nsz Git - cparser/blob - lexer.c

   1 /*
   2  * This file is part of cparser.
   3  * Copyright (C) 2007-2008 Matthias Braun <matze@braunis.de>
   4  *
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU General Public License
   7  * as published by the Free Software Foundation; either version 2
   8  * of the License, or (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
  18  * 02111-1307, USA.
  19  */
  20 #include <config.h>
  21
  22 #include "diagnostic.h"
  23 #include "lexer.h"
  24 #include "symbol_t.h"
  25 #include "token_t.h"
  26 #include "symbol_table_t.h"
  27 #include "adt/error.h"
  28 #include "adt/strset.h"
  29 #include "adt/util.h"
  30 #include "types.h"
  31 #include "type_t.h"
  32 #include "target_architecture.h"
  33 #include "parser.h"
  34 #include "warning.h"
  35 #include "lang_features.h"
  36
  37 #include <assert.h>
  38 #include <errno.h>
  39 #include <string.h>
  40 #include <stdbool.h>
  41 #include <ctype.h>
  42
  43 //#define DEBUG_CHARS
  44 #define MAX_PUTBACK 3
  45
  46 #ifdef _WIN32
  47 /* No strtold on windows and no replacement yet */
  48 #define strtold(s, e) strtod(s, e)
  49 #endif
  50
  51 static int         c;
  52 token_t            lexer_token;
  53 symbol_t          *symbol_L;
  54 static FILE       *input;
  55 static char        buf[1024 + MAX_PUTBACK];
  56 static const char *bufend;
  57 static const char *bufpos;
  58 static strset_t    stringset;
  59
  60 /**
  61  * Prints a parse error message at the current token.
  62  *
  63  * @param msg   the error message
  64  */
  65 static void parse_error(const char *msg)
  66 {
  67         errorf(lexer_token.source_position,  "%s", msg);
  68 }
  69
  70 /**
  71  * Prints an internal error message at the current token.
  72  *
  73  * @param msg   the error message
  74  */
  75 static NORETURN internal_error(const char *msg)
  76 {
  77         internal_errorf(lexer_token.source_position,  "%s", msg);
  78 }
  79
  80 static inline void next_real_char(void)
  81 {
  82         assert(bufpos <= bufend);
  83         if (bufpos >= bufend) {
  84                 size_t s = fread(buf + MAX_PUTBACK, 1, sizeof(buf) - MAX_PUTBACK,
  85                                  input);
  86                 if(s == 0) {
  87                         c = EOF;
  88                         return;
  89                 }
  90                 bufpos = buf + MAX_PUTBACK;
  91                 bufend = buf + MAX_PUTBACK + s;
  92         }
  93         c = *bufpos++;
  94 }
  95
  96 /**
  97  * Put a character back into the buffer.
  98  *
  99  * @param pc  the character to put back
 100  */
 101 static inline void put_back(int pc)
 102 {
 103         assert(bufpos > buf);
 104         *(--bufpos - buf + buf) = (char) pc;
 105
 106 #ifdef DEBUG_CHARS
 107         printf("putback '%c'\n", pc);
 108 #endif
 109 }
 110
 111 static inline void next_char(void);
 112
 113 #define MATCH_NEWLINE(code)                   \
 114         case '\r':                                \
 115                 next_char();                          \
 116                 if(c == '\n') {                       \
 117                         next_char();                      \
 118                 }                                     \
 119                 lexer_token.source_position.linenr++; \
 120                 code                                  \
 121         case '\n':                                \
 122                 next_char();                          \
 123                 lexer_token.source_position.linenr++; \
 124                 code
 125
 126 #define eat(c_type)  do { assert(c == c_type); next_char(); } while(0)
 127
 128 static void maybe_concat_lines(void)
 129 {
 130         eat('\\');
 131
 132         switch(c) {
 133         MATCH_NEWLINE(return;)
 134
 135         default:
 136                 break;
 137         }
 138
 139         put_back(c);
 140         c = '\\';
 141 }
 142
 143 /**
 144  * Set c to the next input character, ie.
 145  * after expanding trigraphs.
 146  */
 147 static inline void next_char(void)
 148 {
 149         next_real_char();
 150
 151         /* filter trigraphs */
 152         if(UNLIKELY(c == '\\')) {
 153                 maybe_concat_lines();
 154                 goto end_of_next_char;
 155         }
 156
 157         if(LIKELY(c != '?'))
 158                 goto end_of_next_char;
 159
 160         next_real_char();
 161         if(LIKELY(c != '?')) {
 162                 put_back(c);
 163                 c = '?';
 164                 goto end_of_next_char;
 165         }
 166
 167         next_real_char();
 168         switch(c) {
 169         case '=': c = '#'; break;
 170         case '(': c = '['; break;
 171         case '/': c = '\\'; maybe_concat_lines(); break;
 172         case ')': c = ']'; break;
 173         case '\'': c = '^'; break;
 174         case '<': c = '{'; break;
 175         case '!': c = '|'; break;
 176         case '>': c = '}'; break;
 177         case '-': c = '~'; break;
 178         default:
 179                 put_back(c);
 180                 put_back('?');
 181                 c = '?';
 182                 break;
 183         }
 184
 185 end_of_next_char:;
 186 #ifdef DEBUG_CHARS
 187         printf("nchar '%c'\n", c);
 188 #endif
 189 }
 190
 191 #define SYMBOL_CHARS  \
 192         case 'a':         \
 193         case 'b':         \
 194         case 'c':         \
 195         case 'd':         \
 196         case 'e':         \
 197         case 'f':         \
 198         case 'g':         \
 199         case 'h':         \
 200         case 'i':         \
 201         case 'j':         \
 202         case 'k':         \
 203         case 'l':         \
 204         case 'm':         \
 205         case 'n':         \
 206         case 'o':         \
 207         case 'p':         \
 208         case 'q':         \
 209         case 'r':         \
 210         case 's':         \
 211         case 't':         \
 212         case 'u':         \
 213         case 'v':         \
 214         case 'w':         \
 215         case 'x':         \
 216         case 'y':         \
 217         case 'z':         \
 218         case 'A':         \
 219         case 'B':         \
 220         case 'C':         \
 221         case 'D':         \
 222         case 'E':         \
 223         case 'F':         \
 224         case 'G':         \
 225         case 'H':         \
 226         case 'I':         \
 227         case 'J':         \
 228         case 'K':         \
 229         case 'L':         \
 230         case 'M':         \
 231         case 'N':         \
 232         case 'O':         \
 233         case 'P':         \
 234         case 'Q':         \
 235         case 'R':         \
 236         case 'S':         \
 237         case 'T':         \
 238         case 'U':         \
 239         case 'V':         \
 240         case 'W':         \
 241         case 'X':         \
 242         case 'Y':         \
 243         case 'Z':         \
 244         case '_':
 245
 246 #define DIGITS        \
 247         case '0':         \
 248         case '1':         \
 249         case '2':         \
 250         case '3':         \
 251         case '4':         \
 252         case '5':         \
 253         case '6':         \
 254         case '7':         \
 255         case '8':         \
 256         case '9':
 257
 258 /**
 259  * Read a symbol from the input and build
 260  * the lexer_token.
 261  */
 262 static void parse_symbol(void)
 263 {
 264         symbol_t *symbol;
 265         char     *string;
 266
 267         obstack_1grow(&symbol_obstack, (char) c);
 268         next_char();
 269
 270         while(1) {
 271                 switch(c) {
 272                 DIGITS
 273                 SYMBOL_CHARS
 274                         obstack_1grow(&symbol_obstack, (char) c);
 275                         next_char();
 276                         break;
 277
 278                 default:
 279                         goto end_symbol;
 280                 }
 281         }
 282
 283 end_symbol:
 284         obstack_1grow(&symbol_obstack, '\0');
 285
 286         string = obstack_finish(&symbol_obstack);
 287         symbol = symbol_table_insert(string);
 288
 289         lexer_token.type     = symbol->ID;
 290         lexer_token.v.symbol = symbol;
 291
 292         if(symbol->string != string) {
 293                 obstack_free(&symbol_obstack, string);
 294         }
 295 }
 296
 297 static void parse_integer_suffix(bool is_oct_hex)
 298 {
 299         bool is_unsigned  = false;
 300         bool min_long     = false;
 301         bool min_longlong = false;
 302
 303         if(c == 'U' || c == 'u') {
 304                 is_unsigned = true;
 305                 next_char();
 306                 if(c == 'L' || c == 'l') {
 307                         min_long = true;
 308                         next_char();
 309                         if(c == 'L' || c == 'l') {
 310                                 min_longlong = true;
 311                                 next_char();
 312                         }
 313                 }
 314         } else if(c == 'l' || c == 'L') {
 315                 min_long = true;
 316                 next_char();
 317                 if(c == 'l' || c == 'L') {
 318                         min_longlong = true;
 319                         next_char();
 320                         if(c == 'u' || c == 'U') {
 321                                 is_unsigned = true;
 322                                 next_char();
 323                         }
 324                 } else if(c == 'u' || c == 'U') {
 325                         is_unsigned = true;
 326                         next_char();
 327                         lexer_token.datatype = type_unsigned_long;
 328                 }
 329         }
 330
 331         if(!is_unsigned) {
 332                 long long v = lexer_token.v.intvalue;
 333                 if(!min_long) {
 334                         if(v >= TARGET_INT_MIN && v <= TARGET_INT_MAX) {
 335                                 lexer_token.datatype = type_int;
 336                                 return;
 337                         } else if(is_oct_hex && v >= 0 && v <= TARGET_UINT_MAX) {
 338                                 lexer_token.datatype = type_unsigned_int;
 339                                 return;
 340                         }
 341                 }
 342                 if(!min_longlong) {
 343                         if(v >= TARGET_LONG_MIN && v <= TARGET_LONG_MAX) {
 344                                 lexer_token.datatype = type_long;
 345                                 return;
 346                         } else if(is_oct_hex && v >= 0 && v <= TARGET_ULONG_MAX) {
 347                                 lexer_token.datatype = type_unsigned_long;
 348                                 return;
 349                         }
 350                 }
 351                 unsigned long long uv = (unsigned long long) v;
 352                 if(is_oct_hex && uv > (unsigned long long) TARGET_LONGLONG_MAX) {
 353                         lexer_token.datatype = type_unsigned_long_long;
 354                         return;
 355                 }
 356
 357                 lexer_token.datatype = type_long_long;
 358         } else {
 359                 unsigned long long v = (unsigned long long) lexer_token.v.intvalue;
 360                 if(!min_long && v <= TARGET_UINT_MAX) {
 361                         lexer_token.datatype = type_unsigned_int;
 362                         return;
 363                 }
 364                 if(!min_longlong && v <= TARGET_ULONG_MAX) {
 365                         lexer_token.datatype = type_unsigned_long;
 366                         return;
 367                 }
 368                 lexer_token.datatype = type_unsigned_long_long;
 369         }
 370 }
 371
 372 static void parse_floating_suffix(void)
 373 {
 374         switch(c) {
 375         /* TODO: do something useful with the suffixes... */
 376         case 'f':
 377         case 'F':
 378                 next_char();
 379                 lexer_token.datatype = type_float;
 380                 break;
 381         case 'l':
 382         case 'L':
 383                 next_char();
 384                 lexer_token.datatype = type_long_double;
 385                 break;
 386         default:
 387                 lexer_token.datatype = type_double;
 388                 break;
 389         }
 390 }
 391
 392 /**
 393  * A replacement for strtoull. Only those parts needed for
 394  * our parser are implemented.
 395  */
 396 static unsigned long long parse_int_string(const char *s, const char **endptr, int base) {
 397         unsigned long long v = 0;
 398
 399         switch (base) {
 400         case 16:
 401                 for (;; ++s) {
 402                         /* check for overrun */
 403                         if (v >= 0x1000000000000000ULL)
 404                                 break;
 405                         switch (tolower(*s)) {
 406                         case '0': v <<= 4; break;
 407                         case '1': v <<= 4; v |= 0x1; break;
 408                         case '2': v <<= 4; v |= 0x2; break;
 409                         case '3': v <<= 4; v |= 0x3; break;
 410                         case '4': v <<= 4; v |= 0x4; break;
 411                         case '5': v <<= 4; v |= 0x5; break;
 412                         case '6': v <<= 4; v |= 0x6; break;
 413                         case '7': v <<= 4; v |= 0x7; break;
 414                         case '8': v <<= 4; v |= 0x8; break;
 415                         case '9': v <<= 4; v |= 0x9; break;
 416                         case 'a': v <<= 4; v |= 0xa; break;
 417                         case 'b': v <<= 4; v |= 0xb; break;
 418                         case 'c': v <<= 4; v |= 0xc; break;
 419                         case 'd': v <<= 4; v |= 0xd; break;
 420                         case 'e': v <<= 4; v |= 0xe; break;
 421                         case 'f': v <<= 4; v |= 0xf; break;
 422                         default:
 423                                 goto end;
 424                         }
 425                 }
 426                 break;
 427         case 8:
 428                 for (;; ++s) {
 429                         /* check for overrun */
 430                         if (v >= 0x2000000000000000ULL)
 431                                 break;
 432                         switch (tolower(*s)) {
 433                         case '0': v <<= 3; break;
 434                         case '1': v <<= 3; v |= 1; break;
 435                         case '2': v <<= 3; v |= 2; break;
 436                         case '3': v <<= 3; v |= 3; break;
 437                         case '4': v <<= 3; v |= 4; break;
 438                         case '5': v <<= 3; v |= 5; break;
 439                         case '6': v <<= 3; v |= 6; break;
 440                         case '7': v <<= 3; v |= 7; break;
 441                         default:
 442                                 goto end;
 443                         }
 444                 }
 445                 break;
 446         case 10:
 447                 for (;; ++s) {
 448                         /* check for overrun */
 449                         if (v > 0x1999999999999999ULL)
 450                                 break;
 451                         switch (tolower(*s)) {
 452                         case '0': v *= 10; break;
 453                         case '1': v *= 10; v += 1; break;
 454                         case '2': v *= 10; v += 2; break;
 455                         case '3': v *= 10; v += 3; break;
 456                         case '4': v *= 10; v += 4; break;
 457                         case '5': v *= 10; v += 5; break;
 458                         case '6': v *= 10; v += 6; break;
 459                         case '7': v *= 10; v += 7; break;
 460                         case '8': v *= 10; v += 8; break;
 461                         case '9': v *= 10; v += 9; break;
 462                         default:
 463                                 goto end;
 464                         }
 465                 }
 466                 break;
 467         default:
 468                 assert(0);
 469                 break;
 470         }
 471 end:
 472         *endptr = s;
 473         return v;
 474 }
 475
 476 /**
 477  * Parses a hex number including hex floats and set the
 478  * lexer_token.
 479  */
 480 static void parse_number_hex(void)
 481 {
 482         assert(c == 'x' || c == 'X');
 483         next_char();
 484
 485         while(isxdigit(c)) {
 486                 obstack_1grow(&symbol_obstack, (char) c);
 487                 next_char();
 488         }
 489         obstack_1grow(&symbol_obstack, '\0');
 490         char *string = obstack_finish(&symbol_obstack);
 491
 492         if(c == '.' || c == 'p' || c == 'P') {
 493                 next_char();
 494                 internal_error("Hex floating point numbers not implemented yet");
 495         }
 496         if(*string == '\0') {
 497                 parse_error("invalid hex number");
 498                 lexer_token.type = T_ERROR;
 499         }
 500
 501         const char *endptr;
 502         lexer_token.type       = T_INTEGER;
 503         lexer_token.v.intvalue = parse_int_string(string, &endptr, 16);
 504         if(*endptr != '\0') {
 505                 parse_error("hex number literal too long");
 506         }
 507
 508         obstack_free(&symbol_obstack, string);
 509         parse_integer_suffix(true);
 510 }
 511
 512 /**
 513  * Returns true if the given char is a octal digit.
 514  *
 515  * @param char  the character to check
 516  */
 517 static inline bool is_octal_digit(int chr)
 518 {
 519         switch(chr) {
 520         case '0':
 521         case '1':
 522         case '2':
 523         case '3':
 524         case '4':
 525         case '5':
 526         case '6':
 527         case '7':
 528                 return true;
 529         default:
 530                 return false;
 531         }
 532 }
 533
 534 /**
 535  * Parses a octal number and set the lexer_token.
 536  */
 537 static void parse_number_oct(void)
 538 {
 539         while(is_octal_digit(c)) {
 540                 obstack_1grow(&symbol_obstack, (char) c);
 541                 next_char();
 542         }
 543         obstack_1grow(&symbol_obstack, '\0');
 544         char *string = obstack_finish(&symbol_obstack);
 545
 546         const char *endptr;
 547         lexer_token.type       = T_INTEGER;
 548         lexer_token.v.intvalue = parse_int_string(string, &endptr, 8);
 549         if(*endptr != '\0') {
 550                 parse_error("octal number literal too long");
 551         }
 552
 553         obstack_free(&symbol_obstack, string);
 554         parse_integer_suffix(true);
 555 }
 556
 557 /**
 558  * Parses a decimal including float number and set the
 559  * lexer_token.
 560  */
 561 static void parse_number_dec(void)
 562 {
 563         bool is_float = false;
 564         while(isdigit(c)) {
 565                 obstack_1grow(&symbol_obstack, (char) c);
 566                 next_char();
 567         }
 568
 569         if(c == '.') {
 570                 obstack_1grow(&symbol_obstack, '.');
 571                 next_char();
 572
 573                 while(isdigit(c)) {
 574                         obstack_1grow(&symbol_obstack, (char) c);
 575                         next_char();
 576                 }
 577                 is_float = true;
 578         }
 579         if(c == 'e' || c == 'E') {
 580                 obstack_1grow(&symbol_obstack, 'e');
 581                 next_char();
 582
 583                 if(c == '-' || c == '+') {
 584                         obstack_1grow(&symbol_obstack, (char) c);
 585                         next_char();
 586                 }
 587
 588                 while(isdigit(c)) {
 589                         obstack_1grow(&symbol_obstack, (char) c);
 590                         next_char();
 591                 }
 592                 is_float = true;
 593         }
 594
 595         obstack_1grow(&symbol_obstack, '\0');
 596         char *string = obstack_finish(&symbol_obstack);
 597
 598         if(is_float) {
 599                 char *endptr;
 600                 lexer_token.type         = T_FLOATINGPOINT;
 601                 lexer_token.v.floatvalue = strtold(string, &endptr);
 602
 603                 if(*endptr != '\0') {
 604                         parse_error("invalid number literal");
 605                 }
 606
 607                 parse_floating_suffix();
 608         } else {
 609                 const char *endptr;
 610                 lexer_token.type       = T_INTEGER;
 611                 lexer_token.v.intvalue = parse_int_string(string, &endptr, 10);
 612
 613                 if(*endptr != '\0') {
 614                         parse_error("invalid number literal");
 615                 }
 616
 617                 parse_integer_suffix(false);
 618         }
 619         obstack_free(&symbol_obstack, string);
 620 }
 621
 622 /**
 623  * Parses a number and sets the lexer_token.
 624  */
 625 static void parse_number(void)
 626 {
 627         if (c == '0') {
 628                 next_char();
 629                 switch (c) {
 630                         case 'X':
 631                         case 'x':
 632                                 parse_number_hex();
 633                                 break;
 634                         case '0':
 635                         case '1':
 636                         case '2':
 637                         case '3':
 638                         case '4':
 639                         case '5':
 640                         case '6':
 641                         case '7':
 642                                 parse_number_oct();
 643                                 break;
 644                         case '8':
 645                         case '9':
 646                                 next_char();
 647                                 parse_error("invalid octal number");
 648                                 lexer_token.type = T_ERROR;
 649                                 return;
 650                         case '.':
 651                         case 'e':
 652                         case 'E':
 653                         default:
 654                                 obstack_1grow(&symbol_obstack, '0');
 655                                 parse_number_dec();
 656                                 return;
 657                 }
 658         } else {
 659                 parse_number_dec();
 660         }
 661 }
 662
 663 /**
 664  * Returns the value of a digit.
 665  * The only portable way to do it ...
 666  */
 667 static int digit_value(int digit) {
 668         switch (digit) {
 669         case '0': return 0;
 670         case '1': return 1;
 671         case '2': return 2;
 672         case '3': return 3;
 673         case '4': return 4;
 674         case '5': return 5;
 675         case '6': return 6;
 676         case '7': return 7;
 677         case '8': return 8;
 678         case '9': return 9;
 679         case 'a':
 680         case 'A': return 10;
 681         case 'b':
 682         case 'B': return 11;
 683         case 'c':
 684         case 'C': return 12;
 685         case 'd':
 686         case 'D': return 13;
 687         case 'e':
 688         case 'E': return 14;
 689         case 'f':
 690         case 'F': return 15;
 691         default:
 692                 internal_error("wrong character given");
 693         }
 694 }
 695
 696 /**
 697  * Parses an octal character sequence.
 698  *
 699  * @param first_digit  the already read first digit
 700  */
 701 static int parse_octal_sequence(const int first_digit)
 702 {
 703         assert(is_octal_digit(first_digit));
 704         int value = digit_value(first_digit);
 705         if (!is_octal_digit(c)) return value;
 706         value = 8 * value + digit_value(c);
 707         next_char();
 708         if (!is_octal_digit(c)) return value;
 709         value = 8 * value + digit_value(c);
 710         next_char();
 711
 712         if(char_is_signed) {
 713                 return (signed char) value;
 714         } else {
 715                 return (unsigned char) value;
 716         }
 717 }
 718
 719 /**
 720  * Parses a hex character sequence.
 721  */
 722 static int parse_hex_sequence(void)
 723 {
 724         int value = 0;
 725         while(isxdigit(c)) {
 726                 value = 16 * value + digit_value(c);
 727                 next_char();
 728         }
 729
 730         if(char_is_signed) {
 731                 return (signed char) value;
 732         } else {
 733                 return (unsigned char) value;
 734         }
 735 }
 736
 737 /**
 738  * Parse an escape sequence.
 739  */
 740 static int parse_escape_sequence(void)
 741 {
 742         eat('\\');
 743
 744         int ec = c;
 745         next_char();
 746
 747         switch(ec) {
 748         case '"':  return '"';
 749         case '\'': return '\'';
 750         case '\\': return '\\';
 751         case '?': return '\?';
 752         case 'a': return '\a';
 753         case 'b': return '\b';
 754         case 'f': return '\f';
 755         case 'n': return '\n';
 756         case 'r': return '\r';
 757         case 't': return '\t';
 758         case 'v': return '\v';
 759         case 'x':
 760                 return parse_hex_sequence();
 761         case '0':
 762         case '1':
 763         case '2':
 764         case '3':
 765         case '4':
 766         case '5':
 767         case '6':
 768         case '7':
 769                 return parse_octal_sequence(ec);
 770         case EOF:
 771                 parse_error("reached end of file while parsing escape sequence");
 772                 return EOF;
 773         default:
 774                 parse_error("unknown escape sequence");
 775                 return EOF;
 776         }
 777 }
 778
 779 /**
 780  * Concatenate two strings.
 781  */
 782 string_t concat_strings(const string_t *const s1, const string_t *const s2)
 783 {
 784         const size_t len1 = s1->size - 1;
 785         const size_t len2 = s2->size - 1;
 786
 787         char *const concat = obstack_alloc(&symbol_obstack, len1 + len2 + 1);
 788         memcpy(concat, s1->begin, len1);
 789         memcpy(concat + len1, s2->begin, len2 + 1);
 790
 791 #if 0 /* TODO hash */
 792         const char *result = strset_insert(&stringset, concat);
 793         if(result != concat) {
 794                 obstack_free(&symbol_obstack, concat);
 795         }
 796
 797         return result;
 798 #else
 799         return (string_t){ concat, len1 + len2 + 1 };
 800 #endif
 801 }
 802
 803 /**
 804  * Concatenate a string and a wide string.
 805  */
 806 wide_string_t concat_string_wide_string(const string_t *const s1, const wide_string_t *const s2)
 807 {
 808         const size_t len1 = s1->size - 1;
 809         const size_t len2 = s2->size - 1;
 810
 811         wchar_rep_t *const concat = obstack_alloc(&symbol_obstack, (len1 + len2 + 1) * sizeof(*concat));
 812         const char *const src = s1->begin;
 813         for (size_t i = 0; i != len1; ++i) {
 814                 concat[i] = src[i];
 815         }
 816         memcpy(concat + len1, s2->begin, (len2 + 1) * sizeof(*concat));
 817
 818         return (wide_string_t){ concat, len1 + len2 + 1 };
 819 }
 820
 821 /**
 822  * Concatenate two wide strings.
 823  */
 824 wide_string_t concat_wide_strings(const wide_string_t *const s1, const wide_string_t *const s2)
 825 {
 826         const size_t len1 = s1->size - 1;
 827         const size_t len2 = s2->size - 1;
 828
 829         wchar_rep_t *const concat = obstack_alloc(&symbol_obstack, (len1 + len2 + 1) * sizeof(*concat));
 830         memcpy(concat,        s1->begin, len1       * sizeof(*concat));
 831         memcpy(concat + len1, s2->begin, (len2 + 1) * sizeof(*concat));
 832
 833         return (wide_string_t){ concat, len1 + len2 + 1 };
 834 }
 835
 836 /**
 837  * Concatenate a wide string and a string.
 838  */
 839 wide_string_t concat_wide_string_string(const wide_string_t *const s1, const string_t *const s2)
 840 {
 841         const size_t len1 = s1->size - 1;
 842         const size_t len2 = s2->size - 1;
 843
 844         wchar_rep_t *const concat = obstack_alloc(&symbol_obstack, (len1 + len2 + 1) * sizeof(*concat));
 845         memcpy(concat, s1->begin, len1 * sizeof(*concat));
 846         const char *const src = s2->begin;
 847         for (size_t i = 0; i != len2 + 1; ++i) {
 848                 concat[i] = src[i];
 849         }
 850
 851         return (wide_string_t){ concat, len1 + len2 + 1 };
 852 }
 853
 854 /**
 855  * Parse a string literal and set lexer_token.
 856  */
 857 static void parse_string_literal(void)
 858 {
 859         const unsigned start_linenr = lexer_token.source_position.linenr;
 860
 861         eat('"');
 862
 863         int tc;
 864         while(1) {
 865                 switch(c) {
 866                 case '\\':
 867                         tc = parse_escape_sequence();
 868                         obstack_1grow(&symbol_obstack, (char) tc);
 869                         break;
 870
 871                 case EOF: {
 872                         source_position_t source_position;
 873                         source_position.input_name = lexer_token.source_position.input_name;
 874                         source_position.linenr     = start_linenr;
 875                         errorf(source_position, "string has no end");
 876                         lexer_token.type = T_ERROR;
 877                         return;
 878                 }
 879
 880                 case '"':
 881                         next_char();
 882                         goto end_of_string;
 883
 884                 default:
 885                         obstack_1grow(&symbol_obstack, (char) c);
 886                         next_char();
 887                         break;
 888                 }
 889         }
 890
 891 end_of_string:
 892
 893         /* TODO: concatenate multiple strings separated by whitespace... */
 894
 895         /* add finishing 0 to the string */
 896         obstack_1grow(&symbol_obstack, '\0');
 897         const size_t      size   = (size_t)obstack_object_size(&symbol_obstack);
 898         const char *const string = obstack_finish(&symbol_obstack);
 899
 900 #if 0 /* TODO hash */
 901         /* check if there is already a copy of the string */
 902         result = strset_insert(&stringset, string);
 903         if(result != string) {
 904                 obstack_free(&symbol_obstack, string);
 905         }
 906 #else
 907         const char *const result = string;
 908 #endif
 909
 910         lexer_token.type           = T_STRING_LITERAL;
 911         lexer_token.v.string.begin = result;
 912         lexer_token.v.string.size  = size;
 913 }
 914
 915 /**
 916  * Parse a wide character constant and set lexer_token.
 917  */
 918 static void parse_wide_character_constant(void)
 919 {
 920         const unsigned start_linenr = lexer_token.source_position.linenr;
 921
 922         eat('\'');
 923
 924         while(1) {
 925                 switch(c) {
 926                 case '\\': {
 927                         wchar_rep_t tc = parse_escape_sequence();
 928                         obstack_grow(&symbol_obstack, &tc, sizeof(tc));
 929                         break;
 930                 }
 931
 932                 MATCH_NEWLINE(
 933                         parse_error("newline while parsing character constant");
 934                         break;
 935                 )
 936
 937                 case '\'':
 938                         next_char();
 939                         goto end_of_wide_char_constant;
 940
 941                 case EOF: {
 942                         source_position_t source_position = lexer_token.source_position;
 943                         source_position.linenr = start_linenr;
 944                         errorf(source_position, "EOF while parsing character constant");
 945                         lexer_token.type = T_ERROR;
 946                         return;
 947                 }
 948
 949                 default: {
 950                         wchar_rep_t tc = (wchar_rep_t) c;
 951                         obstack_grow(&symbol_obstack, &tc, sizeof(tc));
 952                         next_char();
 953                         break;
 954                 }
 955                 }
 956         }
 957
 958 end_of_wide_char_constant:;
 959         size_t             size   = (size_t) obstack_object_size(&symbol_obstack);
 960         const wchar_rep_t *string = obstack_finish(&symbol_obstack);
 961
 962         lexer_token.type                = T_WIDE_CHARACTER_CONSTANT;
 963         lexer_token.v.wide_string.begin = string;
 964         lexer_token.v.wide_string.size  = size;
 965         lexer_token.datatype            = type_wchar_t;
 966 }
 967
 968 /**
 969  * Parse a wide string literal and set lexer_token.
 970  */
 971 static void parse_wide_string_literal(void)
 972 {
 973         const unsigned start_linenr = lexer_token.source_position.linenr;
 974
 975         assert(c == '"');
 976         next_char();
 977
 978         while(1) {
 979                 switch(c) {
 980                 case '\\': {
 981                         wchar_rep_t tc = parse_escape_sequence();
 982                         obstack_grow(&symbol_obstack, &tc, sizeof(tc));
 983                         break;
 984                 }
 985
 986                 case EOF: {
 987                         source_position_t source_position;
 988                         source_position.input_name = lexer_token.source_position.input_name;
 989                         source_position.linenr     = start_linenr;
 990                         errorf(source_position, "string has no end");
 991                         lexer_token.type = T_ERROR;
 992                         return;
 993                 }
 994
 995                 case '"':
 996                         next_char();
 997                         goto end_of_string;
 998
 999                 default: {
1000                         wchar_rep_t tc = c;
1001                         obstack_grow(&symbol_obstack, &tc, sizeof(tc));
1002                         next_char();
1003                         break;
1004                 }
1005                 }
1006         }
1007
1008 end_of_string:;
1009
1010         /* TODO: concatenate multiple strings separated by whitespace... */
1011
1012         /* add finishing 0 to the string */
1013         wchar_rep_t nul = L'\0';
1014         obstack_grow(&symbol_obstack, &nul, sizeof(nul));
1015         const size_t             size   = (size_t)obstack_object_size(&symbol_obstack) / sizeof(wchar_rep_t);
1016         const wchar_rep_t *const string = obstack_finish(&symbol_obstack);
1017
1018 #if 0 /* TODO hash */
1019         /* check if there is already a copy of the string */
1020         const wchar_rep_t *const result = strset_insert(&stringset, string);
1021         if(result != string) {
1022                 obstack_free(&symbol_obstack, string);
1023         }
1024 #else
1025         const wchar_rep_t *const result = string;
1026 #endif
1027
1028         lexer_token.type                = T_WIDE_STRING_LITERAL;
1029         lexer_token.v.wide_string.begin = result;
1030         lexer_token.v.wide_string.size  = size;
1031 }
1032
1033 /**
1034  * Parse a character constant and set lexer_token.
1035  */
1036 static void parse_character_constant(void)
1037 {
1038         const unsigned start_linenr = lexer_token.source_position.linenr;
1039
1040         eat('\'');
1041
1042         while(1) {
1043                 switch(c) {
1044                 case '\\': {
1045                         int tc = parse_escape_sequence();
1046                         obstack_1grow(&symbol_obstack, (char) tc);
1047                         break;
1048                 }
1049
1050                 MATCH_NEWLINE(
1051                         parse_error("newline while parsing character constant");
1052                         break;
1053                 )
1054
1055                 case '\'':
1056                         next_char();
1057                         goto end_of_char_constant;
1058
1059                 case EOF: {
1060                         source_position_t source_position;
1061                         source_position.input_name = lexer_token.source_position.input_name;
1062                         source_position.linenr     = start_linenr;
1063                         errorf(source_position, "EOF while parsing character constant");
1064                         lexer_token.type = T_ERROR;
1065                         return;
1066                 }
1067
1068                 default:
1069                         obstack_1grow(&symbol_obstack, (char) c);
1070                         next_char();
1071                         break;
1072
1073                 }
1074         }
1075
1076 end_of_char_constant:;
1077         const size_t      size   = (size_t)obstack_object_size(&symbol_obstack);
1078         const char *const string = obstack_finish(&symbol_obstack);
1079
1080         lexer_token.type           = T_CHARACTER_CONSTANT;
1081         lexer_token.v.string.begin = string;
1082         lexer_token.v.string.size  = size;
1083         lexer_token.datatype       = type_int;
1084 }
1085
1086 /**
1087  * Skip a multiline comment.
1088  */
1089 static void skip_multiline_comment(void)
1090 {
1091         unsigned start_linenr = lexer_token.source_position.linenr;
1092
1093         while(1) {
1094                 switch(c) {
1095                 case '/':
1096                         next_char();
1097                         if (c == '*') {
1098                                 /* TODO: nested comment, warn here */
1099                         }
1100                         break;
1101                 case '*':
1102                         next_char();
1103                         if(c == '/') {
1104                                 next_char();
1105                                 return;
1106                         }
1107                         break;
1108
1109                 MATCH_NEWLINE(break;)
1110
1111                 case EOF: {
1112                         source_position_t source_position;
1113                         source_position.input_name = lexer_token.source_position.input_name;
1114                         source_position.linenr     = start_linenr;
1115                         errorf(source_position, "at end of file while looking for comment end");
1116                         return;
1117                 }
1118
1119                 default:
1120                         next_char();
1121                         break;
1122                 }
1123         }
1124 }
1125
1126 /**
1127  * Skip a single line comment.
1128  */
1129 static void skip_line_comment(void)
1130 {
1131         while(1) {
1132                 switch(c) {
1133                 case EOF:
1134                         return;
1135
1136                 case '\n':
1137                 case '\r':
1138                         return;
1139
1140                 default:
1141                         next_char();
1142                         break;
1143                 }
1144         }
1145 }
1146
1147 /** The current preprocessor token. */
1148 static token_t pp_token;
1149
1150 /**
1151  * Read the next preprocessor token.
1152  */
1153 static inline void next_pp_token(void)
1154 {
1155         lexer_next_preprocessing_token();
1156         pp_token = lexer_token;
1157 }
1158
1159 /**
1160  * Eat all preprocessor tokens until newline.
1161  */
1162 static void eat_until_newline(void)
1163 {
1164         while(pp_token.type != '\n' && pp_token.type != T_EOF) {
1165                 next_pp_token();
1166         }
1167 }
1168
1169 /**
1170  * Handle the define directive.
1171  */
1172 static void define_directive(void)
1173 {
1174         lexer_next_preprocessing_token();
1175         if(lexer_token.type != T_IDENTIFIER) {
1176                 parse_error("expected identifier after #define\n");
1177                 eat_until_newline();
1178         }
1179 }
1180
1181 /**
1182  * Handle the ifdef directive.
1183  */
1184 static void ifdef_directive(int is_ifndef)
1185 {
1186         (void) is_ifndef;
1187         lexer_next_preprocessing_token();
1188         //expect_identifier();
1189         //extect_newline();
1190 }
1191
1192 /**
1193  * Handle the endif directive.
1194  */
1195 static void endif_directive(void)
1196 {
1197         //expect_newline();
1198 }
1199
1200 /**
1201  * Parse the line directive.
1202  */
1203 static void parse_line_directive(void)
1204 {
1205         if(pp_token.type != T_INTEGER) {
1206                 parse_error("expected integer");
1207         } else {
1208                 lexer_token.source_position.linenr = (unsigned int)(pp_token.v.intvalue - 1);
1209                 next_pp_token();
1210         }
1211         if(pp_token.type == T_STRING_LITERAL) {
1212                 lexer_token.source_position.input_name = pp_token.v.string.begin;
1213                 next_pp_token();
1214         }
1215
1216         eat_until_newline();
1217 }
1218
1219 /**
1220  * STDC pragmas.
1221  */
1222 typedef enum {
1223         STDC_UNKNOWN,
1224         STDC_FP_CONTRACT,
1225         STDC_FENV_ACCESS,
1226         STDC_CX_LIMITED_RANGE
1227 } stdc_pragma_kind_t;
1228
1229 /**
1230  * STDC pragma values.
1231  */
1232 typedef enum {
1233         STDC_VALUE_UNKNOWN,
1234         STDC_VALUE_ON,
1235         STDC_VALUE_OFF,
1236         STDC_VALUE_DEFAULT
1237 } stdc_pragma_value_kind_t;
1238
1239 /**
1240  * Parse a pragma directive.
1241  */
1242 static void parse_pragma(void) {
1243         bool unknown_pragma = true;
1244
1245         next_pp_token();
1246         if (pp_token.v.symbol->pp_ID == TP_STDC) {
1247                 stdc_pragma_kind_t kind = STDC_UNKNOWN;
1248                 /* a STDC pragma */
1249                 if (c_mode & _C99) {
1250                         next_pp_token();
1251
1252                         switch (pp_token.v.symbol->pp_ID) {
1253                         case TP_FP_CONTRACT:
1254                                 kind = STDC_FP_CONTRACT;
1255                                 break;
1256                         case TP_FENV_ACCESS:
1257                                 kind = STDC_FENV_ACCESS;
1258                                 break;
1259                         case TP_CX_LIMITED_RANGE:
1260                                 kind = STDC_CX_LIMITED_RANGE;
1261                                 break;
1262                         default:
1263                                 break;
1264                         }
1265                         if (kind != STDC_UNKNOWN) {
1266                                 stdc_pragma_value_kind_t value = STDC_VALUE_UNKNOWN;
1267                                 next_pp_token();
1268                                 switch (pp_token.v.symbol->pp_ID) {
1269                                 case TP_ON:
1270                                         value = STDC_VALUE_ON;
1271                                         break;
1272                                 case TP_OFF:
1273                                         value = STDC_VALUE_OFF;
1274                                         break;
1275                                 case TP_DEFAULT:
1276                                         value = STDC_VALUE_DEFAULT;
1277                                         break;
1278                                 default:
1279                                         break;
1280                                 }
1281                                 if (value != STDC_VALUE_UNKNOWN) {
1282                                         unknown_pragma = false;
1283                                 } else {
1284                                         errorf(pp_token.source_position, "bad STDC pragma argument");
1285                                 }
1286                         }
1287                 }
1288         } else {
1289                 unknown_pragma = true;
1290         }
1291         eat_until_newline();
1292         if (unknown_pragma && warning.unknown_pragmas) {
1293                 warningf(pp_token.source_position, "encountered unknown #pragma");
1294         }
1295 }
1296
1297 /**
1298  * Parse a preprocessor non-null directive.
1299  */
1300 static void parse_preprocessor_identifier(void)
1301 {
1302         assert(pp_token.type == T_IDENTIFIER);
1303         symbol_t *symbol = pp_token.v.symbol;
1304
1305         switch(symbol->pp_ID) {
1306         case TP_include:
1307                 printf("include - enable header name parsing!\n");
1308                 break;
1309         case TP_define:
1310                 define_directive();
1311                 break;
1312         case TP_ifdef:
1313                 ifdef_directive(0);
1314                 break;
1315         case TP_ifndef:
1316                 ifdef_directive(1);
1317                 break;
1318         case TP_endif:
1319                 endif_directive();
1320                 break;
1321         case TP_line:
1322                 next_pp_token();
1323                 parse_line_directive();
1324                 break;
1325         case TP_if:
1326         case TP_else:
1327         case TP_elif:
1328         case TP_undef:
1329         case TP_error:
1330                 /* TODO; output the rest of the line */
1331                 parse_error("#error directive: ");
1332                 break;
1333         case TP_pragma:
1334                 parse_pragma();
1335                 break;
1336         }
1337 }
1338
1339 /**
1340  * Parse a preprocessor directive.
1341  */
1342 static void parse_preprocessor_directive(void)
1343 {
1344         next_pp_token();
1345
1346         switch(pp_token.type) {
1347         case T_IDENTIFIER:
1348                 parse_preprocessor_identifier();
1349                 break;
1350         case T_INTEGER:
1351                 parse_line_directive();
1352                 break;
1353         case '\n':
1354                 /* NULL directive, see § 6.10.7 */
1355                 break;
1356         default:
1357                 parse_error("invalid preprocessor directive");
1358                 eat_until_newline();
1359                 break;
1360         }
1361 }
1362
1363 #define MAYBE_PROLOG                                       \
1364                         next_char();                                   \
1365                         while(1) {                                     \
1366                                 switch(c) {
1367
1368 #define MAYBE(ch, set_type)                                \
1369                                 case ch:                                   \
1370                                         next_char();                           \
1371                                         lexer_token.type = set_type;           \
1372                                         return;
1373
1374 #define ELSE_CODE(code)                                    \
1375                                 default:                                   \
1376                                         code;                                  \
1377                                 }                                          \
1378                         } /* end of while(1) */                        \
1379                         break;
1380
1381 #define ELSE(set_type)                                     \
1382                 ELSE_CODE(                                         \
1383                         lexer_token.type = set_type;                   \
1384                         return;                                        \
1385                 )
1386
1387 void lexer_next_preprocessing_token(void)
1388 {
1389         while(1) {
1390                 switch(c) {
1391                 case ' ':
1392                 case '\t':
1393                         next_char();
1394                         break;
1395
1396                 MATCH_NEWLINE(
1397                         lexer_token.type = '\n';
1398                         return;
1399                 )
1400
1401                 SYMBOL_CHARS
1402                         parse_symbol();
1403                         /* might be a wide string ( L"string" ) */
1404                         if(lexer_token.type == T_IDENTIFIER &&
1405                             lexer_token.v.symbol == symbol_L) {
1406                             if(c == '"') {
1407                                         parse_wide_string_literal();
1408                                 } else if(c == '\'') {
1409                                         parse_wide_character_constant();
1410                                 }
1411                         }
1412                         return;
1413
1414                 DIGITS
1415                         parse_number();
1416                         return;
1417
1418                 case '"':
1419                         parse_string_literal();
1420                         return;
1421
1422                 case '\'':
1423                         parse_character_constant();
1424                         return;
1425
1426                 case '.':
1427                         MAYBE_PROLOG
1428                                 case '0':
1429                                 case '1':
1430                                 case '2':
1431                                 case '3':
1432                                 case '4':
1433                                 case '5':
1434                                 case '6':
1435                                 case '7':
1436                                 case '8':
1437                                 case '9':
1438                                         put_back(c);
1439                                         c = '.';
1440                                         parse_number_dec();
1441                                         return;
1442
1443                                 case '.':
1444                                         MAYBE_PROLOG
1445                                         MAYBE('.', T_DOTDOTDOT)
1446                                         ELSE_CODE(
1447                                                 put_back(c);
1448                                                 c = '.';
1449                                                 lexer_token.type = '.';
1450                                                 return;
1451                                         )
1452                         ELSE('.')
1453                 case '&':
1454                         MAYBE_PROLOG
1455                         MAYBE('&', T_ANDAND)
1456                         MAYBE('=', T_ANDEQUAL)
1457                         ELSE('&')
1458                 case '*':
1459                         MAYBE_PROLOG
1460                         MAYBE('=', T_ASTERISKEQUAL)
1461                         ELSE('*')
1462                 case '+':
1463                         MAYBE_PROLOG
1464                         MAYBE('+', T_PLUSPLUS)
1465                         MAYBE('=', T_PLUSEQUAL)
1466                         ELSE('+')
1467                 case '-':
1468                         MAYBE_PROLOG
1469                         MAYBE('>', T_MINUSGREATER)
1470                         MAYBE('-', T_MINUSMINUS)
1471                         MAYBE('=', T_MINUSEQUAL)
1472                         ELSE('-')
1473                 case '!':
1474                         MAYBE_PROLOG
1475                         MAYBE('=', T_EXCLAMATIONMARKEQUAL)
1476                         ELSE('!')
1477                 case '/':
1478                         MAYBE_PROLOG
1479                         MAYBE('=', T_SLASHEQUAL)
1480                                 case '*':
1481                                         next_char();
1482                                         skip_multiline_comment();
1483                                         lexer_next_preprocessing_token();
1484                                         return;
1485                                 case '/':
1486                                         next_char();
1487                                         skip_line_comment();
1488                                         lexer_next_preprocessing_token();
1489                                         return;
1490                         ELSE('/')
1491                 case '%':
1492                         MAYBE_PROLOG
1493                         MAYBE('>', '}')
1494                         MAYBE('=', T_PERCENTEQUAL)
1495                                 case ':':
1496                                         MAYBE_PROLOG
1497                                                 case '%':
1498                                                         MAYBE_PROLOG
1499                                                         MAYBE(':', T_HASHHASH)
1500                                                         ELSE_CODE(
1501                                                                 put_back(c);
1502                                                                 c = '%';
1503                                                                 lexer_token.type = '#';
1504                                                                 return;
1505                                                         )
1506                                         ELSE('#')
1507                         ELSE('%')
1508                 case '<':
1509                         MAYBE_PROLOG
1510                         MAYBE(':', '[')
1511                         MAYBE('%', '{')
1512                         MAYBE('=', T_LESSEQUAL)
1513                                 case '<':
1514                                         MAYBE_PROLOG
1515                                         MAYBE('=', T_LESSLESSEQUAL)
1516                                         ELSE(T_LESSLESS)
1517                         ELSE('<')
1518                 case '>':
1519                         MAYBE_PROLOG
1520                         MAYBE('=', T_GREATEREQUAL)
1521                                 case '>':
1522                                         MAYBE_PROLOG
1523                                         MAYBE('=', T_GREATERGREATEREQUAL)
1524                                         ELSE(T_GREATERGREATER)
1525                         ELSE('>')
1526                 case '^':
1527                         MAYBE_PROLOG
1528                         MAYBE('=', T_CARETEQUAL)
1529                         ELSE('^')
1530                 case '|':
1531                         MAYBE_PROLOG
1532                         MAYBE('=', T_PIPEEQUAL)
1533                         MAYBE('|', T_PIPEPIPE)
1534                         ELSE('|')
1535                 case ':':
1536                         MAYBE_PROLOG
1537                         MAYBE('>', ']')
1538                         ELSE(':')
1539                 case '=':
1540                         MAYBE_PROLOG
1541                         MAYBE('=', T_EQUALEQUAL)
1542                         ELSE('=')
1543                 case '#':
1544                         MAYBE_PROLOG
1545                         MAYBE('#', T_HASHHASH)
1546                         ELSE('#')
1547
1548                 case '?':
1549                 case '[':
1550                 case ']':
1551                 case '(':
1552                 case ')':
1553                 case '{':
1554                 case '}':
1555                 case '~':
1556                 case ';':
1557                 case ',':
1558                 case '\\':
1559                         lexer_token.type = c;
1560                         next_char();
1561                         return;
1562
1563                 case EOF:
1564                         lexer_token.type = T_EOF;
1565                         return;
1566
1567                 default:
1568                         next_char();
1569                         errorf(lexer_token.source_position, "unknown character '%c' found\n", c);
1570                         lexer_token.type = T_ERROR;
1571                         return;
1572                 }
1573         }
1574 }
1575
1576 void lexer_next_token(void)
1577 {
1578         lexer_next_preprocessing_token();
1579         if(lexer_token.type != '\n')
1580                 return;
1581
1582 newline_found:
1583         do {
1584                 lexer_next_preprocessing_token();
1585         } while(lexer_token.type == '\n');
1586
1587         if(lexer_token.type == '#') {
1588                 parse_preprocessor_directive();
1589                 goto newline_found;
1590         }
1591 }
1592
1593 void init_lexer(void)
1594 {
1595         strset_init(&stringset);
1596 }
1597
1598 void lexer_open_stream(FILE *stream, const char *input_name)
1599 {
1600         input                                  = stream;
1601         lexer_token.source_position.linenr     = 0;
1602         lexer_token.source_position.input_name = input_name;
1603
1604         symbol_L = symbol_table_insert("L");
1605         bufpos = NULL;
1606         bufend = NULL;
1607
1608         /* place a virtual \n at the beginning so the lexer knows that we're
1609          * at the beginning of a line */
1610         c = '\n';
1611 }
1612
1613 void exit_lexer(void)
1614 {
1615         strset_destroy(&stringset);
1616 }
1617
1618 static __attribute__((unused))
1619 void dbg_pos(const source_position_t source_position)
1620 {
1621         fprintf(stdout, "%s:%u\n", source_position.input_name,
1622                 source_position.linenr);
1623         fflush(stdout);
1624 }