Ejemplo n.º 1
0
int
__printf_render_float(struct __printf_io* io, const struct printf_info* pi, const void* const* arg) {
    int prec;       /* precision from format; <0 for N/A */
    char* dtoaresult;   /* buffer allocated by dtoa */
    char expchar;       /* exponent character: [eEpP\0] */
    char* cp;
    int expt;       /* integer value of exponent */
    int signflag;       /* true if float is negative */
    char* dtoaend;      /* pointer to end of converted digits */
    char sign;      /* sign prefix (' ', '+', '-', or \0) */
    int size;       /* size of converted field or string */
    int ndig;       /* actual number of digits returned by dtoa */
    int expsize;        /* character count for expstr */
    char expstr[MAXEXPDIG + 2]; /* buffer for exponent string: e+ZZZ */
    int nseps;      /* number of group separators with ' */
    int nrepeats;       /* number of repeats of the last group */
    const char* grouping;   /* locale specific numeric grouping rules */
    int lead;       /* sig figs before decimal or group sep */
    long double ld;
    double d;
    int realsz;     /* field size expanded by dprec, sign, etc */
    int dprec;      /* a copy of prec if [diouxX], 0 otherwise */
    char ox[2];     /* space for 0x; ox[1] is either x, X, or \0 */
    int prsize;             /* max size of printed field */
    int ret;        /* return value accumulator */
    char* decimal_point;    /* locale specific decimal point */
    int n2;         /* XXX: for PRINTANDPAD */
    char thousands_sep; /* locale specific thousands separator */
    char buf[BUF];      /* buffer with space for digits of uintmax_t */
    const char* xdigs;
    int flag;
    prec = pi->prec;
    ox[1] = '\0';
    sign = pi->showsign;
    flag = 0;
    ret = 0;
    thousands_sep = *(localeconv()->thousands_sep);
    grouping = NULL;

    if (pi->alt) {
        grouping = localeconv()->grouping;
    }

    decimal_point = localeconv()->decimal_point;
    dprec = -1;

    switch (pi->spec) {
    case 'a':
    case 'A':
        if (pi->spec == 'a') {
            ox[1] = 'x';
            xdigs = __lowercase_hex;
            expchar = 'p';
        } else {
            ox[1] = 'X';
            xdigs = __uppercase_hex;
            expchar = 'P';
        }

        if (prec >= 0) {
            prec++;
        }

        if (pi->is_long_double) {
            ld = *((long double*)arg[0]);
            dtoaresult = cp =
                             __hldtoa(ld, xdigs, prec,
                                      &expt, &signflag, &dtoaend);
        } else {
            d = *((double*)arg[0]);
            dtoaresult = cp =
                             __hdtoa(d, xdigs, prec,
                                     &expt, &signflag, &dtoaend);
        }

        if (prec < 0) {
            prec = dtoaend - cp;
        }

        if (expt == INT_MAX) {
            ox[1] = '\0';
        }

        goto fp_common;

    case 'e':
    case 'E':
        expchar = pi->spec;

        if (prec < 0) { /* account for digit before decpt */
            prec = DEFPREC + 1;
        } else {
            prec++;
        }

        break;

    case 'f':
    case 'F':
        expchar = '\0';
        break;

    case 'g':
    case 'G':
        expchar = pi->spec - ('g' - 'e');

        if (prec == 0) {
            prec = 1;
        }

        break;

    default:
        assert(pi->spec == 'f');
    }

    if (prec < 0) {
        prec = DEFPREC;
    }

    if (pi->is_long_double) {
        ld = *((long double*)arg[0]);
        dtoaresult = cp =
                         __ldtoa(&ld, expchar ? 2 : 3, prec,
                                 &expt, &signflag, &dtoaend);
    } else {
        d = *((double*)arg[0]);
        dtoaresult = cp =
                         dtoa(d, expchar ? 2 : 3, prec,
                              &expt, &signflag, &dtoaend);

        if (expt == 9999) {
            expt = INT_MAX;
        }
    }

fp_common:

    if (signflag) {
        sign = '-';
    }

    if (expt == INT_MAX) {  /* inf or nan */
        if (*cp == 'N') {
            cp = (pi->spec >= 'a') ? "nan" : "NAN";
            sign = '\0';
        } else {
            cp = (pi->spec >= 'a') ? "inf" : "INF";
        }

        size = 3;
        flag = 1;
        goto here;
    }

    ndig = dtoaend - cp;

    if (pi->spec == 'g' || pi->spec == 'G') {
        if (expt > -4 && expt <= prec) {
            /* Make %[gG] smell like %[fF] */
            expchar = '\0';

            if (pi->alt) {
                prec -= expt;
            } else {
                prec = ndig - expt;
            }

            if (prec < 0) {
                prec = 0;
            }
        } else {
            /*
             * Make %[gG] smell like %[eE], but
             * trim trailing zeroes if no # flag.
             */
            if (!pi->alt) {
                prec = ndig;
            }
        }
    }

    if (expchar) {
        expsize = exponent(expstr, expt - 1, expchar);
        size = expsize + prec;

        if (prec > 1 || pi->alt) {
            ++size;
        }
    } else {
        /* space for digits before decimal point */
        if (expt > 0) {
            size = expt;
        } else { /* "0" */
            size = 1;
        }

        /* space for decimal pt and following digits */
        if (prec || pi->alt) {
            size += prec + 1;
        }

        if (grouping && expt > 0) {
            /* space for thousands' grouping */
            nseps = nrepeats = 0;
            lead = expt;

            while (*grouping != CHAR_MAX) {
                if (lead <= *grouping) {
                    break;
                }

                lead -= *grouping;

                if (*(grouping + 1)) {
                    nseps++;
                    grouping++;
                } else {
                    nrepeats++;
                }
            }

            size += nseps + nrepeats;
        } else {
            lead = expt;
        }
    }

here:
    /*
     * 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++;
    }

    if (ox[1]) {
        realsz += 2;
    }

    prsize = pi->width > realsz ? pi->width : realsz;

    /* right-adjusting blank padding */
    if (pi->pad != '0' && pi->left == 0) {
        ret += __printf_pad(io, pi->width - realsz, 0);
    }

    /* prefix */
    if (sign) {
        ret += __printf_puts(io, &sign, 1);
    }

    if (ox[1]) {    /* ox[1] is either x, X, or \0 */
        ox[0] = '0';
        ret += __printf_puts(io, ox, 2);
    }

    /* right-adjusting zero padding */
    if (pi->pad == '0' && pi->left == 0) {
        ret += __printf_pad(io, pi->width - realsz, 1);
    }

    /* leading zeroes from decimal precision */
    ret += __printf_pad(io, dprec - size, 1);

    if (flag) {
        ret += __printf_puts(io, cp, size);
    } else {
        /* glue together f_p fragments */
        if (!expchar) { /* %[fF] or sufficiently short %[gG] */
            if (expt <= 0) {
                ret += __printf_puts(io, "0", 1);

                if (prec || pi->alt) {
                    ret += __printf_puts(io, decimal_point, 1);
                }

                ret += __printf_pad(io, -expt, 1);
                /* already handled initial 0's */
                prec += expt;
            } else {
                PRINTANDPAD(cp, dtoaend, lead, 1);
                cp += lead;

                if (grouping) {
                    while (nseps > 0 || nrepeats > 0) {
                        if (nrepeats > 0) {
                            nrepeats--;
                        } else {
                            grouping--;
                            nseps--;
                        }

                        ret += __printf_puts(io, &thousands_sep, 1);
                        PRINTANDPAD(cp, dtoaend,
                                    *grouping, 1);
                        cp += *grouping;
                    }

                    if (cp > dtoaend) {
                        cp = dtoaend;
                    }
                }

                if (prec || pi->alt) {
                    ret += __printf_puts(io, decimal_point, 1);
                }
            }

            PRINTANDPAD(cp, dtoaend, prec, 1);
        } else {    /* %[eE] or sufficiently long %[gG] */
            if (prec > 1 || pi->alt) {
                buf[0] = *cp++;
                buf[1] = *decimal_point;
                ret += __printf_puts(io, buf, 2);
                ret += __printf_puts(io, cp, ndig - 1);
                ret += __printf_pad(io, prec - ndig, 1);
            } else { /* XeYYY */
                ret += __printf_puts(io, cp, 1);
            }

            ret += __printf_puts(io, expstr, expsize);
        }
    }

    /* left-adjusting padding (always blank) */
    if (pi->left) {
        ret += __printf_pad(io, pi->width - realsz, 0);
    }

    __printf_flush(io);

    if (dtoaresult != NULL) {
        freedtoa(dtoaresult);
    }

    return (ret);
}
Ejemplo n.º 2
0
int
__vfprintf(FILE *fp, const char *fmt0, __va_list ap)
{
	char *fmt;		/* format string */
	int ch;			/* character from fmt */
	int n, n2;		/* handy integers (short term usage) */
	char *cp;		/* handy char pointer (short term usage) */
	struct __siov *iovp;	/* for PRINT macro */
	int flags;		/* flags as above */
	int ret;		/* return value accumulator */
	int width;		/* width from format (%8d), or 0 */
	int prec;		/* precision from format; <0 for N/A */
	char sign;		/* sign prefix (' ', '+', '-', or \0) */
	wchar_t wc;
	mbstate_t ps;
#ifdef FLOATING_POINT
	/*
	 * We can decompose the printed representation of floating
	 * point numbers into several parts, some of which may be empty:
	 *
	 * [+|-| ] [0x|0X] MMM . NNN [e|E|p|P] [+|-] ZZ
	 *    A       B     ---C---      D       E   F
	 *
	 * A:	'sign' holds this value if present; '\0' otherwise
	 * B:	ox[1] holds the 'x' or 'X'; '\0' if not hexadecimal
	 * C:	cp points to the string MMMNNN.  Leading and trailing
	 *	zeros are not in the string and must be added.
	 * D:	expchar holds this character; '\0' if no exponent, e.g. %f
	 * F:	at least two digits for decimal, at least one digit for hex
	 */
	char *decimal_point = NULL;
	int signflag;		/* true if float is negative */
	union {			/* floating point arguments %[aAeEfFgG] */
		double dbl;
		long double ldbl;
	} fparg;
	int expt;		/* integer value of exponent */
	char expchar;		/* exponent character: [eEpP\0] */
	char *dtoaend;		/* pointer to end of converted digits */
	int expsize;		/* character count for expstr */
	int lead;		/* sig figs before decimal or group sep */
	int ndig;		/* actual number of digits returned by dtoa */
	char expstr[MAXEXPDIG+2];	/* buffer for exponent string: e+ZZZ */
	char *dtoaresult = NULL;
#endif

	uintmax_t _umax;	/* 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 */
#define NIOV 8
	struct __suio uio;	/* output information: summary */
	struct __siov iov[NIOV];/* ... and individual io vectors */
	char buf[BUF];		/* buffer with space for digits of uintmax_t */
	char ox[2];		/* space for 0x; ox[1] is either x, X, or \0 */
	union arg *argtable;	/* args, built due to positional arg */
	union arg statargtable[STATIC_ARG_TBL_SIZE];
	size_t argtablesiz;
	int nextarg;		/* 1-based argument index */
	va_list orgap;		/* original argument pointer */
#ifdef PRINTF_WIDE_CHAR
	char *convbuf;		/* buffer for wide to multi-byte conversion */
#endif

	/*
	 * 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 blanks[PADSIZE] =
	 {' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' '};
	static char zeroes[PADSIZE] =
	 {'0','0','0','0','0','0','0','0','0','0','0','0','0','0','0','0'};

	static const char xdigs_lower[16] = "0123456789abcdef";
	static const char xdigs_upper[16] = "0123456789ABCDEF";

	/*
	 * BEWARE, these `goto error' on error, and PAD uses `n'.
	 */
#define	PRINT(ptr, len) do { \
	iovp->iov_base = (ptr); \
	iovp->iov_len = (len); \
	uio.uio_resid += (len); \
	iovp++; \
	if (++uio.uio_iovcnt >= NIOV) { \
		if (__sprint(fp, &uio)) \
			goto error; \
		iovp = iov; \
	} \
} while (0)
#define	PAD(howmany, with) do { \
	if ((n = (howmany)) > 0) { \
		while (n > PADSIZE) { \
			PRINT(with, PADSIZE); \
			n -= PADSIZE; \
		} \
		PRINT(with, n); \
	} \
} while (0)
#define	PRINTANDPAD(p, ep, len, with) do {	\
	n2 = (ep) - (p);       			\
	if (n2 > (len))				\
		n2 = (len);			\
	if (n2 > 0)				\
		PRINT((p), n2);			\
	PAD((len) - (n2 > 0 ? n2 : 0), (with));	\
} while(0)
#define	FLUSH() do { \
	if (uio.uio_resid && __sprint(fp, &uio)) \
		goto error; \
	uio.uio_iovcnt = 0; \
	iovp = iov; \
} while (0)

	/*
	 * To extend shorts properly, we need both signed and unsigned
	 * argument extraction methods.
	 */
#define	SARG() \
	((intmax_t)(flags&MAXINT ? GETARG(intmax_t) : \
	    flags&LLONGINT ? GETARG(long long) : \
	    flags&LONGINT ? GETARG(long) : \
	    flags&PTRINT ? GETARG(ptrdiff_t) : \
	    flags&SIZEINT ? GETARG(ssize_t) : \
	    flags&SHORTINT ? (short)GETARG(int) : \
	    flags&CHARINT ? (__signed char)GETARG(int) : \
	    GETARG(int)))
#define	UARG() \
	((uintmax_t)(flags&MAXINT ? GETARG(uintmax_t) : \
	    flags&LLONGINT ? GETARG(unsigned long long) : \
	    flags&LONGINT ? GETARG(unsigned long) : \
	    flags&PTRINT ? (uintptr_t)GETARG(ptrdiff_t) : /* XXX */ \
	    flags&SIZEINT ? GETARG(size_t) : \
	    flags&SHORTINT ? (unsigned short)GETARG(int) : \
	    flags&CHARINT ? (unsigned char)GETARG(int) : \
	    GETARG(unsigned int)))

	/*
	 * Append a digit to a value and check for overflow.
	 */
#define APPEND_DIGIT(val, dig) do { \
	if ((val) > INT_MAX / 10) \
		goto overflow; \
	(val) *= 10; \
	if ((val) > INT_MAX - to_digit((dig))) \
		goto overflow; \
	(val) += to_digit((dig)); \
} while (0)

	 /*
	  * Get * arguments, including the form *nn$.  Preserve the nextarg
	  * that the argument can be gotten once the type is determined.
	  */
#define GETASTER(val) \
	n2 = 0; \
	cp = fmt; \
	while (is_digit(*cp)) { \
		APPEND_DIGIT(n2, *cp); \
		cp++; \
	} \
	if (*cp == '$') { \
		int hold = nextarg; \
		if (argtable == NULL) { \
			argtable = statargtable; \
			__find_arguments(fmt0, orgap, &argtable, &argtablesiz); \
		} \
		nextarg = n2; \
		val = GETARG(int); \
		nextarg = hold; \
		fmt = ++cp; \
	} else { \
		val = GETARG(int); \
	}

/*
* Get the argument indexed by nextarg.   If the argument table is
* built, use it to get the argument.  If its not, get the next
* argument (and arguments must be gotten sequentially).
*/
#define GETARG(type) \
	((argtable != NULL) ? *((type*)(&argtable[nextarg++])) : \
		(nextarg++, va_arg(ap, type)))

	_SET_ORIENTATION(fp, -1);
	/* sorry, fprintf(read_only_file, "") returns EOF, not 0 */
	if (cantwrite(fp)) {
		errno = EBADF;
		return (EOF);
	}

	/* optimise fprintf(stderr) (and other unbuffered Unix files) */
	if ((fp->_flags & (__SNBF|__SWR|__SRW)) == (__SNBF|__SWR) &&
	    fp->_file >= 0)
		return (__sbprintf(fp, fmt0, ap));

	fmt = (char *)fmt0;
	argtable = NULL;
	nextarg = 1;
	va_copy(orgap, ap);
	uio.uio_iov = iovp = iov;
	uio.uio_resid = 0;
	uio.uio_iovcnt = 0;
	ret = 0;
#ifdef PRINTF_WIDE_CHAR
	convbuf = NULL;
#endif

	memset(&ps, 0, sizeof(ps));
	/*
	 * Scan the format for conversions (`%' character).
	 */
	for (;;) {
		cp = fmt;
		while ((n = mbrtowc(&wc, fmt, MB_CUR_MAX, &ps)) > 0) {
			fmt += n;
			if (wc == '%') {
				fmt--;
				break;
			}
		}
		if (fmt != cp) {
			ptrdiff_t m = fmt - cp;
			if (m < 0 || m > INT_MAX - ret)
				goto overflow;
			PRINT(cp, m);
			ret += m;
		}
		if (n <= 0)
			goto done;
		fmt++;		/* skip over '%' */

		flags = 0;
		dprec = 0;
		width = 0;
		prec = -1;
		sign = '\0';
		ox[1] = '\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 '\'':
			/* grouping not implemented */
			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.
			 */
			GETASTER(width);
			if (width >= 0)
				goto rflag;
			if (width == INT_MIN)
				goto overflow;
			width = -width;
			/* FALLTHROUGH */
		case '-':
			flags |= LADJUST;
			goto rflag;
		case '+':
			sign = '+';
			goto rflag;
		case '.':
			if ((ch = *fmt++) == '*') {
				GETASTER(n);
				prec = n < 0 ? -1 : n;
				goto rflag;
			}
			n = 0;
			while (is_digit(ch)) {
				APPEND_DIGIT(n, ch);
				ch = *fmt++;
			}
			if (ch == '$') {
				nextarg = n;
				if (argtable == NULL) {
					argtable = statargtable;
					__find_arguments(fmt0, orgap,
					    &argtable, &argtablesiz);
				}
				goto rflag;
			}
			prec = n;
			goto reswitch;
		case '0':
			/*
			 * ``Note that 0 is taken as a flag, not as the
			 * beginning of a field width.''
			 *	-- ANSI X3J11
			 */
			flags |= ZEROPAD;
			goto rflag;
		case '1': case '2': case '3': case '4':
		case '5': case '6': case '7': case '8': case '9':
			n = 0;
			do {
				APPEND_DIGIT(n, ch);
				ch = *fmt++;
			} while (is_digit(ch));
			if (ch == '$') {
				nextarg = n;
				if (argtable == NULL) {
					argtable = statargtable;
					__find_arguments(fmt0, orgap,
					    &argtable, &argtablesiz);
				}
				goto rflag;
			}
			width = n;
			goto reswitch;
#ifdef FLOATING_POINT
		case 'L':
			flags |= LONGDBL;
			goto rflag;
#endif
		case 'h':
			if (*fmt == 'h') {
				fmt++;
				flags |= CHARINT;
			} else {
				flags |= SHORTINT;
			}
			goto rflag;
		case 'j':
			flags |= MAXINT;
			goto rflag;
		case 'l':
			if (*fmt == 'l') {
				fmt++;
				flags |= LLONGINT;
			} else {
				flags |= LONGINT;
			}
			goto rflag;
		case 'q':
			flags |= LLONGINT;
			goto rflag;
		case 't':
			flags |= PTRINT;
			goto rflag;
		case 'z':
			flags |= SIZEINT;
			goto rflag;
		case 'c':
#ifdef PRINTF_WIDE_CHAR
			if (flags & LONGINT) {
				mbstate_t mbs;
				size_t mbseqlen;

				memset(&mbs, 0, sizeof(mbs));
				mbseqlen = wcrtomb(buf,
				    (wchar_t)GETARG(wint_t), &mbs);
				if (mbseqlen == (size_t)-1) {
					fp->_flags |= __SERR;
					errno = EILSEQ;
					goto error;
				}
				cp = buf;
				size = (int)mbseqlen;
			} else {
#endif
				*(cp = buf) = GETARG(int);
				size = 1;
#ifdef PRINTF_WIDE_CHAR
			}
#endif
			sign = '\0';
			break;
		case 'D':
			flags |= LONGINT;
			/*FALLTHROUGH*/
		case 'd':
		case 'i':
			_umax = SARG();
			if ((intmax_t)_umax < 0) {
				_umax = -_umax;
				sign = '-';
			}
			base = DEC;
			goto number;
#ifdef FLOATING_POINT
		case 'a':
		case 'A':
			if (ch == 'a') {
				ox[1] = 'x';
				xdigs = xdigs_lower;
				expchar = 'p';
			} else {
				ox[1] = 'X';
				xdigs = xdigs_upper;
				expchar = 'P';
			}
			if (prec >= 0)
				prec++;
			if (dtoaresult)
				__freedtoa(dtoaresult);
			if (flags & LONGDBL) {
				fparg.ldbl = GETARG(long double);
				dtoaresult = cp =
				    __hldtoa(fparg.ldbl, xdigs, prec,
				    &expt, &signflag, &dtoaend);
				if (dtoaresult == NULL) {
					errno = ENOMEM;
					goto error;
				}
			} else {
				fparg.dbl = GETARG(double);
				dtoaresult = cp =
				    __hdtoa(fparg.dbl, xdigs, prec,
				    &expt, &signflag, &dtoaend);
				if (dtoaresult == NULL) {
					errno = ENOMEM;
					goto error;
				}
			}
			if (prec < 0)
				prec = dtoaend - cp;
			if (expt == INT_MAX)
				ox[1] = '\0';
			goto fp_common;
		case 'e':
		case 'E':
			expchar = ch;
			if (prec < 0)	/* account for digit before decpt */
				prec = DEFPREC + 1;
			else
				prec++;
			goto fp_begin;
		case 'f':
		case 'F':
			expchar = '\0';
			goto fp_begin;
		case 'g':
		case 'G':
			expchar = ch - ('g' - 'e');
 			if (prec == 0)
 				prec = 1;
fp_begin:
			if (prec < 0)
				prec = DEFPREC;
			if (dtoaresult)
				__freedtoa(dtoaresult);
			if (flags & LONGDBL) {
				fparg.ldbl = GETARG(long double);
				dtoaresult = cp =
				    __ldtoa(&fparg.ldbl, expchar ? 2 : 3, prec,
				    &expt, &signflag, &dtoaend);
				if (dtoaresult == NULL) {
					errno = ENOMEM;
					goto error;
				}
			} else {
Ejemplo n.º 3
0
/*
 * Non-MT-safe version
 */
int
__vfprintf(FILE *fp, locale_t locale, const char *fmt0, __va_list ap)
{
	char *fmt;		/* format string */
	int ch;			/* character from fmt */
	int n, n2;		/* handy integers (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; <0 for N/A */
	char sign;		/* sign prefix (' ', '+', '-', or \0) */
	struct grouping_state gs; /* thousands' grouping info */

#ifdef FLOATING_POINT
	/*
	 * We can decompose the printed representation of floating
	 * point numbers into several parts, some of which may be empty:
	 *
	 * [+|-| ] [0x|0X] MMM . NNN [e|E|p|P] [+|-] ZZ
	 *    A       B     ---C---      D       E   F
	 *
	 * A:	'sign' holds this value if present; '\0' otherwise
	 * B:	ox[1] holds the 'x' or 'X'; '\0' if not hexadecimal
	 * C:	cp points to the string MMMNNN.  Leading and trailing
	 *	zeros are not in the string and must be added.
	 * D:	expchar holds this character; '\0' if no exponent, e.g. %f
	 * F:	at least two digits for decimal, at least one digit for hex
	 */
	char *decimal_point = NULL;	/* locale specific decimal point */
	int decpt_len;		/* length of decimal_point */
	int signflag;		/* true if float is negative */
	union {			/* floating point arguments %[aAeEfFgG] */
		double dbl;
		long double ldbl;
	} fparg;
	int expt;		/* integer value of exponent */
	char expchar;		/* exponent character: [eEpP\0] */
	char *dtoaend;		/* pointer to end of converted digits */
	int expsize;		/* character count for expstr */
	int ndig;		/* actual number of digits returned by dtoa */
	char expstr[MAXEXPDIG+2];	/* buffer for exponent string: e+ZZZ */
	char *dtoaresult = NULL;	/* buffer allocated by dtoa */
#endif
	u_long	ulval;		/* integer arguments %[diouxX] */
	uintmax_t ujval;	/* %j, %ll, %q, %t, %z integers */
	int base;		/* base for [diouxX] conversion */
	int dprec;		/* a copy of prec if [diouxX], 0 otherwise */
	int realsz;		/* field size expanded by dprec, sign, etc */
	int size;		/* size of converted field or string */
	const char *xdigs;     	/* digits for %[xX] conversion */
	struct io_state io;	/* I/O buffering state */
	char buf[BUF];		/* buffer with space for digits of uintmax_t */
	char ox[2];		/* space for 0x; ox[1] is either x, X, or \0 */
	union arg *argtable;    /* args, built due to positional arg */
	union arg statargtable [STATIC_ARG_TBL_SIZE];
	int nextarg;            /* 1-based argument index */
	va_list orgap;          /* original argument pointer */
	char *convbuf;		/* wide to multibyte conversion result */

	static const char xdigs_lower[16] = "0123456789abcdef";
	static const char xdigs_upper[16] = "0123456789ABCDEF";

	/* BEWARE, these `goto error' on error. */
#define	PRINT(ptr, len) { \
	if (io_print(&io, (ptr), (len), locale))	\
		goto error; \
}
#define	PAD(howmany, with) { \
	if (io_pad(&io, (howmany), (with), locale)) \
		goto error; \
}
#define	PRINTANDPAD(p, ep, len, with) {	\
	if (io_printandpad(&io, (p), (ep), (len), (with), locale)) \
		goto error; \
}
#define	FLUSH() { \
	if (io_flush(&io, locale)) \
		goto error; \
}
	/*
	 * Get the argument indexed by nextarg.   If the argument table is
	 * built, use it to get the argument.  If its not, get the next
	 * argument (and arguments must be gotten sequentially).
	 */
#define GETARG(type) \
	((argtable != NULL) ? *((type*)(&argtable[nextarg++])) : \
	    (nextarg++, va_arg(ap, type)))

	/*
	 * To extend shorts properly, we need both signed and unsigned
	 * argument extraction methods.
	 */
#define	SARG() \
	(flags&LONGINT ? GETARG(long) : \
	    flags&SHORTINT ? (long)(short)GETARG(int) : \
	    flags&CHARINT ? (long)(signed char)GETARG(int) : \
	    (long)GETARG(int))
#define	UARG() \
	(flags&LONGINT ? GETARG(u_long) : \
	    flags&SHORTINT ? (u_long)(u_short)GETARG(int) : \
	    flags&CHARINT ? (u_long)(u_char)GETARG(int) : \
	    (u_long)GETARG(u_int))
#define	INTMAX_SIZE	(INTMAXT|SIZET|PTRDIFFT|LLONGINT)
#define SJARG() \
	(flags&INTMAXT ? GETARG(intmax_t) : \
	    flags&SIZET ? (intmax_t)GETARG(ssize_t) : \
	    flags&PTRDIFFT ? (intmax_t)GETARG(ptrdiff_t) : \
	    (intmax_t)GETARG(long long))
#define	UJARG() \
	(flags&INTMAXT ? GETARG(uintmax_t) : \
	    flags&SIZET ? (uintmax_t)GETARG(size_t) : \
	    flags&PTRDIFFT ? (uintmax_t)GETARG(ptrdiff_t) : \
	    (uintmax_t)GETARG(unsigned long long))

	/*
	 * Append a digit to a value and check for overflow.
	 */
#define APPEND_DIGIT(val, dig) do { \
	if ((val) > INT_MAX / 10) \
		goto overflow; \
	(val) *= 10; \
	if ((val) > INT_MAX - to_digit((dig))) \
		goto overflow; \
	(val) += to_digit((dig)); \
} while (0)

	/*
	 * Get * arguments, including the form *nn$.  Preserve the nextarg
	 * that the argument can be gotten once the type is determined.
	 */
#define GETASTER(val) \
	n2 = 0; \
	cp = fmt; \
	while (is_digit(*cp)) { \
		APPEND_DIGIT(n2, *cp); \
		cp++; \
	} \
	if (*cp == '$') { \
		int hold = nextarg; \
		if (argtable == NULL) { \
			argtable = statargtable; \
			if (__find_arguments (fmt0, orgap, &argtable)) { \
				ret = EOF; \
				goto error; \
			} \
		} \
		nextarg = n2; \
		val = GETARG(int); \
		nextarg = hold; \
		fmt = ++cp; \
	} else { \
		val = GETARG(int); \
	}

	_SET_ORIENTATION(fp, -1);
	/* sorry, fprintf(read_only_file, "") returns EOF, not 0 */
	if (cantwrite(fp)) {
		errno = EBADF;
		return (EOF);
	}

	fmt = (char *)fmt0;
	argtable = NULL;
	nextarg = 1;
	va_copy(orgap, ap);
	io_init(&io, fp);
	ret = 0;
#ifdef FLOATING_POINT
	decimal_point = localeconv_l(locale)->decimal_point;
	/* The overwhelmingly common case is decpt_len == 1. */
	decpt_len = (decimal_point[1] == '\0' ? 1 : strlen(decimal_point));
#endif
#ifdef PRINTF_WIDE_CHAR
	convbuf = NULL;
#endif

	/*
	 * Scan the format for conversions (`%' character).
	 */
	for (;;) {
		for (cp = fmt; (ch = *fmt) != '\0' && ch != '%'; fmt++)
			/* void */;
		if (fmt != cp) {
			ptrdiff_t m = fmt - cp;
			if (m < 0 || m > INT_MAX - ret)
				goto overflow;
			PRINT(cp, m);
			ret += m;
		}
		if (ch == '\0')
			goto done;
		fmt++;		/* skip over '%' */

		flags = 0;
		dprec = 0;
		width = 0;
		prec = -1;
		gs.grouping = NULL;
		sign = '\0';
		ox[1] = '\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.
			 */
			GETASTER(width);
			if (width >= 0)
				goto rflag;
			if (width == INT_MIN)
				goto overflow;
			width = -width;
			/* FALLTHROUGH */
		case '-':
			flags |= LADJUST;
			goto rflag;
		case '+':
			sign = '+';
			goto rflag;
		case '\'':
			flags |= GROUPING;
			goto rflag;
		case '.':
			if ((ch = *fmt++) == '*') {
				GETASTER(n);
				prec = n < 0 ? -1 : n;
				goto rflag;
			}
			n = 0;
			while (is_digit(ch)) {
				APPEND_DIGIT(n, ch);
				ch = *fmt++;
			}
			if (ch == '$') {
				nextarg = n;
				if (argtable == NULL) {
					argtable = statargtable;
					if (__find_arguments (fmt0, orgap,
							      &argtable)) {
						ret = EOF;
						goto error;
					}
				}
				goto rflag;
			}
			prec = n;
			goto reswitch;
		case '0':
			/*
			 * ``Note that 0 is taken as a flag, not as the
			 * beginning of a field width.''
			 *	-- ANSI X3J11
			 */
			flags |= ZEROPAD;
			goto rflag;
		case '1': case '2': case '3': case '4':
		case '5': case '6': case '7': case '8': case '9':
			n = 0;
			do {
				APPEND_DIGIT(n, ch);
				ch = *fmt++;
			} while (is_digit(ch));
			if (ch == '$') {
				nextarg = n;
				if (argtable == NULL) {
					argtable = statargtable;
					if (__find_arguments (fmt0, orgap,
							      &argtable)) {
						ret = EOF;
						goto error;
					}
				}
				goto rflag;
			}
			width = n;
			goto reswitch;
#ifdef FLOATING_POINT
		case 'L':
			flags |= LONGDBL;
			goto rflag;
#endif
		case 'h':
			if (flags & SHORTINT) {
				flags &= ~SHORTINT;
				flags |= CHARINT;
			} else {
				flags |= SHORTINT;
			}
			goto rflag;
		case 'j':
			flags |= INTMAXT;
			goto rflag;
		case 'l':
			if (flags & LONGINT) {
				flags &= ~LONGINT;
				flags |= LLONGINT;
			} else {
				flags |= LONGINT;
			}
			goto rflag;
		case 'q':
			flags |= LLONGINT;	/* not necessarily */
			goto rflag;
		case 't':
			flags |= PTRDIFFT;
			goto rflag;
		case 'z':
			flags |= SIZET;
			goto rflag;
		case 'C':
			flags |= LONGINT;
			/*FALLTHROUGH*/
		case 'c':
#ifdef PRINTF_WIDE_CHAR
			if (flags & LONGINT) {
				mbstate_t mbs;
				size_t mbseqlen;

				memset(&mbs, 0, sizeof(mbs));
				mbseqlen = wcrtomb(buf,
				    (wchar_t)GETARG(wint_t), &mbs);
				if (mbseqlen == (size_t)-1) {
					fp->_flags |= __SERR;
					errno = EILSEQ;
					goto error;
				}
				cp = buf;
				size = (int)mbseqlen;
			} else {
#endif
				*(cp = buf) = GETARG(int);
				size = 1;
#ifdef PRINTF_WIDE_CHAR
			}
#endif
			sign = '\0';
			break;
		case 'D':
			flags |= LONGINT;
			/*FALLTHROUGH*/
		case 'd':
		case 'i':
			if (flags & INTMAX_SIZE) {
				ujval = SJARG();
				if ((intmax_t)ujval < 0) {
					ujval = -ujval;
					sign = '-';
				}
			} else {
				ulval = SARG();
				if ((long)ulval < 0) {
					ulval = -ulval;
					sign = '-';
				}
			}
			base = 10;
			goto number;
#ifdef FLOATING_POINT
		case 'a':
		case 'A':
			if (ch == 'a') {
				ox[1] = 'x';
				xdigs = xdigs_lower;
				expchar = 'p';
			} else {
				ox[1] = 'X';
				xdigs = xdigs_upper;
				expchar = 'P';
			}
			if (prec >= 0)
				prec++;
			if (dtoaresult != NULL)
				__freedtoa(dtoaresult);
			if (flags & LONGDBL) {
				fparg.ldbl = GETARG(long double);
				dtoaresult = cp =
				    __hldtoa(fparg.ldbl, xdigs, prec,
				    &expt, &signflag, &dtoaend);
				if (dtoaresult == NULL) {
					errno = ENOMEM;
					goto error;
				}
			} else {
				fparg.dbl = GETARG(double);
				dtoaresult = cp =
				    __hdtoa(fparg.dbl, xdigs, prec,
				    &expt, &signflag, &dtoaend);
				if (dtoaresult == NULL) {
					errno = ENOMEM;
					goto error;
				}
			}
			if (prec < 0)
				prec = dtoaend - cp;
			if (expt == INT_MAX)
				ox[1] = '\0';
			goto fp_common;
		case 'e':
		case 'E':
			expchar = ch;
			if (prec < 0)	/* account for digit before decpt */
				prec = DEFPREC + 1;
			else
				prec++;
			goto fp_begin;
		case 'f':
		case 'F':
			expchar = '\0';
			goto fp_begin;
		case 'g':
		case 'G':
			expchar = ch - ('g' - 'e');
			if (prec == 0)
				prec = 1;
fp_begin:
			if (prec < 0)
				prec = DEFPREC;
			if (dtoaresult != NULL)
				__freedtoa(dtoaresult);
			if (flags & LONGDBL) {
				fparg.ldbl = GETARG(long double);
				dtoaresult = cp =
				    __ldtoa(&fparg.ldbl, expchar ? 2 : 3, prec,
				    &expt, &signflag, &dtoaend);
				if (dtoaresult == NULL) {
					errno = ENOMEM;
					goto error;
				}
			} else {