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Sync libc/stdio with FreeBSD:
[dragonfly.git] / lib / libc / stdio / xprintf_float.c
blob90b41a790d6b3ae63f8c961d7087bf4cfbec9285
1 /*-
2 * Copyright (c) 2005 Poul-Henning Kamp
3 * Copyright (c) 1990, 1993
4 * The Regents of the University of California. All rights reserved.
5 *
6 * This code is derived from software contributed to Berkeley by
7 * Chris Torek.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
17 * 3. Neither the name of the University nor the names of its contributors
18 * may be used to endorse or promote products derived from this software
19 * without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 *
33 * $FreeBSD: src/lib/libc/stdio/xprintf_float.c,v 1.1 2005/12/16 18:56:38 phk Exp $
34 */
35
36 #include "namespace.h"
37 #include <stdio.h>
38 #include <wchar.h>
39 #include <assert.h>
40 #include <locale.h>
41 #include <limits.h>
42
43 #define dtoa __dtoa
44 #define freedtoa __freedtoa
45
46 #include <float.h>
47 #include <math.h>
48 #include "un-namespace.h"
49 #include "gdtoa.h"
50 #include "floatio.h"
51 #include "printf.h"
52
53 /*
54 * The size of the buffer we use as scratch space for integer
55 * conversions, among other things. Technically, we would need the
56 * most space for base 10 conversions with thousands' grouping
57 * characters between each pair of digits. 100 bytes is a
58 * conservative overestimate even for a 128-bit uintmax_t.
59 */
60 #define BUF 100
61
62 #define DEFPREC 6 /* Default FP precision */
63
64
65 /* various globals ---------------------------------------------------*/
66
67
68 /* padding function---------------------------------------------------*/
69
70 #define PRINTANDPAD(p, ep, len, with) do { \
71 n2 = (ep) - (p); \
72 if (n2 > (len)) \
73 n2 = (len); \
74 if (n2 > 0) \
75 ret += __printf_puts(io, (p), n2); \
76 ret += __printf_pad(io, (len) - (n2 > 0 ? n2 : 0), (with)); \
77 } while(0)
78
79 /* misc --------------------------------------------------------------*/
80
81 #define to_char(n) ((n) + '0')
82
83 static int
84 exponent(char *p0, int expo, int fmtch)
85 {
86 char *p, *t;
87 char expbuf[MAXEXPDIG];
88
89 p = p0;
90 *p++ = fmtch;
91 if (expo < 0) {
92 expo = -expo;
93 *p++ = '-';
94 } else {
95 *p++ = '+';
96 }
97 t = expbuf + MAXEXPDIG;
98 if (expo > 9) {
99 do {
100 *--t = to_char(expo % 10);
101 } while ((expo /= 10) > 9);
102 *--t = to_char(expo);
103 for (; t < expbuf + MAXEXPDIG; *p++ = *t++)
104 ;
105 } else {
106 /*
107 * Exponents for decimal floating point conversions
108 * (%[eEgG]) must be at least two characters long,
109 * whereas exponents for hexadecimal conversions can
110 * be only one character long.
111 */
112 if (fmtch == 'e' || fmtch == 'E')
113 *p++ = '0';
114 *p++ = to_char(expo);
115 }
116 return (p - p0);
117 }
118
119 /* 'f' ---------------------------------------------------------------*/
120
121 int
122 __printf_arginfo_float(const struct printf_info *pi, size_t n, int *argt)
123 {
124 assert (n > 0);
125 argt[0] = PA_DOUBLE;
126 if (pi->is_long_double)
127 argt[0] |= PA_FLAG_LONG_DOUBLE;
128 return (1);
129 }
130
131 /*
132 * We can decompose the printed representation of floating
133 * point numbers into several parts, some of which may be empty:
134 *
135 * [+|-| ] [0x|0X] MMM . NNN [e|E|p|P] [+|-] ZZ
136 * A B ---C--- D E F
137 *
138 * A: 'sign' holds this value if present; '\0' otherwise
139 * B: ox[1] holds the 'x' or 'X'; '\0' if not hexadecimal
140 * C: cp points to the string MMMNNN. Leading and trailing
141 * zeroes are not in the string and must be added.
142 * D: expchar holds this character; '\0' if no exponent, e.g. %f
143 * F: at least two digits for decimal, at least one digit for hex
144 */
145
146 int
147 __printf_render_float(struct __printf_io *io, const struct printf_info *pi,
148 const void *const *arg)
149 {
150 int prec; /* precision from format; <0 for N/A */
151 char *dtoaresult; /* buffer allocated by dtoa */
152 char expchar; /* exponent character: [eEpP\0] */
153 char *cp;
154 int expt; /* integer value of exponent */
155 int signflag; /* true if float is negative */
156 char *dtoaend; /* pointer to end of converted digits */
157 char sign; /* sign prefix (' ', '+', '-', or \0) */
158 int size; /* size of converted field or string */
159 int ndig; /* actual number of digits returned by dtoa */
160 int expsize; /* character count for expstr */
161 char expstr[MAXEXPDIG+2]; /* buffer for exponent string: e+ZZZ */
162 int nseps; /* number of group separators with ' */
163 int nrepeats; /* number of repeats of the last group */
164 const char *grouping; /* locale specific numeric grouping rules */
165 int lead; /* sig figs before decimal or group sep */
166 long double ld;
167 double d;
168 int realsz; /* field size expanded by dprec, sign, etc */
169 int dprec; /* a copy of prec if [diouxX], 0 otherwise */
170 char ox[2]; /* space for 0x; ox[1] is either x, X, or \0 */
171 int prsize; /* max size of printed field */
172 int ret; /* return value accumulator */
173 char *decimal_point; /* locale specific decimal point */
174 int n2; /* XXX: for PRINTANDPAD */
175 char thousands_sep; /* locale specific thousands separator */
176 char buf[BUF]; /* buffer with space for digits of uintmax_t */
177 const char *xdigs;
178 int flag;
179
180 prec = pi->prec;
181 ox[1] = '\0';
182 sign = pi->showsign;
183 flag = 0;
184 ret = 0;
185
186 thousands_sep = *(localeconv()->thousands_sep);
187 grouping = NULL;
188 if (pi->alt)
189 grouping = localeconv()->grouping;
190 decimal_point = localeconv()->decimal_point;
191 dprec = -1;
192
193 switch(pi->spec) {
194 case 'a':
195 case 'A':
196 if (pi->spec == 'a') {
197 ox[1] = 'x';
198 xdigs = __lowercase_hex;
199 expchar = 'p';
200 } else {
201 ox[1] = 'X';
202 xdigs = __uppercase_hex;
203 expchar = 'P';
204 }
205 if (prec >= 0)
206 prec++;
207 if (pi->is_long_double) {
208 ld = *((long double *)arg[0]);
209 dtoaresult = cp =
210 __hldtoa(ld, xdigs, prec,
211 &expt, &signflag, &dtoaend);
212 } else {
213 d = *((double *)arg[0]);
214 dtoaresult = cp =
215 __hdtoa(d, xdigs, prec,
216 &expt, &signflag, &dtoaend);
217 }
218 if (prec < 0)
219 prec = dtoaend - cp;
220 if (expt == INT_MAX)
221 ox[1] = '\0';
222 goto fp_common;
223 case 'e':
224 case 'E':
225 expchar = pi->spec;
226 if (prec < 0) /* account for digit before decpt */
227 prec = DEFPREC + 1;
228 else
229 prec++;
230 break;
231 case 'f':
232 case 'F':
233 expchar = '\0';
234 break;
235 case 'g':
236 case 'G':
237 expchar = pi->spec - ('g' - 'e');
238 if (prec == 0)
239 prec = 1;
240 break;
241 default:
242 assert(pi->spec == 'f');
243 }
244
245 if (prec < 0)
246 prec = DEFPREC;
247 if (pi->is_long_double) {
248 ld = *((long double *)arg[0]);
249 dtoaresult = cp =
250 __ldtoa(&ld, expchar ? 2 : 3, prec,
251 &expt, &signflag, &dtoaend);
252 } else {
253 d = *((double *)arg[0]);
254 dtoaresult = cp =
255 dtoa(d, expchar ? 2 : 3, prec,
256 &expt, &signflag, &dtoaend);
257 if (expt == 9999)
258 expt = INT_MAX;
259 }
260 fp_common:
261 if (signflag)
262 sign = '-';
263 if (expt == INT_MAX) { /* inf or nan */
264 if (*cp == 'N') {
265 cp = (pi->spec >= 'a') ? "nan" : "NAN";
266 sign = '\0';
267 } else {
268 cp = (pi->spec >= 'a') ? "inf" : "INF";
269 }
270 size = 3;
271 flag = 1;
272 goto here;
273 }
274 ndig = dtoaend - cp;
275 if (pi->spec == 'g' || pi->spec == 'G') {
276 if (expt > -4 && expt <= prec) {
277 /* Make %[gG] smell like %[fF] */
278 expchar = '\0';
279 if (pi->alt)
280 prec -= expt;
281 else
282 prec = ndig - expt;
283 if (prec < 0)
284 prec = 0;
285 } else {
286 /*
287 * Make %[gG] smell like %[eE], but
288 * trim trailing zeroes if no # flag.
289 */
290 if (!pi->alt)
291 prec = ndig;
292 }
293 }
294 if (expchar) {
295 expsize = exponent(expstr, expt - 1, expchar);
296 size = expsize + prec;
297 if (prec > 1 || pi->alt)
298 ++size;
299 } else {
300 /* space for digits before decimal point */
301 if (expt > 0)
302 size = expt;
303 else /* "0" */
304 size = 1;
305 /* space for decimal pt and following digits */
306 if (prec || pi->alt)
307 size += prec + 1;
308 if (grouping && expt > 0) {
309 /* space for thousands' grouping */
310 nseps = nrepeats = 0;
311 lead = expt;
312 while (*grouping != CHAR_MAX) {
313 if (lead <= *grouping)
314 break;
315 lead -= *grouping;
316 if (*(grouping+1)) {
317 nseps++;
318 grouping++;
319 } else {
320 nrepeats++;
321 }
322 }
323 size += nseps + nrepeats;
324 } else {
325 lead = expt;
326 }
327 }
328
329 here:
330 /*
331 * All reasonable formats wind up here. At this point, `cp'
332 * points to a string which (if not flags&LADJUST) should be
333 * padded out to `width' places. If flags&ZEROPAD, it should
334 * first be prefixed by any sign or other prefix; otherwise,
335 * it should be blank padded before the prefix is emitted.
336 * After any left-hand padding and prefixing, emit zeroes
337 * required by a decimal [diouxX] precision, then print the
338 * string proper, then emit zeroes required by any leftover
339 * floating precision; finally, if LADJUST, pad with blanks.
340 *
341 * Compute actual size, so we know how much to pad.
342 * size excludes decimal prec; realsz includes it.
343 */
344 realsz = dprec > size ? dprec : size;
345 if (sign)
346 realsz++;
347 if (ox[1])
348 realsz += 2;
349
350 prsize = pi->width > realsz ? pi->width : realsz;
351
352 /* right-adjusting blank padding */
353 if (pi->pad != '0' && pi->left == 0)
354 ret += __printf_pad(io, pi->width - realsz, 0);
355
356 /* prefix */
357 if (sign)
358 ret += __printf_puts(io, &sign, 1);
359
360 if (ox[1]) { /* ox[1] is either x, X, or \0 */
361 ox[0] = '0';
362 ret += __printf_puts(io, ox, 2);
363 }
364
365 /* right-adjusting zero padding */
366 if (pi->pad == '0' && pi->left == 0)
367 ret += __printf_pad(io, pi->width - realsz, 1);
368
369 /* leading zeroes from decimal precision */
370 ret += __printf_pad(io, dprec - size, 1);
371
372 if (flag) {
373 ret += __printf_puts(io, cp, size);
374 } else {
375 /* glue together f_p fragments */
376 if (!expchar) { /* %[fF] or sufficiently short %[gG] */
377 if (expt <= 0) {
378 ret += __printf_puts(io, "0", 1);
379 if (prec || pi->alt)
380 ret += __printf_puts(io, decimal_point, 1);
381 ret += __printf_pad(io, -expt, 1);
382 /* already handled initial 0's */
383 prec += expt;
384 } else {
385 PRINTANDPAD(cp, dtoaend, lead, 1);
386 cp += lead;
387 if (grouping) {
388 while (nseps>0 || nrepeats>0) {
389 if (nrepeats > 0) {
390 nrepeats--;
391 } else {
392 grouping--;
393 nseps--;
394 }
395 ret += __printf_puts(io, &thousands_sep, 1);
396 PRINTANDPAD(cp,dtoaend,
397 *grouping, 1);
398 cp += *grouping;
399 }
400 if (cp > dtoaend)
401 cp = dtoaend;
402 }
403 if (prec || pi->alt)
404 ret += __printf_puts(io, decimal_point,1);
405 }
406 PRINTANDPAD(cp, dtoaend, prec, 1);
407 } else { /* %[eE] or sufficiently long %[gG] */
408 if (prec > 1 || pi->alt) {
409 buf[0] = *cp++;
410 buf[1] = *decimal_point;
411 ret += __printf_puts(io, buf, 2);
412 ret += __printf_puts(io, cp, ndig-1);
413 ret += __printf_pad(io, prec - ndig, 1);
414 } else { /* XeYYY */
415 ret += __printf_puts(io, cp, 1);
416 }
417 ret += __printf_puts(io, expstr, expsize);
418 }
419 }
420 /* left-adjusting padding (always blank) */
421 if (pi->left)
422 ret += __printf_pad(io, pi->width - realsz, 0);
423
424 __printf_flush(io);
425 if (dtoaresult != NULL)
426 freedtoa(dtoaresult);
427
428 return (ret);
429 }
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