freebsd-dev/lib/libc/stdio/vfscanf.c
David Xu 3b52e4d1b7 With current pthread implementations, a mutex initialization will
allocate a memory block. sscanf calls __svfscanf which in turn calls
fread, fread triggers mutex initialization but the mutex is not
destroyed in sscanf, this leads to memory leak. To avoid the memory
leak and performance issue, we create a none MT-safe version of fread:
__fread, and instead let __svfscanf call __fread.

PR: threads/90392
Patch submitted by: dhartmei
MFC after: 7 days
2005-12-16 02:50:53 +00:00

1067 lines
24 KiB
C

/*-
* 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.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 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 *);
static int parsefloat(FILE *, char *, char *);
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