xref: /openbsd-src/lib/libc/stdio/vfprintf.c (revision c672277d09e3f4bb5c33d9382d82ef5de5446d4f)
1 /*-
2  * Copyright (c) 1990 The Regents of the University of California.
3  * All rights reserved.
4  *
5  * This code is derived from software contributed to Berkeley by
6  * Chris Torek.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. Neither the name of the University nor the names of its contributors
17  *    may be used to endorse or promote products derived from this software
18  *    without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  */
32 
33 #if defined(LIBC_SCCS) && !defined(lint)
34 static char *rcsid = "$OpenBSD: vfprintf.c,v 1.23 2004/09/18 19:28:06 otto Exp $";
35 #endif /* LIBC_SCCS and not lint */
36 
37 /*
38  * Actual printf innards.
39  *
40  * This code is large and complicated...
41  */
42 
43 #include <sys/types.h>
44 #include <sys/mman.h>
45 
46 #include <stddef.h>
47 #include <stdio.h>
48 #include <stdlib.h>
49 #include <string.h>
50 #include <errno.h>
51 #include <stdarg.h>
52 
53 #include "local.h"
54 #include "fvwrite.h"
55 
56 static void __find_arguments(const char *fmt0, va_list ap, va_list **argtable,
57     size_t *argtablesiz);
58 static int __grow_type_table(unsigned char **typetable, int *tablesize);
59 
60 /*
61  * Flush out all the vectors defined by the given uio,
62  * then reset it so that it can be reused.
63  */
64 static int
65 __sprint(fp, uio)
66 	FILE *fp;
67 	register struct __suio *uio;
68 {
69 	register int err;
70 
71 	if (uio->uio_resid == 0) {
72 		uio->uio_iovcnt = 0;
73 		return (0);
74 	}
75 	err = __sfvwrite(fp, uio);
76 	uio->uio_resid = 0;
77 	uio->uio_iovcnt = 0;
78 	return (err);
79 }
80 
81 /*
82  * Helper function for `fprintf to unbuffered unix file': creates a
83  * temporary buffer.  We only work on write-only files; this avoids
84  * worries about ungetc buffers and so forth.
85  */
86 static int
87 __sbprintf(fp, fmt, ap)
88 	register FILE *fp;
89 	const char *fmt;
90 	va_list ap;
91 {
92 	int ret;
93 	FILE fake;
94 	unsigned char buf[BUFSIZ];
95 
96 	/* copy the important variables */
97 	fake._flags = fp->_flags & ~__SNBF;
98 	fake._file = fp->_file;
99 	fake._cookie = fp->_cookie;
100 	fake._write = fp->_write;
101 
102 	/* set up the buffer */
103 	fake._bf._base = fake._p = buf;
104 	fake._bf._size = fake._w = sizeof(buf);
105 	fake._lbfsize = 0;	/* not actually used, but Just In Case */
106 
107 	/* do the work, then copy any error status */
108 	ret = vfprintf(&fake, fmt, ap);
109 	if (ret >= 0 && fflush(&fake))
110 		ret = EOF;
111 	if (fake._flags & __SERR)
112 		fp->_flags |= __SERR;
113 	return (ret);
114 }
115 
116 
117 #ifdef FLOATING_POINT
118 #include <locale.h>
119 #include <math.h>
120 #include "floatio.h"
121 
122 #define	BUF		(MAXEXP+MAXFRACT+1)	/* + decimal point */
123 #define	DEFPREC		6
124 
125 static char *cvt(double, int, int, char *, int *, int, int *);
126 static int exponent(char *, int, int);
127 
128 #else /* no FLOATING_POINT */
129 #define	BUF		40
130 #endif /* FLOATING_POINT */
131 
132 #define STATIC_ARG_TBL_SIZE 8	/* Size of static argument table. */
133 
134 
135 /*
136  * Macros for converting digits to letters and vice versa
137  */
138 #define	to_digit(c)	((c) - '0')
139 #define is_digit(c)	((unsigned)to_digit(c) <= 9)
140 #define	to_char(n)	((n) + '0')
141 
142 /*
143  * Flags used during conversion.
144  */
145 #define	ALT		0x001		/* alternate form */
146 #define	HEXPREFIX	0x002		/* add 0x or 0X prefix */
147 #define	LADJUST		0x004		/* left adjustment */
148 #define	LONGDBL		0x008		/* long double; unimplemented */
149 #define	LONGINT		0x010		/* long integer */
150 #define	QUADINT		0x020		/* quad integer */
151 #define	SHORTINT	0x040		/* short integer */
152 #define	ZEROPAD		0x080		/* zero (as opposed to blank) pad */
153 #define FPT		0x100		/* Floating point number */
154 #define PTRINT		0x200		/* (unsigned) ptrdiff_t */
155 #define SIZEINT		0x400		/* (signed) size_t */
156 
157 int
158 vfprintf(fp, fmt0, ap)
159 	FILE *fp;
160 	const char *fmt0;
161 	_BSD_VA_LIST_ ap;
162 {
163 	register char *fmt;	/* format string */
164 	register int ch;	/* character from fmt */
165 	register int n, m, n2;	/* handy integers (short term usage) */
166 	register char *cp;	/* handy char pointer (short term usage) */
167 	register struct __siov *iovp;/* for PRINT macro */
168 	register int flags;	/* flags as above */
169 	int ret;		/* return value accumulator */
170 	int width;		/* width from format (%8d), or 0 */
171 	int prec;		/* precision from format (%.3d), or -1 */
172 	char sign;		/* sign prefix (' ', '+', '-', or \0) */
173 	wchar_t wc;
174 #ifdef FLOATING_POINT
175 	char *decimal_point = localeconv()->decimal_point;
176 	char softsign;		/* temporary negative sign for floats */
177 	double _double;		/* double precision arguments %[eEfgG] */
178 	int expt;		/* integer value of exponent */
179 	int expsize;		/* character count for expstr */
180 	int ndig;		/* actual number of digits returned by cvt */
181 	char expstr[7];		/* buffer for exponent string */
182 #endif
183 
184 #ifdef __GNUC__			/* gcc has builtin quad type (long long) SOS */
185 #define	quad_t	  long long
186 #define	u_quad_t  unsigned long long
187 #endif
188 
189 	u_quad_t _uquad;	/* integer arguments %[diouxX] */
190 	enum { OCT, DEC, HEX } base;/* base for [diouxX] conversion */
191 	int dprec;		/* a copy of prec if [diouxX], 0 otherwise */
192 	int realsz;		/* field size expanded by dprec */
193 	int size;		/* size of converted field or string */
194 	char *xdigs;		/* digits for [xX] conversion */
195 #define NIOV 8
196 	struct __suio uio;	/* output information: summary */
197 	struct __siov iov[NIOV];/* ... and individual io vectors */
198 	char buf[BUF];		/* space for %c, %[diouxX], %[eEfgG] */
199 	char ox[2];		/* space for 0x hex-prefix */
200 	va_list *argtable;	/* args, built due to positional arg */
201 	va_list statargtable[STATIC_ARG_TBL_SIZE];
202 	size_t argtablesiz;
203 	int nextarg;		/* 1-based argument index */
204 	va_list orgap;		/* original argument pointer */
205 
206 	/*
207 	 * Choose PADSIZE to trade efficiency vs. size.  If larger printf
208 	 * fields occur frequently, increase PADSIZE and make the initialisers
209 	 * below longer.
210 	 */
211 #define	PADSIZE	16		/* pad chunk size */
212 	static char blanks[PADSIZE] =
213 	 {' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' '};
214 	static char zeroes[PADSIZE] =
215 	 {'0','0','0','0','0','0','0','0','0','0','0','0','0','0','0','0'};
216 
217 	/*
218 	 * BEWARE, these `goto error' on error, and PAD uses `n'.
219 	 */
220 #define	PRINT(ptr, len) do { \
221 	iovp->iov_base = (ptr); \
222 	iovp->iov_len = (len); \
223 	uio.uio_resid += (len); \
224 	iovp++; \
225 	if (++uio.uio_iovcnt >= NIOV) { \
226 		if (__sprint(fp, &uio)) \
227 			goto error; \
228 		iovp = iov; \
229 	} \
230 } while (0)
231 #define	PAD(howmany, with) do { \
232 	if ((n = (howmany)) > 0) { \
233 		while (n > PADSIZE) { \
234 			PRINT(with, PADSIZE); \
235 			n -= PADSIZE; \
236 		} \
237 		PRINT(with, n); \
238 	} \
239 } while (0)
240 #define	FLUSH() do { \
241 	if (uio.uio_resid && __sprint(fp, &uio)) \
242 		goto error; \
243 	uio.uio_iovcnt = 0; \
244 	iovp = iov; \
245 } while (0)
246 
247 	/*
248 	 * To extend shorts properly, we need both signed and unsigned
249 	 * argument extraction methods.
250 	 */
251 #define	SARG() \
252 	(flags&QUADINT ? va_arg(ap, quad_t) : \
253 	    flags&LONGINT ? GETARG(long) : \
254 	    flags&PTRINT ? GETARG(ptrdiff_t) : \
255 	    flags&SIZEINT ? GETARG(ssize_t) : \
256 	    flags&SHORTINT ? (long)(short)GETARG(int) : \
257 	    (long)GETARG(int))
258 #define	UARG() \
259 	(flags&QUADINT ? va_arg(ap, u_quad_t) : \
260 	    flags&LONGINT ? GETARG(u_long) : \
261 	    flags&PTRINT ? GETARG(ptrdiff_t) : /* XXX */ \
262 	    flags&SIZEINT ? GETARG(size_t) : \
263 	    flags&SHORTINT ? (u_long)(u_short)GETARG(int) : \
264 	    (u_long)GETARG(u_int))
265 
266 	 /*
267 	  * Get * arguments, including the form *nn$.  Preserve the nextarg
268 	  * that the argument can be gotten once the type is determined.
269 	  */
270 #define GETASTER(val) \
271 	n2 = 0; \
272 	cp = fmt; \
273 	while (is_digit(*cp)) { \
274 		n2 = 10 * n2 + to_digit(*cp); \
275 		cp++; \
276 	} \
277 	if (*cp == '$') { \
278 		int hold = nextarg; \
279 		if (argtable == NULL) { \
280 			argtable = statargtable; \
281 			__find_arguments(fmt0, orgap, &argtable, &argtablesiz); \
282 		} \
283 		nextarg = n2; \
284 		val = GETARG(int); \
285 		nextarg = hold; \
286 		fmt = ++cp; \
287 	} else { \
288 		val = GETARG(int); \
289 	}
290 
291 /*
292 * Get the argument indexed by nextarg.   If the argument table is
293 * built, use it to get the argument.  If its not, get the next
294 * argument (and arguments must be gotten sequentially).
295 */
296 #define GETARG(type) \
297 	(((argtable != NULL) ? (void)(ap = argtable[nextarg]) : (void)0), \
298 	 nextarg++, va_arg(ap, type))
299 
300 	/* sorry, fprintf(read_only_file, "") returns EOF, not 0 */
301 	if (cantwrite(fp)) {
302 		errno = EBADF;
303 		return (EOF);
304 	}
305 
306 	/* optimise fprintf(stderr) (and other unbuffered Unix files) */
307 	if ((fp->_flags & (__SNBF|__SWR|__SRW)) == (__SNBF|__SWR) &&
308 	    fp->_file >= 0)
309 		return (__sbprintf(fp, fmt0, ap));
310 
311 	fmt = (char *)fmt0;
312 	argtable = NULL;
313 	nextarg = 1;
314 	va_copy(orgap, ap);
315 	uio.uio_iov = iovp = iov;
316 	uio.uio_resid = 0;
317 	uio.uio_iovcnt = 0;
318 	ret = 0;
319 
320 	/*
321 	 * Scan the format for conversions (`%' character).
322 	 */
323 	for (;;) {
324 		cp = fmt;
325 		while ((n = mbtowc(&wc, fmt, MB_CUR_MAX)) > 0) {
326 			fmt += n;
327 			if (wc == '%') {
328 				fmt--;
329 				break;
330 			}
331 		}
332 		if ((m = fmt - cp) != 0) {
333 			PRINT(cp, m);
334 			ret += m;
335 		}
336 		if (n <= 0)
337 			goto done;
338 		fmt++;		/* skip over '%' */
339 
340 		flags = 0;
341 		dprec = 0;
342 		width = 0;
343 		prec = -1;
344 		sign = '\0';
345 
346 rflag:		ch = *fmt++;
347 reswitch:	switch (ch) {
348 		case ' ':
349 			/*
350 			 * ``If the space and + flags both appear, the space
351 			 * flag will be ignored.''
352 			 *	-- ANSI X3J11
353 			 */
354 			if (!sign)
355 				sign = ' ';
356 			goto rflag;
357 		case '#':
358 			flags |= ALT;
359 			goto rflag;
360 		case '*':
361 			/*
362 			 * ``A negative field width argument is taken as a
363 			 * - flag followed by a positive field width.''
364 			 *	-- ANSI X3J11
365 			 * They don't exclude field widths read from args.
366 			 */
367 			GETASTER(width);
368 			if (width >= 0)
369 				goto rflag;
370 			width = -width;
371 			/* FALLTHROUGH */
372 		case '-':
373 			flags |= LADJUST;
374 			goto rflag;
375 		case '+':
376 			sign = '+';
377 			goto rflag;
378 		case '.':
379 			if ((ch = *fmt++) == '*') {
380 				GETASTER(n);
381 				prec = n < 0 ? -1 : n;
382 				goto rflag;
383 			}
384 			n = 0;
385 			while (is_digit(ch)) {
386 				n = 10 * n + to_digit(ch);
387 				ch = *fmt++;
388 			}
389 			if (ch == '$') {
390 				nextarg = n;
391 				if (argtable == NULL) {
392 					argtable = statargtable;
393 					__find_arguments(fmt0, orgap,
394 					    &argtable, &argtablesiz);
395 				}
396 				goto rflag;
397 			}
398 			prec = n < 0 ? -1 : n;
399 			goto reswitch;
400 		case '0':
401 			/*
402 			 * ``Note that 0 is taken as a flag, not as the
403 			 * beginning of a field width.''
404 			 *	-- ANSI X3J11
405 			 */
406 			flags |= ZEROPAD;
407 			goto rflag;
408 		case '1': case '2': case '3': case '4':
409 		case '5': case '6': case '7': case '8': case '9':
410 			n = 0;
411 			do {
412 				n = 10 * n + to_digit(ch);
413 				ch = *fmt++;
414 			} while (is_digit(ch));
415 			if (ch == '$') {
416 				nextarg = n;
417 				if (argtable == NULL) {
418 					argtable = statargtable;
419 					__find_arguments(fmt0, orgap,
420 					    &argtable, &argtablesiz);
421 				}
422 				goto rflag;
423 			}
424 			width = n;
425 			goto reswitch;
426 #ifdef FLOATING_POINT
427 		case 'L':
428 			flags |= LONGDBL;
429 			goto rflag;
430 #endif
431 		case 'h':
432 			flags |= SHORTINT;
433 			goto rflag;
434 		case 'l':
435 			if (*fmt == 'l') {
436 				fmt++;
437 				flags |= QUADINT;
438 			} else {
439 				flags |= LONGINT;
440 			}
441 			goto rflag;
442 		case 'q':
443 			flags |= QUADINT;
444 			goto rflag;
445 		case 't':
446 			flags |= PTRINT;
447 			goto rflag;
448 		case 'z':
449 			flags |= SIZEINT;
450 			goto rflag;
451 		case 'c':
452 			*(cp = buf) = GETARG(int);
453 			size = 1;
454 			sign = '\0';
455 			break;
456 		case 'D':
457 			flags |= LONGINT;
458 			/*FALLTHROUGH*/
459 		case 'd':
460 		case 'i':
461 			_uquad = SARG();
462 			if ((quad_t)_uquad < 0) {
463 				_uquad = -_uquad;
464 				sign = '-';
465 			}
466 			base = DEC;
467 			goto number;
468 #ifdef FLOATING_POINT
469 		case 'e':
470 		case 'E':
471 		case 'f':
472 		case 'g':
473 		case 'G':
474 			if (prec == -1) {
475 				prec = DEFPREC;
476 			} else if ((ch == 'g' || ch == 'G') && prec == 0) {
477 				prec = 1;
478 			}
479 
480 			if (flags & LONGDBL) {
481 				_double = (double) GETARG(long double);
482 			} else {
483 				_double = GETARG(double);
484 			}
485 
486 			/* do this before tricky precision changes */
487 			if (isinf(_double)) {
488 				if (_double < 0)
489 					sign = '-';
490 				cp = "Inf";
491 				size = 3;
492 				break;
493 			}
494 			if (isnan(_double)) {
495 				cp = "NaN";
496 				size = 3;
497 				break;
498 			}
499 
500 			flags |= FPT;
501 			cp = cvt(_double, prec, flags, &softsign,
502 				&expt, ch, &ndig);
503 			if (ch == 'g' || ch == 'G') {
504 				if (expt <= -4 || expt > prec)
505 					ch = (ch == 'g') ? 'e' : 'E';
506 				else
507 					ch = 'g';
508 			}
509 			if (ch <= 'e') {	/* 'e' or 'E' fmt */
510 				--expt;
511 				expsize = exponent(expstr, expt, ch);
512 				size = expsize + ndig;
513 				if (ndig > 1 || flags & ALT)
514 					++size;
515 			} else if (ch == 'f') {		/* f fmt */
516 				if (expt > 0) {
517 					size = expt;
518 					if (prec || flags & ALT)
519 						size += prec + 1;
520 				} else	/* "0.X" */
521 					size = prec + 2;
522 			} else if (expt >= ndig) {	/* fixed g fmt */
523 				size = expt;
524 				if (flags & ALT)
525 					++size;
526 			} else
527 				size = ndig + (expt > 0 ?
528 					1 : 2 - expt);
529 
530 			if (softsign)
531 				sign = '-';
532 			break;
533 #endif /* FLOATING_POINT */
534 		case 'n':
535 			if (flags & QUADINT)
536 				*GETARG(quad_t *) = ret;
537 			else if (flags & LONGINT)
538 				*GETARG(long *) = ret;
539 			else if (flags & SHORTINT)
540 				*GETARG(short *) = ret;
541 			else if (flags & PTRINT)
542 				*GETARG(ptrdiff_t *) = ret;
543 			else if (flags & SIZEINT)
544 				*GETARG(ssize_t *) = ret;
545 			else
546 				*GETARG(int *) = ret;
547 			continue;	/* no output */
548 		case 'O':
549 			flags |= LONGINT;
550 			/*FALLTHROUGH*/
551 		case 'o':
552 			_uquad = UARG();
553 			base = OCT;
554 			goto nosign;
555 		case 'p':
556 			/*
557 			 * ``The argument shall be a pointer to void.  The
558 			 * value of the pointer is converted to a sequence
559 			 * of printable characters, in an implementation-
560 			 * defined manner.''
561 			 *	-- ANSI X3J11
562 			 */
563 			/* NOSTRICT */
564 			_uquad = (u_long)GETARG(void *);
565 			base = HEX;
566 			xdigs = "0123456789abcdef";
567 			flags |= HEXPREFIX;
568 			ch = 'x';
569 			goto nosign;
570 		case 's':
571 			if ((cp = GETARG(char *)) == NULL)
572 				cp = "(null)";
573 			if (prec >= 0) {
574 				/*
575 				 * can't use strlen; can only look for the
576 				 * NUL in the first `prec' characters, and
577 				 * strlen() will go further.
578 				 */
579 				char *p = memchr(cp, 0, prec);
580 
581 				if (p != NULL) {
582 					size = p - cp;
583 					if (size > prec)
584 						size = prec;
585 				} else
586 					size = prec;
587 			} else
588 				size = strlen(cp);
589 			sign = '\0';
590 			break;
591 		case 'U':
592 			flags |= LONGINT;
593 			/*FALLTHROUGH*/
594 		case 'u':
595 			_uquad = UARG();
596 			base = DEC;
597 			goto nosign;
598 		case 'X':
599 			xdigs = "0123456789ABCDEF";
600 			goto hex;
601 		case 'x':
602 			xdigs = "0123456789abcdef";
603 hex:			_uquad = UARG();
604 			base = HEX;
605 			/* leading 0x/X only if non-zero */
606 			if (flags & ALT && _uquad != 0)
607 				flags |= HEXPREFIX;
608 
609 			/* unsigned conversions */
610 nosign:			sign = '\0';
611 			/*
612 			 * ``... diouXx conversions ... if a precision is
613 			 * specified, the 0 flag will be ignored.''
614 			 *	-- ANSI X3J11
615 			 */
616 number:			if ((dprec = prec) >= 0)
617 				flags &= ~ZEROPAD;
618 
619 			/*
620 			 * ``The result of converting a zero value with an
621 			 * explicit precision of zero is no characters.''
622 			 *	-- ANSI X3J11
623 			 */
624 			cp = buf + BUF;
625 			if (_uquad != 0 || prec != 0) {
626 				/*
627 				 * Unsigned mod is hard, and unsigned mod
628 				 * by a constant is easier than that by
629 				 * a variable; hence this switch.
630 				 */
631 				switch (base) {
632 				case OCT:
633 					do {
634 						*--cp = to_char(_uquad & 7);
635 						_uquad >>= 3;
636 					} while (_uquad);
637 					/* handle octal leading 0 */
638 					if (flags & ALT && *cp != '0')
639 						*--cp = '0';
640 					break;
641 
642 				case DEC:
643 					/* many numbers are 1 digit */
644 					while (_uquad >= 10) {
645 						*--cp = to_char(_uquad % 10);
646 						_uquad /= 10;
647 					}
648 					*--cp = to_char(_uquad);
649 					break;
650 
651 				case HEX:
652 					do {
653 						*--cp = xdigs[_uquad & 15];
654 						_uquad >>= 4;
655 					} while (_uquad);
656 					break;
657 
658 				default:
659 					cp = "bug in vfprintf: bad base";
660 					size = strlen(cp);
661 					goto skipsize;
662 				}
663 			}
664 			size = buf + BUF - cp;
665 		skipsize:
666 			break;
667 		default:	/* "%?" prints ?, unless ? is NUL */
668 			if (ch == '\0')
669 				goto done;
670 			/* pretend it was %c with argument ch */
671 			cp = buf;
672 			*cp = ch;
673 			size = 1;
674 			sign = '\0';
675 			break;
676 		}
677 
678 		/*
679 		 * All reasonable formats wind up here.  At this point, `cp'
680 		 * points to a string which (if not flags&LADJUST) should be
681 		 * padded out to `width' places.  If flags&ZEROPAD, it should
682 		 * first be prefixed by any sign or other prefix; otherwise,
683 		 * it should be blank padded before the prefix is emitted.
684 		 * After any left-hand padding and prefixing, emit zeroes
685 		 * required by a decimal [diouxX] precision, then print the
686 		 * string proper, then emit zeroes required by any leftover
687 		 * floating precision; finally, if LADJUST, pad with blanks.
688 		 *
689 		 * Compute actual size, so we know how much to pad.
690 		 * size excludes decimal prec; realsz includes it.
691 		 */
692 		realsz = dprec > size ? dprec : size;
693 		if (sign)
694 			realsz++;
695 		else if (flags & HEXPREFIX)
696 			realsz+= 2;
697 
698 		/* right-adjusting blank padding */
699 		if ((flags & (LADJUST|ZEROPAD)) == 0)
700 			PAD(width - realsz, blanks);
701 
702 		/* prefix */
703 		if (sign) {
704 			PRINT(&sign, 1);
705 		} else if (flags & HEXPREFIX) {
706 			ox[0] = '0';
707 			ox[1] = ch;
708 			PRINT(ox, 2);
709 		}
710 
711 		/* right-adjusting zero padding */
712 		if ((flags & (LADJUST|ZEROPAD)) == ZEROPAD)
713 			PAD(width - realsz, zeroes);
714 
715 		/* leading zeroes from decimal precision */
716 		PAD(dprec - size, zeroes);
717 
718 		/* the string or number proper */
719 #ifdef FLOATING_POINT
720 		if ((flags & FPT) == 0) {
721 			PRINT(cp, size);
722 		} else {	/* glue together f_p fragments */
723 			if (ch >= 'f') {	/* 'f' or 'g' */
724 				if (_double == 0) {
725 					/* kludge for __dtoa irregularity */
726 					PRINT("0", 1);
727 					if (expt < ndig || (flags & ALT) != 0) {
728 						PRINT(decimal_point, 1);
729 						PAD(ndig - 1, zeroes);
730 					}
731 				} else if (expt <= 0) {
732 					PRINT("0", 1);
733 					PRINT(decimal_point, 1);
734 					PAD(-expt, zeroes);
735 					PRINT(cp, ndig);
736 				} else if (expt >= ndig) {
737 					PRINT(cp, ndig);
738 					PAD(expt - ndig, zeroes);
739 					if (flags & ALT)
740 						PRINT(".", 1);
741 				} else {
742 					PRINT(cp, expt);
743 					cp += expt;
744 					PRINT(".", 1);
745 					PRINT(cp, ndig-expt);
746 				}
747 			} else {	/* 'e' or 'E' */
748 				if (ndig > 1 || flags & ALT) {
749 					ox[0] = *cp++;
750 					ox[1] = '.';
751 					PRINT(ox, 2);
752 					if (_double) {
753 						PRINT(cp, ndig-1);
754 					} else	/* 0.[0..] */
755 						/* __dtoa irregularity */
756 						PAD(ndig - 1, zeroes);
757 				} else	/* XeYYY */
758 					PRINT(cp, 1);
759 				PRINT(expstr, expsize);
760 			}
761 		}
762 #else
763 		PRINT(cp, size);
764 #endif
765 		/* left-adjusting padding (always blank) */
766 		if (flags & LADJUST)
767 			PAD(width - realsz, blanks);
768 
769 		/* finally, adjust ret */
770 		ret += width > realsz ? width : realsz;
771 
772 		FLUSH();	/* copy out the I/O vectors */
773 	}
774 done:
775 	FLUSH();
776 error:
777 	if (argtable != NULL && argtable != statargtable) {
778 		munmap(argtable, argtablesiz);
779 		argtable = NULL;
780 	}
781 	return (__sferror(fp) ? EOF : ret);
782 	/* NOTREACHED */
783 }
784 
785 /*
786  * Type ids for argument type table.
787  */
788 #define T_UNUSED	0
789 #define T_SHORT		1
790 #define T_U_SHORT	2
791 #define TP_SHORT	3
792 #define T_INT		4
793 #define T_U_INT		5
794 #define TP_INT		6
795 #define T_LONG		7
796 #define T_U_LONG	8
797 #define TP_LONG		9
798 #define T_QUAD		10
799 #define T_U_QUAD	11
800 #define TP_QUAD		12
801 #define T_DOUBLE	13
802 #define T_LONG_DOUBLE	14
803 #define TP_CHAR		15
804 #define TP_VOID		16
805 #define T_PTRINT	17
806 #define TP_PTRINT	18
807 #define T_SIZEINT	19
808 #define T_SSIZEINT	20
809 #define TP_SSIZEINT	21
810 
811 /*
812  * Find all arguments when a positional parameter is encountered.  Returns a
813  * table, indexed by argument number, of pointers to each arguments.  The
814  * initial argument table should be an array of STATIC_ARG_TBL_SIZE entries.
815  * It will be replaces with a malloc-ed on if it overflows.
816  */
817 static void
818 __find_arguments(fmt0, ap, argtable, argtablesiz)
819 	const char *fmt0;
820 	va_list ap;
821 	va_list **argtable;
822 	size_t *argtablesiz;
823 {
824 	register char *fmt;	/* format string */
825 	register int ch;	/* character from fmt */
826 	register int n, n2;	/* handy integer (short term usage) */
827 	register char *cp;	/* handy char pointer (short term usage) */
828 	register int flags;	/* flags as above */
829 	unsigned char *typetable; /* table of types */
830 	unsigned char stattypetable[STATIC_ARG_TBL_SIZE];
831 	int tablesize;		/* current size of type table */
832 	int tablemax;		/* largest used index in table */
833 	int nextarg;		/* 1-based argument index */
834 
835 	/*
836 	 * Add an argument type to the table, expanding if necessary.
837 	 */
838 #define ADDTYPE(type) \
839 	((nextarg >= tablesize) ? \
840 		__grow_type_table(&typetable, &tablesize) : 0, \
841 	typetable[nextarg++] = type, \
842 	(nextarg > tablemax) ? tablemax = nextarg : 0)
843 
844 #define	ADDSARG() \
845 	((flags&LONGINT) ? ADDTYPE(T_LONG) : \
846 		((flags&SHORTINT) ? ADDTYPE(T_SHORT) : ADDTYPE(T_INT)))
847 
848 #define	ADDUARG() \
849 	((flags&LONGINT) ? ADDTYPE(T_U_LONG) : \
850 		((flags&SHORTINT) ? ADDTYPE(T_U_SHORT) : ADDTYPE(T_U_INT)))
851 
852 	/*
853 	 * Add * arguments to the type array.
854 	 */
855 #define ADDASTER() \
856 	n2 = 0; \
857 	cp = fmt; \
858 	while (is_digit(*cp)) { \
859 		n2 = 10 * n2 + to_digit(*cp); \
860 		cp++; \
861 	} \
862 	if (*cp == '$') { \
863 		int hold = nextarg; \
864 		nextarg = n2; \
865 		ADDTYPE(T_INT); \
866 		nextarg = hold; \
867 		fmt = ++cp; \
868 	} else { \
869 		ADDTYPE(T_INT); \
870 	}
871 	fmt = (char *)fmt0;
872 	typetable = stattypetable;
873 	tablesize = STATIC_ARG_TBL_SIZE;
874 	tablemax = 0;
875 	nextarg = 1;
876 	memset(typetable, T_UNUSED, STATIC_ARG_TBL_SIZE);
877 
878 	/*
879 	 * Scan the format for conversions (`%' character).
880 	 */
881 	for (;;) {
882 		for (cp = fmt; (ch = *fmt) != '\0' && ch != '%'; fmt++)
883 			/* void */;
884 		if (ch == '\0')
885 			goto done;
886 		fmt++;		/* skip over '%' */
887 
888 		flags = 0;
889 
890 rflag:		ch = *fmt++;
891 reswitch:	switch (ch) {
892 		case ' ':
893 		case '#':
894 			goto rflag;
895 		case '*':
896 			ADDASTER();
897 			goto rflag;
898 		case '-':
899 		case '+':
900 			goto rflag;
901 		case '.':
902 			if ((ch = *fmt++) == '*') {
903 				ADDASTER();
904 				goto rflag;
905 			}
906 			while (is_digit(ch)) {
907 				ch = *fmt++;
908 			}
909 			goto reswitch;
910 		case '0':
911 			goto rflag;
912 		case '1': case '2': case '3': case '4':
913 		case '5': case '6': case '7': case '8': case '9':
914 			n = 0;
915 			do {
916 				n = 10 * n + to_digit(ch);
917 				ch = *fmt++;
918 			} while (is_digit(ch));
919 			if (ch == '$') {
920 				nextarg = n;
921 				goto rflag;
922 			}
923 			goto reswitch;
924 #ifdef FLOATING_POINT
925 		case 'L':
926 			flags |= LONGDBL;
927 			goto rflag;
928 #endif
929 		case 'h':
930 			flags |= SHORTINT;
931 			goto rflag;
932 		case 'l':
933 			if (*fmt == 'l') {
934 				fmt++;
935 				flags |= QUADINT;
936 			} else {
937 				flags |= LONGINT;
938 			}
939 			goto rflag;
940 		case 'q':
941 			flags |= QUADINT;
942 			goto rflag;
943 		case 't':
944 			flags |= PTRINT;
945 			goto rflag;
946 		case 'z':
947 			flags |= SIZEINT;
948 			goto rflag;
949 		case 'c':
950 			ADDTYPE(T_INT);
951 			break;
952 		case 'D':
953 			flags |= LONGINT;
954 			/*FALLTHROUGH*/
955 		case 'd':
956 		case 'i':
957 			if (flags & QUADINT)
958 				ADDTYPE(T_QUAD);
959 			else if (flags & PTRINT)
960 				ADDTYPE(T_PTRINT);
961 			else if (flags & SIZEINT)
962 				ADDTYPE(T_SSIZEINT);
963 			else
964 				ADDSARG();
965 			break;
966 #ifdef FLOATING_POINT
967 		case 'e':
968 		case 'E':
969 		case 'f':
970 		case 'g':
971 		case 'G':
972 			if (flags & LONGDBL)
973 				ADDTYPE(T_LONG_DOUBLE);
974 			else
975 				ADDTYPE(T_DOUBLE);
976 			break;
977 #endif /* FLOATING_POINT */
978 		case 'n':
979 			if (flags & QUADINT)
980 				ADDTYPE(TP_QUAD);
981 			else if (flags & LONGINT)
982 				ADDTYPE(TP_LONG);
983 			else if (flags & SHORTINT)
984 				ADDTYPE(TP_SHORT);
985 			else if (flags & PTRINT)
986 				ADDTYPE(TP_PTRINT);
987 			else if (flags & SIZEINT)
988 				ADDTYPE(TP_SSIZEINT);
989 			else
990 				ADDTYPE(TP_INT);
991 			continue;	/* no output */
992 		case 'O':
993 			flags |= LONGINT;
994 			/*FALLTHROUGH*/
995 		case 'o':
996 			if (flags & QUADINT)
997 				ADDTYPE(T_U_QUAD);
998 			else
999 				ADDUARG();
1000 			break;
1001 		case 'p':
1002 			ADDTYPE(TP_VOID);
1003 			break;
1004 		case 's':
1005 			ADDTYPE(TP_CHAR);
1006 			break;
1007 		case 'U':
1008 			flags |= LONGINT;
1009 			/*FALLTHROUGH*/
1010 		case 'u':
1011 			if (flags & QUADINT)
1012 				ADDTYPE(T_U_QUAD);
1013 			else
1014 				ADDUARG();
1015 			break;
1016 		case 'X':
1017 		case 'x':
1018 			if (flags & QUADINT)
1019 				ADDTYPE(T_U_QUAD);
1020 			else if (flags & PTRINT)
1021 				ADDTYPE(T_PTRINT);
1022 			else if (flags & SIZEINT)
1023 				ADDTYPE(T_SIZEINT);
1024 			else
1025 				ADDUARG();
1026 			break;
1027 		default:	/* "%?" prints ?, unless ? is NUL */
1028 			if (ch == '\0')
1029 				goto done;
1030 			break;
1031 		}
1032 	}
1033 done:
1034 	/*
1035 	 * Build the argument table.
1036 	 */
1037 	if (tablemax >= STATIC_ARG_TBL_SIZE) {
1038 		*argtablesiz = sizeof (va_list) * (tablemax + 1);
1039 		*argtable = (va_list *)mmap(NULL, *argtablesiz,
1040 		    PROT_WRITE|PROT_READ, MAP_ANON|MAP_PRIVATE, -1, 0);
1041 	}
1042 
1043 #if 0
1044 	/* XXX is this required? */
1045 	(*argtable) [0] = NULL;
1046 #endif
1047 	for (n = 1; n <= tablemax; n++) {
1048 		va_copy((*argtable)[n], ap);
1049 		switch (typetable[n]) {
1050 		case T_UNUSED:
1051 			(void) va_arg(ap, int);
1052 			break;
1053 		case T_SHORT:
1054 			(void) va_arg(ap, int);
1055 			break;
1056 		case T_U_SHORT:
1057 			(void) va_arg(ap, int);
1058 			break;
1059 		case TP_SHORT:
1060 			(void) va_arg(ap, short *);
1061 			break;
1062 		case T_INT:
1063 			(void) va_arg(ap, int);
1064 			break;
1065 		case T_U_INT:
1066 			(void) va_arg(ap, unsigned int);
1067 			break;
1068 		case TP_INT:
1069 			(void) va_arg(ap, int *);
1070 			break;
1071 		case T_LONG:
1072 			(void) va_arg(ap, long);
1073 			break;
1074 		case T_U_LONG:
1075 			(void) va_arg(ap, unsigned long);
1076 			break;
1077 		case TP_LONG:
1078 			(void) va_arg(ap, long *);
1079 			break;
1080 		case T_QUAD:
1081 			(void) va_arg(ap, quad_t);
1082 			break;
1083 		case T_U_QUAD:
1084 			(void) va_arg(ap, u_quad_t);
1085 			break;
1086 		case TP_QUAD:
1087 			(void) va_arg(ap, quad_t *);
1088 			break;
1089 		case T_DOUBLE:
1090 			(void) va_arg(ap, double);
1091 			break;
1092 		case T_LONG_DOUBLE:
1093 			(void) va_arg(ap, long double);
1094 			break;
1095 		case TP_CHAR:
1096 			(void) va_arg(ap, char *);
1097 			break;
1098 		case TP_VOID:
1099 			(void) va_arg(ap, void *);
1100 			break;
1101 		case T_PTRINT:
1102 			(void) va_arg(ap, ptrdiff_t);
1103 			break;
1104 		case TP_PTRINT:
1105 			(void) va_arg(ap, ptrdiff_t *);
1106 			break;
1107 		case T_SIZEINT:
1108 			(void) va_arg(ap, size_t);
1109 			break;
1110 		case T_SSIZEINT:
1111 			(void) va_arg(ap, ssize_t);
1112 			break;
1113 		case TP_SSIZEINT:
1114 			(void) va_arg(ap, ssize_t *);
1115 			break;
1116 		}
1117 	}
1118 
1119 	if (typetable != NULL && typetable != stattypetable) {
1120 		munmap(typetable, *argtablesiz);
1121 		typetable = NULL;
1122 	}
1123 }
1124 
1125 /*
1126  * Increase the size of the type table.
1127  */
1128 static int
1129 __grow_type_table(typetable, tablesize)
1130 	unsigned char **typetable;
1131 	int *tablesize;
1132 {
1133 	unsigned char *oldtable = *typetable;
1134 	int newsize = *tablesize * 2;
1135 
1136 	if (*tablesize == STATIC_ARG_TBL_SIZE) {
1137 		*typetable = (unsigned char *)mmap(NULL,
1138 		    sizeof (unsigned char) * newsize, PROT_WRITE|PROT_READ,
1139 		    MAP_ANON|MAP_PRIVATE, -1, 0);
1140 		/* XXX unchecked */
1141 		bcopy(oldtable, *typetable, *tablesize);
1142 	} else {
1143 		unsigned char *new = (unsigned char *)mmap(NULL,
1144 		    sizeof (unsigned char) * newsize, PROT_WRITE|PROT_READ,
1145 		    MAP_ANON|MAP_PRIVATE, -1, 0);
1146 		memmove(new, *typetable, *tablesize);
1147 		munmap(*typetable, *tablesize);
1148 		*typetable = new;
1149 		/* XXX unchecked */
1150 	}
1151 	memset(*typetable + *tablesize, T_UNUSED, (newsize - *tablesize));
1152 
1153 	*tablesize = newsize;
1154 	return(0);
1155 }
1156 
1157 
1158 #ifdef FLOATING_POINT
1159 
1160 extern char *__dtoa(double, int, int, int *, int *, char **);
1161 
1162 static char *
1163 cvt(value, ndigits, flags, sign, decpt, ch, length)
1164 	double value;
1165 	int ndigits, flags, *decpt, ch, *length;
1166 	char *sign;
1167 {
1168 	int mode, dsgn;
1169 	char *digits, *bp, *rve;
1170 
1171 	if (ch == 'f') {
1172 		mode = 3;		/* ndigits after the decimal point */
1173 	} else {
1174 		/* To obtain ndigits after the decimal point for the 'e'
1175 		 * and 'E' formats, round to ndigits + 1 significant
1176 		 * figures.
1177 		 */
1178 		if (ch == 'e' || ch == 'E') {
1179 			ndigits++;
1180 		}
1181 		mode = 2;		/* ndigits significant digits */
1182 	}
1183 
1184 	if (value < 0) {
1185 		value = -value;
1186 		*sign = '-';
1187 	} else
1188 		*sign = '\000';
1189 	digits = __dtoa(value, mode, ndigits, decpt, &dsgn, &rve);
1190 	if ((ch != 'g' && ch != 'G') || flags & ALT) {	/* Print trailing zeros */
1191 		bp = digits + ndigits;
1192 		if (ch == 'f') {
1193 			if (*digits == '0' && value)
1194 				*decpt = -ndigits + 1;
1195 			bp += *decpt;
1196 		}
1197 		if (value == 0)	/* kludge for __dtoa irregularity */
1198 			rve = bp;
1199 		while (rve < bp)
1200 			*rve++ = '0';
1201 	}
1202 	*length = rve - digits;
1203 	return (digits);
1204 }
1205 
1206 static int
1207 exponent(p0, exp, fmtch)
1208 	char *p0;
1209 	int exp, fmtch;
1210 {
1211 	register char *p, *t;
1212 	char expbuf[MAXEXP];
1213 
1214 	p = p0;
1215 	*p++ = fmtch;
1216 	if (exp < 0) {
1217 		exp = -exp;
1218 		*p++ = '-';
1219 	}
1220 	else
1221 		*p++ = '+';
1222 	t = expbuf + MAXEXP;
1223 	if (exp > 9) {
1224 		do {
1225 			*--t = to_char(exp % 10);
1226 		} while ((exp /= 10) > 9);
1227 		*--t = to_char(exp);
1228 		for (; t < expbuf + MAXEXP; *p++ = *t++);
1229 	}
1230 	else {
1231 		*p++ = '0';
1232 		*p++ = to_char(exp);
1233 	}
1234 	return (p - p0);
1235 }
1236 #endif /* FLOATING_POINT */
1237