NetBSD/gnu/lib/libg++/iostream/sbufvform.C

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/*
* Copyright (c) 1990 Regents of the University of California.
* All rights reserved.
*
* Redistribution and use in source and binary forms are permitted
* provided that the above copyright notice and this paragraph are
* duplicated in all such forms and that any documentation,
* advertising materials, and other materials related to such
* distribution and use acknowledge that the software was developed
* by the University of California, Berkeley. The name of the
* University may not be used to endorse or promote products derived
* from this software without specific prior written permission.
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
*/
#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "%W% (Berkeley) %G%";
#endif /* LIBC_SCCS and not lint */
/*
* Actual printf innards.
*
* This code is large and complicated...
*/
#include <sys/types.h>
#include "ioprivate.h"
#include <string.h>
#include <stdarg.h>
/*
* Define FLOATING_POINT to get floating point.
*/
#ifndef NO_FLOATING_POINT
#define FLOATING_POINT
#endif
/* end of configuration stuff */
/*
* Helper class and function for `fprintf to unbuffered': creates a
* temporary buffer. We only work on write-only files; this avoids
* worries about ungetc buffers and so forth.
*/
class help_streambuf : public backupbuf {
public:
char *buffer;
int buf_size;
streambuf *sb;
help_streambuf(streambuf *sbuf, char *buf, int n) {
sb = sbuf; buffer = buf; buf_size = n;
setp(buffer, buffer+buf_size); }
~help_streambuf();
virtual int overflow(int c = EOF);
};
int help_streambuf::overflow(int c)
{
int used = pptr() - pbase();
if (used) {
sb->sputn(pbase(), used);
pbump(-used);
}
if (c == EOF || buf_size == 0)
return sb->overflow(c);
return sputc(c);
}
help_streambuf::~help_streambuf()
{
int used = pptr() - pbase();
if (used) {
sb->sputn(pbase(), used);
pbump(-used);
}
}
int help_vform(streambuf *sb, char const *fmt0, va_list ap)
{
char buf[_G_BUFSIZ];
help_streambuf helper(sb, buf, _G_BUFSIZ);
return helper.vform(fmt0, ap);
}
#ifdef FLOATING_POINT
#include "floatio.h"
#define BUF (MAXEXP+MAXFRACT+1) /* + decimal point */
#define DEFPREC 6
extern "C" double modf(double, double*);
#else /* no FLOATING_POINT */
#define BUF 40
#endif /* FLOATING_POINT */
/*
* Macros for converting digits to letters and vice versa
*/
#define to_digit(c) ((c) - '0')
#define is_digit(c) ((unsigned)to_digit(c) <= 9)
#define to_char(n) ((n) + '0')
/*
* Flags used during conversion.
*/
#define LONGINT 0x01 /* long integer */
#define LONGDBL 0x02 /* long double; unimplemented */
#define SHORTINT 0x04 /* short integer */
#define ALT 0x08 /* alternate form */
#define LADJUST 0x10 /* left adjustment */
#define ZEROPAD 0x20 /* zero (as opposed to blank) pad */
#define HEXPREFIX 0x40 /* add 0x or 0X prefix */
int streambuf::vform(char const *fmt0, _G_va_list ap)
{
register const char *fmt; /* format string */
register int ch; /* character from fmt */
register int n; /* handy integer (short term usage) */
register char *cp; /* handy char pointer (short term usage) */
const char *fmark; /* for remembering a place in fmt */
register int flags; /* flags as above */
int ret; /* return value accumulator */
int width; /* width from format (%8d), or 0 */
int prec; /* precision from format (%.3d), or -1 */
char sign; /* sign prefix (' ', '+', '-', or \0) */
#ifdef FLOATING_POINT
int softsign; /* temporary negative sign for floats */
double _double; /* double precision arguments %[eEfgG] */
#ifndef USE_DTOA
int fpprec; /* `extra' floating precision in [eEfgG] */
#endif
#endif
unsigned long _ulong; /* integer arguments %[diouxX] */
enum { OCT, DEC, HEX } base;/* base for [diouxX] conversion */
int dprec; /* a copy of prec if [diouxX], 0 otherwise */
int dpad; /* extra 0 padding needed for integers */
int fieldsz; /* field size expanded by sign, dpad etc */
// The initialization of 'size' is to suppress a warning that
// 'size' might be used unitialized. It seems gcc can't
// quite grok this spaghetti code ...
int size = 0; /* size of converted field or string */
char buf[BUF]; /* space for %c, %[diouxX], %[eEfgG] */
char ox[2]; /* space for 0x hex-prefix */
/*
* Choose PADSIZE to trade efficiency vs size. If larger
* printf fields occur frequently, increase PADSIZE (and make
* the initialisers below longer).
*/
#define PADSIZE 16 /* pad chunk size */
static char const blanks[PADSIZE] =
{' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' '};
static char const zeroes[PADSIZE] =
{'0','0','0','0','0','0','0','0','0','0','0','0','0','0','0','0'};
/*
* BEWARE, these `goto error' on error, and PAD uses `n'.
*/
#define PRINT(ptr, len) \
do { if (sputn(ptr, len) != len) goto error; } while (0)
#if 1
#define PAD_SP(howmany) if (padn(' ', howmany) < 0) goto error;
#define PAD_0(howmany) if (padn('0', howmany) < 0) goto error;
#else
#define PAD(howmany, with) { \
if ((n = (howmany)) > 0) { \
while (n > PADSIZE) { \
PRINT(with, PADSIZE); \
n -= PADSIZE; \
} \
PRINT(with, n); \
} \
}
#define PAD_SP(howmany) PAD(howmany, blanks)
#define PAD_0(howmany) PAD(howmany, zeroes)
#endif
/*
* To extend shorts properly, we need both signed and unsigned
* argument extraction methods.
*/
#define SARG() \
(flags&LONGINT ? va_arg(ap, long) : \
flags&SHORTINT ? (long)(short)va_arg(ap, int) : \
(long)va_arg(ap, int))
#define UARG() \
(flags&LONGINT ? va_arg(ap, unsigned long) : \
flags&SHORTINT ? (unsigned long)(unsigned short)va_arg(ap, int) : \
(unsigned long)va_arg(ap, unsigned int))
/* optimise cerr (and other unbuffered Unix files) */
if (unbuffered())
return help_vform(this, fmt0, ap);
fmt = fmt0;
ret = 0;
/*
* Scan the format for conversions (`%' character).
*/
for (;;) {
for (fmark = fmt; (ch = *fmt) != '\0' && ch != '%'; fmt++)
/* void */;
if ((n = fmt - fmark) != 0) {
PRINT(fmark, n);
ret += n;
}
if (ch == '\0')
goto done;
fmt++; /* skip over '%' */
flags = 0;
dprec = 0;
#if defined(FLOATING_POINT) && !defined (USE_DTOA)
fpprec = 0;
#endif
width = 0;
prec = -1;
sign = '\0';
rflag: ch = *fmt++;
reswitch: switch (ch) {
case ' ':
/*
* ``If the space and + flags both appear, the space
* flag will be ignored.''
* -- ANSI X3J11
*/
if (!sign)
sign = ' ';
goto rflag;
case '#':
flags |= ALT;
goto rflag;
case '*':
/*
* ``A negative field width argument is taken as a
* - flag followed by a positive field width.''
* -- ANSI X3J11
* They don't exclude field widths read from args.
*/
if ((width = va_arg(ap, int)) >= 0)
goto rflag;
width = -width;
/* FALLTHROUGH */
case '-':
flags |= LADJUST;
flags &= ~ZEROPAD; /* '-' disables '0' */
goto rflag;
case '+':
sign = '+';
goto rflag;
case '.':
if ((ch = *fmt++) == '*') {
n = va_arg(ap, int);
prec = n < 0 ? -1 : n;
goto rflag;
}
n = 0;
while (is_digit(ch)) {
n = 10 * n + to_digit(ch);
ch = *fmt++;
}
prec = n < 0 ? -1 : n;
goto reswitch;
case '0':
/*
* ``Note that 0 is taken as a flag, not as the
* beginning of a field width.''
* -- ANSI X3J11
*/
if (!(flags & LADJUST))
flags |= ZEROPAD; /* '-' disables '0' */
goto rflag;
case '1': case '2': case '3': case '4':
case '5': case '6': case '7': case '8': case '9':
n = 0;
do {
n = 10 * n + to_digit(ch);
ch = *fmt++;
} while (is_digit(ch));
width = n;
goto reswitch;
#ifdef FLOATING_POINT
case 'L':
flags |= LONGDBL;
goto rflag;
#endif
case 'h':
flags |= SHORTINT;
goto rflag;
case 'l':
flags |= LONGINT;
goto rflag;
case 'c':
*(cp = buf) = va_arg(ap, int);
size = 1;
sign = '\0';
break;
case 'D':
flags |= LONGINT;
/*FALLTHROUGH*/
case 'd':
case 'i':
_ulong = SARG();
if ((long)_ulong < 0) {
_ulong = -_ulong;
sign = '-';
}
base = DEC;
goto number;
#ifdef FLOATING_POINT
case 'e':
case 'E':
case 'f':
case 'F':
case 'g':
case 'G':
_double = va_arg(ap, double);
#ifdef USE_DTOA
{
ios::fmtflags fmt_flags = 0;
int fill = ' ';
if (flags & ALT)
fmt_flags |= ios::showpoint;
if (flags & LADJUST)
fmt_flags |= ios::left;
else if (flags & ZEROPAD)
fmt_flags |= ios::internal, fill = '0';
n = __outfloat(_double, this, ch, width,
prec < 0 ? DEFPREC : prec,
fmt_flags, sign, fill);
if (n < 0)
goto error;
ret += n;
}
// CHECK ERROR!
continue;
#else
/*
* 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_double 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(_double, prec, flags, &softsign,
ch, cp, buf + sizeof(buf));
if (softsign)
sign = '-';
if (*cp == '\0')
cp++;
break;
#endif
#endif /* FLOATING_POINT */
case 'n':
if (flags & LONGINT)
*va_arg(ap, long *) = ret;
else if (flags & SHORTINT)
*va_arg(ap, short *) = ret;
else
*va_arg(ap, int *) = ret;
continue; /* no output */
case 'O':
flags |= LONGINT;
/*FALLTHROUGH*/
case 'o':
_ulong = 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 */
_ulong = (unsigned long)va_arg(ap, void *);
base = HEX;
flags |= HEXPREFIX;
ch = 'x';
goto nosign;
case 's':
if ((cp = va_arg(ap, 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':
_ulong = UARG();
base = DEC;
goto nosign;
case 'X':
case 'x':
_ulong = UARG();
base = HEX;
/* leading 0x/X only if non-zero */
if (flags & ALT && _ulong != 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 (_ulong != 0 || prec != 0) {
char *xdigs; /* digits for [xX] conversion */
/*
* 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(_ulong & 7);
_ulong >>= 3;
} while (_ulong);
/* handle octal leading 0 */
if (flags & ALT && *cp != '0')
*--cp = '0';
break;
case DEC:
/* many numbers are 1 digit */
while (_ulong >= 10) {
*--cp = to_char(_ulong % 10);
_ulong /= 10;
}
*--cp = to_char(_ulong);
break;
case HEX:
if (ch == 'X')
xdigs = "0123456789ABCDEF";
else /* ch == 'x' || ch == 'p' */
xdigs = "0123456789abcdef";
do {
*--cp = xdigs[_ulong & 15];
_ulong >>= 4;
} while (_ulong);
break;
default:
cp = "bug in vform: bad base";
goto skipsize;
}
}
size = buf + BUF - cp;
skipsize:
break;
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.
*/
#if defined(FLOATING_POINT) && !defined (USE_DTOA)
fieldsz = size + fpprec;
#else
fieldsz = size;
#endif
dpad = dprec - size;
if (dpad < 0)
dpad = 0;
if (sign)
fieldsz++;
else if (flags & HEXPREFIX)
fieldsz += 2;
fieldsz += dpad;
/* right-adjusting blank padding */
if ((flags & (LADJUST|ZEROPAD)) == 0)
PAD_SP(width - fieldsz);
/* prefix */
if (sign) {
PRINT(&sign, 1);
} else if (flags & HEXPREFIX) {
ox[0] = '0';
ox[1] = ch;
PRINT(ox, 2);
}
/* right-adjusting zero padding */
if ((flags & (LADJUST|ZEROPAD)) == ZEROPAD)
PAD_0(width - fieldsz);
/* leading zeroes from decimal precision */
PAD_0(dpad);
/* the string or number proper */
PRINT(cp, size);
#if defined(FLOATING_POINT) && !defined (USE_DTOA)
/* trailing f.p. zeroes */
PAD_0(fpprec);
#endif
/* left-adjusting padding (always blank) */
if (flags & LADJUST)
PAD_SP(width - fieldsz);
/* finally, adjust ret */
ret += width > fieldsz ? width : fieldsz;
}
done:
return ret;
error:
return EOF;
/* NOTREACHED */
}
#if defined(FLOATING_POINT) && !defined(USE_DTOA)
static char *exponent(register char *p, register int exp, int fmtch)
{
register char *t;
char expbuf[MAXEXP];
*p++ = fmtch;
if (exp < 0) {
exp = -exp;
*p++ = '-';
}
else
*p++ = '+';
t = expbuf + MAXEXP;
if (exp > 9) {
do {
*--t = to_char(exp % 10);
} while ((exp /= 10) > 9);
*--t = to_char(exp);
for (; t < expbuf + MAXEXP; *p++ = *t++);
}
else {
*p++ = '0';
*p++ = to_char(exp);
}
return (p);
}
static char * round(double fract, int *exp,
register char *start, register char *end,
char ch, int *signp)
{
double tmp;
if (fract)
(void)modf(fract * 10, &tmp);
else
tmp = to_digit(ch);
if (tmp > 4)
for (;; --end) {
if (*end == '.')
--end;
if (++*end <= '9')
break;
*end = '0';
if (end == start) {
if (exp) { /* e/E; increment exponent */
*end = '1';
++*exp;
}
else { /* f; add extra digit */
*--end = '1';
--start;
}
break;
}
}
/* ``"%.3f", (double)-0.0004'' gives you a negative 0. */
else if (*signp == '-')
for (;; --end) {
if (*end == '.')
--end;
if (*end != '0')
break;
if (end == start)
*signp = 0;
}
return (start);
}
int __cvt_double(double number, register int prec, int flags, int *signp,
int fmtch, char *startp, char *endp)
{
register char *p, *t;
register double fract;
int dotrim = 0, expcnt, gformat = 0;
double integer, tmp;
expcnt = 0;
if (number < 0) {
number = -number;
*signp = '-';
} else
*signp = 0;
fract = modf(number, &integer);
/* get an extra slot for rounding. */
t = ++startp;
/*
* get integer portion of number; put into the end of the buffer; the
* .01 is added for modf(356.0 / 10, &integer) returning .59999999...
*/
for (p = endp - 1; integer; ++expcnt) {
tmp = modf(integer / 10, &integer);
*p-- = to_char((int)((tmp + .01) * 10));
}
switch (fmtch) {
case 'f':
case 'F':
/* reverse integer into beginning of buffer */
if (expcnt)
for (; ++p < endp; *t++ = *p);
else
*t++ = '0';
/*
* if precision required or alternate flag set, add in a
* decimal point.
*/
if (prec || flags&ALT)
*t++ = '.';
/* if requires more precision and some fraction left */
if (fract) {
if (prec)
do {
fract = modf(fract * 10, &tmp);
*t++ = to_char((int)tmp);
} while (--prec && fract);
if (fract)
startp = round(fract, (int *)NULL, startp,
t - 1, (char)0, signp);
}
for (; prec--; *t++ = '0');
break;
case 'e':
case 'E':
eformat: if (expcnt) {
*t++ = *++p;
if (prec || flags&ALT)
*t++ = '.';
/* if requires more precision and some integer left */
for (; prec && ++p < endp; --prec)
*t++ = *p;
/*
* if done precision and more of the integer component,
* round using it; adjust fract so we don't re-round
* later.
*/
if (!prec && ++p < endp) {
fract = 0;
startp = round((double)0, &expcnt, startp,
t - 1, *p, signp);
}
/* adjust expcnt for digit in front of decimal */
--expcnt;
}
/* until first fractional digit, decrement exponent */
else if (fract) {
/* adjust expcnt for digit in front of decimal */
for (expcnt = -1;; --expcnt) {
fract = modf(fract * 10, &tmp);
if (tmp)
break;
}
*t++ = to_char((int)tmp);
if (prec || flags&ALT)
*t++ = '.';
}
else {
*t++ = '0';
if (prec || flags&ALT)
*t++ = '.';
}
/* if requires more precision and some fraction left */
if (fract) {
if (prec)
do {
fract = modf(fract * 10, &tmp);
*t++ = to_char((int)tmp);
} while (--prec && fract);
if (fract)
startp = round(fract, &expcnt, startp,
t - 1, (char)0, signp);
}
/* if requires more precision */
for (; prec--; *t++ = '0');
/* unless alternate flag, trim any g/G format trailing 0's */
if (gformat && !(flags&ALT)) {
while (t > startp && *--t == '0');
if (*t == '.')
--t;
++t;
}
t = exponent(t, expcnt, fmtch);
break;
case 'g':
case 'G':
/* a precision of 0 is treated as a precision of 1. */
if (!prec)
++prec;
/*
* ``The style used depends on the value converted; style e
* will be used only if the exponent resulting from the
* conversion is less than -4 or greater than the precision.''
* -- ANSI X3J11
*/
if (expcnt > prec || (!expcnt && fract && fract < .0001)) {
/*
* g/G format counts "significant digits, not digits of
* precision; for the e/E format, this just causes an
* off-by-one problem, i.e. g/G considers the digit
* before the decimal point significant and e/E doesn't
* count it as precision.
*/
--prec;
fmtch -= 2; /* G->E, g->e */
gformat = 1;
goto eformat;
}
/*
* reverse integer into beginning of buffer,
* note, decrement precision
*/
if (expcnt)
for (; ++p < endp; *t++ = *p, --prec);
else
*t++ = '0';
/*
* if precision required or alternate flag set, add in a
* decimal point. If no digits yet, add in leading 0.
*/
if (prec || flags&ALT) {
dotrim = 1;
*t++ = '.';
}
else
dotrim = 0;
/* if requires more precision and some fraction left */
if (fract) {
if (prec) {
/* If no integer part, don't count initial
* zeros as significant digits. */
do {
fract = modf(fract * 10, &tmp);
*t++ = to_char((int)tmp);
} while(!tmp && !expcnt);
while (--prec && fract) {
fract = modf(fract * 10, &tmp);
*t++ = to_char((int)tmp);
}
}
if (fract)
startp = round(fract, (int *)NULL, startp,
t - 1, (char)0, signp);
}
/* alternate format, adds 0's for precision, else trim 0's */
if (flags&ALT)
for (; prec--; *t++ = '0');
else if (dotrim) {
while (t > startp && *--t == '0');
if (*t != '.')
++t;
}
}
return (t - startp);
}
#endif /* defined(FLOATING_POINT) && !defined(USE_DTOA) */
int streambuf::form(char const *format ...)
{
va_list ap;
va_start(ap, format);
int count = vform(format, ap);
va_end(ap);
return count;
}