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.MethodIsStatic)
4030                                 arg_idx++;
4031
4032
4033                         EmitLdArg (ig, arg_idx);
4034
4035                         //
4036                         // FIXME: Review for anonymous methods
4037                         //
4038                 }
4039
4040                 public override void Emit (EmitContext ec)
4041                 {
4042                         if (ec.HaveCaptureInfo && ec.IsParameterCaptured (name)){
4043                                 ec.EmitParameter (name);
4044                                 return;
4045                         }
4046
4047                         Emit (ec, false);
4048                 }
4049
4050                 public void Emit (EmitContext ec, bool leave_copy)
4051                 {
4052                         ILGenerator ig = ec.ig;
4053                         int arg_idx = idx;
4054
4055                         if (!ec.MethodIsStatic)
4056                                 arg_idx++;
4057
4058                         EmitLdArg (ig, arg_idx);
4059
4060                         if (is_ref) {
4061                                 if (prepared)
4062                                         ec.ig.Emit (OpCodes.Dup);
4063
4064                                 //
4065                                 // If we are a reference, we loaded on the stack a pointer
4066                                 // Now lets load the real value
4067                                 //
4068                                 LoadFromPtr (ig, type);
4069                         }
4070
4071                         if (leave_copy) {
4072                                 ec.ig.Emit (OpCodes.Dup);
4073
4074                                 if (is_ref) {
4075                                         temp = new LocalTemporary (ec, type);
4076                                         temp.Store (ec);
4077                                 }
4078                         }
4079                 }
4080
4081                 public void EmitAssign (EmitContext ec, Expression source, bool leave_copy, bool prepare_for_load)
4082                 {
4083                         if (ec.HaveCaptureInfo && ec.IsParameterCaptured (name)){
4084                                 ec.EmitAssignParameter (name, source, leave_copy, prepare_for_load);
4085                                 return;
4086                         }
4087
4088                         ILGenerator ig = ec.ig;
4089                         int arg_idx = idx;
4090
4091                         prepared = prepare_for_load;
4092
4093                         if (!ec.MethodIsStatic)
4094                                 arg_idx++;
4095
4096                         if (is_ref && !prepared)
4097                                 EmitLdArg (ig, arg_idx);
4098
4099                         source.Emit (ec);
4100
4101                         if (leave_copy)
4102                                 ec.ig.Emit (OpCodes.Dup);
4103
4104                         if (is_ref) {
4105                                 if (leave_copy) {
4106                                         temp = new LocalTemporary (ec, type);
4107                                         temp.Store (ec);
4108                                 }
4109
4110                                 StoreFromPtr (ig, type);
4111
4112                                 if (temp != null)
4113                                         temp.Emit (ec);
4114                         } else {
4115                                 if (arg_idx <= 255)
4116                                         ig.Emit (OpCodes.Starg_S, (byte) arg_idx);
4117                                 else
4118                                         ig.Emit (OpCodes.Starg, arg_idx);
4119                         }
4120                 }
4121
4122                 public void AddressOf (EmitContext ec, AddressOp mode)
4123                 {
4124                         if (ec.HaveCaptureInfo && ec.IsParameterCaptured (name)){
4125                                 ec.EmitAddressOfParameter (name);
4126                                 return;
4127                         }
4128
4129                         int arg_idx = idx;
4130
4131                         if (!ec.MethodIsStatic)
4132                                 arg_idx++;
4133
4134                         if (is_ref){
4135                                 if (arg_idx <= 255)
4136                                         ec.ig.Emit (OpCodes.Ldarg_S, (byte) arg_idx);
4137                                 else
4138                                         ec.ig.Emit (OpCodes.Ldarg, arg_idx);
4139                         } else {
4140                                 if (arg_idx <= 255)
4141                                         ec.ig.Emit (OpCodes.Ldarga_S, (byte) arg_idx);
4142                                 else
4143                                         ec.ig.Emit (OpCodes.Ldarga, arg_idx);
4144                         }
4145                 }
4146
4147         }
4148
4149         /// <summary>
4150         ///   Used for arguments to New(), Invocation()
4151         /// </summary>
4152         public class Argument {
4153                 public enum AType : byte {
4154                         Expression,
4155                         Ref,
4156                         Out,
4157                         ArgList
4158                 };
4159
4160                 public readonly AType ArgType;
4161                 public Expression Expr;
4162
4163                 public Argument (Expression expr, AType type)
4164                 {
4165                         this.Expr = expr;
4166                         this.ArgType = type;
4167                 }
4168
4169                 public Argument (Expression expr)
4170                 {
4171                         this.Expr = expr;
4172                         this.ArgType = AType.Expression;
4173                 }
4174
4175                 public Type Type {
4176                         get {
4177                                 if (ArgType == AType.Ref || ArgType == AType.Out)
4178                                         return TypeManager.GetReferenceType (Expr.Type);
4179                                 else
4180                                         return Expr.Type;
4181                         }
4182                 }
4183
4184                 public Parameter.Modifier GetParameterModifier ()
4185                 {
4186                         switch (ArgType) {
4187                         case AType.Out:
4188                                 return Parameter.Modifier.OUT | Parameter.Modifier.ISBYREF;
4189
4190                         case AType.Ref:
4191                                 return Parameter.Modifier.REF | Parameter.Modifier.ISBYREF;
4192
4193                         default:
4194                                 return Parameter.Modifier.NONE;
4195                         }
4196                 }
4197
4198                 public static string FullDesc (Argument a)
4199                 {
4200                         if (a.ArgType == AType.ArgList)
4201                                 return "__arglist";
4202
4203                         return (a.ArgType == AType.Ref ? "ref " :
4204                                 (a.ArgType == AType.Out ? "out " : "")) +
4205                                 TypeManager.CSharpName (a.Expr.Type);
4206                 }
4207
4208                 public bool ResolveMethodGroup (EmitContext ec, Location loc)
4209                 {
4210                         ConstructedType ctype = Expr as ConstructedType;
4211                         if (ctype != null)
4212                                 Expr = ctype.GetSimpleName (ec);
4213
4214                         // FIXME: csc doesn't report any error if you try to use `ref' or
4215                         //        `out' in a delegate creation expression.
4216                         Expr = Expr.Resolve (ec, ResolveFlags.VariableOrValue | ResolveFlags.MethodGroup);
4217                         if (Expr == null)
4218                                 return false;
4219
4220                         return true;
4221                 }
4222
4223                 public bool Resolve (EmitContext ec, Location loc)
4224                 {
4225                         if (ArgType == AType.Ref) {
4226                                 Expr = Expr.Resolve (ec);
4227                                 if (Expr == null)
4228                                         return false;
4229
4230                                 if (!ec.IsConstructor) {
4231                                         FieldExpr fe = Expr as FieldExpr;
4232                                         if (fe != null && fe.FieldInfo.IsInitOnly) {
4233                                                 if (fe.FieldInfo.IsStatic)
4234                                                         Report.Error (199, loc, "A static readonly field cannot be passed ref or out (except in a static constructor)");
4235                                                 else
4236                                                         Report.Error (192, loc, "A readonly field cannot be passed ref or out (except in a constructor)");
4237                                                 return false;
4238                                         }
4239                                 }
4240                                 Expr = Expr.ResolveLValue (ec, Expr);
4241                         } else if (ArgType == AType.Out)
4242                                 Expr = Expr.ResolveLValue (ec, EmptyExpression.Null);
4243                         else
4244                                 Expr = Expr.Resolve (ec);
4245
4246                         if (Expr == null)
4247                                 return false;
4248
4249                         if (ArgType == AType.Expression)
4250                                 return true;
4251                         else {
4252                                 //
4253                                 // Catch errors where fields of a MarshalByRefObject are passed as ref or out
4254                                 // This is only allowed for `this'
4255                                 //
4256                                 FieldExpr fe = Expr as FieldExpr;
4257                                 if (fe != null && !fe.IsStatic){
4258                                         Expression instance = fe.InstanceExpression;
4259
4260                                         if (instance.GetType () != typeof (This)){
4261                                                 if (fe.InstanceExpression.Type.IsSubclassOf (TypeManager.mbr_type)){
4262                                                         Report.SymbolRelatedToPreviousError (fe.InstanceExpression.Type);
4263                                                         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",
4264                                                                 fe.Name);
4265                                                         return false;
4266                                                 }
4267                                         }
4268                                 }
4269                         }
4270
4271                         if (Expr.eclass != ExprClass.Variable){
4272                                 //
4273                                 // We just probe to match the CSC output
4274                                 //
4275                                 if (Expr.eclass == ExprClass.PropertyAccess ||
4276                                     Expr.eclass == ExprClass.IndexerAccess){
4277                                         Report.Error (
4278                                                 206, loc,
4279                                                 "A property or indexer can not be passed as an out or ref " +
4280                                                 "parameter");
4281                                 } else {
4282                                         Report.Error (
4283                                                 1510, loc,
4284                                                 "An lvalue is required as an argument to out or ref");
4285                                 }
4286                                 return false;
4287                         }
4288
4289                         return true;
4290                 }
4291
4292                 public void Emit (EmitContext ec)
4293                 {
4294                         //
4295                         // Ref and Out parameters need to have their addresses taken.
4296                         //
4297                         // ParameterReferences might already be references, so we want
4298                         // to pass just the value
4299                         //
4300                         if (ArgType == AType.Ref || ArgType == AType.Out){
4301                                 AddressOp mode = AddressOp.Store;
4302
4303                                 if (ArgType == AType.Ref)
4304                                         mode |= AddressOp.Load;
4305
4306                                 if (Expr is ParameterReference){
4307                                         ParameterReference pr = (ParameterReference) Expr;
4308
4309                                         if (pr.IsRef)
4310                                                 pr.EmitLoad (ec);
4311                                         else {
4312
4313                                                 pr.AddressOf (ec, mode);
4314                                         }
4315                                 } else {
4316                                         if (Expr is IMemoryLocation)
4317                                                ((IMemoryLocation) Expr).AddressOf (ec, mode);
4318                                         else {
4319                                                 Report.Error (
4320                                                         1510, Expr.Location,
4321                                                         "An lvalue is required as an argument to out or ref");
4322                                                 return;
4323                                         }
4324                                 }
4325                         } else
4326                                 Expr.Emit (ec);
4327                 }
4328         }
4329
4330         /// <summary>
4331         ///   Invocation of methods or delegates.
4332         /// </summary>
4333         public class Invocation : ExpressionStatement {
4334                 public readonly ArrayList Arguments;
4335
4336                 Expression expr;
4337                 MethodBase method = null;
4338
4339                 //
4340                 // arguments is an ArrayList, but we do not want to typecast,
4341                 // as it might be null.
4342                 //
4343                 // FIXME: only allow expr to be a method invocation or a
4344                 // delegate invocation (7.5.5)
4345                 //
4346                 public Invocation (Expression expr, ArrayList arguments, Location l)
4347                 {
4348                         this.expr = expr;
4349                         Arguments = arguments;
4350                         loc = l;
4351                 }
4352
4353                 public Expression Expr {
4354                         get {
4355                                 return expr;
4356                         }
4357                 }
4358
4359                 /// <summary>
4360                 ///   Determines "better conversion" as specified in 7.4.2.3
4361                 ///
4362                 ///    Returns : p    if a->p is better,
4363                 ///              q    if a->q is better,
4364                 ///              null if neither is better
4365                 /// </summary>
4366                 static Type BetterConversion (EmitContext ec, Argument a, Type p, Type q, Location loc)
4367                 {
4368                         Type argument_type = TypeManager.TypeToCoreType (a.Type);
4369                         Expression argument_expr = a.Expr;
4370
4371                         // p = TypeManager.TypeToCoreType (p);
4372                         // q = TypeManager.TypeToCoreType (q);
4373
4374                         if (argument_type == null)
4375                                 throw new Exception ("Expression of type " + a.Expr +
4376                                                      " does not resolve its type");
4377
4378                         if (p == null || q == null)
4379                                 throw new InternalErrorException ("BetterConversion Got a null conversion");
4380
4381                         if (p == q)
4382                                 return null;
4383
4384                         if (argument_expr is NullLiteral) {
4385                         //
4386                                 // If the argument is null and one of the types to compare is 'object' and
4387                                 // the other is a reference type, we prefer the other.
4388                         //
4389                                 // This follows from the usual rules:
4390                                 //   * There is an implicit conversion from 'null' to type 'object'
4391                                 //   * There is an implicit conversion from 'null' to any reference type
4392                                 //   * There is an implicit conversion from any reference type to type 'object'
4393                                 //   * There is no implicit conversion from type 'object' to other reference types
4394                                 //  => Conversion of 'null' to a reference type is better than conversion to 'object'
4395                                 //
4396                                 //  FIXME: This probably isn't necessary, since the type of a NullLiteral is the
4397                                 //         null type. I think it used to be 'object' and thus needed a special
4398                                 //         case to avoid the immediately following two checks.
4399                                 //
4400                                 if (!p.IsValueType && q == TypeManager.object_type)
4401                                         return p;
4402                                 if (!q.IsValueType && p == TypeManager.object_type)
4403                                         return q;
4404                         }
4405
4406                         if (argument_type == p)
4407                                 return p;
4408
4409                         if (argument_type == q)
4410                                 return q;
4411
4412                         Expression p_tmp = new EmptyExpression (p);
4413                         Expression q_tmp = new EmptyExpression (q);
4414
4415                         bool p_to_q = Convert.ImplicitConversionExists (ec, p_tmp, q);
4416                         bool q_to_p = Convert.ImplicitConversionExists (ec, q_tmp, p);
4417
4418                         if (p_to_q && !q_to_p)
4419                                 return p;
4420
4421                         if (q_to_p && !p_to_q)
4422                                 return q;
4423
4424                         if (p == TypeManager.sbyte_type)
4425                                 if (q == TypeManager.byte_type || q == TypeManager.ushort_type ||
4426                                     q == TypeManager.uint32_type || q == TypeManager.uint64_type)
4427                                         return p;
4428                         if (q == TypeManager.sbyte_type)
4429                                 if (p == TypeManager.byte_type || p == TypeManager.ushort_type ||
4430                                     p == TypeManager.uint32_type || p == TypeManager.uint64_type)
4431                                         return q;
4432
4433                         if (p == TypeManager.short_type)
4434                                 if (q == TypeManager.ushort_type || q == TypeManager.uint32_type ||
4435                                     q == TypeManager.uint64_type)
4436                                         return p;
4437
4438                         if (q == TypeManager.short_type)
4439                                 if (p == TypeManager.ushort_type || p == TypeManager.uint32_type ||
4440                                     p == TypeManager.uint64_type)
4441                                         return q;
4442
4443                         if (p == TypeManager.int32_type)
4444                                 if (q == TypeManager.uint32_type || q == TypeManager.uint64_type)
4445                                         return p;
4446
4447                         if (q == TypeManager.int32_type)
4448                                 if (p == TypeManager.uint32_type || p == TypeManager.uint64_type)
4449                                         return q;
4450
4451                         if (p == TypeManager.int64_type)
4452                                 if (q == TypeManager.uint64_type)
4453                                         return p;
4454                         if (q == TypeManager.int64_type)
4455                                 if (p == TypeManager.uint64_type)
4456                                         return q;
4457
4458                         return null;
4459                 }
4460
4461                 /// <summary>
4462                 ///   Determines "Better function" between candidate
4463                 ///   and the current best match
4464                 /// </summary>
4465                 /// <remarks>
4466                 ///    Returns a boolean indicating :
4467                 ///     false if candidate ain't better
4468                 ///     true  if candidate is better than the current best match
4469                 /// </remarks>
4470                 static bool BetterFunction (EmitContext ec, ArrayList args, int argument_count,
4471                                            MethodBase candidate, bool candidate_params,
4472                                            MethodBase best, bool best_params, Location loc)
4473                 {
4474                         ParameterData candidate_pd = TypeManager.GetParameterData (candidate);
4475                         ParameterData best_pd = TypeManager.GetParameterData (best);
4476
4477                         bool better_at_least_one = false;
4478                         bool same = true;
4479                         for (int j = 0; j < argument_count; ++j) {
4480                                 Argument a = (Argument) args [j];
4481
4482                                 Type ct = TypeManager.TypeToCoreType (candidate_pd.ParameterType (j));
4483                                 Type bt = TypeManager.TypeToCoreType (best_pd.ParameterType (j));
4484
4485                                 if (candidate_pd.ParameterModifier (j) == Parameter.Modifier.PARAMS)
4486                                         if (candidate_params)
4487                                                 ct = TypeManager.GetElementType (ct);
4488
4489                                 if (best_pd.ParameterModifier (j) == Parameter.Modifier.PARAMS)
4490                                         if (best_params)
4491                                                 bt = TypeManager.GetElementType (bt);
4492
4493                                 if (ct.Equals (bt))
4494                                         continue;
4495
4496                                 same = false;
4497                                 Type better = BetterConversion (ec, a, ct, bt, loc);
4498                                 // for each argument, the conversion to 'ct' should be no worse than
4499                                 // the conversion to 'bt'.
4500                                 if (better == bt)
4501                                         return false;
4502
4503                                 // for at least one argument, the conversion to 'ct' should be better than
4504                                 // the conversion to 'bt'.
4505                                 if (better == ct)
4506                                         better_at_least_one = true;
4507                         }
4508
4509                         if (better_at_least_one)
4510                                 return true;
4511
4512                         if (!same)
4513                                 return false;
4514
4515                         //
4516                         // If two methods have equal parameter types, but
4517                         // only one of them is generic, the non-generic one wins.
4518                         //
4519                         if (TypeManager.IsGenericMethod (best) && !TypeManager.IsGenericMethod (candidate))
4520                                 return true;
4521                         else if (!TypeManager.IsGenericMethod (best) && TypeManager.IsGenericMethod (candidate))
4522                                 return false;
4523
4524                         //
4525                         // This handles the case
4526                         //
4527                         //   Add (float f1, float f2, float f3);
4528                         //   Add (params decimal [] foo);
4529                         //
4530                         // The call Add (3, 4, 5) should be ambiguous.  Without this check, the
4531                         // first candidate would've chosen as better.
4532                         //
4533                         //
4534                         // This handles the following cases:
4535                         //
4536                         //   Trim () is better than Trim (params char[] chars)
4537                         //   Concat (string s1, string s2, string s3) is better than
4538                         //     Concat (string s1, params string [] srest)
4539                         //
4540                         return !candidate_params && best_params;
4541                 }
4542
4543                 static bool IsOverride (MethodBase cand_method, MethodBase base_method)
4544                 {
4545                         if (!IsAncestralType (base_method.DeclaringType, cand_method.DeclaringType))
4546                                 return false;
4547
4548                         ParameterData cand_pd = TypeManager.GetParameterData (cand_method);
4549                         ParameterData base_pd = TypeManager.GetParameterData (base_method);
4550
4551                         if (cand_pd.Count != base_pd.Count)
4552                                 return false;
4553
4554                         for (int j = 0; j < cand_pd.Count; ++j) {
4555                                 Parameter.Modifier cm = cand_pd.ParameterModifier (j);
4556                                 Parameter.Modifier bm = base_pd.ParameterModifier (j);
4557                                 Type ct = TypeManager.TypeToCoreType (cand_pd.ParameterType (j));
4558                                 Type bt = TypeManager.TypeToCoreType (base_pd.ParameterType (j));
4559
4560                                 if (cm != bm || ct != bt)
4561                                         return false;
4562                         }
4563
4564                         return true;
4565                 }
4566
4567                 public static string FullMethodDesc (MethodBase mb)
4568                 {
4569                         string ret_type = "";
4570
4571                         if (mb == null)
4572                                 return "";
4573
4574                         if (mb is MethodInfo)
4575                                 ret_type = TypeManager.CSharpName (((MethodInfo) mb).ReturnType);
4576
4577                         StringBuilder sb = new StringBuilder (ret_type);
4578                         sb.Append (" ");
4579                         sb.Append (mb.ReflectedType.ToString ());
4580                         sb.Append (".");
4581                         sb.Append (mb.Name);
4582
4583                         ParameterData pd = TypeManager.GetParameterData (mb);
4584
4585                         int count = pd.Count;
4586                         sb.Append (" (");
4587
4588                         for (int i = count; i > 0; ) {
4589                                 i--;
4590
4591                                 sb.Append (pd.ParameterDesc (count - i - 1));
4592                                 if (i != 0)
4593                                         sb.Append (", ");
4594                         }
4595
4596                         sb.Append (")");
4597                         return sb.ToString ();
4598                 }
4599
4600                 public static MethodGroupExpr MakeUnionSet (Expression mg1, Expression mg2, Location loc)
4601                 {
4602                         MemberInfo [] miset;
4603                         MethodGroupExpr union;
4604
4605                         if (mg1 == null) {
4606                                 if (mg2 == null)
4607                                         return null;
4608                                 return (MethodGroupExpr) mg2;
4609                         } else {
4610                                 if (mg2 == null)
4611                                         return (MethodGroupExpr) mg1;
4612                         }
4613
4614                         MethodGroupExpr left_set = null, right_set = null;
4615                         int length1 = 0, length2 = 0;
4616
4617                         left_set = (MethodGroupExpr) mg1;
4618                         length1 = left_set.Methods.Length;
4619
4620                         right_set = (MethodGroupExpr) mg2;
4621                         length2 = right_set.Methods.Length;
4622
4623                         ArrayList common = new ArrayList ();
4624
4625                         foreach (MethodBase r in right_set.Methods){
4626                                 if (TypeManager.ArrayContainsMethod (left_set.Methods, r))
4627                                         common.Add (r);
4628                         }
4629
4630                         miset = new MemberInfo [length1 + length2 - common.Count];
4631                         left_set.Methods.CopyTo (miset, 0);
4632
4633                         int k = length1;
4634
4635                         foreach (MethodBase r in right_set.Methods) {
4636                                 if (!common.Contains (r))
4637                                         miset [k++] = r;
4638                         }
4639
4640                         union = new MethodGroupExpr (miset, loc);
4641
4642                         return union;
4643                 }
4644
4645                 static bool IsParamsMethodApplicable (EmitContext ec, MethodGroupExpr me,
4646                                                       ArrayList arguments, int arg_count,
4647                                                       ref MethodBase candidate)
4648                 {
4649                         return IsParamsMethodApplicable (
4650                                 ec, me, arguments, arg_count, false, ref candidate) ||
4651                                 IsParamsMethodApplicable (
4652                                         ec, me, arguments, arg_count, true, ref candidate);
4653
4654
4655                 }
4656
4657                 static bool IsParamsMethodApplicable (EmitContext ec, MethodGroupExpr me,
4658                                                       ArrayList arguments, int arg_count,
4659                                                       bool do_varargs, ref MethodBase candidate)
4660                 {
4661                         if (!me.HasTypeArguments &&
4662                             !TypeManager.InferParamsTypeArguments (ec, arguments, ref candidate))
4663                                 return false;
4664
4665                         return IsParamsMethodApplicable (
4666                                 ec, arguments, arg_count, candidate, do_varargs);
4667                 }
4668
4669                 /// <summary>
4670                 ///   Determines if the candidate method, if a params method, is applicable
4671                 ///   in its expanded form to the given set of arguments
4672                 /// </summary>
4673                 static bool IsParamsMethodApplicable (EmitContext ec, ArrayList arguments,
4674                                                       int arg_count, MethodBase candidate,
4675                                                       bool do_varargs)
4676                 {
4677                         ParameterData pd = TypeManager.GetParameterData (candidate);
4678
4679                         int pd_count = pd.Count;
4680
4681                         if (pd_count == 0)
4682                                 return false;
4683
4684                         int count = pd_count - 1;
4685                         if (do_varargs) {
4686                                 if (pd.ParameterModifier (count) != Parameter.Modifier.ARGLIST)
4687                                         return false;
4688                                 if (pd_count != arg_count)
4689                                         return false;
4690                         } else {
4691                                 if (pd.ParameterModifier (count) != Parameter.Modifier.PARAMS)
4692                                 return false;
4693                         }
4694
4695                         if (count > arg_count)
4696                                 return false;
4697
4698                         if (pd_count == 1 && arg_count == 0)
4699                                 return true;
4700
4701                         //
4702                         // If we have come this far, the case which
4703                         // remains is when the number of parameters is
4704                         // less than or equal to the argument count.
4705                         //
4706                         for (int i = 0; i < count; ++i) {
4707
4708                                 Argument a = (Argument) arguments [i];
4709
4710                                 Parameter.Modifier a_mod = a.GetParameterModifier () &
4711                                         (unchecked (~(Parameter.Modifier.OUT | Parameter.Modifier.REF)));
4712                                 Parameter.Modifier p_mod = pd.ParameterModifier (i) &
4713                                         (unchecked (~(Parameter.Modifier.OUT | Parameter.Modifier.REF)));
4714
4715                                 if (a_mod == p_mod) {
4716
4717                                         if (a_mod == Parameter.Modifier.NONE)
4718                                                 if (!Convert.ImplicitConversionExists (ec,
4719                                                                                        a.Expr,
4720                                                                                        pd.ParameterType (i)))
4721                                                         return false;
4722
4723                                         if ((a_mod & Parameter.Modifier.ISBYREF) != 0) {
4724                                                 Type pt = pd.ParameterType (i);
4725
4726                                                 if (!pt.IsByRef)
4727                                                         pt = TypeManager.GetReferenceType (pt);
4728
4729                                                 if (pt != a.Type)
4730                                                         return false;
4731                                         }
4732                                 } else
4733                                         return false;
4734
4735                         }
4736
4737                         if (do_varargs) {
4738                                 Argument a = (Argument) arguments [count];
4739                                 if (!(a.Expr is Arglist))
4740                                         return false;
4741
4742                                 return true;
4743                         }
4744
4745                         Type element_type = TypeManager.GetElementType (pd.ParameterType (pd_count - 1));
4746
4747                         for (int i = pd_count - 1; i < arg_count; i++) {
4748                                 Argument a = (Argument) arguments [i];
4749
4750                                 if (!Convert.ImplicitConversionExists (ec, a.Expr, element_type))
4751                                         return false;
4752                         }
4753
4754                         return true;
4755                 }
4756
4757                 static bool IsApplicable (EmitContext ec, MethodGroupExpr me,
4758                                           ArrayList arguments, int arg_count,
4759                                           ref MethodBase candidate)
4760                 {
4761                         if (!me.HasTypeArguments &&
4762                             !TypeManager.InferTypeArguments (ec, arguments, ref candidate))
4763                                 return false;
4764
4765                         return IsApplicable (ec, arguments, arg_count, candidate);
4766                 }
4767
4768                 /// <summary>
4769                 ///   Determines if the candidate method is applicable (section 14.4.2.1)
4770                 ///   to the given set of arguments
4771                 /// </summary>
4772                 static bool IsApplicable (EmitContext ec, ArrayList arguments, int arg_count,
4773                                           MethodBase candidate)
4774                 {
4775                         ParameterData pd = TypeManager.GetParameterData (candidate);
4776
4777                         if (arg_count != pd.Count)
4778                                 return false;
4779
4780                         for (int i = arg_count; i > 0; ) {
4781                                 i--;
4782
4783                                 Argument a = (Argument) arguments [i];
4784
4785                                 Parameter.Modifier a_mod = a.GetParameterModifier () &
4786                                         unchecked (~(Parameter.Modifier.OUT | Parameter.Modifier.REF));
4787                                 Parameter.Modifier p_mod = pd.ParameterModifier (i) &
4788                                         unchecked (~(Parameter.Modifier.OUT | Parameter.Modifier.REF));
4789
4790
4791                                 if (a_mod == p_mod ||
4792                                     (a_mod == Parameter.Modifier.NONE && p_mod == Parameter.Modifier.PARAMS)) {
4793                                         if (a_mod == Parameter.Modifier.NONE) {
4794                                                 if (!Convert.ImplicitConversionExists (ec,
4795                                                                                        a.Expr,
4796                                                                                        pd.ParameterType (i)))
4797                                                         return false;
4798                                         }
4799
4800                                         if ((a_mod & Parameter.Modifier.ISBYREF) != 0) {
4801                                                 Type pt = pd.ParameterType (i);
4802
4803                                                 if (!pt.IsByRef)
4804                                                         pt = TypeManager.GetReferenceType (pt);
4805
4806                                                 if (pt != a.Type)
4807                                                         return false;
4808                                         }
4809                                 } else
4810                                         return false;
4811                         }
4812
4813                         return true;
4814                 }
4815
4816                 static private bool IsAncestralType (Type first_type, Type second_type)
4817                 {
4818                         return first_type != second_type &&
4819                                 (second_type.IsSubclassOf (first_type) ||
4820                                  TypeManager.ImplementsInterface (second_type, first_type));
4821                 }
4822
4823                 /// <summary>
4824                 ///   Find the Applicable Function Members (7.4.2.1)
4825                 ///
4826                 ///   me: Method Group expression with the members to select.
4827                 ///       it might contain constructors or methods (or anything
4828                 ///       that maps to a method).
4829                 ///
4830                 ///   Arguments: ArrayList containing resolved Argument objects.
4831                 ///
4832                 ///   loc: The location if we want an error to be reported, or a Null
4833                 ///        location for "probing" purposes.
4834                 ///
4835                 ///   Returns: The MethodBase (either a ConstructorInfo or a MethodInfo)
4836                 ///            that is the best match of me on Arguments.
4837                 ///
4838                 /// </summary>
4839                 public static MethodBase OverloadResolve (EmitContext ec, MethodGroupExpr me,
4840                                                           ArrayList Arguments, bool may_fail,
4841                                                           Location loc)
4842                 {
4843                         MethodBase method = null;
4844                         bool method_params = false;
4845                         Type applicable_type = null;
4846                         int arg_count = 0;
4847                         ArrayList candidates = new ArrayList ();
4848                         ArrayList candidate_overrides = new ArrayList ();
4849
4850                         //
4851                         // Used to keep a map between the candidate
4852                         // and whether it is being considered in its
4853                         // normal or expanded form
4854                         //
4855                         // false is normal form, true is expanded form
4856                         //
4857                         Hashtable candidate_to_form = null;
4858
4859                         if (Arguments != null)
4860                                 arg_count = Arguments.Count;
4861
4862                         if ((me.Name == "Invoke") &&
4863                             TypeManager.IsDelegateType (me.DeclaringType)) {
4864                                 Error_InvokeOnDelegate (loc);
4865                                 return null;
4866                         }
4867
4868                         MethodBase[] methods = me.Methods;
4869
4870                         //
4871                         // First we construct the set of applicable methods
4872                         //
4873                         bool is_sorted = true;
4874                         for (int i = 0; i < methods.Length; i++){
4875                                 Type decl_type = methods [i].DeclaringType;
4876
4877                                 //
4878                                 // If we have already found an applicable method
4879                                 // we eliminate all base types (Section 14.5.5.1)
4880                                 //
4881                                 if ((applicable_type != null) &&
4882                                     IsAncestralType (decl_type, applicable_type))
4883                                         continue;
4884
4885                                 //
4886                                 // Methods marked 'override' don't take part in 'applicable_type'
4887                                 // computation, nor in the actual overload resolution.
4888                                 // However, they still need to be emitted instead of a base virtual method.
4889                                 // We avoid doing the 'applicable' test here, since it'll anyway be applied
4890                                 // to the base virtual function, and IsOverride is much faster than IsApplicable.
4891                                 //
4892                                 if (!me.IsBase &&
4893                                     methods [i].IsVirtual &&
4894                                     (methods [i].Attributes & MethodAttributes.NewSlot) == 0) {
4895                                         candidate_overrides.Add (methods [i]);
4896                                         continue;
4897                                 }
4898
4899                                 //
4900                                 // Check if candidate is applicable (section 14.4.2.1)
4901                                 //   Is candidate applicable in normal form?
4902                                 //
4903                                 bool is_applicable = IsApplicable (
4904                                         ec, me, Arguments, arg_count, ref methods [i]);
4905
4906                                 if (!is_applicable &&
4907                                     (IsParamsMethodApplicable (
4908                                             ec, me, Arguments, arg_count, ref methods [i]))) {
4909                                         MethodBase candidate = methods [i];
4910                                         if (candidate_to_form == null)
4911                                                 candidate_to_form = new PtrHashtable ();
4912                                         candidate_to_form [candidate] = candidate;
4913                                         // Candidate is applicable in expanded form
4914                                         is_applicable = true;
4915                                 }
4916
4917                                 if (!is_applicable)
4918                                         continue;
4919
4920                                 candidates.Add (methods [i]);
4921
4922                                 if (applicable_type == null)
4923                                         applicable_type = decl_type;
4924                                 else if (applicable_type != decl_type) {
4925                                         is_sorted = false;
4926                                         if (IsAncestralType (applicable_type, decl_type))
4927                                                 applicable_type = decl_type;
4928                                 }
4929                         }
4930
4931                         int candidate_top = candidates.Count;
4932
4933                         if (applicable_type == null) {
4934                                 //
4935                                 // Okay so we have failed to find anything so we
4936                                 // return by providing info about the closest match
4937                                 //
4938                                 for (int i = 0; i < methods.Length; ++i) {
4939                                         MethodBase c = (MethodBase) methods [i];
4940                                         ParameterData pd = TypeManager.GetParameterData (c);
4941
4942                                         if (pd.Count != arg_count)
4943                                                 continue;
4944
4945                                         if (!TypeManager.InferTypeArguments (ec, Arguments, ref c))
4946                                                 continue;
4947
4948                                         VerifyArgumentsCompat (ec, Arguments, arg_count,
4949                                                                c, false, null, may_fail, loc);
4950                                         break;
4951                                 }
4952
4953                                 if (!may_fail) {
4954                                         string report_name = me.Name;
4955                                         if (report_name == ".ctor")
4956                                                 report_name = me.DeclaringType.ToString ();
4957
4958                                         for (int i = 0; i < methods.Length; ++i) {
4959                                                 MethodBase c = methods [i];
4960                                                 ParameterData pd = TypeManager.GetParameterData (c);
4961
4962                                                 if (pd.Count != arg_count)
4963                                                         continue;
4964
4965                                                 if (TypeManager.InferTypeArguments (ec, Arguments, ref c))
4966                                                         continue;
4967
4968                                                 Report.Error (
4969                                                         411, loc, "The type arguments for " +
4970                                                         "method `{0}' cannot be infered from " +
4971                                                         "the usage. Try specifying the type " +
4972                                                         "arguments explicitly.", report_name);
4973                                                 return null;
4974                                         }
4975
4976                                         Error_WrongNumArguments (
4977                                                 loc, report_name, arg_count);
4978                                         return null;
4979                                 }
4980
4981                                 return null;
4982                         }
4983
4984                         if (!is_sorted) {
4985                                 //
4986                                 // At this point, applicable_type is _one_ of the most derived types
4987                                 // in the set of types containing the methods in this MethodGroup.
4988                                 // Filter the candidates so that they only contain methods from the
4989                                 // most derived types.
4990                                 //
4991
4992                                 int finalized = 0; // Number of finalized candidates
4993
4994                                 do {
4995                                         // Invariant: applicable_type is a most derived type
4996
4997                                         // We'll try to complete Section 14.5.5.1 for 'applicable_type' by
4998                                         // eliminating all it's base types.  At the same time, we'll also move
4999                                         // every unrelated type to the end of the array, and pick the next
5000                                         // 'applicable_type'.
5001
5002                                         Type next_applicable_type = null;
5003                                         int j = finalized; // where to put the next finalized candidate
5004                                         int k = finalized; // where to put the next undiscarded candidate
5005                                         for (int i = finalized; i < candidate_top; ++i) {
5006                                                 MethodBase candidate = (MethodBase) candidates [i];
5007                                                 Type decl_type = candidate.DeclaringType;
5008
5009                                                 if (decl_type == applicable_type) {
5010                                                         candidates [k++] = candidates [j];
5011                                                         candidates [j++] = candidates [i];
5012                                                         continue;
5013                                                 }
5014
5015                                                 if (IsAncestralType (decl_type, applicable_type))
5016                                                         continue;
5017
5018                                                 if (next_applicable_type != null &&
5019                                                     IsAncestralType (decl_type, next_applicable_type))
5020                                                         continue;
5021
5022                                                 candidates [k++] = candidates [i];
5023
5024 #if false
5025                                                 //
5026                                                 // Methods marked 'override' don't take part in 'applicable_type'
5027                                                 // computation.
5028                                                 //
5029                                                 if (!me.IsBase &&
5030                                                     candidate.IsVirtual &&
5031                                                     (candidate.Attributes & MethodAttributes.NewSlot) == 0)
5032                                                         continue;
5033 #endif
5034
5035                                                 if (next_applicable_type == null ||
5036                                                     IsAncestralType (next_applicable_type, decl_type))
5037                                                         next_applicable_type = decl_type;
5038                                         }
5039
5040                                         applicable_type = next_applicable_type;
5041                                         finalized = j;
5042                                         candidate_top = k;
5043                                 } while (applicable_type != null);
5044                         }
5045
5046                         //
5047                         // Now we actually find the best method
5048                         //
5049
5050                         method = (MethodBase) candidates [0];
5051                         method_params = candidate_to_form != null && candidate_to_form.Contains (method);
5052                         for (int ix = 1; 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
5060                                 if (BetterFunction (ec, Arguments, arg_count,
5061                                                     candidate, cand_params,
5062                                                     method, method_params, loc)) {
5063                                         method = candidate;
5064                                         method_params = cand_params;
5065                                 }
5066                         }
5067
5068                         //
5069                         // Now check that there are no ambiguities i.e the selected method
5070                         // should be better than all the others
5071                         //
5072                         bool ambiguous = false;
5073                         for (int ix = 0; ix < candidate_top; ix++){
5074                                 MethodBase candidate = (MethodBase) candidates [ix];
5075
5076                                 if (candidate == method)
5077                                         continue;
5078
5079                                 bool cand_params = candidate_to_form != null && candidate_to_form.Contains (candidate);
5080                                 if (!BetterFunction (ec, Arguments, arg_count,
5081                                                     method, method_params,
5082                                                     candidate, cand_params,
5083                                                      loc)) {
5084                                         Report.SymbolRelatedToPreviousError (candidate);
5085                                         ambiguous = true;
5086                                 }
5087                         }
5088
5089                         if (ambiguous) {
5090                                 Report.SymbolRelatedToPreviousError (method);
5091                                 Report.Error (121, loc, "Ambiguous call when selecting function due to implicit casts");
5092                                 return null;
5093                         }
5094
5095                         //
5096                         // If the method is a virtual function, pick an override closer to the LHS type.
5097                         //
5098                         if (!me.IsBase && method.IsVirtual) {
5099                                 if ((method.Attributes & MethodAttributes.NewSlot) != MethodAttributes.NewSlot)
5100                                         throw new InternalErrorException (
5101                                                 "Should not happen.  An 'override' method took part in overload resolution: " + method);
5102
5103                                 foreach (MethodBase candidate in candidate_overrides) {
5104                                         if (IsOverride (candidate, method))
5105                                                 method = candidate;
5106                                 }
5107                         }
5108
5109                         //
5110                         // And now check if the arguments are all
5111                         // compatible, perform conversions if
5112                         // necessary etc. and return if everything is
5113                         // all right
5114                         //
5115                         if (!VerifyArgumentsCompat (ec, Arguments, arg_count, method,
5116                                                     method_params, null, may_fail, loc))
5117                                 return null;
5118
5119                         return method;
5120                 }
5121
5122                 static void Error_WrongNumArguments (Location loc, String name, int arg_count)
5123                 {
5124                         Report.Error (1501, loc,
5125                                       "No overload for method `" + name + "' takes `" +
5126                                       arg_count + "' arguments");
5127                 }
5128
5129                 static void Error_InvokeOnDelegate (Location loc)
5130                 {
5131                         Report.Error (1533, loc,
5132                                       "Invoke cannot be called directly on a delegate");
5133                 }
5134
5135                 static void Error_InvalidArguments (Location loc, int idx, MethodBase method,
5136                                                     Type delegate_type, string arg_sig, string par_desc)
5137                 {
5138                         if (delegate_type == null)
5139                                 Report.Error (1502, loc,
5140                                               "The best overloaded match for method '" +
5141                                               FullMethodDesc (method) +
5142                                               "' has some invalid arguments");
5143                         else
5144                                 Report.Error (1594, loc,
5145                                               "Delegate '" + delegate_type.ToString () +
5146                                               "' has some invalid arguments.");
5147                         Report.Error (1503, loc,
5148                                       String.Format ("Argument {0}: Cannot convert from '{1}' to '{2}'",
5149                                                      idx, arg_sig, par_desc));
5150                 }
5151
5152                 public static bool VerifyArgumentsCompat (EmitContext ec, ArrayList Arguments,
5153                                                           int arg_count, MethodBase method,
5154                                                           bool chose_params_expanded,
5155                                                           Type delegate_type, bool may_fail,
5156                                                           Location loc)
5157                 {
5158                         ParameterData pd = TypeManager.GetParameterData (method);
5159                         int pd_count = pd.Count;
5160
5161                         for (int j = 0; j < arg_count; j++) {
5162                                 Argument a = (Argument) Arguments [j];
5163                                 Expression a_expr = a.Expr;
5164                                 Type parameter_type = pd.ParameterType (j);
5165                                 Parameter.Modifier pm = pd.ParameterModifier (j);
5166
5167                                 if (pm == Parameter.Modifier.PARAMS){
5168                                         if ((pm & ~Parameter.Modifier.PARAMS) != a.GetParameterModifier ()) {
5169                                                 if (!may_fail)
5170                                                         Error_InvalidArguments (
5171                                                                 loc, j, method, delegate_type,
5172                                                                 Argument.FullDesc (a), pd.ParameterDesc (j));
5173                                                 return false;
5174                                         }
5175
5176                                         if (chose_params_expanded)
5177                                                 parameter_type = TypeManager.GetElementType (parameter_type);
5178                                 } else if (pm == Parameter.Modifier.ARGLIST){
5179                                         continue;
5180                                 } else {
5181                                         //
5182                                         // Check modifiers
5183                                         //
5184                                         if (pd.ParameterModifier (j) != a.GetParameterModifier ()){
5185                                                 if (!may_fail)
5186                                                         Error_InvalidArguments (
5187                                                                 loc, j, method, delegate_type,
5188                                                                 Argument.FullDesc (a), pd.ParameterDesc (j));
5189                                                 return false;
5190                                         }
5191                                 }
5192
5193                                 //
5194                                 // Check Type
5195                                 //
5196                                 if (!TypeManager.IsEqual (a.Type, parameter_type)){
5197                                         Expression conv;
5198
5199                                         conv = Convert.ImplicitConversion (ec, a_expr, parameter_type, loc);
5200
5201                                         if (conv == null) {
5202                                                 if (!may_fail)
5203                                                         Error_InvalidArguments (
5204                                                                 loc, j, method, delegate_type,
5205                                                                 Argument.FullDesc (a), pd.ParameterDesc (j));
5206                                                 return false;
5207                                         }
5208
5209                                         //
5210                                         // Update the argument with the implicit conversion
5211                                         //
5212                                         if (a_expr != conv)
5213                                                 a.Expr = conv;
5214                                 }
5215
5216                                 if (parameter_type.IsPointer){
5217                                         if (!ec.InUnsafe){
5218                                                 UnsafeError (loc);
5219                                                 return false;
5220                                         }
5221                                 }
5222
5223                                 Parameter.Modifier a_mod = a.GetParameterModifier () &
5224                                         unchecked (~(Parameter.Modifier.OUT | Parameter.Modifier.REF));
5225                                 Parameter.Modifier p_mod = pd.ParameterModifier (j) &
5226                                         unchecked (~(Parameter.Modifier.OUT | Parameter.Modifier.REF));
5227
5228                                 if (a_mod != p_mod &&
5229                                     pd.ParameterModifier (pd_count - 1) != Parameter.Modifier.PARAMS) {
5230                                         if (!may_fail) {
5231                                                 Report.Error (1502, loc,
5232                                                        "The best overloaded match for method '" + FullMethodDesc (method)+
5233                                                        "' has some invalid arguments");
5234                                                 Report.Error (1503, loc,
5235                                                        "Argument " + (j+1) +
5236                                                        ": Cannot convert from '" + Argument.FullDesc (a)
5237                                                        + "' to '" + pd.ParameterDesc (j) + "'");
5238                                         }
5239
5240                                         return false;
5241                                 }
5242                         }
5243
5244                         return true;
5245                 }
5246
5247                 public override Expression DoResolve (EmitContext ec)
5248                 {
5249                         //
5250                         // First, resolve the expression that is used to
5251                         // trigger the invocation
5252                         //
5253                         if (expr is ConstructedType)
5254                                 expr = ((ConstructedType) expr).GetSimpleName (ec);
5255
5256                         expr = expr.Resolve (ec, ResolveFlags.VariableOrValue | ResolveFlags.MethodGroup);
5257                         if (expr == null)
5258                                 return null;
5259
5260                         if (!(expr is MethodGroupExpr)) {
5261                                 Type expr_type = expr.Type;
5262
5263                                 if (expr_type != null){
5264                                         bool IsDelegate = TypeManager.IsDelegateType (expr_type);
5265                                         if (IsDelegate)
5266                                                 return (new DelegateInvocation (
5267                                                         this.expr, Arguments, loc)).Resolve (ec);
5268                                 }
5269                         }
5270
5271                         if (!(expr is MethodGroupExpr)){
5272                                 expr.Error_UnexpectedKind (ResolveFlags.MethodGroup, loc);
5273                                 return null;
5274                         }
5275
5276                         //
5277                         // Next, evaluate all the expressions in the argument list
5278                         //
5279                         if (Arguments != null){
5280                                 foreach (Argument a in Arguments){
5281                                         if (!a.Resolve (ec, loc))
5282                                                 return null;
5283                                 }
5284                         }
5285
5286                         MethodGroupExpr mg = (MethodGroupExpr) expr;
5287                         method = OverloadResolve (ec, mg, Arguments, false, loc);
5288
5289                         if (method == null)
5290                                 return null;
5291
5292                         MethodInfo mi = method as MethodInfo;
5293                         if (mi != null) {
5294                                 type = TypeManager.TypeToCoreType (mi.ReturnType);
5295                                 if (!mi.IsStatic && !mg.IsExplicitImpl && (mg.InstanceExpression == null)) {
5296                                         SimpleName.Error_ObjectRefRequired (ec, loc, mi.Name);
5297                                         return null;
5298                                 }
5299
5300                                 Expression iexpr = mg.InstanceExpression;
5301                                 if (mi.IsStatic && (iexpr != null) && !(iexpr is This)) {
5302                                         if (mg.IdenticalTypeName)
5303                                                 mg.InstanceExpression = null;
5304                                         else {
5305                                                 MemberAccess.error176 (loc, mi.Name);
5306                                                 return null;
5307                                         }
5308                                 }
5309                         }
5310
5311                         if (type.IsPointer){
5312                                 if (!ec.InUnsafe){
5313                                         UnsafeError (loc);
5314                                         return null;
5315                                 }
5316                         }
5317
5318                         //
5319                         // Only base will allow this invocation to happen.
5320                         //
5321                         if (mg.IsBase && method.IsAbstract){
5322                                 Report.Error (205, loc, "Cannot call an abstract base member: " +
5323                                               FullMethodDesc (method));
5324                                 return null;
5325                         }
5326
5327                         if (method.Name == "Finalize" && Arguments == null) {
5328                                 if (mg.IsBase)
5329                                         Report.Error (250, loc, "Do not directly call your base class Finalize method. It is called automatically from your destructor");
5330                                 else
5331                                         Report.Error (245, loc, "Destructors and object.Finalize cannot be called directly. Consider calling IDisposable.Dispose if available");
5332                                 return null;
5333                         }
5334
5335                         if ((method.Attributes & MethodAttributes.SpecialName) != 0){
5336                                 if (TypeManager.LookupDeclSpace (method.DeclaringType) != null || TypeManager.IsSpecialMethod (method)) {
5337                                         Report.Error (571, loc, TypeManager.CSharpSignature (method) + ": can not call operator or accessor");
5338                                         return null;
5339                                 }
5340                         }
5341
5342                         if (mg.InstanceExpression != null)
5343                                 mg.InstanceExpression.CheckMarshallByRefAccess (ec.ContainerType);
5344
5345                         eclass = ExprClass.Value;
5346                         return this;
5347                 }
5348
5349                 // <summary>
5350                 //   Emits the list of arguments as an array
5351                 // </summary>
5352                 static void EmitParams (EmitContext ec, int idx, ArrayList arguments)
5353                 {
5354                         ILGenerator ig = ec.ig;
5355                         int count = arguments.Count - idx;
5356                         Argument a = (Argument) arguments [idx];
5357                         Type t = a.Expr.Type;
5358
5359                         IntConstant.EmitInt (ig, count);
5360                         ig.Emit (OpCodes.Newarr, TypeManager.TypeToCoreType (t));
5361
5362                         int top = arguments.Count;
5363                         for (int j = idx; j < top; j++){
5364                                 a = (Argument) arguments [j];
5365
5366                                 ig.Emit (OpCodes.Dup);
5367                                 IntConstant.EmitInt (ig, j - idx);
5368
5369                                 bool is_stobj, has_type_arg;
5370                                 OpCode op = ArrayAccess.GetStoreOpcode (t, out is_stobj, out has_type_arg);
5371                                 if (is_stobj)
5372                                         ig.Emit (OpCodes.Ldelema, t);
5373
5374                                 a.Emit (ec);
5375
5376                                 if (has_type_arg)
5377                                         ig.Emit (op, t);
5378                                 else
5379                                         ig.Emit (op);
5380                         }
5381                 }
5382
5383                 /// <summary>
5384                 ///   Emits a list of resolved Arguments that are in the arguments
5385                 ///   ArrayList.
5386                 ///
5387                 ///   The MethodBase argument might be null if the
5388                 ///   emission of the arguments is known not to contain
5389                 ///   a `params' field (for example in constructors or other routines
5390                 ///   that keep their arguments in this structure)
5391                 ///
5392                 ///   if `dup_args' is true, a copy of the arguments will be left
5393                 ///   on the stack. If `dup_args' is true, you can specify `this_arg'
5394                 ///   which will be duplicated before any other args. Only EmitCall
5395                 ///   should be using this interface.
5396                 /// </summary>
5397                 public static void EmitArguments (EmitContext ec, MethodBase mb, ArrayList arguments, bool dup_args, LocalTemporary this_arg)
5398                 {
5399                         ParameterData pd;
5400                         if (mb != null)
5401                                 pd = TypeManager.GetParameterData (mb);
5402                         else
5403                                 pd = null;
5404
5405                         LocalTemporary [] temps = null;
5406
5407                         if (dup_args)
5408                                 temps = new LocalTemporary [arguments.Count];
5409
5410                         //
5411                         // If we are calling a params method with no arguments, special case it
5412                         //
5413                         if (arguments == null){
5414                                 if (pd != null && pd.Count > 0 &&
5415                                     pd.ParameterModifier (0) == Parameter.Modifier.PARAMS){
5416                                         ILGenerator ig = ec.ig;
5417
5418                                         IntConstant.EmitInt (ig, 0);
5419                                         ig.Emit (OpCodes.Newarr, TypeManager.GetElementType (pd.ParameterType (0)));
5420                                 }
5421
5422                                 return;
5423                         }
5424
5425                         int top = arguments.Count;
5426
5427                         for (int i = 0; i < top; i++){
5428                                 Argument a = (Argument) arguments [i];
5429
5430                                 if (pd != null){
5431                                         if (pd.ParameterModifier (i) == Parameter.Modifier.PARAMS){
5432                                                 //
5433                                                 // Special case if we are passing the same data as the
5434                                                 // params argument, do not put it in an array.
5435                                                 //
5436                                                 if (pd.ParameterType (i) == a.Type)
5437                                                         a.Emit (ec);
5438                                                 else
5439                                                         EmitParams (ec, i, arguments);
5440                                                 return;
5441                                         }
5442                                 }
5443
5444                                 a.Emit (ec);
5445                                 if (dup_args) {
5446                                         ec.ig.Emit (OpCodes.Dup);
5447                                         (temps [i] = new LocalTemporary (ec, a.Type)).Store (ec);
5448                                 }
5449                         }
5450
5451                         if (dup_args) {
5452                                 if (this_arg != null)
5453                                         this_arg.Emit (ec);
5454
5455                                 for (int i = 0; i < top; i ++)
5456                                         temps [i].Emit (ec);
5457                         }
5458
5459                         if (pd != null && pd.Count > top &&
5460                             pd.ParameterModifier (top) == Parameter.Modifier.PARAMS){
5461                                 ILGenerator ig = ec.ig;
5462
5463                                 IntConstant.EmitInt (ig, 0);
5464                                 ig.Emit (OpCodes.Newarr, TypeManager.GetElementType (pd.ParameterType (top)));
5465                         }
5466                 }
5467
5468                 static Type[] GetVarargsTypes (EmitContext ec, MethodBase mb,
5469                                                ArrayList arguments)
5470                 {
5471                         ParameterData pd = TypeManager.GetParameterData (mb);
5472
5473                         if (arguments == null)
5474                                 return new Type [0];
5475
5476                         Argument a = (Argument) arguments [pd.Count - 1];
5477                         Arglist list = (Arglist) a.Expr;
5478
5479                         return list.ArgumentTypes;
5480                 }
5481
5482                 /// <summary>
5483                 /// This checks the ConditionalAttribute on the method
5484                 /// </summary>
5485                 static bool IsMethodExcluded (MethodBase method, EmitContext ec)
5486                 {
5487                         if (method.IsConstructor)
5488                                 return false;
5489
5490                         IMethodData md = TypeManager.GetMethod (method);
5491                         if (md != null)
5492                                 return md.IsExcluded (ec);
5493
5494                         // For some methods (generated by delegate class) GetMethod returns null
5495                         // because they are not included in builder_to_method table
5496                         if (method.DeclaringType is TypeBuilder)
5497                                 return false;
5498
5499                         return AttributeTester.IsConditionalMethodExcluded (method);
5500                 }
5501
5502                 /// <remarks>
5503                 ///   is_base tells whether we want to force the use of the `call'
5504                 ///   opcode instead of using callvirt.  Call is required to call
5505                 ///   a specific method, while callvirt will always use the most
5506                 ///   recent method in the vtable.
5507                 ///
5508                 ///   is_static tells whether this is an invocation on a static method
5509                 ///
5510                 ///   instance_expr is an expression that represents the instance
5511                 ///   it must be non-null if is_static is false.
5512                 ///
5513                 ///   method is the method to invoke.
5514                 ///
5515                 ///   Arguments is the list of arguments to pass to the method or constructor.
5516                 /// </remarks>
5517                 public static void EmitCall (EmitContext ec, bool is_base,
5518                                              bool is_static, Expression instance_expr,
5519                                              MethodBase method, ArrayList Arguments, Location loc)
5520                 {
5521                         EmitCall (ec, is_base, is_static, instance_expr, method, Arguments, loc, false, false);
5522                 }
5523
5524                 // `dup_args' leaves an extra copy of the arguments on the stack
5525                 // `omit_args' does not leave any arguments at all.
5526                 // So, basically, you could make one call with `dup_args' set to true,
5527                 // and then another with `omit_args' set to true, and the two calls
5528                 // would have the same set of arguments. However, each argument would
5529                 // only have been evaluated once.
5530                 public static void EmitCall (EmitContext ec, bool is_base,
5531                                              bool is_static, Expression instance_expr,
5532                                              MethodBase method, ArrayList Arguments, Location loc,
5533                                              bool dup_args, bool omit_args)
5534                 {
5535                         ILGenerator ig = ec.ig;
5536                         bool struct_call = false;
5537                         bool this_call = false;
5538                         LocalTemporary this_arg = null;
5539
5540                         Type decl_type = method.DeclaringType;
5541
5542                         if (!RootContext.StdLib) {
5543                                 // Replace any calls to the system's System.Array type with calls to
5544                                 // the newly created one.
5545                                 if (method == TypeManager.system_int_array_get_length)
5546                                         method = TypeManager.int_array_get_length;
5547                                 else if (method == TypeManager.system_int_array_get_rank)
5548                                         method = TypeManager.int_array_get_rank;
5549                                 else if (method == TypeManager.system_object_array_clone)
5550                                         method = TypeManager.object_array_clone;
5551                                 else if (method == TypeManager.system_int_array_get_length_int)
5552                                         method = TypeManager.int_array_get_length_int;
5553                                 else if (method == TypeManager.system_int_array_get_lower_bound_int)
5554                                         method = TypeManager.int_array_get_lower_bound_int;
5555                                 else if (method == TypeManager.system_int_array_get_upper_bound_int)
5556                                         method = TypeManager.int_array_get_upper_bound_int;
5557                                 else if (method == TypeManager.system_void_array_copyto_array_int)
5558                                         method = TypeManager.void_array_copyto_array_int;
5559                         }
5560
5561                         if (ec.TestObsoleteMethodUsage) {
5562                                 //
5563                                 // This checks ObsoleteAttribute on the method and on the declaring type
5564                                 //
5565                                 ObsoleteAttribute oa = AttributeTester.GetMethodObsoleteAttribute (method);
5566                                 if (oa != null)
5567                                         AttributeTester.Report_ObsoleteMessage (oa, TypeManager.CSharpSignature (method), loc);
5568
5569                                 oa = AttributeTester.GetObsoleteAttribute (method.DeclaringType);
5570                                 if (oa != null) {
5571                                         AttributeTester.Report_ObsoleteMessage (oa, method.DeclaringType.FullName, loc);
5572                                 }
5573                         }
5574
5575                         if (IsMethodExcluded (method, ec))
5576                                 return;
5577
5578                         if (!is_static){
5579                                 this_call = instance_expr == null;
5580                                 if (decl_type.IsValueType || (!this_call && instance_expr.Type.IsValueType))
5581                                         struct_call = true;
5582
5583                                 //
5584                                 // If this is ourselves, push "this"
5585                                 //
5586                                 if (!omit_args) {
5587                                         Type t = null;
5588                                         if (this_call) {
5589                                                 ig.Emit (OpCodes.Ldarg_0);
5590                                                 t = decl_type;
5591                                         } else {
5592                                                 Type iexpr_type = instance_expr.Type;
5593
5594                                                 //
5595                                                 // Push the instance expression
5596                                                 //
5597                                                 if (TypeManager.IsValueType (iexpr_type)) {
5598                                                         //
5599                                                         // Special case: calls to a function declared in a
5600                                                         // reference-type with a value-type argument need
5601                                                         // to have their value boxed.
5602                                                         if (decl_type.IsValueType ||
5603                                                             iexpr_type.IsGenericParameter) {
5604                                                                 //
5605                                                                 // If the expression implements IMemoryLocation, then
5606                                                                 // we can optimize and use AddressOf on the
5607                                                                 // return.
5608                                                                 //
5609                                                                 // If not we have to use some temporary storage for
5610                                                                 // it.
5611                                                                 if (instance_expr is IMemoryLocation) {
5612                                                                         ((IMemoryLocation)instance_expr).
5613                                                                                 AddressOf (ec, AddressOp.LoadStore);
5614                                                                 } else {
5615                                                                         LocalTemporary temp = new LocalTemporary (ec, iexpr_type);
5616                                                                         instance_expr.Emit (ec);
5617                                                                         temp.Store (ec);
5618                                                                         temp.AddressOf (ec, AddressOp.Load);
5619                                                                 }
5620
5621                                                                 // avoid the overhead of doing this all the time.
5622                                                                 if (dup_args)
5623                                                                         t = TypeManager.GetReferenceType (iexpr_type);
5624                                                         } else {
5625                                                                 instance_expr.Emit (ec);
5626                                                                 ig.Emit (OpCodes.Box, instance_expr.Type);
5627                                                                 t = TypeManager.object_type;
5628                                                         }
5629                                                 } else {
5630                                                         instance_expr.Emit (ec);
5631                                                         t = instance_expr.Type;
5632                                                 }
5633                                         }
5634
5635                                         if (dup_args) {
5636                                                 this_arg = new LocalTemporary (ec, t);
5637                                                 ig.Emit (OpCodes.Dup);
5638                                                 this_arg.Store (ec);
5639                                         }
5640                                 }
5641                         }
5642
5643                         if (!omit_args)
5644                                 EmitArguments (ec, method, Arguments, dup_args, this_arg);
5645
5646                         if ((instance_expr != null) && (instance_expr.Type.IsGenericParameter))
5647                                 ig.Emit (OpCodes.Constrained, instance_expr.Type);
5648
5649                         OpCode call_op;
5650                         if (is_static || struct_call || is_base || (this_call && !method.IsVirtual))
5651                                 call_op = OpCodes.Call;
5652                         else
5653                                 call_op = OpCodes.Callvirt;
5654
5655                         if ((method.CallingConvention & CallingConventions.VarArgs) != 0) {
5656                                 Type[] varargs_types = GetVarargsTypes (ec, method, Arguments);
5657                                 ig.EmitCall (call_op, (MethodInfo) method, varargs_types);
5658                                 return;
5659                         }
5660
5661                         //
5662                         // If you have:
5663                         // this.DoFoo ();
5664                         // and DoFoo is not virtual, you can omit the callvirt,
5665                         // because you don't need the null checking behavior.
5666                         //
5667                         if (method is MethodInfo)
5668                                 ig.Emit (call_op, (MethodInfo) method);
5669                         else
5670                                 ig.Emit (call_op, (ConstructorInfo) method);
5671                 }
5672
5673                 public override void Emit (EmitContext ec)
5674                 {
5675                         MethodGroupExpr mg = (MethodGroupExpr) this.expr;
5676
5677                         EmitCall (ec, mg.IsBase, method.IsStatic, mg.InstanceExpression, method, Arguments, loc);
5678                 }
5679
5680                 public override void EmitStatement (EmitContext ec)
5681                 {
5682                         Emit (ec);
5683
5684                         //
5685                         // Pop the return value if there is one
5686                         //
5687                         if (method is MethodInfo){
5688                                 Type ret = ((MethodInfo)method).ReturnType;
5689                                 if (TypeManager.TypeToCoreType (ret) != TypeManager.void_type)
5690                                         ec.ig.Emit (OpCodes.Pop);
5691                         }
5692                 }
5693         }
5694
5695         public class InvocationOrCast : ExpressionStatement
5696         {
5697                 Expression expr;
5698                 Expression argument;
5699
5700                 public InvocationOrCast (Expression expr, Expression argument, Location loc)
5701                 {
5702                         this.expr = expr;
5703                         this.argument = argument;
5704                         this.loc = loc;
5705                 }
5706
5707                 public override Expression DoResolve (EmitContext ec)
5708                 {
5709                         //
5710                         // First try to resolve it as a cast.
5711                         //
5712                         TypeExpr te = expr.ResolveAsTypeStep (ec) as TypeExpr;
5713                         if ((te != null) && (te.eclass == ExprClass.Type)) {
5714                                 Cast cast = new Cast (te, argument, loc);
5715                                 return cast.Resolve (ec);
5716                         }
5717
5718                         //
5719                         // This can either be a type or a delegate invocation.
5720                         // Let's just resolve it and see what we'll get.
5721                         //
5722                         expr = expr.Resolve (ec, ResolveFlags.Type | ResolveFlags.VariableOrValue);
5723                         if (expr == null)
5724                                 return null;
5725
5726                         //
5727                         // Ok, so it's a Cast.
5728                         //
5729                         if (expr.eclass == ExprClass.Type) {
5730                                 Cast cast = new Cast (new TypeExpression (expr.Type, loc), argument, loc);
5731                                 return cast.Resolve (ec);
5732                         }
5733
5734                         //
5735                         // It's a delegate invocation.
5736                         //
5737                         if (!TypeManager.IsDelegateType (expr.Type)) {
5738                                 Error (149, "Method name expected");
5739                                 return null;
5740                         }
5741
5742                         ArrayList args = new ArrayList ();
5743                         args.Add (new Argument (argument, Argument.AType.Expression));
5744                         DelegateInvocation invocation = new DelegateInvocation (expr, args, loc);
5745                         return invocation.Resolve (ec);
5746                 }
5747
5748                 void error201 ()
5749                 {
5750                         Error (201, "Only assignment, call, increment, decrement and new object " +
5751                                "expressions can be used as a statement");
5752                 }
5753
5754                 public override ExpressionStatement ResolveStatement (EmitContext ec)
5755                 {
5756                         //
5757                         // First try to resolve it as a cast.
5758                         //
5759                         TypeExpr te = expr.ResolveAsTypeStep (ec) as TypeExpr;
5760                         if ((te != null) && (te.eclass == ExprClass.Type)) {
5761                                 error201 ();
5762                                 return null;
5763                         }
5764
5765                         //
5766                         // This can either be a type or a delegate invocation.
5767                         // Let's just resolve it and see what we'll get.
5768                         //
5769                         expr = expr.Resolve (ec, ResolveFlags.Type | ResolveFlags.VariableOrValue);
5770                         if ((expr == null) || (expr.eclass == ExprClass.Type)) {
5771                                 error201 ();
5772                                 return null;
5773                         }
5774
5775                         //
5776                         // It's a delegate invocation.
5777                         //
5778                         if (!TypeManager.IsDelegateType (expr.Type)) {
5779                                 Error (149, "Method name expected");
5780                                 return null;
5781                         }
5782
5783                         ArrayList args = new ArrayList ();
5784                         args.Add (new Argument (argument, Argument.AType.Expression));
5785                         DelegateInvocation invocation = new DelegateInvocation (expr, args, loc);
5786                         return invocation.ResolveStatement (ec);
5787                 }
5788
5789                 public override void Emit (EmitContext ec)
5790                 {
5791                         throw new Exception ("Cannot happen");
5792                 }
5793
5794                 public override void EmitStatement (EmitContext ec)
5795                 {
5796                         throw new Exception ("Cannot happen");
5797                 }
5798         }
5799
5800         //
5801         // This class is used to "disable" the code generation for the
5802         // temporary variable when initializing value types.
5803         //
5804         class EmptyAddressOf : EmptyExpression, IMemoryLocation {
5805                 public void AddressOf (EmitContext ec, AddressOp Mode)
5806                 {
5807                         // nothing
5808                 }
5809         }
5810
5811         /// <summary>
5812         ///    Implements the new expression
5813         /// </summary>
5814         public class New : ExpressionStatement, IMemoryLocation {
5815                 public readonly ArrayList Arguments;
5816
5817                 //
5818                 // During bootstrap, it contains the RequestedType,
5819                 // but if `type' is not null, it *might* contain a NewDelegate
5820                 // (because of field multi-initialization)
5821                 //
5822                 public Expression RequestedType;
5823
5824                 MethodBase method = null;
5825
5826                 //
5827                 // If set, the new expression is for a value_target, and
5828                 // we will not leave anything on the stack.
5829                 //
5830                 Expression value_target;
5831                 bool value_target_set = false;
5832                 bool is_type_parameter = false;
5833
5834                 public New (Expression requested_type, ArrayList arguments, Location l)
5835                 {
5836                         RequestedType = requested_type;
5837                         Arguments = arguments;
5838                         loc = l;
5839                 }
5840
5841                 public bool SetValueTypeVariable (Expression value)
5842                 {
5843                         value_target = value;
5844                         value_target_set = true;
5845                         if (!(value_target is IMemoryLocation)){
5846                                 Error_UnexpectedKind ("variable", loc);
5847                                 return false;
5848                         }
5849                         return true;
5850                 }
5851
5852                 //
5853                 // This function is used to disable the following code sequence for
5854                 // value type initialization:
5855                 //
5856                 // AddressOf (temporary)
5857                 // Construct/Init
5858                 // LoadTemporary
5859                 //
5860                 // Instead the provide will have provided us with the address on the
5861                 // stack to store the results.
5862                 //
5863                 static Expression MyEmptyExpression;
5864
5865                 public void DisableTemporaryValueType ()
5866                 {
5867                         if (MyEmptyExpression == null)
5868                                 MyEmptyExpression = new EmptyAddressOf ();
5869
5870                         //
5871                         // To enable this, look into:
5872                         // test-34 and test-89 and self bootstrapping.
5873                         //
5874                         // For instance, we can avoid a copy by using `newobj'
5875                         // instead of Call + Push-temp on value types.
5876 //                      value_target = MyEmptyExpression;
5877                 }
5878
5879
5880                 /// <summary>
5881                 /// Converts complex core type syntax like 'new int ()' to simple constant
5882                 /// </summary>
5883                 Expression Constantify (Type t)
5884                 {
5885                         if (t == TypeManager.int32_type)
5886                                 return new IntConstant (0);
5887                         if (t == TypeManager.uint32_type)
5888                                 return new UIntConstant (0);
5889                         if (t == TypeManager.int64_type)
5890                                 return new LongConstant (0);
5891                         if (t == TypeManager.uint64_type)
5892                                 return new ULongConstant (0);
5893                         if (t == TypeManager.float_type)
5894                                 return new FloatConstant (0);
5895                         if (t == TypeManager.double_type)
5896                                 return new DoubleConstant (0);
5897                         if (t == TypeManager.short_type)
5898                                 return new ShortConstant (0);
5899                         if (t == TypeManager.ushort_type)
5900                                 return new UShortConstant (0);
5901                         if (t == TypeManager.sbyte_type)
5902                                 return new SByteConstant (0);
5903                         if (t == TypeManager.byte_type)
5904                                 return new ByteConstant (0);
5905                         if (t == TypeManager.char_type)
5906                                 return new CharConstant ('\0');
5907                         if (t == TypeManager.bool_type)
5908                                 return new BoolConstant (false);
5909                         if (t == TypeManager.decimal_type)
5910                                 return new DecimalConstant (0);
5911
5912                         return null;
5913                 }
5914
5915                 public override Expression DoResolve (EmitContext ec)
5916                 {
5917                         //
5918                         // The New DoResolve might be called twice when initializing field
5919                         // expressions (see EmitFieldInitializers, the call to
5920                         // GetInitializerExpression will perform a resolve on the expression,
5921                         // and later the assign will trigger another resolution
5922                         //
5923                         // This leads to bugs (#37014)
5924                         //
5925                         if (type != null){
5926                                 if (RequestedType is NewDelegate)
5927                                         return RequestedType;
5928                                 return this;
5929                         }
5930
5931                         TypeExpr texpr = RequestedType.ResolveAsTypeTerminal (ec);
5932                         if (texpr == null)
5933                                 return null;
5934
5935                         if (Arguments == null) {
5936                                 Expression c = Constantify (type);
5937                                 if (c != null)
5938                                         return c;
5939                         }
5940
5941                         type = texpr.Type;
5942                         if (type == null)
5943                                 return null;
5944
5945                         CheckObsoleteAttribute (type);
5946
5947                         bool IsDelegate = TypeManager.IsDelegateType (type);
5948
5949                         if (IsDelegate){
5950                                 RequestedType = (new NewDelegate (type, Arguments, loc)).Resolve (ec);
5951                                 if (RequestedType != null)
5952                                         if (!(RequestedType is DelegateCreation))
5953                                                 throw new Exception ("NewDelegate.Resolve returned a non NewDelegate: " + RequestedType.GetType ());
5954                                 return RequestedType;
5955                         }
5956
5957                         if (type.IsGenericParameter) {
5958                                 if (!TypeManager.HasConstructorConstraint (type)) {
5959                                         Error (304, String.Format (
5960                                                        "Cannot create an instance of the " +
5961                                                        "variable type '{0}' because it " +
5962                                                        "doesn't have the new() constraint",
5963                                                        type));
5964                                         return null;
5965                                 }
5966
5967                                 if ((Arguments != null) && (Arguments.Count != 0)) {
5968                                         Error (417, String.Format (
5969                                                        "`{0}': cannot provide arguments " +
5970                                                        "when creating an instance of a " +
5971                                                        "variable type.", type));
5972                                         return null;
5973                                 }
5974
5975                                 is_type_parameter = true;
5976                                 eclass = ExprClass.Value;
5977                                 return this;
5978                         }
5979
5980                         if (type.IsInterface || type.IsAbstract){
5981                                 Error (144, "It is not possible to create instances of interfaces or abstract classes");
5982                                 return null;
5983                         }
5984
5985                         if (type.IsAbstract && type.IsSealed) {
5986                                 Report.Error (712, loc, "Cannot create an instance of the static class '{0}'", TypeManager.CSharpName (type));
5987                                 return null;
5988                         }
5989
5990                         bool is_struct = type.IsValueType;
5991                         eclass = ExprClass.Value;
5992
5993                         //
5994                         // SRE returns a match for .ctor () on structs (the object constructor),
5995                         // so we have to manually ignore it.
5996                         //
5997                         if (is_struct && Arguments == null)
5998                                 return this;
5999
6000                         Expression ml;
6001                         ml = MemberLookupFinal (ec, type, type, ".ctor",
6002                                                 // For member-lookup, treat 'new Foo (bar)' as call to 'foo.ctor (bar)', where 'foo' is of type 'Foo'.
6003                                                 MemberTypes.Constructor,
6004                                                 AllBindingFlags | BindingFlags.DeclaredOnly, loc);
6005
6006                         if (ml == null)
6007                                 return null;
6008
6009                         if (! (ml is MethodGroupExpr)){
6010                                 if (!is_struct){
6011                                         ml.Error_UnexpectedKind ("method group", loc);
6012                                         return null;
6013                                 }
6014                         }
6015
6016                         if (ml != null) {
6017                                 if (Arguments != null){
6018                                         foreach (Argument a in Arguments){
6019                                                 if (!a.Resolve (ec, loc))
6020                                                         return null;
6021                                         }
6022                                 }
6023
6024                                 method = Invocation.OverloadResolve (
6025                                         ec, (MethodGroupExpr) ml, Arguments, true, loc);
6026
6027                         }
6028
6029                         if (method == null) {
6030                                 if (almostMatchedMembers.Count != 0) {
6031                                         MemberLookupFailed (ec, type, type, ".ctor", null, loc);
6032                                         return null;
6033                                 }
6034
6035                                 if (!is_struct || Arguments.Count > 0) {
6036                                         Error (1501, String.Format (
6037                                             "New invocation: Can not find a constructor in `{0}' for this argument list",
6038                                             TypeManager.CSharpName (type)));
6039                                         return null;
6040                                 }
6041                         }
6042
6043                         return this;
6044                 }
6045
6046                 bool DoEmitTypeParameter (EmitContext ec)
6047                 {
6048                         ILGenerator ig = ec.ig;
6049
6050                         ig.Emit (OpCodes.Ldtoken, type);
6051                         ig.Emit (OpCodes.Call, TypeManager.system_type_get_type_from_handle);
6052                         ig.Emit (OpCodes.Call, TypeManager.activator_create_instance);
6053                         ig.Emit (OpCodes.Unbox_Any, type);
6054
6055                         return true;
6056                 }
6057
6058                 //
6059                 // This DoEmit can be invoked in two contexts:
6060                 //    * As a mechanism that will leave a value on the stack (new object)
6061                 //    * As one that wont (init struct)
6062                 //
6063                 // You can control whether a value is required on the stack by passing
6064                 // need_value_on_stack.  The code *might* leave a value on the stack
6065                 // so it must be popped manually
6066                 //
6067                 // If we are dealing with a ValueType, we have a few
6068                 // situations to deal with:
6069                 //
6070                 //    * The target is a ValueType, and we have been provided
6071                 //      the instance (this is easy, we are being assigned).
6072                 //
6073                 //    * The target of New is being passed as an argument,
6074                 //      to a boxing operation or a function that takes a
6075                 //      ValueType.
6076                 //
6077                 //      In this case, we need to create a temporary variable
6078                 //      that is the argument of New.
6079                 //
6080                 // Returns whether a value is left on the stack
6081                 //
6082                 bool DoEmit (EmitContext ec, bool need_value_on_stack)
6083                 {
6084                         bool is_value_type = TypeManager.IsValueType (type);
6085                         ILGenerator ig = ec.ig;
6086
6087                         if (is_value_type){
6088                                 IMemoryLocation ml;
6089
6090                                 // Allow DoEmit() to be called multiple times.
6091                                 // We need to create a new LocalTemporary each time since
6092                                 // you can't share LocalBuilders among ILGeneators.
6093                                 if (!value_target_set)
6094                                         value_target = new LocalTemporary (ec, type);
6095
6096                                 ml = (IMemoryLocation) value_target;
6097                                 ml.AddressOf (ec, AddressOp.Store);
6098                         }
6099
6100                         if (method != null)
6101                                 Invocation.EmitArguments (ec, method, Arguments, false, null);
6102
6103                         if (is_value_type){
6104                                 if (method == null)
6105                                         ig.Emit (OpCodes.Initobj, type);
6106                                 else
6107                                         ig.Emit (OpCodes.Call, (ConstructorInfo) method);
6108                                 if (need_value_on_stack){
6109                                         value_target.Emit (ec);
6110                                         return true;
6111                                 }
6112                                 return false;
6113                         } else {
6114                                 ig.Emit (OpCodes.Newobj, (ConstructorInfo) method);
6115                                 return true;
6116                         }
6117                 }
6118
6119                 public override void Emit (EmitContext ec)
6120                 {
6121                         if (is_type_parameter)
6122                                 DoEmitTypeParameter (ec);
6123                         else
6124                                 DoEmit (ec, true);
6125                 }
6126
6127                 public override void EmitStatement (EmitContext ec)
6128                 {
6129                         if (is_type_parameter)
6130                                 throw new InvalidOperationException ();
6131
6132                         if (DoEmit (ec, false))
6133                                 ec.ig.Emit (OpCodes.Pop);
6134                 }
6135
6136                 public void AddressOf (EmitContext ec, AddressOp Mode)
6137                 {
6138                         if (is_type_parameter)
6139                                 throw new InvalidOperationException ();
6140
6141                         if (!type.IsValueType){
6142                                 //
6143                                 // We throw an exception.  So far, I believe we only need to support
6144                                 // value types:
6145                                 // foreach (int j in new StructType ())
6146                                 // see bug 42390
6147                                 //
6148                                 throw new Exception ("AddressOf should not be used for classes");
6149                         }
6150
6151                         if (!value_target_set)
6152                                 value_target = new LocalTemporary (ec, type);
6153
6154                         IMemoryLocation ml = (IMemoryLocation) value_target;
6155                         ml.AddressOf (ec, AddressOp.Store);
6156                         if (method != null)
6157                                 Invocation.EmitArguments (ec, method, Arguments, false, null);
6158
6159                         if (method == null)
6160                                 ec.ig.Emit (OpCodes.Initobj, type);
6161                         else
6162                                 ec.ig.Emit (OpCodes.Call, (ConstructorInfo) method);
6163
6164                         ((IMemoryLocation) value_target).AddressOf (ec, Mode);
6165                 }
6166         }
6167
6168         /// <summary>
6169         ///   14.5.10.2: Represents an array creation expression.
6170         /// </summary>
6171         ///
6172         /// <remarks>
6173         ///   There are two possible scenarios here: one is an array creation
6174         ///   expression that specifies the dimensions and optionally the
6175         ///   initialization data and the other which does not need dimensions
6176         ///   specified but where initialization data is mandatory.
6177         /// </remarks>
6178         public class ArrayCreation : Expression {
6179                 Expression requested_base_type;
6180                 ArrayList initializers;
6181
6182                 //
6183                 // The list of Argument types.
6184                 // This is used to construct the `newarray' or constructor signature
6185                 //
6186                 ArrayList arguments;
6187
6188                 //
6189                 // Method used to create the array object.
6190                 //
6191                 MethodBase new_method = null;
6192
6193                 Type array_element_type;
6194                 Type underlying_type;
6195                 bool is_one_dimensional = false;
6196                 bool is_builtin_type = false;
6197                 bool expect_initializers = false;
6198                 int num_arguments = 0;
6199                 int dimensions = 0;
6200                 string rank;
6201
6202                 ArrayList array_data;
6203
6204                 Hashtable bounds;
6205
6206                 //
6207                 // The number of array initializers that we can handle
6208                 // via the InitializeArray method - through EmitStaticInitializers
6209                 //
6210                 int num_automatic_initializers;
6211
6212                 const int max_automatic_initializers = 6;
6213
6214                 public ArrayCreation (Expression requested_base_type, ArrayList exprs, string rank, ArrayList initializers, Location l)
6215                 {
6216                         this.requested_base_type = requested_base_type;
6217                         this.initializers = initializers;
6218                         this.rank = rank;
6219                         loc = l;
6220
6221                         arguments = new ArrayList ();
6222
6223                         foreach (Expression e in exprs) {
6224                                 arguments.Add (new Argument (e, Argument.AType.Expression));
6225                                 num_arguments++;
6226                         }
6227                 }
6228
6229                 public ArrayCreation (Expression requested_base_type, string rank, ArrayList initializers, Location l)
6230                 {
6231                         this.requested_base_type = requested_base_type;
6232                         this.initializers = initializers;
6233                         this.rank = rank;
6234                         loc = l;
6235
6236                         //this.rank = rank.Substring (0, rank.LastIndexOf ('['));
6237                         //
6238                         //string tmp = rank.Substring (rank.LastIndexOf ('['));
6239                         //
6240                         //dimensions = tmp.Length - 1;
6241                         expect_initializers = true;
6242                 }
6243
6244                 public Expression FormArrayType (Expression base_type, int idx_count, string rank)
6245                 {
6246                         StringBuilder sb = new StringBuilder (rank);
6247
6248                         sb.Append ("[");
6249                         for (int i = 1; i < idx_count; i++)
6250                                 sb.Append (",");
6251
6252                         sb.Append ("]");
6253
6254                         return new ComposedCast (base_type, sb.ToString (), loc);
6255                 }
6256
6257                 void Error_IncorrectArrayInitializer ()
6258                 {
6259                         Error (178, "Incorrectly structured array initializer");
6260                 }
6261
6262                 public bool CheckIndices (EmitContext ec, ArrayList probe, int idx, bool specified_dims)
6263                 {
6264                         if (specified_dims) {
6265                                 Argument a = (Argument) arguments [idx];
6266
6267                                 if (!a.Resolve (ec, loc))
6268                                         return false;
6269
6270                                 if (!(a.Expr is Constant)) {
6271                                         Error (150, "A constant value is expected");
6272                                         return false;
6273                                 }
6274
6275                                 int value = (int) ((Constant) a.Expr).GetValue ();
6276
6277                                 if (value != probe.Count) {
6278                                         Error_IncorrectArrayInitializer ();
6279                                         return false;
6280                                 }
6281
6282                                 bounds [idx] = value;
6283                         }
6284
6285                         int child_bounds = -1;
6286                         foreach (object o in probe) {
6287                                 if (o is ArrayList) {
6288                                         int current_bounds = ((ArrayList) o).Count;
6289
6290                                         if (child_bounds == -1)
6291                                                 child_bounds = current_bounds;
6292
6293                                         else if (child_bounds != current_bounds){
6294                                                 Error_IncorrectArrayInitializer ();
6295                                                 return false;
6296                                         }
6297                                         if (specified_dims && (idx + 1 >= arguments.Count)){
6298                                                 Error (623, "Array initializers can only be used in a variable or field initializer, try using the new expression");
6299                                                 return false;
6300                                         }
6301
6302                                         bool ret = CheckIndices (ec, (ArrayList) o, idx + 1, specified_dims);
6303                                         if (!ret)
6304                                                 return false;
6305                                 } else {
6306                                         if (child_bounds != -1){
6307                                                 Error_IncorrectArrayInitializer ();
6308                                                 return false;
6309                                         }
6310
6311                                         Expression tmp = (Expression) o;
6312                                         tmp = tmp.Resolve (ec);
6313                                         if (tmp == null)
6314                                                 return false;
6315
6316                                         // Console.WriteLine ("I got: " + tmp);
6317                                         // Handle initialization from vars, fields etc.
6318
6319                                         Expression conv = Convert.ImplicitConversionRequired (
6320                                                 ec, tmp, underlying_type, loc);
6321
6322                                         if (conv == null)
6323                                                 return false;
6324
6325                                         if (conv is StringConstant || conv is DecimalConstant || conv is NullCast) {
6326                                                 // These are subclasses of Constant that can appear as elements of an
6327                                                 // array that cannot be statically initialized (with num_automatic_initializers
6328                                                 // > max_automatic_initializers), so num_automatic_initializers should be left as zero.
6329                                                 array_data.Add (conv);
6330                                         } else if (conv is Constant) {
6331                                                 // These are the types of Constant that can appear in arrays that can be
6332                                                 // statically allocated.
6333                                                 array_data.Add (conv);
6334                                                 num_automatic_initializers++;
6335                                         } else
6336                                                 array_data.Add (conv);
6337                                 }
6338                         }
6339
6340                         return true;
6341                 }
6342
6343                 public void UpdateIndices (EmitContext ec)
6344                 {
6345                         int i = 0;
6346                         for (ArrayList probe = initializers; probe != null;) {
6347                                 if (probe.Count > 0 && probe [0] is ArrayList) {
6348                                         Expression e = new IntConstant (probe.Count);
6349                                         arguments.Add (new Argument (e, Argument.AType.Expression));
6350
6351                                         bounds [i++] =  probe.Count;
6352
6353                                         probe = (ArrayList) probe [0];
6354
6355                                 } else {
6356                                         Expression e = new IntConstant (probe.Count);
6357                                         arguments.Add (new Argument (e, Argument.AType.Expression));
6358
6359                                         bounds [i++] = probe.Count;
6360                                         probe = null;
6361                                 }
6362                         }
6363
6364                 }
6365
6366                 public bool ValidateInitializers (EmitContext ec, Type array_type)
6367                 {
6368                         if (initializers == null) {
6369                                 if (expect_initializers)
6370                                         return false;
6371                                 else
6372                                         return true;
6373                         }
6374
6375                         if (underlying_type == null)
6376                                 return false;
6377
6378                         //
6379                         // We use this to store all the date values in the order in which we
6380                         // will need to store them in the byte blob later
6381                         //
6382                         array_data = new ArrayList ();
6383                         bounds = new Hashtable ();
6384
6385                         bool ret;
6386
6387                         if (arguments != null) {
6388                                 ret = CheckIndices (ec, initializers, 0, true);
6389                                 return ret;
6390                         } else {
6391                                 arguments = new ArrayList ();
6392
6393                                 ret = CheckIndices (ec, initializers, 0, false);
6394
6395                                 if (!ret)
6396                                         return false;
6397
6398                                 UpdateIndices (ec);
6399
6400                                 if (arguments.Count != dimensions) {
6401                                         Error_IncorrectArrayInitializer ();
6402                                         return false;
6403                                 }
6404
6405                                 return ret;
6406                         }
6407                 }
6408
6409                 //
6410                 // Converts `source' to an int, uint, long or ulong.
6411                 //
6412                 Expression ExpressionToArrayArgument (EmitContext ec, Expression source)
6413                 {
6414                         Expression target;
6415
6416                         bool old_checked = ec.CheckState;
6417                         ec.CheckState = true;
6418
6419                         target = Convert.ImplicitConversion (ec, source, TypeManager.int32_type, loc);
6420                         if (target == null){
6421                                 target = Convert.ImplicitConversion (ec, source, TypeManager.uint32_type, loc);
6422                                 if (target == null){
6423                                         target = Convert.ImplicitConversion (ec, source, TypeManager.int64_type, loc);
6424                                         if (target == null){
6425                                                 target = Convert.ImplicitConversion (ec, source, TypeManager.uint64_type, loc);
6426                                                 if (target == null)
6427                                                         Convert.Error_CannotImplicitConversion (loc, source.Type, TypeManager.int32_type);
6428                                         }
6429                                 }
6430                         }
6431                         ec.CheckState = old_checked;
6432
6433                         //
6434                         // Only positive constants are allowed at compile time
6435                         //
6436                         if (target is Constant){
6437                                 if (target is IntConstant){
6438                                         if (((IntConstant) target).Value < 0){
6439                                                 Expression.Error_NegativeArrayIndex (loc);
6440                                                 return null;
6441                                         }
6442                                 }
6443
6444                                 if (target is LongConstant){
6445                                         if (((LongConstant) target).Value < 0){
6446                                                 Expression.Error_NegativeArrayIndex (loc);
6447                                                 return null;
6448                                         }
6449                                 }
6450
6451                         }
6452
6453                         return target;
6454                 }
6455
6456                 //
6457                 // Creates the type of the array
6458                 //
6459                 bool LookupType (EmitContext ec)
6460                 {
6461                         StringBuilder array_qualifier = new StringBuilder (rank);
6462
6463                         //
6464                         // `In the first form allocates an array instace of the type that results
6465                         // from deleting each of the individual expression from the expression list'
6466                         //
6467                         if (num_arguments > 0) {
6468                                 array_qualifier.Append ("[");
6469                                 for (int i = num_arguments-1; i > 0; i--)
6470                                         array_qualifier.Append (",");
6471                                 array_qualifier.Append ("]");
6472                         }
6473
6474                         //
6475                         // Lookup the type
6476                         //
6477                         TypeExpr array_type_expr;
6478                         array_type_expr = new ComposedCast (requested_base_type, array_qualifier.ToString (), loc);
6479                         array_type_expr = array_type_expr.ResolveAsTypeTerminal (ec);
6480                         if (array_type_expr == null)
6481                                 return false;
6482
6483                         type = array_type_expr.Type;
6484
6485                         if (!type.IsArray) {
6486                                 Error (622, "Can only use array initializer expressions to assign to array types. Try using a new expression instead.");
6487                                 return false;
6488                         }
6489                         underlying_type = TypeManager.GetElementType (type);
6490                         dimensions = type.GetArrayRank ();
6491
6492                         return true;
6493                 }
6494
6495                 public override Expression DoResolve (EmitContext ec)
6496                 {
6497                         int arg_count;
6498
6499                         if (!LookupType (ec))
6500                                 return null;
6501
6502                         //
6503                         // First step is to validate the initializers and fill
6504                         // in any missing bits
6505                         //
6506                         if (!ValidateInitializers (ec, type))
6507                                 return null;
6508
6509                         if (arguments == null)
6510                                 arg_count = 0;
6511                         else {
6512                                 arg_count = arguments.Count;
6513                                 foreach (Argument a in arguments){
6514                                         if (!a.Resolve (ec, loc))
6515                                                 return null;
6516
6517                                         Expression real_arg = ExpressionToArrayArgument (ec, a.Expr, loc);
6518                                         if (real_arg == null)
6519                                                 return null;
6520
6521                                         a.Expr = real_arg;
6522                                 }
6523                         }
6524
6525                         array_element_type = TypeManager.GetElementType (type);
6526
6527                         if (array_element_type.IsAbstract && array_element_type.IsSealed) {
6528                                 Report.Error (719, loc, "'{0}': array elements cannot be of static type", TypeManager.CSharpName (array_element_type));
6529                                 return null;
6530                         }
6531
6532                         if (arg_count == 1) {
6533                                 is_one_dimensional = true;
6534                                 eclass = ExprClass.Value;
6535                                 return this;
6536                         }
6537
6538                         is_builtin_type = TypeManager.IsBuiltinType (type);
6539
6540                         if (is_builtin_type) {
6541                                 Expression ml;
6542
6543                                 ml = MemberLookup (ec, type, ".ctor", MemberTypes.Constructor,
6544                                                    AllBindingFlags, loc);
6545
6546                                 if (!(ml is MethodGroupExpr)) {
6547                                         ml.Error_UnexpectedKind ("method group", loc);
6548                                         return null;
6549                                 }
6550
6551                                 if (ml == null) {
6552                                         Error (-6, "New invocation: Can not find a constructor for " +
6553                                                       "this argument list");
6554                                         return null;
6555                                 }
6556
6557                                 new_method = Invocation.OverloadResolve (
6558                                         ec, (MethodGroupExpr) ml, arguments, false, loc);
6559
6560                                 if (new_method == null) {
6561                                         Error (-6, "New invocation: Can not find a constructor for " +
6562                                                       "this argument list");
6563                                         return null;
6564                                 }
6565
6566                                 eclass = ExprClass.Value;
6567                                 return this;
6568                         } else {
6569                                 ModuleBuilder mb = CodeGen.Module.Builder;
6570                                 ArrayList args = new ArrayList ();
6571
6572                                 if (arguments != null) {
6573                                         for (int i = 0; i < arg_count; i++)
6574                                                 args.Add (TypeManager.int32_type);
6575                                 }
6576
6577                                 Type [] arg_types = null;
6578
6579                                 if (args.Count > 0)
6580                                         arg_types = new Type [args.Count];
6581
6582                                 args.CopyTo (arg_types, 0);
6583
6584                                 new_method = mb.GetArrayMethod (type, ".ctor", CallingConventions.HasThis, null,
6585                                                             arg_types);
6586
6587                                 if (new_method == null) {
6588                                         Error (-6, "New invocation: Can not find a constructor for " +
6589                                                       "this argument list");
6590                                         return null;
6591                                 }
6592
6593                                 eclass = ExprClass.Value;
6594                                 return this;
6595                         }
6596                 }
6597
6598                 public static byte [] MakeByteBlob (ArrayList array_data, Type underlying_type, Location loc)
6599                 {
6600                         int factor;
6601                         byte [] data;
6602                         byte [] element;
6603                         int count = array_data.Count;
6604
6605                         if (underlying_type.IsEnum)
6606                                 underlying_type = TypeManager.EnumToUnderlying (underlying_type);
6607
6608                         factor = GetTypeSize (underlying_type);
6609                         if (factor == 0)
6610                                 throw new Exception ("unrecognized type in MakeByteBlob: " + underlying_type);
6611
6612                         data = new byte [(count * factor + 4) & ~3];
6613                         int idx = 0;
6614
6615                         for (int i = 0; i < count; ++i) {
6616                                 object v = array_data [i];
6617
6618                                 if (v is EnumConstant)
6619                                         v = ((EnumConstant) v).Child;
6620
6621                                 if (v is Constant && !(v is StringConstant))
6622                                         v = ((Constant) v).GetValue ();
6623                                 else {
6624                                         idx += factor;
6625                                         continue;
6626                                 }
6627
6628                                 if (underlying_type == TypeManager.int64_type){
6629                                         if (!(v is Expression)){
6630                                                 long val = (long) v;
6631
6632                                                 for (int j = 0; j < factor; ++j) {
6633                                                         data [idx + j] = (byte) (val & 0xFF);
6634                                                         val = (val >> 8);
6635                                                 }
6636                                         }
6637                                 } else if (underlying_type == TypeManager.uint64_type){
6638                                         if (!(v is Expression)){
6639                                                 ulong val = (ulong) v;
6640
6641                                                 for (int j = 0; j < factor; ++j) {
6642                                                         data [idx + j] = (byte) (val & 0xFF);
6643                                                         val = (val >> 8);
6644                                                 }
6645                                         }
6646                                 } else if (underlying_type == TypeManager.float_type) {
6647                                         if (!(v is Expression)){
6648                                                 element = BitConverter.GetBytes ((float) v);
6649
6650                                                 for (int j = 0; j < factor; ++j)
6651                                                         data [idx + j] = element [j];
6652                                         }
6653                                 } else if (underlying_type == TypeManager.double_type) {
6654                                         if (!(v is Expression)){
6655                                                 element = BitConverter.GetBytes ((double) v);
6656
6657                                                 for (int j = 0; j < factor; ++j)
6658                                                         data [idx + j] = element [j];
6659                                         }
6660                                 } else if (underlying_type == TypeManager.char_type){
6661                                         if (!(v is Expression)){
6662                                                 int val = (int) ((char) v);
6663
6664                                                 data [idx] = (byte) (val & 0xff);
6665                                                 data [idx+1] = (byte) (val >> 8);
6666                                         }
6667                                 } else if (underlying_type == TypeManager.short_type){
6668                                         if (!(v is Expression)){
6669                                                 int val = (int) ((short) v);
6670
6671                                                 data [idx] = (byte) (val & 0xff);
6672                                                 data [idx+1] = (byte) (val >> 8);
6673                                         }
6674                                 } else if (underlying_type == TypeManager.ushort_type){
6675                                         if (!(v is Expression)){
6676                                                 int val = (int) ((ushort) v);
6677
6678                                                 data [idx] = (byte) (val & 0xff);
6679                                                 data [idx+1] = (byte) (val >> 8);
6680                                         }
6681                                 } else if (underlying_type == TypeManager.int32_type) {
6682                                         if (!(v is Expression)){
6683                                                 int val = (int) v;
6684
6685                                                 data [idx]   = (byte) (val & 0xff);
6686                                                 data [idx+1] = (byte) ((val >> 8) & 0xff);
6687                                                 data [idx+2] = (byte) ((val >> 16) & 0xff);
6688                                                 data [idx+3] = (byte) (val >> 24);
6689                                         }
6690                                 } else if (underlying_type == TypeManager.uint32_type) {
6691                                         if (!(v is Expression)){
6692                                                 uint val = (uint) v;
6693
6694                                                 data [idx]   = (byte) (val & 0xff);
6695                                                 data [idx+1] = (byte) ((val >> 8) & 0xff);
6696                                                 data [idx+2] = (byte) ((val >> 16) & 0xff);
6697                                                 data [idx+3] = (byte) (val >> 24);
6698                                         }
6699                                 } else if (underlying_type == TypeManager.sbyte_type) {
6700                                         if (!(v is Expression)){
6701                                                 sbyte val = (sbyte) v;
6702                                                 data [idx] = (byte) val;
6703                                         }
6704                                 } else if (underlying_type == TypeManager.byte_type) {
6705                                         if (!(v is Expression)){
6706                                                 byte val = (byte) v;
6707                                                 data [idx] = (byte) val;
6708                                         }
6709                                 } else if (underlying_type == TypeManager.bool_type) {
6710                                         if (!(v is Expression)){
6711                                                 bool val = (bool) v;
6712                                                 data [idx] = (byte) (val ? 1 : 0);
6713                                         }
6714                                 } else if (underlying_type == TypeManager.decimal_type){
6715                                         if (!(v is Expression)){
6716                                                 int [] bits = Decimal.GetBits ((decimal) v);
6717                                                 int p = idx;
6718
6719                                                 // FIXME: For some reason, this doesn't work on the MS runtime.
6720                                                 int [] nbits = new int [4];
6721                                                 nbits [0] = bits [3];
6722                                                 nbits [1] = bits [2];
6723                                                 nbits [2] = bits [0];
6724                                                 nbits [3] = bits [1];
6725
6726                                                 for (int j = 0; j < 4; j++){
6727                                                         data [p++] = (byte) (nbits [j] & 0xff);
6728                                                         data [p++] = (byte) ((nbits [j] >> 8) & 0xff);
6729                                                         data [p++] = (byte) ((nbits [j] >> 16) & 0xff);
6730                                                         data [p++] = (byte) (nbits [j] >> 24);
6731                                                 }
6732                                         }
6733                                 } else
6734                                         throw new Exception ("Unrecognized type in MakeByteBlob: " + underlying_type);
6735
6736                                 idx += factor;
6737                         }
6738
6739                         return data;
6740                 }
6741
6742                 //
6743                 // Emits the initializers for the array
6744                 //
6745                 void EmitStaticInitializers (EmitContext ec)
6746                 {
6747                         //
6748                         // First, the static data
6749                         //
6750                         FieldBuilder fb;
6751                         ILGenerator ig = ec.ig;
6752
6753                         byte [] data = MakeByteBlob (array_data, underlying_type, loc);
6754
6755                         fb = RootContext.MakeStaticData (data);
6756
6757                         ig.Emit (OpCodes.Dup);
6758                         ig.Emit (OpCodes.Ldtoken, fb);
6759                         ig.Emit (OpCodes.Call,
6760                                  TypeManager.void_initializearray_array_fieldhandle);
6761                 }
6762
6763                 //
6764                 // Emits pieces of the array that can not be computed at compile
6765                 // time (variables and string locations).
6766                 //
6767                 // This always expect the top value on the stack to be the array
6768                 //
6769                 void EmitDynamicInitializers (EmitContext ec)
6770                 {
6771                         ILGenerator ig = ec.ig;
6772                         int dims = bounds.Count;
6773                         int [] current_pos = new int [dims];
6774                         int top = array_data.Count;
6775
6776                         MethodInfo set = null;
6777
6778                         if (dims != 1){
6779                                 Type [] args;
6780                                 ModuleBuilder mb = null;
6781                                 mb = CodeGen.Module.Builder;
6782                                 args = new Type [dims + 1];
6783
6784                                 int j;
6785                                 for (j = 0; j < dims; j++)
6786                                         args [j] = TypeManager.int32_type;
6787
6788                                 args [j] = array_element_type;
6789
6790                                 set = mb.GetArrayMethod (
6791                                         type, "Set",
6792                                         CallingConventions.HasThis | CallingConventions.Standard,
6793                                         TypeManager.void_type, args);
6794                         }
6795
6796                         for (int i = 0; i < top; i++){
6797
6798                                 Expression e = null;
6799
6800                                 if (array_data [i] is Expression)
6801                                         e = (Expression) array_data [i];
6802
6803                                 if (e != null) {
6804                                         //
6805                                         // Basically we do this for string literals and
6806                                         // other non-literal expressions
6807                                         //
6808                                         if (e is EnumConstant){
6809                                                 e = ((EnumConstant) e).Child;
6810                                         }
6811
6812                                         if (e is StringConstant || e is DecimalConstant || !(e is Constant) ||
6813                                             num_automatic_initializers <= max_automatic_initializers) {
6814                                                 Type etype = e.Type;
6815
6816                                                 ig.Emit (OpCodes.Dup);
6817
6818                                                 for (int idx = 0; idx < dims; idx++)
6819                                                         IntConstant.EmitInt (ig, current_pos [idx]);
6820
6821                                                 //
6822                                                 // If we are dealing with a struct, get the
6823                                                 // address of it, so we can store it.
6824                                                 //
6825                                                 if ((dims == 1) && etype.IsValueType &&
6826                                                     (!TypeManager.IsBuiltinOrEnum (etype) ||
6827                                                      etype == TypeManager.decimal_type)) {
6828                                                         if (e is New){
6829                                                                 New n = (New) e;
6830
6831                                                                 //
6832                                                                 // Let new know that we are providing
6833                                                                 // the address where to store the results
6834                                                                 //
6835                                                                 n.DisableTemporaryValueType ();
6836                                                         }
6837
6838                                                         ig.Emit (OpCodes.Ldelema, etype);
6839                                                 }
6840
6841                                                 e.Emit (ec);
6842
6843                                                 if (dims == 1) {
6844                                                         bool is_stobj, has_type_arg;
6845                                                         OpCode op = ArrayAccess.GetStoreOpcode (
6846                                                                 etype, out is_stobj,
6847                                                                 out has_type_arg);
6848                                                         if (is_stobj)
6849                                                                 ig.Emit (OpCodes.Stobj, etype);
6850                                                         else if (has_type_arg)
6851                                                                 ig.Emit (op, etype);
6852                                                         else
6853                                                                 ig.Emit (op);
6854                                                 } else
6855                                                         ig.Emit (OpCodes.Call, set);
6856                                         }
6857                                 }
6858
6859                                 //
6860                                 // Advance counter
6861                                 //
6862                                 for (int j = dims - 1; j >= 0; j--){
6863                                         current_pos [j]++;
6864                                         if (current_pos [j] < (int) bounds [j])
6865                                                 break;
6866                                         current_pos [j] = 0;
6867                                 }
6868                         }
6869                 }
6870
6871                 void EmitArrayArguments (EmitContext ec)
6872                 {
6873                         ILGenerator ig = ec.ig;
6874
6875                         foreach (Argument a in arguments) {
6876                                 Type atype = a.Type;
6877                                 a.Emit (ec);
6878
6879                                 if (atype == TypeManager.uint64_type)
6880                                         ig.Emit (OpCodes.Conv_Ovf_U4);
6881                                 else if (atype == TypeManager.int64_type)
6882                                         ig.Emit (OpCodes.Conv_Ovf_I4);
6883                         }
6884                 }
6885
6886                 public override void Emit (EmitContext ec)
6887                 {
6888                         ILGenerator ig = ec.ig;
6889
6890                         EmitArrayArguments (ec);
6891                         if (is_one_dimensional)
6892                                 ig.Emit (OpCodes.Newarr, array_element_type);
6893                         else {
6894                                 if (is_builtin_type)
6895                                         ig.Emit (OpCodes.Newobj, (ConstructorInfo) new_method);
6896                                 else
6897                                         ig.Emit (OpCodes.Newobj, (MethodInfo) new_method);
6898                         }
6899
6900                         if (initializers != null){
6901                                 //
6902                                 // FIXME: Set this variable correctly.
6903                                 //
6904                                 bool dynamic_initializers = true;
6905
6906                                 // This will never be true for array types that cannot be statically
6907                                 // initialized. num_automatic_initializers will always be zero.  See
6908                                 // CheckIndices.
6909                                         if (num_automatic_initializers > max_automatic_initializers)
6910                                                 EmitStaticInitializers (ec);
6911
6912                                 if (dynamic_initializers)
6913                                         EmitDynamicInitializers (ec);
6914                         }
6915                 }
6916
6917                 public object EncodeAsAttribute ()
6918                 {
6919                         if (!is_one_dimensional){
6920                                 Report.Error (-211, Location, "attribute can not encode multi-dimensional arrays");
6921                                 return null;
6922                         }
6923
6924                         if (array_data == null){
6925                                 Report.Error (-212, Location, "array should be initialized when passing it to an attribute");
6926                                 return null;
6927                         }
6928
6929                         object [] ret = new object [array_data.Count];
6930                         int i = 0;
6931                         foreach (Expression e in array_data){
6932                                 object v;
6933
6934                                 if (e is NullLiteral)
6935                                         v = null;
6936                                 else {
6937                                         if (!Attribute.GetAttributeArgumentExpression (e, Location, array_element_type, out v))
6938                                                 return null;
6939                                 }
6940                                 ret [i++] = v;
6941                         }
6942                         return ret;
6943                 }
6944         }
6945
6946         /// <summary>
6947         ///   Represents the `this' construct
6948         /// </summary>
6949         public class This : Expression, IAssignMethod, IMemoryLocation, IVariable {
6950
6951                 Block block;
6952                 VariableInfo variable_info;
6953
6954                 public This (Block block, Location loc)
6955                 {
6956                         this.loc = loc;
6957                         this.block = block;
6958                 }
6959
6960                 public This (Location loc)
6961                 {
6962                         this.loc = loc;
6963                 }
6964
6965                 public VariableInfo VariableInfo {
6966                         get { return variable_info; }
6967                 }
6968
6969                 public bool VerifyFixed (bool is_expression)
6970                 {
6971                         if ((variable_info == null) || (variable_info.LocalInfo == null))
6972                                 return false;
6973                         else
6974                                 return variable_info.LocalInfo.IsFixed;
6975                 }
6976
6977                 public bool ResolveBase (EmitContext ec)
6978                 {
6979                         eclass = ExprClass.Variable;
6980
6981                         if (ec.TypeContainer.CurrentType != null)
6982                                 type = ec.TypeContainer.CurrentType;
6983                         else
6984                                 type = ec.ContainerType;
6985
6986                         if (ec.IsStatic) {
6987                                 Error (26, "Keyword this not valid in static code");
6988                                 return false;
6989                         }
6990
6991                         if ((block != null) && (block.ThisVariable != null))
6992                                 variable_info = block.ThisVariable.VariableInfo;
6993
6994                         if (ec.CurrentAnonymousMethod != null)
6995                                 ec.CaptureThis ();
6996
6997                         return true;
6998                 }
6999
7000                 public override Expression DoResolve (EmitContext ec)
7001                 {
7002                         if (!ResolveBase (ec))
7003                                 return null;
7004
7005                         if ((variable_info != null) && !variable_info.IsAssigned (ec)) {
7006                                 Error (188, "The this object cannot be used before all " +
7007                                        "of its fields are assigned to");
7008                                 variable_info.SetAssigned (ec);
7009                                 return this;
7010                         }
7011
7012                         if (ec.IsFieldInitializer) {
7013                                 Error (27, "Keyword `this' can't be used outside a constructor, " +
7014                                        "a method or a property.");
7015                                 return null;
7016                         }
7017
7018                         return this;
7019                 }
7020
7021                 override public Expression DoResolveLValue (EmitContext ec, Expression right_side)
7022                 {
7023                         if (!ResolveBase (ec))
7024                                 return null;
7025
7026                         if (variable_info != null)
7027                                 variable_info.SetAssigned (ec);
7028
7029                         if (ec.TypeContainer is Class){
7030                                 Error (1604, "Cannot assign to `this'");
7031                                 return null;
7032                         }
7033
7034                         return this;
7035                 }
7036
7037                 public void Emit (EmitContext ec, bool leave_copy)
7038                 {
7039                         Emit (ec);
7040                         if (leave_copy)
7041                                 ec.ig.Emit (OpCodes.Dup);
7042                 }
7043
7044                 public void EmitAssign (EmitContext ec, Expression source, bool leave_copy, bool prepare_for_load)
7045                 {
7046                         ILGenerator ig = ec.ig;
7047
7048                         if (ec.TypeContainer is Struct){
7049                                 ec.EmitThis ();
7050                                 source.Emit (ec);
7051                                 if (leave_copy)
7052                                         ec.ig.Emit (OpCodes.Dup);
7053                                 ig.Emit (OpCodes.Stobj, type);
7054                         } else {
7055                                 throw new Exception ("how did you get here");
7056                         }
7057                 }
7058
7059                 public override void Emit (EmitContext ec)
7060                 {
7061                         ILGenerator ig = ec.ig;
7062
7063                         ec.EmitThis ();
7064                         if (ec.TypeContainer is Struct)
7065                                 ig.Emit (OpCodes.Ldobj, type);
7066                 }
7067
7068                 public void AddressOf (EmitContext ec, AddressOp mode)
7069                 {
7070                         ec.EmitThis ();
7071
7072                         // FIMXE
7073                         // FIGURE OUT WHY LDARG_S does not work
7074                         //
7075                         // consider: struct X { int val; int P { set { val = value; }}}
7076                         //
7077                         // Yes, this looks very bad. Look at `NOTAS' for
7078                         // an explanation.
7079                         // ec.ig.Emit (OpCodes.Ldarga_S, (byte) 0);
7080                 }
7081         }
7082
7083         /// <summary>
7084         ///   Represents the `__arglist' construct
7085         /// </summary>
7086         public class ArglistAccess : Expression
7087         {
7088                 public ArglistAccess (Location loc)
7089                 {
7090                         this.loc = loc;
7091                 }
7092
7093                 public bool ResolveBase (EmitContext ec)
7094                 {
7095                         eclass = ExprClass.Variable;
7096                         type = TypeManager.runtime_argument_handle_type;
7097                         return true;
7098                 }
7099
7100                 public override Expression DoResolve (EmitContext ec)
7101                 {
7102                         if (!ResolveBase (ec))
7103                                 return null;
7104
7105                         if (ec.IsFieldInitializer || !ec.CurrentBlock.HasVarargs) {
7106                                 Error (190, "The __arglist construct is valid only within " +
7107                                        "a variable argument method.");
7108                                 return null;
7109                         }
7110
7111                         return this;
7112                 }
7113
7114                 public override void Emit (EmitContext ec)
7115                 {
7116                         ec.ig.Emit (OpCodes.Arglist);
7117                 }
7118         }
7119
7120         /// <summary>
7121         ///   Represents the `__arglist (....)' construct
7122         /// </summary>
7123         public class Arglist : Expression
7124         {
7125                 public readonly Argument[] Arguments;
7126
7127                 public Arglist (Argument[] args, Location l)
7128                 {
7129                         Arguments = args;
7130                         loc = l;
7131                 }
7132
7133                 public Type[] ArgumentTypes {
7134                         get {
7135                                 Type[] retval = new Type [Arguments.Length];
7136                                 for (int i = 0; i < Arguments.Length; i++)
7137                                         retval [i] = Arguments [i].Type;
7138                                 return retval;
7139                         }
7140                 }
7141
7142                 public override Expression DoResolve (EmitContext ec)
7143                 {
7144                         eclass = ExprClass.Variable;
7145                         type = TypeManager.runtime_argument_handle_type;
7146
7147                         foreach (Argument arg in Arguments) {
7148                                 if (!arg.Resolve (ec, loc))
7149                                         return null;
7150                         }
7151
7152                         return this;
7153                 }
7154
7155                 public override void Emit (EmitContext ec)
7156                 {
7157                         foreach (Argument arg in Arguments)
7158                                 arg.Emit (ec);
7159                 }
7160         }
7161
7162         //
7163         // This produces the value that renders an instance, used by the iterators code
7164         //
7165         public class ProxyInstance : Expression, IMemoryLocation  {
7166                 public override Expression DoResolve (EmitContext ec)
7167                 {
7168                         eclass = ExprClass.Variable;
7169                         type = ec.ContainerType;
7170                         return this;
7171                 }
7172
7173                 public override void Emit (EmitContext ec)
7174                 {
7175                         ec.ig.Emit (OpCodes.Ldarg_0);
7176
7177                 }
7178
7179                 public void AddressOf (EmitContext ec, AddressOp mode)
7180                 {
7181                         ec.ig.Emit (OpCodes.Ldarg_0);
7182                 }
7183         }
7184
7185         /// <summary>
7186         ///   Implements the typeof operator
7187         /// </summary>
7188         public class TypeOf : Expression {
7189                 public Expression QueriedType;
7190                 protected Type typearg;
7191
7192                 public TypeOf (Expression queried_type, Location l)
7193                 {
7194                         QueriedType = queried_type;
7195                         loc = l;
7196                 }
7197
7198                 public override Expression DoResolve (EmitContext ec)
7199                 {
7200                         TypeExpr texpr = QueriedType.ResolveAsTypeTerminal (ec);
7201                         if (texpr == null)
7202                                 return null;
7203
7204                         typearg = texpr.Type;
7205
7206                         if (typearg == TypeManager.void_type) {
7207                                 Error (673, "System.Void cannot be used from C# - " +
7208                                        "use typeof (void) to get the void type object");
7209                                 return null;
7210                         }
7211
7212                         if (typearg.IsPointer && !ec.InUnsafe){
7213                                 UnsafeError (loc);
7214                                 return null;
7215                         }
7216                         CheckObsoleteAttribute (typearg);
7217
7218                         type = TypeManager.type_type;
7219                         eclass = ExprClass.Type;
7220                         return this;
7221                 }
7222
7223                 public override void Emit (EmitContext ec)
7224                 {
7225                         ec.ig.Emit (OpCodes.Ldtoken, typearg);
7226                         ec.ig.Emit (OpCodes.Call, TypeManager.system_type_get_type_from_handle);
7227                 }
7228
7229                 public Type TypeArg {
7230                         get { return typearg; }
7231                 }
7232         }
7233
7234         /// <summary>
7235         ///   Implements the `typeof (void)' operator
7236         /// </summary>
7237         public class TypeOfVoid : TypeOf {
7238                 public TypeOfVoid (Location l) : base (null, l)
7239                 {
7240                         loc = l;
7241                 }
7242
7243                 public override Expression DoResolve (EmitContext ec)
7244                 {
7245                         type = TypeManager.type_type;
7246                         typearg = TypeManager.void_type;
7247                         eclass = ExprClass.Type;
7248                         return this;
7249                 }
7250         }
7251
7252         /// <summary>
7253         ///   Implements the sizeof expression
7254         /// </summary>
7255         public class SizeOf : Expression {
7256                 public Expression QueriedType;
7257                 Type type_queried;
7258
7259                 public SizeOf (Expression queried_type, Location l)
7260                 {
7261                         this.QueriedType = queried_type;
7262                         loc = l;
7263                 }
7264
7265                 public override Expression DoResolve (EmitContext ec)
7266                 {
7267                         if (!ec.InUnsafe) {
7268                                 Report.Error (
7269                                         233, loc, "Sizeof may only be used in an unsafe context " +
7270                                         "(consider using System.Runtime.InteropServices.Marshal.SizeOf");
7271                                 return null;
7272                         }
7273
7274                         TypeExpr texpr = QueriedType.ResolveAsTypeTerminal (ec);
7275                         if (texpr == null)
7276                                 return null;
7277
7278                         if (texpr is TypeParameterExpr){
7279                                 ((TypeParameterExpr)texpr).Error_CannotUseAsUnmanagedType (loc);
7280                                 return null;
7281                         }
7282
7283                         type_queried = texpr.Type;
7284
7285                         CheckObsoleteAttribute (type_queried);
7286
7287                         if (!TypeManager.IsUnmanagedType (type_queried)){
7288                                 Report.Error (208, loc, "Cannot take the size of an unmanaged type (" + TypeManager.CSharpName (type_queried) + ")");
7289                                 return null;
7290                         }
7291
7292                         type = TypeManager.int32_type;
7293                         eclass = ExprClass.Value;
7294                         return this;
7295                 }
7296
7297                 public override void Emit (EmitContext ec)
7298                 {
7299                         int size = GetTypeSize (type_queried);
7300
7301                         if (size == 0)
7302                                 ec.ig.Emit (OpCodes.Sizeof, type_queried);
7303                         else
7304                                 IntConstant.EmitInt (ec.ig, size);
7305                 }
7306         }
7307
7308         /// <summary>
7309         ///   Implements the member access expression
7310         /// </summary>
7311         public class MemberAccess : Expression {
7312                 public string Identifier;
7313                 protected Expression expr;
7314                 protected TypeArguments args;
7315
7316                 public MemberAccess (Expression expr, string id, Location l)
7317                 {
7318                         this.expr = expr;
7319                         Identifier = id;
7320                         loc = l;
7321                 }
7322
7323                 public MemberAccess (Expression expr, string id, TypeArguments args,
7324                                      Location l)
7325                         : this (expr, id, l)
7326                 {
7327                         this.args = args;
7328                 }
7329
7330                 public Expression Expr {
7331                         get {
7332                                 return expr;
7333                         }
7334                 }
7335
7336                 public static void error176 (Location loc, string name)
7337                 {
7338                         Report.Error (176, loc, "Static member `" +
7339                                       name + "' cannot be accessed " +
7340                                       "with an instance reference, qualify with a " +
7341                                       "type name instead");
7342                 }
7343
7344                 public static bool IdenticalNameAndTypeName (EmitContext ec, Expression left_original, Expression left, Location loc)
7345                 {
7346                         SimpleName sn = left_original as SimpleName;
7347                         if (sn == null || left == null || left.Type.Name != sn.Name)
7348                                 return false;
7349
7350                         return ec.DeclSpace.LookupType (sn.Name, loc, /*silent=*/ true, /*ignore_cs0104*/ true) != null;
7351                 }
7352
7353                 // TODO: possible optimalization
7354                 // Cache resolved constant result in FieldBuilder <-> expresion map
7355                 public static Expression ResolveMemberAccess (EmitContext ec, Expression member_lookup,
7356                                                               Expression left, Location loc,
7357                                                               Expression left_original)
7358                 {
7359                         bool left_is_type, left_is_explicit;
7360
7361                         // If `left' is null, then we're called from SimpleNameResolve and this is
7362                         // a member in the currently defining class.
7363                         if (left == null) {
7364                                 left_is_type = ec.IsStatic || ec.IsFieldInitializer;
7365                                 left_is_explicit = false;
7366
7367                                 // Implicitly default to `this' unless we're static.
7368                                 if (!ec.IsStatic && !ec.IsFieldInitializer && !ec.InEnumContext)
7369                                         left = ec.GetThis (loc);
7370                         } else {
7371                                 left_is_type = left is TypeExpr;
7372                                 left_is_explicit = true;
7373                         }
7374
7375                         if (member_lookup is FieldExpr){
7376                                 FieldExpr fe = (FieldExpr) member_lookup;
7377                                 FieldInfo fi = fe.FieldInfo.Mono_GetGenericFieldDefinition ();
7378                                 Type decl_type = fi.DeclaringType;
7379
7380                                 bool is_emitted = fi is FieldBuilder;
7381                                 Type t = fi.FieldType;
7382
7383                                 if (is_emitted) {
7384                                         Const c = TypeManager.LookupConstant ((FieldBuilder) fi);
7385
7386                                         if (c != null) {
7387                                                 object o;
7388                                                 if (!c.LookupConstantValue (out o))
7389                                                         return null;
7390
7391                                                 object real_value = ((Constant) c.Expr).GetValue ();
7392
7393                                                 Expression exp = Constantify (real_value, t);
7394
7395                                                 if (left_is_explicit && !left_is_type && !IdenticalNameAndTypeName (ec, left_original, left, loc)) {
7396                                                         Report.SymbolRelatedToPreviousError (c);
7397                                                         error176 (loc, c.GetSignatureForError ());
7398                                                         return null;
7399                                                 }
7400
7401                                                 return exp;
7402                                         }
7403                                 }
7404
7405                                 // IsInitOnly is because of MS compatibility, I don't know why but they emit decimal constant as InitOnly
7406                                 if (fi.IsInitOnly && !is_emitted && t == TypeManager.decimal_type) {
7407                                         object[] attrs = fi.GetCustomAttributes (TypeManager.decimal_constant_attribute_type, false);
7408                                         if (attrs.Length == 1)
7409                                                 return new DecimalConstant (((System.Runtime.CompilerServices.DecimalConstantAttribute) attrs [0]).Value);
7410                                 }
7411
7412                                 if (fi.IsLiteral) {
7413                                         object o;
7414
7415                                         if (is_emitted)
7416                                                 o = TypeManager.GetValue ((FieldBuilder) fi);
7417                                         else
7418                                                 o = fi.GetValue (fi);
7419
7420                                         if (decl_type.IsSubclassOf (TypeManager.enum_type)) {
7421                                                 if (left_is_explicit && !left_is_type &&
7422                                                     !IdenticalNameAndTypeName (ec, left_original, member_lookup, loc)) {
7423                                                         error176 (loc, fe.FieldInfo.Name);
7424                                                         return null;
7425                                                 }
7426
7427                                                 Expression enum_member = MemberLookup (
7428                                                         ec, decl_type, "value__", MemberTypes.Field,
7429                                                         AllBindingFlags, loc);
7430
7431                                                 Enum en = TypeManager.LookupEnum (decl_type);
7432
7433                                                 Constant c;
7434                                                 if (en != null)
7435                                                         c = Constantify (o, en.UnderlyingType);
7436                                                 else
7437                                                         c = Constantify (o, enum_member.Type);
7438
7439                                                 return new EnumConstant (c, decl_type);
7440                                         }
7441
7442                                         Expression exp = Constantify (o, t);
7443
7444                                         if (left_is_explicit && !left_is_type) {
7445                                                 error176 (loc, fe.FieldInfo.Name);
7446                                                 return null;
7447                                         }
7448
7449                                         return exp;
7450                                 }
7451
7452                                 if (t.IsPointer && !ec.InUnsafe){
7453                                         UnsafeError (loc);
7454                                         return null;
7455                                 }
7456                         }
7457
7458                         if (member_lookup is EventExpr) {
7459                                 EventExpr ee = (EventExpr) member_lookup;
7460
7461                                 //
7462                                 // If the event is local to this class, we transform ourselves into
7463                                 // a FieldExpr
7464                                 //
7465
7466                                 if (ee.EventInfo.DeclaringType == ec.ContainerType ||
7467                                     TypeManager.IsNestedChildOf(ec.ContainerType, ee.EventInfo.DeclaringType)) {
7468                                         MemberInfo mi = GetFieldFromEvent (ee);
7469
7470                                         if (mi == null) {
7471                                                 //
7472                                                 // If this happens, then we have an event with its own
7473                                                 // accessors and private field etc so there's no need
7474                                                 // to transform ourselves.
7475                                                 //
7476                                                 ee.InstanceExpression = left;
7477                                                 return ee;
7478                                         }
7479
7480                                         Expression ml = ExprClassFromMemberInfo (ec, mi, loc);
7481
7482                                         if (ml == null) {
7483                                                 Report.Error (-200, loc, "Internal error!!");
7484                                                 return null;
7485                                         }
7486
7487                                         if (!left_is_explicit)
7488                                                 left = null;
7489
7490                                         ee.InstanceExpression = left;
7491
7492                                         return ResolveMemberAccess (ec, ml, left, loc, left_original);
7493                                 }
7494                         }
7495
7496                         if (member_lookup is IMemberExpr) {
7497                                 IMemberExpr me = (IMemberExpr) member_lookup;
7498                                 MethodGroupExpr mg = me as MethodGroupExpr;
7499
7500                                 if (left_is_type){
7501                                         if ((mg != null) && left_is_explicit && left.Type.IsInterface)
7502                                                 mg.IsExplicitImpl = left_is_explicit;
7503
7504                                         if (!me.IsStatic){
7505                                                 if ((ec.IsFieldInitializer || ec.IsStatic) &&
7506                                                     IdenticalNameAndTypeName (ec, left_original, member_lookup, loc))
7507                                                         return member_lookup;
7508
7509                                                 SimpleName.Error_ObjectRefRequired (ec, loc, me.Name);
7510                                                 return null;
7511                                         }
7512
7513                                 } else {
7514                                         if (!me.IsInstance){
7515                                                 if (IdenticalNameAndTypeName (ec, left_original, left, loc))
7516                                                         return member_lookup;
7517
7518                                                 if (left_is_explicit) {
7519                                                         error176 (loc, me.Name);
7520                                                         return null;
7521                                                 }
7522                                         }
7523
7524                                         //
7525                                         // Since we can not check for instance objects in SimpleName,
7526                                         // becaue of the rule that allows types and variables to share
7527                                         // the name (as long as they can be de-ambiguated later, see
7528                                         // IdenticalNameAndTypeName), we have to check whether left
7529                                         // is an instance variable in a static context
7530                                         //
7531                                         // However, if the left-hand value is explicitly given, then
7532                                         // it is already our instance expression, so we aren't in
7533                                         // static context.
7534                                         //
7535
7536                                         if (ec.IsStatic && !left_is_explicit && left is IMemberExpr){
7537                                                 IMemberExpr mexp = (IMemberExpr) left;
7538
7539                                                 if (!mexp.IsStatic){
7540                                                         SimpleName.Error_ObjectRefRequired (ec, loc, mexp.Name);
7541                                                         return null;
7542                                                 }
7543                                         }
7544
7545                                         if ((mg != null) && IdenticalNameAndTypeName (ec, left_original, left, loc))
7546                                                 mg.IdenticalTypeName = true;
7547
7548                                         me.InstanceExpression = left;
7549                                 }
7550
7551                                 return member_lookup;
7552                         }
7553
7554                         Console.WriteLine ("Left is: " + left);
7555                         Report.Error (-100, loc, "Support for [" + member_lookup + "] is not present yet");
7556                         Environment.Exit (1);
7557                         return null;
7558                 }
7559
7560                 public virtual Expression DoResolve (EmitContext ec, Expression right_side,
7561                                                      ResolveFlags flags)
7562                 {
7563                         if (type != null)
7564                                 throw new Exception ();
7565
7566                         //
7567                         // Resolve the expression with flow analysis turned off, we'll do the definite
7568                         // assignment checks later.  This is because we don't know yet what the expression
7569                         // will resolve to - it may resolve to a FieldExpr and in this case we must do the
7570                         // definite assignment check on the actual field and not on the whole struct.
7571                         //
7572
7573                         Expression original = expr;
7574                         expr = expr.Resolve (ec, flags | ResolveFlags.Intermediate | ResolveFlags.DisableFlowAnalysis);
7575                         if (expr == null)
7576                                 return null;
7577
7578                         if (expr is Namespace) {
7579                                 Namespace ns = (Namespace) expr;
7580                                 string lookup_id = MemberName.MakeName (Identifier, args);
7581                                 FullNamedExpression retval = ns.Lookup (ec.DeclSpace, lookup_id, loc);
7582                                 if ((retval != null) && (args != null))
7583                                         retval = new ConstructedType (retval, args, loc).ResolveAsTypeStep (ec);
7584                                 if (retval == null)
7585                                         Report.Error (234, loc, "The type or namespace name `{0}' could not be found in namespace `{1}'", Identifier, ns.FullName);
7586                                 return retval;
7587                         }
7588
7589                         //
7590                         // TODO: I mailed Ravi about this, and apparently we can get rid
7591                         // of this and put it in the right place.
7592                         //
7593                         // Handle enums here when they are in transit.
7594                         // Note that we cannot afford to hit MemberLookup in this case because
7595                         // it will fail to find any members at all
7596                         //
7597
7598                         Type expr_type;
7599                         if (expr is TypeExpr){
7600                                 expr_type = expr.Type;
7601
7602                                 if (!ec.DeclSpace.CheckAccessLevel (expr_type)){
7603                                         Report.Error (122, loc, "'{0}' is inaccessible due to its protection level", expr_type);
7604                                         return null;
7605                                 }
7606
7607                                 if (expr_type == TypeManager.enum_type || expr_type.IsSubclassOf (TypeManager.enum_type)){
7608                                         Enum en = TypeManager.LookupEnum (expr_type);
7609
7610                                         if (en != null) {
7611                                                 object value = en.LookupEnumValue (ec, Identifier, loc);
7612
7613                                                 if (value != null){
7614                                                         MemberCore mc = en.GetDefinition (Identifier);
7615                                                         ObsoleteAttribute oa = mc.GetObsoleteAttribute (en);
7616                                                         if (oa != null) {
7617                                                                 AttributeTester.Report_ObsoleteMessage (oa, mc.GetSignatureForError (), Location);
7618                                                         }
7619                                                         oa = en.GetObsoleteAttribute (en);
7620                                                         if (oa != null) {
7621                                                                 AttributeTester.Report_ObsoleteMessage (oa, en.GetSignatureForError (), Location);
7622                                                         }
7623
7624                                                         Constant c = Constantify (value, en.UnderlyingType);
7625                                                         return new EnumConstant (c, expr_type);
7626                                                 }
7627                                         } else {
7628                                                 CheckObsoleteAttribute (expr_type);
7629
7630                                                 FieldInfo fi = expr_type.GetField (Identifier);
7631                                                 if (fi != null) {
7632                                                         ObsoleteAttribute oa = AttributeTester.GetMemberObsoleteAttribute (fi);
7633                                                         if (oa != null)
7634                                                                 AttributeTester.Report_ObsoleteMessage (oa, TypeManager.GetFullNameSignature (fi), Location);
7635                                                 }
7636                                         }
7637                                 }
7638                         } else
7639                                 expr_type = expr.Type;
7640
7641                         if (expr_type.IsPointer){
7642                                 Error (23, "The `.' operator can not be applied to pointer operands (" +
7643                                        TypeManager.CSharpName (expr_type) + ")");
7644                                 return null;
7645                         }
7646
7647                         Expression member_lookup;
7648                         member_lookup = MemberLookup (
7649                                 ec, expr_type, expr_type, Identifier, loc);
7650                         if ((member_lookup == null) && (args != null)) {
7651                                 string lookup_id = MemberName.MakeName (Identifier, args);
7652                                 member_lookup = MemberLookup (
7653                                         ec, expr_type, expr_type, lookup_id, loc);
7654                         }
7655                         if (member_lookup == null) {
7656                                 MemberLookupFailed (
7657                                         ec, expr_type, expr_type, Identifier, null, loc);
7658                                 return null;
7659                         }
7660
7661                         if (member_lookup is TypeExpr) {
7662                                 if (!(expr is TypeExpr) &&
7663                                     !IdenticalNameAndTypeName (ec, original, expr, loc)) {
7664                                         Error (572, "Can't reference type `" + Identifier + "' through an expression; try `" +
7665                                                member_lookup.Type + "' instead");
7666                                         return null;
7667                                 }
7668
7669                                 return member_lookup;
7670                         }
7671
7672                         if (args != null) {
7673                                 string full_name = expr_type + "." + Identifier;
7674
7675                                 if (member_lookup is FieldExpr) {
7676                                         Report.Error (307, loc, "The field `{0}' cannot " +
7677                                                       "be used with type arguments", full_name);
7678                                         return null;
7679                                 } else if (member_lookup is EventExpr) {
7680                                         Report.Error (307, loc, "The event `{0}' cannot " +
7681                                                       "be used with type arguments", full_name);
7682                                         return null;
7683                                 } else if (member_lookup is PropertyExpr) {
7684                                         Report.Error (307, loc, "The property `{0}' cannot " +
7685                                                       "be used with type arguments", full_name);
7686                                         return null;
7687                                 }
7688                         }
7689
7690                         member_lookup = ResolveMemberAccess (ec, member_lookup, expr, loc, original);
7691                         if (member_lookup == null)
7692                                 return null;
7693
7694                         if (args != null) {
7695                                 MethodGroupExpr mg = member_lookup as MethodGroupExpr;
7696                                 if (mg == null)
7697                                         throw new InternalErrorException ();
7698
7699                                 return mg.ResolveGeneric (ec, args);
7700                         }
7701
7702                         // The following DoResolve/DoResolveLValue will do the definite assignment
7703                         // check.
7704
7705                         if (right_side != null)
7706                                 member_lookup = member_lookup.DoResolveLValue (ec, right_side);
7707                         else
7708                                 member_lookup = member_lookup.DoResolve (ec);
7709
7710                         return member_lookup;
7711                 }
7712
7713                 public override Expression DoResolve (EmitContext ec)
7714                 {
7715                         return DoResolve (ec, null, ResolveFlags.VariableOrValue | ResolveFlags.Type);
7716                 }
7717
7718                 public override Expression DoResolveLValue (EmitContext ec, Expression right_side)
7719                 {
7720                         return DoResolve (ec, right_side, ResolveFlags.VariableOrValue | ResolveFlags.Type);
7721                 }
7722
7723                 public override FullNamedExpression ResolveAsTypeStep (EmitContext ec)
7724                 {
7725                         return ResolveNamespaceOrType (ec, false);
7726                 }
7727
7728                 public FullNamedExpression ResolveNamespaceOrType (EmitContext ec, bool silent)
7729                 {
7730                         FullNamedExpression new_expr = expr.ResolveAsTypeStep (ec);
7731
7732                         if (new_expr == null)
7733                                 return null;
7734
7735                         string lookup_id = MemberName.MakeName (Identifier, args);
7736
7737                         if (new_expr is Namespace) {
7738                                 Namespace ns = (Namespace) new_expr;
7739                                 FullNamedExpression retval = ns.Lookup (ec.DeclSpace, lookup_id, loc);
7740                                 if ((retval != null) && (args != null))
7741                                         retval = new ConstructedType (retval, args, loc).ResolveAsTypeStep (ec);
7742                                 if (!silent && retval == null)
7743                                         Report.Error (234, loc, "The type or namespace name `{0}' could not be found in namespace `{1}'", Identifier, ns.FullName);
7744                                 return retval;
7745                         }
7746
7747                         TypeExpr tnew_expr = new_expr.ResolveAsTypeTerminal (ec);
7748                         if (tnew_expr == null)
7749                                 return null;
7750
7751                         Type expr_type = tnew_expr.Type;
7752
7753                         if (expr_type.IsPointer){
7754                                 Error (23, "The `.' operator can not be applied to pointer operands (" +
7755                                        TypeManager.CSharpName (expr_type) + ")");
7756                                 return null;
7757                         }
7758
7759                         Expression member_lookup;
7760                         member_lookup = MemberLookupFinal (ec, expr_type, expr_type, lookup_id, loc);
7761                         if (!silent && member_lookup == null) {
7762                                 Report.Error (234, loc, "The type name `{0}' could not be found in type `{1}'",
7763                                               Identifier, new_expr.FullName);
7764                                 return null;
7765                         }
7766
7767                         if (!(member_lookup is TypeExpr)) {
7768                                 Report.Error (118, loc, "'{0}.{1}' denotes a '{2}', where a type was expected",
7769                                               new_expr.FullName, Identifier, member_lookup.ExprClassName ());
7770                                 return null;
7771                         }
7772
7773                         TypeExpr texpr = member_lookup.ResolveAsTypeTerminal (ec);
7774                         if (texpr == null)
7775                                 return null;
7776
7777                         TypeArguments the_args = args;
7778                         if (TypeManager.HasGenericArguments (expr_type)) {
7779                                 Type[] decl_args = TypeManager.GetTypeArguments (expr_type);
7780
7781                                 TypeArguments new_args = new TypeArguments (loc);
7782                                 foreach (Type decl in decl_args)
7783                                         new_args.Add (new TypeExpression (decl, loc));
7784
7785                                 if (args != null)
7786                                         new_args.Add (args);
7787
7788                                 the_args = new_args;
7789                         }
7790
7791                         if (the_args != null) {
7792                                 ConstructedType ctype = new ConstructedType (texpr.Type, the_args, loc);
7793                                 return ctype.ResolveAsTypeStep (ec);
7794                         }
7795
7796                         return texpr;
7797                 }
7798
7799                 public override void Emit (EmitContext ec)
7800                 {
7801                         throw new Exception ("Should not happen");
7802                 }
7803
7804                 public override string ToString ()
7805                 {
7806                         return expr + "." + MemberName.MakeName (Identifier, args);
7807                 }
7808         }
7809
7810         /// <summary>
7811         ///   Implements checked expressions
7812         /// </summary>
7813         public class CheckedExpr : Expression {
7814
7815                 public Expression Expr;
7816
7817                 public CheckedExpr (Expression e, Location l)
7818                 {
7819                         Expr = e;
7820                         loc = l;
7821                 }
7822
7823                 public override Expression DoResolve (EmitContext ec)
7824                 {
7825                         bool last_check = ec.CheckState;
7826                         bool last_const_check = ec.ConstantCheckState;
7827
7828                         ec.CheckState = true;
7829                         ec.ConstantCheckState = true;
7830                         Expr = Expr.Resolve (ec);
7831                         ec.CheckState = last_check;
7832                         ec.ConstantCheckState = last_const_check;
7833
7834                         if (Expr == null)
7835                                 return null;
7836
7837                         if (Expr is Constant)
7838                                 return Expr;
7839
7840                         eclass = Expr.eclass;
7841                         type = Expr.Type;
7842                         return this;
7843                 }
7844
7845                 public override void Emit (EmitContext ec)
7846                 {
7847                         bool last_check = ec.CheckState;
7848                         bool last_const_check = ec.ConstantCheckState;
7849
7850                         ec.CheckState = true;
7851                         ec.ConstantCheckState = true;
7852                         Expr.Emit (ec);
7853                         ec.CheckState = last_check;
7854                         ec.ConstantCheckState = last_const_check;
7855                 }
7856
7857         }
7858
7859         /// <summary>
7860         ///   Implements the unchecked expression
7861         /// </summary>
7862         public class UnCheckedExpr : Expression {
7863
7864                 public Expression Expr;
7865
7866                 public UnCheckedExpr (Expression e, Location l)
7867                 {
7868                         Expr = e;
7869                         loc = l;
7870                 }
7871
7872                 public override Expression DoResolve (EmitContext ec)
7873                 {
7874                         bool last_check = ec.CheckState;
7875                         bool last_const_check = ec.ConstantCheckState;
7876
7877                         ec.CheckState = false;
7878                         ec.ConstantCheckState = false;
7879                         Expr = Expr.Resolve (ec);
7880                         ec.CheckState = last_check;
7881                         ec.ConstantCheckState = last_const_check;
7882
7883                         if (Expr == null)
7884                                 return null;
7885
7886                         if (Expr is Constant)
7887                                 return Expr;
7888
7889                         eclass = Expr.eclass;
7890                         type = Expr.Type;
7891                         return this;
7892                 }
7893
7894                 public override void Emit (EmitContext ec)
7895                 {
7896                         bool last_check = ec.CheckState;
7897                         bool last_const_check = ec.ConstantCheckState;
7898
7899                         ec.CheckState = false;
7900                         ec.ConstantCheckState = false;
7901                         Expr.Emit (ec);
7902                         ec.CheckState = last_check;
7903                         ec.ConstantCheckState = last_const_check;
7904                 }
7905
7906         }
7907
7908         /// <summary>
7909         ///   An Element Access expression.
7910         ///
7911         ///   During semantic analysis these are transformed into
7912         ///   IndexerAccess, ArrayAccess or a PointerArithmetic.
7913         /// </summary>
7914         public class ElementAccess : Expression {
7915                 public ArrayList  Arguments;
7916                 public Expression Expr;
7917
7918                 public ElementAccess (Expression e, ArrayList e_list, Location l)
7919                 {
7920                         Expr = e;
7921
7922                         loc  = l;
7923
7924                         if (e_list == null)
7925                                 return;
7926
7927                         Arguments = new ArrayList ();
7928                         foreach (Expression tmp in e_list)
7929                                 Arguments.Add (new Argument (tmp, Argument.AType.Expression));
7930
7931                 }
7932
7933                 bool CommonResolve (EmitContext ec)
7934                 {
7935                         Expr = Expr.Resolve (ec);
7936
7937                         if (Expr == null)
7938                                 return false;
7939
7940                         if (Arguments == null)
7941                                 return false;
7942
7943                         foreach (Argument a in Arguments){
7944                                 if (!a.Resolve (ec, loc))
7945                                         return false;
7946                         }
7947
7948                         return true;
7949                 }
7950
7951                 Expression MakePointerAccess (EmitContext ec, Type t)
7952                 {
7953                         if (t == TypeManager.void_ptr_type){
7954                                 Error (242, "The array index operation is not valid for void pointers");
7955                                 return null;
7956                         }
7957                         if (Arguments.Count != 1){
7958                                 Error (196, "A pointer must be indexed by a single value");
7959                                 return null;
7960                         }
7961                         Expression p;
7962
7963                         p = new PointerArithmetic (true, Expr, ((Argument)Arguments [0]).Expr, t, loc).Resolve (ec);
7964                         if (p == null)
7965                                 return null;
7966                         return new Indirection (p, loc).Resolve (ec);
7967                 }
7968
7969                 public override Expression DoResolve (EmitContext ec)
7970                 {
7971                         if (!CommonResolve (ec))
7972                                 return null;
7973
7974                         //
7975                         // We perform some simple tests, and then to "split" the emit and store
7976                         // code we create an instance of a different class, and return that.
7977                         //
7978                         // I am experimenting with this pattern.
7979                         //
7980                         Type t = Expr.Type;
7981
7982                         if (t == TypeManager.array_type){
7983                                 Report.Error (21, loc, "Cannot use indexer on System.Array");
7984                                 return null;
7985                         }
7986
7987                         if (t.IsArray)
7988                                 return (new ArrayAccess (this, loc)).Resolve (ec);
7989                         if (t.IsPointer)
7990                                 return MakePointerAccess (ec, Expr.Type);
7991
7992                         FieldExpr fe = Expr as FieldExpr;
7993                         if (fe != null) {
7994                                 IFixedBuffer ff = AttributeTester.GetFixedBuffer (fe.FieldInfo);
7995                                 if (ff != null) {
7996                                         return MakePointerAccess (ec, ff.ElementType);
7997                                 }
7998                         }
7999                         return (new IndexerAccess (this, loc)).Resolve (ec);
8000                 }
8001
8002                 public override Expression DoResolveLValue (EmitContext ec, Expression right_side)
8003                 {
8004                         if (!CommonResolve (ec))
8005                                 return null;
8006
8007                         Type t = Expr.Type;
8008                         if (t.IsArray)
8009                                 return (new ArrayAccess (this, loc)).ResolveLValue (ec, right_side);
8010
8011                         if (t.IsPointer)
8012                                 return MakePointerAccess (ec, Expr.Type);
8013
8014                         FieldExpr fe = Expr as FieldExpr;
8015                         if (fe != null) {
8016                                 IFixedBuffer ff = AttributeTester.GetFixedBuffer (fe.FieldInfo);
8017                                 if (ff != null) {
8018 // TODO: not sure whether it is correct
8019 //                                      if (!ec.InFixedInitializer) {
8020 //                                      if (!ec.InFixedInitializer) {
8021 //                                              Error (1666, "You cannot use fixed sized buffers contained in unfixed expressions. Try using the fixed statement.");
8022 //                                              return null;
8023 //                                      }
8024                                         return MakePointerAccess (ec, ff.ElementType);
8025                                 }
8026                         }
8027                         return (new IndexerAccess (this, loc)).ResolveLValue (ec, right_side);
8028                 }
8029
8030                 public override void Emit (EmitContext ec)
8031                 {
8032                         throw new Exception ("Should never be reached");
8033                 }
8034         }
8035
8036         /// <summary>
8037         ///   Implements array access
8038         /// </summary>
8039         public class ArrayAccess : Expression, IAssignMethod, IMemoryLocation {
8040                 //
8041                 // Points to our "data" repository
8042                 //
8043                 ElementAccess ea;
8044
8045                 LocalTemporary temp;
8046                 bool prepared;
8047
8048                 public ArrayAccess (ElementAccess ea_data, Location l)
8049                 {
8050                         ea = ea_data;
8051                         eclass = ExprClass.Variable;
8052                         loc = l;
8053                 }
8054
8055                 public override Expression DoResolve (EmitContext ec)
8056                 {
8057 #if false
8058                         ExprClass eclass = ea.Expr.eclass;
8059
8060                         // As long as the type is valid
8061                         if (!(eclass == ExprClass.Variable || eclass == ExprClass.PropertyAccess ||
8062                               eclass == ExprClass.Value)) {
8063                                 ea.Expr.Error_UnexpectedKind ("variable or value");
8064                                 return null;
8065                         }
8066 #endif
8067
8068                         Type t = ea.Expr.Type;
8069                         if (t.GetArrayRank () != ea.Arguments.Count){
8070                                 ea.Error (22,
8071                                           "Incorrect number of indexes for array " +
8072                                           " expected: " + t.GetArrayRank () + " got: " +
8073                                           ea.Arguments.Count);
8074                                 return null;
8075                         }
8076
8077                         type = TypeManager.GetElementType (t);
8078                         if (type.IsPointer && !ec.InUnsafe){
8079                                 UnsafeError (ea.Location);
8080                                 return null;
8081                         }
8082
8083                         foreach (Argument a in ea.Arguments){
8084                                 Type argtype = a.Type;
8085
8086                                 if (argtype == TypeManager.int32_type ||
8087                                     argtype == TypeManager.uint32_type ||
8088                                     argtype == TypeManager.int64_type ||
8089                                     argtype == TypeManager.uint64_type) {
8090                                         Constant c = a.Expr as Constant;
8091                                         if (c != null && c.IsNegative) {
8092                                                 Report.Warning (251, 2, a.Expr.Location, "Indexing an array with a negative index (array indices always start at zero)");
8093                                         }
8094                                         continue;
8095                                 }
8096
8097                                 //
8098                                 // Mhm.  This is strage, because the Argument.Type is not the same as
8099                                 // Argument.Expr.Type: the value changes depending on the ref/out setting.
8100                                 //
8101                                 // Wonder if I will run into trouble for this.
8102                                 //
8103                                 a.Expr = ExpressionToArrayArgument (ec, a.Expr, ea.Location);
8104                                 if (a.Expr == null)
8105                                         return null;
8106                         }
8107
8108                         eclass = ExprClass.Variable;
8109
8110                         return this;
8111                 }
8112
8113                 /// <summary>
8114                 ///    Emits the right opcode to load an object of Type `t'
8115                 ///    from an array of T
8116                 /// </summary>
8117                 static public void EmitLoadOpcode (ILGenerator ig, Type type)
8118                 {
8119                         if (type == TypeManager.byte_type || type == TypeManager.bool_type)
8120                                 ig.Emit (OpCodes.Ldelem_U1);
8121                         else if (type == TypeManager.sbyte_type)
8122                                 ig.Emit (OpCodes.Ldelem_I1);
8123                         else if (type == TypeManager.short_type)
8124                                 ig.Emit (OpCodes.Ldelem_I2);
8125                         else if (type == TypeManager.ushort_type || type == TypeManager.char_type)
8126                                 ig.Emit (OpCodes.Ldelem_U2);
8127                         else if (type == TypeManager.int32_type)
8128                                 ig.Emit (OpCodes.Ldelem_I4);
8129                         else if (type == TypeManager.uint32_type)
8130                                 ig.Emit (OpCodes.Ldelem_U4);
8131                         else if (type == TypeManager.uint64_type)
8132                                 ig.Emit (OpCodes.Ldelem_I8);
8133                         else if (type == TypeManager.int64_type)
8134                                 ig.Emit (OpCodes.Ldelem_I8);
8135                         else if (type == TypeManager.float_type)
8136                                 ig.Emit (OpCodes.Ldelem_R4);
8137                         else if (type == TypeManager.double_type)
8138                                 ig.Emit (OpCodes.Ldelem_R8);
8139                         else if (type == TypeManager.intptr_type)
8140                                 ig.Emit (OpCodes.Ldelem_I);
8141                         else if (TypeManager.IsEnumType (type)){
8142                                 EmitLoadOpcode (ig, TypeManager.EnumToUnderlying (type));
8143                         } else if (type.IsValueType){
8144                                 ig.Emit (OpCodes.Ldelema, type);
8145                                 ig.Emit (OpCodes.Ldobj, type);
8146                         } else if (type.IsGenericParameter)
8147                                 ig.Emit (OpCodes.Ldelem_Any, type);
8148                         else
8149                                 ig.Emit (OpCodes.Ldelem_Ref);
8150                 }
8151
8152                 /// <summary>
8153                 ///    Returns the right opcode to store an object of Type `t'
8154                 ///    from an array of T.
8155                 /// </summary>
8156                 static public OpCode GetStoreOpcode (Type t, out bool is_stobj, out bool has_type_arg)
8157                 {
8158                         //Console.WriteLine (new System.Diagnostics.StackTrace ());
8159                         has_type_arg = false; is_stobj = false;
8160                         t = TypeManager.TypeToCoreType (t);
8161                         if (TypeManager.IsEnumType (t))
8162                                 t = TypeManager.EnumToUnderlying (t);
8163                         if (t == TypeManager.byte_type || t == TypeManager.sbyte_type ||
8164                             t == TypeManager.bool_type)
8165                                 return OpCodes.Stelem_I1;
8166                         else if (t == TypeManager.short_type || t == TypeManager.ushort_type ||
8167                                  t == TypeManager.char_type)
8168                                 return OpCodes.Stelem_I2;
8169                         else if (t == TypeManager.int32_type || t == TypeManager.uint32_type)
8170                                 return OpCodes.Stelem_I4;
8171                         else if (t == TypeManager.int64_type || t == TypeManager.uint64_type)
8172                                 return OpCodes.Stelem_I8;
8173                         else if (t == TypeManager.float_type)
8174                                 return OpCodes.Stelem_R4;
8175                         else if (t == TypeManager.double_type)
8176                                 return OpCodes.Stelem_R8;
8177                         else if (t == TypeManager.intptr_type) {
8178                                 has_type_arg = true;
8179                                 is_stobj = true;
8180                                 return OpCodes.Stobj;
8181                         } else if (t.IsValueType) {
8182                                 has_type_arg = true;
8183                                 is_stobj = true;
8184                                 return OpCodes.Stobj;
8185                         } else if (t.IsGenericParameter) {
8186                                 has_type_arg = true;
8187                                 return OpCodes.Stelem_Any;
8188                         } else
8189                                 return OpCodes.Stelem_Ref;
8190                 }
8191
8192                 MethodInfo FetchGetMethod ()
8193                 {
8194                         ModuleBuilder mb = CodeGen.Module.Builder;
8195                         int arg_count = ea.Arguments.Count;
8196                         Type [] args = new Type [arg_count];
8197                         MethodInfo get;
8198
8199                         for (int i = 0; i < arg_count; i++){
8200                                 //args [i++] = a.Type;
8201                                 args [i] = TypeManager.int32_type;
8202                         }
8203
8204                         get = mb.GetArrayMethod (
8205                                 ea.Expr.Type, "Get",
8206                                 CallingConventions.HasThis |
8207                                 CallingConventions.Standard,
8208                                 type, args);
8209                         return get;
8210                 }
8211
8212
8213                 MethodInfo FetchAddressMethod ()
8214                 {
8215                         ModuleBuilder mb = CodeGen.Module.Builder;
8216                         int arg_count = ea.Arguments.Count;
8217                         Type [] args = new Type [arg_count];
8218                         MethodInfo address;
8219                         Type ret_type;
8220
8221                         ret_type = TypeManager.GetReferenceType (type);
8222
8223                         for (int i = 0; i < arg_count; i++){
8224                                 //args [i++] = a.Type;
8225                                 args [i] = TypeManager.int32_type;
8226                         }
8227
8228                         address = mb.GetArrayMethod (
8229                                 ea.Expr.Type, "Address",
8230                                 CallingConventions.HasThis |
8231                                 CallingConventions.Standard,
8232                                 ret_type, args);
8233
8234                         return address;
8235                 }
8236
8237                 //
8238                 // Load the array arguments into the stack.
8239                 //
8240                 // If we have been requested to cache the values (cached_locations array
8241                 // initialized), then load the arguments the first time and store them
8242                 // in locals.  otherwise load from local variables.
8243                 //
8244                 void LoadArrayAndArguments (EmitContext ec)
8245                 {
8246                         ILGenerator ig = ec.ig;
8247
8248                         ea.Expr.Emit (ec);
8249                         foreach (Argument a in ea.Arguments){
8250                                 Type argtype = a.Expr.Type;
8251
8252                                 a.Expr.Emit (ec);
8253
8254                                 if (argtype == TypeManager.int64_type)
8255                                         ig.Emit (OpCodes.Conv_Ovf_I);
8256                                 else if (argtype == TypeManager.uint64_type)
8257                                         ig.Emit (OpCodes.Conv_Ovf_I_Un);
8258                         }
8259                 }
8260
8261                 public void Emit (EmitContext ec, bool leave_copy)
8262                 {
8263                         int rank = ea.Expr.Type.GetArrayRank ();
8264                         ILGenerator ig = ec.ig;
8265
8266                         if (!prepared) {
8267                                 LoadArrayAndArguments (ec);
8268
8269                                 if (rank == 1)
8270                                         EmitLoadOpcode (ig, type);
8271                                 else {
8272                                         MethodInfo method;
8273
8274                                         method = FetchGetMethod ();
8275                                         ig.Emit (OpCodes.Call, method);
8276                                 }
8277                         } else
8278                                 LoadFromPtr (ec.ig, this.type);
8279
8280                         if (leave_copy) {
8281                                 ec.ig.Emit (OpCodes.Dup);
8282                                 temp = new LocalTemporary (ec, this.type);
8283                                 temp.Store (ec);
8284                         }
8285                 }
8286
8287                 public override void Emit (EmitContext ec)
8288                 {
8289                         Emit (ec, false);
8290                 }
8291
8292                 public void EmitAssign (EmitContext ec, Expression source, bool leave_copy, bool prepare_for_load)
8293                 {
8294                         int rank = ea.Expr.Type.GetArrayRank ();
8295                         ILGenerator ig = ec.ig;
8296                         Type t = source.Type;
8297                         prepared = prepare_for_load;
8298
8299                         if (prepare_for_load) {
8300                                 AddressOf (ec, AddressOp.LoadStore);
8301                                 ec.ig.Emit (OpCodes.Dup);
8302                                 source.Emit (ec);
8303                                 if (leave_copy) {
8304                                         ec.ig.Emit (OpCodes.Dup);
8305                                         temp = new LocalTemporary (ec, this.type);
8306                                         temp.Store (ec);
8307                                 }
8308                                 StoreFromPtr (ec.ig, t);
8309
8310                                 if (temp != null)
8311                                         temp.Emit (ec);
8312
8313                                 return;
8314                         }
8315
8316                         LoadArrayAndArguments (ec);
8317
8318                         if (rank == 1) {
8319                                 bool is_stobj, has_type_arg;
8320                                 OpCode op = GetStoreOpcode (t, out is_stobj, out has_type_arg);
8321
8322                                 //
8323                                 // The stobj opcode used by value types will need
8324                                 // an address on the stack, not really an array/array
8325                                 // pair
8326                                 //
8327                                 if (is_stobj)
8328                                         ig.Emit (OpCodes.Ldelema, t);
8329
8330                                 source.Emit (ec);
8331                                 if (leave_copy) {
8332                                         ec.ig.Emit (OpCodes.Dup);
8333                                         temp = new LocalTemporary (ec, this.type);
8334                                         temp.Store (ec);
8335                                 }
8336
8337                                 if (is_stobj)
8338                                         ig.Emit (OpCodes.Stobj, t);
8339                                 else if (has_type_arg)
8340                                         ig.Emit (op, t);
8341                                 else
8342                                         ig.Emit (op);
8343                         } else {
8344                                 ModuleBuilder mb = CodeGen.Module.Builder;
8345                                 int arg_count = ea.Arguments.Count;
8346                                 Type [] args = new Type [arg_count + 1];
8347                                 MethodInfo set;
8348
8349                                 source.Emit (ec);
8350                                 if (leave_copy) {
8351                                         ec.ig.Emit (OpCodes.Dup);
8352                                         temp = new LocalTemporary (ec, this.type);
8353                                         temp.Store (ec);
8354                                 }
8355
8356                                 for (int i = 0; i < arg_count; i++){
8357                                         //args [i++] = a.Type;
8358                                         args [i] = TypeManager.int32_type;
8359                                 }
8360
8361                                 args [arg_count] = type;
8362
8363                                 set = mb.GetArrayMethod (
8364                                         ea.Expr.Type, "Set",
8365                                         CallingConventions.HasThis |
8366                                         CallingConventions.Standard,
8367                                         TypeManager.void_type, args);
8368
8369                                 ig.Emit (OpCodes.Call, set);
8370                         }
8371
8372                         if (temp != null)
8373                                 temp.Emit (ec);
8374                 }
8375
8376                 public void AddressOf (EmitContext ec, AddressOp mode)
8377                 {
8378                         int rank = ea.Expr.Type.GetArrayRank ();
8379                         ILGenerator ig = ec.ig;
8380
8381                         LoadArrayAndArguments (ec);
8382
8383                         if (rank == 1){
8384                                 ig.Emit (OpCodes.Ldelema, type);
8385                         } else {
8386                                 MethodInfo address = FetchAddressMethod ();
8387                                 ig.Emit (OpCodes.Call, address);
8388                         }
8389                 }
8390         }
8391
8392
8393         class Indexers {
8394                 public ArrayList Properties;
8395                 static Hashtable map;
8396
8397                 public struct Indexer {
8398                         public readonly Type Type;
8399                         public readonly MethodInfo Getter, Setter;
8400
8401                         public Indexer (Type type, MethodInfo get, MethodInfo set)
8402                         {
8403                                 this.Type = type;
8404                                 this.Getter = get;
8405                                 this.Setter = set;
8406                         }
8407                 }
8408
8409                 static Indexers ()
8410                 {
8411                         map = new Hashtable ();
8412                 }
8413
8414                 Indexers ()
8415                 {
8416                         Properties = new ArrayList ();
8417                 }
8418
8419                 void Append (MemberInfo [] mi)
8420                 {
8421                         foreach (PropertyInfo property in mi){
8422                                 MethodInfo get, set;
8423
8424                                 get = property.GetGetMethod (true);
8425                                 set = property.GetSetMethod (true);
8426                                 Properties.Add (new Indexer (property.PropertyType, get, set));
8427                         }
8428                 }
8429
8430                 static private MemberInfo [] GetIndexersForTypeOrInterface (Type caller_type, Type lookup_type)
8431                 {
8432                         string p_name = TypeManager.IndexerPropertyName (lookup_type);
8433
8434                         MemberInfo [] mi = TypeManager.MemberLookup (
8435                                 caller_type, caller_type, lookup_type, MemberTypes.Property,
8436                                 BindingFlags.Public | BindingFlags.Instance |
8437                                 BindingFlags.DeclaredOnly, p_name, null);
8438
8439                         if (mi == null || mi.Length == 0)
8440                                 return null;
8441
8442                         return mi;
8443                 }
8444
8445                 static public Indexers GetIndexersForType (Type caller_type, Type lookup_type, Location loc)
8446                 {
8447                         Indexers ix = (Indexers) map [lookup_type];
8448
8449                         if (ix != null)
8450                                 return ix;
8451
8452                         Type copy = lookup_type;
8453                         while (copy != TypeManager.object_type && copy != null){
8454                                 MemberInfo [] mi = GetIndexersForTypeOrInterface (caller_type, copy);
8455
8456                                 if (mi != null){
8457                                         if (ix == null)
8458                                                 ix = new Indexers ();
8459
8460                                         ix.Append (mi);
8461                                 }
8462
8463                                 copy = copy.BaseType;
8464                         }
8465
8466                         if (!lookup_type.IsInterface)
8467                                 return ix;
8468
8469                         Type [] ifaces = TypeManager.GetInterfaces (lookup_type);
8470                         if (ifaces != null) {
8471                                 foreach (Type itype in ifaces) {
8472                                         MemberInfo [] mi = GetIndexersForTypeOrInterface (caller_type, itype);
8473                                         if (mi != null){
8474                                                 if (ix == null)
8475                                                         ix = new Indexers ();
8476
8477                                                 ix.Append (mi);
8478                                         }
8479                                 }
8480                         }
8481
8482                         return ix;
8483                 }
8484         }
8485
8486         /// <summary>
8487         ///   Expressions that represent an indexer call.
8488         /// </summary>
8489         public class IndexerAccess : Expression, IAssignMethod {
8490                 //
8491                 // Points to our "data" repository
8492                 //
8493                 MethodInfo get, set;
8494                 ArrayList set_arguments;
8495                 bool is_base_indexer;
8496
8497                 protected Type indexer_type;
8498                 protected Type current_type;
8499                 protected Expression instance_expr;
8500                 protected ArrayList arguments;
8501
8502                 public IndexerAccess (ElementAccess ea, Location loc)
8503                         : this (ea.Expr, false, loc)
8504                 {
8505                         this.arguments = ea.Arguments;
8506                 }
8507
8508                 protected IndexerAccess (Expression instance_expr, bool is_base_indexer,
8509                                          Location loc)
8510                 {
8511                         this.instance_expr = instance_expr;
8512                         this.is_base_indexer = is_base_indexer;
8513                         this.eclass = ExprClass.Value;
8514                         this.loc = loc;
8515                 }
8516
8517                 protected virtual bool CommonResolve (EmitContext ec)
8518                 {
8519                         indexer_type = instance_expr.Type;
8520                         current_type = ec.ContainerType;
8521
8522                         return true;
8523                 }
8524
8525                 public override Expression DoResolve (EmitContext ec)
8526                 {
8527                         ArrayList AllGetters = new ArrayList();
8528                         if (!CommonResolve (ec))
8529                                 return null;
8530
8531                         //
8532                         // Step 1: Query for all `Item' *properties*.  Notice
8533                         // that the actual methods are pointed from here.
8534                         //
8535                         // This is a group of properties, piles of them.
8536
8537                         bool found_any = false, found_any_getters = false;
8538                         Type lookup_type = indexer_type;
8539
8540                         Indexers ilist;
8541                         ilist = Indexers.GetIndexersForType (current_type, lookup_type, loc);
8542                         if (ilist != null) {
8543                                 found_any = true;
8544                                 if (ilist.Properties != null) {
8545                                         foreach (Indexers.Indexer ix in ilist.Properties) {
8546                                                 if (ix.Getter != null)
8547                                                         AllGetters.Add(ix.Getter);
8548                                         }
8549                                 }
8550                         }
8551
8552                         if (AllGetters.Count > 0) {
8553                                 found_any_getters = true;
8554                                 get = (MethodInfo) Invocation.OverloadResolve (
8555                                         ec, new MethodGroupExpr (AllGetters, loc),
8556                                         arguments, false, loc);
8557                         }
8558
8559                         if (!found_any) {
8560                                 Report.Error (21, loc,
8561                                               "Type `" + TypeManager.CSharpName (indexer_type) +
8562                                               "' does not have any indexers defined");
8563                                 return null;
8564                         }
8565
8566                         if (!found_any_getters) {
8567                                 Error (154, "indexer can not be used in this context, because " +
8568                                        "it lacks a `get' accessor");
8569                                 return null;
8570                         }
8571
8572                         if (get == null) {
8573                                 Error (1501, "No Overload for method `this' takes `" +
8574                                        arguments.Count + "' arguments");
8575                                 return null;
8576                         }
8577
8578                         //
8579                         // Only base will allow this invocation to happen.
8580                         //
8581                         if (get.IsAbstract && this is BaseIndexerAccess){
8582                                 Report.Error (205, loc, "Cannot call an abstract base indexer: " + Invocation.FullMethodDesc (get));
8583                                 return null;
8584                         }
8585
8586                         type = get.ReturnType;
8587                         if (type.IsPointer && !ec.InUnsafe){
8588                                 UnsafeError (loc);
8589                                 return null;
8590                         }
8591
8592                         instance_expr.CheckMarshallByRefAccess (ec.ContainerType);
8593
8594                         eclass = ExprClass.IndexerAccess;
8595                         return this;
8596                 }
8597
8598                 public override Expression DoResolveLValue (EmitContext ec, Expression right_side)
8599                 {
8600                         ArrayList AllSetters = new ArrayList();
8601                         if (!CommonResolve (ec))
8602                                 return null;
8603
8604                         bool found_any = false, found_any_setters = false;
8605
8606                         Indexers ilist = Indexers.GetIndexersForType (current_type, indexer_type, loc);
8607                         if (ilist != null) {
8608                                 found_any = true;
8609                                 if (ilist.Properties != null) {
8610                                         foreach (Indexers.Indexer ix in ilist.Properties) {
8611                                                 if (ix.Setter != null)
8612                                                         AllSetters.Add(ix.Setter);
8613                                         }
8614                                 }
8615                         }
8616                         if (AllSetters.Count > 0) {
8617                                 found_any_setters = true;
8618                                 set_arguments = (ArrayList) arguments.Clone ();
8619                                 set_arguments.Add (new Argument (right_side, Argument.AType.Expression));
8620                                 set = (MethodInfo) Invocation.OverloadResolve (
8621                                         ec, new MethodGroupExpr (AllSetters, loc),
8622                                         set_arguments, false, loc);
8623                         }
8624
8625                         if (!found_any) {
8626                                 Report.Error (21, loc,
8627                                               "Type `" + TypeManager.CSharpName (indexer_type) +
8628                                               "' does not have any indexers defined");
8629                                 return null;
8630                         }
8631
8632                         if (!found_any_setters) {
8633                                 Error (154, "indexer can not be used in this context, because " +
8634                                        "it lacks a `set' accessor");
8635                                 return null;
8636                         }
8637
8638                         if (set == null) {
8639                                 Error (1501, "No Overload for method `this' takes `" +
8640                                        arguments.Count + "' arguments");
8641                                 return null;
8642                         }
8643
8644                         //
8645                         // Only base will allow this invocation to happen.
8646                         //
8647                         if (set.IsAbstract && this is BaseIndexerAccess){
8648                                 Report.Error (205, loc, "Cannot call an abstract base indexer: " + Invocation.FullMethodDesc (set));
8649                                 return null;
8650                         }
8651
8652                         //
8653                         // Now look for the actual match in the list of indexers to set our "return" type
8654                         //
8655                         type = TypeManager.void_type;   // default value
8656                         foreach (Indexers.Indexer ix in ilist.Properties){
8657                                 if (ix.Setter == set){
8658                                         type = ix.Type;
8659                                         break;
8660                                 }
8661                         }
8662
8663                         instance_expr.CheckMarshallByRefAccess (ec.ContainerType);
8664
8665                         eclass = ExprClass.IndexerAccess;
8666                         return this;
8667                 }
8668
8669                 bool prepared = false;
8670                 LocalTemporary temp;
8671
8672                 public void Emit (EmitContext ec, bool leave_copy)
8673                 {
8674                         Invocation.EmitCall (ec, is_base_indexer, false, instance_expr, get, arguments, loc, prepared, false);
8675                         if (leave_copy) {
8676                                 ec.ig.Emit (OpCodes.Dup);
8677                                 temp = new LocalTemporary (ec, Type);
8678                                 temp.Store (ec);
8679                         }
8680                 }
8681
8682                 //
8683                 // source is ignored, because we already have a copy of it from the
8684                 // LValue resolution and we have already constructed a pre-cached
8685                 // version of the arguments (ea.set_arguments);
8686                 //
8687                 public void EmitAssign (EmitContext ec, Expression source, bool leave_copy, bool prepare_for_load)
8688                 {
8689                         prepared = prepare_for_load;
8690                         Argument a = (Argument) set_arguments [set_arguments.Count - 1];
8691
8692                         if (prepared) {
8693                                 source.Emit (ec);
8694                                 if (leave_copy) {
8695                                         ec.ig.Emit (OpCodes.Dup);
8696                                         temp = new LocalTemporary (ec, Type);
8697                                         temp.Store (ec);
8698                                 }
8699                         } else if (leave_copy) {
8700                                 temp = new LocalTemporary (ec, Type);
8701                                 source.Emit (ec);
8702                                 temp.Store (ec);
8703                                 a.Expr = temp;
8704                         }
8705
8706                         Invocation.EmitCall (ec, is_base_indexer, false, instance_expr, set, set_arguments, loc, false, prepared);
8707
8708                         if (temp != null)
8709                                 temp.Emit (ec);
8710                 }
8711
8712
8713                 public override void Emit (EmitContext ec)
8714                 {
8715                         Emit (ec, false);
8716                 }
8717         }
8718
8719         /// <summary>
8720         ///   The base operator for method names
8721         /// </summary>
8722         public class BaseAccess : Expression {
8723                 string member;
8724
8725                 public BaseAccess (string member, Location l)
8726                 {
8727                         this.member = member;
8728                         loc = l;
8729                 }
8730
8731                 public override Expression DoResolve (EmitContext ec)
8732                 {
8733                         Expression c = CommonResolve (ec);
8734
8735                         if (c == null)
8736                                 return null;
8737
8738                         //
8739                         // MethodGroups use this opportunity to flag an error on lacking ()
8740                         //
8741                         if (!(c is MethodGroupExpr))
8742                                 return c.Resolve (ec);
8743                         return c;
8744                 }
8745
8746                 public override Expression DoResolveLValue (EmitContext ec, Expression right_side)
8747                 {
8748                         Expression c = CommonResolve (ec);
8749
8750                         if (c == null)
8751                                 return null;
8752
8753                         //
8754                         // MethodGroups use this opportunity to flag an error on lacking ()
8755                         //
8756                         if (! (c is MethodGroupExpr))
8757                                 return c.DoResolveLValue (ec, right_side);
8758
8759                         return c;
8760                 }
8761
8762                 Expression CommonResolve (EmitContext ec)
8763                 {
8764                         Expression member_lookup;
8765                         Type current_type = ec.ContainerType;
8766                         Type base_type = current_type.BaseType;
8767                         Expression e;
8768
8769                         if (ec.IsStatic){
8770                                 Error (1511, "Keyword base is not allowed in static method");
8771                                 return null;
8772                         }
8773
8774                         if (ec.IsFieldInitializer){
8775                                 Error (1512, "Keyword base is not available in the current context");
8776                                 return null;
8777                         }
8778
8779                         member_lookup = MemberLookup (ec, ec.ContainerType, null, base_type,
8780                                                       member, AllMemberTypes, AllBindingFlags,
8781                                                       loc);
8782                         if (member_lookup == null) {
8783                                 MemberLookupFailed (
8784                                         ec, base_type, base_type, member, null, loc);
8785                                 return null;
8786                         }
8787
8788                         Expression left;
8789
8790                         if (ec.IsStatic)
8791                                 left = new TypeExpression (base_type, loc);
8792                         else
8793                                 left = ec.GetThis (loc);
8794
8795                         e = MemberAccess.ResolveMemberAccess (ec, member_lookup, left, loc, null);
8796
8797                         if (e is PropertyExpr){
8798                                 PropertyExpr pe = (PropertyExpr) e;
8799
8800                                 pe.IsBase = true;
8801                         }
8802
8803                         if (e is MethodGroupExpr)
8804                                 ((MethodGroupExpr) e).IsBase = true;
8805
8806                         return e;
8807                 }
8808
8809                 public override void Emit (EmitContext ec)
8810                 {
8811                         throw new Exception ("Should never be called");
8812                 }
8813         }
8814
8815         /// <summary>
8816         ///   The base indexer operator
8817         /// </summary>
8818         public class BaseIndexerAccess : IndexerAccess {
8819                 public BaseIndexerAccess (ArrayList args, Location loc)
8820                         : base (null, true, loc)
8821                 {
8822                         arguments = new ArrayList ();
8823                         foreach (Expression tmp in args)
8824                                 arguments.Add (new Argument (tmp, Argument.AType.Expression));
8825                 }
8826
8827                 protected override bool CommonResolve (EmitContext ec)
8828                 {
8829                         instance_expr = ec.GetThis (loc);
8830
8831                         current_type = ec.ContainerType.BaseType;
8832                         indexer_type = current_type;
8833
8834                         foreach (Argument a in arguments){
8835                                 if (!a.Resolve (ec, loc))
8836                                         return false;
8837                         }
8838
8839                         return true;
8840                 }
8841         }
8842
8843         /// <summary>
8844         ///   This class exists solely to pass the Type around and to be a dummy
8845         ///   that can be passed to the conversion functions (this is used by
8846         ///   foreach implementation to typecast the object return value from
8847         ///   get_Current into the proper type.  All code has been generated and
8848         ///   we only care about the side effect conversions to be performed
8849         ///
8850         ///   This is also now used as a placeholder where a no-action expression
8851         ///   is needed (the `New' class).
8852         /// </summary>
8853         public class EmptyExpression : Expression {
8854                 public static readonly EmptyExpression Null = new EmptyExpression ();
8855
8856                 // TODO: should be protected
8857                 public EmptyExpression ()
8858                 {
8859                         type = TypeManager.object_type;
8860                         eclass = ExprClass.Value;
8861                         loc = Location.Null;
8862                 }
8863
8864                 public EmptyExpression (Type t)
8865                 {
8866                         type = t;
8867                         eclass = ExprClass.Value;
8868                         loc = Location.Null;
8869                 }
8870
8871                 public override Expression DoResolve (EmitContext ec)
8872                 {
8873                         return this;
8874                 }
8875
8876                 public override void Emit (EmitContext ec)
8877                 {
8878                         // nothing, as we only exist to not do anything.
8879                 }
8880
8881                 //
8882                 // This is just because we might want to reuse this bad boy
8883                 // instead of creating gazillions of EmptyExpressions.
8884                 // (CanImplicitConversion uses it)
8885                 //
8886                 public void SetType (Type t)
8887                 {
8888                         type = t;
8889                 }
8890         }
8891
8892         public class UserCast : Expression {
8893                 MethodBase method;
8894                 Expression source;
8895
8896                 public UserCast (MethodInfo method, Expression source, Location l)
8897                 {
8898                         this.method = method;
8899                         this.source = source;
8900                         type = method.ReturnType;
8901                         eclass = ExprClass.Value;
8902                         loc = l;
8903                 }
8904
8905                 public Expression Source {
8906                         get {
8907                                 return source;
8908                         }
8909                 }
8910
8911                 public override Expression DoResolve (EmitContext ec)
8912                 {
8913                         //
8914                         // We are born fully resolved
8915                         //
8916                         return this;
8917                 }
8918
8919                 public override void Emit (EmitContext ec)
8920                 {
8921                         ILGenerator ig = ec.ig;
8922
8923                         source.Emit (ec);
8924
8925                         if (method is MethodInfo)
8926                                 ig.Emit (OpCodes.Call, (MethodInfo) method);
8927                         else
8928                                 ig.Emit (OpCodes.Call, (ConstructorInfo) method);
8929
8930                 }
8931         }
8932
8933         // <summary>
8934         //   This class is used to "construct" the type during a typecast
8935         //   operation.  Since the Type.GetType class in .NET can parse
8936         //   the type specification, we just use this to construct the type
8937         //   one bit at a time.
8938         // </summary>
8939         public class ComposedCast : TypeExpr {
8940                 Expression left;
8941                 string dim;
8942
8943                 public ComposedCast (Expression left, string dim, Location l)
8944                 {
8945                         this.left = left;
8946                         this.dim = dim;
8947                         loc = l;
8948                 }
8949
8950                 protected override TypeExpr DoResolveAsTypeStep (EmitContext ec)
8951                 {
8952                         TypeExpr lexpr = left.ResolveAsTypeTerminal (ec);
8953                         if (lexpr == null)
8954                                 return null;
8955
8956                         Type ltype = lexpr.Type;
8957
8958                         if ((ltype == TypeManager.void_type) && (dim != "*")) {
8959                                 Report.Error (1547, Location,
8960                                               "Keyword 'void' cannot be used in this context");
8961                                 return null;
8962                         }
8963
8964                         if ((dim.Length > 0) && (dim [0] == '?')) {
8965                                 TypeExpr nullable = new NullableType (left, loc);
8966                                 if (dim.Length > 1)
8967                                         nullable = new ComposedCast (nullable, dim.Substring (1), loc);
8968                                 return nullable.ResolveAsTypeTerminal (ec);
8969                         }
8970
8971                         int pos = 0;
8972                         while ((pos < dim.Length) && (dim [pos] == '[')) {
8973                                 pos++;
8974
8975                                 if (dim [pos] == ']') {
8976                                         ltype = ltype.MakeArrayType ();
8977                                         pos++;
8978
8979                                         if (pos < dim.Length)
8980                                                 continue;
8981
8982                                         type = ltype;
8983                                         eclass = ExprClass.Type;
8984                                         return this;
8985                                 }
8986
8987                                 int rank = 0;
8988                                 while (dim [pos] == ',') {
8989                                         pos++; rank++;
8990                                 }
8991
8992                                 if ((dim [pos] != ']') || (pos != dim.Length-1))
8993                                         return null;
8994
8995                                 type = ltype.MakeArrayType (rank + 1);
8996                                 eclass = ExprClass.Type;
8997                                 return this;
8998                         }
8999
9000                         if (dim != "") {
9001                                 //
9002                                 // ltype.Fullname is already fully qualified, so we can skip
9003                                 // a lot of probes, and go directly to TypeManager.LookupType
9004                                 //
9005                                 // For now, fall back to the full lookup in that case.
9006                                 //
9007                                 string fname = ltype.FullName != null ? ltype.FullName : ltype.Name;
9008                                 string cname = fname + dim;
9009                                 FullNamedExpression e = ec.DeclSpace.LookupType (
9010                                         cname, loc, /*silent=*/ false, /*ignore_cs0104=*/ false);
9011                                 if (e is TypeExpr)
9012                                         type = ((TypeExpr) e).ResolveType (ec);
9013                                 if (type == null)
9014                                         return null;
9015                         }
9016
9017                         if (!ec.InUnsafe && type.IsPointer){
9018                                 UnsafeError (loc);
9019                                 return null;
9020                         }
9021
9022                         if (type.IsArray && (type.GetElementType () == TypeManager.arg_iterator_type ||
9023                                 type.GetElementType () == TypeManager.typed_reference_type)) {
9024                                 Report.Error (611, loc, "Array elements cannot be of type '{0}'", TypeManager.CSharpName (type.GetElementType ()));
9025                                 return null;
9026                         }
9027
9028                         eclass = ExprClass.Type;
9029                         return this;
9030                 }
9031
9032                 public override string Name {
9033                         get {
9034                                 return left + dim;
9035                         }
9036                 }
9037
9038                 public override string FullName {
9039                         get {
9040                                 return type.FullName;
9041                         }
9042                 }
9043         }
9044
9045         public class FixedBufferPtr: Expression {
9046                 Expression array;
9047
9048                 public FixedBufferPtr (Expression array, Type array_type, Location l)
9049                 {
9050                         this.array = array;
9051                         this.loc = l;
9052
9053                         type = TypeManager.GetPointerType (array_type);
9054                         eclass = ExprClass.Value;
9055                 }
9056
9057                 public override void Emit(EmitContext ec)
9058                 {
9059                         array.Emit (ec);
9060                 }
9061
9062                 public override Expression DoResolve (EmitContext ec)
9063                 {
9064                         //
9065                         // We are born fully resolved
9066                         //
9067                         return this;
9068                 }
9069         }
9070
9071
9072         //
9073         // This class is used to represent the address of an array, used
9074         // only by the Fixed statement, this generates "&a [0]" construct
9075         // for fixed (char *pa = a)
9076         //
9077         public class ArrayPtr : FixedBufferPtr {
9078                 Type array_type;
9079
9080                 public ArrayPtr (Expression array, Type array_type, Location l):
9081                         base (array, array_type, l)
9082                 {
9083                         this.array_type = array_type;
9084                 }
9085
9086                 public override void Emit (EmitContext ec)
9087                 {
9088                         base.Emit (ec);
9089
9090                         ILGenerator ig = ec.ig;
9091                         IntLiteral.EmitInt (ig, 0);
9092                         ig.Emit (OpCodes.Ldelema, array_type);
9093                 }
9094         }
9095
9096         //
9097         // Used by the fixed statement
9098         //
9099         public class StringPtr : Expression {
9100                 LocalBuilder b;
9101
9102                 public StringPtr (LocalBuilder b, Location l)
9103                 {
9104                         this.b = b;
9105                         eclass = ExprClass.Value;
9106                         type = TypeManager.char_ptr_type;
9107                         loc = l;
9108                 }
9109
9110                 public override Expression DoResolve (EmitContext ec)
9111                 {
9112                         // This should never be invoked, we are born in fully
9113                         // initialized state.
9114
9115                         return this;
9116                 }
9117
9118                 public override void Emit (EmitContext ec)
9119                 {
9120                         ILGenerator ig = ec.ig;
9121
9122                         ig.Emit (OpCodes.Ldloc, b);
9123                         ig.Emit (OpCodes.Conv_I);
9124                         ig.Emit (OpCodes.Call, TypeManager.int_get_offset_to_string_data);
9125                         ig.Emit (OpCodes.Add);
9126                 }
9127         }
9128
9129         //
9130         // Implements the `stackalloc' keyword
9131         //
9132         public class StackAlloc : Expression {
9133                 Type otype;
9134                 Expression t;
9135                 Expression count;
9136
9137                 public StackAlloc (Expression type, Expression count, Location l)
9138                 {
9139                         t = type;
9140                         this.count = count;
9141                         loc = l;
9142                 }
9143
9144                 public override Expression DoResolve (EmitContext ec)
9145                 {
9146                         count = count.Resolve (ec);
9147                         if (count == null)
9148                                 return null;
9149
9150                         if (count.Type != TypeManager.int32_type){
9151                                 count = Convert.ImplicitConversionRequired (ec, count, TypeManager.int32_type, loc);
9152                                 if (count == null)
9153                                         return null;
9154                         }
9155
9156                         Constant c = count as Constant;
9157                         if (c != null && c.IsNegative) {
9158                                 Report.Error (247, loc, "Cannot use a negative size with stackalloc");
9159                                 return null;
9160                         }
9161
9162                         if (ec.CurrentBranching.InCatch () ||
9163                             ec.CurrentBranching.InFinally (true)) {
9164                                 Error (255,
9165                                               "stackalloc can not be used in a catch or finally block");
9166                                 return null;
9167                         }
9168
9169                         TypeExpr texpr = t.ResolveAsTypeTerminal (ec);
9170                         if (texpr == null)
9171                                 return null;
9172
9173                         otype = texpr.Type;
9174
9175                         if (!TypeManager.VerifyUnManaged (otype, loc))
9176                                 return null;
9177
9178                         type = TypeManager.GetPointerType (otype);
9179                         eclass = ExprClass.Value;
9180
9181                         return this;
9182                 }
9183
9184                 public override void Emit (EmitContext ec)
9185                 {
9186                         int size = GetTypeSize (otype);
9187                         ILGenerator ig = ec.ig;
9188
9189                         if (size == 0)
9190                                 ig.Emit (OpCodes.Sizeof, otype);
9191                         else
9192                                 IntConstant.EmitInt (ig, size);
9193                         count.Emit (ec);
9194                         ig.Emit (OpCodes.Mul);
9195                         ig.Emit (OpCodes.Localloc);
9196                 }
9197         }
9198 }