
6886                 }
6887
6888                 public VariableInfo VariableInfo {
6889                         get { return variable_info; }
6890                 }
6891
6892                 public bool VerifyFixed (bool is_expression)
6893                 {
6894                         if ((variable_info == null) || (variable_info.LocalInfo == null))
6895                                 return false;
6896                         else
6897                                 return variable_info.LocalInfo.IsFixed;
6898                 }
6899
6900                 public bool ResolveBase (EmitContext ec)
6901                 {
6902                         eclass = ExprClass.Variable;
6903
6904                         if (ec.TypeContainer.CurrentType != null)
6905                                 type = ec.TypeContainer.CurrentType;
6906                         else
6907                                 type = ec.ContainerType;
6908
6909                         if (ec.IsStatic) {
6910                                 Error (26, "Keyword this not valid in static code");
6911                                 return false;
6912                         }
6913
6914                         if ((block != null) && (block.ThisVariable != null))
6915                                 variable_info = block.ThisVariable.VariableInfo;
6916
6917                         if (ec.CurrentAnonymousMethod != null)
6918                                 ec.CaptureThis ();
6919
6920                         return true;
6921                 }
6922
6923                 public override Expression DoResolve (EmitContext ec)
6924                 {
6925                         if (!ResolveBase (ec))
6926                                 return null;
6927
6928                         if ((variable_info != null) && !variable_info.IsAssigned (ec)) {
6929                                 Error (188, "The this object cannot be used before all " +
6930                                        "of its fields are assigned to");
6931                                 variable_info.SetAssigned (ec);
6932                                 return this;
6933                         }
6934
6935                         if (ec.IsFieldInitializer) {
6936                                 Error (27, "Keyword `this' can't be used outside a constructor, " +
6937                                        "a method or a property.");
6938                                 return null;
6939                         }
6940
6941                         return this;
6942                 }
6943
6944                 override public Expression DoResolveLValue (EmitContext ec, Expression right_side)
6945                 {
6946                         if (!ResolveBase (ec))
6947                                 return null;
6948
6949                         if (variable_info != null)
6950                                 variable_info.SetAssigned (ec);
6951
6952                         if (ec.TypeContainer is Class){
6953                                 Error (1604, "Cannot assign to `this'");
6954                                 return null;
6955                         }
6956
6957                         return this;
6958                 }
6959
6960                 public void Emit (EmitContext ec, bool leave_copy)
6961                 {
6962                         Emit (ec);
6963                         if (leave_copy)
6964                                 ec.ig.Emit (OpCodes.Dup);
6965                 }
6966
6967                 public void EmitAssign (EmitContext ec, Expression source, bool leave_copy, bool prepare_for_load)
6968                 {
6969                         ILGenerator ig = ec.ig;
6970
6971                         if (ec.TypeContainer is Struct){
6972                                 ec.EmitThis ();
6973                                 source.Emit (ec);
6974                                 if (leave_copy)
6975                                         ec.ig.Emit (OpCodes.Dup);
6976                                 ig.Emit (OpCodes.Stobj, type);
6977                         } else {
6978                                 throw new Exception ("how did you get here");
6979                         }
6980                 }
6981
6982                 public override void Emit (EmitContext ec)
6983                 {
6984                         ILGenerator ig = ec.ig;
6985
6986                         ec.EmitThis ();
6987                         if (ec.TypeContainer is Struct)
6988                                 ig.Emit (OpCodes.Ldobj, type);
6989                 }
6990
6991                 public void AddressOf (EmitContext ec, AddressOp mode)
6992                 {
6993                         ec.EmitThis ();
6994
6995                         // FIMXE
6996                         // FIGURE OUT WHY LDARG_S does not work
6997                         //
6998                         // consider: struct X { int val; int P { set { val = value; }}}
6999                         //
7000                         // Yes, this looks very bad. Look at `NOTAS' for
7001                         // an explanation.
7002                         // ec.ig.Emit (OpCodes.Ldarga_S, (byte) 0);
7003                 }
7004         }
7005
7006         /// <summary>
7007         ///   Represents the `__arglist' construct
7008         /// </summary>
7009         public class ArglistAccess : Expression
7010         {
7011                 public ArglistAccess (Location loc)
7012                 {
7013                         this.loc = loc;
7014                 }
7015
7016                 public bool ResolveBase (EmitContext ec)
7017                 {
7018                         eclass = ExprClass.Variable;
7019                         type = TypeManager.runtime_argument_handle_type;
7020                         return true;
7021                 }
7022
7023                 public override Expression DoResolve (EmitContext ec)
7024                 {
7025                         if (!ResolveBase (ec))
7026                                 return null;
7027
7028                         if (ec.IsFieldInitializer || !ec.CurrentBlock.HasVarargs) {
7029                                 Error (190, "The __arglist construct is valid only within " +
7030                                        "a variable argument method.");
7031                                 return null;
7032                         }
7033
7034                         return this;
7035                 }
7036
7037                 public override void Emit (EmitContext ec)
7038                 {
7039                         ec.ig.Emit (OpCodes.Arglist);
7040                 }
7041         }
7042
7043         /// <summary>
7044         ///   Represents the `__arglist (....)' construct
7045         /// </summary>
7046         public class Arglist : Expression
7047         {
7048                 public readonly Argument[] Arguments;
7049
7050                 public Arglist (Argument[] args, Location l)
7051                 {
7052                         Arguments = args;
7053                         loc = l;
7054                 }
7055
7056                 public Type[] ArgumentTypes {
7057                         get {
7058                                 Type[] retval = new Type [Arguments.Length];
7059                                 for (int i = 0; i < Arguments.Length; i++)
7060                                         retval [i] = Arguments [i].Type;
7061                                 return retval;
7062                         }
7063                 }
7064
7065                 public override Expression DoResolve (EmitContext ec)
7066                 {
7067                         eclass = ExprClass.Variable;
7068                         type = TypeManager.runtime_argument_handle_type;
7069
7070                         foreach (Argument arg in Arguments) {
7071                                 if (!arg.Resolve (ec, loc))
7072                                         return null;
7073                         }
7074
7075                         return this;
7076                 }
7077
7078                 public override void Emit (EmitContext ec)
7079                 {
7080                         foreach (Argument arg in Arguments)
7081                                 arg.Emit (ec);
7082                 }
7083         }
7084
7085         //
7086         // This produces the value that renders an instance, used by the iterators code
7087         //
7088         public class ProxyInstance : Expression, IMemoryLocation  {
7089                 public override Expression DoResolve (EmitContext ec)
7090                 {
7091                         eclass = ExprClass.Variable;
7092                         type = ec.ContainerType;
7093                         return this;
7094                 }
7095
7096                 public override void Emit (EmitContext ec)
7097                 {
7098                         ec.ig.Emit (OpCodes.Ldarg_0);
7099
7100                 }
7101
7102                 public void AddressOf (EmitContext ec, AddressOp mode)
7103                 {
7104                         ec.ig.Emit (OpCodes.Ldarg_0);
7105                 }
7106         }
7107
7108         /// <summary>
7109         ///   Implements the typeof operator
7110         /// </summary>
7111         public class TypeOf : Expression {
7112                 public Expression QueriedType;
7113                 protected Type typearg;
7114
7115                 public TypeOf (Expression queried_type, Location l)
7116                 {
7117                         QueriedType = queried_type;
7118                         loc = l;
7119                 }
7120
7121                 public override Expression DoResolve (EmitContext ec)
7122                 {
7123                         TypeExpr texpr = QueriedType.ResolveAsTypeTerminal (ec);
7124                         if (texpr == null)
7125                                 return null;
7126
7127                         typearg = texpr.Type;
7128
7129                         if (typearg == TypeManager.void_type) {
7130                                 Error (673, "System.Void cannot be used from C# - " +
7131                                        "use typeof (void) to get the void type object");
7132                                 return null;
7133                         }
7134
7135                         if (typearg.IsPointer && !ec.InUnsafe){
7136                                 UnsafeError (loc);
7137                                 return null;
7138                         }
7139                         CheckObsoleteAttribute (typearg);
7140
7141                         type = TypeManager.type_type;
7142                         eclass = ExprClass.Type;
7143                         return this;
7144                 }
7145
7146                 public override void Emit (EmitContext ec)
7147                 {
7148                         ec.ig.Emit (OpCodes.Ldtoken, typearg);
7149                         ec.ig.Emit (OpCodes.Call, TypeManager.system_type_get_type_from_handle);
7150                 }
7151
7152                 public Type TypeArg {
7153                         get { return typearg; }
7154                 }
7155         }
7156
7157         /// <summary>
7158         ///   Implements the `typeof (void)' operator
7159         /// </summary>
7160         public class TypeOfVoid : TypeOf {
7161                 public TypeOfVoid (Location l) : base (null, l)
7162                 {
7163                         loc = l;
7164                 }
7165
7166                 public override Expression DoResolve (EmitContext ec)
7167                 {
7168                         type = TypeManager.type_type;
7169                         typearg = TypeManager.void_type;
7170                         eclass = ExprClass.Type;
7171                         return this;
7172                 }
7173         }
7174
7175         /// <summary>
7176         ///   Implements the sizeof expression
7177         /// </summary>
7178         public class SizeOf : Expression {
7179                 public Expression QueriedType;
7180                 Type type_queried;
7181
7182                 public SizeOf (Expression queried_type, Location l)
7183                 {
7184                         this.QueriedType = queried_type;
7185                         loc = l;
7186                 }
7187
7188                 public override Expression DoResolve (EmitContext ec)
7189                 {
7190                         if (!ec.InUnsafe) {
7191                                 Report.Error (
7192                                         233, loc, "Sizeof may only be used in an unsafe context " +
7193                                         "(consider using System.Runtime.InteropServices.Marshal.SizeOf");
7194                                 return null;
7195                         }
7196
7197                         TypeExpr texpr = QueriedType.ResolveAsTypeTerminal (ec);
7198                         if (texpr == null)
7199                                 return null;
7200
7201                         if (texpr is TypeParameterExpr){
7202                                 ((TypeParameterExpr)texpr).Error_CannotUseAsUnmanagedType (loc);
7203                                 return null;
7204                         }
7205
7206                         type_queried = texpr.Type;
7207
7208                         CheckObsoleteAttribute (type_queried);
7209
7210                         if (!TypeManager.IsUnmanagedType (type_queried)){
7211                                 Report.Error (208, loc, "Cannot take the size of an unmanaged type (" + TypeManager.CSharpName (type_queried) + ")");
7212                                 return null;
7213                         }
7214
7215                         type = TypeManager.int32_type;
7216                         eclass = ExprClass.Value;
7217                         return this;
7218                 }
7219
7220                 public override void Emit (EmitContext ec)
7221                 {
7222                         int size = GetTypeSize (type_queried);
7223
7224                         if (size == 0)
7225                                 ec.ig.Emit (OpCodes.Sizeof, type_queried);
7226                         else
7227                                 IntConstant.EmitInt (ec.ig, size);
7228                 }
7229         }
7230
7231         /// <summary>
7232         ///   Implements the member access expression
7233         /// </summary>
7234         public class MemberAccess : Expression {
7235                 public string Identifier;
7236                 protected Expression expr;
7237                 protected TypeArguments args;
7238
7239                 public MemberAccess (Expression expr, string id, Location l)
7240                 {
7241                         this.expr = expr;
7242                         Identifier = id;
7243                         loc = l;
7244                 }
7245
7246                 public MemberAccess (Expression expr, string id, TypeArguments args,
7247                                      Location l)
7248                         : this (expr, id, l)
7249                 {
7250                         this.args = args;
7251                 }
7252
7253                 public Expression Expr {
7254                         get {
7255                                 return expr;
7256                         }
7257                 }
7258
7259                 public static void error176 (Location loc, string name)
7260                 {
7261                         Report.Error (176, loc, "Static member `" +
7262                                       name + "' cannot be accessed " +
7263                                       "with an instance reference, qualify with a " +
7264                                       "type name instead");
7265                 }
7266
7267                 public static bool IdenticalNameAndTypeName (EmitContext ec, Expression left_original, Expression left, Location loc)
7268                 {
7269                         SimpleName sn = left_original as SimpleName;
7270                         if (sn == null || left == null || left.Type.Name != sn.Name)
7271                                 return false;
7272
7273                         return ec.DeclSpace.LookupType (sn.Name, true, loc) != null;
7274                 }
7275
7276                 // TODO: possible optimalization
7277                 // Cache resolved constant result in FieldBuilder <-> expresion map
7278                 public static Expression ResolveMemberAccess (EmitContext ec, Expression member_lookup,
7279                                                               Expression left, Location loc,
7280                                                               Expression left_original)
7281                 {
7282                         bool left_is_type, left_is_explicit;
7283
7284                         // If `left' is null, then we're called from SimpleNameResolve and this is
7285                         // a member in the currently defining class.
7286                         if (left == null) {
7287                                 left_is_type = ec.IsStatic || ec.IsFieldInitializer;
7288                                 left_is_explicit = false;
7289
7290                                 // Implicitly default to `this' unless we're static.
7291                                 if (!ec.IsStatic && !ec.IsFieldInitializer && !ec.InEnumContext)
7292                                         left = ec.GetThis (loc);
7293                         } else {
7294                                 left_is_type = left is TypeExpr;
7295                                 left_is_explicit = true;
7296                         }
7297
7298                         if (member_lookup is FieldExpr){
7299                                 FieldExpr fe = (FieldExpr) member_lookup;
7300                                 FieldInfo fi = fe.FieldInfo.Mono_GetGenericFieldDefinition ();
7301                                 Type decl_type = fi.DeclaringType;
7302
7303                                 bool is_emitted = fi is FieldBuilder;
7304                                 Type t = fi.FieldType;
7305
7306                                 if (is_emitted) {
7307                                         Const c = TypeManager.LookupConstant ((FieldBuilder) fi);
7308
7309                                         if (c != null) {
7310                                                 object o;
7311                                                 if (!c.LookupConstantValue (out o))
7312                                                         return null;
7313
7314                                                 object real_value = ((Constant) c.Expr).GetValue ();
7315
7316                                                 Expression exp = Constantify (real_value, t);
7317
7318                                                 if (left_is_explicit && !left_is_type && !IdenticalNameAndTypeName (ec, left_original, left, loc)) {
7319                                                         Report.SymbolRelatedToPreviousError (c);
7320                                                         error176 (loc, c.GetSignatureForError ());
7321                                                         return null;
7322                                                 }
7323
7324                                                 return exp;
7325                                         }
7326                                 }
7327
7328                                 // IsInitOnly is because of MS compatibility, I don't know why but they emit decimal constant as InitOnly
7329                                 if (fi.IsInitOnly && !is_emitted && t == TypeManager.decimal_type) {
7330                                         object[] attrs = fi.GetCustomAttributes (TypeManager.decimal_constant_attribute_type, false);
7331                                         if (attrs.Length == 1)
7332                                                 return new DecimalConstant (((System.Runtime.CompilerServices.DecimalConstantAttribute) attrs [0]).Value);
7333                                 }
7334
7335                                 if (fi.IsLiteral) {
7336                                         object o;
7337
7338                                         if (is_emitted)
7339                                                 o = TypeManager.GetValue ((FieldBuilder) fi);
7340                                         else
7341                                                 o = fi.GetValue (fi);
7342
7343                                         if (decl_type.IsSubclassOf (TypeManager.enum_type)) {
7344                                                 if (left_is_explicit && !left_is_type &&
7345                                                     !IdenticalNameAndTypeName (ec, left_original, member_lookup, loc)) {
7346                                                         error176 (loc, fe.FieldInfo.Name);
7347                                                         return null;
7348                                                 }
7349
7350                                                 Expression enum_member = MemberLookup (
7351                                                         ec, decl_type, "value__", MemberTypes.Field,
7352                                                         AllBindingFlags, loc);
7353
7354                                                 Enum en = TypeManager.LookupEnum (decl_type);
7355
7356                                                 Constant c;
7357                                                 if (en != null)
7358                                                         c = Constantify (o, en.UnderlyingType);
7359                                                 else
7360                                                         c = Constantify (o, enum_member.Type);
7361
7362                                                 return new EnumConstant (c, decl_type);
7363                                         }
7364
7365                                         Expression exp = Constantify (o, t);
7366
7367                                         if (left_is_explicit && !left_is_type) {
7368                                                 error176 (loc, fe.FieldInfo.Name);
7369                                                 return null;
7370                                         }
7371
7372                                         return exp;
7373                                 }
7374
7375                                 if (t.IsPointer && !ec.InUnsafe){
7376                                         UnsafeError (loc);
7377                                         return null;
7378                                 }
7379                         }
7380
7381                         if (member_lookup is EventExpr) {
7382                                 EventExpr ee = (EventExpr) member_lookup;
7383
7384                                 //
7385                                 // If the event is local to this class, we transform ourselves into
7386                                 // a FieldExpr
7387                                 //
7388
7389                                 if (ee.EventInfo.DeclaringType == ec.ContainerType ||
7390                                     TypeManager.IsNestedChildOf(ec.ContainerType, ee.EventInfo.DeclaringType)) {
7391                                         MemberInfo mi = GetFieldFromEvent (ee);
7392
7393                                         if (mi == null) {
7394                                                 //
7395                                                 // If this happens, then we have an event with its own
7396                                                 // accessors and private field etc so there's no need
7397                                                 // to transform ourselves.
7398                                                 //
7399                                                 ee.InstanceExpression = left;
7400                                                 return ee;
7401                                         }
7402
7403                                         Expression ml = ExprClassFromMemberInfo (ec, mi, loc);
7404
7405                                         if (ml == null) {
7406                                                 Report.Error (-200, loc, "Internal error!!");
7407                                                 return null;
7408                                         }
7409
7410                                         if (!left_is_explicit)
7411                                                 left = null;
7412
7413                                         ee.InstanceExpression = left;
7414
7415                                         return ResolveMemberAccess (ec, ml, left, loc, left_original);
7416                                 }
7417                         }
7418
7419                         if (member_lookup is IMemberExpr) {
7420                                 IMemberExpr me = (IMemberExpr) member_lookup;
7421                                 MethodGroupExpr mg = me as MethodGroupExpr;
7422
7423                                 if (left_is_type){
7424                                         if ((mg != null) && left_is_explicit && left.Type.IsInterface)
7425                                                 mg.IsExplicitImpl = left_is_explicit;
7426
7427                                         if (!me.IsStatic){
7428                                                 if ((ec.IsFieldInitializer || ec.IsStatic) &&
7429                                                     IdenticalNameAndTypeName (ec, left_original, member_lookup, loc))
7430                                                         return member_lookup;
7431
7432                                                 SimpleName.Error_ObjectRefRequired (ec, loc, me.Name);
7433                                                 return null;
7434                                         }
7435
7436                                 } else {
7437                                         if (!me.IsInstance){
7438                                                 if (IdenticalNameAndTypeName (ec, left_original, left, loc))
7439                                                         return member_lookup;
7440
7441                                                 if (left_is_explicit) {
7442                                                         error176 (loc, me.Name);
7443                                                         return null;
7444                                                 }
7445                                         }
7446
7447                                         //
7448                                         // Since we can not check for instance objects in SimpleName,
7449                                         // becaue of the rule that allows types and variables to share
7450                                         // the name (as long as they can be de-ambiguated later, see
7451                                         // IdenticalNameAndTypeName), we have to check whether left
7452                                         // is an instance variable in a static context
7453                                         //
7454                                         // However, if the left-hand value is explicitly given, then
7455                                         // it is already our instance expression, so we aren't in
7456                                         // static context.
7457                                         //
7458
7459                                         if (ec.IsStatic && !left_is_explicit && left is IMemberExpr){
7460                                                 IMemberExpr mexp = (IMemberExpr) left;
7461
7462                                                 if (!mexp.IsStatic){
7463                                                         SimpleName.Error_ObjectRefRequired (ec, loc, mexp.Name);
7464                                                         return null;
7465                                                 }
7466                                         }
7467
7468                                         if ((mg != null) && IdenticalNameAndTypeName (ec, left_original, left, loc))
7469                                                 mg.IdenticalTypeName = true;
7470
7471                                         me.InstanceExpression = left;
7472                                 }
7473
7474                                 return member_lookup;
7475                         }
7476
7477                         Console.WriteLine ("Left is: " + left);
7478                         Report.Error (-100, loc, "Support for [" + member_lookup + "] is not present yet");
7479                         Environment.Exit (1);
7480                         return null;
7481                 }
7482
7483                 public virtual Expression DoResolve (EmitContext ec, Expression right_side,
7484                                                      ResolveFlags flags)
7485                 {
7486                         if (type != null)
7487                                 throw new Exception ();
7488
7489                         //
7490                         // Resolve the expression with flow analysis turned off, we'll do the definite
7491                         // assignment checks later.  This is because we don't know yet what the expression
7492                         // will resolve to - it may resolve to a FieldExpr and in this case we must do the
7493                         // definite assignment check on the actual field and not on the whole struct.
7494                         //
7495
7496                         Expression original = expr;
7497                         expr = expr.Resolve (ec, flags | ResolveFlags.Intermediate | ResolveFlags.DisableFlowAnalysis);
7498                         if (expr == null)
7499                                 return null;
7500
7501                         if (expr is Namespace) {
7502                                 Namespace ns = (Namespace) expr;
7503                                 string lookup_id = MemberName.MakeName (Identifier, args);
7504                                 FullNamedExpression retval = ns.Lookup (ec.DeclSpace, lookup_id, loc);
7505                                 if ((retval != null) && (args != null))
7506                                         retval = new ConstructedType (retval, args, loc).ResolveAsTypeStep (ec);
7507                                 if (retval == null)
7508                                         Report.Error (234, loc, "The type or namespace name `{0}' could not be found in namespace `{1}'", Identifier, ns.FullName);
7509                                 return retval;
7510                         }
7511
7512                         //
7513                         // TODO: I mailed Ravi about this, and apparently we can get rid
7514                         // of this and put it in the right place.
7515                         //
7516                         // Handle enums here when they are in transit.
7517                         // Note that we cannot afford to hit MemberLookup in this case because
7518                         // it will fail to find any members at all
7519                         //
7520
7521                         Type expr_type;
7522                         if (expr is TypeExpr){
7523                                 expr_type = expr.Type;
7524
7525                                 if (!ec.DeclSpace.CheckAccessLevel (expr_type)){
7526                                         Report.Error (122, loc, "'{0}' is inaccessible due to its protection level", expr_type);
7527                                         return null;
7528                                 }
7529
7530                                 if (expr_type == TypeManager.enum_type || expr_type.IsSubclassOf (TypeManager.enum_type)){
7531                                         Enum en = TypeManager.LookupEnum (expr_type);
7532
7533                                         if (en != null) {
7534                                                 object value = en.LookupEnumValue (ec, Identifier, loc);
7535
7536                                                 if (value != null){
7537                                                         MemberCore mc = en.GetDefinition (Identifier);
7538                                                         ObsoleteAttribute oa = mc.GetObsoleteAttribute (en);
7539                                                         if (oa != null) {
7540                                                                 AttributeTester.Report_ObsoleteMessage (oa, mc.GetSignatureForError (), Location);
7541                                                         }
7542                                                         oa = en.GetObsoleteAttribute (en);
7543                                                         if (oa != null) {
7544                                                                 AttributeTester.Report_ObsoleteMessage (oa, en.GetSignatureForError (), Location);
7545                                                         }
7546
7547                                                         Constant c = Constantify (value, en.UnderlyingType);
7548                                                         return new EnumConstant (c, expr_type);
7549                                                 }
7550                                         } else {
7551                                                 CheckObsoleteAttribute (expr_type);
7552
7553                                                 FieldInfo fi = expr_type.GetField (Identifier);
7554                                                 if (fi != null) {
7555                                                         ObsoleteAttribute oa = AttributeTester.GetMemberObsoleteAttribute (fi);
7556                                                         if (oa != null)
7557                                                                 AttributeTester.Report_ObsoleteMessage (oa, TypeManager.GetFullNameSignature (fi), Location);
7558                                                 }
7559                                         }
7560                                 }
7561                         } else
7562                                 expr_type = expr.Type;
7563
7564                         if (expr_type.IsPointer){
7565                                 Error (23, "The `.' operator can not be applied to pointer operands (" +
7566                                        TypeManager.CSharpName (expr_type) + ")");
7567                                 return null;
7568                         }
7569
7570                         Expression member_lookup;
7571                         member_lookup = MemberLookup (
7572                                 ec, expr_type, expr_type, Identifier, loc);
7573                         if ((member_lookup == null) && (args != null)) {
7574                                 string lookup_id = MemberName.MakeName (Identifier, args);
7575                                 member_lookup = MemberLookup (
7576                                         ec, expr_type, expr_type, lookup_id, loc);
7577                         }
7578                         if (member_lookup == null) {
7579                                 MemberLookupFailed (
7580                                         ec, expr_type, expr_type, Identifier, null, loc);
7581                                 return null;
7582                         }
7583
7584                         if (member_lookup is TypeExpr) {
7585                                 if (!(expr is TypeExpr) &&
7586                                     !IdenticalNameAndTypeName (ec, original, expr, loc)) {
7587                                         Error (572, "Can't reference type `" + Identifier + "' through an expression; try `" +
7588                                                member_lookup.Type + "' instead");
7589                                         return null;
7590                                 }
7591
7592                                 return member_lookup;
7593                         }
7594
7595                         if (args != null) {
7596                                 string full_name = expr_type + "." + Identifier;
7597
7598                                 if (member_lookup is FieldExpr) {
7599                                         Report.Error (307, loc, "The field `{0}' cannot " +
7600                                                       "be used with type arguments", full_name);
7601                                         return null;
7602                                 } else if (member_lookup is EventExpr) {
7603                                         Report.Error (307, loc, "The event `{0}' cannot " +
7604                                                       "be used with type arguments", full_name);
7605                                         return null;
7606                                 } else if (member_lookup is PropertyExpr) {
7607                                         Report.Error (307, loc, "The property `{0}' cannot " +
7608                                                       "be used with type arguments", full_name);
7609                                         return null;
7610                                 }
7611                         }
7612
7613                         member_lookup = ResolveMemberAccess (ec, member_lookup, expr, loc, original);
7614                         if (member_lookup == null)
7615                                 return null;
7616
7617                         if (args != null) {
7618                                 MethodGroupExpr mg = member_lookup as MethodGroupExpr;
7619                                 if (mg == null)
7620                                         throw new InternalErrorException ();
7621
7622                                 return mg.ResolveGeneric (ec, args);
7623                         }
7624
7625                         // The following DoResolve/DoResolveLValue will do the definite assignment
7626                         // check.
7627
7628                         if (right_side != null)
7629                                 member_lookup = member_lookup.DoResolveLValue (ec, right_side);
7630                         else
7631                                 member_lookup = member_lookup.DoResolve (ec);
7632
7633                         return member_lookup;
7634                 }
7635
7636                 public override Expression DoResolve (EmitContext ec)
7637                 {
7638                         return DoResolve (ec, null, ResolveFlags.VariableOrValue | ResolveFlags.Type);
7639                 }
7640
7641                 public override Expression DoResolveLValue (EmitContext ec, Expression right_side)
7642                 {
7643                         return DoResolve (ec, right_side, ResolveFlags.VariableOrValue | ResolveFlags.Type);
7644                 }
7645
7646                 public override FullNamedExpression ResolveAsTypeStep (EmitContext ec)
7647                 {
7648                         return ResolveNamespaceOrType (ec, false);
7649                 }
7650
7651                 public FullNamedExpression ResolveNamespaceOrType (EmitContext ec, bool silent)
7652                 {
7653                         FullNamedExpression new_expr = expr.ResolveAsTypeStep (ec);
7654
7655                         if (new_expr == null)
7656                                 return null;
7657
7658                         string lookup_id = MemberName.MakeName (Identifier, args);
7659
7660                         if (new_expr is Namespace) {
7661                                 Namespace ns = (Namespace) new_expr;
7662                                 FullNamedExpression retval = ns.Lookup (ec.DeclSpace, lookup_id, loc);
7663                                 if ((retval != null) && (args != null))
7664                                         retval = new ConstructedType (retval, args, loc).ResolveAsTypeStep (ec);
7665                                 if (!silent && retval == null)
7666                                         Report.Error (234, loc, "The type or namespace name `{0}' could not be found in namespace `{1}'", Identifier, ns.FullName);
7667                                 return retval;
7668                         }
7669
7670                         TypeExpr tnew_expr = new_expr.ResolveAsTypeTerminal (ec);
7671                         if (tnew_expr == null)
7672                                 return null;
7673
7674                         Type expr_type = tnew_expr.Type;
7675
7676                         if (expr_type.IsPointer){
7677                                 Error (23, "The `.' operator can not be applied to pointer operands (" +
7678                                        TypeManager.CSharpName (expr_type) + ")");
7679                                 return null;
7680                         }
7681
7682                         Expression member_lookup;
7683                         member_lookup = MemberLookupFinal (ec, expr_type, expr_type, lookup_id, loc);
7684                         if (!silent && member_lookup == null) {
7685                                 Report.Error (234, loc, "The type name `{0}' could not be found in type `{1}'",
7686                                               Identifier, new_expr.FullName);
7687                                 return null;
7688                         }
7689
7690                         if (!(member_lookup is TypeExpr)) {
7691                                 Report.Error (118, loc, "'{0}.{1}' denotes a '{2}', where a type was expected",
7692                                               new_expr.FullName, Identifier, member_lookup.ExprClassName ());
7693                                 return null;
7694                         }
7695
7696                         TypeExpr texpr = member_lookup.ResolveAsTypeTerminal (ec);
7697                         if (texpr == null)
7698                                 return null;
7699
7700                         TypeArguments the_args = args;
7701                         if (TypeManager.HasGenericArguments (expr_type)) {
7702                                 Type[] decl_args = TypeManager.GetTypeArguments (expr_type);
7703
7704                                 TypeArguments new_args = new TypeArguments (loc);
7705                                 foreach (Type decl in decl_args)
7706                                         new_args.Add (new TypeExpression (decl, loc));
7707
7708                                 if (args != null)
7709                                         new_args.Add (args);
7710
7711                                 the_args = new_args;
7712                         }
7713
7714                         if (the_args != null) {
7715                                 ConstructedType ctype = new ConstructedType (texpr.Type, the_args, loc);
7716                                 return ctype.ResolveAsTypeStep (ec);
7717                         }
7718
7719                         return texpr;
7720                 }
7721
7722                 public override void Emit (EmitContext ec)
7723                 {
7724                         throw new Exception ("Should not happen");
7725                 }
7726
7727                 public override string ToString ()
7728                 {
7729                         return expr + "." + MemberName.MakeName (Identifier, args);
7730                 }
7731         }
7732
7733         /// <summary>
7734         ///   Implements checked expressions
7735         /// </summary>
7736         public class CheckedExpr : Expression {
7737
7738                 public Expression Expr;
7739
7740                 public CheckedExpr (Expression e, Location l)
7741                 {
7742                         Expr = e;
7743                         loc = l;
7744                 }
7745
7746                 public override Expression DoResolve (EmitContext ec)
7747                 {
7748                         bool last_check = ec.CheckState;
7749                         bool last_const_check = ec.ConstantCheckState;
7750
7751                         ec.CheckState = true;
7752                         ec.ConstantCheckState = true;
7753                         Expr = Expr.Resolve (ec);
7754                         ec.CheckState = last_check;
7755                         ec.ConstantCheckState = last_const_check;
7756
7757                         if (Expr == null)
7758                                 return null;
7759
7760                         if (Expr is Constant)
7761                                 return Expr;
7762
7763                         eclass = Expr.eclass;
7764                         type = Expr.Type;
7765                         return this;
7766                 }
7767
7768                 public override void Emit (EmitContext ec)
7769                 {
7770                         bool last_check = ec.CheckState;
7771                         bool last_const_check = ec.ConstantCheckState;
7772
7773                         ec.CheckState = true;
7774                         ec.ConstantCheckState = true;
7775                         Expr.Emit (ec);
7776                         ec.CheckState = last_check;
7777                         ec.ConstantCheckState = last_const_check;
7778                 }
7779
7780         }
7781
7782         /// <summary>
7783         ///   Implements the unchecked expression
7784         /// </summary>
7785         public class UnCheckedExpr : Expression {
7786
7787                 public Expression Expr;
7788
7789                 public UnCheckedExpr (Expression e, Location l)
7790                 {
7791                         Expr = e;
7792                         loc = l;
7793                 }
7794
7795                 public override Expression DoResolve (EmitContext ec)
7796                 {
7797                         bool last_check = ec.CheckState;
7798                         bool last_const_check = ec.ConstantCheckState;
7799
7800                         ec.CheckState = false;
7801                         ec.ConstantCheckState = false;
7802                         Expr = Expr.Resolve (ec);
7803                         ec.CheckState = last_check;
7804                         ec.ConstantCheckState = last_const_check;
7805
7806                         if (Expr == null)
7807                                 return null;
7808
7809                         if (Expr is Constant)
7810                                 return Expr;
7811
7812                         eclass = Expr.eclass;
7813                         type = Expr.Type;
7814                         return this;
7815                 }
7816
7817                 public override void Emit (EmitContext ec)
7818                 {
7819                         bool last_check = ec.CheckState;
7820                         bool last_const_check = ec.ConstantCheckState;
7821
7822                         ec.CheckState = false;
7823                         ec.ConstantCheckState = false;
7824                         Expr.Emit (ec);
7825                         ec.CheckState = last_check;
7826                         ec.ConstantCheckState = last_const_check;
7827                 }
7828
7829         }
7830
7831         /// <summary>
7832         ///   An Element Access expression.
7833         ///
7834         ///   During semantic analysis these are transformed into
7835         ///   IndexerAccess, ArrayAccess or a PointerArithmetic.
7836         /// </summary>
7837         public class ElementAccess : Expression {
7838                 public ArrayList  Arguments;
7839                 public Expression Expr;
7840
7841                 public ElementAccess (Expression e, ArrayList e_list, Location l)
7842                 {
7843                         Expr = e;
7844
7845                         loc  = l;
7846
7847                         if (e_list == null)
7848                                 return;
7849
7850                         Arguments = new ArrayList ();
7851                         foreach (Expression tmp in e_list)
7852                                 Arguments.Add (new Argument (tmp, Argument.AType.Expression));
7853
7854                 }
7855
7856                 bool CommonResolve (EmitContext ec)
7857                 {
7858                         Expr = Expr.Resolve (ec);
7859
7860                         if (Expr == null)
7861                                 return false;
7862
7863                         if (Arguments == null)
7864                                 return false;
7865
7866                         foreach (Argument a in Arguments){
7867                                 if (!a.Resolve (ec, loc))
7868                                         return false;
7869                         }
7870
7871                         return true;
7872                 }
7873
7874                 Expression MakePointerAccess (EmitContext ec, Type t)
7875                 {
7876                         if (t == TypeManager.void_ptr_type){
7877                                 Error (242, "The array index operation is not valid for void pointers");
7878                                 return null;
7879                         }
7880                         if (Arguments.Count != 1){
7881                                 Error (196, "A pointer must be indexed by a single value");
7882                                 return null;
7883                         }
7884                         Expression p;
7885
7886                         p = new PointerArithmetic (true, Expr, ((Argument)Arguments [0]).Expr, t, loc).Resolve (ec);
7887                         if (p == null)
7888                                 return null;
7889                         return new Indirection (p, loc).Resolve (ec);
7890                 }
7891
7892                 public override Expression DoResolve (EmitContext ec)
7893                 {
7894                         if (!CommonResolve (ec))
7895                                 return null;
7896
7897                         //
7898                         // We perform some simple tests, and then to "split" the emit and store
7899                         // code we create an instance of a different class, and return that.
7900                         //
7901                         // I am experimenting with this pattern.
7902                         //
7903                         Type t = Expr.Type;
7904
7905                         if (t == TypeManager.array_type){
7906                                 Report.Error (21, loc, "Cannot use indexer on System.Array");
7907                                 return null;
7908                         }
7909
7910                         if (t.IsArray)
7911                                 return (new ArrayAccess (this, loc)).Resolve (ec);
7912                         if (t.IsPointer)
7913                                 return MakePointerAccess (ec, Expr.Type);
7914
7915                         FieldExpr fe = Expr as FieldExpr;
7916                         if (fe != null) {
7917                                 IFixedBuffer ff = AttributeTester.GetFixedBuffer (fe.FieldInfo);
7918                                 if (ff != null) {
7919                                         return MakePointerAccess (ec, ff.ElementType);
7920                                 }
7921                         }
7922                         return (new IndexerAccess (this, loc)).Resolve (ec);
7923                 }
7924
7925                 public override Expression DoResolveLValue (EmitContext ec, Expression right_side)
7926                 {
7927                         if (!CommonResolve (ec))
7928                                 return null;
7929
7930                         Type t = Expr.Type;
7931                         if (t.IsArray)
7932                                 return (new ArrayAccess (this, loc)).ResolveLValue (ec, right_side);
7933
7934                         if (t.IsPointer)
7935                                 return MakePointerAccess (ec, Expr.Type);
7936
7937                         FieldExpr fe = Expr as FieldExpr;
7938                         if (fe != null) {
7939                                 IFixedBuffer ff = AttributeTester.GetFixedBuffer (fe.FieldInfo);
7940                                 if (ff != null) {
7941 // TODO: not sure whether it is correct
7942 //                                      if (!ec.InFixedInitializer) {
7943 //                                      if (!ec.InFixedInitializer) {
7944 //                                              Error (1666, "You cannot use fixed sized buffers contained in unfixed expressions. Try using the fixed statement.");
7945 //                                              return null;
7946 //                                      }
7947                                         return MakePointerAccess (ec, ff.ElementType);
7948                                 }
7949                         }
7950                         return (new IndexerAccess (this, loc)).ResolveLValue (ec, right_side);
7951                 }
7952
7953                 public override void Emit (EmitContext ec)
7954                 {
7955                         throw new Exception ("Should never be reached");
7956                 }
7957         }
7958
7959         /// <summary>
7960         ///   Implements array access
7961         /// </summary>
7962         public class ArrayAccess : Expression, IAssignMethod, IMemoryLocation {
7963                 //
7964                 // Points to our "data" repository
7965                 //
7966                 ElementAccess ea;
7967
7968                 LocalTemporary temp;
7969                 bool prepared;
7970
7971                 public ArrayAccess (ElementAccess ea_data, Location l)
7972                 {
7973                         ea = ea_data;
7974                         eclass = ExprClass.Variable;
7975                         loc = l;
7976                 }
7977
7978                 public override Expression DoResolve (EmitContext ec)
7979                 {
7980 #if false
7981                         ExprClass eclass = ea.Expr.eclass;
7982
7983                         // As long as the type is valid
7984                         if (!(eclass == ExprClass.Variable || eclass == ExprClass.PropertyAccess ||
7985                               eclass == ExprClass.Value)) {
7986                                 ea.Expr.Error_UnexpectedKind ("variable or value");
7987                                 return null;
7988                         }
7989 #endif
7990
7991                         Type t = ea.Expr.Type;
7992                         if (t.GetArrayRank () != ea.Arguments.Count){
7993                                 ea.Error (22,
7994                                           "Incorrect number of indexes for array " +
7995                                           " expected: " + t.GetArrayRank () + " got: " +
7996                                           ea.Arguments.Count);
7997                                 return null;
7998                         }
7999
8000                         type = TypeManager.GetElementType (t);
8001                         if (type.IsPointer && !ec.InUnsafe){
8002                                 UnsafeError (ea.Location);
8003                                 return null;
8004                         }
8005
8006                         foreach (Argument a in ea.Arguments){
8007                                 Type argtype = a.Type;
8008
8009                                 if (argtype == TypeManager.int32_type ||
8010                                     argtype == TypeManager.uint32_type ||
8011                                     argtype == TypeManager.int64_type ||
8012                                     argtype == TypeManager.uint64_type) {
8013                                         Constant c = a.Expr as Constant;
8014                                         if (c != null && c.IsNegative) {
8015                                                 Report.Warning (251, 2, a.Expr.Location, "Indexing an array with a negative index (array indices always start at zero)");
8016                                         }
8017                                         continue;
8018                                 }
8019
8020                                 //
8021                                 // Mhm.  This is strage, because the Argument.Type is not the same as
8022                                 // Argument.Expr.Type: the value changes depending on the ref/out setting.
8023                                 //
8024                                 // Wonder if I will run into trouble for this.
8025                                 //
8026                                 a.Expr = ExpressionToArrayArgument (ec, a.Expr, ea.Location);
8027                                 if (a.Expr == null)
8028                                         return null;
8029                         }
8030
8031                         eclass = ExprClass.Variable;
8032
8033                         return this;
8034                 }
8035
8036                 /// <summary>
8037                 ///    Emits the right opcode to load an object of Type `t'
8038                 ///    from an array of T
8039                 /// </summary>
8040                 static public void EmitLoadOpcode (ILGenerator ig, Type type)
8041                 {
8042                         if (type == TypeManager.byte_type || type == TypeManager.bool_type)
8043                                 ig.Emit (OpCodes.Ldelem_U1);
8044                         else if (type == TypeManager.sbyte_type)
8045                                 ig.Emit (OpCodes.Ldelem_I1);
8046                         else if (type == TypeManager.short_type)
8047                                 ig.Emit (OpCodes.Ldelem_I2);
8048                         else if (type == TypeManager.ushort_type || type == TypeManager.char_type)
8049                                 ig.Emit (OpCodes.Ldelem_U2);
8050                         else if (type == TypeManager.int32_type)
8051                                 ig.Emit (OpCodes.Ldelem_I4);
8052                         else if (type == TypeManager.uint32_type)
8053                                 ig.Emit (OpCodes.Ldelem_U4);
8054                         else if (type == TypeManager.uint64_type)
8055                                 ig.Emit (OpCodes.Ldelem_I8);
8056                         else if (type == TypeManager.int64_type)
8057                                 ig.Emit (OpCodes.Ldelem_I8);
8058                         else if (type == TypeManager.float_type)
8059                                 ig.Emit (OpCodes.Ldelem_R4);
8060                         else if (type == TypeManager.double_type)
8061                                 ig.Emit (OpCodes.Ldelem_R8);
8062                         else if (type == TypeManager.intptr_type)
8063                                 ig.Emit (OpCodes.Ldelem_I);
8064                         else if (TypeManager.IsEnumType (type)){
8065                                 EmitLoadOpcode (ig, TypeManager.EnumToUnderlying (type));
8066                         } else if (type.IsValueType){
8067                                 ig.Emit (OpCodes.Ldelema, type);
8068                                 ig.Emit (OpCodes.Ldobj, type);
8069                         } else if (type.IsGenericParameter)
8070                                 ig.Emit (OpCodes.Ldelem_Any, type);
8071                         else
8072                                 ig.Emit (OpCodes.Ldelem_Ref);
8073                 }
8074
8075                 /// <summary>
8076                 ///    Returns the right opcode to store an object of Type `t'
8077                 ///    from an array of T.
8078                 /// </summary>
8079                 static public OpCode GetStoreOpcode (Type t, out bool is_stobj, out bool has_type_arg)
8080                 {
8081                         //Console.WriteLine (new System.Diagnostics.StackTrace ());
8082                         has_type_arg = false; is_stobj = false;
8083                         t = TypeManager.TypeToCoreType (t);
8084                         if (TypeManager.IsEnumType (t))
8085                                 t = TypeManager.EnumToUnderlying (t);
8086                         if (t == TypeManager.byte_type || t == TypeManager.sbyte_type ||
8087                             t == TypeManager.bool_type)
8088                                 return OpCodes.Stelem_I1;
8089                         else if (t == TypeManager.short_type || t == TypeManager.ushort_type ||
8090                                  t == TypeManager.char_type)
8091                                 return OpCodes.Stelem_I2;
8092                         else if (t == TypeManager.int32_type || t == TypeManager.uint32_type)
8093                                 return OpCodes.Stelem_I4;
8094                         else if (t == TypeManager.int64_type || t == TypeManager.uint64_type)
8095                                 return OpCodes.Stelem_I8;
8096                         else if (t == TypeManager.float_type)
8097                                 return OpCodes.Stelem_R4;
8098                         else if (t == TypeManager.double_type)
8099                                 return OpCodes.Stelem_R8;
8100                         else if (t == TypeManager.intptr_type) {
8101                                 has_type_arg = true;
8102                                 is_stobj = true;
8103                                 return OpCodes.Stobj;
8104                         } else if (t.IsValueType) {
8105                                 has_type_arg = true;
8106                                 is_stobj = true;
8107                                 return OpCodes.Stobj;
8108                         } else if (t.IsGenericParameter) {
8109                                 has_type_arg = true;
8110                                 return OpCodes.Stelem_Any;
8111                         } else
8112                                 return OpCodes.Stelem_Ref;
8113                 }
8114
8115                 MethodInfo FetchGetMethod ()
8116                 {
8117                         ModuleBuilder mb = CodeGen.Module.Builder;
8118                         int arg_count = ea.Arguments.Count;
8119                         Type [] args = new Type [arg_count];
8120                         MethodInfo get;
8121
8122                         for (int i = 0; i < arg_count; i++){
8123                                 //args [i++] = a.Type;
8124                                 args [i] = TypeManager.int32_type;
8125                         }
8126
8127                         get = mb.GetArrayMethod (
8128                                 ea.Expr.Type, "Get",
8129                                 CallingConventions.HasThis |
8130                                 CallingConventions.Standard,
8131                                 type, args);
8132                         return get;
8133                 }
8134
8135
8136                 MethodInfo FetchAddressMethod ()
8137                 {
8138                         ModuleBuilder mb = CodeGen.Module.Builder;
8139                         int arg_count = ea.Arguments.Count;
8140                         Type [] args = new Type [arg_count];
8141                         MethodInfo address;
8142                         Type ret_type;
8143
8144                         ret_type = TypeManager.GetReferenceType (type);
8145
8146                         for (int i = 0; i < arg_count; i++){
8147                                 //args [i++] = a.Type;
8148                                 args [i] = TypeManager.int32_type;
8149                         }
8150
8151                         address = mb.GetArrayMethod (
8152                                 ea.Expr.Type, "Address",
8153                                 CallingConventions.HasThis |
8154                                 CallingConventions.Standard,
8155                                 ret_type, args);
8156
8157                         return address;
8158                 }
8159
8160                 //
8161                 // Load the array arguments into the stack.
8162                 //
8163                 // If we have been requested to cache the values (cached_locations array
8164                 // initialized), then load the arguments the first time and store them
8165                 // in locals.  otherwise load from local variables.
8166                 //
8167                 void LoadArrayAndArguments (EmitContext ec)
8168                 {
8169                         ILGenerator ig = ec.ig;
8170
8171                         ea.Expr.Emit (ec);
8172                         foreach (Argument a in ea.Arguments){
8173                                 Type argtype = a.Expr.Type;
8174
8175                                 a.Expr.Emit (ec);
8176
8177                                 if (argtype == TypeManager.int64_type)
8178                                         ig.Emit (OpCodes.Conv_Ovf_I);
8179                                 else if (argtype == TypeManager.uint64_type)
8180                                         ig.Emit (OpCodes.Conv_Ovf_I_Un);
8181                         }
8182                 }
8183
8184                 public void Emit (EmitContext ec, bool leave_copy)
8185                 {
8186                         int rank = ea.Expr.Type.GetArrayRank ();
8187                         ILGenerator ig = ec.ig;
8188
8189                         if (!prepared) {
8190                                 LoadArrayAndArguments (ec);
8191
8192                                 if (rank == 1)
8193                                         EmitLoadOpcode (ig, type);
8194                                 else {
8195                                         MethodInfo method;
8196
8197                                         method = FetchGetMethod ();
8198                                         ig.Emit (OpCodes.Call, method);
8199                                 }
8200                         } else
8201                                 LoadFromPtr (ec.ig, this.type);
8202
8203                         if (leave_copy) {
8204                                 ec.ig.Emit (OpCodes.Dup);
8205                                 temp = new LocalTemporary (ec, this.type);
8206                                 temp.Store (ec);
8207                         }
8208                 }
8209
8210                 public override void Emit (EmitContext ec)
8211                 {
8212                         Emit (ec, false);
8213                 }
8214
8215                 public void EmitAssign (EmitContext ec, Expression source, bool leave_copy, bool prepare_for_load)
8216                 {
8217                         int rank = ea.Expr.Type.GetArrayRank ();
8218                         ILGenerator ig = ec.ig;
8219                         Type t = source.Type;
8220                         prepared = prepare_for_load;
8221
8222                         if (prepare_for_load) {
8223                                 AddressOf (ec, AddressOp.LoadStore);
8224                                 ec.ig.Emit (OpCodes.Dup);
8225                                 source.Emit (ec);
8226                                 if (leave_copy) {
8227                                         ec.ig.Emit (OpCodes.Dup);
8228                                         temp = new LocalTemporary (ec, this.type);
8229                                         temp.Store (ec);
8230                                 }
8231                                 StoreFromPtr (ec.ig, t);
8232
8233                                 if (temp != null)
8234                                         temp.Emit (ec);
8235
8236                                 return;
8237                         }
8238
8239                         LoadArrayAndArguments (ec);
8240
8241                         if (rank == 1) {
8242                                 bool is_stobj, has_type_arg;
8243                                 OpCode op = GetStoreOpcode (t, out is_stobj, out has_type_arg);
8244
8245                                 //
8246                                 // The stobj opcode used by value types will need
8247                                 // an address on the stack, not really an array/array
8248                                 // pair
8249                                 //
8250                                 if (is_stobj)
8251                                         ig.Emit (OpCodes.Ldelema, t);
8252
8253                                 source.Emit (ec);
8254                                 if (leave_copy) {
8255                                         ec.ig.Emit (OpCodes.Dup);
8256                                         temp = new LocalTemporary (ec, this.type);
8257                                         temp.Store (ec);
8258                                 }
8259
8260                                 if (is_stobj)
8261                                         ig.Emit (OpCodes.Stobj, t);
8262                                 else if (has_type_arg)
8263                                         ig.Emit (op, t);
8264                                 else
8265                                         ig.Emit (op);
8266                         } else {
8267                                 ModuleBuilder mb = CodeGen.Module.Builder;
8268                                 int arg_count = ea.Arguments.Count;
8269                                 Type [] args = new Type [arg_count + 1];
8270                                 MethodInfo set;
8271
8272                                 source.Emit (ec);
8273                                 if (leave_copy) {
8274                                         ec.ig.Emit (OpCodes.Dup);
8275                                         temp = new LocalTemporary (ec, this.type);
8276                                         temp.Store (ec);
8277                                 }
8278
8279                                 for (int i = 0; i < arg_count; i++){
8280                                         //args [i++] = a.Type;
8281                                         args [i] = TypeManager.int32_type;
8282                                 }
8283
8284                                 args [arg_count] = type;
8285
8286                                 set = mb.GetArrayMethod (
8287                                         ea.Expr.Type, "Set",
8288                                         CallingConventions.HasThis |
8289                                         CallingConventions.Standard,
8290                                         TypeManager.void_type, args);
8291
8292                                 ig.Emit (OpCodes.Call, set);
8293                         }
8294
8295                         if (temp != null)
8296                                 temp.Emit (ec);
8297                 }
8298
8299                 public void AddressOf (EmitContext ec, AddressOp mode)
8300                 {
8301                         int rank = ea.Expr.Type.GetArrayRank ();
8302                         ILGenerator ig = ec.ig;
8303
8304                         LoadArrayAndArguments (ec);
8305
8306                         if (rank == 1){
8307                                 ig.Emit (OpCodes.Ldelema, type);
8308                         } else {
8309                                 MethodInfo address = FetchAddressMethod ();
8310                                 ig.Emit (OpCodes.Call, address);
8311                         }
8312                 }
8313         }
8314
8315
8316         class Indexers {
8317                 public ArrayList Properties;
8318                 static Hashtable map;
8319
8320                 public struct Indexer {
8321                         public readonly Type Type;
8322                         public readonly MethodInfo Getter, Setter;
8323
8324                         public Indexer (Type type, MethodInfo get, MethodInfo set)
8325                         {
8326                                 this.Type = type;
8327                                 this.Getter = get;
8328                                 this.Setter = set;
8329                         }
8330                 }
8331
8332                 static Indexers ()
8333                 {
8334                         map = new Hashtable ();
8335                 }
8336
8337                 Indexers ()
8338                 {
8339                         Properties = new ArrayList ();
8340                 }
8341
8342                 void Append (MemberInfo [] mi)
8343                 {
8344                         foreach (PropertyInfo property in mi){
8345                                 MethodInfo get, set;
8346
8347                                 get = property.GetGetMethod (true);
8348                                 set = property.GetSetMethod (true);
8349                                 Properties.Add (new Indexer (property.PropertyType, get, set));
8350                         }
8351                 }
8352
8353                 static private MemberInfo [] GetIndexersForTypeOrInterface (Type caller_type, Type lookup_type)
8354                 {
8355                         string p_name = TypeManager.IndexerPropertyName (lookup_type);
8356
8357                         MemberInfo [] mi = TypeManager.MemberLookup (
8358                                 caller_type, caller_type, lookup_type, MemberTypes.Property,
8359                                 BindingFlags.Public | BindingFlags.Instance |
8360                                 BindingFlags.DeclaredOnly, p_name, null);
8361
8362                         if (mi == null || mi.Length == 0)
8363                                 return null;
8364
8365                         return mi;
8366                 }
8367
8368                 static public Indexers GetIndexersForType (Type caller_type, Type lookup_type, Location loc)
8369                 {
8370                         Indexers ix = (Indexers) map [lookup_type];
8371
8372                         if (ix != null)
8373                                 return ix;
8374
8375                         Type copy = lookup_type;
8376                         while (copy != TypeManager.object_type && copy != null){
8377                                 MemberInfo [] mi = GetIndexersForTypeOrInterface (caller_type, copy);
8378
8379                                 if (mi != null){
8380                                         if (ix == null)
8381                                                 ix = new Indexers ();
8382
8383                                         ix.Append (mi);
8384                                 }
8385
8386                                 copy = copy.BaseType;
8387                         }
8388
8389                         if (!lookup_type.IsInterface)
8390                                 return ix;
8391
8392                         Type [] ifaces = TypeManager.GetInterfaces (lookup_type);
8393                         if (ifaces != null) {
8394                                 foreach (Type itype in ifaces) {
8395                                         MemberInfo [] mi = GetIndexersForTypeOrInterface (caller_type, itype);
8396                                         if (mi != null){
8397                                                 if (ix == null)
8398                                                         ix = new Indexers ();
8399
8400                                                 ix.Append (mi);
8401                                         }
8402                                 }
8403                         }
8404
8405                         return ix;
8406                 }
8407         }
8408
8409         /// <summary>
8410         ///   Expressions that represent an indexer call.
8411         /// </summary>
8412         public class IndexerAccess : Expression, IAssignMethod {
8413                 //
8414                 // Points to our "data" repository
8415                 //
8416                 MethodInfo get, set;
8417                 ArrayList set_arguments;
8418                 bool is_base_indexer;
8419
8420                 protected Type indexer_type;
8421                 protected Type current_type;
8422                 protected Expression instance_expr;
8423                 protected ArrayList arguments;
8424
8425                 public IndexerAccess (ElementAccess ea, Location loc)
8426                         : this (ea.Expr, false, loc)
8427                 {
8428                         this.arguments = ea.Arguments;
8429                 }
8430
8431                 protected IndexerAccess (Expression instance_expr, bool is_base_indexer,
8432                                          Location loc)
8433                 {
8434                         this.instance_expr = instance_expr;
8435                         this.is_base_indexer = is_base_indexer;
8436                         this.eclass = ExprClass.Value;
8437                         this.loc = loc;
8438                 }
8439
8440                 protected virtual bool CommonResolve (EmitContext ec)
8441                 {
8442                         indexer_type = instance_expr.Type;
8443                         current_type = ec.ContainerType;
8444
8445                         return true;
8446                 }
8447
8448                 public override Expression DoResolve (EmitContext ec)
8449                 {
8450                         ArrayList AllGetters = new ArrayList();
8451                         if (!CommonResolve (ec))
8452                                 return null;
8453
8454                         //
8455                         // Step 1: Query for all `Item' *properties*.  Notice
8456                         // that the actual methods are pointed from here.
8457                         //
8458                         // This is a group of properties, piles of them.
8459
8460                         bool found_any = false, found_any_getters = false;
8461                         Type lookup_type = indexer_type;
8462
8463                         Indexers ilist;
8464                         ilist = Indexers.GetIndexersForType (current_type, lookup_type, loc);
8465                         if (ilist != null) {
8466                                 found_any = true;
8467                                 if (ilist.Properties != null) {
8468                                         foreach (Indexers.Indexer ix in ilist.Properties) {
8469                                                 if (ix.Getter != null)
8470                                                         AllGetters.Add(ix.Getter);
8471                                         }
8472                                 }
8473                         }
8474
8475                         if (AllGetters.Count > 0) {
8476                                 found_any_getters = true;
8477                                 get = (MethodInfo) Invocation.OverloadResolve (
8478                                         ec, new MethodGroupExpr (AllGetters, loc),
8479                                         arguments, false, loc);
8480                         }
8481
8482                         if (!found_any) {
8483                                 Report.Error (21, loc,
8484                                               "Type `" + TypeManager.CSharpName (indexer_type) +
8485                                               "' does not have any indexers defined");
8486                                 return null;
8487                         }
8488
8489                         if (!found_any_getters) {
8490                                 Error (154, "indexer can not be used in this context, because " +
8491                                        "it lacks a `get' accessor");
8492                                 return null;
8493                         }
8494
8495                         if (get == null) {
8496                                 Error (1501, "No Overload for method `this' takes `" +
8497                                        arguments.Count + "' arguments");
8498                                 return null;
8499                         }
8500
8501                         //
8502                         // Only base will allow this invocation to happen.
8503                         //
8504                         if (get.IsAbstract && this is BaseIndexerAccess){
8505                                 Report.Error (205, loc, "Cannot call an abstract base indexer: " + Invocation.FullMethodDesc (get));
8506                                 return null;
8507                         }
8508
8509                         type = get.ReturnType;
8510                         if (type.IsPointer && !ec.InUnsafe){
8511                                 UnsafeError (loc);
8512                                 return null;
8513                         }
8514
8515                         instance_expr.CheckMarshallByRefAccess (ec.ContainerType);
8516
8517                         eclass = ExprClass.IndexerAccess;
8518                         return this;
8519                 }
8520
8521                 public override Expression DoResolveLValue (EmitContext ec, Expression right_side)
8522                 {
8523                         ArrayList AllSetters = new ArrayList();
8524                         if (!CommonResolve (ec))
8525                                 return null;
8526
8527                         bool found_any = false, found_any_setters = false;
8528
8529                         Indexers ilist = Indexers.GetIndexersForType (current_type, indexer_type, loc);
8530                         if (ilist != null) {
8531                                 found_any = true;
8532                                 if (ilist.Properties != null) {
8533                                         foreach (Indexers.Indexer ix in ilist.Properties) {
8534                                                 if (ix.Setter != null)
8535                                                         AllSetters.Add(ix.Setter);
8536                                         }
8537                                 }
8538                         }
8539                         if (AllSetters.Count > 0) {
8540                                 found_any_setters = true;
8541                                 set_arguments = (ArrayList) arguments.Clone ();
8542                                 set_arguments.Add (new Argument (right_side, Argument.AType.Expression));
8543                                 set = (MethodInfo) Invocation.OverloadResolve (
8544                                         ec, new MethodGroupExpr (AllSetters, loc),
8545                                         set_arguments, false, loc);
8546                         }
8547
8548                         if (!found_any) {
8549                                 Report.Error (21, loc,
8550                                               "Type `" + TypeManager.CSharpName (indexer_type) +
8551                                               "' does not have any indexers defined");
8552                                 return null;
8553                         }
8554
8555                         if (!found_any_setters) {
8556                                 Error (154, "indexer can not be used in this context, because " +
8557                                        "it lacks a `set' accessor");
8558                                 return null;
8559                         }
8560
8561                         if (set == null) {
8562                                 Error (1501, "No Overload for method `this' takes `" +
8563                                        arguments.Count + "' arguments");
8564                                 return null;
8565                         }
8566
8567                         //
8568                         // Only base will allow this invocation to happen.
8569                         //
8570                         if (set.IsAbstract && this is BaseIndexerAccess){
8571                                 Report.Error (205, loc, "Cannot call an abstract base indexer: " + Invocation.FullMethodDesc (set));
8572                                 return null;
8573                         }
8574
8575                         //
8576                         // Now look for the actual match in the list of indexers to set our "return" type
8577                         //
8578                         type = TypeManager.void_type;   // default value
8579                         foreach (Indexers.Indexer ix in ilist.Properties){
8580                                 if (ix.Setter == set){
8581                                         type = ix.Type;
8582                                         break;
8583                                 }
8584                         }
8585
8586                         instance_expr.CheckMarshallByRefAccess (ec.ContainerType);
8587
8588                         eclass = ExprClass.IndexerAccess;
8589                         return this;
8590                 }
8591
8592                 bool prepared = false;
8593                 LocalTemporary temp;
8594
8595                 public void Emit (EmitContext ec, bool leave_copy)
8596                 {
8597                         Invocation.EmitCall (ec, is_base_indexer, false, instance_expr, get, arguments, loc, prepared, false);
8598                         if (leave_copy) {
8599                                 ec.ig.Emit (OpCodes.Dup);
8600                                 temp = new LocalTemporary (ec, Type);
8601                                 temp.Store (ec);
8602                         }
8603                 }
8604
8605                 //
8606                 // source is ignored, because we already have a copy of it from the
8607                 // LValue resolution and we have already constructed a pre-cached
8608                 // version of the arguments (ea.set_arguments);
8609                 //
8610                 public void EmitAssign (EmitContext ec, Expression source, bool leave_copy, bool prepare_for_load)
8611                 {
8612                         prepared = prepare_for_load;
8613                         Argument a = (Argument) set_arguments [set_arguments.Count - 1];
8614
8615                         if (prepared) {
8616                                 source.Emit (ec);
8617                                 if (leave_copy) {
8618                                         ec.ig.Emit (OpCodes.Dup);
8619                                         temp = new LocalTemporary (ec, Type);
8620                                         temp.Store (ec);
8621                                 }
8622                         } else if (leave_copy) {
8623                                 temp = new LocalTemporary (ec, Type);
8624                                 source.Emit (ec);
8625                                 temp.Store (ec);
8626                                 a.Expr = temp;
8627                         }
8628
8629                         Invocation.EmitCall (ec, is_base_indexer, false, instance_expr, set, set_arguments, loc, false, prepared);
8630
8631                         if (temp != null)
8632                                 temp.Emit (ec);
8633                 }
8634
8635
8636                 public override void Emit (EmitContext ec)
8637                 {
8638                         Emit (ec, false);
8639                 }
8640         }
8641
8642         /// <summary>
8643         ///   The base operator for method names
8644         /// </summary>
8645         public class BaseAccess : Expression {
8646                 string member;
8647
8648                 public BaseAccess (string member, Location l)
8649                 {
8650                         this.member = member;
8651                         loc = l;
8652                 }
8653
8654                 public override Expression DoResolve (EmitContext ec)
8655                 {
8656                         Expression c = CommonResolve (ec);
8657
8658                         if (c == null)
8659                                 return null;
8660
8661                         //
8662                         // MethodGroups use this opportunity to flag an error on lacking ()
8663                         //
8664                         if (!(c is MethodGroupExpr))
8665                                 return c.Resolve (ec);
8666                         return c;
8667                 }
8668
8669                 public override Expression DoResolveLValue (EmitContext ec, Expression right_side)
8670                 {
8671                         Expression c = CommonResolve (ec);
8672
8673                         if (c == null)
8674                                 return null;
8675
8676                         //
8677                         // MethodGroups use this opportunity to flag an error on lacking ()
8678                         //
8679                         if (! (c is MethodGroupExpr))
8680                                 return c.DoResolveLValue (ec, right_side);
8681
8682                         return c;
8683                 }
8684
8685                 Expression CommonResolve (EmitContext ec)
8686                 {
8687                         Expression member_lookup;
8688                         Type current_type = ec.ContainerType;
8689                         Type base_type = current_type.BaseType;
8690                         Expression e;
8691
8692                         if (ec.IsStatic){
8693                                 Error (1511, "Keyword base is not allowed in static method");
8694                                 return null;
8695                         }
8696
8697                         if (ec.IsFieldInitializer){
8698                                 Error (1512, "Keyword base is not available in the current context");
8699                                 return null;
8700                         }
8701
8702                         member_lookup = MemberLookup (ec, ec.ContainerType, null, base_type,
8703                                                       member, AllMemberTypes, AllBindingFlags,
8704                                                       loc);
8705                         if (member_lookup == null) {
8706                                 MemberLookupFailed (
8707                                         ec, base_type, base_type, member, null, loc);
8708                                 return null;
8709                         }
8710
8711                         Expression left;
8712
8713                         if (ec.IsStatic)
8714                                 left = new TypeExpression (base_type, loc);
8715                         else
8716                                 left = ec.GetThis (loc);
8717
8718                         e = MemberAccess.ResolveMemberAccess (ec, member_lookup, left, loc, null);
8719
8720                         if (e is PropertyExpr){
8721                                 PropertyExpr pe = (PropertyExpr) e;
8722
8723                                 pe.IsBase = true;
8724                         }
8725
8726                         if (e is MethodGroupExpr)
8727                                 ((MethodGroupExpr) e).IsBase = true;
8728
8729                         return e;
8730                 }
8731
8732                 public override void Emit (EmitContext ec)
8733                 {
8734                         throw new Exception ("Should never be called");
8735                 }
8736         }
8737
8738         /// <summary>
8739         ///   The base indexer operator
8740         /// </summary>
8741         public class BaseIndexerAccess : IndexerAccess {
8742                 public BaseIndexerAccess (ArrayList args, Location loc)
8743                         : base (null, true, loc)
8744                 {
8745                         arguments = new ArrayList ();
8746                         foreach (Expression tmp in args)
8747                                 arguments.Add (new Argument (tmp, Argument.AType.Expression));
8748                 }
8749
8750                 protected override bool CommonResolve (EmitContext ec)
8751                 {
8752                         instance_expr = ec.GetThis (loc);
8753
8754                         current_type = ec.ContainerType.BaseType;
8755                         indexer_type = current_type;
8756
8757                         foreach (Argument a in arguments){
8758                                 if (!a.Resolve (ec, loc))
8759                                         return false;
8760                         }
8761
8762                         return true;
8763                 }
8764         }
8765
8766         /// <summary>
8767         ///   This class exists solely to pass the Type around and to be a dummy
8768         ///   that can be passed to the conversion functions (this is used by
8769         ///   foreach implementation to typecast the object return value from
8770         ///   get_Current into the proper type.  All code has been generated and
8771         ///   we only care about the side effect conversions to be performed
8772         ///
8773         ///   This is also now used as a placeholder where a no-action expression
8774         ///   is needed (the `New' class).
8775         /// </summary>
8776         public class EmptyExpression : Expression {
8777                 public static readonly EmptyExpression Null = new EmptyExpression ();
8778
8779                 // TODO: should be protected
8780                 public EmptyExpression ()
8781                 {
8782                         type = TypeManager.object_type;
8783                         eclass = ExprClass.Value;
8784                         loc = Location.Null;
8785                 }
8786
8787                 public EmptyExpression (Type t)
8788                 {
8789                         type = t;
8790                         eclass = ExprClass.Value;
8791                         loc = Location.Null;
8792                 }
8793
8794                 public override Expression DoResolve (EmitContext ec)
8795                 {
8796                         return this;
8797                 }
8798
8799                 public override void Emit (EmitContext ec)
8800                 {
8801                         // nothing, as we only exist to not do anything.
8802                 }
8803
8804                 //
8805                 // This is just because we might want to reuse this bad boy
8806                 // instead of creating gazillions of EmptyExpressions.
8807                 // (CanImplicitConversion uses it)
8808                 //
8809                 public void SetType (Type t)
8810                 {
8811                         type = t;
8812                 }
8813         }
8814
8815         public class UserCast : Expression {
8816                 MethodBase method;
8817                 Expression source;
8818
8819                 public UserCast (MethodInfo method, Expression source, Location l)
8820                 {
8821                         this.method = method;
8822                         this.source = source;
8823                         type = method.ReturnType;
8824                         eclass = ExprClass.Value;
8825                         loc = l;
8826                 }
8827
8828                 public Expression Source {
8829                         get {
8830                                 return source;
8831                         }
8832                 }
8833
8834                 public override Expression DoResolve (EmitContext ec)
8835                 {
8836                         //
8837                         // We are born fully resolved
8838                         //
8839                         return this;
8840                 }
8841
8842                 public override void Emit (EmitContext ec)
8843                 {
8844                         ILGenerator ig = ec.ig;
8845
8846                         source.Emit (ec);
8847
8848                         if (method is MethodInfo)
8849                                 ig.Emit (OpCodes.Call, (MethodInfo) method);
8850                         else
8851                                 ig.Emit (OpCodes.Call, (ConstructorInfo) method);
8852
8853                 }
8854         }
8855
8856         // <summary>
8857         //   This class is used to "construct" the type during a typecast
8858         //   operation.  Since the Type.GetType class in .NET can parse
8859         //   the type specification, we just use this to construct the type
8860         //   one bit at a time.
8861         // </summary>
8862         public class ComposedCast : TypeExpr {
8863                 Expression left;
8864                 string dim;
8865
8866                 public ComposedCast (Expression left, string dim, Location l)
8867                 {
8868                         this.left = left;
8869                         this.dim = dim;
8870                         loc = l;
8871                 }
8872
8873                 protected override TypeExpr DoResolveAsTypeStep (EmitContext ec)
8874                 {
8875                         TypeExpr lexpr = left.ResolveAsTypeTerminal (ec);
8876                         if (lexpr == null)
8877                                 return null;
8878
8879                         Type ltype = lexpr.Type;
8880
8881                         if ((ltype == TypeManager.void_type) && (dim != "*")) {
8882                                 Report.Error (1547, Location,
8883                                               "Keyword 'void' cannot be used in this context");
8884                                 return null;
8885                         }
8886
8887                         if ((dim.Length > 0) && (dim [0] == '?')) {
8888                                 TypeExpr nullable = new NullableType (left, loc);
8889                                 if (dim.Length > 1)
8890                                         nullable = new ComposedCast (nullable, dim.Substring (1), loc);
8891                                 return nullable.ResolveAsTypeTerminal (ec);
8892                         }
8893
8894                         int pos = 0;
8895                         while ((pos < dim.Length) && (dim [pos] == '[')) {
8896                                 pos++;
8897
8898                                 if (dim [pos] == ']') {
8899                                         ltype = ltype.MakeArrayType ();
8900                                         pos++;
8901
8902                                         if (pos < dim.Length)
8903                                                 continue;
8904
8905                                         type = ltype;
8906                                         eclass = ExprClass.Type;
8907                                         return this;
8908                                 }
8909
8910                                 int rank = 0;
8911                                 while (dim [pos] == ',') {
8912                                         pos++; rank++;
8913                                 }
8914
8915                                 if ((dim [pos] != ']') || (pos != dim.Length-1))
8916                                         return null;
8917
8918                                 type = ltype.MakeArrayType (rank + 1);
8919                                 eclass = ExprClass.Type;
8920                                 return this;
8921                         }
8922
8923                         if (dim != "") {
8924                                 //
8925                                 // ltype.Fullname is already fully qualified, so we can skip
8926                                 // a lot of probes, and go directly to TypeManager.LookupType
8927                                 //
8928                                 string fname = ltype.FullName != null ? ltype.FullName : ltype.Name;
8929                                 string cname = fname + dim;
8930                                 type = TypeManager.LookupTypeDirect (cname);
8931                                 if (type == null){
8932                                         //
8933                                         // For arrays of enumerations we are having a problem
8934                                         // with the direct lookup.  Need to investigate.
8935                                         //
8936                                         // For now, fall back to the full lookup in that case.
8937                                         //
8938                                         FullNamedExpression e = ec.DeclSpace.LookupType (cname, false, loc);
8939                                         if (e is TypeExpr)
8940                                                 type = ((TypeExpr) e).ResolveType (ec);
8941                                         if (type == null)
8942                                                 return null;
8943                                 }
8944                         } else {
8945                                 type = ltype;
8946                         }
8947
8948                         if (!ec.InUnsafe && type.IsPointer){
8949                                 UnsafeError (loc);
8950                                 return null;
8951                         }
8952
8953                         if (type.IsArray && (type.GetElementType () == TypeManager.arg_iterator_type ||
8954                                 type.GetElementType () == TypeManager.typed_reference_type)) {
8955                                 Report.Error (611, loc, "Array elements cannot be of type '{0}'", TypeManager.CSharpName (type.GetElementType ()));
8956                                 return null;
8957                         }
8958
8959                         eclass = ExprClass.Type;
8960                         return this;
8961                 }
8962
8963                 public override string Name {
8964                         get {
8965                                 return left + dim;
8966                         }
8967                 }
8968
8969                 public override string FullName {
8970                         get {
8971                                 return type.FullName;
8972                         }
8973                 }
8974         }
8975
8976         public class FixedBufferPtr: Expression {
8977                 Expression array;
8978
8979                 public FixedBufferPtr (Expression array, Type array_type, Location l)
8980                 {
8981                         this.array = array;
8982                         this.loc = l;
8983
8984                         type = TypeManager.GetPointerType (array_type);
8985                         eclass = ExprClass.Value;
8986                 }
8987
8988                 public override void Emit(EmitContext ec)
8989                 {
8990                         array.Emit (ec);
8991                 }
8992
8993                 public override Expression DoResolve (EmitContext ec)
8994                 {
8995                         //
8996                         // We are born fully resolved
8997                         //
8998                         return this;
8999                 }
9000         }
9001
9002
9003         //
9004         // This class is used to represent the address of an array, used
9005         // only by the Fixed statement, this generates "&a [0]" construct
9006         // for fixed (char *pa = a)
9007         //
9008         public class ArrayPtr : FixedBufferPtr {
9009                 Type array_type;
9010
9011                 public ArrayPtr (Expression array, Type array_type, Location l):
9012                         base (array, array_type, l)
9013                 {
9014                         this.array_type = array_type;
9015                 }
9016
9017                 public override void Emit (EmitContext ec)
9018                 {
9019                         base.Emit (ec);
9020
9021                         ILGenerator ig = ec.ig;
9022                         IntLiteral.EmitInt (ig, 0);
9023                         ig.Emit (OpCodes.Ldelema, array_type);
9024                 }
9025         }
9026
9027         //
9028         // Used by the fixed statement
9029         //
9030         public class StringPtr : Expression {
9031                 LocalBuilder b;
9032
9033                 public StringPtr (LocalBuilder b, Location l)
9034                 {
9035                         this.b = b;
9036                         eclass = ExprClass.Value;
9037                         type = TypeManager.char_ptr_type;
9038                         loc = l;
9039                 }
9040
9041                 public override Expression DoResolve (EmitContext ec)
9042                 {
9043                         // This should never be invoked, we are born in fully
9044                         // initialized state.
9045
9046                         return this;
9047                 }
9048
9049                 public override void Emit (EmitContext ec)
9050                 {
9051                         ILGenerator ig = ec.ig;
9052
9053                         ig.Emit (OpCodes.Ldloc, b);
9054                         ig.Emit (OpCodes.Conv_I);
9055                         ig.Emit (OpCodes.Call, TypeManager.int_get_offset_to_string_data);
9056                         ig.Emit (OpCodes.Add);
9057                 }
9058         }
9059
9060         //
9061         // Implements the `stackalloc' keyword
9062         //
9063         public class StackAlloc : Expression {
9064                 Type otype;
9065                 Expression t;
9066                 Expression count;
9067
9068                 public StackAlloc (Expression type, Expression count, Location l)
9069                 {
9070                         t = type;
9071                         this.count = count;
9072                         loc = l;
9073                 }
9074
9075                 public override Expression DoResolve (EmitContext ec)
9076                 {
9077                         count = count.Resolve (ec);
9078                         if (count == null)
9079                                 return null;
9080
9081                         if (count.Type != TypeManager.int32_type){
9082                                 count = Convert.ImplicitConversionRequired (ec, count, TypeManager.int32_type, loc);
9083                                 if (count == null)
9084                                         return null;
9085                         }
9086
9087                         Constant c = count as Constant;
9088                         if (c != null && c.IsNegative) {
9089                                 Report.Error (247, loc, "Cannot use a negative size with stackalloc");
9090                                 return null;
9091                         }
9092
9093                         if (ec.CurrentBranching.InCatch () ||
9094                             ec.CurrentBranching.InFinally (true)) {
9095                                 Error (255,
9096                                               "stackalloc can not be used in a catch or finally block");
9097                                 return null;
9098                         }
9099
9100                         TypeExpr texpr = t.ResolveAsTypeTerminal (ec);
9101                         if (texpr == null)
9102                                 return null;
9103
9104                         otype = texpr.Type;
9105
9106                         if (!TypeManager.VerifyUnManaged (otype, loc))
9107                                 return null;
9108
9109                         type = TypeManager.GetPointerType (otype);
9110                         eclass = ExprClass.Value;
9111
9112                         return this;
9113                 }
9114
9115                 public override void Emit (EmitContext ec)
9116                 {
9117                         int size = GetTypeSize (otype);
9118                         ILGenerator ig = ec.ig;
9119
9120                         if (size == 0)
9121                                 ig.Emit (OpCodes.Sizeof, otype);
9122                         else
9123                                 IntConstant.EmitInt (ig, size);
9124                         count.Emit (ec);
9125                         ig.Emit (OpCodes.Mul);
9126                         ig.Emit (OpCodes.Localloc);
9127                 }
9128         }
9129 }