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Diffstat (limited to 'lib/libc/stdio/vfwscanf.c')
-rw-r--r--lib/libc/stdio/vfwscanf.c876
1 files changed, 876 insertions, 0 deletions
diff --git a/lib/libc/stdio/vfwscanf.c b/lib/libc/stdio/vfwscanf.c
new file mode 100644
index 0000000..b6d97e3
--- /dev/null
+++ b/lib/libc/stdio/vfwscanf.c
@@ -0,0 +1,876 @@
+/*-
+ * 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 0
+#if defined(LIBC_SCCS) && !defined(lint)
+static char sccsid[] = "@(#)vfscanf.c 8.1 (Berkeley) 6/4/93";
+#endif /* LIBC_SCCS and not lint */
+#endif
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include "namespace.h"
+#include <ctype.h>
+#include <inttypes.h>
+#include <limits.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 "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 */
+
+#ifndef NO_FLOATING_POINT
+static int parsefloat(FILE *, wchar_t *, wchar_t *);
+#endif
+
+extern int __scanfdebug;
+
+#define INCCL(_c) \
+ (cclcompl ? (wmemchr(ccls, (_c), ccle - ccls) == NULL) : \
+ (wmemchr(ccls, (_c), ccle - ccls) != NULL))
+
+/*
+ * MT-safe version.
+ */
+int
+vfwscanf(FILE * __restrict fp, const wchar_t * __restrict fmt, va_list ap)
+{
+ int ret;
+
+ FLOCKFILE(fp);
+ ORIENT(fp, 1);
+ ret = __vfwscanf(fp, fmt, ap);
+ FUNLOCKFILE(fp);
+ return (ret);
+}
+
+/*
+ * Non-MT-safe version.
+ */
+int
+__vfwscanf(FILE * __restrict fp, const wchar_t * __restrict fmt, va_list ap)
+{
+ wint_t c; /* character from format, or conversion */
+ size_t width; /* field width, or 0 */
+ wchar_t *p; /* points into all kinds of strings */
+ int n; /* handy integer */
+ int flags; /* flags as defined above */
+ wchar_t *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 */
+ wchar_t buf[BUF]; /* buffer for numeric conversions */
+ const wchar_t *ccls; /* character class start */
+ const wchar_t *ccle; /* character class end */
+ int cclcompl; /* ccl is complemented? */
+ wint_t wi; /* handy wint_t */
+ char *mbp; /* multibyte string pointer for %c %s %[ */
+ size_t nconv; /* number of bytes in mb. conversion */
+ char mbbuf[MB_LEN_MAX]; /* temporary mb. character buffer */
+ 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 };
+
+ nassigned = 0;
+ nconversions = 0;
+ nread = 0;
+ ccls = ccle = NULL;
+ for (;;) {
+ c = *fmt++;
+ if (c == 0)
+ return (nassigned);
+ if (iswspace(c)) {
+ while ((c = __fgetwc(fp)) != WEOF &&
+ iswspace(c))
+ ;
+ if (c != WEOF)
+ __ungetwc(c, fp);
+ 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 ((wi = __fgetwc(fp)) == WEOF)
+ goto input_failure;
+ if (wi != c) {
+ __ungetwc(wi, fp);
+ goto input_failure;
+ }
+ 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 '[':
+ ccls = fmt;
+ if (*fmt == '^') {
+ cclcompl = 1;
+ fmt++;
+ } else
+ cclcompl = 0;
+ if (*fmt == ']')
+ fmt++;
+ while (*fmt != '\0' && *fmt != ']')
+ fmt++;
+ ccle = fmt;
+ 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);
+ }
+
+ /*
+ * Consume leading white space, except for formats
+ * that suppress this.
+ */
+ if ((flags & NOSKIP) == 0) {
+ while ((wi = __fgetwc(fp)) != WEOF && iswspace(wi))
+ nread++;
+ if (wi == WEOF)
+ goto input_failure;
+ __ungetwc(wi, fp);
+ }
+
+ /*
+ * Do the conversion.
+ */
+ switch (c) {
+
+ case CT_CHAR:
+ /* scan arbitrary characters (sets NOSKIP) */
+ if (width == 0)
+ width = 1;
+ if (flags & LONG) {
+ if (!(flags & SUPPRESS))
+ p = va_arg(ap, wchar_t *);
+ n = 0;
+ while (width-- != 0 &&
+ (wi = __fgetwc(fp)) != WEOF) {
+ if (!(flags & SUPPRESS))
+ *p++ = (wchar_t)wi;
+ n++;
+ }
+ if (n == 0)
+ goto input_failure;
+ nread += n;
+ if (!(flags & SUPPRESS))
+ nassigned++;
+ } else {
+ if (!(flags & SUPPRESS))
+ mbp = va_arg(ap, char *);
+ n = 0;
+ mbs = initial;
+ while (width != 0 &&
+ (wi = __fgetwc(fp)) != WEOF) {
+ if (width >= MB_CUR_MAX &&
+ !(flags & SUPPRESS)) {
+ nconv = wcrtomb(mbp, wi, &mbs);
+ if (nconv == (size_t)-1)
+ goto input_failure;
+ } else {
+ nconv = wcrtomb(mbbuf, wi,
+ &mbs);
+ if (nconv == (size_t)-1)
+ goto input_failure;
+ if (nconv > width) {
+ __ungetwc(wi, fp);
+ break;
+ }
+ if (!(flags & SUPPRESS))
+ memcpy(mbp, mbbuf,
+ nconv);
+ }
+ if (!(flags & SUPPRESS))
+ mbp += nconv;
+ width -= nconv;
+ n++;
+ }
+ if (n == 0)
+ goto input_failure;
+ nread += n;
+ if (!(flags & SUPPRESS))
+ 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 & SUPPRESS) && (flags & LONG)) {
+ n = 0;
+ while ((wi = __fgetwc(fp)) != WEOF &&
+ width-- != 0 && INCCL(wi))
+ n++;
+ if (wi != WEOF)
+ __ungetwc(wi, fp);
+ if (n == 0)
+ goto match_failure;
+ } else if (flags & LONG) {
+ p0 = p = va_arg(ap, wchar_t *);
+ while ((wi = __fgetwc(fp)) != WEOF &&
+ width-- != 0 && INCCL(wi))
+ *p++ = (wchar_t)wi;
+ if (wi != WEOF)
+ __ungetwc(wi, fp);
+ n = p - p0;
+ if (n == 0)
+ goto match_failure;
+ *p = 0;
+ nassigned++;
+ } else {
+ if (!(flags & SUPPRESS))
+ mbp = va_arg(ap, char *);
+ n = 0;
+ mbs = initial;
+ while ((wi = __fgetwc(fp)) != WEOF &&
+ width != 0 && INCCL(wi)) {
+ if (width >= MB_CUR_MAX &&
+ !(flags & SUPPRESS)) {
+ nconv = wcrtomb(mbp, wi, &mbs);
+ if (nconv == (size_t)-1)
+ goto input_failure;
+ } else {
+ nconv = wcrtomb(mbbuf, wi,
+ &mbs);
+ if (nconv == (size_t)-1)
+ goto input_failure;
+ if (nconv > width)
+ break;
+ if (!(flags & SUPPRESS))
+ memcpy(mbp, mbbuf,
+ nconv);
+ }
+ if (!(flags & SUPPRESS))
+ mbp += nconv;
+ width -= nconv;
+ n++;
+ }
+ if (wi != WEOF)
+ __ungetwc(wi, fp);
+ if (!(flags & SUPPRESS)) {
+ *mbp = 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 & SUPPRESS) && (flags & LONG)) {
+ while ((wi = __fgetwc(fp)) != WEOF &&
+ width-- != 0 &&
+ !iswspace(wi))
+ nread++;
+ if (wi != WEOF)
+ __ungetwc(wi, fp);
+ } else if (flags & LONG) {
+ p0 = p = va_arg(ap, wchar_t *);
+ while ((wi = __fgetwc(fp)) != WEOF &&
+ width-- != 0 &&
+ !iswspace(wi)) {
+ *p++ = (wchar_t)wi;
+ nread++;
+ }
+ if (wi != WEOF)
+ __ungetwc(wi, fp);
+ *p = '\0';
+ nassigned++;
+ } else {
+ if (!(flags & SUPPRESS))
+ mbp = va_arg(ap, char *);
+ mbs = initial;
+ while ((wi = __fgetwc(fp)) != WEOF &&
+ width != 0 &&
+ !iswspace(wi)) {
+ if (width >= MB_CUR_MAX &&
+ !(flags & SUPPRESS)) {
+ nconv = wcrtomb(mbp, wi, &mbs);
+ if (nconv == (size_t)-1)
+ goto input_failure;
+ } else {
+ nconv = wcrtomb(mbbuf, wi,
+ &mbs);
+ if (nconv == (size_t)-1)
+ goto input_failure;
+ if (nconv > width)
+ break;
+ if (!(flags & SUPPRESS))
+ memcpy(mbp, mbbuf,
+ nconv);
+ }
+ if (!(flags & SUPPRESS))
+ mbp += nconv;
+ width -= nconv;
+ nread++;
+ }
+ if (wi != WEOF)
+ __ungetwc(wi, fp);
+ if (!(flags & SUPPRESS)) {
+ *mbp = 0;
+ nassigned++;
+ }
+ }
+ nconversions++;
+ continue;
+
+ case CT_INT:
+ /* scan an integer as if by the conversion function */
+ if (width == 0 || width > sizeof(buf) /
+ sizeof(*buf) - 1)
+ width = sizeof(buf) / sizeof(*buf) - 1;
+ flags |= SIGNOK | NDIGITS | NZDIGITS;
+ for (p = buf; width; width--) {
+ c = __fgetwc(fp);
+ /*
+ * 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.
+ */
+ if (c != WEOF)
+ __ungetwc(c, fp);
+ break;
+ ok:
+ /*
+ * c is legal: store it and look at the next.
+ */
+ *p++ = (wchar_t)c;
+ }
+ /*
+ * 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)
+ __ungetwc(*--p, fp);
+ goto match_failure;
+ }
+ c = p[-1];
+ if (c == 'x' || c == 'X') {
+ --p;
+ __ungetwc(c, fp);
+ }
+ if ((flags & SUPPRESS) == 0) {
+ uintmax_t res;
+
+ *p = 0;
+ if ((flags & UNSIGNED) == 0)
+ res = wcstoimax(buf, NULL, base);
+ else
+ res = wcstoumax(buf, 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) /
+ sizeof(*buf) - 1)
+ width = sizeof(buf) / sizeof(*buf) - 1;
+ if ((width = parsefloat(fp, buf, buf + width)) == 0)
+ goto match_failure;
+ if ((flags & SUPPRESS) == 0) {
+ if (flags & LONGDBL) {
+ long double res = wcstold(buf, &p);
+ *va_arg(ap, long double *) = res;
+ } else if (flags & LONG) {
+ double res = wcstod(buf, &p);
+ *va_arg(ap, double *) = res;
+ } else {
+ float res = wcstof(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);
+}
+
+#ifndef NO_FLOATING_POINT
+static int
+parsefloat(FILE *fp, wchar_t *buf, wchar_t *end)
+{
+ wchar_t *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;
+ wchar_t c;
+ wchar_t decpt = (wchar_t)(unsigned char)*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;
+ c = WEOF;
+ for (p = buf; p < end; ) {
+ if ((c = __fgetwc(fp)) == WEOF)
+ break;
+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 (!iswalnum(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 && iswxdigit(c)) || iswdigit(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 && iswxdigit(c)) || iswdigit(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 (iswdigit(c))
+ commit = p;
+ else
+ goto parsedone;
+ break;
+ default:
+ abort();
+ }
+ *p++ = c;
+ c = WEOF;
+ }
+
+parsedone:
+ if (c != WEOF)
+ __ungetwc(c, fp);
+ while (commit < --p)
+ __ungetwc(*p, fp);
+ *++commit = '\0';
+ return (commit - buf);
+}
+#endif
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