NetBSD/lib/libc/stdio/vsnprintf_ss.c

499 lines
12 KiB
C

/* $NetBSD: vsnprintf_ss.c,v 1.10 2011/07/17 20:54:34 joerg Exp $ */
/*-
* 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. 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.
*/
#include <sys/cdefs.h>
#if defined(LIBC_SCCS) && !defined(lint)
#if 0
static char sccsid[] = "@(#)vsnprintf.c 8.1 (Berkeley) 6/4/93";
#else
__RCSID("$NetBSD: vsnprintf_ss.c,v 1.10 2011/07/17 20:54:34 joerg Exp $");
#endif
#endif /* LIBC_SCCS and not lint */
#include "namespace.h"
#include <sys/types.h>
#include <inttypes.h>
#include <assert.h>
#include <stdio.h>
#include <errno.h>
#include <stdarg.h>
#include <string.h>
#include "reentrant.h"
#include "extern.h"
#include "local.h"
#ifdef __weak_alias
__weak_alias(vsnprintf_ss,_vsnprintf_ss)
#endif
/*
* vsnprintf_ss: scaled down version of printf(3).
*
* this version based on vfprintf() from libc which was derived from
* software contributed to Berkeley by Chris Torek.
*
*/
/*
* 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) (char)((n) + '0')
/*
* flags used during conversion.
*/
#define ALT 0x001 /* alternate form */
#define HEXPREFIX 0x002 /* add 0x or 0X prefix */
#define LADJUST 0x004 /* left adjustment */
#define LONGDBL 0x008 /* long double; unimplemented */
#define LONGINT 0x010 /* long integer */
#define QUADINT 0x020 /* quad integer */
#define SHORTINT 0x040 /* short integer */
#define MAXINT 0x080 /* intmax_t */
#define PTRINT 0x100 /* intptr_t */
#define SIZEINT 0x200 /* size_t */
#define ZEROPAD 0x400 /* zero (as opposed to blank) pad */
#define FPT 0x800 /* Floating point number */
/*
* To extend shorts properly, we need both signed and unsigned
* argument extraction methods.
*/
#define SARG() \
(flags&MAXINT ? va_arg(ap, intmax_t) : \
flags&PTRINT ? va_arg(ap, intptr_t) : \
flags&SIZEINT ? va_arg(ap, ssize_t) : /* XXX */ \
flags&QUADINT ? va_arg(ap, quad_t) : \
flags&LONGINT ? va_arg(ap, long) : \
flags&SHORTINT ? (long)(short)va_arg(ap, int) : \
(long)va_arg(ap, int))
#define UARG() \
(flags&MAXINT ? va_arg(ap, uintmax_t) : \
flags&PTRINT ? va_arg(ap, uintptr_t) : \
flags&SIZEINT ? va_arg(ap, size_t) : \
flags&QUADINT ? va_arg(ap, u_quad_t) : \
flags&LONGINT ? va_arg(ap, u_long) : \
flags&SHORTINT ? (u_long)(u_short)va_arg(ap, int) : \
(u_long)va_arg(ap, u_int))
#define PUTCHAR(C) do { \
if (sbuf < tailp) \
*sbuf++ = (C); \
} while (/*CONSTCOND*/0)
int
vsnprintf_ss(char *sbuf, size_t slen, const char *fmt0, va_list ap)
{
const char *fmt; /* format string */
int ch; /* character from fmt */
int n; /* handy integer (short term usage) */
char *cp; /* handy char pointer (short term usage) */
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) */
u_quad_t _uquad; /* integer arguments %[diouxX] */
enum { OCT, DEC, HEX } base;/* base for [diouxX] conversion */
int dprec; /* a copy of prec if [diouxX], 0 otherwise */
int realsz; /* field size expanded by dprec */
int size; /* size of converted field or string */
const char *xdigs; /* digits for [xX] conversion */
char bf[128]; /* space for %c, %[diouxX] */
char *tailp; /* tail pointer for snprintf */
static const char xdigs_lower[16] = "0123456789abcdef";
static const char xdigs_upper[16] = "0123456789ABCDEF";
_DIAGASSERT(slen == 0 || sbuf != NULL);
_DIAGASSERT(fmt0 != NULL);
if ((int)slen < 0) {
errno = EINVAL;
return (-1);
}
tailp = sbuf + slen;
cp = NULL; /* XXX: shutup gcc */
size = 0; /* XXX: shutup gcc */
fmt = fmt0;
ret = 0;
xdigs = NULL; /* XXX: shut up gcc warning */
/*
* Scan the format for conversions (`%' character).
*/
for (;;) {
while (*fmt != '%' && *fmt) {
ret++;
PUTCHAR(*fmt);
fmt++;
}
if (*fmt == 0)
goto done;
fmt++; /* skip over '%' */
flags = 0;
dprec = 0;
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;
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
*/
flags |= ZEROPAD;
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;
case 'h':
flags |= SHORTINT;
goto rflag;
case 'j':
flags |= MAXINT;
goto rflag;
case 'l':
if (*fmt == 'l') {
fmt++;
flags |= QUADINT;
} else {
flags |= LONGINT;
}
goto rflag;
case 'q':
flags |= QUADINT;
goto rflag;
case 't':
flags |= PTRINT;
goto rflag;
case 'z':
flags |= SIZEINT;
goto rflag;
case 'c':
*(cp = bf) = va_arg(ap, int);
size = 1;
sign = '\0';
break;
case 'D':
flags |= LONGINT;
/*FALLTHROUGH*/
case 'd':
case 'i':
_uquad = SARG();
if ((quad_t)_uquad < 0) {
_uquad = -_uquad;
sign = '-';
}
base = DEC;
goto number;
case 'n':
if (flags & MAXINT)
*va_arg(ap, intmax_t *) = ret;
else if (flags & PTRINT)
*va_arg(ap, intptr_t *) = ret;
else if (flags & SIZEINT)
*va_arg(ap, ssize_t *) = ret;
else if (flags & QUADINT)
*va_arg(ap, quad_t *) = ret;
else 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':
_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 = (u_long)va_arg(ap, void *);
base = HEX;
xdigs = xdigs_lower;
flags |= HEXPREFIX;
ch = 'x';
goto nosign;
case 's':
if ((cp = va_arg(ap, char *)) == NULL)
/*XXXUNCONST*/
cp = __UNCONST("(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 = memchr(cp, 0, (size_t)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 = xdigs_upper;
goto hex;
case 'x':
xdigs = xdigs_lower;
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 = bf + sizeof(bf);
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[(size_t)_uquad & 15];
_uquad >>= 4;
} while (_uquad);
break;
default:
/*XXXUNCONST*/
cp = __UNCONST("bug bad base");
size = strlen(cp);
goto skipsize;
}
}
size = bf + sizeof(bf) - cp;
skipsize:
break;
default: /* "%?" prints ?, unless ? is NUL */
if (ch == '\0')
goto done;
/* pretend it was %c with argument ch */
cp = bf;
*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.
* size excludes decimal prec; realsz includes it.
*/
realsz = dprec > size ? dprec : size;
if (sign)
realsz++;
else if (flags & HEXPREFIX)
realsz+= 2;
/* adjust ret */
ret += width > realsz ? width : realsz;
/* right-adjusting blank padding */
if ((flags & (LADJUST|ZEROPAD)) == 0) {
n = width - realsz;
while (n-- > 0)
PUTCHAR(' ');
}
/* prefix */
if (sign) {
PUTCHAR(sign);
} else if (flags & HEXPREFIX) {
PUTCHAR('0');
PUTCHAR(ch);
}
/* right-adjusting zero padding */
if ((flags & (LADJUST|ZEROPAD)) == ZEROPAD) {
n = width - realsz;
while (n-- > 0)
PUTCHAR('0');
}
/* leading zeroes from decimal precision */
n = dprec - size;
while (n-- > 0)
PUTCHAR('0');
/* the string or number proper */
while (size--)
PUTCHAR(*cp++);
/* left-adjusting padding (always blank) */
if (flags & LADJUST) {
n = width - realsz;
while (n-- > 0)
PUTCHAR(' ');
}
}
done:
if (sbuf == tailp)
sbuf[-1] = '\0';
else
*sbuf = '\0';
return (ret);
/* NOTREACHED */
}