2 * SPDX-License-Identifier: BSD-3-Clause
4 * Copyright (c) 2005 Poul-Henning Kamp
5 * Copyright (c) 1990, 1993
6 * The Regents of the University of California. All rights reserved.
8 * This code is derived from software contributed to Berkeley by
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in the
18 * documentation and/or other materials provided with the distribution.
19 * 3. Neither the name of the University nor the names of its contributors
20 * may be used to endorse or promote products derived from this software
21 * without specific prior written permission.
23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
38 #include <namespace.h>
46 #define freedtoa __freedtoa
53 #include <un-namespace.h>
56 * The size of the buffer we use as scratch space for integer
57 * conversions, among other things. Technically, we would need the
58 * most space for base 10 conversions with thousands' grouping
59 * characters between each pair of digits. 100 bytes is a
60 * conservative overestimate even for a 128-bit uintmax_t.
64 #define DEFPREC 6 /* Default FP precision */
67 /* various globals ---------------------------------------------------*/
70 /* padding function---------------------------------------------------*/
72 #define PRINTANDPAD(p, ep, len, with) do { \
77 ret += __printf_puts(io, (p), n2); \
78 ret += __printf_pad(io, (len) - (n2 > 0 ? n2 : 0), (with)); \
81 /* misc --------------------------------------------------------------*/
83 #define to_char(n) ((n) + '0')
86 exponent(char *p0, int expo, int fmtch)
89 char expbuf[MAXEXPDIG];
99 t = expbuf + MAXEXPDIG;
102 *--t = to_char(expo % 10);
103 } while ((expo /= 10) > 9);
104 *--t = to_char(expo);
105 for (; t < expbuf + MAXEXPDIG; *p++ = *t++)
110 * Exponents for decimal floating point conversions
111 * (%[eEgG]) must be at least two characters long,
112 * whereas exponents for hexadecimal conversions can
113 * be only one character long.
115 if (fmtch == 'e' || fmtch == 'E')
117 *p++ = to_char(expo);
122 /* 'f' ---------------------------------------------------------------*/
125 __printf_arginfo_float(const struct printf_info *pi, size_t n, int *argt)
129 if (pi->is_long_double)
130 argt[0] |= PA_FLAG_LONG_DOUBLE;
135 * We can decompose the printed representation of floating
136 * point numbers into several parts, some of which may be empty:
138 * [+|-| ] [0x|0X] MMM . NNN [e|E|p|P] [+|-] ZZ
141 * A: 'sign' holds this value if present; '\0' otherwise
142 * B: ox[1] holds the 'x' or 'X'; '\0' if not hexadecimal
143 * C: cp points to the string MMMNNN. Leading and trailing
144 * zeros are not in the string and must be added.
145 * D: expchar holds this character; '\0' if no exponent, e.g. %f
146 * F: at least two digits for decimal, at least one digit for hex
150 __printf_render_float(struct __printf_io *io, const struct printf_info *pi, const void *const *arg)
152 int prec; /* precision from format; <0 for N/A */
153 char *dtoaresult; /* buffer allocated by dtoa */
154 char expchar; /* exponent character: [eEpP\0] */
156 int expt; /* integer value of exponent */
157 int signflag; /* true if float is negative */
158 char *dtoaend; /* pointer to end of converted digits */
159 char sign; /* sign prefix (' ', '+', '-', or \0) */
160 int size; /* size of converted field or string */
161 int ndig; /* actual number of digits returned by dtoa */
162 int expsize; /* character count for expstr */
163 char expstr[MAXEXPDIG+2]; /* buffer for exponent string: e+ZZZ */
164 int nseps; /* number of group separators with ' */
165 int nrepeats; /* number of repeats of the last group */
166 const char *grouping; /* locale specific numeric grouping rules */
167 int lead; /* sig figs before decimal or group sep */
170 int realsz; /* field size expanded by dprec, sign, etc */
171 int dprec; /* a copy of prec if [diouxX], 0 otherwise */
172 char ox[2]; /* space for 0x; ox[1] is either x, X, or \0 */
173 int ret; /* return value accumulator */
174 char *decimal_point; /* locale specific decimal point */
175 int n2; /* XXX: for PRINTANDPAD */
176 char thousands_sep; /* locale specific thousands separator */
177 char buf[BUF]; /* buffer with space for digits of uintmax_t */
187 thousands_sep = *(localeconv()->thousands_sep);
190 grouping = localeconv()->grouping;
191 decimal_point = localeconv()->decimal_point;
197 if (pi->spec == 'a') {
199 xdigs = __lowercase_hex;
203 xdigs = __uppercase_hex;
208 if (pi->is_long_double) {
209 ld = *((long double *)arg[0]);
211 __hldtoa(ld, xdigs, prec,
212 &expt, &signflag, &dtoaend);
214 d = *((double *)arg[0]);
216 __hdtoa(d, xdigs, prec,
217 &expt, &signflag, &dtoaend);
227 if (prec < 0) /* account for digit before decpt */
238 expchar = pi->spec - ('g' - 'e');
243 assert(pi->spec == 'f');
248 if (pi->is_long_double) {
249 ld = *((long double *)arg[0]);
251 __ldtoa(&ld, expchar ? 2 : 3, prec,
252 &expt, &signflag, &dtoaend);
254 d = *((double *)arg[0]);
256 dtoa(d, expchar ? 2 : 3, prec,
257 &expt, &signflag, &dtoaend);
264 if (expt == INT_MAX) { /* inf or nan */
266 cp = (pi->spec >= 'a') ? "nan" : "NAN";
269 cp = (pi->spec >= 'a') ? "inf" : "INF";
275 if (pi->spec == 'g' || pi->spec == 'G') {
276 if (expt > -4 && expt <= prec) {
277 /* Make %[gG] smell like %[fF] */
287 * Make %[gG] smell like %[eE], but
288 * trim trailing zeroes if no # flag.
295 expsize = exponent(expstr, expt - 1, expchar);
296 size = expsize + prec;
297 if (prec > 1 || pi->alt)
300 /* space for digits before decimal point */
305 /* space for decimal pt and following digits */
308 if (grouping && expt > 0) {
309 /* space for thousands' grouping */
310 nseps = nrepeats = 0;
312 while (*grouping != CHAR_MAX) {
313 if (lead <= *grouping)
322 size += nseps + nrepeats;
329 * All reasonable formats wind up here. At this point, `cp'
330 * points to a string which (if not flags&LADJUST) should be
331 * padded out to `width' places. If flags&ZEROPAD, it should
332 * first be prefixed by any sign or other prefix; otherwise,
333 * it should be blank padded before the prefix is emitted.
334 * After any left-hand padding and prefixing, emit zeroes
335 * required by a decimal [diouxX] precision, then print the
336 * string proper, then emit zeroes required by any leftover
337 * floating precision; finally, if LADJUST, pad with blanks.
339 * Compute actual size, so we know how much to pad.
340 * size excludes decimal prec; realsz includes it.
342 realsz = dprec > size ? dprec : size;
348 /* right-adjusting blank padding */
349 if (pi->pad != '0' && pi->left == 0)
350 ret += __printf_pad(io, pi->width - realsz, 0);
354 ret += __printf_puts(io, &sign, 1);
356 if (ox[1]) { /* ox[1] is either x, X, or \0 */
358 ret += __printf_puts(io, ox, 2);
361 /* right-adjusting zero padding */
362 if (pi->pad == '0' && pi->left == 0)
363 ret += __printf_pad(io, pi->width - realsz, 1);
365 /* leading zeroes from decimal precision */
366 ret += __printf_pad(io, dprec - size, 1);
369 ret += __printf_puts(io, cp, size);
371 /* glue together f_p fragments */
372 if (!expchar) { /* %[fF] or sufficiently short %[gG] */
374 ret += __printf_puts(io, "0", 1);
376 ret += __printf_puts(io, decimal_point, 1);
377 ret += __printf_pad(io, -expt, 1);
378 /* already handled initial 0's */
381 PRINTANDPAD(cp, dtoaend, lead, 1);
384 while (nseps>0 || nrepeats>0) {
391 ret += __printf_puts(io, &thousands_sep, 1);
392 PRINTANDPAD(cp,dtoaend,
400 ret += __printf_puts(io, decimal_point,1);
402 PRINTANDPAD(cp, dtoaend, prec, 1);
403 } else { /* %[eE] or sufficiently long %[gG] */
404 if (prec > 1 || pi->alt) {
406 buf[1] = *decimal_point;
407 ret += __printf_puts(io, buf, 2);
408 ret += __printf_puts(io, cp, ndig-1);
409 ret += __printf_pad(io, prec - ndig, 1);
411 ret += __printf_puts(io, cp, 1);
412 ret += __printf_puts(io, expstr, expsize);
415 /* left-adjusting padding (always blank) */
417 ret += __printf_pad(io, pi->width - realsz, 0);
420 if (dtoaresult != NULL)
421 freedtoa(dtoaresult);