vfwscanf.c revision 128822
1/*- 2 * Copyright (c) 1990, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * This code is derived from software contributed to Berkeley by 6 * Chris Torek. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. All advertising materials mentioning features or use of this software 17 * must display the following acknowledgement: 18 * This product includes software developed by the University of 19 * California, Berkeley and its contributors. 20 * 4. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 */ 36 37#include <sys/cdefs.h> 38#if 0 39#if defined(LIBC_SCCS) && !defined(lint) 40static char sccsid[] = "@(#)vfscanf.c 8.1 (Berkeley) 6/4/93"; 41#endif /* LIBC_SCCS and not lint */ 42__FBSDID("FreeBSD: src/lib/libc/stdio/vfscanf.c,v 1.37 2004/05/02 10:55:05 das 43Exp"); 44#endif 45__FBSDID("$FreeBSD: head/lib/libc/stdio/vfwscanf.c 128822 2004-05-02 10:56:26Z das $"); 46 47#include "namespace.h" 48#include <ctype.h> 49#include <inttypes.h> 50#include <stdio.h> 51#include <stdlib.h> 52#include <stddef.h> 53#include <stdarg.h> 54#include <string.h> 55#include <wchar.h> 56#include <wctype.h> 57#include "un-namespace.h" 58 59#include "libc_private.h" 60#include "local.h" 61 62#ifndef NO_FLOATING_POINT 63#include <locale.h> 64#endif 65 66#define BUF 513 /* Maximum length of numeric string. */ 67 68/* 69 * Flags used during conversion. 70 */ 71#define LONG 0x01 /* l: long or double */ 72#define LONGDBL 0x02 /* L: long double */ 73#define SHORT 0x04 /* h: short */ 74#define SUPPRESS 0x08 /* *: suppress assignment */ 75#define POINTER 0x10 /* p: void * (as hex) */ 76#define NOSKIP 0x20 /* [ or c: do not skip blanks */ 77#define LONGLONG 0x400 /* ll: long long (+ deprecated q: quad) */ 78#define INTMAXT 0x800 /* j: intmax_t */ 79#define PTRDIFFT 0x1000 /* t: ptrdiff_t */ 80#define SIZET 0x2000 /* z: size_t */ 81#define SHORTSHORT 0x4000 /* hh: char */ 82#define UNSIGNED 0x8000 /* %[oupxX] conversions */ 83 84/* 85 * The following are used in integral conversions only: 86 * SIGNOK, NDIGITS, PFXOK, and NZDIGITS 87 */ 88#define SIGNOK 0x40 /* +/- is (still) legal */ 89#define NDIGITS 0x80 /* no digits detected */ 90#define PFXOK 0x100 /* 0x prefix is (still) legal */ 91#define NZDIGITS 0x200 /* no zero digits detected */ 92#define HAVESIGN 0x10000 /* sign detected */ 93 94/* 95 * Conversion types. 96 */ 97#define CT_CHAR 0 /* %c conversion */ 98#define CT_CCL 1 /* %[...] conversion */ 99#define CT_STRING 2 /* %s conversion */ 100#define CT_INT 3 /* %[dioupxX] conversion */ 101#define CT_FLOAT 4 /* %[efgEFG] conversion */ 102 103static int parsefloat(FILE *, wchar_t *, wchar_t *); 104 105extern int __scanfdebug; 106 107#define INCCL(_c) \ 108 (cclcompl ? (wmemchr(ccls, (_c), ccle - ccls) == NULL) : \ 109 (wmemchr(ccls, (_c), ccle - ccls) != NULL)) 110 111/* 112 * MT-safe version. 113 */ 114int 115vfwscanf(FILE * __restrict fp, const wchar_t * __restrict fmt, va_list ap) 116{ 117 int ret; 118 119 FLOCKFILE(fp); 120 ORIENT(fp, 1); 121 ret = __vfwscanf(fp, fmt, ap); 122 FUNLOCKFILE(fp); 123 return (ret); 124} 125 126/* 127 * Non-MT-safe version. 128 */ 129int 130__vfwscanf(FILE * __restrict fp, const wchar_t * __restrict fmt, va_list ap) 131{ 132 wint_t c; /* character from format, or conversion */ 133 size_t width; /* field width, or 0 */ 134 wchar_t *p; /* points into all kinds of strings */ 135 int n; /* handy integer */ 136 int flags; /* flags as defined above */ 137 wchar_t *p0; /* saves original value of p when necessary */ 138 int nassigned; /* number of fields assigned */ 139 int nconversions; /* number of conversions */ 140 int nread; /* number of characters consumed from fp */ 141 int base; /* base argument to conversion function */ 142 wchar_t buf[BUF]; /* buffer for numeric conversions */ 143 const wchar_t *ccls; /* character class start */ 144 const wchar_t *ccle; /* character class end */ 145 int cclcompl; /* ccl is complemented? */ 146 wint_t wi; /* handy wint_t */ 147 char *mbp; /* multibyte string pointer for %c %s %[ */ 148 size_t nconv; /* number of bytes in mb. conversion */ 149 char mbbuf[MB_LEN_MAX]; /* temporary mb. character buffer */ 150 static const mbstate_t initial; 151 mbstate_t mbs; 152 153 /* `basefix' is used to avoid `if' tests in the integer scanner */ 154 static short basefix[17] = 155 { 10, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16 }; 156 157 nassigned = 0; 158 nconversions = 0; 159 nread = 0; 160 ccls = ccle = NULL; 161 for (;;) { 162 c = *fmt++; 163 if (c == 0) 164 return (nassigned); 165 if (iswspace(c)) { 166 while ((c = __fgetwc(fp)) != WEOF && 167 iswspace(c)) 168 ; 169 if (c != WEOF) 170 __ungetwc(c, fp); 171 continue; 172 } 173 if (c != '%') 174 goto literal; 175 width = 0; 176 flags = 0; 177 /* 178 * switch on the format. continue if done; 179 * break once format type is derived. 180 */ 181again: c = *fmt++; 182 switch (c) { 183 case '%': 184literal: 185 if ((wi = __fgetwc(fp)) == WEOF) 186 goto input_failure; 187 if (wi != c) { 188 __ungetwc(wi, fp); 189 goto input_failure; 190 } 191 nread++; 192 continue; 193 194 case '*': 195 flags |= SUPPRESS; 196 goto again; 197 case 'j': 198 flags |= INTMAXT; 199 goto again; 200 case 'l': 201 if (flags & LONG) { 202 flags &= ~LONG; 203 flags |= LONGLONG; 204 } else 205 flags |= LONG; 206 goto again; 207 case 'q': 208 flags |= LONGLONG; /* not quite */ 209 goto again; 210 case 't': 211 flags |= PTRDIFFT; 212 goto again; 213 case 'z': 214 flags |= SIZET; 215 goto again; 216 case 'L': 217 flags |= LONGDBL; 218 goto again; 219 case 'h': 220 if (flags & SHORT) { 221 flags &= ~SHORT; 222 flags |= SHORTSHORT; 223 } else 224 flags |= SHORT; 225 goto again; 226 227 case '0': case '1': case '2': case '3': case '4': 228 case '5': case '6': case '7': case '8': case '9': 229 width = width * 10 + c - '0'; 230 goto again; 231 232 /* 233 * Conversions. 234 */ 235 case 'd': 236 c = CT_INT; 237 base = 10; 238 break; 239 240 case 'i': 241 c = CT_INT; 242 base = 0; 243 break; 244 245 case 'o': 246 c = CT_INT; 247 flags |= UNSIGNED; 248 base = 8; 249 break; 250 251 case 'u': 252 c = CT_INT; 253 flags |= UNSIGNED; 254 base = 10; 255 break; 256 257 case 'X': 258 case 'x': 259 flags |= PFXOK; /* enable 0x prefixing */ 260 c = CT_INT; 261 flags |= UNSIGNED; 262 base = 16; 263 break; 264 265#ifndef NO_FLOATING_POINT 266 case 'A': case 'E': case 'F': case 'G': 267 case 'a': case 'e': case 'f': case 'g': 268 c = CT_FLOAT; 269 break; 270#endif 271 272 case 'S': 273 flags |= LONG; 274 /* FALLTHROUGH */ 275 case 's': 276 c = CT_STRING; 277 break; 278 279 case '[': 280 ccls = fmt; 281 if (*fmt == '^') { 282 cclcompl = 1; 283 fmt++; 284 } else 285 cclcompl = 0; 286 if (*fmt == ']') 287 fmt++; 288 while (*fmt != '\0' && *fmt != ']') 289 fmt++; 290 ccle = fmt; 291 fmt++; 292 flags |= NOSKIP; 293 c = CT_CCL; 294 break; 295 296 case 'C': 297 flags |= LONG; 298 /* FALLTHROUGH */ 299 case 'c': 300 flags |= NOSKIP; 301 c = CT_CHAR; 302 break; 303 304 case 'p': /* pointer format is like hex */ 305 flags |= POINTER | PFXOK; 306 c = CT_INT; /* assumes sizeof(uintmax_t) */ 307 flags |= UNSIGNED; /* >= sizeof(uintptr_t) */ 308 base = 16; 309 break; 310 311 case 'n': 312 nconversions++; 313 if (flags & SUPPRESS) /* ??? */ 314 continue; 315 if (flags & SHORTSHORT) 316 *va_arg(ap, char *) = nread; 317 else if (flags & SHORT) 318 *va_arg(ap, short *) = nread; 319 else if (flags & LONG) 320 *va_arg(ap, long *) = nread; 321 else if (flags & LONGLONG) 322 *va_arg(ap, long long *) = nread; 323 else if (flags & INTMAXT) 324 *va_arg(ap, intmax_t *) = nread; 325 else if (flags & SIZET) 326 *va_arg(ap, size_t *) = nread; 327 else if (flags & PTRDIFFT) 328 *va_arg(ap, ptrdiff_t *) = nread; 329 else 330 *va_arg(ap, int *) = nread; 331 continue; 332 333 default: 334 goto match_failure; 335 336 /* 337 * Disgusting backwards compatibility hack. XXX 338 */ 339 case '\0': /* compat */ 340 return (EOF); 341 } 342 343 /* 344 * Consume leading white space, except for formats 345 * that suppress this. 346 */ 347 if ((flags & NOSKIP) == 0) { 348 while ((wi = __fgetwc(fp)) != WEOF && iswspace(wi)) 349 nread++; 350 if (wi == WEOF) 351 goto input_failure; 352 __ungetwc(wi, fp); 353 } 354 355 /* 356 * Do the conversion. 357 */ 358 switch (c) { 359 360 case CT_CHAR: 361 /* scan arbitrary characters (sets NOSKIP) */ 362 if (width == 0) 363 width = 1; 364 if (flags & LONG) { 365 if (!(flags & SUPPRESS)) 366 p = va_arg(ap, wchar_t *); 367 n = 0; 368 while (width-- != 0 && 369 (wi = __fgetwc(fp)) != WEOF) { 370 if (!(flags & SUPPRESS)) 371 *p++ = (wchar_t)wi; 372 n++; 373 } 374 if (n == 0) 375 goto input_failure; 376 nread += n; 377 if (!(flags & SUPPRESS)) 378 nassigned++; 379 } else { 380 if (!(flags & SUPPRESS)) 381 mbp = va_arg(ap, char *); 382 n = 0; 383 mbs = initial; 384 while (width != 0 && 385 (wi = __fgetwc(fp)) != WEOF) { 386 if (width >= MB_CUR_MAX && 387 !(flags & SUPPRESS)) { 388 nconv = wcrtomb(mbp, wi, &mbs); 389 if (nconv == (size_t)-1) 390 goto input_failure; 391 } else { 392 nconv = wcrtomb(mbbuf, wi, 393 &mbs); 394 if (nconv == (size_t)-1) 395 goto input_failure; 396 if (nconv > width) { 397 __ungetwc(wi, fp); 398 break; 399 } 400 if (!(flags & SUPPRESS)) 401 memcpy(mbp, mbbuf, 402 nconv); 403 } 404 if (!(flags & SUPPRESS)) 405 mbp += nconv; 406 width -= nconv; 407 n++; 408 } 409 if (n == 0) 410 goto input_failure; 411 nread += n; 412 if (!(flags & SUPPRESS)) 413 nassigned++; 414 } 415 nconversions++; 416 break; 417 418 case CT_CCL: 419 /* scan a (nonempty) character class (sets NOSKIP) */ 420 if (width == 0) 421 width = (size_t)~0; /* `infinity' */ 422 /* take only those things in the class */ 423 if ((flags & SUPPRESS) && (flags & LONG)) { 424 n = 0; 425 while ((wi = __fgetwc(fp)) != WEOF && 426 width-- != 0 && INCCL(wi)) 427 n++; 428 if (wi != WEOF) 429 __ungetwc(wi, fp); 430 if (n == 0) 431 goto match_failure; 432 } else if (flags & LONG) { 433 p0 = p = va_arg(ap, wchar_t *); 434 while ((wi = __fgetwc(fp)) != WEOF && 435 width-- != 0 && INCCL(wi)) 436 *p++ = (wchar_t)wi; 437 if (wi != WEOF) 438 __ungetwc(wi, fp); 439 n = p - p0; 440 if (n == 0) 441 goto match_failure; 442 *p = 0; 443 nassigned++; 444 } else { 445 if (!(flags & SUPPRESS)) 446 mbp = va_arg(ap, char *); 447 n = 0; 448 mbs = initial; 449 while ((wi = __fgetwc(fp)) != WEOF && 450 width != 0 && INCCL(wi)) { 451 if (width >= MB_CUR_MAX && 452 !(flags & SUPPRESS)) { 453 nconv = wcrtomb(mbp, wi, &mbs); 454 if (nconv == (size_t)-1) 455 goto input_failure; 456 } else { 457 nconv = wcrtomb(mbbuf, wi, 458 &mbs); 459 if (nconv == (size_t)-1) 460 goto input_failure; 461 if (nconv > width) 462 break; 463 if (!(flags & SUPPRESS)) 464 memcpy(mbp, mbbuf, 465 nconv); 466 } 467 if (!(flags & SUPPRESS)) 468 mbp += nconv; 469 width -= nconv; 470 n++; 471 } 472 if (wi != WEOF) 473 __ungetwc(wi, fp); 474 if (!(flags & SUPPRESS)) { 475 *mbp = 0; 476 nassigned++; 477 } 478 } 479 nread += n; 480 nconversions++; 481 break; 482 483 case CT_STRING: 484 /* like CCL, but zero-length string OK, & no NOSKIP */ 485 if (width == 0) 486 width = (size_t)~0; 487 if ((flags & SUPPRESS) && (flags & LONG)) { 488 while ((wi = __fgetwc(fp)) != WEOF && 489 width-- != 0 && 490 !iswspace(wi)) 491 nread++; 492 if (wi != WEOF) 493 __ungetwc(wi, fp); 494 } else if (flags & LONG) { 495 p0 = p = va_arg(ap, wchar_t *); 496 while ((wi = __fgetwc(fp)) != WEOF && 497 width-- != 0 && 498 !iswspace(wi)) { 499 *p++ = (wchar_t)wi; 500 nread++; 501 } 502 if (wi != WEOF) 503 __ungetwc(wi, fp); 504 *p = '\0'; 505 nassigned++; 506 } else { 507 if (!(flags & SUPPRESS)) 508 mbp = va_arg(ap, char *); 509 mbs = initial; 510 while ((wi = __fgetwc(fp)) != WEOF && 511 width != 0 && 512 !iswspace(wi)) { 513 if (width >= MB_CUR_MAX && 514 !(flags & SUPPRESS)) { 515 nconv = wcrtomb(mbp, wi, &mbs); 516 if (nconv == (size_t)-1) 517 goto input_failure; 518 } else { 519 nconv = wcrtomb(mbbuf, wi, 520 &mbs); 521 if (nconv == (size_t)-1) 522 goto input_failure; 523 if (nconv > width) 524 break; 525 if (!(flags & SUPPRESS)) 526 memcpy(mbp, mbbuf, 527 nconv); 528 } 529 if (!(flags & SUPPRESS)) 530 mbp += nconv; 531 width -= nconv; 532 nread++; 533 } 534 if (wi != WEOF) 535 __ungetwc(wi, fp); 536 if (!(flags & SUPPRESS)) { 537 *mbp = 0; 538 nassigned++; 539 } 540 } 541 nconversions++; 542 continue; 543 544 case CT_INT: 545 /* scan an integer as if by the conversion function */ 546 if (width == 0 || width > sizeof(buf) / 547 sizeof(*buf) - 1) 548 width = sizeof(buf) / sizeof(*buf) - 1; 549 flags |= SIGNOK | NDIGITS | NZDIGITS; 550 for (p = buf; width; width--) { 551 c = __fgetwc(fp); 552 /* 553 * Switch on the character; `goto ok' 554 * if we accept it as a part of number. 555 */ 556 switch (c) { 557 558 /* 559 * The digit 0 is always legal, but is 560 * special. For %i conversions, if no 561 * digits (zero or nonzero) have been 562 * scanned (only signs), we will have 563 * base==0. In that case, we should set 564 * it to 8 and enable 0x prefixing. 565 * Also, if we have not scanned zero digits 566 * before this, do not turn off prefixing 567 * (someone else will turn it off if we 568 * have scanned any nonzero digits). 569 */ 570 case '0': 571 if (base == 0) { 572 base = 8; 573 flags |= PFXOK; 574 } 575 if (flags & NZDIGITS) 576 flags &= ~(SIGNOK|NZDIGITS|NDIGITS); 577 else 578 flags &= ~(SIGNOK|PFXOK|NDIGITS); 579 goto ok; 580 581 /* 1 through 7 always legal */ 582 case '1': case '2': case '3': 583 case '4': case '5': case '6': case '7': 584 base = basefix[base]; 585 flags &= ~(SIGNOK | PFXOK | NDIGITS); 586 goto ok; 587 588 /* digits 8 and 9 ok iff decimal or hex */ 589 case '8': case '9': 590 base = basefix[base]; 591 if (base <= 8) 592 break; /* not legal here */ 593 flags &= ~(SIGNOK | PFXOK | NDIGITS); 594 goto ok; 595 596 /* letters ok iff hex */ 597 case 'A': case 'B': case 'C': 598 case 'D': case 'E': case 'F': 599 case 'a': case 'b': case 'c': 600 case 'd': case 'e': case 'f': 601 /* no need to fix base here */ 602 if (base <= 10) 603 break; /* not legal here */ 604 flags &= ~(SIGNOK | PFXOK | NDIGITS); 605 goto ok; 606 607 /* sign ok only as first character */ 608 case '+': case '-': 609 if (flags & SIGNOK) { 610 flags &= ~SIGNOK; 611 flags |= HAVESIGN; 612 goto ok; 613 } 614 break; 615 616 /* 617 * x ok iff flag still set & 2nd char (or 618 * 3rd char if we have a sign). 619 */ 620 case 'x': case 'X': 621 if (flags & PFXOK && p == 622 buf + 1 + !!(flags & HAVESIGN)) { 623 base = 16; /* if %i */ 624 flags &= ~PFXOK; 625 goto ok; 626 } 627 break; 628 } 629 630 /* 631 * If we got here, c is not a legal character 632 * for a number. Stop accumulating digits. 633 */ 634 if (c != WEOF) 635 __ungetwc(c, fp); 636 break; 637 ok: 638 /* 639 * c is legal: store it and look at the next. 640 */ 641 *p++ = (wchar_t)c; 642 } 643 /* 644 * If we had only a sign, it is no good; push 645 * back the sign. If the number ends in `x', 646 * it was [sign] '0' 'x', so push back the x 647 * and treat it as [sign] '0'. 648 */ 649 if (flags & NDIGITS) { 650 if (p > buf) 651 __ungetwc(*--p, fp); 652 goto match_failure; 653 } 654 c = p[-1]; 655 if (c == 'x' || c == 'X') { 656 --p; 657 __ungetwc(c, fp); 658 } 659 if ((flags & SUPPRESS) == 0) { 660 uintmax_t res; 661 662 *p = 0; 663 if ((flags & UNSIGNED) == 0) 664 res = wcstoimax(buf, NULL, base); 665 else 666 res = wcstoumax(buf, NULL, base); 667 if (flags & POINTER) 668 *va_arg(ap, void **) = 669 (void *)(uintptr_t)res; 670 else if (flags & SHORTSHORT) 671 *va_arg(ap, char *) = res; 672 else if (flags & SHORT) 673 *va_arg(ap, short *) = res; 674 else if (flags & LONG) 675 *va_arg(ap, long *) = res; 676 else if (flags & LONGLONG) 677 *va_arg(ap, long long *) = res; 678 else if (flags & INTMAXT) 679 *va_arg(ap, intmax_t *) = res; 680 else if (flags & PTRDIFFT) 681 *va_arg(ap, ptrdiff_t *) = res; 682 else if (flags & SIZET) 683 *va_arg(ap, size_t *) = res; 684 else 685 *va_arg(ap, int *) = res; 686 nassigned++; 687 } 688 nread += p - buf; 689 nconversions++; 690 break; 691 692#ifndef NO_FLOATING_POINT 693 case CT_FLOAT: 694 /* scan a floating point number as if by strtod */ 695 if (width == 0 || width > sizeof(buf) / 696 sizeof(*buf) - 1) 697 width = sizeof(buf) / sizeof(*buf) - 1; 698 if ((width = parsefloat(fp, buf, buf + width)) == 0) 699 goto match_failure; 700 if ((flags & SUPPRESS) == 0) { 701 if (flags & LONGDBL) { 702 long double res = wcstold(buf, &p); 703 *va_arg(ap, long double *) = res; 704 } else if (flags & LONG) { 705 double res = wcstod(buf, &p); 706 *va_arg(ap, double *) = res; 707 } else { 708 float res = wcstof(buf, &p); 709 *va_arg(ap, float *) = res; 710 } 711 if (__scanfdebug && p - buf != width) 712 abort(); 713 nassigned++; 714 } 715 nread += width; 716 nconversions++; 717 break; 718#endif /* !NO_FLOATING_POINT */ 719 } 720 } 721input_failure: 722 return (nconversions != 0 ? nassigned : EOF); 723match_failure: 724 return (nassigned); 725} 726 727#ifndef NO_FLOATING_POINT 728static int 729parsefloat(FILE *fp, wchar_t *buf, wchar_t *end) 730{ 731 wchar_t *commit, *p; 732 int infnanpos = 0; 733 enum { 734 S_START, S_GOTSIGN, S_INF, S_NAN, S_MAYBEHEX, 735 S_DIGITS, S_FRAC, S_EXP, S_EXPDIGITS 736 } state = S_START; 737 wchar_t c; 738 wchar_t decpt = (wchar_t)(unsigned char)*localeconv()->decimal_point; 739 _Bool gotmantdig = 0, ishex = 0; 740 741 /* 742 * We set commit = p whenever the string we have read so far 743 * constitutes a valid representation of a floating point 744 * number by itself. At some point, the parse will complete 745 * or fail, and we will ungetc() back to the last commit point. 746 * To ensure that the file offset gets updated properly, it is 747 * always necessary to read at least one character that doesn't 748 * match; thus, we can't short-circuit "infinity" or "nan(...)". 749 */ 750 commit = buf - 1; 751 c = WEOF; 752 for (p = buf; p < end; ) { 753 if ((c = __fgetwc(fp)) == WEOF) 754 break; 755reswitch: 756 switch (state) { 757 case S_START: 758 state = S_GOTSIGN; 759 if (c == '-' || c == '+') 760 break; 761 else 762 goto reswitch; 763 case S_GOTSIGN: 764 switch (c) { 765 case '0': 766 state = S_MAYBEHEX; 767 commit = p; 768 break; 769 case 'I': 770 case 'i': 771 state = S_INF; 772 break; 773 case 'N': 774 case 'n': 775 state = S_NAN; 776 break; 777 default: 778 state = S_DIGITS; 779 goto reswitch; 780 } 781 break; 782 case S_INF: 783 if (infnanpos > 6 || 784 (c != "nfinity"[infnanpos] && 785 c != "NFINITY"[infnanpos])) 786 goto parsedone; 787 if (infnanpos == 1 || infnanpos == 6) 788 commit = p; /* inf or infinity */ 789 infnanpos++; 790 break; 791 case S_NAN: 792 switch (infnanpos) { 793 case -1: /* XXX kludge to deal with nan(...) */ 794 goto parsedone; 795 case 0: 796 if (c != 'A' && c != 'a') 797 goto parsedone; 798 break; 799 case 1: 800 if (c != 'N' && c != 'n') 801 goto parsedone; 802 else 803 commit = p; 804 break; 805 case 2: 806 if (c != '(') 807 goto parsedone; 808 break; 809 default: 810 if (c == ')') { 811 commit = p; 812 infnanpos = -2; 813 } else if (!iswalnum(c) && c != '_') 814 goto parsedone; 815 break; 816 } 817 infnanpos++; 818 break; 819 case S_MAYBEHEX: 820 state = S_DIGITS; 821 if (c == 'X' || c == 'x') { 822 ishex = 1; 823 break; 824 } else { /* we saw a '0', but no 'x' */ 825 gotmantdig = 1; 826 goto reswitch; 827 } 828 case S_DIGITS: 829 if ((ishex && iswxdigit(c)) || iswdigit(c)) 830 gotmantdig = 1; 831 else { 832 state = S_FRAC; 833 if (c != decpt) 834 goto reswitch; 835 } 836 if (gotmantdig) 837 commit = p; 838 break; 839 case S_FRAC: 840 if (((c == 'E' || c == 'e') && !ishex) || 841 ((c == 'P' || c == 'p') && ishex)) { 842 if (!gotmantdig) 843 goto parsedone; 844 else 845 state = S_EXP; 846 } else if ((ishex && iswxdigit(c)) || iswdigit(c)) { 847 commit = p; 848 gotmantdig = 1; 849 } else 850 goto parsedone; 851 break; 852 case S_EXP: 853 state = S_EXPDIGITS; 854 if (c == '-' || c == '+') 855 break; 856 else 857 goto reswitch; 858 case S_EXPDIGITS: 859 if (iswdigit(c)) 860 commit = p; 861 else 862 goto parsedone; 863 break; 864 default: 865 abort(); 866 } 867 *p++ = c; 868 c = WEOF; 869 } 870 871parsedone: 872 if (c != WEOF) 873 __ungetwc(c, fp); 874 while (commit < --p) 875 __ungetwc(*p, fp); 876 *++commit = '\0'; 877 return (commit - buf); 878} 879#endif 880