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                                 Hashtable w_table = Report.warning_ignore_table;
1333                                 foreach (int code in codes) {
1334                                         if (w_table != null && w_table.Contains (code))
1335                                                 Report.Warning (1635, 1, Location, "Cannot restore warning 'CS{0:0000}' because it was disabled globally", code);
1336                                         Report.RegisterWarningRegion (Location).WarningEnable (Location, code);
1337                                 }
1338                                 return;
1339                         }
1340
1341                         if (arg.StartsWith (warning)) {
1342                                 Report.Warning (1634, 1, Location, "Expected disable or restore");
1343                                 return;
1344                         }
1345
1346                         Report.Warning (1633, 1, Location, "Unrecognized #pragma directive");
1347                 }
1348
1349                 int[] ParseNumbers (string text)
1350                 {
1351                         string[] string_array = text.Split (',');
1352                         int[] values = new int [string_array.Length];
1353                         int index = 0;
1354                         foreach (string string_code in string_array) {
1355                                 try {
1356                                         values[index++] = int.Parse (string_code, System.Globalization.CultureInfo.InvariantCulture);
1357                                 }
1358                                 catch (FormatException) {
1359                                         Report.Warning (1692, Location, "Invalid number");
1360                                 }
1361                         }
1362                         return values;
1363                 }
1364
1365                 bool eval_val (string s)
1366                 {
1367                         if (s == "true")
1368                                 return true;
1369                         if (s == "false")
1370                                 return false;
1371
1372                         if (defines == null)
1373                                 return false;
1374                         if (defines.Contains (s))
1375                                 return true;
1376
1377                         return false;
1378                 }
1379
1380                 bool pp_primary (ref string s)
1381                 {
1382                         s = s.Trim ();
1383                         int len = s.Length;
1384
1385                         if (len > 0){
1386                                 char c = s [0];
1387
1388                                 if (c == '('){
1389                                         s = s.Substring (1);
1390                                         bool val = pp_expr (ref s);
1391                                         if (s.Length > 0 && s [0] == ')'){
1392                                                 s = s.Substring (1);
1393                                                 return val;
1394                                         }
1395                                         Error_InvalidDirective ();
1396                                         return false;
1397                                 }
1398
1399                                 if (is_identifier_start_character (c)){
1400                                         int j = 1;
1401
1402                                         while (j < len){
1403                                                 c = s [j];
1404
1405                                                 if (is_identifier_part_character (c)){
1406                                                         j++;
1407                                                         continue;
1408                                                 }
1409                                                 bool v = eval_val (s.Substring (0, j));
1410                                                 s = s.Substring (j);
1411                                                 return v;
1412                                         }
1413                                         bool vv = eval_val (s);
1414                                         s = "";
1415                                         return vv;
1416                                 }
1417                         }
1418                         Error_InvalidDirective ();
1419                         return false;
1420                 }
1421
1422                 bool pp_unary (ref string s)
1423                 {
1424                         s = s.Trim ();
1425                         int len = s.Length;
1426
1427                         if (len > 0){
1428                                 if (s [0] == '!'){
1429                                         if (len > 1 && s [1] == '='){
1430                                                 Error_InvalidDirective ();
1431                                                 return false;
1432                                         }
1433                                         s = s.Substring (1);
1434                                         return ! pp_primary (ref s);
1435                                 } else
1436                                         return pp_primary (ref s);
1437                         } else {
1438                                 Error_InvalidDirective ();
1439                                 return false;
1440                         }
1441                 }
1442
1443                 bool pp_eq (ref string s)
1444                 {
1445                         bool va = pp_unary (ref s);
1446
1447                         s = s.Trim ();
1448                         int len = s.Length;
1449                         if (len > 0){
1450                                 if (s [0] == '='){
1451                                         if (len > 2 && s [1] == '='){
1452                                                 s = s.Substring (2);
1453                                                 return va == pp_unary (ref s);
1454                                         } else {
1455                                                 Error_InvalidDirective ();
1456                                                 return false;
1457                                         }
1458                                 } else if (s [0] == '!' && len > 1 && s [1] == '='){
1459                                         s = s.Substring (2);
1460
1461                                         return va != pp_unary (ref s);
1462
1463                                 }
1464                         }
1465
1466                         return va;
1467
1468                 }
1469
1470                 bool pp_and (ref string s)
1471                 {
1472                         bool va = pp_eq (ref s);
1473
1474                         s = s.Trim ();
1475                         int len = s.Length;
1476                         if (len > 0){
1477                                 if (s [0] == '&'){
1478                                         if (len > 2 && s [1] == '&'){
1479                                                 s = s.Substring (2);
1480                                                 return (va & pp_and (ref s));
1481                                         } else {
1482                                                 Error_InvalidDirective ();
1483                                                 return false;
1484                                         }
1485                                 }
1486                         }
1487                         return va;
1488                 }
1489
1490                 //
1491                 // Evaluates an expression for `#if' or `#elif'
1492                 //
1493                 bool pp_expr (ref string s)
1494                 {
1495                         bool va = pp_and (ref s);
1496                         s = s.Trim ();
1497                         int len = s.Length;
1498                         if (len > 0){
1499                                 char c = s [0];
1500
1501                                 if (c == '|'){
1502                                         if (len > 2 && s [1] == '|'){
1503                                                 s = s.Substring (2);
1504                                                 return va | pp_expr (ref s);
1505                                         } else {
1506                                                 Error_InvalidDirective ();
1507                                                 return false;
1508                                         }
1509                                 }
1510                         }
1511
1512                         return va;
1513                 }
1514
1515                 bool eval (string s)
1516                 {
1517                         bool v = pp_expr (ref s);
1518                         s = s.Trim ();
1519                         if (s.Length != 0){
1520                                 Error_InvalidDirective ();
1521                                 return false;
1522                         }
1523
1524                         return v;
1525                 }
1526
1527                 void Error_InvalidDirective ()
1528                 {
1529                         Report.Error (1517, Location, "Invalid pre-processor directive");
1530                 }
1531
1532                 void Error_UnexpectedDirective (string extra)
1533                 {
1534                         Report.Error (
1535                                 1028, Location,
1536                                 "Unexpected processor directive (" + extra + ")");
1537                 }
1538
1539                 void Error_TokensSeen ()
1540                 {
1541                         Report.Error (
1542                                 1032, Location,
1543                                 "Cannot define or undefine pre-processor symbols after a token in the file");
1544                 }
1545
1546                 //
1547                 // if true, then the code continues processing the code
1548                 // if false, the code stays in a loop until another directive is
1549                 // reached.
1550                 //
1551                 bool handle_preprocessing_directive (bool caller_is_taking)
1552                 {
1553                         string cmd, arg;
1554                         bool region_directive = false;
1555
1556                         get_cmd_arg (out cmd, out arg);
1557
1558                         // Eat any trailing whitespaces and single-line comments
1559                         if (arg.IndexOf ("//") != -1)
1560                                 arg = arg.Substring (0, arg.IndexOf ("//"));
1561                         arg = arg.TrimEnd (' ', '\t');
1562
1563                         //
1564                         // The first group of pre-processing instructions is always processed
1565                         //
1566                         switch (cmd){
1567                         case "pragma":
1568                                 if (RootContext.Version == LanguageVersion.ISO_1) {
1569                                         Report.FeatureIsNotStandardized (Location, "#pragma");
1570                                         return caller_is_taking;
1571                                 }
1572
1573                                 PreProcessPragma (arg);
1574                                 return caller_is_taking;
1575
1576                         case "line":
1577                                 if (!PreProcessLine (arg))
1578                                         Report.Error (
1579                                                 1576, Location,
1580                                                 "Argument to #line directive is missing or invalid");
1581                                 return caller_is_taking;
1582
1583                         case "region":
1584                                 region_directive = true;
1585                                 arg = "true";
1586                                 goto case "if";
1587
1588                         case "endregion":
1589                                 region_directive = true;
1590                                 goto case "endif";
1591
1592                         case "if":
1593                                 if (arg == ""){
1594                                         Error_InvalidDirective ();
1595                                         return true;
1596                                 }
1597                                 bool taking = false;
1598                                 if (ifstack == null)
1599                                         ifstack = new Stack ();
1600
1601                                 if (ifstack.Count == 0){
1602                                         taking = true;
1603                                 } else {
1604                                         int state = (int) ifstack.Peek ();
1605                                         if ((state & TAKING) != 0)
1606                                                 taking = true;
1607                                 }
1608
1609                                 if (eval (arg) && taking){
1610                                         int push = TAKING | TAKEN_BEFORE | PARENT_TAKING;
1611                                         if (region_directive)
1612                                                 push |= REGION;
1613                                         ifstack.Push (push);
1614                                         return true;
1615                                 } else {
1616                                         int push = (taking ? PARENT_TAKING : 0);
1617                                         if (region_directive)
1618                                                 push |= REGION;
1619                                         ifstack.Push (push);
1620                                         return false;
1621                                 }
1622
1623                         case "endif":
1624                                 if (ifstack == null || ifstack.Count == 0){
1625                                         Error_UnexpectedDirective ("no #if for this #endif");
1626                                         return true;
1627                                 } else {
1628                                         int pop = (int) ifstack.Pop ();
1629
1630                                         if (region_directive && ((pop & REGION) == 0))
1631                                                 Report.Error (1027, Location, "#endif directive expected");
1632                                         else if (!region_directive && ((pop & REGION) != 0))
1633                                                 Report.Error (1038, Location, "#endregion directive expected");
1634
1635                                         if (ifstack.Count == 0)
1636                                                 return true;
1637                                         else {
1638                                                 int state = (int) ifstack.Peek ();
1639
1640                                                 if ((state & TAKING) != 0)
1641                                                         return true;
1642                                                 else
1643                                                         return false;
1644                                         }
1645                                 }
1646
1647                         case "elif":
1648                                 if (ifstack == null || ifstack.Count == 0){
1649                                         Error_UnexpectedDirective ("no #if for this #elif");
1650                                         return true;
1651                                 } else {
1652                                         int state = (int) ifstack.Peek ();
1653
1654                                         if ((state & REGION) != 0) {
1655                                                 Report.Error (1038, Location, "#endregion directive expected");
1656                                                 return true;
1657                                         }
1658
1659                                         if ((state & ELSE_SEEN) != 0){
1660                                                 Error_UnexpectedDirective ("#elif not valid after #else");
1661                                                 return true;
1662                                         }
1663
1664                                         if ((state & (TAKEN_BEFORE | TAKING)) != 0)
1665                                                 return false;
1666
1667                                         if (eval (arg) && ((state & PARENT_TAKING) != 0)){
1668                                                 state = (int) ifstack.Pop ();
1669                                                 ifstack.Push (state | TAKING | TAKEN_BEFORE);
1670                                                 return true;
1671                                         } else
1672                                                 return false;
1673                                 }
1674
1675                         case "else":
1676                                 if (ifstack == null || ifstack.Count == 0){
1677                                         Report.Error (
1678                                                 1028, Location,
1679                                                 "Unexpected processor directive (no #if for this #else)");
1680                                         return true;
1681                                 } else {
1682                                         int state = (int) ifstack.Peek ();
1683
1684                                         if ((state & REGION) != 0) {
1685                                                 Report.Error (1038, Location, "#endregion directive expected");
1686                                                 return true;
1687                                         }
1688
1689                                         if ((state & ELSE_SEEN) != 0){
1690                                                 Error_UnexpectedDirective ("#else within #else");
1691                                                 return true;
1692                                         }
1693
1694                                         ifstack.Pop ();
1695
1696                                         bool ret;
1697                                         if ((state & TAKEN_BEFORE) == 0){
1698                                                 ret = ((state & PARENT_TAKING) != 0);
1699                                         } else
1700                                                 ret = false;
1701
1702                                         if (ret)
1703                                                 state |= TAKING;
1704                                         else
1705                                                 state &= ~TAKING;
1706
1707                                         ifstack.Push (state | ELSE_SEEN);
1708
1709                                         return ret;
1710                                 }
1711                         }
1712
1713                         //
1714                         // These are only processed if we are in a `taking' block
1715                         //
1716                         if (!caller_is_taking)
1717                                 return false;
1718
1719                         switch (cmd){
1720                         case "define":
1721                                 if (any_token_seen){
1722                                         Error_TokensSeen ();
1723                                         return true;
1724                                 }
1725                                 PreProcessDefinition (true, arg);
1726                                 return true;
1727
1728                         case "undef":
1729                                 if (any_token_seen){
1730                                         Error_TokensSeen ();
1731                                         return true;
1732                                 }
1733                                 PreProcessDefinition (false, arg);
1734                                 return true;
1735
1736                         case "error":
1737                                 Report.Error (1029, Location, "#error: '" + arg + "'");
1738                                 return true;
1739
1740                         case "warning":
1741                                 Report.Warning (1030, Location, "#warning: '{0}'", arg);
1742                                 return true;
1743                         }
1744
1745                         Report.Error (1024, Location, "Preprocessor directive expected (got: " + cmd + ")");
1746                         return true;
1747
1748                 }
1749
1750                 private int consume_string (bool quoted)
1751                 {
1752                         int c;
1753                         string_builder.Length = 0;
1754
1755                         while ((c = getChar ()) != -1){
1756                                 if (c == '"'){
1757                                         if (quoted && peekChar () == '"'){
1758                                                 string_builder.Append ((char) c);
1759                                                 getChar ();
1760                                                 continue;
1761                                         } else {
1762                                                 val = string_builder.ToString ();
1763                                                 return Token.LITERAL_STRING;
1764                                         }
1765                                 }
1766
1767                                 if (c == '\n'){
1768                                         if (!quoted)
1769                                                 Report.Error (1010, Location, "Newline in constant");
1770                                         line++;
1771                                         ref_line++;
1772                                         col = 0;
1773                                 } else
1774                                         col++;
1775
1776                                 if (!quoted){
1777                                         c = escape (c);
1778                                         if (c == -1)
1779                                                 return Token.ERROR;
1780                                 }
1781                                 string_builder.Append ((char) c);
1782                         }
1783
1784                         Report.Error (1039, Location, "Unterminated string literal");
1785                         return Token.EOF;
1786                 }
1787
1788                 private int consume_identifier (int s)
1789                 {
1790                         int res = consume_identifier (s, false);
1791
1792                         if (doc_state == XmlCommentState.Allowed)
1793                                 doc_state = XmlCommentState.NotAllowed;
1794                         switch (res) {
1795                         case Token.USING:
1796                         case Token.NAMESPACE:
1797                                 check_incorrect_doc_comment ();
1798                                 break;
1799                         }
1800
1801                         if (res == Token.PARTIAL) {
1802                                 // Save current position and parse next token.
1803                                 int old = reader.Position;
1804                                 int old_putback = putback_char;
1805
1806                                 putback_char = -1;
1807
1808                                 int next_token = token ();
1809                                 bool ok = (next_token == Token.CLASS) ||
1810                                         (next_token == Token.STRUCT) ||
1811                                         (next_token == Token.INTERFACE);
1812
1813                                 reader.Position = old;
1814                                 putback_char = old_putback;
1815
1816                                 if (ok)
1817                                         return res;
1818                                 else {
1819                                         val = "partial";
1820                                         return Token.IDENTIFIER;
1821                                 }
1822                         }
1823
1824                         return res;
1825                 }
1826
1827                 private int consume_identifier (int s, bool quoted)
1828                 {
1829                         int pos = 1;
1830                         int c;
1831
1832                         id_builder [0] = (char) s;
1833
1834                         while ((c = reader.Read ()) != -1) {
1835                                 if (is_identifier_part_character ((char) c)){
1836                                         if (pos == max_id_size){
1837                                                 Report.Error (645, Location, "Identifier too long (limit is 512 chars)");
1838                                                 return Token.ERROR;
1839                                         }
1840
1841                                         id_builder [pos++] = (char) c;
1842                                         putback_char = -1;
1843                                         col++;
1844                                 } else {
1845                                         putback_char = c;
1846                                         break;
1847                                 }
1848                         }
1849
1850                         //
1851                         // Optimization: avoids doing the keyword lookup
1852                         // on uppercase letters and _
1853                         //
1854                         if (!quoted && (s >= 'a' || s == '_')){
1855                                 int keyword = GetKeyword (id_builder, pos);
1856                                 if (keyword != -1)
1857                                         return keyword;
1858                         }
1859
1860                         //
1861                         // Keep identifiers in an array of hashtables to avoid needless
1862                         // allocations
1863                         //
1864
1865                         if (identifiers [pos] != null) {
1866                                 val = identifiers [pos][id_builder];
1867                                 if (val != null) {
1868                                         return Token.IDENTIFIER;
1869                                 }
1870                         }
1871                         else
1872                                 identifiers [pos] = new CharArrayHashtable (pos);
1873
1874                         val = new String (id_builder, 0, pos);
1875
1876                         char [] chars = new char [pos];
1877                         Array.Copy (id_builder, chars, pos);
1878
1879                         identifiers [pos] [chars] = val;
1880
1881                         return Token.IDENTIFIER;
1882                 }
1883
1884                 public int xtoken ()
1885                 {
1886                         int t;
1887                         bool doread = false;
1888                         int c;
1889
1890                         // Whether we have seen comments on the current line
1891                         bool comments_seen = false;
1892
1893                         val = null;
1894                         // optimization: eliminate col and implement #directive semantic correctly.
1895                         for (;(c = getChar ()) != -1; col++) {
1896                                 if (c == ' ')
1897                                         continue;
1898
1899                                 if (c == '\t') {
1900                                         col = (((col + 8) / 8) * 8) - 1;
1901                                         continue;
1902                                 }
1903
1904                                 if (c == ' ' || c == '\f' || c == '\v' || c == 0xa0)
1905                                         continue;
1906
1907                                 if (c == '\r') {
1908                                         if (peekChar () == '\n')
1909                                                 getChar ();
1910
1911                                         line++;
1912                                         ref_line++;
1913                                         col = 0;
1914                                         any_token_seen |= tokens_seen;
1915                                         tokens_seen = false;
1916                                         comments_seen = false;
1917                                         continue;
1918                                 }
1919
1920                                 // Handle double-slash comments.
1921                                 if (c == '/'){
1922                                         int d = peekChar ();
1923
1924                                         if (d == '/'){
1925                                                 getChar ();
1926                                                 if (RootContext.Documentation != null && peekChar () == '/') {
1927                                                         getChar ();
1928                                                         // Don't allow ////.
1929                                                         if ((d = peekChar ()) != '/') {
1930                                                                 if (doc_state == XmlCommentState.Allowed)
1931                                                                         handle_one_line_xml_comment ();
1932                                                                 else if (doc_state == XmlCommentState.NotAllowed)
1933                                                                         warn_incorrect_doc_comment ();
1934                                                         }
1935                                                 }
1936                                                 while ((d = getChar ()) != -1 && (d != '\n') && d != '\r')
1937                                                         col++;
1938                                                 if (d == '\n'){
1939                                                         line++;
1940                                                         ref_line++;
1941                                                         col = 0;
1942                                                 }
1943                                                 any_token_seen |= tokens_seen;
1944                                                 tokens_seen = false;
1945                                                 comments_seen = false;
1946                                                 continue;
1947                                         } else if (d == '*'){
1948                                                 getChar ();
1949                                                 bool docAppend = false;
1950                                                 if (RootContext.Documentation != null && peekChar () == '*') {
1951                                                         getChar ();
1952                                                         // But when it is /**/, just do nothing.
1953                                                         if (peekChar () == '/') {
1954                                                                 getChar ();
1955                                                                 continue;
1956                                                         }
1957                                                         if (doc_state == XmlCommentState.Allowed)
1958                                                                 docAppend = true;
1959                                                         else if (doc_state == XmlCommentState.NotAllowed)
1960                                                                 warn_incorrect_doc_comment ();
1961                                                 }
1962
1963                                                 int current_comment_start = 0;
1964                                                 if (docAppend) {
1965                                                         current_comment_start = xml_comment_buffer.Length;
1966                                                         xml_comment_buffer.Append (Environment.NewLine);
1967                                                 }
1968
1969                                                 Location start_location = Location;
1970
1971                                                 while ((d = getChar ()) != -1){
1972                                                         if (d == '*' && peekChar () == '/'){
1973                                                                 getChar ();
1974                                                                 col++;
1975                                                                 comments_seen = true;
1976                                                                 break;
1977                                                         }
1978                                                         if (docAppend)
1979                                                                 xml_comment_buffer.Append ((char) d);
1980
1981                                                         if (d == '\n'){
1982                                                                 line++;
1983                                                                 ref_line++;
1984                                                                 col = 0;
1985                                                                 any_token_seen |= tokens_seen;
1986                                                                 tokens_seen = false;
1987                                                                 //
1988                                                                 // Reset 'comments_seen' just to be consistent.
1989                                                                 // It doesn't matter either way, here.
1990                                                                 //
1991                                                                 comments_seen = false;
1992                                                         }
1993                                                 }
1994                                                 if (!comments_seen)
1995                                                         Report.Error (1035, start_location, "End-of-file found, '*/' expected");
1996
1997                                                 if (docAppend)
1998                                                         update_formatted_doc_comment (current_comment_start);
1999                                                 continue;
2000                                         }
2001                                         goto is_punct_label;
2002                                 }
2003
2004
2005                                 if (is_identifier_start_character ((char)c)){
2006                                         tokens_seen = true;
2007                                         return consume_identifier (c);
2008                                 }
2009
2010                         is_punct_label:
2011                                 if ((t = is_punct ((char)c, ref doread)) != Token.ERROR){
2012                                         tokens_seen = true;
2013                                         if (doread){
2014                                                 getChar ();
2015                                                 col++;
2016                                         }
2017                                         return t;
2018                                 }
2019
2020                                 // white space
2021                                 if (c == '\n'){
2022                                         line++;
2023                                         ref_line++;
2024                                         col = 0;
2025                                         any_token_seen |= tokens_seen;
2026                                         tokens_seen = false;
2027                                         comments_seen = false;
2028                                         continue;
2029                                 }
2030
2031                                 if (c >= '0' && c <= '9'){
2032                                         tokens_seen = true;
2033                                         return is_number (c);
2034                                 }
2035
2036                                 if (c == '.'){
2037                                         tokens_seen = true;
2038                                         int peek = peekChar ();
2039                                         if (peek >= '0' && peek <= '9')
2040                                                 return is_number (c);
2041                                         return Token.DOT;
2042                                 }
2043
2044                                 /* For now, ignore pre-processor commands */
2045                                 // FIXME: In C# the '#' is not limited to appear
2046                                 // on the first column.
2047                                 if (c == '#') {
2048                                         bool cont = true;
2049
2050                                         if (tokens_seen || comments_seen) {
2051                                                error_details = "Preprocessor directives must appear as the first non-whitespace " +
2052                                                        "character on a line.";
2053
2054                                                Report.Error (1040, Location, error_details);
2055
2056                                                return Token.ERROR;
2057                                        }
2058
2059                                 start_again:
2060
2061                                         cont = handle_preprocessing_directive (cont);
2062
2063                                         if (cont){
2064                                                 col = 0;
2065                                                 continue;
2066                                         }
2067                                         col = 1;
2068
2069                                         bool skipping = false;
2070                                         for (;(c = getChar ()) != -1; col++){
2071                                                 if (c == '\n'){
2072                                                         col = 0;
2073                                                         line++;
2074                                                         ref_line++;
2075                                                         skipping = false;
2076                                                 } else if (c == ' ' || c == '\t' || c == '\v' || c == '\r' || c == 0xa0)
2077                                                         continue;
2078                                                 else if (c != '#')
2079                                                         skipping = true;
2080                                                 if (c == '#' && !skipping)
2081                                                         goto start_again;
2082                                         }
2083                                         any_token_seen |= tokens_seen;
2084                                         tokens_seen = false;
2085                                         if (c == -1)
2086                                                 Report.Error (1027, Location, "#endif/#endregion expected");
2087                                         continue;
2088                                 }
2089
2090                                 if (c == '"')
2091                                         return consume_string (false);
2092
2093                                 if (c == '\''){
2094                                         c = getChar ();
2095                                         tokens_seen = true;
2096                                         if (c == '\''){
2097                                                 error_details = "Empty character literal";
2098                                                 Report.Error (1011, Location, error_details);
2099                                                 return Token.ERROR;
2100                                         }
2101                                         c = escape (c);
2102                                         if (c == -1)
2103                                                 return Token.ERROR;
2104                                         val = new System.Char ();
2105                                         val = (char) c;
2106                                         c = getChar ();
2107
2108                                         if (c != '\''){
2109                                                 error_details = "Too many characters in character literal";
2110                                                 Report.Error (1012, Location, error_details);
2111
2112                                                 // Try to recover, read until newline or next "'"
2113                                                 while ((c = getChar ()) != -1){
2114                                                         if (c == '\n' || c == '\''){
2115                                                                 line++;
2116                                                                 ref_line++;
2117                                                                 col = 0;
2118                                                                 break;
2119                                                         } else
2120                                                                 col++;
2121
2122                                                 }
2123                                                 return Token.ERROR;
2124                                         }
2125                                         return Token.LITERAL_CHARACTER;
2126                                 }
2127
2128                                 if (c == '@') {
2129                                         c = getChar ();
2130                                         if (c == '"') {
2131                                                 tokens_seen = true;
2132                                                 return consume_string (true);
2133                                         } else if (is_identifier_start_character ((char) c)){
2134                                                 return consume_identifier (c, true);
2135                                         } else {
2136                                                 Report.Error (1646, Location, "Keyword, identifier, or string expected after verbatim specifier: @");
2137                                         }
2138                                 }
2139
2140                                 error_details = ((char)c).ToString ();
2141
2142                                 return Token.ERROR;
2143                         }
2144
2145                         return Token.EOF;
2146                 }
2147
2148                 //
2149                 // Handles one line xml comment
2150                 //
2151                 private void handle_one_line_xml_comment ()
2152                 {
2153                         int c;
2154                         while ((c = peekChar ()) == ' ')
2155                                 getChar (); // skip heading whitespaces.
2156                         while ((c = peekChar ()) != -1 && c != '\n' && c != '\r') {
2157                                 col++;
2158                                 xml_comment_buffer.Append ((char) getChar ());
2159                         }
2160                         if (c == '\r' || c == '\n')
2161                                 xml_comment_buffer.Append (Environment.NewLine);
2162                 }
2163
2164                 //
2165                 // Remove heading "*" in Javadoc-like xml documentation.
2166                 //
2167                 private void update_formatted_doc_comment (int current_comment_start)
2168                 {
2169                         int length = xml_comment_buffer.Length - current_comment_start;
2170                         string [] lines = xml_comment_buffer.ToString (
2171                                 current_comment_start,
2172                                 length).Replace ("\r", "").Split ('\n');
2173
2174                         // The first line starts with /**, thus it is not target
2175                         // for the format check.
2176                         for (int i = 1; i < lines.Length; i++) {
2177                                 string s = lines [i];
2178                                 int idx = s.IndexOf ('*');
2179                                 string head = null;
2180                                 if (idx < 0) {
2181                                         if (i < lines.Length - 1)
2182                                                 return;
2183                                         head = s;
2184                                 } else
2185                                         head = s.Substring (0, idx);
2186                                 foreach (char c in head)
2187                                         if (c != ' ')
2188                                                 return;
2189                                 lines [i] = s.Substring (idx + 1);
2190                         }
2191                         xml_comment_buffer.Remove (current_comment_start, length);
2192                         xml_comment_buffer.Insert (current_comment_start, String.Join (Environment.NewLine, lines));
2193                 }
2194
2195                 //
2196                 // Checks if there was incorrect doc comments and raise
2197                 // warnings.
2198                 //
2199                 public void check_incorrect_doc_comment ()
2200                 {
2201                         if (xml_comment_buffer.Length > 0)
2202                                 warn_incorrect_doc_comment ();
2203                 }
2204
2205                 //
2206                 // Raises a warning when tokenizer found incorrect doccomment
2207                 // markup.
2208                 //
2209                 private void warn_incorrect_doc_comment ()
2210                 {
2211                         doc_state = XmlCommentState.Error;
2212                         // in csc, it is 'XML comment is not placed on a valid
2213                         // language element'. But that does not make sense.
2214                         Report.Warning (1587, 2, Location, "XML comment is placed on an invalid language element which can not accept it.");
2215                 }
2216
2217                 //
2218                 // Consumes the saved xml comment lines (if any)
2219                 // as for current target member or type.
2220                 //
2221                 public string consume_doc_comment ()
2222                 {
2223                         if (xml_comment_buffer.Length > 0) {
2224                                 string ret = xml_comment_buffer.ToString ();
2225                                 xml_comment_buffer.Length = 0;
2226                                 return ret;
2227                         }
2228                         return null;
2229                 }
2230
2231                 public void cleanup ()
2232                 {
2233                         if (ifstack != null && ifstack.Count >= 1) {
2234                                 int state = (int) ifstack.Pop ();
2235                                 if ((state & REGION) != 0)
2236                                         Report.Error (1038, Location, "#endregion directive expected");
2237                                 else
2238                                         Report.Error (1027, "#endif directive expected");
2239                         }
2240
2241                 }
2242         }
2243
2244         //
2245         // Indicates whether it accepts XML documentation or not.
2246         //
2247         public enum XmlCommentState {
2248                 // comment is allowed in this state.
2249                 Allowed,
2250                 // comment is not allowed in this state.
2251                 NotAllowed,
2252                 // once comments appeared when it is NotAllowed, then the
2253                 // state is changed to it, until the state is changed to
2254                 // .Allowed.
2255                 Error
2256         }
2257 }