mcs/gmcs/constant.cs

   1 //
   2 // constant.cs: Constants.
   3 //
   4 // Author:
   5 //   Miguel de Icaza (miguel@ximian.com)
   6 //   Marek Safar (marek.safar@seznam.cz)
   7 //
   8 // (C) 2001 Ximian, Inc.
   9 //
  10 //
  11
  12 namespace Mono.CSharp {
  13
  14         using System;
  15         using System.Reflection.Emit;
  16
  17         /// <summary>
  18         ///   Base class for constants and literals.
  19         /// </summary>
  20         public abstract class Constant : Expression {
  21
  22                 protected Constant (Location loc)
  23                 {
  24                         this.loc = loc;
  25                 }
  26
  27                 /// <remarks>
  28                 ///   This is different from ToString in that ToString
  29                 ///   is supposed to be there for debugging purposes,
  30                 ///   and is not guaranteed to be useful for anything else,
  31                 ///   AsString() will provide something that can be used
  32                 ///   for round-tripping C# code.  Maybe it can be used
  33                 ///   for IL assembly as well.
  34                 /// </remarks>
  35                 public abstract string AsString ();
  36
  37                 override public string ToString ()
  38                 {
  39                         return this.GetType ().Name + " (" + AsString () + ")";
  40                 }
  41
  42                 public override bool GetAttributableValue (Type valueType, out object value)
  43                 {
  44                         Constant c = ToType (valueType, loc);
  45                         if (c == null) {
  46                                 value = null;
  47                                 return false;
  48                         }
  49
  50                         value = c.GetTypedValue ();
  51                         return true;
  52                 }
  53
  54                 /// <summary>
  55                 ///  This is used to obtain the actual value of the literal
  56                 ///  cast into an object.
  57                 /// </summary>
  58                 public abstract object GetValue ();
  59
  60                 public virtual object GetTypedValue ()
  61                 {
  62                         return GetValue ();
  63                 }
  64
  65                 /// <summary>
  66                 ///   Constants are always born in a fully resolved state
  67                 /// </summary>
  68                 public override Expression DoResolve (EmitContext ec)
  69                 {
  70                         return this;
  71                 }
  72
  73                 //
  74                 // The various ToXXXX conversion functions are used by the constant
  75                 // folding evaluator.   A null value is returned if the conversion is
  76                 // not possible.
  77                 //
  78                 // Note: not all the patterns for catching `implicit_conv' are the same.
  79                 // some implicit conversions can never be performed between two types
  80                 // even if the conversion would be lossless (for example short to uint),
  81                 // but some conversions are explicitly permitted by the standard provided
  82                 // that there will be no loss of information (for example, int to uint).
  83                 //
  84                 public DoubleConstant ToDouble (Location loc)
  85                 {
  86                         DoubleConstant c = ConvertToDouble ();
  87
  88                         if (c == null)
  89                                 Error_ValueCannotBeConverted (loc, TypeManager.double_type, false);
  90
  91                         return c;
  92                 }
  93
  94                 public FloatConstant ToFloat (Location loc)
  95                 {
  96                         FloatConstant c = ConvertToFloat ();
  97
  98                         if (c == null)
  99                                 Error_ValueCannotBeConverted (loc, TypeManager.float_type, false);
 100
 101                         return c;
 102                 }
 103
 104                 public ULongConstant ToULong (Location loc)
 105                 {
 106                         ULongConstant c = ConvertToULong ();
 107
 108                         if (c == null)
 109                                 Error_ValueCannotBeConverted (loc, TypeManager.uint64_type, false);
 110
 111                         return c;
 112                 }
 113
 114                 public LongConstant ToLong (Location loc)
 115                 {
 116                         LongConstant c = ConvertToLong ();
 117
 118                         if (c == null)
 119                                 Error_ValueCannotBeConverted (loc, TypeManager.int64_type, false);
 120
 121                         return c;
 122                 }
 123
 124                 public UIntConstant ToUInt (Location loc)
 125                 {
 126                         UIntConstant c = ConvertToUInt ();
 127
 128                         if (c == null)
 129                                 Error_ValueCannotBeConverted (loc, TypeManager.uint32_type, false);
 130
 131                         return c;
 132                 }
 133
 134                 public IntConstant ToInt (Location loc)
 135                 {
 136                         IntConstant c = ConvertToInt ();
 137
 138                         if (c == null)
 139                                 Error_ValueCannotBeConverted (loc, TypeManager.int32_type, false);
 140
 141                         return c;
 142                 }
 143
 144                 public DecimalConstant ToDecimal (Location loc)
 145                 {
 146                         DecimalConstant c = ConvertToDecimal ();
 147
 148                         if (c == null)
 149                                 Error_ValueCannotBeConverted (loc, TypeManager.decimal_type, false);
 150
 151                         return c;
 152                 }
 153
 154                 public virtual Constant ToType (Type type, Location loc)
 155                 {
 156                         if (Type == type)
 157                                 return this;
 158
 159                         if (type == TypeManager.object_type)
 160                                 return this;
 161
 162                         if (!Convert.ImplicitStandardConversionExists (this, type)){
 163                                 Error_ValueCannotBeConverted (loc, type, false);
 164                                 return null;
 165                         }
 166
 167                         // Special-case: The 0 literal can be converted to an enum value,
 168                         // and ImplicitStandardConversionExists will return true in that case.
 169                         if (IsZeroInteger && Type == TypeManager.int32_type && TypeManager.IsEnumType (type)) {
 170                                 return new EnumConstant (this, type);
 171                         }
 172
 173                         bool fail;
 174                         object constant_value = TypeManager.ChangeType (GetValue (), type, out fail);
 175                         if (fail){
 176                                 Error_ValueCannotBeConverted (loc, type, false);
 177
 178                                 //
 179                                 // We should always catch the error before this is ever
 180                                 // reached, by calling Convert.ImplicitStandardConversionExists
 181                                 //
 182                                 throw new Exception (
 183                                         String.Format ("LookupConstantValue: This should never be reached {0} {1}", Type, type));
 184                         }
 185
 186                         Constant retval;
 187                         if (type == TypeManager.int32_type)
 188                                 retval = new IntConstant ((int) constant_value, loc);
 189                         else if (type == TypeManager.uint32_type)
 190                                 retval = new UIntConstant ((uint) constant_value, loc);
 191                         else if (type == TypeManager.int64_type)
 192                                 retval = new LongConstant ((long) constant_value, loc);
 193                         else if (type == TypeManager.uint64_type)
 194                                 retval = new ULongConstant ((ulong) constant_value, loc);
 195                         else if (type == TypeManager.float_type)
 196                                 retval = new FloatConstant ((float) constant_value, loc);
 197                         else if (type == TypeManager.double_type)
 198                                 retval = new DoubleConstant ((double) constant_value, loc);
 199                         else if (type == TypeManager.string_type)
 200                                 retval = new StringConstant ((string) constant_value, loc);
 201                         else if (type == TypeManager.short_type)
 202                                 retval = new ShortConstant ((short) constant_value, loc);
 203                         else if (type == TypeManager.ushort_type)
 204                                 retval = new UShortConstant ((ushort) constant_value, loc);
 205                         else if (type == TypeManager.sbyte_type)
 206                                 retval = new SByteConstant ((sbyte) constant_value, loc);
 207                         else if (type == TypeManager.byte_type)
 208                                 retval = new ByteConstant ((byte) constant_value, loc);
 209                         else if (type == TypeManager.char_type)
 210                                 retval = new CharConstant ((char) constant_value, loc);
 211                         else if (type == TypeManager.bool_type)
 212                                 retval = new BoolConstant ((bool) constant_value, loc);
 213                         else if (type == TypeManager.decimal_type)
 214                                 retval = new DecimalConstant ((decimal) constant_value, loc);
 215                         else
 216                                 throw new Exception ("LookupConstantValue: Unhandled constant type: " + type);
 217
 218                         return retval;
 219                 }
 220
 221                 protected static void CheckRange (bool inCheckedContext, ulong value, ulong max)
 222                 {
 223                         if (!inCheckedContext)
 224                                 return;
 225
 226                         if (value > max)
 227                                 throw new OverflowException ();
 228                 }
 229
 230                 protected static void CheckRange (bool inCheckedContext, double value, long min, long max)
 231                 {
 232                         if (!inCheckedContext)
 233                                 return;
 234
 235                         if (((value < min) || (value > max)))
 236                                 throw new OverflowException ();
 237                 }
 238
 239                 protected static void CheckUnsigned (bool inCheckedContext, long value)
 240                 {
 241                         if (!inCheckedContext)
 242                                 return;
 243
 244                         if (value < 0)
 245                                 throw new OverflowException ();
 246                 }
 247
 248                 /// <summary>
 249                 /// Maybe ConvertTo name is better. It tries to convert `this' constant to target_type.
 250                 /// It throws OverflowException
 251                 /// </summary>
 252                 public abstract Constant Reduce (bool inCheckedContext, Type target_type);
 253
 254                 /// <summary>
 255                 ///   Attempts to do a compile-time folding of a constant cast.
 256                 /// </summary>
 257                 public Constant TryReduce (EmitContext ec, Type target_type, Location loc)
 258                 {
 259                         try {
 260                                 return  TryReduce (ec, target_type);
 261                         }
 262                         catch (OverflowException) {
 263                                 Report.Error (221, loc, "Constant value `{0}' cannot be converted to a `{1}' (use `unchecked' syntax to override)",
 264                                         GetValue ().ToString (), TypeManager.CSharpName (target_type));
 265                                 throw;
 266                         }
 267                 }
 268
 269                 Constant TryReduce (EmitContext ec, Type target_type)
 270                 {
 271                         if (Type == target_type)
 272                                 return this;
 273
 274                         if (TypeManager.IsEnumType (target_type)) {
 275                                 Constant c = TryReduce (ec, TypeManager.EnumToUnderlying (target_type));
 276                                 if (c == null)
 277                                         return null;
 278
 279                                 return new EnumConstant (c, target_type);
 280                         }
 281
 282                         return Reduce (ec.ConstantCheckState, target_type);
 283                 }
 284
 285
 286                 public virtual DecimalConstant ConvertToDecimal ()
 287                 {
 288                         return null;
 289                 }
 290
 291                 public virtual DoubleConstant ConvertToDouble ()
 292                 {
 293                         return null;
 294                 }
 295
 296                 public virtual FloatConstant ConvertToFloat ()
 297                 {
 298                         return null;
 299                 }
 300
 301                 public virtual ULongConstant ConvertToULong ()
 302                 {
 303                         return null;
 304                 }
 305
 306                 public virtual LongConstant ConvertToLong ()
 307                 {
 308                         return null;
 309                 }
 310
 311                 public virtual UIntConstant ConvertToUInt ()
 312                 {
 313                         return null;
 314                 }
 315
 316                 public virtual IntConstant ConvertToInt ()
 317                 {
 318                         return null;
 319                 }
 320
 321                 public abstract Constant Increment ();
 322
 323                 public abstract bool IsDefaultValue {
 324                         get;
 325                 }
 326
 327                 public abstract bool IsNegative {
 328                         get;
 329                 }
 330
 331                 //
 332                 // Returns true iff 1) the stack type of this is one of Object,
 333                 // int32, int64 and 2) this == 0 or this == null.
 334                 //
 335                 public virtual bool IsZeroInteger {
 336                         get { return false; }
 337                 }
 338         }
 339
 340         public abstract class IntegralConstant : Constant {
 341                 protected IntegralConstant (Location loc) :
 342                         base (loc)
 343                 {
 344                 }
 345
 346                 public override void Error_ValueCannotBeConverted (Location loc, Type target, bool expl)
 347                 {
 348                         try {
 349                                 Reduce (true, target);
 350                                 base.Error_ValueCannotBeConverted (loc, target, expl);
 351                         }
 352                         catch
 353                         {
 354                                 Report.Error (31, loc, "Constant value `{0}' cannot be converted to a `{1}'",
 355                                         GetValue ().ToString (), TypeManager.CSharpName (target));
 356                         }
 357                 }
 358         }
 359
 360         public class BoolConstant : Constant {
 361                 public readonly bool Value;
 362
 363                 public BoolConstant (bool val, Location loc):
 364                         base (loc)
 365                 {
 366                         type = TypeManager.bool_type;
 367                         eclass = ExprClass.Value;
 368
 369                         Value = val;
 370                 }
 371
 372                 override public string AsString ()
 373                 {
 374                         return Value ? "true" : "false";
 375                 }
 376
 377                 public override object GetValue ()
 378                 {
 379                         return (object) Value;
 380                 }
 381
 382
 383                 public override void Emit (EmitContext ec)
 384                 {
 385                         if (Value)
 386                                 ec.ig.Emit (OpCodes.Ldc_I4_1);
 387                         else
 388                                 ec.ig.Emit (OpCodes.Ldc_I4_0);
 389                 }
 390
 391                 public override Constant Increment ()
 392                 {
 393                         throw new NotSupportedException ();
 394                 }
 395
 396                 public override bool IsDefaultValue {
 397                         get {
 398                                 return !Value;
 399                         }
 400                 }
 401
 402                 public override bool IsNegative {
 403                         get {
 404                                 return false;
 405                         }
 406                 }
 407
 408                 public override bool IsZeroInteger {
 409                         get { return Value == false; }
 410                 }
 411
 412                 public override Constant Reduce (bool inCheckedContext, Type target_type)
 413                 {
 414                         return null;
 415                 }
 416
 417         }
 418
 419         public class ByteConstant : IntegralConstant {
 420                 public readonly byte Value;
 421
 422                 public ByteConstant (byte v, Location loc):
 423                         base (loc)
 424                 {
 425                         type = TypeManager.byte_type;
 426                         eclass = ExprClass.Value;
 427                         Value = v;
 428                 }
 429
 430                 public override void Emit (EmitContext ec)
 431                 {
 432                         IntLiteral.EmitInt (ec.ig, Value);
 433                 }
 434
 435                 public override string AsString ()
 436                 {
 437                         return Value.ToString ();
 438                 }
 439
 440                 public override object GetValue ()
 441                 {
 442                         return Value;
 443                 }
 444
 445                 public override DoubleConstant ConvertToDouble ()
 446                 {
 447                         return new DoubleConstant (Value, loc);
 448                 }
 449
 450                 public override FloatConstant ConvertToFloat ()
 451                 {
 452                         return new FloatConstant (Value, loc);
 453                 }
 454
 455                 public override ULongConstant ConvertToULong ()
 456                 {
 457                         return new ULongConstant (Value, loc);
 458                 }
 459
 460                 public override LongConstant ConvertToLong ()
 461                 {
 462                         return new LongConstant (Value, loc);
 463                 }
 464
 465                 public override UIntConstant ConvertToUInt ()
 466                 {
 467                         return new UIntConstant (Value, loc);
 468                 }
 469
 470                 public override IntConstant ConvertToInt ()
 471                 {
 472                         return new IntConstant (Value, loc);
 473                 }
 474
 475                 public override Constant Increment ()
 476                 {
 477                         return new ByteConstant (checked ((byte)(Value + 1)), loc);
 478                 }
 479
 480                 public override bool IsDefaultValue {
 481                         get {
 482                                 return Value == 0;
 483                         }
 484                 }
 485
 486                 public override bool IsNegative {
 487                         get {
 488                                 return false;
 489                         }
 490                 }
 491
 492                 public override bool IsZeroInteger {
 493                         get { return Value == 0; }
 494                 }
 495
 496                 public override Constant Reduce (bool inCheckedContext, Type target_type)
 497                 {
 498                         if (target_type == TypeManager.sbyte_type) {
 499                                 CheckRange (inCheckedContext, Value, SByte.MinValue, SByte.MaxValue);
 500                                 return new SByteConstant ((sbyte) Value, Location);
 501                         }
 502                         if (target_type == TypeManager.short_type)
 503                                 return new ShortConstant ((short) Value, Location);
 504                         if (target_type == TypeManager.ushort_type)
 505                                 return new UShortConstant ((ushort) Value, Location);
 506                         if (target_type == TypeManager.int32_type)
 507                                 return new IntConstant ((int) Value, Location);
 508                         if (target_type == TypeManager.uint32_type)
 509                                 return new UIntConstant ((uint) Value, Location);
 510                         if (target_type == TypeManager.int64_type)
 511                                 return new LongConstant ((long) Value, Location);
 512                         if (target_type == TypeManager.uint64_type)
 513                                 return new ULongConstant ((ulong) Value, Location);
 514                         if (target_type == TypeManager.float_type)
 515                                 return new FloatConstant ((float) Value, Location);
 516                         if (target_type == TypeManager.double_type)
 517                                 return new DoubleConstant ((double) Value, Location);
 518                         if (target_type == TypeManager.char_type)
 519                                 return new CharConstant ((char) Value, Location);
 520                         if (target_type == TypeManager.decimal_type)
 521                                 return new DecimalConstant ((decimal) Value, Location);
 522
 523                         return null;
 524                 }
 525
 526         }
 527
 528         public class CharConstant : Constant {
 529                 public readonly char Value;
 530
 531                 public CharConstant (char v, Location loc):
 532                         base (loc)
 533                 {
 534                         type = TypeManager.char_type;
 535                         eclass = ExprClass.Value;
 536                         Value = v;
 537                 }
 538
 539                 public override void Emit (EmitContext ec)
 540                 {
 541                         IntLiteral.EmitInt (ec.ig, Value);
 542                 }
 543
 544                 static public string descape (char c)
 545                 {
 546                         switch (c){
 547                         case '\a':
 548                                 return "\\a";
 549                         case '\b':
 550                                 return "\\b";
 551                         case '\n':
 552                                 return "\\n";
 553                         case '\t':
 554                                 return "\\t";
 555                         case '\v':
 556                                 return "\\v";
 557                         case '\r':
 558                                 return "\\r";
 559                         case '\\':
 560                                 return "\\\\";
 561                         case '\f':
 562                                 return "\\f";
 563                         case '\0':
 564                                 return "\\0";
 565                         case '"':
 566                                 return "\\\"";
 567                         case '\'':
 568                                 return "\\\'";
 569                         }
 570                         return c.ToString ();
 571                 }
 572
 573                 public override string AsString ()
 574                 {
 575                         return "\"" + descape (Value) + "\"";
 576                 }
 577
 578                 public override object GetValue ()
 579                 {
 580                         return Value;
 581                 }
 582
 583                 public override DoubleConstant ConvertToDouble ()
 584                 {
 585                         return new DoubleConstant (Value, loc);
 586                 }
 587
 588                 public override FloatConstant ConvertToFloat ()
 589                 {
 590                         return new FloatConstant (Value, loc);
 591                 }
 592
 593                 public override ULongConstant ConvertToULong ()
 594                 {
 595                         return new ULongConstant (Value, loc);
 596                 }
 597
 598                 public override LongConstant ConvertToLong ()
 599                 {
 600                         return new LongConstant (Value, loc);
 601                 }
 602
 603                 public override UIntConstant ConvertToUInt ()
 604                 {
 605                         return new UIntConstant (Value, loc);
 606                 }
 607
 608                 public override IntConstant ConvertToInt ()
 609                 {
 610                         return new IntConstant (Value, loc);
 611                 }
 612
 613                 public override Constant Increment ()
 614                 {
 615                         return new CharConstant (checked ((char)(Value + 1)), loc);
 616                 }
 617
 618                 public override bool IsDefaultValue {
 619                         get {
 620                                 return Value == 0;
 621                         }
 622                 }
 623
 624                 public override bool IsNegative {
 625                         get {
 626                                 return false;
 627                         }
 628                 }
 629
 630                 public override bool IsZeroInteger {
 631                         get { return Value == '\0'; }
 632                 }
 633
 634                 public override Constant Reduce (bool inCheckedContext, Type target_type)
 635                 {
 636                         if (target_type == TypeManager.byte_type) {
 637                                 CheckRange (inCheckedContext, Value, Byte.MinValue, Byte.MaxValue);
 638                                 return new ByteConstant ((byte) Value, Location);
 639                         }
 640                         if (target_type == TypeManager.sbyte_type) {
 641                                 CheckRange (inCheckedContext, Value, SByte.MinValue, SByte.MaxValue);
 642                                 return new SByteConstant ((sbyte) Value, Location);
 643                         }
 644                         if (target_type == TypeManager.short_type) {
 645                                 CheckRange (inCheckedContext, Value, Int16.MinValue, Int16.MaxValue);
 646                                 return new ShortConstant ((short) Value, Location);
 647                         }
 648                         if (target_type == TypeManager.int32_type)
 649                                 return new IntConstant ((int) Value, Location);
 650                         if (target_type == TypeManager.uint32_type)
 651                                 return new UIntConstant ((uint) Value, Location);
 652                         if (target_type == TypeManager.int64_type)
 653                                 return new LongConstant ((long) Value, Location);
 654                         if (target_type == TypeManager.uint64_type)
 655                                 return new ULongConstant ((ulong) Value, Location);
 656                         if (target_type == TypeManager.float_type)
 657                                 return new FloatConstant ((float) Value, Location);
 658                         if (target_type == TypeManager.double_type)
 659                                 return new DoubleConstant ((double) Value, Location);
 660                         if (target_type == TypeManager.decimal_type)
 661                                 return new DecimalConstant ((decimal) Value, Location);
 662
 663                         return null;
 664                 }
 665
 666         }
 667
 668         public class SByteConstant : IntegralConstant {
 669                 public readonly sbyte Value;
 670
 671                 public SByteConstant (sbyte v, Location loc):
 672                         base (loc)
 673                 {
 674                         type = TypeManager.sbyte_type;
 675                         eclass = ExprClass.Value;
 676                         Value = v;
 677                 }
 678
 679                 public override void Emit (EmitContext ec)
 680                 {
 681                         IntLiteral.EmitInt (ec.ig, Value);
 682                 }
 683
 684                 public override string AsString ()
 685                 {
 686                         return Value.ToString ();
 687                 }
 688
 689                 public override object GetValue ()
 690                 {
 691                         return Value;
 692                 }
 693
 694                 public override DoubleConstant ConvertToDouble ()
 695                 {
 696                         return new DoubleConstant (Value, loc);
 697                 }
 698
 699                 public override FloatConstant ConvertToFloat ()
 700                 {
 701                         return new FloatConstant (Value, loc);
 702                 }
 703
 704                 public override ULongConstant ConvertToULong ()
 705                 {
 706                         if (Value >= 0)
 707                                 return new ULongConstant ((ulong) Value, loc);
 708
 709                         return null;
 710                 }
 711
 712                 public override LongConstant ConvertToLong ()
 713                 {
 714                         return new LongConstant (Value, loc);
 715                 }
 716
 717                 public override UIntConstant ConvertToUInt ()
 718                 {
 719                         return null;
 720                 }
 721
 722                 public override IntConstant ConvertToInt ()
 723                 {
 724                         return new IntConstant (Value, loc);
 725                 }
 726
 727                 public override Constant Increment ()
 728                 {
 729                     return new SByteConstant (checked((sbyte)(Value + 1)), loc);
 730                 }
 731
 732                 public override bool IsDefaultValue {
 733                         get {
 734                                 return Value == 0;
 735                         }
 736                 }
 737
 738                 public override bool IsNegative {
 739                         get {
 740                                 return Value < 0;
 741                         }
 742                 }
 743
 744                 public override bool IsZeroInteger {
 745                         get { return Value == 0; }
 746                 }
 747
 748                 public override Constant Reduce (bool inCheckedContext, Type target_type)
 749                 {
 750                         if (target_type == TypeManager.byte_type) {
 751                                 CheckUnsigned (inCheckedContext, Value);
 752                                 return new ByteConstant ((byte) Value, Location);
 753                         }
 754                         if (target_type == TypeManager.short_type)
 755                                 return new ShortConstant ((short) Value, Location);
 756                         if (target_type == TypeManager.ushort_type) {
 757                                 CheckUnsigned (inCheckedContext, Value);
 758                                 return new UShortConstant ((ushort) Value, Location);
 759                         } if (target_type == TypeManager.int32_type)
 760                                   return new IntConstant ((int) Value, Location);
 761                         if (target_type == TypeManager.uint32_type) {
 762                                 CheckUnsigned (inCheckedContext, Value);
 763                                 return new UIntConstant ((uint) Value, Location);
 764                         } if (target_type == TypeManager.int64_type)
 765                                   return new LongConstant ((long) Value, Location);
 766                         if (target_type == TypeManager.uint64_type) {
 767                                 CheckUnsigned (inCheckedContext, Value);
 768                                 return new ULongConstant ((ulong) Value, Location);
 769                         }
 770                         if (target_type == TypeManager.float_type)
 771                                 return new FloatConstant ((float) Value, Location);
 772                         if (target_type == TypeManager.double_type)
 773                                 return new DoubleConstant ((double) Value, Location);
 774                         if (target_type == TypeManager.char_type) {
 775                                 CheckUnsigned (inCheckedContext, Value);
 776                                 return new CharConstant ((char) Value, Location);
 777                         }
 778                         if (target_type == TypeManager.decimal_type)
 779                                 return new DecimalConstant ((decimal) Value, Location);
 780
 781                         return null;
 782                 }
 783
 784         }
 785
 786         public class ShortConstant : IntegralConstant {
 787                 public readonly short Value;
 788
 789                 public ShortConstant (short v, Location loc):
 790                         base (loc)
 791                 {
 792                         type = TypeManager.short_type;
 793                         eclass = ExprClass.Value;
 794                         Value = v;
 795                 }
 796
 797                 public override void Emit (EmitContext ec)
 798                 {
 799                         IntLiteral.EmitInt (ec.ig, Value);
 800                 }
 801
 802                 public override string AsString ()
 803                 {
 804                         return Value.ToString ();
 805                 }
 806
 807                 public override object GetValue ()
 808                 {
 809                         return Value;
 810                 }
 811
 812                 public override DoubleConstant ConvertToDouble ()
 813                 {
 814                         return new DoubleConstant (Value, loc);
 815                 }
 816
 817                 public override FloatConstant ConvertToFloat ()
 818                 {
 819                         return new FloatConstant (Value, loc);
 820                 }
 821
 822                 public override ULongConstant ConvertToULong ()
 823                 {
 824                         return null;
 825                 }
 826
 827                 public override LongConstant ConvertToLong ()
 828                 {
 829                         return new LongConstant (Value, loc);
 830                 }
 831
 832                 public override UIntConstant ConvertToUInt ()
 833                 {
 834                         return null;
 835                 }
 836
 837                 public override IntConstant ConvertToInt ()
 838                 {
 839                         return new IntConstant (Value, loc);
 840                 }
 841
 842                 public override Constant Increment ()
 843                 {
 844                         return new ShortConstant (checked((short)(Value + 1)), loc);
 845                 }
 846
 847                 public override bool IsDefaultValue {
 848                         get {
 849                                 return Value == 0;
 850                         }
 851                 }
 852
 853                 public override bool IsZeroInteger {
 854                         get { return Value == 0; }
 855                 }
 856
 857                 public override bool IsNegative {
 858                         get {
 859                                 return Value < 0;
 860                         }
 861                 }
 862
 863                 public override Constant Reduce (bool inCheckedContext, Type target_type)
 864                 {
 865                         if (target_type == TypeManager.byte_type) {
 866                                 CheckRange (inCheckedContext, Value, Byte.MinValue, Byte.MaxValue);
 867                                 return new ByteConstant ((byte) Value, Location);
 868                         }
 869                         if (target_type == TypeManager.sbyte_type) {
 870                                 CheckRange (inCheckedContext, Value, SByte.MinValue, SByte.MaxValue);
 871                                 return new SByteConstant ((sbyte) Value, Location);
 872                         }
 873                         if (target_type == TypeManager.ushort_type) {
 874                                 CheckUnsigned (inCheckedContext, Value);
 875                                 return new UShortConstant ((ushort) Value, Location);
 876                         }
 877                         if (target_type == TypeManager.int32_type)
 878                                 return new IntConstant ((int) Value, Location);
 879                         if (target_type == TypeManager.uint32_type) {
 880                                 CheckUnsigned (inCheckedContext, Value);
 881                                 return new UIntConstant ((uint) Value, Location);
 882                         }
 883                         if (target_type == TypeManager.int64_type)
 884                                 return new LongConstant ((long) Value, Location);
 885                         if (target_type == TypeManager.uint64_type) {
 886                                 CheckUnsigned (inCheckedContext, Value);
 887                                 return new ULongConstant ((ulong) Value, Location);
 888                         }
 889                         if (target_type == TypeManager.float_type)
 890                                 return new FloatConstant ((float) Value, Location);
 891                         if (target_type == TypeManager.double_type)
 892                                 return new DoubleConstant ((double) Value, Location);
 893                         if (target_type == TypeManager.char_type) {
 894                                 CheckRange (inCheckedContext, Value, Char.MinValue, Char.MaxValue);
 895                                 return new CharConstant ((char) Value, Location);
 896                         }
 897                         if (target_type == TypeManager.decimal_type)
 898                                 return new DecimalConstant ((decimal) Value, Location);
 899
 900                         return null;
 901                 }
 902
 903         }
 904
 905         public class UShortConstant : IntegralConstant {
 906                 public readonly ushort Value;
 907
 908                 public UShortConstant (ushort v, Location loc):
 909                         base (loc)
 910                 {
 911                         type = TypeManager.ushort_type;
 912                         eclass = ExprClass.Value;
 913                         Value = v;
 914                 }
 915
 916                 public override void Emit (EmitContext ec)
 917                 {
 918                         IntLiteral.EmitInt (ec.ig, Value);
 919                 }
 920
 921                 public override string AsString ()
 922                 {
 923                         return Value.ToString ();
 924                 }
 925
 926                 public override object GetValue ()
 927                 {
 928                         return Value;
 929                 }
 930
 931                 public override DoubleConstant ConvertToDouble ()
 932                 {
 933                         return new DoubleConstant (Value, loc);
 934                 }
 935
 936                 public override FloatConstant ConvertToFloat ()
 937                 {
 938                         return new FloatConstant (Value, loc);
 939                 }
 940
 941                 public override ULongConstant ConvertToULong ()
 942                 {
 943                         return new ULongConstant (Value, loc);
 944                 }
 945
 946                 public override LongConstant ConvertToLong ()
 947                 {
 948                         return new LongConstant (Value, loc);
 949                 }
 950
 951                 public override UIntConstant ConvertToUInt ()
 952                 {
 953                         return new UIntConstant (Value, loc);
 954                 }
 955
 956                 public override IntConstant ConvertToInt ()
 957                 {
 958                         return new IntConstant (Value, loc);
 959                 }
 960
 961                 public override Constant Increment ()
 962                 {
 963                         return new UShortConstant (checked((ushort)(Value + 1)), loc);
 964                 }
 965
 966                 public override bool IsDefaultValue {
 967                         get {
 968                                 return Value == 0;
 969                         }
 970                 }
 971
 972                 public override bool IsNegative {
 973                         get {
 974                                 return false;
 975                         }
 976                 }
 977
 978                 public override bool IsZeroInteger {
 979                         get { return Value == 0; }
 980                 }
 981
 982                 public override Constant Reduce (bool inCheckedContext, Type target_type)
 983                 {
 984                         if (target_type == TypeManager.byte_type) {
 985                                 CheckRange (inCheckedContext, Value, Byte.MinValue, Byte.MaxValue);
 986                                 return new ByteConstant ((byte) Value, Location);
 987                         }
 988                         if (target_type == TypeManager.sbyte_type) {
 989                                 CheckRange (inCheckedContext, Value, SByte.MinValue, SByte.MaxValue);
 990                                 return new SByteConstant ((sbyte) Value, Location);
 991                         }
 992                         if (target_type == TypeManager.short_type) {
 993                                 CheckRange (inCheckedContext, Value, Int16.MinValue, Int16.MaxValue);
 994                                 return new ShortConstant ((short) Value, Location);
 995                         }
 996                         if (target_type == TypeManager.int32_type)
 997                                 return new IntConstant ((int) Value, Location);
 998                         if (target_type == TypeManager.uint32_type)
 999                                 return new UIntConstant ((uint) Value, Location);
1000                         if (target_type == TypeManager.int64_type)
1001                                 return new LongConstant ((long) Value, Location);
1002                         if (target_type == TypeManager.uint64_type)
1003                                 return new ULongConstant ((ulong) Value, Location);
1004                         if (target_type == TypeManager.float_type)
1005                                 return new FloatConstant ((float) Value, Location);
1006                         if (target_type == TypeManager.double_type)
1007                                 return new DoubleConstant ((double) Value, Location);
1008                         if (target_type == TypeManager.char_type) {
1009                                 CheckRange (inCheckedContext, Value, Char.MinValue, Char.MaxValue);
1010                                 return new CharConstant ((char) Value, Location);
1011                         }
1012                         if (target_type == TypeManager.decimal_type)
1013                                 return new DecimalConstant ((decimal) Value, Location);
1014
1015                         return null;
1016                 }
1017         }
1018
1019         public class IntConstant : IntegralConstant {
1020                 public readonly int Value;
1021
1022                 public IntConstant (int v, Location loc):
1023                         base (loc)
1024                 {
1025                         type = TypeManager.int32_type;
1026                         eclass = ExprClass.Value;
1027                         Value = v;
1028                 }
1029
1030                 static public void EmitInt (ILGenerator ig, int i)
1031                 {
1032                         switch (i){
1033                         case -1:
1034                                 ig.Emit (OpCodes.Ldc_I4_M1);
1035                                 break;
1036
1037                         case 0:
1038                                 ig.Emit (OpCodes.Ldc_I4_0);
1039                                 break;
1040
1041                         case 1:
1042                                 ig.Emit (OpCodes.Ldc_I4_1);
1043                                 break;
1044
1045                         case 2:
1046                                 ig.Emit (OpCodes.Ldc_I4_2);
1047                                 break;
1048
1049                         case 3:
1050                                 ig.Emit (OpCodes.Ldc_I4_3);
1051                                 break;
1052
1053                         case 4:
1054                                 ig.Emit (OpCodes.Ldc_I4_4);
1055                                 break;
1056
1057                         case 5:
1058                                 ig.Emit (OpCodes.Ldc_I4_5);
1059                                 break;
1060
1061                         case 6:
1062                                 ig.Emit (OpCodes.Ldc_I4_6);
1063                                 break;
1064
1065                         case 7:
1066                                 ig.Emit (OpCodes.Ldc_I4_7);
1067                                 break;
1068
1069                         case 8:
1070                                 ig.Emit (OpCodes.Ldc_I4_8);
1071                                 break;
1072
1073                         default:
1074                                 if (i >= -128 && i <= 127){
1075                                         ig.Emit (OpCodes.Ldc_I4_S, (sbyte) i);
1076                                 } else
1077                                         ig.Emit (OpCodes.Ldc_I4, i);
1078                                 break;
1079                         }
1080                 }
1081
1082                 public override void Emit (EmitContext ec)
1083                 {
1084                         EmitInt (ec.ig, Value);
1085                 }
1086
1087                 public override string AsString ()
1088                 {
1089                         return Value.ToString ();
1090                 }
1091
1092                 public override object GetValue ()
1093                 {
1094                         return Value;
1095                 }
1096
1097                 public override DecimalConstant ConvertToDecimal()
1098                 {
1099                         return new DecimalConstant (Value, loc);
1100                 }
1101
1102                 public override DoubleConstant ConvertToDouble ()
1103                 {
1104                         return new DoubleConstant (Value, loc);
1105                 }
1106
1107                 public override FloatConstant ConvertToFloat ()
1108                 {
1109                         return new FloatConstant (Value, loc);
1110                 }
1111
1112                 public override ULongConstant ConvertToULong ()
1113                 {
1114                         if (Value < 0)
1115                                 return null;
1116
1117                         return new ULongConstant ((ulong) Value, loc);
1118                 }
1119
1120                 public override LongConstant ConvertToLong ()
1121                 {
1122                         return new LongConstant (Value, loc);
1123                 }
1124
1125                 public override UIntConstant ConvertToUInt ()
1126                 {
1127                         if (Value < 0)
1128                                 return null;
1129
1130                         return new UIntConstant ((uint) Value, loc);
1131                 }
1132
1133                 public override IntConstant ConvertToInt ()
1134                 {
1135                         return this;
1136                 }
1137
1138                 public override Constant Increment ()
1139                 {
1140                         return new IntConstant (checked(Value + 1), loc);
1141                 }
1142
1143                 public override bool IsDefaultValue {
1144                         get {
1145                                 return Value == 0;
1146                         }
1147                 }
1148
1149                 public override bool IsNegative {
1150                         get {
1151                                 return Value < 0;
1152                         }
1153                 }
1154
1155                 public override bool IsZeroInteger {
1156                         get { return Value == 0; }
1157                 }
1158
1159                 public override Constant Reduce (bool inCheckedContext, Type target_type)
1160                 {
1161                         if (target_type == TypeManager.byte_type) {
1162                                 CheckRange (inCheckedContext, Value, Byte.MinValue, Byte.MaxValue);
1163                                 return new ByteConstant ((byte) Value, Location);
1164                         }
1165                         if (target_type == TypeManager.sbyte_type) {
1166                                 CheckRange (inCheckedContext, Value, SByte.MinValue, SByte.MaxValue);
1167                                 return new SByteConstant ((sbyte) Value, Location);
1168                         }
1169                         if (target_type == TypeManager.short_type) {
1170                                 CheckRange (inCheckedContext, Value, Int16.MinValue, Int16.MaxValue);
1171                                 return new ShortConstant ((short) Value, Location);
1172                         }
1173                         if (target_type == TypeManager.ushort_type) {
1174                                 CheckRange (inCheckedContext, Value, UInt16.MinValue, UInt16.MaxValue);
1175                                 return new UShortConstant ((ushort) Value, Location);
1176                         }
1177                         if (target_type == TypeManager.uint32_type) {
1178                                 CheckRange (inCheckedContext, Value, UInt32.MinValue, UInt32.MaxValue);
1179                                 return new UIntConstant ((uint) Value, Location);
1180                         }
1181                         if (target_type == TypeManager.int64_type)
1182                                 return new LongConstant ((long) Value, Location);
1183                         if (target_type == TypeManager.uint64_type) {
1184                                 CheckUnsigned (inCheckedContext, Value);
1185                                 return new ULongConstant ((ulong) Value, Location);
1186                         }
1187                         if (target_type == TypeManager.float_type)
1188                                 return new FloatConstant ((float) Value, Location);
1189                         if (target_type == TypeManager.double_type)
1190                                 return new DoubleConstant ((double) Value, Location);
1191                         if (target_type == TypeManager.char_type) {
1192                                 CheckRange (inCheckedContext, Value, Char.MinValue, Char.MaxValue);
1193                                 return new CharConstant ((char) Value, Location);
1194                         }
1195                         if (target_type == TypeManager.decimal_type)
1196                                 return new DecimalConstant ((decimal) Value, Location);
1197
1198                         return null;
1199                 }
1200         }
1201
1202         public class UIntConstant : IntegralConstant {
1203                 public readonly uint Value;
1204
1205                 public UIntConstant (uint v, Location loc):
1206                         base (loc)
1207                 {
1208                         type = TypeManager.uint32_type;
1209                         eclass = ExprClass.Value;
1210                         Value = v;
1211                 }
1212
1213                 public override void Emit (EmitContext ec)
1214                 {
1215                         IntLiteral.EmitInt (ec.ig, unchecked ((int) Value));
1216                 }
1217
1218                 public override string AsString ()
1219                 {
1220                         return Value.ToString ();
1221                 }
1222
1223                 public override object GetValue ()
1224                 {
1225                         return Value;
1226                 }
1227
1228                 public override DoubleConstant ConvertToDouble ()
1229                 {
1230                         return new DoubleConstant (Value, loc);
1231                 }
1232
1233                 public override FloatConstant ConvertToFloat ()
1234                 {
1235                         return new FloatConstant (Value, loc);
1236                 }
1237
1238                 public override ULongConstant ConvertToULong ()
1239                 {
1240                         return new ULongConstant (Value, loc);
1241                 }
1242
1243                 public override LongConstant ConvertToLong ()
1244                 {
1245                         return new LongConstant (Value, loc);
1246                 }
1247
1248                 public override UIntConstant ConvertToUInt ()
1249                 {
1250                         return this;
1251                 }
1252
1253                 public override IntConstant ConvertToInt ()
1254                 {
1255                         return null;
1256                 }
1257
1258                 public override Constant Increment ()
1259                 {
1260                         return new UIntConstant (checked(Value + 1), loc);
1261                 }
1262
1263                 public override bool IsDefaultValue {
1264                         get {
1265                                 return Value == 0;
1266                         }
1267                 }
1268
1269                 public override bool IsNegative {
1270                         get {
1271                                 return false;
1272                         }
1273                 }
1274
1275                 public override bool IsZeroInteger {
1276                         get { return Value == 0; }
1277                 }
1278
1279                 public override Constant Reduce (bool inCheckedContext, Type target_type)
1280                 {
1281                         if (target_type == TypeManager.byte_type) {
1282                                 CheckRange (inCheckedContext, Value, Char.MinValue, Char.MaxValue);
1283                                 return new ByteConstant ((byte) Value, Location);
1284                         }
1285                         if (target_type == TypeManager.sbyte_type) {
1286                                 CheckRange (inCheckedContext, Value, SByte.MinValue, SByte.MaxValue);
1287                                 return new SByteConstant ((sbyte) Value, Location);
1288                         }
1289                         if (target_type == TypeManager.short_type) {
1290                                 CheckRange (inCheckedContext, Value, Int16.MinValue, Int16.MaxValue);
1291                                 return new ShortConstant ((short) Value, Location);
1292                         }
1293                         if (target_type == TypeManager.ushort_type) {
1294                                 CheckRange (inCheckedContext, Value, UInt16.MinValue, UInt16.MaxValue);
1295                                 return new UShortConstant ((ushort) Value, Location);
1296                         }
1297                         if (target_type == TypeManager.int32_type) {
1298                                 CheckRange (inCheckedContext, Value, Int32.MinValue, Int32.MaxValue);
1299                                 return new IntConstant ((int) Value, Location);
1300                         }
1301                         if (target_type == TypeManager.int64_type)
1302                                 return new LongConstant ((long) Value, Location);
1303                         if (target_type == TypeManager.uint64_type)
1304                                 return new ULongConstant ((ulong) Value, Location);
1305                         if (target_type == TypeManager.float_type)
1306                                 return new FloatConstant ((float) Value, Location);
1307                         if (target_type == TypeManager.double_type)
1308                                 return new DoubleConstant ((double) Value, Location);
1309                         if (target_type == TypeManager.char_type) {
1310                                 CheckRange (inCheckedContext, Value, Char.MinValue, Char.MaxValue);
1311                                 return new CharConstant ((char) Value, Location);
1312                         }
1313                         if (target_type == TypeManager.decimal_type)
1314                                 return new DecimalConstant ((decimal) Value, Location);
1315
1316                         return null;
1317                 }
1318
1319         }
1320
1321         public class LongConstant : IntegralConstant {
1322                 public readonly long Value;
1323
1324                 public LongConstant (long v, Location loc):
1325                         base (loc)
1326                 {
1327                         type = TypeManager.int64_type;
1328                         eclass = ExprClass.Value;
1329                         Value = v;
1330                 }
1331
1332                 public override void Emit (EmitContext ec)
1333                 {
1334                         ILGenerator ig = ec.ig;
1335
1336                         EmitLong (ig, Value);
1337                 }
1338
1339                 static public void EmitLong (ILGenerator ig, long l)
1340                 {
1341                         if ((l >> 32) == 0){
1342                                 IntLiteral.EmitInt (ig, unchecked ((int) l));
1343                                 ig.Emit (OpCodes.Conv_U8);
1344                         } else {
1345                                 ig.Emit (OpCodes.Ldc_I8, l);
1346                         }
1347                 }
1348
1349                 public override string AsString ()
1350                 {
1351                         return Value.ToString ();
1352                 }
1353
1354                 public override object GetValue ()
1355                 {
1356                         return Value;
1357                 }
1358
1359                 public override DoubleConstant ConvertToDouble ()
1360                 {
1361                         return new DoubleConstant (Value, loc);
1362                 }
1363
1364                 public override FloatConstant ConvertToFloat ()
1365                 {
1366                         return new FloatConstant (Value, loc);
1367                 }
1368
1369                 public override ULongConstant ConvertToULong ()
1370                 {
1371                         if (Value < 0)
1372                                 return null;
1373
1374                         return new ULongConstant ((ulong) Value, loc);
1375                 }
1376
1377                 public override LongConstant ConvertToLong ()
1378                 {
1379                         return this;
1380                 }
1381
1382                 public override UIntConstant ConvertToUInt ()
1383                 {
1384                         return null;
1385                 }
1386
1387                 public override IntConstant ConvertToInt ()
1388                 {
1389                         return null;
1390                 }
1391
1392                 public override Constant Increment ()
1393                 {
1394                         return new LongConstant (checked(Value + 1), loc);
1395                 }
1396
1397                 public override bool IsDefaultValue {
1398                         get {
1399                                 return Value == 0;
1400                         }
1401                 }
1402
1403                 public override bool IsNegative {
1404                         get {
1405                                 return Value < 0;
1406                         }
1407                 }
1408
1409                 public override bool IsZeroInteger {
1410                         get { return Value == 0; }
1411                 }
1412
1413                 public override Constant Reduce (bool inCheckedContext, Type target_type)
1414                 {
1415                         if (target_type == TypeManager.byte_type) {
1416                                 CheckRange (inCheckedContext, Value, Byte.MinValue, Byte.MaxValue);
1417                                 return new ByteConstant ((byte) Value, Location);
1418                         }
1419                         if (target_type == TypeManager.sbyte_type) {
1420                                 CheckRange (inCheckedContext, Value, SByte.MinValue, SByte.MaxValue);
1421                                 return new SByteConstant ((sbyte) Value, Location);
1422                         }
1423                         if (target_type == TypeManager.short_type) {
1424                                 CheckRange (inCheckedContext, Value, Int16.MinValue, Int16.MaxValue);
1425                                 return new ShortConstant ((short) Value, Location);
1426                         }
1427                         if (target_type == TypeManager.ushort_type) {
1428                                 CheckRange (inCheckedContext, Value, UInt16.MinValue, UInt16.MaxValue);
1429                                 return new UShortConstant ((ushort) Value, Location);
1430                         }
1431                         if (target_type == TypeManager.int32_type) {
1432                                 CheckRange (inCheckedContext, Value, Int32.MinValue, Int32.MaxValue);
1433                                 return new IntConstant ((int) Value, Location);
1434                         }
1435                         if (target_type == TypeManager.uint32_type) {
1436                                 CheckRange (inCheckedContext, Value, UInt32.MinValue, UInt32.MaxValue);
1437                                 return new UIntConstant ((uint) Value, Location);
1438                         }
1439                         if (target_type == TypeManager.uint64_type) {
1440                                 CheckUnsigned (inCheckedContext, Value);
1441                                 return new ULongConstant ((ulong) Value, Location);
1442                         }
1443                         if (target_type == TypeManager.float_type)
1444                                 return new FloatConstant ((float) Value, Location);
1445                         if (target_type == TypeManager.double_type)
1446                                 return new DoubleConstant ((double) Value, Location);
1447                         if (target_type == TypeManager.char_type) {
1448                                 CheckRange (inCheckedContext, Value, Char.MinValue, Char.MaxValue);
1449                                 return new CharConstant ((char) Value, Location);
1450                         }
1451                         if (target_type == TypeManager.decimal_type)
1452                                 return new DecimalConstant ((decimal) Value, Location);
1453
1454                         return null;
1455                 }
1456
1457         }
1458
1459         public class ULongConstant : IntegralConstant {
1460                 public readonly ulong Value;
1461
1462                 public ULongConstant (ulong v, Location loc):
1463                         base (loc)
1464                 {
1465                         type = TypeManager.uint64_type;
1466                         eclass = ExprClass.Value;
1467                         Value = v;
1468                 }
1469
1470                 public override void Emit (EmitContext ec)
1471                 {
1472                         ILGenerator ig = ec.ig;
1473
1474                         LongLiteral.EmitLong (ig, unchecked ((long) Value));
1475                 }
1476
1477                 public override string AsString ()
1478                 {
1479                         return Value.ToString ();
1480                 }
1481
1482                 public override object GetValue ()
1483                 {
1484                         return Value;
1485                 }
1486
1487                 public override DoubleConstant ConvertToDouble ()
1488                 {
1489                         return new DoubleConstant (Value, loc);
1490                 }
1491
1492                 public override FloatConstant ConvertToFloat ()
1493                 {
1494                         return new FloatConstant (Value, loc);
1495                 }
1496
1497                 public override ULongConstant ConvertToULong ()
1498                 {
1499                         return this;
1500                 }
1501
1502                 public override LongConstant ConvertToLong ()
1503                 {
1504                         return null;
1505                 }
1506
1507                 public override UIntConstant ConvertToUInt ()
1508                 {
1509                         return null;
1510                 }
1511
1512                 public override IntConstant ConvertToInt ()
1513                 {
1514                         return null;
1515                 }
1516
1517                 public override Constant Increment ()
1518                 {
1519                         return new ULongConstant (checked(Value + 1), loc);
1520                 }
1521
1522                 public override bool IsDefaultValue {
1523                         get {
1524                                 return Value == 0;
1525                         }
1526                 }
1527
1528                 public override bool IsNegative {
1529                         get {
1530                                 return false;
1531                         }
1532                 }
1533
1534                 public override bool IsZeroInteger {
1535                         get { return Value == 0; }
1536                 }
1537
1538                 public override Constant Reduce (bool inCheckedContext, Type target_type)
1539                 {
1540                         if (target_type == TypeManager.byte_type) {
1541                                 CheckRange (inCheckedContext, Value, Byte.MaxValue);
1542                                 return new ByteConstant ((byte) Value, Location);
1543                         }
1544                         if (target_type == TypeManager.sbyte_type) {
1545                                 CheckRange (inCheckedContext, Value, (ulong) SByte.MaxValue);
1546                                 return new SByteConstant ((sbyte) Value, Location);
1547                         }
1548                         if (target_type == TypeManager.short_type) {
1549                                 CheckRange (inCheckedContext, Value, (ulong) Int16.MaxValue);
1550                                 return new ShortConstant ((short) Value, Location);
1551                         }
1552                         if (target_type == TypeManager.ushort_type) {
1553                                 CheckRange (inCheckedContext, Value, UInt16.MaxValue);
1554                                 return new UShortConstant ((ushort) Value, Location);
1555                         }
1556                         if (target_type == TypeManager.int32_type) {
1557                                 CheckRange (inCheckedContext, Value, Int32.MaxValue);
1558                                 return new IntConstant ((int) Value, Location);
1559                         }
1560                         if (target_type == TypeManager.uint32_type) {
1561                                 CheckRange (inCheckedContext, Value, UInt32.MaxValue);
1562                                 return new UIntConstant ((uint) Value, Location);
1563                         }
1564                         if (target_type == TypeManager.int64_type) {
1565                                 CheckRange (inCheckedContext, Value, (ulong) Int64.MaxValue);
1566                                 return new LongConstant ((long) Value, Location);
1567                         }
1568                         if (target_type == TypeManager.float_type)
1569                                 return new FloatConstant ((float) Value, Location);
1570                         if (target_type == TypeManager.double_type)
1571                                 return new DoubleConstant ((double) Value, Location);
1572                         if (target_type == TypeManager.char_type) {
1573                                 CheckRange (inCheckedContext, Value, Char.MaxValue);
1574                                 return new CharConstant ((char) Value, Location);
1575                         }
1576                         if (target_type == TypeManager.decimal_type)
1577                                 return new DecimalConstant ((decimal) Value, Location);
1578
1579                         return null;
1580                 }
1581
1582         }
1583
1584         public class FloatConstant : Constant {
1585                 public readonly float Value;
1586
1587                 public FloatConstant (float v, Location loc):
1588                         base (loc)
1589                 {
1590                         type = TypeManager.float_type;
1591                         eclass = ExprClass.Value;
1592                         Value = v;
1593                 }
1594
1595                 public override void Emit (EmitContext ec)
1596                 {
1597                         ec.ig.Emit (OpCodes.Ldc_R4, Value);
1598                 }
1599
1600                 public override string AsString ()
1601                 {
1602                         return Value.ToString ();
1603                 }
1604
1605                 public override object GetValue ()
1606                 {
1607                         return Value;
1608                 }
1609
1610                 public override DoubleConstant ConvertToDouble ()
1611                 {
1612                         return new DoubleConstant (Value, loc);
1613                 }
1614
1615                 public override FloatConstant ConvertToFloat ()
1616                 {
1617                         return this;
1618                 }
1619
1620                 public override LongConstant ConvertToLong ()
1621                 {
1622                         return null;
1623                 }
1624
1625                 public override UIntConstant ConvertToUInt ()
1626                 {
1627                         return null;
1628                 }
1629
1630                 public override IntConstant ConvertToInt ()
1631                 {
1632                         return null;
1633                 }
1634
1635                 public override Constant Increment ()
1636                 {
1637                         return new FloatConstant (checked(Value + 1), loc);
1638                 }
1639
1640                 public override bool IsDefaultValue {
1641                         get {
1642                                 return Value == 0;
1643                         }
1644                 }
1645
1646                 public override bool IsNegative {
1647                         get {
1648                                 return Value < 0;
1649                         }
1650                 }
1651
1652                 public override Constant Reduce (bool inCheckedContext, Type target_type)
1653                 {
1654                         if (target_type == TypeManager.byte_type)
1655                                 return new ByteConstant ((byte) Value, Location);
1656                         if (target_type == TypeManager.sbyte_type)
1657                                 return new SByteConstant ((sbyte) Value, Location);
1658                         if (target_type == TypeManager.short_type)
1659                                 return new ShortConstant ((short) Value, Location);
1660                         if (target_type == TypeManager.ushort_type)
1661                                 return new UShortConstant ((ushort) Value, Location);
1662                         if (target_type == TypeManager.int32_type)
1663                                 return new IntConstant ((int) Value, Location);
1664                         if (target_type == TypeManager.uint32_type)
1665                                 return new UIntConstant ((uint) Value, Location);
1666                         if (target_type == TypeManager.int64_type)
1667                                 return new LongConstant ((long) Value, Location);
1668                         if (target_type == TypeManager.uint64_type)
1669                                 return new ULongConstant ((ulong) Value, Location);
1670                         if (target_type == TypeManager.double_type)
1671                                 return new DoubleConstant ((double) Value, Location);
1672                         if (target_type == TypeManager.char_type)
1673                                 return new CharConstant ((char) Value, Location);
1674                         if (target_type == TypeManager.decimal_type)
1675                                 return new DecimalConstant ((decimal) Value, Location);
1676
1677                         return null;
1678                 }
1679
1680         }
1681
1682         public class DoubleConstant : Constant {
1683                 public readonly double Value;
1684
1685                 public DoubleConstant (double v, Location loc):
1686                         base (loc)
1687                 {
1688                         type = TypeManager.double_type;
1689                         eclass = ExprClass.Value;
1690                         Value = v;
1691                 }
1692
1693                 public override void Emit (EmitContext ec)
1694                 {
1695                         ec.ig.Emit (OpCodes.Ldc_R8, Value);
1696                 }
1697
1698                 public override string AsString ()
1699                 {
1700                         return Value.ToString ();
1701                 }
1702
1703                 public override object GetValue ()
1704                 {
1705                         return Value;
1706                 }
1707
1708                 public override DoubleConstant ConvertToDouble ()
1709                 {
1710                         return this;
1711                 }
1712
1713                 public override FloatConstant ConvertToFloat ()
1714                 {
1715                         return null;
1716                 }
1717
1718                 public override ULongConstant ConvertToULong ()
1719                 {
1720                         return null;
1721                 }
1722
1723                 public override LongConstant ConvertToLong ()
1724                 {
1725                         return null;
1726                 }
1727
1728                 public override UIntConstant ConvertToUInt ()
1729                 {
1730                         return null;
1731                 }
1732
1733                 public override IntConstant ConvertToInt ()
1734                 {
1735                         return null;
1736                 }
1737
1738                 public override Constant Increment ()
1739                 {
1740                         return new DoubleConstant (checked(Value + 1), loc);
1741                 }
1742
1743                 public override bool IsDefaultValue {
1744                         get {
1745                                 return Value == 0;
1746                         }
1747                 }
1748
1749                 public override bool IsNegative {
1750                         get {
1751                                 return Value < 0;
1752                         }
1753                 }
1754
1755                 public override Constant Reduce (bool inCheckedContext, Type target_type)
1756                 {
1757                         if (target_type == TypeManager.byte_type) {
1758                                 CheckRange (inCheckedContext, Value, Byte.MinValue, Byte.MaxValue);
1759                                 return new ByteConstant ((byte) Value, Location);
1760                         }
1761                         if (target_type == TypeManager.sbyte_type) {
1762                                 CheckRange (inCheckedContext, Value, SByte.MinValue, SByte.MaxValue);
1763                                 return new SByteConstant ((sbyte) Value, Location);
1764                         }
1765                         if (target_type == TypeManager.short_type)
1766                                 return new ShortConstant ((short) Value, Location);
1767                         if (target_type == TypeManager.ushort_type)
1768                                 return new UShortConstant ((ushort) Value, Location);
1769                         if (target_type == TypeManager.int32_type)
1770                                 return new IntConstant ((int) Value, Location);
1771                         if (target_type == TypeManager.uint32_type)
1772                                 return new UIntConstant ((uint) Value, Location);
1773                         if (target_type == TypeManager.int64_type)
1774                                 return new LongConstant ((long) Value, Location);
1775                         if (target_type == TypeManager.uint64_type)
1776                                 return new ULongConstant ((ulong) Value, Location);
1777                         if (target_type == TypeManager.float_type)
1778                                 return new FloatConstant ((float) Value, Location);
1779                         if (target_type == TypeManager.char_type) {
1780                                 CheckRange (inCheckedContext, Value, char.MinValue, char.MaxValue);
1781                                 return new CharConstant ((char) Value, Location);
1782                         }
1783                         if (target_type == TypeManager.decimal_type)
1784                                 return new DecimalConstant ((decimal) Value, Location);
1785
1786                         return null;
1787                 }
1788
1789         }
1790
1791         public class DecimalConstant : Constant {
1792                 public readonly decimal Value;
1793
1794                 public DecimalConstant (decimal d, Location loc):
1795                         base (loc)
1796                 {
1797                         type = TypeManager.decimal_type;
1798                         eclass = ExprClass.Value;
1799                         Value = d;
1800                 }
1801
1802                 override public string AsString ()
1803                 {
1804                         return Value.ToString ();
1805                 }
1806
1807                 public override object GetValue ()
1808                 {
1809                         return (object) Value;
1810                 }
1811
1812                 public override void Emit (EmitContext ec)
1813                 {
1814                         ILGenerator ig = ec.ig;
1815
1816                         int [] words = Decimal.GetBits (Value);
1817                         int power = (words [3] >> 16) & 0xff;
1818
1819                         if (power == 0 && Value <= int.MaxValue && Value >= int.MinValue)
1820                         {
1821                                 IntConstant.EmitInt (ig, (int)Value);
1822                                 ig.Emit (OpCodes.Newobj, TypeManager.void_decimal_ctor_int_arg);
1823                                 return;
1824                         }
1825
1826
1827                         //
1828                         // FIXME: we could optimize this, and call a better
1829                         // constructor
1830                         //
1831
1832                         IntConstant.EmitInt (ig, words [0]);
1833                         IntConstant.EmitInt (ig, words [1]);
1834                         IntConstant.EmitInt (ig, words [2]);
1835
1836                         // sign
1837                         IntConstant.EmitInt (ig, words [3] >> 31);
1838
1839                         // power
1840                         IntConstant.EmitInt (ig, power);
1841
1842                         ig.Emit (OpCodes.Newobj, TypeManager.void_decimal_ctor_five_args);
1843                 }
1844
1845                 public override Constant Increment ()
1846                 {
1847                         return new DecimalConstant (checked (Value + 1), loc);
1848                 }
1849
1850                 public override bool IsDefaultValue {
1851                         get {
1852                                 return Value == 0;
1853                         }
1854                 }
1855
1856                 public override bool IsNegative {
1857                         get {
1858                                 return Value < 0;
1859                         }
1860                 }
1861
1862                 public override Constant Reduce (bool inCheckedContext, Type target_type)
1863                 {
1864                         if (target_type == TypeManager.sbyte_type)
1865                                 return new SByteConstant ((sbyte)Value, loc);
1866                         if (target_type == TypeManager.byte_type)
1867                                 return new ByteConstant ((byte)Value, loc);
1868                         if (target_type == TypeManager.short_type)
1869                                 return new ShortConstant ((short)Value, loc);
1870                         if (target_type == TypeManager.ushort_type)
1871                                 return new UShortConstant ((ushort)Value, loc);
1872                         if (target_type == TypeManager.int32_type)
1873                                 return new IntConstant ((int)Value, loc);
1874                         if (target_type == TypeManager.uint32_type)
1875                                 return new UIntConstant ((uint)Value, loc);
1876                         if (target_type == TypeManager.int64_type)
1877                                 return new LongConstant ((long)Value, loc);
1878                         if (target_type == TypeManager.uint64_type)
1879                                 return new ULongConstant ((ulong)Value, loc);
1880                         if (target_type == TypeManager.char_type)
1881                                 return new CharConstant ((char)Value, loc);
1882                         if (target_type == TypeManager.float_type)
1883                                 return new FloatConstant ((float)Value, loc);
1884                         if (target_type == TypeManager.double_type)
1885                                 return new DoubleConstant ((double)Value, loc);
1886
1887                         return null;
1888                 }
1889
1890         }
1891
1892         public class StringConstant : Constant {
1893                 public readonly string Value;
1894
1895                 public StringConstant (string s, Location loc):
1896                         base (loc)
1897                 {
1898                         type = TypeManager.string_type;
1899                         eclass = ExprClass.Value;
1900                         Value = s;
1901                 }
1902
1903                 // FIXME: Escape the string.
1904                 override public string AsString ()
1905                 {
1906                         return "\"" + Value + "\"";
1907                 }
1908
1909                 public override object GetValue ()
1910                 {
1911                         return Value;
1912                 }
1913
1914                 public override void Emit (EmitContext ec)
1915                 {
1916                         if (Value == null)
1917                                 ec.ig.Emit (OpCodes.Ldnull);
1918                         else
1919                                 ec.ig.Emit (OpCodes.Ldstr, Value);
1920                 }
1921
1922                 public override Constant Increment ()
1923                 {
1924                         throw new NotSupportedException ();
1925                 }
1926
1927                 public override bool IsDefaultValue {
1928                         get {
1929                                 return Value == null;
1930                         }
1931                 }
1932
1933                 public override bool IsNegative {
1934                         get {
1935                                 return false;
1936                         }
1937                 }
1938
1939                 public override Constant Reduce (bool inCheckedContext, Type target_type)
1940                 {
1941                         return null;
1942                 }
1943         }
1944
1945 }
1946
1947