📄 vfnprintf.cxx
字号:
case '.':
if ((ch = *fmt++) == '*') {
x = va_arg(arg, int);
prec = x < 0 ? -1 : x;
goto rflag;
}
x = 0;
while (is_digit(ch)) {
x = 10 * x + to_digit(ch);
ch = *fmt++;
}
prec = x < 0 ? -1 : x;
goto reswitch;
case '0':
/*
* ``Note that 0 is taken as a flag, not as the
* beginning of a field width.''
* -- ANSI X3J11
*/
flags |= ZEROPAD;
goto rflag;
case '1': case '2': case '3': case '4':
case '5': case '6': case '7': case '8': case '9':
x = 0;
do {
x = 10 * x + to_digit(ch);
ch = *fmt++;
} while (is_digit(ch));
width = x;
goto reswitch;
#ifdef CYGSEM_LIBC_STDIO_PRINTF_FLOATING_POINT
case 'L':
flags |= LONGDBL;
goto rflag;
#endif
case 'h':
flags |= SHORTINT;
goto rflag;
case 'l':
if (*fmt == 'l') {
fmt++;
flags |= QUADINT;
} else {
flags |= LONGINT;
}
goto rflag;
case 'q':
flags |= QUADINT;
goto rflag;
case 'c':
*(cp = buf) = va_arg(arg, int);
size = 1;
sign = '\0';
break;
case 'D':
flags |= LONGINT;
/*FALLTHROUGH*/
case 'd':
case 'i':
_uquad = SARG();
#ifndef _NO_LONGLONG
if ((quad_t)_uquad < 0)
#else
if ((long) _uquad < 0)
#endif
{
_uquad = -_uquad;
sign = '-';
}
base = DEC;
goto number;
#ifdef CYGSEM_LIBC_STDIO_PRINTF_FLOATING_POINT
case 'e':
case 'E':
case 'f':
case 'g':
case 'G':
_double = va_arg(arg, double);
/*
* don't do unrealistic precision; just pad it with
* zeroes later, so buffer size stays rational.
*/
if (prec > MAXFRACT) {
if ((ch != 'g' && ch != 'G') || (flags&ALT))
fpprec = prec - MAXFRACT;
prec = MAXFRACT;
} else if (prec == -1)
prec = DEFPREC;
/*
* cvt may have to round up before the "start" of
* its buffer, i.e. ``intf("%.2f", (double)9.999);'';
* if the first character is still NUL, it did.
* softsign avoids negative 0 if _double < 0 but
* no significant digits will be shown.
*/
cp = buf;
*cp = '\0';
size = cvt(_double, prec, flags, &softsign, ch,
cp, buf + sizeof(buf));
if (softsign)
sign = '-';
if (*cp == '\0')
cp++;
break;
#else
case 'e':
case 'E':
case 'f':
case 'g':
case 'G':
// Output nothing at all
(void) va_arg(arg, double); // take off arg anyway
cp = "";
size = 0;
sign = '\0';
break;
#endif // ifdef CYGSEM_LIBC_STDIO_PRINTF_FLOATING_POINT
case 'n':
#ifndef _NO_LONGLONG
if (flags & QUADINT)
*va_arg(arg, quad_t *) = ret;
else
#endif
if (flags & LONGINT)
*va_arg(arg, long *) = ret;
else if (flags & SHORTINT)
*va_arg(arg, short *) = ret;
else if (flags & SIZET)
*va_arg(arg, size_t *) = ret;
else
*va_arg(arg, int *) = ret;
continue; /* no output */
case 'O':
flags |= LONGINT;
/*FALLTHROUGH*/
case 'o':
_uquad = UARG();
base = OCT;
goto nosign;
case 'p':
/*
* ``The argument shall be a pointer to void. The
* value of the pointer is converted to a sequence
* of printable characters, in an implementation-
* defined manner.''
* -- ANSI X3J11
*/
/* NOSTRICT */
_uquad = (unsigned long)va_arg(arg, void *);
base = HEX;
xdigs = "0123456789abcdef";
flags |= HEXPREFIX;
ch = 'x';
goto nosign;
case 's':
if ((cp = va_arg(arg, char *)) == NULL)
cp = "(null)";
if (prec >= 0) {
/*
* can't use strlen; can only look for the
* NUL in the first `prec' characters, and
* strlen() will go further.
*/
char *p = (char *)memchr(cp, 0, prec);
if (p != NULL) {
size = p - cp;
if (size > prec)
size = prec;
} else
size = prec;
} else
size = strlen(cp);
sign = '\0';
break;
case 'U':
flags |= LONGINT;
/*FALLTHROUGH*/
case 'u':
_uquad = UARG();
base = DEC;
goto nosign;
case 'X':
xdigs = "0123456789ABCDEF";
goto hex;
case 'x':
xdigs = "0123456789abcdef";
hex: _uquad = UARG();
base = HEX;
/* leading 0x/X only if non-zero */
if (flags & ALT && _uquad != 0)
flags |= HEXPREFIX;
/* unsigned conversions */
nosign: sign = '\0';
/*
* ``... diouXx conversions ... if a precision is
* specified, the 0 flag will be ignored.''
* -- ANSI X3J11
*/
number: if ((dprec = prec) >= 0)
flags &= ~ZEROPAD;
/*
* ``The result of converting a zero value with an
* explicit precision of zero is no characters.''
* -- ANSI X3J11
*/
cp = buf + BUF;
if (_uquad != 0 || prec != 0) {
/*
* Unsigned mod is hard, and unsigned mod
* by a constant is easier than that by
* a variable; hence this switch.
*/
switch (base) {
case OCT:
do {
*--cp = to_char(_uquad & 7);
_uquad >>= 3;
} while (_uquad);
/* handle octal leading 0 */
if (flags & ALT && *cp != '0')
*--cp = '0';
break;
case DEC:
/* many numbers are 1 digit */
while (_uquad >= 10) {
*--cp = to_char(_uquad % 10);
_uquad /= 10;
}
*--cp = to_char(_uquad);
break;
case HEX:
do {
*--cp = xdigs[_uquad & 15];
_uquad >>= 4;
} while (_uquad);
break;
default:
cp = "bug in vfprintf: bad base";
size = strlen(cp);
goto skipsize;
}
}
size = buf + BUF - cp;
skipsize:
break;
case 'z':
flags |= SIZET;
goto rflag;
default: /* "%?" prints ?, unless ? is NUL */
if (ch == '\0')
goto done;
/* pretend it was %c with argument ch */
cp = buf;
*cp = ch;
size = 1;
sign = '\0';
break;
}
/*
* All reasonable formats wind up here. At this point, `cp'
* points to a string which (if not flags&LADJUST) should be
* padded out to `width' places. If flags&ZEROPAD, it should
* first be prefixed by any sign or other prefix; otherwise,
* it should be blank padded before the prefix is emitted.
* After any left-hand padding and prefixing, emit zeroes
* required by a decimal [diouxX] precision, then print the
* string proper, then emit zeroes required by any leftover
* floating precision; finally, if LADJUST, pad with blanks.
*
* Compute actual size, so we know how much to pad.
* fieldsz excludes decimal prec; realsz includes it.
*/
#ifdef CYGSEM_LIBC_STDIO_PRINTF_FLOATING_POINT
fieldsz = size + fpprec;
#else
fieldsz = size;
#endif
if (sign)
fieldsz++;
else if (flags & HEXPREFIX)
fieldsz+= 2;
realsz = dprec > fieldsz ? dprec : fieldsz;
/* right-adjusting blank padding */
if ((flags & (LADJUST|ZEROPAD)) == 0) {
if (width - realsz > 0) {
PAD(width - realsz, blanks);
ret += width - realsz;
}
}
/* prefix */
if (sign) {
PRINT(&sign, 1);
ret++;
} else if (flags & HEXPREFIX) {
ox[0] = '0';
ox[1] = ch;
PRINT(ox, 2);
ret += 2;
}
/* right-adjusting zero padding */
if ((flags & (LADJUST|ZEROPAD)) == ZEROPAD) {
if (width - realsz > 0) {
PAD(width - realsz, zeroes);
ret += width - realsz;
}
}
if (dprec - fieldsz > 0) {
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