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Diffstat (limited to 'lib/libc/stdio/vfscanf.c')
| -rw-r--r-- | lib/libc/stdio/vfscanf.c | 1064 |
1 files changed, 1064 insertions, 0 deletions
diff --git a/lib/libc/stdio/vfscanf.c b/lib/libc/stdio/vfscanf.c new file mode 100644 index 0000000..452eb65 --- /dev/null +++ b/lib/libc/stdio/vfscanf.c @@ -0,0 +1,1064 @@ +/*- + * Copyright (c) 1990, 1993 + * The Regents of the University of California. All rights reserved. + * + * This code is derived from software contributed to Berkeley by + * Chris Torek. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 4. Neither the name of the University nor the names of its contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +#if defined(LIBC_SCCS) && !defined(lint) +static char sccsid[] = "@(#)vfscanf.c 8.1 (Berkeley) 6/4/93"; +#endif /* LIBC_SCCS and not lint */ +#include <sys/cdefs.h> +__FBSDID("$FreeBSD$"); + +#include "namespace.h" +#include <ctype.h> +#include <inttypes.h> +#include <stdio.h> +#include <stdlib.h> +#include <stddef.h> +#include <stdarg.h> +#include <string.h> +#include <wchar.h> +#include <wctype.h> +#include "un-namespace.h" + +#include "collate.h" +#include "libc_private.h" +#include "local.h" + +#ifndef NO_FLOATING_POINT +#include <locale.h> +#endif + +#define BUF 513 /* Maximum length of numeric string. */ + +/* + * Flags used during conversion. + */ +#define LONG 0x01 /* l: long or double */ +#define LONGDBL 0x02 /* L: long double */ +#define SHORT 0x04 /* h: short */ +#define SUPPRESS 0x08 /* *: suppress assignment */ +#define POINTER 0x10 /* p: void * (as hex) */ +#define NOSKIP 0x20 /* [ or c: do not skip blanks */ +#define LONGLONG 0x400 /* ll: long long (+ deprecated q: quad) */ +#define INTMAXT 0x800 /* j: intmax_t */ +#define PTRDIFFT 0x1000 /* t: ptrdiff_t */ +#define SIZET 0x2000 /* z: size_t */ +#define SHORTSHORT 0x4000 /* hh: char */ +#define UNSIGNED 0x8000 /* %[oupxX] conversions */ + +/* + * The following are used in integral conversions only: + * SIGNOK, NDIGITS, PFXOK, and NZDIGITS + */ +#define SIGNOK 0x40 /* +/- is (still) legal */ +#define NDIGITS 0x80 /* no digits detected */ +#define PFXOK 0x100 /* 0x prefix is (still) legal */ +#define NZDIGITS 0x200 /* no zero digits detected */ +#define HAVESIGN 0x10000 /* sign detected */ + +/* + * Conversion types. + */ +#define CT_CHAR 0 /* %c conversion */ +#define CT_CCL 1 /* %[...] conversion */ +#define CT_STRING 2 /* %s conversion */ +#define CT_INT 3 /* %[dioupxX] conversion */ +#define CT_FLOAT 4 /* %[efgEFG] conversion */ + +static const u_char *__sccl(char *, const u_char *); +#ifndef NO_FLOATING_POINT +static int parsefloat(FILE *, char *, char *); +#endif + +int __scanfdebug = 0; + +__weak_reference(__vfscanf, vfscanf); + +/* + * __vfscanf - MT-safe version + */ +int +__vfscanf(FILE *fp, char const *fmt0, va_list ap) +{ + int ret; + + FLOCKFILE(fp); + ret = __svfscanf(fp, fmt0, ap); + FUNLOCKFILE(fp); + return (ret); +} + +/* + * __svfscanf - non-MT-safe version of __vfscanf + */ +int +__svfscanf(FILE *fp, const char *fmt0, va_list ap) +{ + const u_char *fmt = (const u_char *)fmt0; + int c; /* character from format, or conversion */ + size_t width; /* field width, or 0 */ + char *p; /* points into all kinds of strings */ + int n; /* handy integer */ + int flags; /* flags as defined above */ + char *p0; /* saves original value of p when necessary */ + int nassigned; /* number of fields assigned */ + int nconversions; /* number of conversions */ + int nread; /* number of characters consumed from fp */ + int base; /* base argument to conversion function */ + char ccltab[256]; /* character class table for %[...] */ + char buf[BUF]; /* buffer for numeric and mb conversions */ + wchar_t *wcp; /* handy wide character pointer */ + size_t nconv; /* length of multibyte sequence converted */ + static const mbstate_t initial; + mbstate_t mbs; + + /* `basefix' is used to avoid `if' tests in the integer scanner */ + static short basefix[17] = + { 10, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16 }; + + ORIENT(fp, -1); + + nassigned = 0; + nconversions = 0; + nread = 0; + for (;;) { + c = *fmt++; + if (c == 0) + return (nassigned); + if (isspace(c)) { + while ((fp->_r > 0 || __srefill(fp) == 0) && isspace(*fp->_p)) + nread++, fp->_r--, fp->_p++; + continue; + } + if (c != '%') + goto literal; + width = 0; + flags = 0; + /* + * switch on the format. continue if done; + * break once format type is derived. + */ +again: c = *fmt++; + switch (c) { + case '%': +literal: + if (fp->_r <= 0 && __srefill(fp)) + goto input_failure; + if (*fp->_p != c) + goto match_failure; + fp->_r--, fp->_p++; + nread++; + continue; + + case '*': + flags |= SUPPRESS; + goto again; + case 'j': + flags |= INTMAXT; + goto again; + case 'l': + if (flags & LONG) { + flags &= ~LONG; + flags |= LONGLONG; + } else + flags |= LONG; + goto again; + case 'q': + flags |= LONGLONG; /* not quite */ + goto again; + case 't': + flags |= PTRDIFFT; + goto again; + case 'z': + flags |= SIZET; + goto again; + case 'L': + flags |= LONGDBL; + goto again; + case 'h': + if (flags & SHORT) { + flags &= ~SHORT; + flags |= SHORTSHORT; + } else + flags |= SHORT; + goto again; + + case '0': case '1': case '2': case '3': case '4': + case '5': case '6': case '7': case '8': case '9': + width = width * 10 + c - '0'; + goto again; + + /* + * Conversions. + */ + case 'd': + c = CT_INT; + base = 10; + break; + + case 'i': + c = CT_INT; + base = 0; + break; + + case 'o': + c = CT_INT; + flags |= UNSIGNED; + base = 8; + break; + + case 'u': + c = CT_INT; + flags |= UNSIGNED; + base = 10; + break; + + case 'X': + case 'x': + flags |= PFXOK; /* enable 0x prefixing */ + c = CT_INT; + flags |= UNSIGNED; + base = 16; + break; + +#ifndef NO_FLOATING_POINT + case 'A': case 'E': case 'F': case 'G': + case 'a': case 'e': case 'f': case 'g': + c = CT_FLOAT; + break; +#endif + + case 'S': + flags |= LONG; + /* FALLTHROUGH */ + case 's': + c = CT_STRING; + break; + + case '[': + fmt = __sccl(ccltab, fmt); + flags |= NOSKIP; + c = CT_CCL; + break; + + case 'C': + flags |= LONG; + /* FALLTHROUGH */ + case 'c': + flags |= NOSKIP; + c = CT_CHAR; + break; + + case 'p': /* pointer format is like hex */ + flags |= POINTER | PFXOK; + c = CT_INT; /* assumes sizeof(uintmax_t) */ + flags |= UNSIGNED; /* >= sizeof(uintptr_t) */ + base = 16; + break; + + case 'n': + nconversions++; + if (flags & SUPPRESS) /* ??? */ + continue; + if (flags & SHORTSHORT) + *va_arg(ap, char *) = nread; + else if (flags & SHORT) + *va_arg(ap, short *) = nread; + else if (flags & LONG) + *va_arg(ap, long *) = nread; + else if (flags & LONGLONG) + *va_arg(ap, long long *) = nread; + else if (flags & INTMAXT) + *va_arg(ap, intmax_t *) = nread; + else if (flags & SIZET) + *va_arg(ap, size_t *) = nread; + else if (flags & PTRDIFFT) + *va_arg(ap, ptrdiff_t *) = nread; + else + *va_arg(ap, int *) = nread; + continue; + + default: + goto match_failure; + + /* + * Disgusting backwards compatibility hack. XXX + */ + case '\0': /* compat */ + return (EOF); + } + + /* + * We have a conversion that requires input. + */ + if (fp->_r <= 0 && __srefill(fp)) + goto input_failure; + + /* + * Consume leading white space, except for formats + * that suppress this. + */ + if ((flags & NOSKIP) == 0) { + while (isspace(*fp->_p)) { + nread++; + if (--fp->_r > 0) + fp->_p++; + else if (__srefill(fp)) + goto input_failure; + } + /* + * Note that there is at least one character in + * the buffer, so conversions that do not set NOSKIP + * ca no longer result in an input failure. + */ + } + + /* + * Do the conversion. + */ + switch (c) { + + case CT_CHAR: + /* scan arbitrary characters (sets NOSKIP) */ + if (width == 0) + width = 1; + if (flags & LONG) { + if ((flags & SUPPRESS) == 0) + wcp = va_arg(ap, wchar_t *); + else + wcp = NULL; + n = 0; + while (width != 0) { + if (n == MB_CUR_MAX) { + fp->_flags |= __SERR; + goto input_failure; + } + buf[n++] = *fp->_p; + fp->_p++; + fp->_r--; + mbs = initial; + nconv = mbrtowc(wcp, buf, n, &mbs); + if (nconv == (size_t)-1) { + fp->_flags |= __SERR; + goto input_failure; + } + if (nconv == 0 && !(flags & SUPPRESS)) + *wcp = L'\0'; + if (nconv != (size_t)-2) { + nread += n; + width--; + if (!(flags & SUPPRESS)) + wcp++; + n = 0; + } + if (fp->_r <= 0 && __srefill(fp)) { + if (n != 0) { + fp->_flags |= __SERR; + goto input_failure; + } + break; + } + } + if (!(flags & SUPPRESS)) + nassigned++; + } else if (flags & SUPPRESS) { + size_t sum = 0; + for (;;) { + if ((n = fp->_r) < width) { + sum += n; + width -= n; + fp->_p += n; + if (__srefill(fp)) { + if (sum == 0) + goto input_failure; + break; + } + } else { + sum += width; + fp->_r -= width; + fp->_p += width; + break; + } + } + nread += sum; + } else { + size_t r = __fread((void *)va_arg(ap, char *), 1, + width, fp); + + if (r == 0) + goto input_failure; + nread += r; + nassigned++; + } + nconversions++; + break; + + case CT_CCL: + /* scan a (nonempty) character class (sets NOSKIP) */ + if (width == 0) + width = (size_t)~0; /* `infinity' */ + /* take only those things in the class */ + if (flags & LONG) { + wchar_t twc; + int nchars; + + if ((flags & SUPPRESS) == 0) + wcp = va_arg(ap, wchar_t *); + else + wcp = &twc; + n = 0; + nchars = 0; + while (width != 0) { + if (n == MB_CUR_MAX) { + fp->_flags |= __SERR; + goto input_failure; + } + buf[n++] = *fp->_p; + fp->_p++; + fp->_r--; + mbs = initial; + nconv = mbrtowc(wcp, buf, n, &mbs); + if (nconv == (size_t)-1) { + fp->_flags |= __SERR; + goto input_failure; + } + if (nconv == 0) + *wcp = L'\0'; + if (nconv != (size_t)-2) { + if (wctob(*wcp) != EOF && + !ccltab[wctob(*wcp)]) { + while (n != 0) { + n--; + __ungetc(buf[n], + fp); + } + break; + } + nread += n; + width--; + if (!(flags & SUPPRESS)) + wcp++; + nchars++; + n = 0; + } + if (fp->_r <= 0 && __srefill(fp)) { + if (n != 0) { + fp->_flags |= __SERR; + goto input_failure; + } + break; + } + } + if (n != 0) { + fp->_flags |= __SERR; + goto input_failure; + } + n = nchars; + if (n == 0) + goto match_failure; + if (!(flags & SUPPRESS)) { + *wcp = L'\0'; + nassigned++; + } + } else if (flags & SUPPRESS) { + n = 0; + while (ccltab[*fp->_p]) { + n++, fp->_r--, fp->_p++; + if (--width == 0) + break; + if (fp->_r <= 0 && __srefill(fp)) { + if (n == 0) + goto input_failure; + break; + } + } + if (n == 0) + goto match_failure; + } else { + p0 = p = va_arg(ap, char *); + while (ccltab[*fp->_p]) { + fp->_r--; + *p++ = *fp->_p++; + if (--width == 0) + break; + if (fp->_r <= 0 && __srefill(fp)) { + if (p == p0) + goto input_failure; + break; + } + } + n = p - p0; + if (n == 0) + goto match_failure; + *p = 0; + nassigned++; + } + nread += n; + nconversions++; + break; + + case CT_STRING: + /* like CCL, but zero-length string OK, & no NOSKIP */ + if (width == 0) + width = (size_t)~0; + if (flags & LONG) { + wchar_t twc; + + if ((flags & SUPPRESS) == 0) + wcp = va_arg(ap, wchar_t *); + else + wcp = &twc; + n = 0; + while (!isspace(*fp->_p) && width != 0) { + if (n == MB_CUR_MAX) { + fp->_flags |= __SERR; + goto input_failure; + } + buf[n++] = *fp->_p; + fp->_p++; + fp->_r--; + mbs = initial; + nconv = mbrtowc(wcp, buf, n, &mbs); + if (nconv == (size_t)-1) { + fp->_flags |= __SERR; + goto input_failure; + } + if (nconv == 0) + *wcp = L'\0'; + if (nconv != (size_t)-2) { + if (iswspace(*wcp)) { + while (n != 0) { + n--; + __ungetc(buf[n], + fp); + } + break; + } + nread += n; + width--; + if (!(flags & SUPPRESS)) + wcp++; + n = 0; + } + if (fp->_r <= 0 && __srefill(fp)) { + if (n != 0) { + fp->_flags |= __SERR; + goto input_failure; + } + break; + } + } + if (!(flags & SUPPRESS)) { + *wcp = L'\0'; + nassigned++; + } + } else if (flags & SUPPRESS) { + n = 0; + while (!isspace(*fp->_p)) { + n++, fp->_r--, fp->_p++; + if (--width == 0) + break; + if (fp->_r <= 0 && __srefill(fp)) + break; + } + nread += n; + } else { + p0 = p = va_arg(ap, char *); + while (!isspace(*fp->_p)) { + fp->_r--; + *p++ = *fp->_p++; + if (--width == 0) + break; + if (fp->_r <= 0 && __srefill(fp)) + break; + } + *p = 0; + nread += p - p0; + nassigned++; + } + nconversions++; + continue; + + case CT_INT: + /* scan an integer as if by the conversion function */ +#ifdef hardway + if (width == 0 || width > sizeof(buf) - 1) + width = sizeof(buf) - 1; +#else + /* size_t is unsigned, hence this optimisation */ + if (--width > sizeof(buf) - 2) + width = sizeof(buf) - 2; + width++; +#endif + flags |= SIGNOK | NDIGITS | NZDIGITS; + for (p = buf; width; width--) { + c = *fp->_p; + /* + * Switch on the character; `goto ok' + * if we accept it as a part of number. + */ + switch (c) { + + /* + * The digit 0 is always legal, but is + * special. For %i conversions, if no + * digits (zero or nonzero) have been + * scanned (only signs), we will have + * base==0. In that case, we should set + * it to 8 and enable 0x prefixing. + * Also, if we have not scanned zero digits + * before this, do not turn off prefixing + * (someone else will turn it off if we + * have scanned any nonzero digits). + */ + case '0': + if (base == 0) { + base = 8; + flags |= PFXOK; + } + if (flags & NZDIGITS) + flags &= ~(SIGNOK|NZDIGITS|NDIGITS); + else + flags &= ~(SIGNOK|PFXOK|NDIGITS); + goto ok; + + /* 1 through 7 always legal */ + case '1': case '2': case '3': + case '4': case '5': case '6': case '7': + base = basefix[base]; + flags &= ~(SIGNOK | PFXOK | NDIGITS); + goto ok; + + /* digits 8 and 9 ok iff decimal or hex */ + case '8': case '9': + base = basefix[base]; + if (base <= 8) + break; /* not legal here */ + flags &= ~(SIGNOK | PFXOK | NDIGITS); + goto ok; + + /* letters ok iff hex */ + case 'A': case 'B': case 'C': + case 'D': case 'E': case 'F': + case 'a': case 'b': case 'c': + case 'd': case 'e': case 'f': + /* no need to fix base here */ + if (base <= 10) + break; /* not legal here */ + flags &= ~(SIGNOK | PFXOK | NDIGITS); + goto ok; + + /* sign ok only as first character */ + case '+': case '-': + if (flags & SIGNOK) { + flags &= ~SIGNOK; + flags |= HAVESIGN; + goto ok; + } + break; + + /* + * x ok iff flag still set & 2nd char (or + * 3rd char if we have a sign). + */ + case 'x': case 'X': + if (flags & PFXOK && p == + buf + 1 + !!(flags & HAVESIGN)) { + base = 16; /* if %i */ + flags &= ~PFXOK; + goto ok; + } + break; + } + + /* + * If we got here, c is not a legal character + * for a number. Stop accumulating digits. + */ + break; + ok: + /* + * c is legal: store it and look at the next. + */ + *p++ = c; + if (--fp->_r > 0) + fp->_p++; + else if (__srefill(fp)) + break; /* EOF */ + } + /* + * If we had only a sign, it is no good; push + * back the sign. If the number ends in `x', + * it was [sign] '0' 'x', so push back the x + * and treat it as [sign] '0'. + */ + if (flags & NDIGITS) { + if (p > buf) + (void) __ungetc(*(u_char *)--p, fp); + goto match_failure; + } + c = ((u_char *)p)[-1]; + if (c == 'x' || c == 'X') { + --p; + (void) __ungetc(c, fp); + } + if ((flags & SUPPRESS) == 0) { + uintmax_t res; + + *p = 0; + if ((flags & UNSIGNED) == 0) + res = strtoimax(buf, (char **)NULL, base); + else + res = strtoumax(buf, (char **)NULL, base); + if (flags & POINTER) + *va_arg(ap, void **) = + (void *)(uintptr_t)res; + else if (flags & SHORTSHORT) + *va_arg(ap, char *) = res; + else if (flags & SHORT) + *va_arg(ap, short *) = res; + else if (flags & LONG) + *va_arg(ap, long *) = res; + else if (flags & LONGLONG) + *va_arg(ap, long long *) = res; + else if (flags & INTMAXT) + *va_arg(ap, intmax_t *) = res; + else if (flags & PTRDIFFT) + *va_arg(ap, ptrdiff_t *) = res; + else if (flags & SIZET) + *va_arg(ap, size_t *) = res; + else + *va_arg(ap, int *) = res; + nassigned++; + } + nread += p - buf; + nconversions++; + break; + +#ifndef NO_FLOATING_POINT + case CT_FLOAT: + /* scan a floating point number as if by strtod */ + if (width == 0 || width > sizeof(buf) - 1) + width = sizeof(buf) - 1; + if ((width = parsefloat(fp, buf, buf + width)) == 0) + goto match_failure; + if ((flags & SUPPRESS) == 0) { + if (flags & LONGDBL) { + long double res = strtold(buf, &p); + *va_arg(ap, long double *) = res; + } else if (flags & LONG) { + double res = strtod(buf, &p); + *va_arg(ap, double *) = res; + } else { + float res = strtof(buf, &p); + *va_arg(ap, float *) = res; + } + if (__scanfdebug && p - buf != width) + abort(); + nassigned++; + } + nread += width; + nconversions++; + break; +#endif /* !NO_FLOATING_POINT */ + } + } +input_failure: + return (nconversions != 0 ? nassigned : EOF); +match_failure: + return (nassigned); +} + +/* + * Fill in the given table from the scanset at the given format + * (just after `['). Return a pointer to the character past the + * closing `]'. The table has a 1 wherever characters should be + * considered part of the scanset. + */ +static const u_char * +__sccl(tab, fmt) + char *tab; + const u_char *fmt; +{ + int c, n, v, i; + + /* first `clear' the whole table */ + c = *fmt++; /* first char hat => negated scanset */ + if (c == '^') { + v = 1; /* default => accept */ + c = *fmt++; /* get new first char */ + } else + v = 0; /* default => reject */ + + /* XXX: Will not work if sizeof(tab*) > sizeof(char) */ + (void) memset(tab, v, 256); + + if (c == 0) + return (fmt - 1);/* format ended before closing ] */ + + /* + * Now set the entries corresponding to the actual scanset + * to the opposite of the above. + * + * The first character may be ']' (or '-') without being special; + * the last character may be '-'. + */ + v = 1 - v; + for (;;) { + tab[c] = v; /* take character c */ +doswitch: + n = *fmt++; /* and examine the next */ + switch (n) { + + case 0: /* format ended too soon */ + return (fmt - 1); + + case '-': + /* + * A scanset of the form + * [01+-] + * is defined as `the digit 0, the digit 1, + * the character +, the character -', but + * the effect of a scanset such as + * [a-zA-Z0-9] + * is implementation defined. The V7 Unix + * scanf treats `a-z' as `the letters a through + * z', but treats `a-a' as `the letter a, the + * character -, and the letter a'. + * + * For compatibility, the `-' is not considerd + * to define a range if the character following + * it is either a close bracket (required by ANSI) + * or is not numerically greater than the character + * we just stored in the table (c). + */ + n = *fmt; + if (n == ']' + || (__collate_load_error ? n < c : + __collate_range_cmp (n, c) < 0 + ) + ) { + c = '-'; + break; /* resume the for(;;) */ + } + fmt++; + /* fill in the range */ + if (__collate_load_error) { + do { + tab[++c] = v; + } while (c < n); + } else { + for (i = 0; i < 256; i ++) + if ( __collate_range_cmp (c, i) < 0 + && __collate_range_cmp (i, n) <= 0 + ) + tab[i] = v; + } +#if 1 /* XXX another disgusting compatibility hack */ + c = n; + /* + * Alas, the V7 Unix scanf also treats formats + * such as [a-c-e] as `the letters a through e'. + * This too is permitted by the standard.... + */ + goto doswitch; +#else + c = *fmt++; + if (c == 0) + return (fmt - 1); + if (c == ']') + return (fmt); +#endif + break; + + case ']': /* end of scanset */ + return (fmt); + + default: /* just another character */ + c = n; + break; + } + } + /* NOTREACHED */ +} + +#ifndef NO_FLOATING_POINT +static int +parsefloat(FILE *fp, char *buf, char *end) +{ + char *commit, *p; + int infnanpos = 0; + enum { + S_START, S_GOTSIGN, S_INF, S_NAN, S_MAYBEHEX, + S_DIGITS, S_FRAC, S_EXP, S_EXPDIGITS + } state = S_START; + unsigned char c; + char decpt = *localeconv()->decimal_point; + _Bool gotmantdig = 0, ishex = 0; + + /* + * We set commit = p whenever the string we have read so far + * constitutes a valid representation of a floating point + * number by itself. At some point, the parse will complete + * or fail, and we will ungetc() back to the last commit point. + * To ensure that the file offset gets updated properly, it is + * always necessary to read at least one character that doesn't + * match; thus, we can't short-circuit "infinity" or "nan(...)". + */ + commit = buf - 1; + for (p = buf; p < end; ) { + c = *fp->_p; +reswitch: + switch (state) { + case S_START: + state = S_GOTSIGN; + if (c == '-' || c == '+') + break; + else + goto reswitch; + case S_GOTSIGN: + switch (c) { + case '0': + state = S_MAYBEHEX; + commit = p; + break; + case 'I': + case 'i': + state = S_INF; + break; + case 'N': + case 'n': + state = S_NAN; + break; + default: + state = S_DIGITS; + goto reswitch; + } + break; + case S_INF: + if (infnanpos > 6 || + (c != "nfinity"[infnanpos] && + c != "NFINITY"[infnanpos])) + goto parsedone; + if (infnanpos == 1 || infnanpos == 6) + commit = p; /* inf or infinity */ + infnanpos++; + break; + case S_NAN: + switch (infnanpos) { + case -1: /* XXX kludge to deal with nan(...) */ + goto parsedone; + case 0: + if (c != 'A' && c != 'a') + goto parsedone; + break; + case 1: + if (c != 'N' && c != 'n') + goto parsedone; + else + commit = p; + break; + case 2: + if (c != '(') + goto parsedone; + break; + default: + if (c == ')') { + commit = p; + infnanpos = -2; + } else if (!isalnum(c) && c != '_') + goto parsedone; + break; + } + infnanpos++; + break; + case S_MAYBEHEX: + state = S_DIGITS; + if (c == 'X' || c == 'x') { + ishex = 1; + break; + } else { /* we saw a '0', but no 'x' */ + gotmantdig = 1; + goto reswitch; + } + case S_DIGITS: + if ((ishex && isxdigit(c)) || isdigit(c)) + gotmantdig = 1; + else { + state = S_FRAC; + if (c != decpt) + goto reswitch; + } + if (gotmantdig) + commit = p; + break; + case S_FRAC: + if (((c == 'E' || c == 'e') && !ishex) || + ((c == 'P' || c == 'p') && ishex)) { + if (!gotmantdig) + goto parsedone; + else + state = S_EXP; + } else if ((ishex && isxdigit(c)) || isdigit(c)) { + commit = p; + gotmantdig = 1; + } else + goto parsedone; + break; + case S_EXP: + state = S_EXPDIGITS; + if (c == '-' || c == '+') + break; + else + goto reswitch; + case S_EXPDIGITS: + if (isdigit(c)) + commit = p; + else + goto parsedone; + break; + default: + abort(); + } + *p++ = c; + if (--fp->_r > 0) + fp->_p++; + else if (__srefill(fp)) + break; /* EOF */ + } + +parsedone: + while (commit < --p) + __ungetc(*(u_char *)p, fp); + *++commit = '\0'; + return (commit - buf); +} +#endif |
