1 /* $OpenBSD: vfprintf.c,v 1.71 2016/01/04 15:47:47 schwarze Exp $ */
2 /*-
3 * Copyright (c) 1990 The Regents of the University of California.
4 * 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
34 #define CHAR_TYPE char
35 #define FUNCTION_NAME __vfprintf
36 #define CHAR_TYPE_STRLEN strlen
37 #define CHAR_TYPE_STRNLEN strnlen
38 #define CHAR_TYPE_INF "INF"
39 #define CHAR_TYPE_inf "inf"
40 #define CHAR_TYPE_NAN "NAN"
41 #define CHAR_TYPE_nan "nan"
42 #define CHAR_TYPE_ORIENTATION -1
43 #include "printf_common.h"
44
FUNCTION_NAME(FILE * fp,const CHAR_TYPE * fmt0,va_list ap)45 int FUNCTION_NAME(FILE* fp, const CHAR_TYPE* fmt0, va_list ap) {
46 int caller_errno = errno;
47 int n, n2;
48 CHAR_TYPE* cp; /* handy char pointer (short term usage) */
49 CHAR_TYPE sign; /* sign prefix (' ', '+', '-', or \0) */
50 int flags; /* flags as above */
51 int ret; /* return value accumulator */
52 int width; /* width from format (%8d), or 0 */
53 int prec; /* precision from format; <0 for N/A */
54 /*
55 * We can decompose the printed representation of floating
56 * point numbers into several parts, some of which may be empty:
57 *
58 * [+|-| ] [0x|0X] MMM . NNN [e|E|p|P] [+|-] ZZ
59 * A B ---C--- D E F
60 *
61 * A: 'sign' holds this value if present; '\0' otherwise
62 * B: ox[1] holds the 'x' or 'X'; '\0' if not hexadecimal
63 * C: cp points to the string MMMNNN. Leading and trailing
64 * zeros are not in the string and must be added.
65 * D: expchar holds this character; '\0' if no exponent, e.g. %f
66 * F: at least two digits for decimal, at least one digit for hex
67 */
68 char* decimal_point = nullptr;
69 int signflag; /* true if float is negative */
70 union { /* floating point arguments %[aAeEfFgG] */
71 double dbl;
72 long double ldbl;
73 } fparg;
74 int expt; /* integer value of exponent */
75 char expchar; /* exponent character: [eEpP\0] */
76 char* dtoaend; /* pointer to end of converted digits */
77 int expsize; /* character count for expstr */
78 int lead; /* sig figs before decimal or group sep */
79 int ndig; /* actual number of digits returned by dtoa */
80 CHAR_TYPE expstr[MAXEXPDIG + 2]; /* buffer for exponent string: e+ZZZ */
81 char* dtoaresult = nullptr;
82
83 uintmax_t _umax; /* integer arguments %[diouxX] */
84 enum { OCT, DEC, HEX } base; /* base for %[diouxX] conversion */
85 int dprec; /* a copy of prec if %[diouxX], 0 otherwise */
86 int realsz; /* field size expanded by dprec */
87 int size; /* size of converted field or string */
88 const char* xdigs; /* digits for %[xX] conversion */
89 #define NIOV 8
90 struct __suio uio; /* output information: summary */
91 struct __siov iov[NIOV]; /* ... and individual io vectors */
92 struct __siov* iovp; /* for PRINT macro */
93 CHAR_TYPE buf[BUF]; /* buffer with space for digits of uintmax_t */
94 CHAR_TYPE ox[2]; /* space for 0x; ox[1] is either x, X, or \0 */
95 union arg* argtable; /* args, built due to positional arg */
96 union arg statargtable[STATIC_ARG_TBL_SIZE];
97 size_t argtablesiz;
98 int nextarg; /* 1-based argument index */
99 va_list orgap; /* original argument pointer */
100 CHAR_TYPE* convbuf; /* buffer for wide/multibyte conversion */
101
102 /*
103 * Choose PADSIZE to trade efficiency vs. size. If larger printf
104 * fields occur frequently, increase PADSIZE and make the initialisers
105 * below longer.
106 */
107 #define PADSIZE 16 /* pad chunk size */
108 static CHAR_TYPE blanks[PADSIZE] = {
109 ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' '
110 };
111 static CHAR_TYPE zeroes[PADSIZE] = {
112 '0', '0', '0', '0', '0', '0', '0', '0', '0', '0', '0', '0', '0', '0', '0', '0'
113 };
114
115 static const char xdigs_lower[] = "0123456789abcdef";
116 static const char xdigs_upper[] = "0123456789ABCDEF";
117
118 #define PRINT(ptr, len) \
119 do { \
120 iovp->iov_base = (ptr); \
121 iovp->iov_len = (len); \
122 uio.uio_resid += (len); \
123 iovp++; \
124 if (++uio.uio_iovcnt >= NIOV) { \
125 if (helpers::sprint(fp, &uio)) goto error; \
126 iovp = iov; \
127 } \
128 } while (0)
129 #define FLUSH() \
130 do { \
131 if (uio.uio_resid && helpers::sprint(fp, &uio)) goto error; \
132 uio.uio_iovcnt = 0; \
133 iovp = iov; \
134 } while (0)
135
136 _SET_ORIENTATION(fp, CHAR_TYPE_ORIENTATION);
137
138 // Writing "" to a read only file returns EOF, not 0.
139 if (cantwrite(fp)) {
140 errno = EBADF;
141 return EOF;
142 }
143
144 // Optimize writes to stderr and other unbuffered files).
145 if ((fp->_flags & (__SNBF | __SWR | __SRW)) == (__SNBF | __SWR) && fp->_file >= 0) {
146 return (__sbprintf(fp, fmt0, ap));
147 }
148
149 CHAR_TYPE* fmt = const_cast<CHAR_TYPE*>(fmt0);
150 argtable = nullptr;
151 nextarg = 1;
152 va_copy(orgap, ap);
153 uio.uio_iov = iovp = iov;
154 uio.uio_resid = 0;
155 uio.uio_iovcnt = 0;
156 ret = 0;
157 convbuf = nullptr;
158
159 /*
160 * Scan the format for conversions (`%' character).
161 */
162 for (;;) {
163 int ch;
164 for (cp = fmt; (ch = *fmt) != '\0' && ch != '%'; fmt++) continue;
165 if (fmt != cp) {
166 ptrdiff_t m = fmt - cp;
167 if (m < 0 || m > INT_MAX - ret) goto overflow;
168 PRINT(cp, m);
169 ret += m;
170 }
171 if (ch == '\0') goto done;
172 fmt++; /* skip over '%' */
173
174 flags = 0;
175 dprec = 0;
176 width = 0;
177 prec = -1;
178 sign = '\0';
179 ox[1] = '\0';
180
181 rflag:
182 ch = *fmt++;
183 reswitch:
184 switch (ch) {
185 case ' ':
186 /*
187 * ``If the space and + flags both appear, the space
188 * flag will be ignored.''
189 * -- ANSI X3J11
190 */
191 if (!sign) sign = ' ';
192 goto rflag;
193 case '#':
194 flags |= ALT;
195 goto rflag;
196 case '\'':
197 /* grouping not implemented */
198 goto rflag;
199 case '*':
200 /*
201 * ``A negative field width argument is taken as a
202 * - flag followed by a positive field width.''
203 * -- ANSI X3J11
204 * They don't exclude field widths read from args.
205 */
206 GETASTER(width);
207 if (width >= 0) goto rflag;
208 if (width == INT_MIN) goto overflow;
209 width = -width;
210 __BIONIC_FALLTHROUGH;
211 case '-':
212 flags |= LADJUST;
213 goto rflag;
214 case '+':
215 sign = '+';
216 goto rflag;
217 case '.':
218 if ((ch = *fmt++) == '*') {
219 GETASTER(n);
220 prec = n < 0 ? -1 : n;
221 goto rflag;
222 }
223 n = 0;
224 while (is_digit(ch)) {
225 APPEND_DIGIT(n, ch);
226 ch = *fmt++;
227 }
228 if (ch == '$') {
229 nextarg = n;
230 if (argtable == nullptr) {
231 argtable = statargtable;
232 if (__find_arguments(fmt0, orgap, &argtable, &argtablesiz) == -1) {
233 ret = -1;
234 goto error;
235 }
236 }
237 goto rflag;
238 }
239 prec = n;
240 goto reswitch;
241 case '0':
242 /*
243 * ``Note that 0 is taken as a flag, not as the
244 * beginning of a field width.''
245 * -- ANSI X3J11
246 */
247 flags |= ZEROPAD;
248 goto rflag;
249 case '1':
250 case '2':
251 case '3':
252 case '4':
253 case '5':
254 case '6':
255 case '7':
256 case '8':
257 case '9':
258 n = 0;
259 do {
260 APPEND_DIGIT(n, ch);
261 ch = *fmt++;
262 } while (is_digit(ch));
263 if (ch == '$') {
264 nextarg = n;
265 if (argtable == nullptr) {
266 argtable = statargtable;
267 if (__find_arguments(fmt0, orgap, &argtable, &argtablesiz) == -1) {
268 ret = -1;
269 goto error;
270 }
271 }
272 goto rflag;
273 }
274 width = n;
275 goto reswitch;
276 case 'L':
277 flags |= LONGDBL;
278 goto rflag;
279 case 'h':
280 if (*fmt == 'h') {
281 fmt++;
282 flags |= CHARINT;
283 } else {
284 flags |= SHORTINT;
285 }
286 goto rflag;
287 case 'j':
288 flags |= MAXINT;
289 goto rflag;
290 case 'l':
291 if (*fmt == 'l') {
292 fmt++;
293 flags |= LLONGINT;
294 } else {
295 flags |= LONGINT;
296 }
297 goto rflag;
298 case 'q':
299 flags |= LLONGINT;
300 goto rflag;
301 case 't':
302 flags |= PTRINT;
303 goto rflag;
304 case 'z':
305 flags |= SIZEINT;
306 goto rflag;
307 case 'C':
308 flags |= LONGINT;
309 __BIONIC_FALLTHROUGH;
310 case 'c':
311 if (flags & LONGINT) {
312 mbstate_t mbs;
313 size_t mbseqlen;
314
315 memset(&mbs, 0, sizeof(mbs));
316 mbseqlen = wcrtomb(buf, (wchar_t)GETARG(wint_t), &mbs);
317 if (mbseqlen == (size_t)-1) {
318 ret = -1;
319 goto error;
320 }
321 cp = buf;
322 size = (int)mbseqlen;
323 } else {
324 *(cp = buf) = GETARG(int);
325 size = 1;
326 }
327 sign = '\0';
328 break;
329 case 'D':
330 flags |= LONGINT;
331 __BIONIC_FALLTHROUGH;
332 case 'd':
333 case 'i':
334 _umax = SARG();
335 if ((intmax_t)_umax < 0) {
336 _umax = -_umax;
337 sign = '-';
338 }
339 base = DEC;
340 goto number;
341 case 'a':
342 case 'A':
343 if (ch == 'a') {
344 ox[1] = 'x';
345 xdigs = xdigs_lower;
346 expchar = 'p';
347 } else {
348 ox[1] = 'X';
349 xdigs = xdigs_upper;
350 expchar = 'P';
351 }
352 if (prec >= 0) prec++;
353 if (dtoaresult) __freedtoa(dtoaresult);
354 if (flags & LONGDBL) {
355 fparg.ldbl = GETARG(long double);
356 dtoaresult = cp = __hldtoa(fparg.ldbl, xdigs, prec, &expt, &signflag, &dtoaend);
357 if (dtoaresult == nullptr) {
358 errno = ENOMEM;
359 goto error;
360 }
361 } else {
362 fparg.dbl = GETARG(double);
363 dtoaresult = cp = __hdtoa(fparg.dbl, xdigs, prec, &expt, &signflag, &dtoaend);
364 if (dtoaresult == nullptr) {
365 errno = ENOMEM;
366 goto error;
367 }
368 }
369 if (prec < 0) prec = dtoaend - dtoaresult;
370 if (expt == INT_MAX) ox[1] = '\0';
371 goto fp_common;
372 case 'e':
373 case 'E':
374 expchar = ch;
375 if (prec < 0) /* account for digit before decpt */
376 prec = DEFPREC + 1;
377 else
378 prec++;
379 goto fp_begin;
380 case 'f':
381 case 'F':
382 expchar = '\0';
383 goto fp_begin;
384 case 'g':
385 case 'G':
386 expchar = ch - ('g' - 'e');
387 if (prec == 0) prec = 1;
388 fp_begin:
389 if (prec < 0) prec = DEFPREC;
390 if (dtoaresult) __freedtoa(dtoaresult);
391 if (flags & LONGDBL) {
392 fparg.ldbl = GETARG(long double);
393 dtoaresult = cp = __ldtoa(&fparg.ldbl, expchar ? 2 : 3, prec, &expt, &signflag, &dtoaend);
394 if (dtoaresult == nullptr) {
395 errno = ENOMEM;
396 goto error;
397 }
398 } else {
399 fparg.dbl = GETARG(double);
400 dtoaresult = cp = __dtoa(fparg.dbl, expchar ? 2 : 3, prec, &expt, &signflag, &dtoaend);
401 if (dtoaresult == nullptr) {
402 errno = ENOMEM;
403 goto error;
404 }
405 if (expt == 9999) expt = INT_MAX;
406 }
407 fp_common:
408 if (signflag) sign = '-';
409 if (expt == INT_MAX) { /* inf or nan */
410 if (*cp == 'N') {
411 cp = const_cast<CHAR_TYPE*>((ch >= 'a') ? CHAR_TYPE_nan : CHAR_TYPE_NAN);
412 } else {
413 cp = const_cast<CHAR_TYPE*>((ch >= 'a') ? CHAR_TYPE_inf : CHAR_TYPE_INF);
414 }
415 size = 3;
416 flags &= ~ZEROPAD;
417 break;
418 }
419 flags |= FPT;
420 ndig = dtoaend - cp;
421 if (ch == 'g' || ch == 'G') {
422 if (expt > -4 && expt <= prec) {
423 /* Make %[gG] smell like %[fF] */
424 expchar = '\0';
425 if (flags & ALT)
426 prec -= expt;
427 else
428 prec = ndig - expt;
429 if (prec < 0) prec = 0;
430 } else {
431 /*
432 * Make %[gG] smell like %[eE], but
433 * trim trailing zeroes if no # flag.
434 */
435 if (!(flags & ALT)) prec = ndig;
436 }
437 }
438 if (expchar) {
439 expsize = exponent(expstr, expt - 1, expchar);
440 size = expsize + prec;
441 if (prec > 1 || flags & ALT) ++size;
442 } else {
443 /* space for digits before decimal point */
444 if (expt > 0)
445 size = expt;
446 else /* "0" */
447 size = 1;
448 /* space for decimal pt and following digits */
449 if (prec || flags & ALT) size += prec + 1;
450 lead = expt;
451 }
452 break;
453 case 'n':
454 __fortify_fatal("%%n not allowed on Android");
455 case 'm':
456 cp = strerror_r(caller_errno, buf, sizeof(buf));
457 goto string;
458 case 'O':
459 flags |= LONGINT;
460 __BIONIC_FALLTHROUGH;
461 case 'o':
462 _umax = UARG();
463 base = OCT;
464 goto nosign;
465 case 'p':
466 /*
467 * ``The argument shall be a pointer to void. The
468 * value of the pointer is converted to a sequence
469 * of printable characters, in an implementation-
470 * defined manner.''
471 * -- ANSI X3J11
472 */
473 _umax = (u_long)GETARG(void*);
474 base = HEX;
475 xdigs = xdigs_lower;
476 ox[1] = 'x';
477 goto nosign;
478 case 'S':
479 flags |= LONGINT;
480 __BIONIC_FALLTHROUGH;
481 case 's':
482 if (flags & LONGINT) {
483 wchar_t* wcp;
484
485 free(convbuf);
486 convbuf = nullptr;
487 if ((wcp = GETARG(wchar_t*)) == nullptr) {
488 cp = const_cast<char*>("(null)");
489 } else {
490 convbuf = helpers::wcsconv(wcp, prec);
491 if (convbuf == nullptr) {
492 ret = -1;
493 goto error;
494 }
495 cp = convbuf;
496 }
497 } else if ((cp = GETARG(char*)) == nullptr) {
498 cp = const_cast<char*>("(null)");
499 }
500 string:
501 if (prec >= 0) {
502 size = CHAR_TYPE_STRNLEN(cp, prec);
503 } else {
504 size_t len;
505
506 if ((len = CHAR_TYPE_STRLEN(cp)) > INT_MAX) goto overflow;
507 size = (int)len;
508 }
509 sign = '\0';
510 break;
511 case 'U':
512 flags |= LONGINT;
513 __BIONIC_FALLTHROUGH;
514 case 'u':
515 _umax = UARG();
516 base = DEC;
517 goto nosign;
518 case 'X':
519 xdigs = xdigs_upper;
520 goto hex;
521 case 'x':
522 xdigs = xdigs_lower;
523 hex:
524 _umax = UARG();
525 base = HEX;
526 /* leading 0x/X only if non-zero */
527 if (flags & ALT && _umax != 0) ox[1] = ch;
528
529 /* unsigned conversions */
530 nosign:
531 sign = '\0';
532 /*
533 * ``... diouXx conversions ... if a precision is
534 * specified, the 0 flag will be ignored.''
535 * -- ANSI X3J11
536 */
537 number:
538 if ((dprec = prec) >= 0) flags &= ~ZEROPAD;
539
540 /*
541 * ``The result of converting a zero value with an
542 * explicit precision of zero is no characters.''
543 * -- ANSI X3J11
544 */
545 cp = buf + BUF;
546 if (_umax != 0 || prec != 0) {
547 /*
548 * Unsigned mod is hard, and unsigned mod
549 * by a constant is easier than that by
550 * a variable; hence this switch.
551 */
552 switch (base) {
553 case OCT:
554 do {
555 *--cp = to_char(_umax & 7);
556 _umax >>= 3;
557 } while (_umax);
558 /* handle octal leading 0 */
559 if (flags & ALT && *cp != '0') *--cp = '0';
560 break;
561
562 case DEC:
563 /* many numbers are 1 digit */
564 while (_umax >= 10) {
565 *--cp = to_char(_umax % 10);
566 _umax /= 10;
567 }
568 *--cp = to_char(_umax);
569 break;
570
571 case HEX:
572 do {
573 *--cp = xdigs[_umax & 15];
574 _umax >>= 4;
575 } while (_umax);
576 break;
577
578 default:
579 abort();
580 }
581 }
582 size = buf + BUF - cp;
583 if (size > BUF) abort(); /* should never happen */
584 break;
585 default: /* "%?" prints ?, unless ? is NUL */
586 if (ch == '\0') goto done;
587 /* pretend it was %c with argument ch */
588 cp = buf;
589 *cp = ch;
590 size = 1;
591 sign = '\0';
592 break;
593 }
594
595 /*
596 * All reasonable formats wind up here. At this point, `cp'
597 * points to a string which (if not flags&LADJUST) should be
598 * padded out to `width' places. If flags&ZEROPAD, it should
599 * first be prefixed by any sign or other prefix; otherwise,
600 * it should be blank padded before the prefix is emitted.
601 * After any left-hand padding and prefixing, emit zeroes
602 * required by a decimal %[diouxX] precision, then print the
603 * string proper, then emit zeroes required by any leftover
604 * floating precision; finally, if LADJUST, pad with blanks.
605 *
606 * Compute actual size, so we know how much to pad.
607 * size excludes decimal prec; realsz includes it.
608 */
609 realsz = dprec > size ? dprec : size;
610 if (sign) realsz++;
611 if (ox[1]) realsz += 2;
612
613 /* right-adjusting blank padding */
614 if ((flags & (LADJUST | ZEROPAD)) == 0) PAD(width - realsz, blanks);
615
616 /* prefix */
617 if (sign) PRINT(&sign, 1);
618 if (ox[1]) { /* ox[1] is either x, X, or \0 */
619 ox[0] = '0';
620 PRINT(ox, 2);
621 }
622
623 /* right-adjusting zero padding */
624 if ((flags & (LADJUST | ZEROPAD)) == ZEROPAD) PAD(width - realsz, zeroes);
625
626 /* leading zeroes from decimal precision */
627 PAD(dprec - size, zeroes);
628
629 /* the string or number proper */
630 if ((flags & FPT) == 0) {
631 PRINT(cp, size);
632 } else { /* glue together f_p fragments */
633 if (decimal_point == nullptr) decimal_point = nl_langinfo(RADIXCHAR);
634 if (!expchar) { /* %[fF] or sufficiently short %[gG] */
635 if (expt <= 0) {
636 PRINT(zeroes, 1);
637 if (prec || flags & ALT) PRINT(decimal_point, 1);
638 PAD(-expt, zeroes);
639 /* already handled initial 0's */
640 prec += expt;
641 } else {
642 PRINTANDPAD(cp, dtoaend, lead, zeroes);
643 cp += lead;
644 if (prec || flags & ALT) PRINT(decimal_point, 1);
645 }
646 PRINTANDPAD(cp, dtoaend, prec, zeroes);
647 } else { /* %[eE] or sufficiently long %[gG] */
648 if (prec > 1 || flags & ALT) {
649 buf[0] = *cp++;
650 buf[1] = *decimal_point;
651 PRINT(buf, 2);
652 PRINT(cp, ndig - 1);
653 PAD(prec - ndig, zeroes);
654 } else { /* XeYYY */
655 PRINT(cp, 1);
656 }
657 PRINT(expstr, expsize);
658 }
659 }
660 /* left-adjusting padding (always blank) */
661 if (flags & LADJUST) PAD(width - realsz, blanks);
662
663 /* finally, adjust ret */
664 if (width < realsz) width = realsz;
665 if (width > INT_MAX - ret) goto overflow;
666 ret += width;
667
668 FLUSH(); /* copy out the I/O vectors */
669 }
670 done:
671 FLUSH();
672 error:
673 va_end(orgap);
674 if (__sferror(fp)) ret = -1;
675 goto finish;
676
677 overflow:
678 errno = ENOMEM;
679 ret = -1;
680
681 finish:
682 free(convbuf);
683 if (dtoaresult) __freedtoa(dtoaresult);
684 if (argtable != nullptr && argtable != statargtable) {
685 munmap(argtable, argtablesiz);
686 argtable = nullptr;
687 }
688 return (ret);
689 }
690