mcs/mcs/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                         return e;
 221                 }
 222
 223                 // <summary>
 224                 //   This routine will attempt to simplify the unary expression when the
 225                 //   argument is a constant.  The result is returned in `result' and the
 226                 //   function returns true or false depending on whether a reduction
 227                 //   was performed or not
 228                 // </summary>
 229                 bool Reduce (EmitContext ec, Constant e, out Expression result)
 230                 {
 231                         Type expr_type = e.Type;
 232
 233                         switch (Oper){
 234                         case Operator.UnaryPlus:
 235                                 result = e;
 236                                 return true;
 237
 238                         case Operator.UnaryNegation:
 239                                 result = TryReduceNegative (e);
 240                                 return true;
 241
 242                         case Operator.LogicalNot:
 243                                 if (expr_type != TypeManager.bool_type) {
 244                                         result = null;
 245                                         Error23 (expr_type);
 246                                         return false;
 247                                 }
 248
 249                                 BoolConstant b = (BoolConstant) e;
 250                                 result = new BoolConstant (!(b.Value));
 251                                 return true;
 252
 253                         case Operator.OnesComplement:
 254                                 if (!((expr_type == TypeManager.int32_type) ||
 255                                       (expr_type == TypeManager.uint32_type) ||
 256                                       (expr_type == TypeManager.int64_type) ||
 257                                       (expr_type == TypeManager.uint64_type) ||
 258                                       (expr_type.IsSubclassOf (TypeManager.enum_type)))){
 259
 260                                         result = null;
 261                                         if (Convert.ImplicitConversionExists (ec, e, TypeManager.int32_type)){
 262                                                 result = new Cast (new TypeExpression (TypeManager.int32_type, loc), e, loc);
 263                                                 result = result.Resolve (ec);
 264                                         } else if (Convert.ImplicitConversionExists (ec, e, TypeManager.uint32_type)){
 265                                                 result = new Cast (new TypeExpression (TypeManager.uint32_type, loc), e, loc);
 266                                                 result = result.Resolve (ec);
 267                                         } else if (Convert.ImplicitConversionExists (ec, e, TypeManager.int64_type)){
 268                                                 result = new Cast (new TypeExpression (TypeManager.int64_type, loc), e, loc);
 269                                                 result = result.Resolve (ec);
 270                                         } else if (Convert.ImplicitConversionExists (ec, e, TypeManager.uint64_type)){
 271                                                 result = new Cast (new TypeExpression (TypeManager.uint64_type, loc), e, loc);
 272                                                 result = result.Resolve (ec);
 273                                         }
 274
 275                                         if (result == null || !(result is Constant)){
 276                                                 result = null;
 277                                                 Error23 (expr_type);
 278                                                 return false;
 279                                         }
 280
 281                                         expr_type = result.Type;
 282                                         e = (Constant) result;
 283                                 }
 284
 285                                 if (e is EnumConstant){
 286                                         EnumConstant enum_constant = (EnumConstant) e;
 287                                         Expression reduced;
 288
 289                                         if (Reduce (ec, enum_constant.Child, out reduced)){
 290                                                 result = new EnumConstant ((Constant) reduced, enum_constant.Type);
 291                                                 return true;
 292                                         } else {
 293                                                 result = null;
 294                                                 return false;
 295                                         }
 296                                 }
 297
 298                                 if (expr_type == TypeManager.int32_type){
 299                                         result = new IntConstant (~ ((IntConstant) e).Value);
 300                                 } else if (expr_type == TypeManager.uint32_type){
 301                                         result = new UIntConstant (~ ((UIntConstant) e).Value);
 302                                 } else if (expr_type == TypeManager.int64_type){
 303                                         result = new LongConstant (~ ((LongConstant) e).Value);
 304                                 } else if (expr_type == TypeManager.uint64_type){
 305                                         result = new ULongConstant (~ ((ULongConstant) e).Value);
 306                                 } else {
 307                                         result = null;
 308                                         Error23 (expr_type);
 309                                         return false;
 310                                 }
 311                                 return true;
 312
 313                         case Operator.AddressOf:
 314                                 result = this;
 315                                 return false;
 316
 317                         case Operator.Indirection:
 318                                 result = this;
 319                                 return false;
 320                         }
 321                         throw new Exception ("Can not constant fold: " + Oper.ToString());
 322                 }
 323
 324                 Expression ResolveOperator (EmitContext ec)
 325                 {
 326                         Type expr_type = Expr.Type;
 327
 328                         //
 329                         // Step 1: Perform Operator Overload location
 330                         //
 331                         Expression mg;
 332                         string op_name;
 333
 334                         op_name = oper_names [(int) Oper];
 335
 336                         mg = MemberLookup (ec, expr_type, op_name, MemberTypes.Method, AllBindingFlags, loc);
 337
 338                         if (mg != null) {
 339                                 Expression e = StaticCallExpr.MakeSimpleCall (
 340                                         ec, (MethodGroupExpr) mg, Expr, loc);
 341
 342                                 if (e == null){
 343                                         Error23 (expr_type);
 344                                         return null;
 345                                 }
 346
 347                                 return e;
 348                         }
 349
 350                         // Only perform numeric promotions on:
 351                         // +, -
 352
 353                         if (expr_type == null)
 354                                 return null;
 355
 356                         //
 357                         // Step 2: Default operations on CLI native types.
 358                         //
 359
 360                         // Attempt to use a constant folding operation.
 361                         if (Expr is Constant){
 362                                 Expression result;
 363
 364                                 if (Reduce (ec, (Constant) Expr, out result))
 365                                         return result;
 366                         }
 367
 368                         switch (Oper){
 369                         case Operator.LogicalNot:
 370                                 if (expr_type != TypeManager.bool_type) {
 371                                         Expr = ResolveBoolean (ec, Expr, loc);
 372                                         if (Expr == null){
 373                                                 Error23 (expr_type);
 374                                                 return null;
 375                                         }
 376                                 }
 377
 378                                 type = TypeManager.bool_type;
 379                                 return this;
 380
 381                         case Operator.OnesComplement:
 382                                 if (!((expr_type == TypeManager.int32_type) ||
 383                                       (expr_type == TypeManager.uint32_type) ||
 384                                       (expr_type == TypeManager.int64_type) ||
 385                                       (expr_type == TypeManager.uint64_type) ||
 386                                       (expr_type.IsSubclassOf (TypeManager.enum_type)))){
 387                                         Expression e;
 388
 389                                         e = Convert.ImplicitConversion (ec, Expr, TypeManager.int32_type, loc);
 390                                         if (e != null){
 391                                                 type = TypeManager.int32_type;
 392                                                 return this;
 393                                         }
 394                                         e = Convert.ImplicitConversion (ec, Expr, TypeManager.uint32_type, loc);
 395                                         if (e != null){
 396                                                 type = TypeManager.uint32_type;
 397                                                 return this;
 398                                         }
 399                                         e = Convert.ImplicitConversion (ec, Expr, TypeManager.int64_type, loc);
 400                                         if (e != null){
 401                                                 type = TypeManager.int64_type;
 402                                                 return this;
 403                                         }
 404                                         e = Convert.ImplicitConversion (ec, Expr, TypeManager.uint64_type, loc);
 405                                         if (e != null){
 406                                                 type = TypeManager.uint64_type;
 407                                                 return this;
 408                                         }
 409                                         Error23 (expr_type);
 410                                         return null;
 411                                 }
 412                                 type = expr_type;
 413                                 return this;
 414
 415                         case Operator.AddressOf:
 416                                 if (Expr.eclass != ExprClass.Variable){
 417                                         Error (211, "Cannot take the address of non-variables");
 418                                         return null;
 419                                 }
 420
 421                                 if (!ec.InUnsafe) {
 422                                         UnsafeError (loc);
 423                                         return null;
 424                                 }
 425
 426                                 if (!TypeManager.VerifyUnManaged (Expr.Type, loc)){
 427                                         return null;
 428                                 }
 429
 430                                 IVariable variable = Expr as IVariable;
 431                                 if (!ec.InFixedInitializer && ((variable == null) || !variable.VerifyFixed (false))) {
 432                                         Error (212, "You can only take the address of an unfixed expression inside " +
 433                                                "of a fixed statement initializer");
 434                                         return null;
 435                                 }
 436
 437                                 if (ec.InFixedInitializer && ((variable != null) && variable.VerifyFixed (false))) {
 438                                         Error (213, "You can not fix an already fixed expression");
 439                                         return null;
 440                                 }
 441
 442                                 // According to the specs, a variable is considered definitely assigned if you take
 443                                 // its address.
 444                                 if ((variable != null) && (variable.VariableInfo != null))
 445                                         variable.VariableInfo.SetAssigned (ec);
 446
 447                                 type = TypeManager.GetPointerType (Expr.Type);
 448                                 return this;
 449
 450                         case Operator.Indirection:
 451                                 if (!ec.InUnsafe){
 452                                         UnsafeError (loc);
 453                                         return null;
 454                                 }
 455
 456                                 if (!expr_type.IsPointer){
 457                                         Error (193, "The * or -> operator can only be applied to pointers");
 458                                         return null;
 459                                 }
 460
 461                                 //
 462                                 // We create an Indirection expression, because
 463                                 // it can implement the IMemoryLocation.
 464                                 //
 465                                 return new Indirection (Expr, loc);
 466
 467                         case Operator.UnaryPlus:
 468                                 //
 469                                 // A plus in front of something is just a no-op, so return the child.
 470                                 //
 471                                 return Expr;
 472
 473                         case Operator.UnaryNegation:
 474                                 //
 475                                 // Deals with -literals
 476                                 // int     operator- (int x)
 477                                 // long    operator- (long x)
 478                                 // float   operator- (float f)
 479                                 // double  operator- (double d)
 480                                 // decimal operator- (decimal d)
 481                                 //
 482                                 Expression expr = null;
 483
 484                                 //
 485                                 // transform - - expr into expr
 486                                 //
 487                                 if (Expr is Unary){
 488                                         Unary unary = (Unary) Expr;
 489
 490                                         if (unary.Oper == Operator.UnaryNegation)
 491                                                 return unary.Expr;
 492                                 }
 493
 494                                 //
 495                                 // perform numeric promotions to int,
 496                                 // long, double.
 497                                 //
 498                                 //
 499                                 // The following is inneficient, because we call
 500                                 // ImplicitConversion too many times.
 501                                 //
 502                                 // It is also not clear if we should convert to Float
 503                                 // or Double initially.
 504                                 //
 505                                 if (expr_type == TypeManager.uint32_type){
 506                                         //
 507                                         // FIXME: handle exception to this rule that
 508                                         // permits the int value -2147483648 (-2^31) to
 509                                         // bt wrote as a decimal interger literal
 510                                         //
 511                                         type = TypeManager.int64_type;
 512                                         Expr = Convert.ImplicitConversion (ec, Expr, type, loc);
 513                                         return this;
 514                                 }
 515
 516                                 if (expr_type == TypeManager.uint64_type){
 517                                         //
 518                                         // FIXME: Handle exception of `long value'
 519                                         // -92233720368547758087 (-2^63) to be wrote as
 520                                         // decimal integer literal.
 521                                         //
 522                                         Error23 (expr_type);
 523                                         return null;
 524                                 }
 525
 526                                 if (expr_type == TypeManager.float_type){
 527                                         type = expr_type;
 528                                         return this;
 529                                 }
 530
 531                                 expr = Convert.ImplicitConversion (ec, Expr, TypeManager.int32_type, loc);
 532                                 if (expr != null){
 533                                         Expr = expr;
 534                                         type = expr.Type;
 535                                         return this;
 536                                 }
 537
 538                                 expr = Convert.ImplicitConversion (ec, Expr, TypeManager.int64_type, loc);
 539                                 if (expr != null){
 540                                         Expr = expr;
 541                                         type = expr.Type;
 542                                         return this;
 543                                 }
 544
 545                                 expr = Convert.ImplicitConversion (ec, Expr, TypeManager.double_type, loc);
 546                                 if (expr != null){
 547                                         Expr = expr;
 548                                         type = expr.Type;
 549                                         return this;
 550                                 }
 551
 552                                 Error23 (expr_type);
 553                                 return null;
 554                         }
 555
 556                         Error (187, "No such operator '" + OperName (Oper) + "' defined for type '" +
 557                                TypeManager.CSharpName (expr_type) + "'");
 558                         return null;
 559                 }
 560
 561                 public override Expression DoResolve (EmitContext ec)
 562                 {
 563                         if (Oper == Operator.AddressOf)
 564                                 Expr = Expr.ResolveLValue (ec, new EmptyExpression ());
 565                         else
 566                                 Expr = Expr.Resolve (ec);
 567
 568                         if (Expr == null)
 569                                 return null;
 570
 571                         eclass = ExprClass.Value;
 572                         return ResolveOperator (ec);
 573                 }
 574
 575                 public override Expression DoResolveLValue (EmitContext ec, Expression right)
 576                 {
 577                         if (Oper == Operator.Indirection)
 578                                 return base.DoResolveLValue (ec, right);
 579
 580                         Error (131, "The left-hand side of an assignment must be a " +
 581                                "variable, property or indexer");
 582                         return null;
 583                 }
 584
 585                 public override void Emit (EmitContext ec)
 586                 {
 587                         ILGenerator ig = ec.ig;
 588
 589                         switch (Oper) {
 590                         case Operator.UnaryPlus:
 591                                 throw new Exception ("This should be caught by Resolve");
 592
 593                         case Operator.UnaryNegation:
 594                                 if (ec.CheckState) {
 595                                         ig.Emit (OpCodes.Ldc_I4_0);
 596                                         if (type == TypeManager.int64_type)
 597                                                 ig.Emit (OpCodes.Conv_U8);
 598                                         Expr.Emit (ec);
 599                                         ig.Emit (OpCodes.Sub_Ovf);
 600                                 } else {
 601                                         Expr.Emit (ec);
 602                                         ig.Emit (OpCodes.Neg);
 603                                 }
 604
 605                                 break;
 606
 607                         case Operator.LogicalNot:
 608                                 Expr.Emit (ec);
 609                                 ig.Emit (OpCodes.Ldc_I4_0);
 610                                 ig.Emit (OpCodes.Ceq);
 611                                 break;
 612
 613                         case Operator.OnesComplement:
 614                                 Expr.Emit (ec);
 615                                 ig.Emit (OpCodes.Not);
 616                                 break;
 617
 618                         case Operator.AddressOf:
 619                                 ((IMemoryLocation)Expr).AddressOf (ec, AddressOp.LoadStore);
 620                                 break;
 621
 622                         default:
 623                                 throw new Exception ("This should not happen: Operator = "
 624                                                      + Oper.ToString ());
 625                         }
 626                 }
 627
 628                 public override void EmitBranchable (EmitContext ec, Label target, bool onTrue)
 629                 {
 630                         if (Oper == Operator.LogicalNot)
 631                                 Expr.EmitBranchable (ec, target, !onTrue);
 632                         else
 633                                 base.EmitBranchable (ec, target, onTrue);
 634                 }
 635
 636                 public override string ToString ()
 637                 {
 638                         return "Unary (" + Oper + ", " + Expr + ")";
 639                 }
 640
 641         }
 642
 643         //
 644         // Unary operators are turned into Indirection expressions
 645         // after semantic analysis (this is so we can take the address
 646         // of an indirection).
 647         //
 648         public class Indirection : Expression, IMemoryLocation, IAssignMethod {
 649                 Expression expr;
 650                 LocalTemporary temporary;
 651                 bool prepared;
 652
 653                 public Indirection (Expression expr, Location l)
 654                 {
 655                         this.expr = expr;
 656                         this.type = TypeManager.GetElementType (expr.Type);
 657                         eclass = ExprClass.Variable;
 658                         loc = l;
 659                 }
 660
 661                 void LoadExprValue (EmitContext ec)
 662                 {
 663                 }
 664
 665                 public override void Emit (EmitContext ec)
 666                 {
 667                         if (!prepared)
 668                                 expr.Emit (ec);
 669
 670                         LoadFromPtr (ec.ig, Type);
 671                 }
 672
 673                 public void Emit (EmitContext ec, bool leave_copy)
 674                 {
 675                         Emit (ec);
 676                         if (leave_copy) {
 677                                 ec.ig.Emit (OpCodes.Dup);
 678                                 temporary = new LocalTemporary (ec, expr.Type);
 679                                 temporary.Store (ec);
 680                         }
 681                 }
 682
 683                 public void EmitAssign (EmitContext ec, Expression source, bool leave_copy, bool prepare_for_load)
 684                 {
 685                         prepared = prepare_for_load;
 686
 687                         expr.Emit (ec);
 688
 689                         if (prepare_for_load)
 690                                 ec.ig.Emit (OpCodes.Dup);
 691
 692                         source.Emit (ec);
 693                         if (leave_copy) {
 694                                 ec.ig.Emit (OpCodes.Dup);
 695                                 temporary = new LocalTemporary (ec, expr.Type);
 696                                 temporary.Store (ec);
 697                         }
 698
 699                         StoreFromPtr (ec.ig, type);
 700
 701                         if (temporary != null)
 702                                 temporary.Emit (ec);
 703                 }
 704
 705                 public void AddressOf (EmitContext ec, AddressOp Mode)
 706                 {
 707                         expr.Emit (ec);
 708                 }
 709
 710                 public override Expression DoResolve (EmitContext ec)
 711                 {
 712                         //
 713                         // Born fully resolved
 714                         //
 715                         return this;
 716                 }
 717
 718                 public override string ToString ()
 719                 {
 720                         return "*(" + expr + ")";
 721                 }
 722         }
 723
 724         /// <summary>
 725         ///   Unary Mutator expressions (pre and post ++ and --)
 726         /// </summary>
 727         ///
 728         /// <remarks>
 729         ///   UnaryMutator implements ++ and -- expressions.   It derives from
 730         ///   ExpressionStatement becuase the pre/post increment/decrement
 731         ///   operators can be used in a statement context.
 732         ///
 733         /// FIXME: Idea, we could split this up in two classes, one simpler
 734         /// for the common case, and one with the extra fields for more complex
 735         /// classes (indexers require temporary access;  overloaded require method)
 736         ///
 737         /// </remarks>
 738         public class UnaryMutator : ExpressionStatement {
 739                 [Flags]
 740                 public enum Mode : byte {
 741                         IsIncrement    = 0,
 742                         IsDecrement    = 1,
 743                         IsPre          = 0,
 744                         IsPost         = 2,
 745
 746                         PreIncrement   = 0,
 747                         PreDecrement   = IsDecrement,
 748                         PostIncrement  = IsPost,
 749                         PostDecrement  = IsPost | IsDecrement
 750                 }
 751
 752                 Mode mode;
 753                 bool is_expr = false;
 754                 bool recurse = false;
 755
 756                 Expression expr;
 757
 758                 //
 759                 // This is expensive for the simplest case.
 760                 //
 761                 StaticCallExpr method;
 762
 763                 public UnaryMutator (Mode m, Expression e, Location l)
 764                 {
 765                         mode = m;
 766                         loc = l;
 767                         expr = e;
 768                 }
 769
 770                 static string OperName (Mode mode)
 771                 {
 772                         return (mode == Mode.PreIncrement || mode == Mode.PostIncrement) ?
 773                                 "++" : "--";
 774                 }
 775
 776                 void Error23 (Type t)
 777                 {
 778                         Error (
 779                                 23, "Operator " + OperName (mode) +
 780                                 " cannot be applied to operand of type `" +
 781                                 TypeManager.CSharpName (t) + "'");
 782                 }
 783
 784                 /// <summary>
 785                 ///   Returns whether an object of type `t' can be incremented
 786                 ///   or decremented with add/sub (ie, basically whether we can
 787                 ///   use pre-post incr-decr operations on it, but it is not a
 788                 ///   System.Decimal, which we require operator overloading to catch)
 789                 /// </summary>
 790                 static bool IsIncrementableNumber (Type t)
 791                 {
 792                         return (t == TypeManager.sbyte_type) ||
 793                                 (t == TypeManager.byte_type) ||
 794                                 (t == TypeManager.short_type) ||
 795                                 (t == TypeManager.ushort_type) ||
 796                                 (t == TypeManager.int32_type) ||
 797                                 (t == TypeManager.uint32_type) ||
 798                                 (t == TypeManager.int64_type) ||
 799                                 (t == TypeManager.uint64_type) ||
 800                                 (t == TypeManager.char_type) ||
 801                                 (t.IsSubclassOf (TypeManager.enum_type)) ||
 802                                 (t == TypeManager.float_type) ||
 803                                 (t == TypeManager.double_type) ||
 804                                 (t.IsPointer && t != TypeManager.void_ptr_type);
 805                 }
 806
 807                 Expression ResolveOperator (EmitContext ec)
 808                 {
 809                         Type expr_type = expr.Type;
 810
 811                         //
 812                         // Step 1: Perform Operator Overload location
 813                         //
 814                         Expression mg;
 815                         string op_name;
 816
 817                         if (mode == Mode.PreIncrement || mode == Mode.PostIncrement)
 818                                 op_name = "op_Increment";
 819                         else
 820                                 op_name = "op_Decrement";
 821
 822                         mg = MemberLookup (ec, expr_type, op_name, MemberTypes.Method, AllBindingFlags, loc);
 823
 824                         if (mg == null && expr_type.BaseType != null)
 825                                 mg = MemberLookup (ec, expr_type.BaseType, op_name,
 826                                                    MemberTypes.Method, AllBindingFlags, loc);
 827
 828                         if (mg != null) {
 829                                 method = StaticCallExpr.MakeSimpleCall (
 830                                         ec, (MethodGroupExpr) mg, expr, loc);
 831
 832                                 type = method.Type;
 833                                 return this;
 834                         }
 835
 836                         //
 837                         // The operand of the prefix/postfix increment decrement operators
 838                         // should be an expression that is classified as a variable,
 839                         // a property access or an indexer access
 840                         //
 841                         type = expr_type;
 842                         if (expr.eclass == ExprClass.Variable){
 843                                 LocalVariableReference var = expr as LocalVariableReference;
 844                                 if ((var != null) && var.IsReadOnly)
 845                                         Error (1604, "cannot assign to `" + var.Name + "' because it is readonly");
 846                                 if (IsIncrementableNumber (expr_type) ||
 847                                     expr_type == TypeManager.decimal_type){
 848                                         return this;
 849                                 }
 850                         } else if (expr.eclass == ExprClass.IndexerAccess){
 851                                 IndexerAccess ia = (IndexerAccess) expr;
 852
 853                                 expr = ia.ResolveLValue (ec, this);
 854                                 if (expr == null)
 855                                         return null;
 856
 857                                 return this;
 858                         } else if (expr.eclass == ExprClass.PropertyAccess){
 859                                 PropertyExpr pe = (PropertyExpr) expr;
 860
 861                                 if (pe.VerifyAssignable ())
 862                                         return this;
 863
 864                                 return null;
 865                         } else {
 866                                 expr.Error_UnexpectedKind ("variable, indexer or property access");
 867                                 return null;
 868                         }
 869
 870                         Error (187, "No such operator '" + OperName (mode) + "' defined for type '" +
 871                                TypeManager.CSharpName (expr_type) + "'");
 872                         return null;
 873                 }
 874
 875                 public override Expression DoResolve (EmitContext ec)
 876                 {
 877                         expr = expr.Resolve (ec);
 878
 879                         if (expr == null)
 880                                 return null;
 881
 882                         eclass = ExprClass.Value;
 883                         return ResolveOperator (ec);
 884                 }
 885
 886                 static int PtrTypeSize (Type t)
 887                 {
 888                         return GetTypeSize (TypeManager.GetElementType (t));
 889                 }
 890
 891                 //
 892                 // Loads the proper "1" into the stack based on the type, then it emits the
 893                 // opcode for the operation requested
 894                 //
 895                 void LoadOneAndEmitOp (EmitContext ec, Type t)
 896                 {
 897                         //
 898                         // Measure if getting the typecode and using that is more/less efficient
 899                         // that comparing types.  t.GetTypeCode() is an internal call.
 900                         //
 901                         ILGenerator ig = ec.ig;
 902
 903                         if (t == TypeManager.uint64_type || t == TypeManager.int64_type)
 904                                 LongConstant.EmitLong (ig, 1);
 905                         else if (t == TypeManager.double_type)
 906                                 ig.Emit (OpCodes.Ldc_R8, 1.0);
 907                         else if (t == TypeManager.float_type)
 908                                 ig.Emit (OpCodes.Ldc_R4, 1.0F);
 909                         else if (t.IsPointer){
 910                                 int n = PtrTypeSize (t);
 911
 912                                 if (n == 0)
 913                                         ig.Emit (OpCodes.Sizeof, t);
 914                                 else
 915                                         IntConstant.EmitInt (ig, n);
 916                         } else
 917                                 ig.Emit (OpCodes.Ldc_I4_1);
 918
 919                         //
 920                         // Now emit the operation
 921                         //
 922                         if (ec.CheckState){
 923                                 if (t == TypeManager.int32_type ||
 924                                     t == TypeManager.int64_type){
 925                                         if ((mode & Mode.IsDecrement) != 0)
 926                                                 ig.Emit (OpCodes.Sub_Ovf);
 927                                         else
 928                                                 ig.Emit (OpCodes.Add_Ovf);
 929                                 } else if (t == TypeManager.uint32_type ||
 930                                            t == TypeManager.uint64_type){
 931                                         if ((mode & Mode.IsDecrement) != 0)
 932                                                 ig.Emit (OpCodes.Sub_Ovf_Un);
 933                                         else
 934                                                 ig.Emit (OpCodes.Add_Ovf_Un);
 935                                 } else {
 936                                         if ((mode & Mode.IsDecrement) != 0)
 937                                                 ig.Emit (OpCodes.Sub_Ovf);
 938                                         else
 939                                                 ig.Emit (OpCodes.Add_Ovf);
 940                                 }
 941                         } else {
 942                                 if ((mode & Mode.IsDecrement) != 0)
 943                                         ig.Emit (OpCodes.Sub);
 944                                 else
 945                                         ig.Emit (OpCodes.Add);
 946                         }
 947
 948                         if (t == TypeManager.sbyte_type){
 949                                 if (ec.CheckState)
 950                                         ig.Emit (OpCodes.Conv_Ovf_I1);
 951                                 else
 952                                         ig.Emit (OpCodes.Conv_I1);
 953                         } else if (t == TypeManager.byte_type){
 954                                 if (ec.CheckState)
 955                                         ig.Emit (OpCodes.Conv_Ovf_U1);
 956                                 else
 957                                         ig.Emit (OpCodes.Conv_U1);
 958                         } else if (t == TypeManager.short_type){
 959                                 if (ec.CheckState)
 960                                         ig.Emit (OpCodes.Conv_Ovf_I2);
 961                                 else
 962                                         ig.Emit (OpCodes.Conv_I2);
 963                         } else if (t == TypeManager.ushort_type || t == TypeManager.char_type){
 964                                 if (ec.CheckState)
 965                                         ig.Emit (OpCodes.Conv_Ovf_U2);
 966                                 else
 967                                         ig.Emit (OpCodes.Conv_U2);
 968                         }
 969
 970                 }
 971
 972                 void EmitCode (EmitContext ec, bool is_expr)
 973                 {
 974                         recurse = true;
 975                         this.is_expr = is_expr;
 976                         ((IAssignMethod) expr).EmitAssign (ec, this, is_expr && (mode == Mode.PreIncrement || mode == Mode.PreDecrement), true);
 977                 }
 978
 979
 980                 public override void Emit (EmitContext ec)
 981                 {
 982                         //
 983                         // We use recurse to allow ourselfs to be the source
 984                         // of an assignment. This little hack prevents us from
 985                         // having to allocate another expression
 986                         //
 987                         if (recurse) {
 988                                 ((IAssignMethod) expr).Emit (ec, is_expr && (mode == Mode.PostIncrement  || mode == Mode.PostDecrement));
 989                                 if (method == null)
 990                                         LoadOneAndEmitOp (ec, expr.Type);
 991                                 else
 992                                         ec.ig.Emit (OpCodes.Call, method.Method);
 993                                 recurse = false;
 994                                 return;
 995                         }
 996
 997                         EmitCode (ec, true);
 998                 }
 999
1000                 public override void EmitStatement (EmitContext ec)
1001                 {
1002                         EmitCode (ec, false);
1003                 }
1004         }
1005
1006         /// <summary>
1007         ///   Base class for the `Is' and `As' classes.
1008         /// </summary>
1009         ///
1010         /// <remarks>
1011         ///   FIXME: Split this in two, and we get to save the `Operator' Oper
1012         ///   size.
1013         /// </remarks>
1014         public abstract class Probe : Expression {
1015                 public readonly Expression ProbeType;
1016                 protected Expression expr;
1017                 protected Type probe_type;
1018
1019                 public Probe (Expression expr, Expression probe_type, Location l)
1020                 {
1021                         ProbeType = probe_type;
1022                         loc = l;
1023                         this.expr = expr;
1024                 }
1025
1026                 public Expression Expr {
1027                         get {
1028                                 return expr;
1029                         }
1030                 }
1031
1032                 public override Expression DoResolve (EmitContext ec)
1033                 {
1034                         probe_type = ec.DeclSpace.ResolveType (ProbeType, false, loc);
1035
1036                         if (probe_type == null)
1037                                 return null;
1038
1039                         CheckObsoleteAttribute (probe_type);
1040
1041                         expr = expr.Resolve (ec);
1042                         if (expr == null)
1043                                 return null;
1044
1045                         if (expr.Type.IsPointer) {
1046                                 Report.Error (244, loc, "\"is\" or \"as\" are not valid on pointer types");
1047                                 return null;
1048                         }
1049                         return this;
1050                 }
1051         }
1052
1053         /// <summary>
1054         ///   Implementation of the `is' operator.
1055         /// </summary>
1056         public class Is : Probe {
1057                 public Is (Expression expr, Expression probe_type, Location l)
1058                         : base (expr, probe_type, l)
1059                 {
1060                 }
1061
1062                 enum Action {
1063                         AlwaysTrue, AlwaysNull, AlwaysFalse, LeaveOnStack, Probe
1064                 }
1065
1066                 Action action;
1067
1068                 public override void Emit (EmitContext ec)
1069                 {
1070                         ILGenerator ig = ec.ig;
1071
1072                         expr.Emit (ec);
1073
1074                         switch (action){
1075                         case Action.AlwaysFalse:
1076                                 ig.Emit (OpCodes.Pop);
1077                                 IntConstant.EmitInt (ig, 0);
1078                                 return;
1079                         case Action.AlwaysTrue:
1080                                 ig.Emit (OpCodes.Pop);
1081                                 IntConstant.EmitInt (ig, 1);
1082                                 return;
1083                         case Action.LeaveOnStack:
1084                                 // the `e != null' rule.
1085                                 ig.Emit (OpCodes.Ldnull);
1086                                 ig.Emit (OpCodes.Ceq);
1087                                 ig.Emit (OpCodes.Ldc_I4_0);
1088                                 ig.Emit (OpCodes.Ceq);
1089                                 return;
1090                         case Action.Probe:
1091                                 ig.Emit (OpCodes.Isinst, probe_type);
1092                                 ig.Emit (OpCodes.Ldnull);
1093                                 ig.Emit (OpCodes.Cgt_Un);
1094                                 return;
1095                         }
1096                         throw new Exception ("never reached");
1097                 }
1098
1099                 public override void EmitBranchable (EmitContext ec, Label target, bool onTrue)
1100                 {
1101                         ILGenerator ig = ec.ig;
1102
1103                         switch (action){
1104                         case Action.AlwaysFalse:
1105                                 if (! onTrue)
1106                                         ig.Emit (OpCodes.Br, target);
1107
1108                                 return;
1109                         case Action.AlwaysTrue:
1110                                 if (onTrue)
1111                                         ig.Emit (OpCodes.Br, target);
1112
1113                                 return;
1114                         case Action.LeaveOnStack:
1115                                 // the `e != null' rule.
1116                                 expr.Emit (ec);
1117                                 ig.Emit (onTrue ? OpCodes.Brtrue : OpCodes.Brfalse, target);
1118                                 return;
1119                         case Action.Probe:
1120                                 expr.Emit (ec);
1121                                 ig.Emit (OpCodes.Isinst, probe_type);
1122                                 ig.Emit (onTrue ? OpCodes.Brtrue : OpCodes.Brfalse, target);
1123                                 return;
1124                         }
1125                         throw new Exception ("never reached");
1126                 }
1127
1128                 public override Expression DoResolve (EmitContext ec)
1129                 {
1130                         Expression e = base.DoResolve (ec);
1131
1132                         if ((e == null) || (expr == null))
1133                                 return null;
1134
1135                         Type etype = expr.Type;
1136                         bool warning_always_matches = false;
1137                         bool warning_never_matches = false;
1138
1139                         type = TypeManager.bool_type;
1140                         eclass = ExprClass.Value;
1141
1142                         //
1143                         // First case, if at compile time, there is an implicit conversion
1144                         // then e != null (objects) or true (value types)
1145                         //
1146                         e = Convert.ImplicitConversionStandard (ec, expr, probe_type, loc);
1147                         if (e != null){
1148                                 expr = e;
1149                                 if (etype.IsValueType)
1150                                         action = Action.AlwaysTrue;
1151                                 else
1152                                         action = Action.LeaveOnStack;
1153
1154                                 warning_always_matches = true;
1155                         } else if (Convert.ExplicitReferenceConversionExists (etype, probe_type)){
1156                                 //
1157                                 // Second case: explicit reference convresion
1158                                 //
1159                                 if (expr is NullLiteral)
1160                                         action = Action.AlwaysFalse;
1161                                 else
1162                                         action = Action.Probe;
1163                         } else {
1164                                 action = Action.AlwaysFalse;
1165                                 warning_never_matches = true;
1166                         }
1167
1168                         if (warning_always_matches)
1169                                 Warning (183, "The given expression is always of the provided ('{0}') type", TypeManager.CSharpName (probe_type));
1170                         else if (warning_never_matches){
1171                                 if (!(probe_type.IsInterface || expr.Type.IsInterface))
1172                                         Warning (184, "The given expression is never of the provided ('{0}') type", TypeManager.CSharpName (probe_type));
1173                         }
1174
1175                         return this;
1176                 }
1177         }
1178
1179         /// <summary>
1180         ///   Implementation of the `as' operator.
1181         /// </summary>
1182         public class As : Probe {
1183                 public As (Expression expr, Expression probe_type, Location l)
1184                         : base (expr, probe_type, l)
1185                 {
1186                 }
1187
1188                 bool do_isinst = false;
1189
1190                 public override void Emit (EmitContext ec)
1191                 {
1192                         ILGenerator ig = ec.ig;
1193
1194                         expr.Emit (ec);
1195
1196                         if (do_isinst)
1197                                 ig.Emit (OpCodes.Isinst, probe_type);
1198                 }
1199
1200                 static void Error_CannotConvertType (Type source, Type target, Location loc)
1201                 {
1202                         Report.Error (
1203                                 39, loc, "as operator can not convert from `" +
1204                                 TypeManager.CSharpName (source) + "' to `" +
1205                                 TypeManager.CSharpName (target) + "'");
1206                 }
1207
1208                 public override Expression DoResolve (EmitContext ec)
1209                 {
1210                         Expression e = base.DoResolve (ec);
1211
1212                         if (e == null)
1213                                 return null;
1214
1215                         type = probe_type;
1216                         eclass = ExprClass.Value;
1217                         Type etype = expr.Type;
1218
1219                         if (TypeManager.IsValueType (probe_type)){
1220                                 Report.Error (77, loc, "The as operator should be used with a reference type only (" +
1221                                               TypeManager.CSharpName (probe_type) + " is a value type)");
1222                                 return null;
1223
1224                         }
1225
1226                         e = Convert.ImplicitConversion (ec, expr, probe_type, loc);
1227                         if (e != null){
1228                                 expr = e;
1229                                 do_isinst = false;
1230                                 return this;
1231                         }
1232
1233                         if (Convert.ExplicitReferenceConversionExists (etype, probe_type)){
1234                                 do_isinst = true;
1235                                 return this;
1236                         }
1237
1238                         Error_CannotConvertType (etype, probe_type, loc);
1239                         return null;
1240                 }
1241         }
1242
1243         /// <summary>
1244         ///   This represents a typecast in the source language.
1245         ///
1246         ///   FIXME: Cast expressions have an unusual set of parsing
1247         ///   rules, we need to figure those out.
1248         /// </summary>
1249         public class Cast : Expression {
1250                 Expression target_type;
1251                 Expression expr;
1252
1253                 public Cast (Expression cast_type, Expression expr, Location loc)
1254                 {
1255                         this.target_type = cast_type;
1256                         this.expr = expr;
1257                         this.loc = loc;
1258                 }
1259
1260                 public Expression TargetType {
1261                         get {
1262                                 return target_type;
1263                         }
1264                 }
1265
1266                 public Expression Expr {
1267                         get {
1268                                 return expr;
1269                         }
1270                         set {
1271                                 expr = value;
1272                         }
1273                 }
1274
1275                 bool CheckRange (EmitContext ec, long value, Type type, long min, long max)
1276                 {
1277                         if (!ec.ConstantCheckState)
1278                                 return true;
1279
1280                         if ((value < min) || (value > max)) {
1281                                 Error (221, "Constant value `" + value + "' cannot be converted " +
1282                                        "to a `" + TypeManager.CSharpName (type) + "' (use `unchecked' " +
1283                                        "syntax to override)");
1284                                 return false;
1285                         }
1286
1287                         return true;
1288                 }
1289
1290                 bool CheckRange (EmitContext ec, ulong value, Type type, ulong max)
1291                 {
1292                         if (!ec.ConstantCheckState)
1293                                 return true;
1294
1295                         if (value > max) {
1296                                 Error (221, "Constant value `" + value + "' cannot be converted " +
1297                                        "to a `" + TypeManager.CSharpName (type) + "' (use `unchecked' " +
1298                                        "syntax to override)");
1299                                 return false;
1300                         }
1301
1302                         return true;
1303                 }
1304
1305                 bool CheckUnsigned (EmitContext ec, long value, Type type)
1306                 {
1307                         if (!ec.ConstantCheckState)
1308                                 return true;
1309
1310                         if (value < 0) {
1311                                 Error (221, "Constant value `" + value + "' cannot be converted " +
1312                                        "to a `" + TypeManager.CSharpName (type) + "' (use `unchecked' " +
1313                                        "syntax to override)");
1314                                 return false;
1315                         }
1316
1317                         return true;
1318                 }
1319
1320                 /// <summary>
1321                 ///   Attempts to do a compile-time folding of a constant cast.
1322                 /// </summary>
1323                 Expression TryReduce (EmitContext ec, Type target_type)
1324                 {
1325                         Expression real_expr = expr;
1326                         if (real_expr is EnumConstant)
1327                                 real_expr = ((EnumConstant) real_expr).Child;
1328
1329                         if (real_expr is ByteConstant){
1330                                 byte v = ((ByteConstant) real_expr).Value;
1331
1332                                 if (target_type == TypeManager.sbyte_type) {
1333                                         if (!CheckRange (ec, v, target_type, SByte.MinValue, SByte.MaxValue))
1334                                                 return null;
1335                                         return new SByteConstant ((sbyte) v);
1336                                 }
1337                                 if (target_type == TypeManager.short_type)
1338                                         return new ShortConstant ((short) v);
1339                                 if (target_type == TypeManager.ushort_type)
1340                                         return new UShortConstant ((ushort) v);
1341                                 if (target_type == TypeManager.int32_type)
1342                                         return new IntConstant ((int) v);
1343                                 if (target_type == TypeManager.uint32_type)
1344                                         return new UIntConstant ((uint) v);
1345                                 if (target_type == TypeManager.int64_type)
1346                                         return new LongConstant ((long) v);
1347                                 if (target_type == TypeManager.uint64_type)
1348                                         return new ULongConstant ((ulong) v);
1349                                 if (target_type == TypeManager.float_type)
1350                                         return new FloatConstant ((float) v);
1351                                 if (target_type == TypeManager.double_type)
1352                                         return new DoubleConstant ((double) v);
1353                                 if (target_type == TypeManager.char_type)
1354                                         return new CharConstant ((char) v);
1355                                 if (target_type == TypeManager.decimal_type)
1356                                         return new DecimalConstant ((decimal) v);
1357                         }
1358                         if (real_expr is SByteConstant){
1359                                 sbyte v = ((SByteConstant) real_expr).Value;
1360
1361                                 if (target_type == TypeManager.byte_type) {
1362                                         if (!CheckUnsigned (ec, v, target_type))
1363                                                 return null;
1364                                         return new ByteConstant ((byte) v);
1365                                 }
1366                                 if (target_type == TypeManager.short_type)
1367                                         return new ShortConstant ((short) v);
1368                                 if (target_type == TypeManager.ushort_type) {
1369                                         if (!CheckUnsigned (ec, v, target_type))
1370                                                 return null;
1371                                         return new UShortConstant ((ushort) v);
1372                                 } if (target_type == TypeManager.int32_type)
1373                                         return new IntConstant ((int) v);
1374                                 if (target_type == TypeManager.uint32_type) {
1375                                         if (!CheckUnsigned (ec, v, target_type))
1376                                                 return null;
1377                                         return new UIntConstant ((uint) v);
1378                                 } if (target_type == TypeManager.int64_type)
1379                                         return new LongConstant ((long) v);
1380                                 if (target_type == TypeManager.uint64_type) {
1381                                         if (!CheckUnsigned (ec, v, target_type))
1382                                                 return null;
1383                                         return new ULongConstant ((ulong) v);
1384                                 }
1385                                 if (target_type == TypeManager.float_type)
1386                                         return new FloatConstant ((float) v);
1387                                 if (target_type == TypeManager.double_type)
1388                                         return new DoubleConstant ((double) v);
1389                                 if (target_type == TypeManager.char_type) {
1390                                         if (!CheckUnsigned (ec, v, target_type))
1391                                                 return null;
1392                                         return new CharConstant ((char) v);
1393                                 }
1394                                 if (target_type == TypeManager.decimal_type)
1395                                         return new DecimalConstant ((decimal) v);
1396                         }
1397                         if (real_expr is ShortConstant){
1398                                 short v = ((ShortConstant) real_expr).Value;
1399
1400                                 if (target_type == TypeManager.byte_type) {
1401                                         if (!CheckRange (ec, v, target_type, Byte.MinValue, Byte.MaxValue))
1402                                                 return null;
1403                                         return new ByteConstant ((byte) v);
1404                                 }
1405                                 if (target_type == TypeManager.sbyte_type) {
1406                                         if (!CheckRange (ec, v, target_type, SByte.MinValue, SByte.MaxValue))
1407                                                 return null;
1408                                         return new SByteConstant ((sbyte) v);
1409                                 }
1410                                 if (target_type == TypeManager.ushort_type) {
1411                                         if (!CheckUnsigned (ec, v, target_type))
1412                                                 return null;
1413                                         return new UShortConstant ((ushort) v);
1414                                 }
1415                                 if (target_type == TypeManager.int32_type)
1416                                         return new IntConstant ((int) v);
1417                                 if (target_type == TypeManager.uint32_type) {
1418                                         if (!CheckUnsigned (ec, v, target_type))
1419                                                 return null;
1420                                         return new UIntConstant ((uint) v);
1421                                 }
1422                                 if (target_type == TypeManager.int64_type)
1423                                         return new LongConstant ((long) v);
1424                                 if (target_type == TypeManager.uint64_type) {
1425                                         if (!CheckUnsigned (ec, v, target_type))
1426                                                 return null;
1427                                         return new ULongConstant ((ulong) v);
1428                                 }
1429                                 if (target_type == TypeManager.float_type)
1430                                         return new FloatConstant ((float) v);
1431                                 if (target_type == TypeManager.double_type)
1432                                         return new DoubleConstant ((double) v);
1433                                 if (target_type == TypeManager.char_type) {
1434                                         if (!CheckRange (ec, v, target_type, Char.MinValue, Char.MaxValue))
1435                                                 return null;
1436                                         return new CharConstant ((char) v);
1437                                 }
1438                                 if (target_type == TypeManager.decimal_type)
1439                                         return new DecimalConstant ((decimal) v);
1440                         }
1441                         if (real_expr is UShortConstant){
1442                                 ushort v = ((UShortConstant) real_expr).Value;
1443
1444                                 if (target_type == TypeManager.byte_type) {
1445                                         if (!CheckRange (ec, v, target_type, Byte.MinValue, Byte.MaxValue))
1446                                                 return null;
1447                                         return new ByteConstant ((byte) v);
1448                                 }
1449                                 if (target_type == TypeManager.sbyte_type) {
1450                                         if (!CheckRange (ec, v, target_type, SByte.MinValue, SByte.MaxValue))
1451                                                 return null;
1452                                         return new SByteConstant ((sbyte) v);
1453                                 }
1454                                 if (target_type == TypeManager.short_type) {
1455                                         if (!CheckRange (ec, v, target_type, Int16.MinValue, Int16.MaxValue))
1456                                                 return null;
1457                                         return new ShortConstant ((short) v);
1458                                 }
1459                                 if (target_type == TypeManager.int32_type)
1460                                         return new IntConstant ((int) v);
1461                                 if (target_type == TypeManager.uint32_type)
1462                                         return new UIntConstant ((uint) v);
1463                                 if (target_type == TypeManager.int64_type)
1464                                         return new LongConstant ((long) v);
1465                                 if (target_type == TypeManager.uint64_type)
1466                                         return new ULongConstant ((ulong) v);
1467                                 if (target_type == TypeManager.float_type)
1468                                         return new FloatConstant ((float) v);
1469                                 if (target_type == TypeManager.double_type)
1470                                         return new DoubleConstant ((double) v);
1471                                 if (target_type == TypeManager.char_type) {
1472                                         if (!CheckRange (ec, v, target_type, Char.MinValue, Char.MaxValue))
1473                                                 return null;
1474                                         return new CharConstant ((char) v);
1475                                 }
1476                                 if (target_type == TypeManager.decimal_type)
1477                                         return new DecimalConstant ((decimal) v);
1478                         }
1479                         if (real_expr is IntConstant){
1480                                 int v = ((IntConstant) real_expr).Value;
1481
1482                                 if (target_type == TypeManager.byte_type) {
1483                                         if (!CheckRange (ec, v, target_type, Byte.MinValue, Byte.MaxValue))
1484                                                 return null;
1485                                         return new ByteConstant ((byte) v);
1486                                 }
1487                                 if (target_type == TypeManager.sbyte_type) {
1488                                         if (!CheckRange (ec, v, target_type, SByte.MinValue, SByte.MaxValue))
1489                                                 return null;
1490                                         return new SByteConstant ((sbyte) v);
1491                                 }
1492                                 if (target_type == TypeManager.short_type) {
1493                                         if (!CheckRange (ec, v, target_type, Int16.MinValue, Int16.MaxValue))
1494                                                 return null;
1495                                         return new ShortConstant ((short) v);
1496                                 }
1497                                 if (target_type == TypeManager.ushort_type) {
1498                                         if (!CheckRange (ec, v, target_type, UInt16.MinValue, UInt16.MaxValue))
1499                                                 return null;
1500                                         return new UShortConstant ((ushort) v);
1501                                 }
1502                                 if (target_type == TypeManager.uint32_type) {
1503                                         if (!CheckRange (ec, v, target_type, Int32.MinValue, Int32.MaxValue))
1504                                                 return null;
1505                                         return new UIntConstant ((uint) v);
1506                                 }
1507                                 if (target_type == TypeManager.int64_type)
1508                                         return new LongConstant ((long) v);
1509                                 if (target_type == TypeManager.uint64_type) {
1510                                         if (!CheckUnsigned (ec, v, target_type))
1511                                                 return null;
1512                                         return new ULongConstant ((ulong) v);
1513                                 }
1514                                 if (target_type == TypeManager.float_type)
1515                                         return new FloatConstant ((float) v);
1516                                 if (target_type == TypeManager.double_type)
1517                                         return new DoubleConstant ((double) v);
1518                                 if (target_type == TypeManager.char_type) {
1519                                         if (!CheckRange (ec, v, target_type, Char.MinValue, Char.MaxValue))
1520                                                 return null;
1521                                         return new CharConstant ((char) v);
1522                                 }
1523                                 if (target_type == TypeManager.decimal_type)
1524                                         return new DecimalConstant ((decimal) v);
1525                         }
1526                         if (real_expr is UIntConstant){
1527                                 uint v = ((UIntConstant) real_expr).Value;
1528
1529                                 if (target_type == TypeManager.byte_type) {
1530                                         if (!CheckRange (ec, v, target_type, Char.MinValue, Char.MaxValue))
1531                                                 return null;
1532                                         return new ByteConstant ((byte) v);
1533                                 }
1534                                 if (target_type == TypeManager.sbyte_type) {
1535                                         if (!CheckRange (ec, v, target_type, SByte.MinValue, SByte.MaxValue))
1536                                                 return null;
1537                                         return new SByteConstant ((sbyte) v);
1538                                 }
1539                                 if (target_type == TypeManager.short_type) {
1540                                         if (!CheckRange (ec, v, target_type, Int16.MinValue, Int16.MaxValue))
1541                                                 return null;
1542                                         return new ShortConstant ((short) v);
1543                                 }
1544                                 if (target_type == TypeManager.ushort_type) {
1545                                         if (!CheckRange (ec, v, target_type, UInt16.MinValue, UInt16.MaxValue))
1546                                                 return null;
1547                                         return new UShortConstant ((ushort) v);
1548                                 }
1549                                 if (target_type == TypeManager.int32_type) {
1550                                         if (!CheckRange (ec, v, target_type, Int32.MinValue, Int32.MaxValue))
1551                                                 return null;
1552                                         return new IntConstant ((int) v);
1553                                 }
1554                                 if (target_type == TypeManager.int64_type)
1555                                         return new LongConstant ((long) v);
1556                                 if (target_type == TypeManager.uint64_type)
1557                                         return new ULongConstant ((ulong) v);
1558                                 if (target_type == TypeManager.float_type)
1559                                         return new FloatConstant ((float) v);
1560                                 if (target_type == TypeManager.double_type)
1561                                         return new DoubleConstant ((double) v);
1562                                 if (target_type == TypeManager.char_type) {
1563                                         if (!CheckRange (ec, v, target_type, Char.MinValue, Char.MaxValue))
1564                                                 return null;
1565                                         return new CharConstant ((char) v);
1566                                 }
1567                                 if (target_type == TypeManager.decimal_type)
1568                                         return new DecimalConstant ((decimal) v);
1569                         }
1570                         if (real_expr is LongConstant){
1571                                 long v = ((LongConstant) real_expr).Value;
1572
1573                                 if (target_type == TypeManager.byte_type) {
1574                                         if (!CheckRange (ec, v, target_type, Byte.MinValue, Byte.MaxValue))
1575                                                 return null;
1576                                         return new ByteConstant ((byte) v);
1577                                 }
1578                                 if (target_type == TypeManager.sbyte_type) {
1579                                         if (!CheckRange (ec, v, target_type, SByte.MinValue, SByte.MaxValue))
1580                                                 return null;
1581                                         return new SByteConstant ((sbyte) v);
1582                                 }
1583                                 if (target_type == TypeManager.short_type) {
1584                                         if (!CheckRange (ec, v, target_type, Int16.MinValue, Int16.MaxValue))
1585                                                 return null;
1586                                         return new ShortConstant ((short) v);
1587                                 }
1588                                 if (target_type == TypeManager.ushort_type) {
1589                                         if (!CheckRange (ec, v, target_type, UInt16.MinValue, UInt16.MaxValue))
1590                                                 return null;
1591                                         return new UShortConstant ((ushort) v);
1592                                 }
1593                                 if (target_type == TypeManager.int32_type) {
1594                                         if (!CheckRange (ec, v, target_type, Int32.MinValue, Int32.MaxValue))
1595                                                 return null;
1596                                         return new IntConstant ((int) v);
1597                                 }
1598                                 if (target_type == TypeManager.uint32_type) {
1599                                         if (!CheckRange (ec, v, target_type, UInt32.MinValue, UInt32.MaxValue))
1600                                                 return null;
1601                                         return new UIntConstant ((uint) v);
1602                                 }
1603                                 if (target_type == TypeManager.uint64_type) {
1604                                         if (!CheckUnsigned (ec, v, target_type))
1605                                                 return null;
1606                                         return new ULongConstant ((ulong) v);
1607                                 }
1608                                 if (target_type == TypeManager.float_type)
1609                                         return new FloatConstant ((float) v);
1610                                 if (target_type == TypeManager.double_type)
1611                                         return new DoubleConstant ((double) v);
1612                                 if (target_type == TypeManager.char_type) {
1613                                         if (!CheckRange (ec, v, target_type, Char.MinValue, Char.MaxValue))
1614                                                 return null;
1615                                         return new CharConstant ((char) v);
1616                                 }
1617                                 if (target_type == TypeManager.decimal_type)
1618                                         return new DecimalConstant ((decimal) v);
1619                         }
1620                         if (real_expr is ULongConstant){
1621                                 ulong v = ((ULongConstant) real_expr).Value;
1622
1623                                 if (target_type == TypeManager.byte_type) {
1624                                         if (!CheckRange (ec, v, target_type, Byte.MaxValue))
1625                                                 return null;
1626                                         return new ByteConstant ((byte) v);
1627                                 }
1628                                 if (target_type == TypeManager.sbyte_type) {
1629                                         if (!CheckRange (ec, v, target_type, (ulong) SByte.MaxValue))
1630                                                 return null;
1631                                         return new SByteConstant ((sbyte) v);
1632                                 }
1633                                 if (target_type == TypeManager.short_type) {
1634                                         if (!CheckRange (ec, v, target_type, (ulong) Int16.MaxValue))
1635                                                 return null;
1636                                         return new ShortConstant ((short) v);
1637                                 }
1638                                 if (target_type == TypeManager.ushort_type) {
1639                                         if (!CheckRange (ec, v, target_type, UInt16.MaxValue))
1640                                                 return null;
1641                                         return new UShortConstant ((ushort) v);
1642                                 }
1643                                 if (target_type == TypeManager.int32_type) {
1644                                         if (!CheckRange (ec, v, target_type, Int32.MaxValue))
1645                                                 return null;
1646                                         return new IntConstant ((int) v);
1647                                 }
1648                                 if (target_type == TypeManager.uint32_type) {
1649                                         if (!CheckRange (ec, v, target_type, UInt32.MaxValue))
1650                                                 return null;
1651                                         return new UIntConstant ((uint) v);
1652                                 }
1653                                 if (target_type == TypeManager.int64_type) {
1654                                         if (!CheckRange (ec, v, target_type, (ulong) Int64.MaxValue))
1655                                                 return null;
1656                                         return new LongConstant ((long) v);
1657                                 }
1658                                 if (target_type == TypeManager.float_type)
1659                                         return new FloatConstant ((float) v);
1660                                 if (target_type == TypeManager.double_type)
1661                                         return new DoubleConstant ((double) v);
1662                                 if (target_type == TypeManager.char_type) {
1663                                         if (!CheckRange (ec, v, target_type, Char.MaxValue))
1664                                                 return null;
1665                                         return new CharConstant ((char) v);
1666                                 }
1667                                 if (target_type == TypeManager.decimal_type)
1668                                         return new DecimalConstant ((decimal) v);
1669                         }
1670                         if (real_expr is FloatConstant){
1671                                 float v = ((FloatConstant) real_expr).Value;
1672
1673                                 if (target_type == TypeManager.byte_type)
1674                                         return new ByteConstant ((byte) v);
1675                                 if (target_type == TypeManager.sbyte_type)
1676                                         return new SByteConstant ((sbyte) v);
1677                                 if (target_type == TypeManager.short_type)
1678                                         return new ShortConstant ((short) v);
1679                                 if (target_type == TypeManager.ushort_type)
1680                                         return new UShortConstant ((ushort) v);
1681                                 if (target_type == TypeManager.int32_type)
1682                                         return new IntConstant ((int) v);
1683                                 if (target_type == TypeManager.uint32_type)
1684                                         return new UIntConstant ((uint) v);
1685                                 if (target_type == TypeManager.int64_type)
1686                                         return new LongConstant ((long) v);
1687                                 if (target_type == TypeManager.uint64_type)
1688                                         return new ULongConstant ((ulong) v);
1689                                 if (target_type == TypeManager.double_type)
1690                                         return new DoubleConstant ((double) v);
1691                                 if (target_type == TypeManager.char_type)
1692                                         return new CharConstant ((char) v);
1693                                 if (target_type == TypeManager.decimal_type)
1694                                         return new DecimalConstant ((decimal) v);
1695                         }
1696                         if (real_expr is DoubleConstant){
1697                                 double v = ((DoubleConstant) real_expr).Value;
1698
1699                                 if (target_type == TypeManager.byte_type){
1700                                         return new ByteConstant ((byte) v);
1701                                 } if (target_type == TypeManager.sbyte_type)
1702                                         return new SByteConstant ((sbyte) v);
1703                                 if (target_type == TypeManager.short_type)
1704                                         return new ShortConstant ((short) v);
1705                                 if (target_type == TypeManager.ushort_type)
1706                                         return new UShortConstant ((ushort) v);
1707                                 if (target_type == TypeManager.int32_type)
1708                                         return new IntConstant ((int) v);
1709                                 if (target_type == TypeManager.uint32_type)
1710                                         return new UIntConstant ((uint) v);
1711                                 if (target_type == TypeManager.int64_type)
1712                                         return new LongConstant ((long) v);
1713                                 if (target_type == TypeManager.uint64_type)
1714                                         return new ULongConstant ((ulong) v);
1715                                 if (target_type == TypeManager.float_type)
1716                                         return new FloatConstant ((float) v);
1717                                 if (target_type == TypeManager.char_type)
1718                                         return new CharConstant ((char) v);
1719                                 if (target_type == TypeManager.decimal_type)
1720                                         return new DecimalConstant ((decimal) v);
1721                         }
1722
1723                         if (real_expr is CharConstant){
1724                                 char v = ((CharConstant) real_expr).Value;
1725
1726                                 if (target_type == TypeManager.byte_type) {
1727                                         if (!CheckRange (ec, v, target_type, Byte.MinValue, Byte.MaxValue))
1728                                                 return null;
1729                                         return new ByteConstant ((byte) v);
1730                                 }
1731                                 if (target_type == TypeManager.sbyte_type) {
1732                                         if (!CheckRange (ec, v, target_type, SByte.MinValue, SByte.MaxValue))
1733                                                 return null;
1734                                         return new SByteConstant ((sbyte) v);
1735                                 }
1736                                 if (target_type == TypeManager.short_type) {
1737                                         if (!CheckRange (ec, v, target_type, Int16.MinValue, Int16.MaxValue))
1738                                                 return null;
1739                                         return new ShortConstant ((short) v);
1740                                 }
1741                                 if (target_type == TypeManager.int32_type)
1742                                         return new IntConstant ((int) v);
1743                                 if (target_type == TypeManager.uint32_type)
1744                                         return new UIntConstant ((uint) v);
1745                                 if (target_type == TypeManager.int64_type)
1746                                         return new LongConstant ((long) v);
1747                                 if (target_type == TypeManager.uint64_type)
1748                                         return new ULongConstant ((ulong) v);
1749                                 if (target_type == TypeManager.float_type)
1750                                         return new FloatConstant ((float) v);
1751                                 if (target_type == TypeManager.double_type)
1752                                         return new DoubleConstant ((double) v);
1753                                 if (target_type == TypeManager.char_type) {
1754                                         if (!CheckRange (ec, v, target_type, Char.MinValue, Char.MaxValue))
1755                                                 return null;
1756                                         return new CharConstant ((char) v);
1757                                 }
1758                                 if (target_type == TypeManager.decimal_type)
1759                                         return new DecimalConstant ((decimal) v);
1760                         }
1761
1762                         return null;
1763                 }
1764
1765                 public override Expression DoResolve (EmitContext ec)
1766                 {
1767                         expr = expr.Resolve (ec);
1768                         if (expr == null)
1769                                 return null;
1770
1771                         type = ec.DeclSpace.ResolveType (target_type, false, Location);
1772
1773                         if (type == null)
1774                                 return null;
1775
1776                         CheckObsoleteAttribute (type);
1777
1778                         if (type.IsAbstract && type.IsSealed) {
1779                                 Report.Error (716, loc, "Cannot convert to static type '{0}'", TypeManager.CSharpName (type));
1780                                 return null;
1781                         }
1782
1783                         eclass = ExprClass.Value;
1784
1785                         if (expr is Constant){
1786                                 Expression e = TryReduce (ec, type);
1787
1788                                 if (e != null)
1789                                         return e;
1790                         }
1791
1792                         if (type.IsPointer && !ec.InUnsafe) {
1793                                 UnsafeError (loc);
1794                                 return null;
1795                         }
1796                         expr = Convert.ExplicitConversion (ec, expr, type, loc);
1797                         return expr;
1798                 }
1799
1800                 public override void Emit (EmitContext ec)
1801                 {
1802                         //
1803                         // This one will never happen
1804                         //
1805                         throw new Exception ("Should not happen");
1806                 }
1807         }
1808
1809         /// <summary>
1810         ///   Binary operators
1811         /// </summary>
1812         public class Binary : Expression {
1813                 public enum Operator : byte {
1814                         Multiply, Division, Modulus,
1815                         Addition, Subtraction,
1816                         LeftShift, RightShift,
1817                         LessThan, GreaterThan, LessThanOrEqual, GreaterThanOrEqual,
1818                         Equality, Inequality,
1819                         BitwiseAnd,
1820                         ExclusiveOr,
1821                         BitwiseOr,
1822                         LogicalAnd,
1823                         LogicalOr,
1824                         TOP
1825                 }
1826
1827                 Operator oper;
1828                 Expression left, right;
1829
1830                 // This must be kept in sync with Operator!!!
1831                 public static readonly string [] oper_names;
1832
1833                 static Binary ()
1834                 {
1835                         oper_names = new string [(int) Operator.TOP];
1836
1837                         oper_names [(int) Operator.Multiply] = "op_Multiply";
1838                         oper_names [(int) Operator.Division] = "op_Division";
1839                         oper_names [(int) Operator.Modulus] = "op_Modulus";
1840                         oper_names [(int) Operator.Addition] = "op_Addition";
1841                         oper_names [(int) Operator.Subtraction] = "op_Subtraction";
1842                         oper_names [(int) Operator.LeftShift] = "op_LeftShift";
1843                         oper_names [(int) Operator.RightShift] = "op_RightShift";
1844                         oper_names [(int) Operator.LessThan] = "op_LessThan";
1845                         oper_names [(int) Operator.GreaterThan] = "op_GreaterThan";
1846                         oper_names [(int) Operator.LessThanOrEqual] = "op_LessThanOrEqual";
1847                         oper_names [(int) Operator.GreaterThanOrEqual] = "op_GreaterThanOrEqual";
1848                         oper_names [(int) Operator.Equality] = "op_Equality";
1849                         oper_names [(int) Operator.Inequality] = "op_Inequality";
1850                         oper_names [(int) Operator.BitwiseAnd] = "op_BitwiseAnd";
1851                         oper_names [(int) Operator.BitwiseOr] = "op_BitwiseOr";
1852                         oper_names [(int) Operator.ExclusiveOr] = "op_ExclusiveOr";
1853                         oper_names [(int) Operator.LogicalOr] = "op_LogicalOr";
1854                         oper_names [(int) Operator.LogicalAnd] = "op_LogicalAnd";
1855                 }
1856
1857                 public Binary (Operator oper, Expression left, Expression right, Location loc)
1858                 {
1859                         this.oper = oper;
1860                         this.left = left;
1861                         this.right = right;
1862                         this.loc = loc;
1863                 }
1864
1865                 public Operator Oper {
1866                         get {
1867                                 return oper;
1868                         }
1869                         set {
1870                                 oper = value;
1871                         }
1872                 }
1873
1874                 public Expression Left {
1875                         get {
1876                                 return left;
1877                         }
1878                         set {
1879                                 left = value;
1880                         }
1881                 }
1882
1883                 public Expression Right {
1884                         get {
1885                                 return right;
1886                         }
1887                         set {
1888                                 right = value;
1889                         }
1890                 }
1891
1892
1893                 /// <summary>
1894                 ///   Returns a stringified representation of the Operator
1895                 /// </summary>
1896                 static string OperName (Operator oper)
1897                 {
1898                         switch (oper){
1899                         case Operator.Multiply:
1900                                 return "*";
1901                         case Operator.Division:
1902                                 return "/";
1903                         case Operator.Modulus:
1904                                 return "%";
1905                         case Operator.Addition:
1906                                 return "+";
1907                         case Operator.Subtraction:
1908                                 return "-";
1909                         case Operator.LeftShift:
1910                                 return "<<";
1911                         case Operator.RightShift:
1912                                 return ">>";
1913                         case Operator.LessThan:
1914                                 return "<";
1915                         case Operator.GreaterThan:
1916                                 return ">";
1917                         case Operator.LessThanOrEqual:
1918                                 return "<=";
1919                         case Operator.GreaterThanOrEqual:
1920                                 return ">=";
1921                         case Operator.Equality:
1922                                 return "==";
1923                         case Operator.Inequality:
1924                                 return "!=";
1925                         case Operator.BitwiseAnd:
1926                                 return "&";
1927                         case Operator.BitwiseOr:
1928                                 return "|";
1929                         case Operator.ExclusiveOr:
1930                                 return "^";
1931                         case Operator.LogicalOr:
1932                                 return "||";
1933                         case Operator.LogicalAnd:
1934                                 return "&&";
1935                         }
1936
1937                         return oper.ToString ();
1938                 }
1939
1940                 public override string ToString ()
1941                 {
1942                         return "operator " + OperName (oper) + "(" + left.ToString () + ", " +
1943                                 right.ToString () + ")";
1944                 }
1945
1946                 Expression ForceConversion (EmitContext ec, Expression expr, Type target_type)
1947                 {
1948                         if (expr.Type == target_type)
1949                                 return expr;
1950
1951                         return Convert.ImplicitConversion (ec, expr, target_type, loc);
1952                 }
1953
1954                 public static void Error_OperatorAmbiguous (Location loc, Operator oper, Type l, Type r)
1955                 {
1956                         Report.Error (
1957                                 34, loc, "Operator `" + OperName (oper)
1958                                 + "' is ambiguous on operands of type `"
1959                                 + TypeManager.CSharpName (l) + "' "
1960                                 + "and `" + TypeManager.CSharpName (r)
1961                                 + "'");
1962                 }
1963
1964                 bool IsOfType (EmitContext ec, Type l, Type r, Type t, bool check_user_conversions)
1965                 {
1966                         if ((l == t) || (r == t))
1967                                 return true;
1968
1969                         if (!check_user_conversions)
1970                                 return false;
1971
1972                         if (Convert.ImplicitUserConversionExists (ec, l, t))
1973                                 return true;
1974                         else if (Convert.ImplicitUserConversionExists (ec, r, t))
1975                                 return true;
1976                         else
1977                                 return false;
1978                 }
1979
1980                 //
1981                 // Note that handling the case l == Decimal || r == Decimal
1982                 // is taken care of by the Step 1 Operator Overload resolution.
1983                 //
1984                 // If `check_user_conv' is true, we also check whether a user-defined conversion
1985                 // exists.  Note that we only need to do this if both arguments are of a user-defined
1986                 // type, otherwise ConvertImplict() already finds the user-defined conversion for us,
1987                 // so we don't explicitly check for performance reasons.
1988                 //
1989                 bool DoNumericPromotions (EmitContext ec, Type l, Type r, bool check_user_conv)
1990                 {
1991                         if (IsOfType (ec, l, r, TypeManager.double_type, check_user_conv)){
1992                                 //
1993                                 // If either operand is of type double, the other operand is
1994                                 // conveted to type double.
1995                                 //
1996                                 if (r != TypeManager.double_type)
1997                                         right = Convert.ImplicitConversion (ec, right, TypeManager.double_type, loc);
1998                                 if (l != TypeManager.double_type)
1999                                         left = Convert.ImplicitConversion (ec, left, TypeManager.double_type, loc);
2000
2001                                 type = TypeManager.double_type;
2002                         } else if (IsOfType (ec, l, r, TypeManager.float_type, check_user_conv)){
2003                                 //
2004                                 // if either operand is of type float, the other operand is
2005                                 // converted to type float.
2006                                 //
2007                                 if (r != TypeManager.double_type)
2008                                         right = Convert.ImplicitConversion (ec, right, TypeManager.float_type, loc);
2009                                 if (l != TypeManager.double_type)
2010                                         left = Convert.ImplicitConversion (ec, left, TypeManager.float_type, loc);
2011                                 type = TypeManager.float_type;
2012                         } else if (IsOfType (ec, l, r, TypeManager.uint64_type, check_user_conv)){
2013                                 Expression e;
2014                                 Type other;
2015                                 //
2016                                 // If either operand is of type ulong, the other operand is
2017                                 // converted to type ulong.  or an error ocurrs if the other
2018                                 // operand is of type sbyte, short, int or long
2019                                 //
2020                                 if (l == TypeManager.uint64_type){
2021                                         if (r != TypeManager.uint64_type){
2022                                                 if (right is IntConstant){
2023                                                         IntConstant ic = (IntConstant) right;
2024
2025                                                         e = Convert.TryImplicitIntConversion (l, ic);
2026                                                         if (e != null)
2027                                                                 right = e;
2028                                                 } else if (right is LongConstant){
2029                                                         long ll = ((LongConstant) right).Value;
2030
2031                                                         if (ll >= 0)
2032                                                                 right = new ULongConstant ((ulong) ll);
2033                                                 } else {
2034                                                         e = Convert.ImplicitNumericConversion (ec, right, l, loc);
2035                                                         if (e != null)
2036                                                                 right = e;
2037                                                 }
2038                                         }
2039                                         other = right.Type;
2040                                 } else {
2041                                         if (left is IntConstant){
2042                                                 e = Convert.TryImplicitIntConversion (r, (IntConstant) left);
2043                                                 if (e != null)
2044                                                         left = e;
2045                                         } else if (left is LongConstant){
2046                                                 long ll = ((LongConstant) left).Value;
2047
2048                                                 if (ll > 0)
2049                                                         left = new ULongConstant ((ulong) ll);
2050                                         } else {
2051                                                 e = Convert.ImplicitNumericConversion (ec, left, r, loc);
2052                                                 if (e != null)
2053                                                         left = e;
2054                                         }
2055                                         other = left.Type;
2056                                 }
2057
2058                                 if ((other == TypeManager.sbyte_type) ||
2059                                     (other == TypeManager.short_type) ||
2060                                     (other == TypeManager.int32_type) ||
2061                                     (other == TypeManager.int64_type))
2062                                         Error_OperatorAmbiguous (loc, oper, l, r);
2063                                 else {
2064                                         left = ForceConversion (ec, left, TypeManager.uint64_type);
2065                                         right = ForceConversion (ec, right, TypeManager.uint64_type);
2066                                 }
2067                                 type = TypeManager.uint64_type;
2068                         } else if (IsOfType (ec, l, r, TypeManager.int64_type, check_user_conv)){
2069                                 //
2070                                 // If either operand is of type long, the other operand is converted
2071                                 // to type long.
2072                                 //
2073                                 if (l != TypeManager.int64_type)
2074                                         left = Convert.ImplicitConversion (ec, left, TypeManager.int64_type, loc);
2075                                 if (r != TypeManager.int64_type)
2076                                         right = Convert.ImplicitConversion (ec, right, TypeManager.int64_type, loc);
2077
2078                                 type = TypeManager.int64_type;
2079                         } else if (IsOfType (ec, l, r, TypeManager.uint32_type, check_user_conv)){
2080                                 //
2081                                 // If either operand is of type uint, and the other
2082                                 // operand is of type sbyte, short or int, othe operands are
2083                                 // converted to type long (unless we have an int constant).
2084                                 //
2085                                 Type other = null;
2086
2087                                 if (l == TypeManager.uint32_type){
2088                                         if (right is IntConstant){
2089                                                 IntConstant ic = (IntConstant) right;
2090                                                 int val = ic.Value;
2091
2092                                                 if (val >= 0){
2093                                                         right = new UIntConstant ((uint) val);
2094                                                         type = l;
2095
2096                                                         return true;
2097                                                 }
2098                                         }
2099                                         other = r;
2100                                 } else if (r == TypeManager.uint32_type){
2101                                         if (left is IntConstant){
2102                                                 IntConstant ic = (IntConstant) left;
2103                                                 int val = ic.Value;
2104
2105                                                 if (val >= 0){
2106                                                         left = new UIntConstant ((uint) val);
2107                                                         type = r;
2108                                                         return true;
2109                                                 }
2110                                         }
2111
2112                                         other = l;
2113                                 }
2114
2115                                 if ((other == TypeManager.sbyte_type) ||
2116                                     (other == TypeManager.short_type) ||
2117                                     (other == TypeManager.int32_type)){
2118                                         left = ForceConversion (ec, left, TypeManager.int64_type);
2119                                         right = ForceConversion (ec, right, TypeManager.int64_type);
2120                                         type = TypeManager.int64_type;
2121                                 } else {
2122                                         //
2123                                         // if either operand is of type uint, the other
2124                                         // operand is converd to type uint
2125                                         //
2126                                         left = ForceConversion (ec, left, TypeManager.uint32_type);
2127                                         right = ForceConversion (ec, right, TypeManager.uint32_type);
2128                                         type = TypeManager.uint32_type;
2129                                 }
2130                         } else if (l == TypeManager.decimal_type || r == TypeManager.decimal_type){
2131                                 if (l != TypeManager.decimal_type)
2132                                         left = Convert.ImplicitConversion (ec, left, TypeManager.decimal_type, loc);
2133
2134                                 if (r != TypeManager.decimal_type)
2135                                         right = Convert.ImplicitConversion (ec, right, TypeManager.decimal_type, loc);
2136                                 type = TypeManager.decimal_type;
2137                         } else {
2138                                 left = ForceConversion (ec, left, TypeManager.int32_type);
2139                                 right = ForceConversion (ec, right, TypeManager.int32_type);
2140
2141                                 type = TypeManager.int32_type;
2142                         }
2143
2144                         return (left != null) && (right != null);
2145                 }
2146
2147                 static public void Error_OperatorCannotBeApplied (Location loc, string name, Type l, Type r)
2148                 {
2149                         Report.Error (19, loc,
2150                                "Operator " + name + " cannot be applied to operands of type `" +
2151                                TypeManager.CSharpName (l) + "' and `" +
2152                                TypeManager.CSharpName (r) + "'");
2153                 }
2154
2155                 void Error_OperatorCannotBeApplied ()
2156                 {
2157                         Error_OperatorCannotBeApplied (loc, OperName (oper), left.Type, right.Type);
2158                 }
2159
2160                 static bool is_unsigned (Type t)
2161                 {
2162                         return (t == TypeManager.uint32_type || t == TypeManager.uint64_type ||
2163                                 t == TypeManager.short_type || t == TypeManager.byte_type);
2164                 }
2165
2166                 static bool is_user_defined (Type t)
2167                 {
2168                         if (t.IsSubclassOf (TypeManager.value_type) &&
2169                             (!TypeManager.IsBuiltinType (t) || t == TypeManager.decimal_type))
2170                                 return true;
2171                         else
2172                                 return false;
2173                 }
2174
2175                 Expression Make32or64 (EmitContext ec, Expression e)
2176                 {
2177                         Type t= e.Type;
2178
2179                         if (t == TypeManager.int32_type || t == TypeManager.uint32_type ||
2180                             t == TypeManager.int64_type || t == TypeManager.uint64_type)
2181                                 return e;
2182                         Expression ee = Convert.ImplicitConversion (ec, e, TypeManager.int32_type, loc);
2183                         if (ee != null)
2184                                 return ee;
2185                         ee = Convert.ImplicitConversion (ec, e, TypeManager.uint32_type, loc);
2186                         if (ee != null)
2187                                 return ee;
2188                         ee = Convert.ImplicitConversion (ec, e, TypeManager.int64_type, loc);
2189                         if (ee != null)
2190                                 return ee;
2191                         ee = Convert.ImplicitConversion (ec, e, TypeManager.uint64_type, loc);
2192                         if (ee != null)
2193                                 return ee;
2194                         return null;
2195                 }
2196
2197                 Expression CheckShiftArguments (EmitContext ec)
2198                 {
2199                         Expression e;
2200
2201                         e = ForceConversion (ec, right, TypeManager.int32_type);
2202                         if (e == null){
2203                                 Error_OperatorCannotBeApplied ();
2204                                 return null;
2205                         }
2206                         right = e;
2207
2208                         if (((e = Convert.ImplicitConversion (ec, left, TypeManager.int32_type, loc)) != null) ||
2209                             ((e = Convert.ImplicitConversion (ec, left, TypeManager.uint32_type, loc)) != null) ||
2210                             ((e = Convert.ImplicitConversion (ec, left, TypeManager.int64_type, loc)) != null) ||
2211                             ((e = Convert.ImplicitConversion (ec, left, TypeManager.uint64_type, loc)) != null)){
2212                                 left = e;
2213                                 type = e.Type;
2214
2215                                 if (type == TypeManager.int32_type || type == TypeManager.uint32_type){
2216                                         right = new Binary (Binary.Operator.BitwiseAnd, right, new IntLiteral (31), loc);
2217                                         right = right.DoResolve (ec);
2218                                 } else {
2219                                         right = new Binary (Binary.Operator.BitwiseAnd, right, new IntLiteral (63), loc);
2220                                         right = right.DoResolve (ec);
2221                                 }
2222
2223                                 return this;
2224                         }
2225                         Error_OperatorCannotBeApplied ();
2226                         return null;
2227                 }
2228
2229                 Expression ResolveOperator (EmitContext ec)
2230                 {
2231                         Type l = left.Type;
2232                         Type r = right.Type;
2233
2234                         //
2235                         // Special cases: string comapred to null
2236                         //
2237                         if (oper == Operator.Equality || oper == Operator.Inequality){
2238                                 if ((l == TypeManager.string_type && (right is NullLiteral)) ||
2239                                     (r == TypeManager.string_type && (left is NullLiteral))){
2240                                         Type = TypeManager.bool_type;
2241
2242                                         return this;
2243                                 }
2244
2245                                 // IntPtr equality
2246                                 if (l == TypeManager.intptr_type && r == TypeManager.intptr_type) {
2247                                         Type = TypeManager.bool_type;
2248
2249                                         return this;
2250                                 }
2251                         }
2252
2253                         //
2254                         // Do not perform operator overload resolution when both sides are
2255                         // built-in types
2256                         //
2257                         if (!(TypeManager.IsCLRType (l) && TypeManager.IsCLRType (r))){
2258                                 //
2259                                 // Step 1: Perform Operator Overload location
2260                                 //
2261                                 Expression left_expr, right_expr;
2262
2263                                 string op = oper_names [(int) oper];
2264
2265                                 MethodGroupExpr union;
2266                                 left_expr = MemberLookup (ec, l, op, MemberTypes.Method, AllBindingFlags, loc);
2267                                 if (r != l){
2268                                         right_expr = MemberLookup (
2269                                                 ec, r, op, MemberTypes.Method, AllBindingFlags, loc);
2270                                         union = Invocation.MakeUnionSet (left_expr, right_expr, loc);
2271                                 } else
2272                                         union = (MethodGroupExpr) left_expr;
2273
2274                                 if (union != null) {
2275                                         ArrayList args = new ArrayList (2);
2276                                         args.Add (new Argument (left, Argument.AType.Expression));
2277                                         args.Add (new Argument (right, Argument.AType.Expression));
2278
2279                                         MethodBase method = Invocation.OverloadResolve (
2280                                                 ec, union, args, true, Location.Null);
2281
2282                                         if (method != null) {
2283                                                 MethodInfo mi = (MethodInfo) method;
2284
2285                                                 return new BinaryMethod (mi.ReturnType, method, args);
2286                                         }
2287                                 }
2288                         }
2289
2290                         //
2291                         // Step 0: String concatenation (because overloading will get this wrong)
2292                         //
2293                         if (oper == Operator.Addition){
2294                                 //
2295                                 // If any of the arguments is a string, cast to string
2296                                 //
2297
2298                                 // Simple constant folding
2299                                 if (left is StringConstant && right is StringConstant)
2300                                         return new StringConstant (((StringConstant) left).Value + ((StringConstant) right).Value);
2301
2302                                 if (l == TypeManager.string_type || r == TypeManager.string_type) {
2303
2304                                         if (r == TypeManager.void_type || l == TypeManager.void_type) {
2305                                                 Error_OperatorCannotBeApplied ();
2306                                                 return null;
2307                                         }
2308
2309                                         // try to fold it in on the left
2310                                         if (left is StringConcat) {
2311
2312                                                 //
2313                                                 // We have to test here for not-null, since we can be doubly-resolved
2314                                                 // take care of not appending twice
2315                                                 //
2316                                                 if (type == null){
2317                                                         type = TypeManager.string_type;
2318                                                         ((StringConcat) left).Append (ec, right);
2319                                                         return left.Resolve (ec);
2320                                                 } else {
2321                                                         return left;
2322                                                 }
2323                                         }
2324
2325                                         // Otherwise, start a new concat expression
2326                                         return new StringConcat (ec, loc, left, right).Resolve (ec);
2327                                 }
2328
2329                                 //
2330                                 // Transform a + ( - b) into a - b
2331                                 //
2332                                 if (right is Unary){
2333                                         Unary right_unary = (Unary) right;
2334
2335                                         if (right_unary.Oper == Unary.Operator.UnaryNegation){
2336                                                 oper = Operator.Subtraction;
2337                                                 right = right_unary.Expr;
2338                                                 r = right.Type;
2339                                         }
2340                                 }
2341                         }
2342
2343                         if (oper == Operator.Equality || oper == Operator.Inequality){
2344                                 if (l == TypeManager.bool_type || r == TypeManager.bool_type){
2345                                         if (r != TypeManager.bool_type || l != TypeManager.bool_type){
2346                                                 Error_OperatorCannotBeApplied ();
2347                                                 return null;
2348                                         }
2349
2350                                         type = TypeManager.bool_type;
2351                                         return this;
2352                                 }
2353
2354                                 //
2355                                 // operator != (object a, object b)
2356                                 // operator == (object a, object b)
2357                                 //
2358                                 // For this to be used, both arguments have to be reference-types.
2359                                 // Read the rationale on the spec (14.9.6)
2360                                 //
2361                                 // Also, if at compile time we know that the classes do not inherit
2362                                 // one from the other, then we catch the error there.
2363                                 //
2364                                 if (!(l.IsValueType || r.IsValueType)){
2365                                         type = TypeManager.bool_type;
2366
2367                                         if (l == r)
2368                                                 return this;
2369
2370                                         if (l.IsSubclassOf (r) || r.IsSubclassOf (l))
2371                                                 return this;
2372
2373                                         //
2374                                         // Also, a standard conversion must exist from either one
2375                                         //
2376                                         if (!(Convert.ImplicitStandardConversionExists (left, r) ||
2377                                               Convert.ImplicitStandardConversionExists (right, l))){
2378                                                 Error_OperatorCannotBeApplied ();
2379                                                 return null;
2380                                         }
2381                                         //
2382                                         // We are going to have to convert to an object to compare
2383                                         //
2384                                         if (l != TypeManager.object_type)
2385                                                 left = new EmptyCast (left, TypeManager.object_type);
2386                                         if (r != TypeManager.object_type)
2387                                                 right = new EmptyCast (right, TypeManager.object_type);
2388
2389                                         //
2390                                         // FIXME: CSC here catches errors cs254 and cs252
2391                                         //
2392                                         return this;
2393                                 }
2394
2395                                 //
2396                                 // One of them is a valuetype, but the other one is not.
2397                                 //
2398                                 if (!l.IsValueType || !r.IsValueType) {
2399                                         Error_OperatorCannotBeApplied ();
2400                                         return null;
2401                                 }
2402                         }
2403
2404                         // Only perform numeric promotions on:
2405                         // +, -, *, /, %, &, |, ^, ==, !=, <, >, <=, >=
2406                         //
2407                         if (oper == Operator.Addition || oper == Operator.Subtraction) {
2408                                 if (l.IsSubclassOf (TypeManager.delegate_type)){
2409                                         if ((right.eclass == ExprClass.MethodGroup) &&
2410                                             (RootContext.Version != LanguageVersion.ISO_1)){
2411                                                 Expression tmp = Convert.ImplicitConversionRequired (ec, right, l, loc);
2412                                                 if (tmp == null)
2413                                                         return null;
2414                                                 right = tmp;
2415                                                 r = right.Type;
2416                                         }
2417
2418                                         if (r.IsSubclassOf (TypeManager.delegate_type)){
2419                                                 MethodInfo method;
2420                                                 ArrayList args = new ArrayList (2);
2421
2422                                                 args = new ArrayList (2);
2423                                                 args.Add (new Argument (left, Argument.AType.Expression));
2424                                                 args.Add (new Argument (right, Argument.AType.Expression));
2425
2426                                                 if (oper == Operator.Addition)
2427                                                         method = TypeManager.delegate_combine_delegate_delegate;
2428                                                 else
2429                                                         method = TypeManager.delegate_remove_delegate_delegate;
2430
2431                                                 if (l != r) {
2432                                                         Error_OperatorCannotBeApplied ();
2433                                                         return null;
2434                                                 }
2435
2436                                                 return new BinaryDelegate (l, method, args);
2437                                         }
2438                                 }
2439
2440                                 //
2441                                 // Pointer arithmetic:
2442                                 //
2443                                 // T* operator + (T* x, int y);
2444                                 // T* operator + (T* x, uint y);
2445                                 // T* operator + (T* x, long y);
2446                                 // T* operator + (T* x, ulong y);
2447                                 //
2448                                 // T* operator + (int y,   T* x);
2449                                 // T* operator + (uint y,  T *x);
2450                                 // T* operator + (long y,  T *x);
2451                                 // T* operator + (ulong y, T *x);
2452                                 //
2453                                 // T* operator - (T* x, int y);
2454                                 // T* operator - (T* x, uint y);
2455                                 // T* operator - (T* x, long y);
2456                                 // T* operator - (T* x, ulong y);
2457                                 //
2458                                 // long operator - (T* x, T *y)
2459                                 //
2460                                 if (l.IsPointer){
2461                                         if (r.IsPointer && oper == Operator.Subtraction){
2462                                                 if (r == l)
2463                                                         return new PointerArithmetic (
2464                                                                 false, left, right, TypeManager.int64_type,
2465                                                                 loc).Resolve (ec);
2466                                         } else {
2467                                                 Expression t = Make32or64 (ec, right);
2468                                                 if (t != null)
2469                                                         return new PointerArithmetic (oper == Operator.Addition, left, t, l, loc).Resolve (ec);
2470                                         }
2471                                 } else if (r.IsPointer && oper == Operator.Addition){
2472                                         Expression t = Make32or64 (ec, left);
2473                                         if (t != null)
2474                                                 return new PointerArithmetic (true, right, t, r, loc).Resolve (ec);
2475                                 }
2476                         }
2477
2478                         //
2479                         // Enumeration operators
2480                         //
2481                         bool lie = TypeManager.IsEnumType (l);
2482                         bool rie = TypeManager.IsEnumType (r);
2483                         if (lie || rie){
2484                                 Expression temp;
2485
2486                                 // U operator - (E e, E f)
2487                                 if (lie && rie){
2488                                         if (oper == Operator.Subtraction){
2489                                                 if (l == r){
2490                                                         type = TypeManager.EnumToUnderlying (l);
2491                                                         return this;
2492                                                 }
2493                                                 Error_OperatorCannotBeApplied ();
2494                                                 return null;
2495                                         }
2496                                 }
2497
2498                                 //
2499                                 // operator + (E e, U x)
2500                                 // operator - (E e, U x)
2501                                 //
2502                                 if (oper == Operator.Addition || oper == Operator.Subtraction){
2503                                         Type enum_type = lie ? l : r;
2504                                         Type other_type = lie ? r : l;
2505                                         Type underlying_type = TypeManager.EnumToUnderlying (enum_type);
2506
2507                                         if (underlying_type != other_type){
2508                                                 temp = Convert.ImplicitConversion (ec, lie ? right : left, underlying_type, loc);
2509                                                 if (temp != null){
2510                                                         if (lie)
2511                                                                 right = temp;
2512                                                         else
2513                                                                 left = temp;
2514                                                         type = enum_type;
2515                                                         return this;
2516                                                 }
2517
2518                                                 Error_OperatorCannotBeApplied ();
2519                                                 return null;
2520                                         }
2521
2522                                         type = enum_type;
2523                                         return this;
2524                                 }
2525
2526                                 if (!rie){
2527                                         temp = Convert.ImplicitConversion (ec, right, l, loc);
2528                                         if (temp != null)
2529                                                 right = temp;
2530                                         else {
2531                                                 Error_OperatorCannotBeApplied ();
2532                                                 return null;
2533                                         }
2534                                 } if (!lie){
2535                                         temp = Convert.ImplicitConversion (ec, left, r, loc);
2536                                         if (temp != null){
2537                                                 left = temp;
2538                                                 l = r;
2539                                         } else {
2540                                                 Error_OperatorCannotBeApplied ();
2541                                                 return null;
2542                                         }
2543                                 }
2544
2545                                 if (oper == Operator.Equality || oper == Operator.Inequality ||
2546                                     oper == Operator.LessThanOrEqual || oper == Operator.LessThan ||
2547                                     oper == Operator.GreaterThanOrEqual || oper == Operator.GreaterThan){
2548                                         if (left.Type != right.Type){
2549                                                 Error_OperatorCannotBeApplied ();
2550                                                 return null;
2551                                         }
2552                                         type = TypeManager.bool_type;
2553                                         return this;
2554                                 }
2555
2556                                 if (oper == Operator.BitwiseAnd ||
2557                                     oper == Operator.BitwiseOr ||
2558                                     oper == Operator.ExclusiveOr){
2559                                         type = l;
2560                                         return this;
2561                                 }
2562                                 Error_OperatorCannotBeApplied ();
2563                                 return null;
2564                         }
2565
2566                         if (oper == Operator.LeftShift || oper == Operator.RightShift)
2567                                 return CheckShiftArguments (ec);
2568
2569                         if (oper == Operator.LogicalOr || oper == Operator.LogicalAnd){
2570                                 if (l == TypeManager.bool_type && r == TypeManager.bool_type) {
2571                                         type = TypeManager.bool_type;
2572                                         return this;
2573                                 }
2574
2575                                 if (l != r) {
2576                                         Error_OperatorCannotBeApplied ();
2577                                         return null;
2578                                 }
2579
2580                                 Expression e = new ConditionalLogicalOperator (
2581                                         oper == Operator.LogicalAnd, left, right, l, loc);
2582                                 return e.Resolve (ec);
2583                         }
2584
2585                         //
2586                         // operator & (bool x, bool y)
2587                         // operator | (bool x, bool y)
2588                         // operator ^ (bool x, bool y)
2589                         //
2590                         if (l == TypeManager.bool_type && r == TypeManager.bool_type){
2591                                 if (oper == Operator.BitwiseAnd ||
2592                                     oper == Operator.BitwiseOr ||
2593                                     oper == Operator.ExclusiveOr){
2594                                         type = l;
2595                                         return this;
2596                                 }
2597                         }
2598
2599                         //
2600                         // Pointer comparison
2601                         //
2602                         if (l.IsPointer && r.IsPointer){
2603                                 if (oper == Operator.Equality || oper == Operator.Inequality ||
2604                                     oper == Operator.LessThan || oper == Operator.LessThanOrEqual ||
2605                                     oper == Operator.GreaterThan || oper == Operator.GreaterThanOrEqual){
2606                                         type = TypeManager.bool_type;
2607                                         return this;
2608                                 }
2609                         }
2610
2611                         //
2612                         // This will leave left or right set to null if there is an error
2613                         //
2614                         bool check_user_conv = is_user_defined (l) && is_user_defined (r);
2615                         DoNumericPromotions (ec, l, r, check_user_conv);
2616                         if (left == null || right == null){
2617                                 Error_OperatorCannotBeApplied (loc, OperName (oper), l, r);
2618                                 return null;
2619                         }
2620
2621                         //
2622                         // reload our cached types if required
2623                         //
2624                         l = left.Type;
2625                         r = right.Type;
2626
2627                         if (oper == Operator.BitwiseAnd ||
2628                             oper == Operator.BitwiseOr ||
2629                             oper == Operator.ExclusiveOr){
2630                                 if (l == r){
2631                                         if (((l == TypeManager.int32_type) ||
2632                                              (l == TypeManager.uint32_type) ||
2633                                              (l == TypeManager.short_type) ||
2634                                              (l == TypeManager.ushort_type) ||
2635                                              (l == TypeManager.int64_type) ||
2636                                              (l == TypeManager.uint64_type))){
2637                                                 type = l;
2638                                         } else {
2639                                                 Error_OperatorCannotBeApplied ();
2640                                                 return null;
2641                                         }
2642                                 } else {
2643                                         Error_OperatorCannotBeApplied ();
2644                                         return null;
2645                                 }
2646                         }
2647
2648                         if (oper == Operator.Equality ||
2649                             oper == Operator.Inequality ||
2650                             oper == Operator.LessThanOrEqual ||
2651                             oper == Operator.LessThan ||
2652                             oper == Operator.GreaterThanOrEqual ||
2653                             oper == Operator.GreaterThan){
2654                                 type = TypeManager.bool_type;
2655                         }
2656
2657                         return this;
2658                 }
2659
2660                 public override Expression DoResolve (EmitContext ec)
2661                 {
2662                         if ((oper == Operator.Subtraction) && (left is ParenthesizedExpression)) {
2663                                 left = ((ParenthesizedExpression) left).Expr;
2664                                 left = left.Resolve (ec, ResolveFlags.VariableOrValue | ResolveFlags.Type);
2665                                 if (left == null)
2666                                         return null;
2667
2668                                 if (left.eclass == ExprClass.Type) {
2669                                         Error (75, "Casting a negative value needs to have the value in parentheses.");
2670                                         return null;
2671                                 }
2672                         } else
2673                                 left = left.Resolve (ec);
2674                         right = right.Resolve (ec);
2675
2676                         if (left == null || right == null)
2677                                 return null;
2678
2679                         eclass = ExprClass.Value;
2680
2681                         Constant rc = right as Constant;
2682                         Constant lc = left as Constant;
2683
2684                         if (rc != null & lc != null){
2685                                 Expression e = ConstantFold.BinaryFold (
2686                                         ec, oper, lc, rc, loc);
2687                                         if (e != null)
2688                                                 return e;
2689                         }
2690
2691                         return ResolveOperator (ec);
2692                 }
2693
2694                 /// <remarks>
2695                 ///   EmitBranchable is called from Statement.EmitBoolExpression in the
2696                 ///   context of a conditional bool expression.  This function will return
2697                 ///   false if it is was possible to use EmitBranchable, or true if it was.
2698                 ///
2699                 ///   The expression's code is generated, and we will generate a branch to `target'
2700                 ///   if the resulting expression value is equal to isTrue
2701                 /// </remarks>
2702                 public override void EmitBranchable (EmitContext ec, Label target, bool onTrue)
2703                 {
2704                         ILGenerator ig = ec.ig;
2705
2706                         //
2707                         // This is more complicated than it looks, but its just to avoid
2708                         // duplicated tests: basically, we allow ==, !=, >, <, >= and <=
2709                         // but on top of that we want for == and != to use a special path
2710                         // if we are comparing against null
2711                         //
2712                         if ((oper == Operator.Equality || oper == Operator.Inequality) && (left is Constant || right is Constant)) {
2713                                 bool my_on_true = oper == Operator.Inequality ? onTrue : !onTrue;
2714
2715                                 //
2716                                 // put the constant on the rhs, for simplicity
2717                                 //
2718                                 if (left is Constant) {
2719                                         Expression swap = right;
2720                                         right = left;
2721                                         left = swap;
2722                                 }
2723
2724                                 if (((Constant) right).IsZeroInteger) {
2725                                         left.Emit (ec);
2726                                         if (my_on_true)
2727                                                 ig.Emit (OpCodes.Brtrue, target);
2728                                         else
2729                                                 ig.Emit (OpCodes.Brfalse, target);
2730
2731                                         return;
2732                                 } else if (right is BoolConstant) {
2733                                         left.Emit (ec);
2734                                         if (my_on_true != ((BoolConstant) right).Value)
2735                                                 ig.Emit (OpCodes.Brtrue, target);
2736                                         else
2737                                                 ig.Emit (OpCodes.Brfalse, target);
2738
2739                                         return;
2740                                 }
2741
2742                         } else if (oper == Operator.LogicalAnd) {
2743
2744                                 if (onTrue) {
2745                                         Label tests_end = ig.DefineLabel ();
2746
2747                                         left.EmitBranchable (ec, tests_end, false);
2748                                         right.EmitBranchable (ec, target, true);
2749                                         ig.MarkLabel (tests_end);
2750                                 } else {
2751                                         left.EmitBranchable (ec, target, false);
2752                                         right.EmitBranchable (ec, target, false);
2753                                 }
2754
2755                                 return;
2756
2757                         } else if (oper == Operator.LogicalOr){
2758                                 if (onTrue) {
2759                                         left.EmitBranchable (ec, target, true);
2760                                         right.EmitBranchable (ec, target, true);
2761
2762                                 } else {
2763                                         Label tests_end = ig.DefineLabel ();
2764                                         left.EmitBranchable (ec, tests_end, true);
2765                                         right.EmitBranchable (ec, target, false);
2766                                         ig.MarkLabel (tests_end);
2767                                 }
2768
2769                                 return;
2770
2771                         } else if (!(oper == Operator.LessThan        || oper == Operator.GreaterThan ||
2772                                      oper == Operator.LessThanOrEqual || oper == Operator.GreaterThanOrEqual ||
2773                                      oper == Operator.Equality        || oper == Operator.Inequality)) {
2774                                 base.EmitBranchable (ec, target, onTrue);
2775                                 return;
2776                         }
2777
2778                         left.Emit (ec);
2779                         right.Emit (ec);
2780
2781                         Type t = left.Type;
2782                         bool isUnsigned = is_unsigned (t) || t == TypeManager.double_type || t == TypeManager.float_type;
2783
2784                         switch (oper){
2785                         case Operator.Equality:
2786                                 if (onTrue)
2787                                         ig.Emit (OpCodes.Beq, target);
2788                                 else
2789                                         ig.Emit (OpCodes.Bne_Un, target);
2790                                 break;
2791
2792                         case Operator.Inequality:
2793                                 if (onTrue)
2794                                         ig.Emit (OpCodes.Bne_Un, target);
2795                                 else
2796                                         ig.Emit (OpCodes.Beq, target);
2797                                 break;
2798
2799                         case Operator.LessThan:
2800                                 if (onTrue)
2801                                         if (isUnsigned)
2802                                                 ig.Emit (OpCodes.Blt_Un, target);
2803                                         else
2804                                                 ig.Emit (OpCodes.Blt, target);
2805                                 else
2806                                         if (isUnsigned)
2807                                                 ig.Emit (OpCodes.Bge_Un, target);
2808                                         else
2809                                                 ig.Emit (OpCodes.Bge, target);
2810                                 break;
2811
2812                         case Operator.GreaterThan:
2813                                 if (onTrue)
2814                                         if (isUnsigned)
2815                                                 ig.Emit (OpCodes.Bgt_Un, target);
2816                                         else
2817                                                 ig.Emit (OpCodes.Bgt, target);
2818                                 else
2819                                         if (isUnsigned)
2820                                                 ig.Emit (OpCodes.Ble_Un, target);
2821                                         else
2822                                                 ig.Emit (OpCodes.Ble, target);
2823                                 break;
2824
2825                         case Operator.LessThanOrEqual:
2826                                 if (onTrue)
2827                                         if (isUnsigned)
2828                                                 ig.Emit (OpCodes.Ble_Un, target);
2829                                         else
2830                                                 ig.Emit (OpCodes.Ble, target);
2831                                 else
2832                                         if (isUnsigned)
2833                                                 ig.Emit (OpCodes.Bgt_Un, target);
2834                                         else
2835                                                 ig.Emit (OpCodes.Bgt, target);
2836                                 break;
2837
2838
2839                         case Operator.GreaterThanOrEqual:
2840                                 if (onTrue)
2841                                         if (isUnsigned)
2842                                                 ig.Emit (OpCodes.Bge_Un, target);
2843                                         else
2844                                                 ig.Emit (OpCodes.Bge, target);
2845                                 else
2846                                         if (isUnsigned)
2847                                                 ig.Emit (OpCodes.Blt_Un, target);
2848                                         else
2849                                                 ig.Emit (OpCodes.Blt, target);
2850                                 break;
2851                         default:
2852                                 Console.WriteLine (oper);
2853                                 throw new Exception ("what is THAT");
2854                         }
2855                 }
2856
2857                 public override void Emit (EmitContext ec)
2858                 {
2859                         ILGenerator ig = ec.ig;
2860                         Type l = left.Type;
2861                         OpCode opcode;
2862
2863                         //
2864                         // Handle short-circuit operators differently
2865                         // than the rest
2866                         //
2867                         if (oper == Operator.LogicalAnd) {
2868                                 Label load_zero = ig.DefineLabel ();
2869                                 Label end = ig.DefineLabel ();
2870
2871                                 left.EmitBranchable (ec, load_zero, false);
2872                                 right.Emit (ec);
2873                                 ig.Emit (OpCodes.Br, end);
2874
2875                                 ig.MarkLabel (load_zero);
2876                                 ig.Emit (OpCodes.Ldc_I4_0);
2877                                 ig.MarkLabel (end);
2878                                 return;
2879                         } else if (oper == Operator.LogicalOr) {
2880                                 Label load_one = ig.DefineLabel ();
2881                                 Label end = ig.DefineLabel ();
2882
2883                                 left.EmitBranchable (ec, load_one, true);
2884                                 right.Emit (ec);
2885                                 ig.Emit (OpCodes.Br, end);
2886
2887                                 ig.MarkLabel (load_one);
2888                                 ig.Emit (OpCodes.Ldc_I4_1);
2889                                 ig.MarkLabel (end);
2890                                 return;
2891                         }
2892
2893                         left.Emit (ec);
2894                         right.Emit (ec);
2895
2896                         bool isUnsigned = is_unsigned (left.Type);
2897
2898                         switch (oper){
2899                         case Operator.Multiply:
2900                                 if (ec.CheckState){
2901                                         if (l == TypeManager.int32_type || l == TypeManager.int64_type)
2902                                                 opcode = OpCodes.Mul_Ovf;
2903                                         else if (isUnsigned)
2904                                                 opcode = OpCodes.Mul_Ovf_Un;
2905                                         else
2906                                                 opcode = OpCodes.Mul;
2907                                 } else
2908                                         opcode = OpCodes.Mul;
2909
2910                                 break;
2911
2912                         case Operator.Division:
2913                                 if (isUnsigned)
2914                                         opcode = OpCodes.Div_Un;
2915                                 else
2916                                         opcode = OpCodes.Div;
2917                                 break;
2918
2919                         case Operator.Modulus:
2920                                 if (isUnsigned)
2921                                         opcode = OpCodes.Rem_Un;
2922                                 else
2923                                         opcode = OpCodes.Rem;
2924                                 break;
2925
2926                         case Operator.Addition:
2927                                 if (ec.CheckState){
2928                                         if (l == TypeManager.int32_type || l == TypeManager.int64_type)
2929                                                 opcode = OpCodes.Add_Ovf;
2930                                         else if (isUnsigned)
2931                                                 opcode = OpCodes.Add_Ovf_Un;
2932                                         else
2933                                                 opcode = OpCodes.Add;
2934                                 } else
2935                                         opcode = OpCodes.Add;
2936                                 break;
2937
2938                         case Operator.Subtraction:
2939                                 if (ec.CheckState){
2940                                         if (l == TypeManager.int32_type || l == TypeManager.int64_type)
2941                                                 opcode = OpCodes.Sub_Ovf;
2942                                         else if (isUnsigned)
2943                                                 opcode = OpCodes.Sub_Ovf_Un;
2944                                         else
2945                                                 opcode = OpCodes.Sub;
2946                                 } else
2947                                         opcode = OpCodes.Sub;
2948                                 break;
2949
2950                         case Operator.RightShift:
2951                                 if (isUnsigned)
2952                                         opcode = OpCodes.Shr_Un;
2953                                 else
2954                                         opcode = OpCodes.Shr;
2955                                 break;
2956
2957                         case Operator.LeftShift:
2958                                 opcode = OpCodes.Shl;
2959                                 break;
2960
2961                         case Operator.Equality:
2962                                 opcode = OpCodes.Ceq;
2963                                 break;
2964
2965                         case Operator.Inequality:
2966                                 ig.Emit (OpCodes.Ceq);
2967                                 ig.Emit (OpCodes.Ldc_I4_0);
2968
2969                                 opcode = OpCodes.Ceq;
2970                                 break;
2971
2972                         case Operator.LessThan:
2973                                 if (isUnsigned)
2974                                         opcode = OpCodes.Clt_Un;
2975                                 else
2976                                         opcode = OpCodes.Clt;
2977                                 break;
2978
2979                         case Operator.GreaterThan:
2980                                 if (isUnsigned)
2981                                         opcode = OpCodes.Cgt_Un;
2982                                 else
2983                                         opcode = OpCodes.Cgt;
2984                                 break;
2985
2986                         case Operator.LessThanOrEqual:
2987                                 Type lt = left.Type;
2988
2989                                 if (isUnsigned || (lt == TypeManager.double_type || lt == TypeManager.float_type))
2990                                         ig.Emit (OpCodes.Cgt_Un);
2991                                 else
2992                                         ig.Emit (OpCodes.Cgt);
2993                                 ig.Emit (OpCodes.Ldc_I4_0);
2994
2995                                 opcode = OpCodes.Ceq;
2996                                 break;
2997
2998                         case Operator.GreaterThanOrEqual:
2999                                 Type le = left.Type;
3000
3001                                 if (isUnsigned || (le == TypeManager.double_type || le == TypeManager.float_type))
3002                                         ig.Emit (OpCodes.Clt_Un);
3003                                 else
3004                                         ig.Emit (OpCodes.Clt);
3005
3006                                 ig.Emit (OpCodes.Ldc_I4_0);
3007
3008                                 opcode = OpCodes.Ceq;
3009                                 break;
3010
3011                         case Operator.BitwiseOr:
3012                                 opcode = OpCodes.Or;
3013                                 break;
3014
3015                         case Operator.BitwiseAnd:
3016                                 opcode = OpCodes.And;
3017                                 break;
3018
3019                         case Operator.ExclusiveOr:
3020                                 opcode = OpCodes.Xor;
3021                                 break;
3022
3023                         default:
3024                                 throw new Exception ("This should not happen: Operator = "
3025                                                      + oper.ToString ());
3026                         }
3027
3028                         ig.Emit (opcode);
3029                 }
3030         }
3031
3032         //
3033         // Object created by Binary when the binary operator uses an method instead of being
3034         // a binary operation that maps to a CIL binary operation.
3035         //
3036         public class BinaryMethod : Expression {
3037                 public MethodBase method;
3038                 public ArrayList  Arguments;
3039
3040                 public BinaryMethod (Type t, MethodBase m, ArrayList args)
3041                 {
3042                         method = m;
3043                         Arguments = args;
3044                         type = t;
3045                         eclass = ExprClass.Value;
3046                 }
3047
3048                 public override Expression DoResolve (EmitContext ec)
3049                 {
3050                         return this;
3051                 }
3052
3053                 public override void Emit (EmitContext ec)
3054                 {
3055                         ILGenerator ig = ec.ig;
3056
3057                         if (Arguments != null)
3058                                 Invocation.EmitArguments (ec, method, Arguments, false, null);
3059
3060                         if (method is MethodInfo)
3061                                 ig.Emit (OpCodes.Call, (MethodInfo) method);
3062                         else
3063                                 ig.Emit (OpCodes.Call, (ConstructorInfo) method);
3064                 }
3065         }
3066
3067         //
3068         // Represents the operation a + b [+ c [+ d [+ ...]]], where a is a string
3069         // b, c, d... may be strings or objects.
3070         //
3071         public class StringConcat : Expression {
3072                 ArrayList operands;
3073                 bool invalid = false;
3074
3075
3076                 public StringConcat (EmitContext ec, Location loc, Expression left, Expression right)
3077                 {
3078                         this.loc = loc;
3079                         type = TypeManager.string_type;
3080                         eclass = ExprClass.Value;
3081
3082                         operands = new ArrayList (2);
3083                         Append (ec, left);
3084                         Append (ec, right);
3085                 }
3086
3087                 public override Expression DoResolve (EmitContext ec)
3088                 {
3089                         if (invalid)
3090                                 return null;
3091
3092                         return this;
3093                 }
3094
3095                 public void Append (EmitContext ec, Expression operand)
3096                 {
3097                         //
3098                         // Constant folding
3099                         //
3100                         if (operand is StringConstant && operands.Count != 0) {
3101                                 StringConstant last_operand = operands [operands.Count - 1] as StringConstant;
3102                                 if (last_operand != null) {
3103                                         operands [operands.Count - 1] = new StringConstant (last_operand.Value + ((StringConstant) operand).Value);
3104                                         return;
3105                                 }
3106                         }
3107
3108                         //
3109                         // Conversion to object
3110                         //
3111                         if (operand.Type != TypeManager.string_type) {
3112                                 Expression no = Convert.ImplicitConversion (ec, operand, TypeManager.object_type, loc);
3113
3114                                 if (no == null) {
3115                                         Binary.Error_OperatorCannotBeApplied (loc, "+", TypeManager.string_type, operand.Type);
3116                                         invalid = true;
3117                                 }
3118                                 operand = no;
3119                         }
3120
3121                         operands.Add (operand);
3122                 }
3123
3124                 public override void Emit (EmitContext ec)
3125                 {
3126                         MethodInfo concat_method = null;
3127
3128                         //
3129                         // Are we also concating objects?
3130                         //
3131                         bool is_strings_only = true;
3132
3133                         //
3134                         // Do conversion to arguments; check for strings only
3135                         //
3136                         for (int i = 0; i < operands.Count; i ++) {
3137                                 Expression e = (Expression) operands [i];
3138                                 is_strings_only &= e.Type == TypeManager.string_type;
3139                         }
3140
3141                         for (int i = 0; i < operands.Count; i ++) {
3142                                 Expression e = (Expression) operands [i];
3143
3144                                 if (! is_strings_only && e.Type == TypeManager.string_type) {
3145                                         // need to make sure this is an object, because the EmitParams
3146                                         // method might look at the type of this expression, see it is a
3147                                         // string and emit a string [] when we want an object [];
3148
3149                                         e = Convert.ImplicitConversion (ec, e, TypeManager.object_type, loc);
3150                                 }
3151                                 operands [i] = new Argument (e, Argument.AType.Expression);
3152                         }
3153
3154                         //
3155                         // Find the right method
3156                         //
3157                         switch (operands.Count) {
3158                         case 1:
3159                                 //
3160                                 // This should not be possible, because simple constant folding
3161                                 // is taken care of in the Binary code.
3162                                 //
3163                                 throw new Exception ("how did you get here?");
3164
3165                         case 2:
3166                                 concat_method = is_strings_only ?
3167                                         TypeManager.string_concat_string_string :
3168                                         TypeManager.string_concat_object_object ;
3169                                 break;
3170                         case 3:
3171                                 concat_method = is_strings_only ?
3172                                         TypeManager.string_concat_string_string_string :
3173                                         TypeManager.string_concat_object_object_object ;
3174                                 break;
3175                         case 4:
3176                                 //
3177                                 // There is not a 4 param overlaod for object (the one that there is
3178                                 // is actually a varargs methods, and is only in corlib because it was
3179                                 // introduced there before.).
3180                                 //
3181                                 if (!is_strings_only)
3182                                         goto default;
3183
3184                                 concat_method = TypeManager.string_concat_string_string_string_string;
3185                                 break;
3186                         default:
3187                                 concat_method = is_strings_only ?
3188                                         TypeManager.string_concat_string_dot_dot_dot :
3189                                         TypeManager.string_concat_object_dot_dot_dot ;
3190                                 break;
3191                         }
3192
3193                         Invocation.EmitArguments (ec, concat_method, operands, false, null);
3194                         ec.ig.Emit (OpCodes.Call, concat_method);
3195                 }
3196         }
3197
3198         //
3199         // Object created with +/= on delegates
3200         //
3201         public class BinaryDelegate : Expression {
3202                 MethodInfo method;
3203                 ArrayList  args;
3204
3205                 public BinaryDelegate (Type t, MethodInfo mi, ArrayList args)
3206                 {
3207                         method = mi;
3208                         this.args = args;
3209                         type = t;
3210                         eclass = ExprClass.Value;
3211                 }
3212
3213                 public override Expression DoResolve (EmitContext ec)
3214                 {
3215                         return this;
3216                 }
3217
3218                 public override void Emit (EmitContext ec)
3219                 {
3220                         ILGenerator ig = ec.ig;
3221
3222                         Invocation.EmitArguments (ec, method, args, false, null);
3223
3224                         ig.Emit (OpCodes.Call, (MethodInfo) method);
3225                         ig.Emit (OpCodes.Castclass, type);
3226                 }
3227
3228                 public Expression Right {
3229                         get {
3230                                 Argument arg = (Argument) args [1];
3231                                 return arg.Expr;
3232                         }
3233                 }
3234
3235                 public bool IsAddition {
3236                         get {
3237                                 return method == TypeManager.delegate_combine_delegate_delegate;
3238                         }
3239                 }
3240         }
3241
3242         //
3243         // User-defined conditional logical operator
3244         public class ConditionalLogicalOperator : Expression {
3245                 Expression left, right;
3246                 bool is_and;
3247
3248                 public ConditionalLogicalOperator (bool is_and, Expression left, Expression right, Type t, Location loc)
3249                 {
3250                         type = t;
3251                         eclass = ExprClass.Value;
3252                         this.loc = loc;
3253                         this.left = left;
3254                         this.right = right;
3255                         this.is_and = is_and;
3256                 }
3257
3258                 protected void Error19 ()
3259                 {
3260                         Binary.Error_OperatorCannotBeApplied (loc, is_and ? "&&" : "||", type, type);
3261                 }
3262
3263                 protected void Error218 ()
3264                 {
3265                         Error (218, "The type ('" + TypeManager.CSharpName (type) + "') must contain " +
3266                                "declarations of operator true and operator false");
3267                 }
3268
3269                 Expression op_true, op_false, op;
3270                 LocalTemporary left_temp;
3271
3272                 public override Expression DoResolve (EmitContext ec)
3273                 {
3274                         MethodInfo method;
3275                         Expression operator_group;
3276
3277                         operator_group = MethodLookup (ec, type, is_and ? "op_BitwiseAnd" : "op_BitwiseOr", loc);
3278                         if (operator_group == null) {
3279                                 Error19 ();
3280                                 return null;
3281                         }
3282
3283                         left_temp = new LocalTemporary (ec, type);
3284
3285                         ArrayList arguments = new ArrayList ();
3286                         arguments.Add (new Argument (left_temp, Argument.AType.Expression));
3287                         arguments.Add (new Argument (right, Argument.AType.Expression));
3288                         method = Invocation.OverloadResolve (
3289                                 ec, (MethodGroupExpr) operator_group, arguments, false, loc)
3290                                 as MethodInfo;
3291                         if ((method == null) || (method.ReturnType != type)) {
3292                                 Error19 ();
3293                                 return null;
3294                         }
3295
3296                         op = new StaticCallExpr (method, arguments, loc);
3297
3298                         op_true = GetOperatorTrue (ec, left_temp, loc);
3299                         op_false = GetOperatorFalse (ec, left_temp, loc);
3300                         if ((op_true == null) || (op_false == null)) {
3301                                 Error218 ();
3302                                 return null;
3303                         }
3304
3305                         return this;
3306                 }
3307
3308                 public override void Emit (EmitContext ec)
3309                 {
3310                         ILGenerator ig = ec.ig;
3311                         Label false_target = ig.DefineLabel ();
3312                         Label end_target = ig.DefineLabel ();
3313
3314                         ig.Emit (OpCodes.Nop);
3315
3316                         left.Emit (ec);
3317                         left_temp.Store (ec);
3318
3319                         (is_and ? op_false : op_true).EmitBranchable (ec, false_target, false);
3320                         left_temp.Emit (ec);
3321                         ig.Emit (OpCodes.Br, end_target);
3322                         ig.MarkLabel (false_target);
3323                         op.Emit (ec);
3324                         ig.MarkLabel (end_target);
3325
3326                         ig.Emit (OpCodes.Nop);
3327                 }
3328         }
3329
3330         public class PointerArithmetic : Expression {
3331                 Expression left, right;
3332                 bool is_add;
3333
3334                 //
3335                 // We assume that `l' is always a pointer
3336                 //
3337                 public PointerArithmetic (bool is_addition, Expression l, Expression r, Type t, Location loc)
3338                 {
3339                         type = t;
3340                         this.loc = loc;
3341                         left = l;
3342                         right = r;
3343                         is_add = is_addition;
3344                 }
3345
3346                 public override Expression DoResolve (EmitContext ec)
3347                 {
3348                         eclass = ExprClass.Variable;
3349
3350                         if (left.Type == TypeManager.void_ptr_type) {
3351                                 Error (242, "The operation in question is undefined on void pointers");
3352                                 return null;
3353                         }
3354
3355                         return this;
3356                 }
3357
3358                 public override void Emit (EmitContext ec)
3359                 {
3360                         Type op_type = left.Type;
3361                         ILGenerator ig = ec.ig;
3362                         Type element = TypeManager.GetElementType (op_type);
3363                         int size = GetTypeSize (element);
3364                         Type rtype = right.Type;
3365
3366                         if (rtype.IsPointer){
3367                                 //
3368                                 // handle (pointer - pointer)
3369                                 //
3370                                 left.Emit (ec);
3371                                 right.Emit (ec);
3372                                 ig.Emit (OpCodes.Sub);
3373
3374                                 if (size != 1){
3375                                         if (size == 0)
3376                                                 ig.Emit (OpCodes.Sizeof, element);
3377                                         else
3378                                                 IntLiteral.EmitInt (ig, size);
3379                                         ig.Emit (OpCodes.Div);
3380                                 }
3381                                 ig.Emit (OpCodes.Conv_I8);
3382                         } else {
3383                                 //
3384                                 // handle + and - on (pointer op int)
3385                                 //
3386                                 left.Emit (ec);
3387                                 ig.Emit (OpCodes.Conv_I);
3388                                 right.Emit (ec);
3389                                 if (size != 1){
3390                                         if (size == 0)
3391                                                 ig.Emit (OpCodes.Sizeof, element);
3392                                         else
3393                                                 IntLiteral.EmitInt (ig, size);
3394                                         if (rtype == TypeManager.int64_type)
3395                                                 ig.Emit (OpCodes.Conv_I8);
3396                                         else if (rtype == TypeManager.uint64_type)
3397                                                 ig.Emit (OpCodes.Conv_U8);
3398                                         ig.Emit (OpCodes.Mul);
3399                                 }
3400
3401                                 if (rtype == TypeManager.int64_type || rtype == TypeManager.uint64_type)
3402                                         ig.Emit (OpCodes.Conv_I);
3403
3404                                 if (is_add)
3405                                         ig.Emit (OpCodes.Add);
3406                                 else
3407                                         ig.Emit (OpCodes.Sub);
3408                         }
3409                 }
3410         }
3411
3412         /// <summary>
3413         ///   Implements the ternary conditional operator (?:)
3414         /// </summary>
3415         public class Conditional : Expression {
3416                 Expression expr, trueExpr, falseExpr;
3417
3418                 public Conditional (Expression expr, Expression trueExpr, Expression falseExpr, Location l)
3419                 {
3420                         this.expr = expr;
3421                         this.trueExpr = trueExpr;
3422                         this.falseExpr = falseExpr;
3423                         this.loc = l;
3424                 }
3425
3426                 public Expression Expr {
3427                         get {
3428                                 return expr;
3429                         }
3430                 }
3431
3432                 public Expression TrueExpr {
3433                         get {
3434                                 return trueExpr;
3435                         }
3436                 }
3437
3438                 public Expression FalseExpr {
3439                         get {
3440                                 return falseExpr;
3441                         }
3442                 }
3443
3444                 public override Expression DoResolve (EmitContext ec)
3445                 {
3446                         expr = expr.Resolve (ec);
3447
3448                         if (expr == null)
3449                                 return null;
3450
3451                         if (expr.Type != TypeManager.bool_type){
3452                                 expr = Expression.ResolveBoolean (
3453                                         ec, expr, loc);
3454
3455                                 if (expr == null)
3456                                         return null;
3457                         }
3458
3459                         trueExpr = trueExpr.Resolve (ec);
3460                         falseExpr = falseExpr.Resolve (ec);
3461
3462                         if (trueExpr == null || falseExpr == null)
3463                                 return null;
3464
3465                         eclass = ExprClass.Value;
3466                         if (trueExpr.Type == falseExpr.Type)
3467                                 type = trueExpr.Type;
3468                         else {
3469                                 Expression conv;
3470                                 Type true_type = trueExpr.Type;
3471                                 Type false_type = falseExpr.Type;
3472
3473                                 //
3474                                 // First, if an implicit conversion exists from trueExpr
3475                                 // to falseExpr, then the result type is of type falseExpr.Type
3476                                 //
3477                                 conv = Convert.ImplicitConversion (ec, trueExpr, false_type, loc);
3478                                 if (conv != null){
3479                                         //
3480                                         // Check if both can convert implicitl to each other's type
3481                                         //
3482                                         if (Convert.ImplicitConversion (ec, falseExpr, true_type, loc) != null){
3483                                                 Error (172,
3484                                                        "Can not compute type of conditional expression " +
3485                                                        "as `" + TypeManager.CSharpName (trueExpr.Type) +
3486                                                        "' and `" + TypeManager.CSharpName (falseExpr.Type) +
3487                                                        "' convert implicitly to each other");
3488                                                 return null;
3489                                         }
3490                                         type = false_type;
3491                                         trueExpr = conv;
3492                                 } else if ((conv = Convert.ImplicitConversion(ec, falseExpr, true_type,loc))!= null){
3493                                         type = true_type;
3494                                         falseExpr = conv;
3495                                 } else {
3496                                         Error (173, "The type of the conditional expression can " +
3497                                                "not be computed because there is no implicit conversion" +
3498                                                " from `" + TypeManager.CSharpName (trueExpr.Type) + "'" +
3499                                                " and `" + TypeManager.CSharpName (falseExpr.Type) + "'");
3500                                         return null;
3501                                 }
3502                         }
3503
3504                         if (expr is BoolConstant){
3505                                 BoolConstant bc = (BoolConstant) expr;
3506
3507                                 if (bc.Value)
3508                                         return trueExpr;
3509                                 else
3510                                         return falseExpr;
3511                         }
3512
3513                         return this;
3514                 }
3515
3516                 public override void Emit (EmitContext ec)
3517                 {
3518                         ILGenerator ig = ec.ig;
3519                         Label false_target = ig.DefineLabel ();
3520                         Label end_target = ig.DefineLabel ();
3521
3522                         expr.EmitBranchable (ec, false_target, false);
3523                         trueExpr.Emit (ec);
3524                         ig.Emit (OpCodes.Br, end_target);
3525                         ig.MarkLabel (false_target);
3526                         falseExpr.Emit (ec);
3527                         ig.MarkLabel (end_target);
3528                 }
3529
3530         }
3531
3532         /// <summary>
3533         ///   Local variables
3534         /// </summary>
3535         public class LocalVariableReference : Expression, IAssignMethod, IMemoryLocation, IVariable {
3536                 public readonly string Name;
3537                 public readonly Block Block;
3538                 LocalInfo local_info;
3539                 bool is_readonly;
3540
3541                 public LocalVariableReference (Block block, string name, Location l)
3542                 {
3543                         Block = block;
3544                         Name = name;
3545                         loc = l;
3546                         eclass = ExprClass.Variable;
3547                 }
3548
3549                 // Setting `is_readonly' to false will allow you to create a writable
3550                 // reference to a read-only variable.  This is used by foreach and using.
3551                 public LocalVariableReference (Block block, string name, Location l,
3552                                                LocalInfo local_info, bool is_readonly)
3553                         : this (block, name, l)
3554                 {
3555                         this.local_info = local_info;
3556                         this.is_readonly = is_readonly;
3557                 }
3558
3559                 public VariableInfo VariableInfo {
3560                         get { return local_info.VariableInfo; }
3561                 }
3562
3563                 public bool IsReadOnly {
3564                         get {
3565                                 return is_readonly;
3566                         }
3567                 }
3568
3569                 protected void DoResolveBase (EmitContext ec)
3570                 {
3571                         if (local_info == null) {
3572                                 local_info = Block.GetLocalInfo (Name);
3573                                 is_readonly = local_info.ReadOnly;
3574                         }
3575
3576                         type = local_info.VariableType;
3577 #if false
3578                         if (ec.InAnonymousMethod)
3579                                 Block.LiftVariable (local_info);
3580 #endif
3581                 }
3582
3583                 protected Expression DoResolve (EmitContext ec, bool is_lvalue)
3584                 {
3585                         Expression e = Block.GetConstantExpression (Name);
3586                         if (e != null) {
3587                                 local_info.Used = true;
3588                                 eclass = ExprClass.Value;
3589                                 return e.Resolve (ec);
3590                         }
3591
3592                         VariableInfo variable_info = local_info.VariableInfo;
3593                         if ((variable_info != null) && !variable_info.IsAssigned (ec, loc))
3594                                 return null;
3595
3596                         if (!is_lvalue)
3597                                 local_info.Used = true;
3598
3599                         if (local_info.LocalBuilder == null)
3600                                 return ec.RemapLocal (local_info);
3601
3602                         return this;
3603                 }
3604
3605                 public override Expression DoResolve (EmitContext ec)
3606                 {
3607                         DoResolveBase (ec);
3608
3609                         return DoResolve (ec, false);
3610                 }
3611
3612                 override public Expression DoResolveLValue (EmitContext ec, Expression right_side)
3613                 {
3614                         DoResolveBase (ec);
3615
3616                         VariableInfo variable_info = local_info.VariableInfo;
3617                         if (variable_info != null)
3618                                 variable_info.SetAssigned (ec);
3619
3620                         Expression e = DoResolve (ec, true);
3621
3622                         if (e == null)
3623                                 return null;
3624
3625                         if (is_readonly){
3626                                 Error (1604, "cannot assign to `" + Name + "' because it is readonly");
3627                                 return null;
3628                         }
3629
3630                         CheckObsoleteAttribute (e.Type);
3631
3632                         if (local_info.LocalBuilder == null)
3633                                 return ec.RemapLocalLValue (local_info, right_side);
3634
3635                         return this;
3636                 }
3637
3638                 public bool VerifyFixed (bool is_expression)
3639                 {
3640                         return !is_expression || local_info.IsFixed;
3641                 }
3642
3643                 public override void Emit (EmitContext ec)
3644                 {
3645                         ILGenerator ig = ec.ig;
3646
3647                         ig.Emit (OpCodes.Ldloc, local_info.LocalBuilder);
3648                 }
3649
3650                 public void Emit (EmitContext ec, bool leave_copy)
3651                 {
3652                         Emit (ec);
3653                         if (leave_copy)
3654                                 ec.ig.Emit (OpCodes.Dup);
3655                 }
3656
3657                 public void EmitAssign (EmitContext ec, Expression source, bool leave_copy, bool prepare_for_load)
3658                 {
3659                         source.Emit (ec);
3660                         if (leave_copy)
3661                                 ec.ig.Emit (OpCodes.Dup);
3662                         ec.ig.Emit (OpCodes.Stloc, local_info.LocalBuilder);
3663                 }
3664
3665                 public void AddressOf (EmitContext ec, AddressOp mode)
3666                 {
3667                         ILGenerator ig = ec.ig;
3668
3669                         ig.Emit (OpCodes.Ldloca, local_info.LocalBuilder);
3670                 }
3671
3672                 public override string ToString ()
3673                 {
3674                         return String.Format ("{0} ({1}:{2})", GetType (), Name, loc);
3675                 }
3676         }
3677
3678         /// <summary>
3679         ///   This represents a reference to a parameter in the intermediate
3680         ///   representation.
3681         /// </summary>
3682         public class ParameterReference : Expression, IAssignMethod, IMemoryLocation, IVariable {
3683                 Parameters pars;
3684                 String name;
3685                 int idx;
3686                 Block block;
3687                 VariableInfo vi;
3688                 public Parameter.Modifier mod;
3689                 public bool is_ref, is_out, prepared;
3690                 LocalTemporary temp;
3691
3692                 public ParameterReference (Parameters pars, Block block, int idx, string name, Location loc)
3693                 {
3694                         this.pars = pars;
3695                         this.block = block;
3696                         this.idx  = idx;
3697                         this.name = name;
3698                         this.loc = loc;
3699                         eclass = ExprClass.Variable;
3700                 }
3701
3702                 public VariableInfo VariableInfo {
3703                         get { return vi; }
3704                 }
3705
3706                 public bool VerifyFixed (bool is_expression)
3707                 {
3708                         return !is_expression || TypeManager.IsValueType (type);
3709                 }
3710
3711                 public bool IsAssigned (EmitContext ec, Location loc)
3712                 {
3713                         if (!ec.DoFlowAnalysis || !is_out ||
3714                             ec.CurrentBranching.IsAssigned (vi))
3715                                 return true;
3716
3717                         Report.Error (165, loc,
3718                                       "Use of unassigned parameter `" + name + "'");
3719                         return false;
3720                 }
3721
3722                 public bool IsFieldAssigned (EmitContext ec, string field_name, Location loc)
3723                 {
3724                         if (!ec.DoFlowAnalysis || !is_out ||
3725                             ec.CurrentBranching.IsFieldAssigned (vi, field_name))
3726                                 return true;
3727
3728                         Report.Error (170, loc,
3729                                       "Use of possibly unassigned field `" + field_name + "'");
3730                         return false;
3731                 }
3732
3733                 public void SetAssigned (EmitContext ec)
3734                 {
3735                         if (is_out && ec.DoFlowAnalysis)
3736                                 ec.CurrentBranching.SetAssigned (vi);
3737                 }
3738
3739                 public void SetFieldAssigned (EmitContext ec, string field_name)
3740                 {
3741                         if (is_out && ec.DoFlowAnalysis)
3742                                 ec.CurrentBranching.SetFieldAssigned (vi, field_name);
3743                 }
3744
3745                 protected void DoResolveBase (EmitContext ec)
3746                 {
3747                         type = pars.GetParameterInfo (ec.DeclSpace, idx, out mod);
3748                         is_ref = (mod & Parameter.Modifier.ISBYREF) != 0;
3749                         is_out = (mod & Parameter.Modifier.OUT) != 0;
3750                         eclass = ExprClass.Variable;
3751
3752                         if (is_out)
3753                                 vi = block.ParameterMap [idx];
3754                 }
3755
3756                 //
3757                 // Notice that for ref/out parameters, the type exposed is not the
3758                 // same type exposed externally.
3759                 //
3760                 // for "ref int a":
3761                 //   externally we expose "int&"
3762                 //   here we expose       "int".
3763                 //
3764                 // We record this in "is_ref".  This means that the type system can treat
3765                 // the type as it is expected, but when we generate the code, we generate
3766                 // the alternate kind of code.
3767                 //
3768                 public override Expression DoResolve (EmitContext ec)
3769                 {
3770                         DoResolveBase (ec);
3771
3772                         if (is_out && ec.DoFlowAnalysis && !IsAssigned (ec, loc))
3773                                 return null;
3774
3775                         if (ec.RemapToProxy)
3776                                 return ec.RemapParameter (idx);
3777
3778                         return this;
3779                 }
3780
3781                 override public Expression DoResolveLValue (EmitContext ec, Expression right_side)
3782                 {
3783                         DoResolveBase (ec);
3784
3785                         SetAssigned (ec);
3786
3787                         if (ec.RemapToProxy)
3788                                 return ec.RemapParameterLValue (idx, right_side);
3789
3790                         return this;
3791                 }
3792
3793                 static public void EmitLdArg (ILGenerator ig, int x)
3794                 {
3795                         if (x <= 255){
3796                                 switch (x){
3797                                 case 0: ig.Emit (OpCodes.Ldarg_0); break;
3798                                 case 1: ig.Emit (OpCodes.Ldarg_1); break;
3799                                 case 2: ig.Emit (OpCodes.Ldarg_2); break;
3800                                 case 3: ig.Emit (OpCodes.Ldarg_3); break;
3801                                 default: ig.Emit (OpCodes.Ldarg_S, (byte) x); break;
3802                                 }
3803                         } else
3804                                 ig.Emit (OpCodes.Ldarg, x);
3805                 }
3806
3807                 //
3808                 // This method is used by parameters that are references, that are
3809                 // being passed as references:  we only want to pass the pointer (that
3810                 // is already stored in the parameter, not the address of the pointer,
3811                 // and not the value of the variable).
3812                 //
3813                 public void EmitLoad (EmitContext ec)
3814                 {
3815                         ILGenerator ig = ec.ig;
3816                         int arg_idx = idx;
3817
3818                         if (!ec.IsStatic)
3819                                 arg_idx++;
3820
3821                         EmitLdArg (ig, arg_idx);
3822                 }
3823
3824                 public override void Emit (EmitContext ec)
3825                 {
3826                         Emit (ec, false);
3827                 }
3828
3829                 public void Emit (EmitContext ec, bool leave_copy)
3830                 {
3831                         ILGenerator ig = ec.ig;
3832
3833                         int arg_idx = idx;
3834
3835                         if (!ec.IsStatic)
3836                                 arg_idx++;
3837
3838                         EmitLdArg (ig, arg_idx);
3839
3840                         if (is_ref) {
3841                                 if (prepared)
3842                                         ec.ig.Emit (OpCodes.Dup);
3843
3844                                 //
3845                                 // If we are a reference, we loaded on the stack a pointer
3846                                 // Now lets load the real value
3847                                 //
3848                                 LoadFromPtr (ig, type);
3849                         }
3850
3851                         if (leave_copy) {
3852                                 ec.ig.Emit (OpCodes.Dup);
3853
3854                                 if (is_ref) {
3855                                         temp = new LocalTemporary (ec, type);
3856                                         temp.Store (ec);
3857                                 }
3858                         }
3859                 }
3860
3861                 public void EmitAssign (EmitContext ec, Expression source, bool leave_copy, bool prepare_for_load)
3862                 {
3863                         ILGenerator ig = ec.ig;
3864                         int arg_idx = idx;
3865
3866                         prepared = prepare_for_load;
3867
3868                         if (!ec.IsStatic)
3869                                 arg_idx++;
3870
3871                         if (is_ref && !prepared)
3872                                 EmitLdArg (ig, arg_idx);
3873
3874                         source.Emit (ec);
3875
3876                         if (leave_copy)
3877                                 ec.ig.Emit (OpCodes.Dup);
3878
3879                         if (is_ref) {
3880                                 if (leave_copy) {
3881                                         temp = new LocalTemporary (ec, type);
3882                                         temp.Store (ec);
3883                                 }
3884
3885                                 StoreFromPtr (ig, type);
3886
3887                                 if (temp != null)
3888                                         temp.Emit (ec);
3889                         } else {
3890                                 if (arg_idx <= 255)
3891                                         ig.Emit (OpCodes.Starg_S, (byte) arg_idx);
3892                                 else
3893                                         ig.Emit (OpCodes.Starg, arg_idx);
3894                         }
3895                 }
3896
3897                 public void AddressOf (EmitContext ec, AddressOp mode)
3898                 {
3899                         int arg_idx = idx;
3900
3901                         if (!ec.IsStatic)
3902                                 arg_idx++;
3903
3904                         if (is_ref){
3905                                 if (arg_idx <= 255)
3906                                         ec.ig.Emit (OpCodes.Ldarg_S, (byte) arg_idx);
3907                                 else
3908                                         ec.ig.Emit (OpCodes.Ldarg, arg_idx);
3909                         } else {
3910                                 if (arg_idx <= 255)
3911                                         ec.ig.Emit (OpCodes.Ldarga_S, (byte) arg_idx);
3912                                 else
3913                                         ec.ig.Emit (OpCodes.Ldarga, arg_idx);
3914                         }
3915                 }
3916
3917         }
3918
3919         /// <summary>
3920         ///   Used for arguments to New(), Invocation()
3921         /// </summary>
3922         public class Argument {
3923                 public enum AType : byte {
3924                         Expression,
3925                         Ref,
3926                         Out,
3927                         ArgList
3928                 };
3929
3930                 public readonly AType ArgType;
3931                 public Expression Expr;
3932
3933                 public Argument (Expression expr, AType type)
3934                 {
3935                         this.Expr = expr;
3936                         this.ArgType = type;
3937                 }
3938
3939                 public Argument (Expression expr)
3940                 {
3941                         this.Expr = expr;
3942                         this.ArgType = AType.Expression;
3943                 }
3944
3945                 public Type Type {
3946                         get {
3947                                 if (ArgType == AType.Ref || ArgType == AType.Out)
3948                                         return TypeManager.GetReferenceType (Expr.Type);
3949                                 else
3950                                         return Expr.Type;
3951                         }
3952                 }
3953
3954                 public Parameter.Modifier GetParameterModifier ()
3955                 {
3956                         switch (ArgType) {
3957                         case AType.Out:
3958                                 return Parameter.Modifier.OUT | Parameter.Modifier.ISBYREF;
3959
3960                         case AType.Ref:
3961                                 return Parameter.Modifier.REF | Parameter.Modifier.ISBYREF;
3962
3963                         default:
3964                                 return Parameter.Modifier.NONE;
3965                         }
3966                 }
3967
3968                 public static string FullDesc (Argument a)
3969                 {
3970                         if (a.ArgType == AType.ArgList)
3971                                 return "__arglist";
3972
3973                         return (a.ArgType == AType.Ref ? "ref " :
3974                                 (a.ArgType == AType.Out ? "out " : "")) +
3975                                 TypeManager.CSharpName (a.Expr.Type);
3976                 }
3977
3978                 public bool ResolveMethodGroup (EmitContext ec, Location loc)
3979                 {
3980                         // FIXME: csc doesn't report any error if you try to use `ref' or
3981                         //        `out' in a delegate creation expression.
3982                         Expr = Expr.Resolve (ec, ResolveFlags.VariableOrValue | ResolveFlags.MethodGroup);
3983                         if (Expr == null)
3984                                 return false;
3985
3986                         return true;
3987                 }
3988
3989                 public bool Resolve (EmitContext ec, Location loc)
3990                 {
3991                         if (ArgType == AType.Ref) {
3992                                 Expr = Expr.Resolve (ec);
3993                                 if (Expr == null)
3994                                         return false;
3995
3996                                 if (!ec.IsConstructor) {
3997                                         FieldExpr fe = Expr as FieldExpr;
3998                                         if (fe != null && fe.FieldInfo.IsInitOnly) {
3999                                                 if (fe.FieldInfo.IsStatic)
4000                                                         Report.Error (199, loc, "A static readonly field cannot be passed ref or out (except in a static constructor)");
4001                                                 else
4002                                                         Report.Error (192, loc, "A readonly field cannot be passed ref or out (except in a constructor)");
4003                                                 return false;
4004                                         }
4005                                 }
4006                                 Expr = Expr.ResolveLValue (ec, Expr);
4007                         } else if (ArgType == AType.Out)
4008                                 Expr = Expr.ResolveLValue (ec, new EmptyExpression ());
4009                         else
4010                                 Expr = Expr.Resolve (ec);
4011
4012                         if (Expr == null)
4013                                 return false;
4014
4015                         if (ArgType == AType.Expression)
4016                                 return true;
4017                         else {
4018                                 //
4019                                 // Catch errors where fields of a MarshalByRefObject are passed as ref or out
4020                                 // This is only allowed for `this'
4021                                 //
4022                                 FieldExpr fe = Expr as FieldExpr;
4023                                 if (fe != null && !fe.IsStatic){
4024                                         Expression instance = fe.InstanceExpression;
4025
4026                                         if (instance.GetType () != typeof (This)){
4027                                                 if (fe.InstanceExpression.Type.IsSubclassOf (TypeManager.mbr_type)){
4028                                                         Report.Error (197, loc,
4029                                                                       "Can not pass a type that derives from MarshalByRefObject with out or ref");
4030                                                         return false;
4031                                                 }
4032                                         }
4033                                 }
4034                         }
4035
4036                         if (Expr.eclass != ExprClass.Variable){
4037                                 //
4038                                 // We just probe to match the CSC output
4039                                 //
4040                                 if (Expr.eclass == ExprClass.PropertyAccess ||
4041                                     Expr.eclass == ExprClass.IndexerAccess){
4042                                         Report.Error (
4043                                                 206, loc,
4044                                                 "A property or indexer can not be passed as an out or ref " +
4045                                                 "parameter");
4046                                 } else {
4047                                         Report.Error (
4048                                                 1510, loc,
4049                                                 "An lvalue is required as an argument to out or ref");
4050                                 }
4051                                 return false;
4052                         }
4053
4054                         return true;
4055                 }
4056
4057                 public void Emit (EmitContext ec)
4058                 {
4059                         //
4060                         // Ref and Out parameters need to have their addresses taken.
4061                         //
4062                         // ParameterReferences might already be references, so we want
4063                         // to pass just the value
4064                         //
4065                         if (ArgType == AType.Ref || ArgType == AType.Out){
4066                                 AddressOp mode = AddressOp.Store;
4067
4068                                 if (ArgType == AType.Ref)
4069                                         mode |= AddressOp.Load;
4070
4071                                 if (Expr is ParameterReference){
4072                                         ParameterReference pr = (ParameterReference) Expr;
4073
4074                                         if (pr.is_ref)
4075                                                 pr.EmitLoad (ec);
4076                                         else {
4077
4078                                                 pr.AddressOf (ec, mode);
4079                                         }
4080                                 } else {
4081                                         ((IMemoryLocation)Expr).AddressOf (ec, mode);
4082                                 }
4083                         } else
4084                                 Expr.Emit (ec);
4085                 }
4086         }
4087
4088         /// <summary>
4089         ///   Invocation of methods or delegates.
4090         /// </summary>
4091         public class Invocation : ExpressionStatement {
4092                 public readonly ArrayList Arguments;
4093
4094                 Expression expr;
4095                 MethodBase method = null;
4096                 bool is_base;
4097
4098                 static Hashtable method_parameter_cache;
4099
4100                 static Invocation ()
4101                 {
4102                         method_parameter_cache = new PtrHashtable ();
4103                 }
4104
4105                 //
4106                 // arguments is an ArrayList, but we do not want to typecast,
4107                 // as it might be null.
4108                 //
4109                 // FIXME: only allow expr to be a method invocation or a
4110                 // delegate invocation (7.5.5)
4111                 //
4112                 public Invocation (Expression expr, ArrayList arguments, Location l)
4113                 {
4114                         this.expr = expr;
4115                         Arguments = arguments;
4116                         loc = l;
4117                 }
4118
4119                 public Expression Expr {
4120                         get {
4121                                 return expr;
4122                         }
4123                 }
4124
4125                 /// <summary>
4126                 ///   Returns the Parameters (a ParameterData interface) for the
4127                 ///   Method `mb'
4128                 /// </summary>
4129                 public static ParameterData GetParameterData (MethodBase mb)
4130                 {
4131                         object pd = method_parameter_cache [mb];
4132                         object ip;
4133
4134                         if (pd != null)
4135                                 return (ParameterData) pd;
4136
4137
4138                         ip = TypeManager.LookupParametersByBuilder (mb);
4139                         if (ip != null){
4140                                 method_parameter_cache [mb] = ip;
4141
4142                                 return (ParameterData) ip;
4143                         } else {
4144                                 ReflectionParameters rp = new ReflectionParameters (mb);
4145                                 method_parameter_cache [mb] = rp;
4146
4147                                 return (ParameterData) rp;
4148                         }
4149                 }
4150
4151                 /// <summary>
4152                 ///   Determines "better conversion" as specified in 7.4.2.3
4153                 ///
4154                 ///    Returns : 1 if a->p is better
4155                 ///              0 if a->q or neither is better
4156                 /// </summary>
4157                 static int BetterConversion (EmitContext ec, Argument a, Type p, Type q, Location loc)
4158                 {
4159                         Type argument_type = a.Type;
4160                         Expression argument_expr = a.Expr;
4161
4162                         if (argument_type == null)
4163                                 throw new Exception ("Expression of type " + a.Expr +
4164                                                      " does not resolve its type");
4165
4166                         if (p == null || q == null)
4167                                 throw new InternalErrorException ("BetterConversion Got a null conversion");
4168
4169                         //
4170                         // This is a special case since csc behaves this way.
4171                         //
4172                         if (argument_expr is NullLiteral &&
4173                             p == TypeManager.string_type &&
4174                             q == TypeManager.object_type)
4175                                 return 1;
4176                         else if (argument_expr is NullLiteral &&
4177                                  p == TypeManager.object_type &&
4178                                  q == TypeManager.string_type)
4179                                 return 0;
4180
4181                         //
4182                         // csc behaves this way so we emulate it. Basically, if the argument
4183                         // is null and one of the types to compare is 'object' and the other
4184                         // is a reference type, we prefer the other.
4185                         //
4186                         // I can't find this anywhere in the spec but we can interpret this
4187                         // to mean that null can be of any type you wish in such a context
4188                         //
4189                         if (argument_expr is NullLiteral &&
4190                             !p.IsValueType &&
4191                             q == TypeManager.object_type)
4192                                 return 1;
4193                         else if (argument_expr is NullLiteral &&
4194                                  !q.IsValueType &&
4195                                  p == TypeManager.object_type)
4196                                 return 0;
4197
4198
4199                         if (p == q)
4200                                 return 0;
4201
4202                         if (argument_type == p)
4203                                 return 1;
4204
4205                         if (argument_type == q)
4206                                 return 0;
4207
4208                         Expression p_tmp = new EmptyExpression (p);
4209                         Expression q_tmp = new EmptyExpression (q);
4210
4211                         if (Convert.ImplicitConversionExists (ec, p_tmp, q) == true &&
4212                             Convert.ImplicitConversionExists (ec, q_tmp, p) == false)
4213                                 return 1;
4214
4215                         if (p == TypeManager.sbyte_type)
4216                                 if (q == TypeManager.byte_type || q == TypeManager.ushort_type ||
4217                                     q == TypeManager.uint32_type || q == TypeManager.uint64_type)
4218                                         return 1;
4219
4220                         if (p == TypeManager.short_type)
4221                                 if (q == TypeManager.ushort_type || q == TypeManager.uint32_type ||
4222                                     q == TypeManager.uint64_type)
4223                                         return 1;
4224
4225                         if (p == TypeManager.int32_type)
4226                                 if (q == TypeManager.uint32_type || q == TypeManager.uint64_type)
4227                                         return 1;
4228
4229                         if (p == TypeManager.int64_type)
4230                                 if (q == TypeManager.uint64_type)
4231                                         return 1;
4232
4233                         return 0;
4234                 }
4235
4236                 /// <summary>
4237                 ///   Determines "Better function" between candidate
4238                 ///   and the current best match
4239                 /// </summary>
4240                 /// <remarks>
4241                 ///    Returns an integer indicating :
4242                 ///     0 if candidate ain't better
4243                 ///     1 if candidate is better than the current best match
4244                 /// </remarks>
4245                 static int BetterFunction (EmitContext ec, ArrayList args, int argument_count,
4246                                            MethodBase candidate, bool candidate_params,
4247                                            MethodBase best, bool best_params, Location loc)
4248                 {
4249                         ParameterData candidate_pd = GetParameterData (candidate);
4250                         ParameterData best_pd = GetParameterData (best);
4251
4252                         int cand_count = candidate_pd.Count;
4253
4254                         //
4255                         // If there is no best method, than this one
4256                         // is better, however, if we already found a
4257                         // best method, we cant tell. This happens
4258                         // if we have:
4259                         //
4260                         //      interface IFoo {
4261                         //              void DoIt ();
4262                         //      }
4263                         //
4264                         //      interface IBar {
4265                         //              void DoIt ();
4266                         //      }
4267                         //
4268                         //      interface IFooBar : IFoo, IBar {}
4269                         //
4270                         // We cant tell if IFoo.DoIt is better than IBar.DoIt
4271                         //
4272                         // However, we have to consider that
4273                         // Trim (); is better than Trim (params char[] chars);
4274                         //
4275                         if (cand_count == 0 && argument_count == 0)
4276                                 return best_params ? 1 : 0;
4277
4278                         if ((candidate_pd.ParameterModifier (cand_count - 1) != Parameter.Modifier.PARAMS) &&
4279                             (candidate_pd.ParameterModifier (cand_count - 1) != Parameter.Modifier.ARGLIST))
4280                                 if (cand_count != argument_count)
4281                                         return 0;
4282
4283
4284                         int rating1 = 0, rating2 = 0;
4285
4286                         for (int j = 0; j < argument_count; ++j) {
4287                                 int x, y;
4288
4289                                 Argument a = (Argument) args [j];
4290
4291                                 Type ct = candidate_pd.ParameterType (j);
4292                                 Type bt = best_pd.ParameterType (j);
4293
4294                                 if (candidate_pd.ParameterModifier (j) == Parameter.Modifier.PARAMS)
4295                                         if (candidate_params)
4296                                                 ct = TypeManager.GetElementType (ct);
4297
4298                                 if (best_pd.ParameterModifier (j) == Parameter.Modifier.PARAMS)
4299                                         if (best_params)
4300                                                 bt = TypeManager.GetElementType (bt);
4301
4302                                 x = BetterConversion (ec, a, ct, bt, loc);
4303                                 y = BetterConversion (ec, a, bt, ct, loc);
4304
4305                                 if (x < y)
4306                                         return 0;
4307
4308                                 rating1 += x;
4309                                 rating2 += y;
4310                         }
4311
4312                         //
4313                         // If a method (in the normal form) with the
4314                         // same signature as the expanded form of the
4315                         // current best params method already exists,
4316                         // the expanded form is not applicable so we
4317                         // force it to select the candidate
4318                         //
4319                         if (!candidate_params && best_params && cand_count == argument_count)
4320                                 return 1;
4321
4322                         if (rating1 > rating2)
4323                                 return 1;
4324                         else
4325                                 return 0;
4326                 }
4327
4328                 public static string FullMethodDesc (MethodBase mb)
4329                 {
4330                         string ret_type = "";
4331
4332                         if (mb == null)
4333                                 return "";
4334
4335                         if (mb is MethodInfo)
4336                                 ret_type = TypeManager.CSharpName (((MethodInfo) mb).ReturnType);
4337
4338                         StringBuilder sb = new StringBuilder (ret_type);
4339                         sb.Append (" ");
4340                         sb.Append (mb.ReflectedType.ToString ());
4341                         sb.Append (".");
4342                         sb.Append (mb.Name);
4343
4344                         ParameterData pd = GetParameterData (mb);
4345
4346                         int count = pd.Count;
4347                         sb.Append (" (");
4348
4349                         for (int i = count; i > 0; ) {
4350                                 i--;
4351
4352                                 sb.Append (pd.ParameterDesc (count - i - 1));
4353                                 if (i != 0)
4354                                         sb.Append (", ");
4355                         }
4356
4357                         sb.Append (")");
4358                         return sb.ToString ();
4359                 }
4360
4361                 public static MethodGroupExpr MakeUnionSet (Expression mg1, Expression mg2, Location loc)
4362                 {
4363                         MemberInfo [] miset;
4364                         MethodGroupExpr union;
4365
4366                         if (mg1 == null) {
4367                                 if (mg2 == null)
4368                                         return null;
4369                                 return (MethodGroupExpr) mg2;
4370                         } else {
4371                                 if (mg2 == null)
4372                                         return (MethodGroupExpr) mg1;
4373                         }
4374
4375                         MethodGroupExpr left_set = null, right_set = null;
4376                         int length1 = 0, length2 = 0;
4377
4378                         left_set = (MethodGroupExpr) mg1;
4379                         length1 = left_set.Methods.Length;
4380
4381                         right_set = (MethodGroupExpr) mg2;
4382                         length2 = right_set.Methods.Length;
4383
4384                         ArrayList common = new ArrayList ();
4385
4386                         foreach (MethodBase r in right_set.Methods){
4387                                 if (TypeManager.ArrayContainsMethod (left_set.Methods, r))
4388                                         common.Add (r);
4389                         }
4390
4391                         miset = new MemberInfo [length1 + length2 - common.Count];
4392                         left_set.Methods.CopyTo (miset, 0);
4393
4394                         int k = length1;
4395
4396                         foreach (MethodBase r in right_set.Methods) {
4397                                 if (!common.Contains (r))
4398                                         miset [k++] = r;
4399                         }
4400
4401                         union = new MethodGroupExpr (miset, loc);
4402
4403                         return union;
4404                 }
4405
4406                 static bool IsParamsMethodApplicable (EmitContext ec, MethodGroupExpr me,
4407                                                       ArrayList arguments, int arg_count,
4408                                                       ref MethodBase candidate)
4409                 {
4410                         return IsParamsMethodApplicable (
4411                                 ec, me, arguments, arg_count, false, ref candidate) ||
4412                                 IsParamsMethodApplicable (
4413                                         ec, me, arguments, arg_count, true, ref candidate);
4414
4415
4416                 }
4417
4418                 static bool IsParamsMethodApplicable (EmitContext ec, MethodGroupExpr me,
4419                                                       ArrayList arguments, int arg_count,
4420                                                       bool do_varargs, ref MethodBase candidate)
4421                 {
4422                         return IsParamsMethodApplicable (
4423                                 ec, arguments, arg_count, candidate, do_varargs);
4424                 }
4425
4426                 /// <summary>
4427                 ///   Determines if the candidate method, if a params method, is applicable
4428                 ///   in its expanded form to the given set of arguments
4429                 /// </summary>
4430                 static bool IsParamsMethodApplicable (EmitContext ec, ArrayList arguments,
4431                                                       int arg_count, MethodBase candidate,
4432                                                       bool do_varargs)
4433                 {
4434                         ParameterData pd = GetParameterData (candidate);
4435
4436                         int pd_count = pd.Count;
4437                         if (pd_count == 0)
4438                                 return false;
4439
4440                         int count = pd_count - 1;
4441                         if (do_varargs) {
4442                                 if (pd.ParameterModifier (count) != Parameter.Modifier.ARGLIST)
4443                                         return false;
4444                                 if (pd_count != arg_count)
4445                                         return false;
4446                         } else {
4447                                 if (pd.ParameterModifier (count) != Parameter.Modifier.PARAMS)
4448                                         return false;
4449                         }
4450
4451                         if (count > arg_count)
4452                                 return false;
4453
4454                         if (pd_count == 1 && arg_count == 0)
4455                                 return true;
4456
4457                         //
4458                         // If we have come this far, the case which
4459                         // remains is when the number of parameters is
4460                         // less than or equal to the argument count.
4461                         //
4462                         for (int i = 0; i < count; ++i) {
4463
4464                                 Argument a = (Argument) arguments [i];
4465
4466                                 Parameter.Modifier a_mod = a.GetParameterModifier () &
4467                                         ~(Parameter.Modifier.OUT | Parameter.Modifier.REF);
4468                                 Parameter.Modifier p_mod = pd.ParameterModifier (i) &
4469                                         ~(Parameter.Modifier.OUT | Parameter.Modifier.REF);
4470
4471                                 if (a_mod == p_mod) {
4472
4473                                         if (a_mod == Parameter.Modifier.NONE)
4474                                                 if (!Convert.ImplicitConversionExists (ec,
4475                                                                                        a.Expr,
4476                                                                                        pd.ParameterType (i)))
4477                                                         return false;
4478
4479                                         if ((a_mod & Parameter.Modifier.ISBYREF) != 0) {
4480                                                 Type pt = pd.ParameterType (i);
4481
4482                                                 if (!pt.IsByRef)
4483                                                         pt = TypeManager.GetReferenceType (pt);
4484
4485                                                 if (pt != a.Type)
4486                                                         return false;
4487                                         }
4488                                 } else
4489                                         return false;
4490
4491                         }
4492
4493                         if (do_varargs) {
4494                                 Argument a = (Argument) arguments [count];
4495                                 if (!(a.Expr is Arglist))
4496                                         return false;
4497
4498                                 return true;
4499                         }
4500
4501                         Type element_type = TypeManager.GetElementType (pd.ParameterType (pd_count - 1));
4502
4503                         for (int i = pd_count - 1; i < arg_count; i++) {
4504                                 Argument a = (Argument) arguments [i];
4505
4506                                 if (!Convert.ImplicitConversionExists (ec, a.Expr, element_type))
4507                                         return false;
4508                         }
4509
4510                         return true;
4511                 }
4512
4513                 static bool IsApplicable (EmitContext ec, MethodGroupExpr me,
4514                                           ArrayList arguments, int arg_count,
4515                                           ref MethodBase candidate)
4516                 {
4517                         return IsApplicable (ec, arguments, arg_count, candidate);
4518                 }
4519
4520                 /// <summary>
4521                 ///   Determines if the candidate method is applicable (section 14.4.2.1)
4522                 ///   to the given set of arguments
4523                 /// </summary>
4524                 static bool IsApplicable (EmitContext ec, ArrayList arguments, int arg_count,
4525                                           MethodBase candidate)
4526                 {
4527                         ParameterData pd = GetParameterData (candidate);
4528
4529                         if (arg_count != pd.Count)
4530                                 return false;
4531
4532                         for (int i = arg_count; i > 0; ) {
4533                                 i--;
4534
4535                                 Argument a = (Argument) arguments [i];
4536
4537                                 Parameter.Modifier a_mod = a.GetParameterModifier () &
4538                                         ~(Parameter.Modifier.OUT | Parameter.Modifier.REF);
4539                                 Parameter.Modifier p_mod = pd.ParameterModifier (i) &
4540                                         ~(Parameter.Modifier.OUT | Parameter.Modifier.REF);
4541
4542
4543                                 if (a_mod == p_mod ||
4544                                     (a_mod == Parameter.Modifier.NONE && p_mod == Parameter.Modifier.PARAMS)) {
4545                                         if (a_mod == Parameter.Modifier.NONE) {
4546                                                 if (!Convert.ImplicitConversionExists (ec,
4547                                                                                        a.Expr,
4548                                                                                        pd.ParameterType (i)))
4549                                                         return false;
4550                                         }
4551
4552                                         if ((a_mod & Parameter.Modifier.ISBYREF) != 0) {
4553                                                 Type pt = pd.ParameterType (i);
4554
4555                                                 if (!pt.IsByRef)
4556                                                         pt = TypeManager.GetReferenceType (pt);
4557
4558                                                 if (pt != a.Type)
4559                                                         return false;
4560                                         }
4561                                 } else
4562                                         return false;
4563                         }
4564
4565                         return true;
4566                 }
4567
4568                 static private bool IsAncestralType (Type first_type, Type second_type)
4569                 {
4570                         return first_type != second_type &&
4571                                 (second_type.IsSubclassOf (first_type) ||
4572                                  TypeManager.ImplementsInterface (second_type, first_type));
4573                 }
4574
4575                 /// <summary>
4576                 ///   Find the Applicable Function Members (7.4.2.1)
4577                 ///
4578                 ///   me: Method Group expression with the members to select.
4579                 ///       it might contain constructors or methods (or anything
4580                 ///       that maps to a method).
4581                 ///
4582                 ///   Arguments: ArrayList containing resolved Argument objects.
4583                 ///
4584                 ///   loc: The location if we want an error to be reported, or a Null
4585                 ///        location for "probing" purposes.
4586                 ///
4587                 ///   Returns: The MethodBase (either a ConstructorInfo or a MethodInfo)
4588                 ///            that is the best match of me on Arguments.
4589                 ///
4590                 /// </summary>
4591                 public static MethodBase OverloadResolve (EmitContext ec, MethodGroupExpr me,
4592                                                           ArrayList Arguments, bool may_fail,
4593                                                           Location loc)
4594                 {
4595                         MethodBase method = null;
4596                         bool method_params = false;
4597                         Type applicable_type = null;
4598                         int arg_count = 0;
4599                         ArrayList candidates = new ArrayList ();
4600
4601                         //
4602                         // Used to keep a map between the candidate
4603                         // and whether it is being considered in its
4604                         // normal or expanded form
4605                         //
4606                         // false is normal form, true is expanded form
4607                         //
4608                         Hashtable candidate_to_form = null;
4609
4610                         if (Arguments != null)
4611                                 arg_count = Arguments.Count;
4612
4613                         if ((me.Name == "Invoke") &&
4614                             TypeManager.IsDelegateType (me.DeclaringType)) {
4615                                 Error_InvokeOnDelegate (loc);
4616                                 return null;
4617                         }
4618
4619                         MethodBase[] methods = me.Methods;
4620
4621                         //
4622                         // First we construct the set of applicable methods
4623                         //
4624                         bool is_sorted = true;
4625                         for (int i = 0; i < methods.Length; i++){
4626                                 Type decl_type = methods [i].DeclaringType;
4627
4628                                 //
4629                                 // If we have already found an applicable method
4630                                 // we eliminate all base types (Section 14.5.5.1)
4631                                 //
4632                                 if ((applicable_type != null) &&
4633                                     IsAncestralType (decl_type, applicable_type))
4634                                         continue;
4635
4636                                 //
4637                                 // Check if candidate is applicable (section 14.4.2.1)
4638                                 //   Is candidate applicable in normal form?
4639                                 //
4640                                 bool is_applicable = IsApplicable (
4641                                         ec, me, Arguments, arg_count, ref methods [i]);
4642
4643                                 if (!is_applicable &&
4644                                     (IsParamsMethodApplicable (
4645                                             ec, me, Arguments, arg_count, ref methods [i]))) {
4646                                         MethodBase candidate = methods [i];
4647                                         if (candidate_to_form == null)
4648                                                 candidate_to_form = new PtrHashtable ();
4649                                         candidate_to_form [candidate] = candidate;
4650                                         // Candidate is applicable in expanded form
4651                                         is_applicable = true;
4652                                 }
4653
4654                                 if (!is_applicable)
4655                                         continue;
4656
4657                                 candidates.Add (methods [i]);
4658
4659                                 if (applicable_type == null)
4660                                         applicable_type = decl_type;
4661                                 else if (applicable_type != decl_type) {
4662                                         is_sorted = false;
4663                                         if (IsAncestralType (applicable_type, decl_type))
4664                                                 applicable_type = decl_type;
4665                                 }
4666                         }
4667
4668                         int candidate_top = candidates.Count;
4669
4670                         if (candidate_top == 0) {
4671                                 //
4672                                 // Okay so we have failed to find anything so we
4673                                 // return by providing info about the closest match
4674                                 //
4675                                 for (int i = 0; i < methods.Length; ++i) {
4676                                         MethodBase c = (MethodBase) methods [i];
4677                                         ParameterData pd = GetParameterData (c);
4678
4679                                         if (pd.Count != arg_count)
4680                                                 continue;
4681
4682                                         VerifyArgumentsCompat (ec, Arguments, arg_count,
4683                                                                c, false, null, may_fail, loc);
4684                                         break;
4685                                 }
4686
4687                                 if (!may_fail) {
4688                                         string report_name = me.Name;
4689                                         if (report_name == ".ctor")
4690                                                 report_name = me.DeclaringType.ToString ();
4691
4692                                         Error_WrongNumArguments (
4693                                                 loc, report_name, arg_count);
4694                                         return null;
4695                                 }
4696
4697                                 return null;
4698                         }
4699
4700                         if (!is_sorted) {
4701                                 //
4702                                 // At this point, applicable_type is _one_ of the most derived types
4703                                 // in the set of types containing the methods in this MethodGroup.
4704                                 // Filter the candidates so that they only contain methods from the
4705                                 // most derived types.
4706                                 //
4707
4708                                 int finalized = 0; // Number of finalized candidates
4709
4710                                 do {
4711                                         // Invariant: applicable_type is a most derived type
4712
4713                                         // We'll try to complete Section 14.5.5.1 for 'applicable_type' by
4714                                         // eliminating all it's base types.  At the same time, we'll also move
4715                                         // every unrelated type to the end of the array, and pick the next
4716                                         // 'applicable_type'.
4717
4718                                         Type next_applicable_type = null;
4719                                         int j = finalized; // where to put the next finalized candidate
4720                                         int k = finalized; // where to put the next undiscarded candidate
4721                                         for (int i = finalized; i < candidate_top; ++i) {
4722                                                 Type decl_type = ((MethodBase) candidates[i]).DeclaringType;
4723
4724                                                 if (decl_type == applicable_type) {
4725                                                         candidates[k++] = candidates[j];
4726                                                         candidates[j++] = candidates[i];
4727                                                         continue;
4728                                                 }
4729
4730                                                 if (IsAncestralType (decl_type, applicable_type))
4731                                                         continue;
4732
4733                                                 if (next_applicable_type != null &&
4734                                                     IsAncestralType (decl_type, next_applicable_type))
4735                                                         continue;
4736
4737                                                 candidates[k++] = candidates[i];
4738
4739                                                 if (next_applicable_type == null ||
4740                                                     IsAncestralType (next_applicable_type, decl_type))
4741                                                         next_applicable_type = decl_type;
4742                                         }
4743
4744                                         applicable_type = next_applicable_type;
4745                                         finalized = j;
4746                                         candidate_top = k;
4747                                 } while (applicable_type != null);
4748                         }
4749
4750                         //
4751                         // Now we actually find the best method
4752                         //
4753
4754                         method = (MethodBase) candidates[0];
4755                         method_params = candidate_to_form != null && candidate_to_form.Contains (method);
4756                         for (int ix = 1; ix < candidate_top; ix++){
4757                                 MethodBase candidate = (MethodBase) candidates [ix];
4758                                 bool cand_params = candidate_to_form != null && candidate_to_form.Contains (candidate);
4759
4760                                 if (BetterFunction (ec, Arguments, arg_count,
4761                                                     candidate, cand_params,
4762                                                     method, method_params, loc) != 0) {
4763                                         method = candidate;
4764                                         method_params = cand_params;
4765                                 }
4766                         }
4767
4768                         //
4769                         // Now check that there are no ambiguities i.e the selected method
4770                         // should be better than all the others
4771                         //
4772                         bool ambiguous = false;
4773                         for (int ix = 0; ix < candidate_top; ix++){
4774                                 MethodBase candidate = (MethodBase) candidates [ix];
4775
4776                                 if (candidate == method)
4777                                         continue;
4778
4779                                 bool cand_params = candidate_to_form != null && candidate_to_form.Contains (candidate);
4780                                 if (BetterFunction (ec, Arguments, arg_count,
4781                                                     method, method_params,
4782                                                     candidate, cand_params,
4783                                                     loc) != 1) {
4784                                         Report.SymbolRelatedToPreviousError (candidate);
4785                                         ambiguous = true;
4786                                 }
4787                         }
4788
4789                         if (ambiguous) {
4790                                 Report.SymbolRelatedToPreviousError (method);
4791                                 Report.Error (121, loc, "Ambiguous call when selecting function due to implicit casts");
4792                                 return null;
4793                         }
4794
4795
4796                         //
4797                         // And now check if the arguments are all
4798                         // compatible, perform conversions if
4799                         // necessary etc. and return if everything is
4800                         // all right
4801                         //
4802                         if (!VerifyArgumentsCompat (ec, Arguments, arg_count, method,
4803                                                     method_params, null, may_fail, loc))
4804                                 return null;
4805
4806                         return method;
4807                 }
4808
4809                 static void Error_WrongNumArguments (Location loc, String name, int arg_count)
4810                 {
4811                         Report.Error (1501, loc,
4812                                       "No overload for method `" + name + "' takes `" +
4813                                       arg_count + "' arguments");
4814                 }
4815
4816                 static void Error_InvokeOnDelegate (Location loc)
4817                 {
4818                         Report.Error (1533, loc,
4819                                       "Invoke cannot be called directly on a delegate");
4820                 }
4821
4822                 static void Error_InvalidArguments (Location loc, int idx, MethodBase method,
4823                                                     Type delegate_type, string arg_sig, string par_desc)
4824                 {
4825                         if (delegate_type == null)
4826                                 Report.Error (1502, loc,
4827                                               "The best overloaded match for method '" +
4828                                               FullMethodDesc (method) +
4829                                               "' has some invalid arguments");
4830                         else
4831                                 Report.Error (1594, loc,
4832                                               "Delegate '" + delegate_type.ToString () +
4833                                               "' has some invalid arguments.");
4834                         Report.Error (1503, loc,
4835                                       String.Format ("Argument {0}: Cannot convert from '{1}' to '{2}'",
4836                                                      idx, arg_sig, par_desc));
4837                 }
4838
4839                 public static bool VerifyArgumentsCompat (EmitContext ec, ArrayList Arguments,
4840                                                           int arg_count, MethodBase method,
4841                                                           bool chose_params_expanded,
4842                                                           Type delegate_type, bool may_fail,
4843                                                           Location loc)
4844                 {
4845                         ParameterData pd = GetParameterData (method);
4846                         int pd_count = pd.Count;
4847
4848                         for (int j = 0; j < arg_count; j++) {
4849                                 Argument a = (Argument) Arguments [j];
4850                                 Expression a_expr = a.Expr;
4851                                 Type parameter_type = pd.ParameterType (j);
4852                                 Parameter.Modifier pm = pd.ParameterModifier (j);
4853
4854                                 if (pm == Parameter.Modifier.PARAMS){
4855                                         if ((pm & ~Parameter.Modifier.PARAMS) != a.GetParameterModifier ()) {
4856                                                 if (!may_fail)
4857                                                         Error_InvalidArguments (
4858                                                                 loc, j, method, delegate_type,
4859                                                                 Argument.FullDesc (a), pd.ParameterDesc (j));
4860                                                 return false;
4861                                         }
4862
4863                                         if (chose_params_expanded)
4864                                                 parameter_type = TypeManager.GetElementType (parameter_type);
4865                                 } else if (pm == Parameter.Modifier.ARGLIST){
4866                                         continue;
4867                                 } else {
4868                                         //
4869                                         // Check modifiers
4870                                         //
4871                                         if (pd.ParameterModifier (j) != a.GetParameterModifier ()){
4872                                                 if (!may_fail)
4873                                                         Error_InvalidArguments (
4874                                                                 loc, j, method, delegate_type,
4875                                                                 Argument.FullDesc (a), pd.ParameterDesc (j));
4876                                                 return false;
4877                                         }
4878                                 }
4879
4880                                 //
4881                                 // Check Type
4882                                 //
4883                                 if (!a.Type.Equals (parameter_type)){
4884                                         Expression conv;
4885
4886                                         conv = Convert.ImplicitConversion (ec, a_expr, parameter_type, loc);
4887
4888                                         if (conv == null) {
4889                                                 if (!may_fail)
4890                                                         Error_InvalidArguments (
4891                                                                 loc, j, method, delegate_type,
4892                                                                 Argument.FullDesc (a), pd.ParameterDesc (j));
4893                                                 return false;
4894                                         }
4895
4896                                         //
4897                                         // Update the argument with the implicit conversion
4898                                         //
4899                                         if (a_expr != conv)
4900                                                 a.Expr = conv;
4901                                 }
4902
4903                                 Parameter.Modifier a_mod = a.GetParameterModifier () &
4904                                         ~(Parameter.Modifier.OUT | Parameter.Modifier.REF);
4905                                 Parameter.Modifier p_mod = pd.ParameterModifier (j) &
4906                                         ~(Parameter.Modifier.OUT | Parameter.Modifier.REF);
4907
4908                                 if (a_mod != p_mod &&
4909                                     pd.ParameterModifier (pd_count - 1) != Parameter.Modifier.PARAMS) {
4910                                         if (!may_fail) {
4911                                                 Report.Error (1502, loc,
4912                                                        "The best overloaded match for method '" + FullMethodDesc (method)+
4913                                                        "' has some invalid arguments");
4914                                                 Report.Error (1503, loc,
4915                                                        "Argument " + (j+1) +
4916                                                        ": Cannot convert from '" + Argument.FullDesc (a)
4917                                                        + "' to '" + pd.ParameterDesc (j) + "'");
4918                                         }
4919
4920                                         return false;
4921                                 }
4922                         }
4923
4924                         return true;
4925                 }
4926
4927                 public override Expression DoResolve (EmitContext ec)
4928                 {
4929                         //
4930                         // First, resolve the expression that is used to
4931                         // trigger the invocation
4932                         //
4933                         if (expr is BaseAccess)
4934                                 is_base = true;
4935
4936                         expr = expr.Resolve (ec, ResolveFlags.VariableOrValue | ResolveFlags.MethodGroup);
4937                         if (expr == null)
4938                                 return null;
4939
4940                         if (!(expr is MethodGroupExpr)) {
4941                                 Type expr_type = expr.Type;
4942
4943                                 if (expr_type != null){
4944                                         bool IsDelegate = TypeManager.IsDelegateType (expr_type);
4945                                         if (IsDelegate)
4946                                                 return (new DelegateInvocation (
4947                                                         this.expr, Arguments, loc)).Resolve (ec);
4948                                 }
4949                         }
4950
4951                         if (!(expr is MethodGroupExpr)){
4952                                 expr.Error_UnexpectedKind (ResolveFlags.MethodGroup);
4953                                 return null;
4954                         }
4955
4956                         //
4957                         // Next, evaluate all the expressions in the argument list
4958                         //
4959                         if (Arguments != null){
4960                                 foreach (Argument a in Arguments){
4961                                         if (!a.Resolve (ec, loc))
4962                                                 return null;
4963                                 }
4964                         }
4965
4966                         MethodGroupExpr mg = (MethodGroupExpr) expr;
4967                         method = OverloadResolve (ec, mg, Arguments, false, loc);
4968
4969                         if (method == null)
4970                                 return null;
4971
4972                         MethodInfo mi = method as MethodInfo;
4973                         if (mi != null) {
4974                                 type = TypeManager.TypeToCoreType (mi.ReturnType);
4975                                 if (!mi.IsStatic && !mg.IsExplicitImpl && (mg.InstanceExpression == null)) {
4976                                         SimpleName.Error_ObjectRefRequired (ec, loc, mi.Name);
4977                                         return null;
4978                                 }
4979
4980                                 Expression iexpr = mg.InstanceExpression;
4981                                 if (mi.IsStatic && (iexpr != null) && !(iexpr is This)) {
4982                                         if (mg.IdenticalTypeName)
4983                                                 mg.InstanceExpression = null;
4984                                         else {
4985                                                 MemberAccess.error176 (loc, mi.Name);
4986                                                 return null;
4987                                         }
4988                                 }
4989                         }
4990
4991                         if (type.IsPointer){
4992                                 if (!ec.InUnsafe){
4993                                         UnsafeError (loc);
4994                                         return null;
4995                                 }
4996                         }
4997
4998                         //
4999                         // Only base will allow this invocation to happen.
5000                         //
5001                         if (is_base && method.IsAbstract){
5002                                 Report.Error (205, loc, "Cannot call an abstract base member: " +
5003                                               FullMethodDesc (method));
5004                                 return null;
5005                         }
5006
5007                         if (method.Name == "Finalize" && Arguments == null) {
5008                                 if (is_base)
5009                                         Report.Error (250, loc, "Do not directly call your base class Finalize method. It is called automatically from your destructor");
5010                                 else
5011                                         Report.Error (245, loc, "Destructors and object.Finalize cannot be called directly. Consider calling IDisposable.Dispose if available");
5012                                 return null;
5013                         }
5014
5015                         if ((method.Attributes & MethodAttributes.SpecialName) != 0){
5016                                 if (TypeManager.IsSpecialMethod (method))
5017                                         Report.Error (571, loc, method.Name + ": can not call operator or accessor");
5018                         }
5019
5020                         eclass = ExprClass.Value;
5021                         return this;
5022                 }
5023
5024                 // <summary>
5025                 //   Emits the list of arguments as an array
5026                 // </summary>
5027                 static void EmitParams (EmitContext ec, int idx, ArrayList arguments)
5028                 {
5029                         ILGenerator ig = ec.ig;
5030                         int count = arguments.Count - idx;
5031                         Argument a = (Argument) arguments [idx];
5032                         Type t = a.Expr.Type;
5033
5034                         IntConstant.EmitInt (ig, count);
5035                         ig.Emit (OpCodes.Newarr, TypeManager.TypeToCoreType (t));
5036
5037                         int top = arguments.Count;
5038                         for (int j = idx; j < top; j++){
5039                                 a = (Argument) arguments [j];
5040
5041                                 ig.Emit (OpCodes.Dup);
5042                                 IntConstant.EmitInt (ig, j - idx);
5043
5044                                 bool is_stobj;
5045                                 OpCode op = ArrayAccess.GetStoreOpcode (t, out is_stobj);
5046                                 if (is_stobj)
5047                                         ig.Emit (OpCodes.Ldelema, t);
5048
5049                                 a.Emit (ec);
5050
5051                                 if (is_stobj)
5052                                         ig.Emit (OpCodes.Stobj, t);
5053                                 else
5054                                         ig.Emit (op);
5055                         }
5056                 }
5057
5058                 /// <summary>
5059                 ///   Emits a list of resolved Arguments that are in the arguments
5060                 ///   ArrayList.
5061                 ///
5062                 ///   The MethodBase argument might be null if the
5063                 ///   emission of the arguments is known not to contain
5064                 ///   a `params' field (for example in constructors or other routines
5065                 ///   that keep their arguments in this structure)
5066                 ///
5067                 ///   if `dup_args' is true, a copy of the arguments will be left
5068                 ///   on the stack. If `dup_args' is true, you can specify `this_arg'
5069                 ///   which will be duplicated before any other args. Only EmitCall
5070                 ///   should be using this interface.
5071                 /// </summary>
5072                 public static void EmitArguments (EmitContext ec, MethodBase mb, ArrayList arguments, bool dup_args, LocalTemporary this_arg)
5073                 {
5074                         ParameterData pd;
5075                         if (mb != null)
5076                                 pd = GetParameterData (mb);
5077                         else
5078                                 pd = null;
5079
5080                         LocalTemporary [] temps = null;
5081
5082                         if (dup_args)
5083                                 temps = new LocalTemporary [arguments.Count];
5084
5085                         //
5086                         // If we are calling a params method with no arguments, special case it
5087                         //
5088                         if (arguments == null){
5089                                 if (pd != null && pd.Count > 0 &&
5090                                     pd.ParameterModifier (0) == Parameter.Modifier.PARAMS){
5091                                         ILGenerator ig = ec.ig;
5092
5093                                         IntConstant.EmitInt (ig, 0);
5094                                         ig.Emit (OpCodes.Newarr, TypeManager.GetElementType (pd.ParameterType (0)));
5095                                 }
5096
5097                                 return;
5098                         }
5099
5100                         int top = arguments.Count;
5101
5102                         for (int i = 0; i < top; i++){
5103                                 Argument a = (Argument) arguments [i];
5104
5105                                 if (pd != null){
5106                                         if (pd.ParameterModifier (i) == Parameter.Modifier.PARAMS){
5107                                                 //
5108                                                 // Special case if we are passing the same data as the
5109                                                 // params argument, do not put it in an array.
5110                                                 //
5111                                                 if (pd.ParameterType (i) == a.Type)
5112                                                         a.Emit (ec);
5113                                                 else
5114                                                         EmitParams (ec, i, arguments);
5115                                                 return;
5116                                         }
5117                                 }
5118
5119                                 a.Emit (ec);
5120                                 if (dup_args) {
5121                                         ec.ig.Emit (OpCodes.Dup);
5122                                         (temps [i] = new LocalTemporary (ec, a.Type)).Store (ec);
5123                                 }
5124                         }
5125
5126                         if (dup_args) {
5127                                 if (this_arg != null)
5128                                         this_arg.Emit (ec);
5129
5130                                 for (int i = 0; i < top; i ++)
5131                                         temps [i].Emit (ec);
5132                         }
5133
5134                         if (pd != null && pd.Count > top &&
5135                             pd.ParameterModifier (top) == Parameter.Modifier.PARAMS){
5136                                 ILGenerator ig = ec.ig;
5137
5138                                 IntConstant.EmitInt (ig, 0);
5139                                 ig.Emit (OpCodes.Newarr, TypeManager.GetElementType (pd.ParameterType (top)));
5140                         }
5141                 }
5142
5143                 static Type[] GetVarargsTypes (EmitContext ec, MethodBase mb,
5144                                                ArrayList arguments)
5145                 {
5146                         ParameterData pd = GetParameterData (mb);
5147
5148                         if (arguments == null)
5149                                 return new Type [0];
5150
5151                         Argument a = (Argument) arguments [pd.Count - 1];
5152                         Arglist list = (Arglist) a.Expr;
5153
5154                         return list.ArgumentTypes;
5155                 }
5156
5157                 /// <summary>
5158                 /// This checks the ConditionalAttribute on the method
5159                 /// </summary>
5160                 static bool IsMethodExcluded (MethodBase method, EmitContext ec)
5161                 {
5162                         if (method.IsConstructor)
5163                                 return false;
5164
5165                         IMethodData md = TypeManager.GetMethod (method);
5166                         if (md != null)
5167                                 return md.IsExcluded (ec);
5168
5169                         // For some methods (generated by delegate class) GetMethod returns null
5170                         // because they are not included in builder_to_method table
5171                         if (method.DeclaringType is TypeBuilder)
5172                                 return false;
5173
5174                         return AttributeTester.IsConditionalMethodExcluded (method);
5175                 }
5176
5177                 /// <remarks>
5178                 ///   is_base tells whether we want to force the use of the `call'
5179                 ///   opcode instead of using callvirt.  Call is required to call
5180                 ///   a specific method, while callvirt will always use the most
5181                 ///   recent method in the vtable.
5182                 ///
5183                 ///   is_static tells whether this is an invocation on a static method
5184                 ///
5185                 ///   instance_expr is an expression that represents the instance
5186                 ///   it must be non-null if is_static is false.
5187                 ///
5188                 ///   method is the method to invoke.
5189                 ///
5190                 ///   Arguments is the list of arguments to pass to the method or constructor.
5191                 /// </remarks>
5192                 public static void EmitCall (EmitContext ec, bool is_base,
5193                                              bool is_static, Expression instance_expr,
5194                                              MethodBase method, ArrayList Arguments, Location loc)
5195                 {
5196                         EmitCall (ec, is_base, is_static, instance_expr, method, Arguments, loc, false, false);
5197                 }
5198
5199                 // `dup_args' leaves an extra copy of the arguments on the stack
5200                 // `omit_args' does not leave any arguments at all.
5201                 // So, basically, you could make one call with `dup_args' set to true,
5202                 // and then another with `omit_args' set to true, and the two calls
5203                 // would have the same set of arguments. However, each argument would
5204                 // only have been evaluated once.
5205                 public static void EmitCall (EmitContext ec, bool is_base,
5206                                              bool is_static, Expression instance_expr,
5207                                              MethodBase method, ArrayList Arguments, Location loc,
5208                                              bool dup_args, bool omit_args)
5209                 {
5210                         ILGenerator ig = ec.ig;
5211                         bool struct_call = false;
5212                         bool this_call = false;
5213                         LocalTemporary this_arg = null;
5214
5215                         Type decl_type = method.DeclaringType;
5216
5217                         if (!RootContext.StdLib) {
5218                                 // Replace any calls to the system's System.Array type with calls to
5219                                 // the newly created one.
5220                                 if (method == TypeManager.system_int_array_get_length)
5221                                         method = TypeManager.int_array_get_length;
5222                                 else if (method == TypeManager.system_int_array_get_rank)
5223                                         method = TypeManager.int_array_get_rank;
5224                                 else if (method == TypeManager.system_object_array_clone)
5225                                         method = TypeManager.object_array_clone;
5226                                 else if (method == TypeManager.system_int_array_get_length_int)
5227                                         method = TypeManager.int_array_get_length_int;
5228                                 else if (method == TypeManager.system_int_array_get_lower_bound_int)
5229                                         method = TypeManager.int_array_get_lower_bound_int;
5230                                 else if (method == TypeManager.system_int_array_get_upper_bound_int)
5231                                         method = TypeManager.int_array_get_upper_bound_int;
5232                                 else if (method == TypeManager.system_void_array_copyto_array_int)
5233                                         method = TypeManager.void_array_copyto_array_int;
5234                         }
5235
5236                         if (ec.TestObsoleteMethodUsage) {
5237                                 //
5238                                 // This checks ObsoleteAttribute on the method and on the declaring type
5239                                 //
5240                                 ObsoleteAttribute oa = AttributeTester.GetMethodObsoleteAttribute (method);
5241                                 if (oa != null)
5242                                         AttributeTester.Report_ObsoleteMessage (oa, TypeManager.CSharpSignature (method), loc);
5243
5244
5245                                 oa = AttributeTester.GetObsoleteAttribute (method.DeclaringType);
5246                                 if (oa != null) {
5247                                         AttributeTester.Report_ObsoleteMessage (oa, method.DeclaringType.FullName, loc);
5248                                 }
5249                         }
5250
5251                         if (IsMethodExcluded (method, ec))
5252                 return;
5253
5254                         if (!is_static){
5255                                 this_call = instance_expr == null;
5256                                 if (decl_type.IsValueType || (!this_call && instance_expr.Type.IsValueType))
5257                                         struct_call = true;
5258
5259                                 //
5260                                 // If this is ourselves, push "this"
5261                                 //
5262                                 if (!omit_args) {
5263                                 Type t = null;
5264                                 if (this_call) {
5265                                         ig.Emit (OpCodes.Ldarg_0);
5266                                         t = decl_type;
5267                                 } else {
5268                                         //
5269                                         // Push the instance expression
5270                                         //
5271                                         if (instance_expr.Type.IsValueType) {
5272                                                 //
5273                                                 // Special case: calls to a function declared in a
5274                                                 // reference-type with a value-type argument need
5275                                                 // to have their value boxed.
5276                                                 if (decl_type.IsValueType) {
5277                                                         //
5278                                                         // If the expression implements IMemoryLocation, then
5279                                                         // we can optimize and use AddressOf on the
5280                                                         // return.
5281                                                         //
5282                                                         // If not we have to use some temporary storage for
5283                                                         // it.
5284                                                         if (instance_expr is IMemoryLocation) {
5285                                                                 ((IMemoryLocation)instance_expr).
5286                                                                         AddressOf (ec, AddressOp.LoadStore);
5287                                                         } else {
5288                                                                 LocalTemporary temp = new LocalTemporary (ec, instance_expr.Type);
5289                                                                 instance_expr.Emit (ec);
5290                                                                 temp.Store (ec);
5291                                                                 temp.AddressOf (ec, AddressOp.Load);
5292                                                         }
5293
5294                                                         // avoid the overhead of doing this all the time.
5295                                                         if (dup_args)
5296                                                                 t = TypeManager.GetReferenceType (instance_expr.Type);
5297                                                 } else {
5298                                                         instance_expr.Emit (ec);
5299                                                         ig.Emit (OpCodes.Box, instance_expr.Type);
5300                                                         t = TypeManager.object_type;
5301                                                 }
5302                                         } else {
5303                                                 instance_expr.Emit (ec);
5304                                                 t = instance_expr.Type;
5305                                         }
5306                                 }
5307
5308                                 if (dup_args) {
5309                                         this_arg = new LocalTemporary (ec, t);
5310                                         ig.Emit (OpCodes.Dup);
5311                                         this_arg.Store (ec);
5312                                 }
5313                                 }
5314                         }
5315
5316                         if (!omit_args)
5317                                 EmitArguments (ec, method, Arguments, dup_args, this_arg);
5318
5319                         OpCode call_op;
5320                         if (is_static || struct_call || is_base || (this_call && !method.IsVirtual))
5321                                 call_op = OpCodes.Call;
5322                         else
5323                                 call_op = OpCodes.Callvirt;
5324
5325                         if ((method.CallingConvention & CallingConventions.VarArgs) != 0) {
5326                                 Type[] varargs_types = GetVarargsTypes (ec, method, Arguments);
5327                                 ig.EmitCall (call_op, (MethodInfo) method, varargs_types);
5328                                 return;
5329                         }
5330
5331                         //
5332                         // If you have:
5333                         // this.DoFoo ();
5334                         // and DoFoo is not virtual, you can omit the callvirt,
5335                         // because you don't need the null checking behavior.
5336                         //
5337                         if (method is MethodInfo)
5338                                 ig.Emit (call_op, (MethodInfo) method);
5339                         else
5340                                 ig.Emit (call_op, (ConstructorInfo) method);
5341                 }
5342
5343                 public override void Emit (EmitContext ec)
5344                 {
5345                         MethodGroupExpr mg = (MethodGroupExpr) this.expr;
5346
5347                         EmitCall (ec, is_base, method.IsStatic, mg.InstanceExpression, method, Arguments, loc);
5348                 }
5349
5350                 public override void EmitStatement (EmitContext ec)
5351                 {
5352                         Emit (ec);
5353
5354                         //
5355                         // Pop the return value if there is one
5356                         //
5357                         if (method is MethodInfo){
5358                                 Type ret = ((MethodInfo)method).ReturnType;
5359                                 if (TypeManager.TypeToCoreType (ret) != TypeManager.void_type)
5360                                         ec.ig.Emit (OpCodes.Pop);
5361                         }
5362                 }
5363         }
5364
5365         public class InvocationOrCast : ExpressionStatement
5366         {
5367                 Expression expr;
5368                 Expression argument;
5369
5370                 public InvocationOrCast (Expression expr, Expression argument, Location loc)
5371                 {
5372                         this.expr = expr;
5373                         this.argument = argument;
5374                         this.loc = loc;
5375                 }
5376
5377                 public override Expression DoResolve (EmitContext ec)
5378                 {
5379                         //
5380                         // First try to resolve it as a cast.
5381                         //
5382                         type = ec.DeclSpace.ResolveType (expr, true, loc);
5383                         if (type != null) {
5384                                 Cast cast = new Cast (new TypeExpression (type, loc), argument, loc);
5385                                 return cast.Resolve (ec);
5386                         }
5387
5388                         //
5389                         // This can either be a type or a delegate invocation.
5390                         // Let's just resolve it and see what we'll get.
5391                         //
5392                         expr = expr.Resolve (ec, ResolveFlags.Type | ResolveFlags.VariableOrValue);
5393                         if (expr == null)
5394                                 return null;
5395
5396                         //
5397                         // Ok, so it's a Cast.
5398                         //
5399                         if (expr.eclass == ExprClass.Type) {
5400                                 Cast cast = new Cast (new TypeExpression (expr.Type, loc), argument, loc);
5401                                 return cast.Resolve (ec);
5402                         }
5403
5404                         //
5405                         // It's a delegate invocation.
5406                         //
5407                         if (!TypeManager.IsDelegateType (expr.Type)) {
5408                                 Error (149, "Method name expected");
5409                                 return null;
5410                         }
5411
5412                         ArrayList args = new ArrayList ();
5413                         args.Add (new Argument (argument, Argument.AType.Expression));
5414                         DelegateInvocation invocation = new DelegateInvocation (expr, args, loc);
5415                         return invocation.Resolve (ec);
5416                 }
5417
5418                 void error201 ()
5419                 {
5420                         Error (201, "Only assignment, call, increment, decrement and new object " +
5421                                "expressions can be used as a statement");
5422                 }
5423
5424                 public override ExpressionStatement ResolveStatement (EmitContext ec)
5425                 {
5426                         //
5427                         // First try to resolve it as a cast.
5428                         //
5429                         type = ec.DeclSpace.ResolveType (expr, true, loc);
5430                         if (type != null) {
5431                                 error201 ();
5432                                 return null;
5433                         }
5434
5435                         //
5436                         // This can either be a type or a delegate invocation.
5437                         // Let's just resolve it and see what we'll get.
5438                         //
5439                         expr = expr.Resolve (ec, ResolveFlags.Type | ResolveFlags.VariableOrValue);
5440                         if ((expr == null) || (expr.eclass == ExprClass.Type)) {
5441                                 error201 ();
5442                                 return null;
5443                         }
5444
5445                         //
5446                         // It's a delegate invocation.
5447                         //
5448                         if (!TypeManager.IsDelegateType (expr.Type)) {
5449                                 Error (149, "Method name expected");
5450                                 return null;
5451                         }
5452
5453                         ArrayList args = new ArrayList ();
5454                         args.Add (new Argument (argument, Argument.AType.Expression));
5455                         DelegateInvocation invocation = new DelegateInvocation (expr, args, loc);
5456                         return invocation.ResolveStatement (ec);
5457                 }
5458
5459                 public override void Emit (EmitContext ec)
5460                 {
5461                         throw new Exception ("Cannot happen");
5462                 }
5463
5464                 public override void EmitStatement (EmitContext ec)
5465                 {
5466                         throw new Exception ("Cannot happen");
5467                 }
5468         }
5469
5470         //
5471         // This class is used to "disable" the code generation for the
5472         // temporary variable when initializing value types.
5473         //
5474         class EmptyAddressOf : EmptyExpression, IMemoryLocation {
5475                 public void AddressOf (EmitContext ec, AddressOp Mode)
5476                 {
5477                         // nothing
5478                 }
5479         }
5480
5481         /// <summary>
5482         ///    Implements the new expression
5483         /// </summary>
5484         public class New : ExpressionStatement, IMemoryLocation {
5485                 public readonly ArrayList Arguments;
5486
5487                 //
5488                 // During bootstrap, it contains the RequestedType,
5489                 // but if `type' is not null, it *might* contain a NewDelegate
5490                 // (because of field multi-initialization)
5491                 //
5492                 public Expression RequestedType;
5493
5494                 MethodBase method = null;
5495
5496                 //
5497                 // If set, the new expression is for a value_target, and
5498                 // we will not leave anything on the stack.
5499                 //
5500                 Expression value_target;
5501                 bool value_target_set = false;
5502
5503                 public New (Expression requested_type, ArrayList arguments, Location l)
5504                 {
5505                         RequestedType = requested_type;
5506                         Arguments = arguments;
5507                         loc = l;
5508                 }
5509
5510                 public bool SetValueTypeVariable (Expression value)
5511                 {
5512                         value_target = value;
5513                         value_target_set = true;
5514                         if (!(value_target is IMemoryLocation)){
5515                                 Error_UnexpectedKind ("variable");
5516                                 return false;
5517                         }
5518                         return true;
5519                 }
5520
5521                 //
5522                 // This function is used to disable the following code sequence for
5523                 // value type initialization:
5524                 //
5525                 // AddressOf (temporary)
5526                 // Construct/Init
5527                 // LoadTemporary
5528                 //
5529                 // Instead the provide will have provided us with the address on the
5530                 // stack to store the results.
5531                 //
5532                 static Expression MyEmptyExpression;
5533
5534                 public void DisableTemporaryValueType ()
5535                 {
5536                         if (MyEmptyExpression == null)
5537                                 MyEmptyExpression = new EmptyAddressOf ();
5538
5539                         //
5540                         // To enable this, look into:
5541                         // test-34 and test-89 and self bootstrapping.
5542                         //
5543                         // For instance, we can avoid a copy by using `newobj'
5544                         // instead of Call + Push-temp on value types.
5545 //                      value_target = MyEmptyExpression;
5546                 }
5547
5548                 public override Expression DoResolve (EmitContext ec)
5549                 {
5550                         //
5551                         // The New DoResolve might be called twice when initializing field
5552                         // expressions (see EmitFieldInitializers, the call to
5553                         // GetInitializerExpression will perform a resolve on the expression,
5554                         // and later the assign will trigger another resolution
5555                         //
5556                         // This leads to bugs (#37014)
5557                         //
5558                         if (type != null){
5559                                 if (RequestedType is NewDelegate)
5560                                         return RequestedType;
5561                                 return this;
5562                         }
5563
5564                         type = ec.DeclSpace.ResolveType (RequestedType, false, loc);
5565
5566                         if (type == null)
5567                                 return null;
5568
5569                         CheckObsoleteAttribute (type);
5570
5571                         bool IsDelegate = TypeManager.IsDelegateType (type);
5572
5573                         if (IsDelegate){
5574                                 RequestedType = (new NewDelegate (type, Arguments, loc)).Resolve (ec);
5575                                 if (RequestedType != null)
5576                                         if (!(RequestedType is NewDelegate))
5577                                                 throw new Exception ("NewDelegate.Resolve returned a non NewDelegate: " + RequestedType.GetType ());
5578                                 return RequestedType;
5579                         }
5580
5581                         if (type.IsAbstract && type.IsSealed) {
5582                                 Report.Error (712, loc, "Cannot create an instance of the static class '{0}'", TypeManager.CSharpName (type));
5583                                 return null;
5584                         }
5585
5586                         if (type.IsInterface || type.IsAbstract){
5587                                 Error (144, "It is not possible to create instances of interfaces or abstract classes");
5588                                 return null;
5589                         }
5590
5591                         bool is_struct = type.IsValueType;
5592                         eclass = ExprClass.Value;
5593
5594                         //
5595                         // SRE returns a match for .ctor () on structs (the object constructor),
5596                         // so we have to manually ignore it.
5597                         //
5598                         if (is_struct && Arguments == null)
5599                                 return this;
5600
5601                         Expression ml;
5602                         // For member-lookup, treat 'new Foo (bar)' as call to 'foo.ctor (bar)', where 'foo' is of type 'Foo'.
5603                         ml = MemberLookupFinal (ec, type, type, ".ctor",
5604                                                 MemberTypes.Constructor,
5605                                                 AllBindingFlags | BindingFlags.DeclaredOnly, loc);
5606
5607                         if (ml == null)
5608                                 return null;
5609
5610                         if (! (ml is MethodGroupExpr)){
5611                                 if (!is_struct){
5612                                         ml.Error_UnexpectedKind ("method group");
5613                                         return null;
5614                                 }
5615                         }
5616
5617                         if (ml != null) {
5618                                 if (Arguments != null){
5619                                         foreach (Argument a in Arguments){
5620                                                 if (!a.Resolve (ec, loc))
5621                                                         return null;
5622                                         }
5623                                 }
5624
5625                                 method = Invocation.OverloadResolve (
5626                                         ec, (MethodGroupExpr) ml, Arguments, false, loc);
5627
5628                         }
5629
5630                         if (method == null) {
5631                                 if (!is_struct || Arguments.Count > 0) {
5632                                         Error (1501, String.Format (
5633                                             "New invocation: Can not find a constructor in `{0}' for this argument list",
5634                                             TypeManager.CSharpName (type)));
5635                                         return null;
5636                                 }
5637                         }
5638
5639                         return this;
5640                 }
5641
5642                 //
5643                 // This DoEmit can be invoked in two contexts:
5644                 //    * As a mechanism that will leave a value on the stack (new object)
5645                 //    * As one that wont (init struct)
5646                 //
5647                 // You can control whether a value is required on the stack by passing
5648                 // need_value_on_stack.  The code *might* leave a value on the stack
5649                 // so it must be popped manually
5650                 //
5651                 // If we are dealing with a ValueType, we have a few
5652                 // situations to deal with:
5653                 //
5654                 //    * The target is a ValueType, and we have been provided
5655                 //      the instance (this is easy, we are being assigned).
5656                 //
5657                 //    * The target of New is being passed as an argument,
5658                 //      to a boxing operation or a function that takes a
5659                 //      ValueType.
5660                 //
5661                 //      In this case, we need to create a temporary variable
5662                 //      that is the argument of New.
5663                 //
5664                 // Returns whether a value is left on the stack
5665                 //
5666                 bool DoEmit (EmitContext ec, bool need_value_on_stack)
5667                 {
5668                         bool is_value_type = type.IsValueType;
5669                         ILGenerator ig = ec.ig;
5670
5671                         if (is_value_type){
5672                                 IMemoryLocation ml;
5673
5674                                 // Allow DoEmit() to be called multiple times.
5675                                 // We need to create a new LocalTemporary each time since
5676                                 // you can't share LocalBuilders among ILGeneators.
5677                                 if (!value_target_set)
5678                                         value_target = new LocalTemporary (ec, type);
5679
5680                                 ml = (IMemoryLocation) value_target;
5681                                 ml.AddressOf (ec, AddressOp.Store);
5682                         }
5683
5684                         if (method != null)
5685                                 Invocation.EmitArguments (ec, method, Arguments, false, null);
5686
5687                         if (is_value_type){
5688                                 if (method == null)
5689                                         ig.Emit (OpCodes.Initobj, type);
5690                                 else
5691                                         ig.Emit (OpCodes.Call, (ConstructorInfo) method);
5692                                 if (need_value_on_stack){
5693                                         value_target.Emit (ec);
5694                                         return true;
5695                                 }
5696                                 return false;
5697                         } else {
5698                                 ig.Emit (OpCodes.Newobj, (ConstructorInfo) method);
5699                                 return true;
5700                         }
5701                 }
5702
5703                 public override void Emit (EmitContext ec)
5704                 {
5705                         DoEmit (ec, true);
5706                 }
5707
5708                 public override void EmitStatement (EmitContext ec)
5709                 {
5710                         if (DoEmit (ec, false))
5711                                 ec.ig.Emit (OpCodes.Pop);
5712                 }
5713
5714                 public void AddressOf (EmitContext ec, AddressOp Mode)
5715                 {
5716                         if (!type.IsValueType){
5717                                 //
5718                                 // We throw an exception.  So far, I believe we only need to support
5719                                 // value types:
5720                                 // foreach (int j in new StructType ())
5721                                 // see bug 42390
5722                                 //
5723                                 throw new Exception ("AddressOf should not be used for classes");
5724                         }
5725
5726                         if (!value_target_set)
5727                                 value_target = new LocalTemporary (ec, type);
5728
5729                         IMemoryLocation ml = (IMemoryLocation) value_target;
5730                         ml.AddressOf (ec, AddressOp.Store);
5731                         if (method != null)
5732                                 Invocation.EmitArguments (ec, method, Arguments, false, null);
5733
5734                         if (method == null)
5735                                 ec.ig.Emit (OpCodes.Initobj, type);
5736                         else
5737                                 ec.ig.Emit (OpCodes.Call, (ConstructorInfo) method);
5738
5739                         ((IMemoryLocation) value_target).AddressOf (ec, Mode);
5740                 }
5741         }
5742
5743         /// <summary>
5744         ///   14.5.10.2: Represents an array creation expression.
5745         /// </summary>
5746         ///
5747         /// <remarks>
5748         ///   There are two possible scenarios here: one is an array creation
5749         ///   expression that specifies the dimensions and optionally the
5750         ///   initialization data and the other which does not need dimensions
5751         ///   specified but where initialization data is mandatory.
5752         /// </remarks>
5753         public class ArrayCreation : Expression {
5754                 Expression requested_base_type;
5755                 ArrayList initializers;
5756
5757                 //
5758                 // The list of Argument types.
5759                 // This is used to construct the `newarray' or constructor signature
5760                 //
5761                 ArrayList arguments;
5762
5763                 //
5764                 // Method used to create the array object.
5765                 //
5766                 MethodBase new_method = null;
5767
5768                 Type array_element_type;
5769                 Type underlying_type;
5770                 bool is_one_dimensional = false;
5771                 bool is_builtin_type = false;
5772                 bool expect_initializers = false;
5773                 int num_arguments = 0;
5774                 int dimensions = 0;
5775                 string rank;
5776
5777                 ArrayList array_data;
5778
5779                 Hashtable bounds;
5780
5781                 //
5782                 // The number of array initializers that we can handle
5783                 // via the InitializeArray method - through EmitStaticInitializers
5784                 //
5785                 int num_automatic_initializers;
5786
5787                 const int max_automatic_initializers = 6;
5788
5789                 public ArrayCreation (Expression requested_base_type, ArrayList exprs, string rank, ArrayList initializers, Location l)
5790                 {
5791                         this.requested_base_type = requested_base_type;
5792                         this.initializers = initializers;
5793                         this.rank = rank;
5794                         loc = l;
5795
5796                         arguments = new ArrayList ();
5797
5798                         foreach (Expression e in exprs) {
5799                                 arguments.Add (new Argument (e, Argument.AType.Expression));
5800                                 num_arguments++;
5801                         }
5802                 }
5803
5804                 public ArrayCreation (Expression requested_base_type, string rank, ArrayList initializers, Location l)
5805                 {
5806                         this.requested_base_type = requested_base_type;
5807                         this.initializers = initializers;
5808                         this.rank = rank;
5809                         loc = l;
5810
5811                         //this.rank = rank.Substring (0, rank.LastIndexOf ('['));
5812                         //
5813                         //string tmp = rank.Substring (rank.LastIndexOf ('['));
5814                         //
5815                         //dimensions = tmp.Length - 1;
5816                         expect_initializers = true;
5817                 }
5818
5819                 public Expression FormArrayType (Expression base_type, int idx_count, string rank)
5820                 {
5821                         StringBuilder sb = new StringBuilder (rank);
5822
5823                         sb.Append ("[");
5824                         for (int i = 1; i < idx_count; i++)
5825                                 sb.Append (",");
5826
5827                         sb.Append ("]");
5828
5829                         return new ComposedCast (base_type, sb.ToString (), loc);
5830                 }
5831
5832                 void Error_IncorrectArrayInitializer ()
5833                 {
5834                         Error (178, "Incorrectly structured array initializer");
5835                 }
5836
5837                 public bool CheckIndices (EmitContext ec, ArrayList probe, int idx, bool specified_dims)
5838                 {
5839                         if (specified_dims) {
5840                                 Argument a = (Argument) arguments [idx];
5841
5842                                 if (!a.Resolve (ec, loc))
5843                                         return false;
5844
5845                                 if (!(a.Expr is Constant)) {
5846                                         Error (150, "A constant value is expected");
5847                                         return false;
5848                                 }
5849
5850                                 int value = (int) ((Constant) a.Expr).GetValue ();
5851
5852                                 if (value != probe.Count) {
5853                                         Error_IncorrectArrayInitializer ();
5854                                         return false;
5855                                 }
5856
5857                                 bounds [idx] = value;
5858                         }
5859
5860                         int child_bounds = -1;
5861                         foreach (object o in probe) {
5862                                 if (o is ArrayList) {
5863                                         int current_bounds = ((ArrayList) o).Count;
5864
5865                                         if (child_bounds == -1)
5866                                                 child_bounds = current_bounds;
5867
5868                                         else if (child_bounds != current_bounds){
5869                                                 Error_IncorrectArrayInitializer ();
5870                                                 return false;
5871                                         }
5872                                         if (specified_dims && (idx + 1 >= arguments.Count)){
5873                                                 Error (623, "Array initializers can only be used in a variable or field initializer, try using the new expression");
5874                                                 return false;
5875                                         }
5876
5877                                         bool ret = CheckIndices (ec, (ArrayList) o, idx + 1, specified_dims);
5878                                         if (!ret)
5879                                                 return false;
5880                                 } else {
5881                                         if (child_bounds != -1){
5882                                                 Error_IncorrectArrayInitializer ();
5883                                                 return false;
5884                                         }
5885
5886                                         Expression tmp = (Expression) o;
5887                                         tmp = tmp.Resolve (ec);
5888                                         if (tmp == null)
5889                                                 return false;
5890
5891                                         // Console.WriteLine ("I got: " + tmp);
5892                                         // Handle initialization from vars, fields etc.
5893
5894                                         Expression conv = Convert.ImplicitConversionRequired (
5895                                                 ec, tmp, underlying_type, loc);
5896
5897                                         if (conv == null)
5898                                                 return false;
5899
5900                                         if (conv is StringConstant || conv is DecimalConstant || conv is NullCast) {
5901                                                 // These are subclasses of Constant that can appear as elements of an
5902                                                 // array that cannot be statically initialized (with num_automatic_initializers
5903                                                 // > max_automatic_initializers), so num_automatic_initializers should be left as zero.
5904                                                 array_data.Add (conv);
5905                                         } else if (conv is Constant) {
5906                                                 // These are the types of Constant that can appear in arrays that can be
5907                                                 // statically allocated.
5908                                                 array_data.Add (conv);
5909                                                 num_automatic_initializers++;
5910                                         } else
5911                                                 array_data.Add (conv);
5912                                 }
5913                         }
5914
5915                         return true;
5916                 }
5917
5918                 public void UpdateIndices (EmitContext ec)
5919                 {
5920                         int i = 0;
5921                         for (ArrayList probe = initializers; probe != null;) {
5922                                 if (probe.Count > 0 && probe [0] is ArrayList) {
5923                                         Expression e = new IntConstant (probe.Count);
5924                                         arguments.Add (new Argument (e, Argument.AType.Expression));
5925
5926                                         bounds [i++] =  probe.Count;
5927
5928                                         probe = (ArrayList) probe [0];
5929
5930                                 } else {
5931                                         Expression e = new IntConstant (probe.Count);
5932                                         arguments.Add (new Argument (e, Argument.AType.Expression));
5933
5934                                         bounds [i++] = probe.Count;
5935                                         probe = null;
5936                                 }
5937                         }
5938
5939                 }
5940
5941                 public bool ValidateInitializers (EmitContext ec, Type array_type)
5942                 {
5943                         if (initializers == null) {
5944                                 if (expect_initializers)
5945                                         return false;
5946                                 else
5947                                         return true;
5948                         }
5949
5950                         if (underlying_type == null)
5951                                 return false;
5952
5953                         //
5954                         // We use this to store all the date values in the order in which we
5955                         // will need to store them in the byte blob later
5956                         //
5957                         array_data = new ArrayList ();
5958                         bounds = new Hashtable ();
5959
5960                         bool ret;
5961
5962                         if (arguments != null) {
5963                                 ret = CheckIndices (ec, initializers, 0, true);
5964                                 return ret;
5965                         } else {
5966                                 arguments = new ArrayList ();
5967
5968                                 ret = CheckIndices (ec, initializers, 0, false);
5969
5970                                 if (!ret)
5971                                         return false;
5972
5973                                 UpdateIndices (ec);
5974
5975                                 if (arguments.Count != dimensions) {
5976                                         Error_IncorrectArrayInitializer ();
5977                                         return false;
5978                                 }
5979
5980                                 return ret;
5981                         }
5982                 }
5983
5984                 //
5985                 // Converts `source' to an int, uint, long or ulong.
5986                 //
5987                 Expression ExpressionToArrayArgument (EmitContext ec, Expression source)
5988                 {
5989                         Expression target;
5990
5991                         bool old_checked = ec.CheckState;
5992                         ec.CheckState = true;
5993
5994                         target = Convert.ImplicitConversion (ec, source, TypeManager.int32_type, loc);
5995                         if (target == null){
5996                                 target = Convert.ImplicitConversion (ec, source, TypeManager.uint32_type, loc);
5997                                 if (target == null){
5998                                         target = Convert.ImplicitConversion (ec, source, TypeManager.int64_type, loc);
5999                                         if (target == null){
6000                                                 target = Convert.ImplicitConversion (ec, source, TypeManager.uint64_type, loc);
6001                                                 if (target == null)
6002                                                         Convert.Error_CannotImplicitConversion (loc, source.Type, TypeManager.int32_type);
6003                                         }
6004                                 }
6005                         }
6006                         ec.CheckState = old_checked;
6007
6008                         //
6009                         // Only positive constants are allowed at compile time
6010                         //
6011                         if (target is Constant){
6012                                 if (target is IntConstant){
6013                                         if (((IntConstant) target).Value < 0){
6014                                                 Expression.Error_NegativeArrayIndex (loc);
6015                                                 return null;
6016                                         }
6017                                 }
6018
6019                                 if (target is LongConstant){
6020                                         if (((LongConstant) target).Value < 0){
6021                                                 Expression.Error_NegativeArrayIndex (loc);
6022                                                 return null;
6023                                         }
6024                                 }
6025
6026                         }
6027
6028                         return target;
6029                 }
6030
6031                 //
6032                 // Creates the type of the array
6033                 //
6034                 bool LookupType (EmitContext ec)
6035                 {
6036                         StringBuilder array_qualifier = new StringBuilder (rank);
6037
6038                         //
6039                         // `In the first form allocates an array instace of the type that results
6040                         // from deleting each of the individual expression from the expression list'
6041                         //
6042                         if (num_arguments > 0) {
6043                                 array_qualifier.Append ("[");
6044                                 for (int i = num_arguments-1; i > 0; i--)
6045                                         array_qualifier.Append (",");
6046                                 array_qualifier.Append ("]");
6047                         }
6048
6049                         //
6050                         // Lookup the type
6051                         //
6052                         Expression array_type_expr;
6053                         array_type_expr = new ComposedCast (requested_base_type, array_qualifier.ToString (), loc);
6054                         type = ec.DeclSpace.ResolveType (array_type_expr, false, loc);
6055
6056                         if (type == null)
6057                                 return false;
6058
6059                         if (!type.IsArray) {
6060                                 Error (622, "Can only use array initializer expressions to assign to array types. Try using a new expression instead.");
6061                                 return false;
6062                         }
6063                         underlying_type = TypeManager.GetElementType (type);
6064                         dimensions = type.GetArrayRank ();
6065
6066                         return true;
6067                 }
6068
6069                 public override Expression DoResolve (EmitContext ec)
6070                 {
6071                         int arg_count;
6072
6073                         if (!LookupType (ec))
6074                                 return null;
6075
6076                         //
6077                         // First step is to validate the initializers and fill
6078                         // in any missing bits
6079                         //
6080                         if (!ValidateInitializers (ec, type))
6081                                 return null;
6082
6083                         if (arguments == null)
6084                                 arg_count = 0;
6085                         else {
6086                                 arg_count = arguments.Count;
6087                                 foreach (Argument a in arguments){
6088                                         if (!a.Resolve (ec, loc))
6089                                                 return null;
6090
6091                                         Expression real_arg = ExpressionToArrayArgument (ec, a.Expr, loc);
6092                                         if (real_arg == null)
6093                                                 return null;
6094
6095                                         a.Expr = real_arg;
6096                                 }
6097                         }
6098
6099                         array_element_type = TypeManager.GetElementType (type);
6100
6101                         if (array_element_type.IsAbstract && array_element_type.IsSealed) {
6102                                 Report.Error (719, loc, "'{0}': array elements cannot be of static type", TypeManager.CSharpName (array_element_type));
6103                                 return null;
6104                         }
6105
6106                         if (arg_count == 1) {
6107                                 is_one_dimensional = true;
6108                                 eclass = ExprClass.Value;
6109                                 return this;
6110                         }
6111
6112                         is_builtin_type = TypeManager.IsBuiltinType (type);
6113
6114                         if (is_builtin_type) {
6115                                 Expression ml;
6116
6117                                 ml = MemberLookup (ec, type, ".ctor", MemberTypes.Constructor,
6118                                                    AllBindingFlags, loc);
6119
6120                                 if (!(ml is MethodGroupExpr)) {
6121                                         ml.Error_UnexpectedKind ("method group");
6122                                         return null;
6123                                 }
6124
6125                                 if (ml == null) {
6126                                         Error (-6, "New invocation: Can not find a constructor for " +
6127                                                       "this argument list");
6128                                         return null;
6129                                 }
6130
6131                                 new_method = Invocation.OverloadResolve (
6132                                         ec, (MethodGroupExpr) ml, arguments, false, loc);
6133
6134                                 if (new_method == null) {
6135                                         Error (-6, "New invocation: Can not find a constructor for " +
6136                                                       "this argument list");
6137                                         return null;
6138                                 }
6139
6140                                 eclass = ExprClass.Value;
6141                                 return this;
6142                         } else {
6143                                 ModuleBuilder mb = CodeGen.Module.Builder;
6144                                 ArrayList args = new ArrayList ();
6145
6146                                 if (arguments != null) {
6147                                         for (int i = 0; i < arg_count; i++)
6148                                                 args.Add (TypeManager.int32_type);
6149                                 }
6150
6151                                 Type [] arg_types = null;
6152
6153                                 if (args.Count > 0)
6154                                         arg_types = new Type [args.Count];
6155
6156                                 args.CopyTo (arg_types, 0);
6157
6158                                 new_method = mb.GetArrayMethod (type, ".ctor", CallingConventions.HasThis, null,
6159                                                             arg_types);
6160
6161                                 if (new_method == null) {
6162                                         Error (-6, "New invocation: Can not find a constructor for " +
6163                                                       "this argument list");
6164                                         return null;
6165                                 }
6166
6167                                 eclass = ExprClass.Value;
6168                                 return this;
6169                         }
6170                 }
6171
6172                 public static byte [] MakeByteBlob (ArrayList array_data, Type underlying_type, Location loc)
6173                 {
6174                         int factor;
6175                         byte [] data;
6176                         byte [] element;
6177                         int count = array_data.Count;
6178
6179                         if (underlying_type.IsEnum)
6180                                 underlying_type = TypeManager.EnumToUnderlying (underlying_type);
6181
6182                         factor = GetTypeSize (underlying_type);
6183                         if (factor == 0)
6184                                 throw new Exception ("unrecognized type in MakeByteBlob: " + underlying_type);
6185
6186                         data = new byte [(count * factor + 4) & ~3];
6187                         int idx = 0;
6188
6189                         for (int i = 0; i < count; ++i) {
6190                                 object v = array_data [i];
6191
6192                                 if (v is EnumConstant)
6193                                         v = ((EnumConstant) v).Child;
6194
6195                                 if (v is Constant && !(v is StringConstant))
6196                                         v = ((Constant) v).GetValue ();
6197                                 else {
6198                                         idx += factor;
6199                                         continue;
6200                                 }
6201
6202                                 if (underlying_type == TypeManager.int64_type){
6203                                         if (!(v is Expression)){
6204                                                 long val = (long) v;
6205
6206                                                 for (int j = 0; j < factor; ++j) {
6207                                                         data [idx + j] = (byte) (val & 0xFF);
6208                                                         val = (val >> 8);
6209                                                 }
6210                                         }
6211                                 } else if (underlying_type == TypeManager.uint64_type){
6212                                         if (!(v is Expression)){
6213                                                 ulong val = (ulong) v;
6214
6215                                                 for (int j = 0; j < factor; ++j) {
6216                                                         data [idx + j] = (byte) (val & 0xFF);
6217                                                         val = (val >> 8);
6218                                                 }
6219                                         }
6220                                 } else if (underlying_type == TypeManager.float_type) {
6221                                         if (!(v is Expression)){
6222                                                 element = BitConverter.GetBytes ((float) v);
6223
6224                                                 for (int j = 0; j < factor; ++j)
6225                                                         data [idx + j] = element [j];
6226                                         }
6227                                 } else if (underlying_type == TypeManager.double_type) {
6228                                         if (!(v is Expression)){
6229                                                 element = BitConverter.GetBytes ((double) v);
6230
6231                                                 for (int j = 0; j < factor; ++j)
6232                                                         data [idx + j] = element [j];
6233                                         }
6234                                 } else if (underlying_type == TypeManager.char_type){
6235                                         if (!(v is Expression)){
6236                                                 int val = (int) ((char) v);
6237
6238                                                 data [idx] = (byte) (val & 0xff);
6239                                                 data [idx+1] = (byte) (val >> 8);
6240                                         }
6241                                 } else if (underlying_type == TypeManager.short_type){
6242                                         if (!(v is Expression)){
6243                                                 int val = (int) ((short) v);
6244
6245                                                 data [idx] = (byte) (val & 0xff);
6246                                                 data [idx+1] = (byte) (val >> 8);
6247                                         }
6248                                 } else if (underlying_type == TypeManager.ushort_type){
6249                                         if (!(v is Expression)){
6250                                                 int val = (int) ((ushort) v);
6251
6252                                                 data [idx] = (byte) (val & 0xff);
6253                                                 data [idx+1] = (byte) (val >> 8);
6254                                         }
6255                                 } else if (underlying_type == TypeManager.int32_type) {
6256                                         if (!(v is Expression)){
6257                                                 int val = (int) v;
6258
6259                                                 data [idx]   = (byte) (val & 0xff);
6260                                                 data [idx+1] = (byte) ((val >> 8) & 0xff);
6261                                                 data [idx+2] = (byte) ((val >> 16) & 0xff);
6262                                                 data [idx+3] = (byte) (val >> 24);
6263                                         }
6264                                 } else if (underlying_type == TypeManager.uint32_type) {
6265                                         if (!(v is Expression)){
6266                                                 uint val = (uint) v;
6267
6268                                                 data [idx]   = (byte) (val & 0xff);
6269                                                 data [idx+1] = (byte) ((val >> 8) & 0xff);
6270                                                 data [idx+2] = (byte) ((val >> 16) & 0xff);
6271                                                 data [idx+3] = (byte) (val >> 24);
6272                                         }
6273                                 } else if (underlying_type == TypeManager.sbyte_type) {
6274                                         if (!(v is Expression)){
6275                                                 sbyte val = (sbyte) v;
6276                                                 data [idx] = (byte) val;
6277                                         }
6278                                 } else if (underlying_type == TypeManager.byte_type) {
6279                                         if (!(v is Expression)){
6280                                                 byte val = (byte) v;
6281                                                 data [idx] = (byte) val;
6282                                         }
6283                                 } else if (underlying_type == TypeManager.bool_type) {
6284                                         if (!(v is Expression)){
6285                                                 bool val = (bool) v;
6286                                                 data [idx] = (byte) (val ? 1 : 0);
6287                                         }
6288                                 } else if (underlying_type == TypeManager.decimal_type){
6289                                         if (!(v is Expression)){
6290                                                 int [] bits = Decimal.GetBits ((decimal) v);
6291                                                 int p = idx;
6292
6293                                                 // FIXME: For some reason, this doesn't work on the MS runtime.
6294                                                 int [] nbits = new int [4];
6295                                                 nbits [0] = bits [3];
6296                                                 nbits [1] = bits [2];
6297                                                 nbits [2] = bits [0];
6298                                                 nbits [3] = bits [1];
6299
6300                                                 for (int j = 0; j < 4; j++){
6301                                                         data [p++] = (byte) (nbits [j] & 0xff);
6302                                                         data [p++] = (byte) ((nbits [j] >> 8) & 0xff);
6303                                                         data [p++] = (byte) ((nbits [j] >> 16) & 0xff);
6304                                                         data [p++] = (byte) (nbits [j] >> 24);
6305                                                 }
6306                                         }
6307                                 } else
6308                                         throw new Exception ("Unrecognized type in MakeByteBlob: " + underlying_type);
6309
6310                                 idx += factor;
6311                         }
6312
6313                         return data;
6314                 }
6315
6316                 //
6317                 // Emits the initializers for the array
6318                 //
6319                 void EmitStaticInitializers (EmitContext ec)
6320                 {
6321                         //
6322                         // First, the static data
6323                         //
6324                         FieldBuilder fb;
6325                         ILGenerator ig = ec.ig;
6326
6327                         byte [] data = MakeByteBlob (array_data, underlying_type, loc);
6328
6329                         fb = RootContext.MakeStaticData (data);
6330
6331                         ig.Emit (OpCodes.Dup);
6332                         ig.Emit (OpCodes.Ldtoken, fb);
6333                         ig.Emit (OpCodes.Call,
6334                                  TypeManager.void_initializearray_array_fieldhandle);
6335                 }
6336
6337                 //
6338                 // Emits pieces of the array that can not be computed at compile
6339                 // time (variables and string locations).
6340                 //
6341                 // This always expect the top value on the stack to be the array
6342                 //
6343                 void EmitDynamicInitializers (EmitContext ec)
6344                 {
6345                         ILGenerator ig = ec.ig;
6346                         int dims = bounds.Count;
6347                         int [] current_pos = new int [dims];
6348                         int top = array_data.Count;
6349
6350                         MethodInfo set = null;
6351
6352                         if (dims != 1){
6353                                 Type [] args;
6354                                 ModuleBuilder mb = null;
6355                                 mb = CodeGen.Module.Builder;
6356                                 args = new Type [dims + 1];
6357
6358                                 int j;
6359                                 for (j = 0; j < dims; j++)
6360                                         args [j] = TypeManager.int32_type;
6361
6362                                 args [j] = array_element_type;
6363
6364                                 set = mb.GetArrayMethod (
6365                                         type, "Set",
6366                                         CallingConventions.HasThis | CallingConventions.Standard,
6367                                         TypeManager.void_type, args);
6368                         }
6369
6370                         for (int i = 0; i < top; i++){
6371
6372                                 Expression e = null;
6373
6374                                 if (array_data [i] is Expression)
6375                                         e = (Expression) array_data [i];
6376
6377                                 if (e != null) {
6378                                         //
6379                                         // Basically we do this for string literals and
6380                                         // other non-literal expressions
6381                                         //
6382                                         if (e is EnumConstant){
6383                                                 e = ((EnumConstant) e).Child;
6384                                         }
6385
6386                                         if (e is StringConstant || e is DecimalConstant || !(e is Constant) ||
6387                                             num_automatic_initializers <= max_automatic_initializers) {
6388                                                 Type etype = e.Type;
6389
6390                                                 ig.Emit (OpCodes.Dup);
6391
6392                                                 for (int idx = 0; idx < dims; idx++)
6393                                                         IntConstant.EmitInt (ig, current_pos [idx]);
6394
6395                                                 //
6396                                                 // If we are dealing with a struct, get the
6397                                                 // address of it, so we can store it.
6398                                                 //
6399                                                 if ((dims == 1) &&
6400                                                     etype.IsSubclassOf (TypeManager.value_type) &&
6401                                                     (!TypeManager.IsBuiltinOrEnum (etype) ||
6402                                                      etype == TypeManager.decimal_type)) {
6403                                                         if (e is New){
6404                                                                 New n = (New) e;
6405
6406                                                                 //
6407                                                                 // Let new know that we are providing
6408                                                                 // the address where to store the results
6409                                                                 //
6410                                                                 n.DisableTemporaryValueType ();
6411                                                         }
6412
6413                                                         ig.Emit (OpCodes.Ldelema, etype);
6414                                                 }
6415
6416                                                 e.Emit (ec);
6417
6418                                                 if (dims == 1) {
6419                                                         bool is_stobj;
6420                                                         OpCode op = ArrayAccess.GetStoreOpcode (etype, out is_stobj);
6421                                                         if (is_stobj)
6422                                                                 ig.Emit (OpCodes.Stobj, etype);
6423                                                         else
6424                                                                 ig.Emit (op);
6425                                                 } else
6426                                                         ig.Emit (OpCodes.Call, set);
6427
6428                                         }
6429                                 }
6430
6431                                 //
6432                                 // Advance counter
6433                                 //
6434                                 for (int j = dims - 1; j >= 0; j--){
6435                                         current_pos [j]++;
6436                                         if (current_pos [j] < (int) bounds [j])
6437                                                 break;
6438                                         current_pos [j] = 0;
6439                                 }
6440                         }
6441                 }
6442
6443                 void EmitArrayArguments (EmitContext ec)
6444                 {
6445                         ILGenerator ig = ec.ig;
6446
6447                         foreach (Argument a in arguments) {
6448                                 Type atype = a.Type;
6449                                 a.Emit (ec);
6450
6451                                 if (atype == TypeManager.uint64_type)
6452                                         ig.Emit (OpCodes.Conv_Ovf_U4);
6453                                 else if (atype == TypeManager.int64_type)
6454                                         ig.Emit (OpCodes.Conv_Ovf_I4);
6455                         }
6456                 }
6457
6458                 public override void Emit (EmitContext ec)
6459                 {
6460                         ILGenerator ig = ec.ig;
6461
6462                         EmitArrayArguments (ec);
6463                         if (is_one_dimensional)
6464                                 ig.Emit (OpCodes.Newarr, array_element_type);
6465                         else {
6466                                 if (is_builtin_type)
6467                                         ig.Emit (OpCodes.Newobj, (ConstructorInfo) new_method);
6468                                 else
6469                                         ig.Emit (OpCodes.Newobj, (MethodInfo) new_method);
6470                         }
6471
6472                         if (initializers != null){
6473                                 //
6474                                 // FIXME: Set this variable correctly.
6475                                 //
6476                                 bool dynamic_initializers = true;
6477
6478                                 // This will never be true for array types that cannot be statically
6479                                 // initialized. num_automatic_initializers will always be zero.  See
6480                                 // CheckIndices.
6481                                 if (num_automatic_initializers > max_automatic_initializers)
6482                                         EmitStaticInitializers (ec);
6483
6484                                 if (dynamic_initializers)
6485                                         EmitDynamicInitializers (ec);
6486                         }
6487                 }
6488
6489                 public object EncodeAsAttribute ()
6490                 {
6491                         if (!is_one_dimensional){
6492                                 Report.Error (-211, Location, "attribute can not encode multi-dimensional arrays");
6493                                 return null;
6494                         }
6495
6496                         if (array_data == null){
6497                                 Report.Error (-212, Location, "array should be initialized when passing it to an attribute");
6498                                 return null;
6499                         }
6500
6501                         object [] ret = new object [array_data.Count];
6502                         int i = 0;
6503                         foreach (Expression e in array_data){
6504                                 object v;
6505
6506                                 if (e is NullLiteral)
6507                                         v = null;
6508                                 else {
6509                                         if (!Attribute.GetAttributeArgumentExpression (e, Location, array_element_type, out v))
6510                                                 return null;
6511                                 }
6512                                 ret [i++] = v;
6513                         }
6514                         return ret;
6515                 }
6516         }
6517
6518         /// <summary>
6519         ///   Represents the `this' construct
6520         /// </summary>
6521         public class This : Expression, IAssignMethod, IMemoryLocation, IVariable {
6522
6523                 Block block;
6524                 VariableInfo variable_info;
6525
6526                 public This (Block block, Location loc)
6527                 {
6528                         this.loc = loc;
6529                         this.block = block;
6530                 }
6531
6532                 public This (Location loc)
6533                 {
6534                         this.loc = loc;
6535                 }
6536
6537                 public VariableInfo VariableInfo {
6538                         get { return variable_info; }
6539                 }
6540
6541                 public bool VerifyFixed (bool is_expression)
6542                 {
6543                         if ((variable_info == null) || (variable_info.LocalInfo == null))
6544                                 return false;
6545                         else
6546                                 return variable_info.LocalInfo.IsFixed;
6547                 }
6548
6549                 public bool ResolveBase (EmitContext ec)
6550                 {
6551                         eclass = ExprClass.Variable;
6552                         type = ec.ContainerType;
6553
6554                         if (ec.IsStatic) {
6555                                 Error (26, "Keyword this not valid in static code");
6556                                 return false;
6557                         }
6558
6559                         if ((block != null) && (block.ThisVariable != null))
6560                                 variable_info = block.ThisVariable.VariableInfo;
6561
6562                         return true;
6563                 }
6564
6565                 public override Expression DoResolve (EmitContext ec)
6566                 {
6567                         if (!ResolveBase (ec))
6568                                 return null;
6569
6570                         if ((variable_info != null) && !variable_info.IsAssigned (ec)) {
6571                                 Error (188, "The this object cannot be used before all " +
6572                                        "of its fields are assigned to");
6573                                 variable_info.SetAssigned (ec);
6574                                 return this;
6575                         }
6576
6577                         if (ec.IsFieldInitializer) {
6578                                 Error (27, "Keyword `this' can't be used outside a constructor, " +
6579                                        "a method or a property.");
6580                                 return null;
6581                         }
6582
6583                         return this;
6584                 }
6585
6586                 override public Expression DoResolveLValue (EmitContext ec, Expression right_side)
6587                 {
6588                         if (!ResolveBase (ec))
6589                                 return null;
6590
6591                         if (variable_info != null)
6592                                 variable_info.SetAssigned (ec);
6593
6594                         if (ec.TypeContainer is Class){
6595                                 Error (1604, "Cannot assign to `this'");
6596                                 return null;
6597                         }
6598
6599                         return this;
6600                 }
6601
6602                 public void Emit (EmitContext ec, bool leave_copy)
6603                 {
6604                         Emit (ec);
6605                         if (leave_copy)
6606                                 ec.ig.Emit (OpCodes.Dup);
6607                 }
6608
6609                 public void EmitAssign (EmitContext ec, Expression source, bool leave_copy, bool prepare_for_load)
6610                 {
6611                         ILGenerator ig = ec.ig;
6612
6613                         if (ec.TypeContainer is Struct){
6614                                 ec.EmitThis ();
6615                                 source.Emit (ec);
6616                                 if (leave_copy)
6617                                         ec.ig.Emit (OpCodes.Dup);
6618                                 ig.Emit (OpCodes.Stobj, type);
6619                         } else {
6620                                 throw new Exception ("how did you get here");
6621                         }
6622                 }
6623
6624                 public override void Emit (EmitContext ec)
6625                 {
6626                         ILGenerator ig = ec.ig;
6627
6628                         ec.EmitThis ();
6629                         if (ec.TypeContainer is Struct)
6630                                 ig.Emit (OpCodes.Ldobj, type);
6631                 }
6632
6633                 public void AddressOf (EmitContext ec, AddressOp mode)
6634                 {
6635                         ec.EmitThis ();
6636
6637                         // FIMXE
6638                         // FIGURE OUT WHY LDARG_S does not work
6639                         //
6640                         // consider: struct X { int val; int P { set { val = value; }}}
6641                         //
6642                         // Yes, this looks very bad. Look at `NOTAS' for
6643                         // an explanation.
6644                         // ec.ig.Emit (OpCodes.Ldarga_S, (byte) 0);
6645                 }
6646         }
6647
6648         /// <summary>
6649         ///   Represents the `__arglist' construct
6650         /// </summary>
6651         public class ArglistAccess : Expression
6652         {
6653                 public ArglistAccess (Location loc)
6654                 {
6655                         this.loc = loc;
6656                 }
6657
6658                 public bool ResolveBase (EmitContext ec)
6659                 {
6660                         eclass = ExprClass.Variable;
6661                         type = TypeManager.runtime_argument_handle_type;
6662                         return true;
6663                 }
6664
6665                 public override Expression DoResolve (EmitContext ec)
6666                 {
6667                         if (!ResolveBase (ec))
6668                                 return null;
6669
6670                         if (ec.IsFieldInitializer || !ec.CurrentBlock.HasVarargs) {
6671                                 Error (190, "The __arglist construct is valid only within " +
6672                                        "a variable argument method.");
6673                                 return null;
6674                         }
6675
6676                         return this;
6677                 }
6678
6679                 public override void Emit (EmitContext ec)
6680                 {
6681                         ec.ig.Emit (OpCodes.Arglist);
6682                 }
6683         }
6684
6685         /// <summary>
6686         ///   Represents the `__arglist (....)' construct
6687         /// </summary>
6688         public class Arglist : Expression
6689         {
6690                 public readonly Argument[] Arguments;
6691
6692                 public Arglist (Argument[] args, Location l)
6693                 {
6694                         Arguments = args;
6695                         loc = l;
6696                 }
6697
6698                 public Type[] ArgumentTypes {
6699                         get {
6700                                 Type[] retval = new Type [Arguments.Length];
6701                                 for (int i = 0; i < Arguments.Length; i++)
6702                                         retval [i] = Arguments [i].Type;
6703                                 return retval;
6704                         }
6705                 }
6706
6707                 public override Expression DoResolve (EmitContext ec)
6708                 {
6709                         eclass = ExprClass.Variable;
6710                         type = TypeManager.runtime_argument_handle_type;
6711
6712                         foreach (Argument arg in Arguments) {
6713                                 if (!arg.Resolve (ec, loc))
6714                                         return null;
6715                         }
6716
6717                         return this;
6718                 }
6719
6720                 public override void Emit (EmitContext ec)
6721                 {
6722                         foreach (Argument arg in Arguments)
6723                                 arg.Emit (ec);
6724                 }
6725         }
6726
6727         //
6728         // This produces the value that renders an instance, used by the iterators code
6729         //
6730         public class ProxyInstance : Expression, IMemoryLocation  {
6731                 public override Expression DoResolve (EmitContext ec)
6732                 {
6733                         eclass = ExprClass.Variable;
6734                         type = ec.ContainerType;
6735                         return this;
6736                 }
6737
6738                 public override void Emit (EmitContext ec)
6739                 {
6740                         ec.ig.Emit (OpCodes.Ldarg_0);
6741
6742                 }
6743
6744                 public void AddressOf (EmitContext ec, AddressOp mode)
6745                 {
6746                         ec.ig.Emit (OpCodes.Ldarg_0);
6747                 }
6748         }
6749
6750         /// <summary>
6751         ///   Implements the typeof operator
6752         /// </summary>
6753         public class TypeOf : Expression {
6754                 public readonly Expression QueriedType;
6755                 protected Type typearg;
6756
6757                 public TypeOf (Expression queried_type, Location l)
6758                 {
6759                         QueriedType = queried_type;
6760                         loc = l;
6761                 }
6762
6763                 public override Expression DoResolve (EmitContext ec)
6764                 {
6765                         typearg = ec.DeclSpace.ResolveType (QueriedType, false, loc);
6766
6767                         if (typearg == null)
6768                                 return null;
6769
6770                         if (typearg == TypeManager.void_type) {
6771                                 Error (673, "System.Void cannot be used from C# - " +
6772                                        "use typeof (void) to get the void type object");
6773                                 return null;
6774                         }
6775
6776                         if (typearg.IsPointer && !ec.InUnsafe){
6777                                 UnsafeError (loc);
6778                                 return null;
6779                         }
6780                         CheckObsoleteAttribute (typearg);
6781
6782                         type = TypeManager.type_type;
6783                         eclass = ExprClass.Type;
6784                         return this;
6785                 }
6786
6787                 public override void Emit (EmitContext ec)
6788                 {
6789                         ec.ig.Emit (OpCodes.Ldtoken, typearg);
6790                         ec.ig.Emit (OpCodes.Call, TypeManager.system_type_get_type_from_handle);
6791                 }
6792
6793                 public Type TypeArg {
6794                         get { return typearg; }
6795                 }
6796         }
6797
6798         /// <summary>
6799         ///   Implements the `typeof (void)' operator
6800         /// </summary>
6801         public class TypeOfVoid : TypeOf {
6802                 public TypeOfVoid (Location l) : base (null, l)
6803                 {
6804                         loc = l;
6805                 }
6806
6807                 public override Expression DoResolve (EmitContext ec)
6808                 {
6809                         type = TypeManager.type_type;
6810                         typearg = TypeManager.void_type;
6811                         eclass = ExprClass.Type;
6812                         return this;
6813                 }
6814         }
6815
6816         /// <summary>
6817         ///   Implements the sizeof expression
6818         /// </summary>
6819         public class SizeOf : Expression {
6820                 public readonly Expression QueriedType;
6821                 Type type_queried;
6822
6823                 public SizeOf (Expression queried_type, Location l)
6824                 {
6825                         this.QueriedType = queried_type;
6826                         loc = l;
6827                 }
6828
6829                 public override Expression DoResolve (EmitContext ec)
6830                 {
6831                         if (!ec.InUnsafe) {
6832                                 Report.Error (
6833                                         233, loc, "Sizeof may only be used in an unsafe context " +
6834                                         "(consider using System.Runtime.InteropServices.Marshal.Sizeof");
6835                                 return null;
6836                         }
6837
6838                         type_queried = ec.DeclSpace.ResolveType (QueriedType, false, loc);
6839                         if (type_queried == null)
6840                                 return null;
6841
6842                         CheckObsoleteAttribute (type_queried);
6843
6844                         if (!TypeManager.IsUnmanagedType (type_queried)){
6845                                 Report.Error (208, loc, "Cannot take the size of an unmanaged type (" + TypeManager.CSharpName (type_queried) + ")");
6846                                 return null;
6847                         }
6848
6849                         type = TypeManager.int32_type;
6850                         eclass = ExprClass.Value;
6851                         return this;
6852                 }
6853
6854                 public override void Emit (EmitContext ec)
6855                 {
6856                         int size = GetTypeSize (type_queried);
6857
6858                         if (size == 0)
6859                                 ec.ig.Emit (OpCodes.Sizeof, type_queried);
6860                         else
6861                                 IntConstant.EmitInt (ec.ig, size);
6862                 }
6863         }
6864
6865         /// <summary>
6866         ///   Implements the member access expression
6867         /// </summary>
6868         public class MemberAccess : Expression {
6869                 public readonly string Identifier;
6870                 Expression expr;
6871
6872                 public MemberAccess (Expression expr, string id, Location l)
6873                 {
6874                         this.expr = expr;
6875                         Identifier = id;
6876                         loc = l;
6877                 }
6878
6879                 public Expression Expr {
6880                         get {
6881                                 return expr;
6882                         }
6883                 }
6884
6885                 public static void error176 (Location loc, string name)
6886                 {
6887                         Report.Error (176, loc, "Static member `" +
6888                                       name + "' cannot be accessed " +
6889                                       "with an instance reference, qualify with a " +
6890                                       "type name instead");
6891                 }
6892
6893                 public static bool IdenticalNameAndTypeName (EmitContext ec, Expression left_original, Expression left, Location loc)
6894                 {
6895                         SimpleName sn = left_original as SimpleName;
6896                         if (sn == null || left == null || left.Type.Name != sn.Name)
6897                                 return false;
6898
6899                         return RootContext.LookupType (ec.DeclSpace, sn.Name, true, loc) != null;
6900                 }
6901
6902                 public static Expression ResolveMemberAccess (EmitContext ec, Expression member_lookup,
6903                                                               Expression left, Location loc,
6904                                                               Expression left_original)
6905                 {
6906                         bool left_is_type, left_is_explicit;
6907
6908                         // If `left' is null, then we're called from SimpleNameResolve and this is
6909                         // a member in the currently defining class.
6910                         if (left == null) {
6911                                 left_is_type = ec.IsStatic || ec.IsFieldInitializer;
6912                                 left_is_explicit = false;
6913
6914                                 // Implicitly default to `this' unless we're static.
6915                                 if (!ec.IsStatic && !ec.IsFieldInitializer && !ec.InEnumContext)
6916                                         left = ec.GetThis (loc);
6917                         } else {
6918                                 left_is_type = left is TypeExpr;
6919                                 left_is_explicit = true;
6920                         }
6921
6922                         if (member_lookup is FieldExpr){
6923                                 FieldExpr fe = (FieldExpr) member_lookup;
6924                                 FieldInfo fi = fe.FieldInfo;
6925                                 Type decl_type = fi.DeclaringType;
6926
6927                                 if (fi is FieldBuilder) {
6928                                         Const c = TypeManager.LookupConstant ((FieldBuilder) fi);
6929
6930                                         if (c != null) {
6931                                                 object o;
6932                                                 if (!c.LookupConstantValue (out o))
6933                                                         return null;
6934
6935                                                 object real_value = ((Constant) c.Expr).GetValue ();
6936
6937                                                 return Constantify (real_value, fi.FieldType);
6938                                         }
6939                                 }
6940
6941                                 if (fi.IsLiteral) {
6942                                         Type t = fi.FieldType;
6943
6944                                         object o;
6945
6946                                         if (fi is FieldBuilder)
6947                                                 o = TypeManager.GetValue ((FieldBuilder) fi);
6948                                         else
6949                                                 o = fi.GetValue (fi);
6950
6951                                         if (decl_type.IsSubclassOf (TypeManager.enum_type)) {
6952                                                 if (left_is_explicit && !left_is_type &&
6953                                                     !IdenticalNameAndTypeName (ec, left_original, member_lookup, loc)) {
6954                                                         error176 (loc, fe.FieldInfo.Name);
6955                                                         return null;
6956                                                 }
6957
6958                                                 Expression enum_member = MemberLookup (
6959                                                         ec, decl_type, "value__", MemberTypes.Field,
6960                                                         AllBindingFlags, loc);
6961
6962                                                 Enum en = TypeManager.LookupEnum (decl_type);
6963
6964                                                 Constant c;
6965                                                 if (en != null)
6966                                                         c = Constantify (o, en.UnderlyingType);
6967                                                 else
6968                                                         c = Constantify (o, enum_member.Type);
6969
6970                                                 return new EnumConstant (c, decl_type);
6971                                         }
6972
6973                                         Expression exp = Constantify (o, t);
6974
6975                                         if (left_is_explicit && !left_is_type) {
6976                                                 error176 (loc, fe.FieldInfo.Name);
6977                                                 return null;
6978                                         }
6979
6980                                         return exp;
6981                                 }
6982
6983                                 if (fi.FieldType.IsPointer && !ec.InUnsafe){
6984                                         UnsafeError (loc);
6985                                         return null;
6986                                 }
6987                         }
6988
6989                         if (member_lookup is EventExpr) {
6990                                 EventExpr ee = (EventExpr) member_lookup;
6991
6992                                 //
6993                                 // If the event is local to this class, we transform ourselves into
6994                                 // a FieldExpr
6995                                 //
6996
6997                                 if (ee.EventInfo.DeclaringType == ec.ContainerType ||
6998                                     TypeManager.IsNestedChildOf(ec.ContainerType, ee.EventInfo.DeclaringType)) {
6999                                         MemberInfo mi = GetFieldFromEvent (ee);
7000
7001                                         if (mi == null) {
7002                                                 //
7003                                                 // If this happens, then we have an event with its own
7004                                                 // accessors and private field etc so there's no need
7005                                                 // to transform ourselves.
7006                                                 //
7007                                                 ee.InstanceExpression = left;
7008                                                 return ee;
7009                                         }
7010
7011                                         Expression ml = ExprClassFromMemberInfo (ec, mi, loc);
7012
7013                                         if (ml == null) {
7014                                                 Report.Error (-200, loc, "Internal error!!");
7015                                                 return null;
7016                                         }
7017
7018                                         if (!left_is_explicit)
7019                                                 left = null;
7020
7021                                         ee.InstanceExpression = left;
7022
7023                                         return ResolveMemberAccess (ec, ml, left, loc, left_original);
7024                                 }
7025                         }
7026
7027                         if (member_lookup is IMemberExpr) {
7028                                 IMemberExpr me = (IMemberExpr) member_lookup;
7029                                 MethodGroupExpr mg = me as MethodGroupExpr;
7030
7031                                 if (left_is_type){
7032                                         if ((mg != null) && left_is_explicit && left.Type.IsInterface)
7033                                                 mg.IsExplicitImpl = left_is_explicit;
7034
7035                                         if (!me.IsStatic){
7036                                                 if ((ec.IsFieldInitializer || ec.IsStatic) &&
7037                                                     IdenticalNameAndTypeName (ec, left_original, member_lookup, loc))
7038                                                         return member_lookup;
7039
7040                                                 SimpleName.Error_ObjectRefRequired (ec, loc, me.Name);
7041                                                 return null;
7042                                         }
7043
7044                                 } else {
7045                                         if (!me.IsInstance) {
7046                                                 if (IdenticalNameAndTypeName (ec, left_original, left, loc))
7047                                                         return member_lookup;
7048
7049                                                 if (left_is_explicit) {
7050                                                         error176 (loc, me.Name);
7051                                                         return null;
7052                                                 }
7053                                         }
7054
7055                                         //
7056                                         // Since we can not check for instance objects in SimpleName,
7057                                         // becaue of the rule that allows types and variables to share
7058                                         // the name (as long as they can be de-ambiguated later, see
7059                                         // IdenticalNameAndTypeName), we have to check whether left
7060                                         // is an instance variable in a static context
7061                                         //
7062                                         // However, if the left-hand value is explicitly given, then
7063                                         // it is already our instance expression, so we aren't in
7064                                         // static context.
7065                                         //
7066
7067                                         if (ec.IsStatic && !left_is_explicit && left is IMemberExpr){
7068                                                 IMemberExpr mexp = (IMemberExpr) left;
7069
7070                                                 if (!mexp.IsStatic){
7071                                                         SimpleName.Error_ObjectRefRequired (ec, loc, mexp.Name);
7072                                                         return null;
7073                                                 }
7074                                         }
7075
7076                                         if ((mg != null) && IdenticalNameAndTypeName (ec, left_original, left, loc))
7077                                                 mg.IdenticalTypeName = true;
7078
7079                                         me.InstanceExpression = left;
7080                                 }
7081
7082                                 return member_lookup;
7083                         }
7084
7085                         Console.WriteLine ("Left is: " + left);
7086                         Report.Error (-100, loc, "Support for [" + member_lookup + "] is not present yet");
7087                         Environment.Exit (1);
7088                         return null;
7089                 }
7090
7091                 public Expression DoResolve (EmitContext ec, Expression right_side, ResolveFlags flags)
7092                 {
7093                         if (type != null)
7094                                 throw new Exception ();
7095
7096                         //
7097                         // Resolve the expression with flow analysis turned off, we'll do the definite
7098                         // assignment checks later.  This is because we don't know yet what the expression
7099                         // will resolve to - it may resolve to a FieldExpr and in this case we must do the
7100                         // definite assignment check on the actual field and not on the whole struct.
7101                         //
7102
7103                         Expression original = expr;
7104                         expr = expr.Resolve (ec, flags | ResolveFlags.Intermediate | ResolveFlags.DisableFlowAnalysis);
7105                         if (expr == null)
7106                                 return null;
7107
7108                         if (expr is SimpleName){
7109                                 SimpleName child_expr = (SimpleName) expr;
7110
7111                                 Expression new_expr = new SimpleName (child_expr.Name, Identifier, loc);
7112
7113                                 return new_expr.Resolve (ec, flags);
7114                         }
7115
7116                         //
7117                         // TODO: I mailed Ravi about this, and apparently we can get rid
7118                         // of this and put it in the right place.
7119                         //
7120                         // Handle enums here when they are in transit.
7121                         // Note that we cannot afford to hit MemberLookup in this case because
7122                         // it will fail to find any members at all
7123                         //
7124
7125                         Type expr_type = expr.Type;
7126                         if (expr is TypeExpr){
7127                                 if (!ec.DeclSpace.CheckAccessLevel (expr_type)){
7128                                         Report.Error (122, loc, "'{0}' is inaccessible due to its protection level", expr_type);
7129                                         return null;
7130                                 }
7131
7132                                 if (expr_type == TypeManager.enum_type || expr_type.IsSubclassOf (TypeManager.enum_type)){
7133                                         Enum en = TypeManager.LookupEnum (expr_type);
7134
7135                                         if (en != null) {
7136                                                 object value = en.LookupEnumValue (ec, Identifier, loc);
7137
7138                                                 if (value != null){
7139                                                         MemberCore mc = en.GetDefinition (Identifier);
7140                                                         ObsoleteAttribute oa = mc.GetObsoleteAttribute (en);
7141                                                         if (oa != null) {
7142                                                                 AttributeTester.Report_ObsoleteMessage (oa, mc.GetSignatureForError (), Location);
7143                                                         }
7144                                                         oa = en.GetObsoleteAttribute (en);
7145                                                         if (oa != null) {
7146                                                                 AttributeTester.Report_ObsoleteMessage (oa, en.GetSignatureForError (), Location);
7147                                                         }
7148
7149                                                         Constant c = Constantify (value, en.UnderlyingType);
7150                                                         return new EnumConstant (c, expr_type);
7151                                                 }
7152                                         } else {
7153                                                 CheckObsoleteAttribute (expr_type);
7154
7155                                                 FieldInfo fi = expr_type.GetField (Identifier);
7156                                                 if (fi != null) {
7157                                                         ObsoleteAttribute oa = AttributeTester.GetMemberObsoleteAttribute (fi);
7158                                                         if (oa != null)
7159                                                                 AttributeTester.Report_ObsoleteMessage (oa, TypeManager.GetFullNameSignature (fi), Location);
7160                                                 }
7161                                         }
7162                                 }
7163                         }
7164
7165                         if (expr_type.IsPointer){
7166                                 Error (23, "The `.' operator can not be applied to pointer operands (" +
7167                                        TypeManager.CSharpName (expr_type) + ")");
7168                                 return null;
7169                         }
7170
7171                         Expression member_lookup;
7172                         member_lookup = MemberLookupFinal (ec, expr_type, expr_type, Identifier, loc);
7173                         if (member_lookup == null)
7174                                 return null;
7175
7176                         if (member_lookup is TypeExpr) {
7177                                 if (!(expr is TypeExpr) && !(expr is SimpleName)) {
7178                                         Error (572, "Can't reference type `" + Identifier + "' through an expression; try `" +
7179                                                member_lookup.Type + "' instead");
7180                                         return null;
7181                                 }
7182
7183                                 return member_lookup;
7184                         }
7185
7186                         member_lookup = ResolveMemberAccess (ec, member_lookup, expr, loc, original);
7187                         if (member_lookup == null)
7188                                 return null;
7189
7190                         // The following DoResolve/DoResolveLValue will do the definite assignment
7191                         // check.
7192
7193                         if (right_side != null)
7194                                 member_lookup = member_lookup.DoResolveLValue (ec, right_side);
7195                         else
7196                                 member_lookup = member_lookup.DoResolve (ec);
7197
7198                         return member_lookup;
7199                 }
7200
7201                 public override Expression DoResolve (EmitContext ec)
7202                 {
7203                         return DoResolve (ec, null, ResolveFlags.VariableOrValue |
7204                                           ResolveFlags.SimpleName | ResolveFlags.Type);
7205                 }
7206
7207                 public override Expression DoResolveLValue (EmitContext ec, Expression right_side)
7208                 {
7209                         return DoResolve (ec, right_side, ResolveFlags.VariableOrValue |
7210                                           ResolveFlags.SimpleName | ResolveFlags.Type);
7211                 }
7212
7213                 public override Expression ResolveAsTypeStep (EmitContext ec)
7214                 {
7215                         string fname = null;
7216                         MemberAccess full_expr = this;
7217                         while (full_expr != null) {
7218                                 if (fname != null)
7219                                         fname = String.Concat (full_expr.Identifier, ".", fname);
7220                                 else
7221                                         fname = full_expr.Identifier;
7222
7223                                 if (full_expr.Expr is SimpleName) {
7224                                         string full_name = String.Concat (((SimpleName) full_expr.Expr).Name, ".", fname);
7225                                         Type fully_qualified = ec.DeclSpace.FindType (loc, full_name);
7226                                         if (fully_qualified != null)
7227                                                 return new TypeExpression (fully_qualified, loc);
7228                                 }
7229
7230                                 full_expr = full_expr.Expr as MemberAccess;
7231                         }
7232
7233                         Expression new_expr = expr.ResolveAsTypeStep (ec);
7234
7235                         if (new_expr == null)
7236                                 return null;
7237
7238                         if (new_expr is SimpleName){
7239                                 SimpleName child_expr = (SimpleName) new_expr;
7240
7241                                 new_expr = new SimpleName (child_expr.Name, Identifier, loc);
7242
7243                                 return new_expr.ResolveAsTypeStep (ec);
7244                         }
7245
7246                         Type expr_type = new_expr.Type;
7247
7248                         if (expr_type.IsPointer){
7249                                 Error (23, "The `.' operator can not be applied to pointer operands (" +
7250                                        TypeManager.CSharpName (expr_type) + ")");
7251                                 return null;
7252                         }
7253
7254                         Expression member_lookup;
7255                         member_lookup = MemberLookupFinal (ec, expr_type, expr_type, Identifier, loc);
7256                         if (member_lookup == null)
7257                                 return null;
7258
7259                         if (member_lookup is TypeExpr){
7260                                 member_lookup.Resolve (ec, ResolveFlags.Type);
7261                                 return member_lookup;
7262                         }
7263
7264                         return null;
7265                 }
7266
7267                 public override void Emit (EmitContext ec)
7268                 {
7269                         throw new Exception ("Should not happen");
7270                 }
7271
7272                 public override string ToString ()
7273                 {
7274                         return expr + "." + Identifier;
7275                 }
7276         }
7277
7278         /// <summary>
7279         ///   Implements checked expressions
7280         /// </summary>
7281         public class CheckedExpr : Expression {
7282
7283                 public Expression Expr;
7284
7285                 public CheckedExpr (Expression e, Location l)
7286                 {
7287                         Expr = e;
7288                         loc = l;
7289                 }
7290
7291                 public override Expression DoResolve (EmitContext ec)
7292                 {
7293                         bool last_check = ec.CheckState;
7294                         bool last_const_check = ec.ConstantCheckState;
7295
7296                         ec.CheckState = true;
7297                         ec.ConstantCheckState = true;
7298                         Expr = Expr.Resolve (ec);
7299                         ec.CheckState = last_check;
7300                         ec.ConstantCheckState = last_const_check;
7301
7302                         if (Expr == null)
7303                                 return null;
7304
7305                         if (Expr is Constant)
7306                                 return Expr;
7307
7308                         eclass = Expr.eclass;
7309                         type = Expr.Type;
7310                         return this;
7311                 }
7312
7313                 public override void Emit (EmitContext ec)
7314                 {
7315                         bool last_check = ec.CheckState;
7316                         bool last_const_check = ec.ConstantCheckState;
7317
7318                         ec.CheckState = true;
7319                         ec.ConstantCheckState = true;
7320                         Expr.Emit (ec);
7321                         ec.CheckState = last_check;
7322                         ec.ConstantCheckState = last_const_check;
7323                 }
7324
7325         }
7326
7327         /// <summary>
7328         ///   Implements the unchecked expression
7329         /// </summary>
7330         public class UnCheckedExpr : Expression {
7331
7332                 public Expression Expr;
7333
7334                 public UnCheckedExpr (Expression e, Location l)
7335                 {
7336                         Expr = e;
7337                         loc = l;
7338                 }
7339
7340                 public override Expression DoResolve (EmitContext ec)
7341                 {
7342                         bool last_check = ec.CheckState;
7343                         bool last_const_check = ec.ConstantCheckState;
7344
7345                         ec.CheckState = false;
7346                         ec.ConstantCheckState = false;
7347                         Expr = Expr.Resolve (ec);
7348                         ec.CheckState = last_check;
7349                         ec.ConstantCheckState = last_const_check;
7350
7351                         if (Expr == null)
7352                                 return null;
7353
7354                         if (Expr is Constant)
7355                                 return Expr;
7356
7357                         eclass = Expr.eclass;
7358                         type = Expr.Type;
7359                         return this;
7360                 }
7361
7362                 public override void Emit (EmitContext ec)
7363                 {
7364                         bool last_check = ec.CheckState;
7365                         bool last_const_check = ec.ConstantCheckState;
7366
7367                         ec.CheckState = false;
7368                         ec.ConstantCheckState = false;
7369                         Expr.Emit (ec);
7370                         ec.CheckState = last_check;
7371                         ec.ConstantCheckState = last_const_check;
7372                 }
7373
7374         }
7375
7376         /// <summary>
7377         ///   An Element Access expression.
7378         ///
7379         ///   During semantic analysis these are transformed into
7380         ///   IndexerAccess, ArrayAccess or a PointerArithmetic.
7381         /// </summary>
7382         public class ElementAccess : Expression {
7383                 public ArrayList  Arguments;
7384                 public Expression Expr;
7385
7386                 public ElementAccess (Expression e, ArrayList e_list, Location l)
7387                 {
7388                         Expr = e;
7389
7390                         loc  = l;
7391
7392                         if (e_list == null)
7393                                 return;
7394
7395                         Arguments = new ArrayList ();
7396                         foreach (Expression tmp in e_list)
7397                                 Arguments.Add (new Argument (tmp, Argument.AType.Expression));
7398
7399                 }
7400
7401                 bool CommonResolve (EmitContext ec)
7402                 {
7403                         Expr = Expr.Resolve (ec);
7404
7405                         if (Expr == null)
7406                                 return false;
7407
7408                         if (Arguments == null)
7409                                 return false;
7410
7411                         foreach (Argument a in Arguments){
7412                                 if (!a.Resolve (ec, loc))
7413                                         return false;
7414                         }
7415
7416                         return true;
7417                 }
7418
7419                 Expression MakePointerAccess (EmitContext ec)
7420                 {
7421                         Type t = Expr.Type;
7422
7423                         if (t == TypeManager.void_ptr_type){
7424                                 Error (242, "The array index operation is not valid for void pointers");
7425                                 return null;
7426                         }
7427                         if (Arguments.Count != 1){
7428                                 Error (196, "A pointer must be indexed by a single value");
7429                                 return null;
7430                         }
7431                         Expression p;
7432
7433                         p = new PointerArithmetic (true, Expr, ((Argument)Arguments [0]).Expr, t, loc).Resolve (ec);
7434                         if (p == null)
7435                                 return null;
7436                         return new Indirection (p, loc).Resolve (ec);
7437                 }
7438
7439                 public override Expression DoResolve (EmitContext ec)
7440                 {
7441                         if (!CommonResolve (ec))
7442                                 return null;
7443
7444                         //
7445                         // We perform some simple tests, and then to "split" the emit and store
7446                         // code we create an instance of a different class, and return that.
7447                         //
7448                         // I am experimenting with this pattern.
7449                         //
7450                         Type t = Expr.Type;
7451
7452                         if (t == TypeManager.array_type){
7453                                 Report.Error (21, loc, "Cannot use indexer on System.Array");
7454                                 return null;
7455                         }
7456
7457                         if (t.IsArray)
7458                                 return (new ArrayAccess (this, loc)).Resolve (ec);
7459                         else if (t.IsPointer)
7460                                 return MakePointerAccess (ec);
7461                         else
7462                                 return (new IndexerAccess (this, loc)).Resolve (ec);
7463                 }
7464
7465                 public override Expression DoResolveLValue (EmitContext ec, Expression right_side)
7466                 {
7467                         if (!CommonResolve (ec))
7468                                 return null;
7469
7470                         Type t = Expr.Type;
7471                         if (t.IsArray)
7472                                 return (new ArrayAccess (this, loc)).ResolveLValue (ec, right_side);
7473                         else if (t.IsPointer)
7474                                 return MakePointerAccess (ec);
7475                         else
7476                                 return (new IndexerAccess (this, loc)).ResolveLValue (ec, right_side);
7477                 }
7478
7479                 public override void Emit (EmitContext ec)
7480                 {
7481                         throw new Exception ("Should never be reached");
7482                 }
7483         }
7484
7485         /// <summary>
7486         ///   Implements array access
7487         /// </summary>
7488         public class ArrayAccess : Expression, IAssignMethod, IMemoryLocation {
7489                 //
7490                 // Points to our "data" repository
7491                 //
7492                 ElementAccess ea;
7493
7494                 LocalTemporary temp;
7495                 bool prepared;
7496
7497                 public ArrayAccess (ElementAccess ea_data, Location l)
7498                 {
7499                         ea = ea_data;
7500                         eclass = ExprClass.Variable;
7501                         loc = l;
7502                 }
7503
7504                 public override Expression DoResolve (EmitContext ec)
7505                 {
7506 #if false
7507                         ExprClass eclass = ea.Expr.eclass;
7508
7509                         // As long as the type is valid
7510                         if (!(eclass == ExprClass.Variable || eclass == ExprClass.PropertyAccess ||
7511                               eclass == ExprClass.Value)) {
7512                                 ea.Expr.Error_UnexpectedKind ("variable or value");
7513                                 return null;
7514                         }
7515 #endif
7516
7517                         Type t = ea.Expr.Type;
7518                         if (t.GetArrayRank () != ea.Arguments.Count){
7519                                 ea.Error (22,
7520                                           "Incorrect number of indexes for array " +
7521                                           " expected: " + t.GetArrayRank () + " got: " +
7522                                           ea.Arguments.Count);
7523                                 return null;
7524                         }
7525
7526                         type = TypeManager.GetElementType (t);
7527                         if (type.IsPointer && !ec.InUnsafe){
7528                                 UnsafeError (ea.Location);
7529                                 return null;
7530                         }
7531
7532                         foreach (Argument a in ea.Arguments){
7533                                 Type argtype = a.Type;
7534
7535                                 if (argtype == TypeManager.int32_type ||
7536                                     argtype == TypeManager.uint32_type ||
7537                                     argtype == TypeManager.int64_type ||
7538                                     argtype == TypeManager.uint64_type)
7539                                         continue;
7540
7541                                 //
7542                                 // Mhm.  This is strage, because the Argument.Type is not the same as
7543                                 // Argument.Expr.Type: the value changes depending on the ref/out setting.
7544                                 //
7545                                 // Wonder if I will run into trouble for this.
7546                                 //
7547                                 a.Expr = ExpressionToArrayArgument (ec, a.Expr, ea.Location);
7548                                 if (a.Expr == null)
7549                                         return null;
7550                         }
7551
7552                         eclass = ExprClass.Variable;
7553
7554                         return this;
7555                 }
7556
7557                 /// <summary>
7558                 ///    Emits the right opcode to load an object of Type `t'
7559                 ///    from an array of T
7560                 /// </summary>
7561                 static public void EmitLoadOpcode (ILGenerator ig, Type type)
7562                 {
7563                         if (type == TypeManager.byte_type || type == TypeManager.bool_type)
7564                                 ig.Emit (OpCodes.Ldelem_U1);
7565                         else if (type == TypeManager.sbyte_type)
7566                                 ig.Emit (OpCodes.Ldelem_I1);
7567                         else if (type == TypeManager.short_type)
7568                                 ig.Emit (OpCodes.Ldelem_I2);
7569                         else if (type == TypeManager.ushort_type || type == TypeManager.char_type)
7570                                 ig.Emit (OpCodes.Ldelem_U2);
7571                         else if (type == TypeManager.int32_type)
7572                                 ig.Emit (OpCodes.Ldelem_I4);
7573                         else if (type == TypeManager.uint32_type)
7574                                 ig.Emit (OpCodes.Ldelem_U4);
7575                         else if (type == TypeManager.uint64_type)
7576                                 ig.Emit (OpCodes.Ldelem_I8);
7577                         else if (type == TypeManager.int64_type)
7578                                 ig.Emit (OpCodes.Ldelem_I8);
7579                         else if (type == TypeManager.float_type)
7580                                 ig.Emit (OpCodes.Ldelem_R4);
7581                         else if (type == TypeManager.double_type)
7582                                 ig.Emit (OpCodes.Ldelem_R8);
7583                         else if (type == TypeManager.intptr_type)
7584                                 ig.Emit (OpCodes.Ldelem_I);
7585                         else if (TypeManager.IsEnumType (type)){
7586                                 EmitLoadOpcode (ig, TypeManager.EnumToUnderlying (type));
7587                         } else if (type.IsValueType){
7588                                 ig.Emit (OpCodes.Ldelema, type);
7589                                 ig.Emit (OpCodes.Ldobj, type);
7590                         } else
7591                                 ig.Emit (OpCodes.Ldelem_Ref);
7592                 }
7593
7594                 /// <summary>
7595                 ///    Returns the right opcode to store an object of Type `t'
7596                 ///    from an array of T.
7597                 /// </summary>
7598                 static public OpCode GetStoreOpcode (Type t, out bool is_stobj)
7599                 {
7600                         //Console.WriteLine (new System.Diagnostics.StackTrace ());
7601                         is_stobj = false;
7602                         t = TypeManager.TypeToCoreType (t);
7603                         if (TypeManager.IsEnumType (t))
7604                                 t = TypeManager.EnumToUnderlying (t);
7605                         if (t == TypeManager.byte_type || t == TypeManager.sbyte_type ||
7606                             t == TypeManager.bool_type)
7607                                 return OpCodes.Stelem_I1;
7608                         else if (t == TypeManager.short_type || t == TypeManager.ushort_type ||
7609                                  t == TypeManager.char_type)
7610                                 return OpCodes.Stelem_I2;
7611                         else if (t == TypeManager.int32_type || t == TypeManager.uint32_type)
7612                                 return OpCodes.Stelem_I4;
7613                         else if (t == TypeManager.int64_type || t == TypeManager.uint64_type)
7614                                 return OpCodes.Stelem_I8;
7615                         else if (t == TypeManager.float_type)
7616                                 return OpCodes.Stelem_R4;
7617                         else if (t == TypeManager.double_type)
7618                                 return OpCodes.Stelem_R8;
7619                         else if (t == TypeManager.intptr_type) {
7620                                 is_stobj = true;
7621                                 return OpCodes.Stobj;
7622                         } else if (t.IsValueType) {
7623                                 is_stobj = true;
7624                                 return OpCodes.Stobj;
7625                         } else
7626                                 return OpCodes.Stelem_Ref;
7627                 }
7628
7629                 MethodInfo FetchGetMethod ()
7630                 {
7631                         ModuleBuilder mb = CodeGen.Module.Builder;
7632                         int arg_count = ea.Arguments.Count;
7633                         Type [] args = new Type [arg_count];
7634                         MethodInfo get;
7635
7636                         for (int i = 0; i < arg_count; i++){
7637                                 //args [i++] = a.Type;
7638                                 args [i] = TypeManager.int32_type;
7639                         }
7640
7641                         get = mb.GetArrayMethod (
7642                                 ea.Expr.Type, "Get",
7643                                 CallingConventions.HasThis |
7644                                 CallingConventions.Standard,
7645                                 type, args);
7646                         return get;
7647                 }
7648
7649
7650                 MethodInfo FetchAddressMethod ()
7651                 {
7652                         ModuleBuilder mb = CodeGen.Module.Builder;
7653                         int arg_count = ea.Arguments.Count;
7654                         Type [] args = new Type [arg_count];
7655                         MethodInfo address;
7656                         Type ret_type;
7657
7658                         ret_type = TypeManager.GetReferenceType (type);
7659
7660                         for (int i = 0; i < arg_count; i++){
7661                                 //args [i++] = a.Type;
7662                                 args [i] = TypeManager.int32_type;
7663                         }
7664
7665                         address = mb.GetArrayMethod (
7666                                 ea.Expr.Type, "Address",
7667                                 CallingConventions.HasThis |
7668                                 CallingConventions.Standard,
7669                                 ret_type, args);
7670
7671                         return address;
7672                 }
7673
7674                 //
7675                 // Load the array arguments into the stack.
7676                 //
7677                 // If we have been requested to cache the values (cached_locations array
7678                 // initialized), then load the arguments the first time and store them
7679                 // in locals.  otherwise load from local variables.
7680                 //
7681                 void LoadArrayAndArguments (EmitContext ec)
7682                 {
7683                         ILGenerator ig = ec.ig;
7684
7685                         ea.Expr.Emit (ec);
7686                         foreach (Argument a in ea.Arguments){
7687                                 Type argtype = a.Expr.Type;
7688
7689                                 a.Expr.Emit (ec);
7690
7691                                 if (argtype == TypeManager.int64_type)
7692                                         ig.Emit (OpCodes.Conv_Ovf_I);
7693                                 else if (argtype == TypeManager.uint64_type)
7694                                         ig.Emit (OpCodes.Conv_Ovf_I_Un);
7695                         }
7696                 }
7697
7698                 public void Emit (EmitContext ec, bool leave_copy)
7699                 {
7700                         int rank = ea.Expr.Type.GetArrayRank ();
7701                         ILGenerator ig = ec.ig;
7702
7703                         if (!prepared) {
7704                                 LoadArrayAndArguments (ec);
7705
7706                                 if (rank == 1)
7707                                         EmitLoadOpcode (ig, type);
7708                                 else {
7709                                         MethodInfo method;
7710
7711                                         method = FetchGetMethod ();
7712                                         ig.Emit (OpCodes.Call, method);
7713                                 }
7714                         } else
7715                                 LoadFromPtr (ec.ig, this.type);
7716
7717                         if (leave_copy) {
7718                                 ec.ig.Emit (OpCodes.Dup);
7719                                 temp = new LocalTemporary (ec, this.type);
7720                                 temp.Store (ec);
7721                         }
7722                 }
7723
7724                 public override void Emit (EmitContext ec)
7725                 {
7726                         Emit (ec, false);
7727                 }
7728
7729                 public void EmitAssign (EmitContext ec, Expression source, bool leave_copy, bool prepare_for_load)
7730                 {
7731                         int rank = ea.Expr.Type.GetArrayRank ();
7732                         ILGenerator ig = ec.ig;
7733                         Type t = source.Type;
7734                         prepared = prepare_for_load;
7735
7736                         if (prepare_for_load) {
7737                                 AddressOf (ec, AddressOp.LoadStore);
7738                                 ec.ig.Emit (OpCodes.Dup);
7739                                 source.Emit (ec);
7740                                 if (leave_copy) {
7741                                         ec.ig.Emit (OpCodes.Dup);
7742                                         temp = new LocalTemporary (ec, this.type);
7743                                         temp.Store (ec);
7744                                 }
7745                                 StoreFromPtr (ec.ig, t);
7746
7747                                 if (temp != null)
7748                                         temp.Emit (ec);
7749
7750                                 return;
7751                         }
7752
7753                         LoadArrayAndArguments (ec);
7754
7755                         if (rank == 1) {
7756                                 bool is_stobj;
7757                                 OpCode op = GetStoreOpcode (t, out is_stobj);
7758                                 //
7759                                 // The stobj opcode used by value types will need
7760                                 // an address on the stack, not really an array/array
7761                                 // pair
7762                                 //
7763                                 if (is_stobj)
7764                                         ig.Emit (OpCodes.Ldelema, t);
7765
7766                                 source.Emit (ec);
7767                                 if (leave_copy) {
7768                                         ec.ig.Emit (OpCodes.Dup);
7769                                         temp = new LocalTemporary (ec, this.type);
7770                                         temp.Store (ec);
7771                                 }
7772
7773                                 if (is_stobj)
7774                                         ig.Emit (OpCodes.Stobj, t);
7775                                 else
7776                                         ig.Emit (op);
7777                         } else {
7778                                 ModuleBuilder mb = CodeGen.Module.Builder;
7779                                 int arg_count = ea.Arguments.Count;
7780                                 Type [] args = new Type [arg_count + 1];
7781                                 MethodInfo set;
7782
7783                                 source.Emit (ec);
7784                                 if (leave_copy) {
7785                                         ec.ig.Emit (OpCodes.Dup);
7786                                         temp = new LocalTemporary (ec, this.type);
7787                                         temp.Store (ec);
7788                                 }
7789
7790                                 for (int i = 0; i < arg_count; i++){
7791                                         //args [i++] = a.Type;
7792                                         args [i] = TypeManager.int32_type;
7793                                 }
7794
7795                                 args [arg_count] = type;
7796
7797                                 set = mb.GetArrayMethod (
7798                                         ea.Expr.Type, "Set",
7799                                         CallingConventions.HasThis |
7800                                         CallingConventions.Standard,
7801                                         TypeManager.void_type, args);
7802
7803                                 ig.Emit (OpCodes.Call, set);
7804                         }
7805
7806                         if (temp != null)
7807                                 temp.Emit (ec);
7808                 }
7809
7810                 public void AddressOf (EmitContext ec, AddressOp mode)
7811                 {
7812                         int rank = ea.Expr.Type.GetArrayRank ();
7813                         ILGenerator ig = ec.ig;
7814
7815                         LoadArrayAndArguments (ec);
7816
7817                         if (rank == 1){
7818                                 ig.Emit (OpCodes.Ldelema, type);
7819                         } else {
7820                                 MethodInfo address = FetchAddressMethod ();
7821                                 ig.Emit (OpCodes.Call, address);
7822                         }
7823                 }
7824         }
7825
7826
7827         class Indexers {
7828                 public ArrayList Properties;
7829                 static Hashtable map;
7830
7831                 public struct Indexer {
7832                         public readonly Type Type;
7833                         public readonly MethodInfo Getter, Setter;
7834
7835                         public Indexer (Type type, MethodInfo get, MethodInfo set)
7836                         {
7837                                 this.Type = type;
7838                                 this.Getter = get;
7839                                 this.Setter = set;
7840                         }
7841                 }
7842
7843                 static Indexers ()
7844                 {
7845                         map = new Hashtable ();
7846                 }
7847
7848                 Indexers ()
7849                 {
7850                         Properties = new ArrayList ();
7851                 }
7852
7853                 void Append (MemberInfo [] mi)
7854                 {
7855                         foreach (PropertyInfo property in mi){
7856                                 MethodInfo get, set;
7857
7858                                 get = property.GetGetMethod (true);
7859                                 set = property.GetSetMethod (true);
7860                                 Properties.Add (new Indexer (property.PropertyType, get, set));
7861                         }
7862                 }
7863
7864                 static private MemberInfo [] GetIndexersForTypeOrInterface (Type caller_type, Type lookup_type)
7865                 {
7866                         string p_name = TypeManager.IndexerPropertyName (lookup_type);
7867
7868                         MemberInfo [] mi = TypeManager.MemberLookup (
7869                                 caller_type, caller_type, lookup_type, MemberTypes.Property,
7870                                 BindingFlags.Public | BindingFlags.Instance |
7871                                 BindingFlags.DeclaredOnly, p_name, null);
7872
7873                         if (mi == null || mi.Length == 0)
7874                                 return null;
7875
7876                         return mi;
7877                 }
7878
7879                 static public Indexers GetIndexersForType (Type caller_type, Type lookup_type, Location loc)
7880                 {
7881                         Indexers ix = (Indexers) map [lookup_type];
7882
7883                         if (ix != null)
7884                                 return ix;
7885
7886                         Type copy = lookup_type;
7887                         while (copy != TypeManager.object_type && copy != null){
7888                                 MemberInfo [] mi = GetIndexersForTypeOrInterface (caller_type, copy);
7889
7890                                 if (mi != null){
7891                                         if (ix == null)
7892                                                 ix = new Indexers ();
7893
7894                                         ix.Append (mi);
7895                                 }
7896
7897                                 copy = copy.BaseType;
7898                         }
7899
7900                         if (!lookup_type.IsInterface)
7901                                 return ix;
7902
7903                         TypeExpr [] ifaces = TypeManager.GetInterfaces (lookup_type);
7904                         if (ifaces != null) {
7905                                 foreach (TypeExpr iface in ifaces) {
7906                                         Type itype = iface.Type;
7907                                         MemberInfo [] mi = GetIndexersForTypeOrInterface (caller_type, itype);
7908                                         if (mi != null){
7909                                                 if (ix == null)
7910                                                         ix = new Indexers ();
7911
7912                                                 ix.Append (mi);
7913                                         }
7914                                 }
7915                         }
7916
7917                         return ix;
7918                 }
7919         }
7920
7921         /// <summary>
7922         ///   Expressions that represent an indexer call.
7923         /// </summary>
7924         public class IndexerAccess : Expression, IAssignMethod {
7925                 //
7926                 // Points to our "data" repository
7927                 //
7928                 MethodInfo get, set;
7929                 ArrayList set_arguments;
7930                 bool is_base_indexer;
7931
7932                 protected Type indexer_type;
7933                 protected Type current_type;
7934                 protected Expression instance_expr;
7935                 protected ArrayList arguments;
7936
7937                 public IndexerAccess (ElementAccess ea, Location loc)
7938                         : this (ea.Expr, false, loc)
7939                 {
7940                         this.arguments = ea.Arguments;
7941                 }
7942
7943                 protected IndexerAccess (Expression instance_expr, bool is_base_indexer,
7944                                          Location loc)
7945                 {
7946                         this.instance_expr = instance_expr;
7947                         this.is_base_indexer = is_base_indexer;
7948                         this.eclass = ExprClass.Value;
7949                         this.loc = loc;
7950                 }
7951
7952                 protected virtual bool CommonResolve (EmitContext ec)
7953                 {
7954                         indexer_type = instance_expr.Type;
7955                         current_type = ec.ContainerType;
7956
7957                         return true;
7958                 }
7959
7960                 public override Expression DoResolve (EmitContext ec)
7961                 {
7962                         ArrayList AllGetters = new ArrayList();
7963                         if (!CommonResolve (ec))
7964                                 return null;
7965
7966                         //
7967                         // Step 1: Query for all `Item' *properties*.  Notice
7968                         // that the actual methods are pointed from here.
7969                         //
7970                         // This is a group of properties, piles of them.
7971
7972                         bool found_any = false, found_any_getters = false;
7973                         Type lookup_type = indexer_type;
7974
7975                         Indexers ilist;
7976                         ilist = Indexers.GetIndexersForType (current_type, lookup_type, loc);
7977                         if (ilist != null) {
7978                                 found_any = true;
7979                                 if (ilist.Properties != null) {
7980                                         foreach (Indexers.Indexer ix in ilist.Properties) {
7981                                                 if (ix.Getter != null)
7982                                                         AllGetters.Add(ix.Getter);
7983                                         }
7984                                 }
7985                         }
7986
7987                         if (AllGetters.Count > 0) {
7988                                 found_any_getters = true;
7989                                 get = (MethodInfo) Invocation.OverloadResolve (
7990                                         ec, new MethodGroupExpr (AllGetters, loc),
7991                                         arguments, false, loc);
7992                         }
7993
7994                         if (!found_any) {
7995                                 Report.Error (21, loc,
7996                                               "Type `" + TypeManager.CSharpName (indexer_type) +
7997                                               "' does not have any indexers defined");
7998                                 return null;
7999                         }
8000
8001                         if (!found_any_getters) {
8002                                 Error (154, "indexer can not be used in this context, because " +
8003                                        "it lacks a `get' accessor");
8004                                 return null;
8005                         }
8006
8007                         if (get == null) {
8008                                 Error (1501, "No Overload for method `this' takes `" +
8009                                        arguments.Count + "' arguments");
8010                                 return null;
8011                         }
8012
8013                         //
8014                         // Only base will allow this invocation to happen.
8015                         //
8016                         if (get.IsAbstract && this is BaseIndexerAccess){
8017                                 Report.Error (205, loc, "Cannot call an abstract base indexer: " + Invocation.FullMethodDesc (get));
8018                                 return null;
8019                         }
8020
8021                         type = get.ReturnType;
8022                         if (type.IsPointer && !ec.InUnsafe){
8023                                 UnsafeError (loc);
8024                                 return null;
8025                         }
8026
8027                         eclass = ExprClass.IndexerAccess;
8028                         return this;
8029                 }
8030
8031                 public override Expression DoResolveLValue (EmitContext ec, Expression right_side)
8032                 {
8033                         ArrayList AllSetters = new ArrayList();
8034                         if (!CommonResolve (ec))
8035                                 return null;
8036
8037                         bool found_any = false, found_any_setters = false;
8038
8039                         Indexers ilist = Indexers.GetIndexersForType (current_type, indexer_type, loc);
8040                         if (ilist != null) {
8041                                 found_any = true;
8042                                 if (ilist.Properties != null) {
8043                                         foreach (Indexers.Indexer ix in ilist.Properties) {
8044                                                 if (ix.Setter != null)
8045                                                         AllSetters.Add(ix.Setter);
8046                                         }
8047                                 }
8048                         }
8049                         if (AllSetters.Count > 0) {
8050                                 found_any_setters = true;
8051                                 set_arguments = (ArrayList) arguments.Clone ();
8052                                 set_arguments.Add (new Argument (right_side, Argument.AType.Expression));
8053                                 set = (MethodInfo) Invocation.OverloadResolve (
8054                                         ec, new MethodGroupExpr (AllSetters, loc),
8055                                         set_arguments, false, loc);
8056                         }
8057
8058                         if (!found_any) {
8059                                 Report.Error (21, loc,
8060                                               "Type `" + TypeManager.CSharpName (indexer_type) +
8061                                               "' does not have any indexers defined");
8062                                 return null;
8063                         }
8064
8065                         if (!found_any_setters) {
8066                                 Error (154, "indexer can not be used in this context, because " +
8067                                        "it lacks a `set' accessor");
8068                                 return null;
8069                         }
8070
8071                         if (set == null) {
8072                                 Error (1501, "No Overload for method `this' takes `" +
8073                                        arguments.Count + "' arguments");
8074                                 return null;
8075                         }
8076
8077                         //
8078                         // Only base will allow this invocation to happen.
8079                         //
8080                         if (set.IsAbstract && this is BaseIndexerAccess){
8081                                 Report.Error (205, loc, "Cannot call an abstract base indexer: " + Invocation.FullMethodDesc (set));
8082                                 return null;
8083                         }
8084
8085                         //
8086                         // Now look for the actual match in the list of indexers to set our "return" type
8087                         //
8088                         type = TypeManager.void_type;   // default value
8089                         foreach (Indexers.Indexer ix in ilist.Properties){
8090                                 if (ix.Setter == set){
8091                                         type = ix.Type;
8092                                         break;
8093                                 }
8094                         }
8095
8096                         eclass = ExprClass.IndexerAccess;
8097                         return this;
8098                 }
8099
8100                 bool prepared = false;
8101                 LocalTemporary temp;
8102
8103                 public void Emit (EmitContext ec, bool leave_copy)
8104                 {
8105                         Invocation.EmitCall (ec, is_base_indexer, false, instance_expr, get, arguments, loc, prepared, false);
8106                         if (leave_copy) {
8107                                 ec.ig.Emit (OpCodes.Dup);
8108                                 temp = new LocalTemporary (ec, Type);
8109                                 temp.Store (ec);
8110                         }
8111                 }
8112
8113                 //
8114                 // source is ignored, because we already have a copy of it from the
8115                 // LValue resolution and we have already constructed a pre-cached
8116                 // version of the arguments (ea.set_arguments);
8117                 //
8118                 public void EmitAssign (EmitContext ec, Expression source, bool leave_copy, bool prepare_for_load)
8119                 {
8120                         prepared = prepare_for_load;
8121                         Argument a = (Argument) set_arguments [set_arguments.Count - 1];
8122
8123                         if (prepared) {
8124                                 source.Emit (ec);
8125                                 if (leave_copy) {
8126                                         ec.ig.Emit (OpCodes.Dup);
8127                                         temp = new LocalTemporary (ec, Type);
8128                                         temp.Store (ec);
8129                                 }
8130                         } else if (leave_copy) {
8131                                 temp = new LocalTemporary (ec, Type);
8132                                 source.Emit (ec);
8133                                 temp.Store (ec);
8134                                 a.Expr = temp;
8135                         }
8136
8137                         Invocation.EmitCall (ec, is_base_indexer, false, instance_expr, set, set_arguments, loc, false, prepared);
8138
8139                         if (temp != null)
8140                                 temp.Emit (ec);
8141                 }
8142
8143
8144                 public override void Emit (EmitContext ec)
8145                 {
8146                         Emit (ec, false);
8147                 }
8148         }
8149
8150         /// <summary>
8151         ///   The base operator for method names
8152         /// </summary>
8153         public class BaseAccess : Expression {
8154                 string member;
8155
8156                 public BaseAccess (string member, Location l)
8157                 {
8158                         this.member = member;
8159                         loc = l;
8160                 }
8161
8162                 public override Expression DoResolve (EmitContext ec)
8163                 {
8164                         Expression c = CommonResolve (ec);
8165
8166                         if (c == null)
8167                                 return null;
8168
8169                         //
8170                         // MethodGroups use this opportunity to flag an error on lacking ()
8171                         //
8172                         if (!(c is MethodGroupExpr))
8173                                 return c.Resolve (ec);
8174                         return c;
8175                 }
8176
8177                 public override Expression DoResolveLValue (EmitContext ec, Expression right_side)
8178                 {
8179                         Expression c = CommonResolve (ec);
8180
8181                         if (c == null)
8182                                 return null;
8183
8184                         //
8185                         // MethodGroups use this opportunity to flag an error on lacking ()
8186                         //
8187                         if (! (c is MethodGroupExpr))
8188                                 return c.DoResolveLValue (ec, right_side);
8189
8190                         return c;
8191                 }
8192
8193                 Expression CommonResolve (EmitContext ec)
8194                 {
8195                         Expression member_lookup;
8196                         Type current_type = ec.ContainerType;
8197                         Type base_type = current_type.BaseType;
8198                         Expression e;
8199
8200                         if (ec.IsStatic){
8201                                 Error (1511, "Keyword base is not allowed in static method");
8202                                 return null;
8203                         }
8204
8205                         if (ec.IsFieldInitializer){
8206                                 Error (1512, "Keyword base is not available in the current context");
8207                                 return null;
8208                         }
8209
8210                         member_lookup = MemberLookup (ec, ec.ContainerType, null, base_type, member,
8211                                                       AllMemberTypes, AllBindingFlags, loc);
8212                         if (member_lookup == null) {
8213                                 MemberLookupFailed (ec, base_type, base_type, member, null, loc);
8214                                 return null;
8215                         }
8216
8217                         Expression left;
8218
8219                         if (ec.IsStatic)
8220                                 left = new TypeExpression (base_type, loc);
8221                         else
8222                                 left = ec.GetThis (loc);
8223
8224                         e = MemberAccess.ResolveMemberAccess (ec, member_lookup, left, loc, null);
8225
8226                         if (e is PropertyExpr){
8227                                 PropertyExpr pe = (PropertyExpr) e;
8228
8229                                 pe.IsBase = true;
8230                         }
8231
8232                         if (e is MethodGroupExpr)
8233                                 ((MethodGroupExpr) e).IsBase = true;
8234
8235                         return e;
8236                 }
8237
8238                 public override void Emit (EmitContext ec)
8239                 {
8240                         throw new Exception ("Should never be called");
8241                 }
8242         }
8243
8244         /// <summary>
8245         ///   The base indexer operator
8246         /// </summary>
8247         public class BaseIndexerAccess : IndexerAccess {
8248                 public BaseIndexerAccess (ArrayList args, Location loc)
8249                         : base (null, true, loc)
8250                 {
8251                         arguments = new ArrayList ();
8252                         foreach (Expression tmp in args)
8253                                 arguments.Add (new Argument (tmp, Argument.AType.Expression));
8254                 }
8255
8256                 protected override bool CommonResolve (EmitContext ec)
8257                 {
8258                         instance_expr = ec.GetThis (loc);
8259
8260                         current_type = ec.ContainerType.BaseType;
8261                         indexer_type = current_type;
8262
8263                         foreach (Argument a in arguments){
8264                                 if (!a.Resolve (ec, loc))
8265                                         return false;
8266                         }
8267
8268                         return true;
8269                 }
8270         }
8271
8272         /// <summary>
8273         ///   This class exists solely to pass the Type around and to be a dummy
8274         ///   that can be passed to the conversion functions (this is used by
8275         ///   foreach implementation to typecast the object return value from
8276         ///   get_Current into the proper type.  All code has been generated and
8277         ///   we only care about the side effect conversions to be performed
8278         ///
8279         ///   This is also now used as a placeholder where a no-action expression
8280         ///   is needed (the `New' class).
8281         /// </summary>
8282         public class EmptyExpression : Expression {
8283                 public EmptyExpression ()
8284                 {
8285                         type = TypeManager.object_type;
8286                         eclass = ExprClass.Value;
8287                         loc = Location.Null;
8288                 }
8289
8290                 public EmptyExpression (Type t)
8291                 {
8292                         type = t;
8293                         eclass = ExprClass.Value;
8294                         loc = Location.Null;
8295                 }
8296
8297                 public override Expression DoResolve (EmitContext ec)
8298                 {
8299                         return this;
8300                 }
8301
8302                 public override void Emit (EmitContext ec)
8303                 {
8304                         // nothing, as we only exist to not do anything.
8305                 }
8306
8307                 //
8308                 // This is just because we might want to reuse this bad boy
8309                 // instead of creating gazillions of EmptyExpressions.
8310                 // (CanImplicitConversion uses it)
8311                 //
8312                 public void SetType (Type t)
8313                 {
8314                         type = t;
8315                 }
8316         }
8317
8318         public class UserCast : Expression {
8319                 MethodBase method;
8320                 Expression source;
8321
8322                 public UserCast (MethodInfo method, Expression source, Location l)
8323                 {
8324                         this.method = method;
8325                         this.source = source;
8326                         type = method.ReturnType;
8327                         eclass = ExprClass.Value;
8328                         loc = l;
8329                 }
8330
8331                 public override Expression DoResolve (EmitContext ec)
8332                 {
8333                         //
8334                         // We are born fully resolved
8335                         //
8336                         return this;
8337                 }
8338
8339                 public override void Emit (EmitContext ec)
8340                 {
8341                         ILGenerator ig = ec.ig;
8342
8343                         source.Emit (ec);
8344
8345                         if (method is MethodInfo)
8346                                 ig.Emit (OpCodes.Call, (MethodInfo) method);
8347                         else
8348                                 ig.Emit (OpCodes.Call, (ConstructorInfo) method);
8349
8350                 }
8351         }
8352
8353         // <summary>
8354         //   This class is used to "construct" the type during a typecast
8355         //   operation.  Since the Type.GetType class in .NET can parse
8356         //   the type specification, we just use this to construct the type
8357         //   one bit at a time.
8358         // </summary>
8359         public class ComposedCast : TypeExpr {
8360                 Expression left;
8361                 string dim;
8362
8363                 public ComposedCast (Expression left, string dim, Location l)
8364                 {
8365                         this.left = left;
8366                         this.dim = dim;
8367                         loc = l;
8368                 }
8369
8370                 public override TypeExpr DoResolveAsTypeStep (EmitContext ec)
8371                 {
8372                         Type ltype = ec.DeclSpace.ResolveType (left, false, loc);
8373                         if (ltype == null)
8374                                 return null;
8375
8376                         if ((ltype == TypeManager.void_type) && (dim != "*")) {
8377                                 Report.Error (1547, Location,
8378                                               "Keyword 'void' cannot be used in this context");
8379                                 return null;
8380                         }
8381
8382                         //
8383                         // ltype.Fullname is already fully qualified, so we can skip
8384                         // a lot of probes, and go directly to TypeManager.LookupType
8385                         //
8386                         string cname = ltype.FullName + dim;
8387                         type = TypeManager.LookupTypeDirect (cname);
8388                         if (type == null){
8389                                 //
8390                                 // For arrays of enumerations we are having a problem
8391                                 // with the direct lookup.  Need to investigate.
8392                                 //
8393                                 // For now, fall back to the full lookup in that case.
8394                                 //
8395                                 type = RootContext.LookupType (
8396                                         ec.DeclSpace, cname, false, loc);
8397
8398                                 if (type == null)
8399                                         return null;
8400                         }
8401
8402                         if (!ec.ResolvingTypeTree){
8403                                 //
8404                                 // If the above flag is set, this is being invoked from the ResolveType function.
8405                                 // Upper layers take care of the type validity in this context.
8406                                 //
8407                         if (!ec.InUnsafe && type.IsPointer){
8408                                 UnsafeError (loc);
8409                                 return null;
8410                         }
8411                         }
8412
8413                         eclass = ExprClass.Type;
8414                         return this;
8415                 }
8416
8417                 public override string Name {
8418                         get {
8419                                 return left + dim;
8420                         }
8421                 }
8422         }
8423
8424         //
8425         // This class is used to represent the address of an array, used
8426         // only by the Fixed statement, this is like the C "&a [0]" construct.
8427         //
8428         public class ArrayPtr : Expression {
8429                 Expression array;
8430
8431                 public ArrayPtr (Expression array, Location l)
8432                 {
8433                         Type array_type = TypeManager.GetElementType (array.Type);
8434
8435                         this.array = array;
8436
8437                         type = TypeManager.GetPointerType (array_type);
8438                         eclass = ExprClass.Value;
8439                         loc = l;
8440                 }
8441
8442                 public override void Emit (EmitContext ec)
8443                 {
8444                         ILGenerator ig = ec.ig;
8445
8446                         array.Emit (ec);
8447                         IntLiteral.EmitInt (ig, 0);
8448                         ig.Emit (OpCodes.Ldelema, TypeManager.GetElementType (array.Type));
8449                 }
8450
8451                 public override Expression DoResolve (EmitContext ec)
8452                 {
8453                         //
8454                         // We are born fully resolved
8455                         //
8456                         return this;
8457                 }
8458         }
8459
8460         //
8461         // Used by the fixed statement
8462         //
8463         public class StringPtr : Expression {
8464                 LocalBuilder b;
8465
8466                 public StringPtr (LocalBuilder b, Location l)
8467                 {
8468                         this.b = b;
8469                         eclass = ExprClass.Value;
8470                         type = TypeManager.char_ptr_type;
8471                         loc = l;
8472                 }
8473
8474                 public override Expression DoResolve (EmitContext ec)
8475                 {
8476                         // This should never be invoked, we are born in fully
8477                         // initialized state.
8478
8479                         return this;
8480                 }
8481
8482                 public override void Emit (EmitContext ec)
8483                 {
8484                         ILGenerator ig = ec.ig;
8485
8486                         ig.Emit (OpCodes.Ldloc, b);
8487                         ig.Emit (OpCodes.Conv_I);
8488                         ig.Emit (OpCodes.Call, TypeManager.int_get_offset_to_string_data);
8489                         ig.Emit (OpCodes.Add);
8490                 }
8491         }
8492
8493         //
8494         // Implements the `stackalloc' keyword
8495         //
8496         public class StackAlloc : Expression {
8497                 Type otype;
8498                 Expression t;
8499                 Expression count;
8500
8501                 public StackAlloc (Expression type, Expression count, Location l)
8502                 {
8503                         t = type;
8504                         this.count = count;
8505                         loc = l;
8506                 }
8507
8508                 public override Expression DoResolve (EmitContext ec)
8509                 {
8510                         count = count.Resolve (ec);
8511                         if (count == null)
8512                                 return null;
8513
8514                         if (count.Type != TypeManager.int32_type){
8515                                 count = Convert.ImplicitConversionRequired (ec, count, TypeManager.int32_type, loc);
8516                                 if (count == null)
8517                                         return null;
8518                         }
8519
8520                         Constant c = count as Constant;
8521                         // TODO: because we don't have property IsNegative
8522                         if (c != null && c.ConvertToUInt () == null) {
8523                                 Report.Error (247, loc, "Cannot use a negative size with stackalloc");
8524                                 return null;
8525                         }
8526
8527                         if (ec.CurrentBranching.InCatch () ||
8528                             ec.CurrentBranching.InFinally (true)) {
8529                                 Error (255,
8530                                        "stackalloc can not be used in a catch or finally block");
8531                                 return null;
8532                         }
8533
8534                         otype = ec.DeclSpace.ResolveType (t, false, loc);
8535
8536                         if (otype == null)
8537                                 return null;
8538
8539                         if (!TypeManager.VerifyUnManaged (otype, loc))
8540                                 return null;
8541
8542                         type = TypeManager.GetPointerType (otype);
8543                         eclass = ExprClass.Value;
8544
8545                         return this;
8546                 }
8547
8548                 public override void Emit (EmitContext ec)
8549                 {
8550                         int size = GetTypeSize (otype);
8551                         ILGenerator ig = ec.ig;
8552
8553                         if (size == 0)
8554                                 ig.Emit (OpCodes.Sizeof, otype);
8555                         else
8556                                 IntConstant.EmitInt (ig, size);
8557                         count.Emit (ec);
8558                         ig.Emit (OpCodes.Mul);
8559                         ig.Emit (OpCodes.Localloc);
8560                 }
8561         }
8562 }