mcs/mcs/cs-tokenizer.cs

   1 //
   2 // cs-tokenizer.cs: The Tokenizer for the C# compiler
   3 //                  This also implements the preprocessor
   4 //
   5 // Author: Miguel de Icaza (miguel@gnu.org)
   6 //
   7 // Licensed under the terms of the GNU GPL
   8 //
   9 // (C) 2001, 2002 Ximian, Inc (http://www.ximian.com)
  10 // (C) 2004 Novell, Inc
  11 //
  12
  13 /*
  14  * TODO:
  15  *   Make sure we accept the proper Unicode ranges, per the spec.
  16  *   Report error 1032
  17 */
  18
  19 using System;
  20 using System.Text;
  21 using System.Collections;
  22 using System.IO;
  23 using System.Globalization;
  24 using System.Reflection;
  25
  26 namespace Mono.CSharp
  27 {
  28         /// <summary>
  29         ///    Tokenizer for C# source code.
  30         /// </summary>
  31
  32         public class Tokenizer : yyParser.yyInput
  33         {
  34                 SeekableStreamReader reader;
  35                 public SourceFile ref_name;
  36                 public SourceFile file_name;
  37                 public int ref_line = 1;
  38                 public int line = 1;
  39                 public int col = 1;
  40                 public int current_token;
  41                 bool handle_get_set = false;
  42                 bool handle_remove_add = false;
  43                 bool handle_assembly = false;
  44
  45                 //
  46                 // XML documentation buffer. The save point is used to divide
  47                 // comments on types and comments on members.
  48                 //
  49                 StringBuilder xml_comment_buffer;
  50
  51                 //
  52                 // See comment on XmlCommentState enumeration.
  53                 //
  54                 XmlCommentState xmlDocState = XmlCommentState.Allowed;
  55
  56                 //
  57                 // Whether tokens have been seen on this line
  58                 //
  59                 bool tokens_seen = false;
  60
  61                 //
  62                 // Whether a token has been seen on the file
  63                 // This is needed because `define' is not allowed to be used
  64                 // after a token has been seen.
  65                 //
  66                 bool any_token_seen = false;
  67
  68                 static Hashtable tokenValues;
  69
  70                 private static Hashtable TokenValueName
  71                 {
  72                         get {
  73                                 if (tokenValues == null)
  74                                         tokenValues = GetTokenValueNameHash ();
  75
  76                                 return tokenValues;
  77                         }
  78                 }
  79
  80                 private static Hashtable GetTokenValueNameHash ()
  81                 {
  82                         Type t = typeof (Token);
  83                         FieldInfo [] fields = t.GetFields ();
  84                         Hashtable hash = new Hashtable ();
  85                         foreach (FieldInfo field in fields) {
  86                                 if (field.IsLiteral && field.IsStatic && field.FieldType == typeof (int))
  87                                         hash.Add (field.GetValue (null), field.Name);
  88                         }
  89                         return hash;
  90                 }
  91
  92                 //
  93                 // Returns a verbose representation of the current location
  94                 //
  95                 public string location {
  96                         get {
  97                                 string det;
  98
  99                                 if (current_token == Token.ERROR)
 100                                         det = "detail: " + error_details;
 101                                 else
 102                                         det = "";
 103
 104                                 // return "Line:     "+line+" Col: "+col + "\n" +
 105                                 //       "VirtLine: "+ref_line +
 106                                 //       " Token: "+current_token + " " + det;
 107                                 string current_token_name = TokenValueName [current_token] as string;
 108                                 if (current_token_name == null)
 109                                         current_token_name = current_token.ToString ();
 110
 111                                 return String.Format ("{0} ({1},{2}), Token: {3} {4}", ref_name.Name,
 112                                                                                        ref_line,
 113                                                                                        col,
 114                                                                                        current_token_name,
 115                                                                                        det);
 116                         }
 117                 }
 118
 119                 public bool PropertyParsing {
 120                         get {
 121                                 return handle_get_set;
 122                         }
 123
 124                         set {
 125                                 handle_get_set = value;
 126                         }
 127                 }
 128
 129                 public bool AssemblyTargetParsing {
 130                         get {
 131                                 return handle_assembly;
 132                         }
 133
 134                         set {
 135                                 handle_assembly = value;
 136                         }
 137                 }
 138
 139                 public bool EventParsing {
 140                         get {
 141                                 return handle_remove_add;
 142                         }
 143
 144                         set {
 145                                 handle_remove_add = value;
 146                         }
 147                 }
 148
 149                 public XmlCommentState doc_state {
 150                         get { return xmlDocState; }
 151                         set {
 152                                 if (value == XmlCommentState.Allowed) {
 153                                         check_incorrect_doc_comment ();
 154                                         consume_doc_comment ();
 155                                 }
 156                                 xmlDocState = value;
 157                         }
 158                 }
 159
 160
 161                 //
 162                 // Class variables
 163                 //
 164                 static CharArrayHashtable[] keywords;
 165                 static NumberStyles styles;
 166                 static NumberFormatInfo csharp_format_info;
 167
 168                 //
 169                 // Values for the associated token returned
 170                 //
 171                 int putback_char;
 172                 Object val;
 173
 174                 //
 175                 // Pre-processor
 176                 //
 177                 Hashtable defines;
 178
 179                 const int TAKING        = 1;
 180                 const int TAKEN_BEFORE  = 2;
 181                 const int ELSE_SEEN     = 4;
 182                 const int PARENT_TAKING = 8;
 183                 const int REGION        = 16;
 184
 185                 //
 186                 // pre-processor if stack state:
 187                 //
 188                 Stack ifstack;
 189
 190                 static System.Text.StringBuilder string_builder;
 191
 192                 const int max_id_size = 512;
 193                 static char [] id_builder = new char [max_id_size];
 194
 195                 static CharArrayHashtable [] identifiers = new CharArrayHashtable [max_id_size + 1];
 196
 197                 const int max_number_size = 128;
 198                 static char [] number_builder = new char [max_number_size];
 199                 static int number_pos;
 200
 201                 //
 202                 // Details about the error encoutered by the tokenizer
 203                 //
 204                 string error_details;
 205
 206                 public string error {
 207                         get {
 208                                 return error_details;
 209                         }
 210                 }
 211
 212                 public int Line {
 213                         get {
 214                                 return ref_line;
 215                         }
 216                 }
 217
 218                 public int Col {
 219                         get {
 220                                 return col;
 221                         }
 222                 }
 223
 224                 static void AddKeyword (string kw, int token) {
 225                         if (keywords [kw.Length] == null) {
 226                                 keywords [kw.Length] = new CharArrayHashtable (kw.Length);
 227                         }
 228                         keywords [kw.Length] [kw.ToCharArray ()] = token;
 229                 }
 230
 231                 static void InitTokens ()
 232                 {
 233                         keywords = new CharArrayHashtable [64];
 234
 235                         AddKeyword ("__arglist", Token.ARGLIST);
 236                         AddKeyword ("abstract", Token.ABSTRACT);
 237                         AddKeyword ("as", Token.AS);
 238                         AddKeyword ("add", Token.ADD);
 239                         AddKeyword ("assembly", Token.ASSEMBLY);
 240                         AddKeyword ("base", Token.BASE);
 241                         AddKeyword ("bool", Token.BOOL);
 242                         AddKeyword ("break", Token.BREAK);
 243                         AddKeyword ("byte", Token.BYTE);
 244                         AddKeyword ("case", Token.CASE);
 245                         AddKeyword ("catch", Token.CATCH);
 246                         AddKeyword ("char", Token.CHAR);
 247                         AddKeyword ("checked", Token.CHECKED);
 248                         AddKeyword ("class", Token.CLASS);
 249                         AddKeyword ("const", Token.CONST);
 250                         AddKeyword ("continue", Token.CONTINUE);
 251                         AddKeyword ("decimal", Token.DECIMAL);
 252                         AddKeyword ("default", Token.DEFAULT);
 253                         AddKeyword ("delegate", Token.DELEGATE);
 254                         AddKeyword ("do", Token.DO);
 255                         AddKeyword ("double", Token.DOUBLE);
 256                         AddKeyword ("else", Token.ELSE);
 257                         AddKeyword ("enum", Token.ENUM);
 258                         AddKeyword ("event", Token.EVENT);
 259                         AddKeyword ("explicit", Token.EXPLICIT);
 260                         AddKeyword ("extern", Token.EXTERN);
 261                         AddKeyword ("false", Token.FALSE);
 262                         AddKeyword ("finally", Token.FINALLY);
 263                         AddKeyword ("fixed", Token.FIXED);
 264                         AddKeyword ("float", Token.FLOAT);
 265                         AddKeyword ("for", Token.FOR);
 266                         AddKeyword ("foreach", Token.FOREACH);
 267                         AddKeyword ("goto", Token.GOTO);
 268                         AddKeyword ("get", Token.GET);
 269                         AddKeyword ("if", Token.IF);
 270                         AddKeyword ("implicit", Token.IMPLICIT);
 271                         AddKeyword ("in", Token.IN);
 272                         AddKeyword ("int", Token.INT);
 273                         AddKeyword ("interface", Token.INTERFACE);
 274                         AddKeyword ("internal", Token.INTERNAL);
 275                         AddKeyword ("is", Token.IS);
 276                         AddKeyword ("lock", Token.LOCK);
 277                         AddKeyword ("long", Token.LONG);
 278                         AddKeyword ("namespace", Token.NAMESPACE);
 279                         AddKeyword ("new", Token.NEW);
 280                         AddKeyword ("null", Token.NULL);
 281                         AddKeyword ("object", Token.OBJECT);
 282                         AddKeyword ("operator", Token.OPERATOR);
 283                         AddKeyword ("out", Token.OUT);
 284                         AddKeyword ("override", Token.OVERRIDE);
 285                         AddKeyword ("params", Token.PARAMS);
 286                         AddKeyword ("private", Token.PRIVATE);
 287                         AddKeyword ("protected", Token.PROTECTED);
 288                         AddKeyword ("public", Token.PUBLIC);
 289                         AddKeyword ("readonly", Token.READONLY);
 290                         AddKeyword ("ref", Token.REF);
 291                         AddKeyword ("remove", Token.REMOVE);
 292                         AddKeyword ("return", Token.RETURN);
 293                         AddKeyword ("sbyte", Token.SBYTE);
 294                         AddKeyword ("sealed", Token.SEALED);
 295                         AddKeyword ("set", Token.SET);
 296                         AddKeyword ("short", Token.SHORT);
 297                         AddKeyword ("sizeof", Token.SIZEOF);
 298                         AddKeyword ("stackalloc", Token.STACKALLOC);
 299                         AddKeyword ("static", Token.STATIC);
 300                         AddKeyword ("string", Token.STRING);
 301                         AddKeyword ("struct", Token.STRUCT);
 302                         AddKeyword ("switch", Token.SWITCH);
 303                         AddKeyword ("this", Token.THIS);
 304                         AddKeyword ("throw", Token.THROW);
 305                         AddKeyword ("true", Token.TRUE);
 306                         AddKeyword ("try", Token.TRY);
 307                         AddKeyword ("typeof", Token.TYPEOF);
 308                         AddKeyword ("uint", Token.UINT);
 309                         AddKeyword ("ulong", Token.ULONG);
 310                         AddKeyword ("unchecked", Token.UNCHECKED);
 311                         AddKeyword ("unsafe", Token.UNSAFE);
 312                         AddKeyword ("ushort", Token.USHORT);
 313                         AddKeyword ("using", Token.USING);
 314                         AddKeyword ("virtual", Token.VIRTUAL);
 315                         AddKeyword ("void", Token.VOID);
 316                         AddKeyword ("volatile", Token.VOLATILE);
 317                         AddKeyword ("while", Token.WHILE);
 318                         AddKeyword ("partial", Token.PARTIAL);
 319                 }
 320
 321                 //
 322                 // Class initializer
 323                 //
 324                 static Tokenizer ()
 325                 {
 326                         InitTokens ();
 327                         csharp_format_info = NumberFormatInfo.InvariantInfo;
 328                         styles = NumberStyles.Float;
 329
 330                         string_builder = new System.Text.StringBuilder ();
 331                 }
 332
 333                 int GetKeyword (char[] id, int id_len)
 334                 {
 335                         /*
 336                          * Keywords are stored in an array of hashtables grouped by their
 337                          * length.
 338                          */
 339
 340                         if ((id_len >= keywords.Length) || (keywords [id_len] == null))
 341                                 return -1;
 342                         object o = keywords [id_len] [id];
 343
 344                         if (o == null)
 345                                 return -1;
 346
 347                         int res = (int) o;
 348
 349                         if (handle_get_set == false && (res == Token.GET || res == Token.SET))
 350                                 return -1;
 351                         if (handle_remove_add == false && (res == Token.REMOVE || res == Token.ADD))
 352                                 return -1;
 353                         if (handle_assembly == false && res == Token.ASSEMBLY)
 354                                 return -1;
 355
 356                         return res;
 357
 358                 }
 359
 360                 public Location Location {
 361                         get {
 362                                 return new Location (ref_line);
 363                         }
 364                 }
 365
 366                 void define (string def)
 367                 {
 368                         if (!RootContext.AllDefines.Contains (def)){
 369                                 RootContext.AllDefines [def] = true;
 370                         }
 371                         if (defines.Contains (def))
 372                                 return;
 373                         defines [def] = true;
 374                 }
 375
 376                 public Tokenizer (SeekableStreamReader input, SourceFile file, ArrayList defs)
 377                 {
 378                         this.ref_name = file;
 379                         this.file_name = file;
 380                         reader = input;
 381
 382                         putback_char = -1;
 383
 384                         if (defs != null){
 385                                 defines = new Hashtable ();
 386                                 foreach (string def in defs)
 387                                         define (def);
 388                         }
 389
 390                         xml_comment_buffer = new StringBuilder ();
 391
 392                         //
 393                         // FIXME: This could be `Location.Push' but we have to
 394                         // find out why the MS compiler allows this
 395                         //
 396                         Mono.CSharp.Location.Push (file);
 397                 }
 398
 399                 public static void Cleanup () {
 400                         identifiers = null;
 401                 }
 402
 403                 static bool is_identifier_start_character (char c)
 404                 {
 405                         return (c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z') || c == '_' || Char.IsLetter (c);
 406                 }
 407
 408                 static bool is_identifier_part_character (char c)
 409                 {
 410                         return (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z') || c == '_' || (c >= '0' && c <= '9') || Char.IsLetter (c);
 411                 }
 412
 413                 public static bool IsValidIdentifier (string s)
 414                 {
 415                         if (s == null || s.Length == 0)
 416                                 return false;
 417
 418                         if (!is_identifier_start_character (s [0]))
 419                                 return false;
 420
 421                         for (int i = 1; i < s.Length; i ++)
 422                                 if (! is_identifier_part_character (s [i]))
 423                                         return false;
 424
 425                         return true;
 426                 }
 427
 428                 int is_punct (char c, ref bool doread)
 429                 {
 430                         int d;
 431                         int t;
 432
 433                         doread = false;
 434
 435                         switch (c){
 436                         case '{':
 437                                 return Token.OPEN_BRACE;
 438                         case '}':
 439                                 return Token.CLOSE_BRACE;
 440                         case '[':
 441                                 // To block doccomment inside attribute declaration.
 442                                 if (doc_state == XmlCommentState.Allowed)
 443                                         doc_state = XmlCommentState.NotAllowed;
 444                                 return Token.OPEN_BRACKET;
 445                         case ']':
 446                                 return Token.CLOSE_BRACKET;
 447                         case '(':
 448                                 return Token.OPEN_PARENS;
 449                         case ')': {
 450                                 if (deambiguate_close_parens == 0)
 451                                         return Token.CLOSE_PARENS;
 452
 453                                 --deambiguate_close_parens;
 454
 455                                 // Save current position and parse next token.
 456                                 int old = reader.Position;
 457                                 int new_token = token ();
 458                                 reader.Position = old;
 459                                 putback_char = -1;
 460
 461                                 if (new_token == Token.OPEN_PARENS)
 462                                         return Token.CLOSE_PARENS_OPEN_PARENS;
 463                                 else if (new_token == Token.MINUS)
 464                                         return Token.CLOSE_PARENS_MINUS;
 465                                 else if (IsCastToken (new_token))
 466                                         return Token.CLOSE_PARENS_CAST;
 467                                 else
 468                                         return Token.CLOSE_PARENS_NO_CAST;
 469                         }
 470
 471                         case ',':
 472                                 return Token.COMMA;
 473                         case ':':
 474                                 return Token.COLON;
 475                         case ';':
 476                                 return Token.SEMICOLON;
 477                         case '~':
 478                                 return Token.TILDE;
 479                         case '?':
 480                                 return Token.INTERR;
 481                         }
 482
 483                         d = peekChar ();
 484                         if (c == '+'){
 485
 486                                 if (d == '+')
 487                                         t = Token.OP_INC;
 488                                 else if (d == '=')
 489                                         t = Token.OP_ADD_ASSIGN;
 490                                 else
 491                                         return Token.PLUS;
 492                                 doread = true;
 493                                 return t;
 494                         }
 495                         if (c == '-'){
 496                                 if (d == '-')
 497                                         t = Token.OP_DEC;
 498                                 else if (d == '=')
 499                                         t = Token.OP_SUB_ASSIGN;
 500                                 else if (d == '>')
 501                                         t = Token.OP_PTR;
 502                                 else
 503                                         return Token.MINUS;
 504                                 doread = true;
 505                                 return t;
 506                         }
 507
 508                         if (c == '!'){
 509                                 if (d == '='){
 510                                         doread = true;
 511                                         return Token.OP_NE;
 512                                 }
 513                                 return Token.BANG;
 514                         }
 515
 516                         if (c == '='){
 517                                 if (d == '='){
 518                                         doread = true;
 519                                         return Token.OP_EQ;
 520                                 }
 521                                 return Token.ASSIGN;
 522                         }
 523
 524                         if (c == '&'){
 525                                 if (d == '&'){
 526                                         doread = true;
 527                                         return Token.OP_AND;
 528                                 } else if (d == '='){
 529                                         doread = true;
 530                                         return Token.OP_AND_ASSIGN;
 531                                 }
 532                                 return Token.BITWISE_AND;
 533                         }
 534
 535                         if (c == '|'){
 536                                 if (d == '|'){
 537                                         doread = true;
 538                                         return Token.OP_OR;
 539                                 } else if (d == '='){
 540                                         doread = true;
 541                                         return Token.OP_OR_ASSIGN;
 542                                 }
 543                                 return Token.BITWISE_OR;
 544                         }
 545
 546                         if (c == '*'){
 547                                 if (d == '='){
 548                                         doread = true;
 549                                         return Token.OP_MULT_ASSIGN;
 550                                 }
 551                                 return Token.STAR;
 552                         }
 553
 554                         if (c == '/'){
 555                                 if (d == '='){
 556                                         doread = true;
 557                                         return Token.OP_DIV_ASSIGN;
 558                                 }
 559                                 return Token.DIV;
 560                         }
 561
 562                         if (c == '%'){
 563                                 if (d == '='){
 564                                         doread = true;
 565                                         return Token.OP_MOD_ASSIGN;
 566                                 }
 567                                 return Token.PERCENT;
 568                         }
 569
 570                         if (c == '^'){
 571                                 if (d == '='){
 572                                         doread = true;
 573                                         return Token.OP_XOR_ASSIGN;
 574                                 }
 575                                 return Token.CARRET;
 576                         }
 577
 578                         if (c == '<'){
 579                                 if (d == '<'){
 580                                         getChar ();
 581                                         d = peekChar ();
 582
 583                                         if (d == '='){
 584                                                 doread = true;
 585                                                 return Token.OP_SHIFT_LEFT_ASSIGN;
 586                                         }
 587                                         return Token.OP_SHIFT_LEFT;
 588                                 } else if (d == '='){
 589                                         doread = true;
 590                                         return Token.OP_LE;
 591                                 }
 592                                 return Token.OP_LT;
 593                         }
 594
 595                         if (c == '>'){
 596                                 if (d == '>'){
 597                                         getChar ();
 598                                         d = peekChar ();
 599
 600                                         if (d == '='){
 601                                                 doread = true;
 602                                                 return Token.OP_SHIFT_RIGHT_ASSIGN;
 603                                         }
 604                                         return Token.OP_SHIFT_RIGHT;
 605                                 } else if (d == '='){
 606                                         doread = true;
 607                                         return Token.OP_GE;
 608                                 }
 609                                 return Token.OP_GT;
 610                         }
 611                         return Token.ERROR;
 612                 }
 613
 614                 int deambiguate_close_parens = 0;
 615
 616                 public void Deambiguate_CloseParens ()
 617                 {
 618                         putback (')');
 619                         deambiguate_close_parens++;
 620                 }
 621
 622                 void Error_NumericConstantTooLong ()
 623                 {
 624                         Report.Error (1021, Location, "Numeric constant too long");
 625                 }
 626
 627                 bool decimal_digits (int c)
 628                 {
 629                         int d;
 630                         bool seen_digits = false;
 631
 632                         if (c != -1){
 633                                 if (number_pos == max_number_size)
 634                                         Error_NumericConstantTooLong ();
 635                                 number_builder [number_pos++] = (char) c;
 636                         }
 637
 638                         //
 639                         // We use peekChar2, because decimal_digits needs to do a
 640                         // 2-character look-ahead (5.ToString for example).
 641                         //
 642                         while ((d = peekChar2 ()) != -1){
 643                                 if (d >= '0' && d <= '9'){
 644                                         if (number_pos == max_number_size)
 645                                                 Error_NumericConstantTooLong ();
 646                                         number_builder [number_pos++] = (char) d;
 647                                         getChar ();
 648                                         seen_digits = true;
 649                                 } else
 650                                         break;
 651                         }
 652
 653                         return seen_digits;
 654                 }
 655
 656                 bool is_hex (int e)
 657                 {
 658                         return (e >= '0' && e <= '9') || (e >= 'A' && e <= 'F') || (e >= 'a' && e <= 'f');
 659                 }
 660
 661                 void hex_digits (int c)
 662                 {
 663                         if (c != -1)
 664                                 number_builder [number_pos++] = (char) c;
 665
 666                 }
 667
 668                 int real_type_suffix (int c)
 669                 {
 670                         int t;
 671
 672                         switch (c){
 673                         case 'F': case 'f':
 674                                 t =  Token.LITERAL_FLOAT;
 675                                 break;
 676                         case 'D': case 'd':
 677                                 t = Token.LITERAL_DOUBLE;
 678                                 break;
 679                         case 'M': case 'm':
 680                                  t= Token.LITERAL_DECIMAL;
 681                                 break;
 682                         default:
 683                                 return Token.NONE;
 684                         }
 685                         return t;
 686                 }
 687
 688                 int integer_type_suffix (ulong ul, int c)
 689                 {
 690                         bool is_unsigned = false;
 691                         bool is_long = false;
 692
 693                         if (c != -1){
 694                                 bool scanning = true;
 695                                 do {
 696                                         switch (c){
 697                                         case 'U': case 'u':
 698                                                 if (is_unsigned)
 699                                                         scanning = false;
 700                                                 is_unsigned = true;
 701                                                 getChar ();
 702                                                 break;
 703
 704                                         case 'l':
 705                                                 if (!is_unsigned && (RootContext.WarningLevel >= 4)){
 706                                                         //
 707                                                         // if we have not seen anything in between
 708                                                         // report this error
 709                                                         //
 710                                                         Report.Warning (78, Location, "The 'l' suffix is easily confused with the digit '1' (use 'L' for clarity)");
 711                                                 }
 712                                                 //
 713                                                 // This goto statement causes the MS CLR 2.0 beta 1 csc to report an error, so
 714                                                 // work around that.
 715                                                 //
 716                                                 //goto case 'L';
 717                                                 if (is_long)
 718                                                         scanning = false;
 719                                                 is_long = true;
 720                                                 getChar ();
 721                                                 break;
 722
 723                                         case 'L':
 724                                                 if (is_long)
 725                                                         scanning = false;
 726                                                 is_long = true;
 727                                                 getChar ();
 728                                                 break;
 729
 730                                         default:
 731                                                 scanning = false;
 732                                                 break;
 733                                         }
 734                                         c = peekChar ();
 735                                 } while (scanning);
 736                         }
 737
 738                         if (is_long && is_unsigned){
 739                                 val = ul;
 740                                 return Token.LITERAL_INTEGER;
 741                         } else if (is_unsigned){
 742                                 // uint if possible, or ulong else.
 743
 744                                 if ((ul & 0xffffffff00000000) == 0)
 745                                         val = (uint) ul;
 746                                 else
 747                                         val = ul;
 748                         } else if (is_long){
 749                                 // long if possible, ulong otherwise
 750                                 if ((ul & 0x8000000000000000) != 0)
 751                                         val = ul;
 752                                 else
 753                                         val = (long) ul;
 754                         } else {
 755                                 // int, uint, long or ulong in that order
 756                                 if ((ul & 0xffffffff00000000) == 0){
 757                                         uint ui = (uint) ul;
 758
 759                                         if ((ui & 0x80000000) != 0)
 760                                                 val = ui;
 761                                         else
 762                                                 val = (int) ui;
 763                                 } else {
 764                                         if ((ul & 0x8000000000000000) != 0)
 765                                                 val = ul;
 766                                         else
 767                                                 val = (long) ul;
 768                                 }
 769                         }
 770                         return Token.LITERAL_INTEGER;
 771                 }
 772
 773                 //
 774                 // given `c' as the next char in the input decide whether
 775                 // we need to convert to a special type, and then choose
 776                 // the best representation for the integer
 777                 //
 778                 int adjust_int (int c)
 779                 {
 780                         try {
 781                                 if (number_pos > 9){
 782                                         ulong ul = (uint) (number_builder [0] - '0');
 783
 784                                         for (int i = 1; i < number_pos; i++){
 785                                                 ul = checked ((ul * 10) + ((uint)(number_builder [i] - '0')));
 786                                         }
 787                                         return integer_type_suffix (ul, c);
 788                                 } else {
 789                                         uint ui = (uint) (number_builder [0] - '0');
 790
 791                                         for (int i = 1; i < number_pos; i++){
 792                                                 ui = checked ((ui * 10) + ((uint)(number_builder [i] - '0')));
 793                                         }
 794                                         return integer_type_suffix (ui, c);
 795                                 }
 796                         } catch (OverflowException) {
 797                                 error_details = "Integral constant is too large";
 798                                 Report.Error (1021, Location, error_details);
 799                                 val = 0ul;
 800                                 return Token.LITERAL_INTEGER;
 801                         }
 802                 }
 803
 804                 int adjust_real (int t)
 805                 {
 806                         string s = new String (number_builder, 0, number_pos);
 807
 808                         switch (t){
 809                         case Token.LITERAL_DECIMAL:
 810                                 try {
 811                                         val = System.Decimal.Parse (s, styles, csharp_format_info);
 812                                 } catch (OverflowException) {
 813                                         val = 0m;
 814                                         error_details = "Floating-point constant is outside the range of the type 'decimal'";
 815                                         Report.Error (594, Location, error_details);
 816                                 }
 817                                 break;
 818                         case Token.LITERAL_FLOAT:
 819                                 try {
 820                                         val = (float) System.Double.Parse (s, styles, csharp_format_info);
 821                                 } catch (OverflowException) {
 822                                         val = 0.0f;
 823                                         error_details = "Floating-point constant is outside the range of the type 'float'";
 824                                         Report.Error (594, Location, error_details);
 825                                 }
 826                                 break;
 827
 828                         case Token.LITERAL_DOUBLE:
 829                         case Token.NONE:
 830                                 t = Token.LITERAL_DOUBLE;
 831                                 try {
 832                                         val = System.Double.Parse (s, styles, csharp_format_info);
 833                                 } catch (OverflowException) {
 834                                         val = 0.0;
 835                                         error_details = "Floating-point constant is outside the range of the type 'double'";
 836                                         Report.Error (594, Location, error_details);
 837                                 }
 838                                 break;
 839                         }
 840                         return t;
 841                 }
 842
 843                 int handle_hex ()
 844                 {
 845                         int d;
 846                         ulong ul;
 847
 848                         getChar ();
 849                         while ((d = peekChar ()) != -1){
 850                                 if (is_hex (d)){
 851                                         number_builder [number_pos++] = (char) d;
 852                                         getChar ();
 853                                 } else
 854                                         break;
 855                         }
 856
 857                         string s = new String (number_builder, 0, number_pos);
 858                         try {
 859                                 if (number_pos <= 8)
 860                                         ul = System.UInt32.Parse (s, NumberStyles.HexNumber);
 861                                 else
 862                                         ul = System.UInt64.Parse (s, NumberStyles.HexNumber);
 863                         } catch (OverflowException){
 864                                 error_details = "Integral constant is too large";
 865                                 Report.Error (1021, Location, error_details);
 866                                 val = 0ul;
 867                                 return Token.LITERAL_INTEGER;
 868                         }
 869                         catch (FormatException) {
 870                                 Report.Error (1013, Location, "Invalid number");
 871                                 val = 0ul;
 872                                 return Token.LITERAL_INTEGER;
 873                         }
 874
 875                         return integer_type_suffix (ul, peekChar ());
 876                 }
 877
 878                 //
 879                 // Invoked if we know we have .digits or digits
 880                 //
 881                 int is_number (int c)
 882                 {
 883                         bool is_real = false;
 884                         int type;
 885
 886                         number_pos = 0;
 887
 888                         if (c >= '0' && c <= '9'){
 889                                 if (c == '0'){
 890                                         int peek = peekChar ();
 891
 892                                         if (peek == 'x' || peek == 'X')
 893                                                 return handle_hex ();
 894                                 }
 895                                 decimal_digits (c);
 896                                 c = getChar ();
 897                         }
 898
 899                         //
 900                         // We need to handle the case of
 901                         // "1.1" vs "1.string" (LITERAL_FLOAT vs NUMBER DOT IDENTIFIER)
 902                         //
 903                         if (c == '.'){
 904                                 if (decimal_digits ('.')){
 905                                         is_real = true;
 906                                         c = getChar ();
 907                                 } else {
 908                                         putback ('.');
 909                                         number_pos--;
 910                                         return adjust_int (-1);
 911                                 }
 912                         }
 913
 914                         if (c == 'e' || c == 'E'){
 915                                 is_real = true;
 916                                 if (number_pos == max_number_size)
 917                                         Error_NumericConstantTooLong ();
 918                                 number_builder [number_pos++] = 'e';
 919                                 c = getChar ();
 920
 921                                 if (c == '+'){
 922                                         if (number_pos == max_number_size)
 923                                                 Error_NumericConstantTooLong ();
 924                                         number_builder [number_pos++] = '+';
 925                                         c = -1;
 926                                 } else if (c == '-') {
 927                                         if (number_pos == max_number_size)
 928                                                 Error_NumericConstantTooLong ();
 929                                         number_builder [number_pos++] = '-';
 930                                         c = -1;
 931                                 } else {
 932                                         if (number_pos == max_number_size)
 933                                                 Error_NumericConstantTooLong ();
 934                                         number_builder [number_pos++] = '+';
 935                                 }
 936
 937                                 decimal_digits (c);
 938                                 c = getChar ();
 939                         }
 940
 941                         type = real_type_suffix (c);
 942                         if (type == Token.NONE && !is_real){
 943                                 putback (c);
 944                                 return adjust_int (c);
 945                         } else
 946                                 is_real = true;
 947
 948                         if (type == Token.NONE){
 949                                 putback (c);
 950                         }
 951
 952                         if (is_real)
 953                                 return adjust_real (type);
 954
 955                         Console.WriteLine ("This should not be reached");
 956                         throw new Exception ("Is Number should never reach this point");
 957                 }
 958
 959                 //
 960                 // Accepts exactly count (4 or 8) hex, no more no less
 961                 //
 962                 int getHex (int count, out bool error)
 963                 {
 964                         int i;
 965                         int total = 0;
 966                         int c;
 967                         int top = count != -1 ? count : 4;
 968
 969                         getChar ();
 970                         error = false;
 971                         for (i = 0; i < top; i++){
 972                                 c = getChar ();
 973
 974                                 if (c >= '0' && c <= '9')
 975                                         c = (int) c - (int) '0';
 976                                 else if (c >= 'A' && c <= 'F')
 977                                         c = (int) c - (int) 'A' + 10;
 978                                 else if (c >= 'a' && c <= 'f')
 979                                         c = (int) c - (int) 'a' + 10;
 980                                 else {
 981                                         error = true;
 982                                         return 0;
 983                                 }
 984
 985                                 total = (total * 16) + c;
 986                                 if (count == -1){
 987                                         int p = peekChar ();
 988                                         if (p == -1)
 989                                                 break;
 990                                         if (!is_hex ((char)p))
 991                                                 break;
 992                                 }
 993                         }
 994                         return total;
 995                 }
 996
 997                 int escape (int c)
 998                 {
 999                         bool error;
1000                         int d;
1001                         int v;
1002
1003                         d = peekChar ();
1004                         if (c != '\\')
1005                                 return c;
1006
1007                         switch (d){
1008                         case 'a':
1009                                 v = '\a'; break;
1010                         case 'b':
1011                                 v = '\b'; break;
1012                         case 'n':
1013                                 v = '\n'; break;
1014                         case 't':
1015                                 v = '\t'; break;
1016                         case 'v':
1017                                 v = '\v'; break;
1018                         case 'r':
1019                                 v = '\r'; break;
1020                         case '\\':
1021                                 v = '\\'; break;
1022                         case 'f':
1023                                 v = '\f'; break;
1024                         case '0':
1025                                 v = 0; break;
1026                         case '"':
1027                                 v = '"'; break;
1028                         case '\'':
1029                                 v = '\''; break;
1030                         case 'x':
1031                                 v = getHex (-1, out error);
1032                                 if (error)
1033                                         goto default;
1034                                 return v;
1035                         case 'u':
1036                                 v = getHex (4, out error);
1037                                 if (error)
1038                                         goto default;
1039                                 return v;
1040                         case 'U':
1041                                 v = getHex (8, out error);
1042                                 if (error)
1043                                         goto default;
1044                                 return v;
1045                         default:
1046                                 Report.Error (1009, Location, "Unrecognized escape sequence in " + (char)d);
1047                                 return d;
1048                         }
1049                         getChar ();
1050                         return v;
1051                 }
1052
1053                 int getChar ()
1054                 {
1055                         if (putback_char != -1){
1056                                 int x = putback_char;
1057                                 putback_char = -1;
1058
1059                                 return x;
1060                         }
1061                         return reader.Read ();
1062                 }
1063
1064                 int peekChar ()
1065                 {
1066                         if (putback_char != -1)
1067                                 return putback_char;
1068                         putback_char = reader.Read ();
1069                         return putback_char;
1070                 }
1071
1072                 int peekChar2 ()
1073                 {
1074                         if (putback_char != -1)
1075                                 return putback_char;
1076                         return reader.Peek ();
1077                 }
1078
1079                 void putback (int c)
1080                 {
1081                         if (putback_char != -1){
1082                                 Console.WriteLine ("Col: " + col);
1083                                 Console.WriteLine ("Row: " + line);
1084                                 Console.WriteLine ("Name: " + ref_name.Name);
1085                                 Console.WriteLine ("Current [{0}] putting back [{1}]  ", putback_char, c);
1086                                 throw new Exception ("This should not happen putback on putback");
1087                         }
1088                         putback_char = c;
1089                 }
1090
1091                 public bool advance ()
1092                 {
1093                         return peekChar () != -1;
1094                 }
1095
1096                 public Object Value {
1097                         get {
1098                                 return val;
1099                         }
1100                 }
1101
1102                 public Object value ()
1103                 {
1104                         return val;
1105                 }
1106
1107                 bool IsCastToken (int token)
1108                 {
1109                         switch (token) {
1110                         case Token.BANG:
1111                         case Token.TILDE:
1112                         case Token.IDENTIFIER:
1113                         case Token.LITERAL_INTEGER:
1114                         case Token.LITERAL_FLOAT:
1115                         case Token.LITERAL_DOUBLE:
1116                         case Token.LITERAL_DECIMAL:
1117                         case Token.LITERAL_CHARACTER:
1118                         case Token.LITERAL_STRING:
1119                         case Token.BASE:
1120                         case Token.CHECKED:
1121                         case Token.FALSE:
1122                         case Token.FIXED:
1123                         case Token.NEW:
1124                         case Token.NULL:
1125                         case Token.SIZEOF:
1126                         case Token.THIS:
1127                         case Token.THROW:
1128                         case Token.TRUE:
1129                         case Token.TYPEOF:
1130                         case Token.UNCHECKED:
1131                         case Token.UNSAFE:
1132
1133                                 //
1134                                 // These can be part of a member access
1135                                 //
1136                         case Token.INT:
1137                         case Token.UINT:
1138                         case Token.SHORT:
1139                         case Token.USHORT:
1140                         case Token.LONG:
1141                         case Token.ULONG:
1142                         case Token.DOUBLE:
1143                         case Token.FLOAT:
1144                         case Token.CHAR:
1145                                 return true;
1146
1147                         default:
1148                                 return false;
1149                         }
1150                 }
1151
1152                 public int token ()
1153                 {
1154                         current_token = xtoken ();
1155                         return current_token;
1156                 }
1157
1158                 static StringBuilder static_cmd_arg = new System.Text.StringBuilder ();
1159
1160                 void get_cmd_arg (out string cmd, out string arg)
1161                 {
1162                         int c;
1163
1164                         tokens_seen = false;
1165                         arg = "";
1166                         static_cmd_arg.Length = 0;
1167
1168                         // skip over white space
1169                         while ((c = getChar ()) != -1 && (c != '\n') && ((c == '\r') || (c == ' ') || (c == '\t')))
1170                                 ;
1171
1172
1173                         while ((c != -1) && (c != '\n') && (c != ' ') && (c != '\t') && (c != '\r')){
1174                                 if (is_identifier_part_character ((char) c)){
1175                                         static_cmd_arg.Append ((char) c);
1176                                         c = getChar ();
1177                                 } else {
1178                                         putback (c);
1179                                         break;
1180                                 }
1181                         }
1182
1183                         cmd = static_cmd_arg.ToString ();
1184
1185                         if (c == '\n'){
1186                                 line++;
1187                                 ref_line++;
1188                                 return;
1189                         } else if (c == '\r')
1190                                 col = 0;
1191
1192                         // skip over white space
1193                         while ((c = getChar ()) != -1 && (c != '\n') && ((c == '\r') || (c == ' ') || (c == '\t')))
1194                                 ;
1195
1196                         if (c == '\n'){
1197                                 line++;
1198                                 ref_line++;
1199                                 return;
1200                         } else if (c == '\r'){
1201                                 col = 0;
1202                                 return;
1203                         }
1204
1205                         static_cmd_arg.Length = 0;
1206                         static_cmd_arg.Append ((char) c);
1207
1208                         while ((c = getChar ()) != -1 && (c != '\n') && (c != '\r')){
1209                                 static_cmd_arg.Append ((char) c);
1210                         }
1211
1212                         if (c == '\n'){
1213                                 line++;
1214                                 ref_line++;
1215                         } else if (c == '\r')
1216                                 col = 0;
1217                         arg = static_cmd_arg.ToString ().Trim ();
1218                 }
1219
1220                 //
1221                 // Handles the #line directive
1222                 //
1223                 bool PreProcessLine (string arg)
1224                 {
1225                         if (arg == "")
1226                                 return false;
1227
1228                         if (arg == "default"){
1229                                 ref_line = line;
1230                                 ref_name = file_name;
1231                                 Location.Push (ref_name);
1232                                 return true;
1233                         } else if (arg == "hidden"){
1234                                 //
1235                                 // We ignore #line hidden
1236                                 //
1237                                 return true;
1238                         }
1239
1240                         try {
1241                                 int pos;
1242
1243                                 if ((pos = arg.IndexOf (' ')) != -1 && pos != 0){
1244                                         ref_line = System.Int32.Parse (arg.Substring (0, pos));
1245                                         pos++;
1246
1247                                         char [] quotes = { '\"' };
1248
1249                                         string name = arg.Substring (pos). Trim (quotes);
1250                                         ref_name = Location.LookupFile (name);
1251                                         file_name.HasLineDirective = true;
1252                                         ref_name.HasLineDirective = true;
1253                                         Location.Push (ref_name);
1254                                 } else {
1255                                         ref_line = System.Int32.Parse (arg);
1256                                 }
1257                         } catch {
1258                                 return false;
1259                         }
1260
1261                         return true;
1262                 }
1263
1264                 //
1265                 // Handles #define and #undef
1266                 //
1267                 void PreProcessDefinition (bool is_define, string arg)
1268                 {
1269                         if (arg == "" || arg == "true" || arg == "false"){
1270                                 Report.Error (1001, Location, "Missing identifer to pre-processor directive");
1271                                 return;
1272                         }
1273
1274                         char[] whitespace = { ' ', '\t' };
1275                         if (arg.IndexOfAny (whitespace) != -1){
1276                                 Report.Error (1025, Location, "Single-line comment or end-of-line expected");
1277                                 return;
1278                         }
1279
1280                         if (!is_identifier_start_character (arg [0]))
1281                                 Report.Error (1001, Location, "Identifier expected: " + arg);
1282
1283                         foreach (char c in arg.Substring (1)){
1284                                 if (!is_identifier_part_character (c)){
1285                                         Report.Error (1001, Location, "Identifier expected: " + arg);
1286                                         return;
1287                                 }
1288                         }
1289
1290                         if (is_define){
1291                                 if (defines == null)
1292                                         defines = new Hashtable ();
1293                                 define (arg);
1294                         } else {
1295                                 if (defines == null)
1296                                         return;
1297                                 if (defines.Contains (arg))
1298                                         defines.Remove (arg);
1299                         }
1300                 }
1301
1302                 /// <summary>
1303                 /// Handles #pragma directive
1304                 /// </summary>
1305                 void PreProcessPragma (string arg)
1306                 {
1307                         const string warning = "warning";
1308                         const string w_disable = warning + " disable";
1309                         const string w_restore = warning + " restore";
1310
1311                         if (arg == w_disable) {
1312                                 Report.RegisterWarningRegion (Location).WarningDisable (line);
1313                                 return;
1314                         }
1315
1316                         if (arg == w_restore) {
1317                                 Report.RegisterWarningRegion (Location).WarningEnable (line);
1318                                 return;
1319                         }
1320
1321                         if (arg.StartsWith (w_disable)) {
1322                                 int[] codes = ParseNumbers (arg.Substring (w_disable.Length));
1323                                 foreach (int code in codes) {
1324                                         if (code != 0)
1325                                                 Report.RegisterWarningRegion (Location).WarningDisable (Location, code);
1326                                 }
1327                                 return;
1328                         }
1329
1330                         if (arg.StartsWith (w_restore)) {
1331                                 int[] codes = ParseNumbers (arg.Substring (w_restore.Length));
1332                                 foreach (int code in codes) {
1333                                         Report.RegisterWarningRegion (Location).WarningEnable (Location, code);
1334                                 }
1335                                 return;
1336                         }
1337
1338                         if (arg.StartsWith (warning)) {
1339                                 Report.Warning (1634, 1, Location , "Expected disable or restore");
1340                                 return;
1341                         }
1342                 }
1343
1344                 int[] ParseNumbers (string text)
1345                 {
1346                         string[] string_array = text.Split (',');
1347                         int[] values = new int [string_array.Length];
1348                         int index = 0;
1349                         foreach (string string_code in string_array) {
1350                                 try {
1351                                         values[index++] = int.Parse (string_code, System.Globalization.CultureInfo.InvariantCulture);
1352                                 }
1353                                 catch (FormatException) {
1354                                         Report.Warning (1692, Location, "Invalid number");
1355                                 }
1356                         }
1357                         return values;
1358                 }
1359
1360                 bool eval_val (string s)
1361                 {
1362                         if (s == "true")
1363                                 return true;
1364                         if (s == "false")
1365                                 return false;
1366
1367                         if (defines == null)
1368                                 return false;
1369                         if (defines.Contains (s))
1370                                 return true;
1371
1372                         return false;
1373                 }
1374
1375                 bool pp_primary (ref string s)
1376                 {
1377                         s = s.Trim ();
1378                         int len = s.Length;
1379
1380                         if (len > 0){
1381                                 char c = s [0];
1382
1383                                 if (c == '('){
1384                                         s = s.Substring (1);
1385                                         bool val = pp_expr (ref s);
1386                                         if (s.Length > 0 && s [0] == ')'){
1387                                                 s = s.Substring (1);
1388                                                 return val;
1389                                         }
1390                                         Error_InvalidDirective ();
1391                                         return false;
1392                                 }
1393
1394                                 if (is_identifier_start_character (c)){
1395                                         int j = 1;
1396
1397                                         while (j < len){
1398                                                 c = s [j];
1399
1400                                                 if (is_identifier_part_character (c)){
1401                                                         j++;
1402                                                         continue;
1403                                                 }
1404                                                 bool v = eval_val (s.Substring (0, j));
1405                                                 s = s.Substring (j);
1406                                                 return v;
1407                                         }
1408                                         bool vv = eval_val (s);
1409                                         s = "";
1410                                         return vv;
1411                                 }
1412                         }
1413                         Error_InvalidDirective ();
1414                         return false;
1415                 }
1416
1417                 bool pp_unary (ref string s)
1418                 {
1419                         s = s.Trim ();
1420                         int len = s.Length;
1421
1422                         if (len > 0){
1423                                 if (s [0] == '!'){
1424                                         if (len > 1 && s [1] == '='){
1425                                                 Error_InvalidDirective ();
1426                                                 return false;
1427                                         }
1428                                         s = s.Substring (1);
1429                                         return ! pp_primary (ref s);
1430                                 } else
1431                                         return pp_primary (ref s);
1432                         } else {
1433                                 Error_InvalidDirective ();
1434                                 return false;
1435                         }
1436                 }
1437
1438                 bool pp_eq (ref string s)
1439                 {
1440                         bool va = pp_unary (ref s);
1441
1442                         s = s.Trim ();
1443                         int len = s.Length;
1444                         if (len > 0){
1445                                 if (s [0] == '='){
1446                                         if (len > 2 && s [1] == '='){
1447                                                 s = s.Substring (2);
1448                                                 return va == pp_unary (ref s);
1449                                         } else {
1450                                                 Error_InvalidDirective ();
1451                                                 return false;
1452                                         }
1453                                 } else if (s [0] == '!' && len > 1 && s [1] == '='){
1454                                         s = s.Substring (2);
1455
1456                                         return va != pp_unary (ref s);
1457
1458                                 }
1459                         }
1460
1461                         return va;
1462
1463                 }
1464
1465                 bool pp_and (ref string s)
1466                 {
1467                         bool va = pp_eq (ref s);
1468
1469                         s = s.Trim ();
1470                         int len = s.Length;
1471                         if (len > 0){
1472                                 if (s [0] == '&'){
1473                                         if (len > 2 && s [1] == '&'){
1474                                                 s = s.Substring (2);
1475                                                 return (va & pp_and (ref s));
1476                                         } else {
1477                                                 Error_InvalidDirective ();
1478                                                 return false;
1479                                         }
1480                                 }
1481                         }
1482                         return va;
1483                 }
1484
1485                 //
1486                 // Evaluates an expression for `#if' or `#elif'
1487                 //
1488                 bool pp_expr (ref string s)
1489                 {
1490                         bool va = pp_and (ref s);
1491                         s = s.Trim ();
1492                         int len = s.Length;
1493                         if (len > 0){
1494                                 char c = s [0];
1495
1496                                 if (c == '|'){
1497                                         if (len > 2 && s [1] == '|'){
1498                                                 s = s.Substring (2);
1499                                                 return va | pp_expr (ref s);
1500                                         } else {
1501                                                 Error_InvalidDirective ();
1502                                                 return false;
1503                                         }
1504                                 }
1505                         }
1506
1507                         return va;
1508                 }
1509
1510                 bool eval (string s)
1511                 {
1512                         bool v = pp_expr (ref s);
1513                         s = s.Trim ();
1514                         if (s.Length != 0){
1515                                 Error_InvalidDirective ();
1516                                 return false;
1517                         }
1518
1519                         return v;
1520                 }
1521
1522                 void Error_InvalidDirective ()
1523                 {
1524                         Report.Error (1517, Location, "Invalid pre-processor directive");
1525                 }
1526
1527                 void Error_UnexpectedDirective (string extra)
1528                 {
1529                         Report.Error (
1530                                 1028, Location,
1531                                 "Unexpected processor directive (" + extra + ")");
1532                 }
1533
1534                 void Error_TokensSeen ()
1535                 {
1536                         Report.Error (
1537                                 1032, Location,
1538                                 "Cannot define or undefine pre-processor symbols after a token in the file");
1539                 }
1540
1541                 //
1542                 // if true, then the code continues processing the code
1543                 // if false, the code stays in a loop until another directive is
1544                 // reached.
1545                 //
1546                 bool handle_preprocessing_directive (bool caller_is_taking)
1547                 {
1548                         string cmd, arg;
1549                         bool region_directive = false;
1550
1551                         get_cmd_arg (out cmd, out arg);
1552
1553                         // Eat any trailing whitespaces and single-line comments
1554                         if (arg.IndexOf ("//") != -1)
1555                                 arg = arg.Substring (0, arg.IndexOf ("//"));
1556                         arg = arg.TrimEnd (' ', '\t');
1557
1558                         //
1559                         // The first group of pre-processing instructions is always processed
1560                         //
1561                         switch (cmd){
1562                         case "pragma":
1563                                 if (RootContext.Version == LanguageVersion.ISO_1) {
1564                                         Report.FeatureIsNotStandardized (Location, "#pragma");
1565                                         return caller_is_taking;
1566                                 }
1567
1568                                 PreProcessPragma (arg);
1569                                 return caller_is_taking;
1570
1571                         case "line":
1572                                 if (!PreProcessLine (arg))
1573                                         Report.Error (
1574                                                 1576, Location,
1575                                                 "Argument to #line directive is missing or invalid");
1576                                 return caller_is_taking;
1577
1578                         case "region":
1579                                 region_directive = true;
1580                                 arg = "true";
1581                                 goto case "if";
1582
1583                         case "endregion":
1584                                 region_directive = true;
1585                                 goto case "endif";
1586
1587                         case "if":
1588                                 if (arg == ""){
1589                                         Error_InvalidDirective ();
1590                                         return true;
1591                                 }
1592                                 bool taking = false;
1593                                 if (ifstack == null)
1594                                         ifstack = new Stack ();
1595
1596                                 if (ifstack.Count == 0){
1597                                         taking = true;
1598                                 } else {
1599                                         int state = (int) ifstack.Peek ();
1600                                         if ((state & TAKING) != 0)
1601                                                 taking = true;
1602                                 }
1603
1604                                 if (eval (arg) && taking){
1605                                         int push = TAKING | TAKEN_BEFORE | PARENT_TAKING;
1606                                         if (region_directive)
1607                                                 push |= REGION;
1608                                         ifstack.Push (push);
1609                                         return true;
1610                                 } else {
1611                                         int push = (taking ? PARENT_TAKING : 0);
1612                                         if (region_directive)
1613                                                 push |= REGION;
1614                                         ifstack.Push (push);
1615                                         return false;
1616                                 }
1617
1618                         case "endif":
1619                                 if (ifstack == null || ifstack.Count == 0){
1620                                         Error_UnexpectedDirective ("no #if for this #endif");
1621                                         return true;
1622                                 } else {
1623                                         int pop = (int) ifstack.Pop ();
1624
1625                                         if (region_directive && ((pop & REGION) == 0))
1626                                                 Report.Error (1027, Location, "#endif directive expected");
1627                                         else if (!region_directive && ((pop & REGION) != 0))
1628                                                 Report.Error (1038, Location, "#endregion directive expected");
1629
1630                                         if (ifstack.Count == 0)
1631                                                 return true;
1632                                         else {
1633                                                 int state = (int) ifstack.Peek ();
1634
1635                                                 if ((state & TAKING) != 0)
1636                                                         return true;
1637                                                 else
1638                                                         return false;
1639                                         }
1640                                 }
1641
1642                         case "elif":
1643                                 if (ifstack == null || ifstack.Count == 0){
1644                                         Error_UnexpectedDirective ("no #if for this #elif");
1645                                         return true;
1646                                 } else {
1647                                         int state = (int) ifstack.Peek ();
1648
1649                                         if ((state & REGION) != 0) {
1650                                                 Report.Error (1038, Location, "#endregion directive expected");
1651                                                 return true;
1652                                         }
1653
1654                                         if ((state & ELSE_SEEN) != 0){
1655                                                 Error_UnexpectedDirective ("#elif not valid after #else");
1656                                                 return true;
1657                                         }
1658
1659                                         if ((state & (TAKEN_BEFORE | TAKING)) != 0)
1660                                                 return false;
1661
1662                                         if (eval (arg) && ((state & PARENT_TAKING) != 0)){
1663                                                 state = (int) ifstack.Pop ();
1664                                                 ifstack.Push (state | TAKING | TAKEN_BEFORE);
1665                                                 return true;
1666                                         } else
1667                                                 return false;
1668                                 }
1669
1670                         case "else":
1671                                 if (ifstack == null || ifstack.Count == 0){
1672                                         Report.Error (
1673                                                 1028, Location,
1674                                                 "Unexpected processor directive (no #if for this #else)");
1675                                         return true;
1676                                 } else {
1677                                         int state = (int) ifstack.Peek ();
1678
1679                                         if ((state & REGION) != 0) {
1680                                                 Report.Error (1038, Location, "#endregion directive expected");
1681                                                 return true;
1682                                         }
1683
1684                                         if ((state & ELSE_SEEN) != 0){
1685                                                 Error_UnexpectedDirective ("#else within #else");
1686                                                 return true;
1687                                         }
1688
1689                                         ifstack.Pop ();
1690
1691                                         bool ret;
1692                                         if ((state & TAKEN_BEFORE) == 0){
1693                                                 ret = ((state & PARENT_TAKING) != 0);
1694                                         } else
1695                                                 ret = false;
1696
1697                                         if (ret)
1698                                                 state |= TAKING;
1699                                         else
1700                                                 state &= ~TAKING;
1701
1702                                         ifstack.Push (state | ELSE_SEEN);
1703
1704                                         return ret;
1705                                 }
1706                         }
1707
1708                         //
1709                         // These are only processed if we are in a `taking' block
1710                         //
1711                         if (!caller_is_taking)
1712                                 return false;
1713
1714                         switch (cmd){
1715                         case "define":
1716                                 if (any_token_seen){
1717                                         Error_TokensSeen ();
1718                                         return true;
1719                                 }
1720                                 PreProcessDefinition (true, arg);
1721                                 return true;
1722
1723                         case "undef":
1724                                 if (any_token_seen){
1725                                         Error_TokensSeen ();
1726                                         return true;
1727                                 }
1728                                 PreProcessDefinition (false, arg);
1729                                 return true;
1730
1731                         case "error":
1732                                 Report.Error (1029, Location, "#error: '" + arg + "'");
1733                                 return true;
1734
1735                         case "warning":
1736                                 Report.Warning (1030, Location, "#warning: '{0}'", arg);
1737                                 return true;
1738                         }
1739
1740                         Report.Error (1024, Location, "Preprocessor directive expected (got: " + cmd + ")");
1741                         return true;
1742
1743                 }
1744
1745                 private int consume_string (bool quoted)
1746                 {
1747                         int c;
1748                         string_builder.Length = 0;
1749
1750                         while ((c = getChar ()) != -1){
1751                                 if (c == '"'){
1752                                         if (quoted && peekChar () == '"'){
1753                                                 string_builder.Append ((char) c);
1754                                                 getChar ();
1755                                                 continue;
1756                                         } else {
1757                                                 val = string_builder.ToString ();
1758                                                 return Token.LITERAL_STRING;
1759                                         }
1760                                 }
1761
1762                                 if (c == '\n'){
1763                                         if (!quoted)
1764                                                 Report.Error (1010, Location, "Newline in constant");
1765                                         line++;
1766                                         ref_line++;
1767                                         col = 0;
1768                                 } else
1769                                         col++;
1770
1771                                 if (!quoted){
1772                                         c = escape (c);
1773                                         if (c == -1)
1774                                                 return Token.ERROR;
1775                                 }
1776                                 string_builder.Append ((char) c);
1777                         }
1778
1779                         Report.Error (1039, Location, "Unterminated string literal");
1780                         return Token.EOF;
1781                 }
1782
1783                 private int consume_identifier (int s)
1784                 {
1785                         int res = consume_identifier (s, false);
1786
1787                         if (doc_state == XmlCommentState.Allowed)
1788                                 doc_state = XmlCommentState.NotAllowed;
1789                         switch (res) {
1790                         case Token.USING:
1791                         case Token.NAMESPACE:
1792                                 check_incorrect_doc_comment ();
1793                                 break;
1794                         }
1795
1796                         if (res == Token.PARTIAL) {
1797                                 // Save current position and parse next token.
1798                                 int old = reader.Position;
1799                                 int old_putback = putback_char;
1800
1801                                 putback_char = -1;
1802
1803                                 int next_token = token ();
1804                                 bool ok = (next_token == Token.CLASS) ||
1805                                         (next_token == Token.STRUCT) ||
1806                                         (next_token == Token.INTERFACE);
1807
1808                                 reader.Position = old;
1809                                 putback_char = old_putback;
1810
1811                                 if (ok)
1812                                         return res;
1813                                 else {
1814                                         val = "partial";
1815                                         return Token.IDENTIFIER;
1816                                 }
1817                         }
1818
1819                         return res;
1820                 }
1821
1822                 private int consume_identifier (int s, bool quoted)
1823                 {
1824                         int pos = 1;
1825                         int c;
1826
1827                         id_builder [0] = (char) s;
1828
1829                         while ((c = reader.Read ()) != -1) {
1830                                 if (is_identifier_part_character ((char) c)){
1831                                         if (pos == max_id_size){
1832                                                 Report.Error (645, Location, "Identifier too long (limit is 512 chars)");
1833                                                 return Token.ERROR;
1834                                         }
1835
1836                                         id_builder [pos++] = (char) c;
1837                                         putback_char = -1;
1838                                         col++;
1839                                 } else {
1840                                         putback_char = c;
1841                                         break;
1842                                 }
1843                         }
1844
1845                         //
1846                         // Optimization: avoids doing the keyword lookup
1847                         // on uppercase letters and _
1848                         //
1849                         if (!quoted && (s >= 'a' || s == '_')){
1850                                 int keyword = GetKeyword (id_builder, pos);
1851                                 if (keyword != -1)
1852                                         return keyword;
1853                         }
1854
1855                         //
1856                         // Keep identifiers in an array of hashtables to avoid needless
1857                         // allocations
1858                         //
1859
1860                         if (identifiers [pos] != null) {
1861                                 val = identifiers [pos][id_builder];
1862                                 if (val != null) {
1863                                         return Token.IDENTIFIER;
1864                                 }
1865                         }
1866                         else
1867                                 identifiers [pos] = new CharArrayHashtable (pos);
1868
1869                         val = new String (id_builder, 0, pos);
1870
1871                         char [] chars = new char [pos];
1872                         Array.Copy (id_builder, chars, pos);
1873
1874                         identifiers [pos] [chars] = val;
1875
1876                         return Token.IDENTIFIER;
1877                 }
1878
1879                 public int xtoken ()
1880                 {
1881                         int t;
1882                         bool doread = false;
1883                         int c;
1884
1885                         // Whether we have seen comments on the current line
1886                         bool comments_seen = false;
1887
1888                         val = null;
1889                         // optimization: eliminate col and implement #directive semantic correctly.
1890                         for (;(c = getChar ()) != -1; col++) {
1891                                 if (c == ' ')
1892                                         continue;
1893
1894                                 if (c == '\t') {
1895                                         col = (((col + 8) / 8) * 8) - 1;
1896                                         continue;
1897                                 }
1898
1899                                 if (c == ' ' || c == '\f' || c == '\v' || c == 0xa0)
1900                                         continue;
1901
1902                                 if (c == '\r') {
1903                                         if (peekChar () == '\n')
1904                                                 getChar ();
1905
1906                                         line++;
1907                                         ref_line++;
1908                                         col = 0;
1909                                         any_token_seen |= tokens_seen;
1910                                         tokens_seen = false;
1911                                         comments_seen = false;
1912                                         continue;
1913                                 }
1914
1915                                 // Handle double-slash comments.
1916                                 if (c == '/'){
1917                                         int d = peekChar ();
1918
1919                                         if (d == '/'){
1920                                                 getChar ();
1921                                                 if (RootContext.Documentation != null && peekChar () == '/') {
1922                                                         getChar ();
1923                                                         // Don't allow ////.
1924                                                         if ((d = peekChar ()) != '/') {
1925                                                                 if (doc_state == XmlCommentState.Allowed)
1926                                                                         handle_one_line_xml_comment ();
1927                                                                 else if (doc_state == XmlCommentState.NotAllowed)
1928                                                                         warn_incorrect_doc_comment ();
1929                                                         }
1930                                                 }
1931                                                 while ((d = getChar ()) != -1 && (d != '\n') && d != '\r')
1932                                                         col++;
1933                                                 if (d == '\n'){
1934                                                         line++;
1935                                                         ref_line++;
1936                                                         col = 0;
1937                                                 }
1938                                                 any_token_seen |= tokens_seen;
1939                                                 tokens_seen = false;
1940                                                 comments_seen = false;
1941                                                 continue;
1942                                         } else if (d == '*'){
1943                                                 getChar ();
1944                                                 bool docAppend = false;
1945                                                 if (RootContext.Documentation != null && peekChar () == '*') {
1946                                                         getChar ();
1947                                                         // But when it is /**/, just do nothing.
1948                                                         if (peekChar () == '/') {
1949                                                                 getChar ();
1950                                                                 continue;
1951                                                         }
1952                                                         if (doc_state == XmlCommentState.Allowed)
1953                                                                 docAppend = true;
1954                                                         else if (doc_state == XmlCommentState.NotAllowed)
1955                                                                 warn_incorrect_doc_comment ();
1956                                                 }
1957
1958                                                 int current_comment_start = 0;
1959                                                 if (docAppend) {
1960                                                         current_comment_start = xml_comment_buffer.Length;
1961                                                         xml_comment_buffer.Append (Environment.NewLine);
1962                                                 }
1963
1964                                                 while ((d = getChar ()) != -1){
1965                                                         if (d == '*' && peekChar () == '/'){
1966                                                                 getChar ();
1967                                                                 col++;
1968                                                                 comments_seen = true;
1969                                                                 break;
1970                                                         }
1971                                                         if (docAppend)
1972                                                                 xml_comment_buffer.Append ((char) d);
1973
1974                                                         if (d == '\n'){
1975                                                                 line++;
1976                                                                 ref_line++;
1977                                                                 col = 0;
1978                                                                 any_token_seen |= tokens_seen;
1979                                                                 tokens_seen = false;
1980                                                                 //
1981                                                                 // Reset 'comments_seen' just to be consistent.
1982                                                                 // It doesn't matter either way, here.
1983                                                                 //
1984                                                                 comments_seen = false;
1985                                                         }
1986                                                 }
1987                                                 if (docAppend)
1988                                                         update_formatted_doc_comment (current_comment_start);
1989                                                 continue;
1990                                         }
1991                                         goto is_punct_label;
1992                                 }
1993
1994
1995                                 if (is_identifier_start_character ((char)c)){
1996                                         tokens_seen = true;
1997                                         return consume_identifier (c);
1998                                 }
1999
2000                         is_punct_label:
2001                                 if ((t = is_punct ((char)c, ref doread)) != Token.ERROR){
2002                                         tokens_seen = true;
2003                                         if (doread){
2004                                                 getChar ();
2005                                                 col++;
2006                                         }
2007                                         return t;
2008                                 }
2009
2010                                 // white space
2011                                 if (c == '\n'){
2012                                         line++;
2013                                         ref_line++;
2014                                         col = 0;
2015                                         any_token_seen |= tokens_seen;
2016                                         tokens_seen = false;
2017                                         comments_seen = false;
2018                                         continue;
2019                                 }
2020
2021                                 if (c >= '0' && c <= '9'){
2022                                         tokens_seen = true;
2023                                         return is_number (c);
2024                                 }
2025
2026                                 if (c == '.'){
2027                                         tokens_seen = true;
2028                                         int peek = peekChar ();
2029                                         if (peek >= '0' && peek <= '9')
2030                                                 return is_number (c);
2031                                         return Token.DOT;
2032                                 }
2033
2034                                 /* For now, ignore pre-processor commands */
2035                                 // FIXME: In C# the '#' is not limited to appear
2036                                 // on the first column.
2037                                 if (c == '#') {
2038                                         bool cont = true;
2039
2040                                         if (tokens_seen || comments_seen) {
2041                                                error_details = "Preprocessor directives must appear as the first non-whitespace " +
2042                                                        "character on a line.";
2043
2044                                                Report.Error (1040, Location, error_details);
2045
2046                                                return Token.ERROR;
2047                                        }
2048
2049                                 start_again:
2050
2051                                         cont = handle_preprocessing_directive (cont);
2052
2053                                         if (cont){
2054                                                 col = 0;
2055                                                 continue;
2056                                         }
2057                                         col = 1;
2058
2059                                         bool skipping = false;
2060                                         for (;(c = getChar ()) != -1; col++){
2061                                                 if (c == '\n'){
2062                                                         col = 0;
2063                                                         line++;
2064                                                         ref_line++;
2065                                                         skipping = false;
2066                                                 } else if (c == ' ' || c == '\t' || c == '\v' || c == '\r' || c == 0xa0)
2067                                                         continue;
2068                                                 else if (c != '#')
2069                                                         skipping = true;
2070                                                 if (c == '#' && !skipping)
2071                                                         goto start_again;
2072                                         }
2073                                         any_token_seen |= tokens_seen;
2074                                         tokens_seen = false;
2075                                         if (c == -1)
2076                                                 Report.Error (1027, Location, "#endif/#endregion expected");
2077                                         continue;
2078                                 }
2079
2080                                 if (c == '"')
2081                                         return consume_string (false);
2082
2083                                 if (c == '\''){
2084                                         c = getChar ();
2085                                         tokens_seen = true;
2086                                         if (c == '\''){
2087                                                 error_details = "Empty character literal";
2088                                                 Report.Error (1011, Location, error_details);
2089                                                 return Token.ERROR;
2090                                         }
2091                                         c = escape (c);
2092                                         if (c == -1)
2093                                                 return Token.ERROR;
2094                                         val = new System.Char ();
2095                                         val = (char) c;
2096                                         c = getChar ();
2097
2098                                         if (c != '\''){
2099                                                 error_details = "Too many characters in character literal";
2100                                                 Report.Error (1012, Location, error_details);
2101
2102                                                 // Try to recover, read until newline or next "'"
2103                                                 while ((c = getChar ()) != -1){
2104                                                         if (c == '\n' || c == '\''){
2105                                                                 line++;
2106                                                                 ref_line++;
2107                                                                 col = 0;
2108                                                                 break;
2109                                                         } else
2110                                                                 col++;
2111
2112                                                 }
2113                                                 return Token.ERROR;
2114                                         }
2115                                         return Token.LITERAL_CHARACTER;
2116                                 }
2117
2118                                 if (c == '@') {
2119                                         c = getChar ();
2120                                         if (c == '"') {
2121                                                 tokens_seen = true;
2122                                                 return consume_string (true);
2123                                         } else if (is_identifier_start_character ((char) c)){
2124                                                 return consume_identifier (c, true);
2125                                         } else {
2126                                                 Report.Error (1646, Location, "Keyword, identifier, or string expected after verbatim specifier: @");
2127                                         }
2128                                 }
2129
2130                                 error_details = ((char)c).ToString ();
2131
2132                                 return Token.ERROR;
2133                         }
2134
2135                         return Token.EOF;
2136                 }
2137
2138                 //
2139                 // Handles one line xml comment
2140                 //
2141                 private void handle_one_line_xml_comment ()
2142                 {
2143                         int c;
2144                         while ((c = peekChar ()) == ' ')
2145                                 getChar (); // skip heading whitespaces.
2146                         while ((c = peekChar ()) != -1 && c != '\n' && c != '\r') {
2147                                 col++;
2148                                 xml_comment_buffer.Append ((char) getChar ());
2149                         }
2150                         if (c == '\r' || c == '\n')
2151                                 xml_comment_buffer.Append (Environment.NewLine);
2152                 }
2153
2154                 //
2155                 // Remove heading "*" in Javadoc-like xml documentation.
2156                 //
2157                 private void update_formatted_doc_comment (int current_comment_start)
2158                 {
2159                         int length = xml_comment_buffer.Length - current_comment_start;
2160                         string [] lines = xml_comment_buffer.ToString (
2161                                 current_comment_start,
2162                                 length).Replace ("\r", "").Split ('\n');
2163
2164                         // The first line starts with /**, thus it is not target
2165                         // for the format check.
2166                         for (int i = 1; i < lines.Length; i++) {
2167                                 string s = lines [i];
2168                                 int idx = s.IndexOf ('*');
2169                                 string head = null;
2170                                 if (idx < 0) {
2171                                         if (i < lines.Length - 1)
2172                                                 return;
2173                                         head = s;
2174                                 } else
2175                                         head = s.Substring (0, idx);
2176                                 foreach (char c in head)
2177                                         if (c != ' ')
2178                                                 return;
2179                                 lines [i] = s.Substring (idx + 1);
2180                         }
2181                         xml_comment_buffer.Remove (current_comment_start, length);
2182                         xml_comment_buffer.Insert (current_comment_start, String.Join (Environment.NewLine, lines));
2183                 }
2184
2185                 //
2186                 // Checks if there was incorrect doc comments and raise
2187                 // warnings.
2188                 //
2189                 public void check_incorrect_doc_comment ()
2190                 {
2191                         if (xml_comment_buffer.Length > 0)
2192                                 warn_incorrect_doc_comment ();
2193                 }
2194
2195                 //
2196                 // Raises a warning when tokenizer found incorrect doccomment
2197                 // markup.
2198                 //
2199                 private void warn_incorrect_doc_comment ()
2200                 {
2201                         doc_state = XmlCommentState.Error;
2202                         // in csc, it is 'XML comment is not placed on a valid
2203                         // language element'. But that does not make sense.
2204                         Report.Warning (1587, 2, Location, "XML comment is placed on an invalid language element which can not accept it.");
2205                 }
2206
2207                 //
2208                 // Consumes the saved xml comment lines (if any)
2209                 // as for current target member or type.
2210                 //
2211                 public string consume_doc_comment ()
2212                 {
2213                         if (xml_comment_buffer.Length > 0) {
2214                                 string ret = xml_comment_buffer.ToString ();
2215                                 xml_comment_buffer.Length = 0;
2216                                 return ret;
2217                         }
2218                         return null;
2219                 }
2220
2221                 public void cleanup ()
2222                 {
2223                         if (ifstack != null && ifstack.Count >= 1) {
2224                                 int state = (int) ifstack.Pop ();
2225                                 if ((state & REGION) != 0)
2226                                         Report.Error (1038, Location, "#endregion directive expected");
2227                                 else
2228                                         Report.Error (1027, "#endif directive expected");
2229                         }
2230
2231                 }
2232         }
2233
2234         //
2235         // Indicates whether it accepts XML documentation or not.
2236         //
2237         public enum XmlCommentState {
2238                 // comment is allowed in this state.
2239                 Allowed,
2240                 // comment is not allowed in this state.
2241                 NotAllowed,
2242                 // once comments appeared when it is NotAllowed, then the
2243                 // state is changed to it, until the state is changed to
2244                 // .Allowed.
2245                 Error
2246         }
2247 }