xref: /dflybsd-src/lib/libc/stdio/vfprintf.c (revision 984263bcb83ad82313113c6ac840d99124d8f90c)
1 /*-
2  * Copyright (c) 1990, 1993
3  *	The Regents of the University of California.  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. All advertising materials mentioning features or use of this software
17  *    must display the following acknowledgement:
18  *	This product includes software developed by the University of
19  *	California, Berkeley and its contributors.
20  * 4. Neither the name of the University nor the names of its contributors
21  *    may be used to endorse or promote products derived from this software
22  *    without specific prior written permission.
23  *
24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34  * SUCH DAMAGE.
35  */
36 
37 #if defined(LIBC_SCCS) && !defined(lint)
38 #if 0
39 static char sccsid[] = "@(#)vfprintf.c	8.1 (Berkeley) 6/4/93";
40 #endif
41 static const char rcsid[] =
42   "$FreeBSD: src/lib/libc/stdio/vfprintf.c,v 1.22.2.5 2002/10/12 10:46:37 schweikh Exp $";
43 #endif /* LIBC_SCCS and not lint */
44 
45 /*
46  * Actual printf innards.
47  *
48  * This code is large and complicated...
49  */
50 
51 #include <sys/types.h>
52 
53 #include <limits.h>
54 #include <stdio.h>
55 #include <stdlib.h>
56 #include <string.h>
57 
58 #if __STDC__
59 #include <stdarg.h>
60 #else
61 #include <varargs.h>
62 #endif
63 
64 #include "libc_private.h"
65 #include "local.h"
66 #include "fvwrite.h"
67 
68 /* Define FLOATING_POINT to get floating point. */
69 #define	FLOATING_POINT
70 
71 static int	__sprint __P((FILE *, struct __suio *));
72 static int	__sbprintf __P((FILE *, const char *, va_list));
73 static char *	__ultoa __P((u_long, char *, int, int, char *));
74 static char *	__uqtoa __P((u_quad_t, char *, int, int, char *));
75 static void	__find_arguments __P((const char *, va_list, void ***));
76 static void	__grow_type_table __P((int, unsigned char **, int *));
77 
78 /*
79  * Flush out all the vectors defined by the given uio,
80  * then reset it so that it can be reused.
81  */
82 static int
83 __sprint(FILE *fp, struct __suio *uio)
84 {
85 	int err;
86 
87 	if (uio->uio_resid == 0) {
88 		uio->uio_iovcnt = 0;
89 		return (0);
90 	}
91 	err = __sfvwrite(fp, uio);
92 	uio->uio_resid = 0;
93 	uio->uio_iovcnt = 0;
94 	return (err);
95 }
96 
97 /*
98  * Helper function for `fprintf to unbuffered unix file': creates a
99  * temporary buffer.  We only work on write-only files; this avoids
100  * worries about ungetc buffers and so forth.
101  */
102 static int
103 __sbprintf(FILE *fp, const char *fmt, va_list ap)
104 {
105 	int ret;
106 	FILE fake;
107 	unsigned char buf[BUFSIZ];
108 
109 	/* copy the important variables */
110 	fake._flags = fp->_flags & ~__SNBF;
111 	fake._file = fp->_file;
112 	fake._cookie = fp->_cookie;
113 	fake._write = fp->_write;
114 
115 	/* set up the buffer */
116 	fake._bf._base = fake._p = buf;
117 	fake._bf._size = fake._w = sizeof(buf);
118 	fake._lbfsize = 0;	/* not actually used, but Just In Case */
119 
120 	/* do the work, then copy any error status */
121 	ret = vfprintf(&fake, fmt, ap);
122 	if (ret >= 0 && fflush(&fake))
123 		ret = EOF;
124 	if (fake._flags & __SERR)
125 		fp->_flags |= __SERR;
126 	return (ret);
127 }
128 
129 /*
130  * Macros for converting digits to letters and vice versa
131  */
132 #define	to_digit(c)	((c) - '0')
133 #define is_digit(c)	((unsigned)to_digit(c) <= 9)
134 #define	to_char(n)	((n) + '0')
135 
136 /*
137  * Convert an unsigned long to ASCII for printf purposes, returning
138  * a pointer to the first character of the string representation.
139  * Octal numbers can be forced to have a leading zero; hex numbers
140  * use the given digits.
141  */
142 static char *
143 __ultoa(u_long val, char *endp, int base, int octzero, char *xdigs)
144 {
145 	register char *cp = endp;
146 	register long sval;
147 
148 	/*
149 	 * Handle the three cases separately, in the hope of getting
150 	 * better/faster code.
151 	 */
152 	switch (base) {
153 	case 10:
154 		if (val < 10) {	/* many numbers are 1 digit */
155 			*--cp = to_char(val);
156 			return (cp);
157 		}
158 		/*
159 		 * On many machines, unsigned arithmetic is harder than
160 		 * signed arithmetic, so we do at most one unsigned mod and
161 		 * divide; this is sufficient to reduce the range of
162 		 * the incoming value to where signed arithmetic works.
163 		 */
164 		if (val > LONG_MAX) {
165 			*--cp = to_char(val % 10);
166 			sval = val / 10;
167 		} else
168 			sval = val;
169 		do {
170 			*--cp = to_char(sval % 10);
171 			sval /= 10;
172 		} while (sval != 0);
173 		break;
174 
175 	case 8:
176 		do {
177 			*--cp = to_char(val & 7);
178 			val >>= 3;
179 		} while (val);
180 		if (octzero && *cp != '0')
181 			*--cp = '0';
182 		break;
183 
184 	case 16:
185 		do {
186 			*--cp = xdigs[val & 15];
187 			val >>= 4;
188 		} while (val);
189 		break;
190 
191 	default:			/* oops */
192 		abort();
193 	}
194 	return (cp);
195 }
196 
197 /* Identical to __ultoa, but for quads. */
198 static char *
199 __uqtoa(u_quad_t val, char *endp, int base, int octzero, char *xdigs)
200 {
201 	char *cp = endp;
202 	quad_t sval;
203 
204 	/* quick test for small values; __ultoa is typically much faster */
205 	/* (perhaps instead we should run until small, then call __ultoa?) */
206 	if (val <= ULONG_MAX)
207 		return (__ultoa((u_long)val, endp, base, octzero, xdigs));
208 	switch (base) {
209 	case 10:
210 		if (val < 10) {
211 			*--cp = to_char(val % 10);
212 			return (cp);
213 		}
214 		if (val > QUAD_MAX) {
215 			*--cp = to_char(val % 10);
216 			sval = val / 10;
217 		} else
218 			sval = val;
219 		do {
220 			*--cp = to_char(sval % 10);
221 			sval /= 10;
222 		} while (sval != 0);
223 		break;
224 
225 	case 8:
226 		do {
227 			*--cp = to_char(val & 7);
228 			val >>= 3;
229 		} while (val);
230 		if (octzero && *cp != '0')
231 			*--cp = '0';
232 		break;
233 
234 	case 16:
235 		do {
236 			*--cp = xdigs[val & 15];
237 			val >>= 4;
238 		} while (val);
239 		break;
240 
241 	default:
242 		abort();
243 	}
244 	return (cp);
245 }
246 
247 #ifdef FLOATING_POINT
248 #include <locale.h>
249 #include <math.h>
250 #include "floatio.h"
251 
252 #define	BUF		(MAXEXP+MAXFRACT+1)	/* + decimal point */
253 #define	DEFPREC		6
254 
255 static char *cvt __P((double, int, int, char *, int *, int, int *, char **));
256 static int exponent __P((char *, int, int));
257 
258 #else /* no FLOATING_POINT */
259 
260 #define	BUF		68
261 
262 #endif /* FLOATING_POINT */
263 
264 #define STATIC_ARG_TBL_SIZE 8           /* Size of static argument table. */
265 
266 /*
267  * Flags used during conversion.
268  */
269 #define	ALT		0x001		/* alternate form */
270 #define	HEXPREFIX	0x002		/* add 0x or 0X prefix */
271 #define	LADJUST		0x004		/* left adjustment */
272 #define	LONGDBL		0x008		/* long double */
273 #define	LONGINT		0x010		/* long integer */
274 #define	QUADINT		0x020		/* quad integer */
275 #define	SHORTINT	0x040		/* short integer */
276 #define	ZEROPAD		0x080		/* zero (as opposed to blank) pad */
277 #define FPT		0x100		/* Floating point number */
278 int
279 vfprintf(FILE *fp, const char *fmt0, va_list ap)
280 {
281 	char *fmt;		/* format string */
282 	int ch;			/* character from fmt */
283 	int n, n2;		/* handy integer (short term usage) */
284 	char *cp;		/* handy char pointer (short term usage) */
285 	struct __siov *iovp;	/* for PRINT macro */
286 	int flags;		/* flags as above */
287 	int ret;		/* return value accumulator */
288 	int width;		/* width from format (%8d), or 0 */
289 	int prec;		/* precision from format (%.3d), or -1 */
290 	char sign;		/* sign prefix (' ', '+', '-', or \0) */
291 #ifdef FLOATING_POINT
292 	char *decimal_point = localeconv()->decimal_point;
293 	char softsign;		/* temporary negative sign for floats */
294 	double _double;		/* double precision arguments %[eEfgG] */
295 	int expt;		/* integer value of exponent */
296 	int expsize;		/* character count for expstr */
297 	int ndig;		/* actual number of digits returned by cvt */
298 	char expstr[7];		/* buffer for exponent string */
299 	char *dtoaresult;	/* buffer allocated by dtoa */
300 #endif
301 	u_long	ulval;		/* integer arguments %[diouxX] */
302 	u_quad_t uqval;		/* %q integers */
303 	int base;		/* base for [diouxX] conversion */
304 	int dprec;		/* a copy of prec if [diouxX], 0 otherwise */
305 	int realsz;		/* field size expanded by dprec, sign, etc */
306 	int size;		/* size of converted field or string */
307 	int prsize;             /* max size of printed field */
308 	char *xdigs;		/* digits for [xX] conversion */
309 #define NIOV 8
310 	struct __suio uio;	/* output information: summary */
311 	struct __siov iov[NIOV];/* ... and individual io vectors */
312 	char buf[BUF];		/* space for %c, %[diouxX], %[eEfgG] */
313 	char ox[2];		/* space for 0x hex-prefix */
314         void **argtable;        /* args, built due to positional arg */
315         void *statargtable [STATIC_ARG_TBL_SIZE];
316         int nextarg;            /* 1-based argument index */
317         va_list orgap;          /* original argument pointer */
318 
319 	/*
320 	 * Choose PADSIZE to trade efficiency vs. size.  If larger printf
321 	 * fields occur frequently, increase PADSIZE and make the initialisers
322 	 * below longer.
323 	 */
324 #define	PADSIZE	16		/* pad chunk size */
325 	static char blanks[PADSIZE] =
326 	 {' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' '};
327 	static char zeroes[PADSIZE] =
328 	 {'0','0','0','0','0','0','0','0','0','0','0','0','0','0','0','0'};
329 
330 	/*
331 	 * BEWARE, these `goto error' on error, and PAD uses `n'.
332 	 */
333 #define	PRINT(ptr, len) { \
334 	iovp->iov_base = (ptr); \
335 	iovp->iov_len = (len); \
336 	uio.uio_resid += (len); \
337 	iovp++; \
338 	if (++uio.uio_iovcnt >= NIOV) { \
339 		if (__sprint(fp, &uio)) \
340 			goto error; \
341 		iovp = iov; \
342 	} \
343 }
344 #define	PAD(howmany, with) { \
345 	if ((n = (howmany)) > 0) { \
346 		while (n > PADSIZE) { \
347 			PRINT(with, PADSIZE); \
348 			n -= PADSIZE; \
349 		} \
350 		PRINT(with, n); \
351 	} \
352 }
353 #define	FLUSH() { \
354 	if (uio.uio_resid && __sprint(fp, &uio)) \
355 		goto error; \
356 	uio.uio_iovcnt = 0; \
357 	iovp = iov; \
358 }
359 
360         /*
361          * Get the argument indexed by nextarg.   If the argument table is
362          * built, use it to get the argument.  If its not, get the next
363          * argument (and arguments must be gotten sequentially).
364          */
365 #define GETARG(type) \
366         ((argtable != NULL) ? *((type*)(argtable[nextarg++])) : \
367             (nextarg++, va_arg(ap, type)))
368 
369 	/*
370 	 * To extend shorts properly, we need both signed and unsigned
371 	 * argument extraction methods.
372 	 */
373 #define	SARG() \
374 	(flags&LONGINT ? GETARG(long) : \
375 	    flags&SHORTINT ? (long)(short)GETARG(int) : \
376 	    (long)GETARG(int))
377 #define	UARG() \
378 	(flags&LONGINT ? GETARG(u_long) : \
379 	    flags&SHORTINT ? (u_long)(u_short)GETARG(int) : \
380 	    (u_long)GETARG(u_int))
381 
382         /*
383          * Get * arguments, including the form *nn$.  Preserve the nextarg
384          * that the argument can be gotten once the type is determined.
385          */
386 #define GETASTER(val) \
387         n2 = 0; \
388         cp = fmt; \
389         while (is_digit(*cp)) { \
390                 n2 = 10 * n2 + to_digit(*cp); \
391                 cp++; \
392         } \
393         if (*cp == '$') { \
394             	int hold = nextarg; \
395                 if (argtable == NULL) { \
396                         argtable = statargtable; \
397                         __find_arguments (fmt0, orgap, &argtable); \
398                 } \
399                 nextarg = n2; \
400                 val = GETARG (int); \
401                 nextarg = hold; \
402                 fmt = ++cp; \
403         } else { \
404 		val = GETARG (int); \
405         }
406 
407 
408 #ifdef FLOATING_POINT
409 	dtoaresult = NULL;
410 #endif
411 	FLOCKFILE(fp);
412 	/* sorry, fprintf(read_only_file, "") returns EOF, not 0 */
413 	if (cantwrite(fp)) {
414 		FUNLOCKFILE(fp);
415 		return (EOF);
416 	}
417 
418 	/* optimise fprintf(stderr) (and other unbuffered Unix files) */
419 	if ((fp->_flags & (__SNBF|__SWR|__SRW)) == (__SNBF|__SWR) &&
420 	    fp->_file >= 0) {
421 		FUNLOCKFILE(fp);
422 		return (__sbprintf(fp, fmt0, ap));
423 	}
424 
425 	fmt = (char *)fmt0;
426         argtable = NULL;
427         nextarg = 1;
428         orgap = ap;
429 	uio.uio_iov = iovp = iov;
430 	uio.uio_resid = 0;
431 	uio.uio_iovcnt = 0;
432 	ret = 0;
433 
434 	/*
435 	 * Scan the format for conversions (`%' character).
436 	 */
437 	for (;;) {
438 		for (cp = fmt; (ch = *fmt) != '\0' && ch != '%'; fmt++)
439 			/* void */;
440 		if ((n = fmt - cp) != 0) {
441 			if ((unsigned)ret + n > INT_MAX) {
442 				ret = EOF;
443 				goto error;
444 			}
445 			PRINT(cp, n);
446 			ret += n;
447 		}
448 		if (ch == '\0')
449 			goto done;
450 		fmt++;		/* skip over '%' */
451 
452 		flags = 0;
453 		dprec = 0;
454 		width = 0;
455 		prec = -1;
456 		sign = '\0';
457 
458 rflag:		ch = *fmt++;
459 reswitch:	switch (ch) {
460 		case ' ':
461 			/*
462 			 * ``If the space and + flags both appear, the space
463 			 * flag will be ignored.''
464 			 *	-- ANSI X3J11
465 			 */
466 			if (!sign)
467 				sign = ' ';
468 			goto rflag;
469 		case '#':
470 			flags |= ALT;
471 			goto rflag;
472 		case '*':
473 			/*
474 			 * ``A negative field width argument is taken as a
475 			 * - flag followed by a positive field width.''
476 			 *	-- ANSI X3J11
477 			 * They don't exclude field widths read from args.
478 			 */
479 			GETASTER (width);
480 			if (width >= 0)
481 				goto rflag;
482 			width = -width;
483 			/* FALLTHROUGH */
484 		case '-':
485 			flags |= LADJUST;
486 			goto rflag;
487 		case '+':
488 			sign = '+';
489 			goto rflag;
490 		case '.':
491 			if ((ch = *fmt++) == '*') {
492 				GETASTER (n);
493 				prec = n < 0 ? -1 : n;
494 				goto rflag;
495 			}
496 			n = 0;
497 			while (is_digit(ch)) {
498 				n = 10 * n + to_digit(ch);
499 				ch = *fmt++;
500 			}
501 			prec = n < 0 ? -1 : n;
502 			goto reswitch;
503 		case '0':
504 			/*
505 			 * ``Note that 0 is taken as a flag, not as the
506 			 * beginning of a field width.''
507 			 *	-- ANSI X3J11
508 			 */
509 			flags |= ZEROPAD;
510 			goto rflag;
511 		case '1': case '2': case '3': case '4':
512 		case '5': case '6': case '7': case '8': case '9':
513 			n = 0;
514 			do {
515 				n = 10 * n + to_digit(ch);
516 				ch = *fmt++;
517 			} while (is_digit(ch));
518 			if (ch == '$') {
519 				nextarg = n;
520                         	if (argtable == NULL) {
521                                 	argtable = statargtable;
522                                 	__find_arguments (fmt0, orgap,
523 						&argtable);
524 				}
525 				goto rflag;
526                         }
527 			width = n;
528 			goto reswitch;
529 #ifdef FLOATING_POINT
530 		case 'L':
531 			flags |= LONGDBL;
532 			goto rflag;
533 #endif
534 		case 'h':
535 			flags |= SHORTINT;
536 			goto rflag;
537 		case 'l':
538 			if (flags & LONGINT)
539 				flags |= QUADINT;
540 			else
541 				flags |= LONGINT;
542 			goto rflag;
543 		case 'q':
544 			flags |= QUADINT;
545 			goto rflag;
546 		case 'c':
547 			*(cp = buf) = GETARG(int);
548 			size = 1;
549 			sign = '\0';
550 			break;
551 		case 'D':
552 			flags |= LONGINT;
553 			/*FALLTHROUGH*/
554 		case 'd':
555 		case 'i':
556 			if (flags & QUADINT) {
557 				uqval = GETARG(quad_t);
558 				if ((quad_t)uqval < 0) {
559 					uqval = -uqval;
560 					sign = '-';
561 				}
562 			} else {
563 				ulval = SARG();
564 				if ((long)ulval < 0) {
565 					ulval = -ulval;
566 					sign = '-';
567 				}
568 			}
569 			base = 10;
570 			goto number;
571 #ifdef FLOATING_POINT
572 		case 'e':
573 		case 'E':
574 		case 'f':
575 			goto fp_begin;
576 		case 'g':
577 		case 'G':
578 			if (prec == 0)
579 				prec = 1;
580 fp_begin:		if (prec == -1)
581 				prec = DEFPREC;
582 			if (flags & LONGDBL)
583 				/* XXX this loses precision. */
584 				_double = (double)GETARG(long double);
585 			else
586 				_double = GETARG(double);
587 			/* do this before tricky precision changes */
588 			if (isinf(_double)) {
589 				if (_double < 0)
590 					sign = '-';
591 				cp = "Inf";
592 				size = 3;
593 				break;
594 			}
595 			if (isnan(_double)) {
596 				cp = "NaN";
597 				size = 3;
598 				break;
599 			}
600 			flags |= FPT;
601 			if (dtoaresult != NULL) {
602 				free(dtoaresult);
603 				dtoaresult = NULL;
604 			}
605 			cp = cvt(_double, prec, flags, &softsign,
606 				&expt, ch, &ndig, &dtoaresult);
607 			if (ch == 'g' || ch == 'G') {
608 				if (expt <= -4 || expt > prec)
609 					ch = (ch == 'g') ? 'e' : 'E';
610 				else
611 					ch = 'g';
612 			}
613 			if (ch <= 'e') {	/* 'e' or 'E' fmt */
614 				--expt;
615 				expsize = exponent(expstr, expt, ch);
616 				size = expsize + ndig;
617 				if (ndig > 1 || flags & ALT)
618 					++size;
619 			} else if (ch == 'f') {		/* f fmt */
620 				if (expt > 0) {
621 					size = expt;
622 					if (prec || flags & ALT)
623 						size += prec + 1;
624 				} else	/* "0.X" */
625 					size = prec + 2;
626 			} else if (expt >= ndig) {	/* fixed g fmt */
627 				size = expt;
628 				if (flags & ALT)
629 					++size;
630 			} else
631 				size = ndig + (expt > 0 ?
632 					1 : 2 - expt);
633 
634 			if (softsign)
635 				sign = '-';
636 			break;
637 #endif /* FLOATING_POINT */
638 		case 'n':
639 			if (flags & QUADINT)
640 				*GETARG(quad_t *) = ret;
641 			else if (flags & LONGINT)
642 				*GETARG(long *) = ret;
643 			else if (flags & SHORTINT)
644 				*GETARG(short *) = ret;
645 			else
646 				*GETARG(int *) = ret;
647 			continue;	/* no output */
648 		case 'O':
649 			flags |= LONGINT;
650 			/*FALLTHROUGH*/
651 		case 'o':
652 			if (flags & QUADINT)
653 				uqval = GETARG(u_quad_t);
654 			else
655 				ulval = UARG();
656 			base = 8;
657 			goto nosign;
658 		case 'p':
659 			/*
660 			 * ``The argument shall be a pointer to void.  The
661 			 * value of the pointer is converted to a sequence
662 			 * of printable characters, in an implementation-
663 			 * defined manner.''
664 			 *	-- ANSI X3J11
665 			 */
666 			ulval = (u_long)GETARG(void *);
667 			base = 16;
668 			xdigs = "0123456789abcdef";
669 			flags = (flags & ~QUADINT) | HEXPREFIX;
670 			ch = 'x';
671 			goto nosign;
672 		case 's':
673 			if ((cp = GETARG(char *)) == NULL)
674 				cp = "(null)";
675 			if (prec >= 0) {
676 				/*
677 				 * can't use strlen; can only look for the
678 				 * NUL in the first `prec' characters, and
679 				 * strlen() will go further.
680 				 */
681 				char *p = memchr(cp, 0, (size_t)prec);
682 
683 				if (p != NULL) {
684 					size = p - cp;
685 					if (size > prec)
686 						size = prec;
687 				} else
688 					size = prec;
689 			} else
690 				size = strlen(cp);
691 			sign = '\0';
692 			break;
693 		case 'U':
694 			flags |= LONGINT;
695 			/*FALLTHROUGH*/
696 		case 'u':
697 			if (flags & QUADINT)
698 				uqval = GETARG(u_quad_t);
699 			else
700 				ulval = UARG();
701 			base = 10;
702 			goto nosign;
703 		case 'X':
704 			xdigs = "0123456789ABCDEF";
705 			goto hex;
706 		case 'x':
707 			xdigs = "0123456789abcdef";
708 hex:			if (flags & QUADINT)
709 				uqval = GETARG(u_quad_t);
710 			else
711 				ulval = UARG();
712 			base = 16;
713 			/* leading 0x/X only if non-zero */
714 			if (flags & ALT &&
715 			    (flags & QUADINT ? uqval != 0 : ulval != 0))
716 				flags |= HEXPREFIX;
717 
718 			/* unsigned conversions */
719 nosign:			sign = '\0';
720 			/*
721 			 * ``... diouXx conversions ... if a precision is
722 			 * specified, the 0 flag will be ignored.''
723 			 *	-- ANSI X3J11
724 			 */
725 number:			if ((dprec = prec) >= 0)
726 				flags &= ~ZEROPAD;
727 
728 			/*
729 			 * ``The result of converting a zero value with an
730 			 * explicit precision of zero is no characters.''
731 			 *	-- ANSI X3J11
732 			 */
733 			cp = buf + BUF;
734 			if (flags & QUADINT) {
735 				if (uqval != 0 || prec != 0)
736 					cp = __uqtoa(uqval, cp, base,
737 					    flags & ALT, xdigs);
738 			} else {
739 				if (ulval != 0 || prec != 0)
740 					cp = __ultoa(ulval, cp, base,
741 					    flags & ALT, xdigs);
742 			}
743 			size = buf + BUF - cp;
744 			break;
745 		default:	/* "%?" prints ?, unless ? is NUL */
746 			if (ch == '\0')
747 				goto done;
748 			/* pretend it was %c with argument ch */
749 			cp = buf;
750 			*cp = ch;
751 			size = 1;
752 			sign = '\0';
753 			break;
754 		}
755 
756 		/*
757 		 * All reasonable formats wind up here.  At this point, `cp'
758 		 * points to a string which (if not flags&LADJUST) should be
759 		 * padded out to `width' places.  If flags&ZEROPAD, it should
760 		 * first be prefixed by any sign or other prefix; otherwise,
761 		 * it should be blank padded before the prefix is emitted.
762 		 * After any left-hand padding and prefixing, emit zeroes
763 		 * required by a decimal [diouxX] precision, then print the
764 		 * string proper, then emit zeroes required by any leftover
765 		 * floating precision; finally, if LADJUST, pad with blanks.
766 		 *
767 		 * Compute actual size, so we know how much to pad.
768 		 * size excludes decimal prec; realsz includes it.
769 		 */
770 		realsz = dprec > size ? dprec : size;
771 		if (sign)
772 			realsz++;
773 		else if (flags & HEXPREFIX)
774 			realsz += 2;
775 
776 		prsize = width > realsz ? width : realsz;
777 		if ((unsigned)ret + prsize > INT_MAX) {
778 			ret = EOF;
779 			goto error;
780 		}
781 
782 		/* right-adjusting blank padding */
783 		if ((flags & (LADJUST|ZEROPAD)) == 0)
784 			PAD(width - realsz, blanks);
785 
786 		/* prefix */
787 		if (sign) {
788 			PRINT(&sign, 1);
789 		} else if (flags & HEXPREFIX) {
790 			ox[0] = '0';
791 			ox[1] = ch;
792 			PRINT(ox, 2);
793 		}
794 
795 		/* right-adjusting zero padding */
796 		if ((flags & (LADJUST|ZEROPAD)) == ZEROPAD)
797 			PAD(width - realsz, zeroes);
798 
799 		/* leading zeroes from decimal precision */
800 		PAD(dprec - size, zeroes);
801 
802 		/* the string or number proper */
803 #ifdef FLOATING_POINT
804 		if ((flags & FPT) == 0) {
805 			PRINT(cp, size);
806 		} else {	/* glue together f_p fragments */
807 			if (ch >= 'f') {	/* 'f' or 'g' */
808 				if (_double == 0) {
809 					/* kludge for __dtoa irregularity */
810 					PRINT("0", 1);
811 					if (expt < ndig || (flags & ALT) != 0) {
812 						PRINT(decimal_point, 1);
813 						PAD(ndig - 1, zeroes);
814 					}
815 				} else if (expt <= 0) {
816 					PRINT("0", 1);
817 					PRINT(decimal_point, 1);
818 					PAD(-expt, zeroes);
819 					PRINT(cp, ndig);
820 				} else if (expt >= ndig) {
821 					PRINT(cp, ndig);
822 					PAD(expt - ndig, zeroes);
823 					if (flags & ALT)
824 						PRINT(decimal_point, 1);
825 				} else {
826 					PRINT(cp, expt);
827 					cp += expt;
828 					PRINT(decimal_point, 1);
829 					PRINT(cp, ndig-expt);
830 				}
831 			} else {	/* 'e' or 'E' */
832 				if (ndig > 1 || flags & ALT) {
833 					ox[0] = *cp++;
834 					ox[1] = *decimal_point;
835 					PRINT(ox, 2);
836 					if (_double) {
837 						PRINT(cp, ndig-1);
838 					} else	/* 0.[0..] */
839 						/* __dtoa irregularity */
840 						PAD(ndig - 1, zeroes);
841 				} else	/* XeYYY */
842 					PRINT(cp, 1);
843 				PRINT(expstr, expsize);
844 			}
845 		}
846 #else
847 		PRINT(cp, size);
848 #endif
849 		/* left-adjusting padding (always blank) */
850 		if (flags & LADJUST)
851 			PAD(width - realsz, blanks);
852 
853 		/* finally, adjust ret */
854 		ret += prsize;
855 
856 		FLUSH();	/* copy out the I/O vectors */
857 	}
858 done:
859 	FLUSH();
860 error:
861 #ifdef FLOATING_POINT
862 	if (dtoaresult != NULL)
863 		free(dtoaresult);
864 #endif
865 	if (__sferror(fp))
866 		ret = EOF;
867 	FUNLOCKFILE(fp);
868         if ((argtable != NULL) && (argtable != statargtable))
869                 free (argtable);
870 	return (ret);
871 	/* NOTREACHED */
872 }
873 
874 /*
875  * Type ids for argument type table.
876  */
877 #define T_UNUSED	0
878 #define T_SHORT		1
879 #define T_U_SHORT	2
880 #define TP_SHORT	3
881 #define T_INT		4
882 #define T_U_INT		5
883 #define TP_INT		6
884 #define T_LONG		7
885 #define T_U_LONG	8
886 #define TP_LONG		9
887 #define T_QUAD		10
888 #define T_U_QUAD	11
889 #define TP_QUAD		12
890 #define T_DOUBLE	13
891 #define T_LONG_DOUBLE	14
892 #define TP_CHAR		15
893 #define TP_VOID		16
894 
895 /*
896  * Find all arguments when a positional parameter is encountered.  Returns a
897  * table, indexed by argument number, of pointers to each arguments.  The
898  * initial argument table should be an array of STATIC_ARG_TBL_SIZE entries.
899  * It will be replaces with a malloc-ed one if it overflows.
900  */
901 static void
902 __find_arguments (const char *fmt0, va_list ap, void ***argtable)
903 {
904 	char *fmt;		/* format string */
905 	int ch;			/* character from fmt */
906 	int n, n2;		/* handy integer (short term usage) */
907 	char *cp;		/* handy char pointer (short term usage) */
908 	int flags;		/* flags as above */
909 	int width;		/* width from format (%8d), or 0 */
910 	unsigned char *typetable; /* table of types */
911 	unsigned char stattypetable [STATIC_ARG_TBL_SIZE];
912 	int tablesize;		/* current size of type table */
913 	int tablemax;		/* largest used index in table */
914 	int nextarg;		/* 1-based argument index */
915 
916 	/*
917 	 * Add an argument type to the table, expanding if necessary.
918 	 */
919 #define ADDTYPE(type) \
920 	((nextarg >= tablesize) ? \
921 		__grow_type_table(nextarg, &typetable, &tablesize) : 0, \
922 	(nextarg > tablemax) ? tablemax = nextarg : 0, \
923 	typetable[nextarg++] = type)
924 
925 #define	ADDSARG() \
926 	((flags&LONGINT) ? ADDTYPE(T_LONG) : \
927 		((flags&SHORTINT) ? ADDTYPE(T_SHORT) : ADDTYPE(T_INT)))
928 
929 #define	ADDUARG() \
930 	((flags&LONGINT) ? ADDTYPE(T_U_LONG) : \
931 		((flags&SHORTINT) ? ADDTYPE(T_U_SHORT) : ADDTYPE(T_U_INT)))
932 
933 	/*
934 	 * Add * arguments to the type array.
935 	 */
936 #define ADDASTER() \
937 	n2 = 0; \
938 	cp = fmt; \
939 	while (is_digit(*cp)) { \
940 		n2 = 10 * n2 + to_digit(*cp); \
941 		cp++; \
942 	} \
943 	if (*cp == '$') { \
944 		int hold = nextarg; \
945 		nextarg = n2; \
946 		ADDTYPE (T_INT); \
947 		nextarg = hold; \
948 		fmt = ++cp; \
949 	} else { \
950 		ADDTYPE (T_INT); \
951 	}
952 	fmt = (char *)fmt0;
953 	typetable = stattypetable;
954 	tablesize = STATIC_ARG_TBL_SIZE;
955 	tablemax = 0;
956 	nextarg = 1;
957 	memset (typetable, T_UNUSED, STATIC_ARG_TBL_SIZE);
958 
959 	/*
960 	 * Scan the format for conversions (`%' character).
961 	 */
962 	for (;;) {
963 		for (cp = fmt; (ch = *fmt) != '\0' && ch != '%'; fmt++)
964 			/* void */;
965 		if (ch == '\0')
966 			goto done;
967 		fmt++;		/* skip over '%' */
968 
969 		flags = 0;
970 		width = 0;
971 
972 rflag:		ch = *fmt++;
973 reswitch:	switch (ch) {
974 		case ' ':
975 		case '#':
976 			goto rflag;
977 		case '*':
978 			ADDASTER ();
979 			goto rflag;
980 		case '-':
981 		case '+':
982 			goto rflag;
983 		case '.':
984 			if ((ch = *fmt++) == '*') {
985 				ADDASTER ();
986 				goto rflag;
987 			}
988 			while (is_digit(ch)) {
989 				ch = *fmt++;
990 			}
991 			goto reswitch;
992 		case '0':
993 			goto rflag;
994 		case '1': case '2': case '3': case '4':
995 		case '5': case '6': case '7': case '8': case '9':
996 			n = 0;
997 			do {
998 				n = 10 * n + to_digit(ch);
999 				ch = *fmt++;
1000 			} while (is_digit(ch));
1001 			if (ch == '$') {
1002 				nextarg = n;
1003 				goto rflag;
1004 			}
1005 			width = n;
1006 			goto reswitch;
1007 #ifdef FLOATING_POINT
1008 		case 'L':
1009 			flags |= LONGDBL;
1010 			goto rflag;
1011 #endif
1012 		case 'h':
1013 			flags |= SHORTINT;
1014 			goto rflag;
1015 		case 'l':
1016 			if (flags & LONGINT)
1017 				flags |= QUADINT;
1018 			else
1019 				flags |= LONGINT;
1020 			goto rflag;
1021 		case 'q':
1022 			flags |= QUADINT;
1023 			goto rflag;
1024 		case 'c':
1025 			ADDTYPE(T_INT);
1026 			break;
1027 		case 'D':
1028 			flags |= LONGINT;
1029 			/*FALLTHROUGH*/
1030 		case 'd':
1031 		case 'i':
1032 			if (flags & QUADINT) {
1033 				ADDTYPE(T_QUAD);
1034 			} else {
1035 				ADDSARG();
1036 			}
1037 			break;
1038 #ifdef FLOATING_POINT
1039 		case 'e':
1040 		case 'E':
1041 		case 'f':
1042 		case 'g':
1043 		case 'G':
1044 			if (flags & LONGDBL)
1045 				ADDTYPE(T_LONG_DOUBLE);
1046 			else
1047 				ADDTYPE(T_DOUBLE);
1048 			break;
1049 #endif /* FLOATING_POINT */
1050 		case 'n':
1051 			if (flags & QUADINT)
1052 				ADDTYPE(TP_QUAD);
1053 			else if (flags & LONGINT)
1054 				ADDTYPE(TP_LONG);
1055 			else if (flags & SHORTINT)
1056 				ADDTYPE(TP_SHORT);
1057 			else
1058 				ADDTYPE(TP_INT);
1059 			continue;	/* no output */
1060 		case 'O':
1061 			flags |= LONGINT;
1062 			/*FALLTHROUGH*/
1063 		case 'o':
1064 			if (flags & QUADINT)
1065 				ADDTYPE(T_U_QUAD);
1066 			else
1067 				ADDUARG();
1068 			break;
1069 		case 'p':
1070 			ADDTYPE(TP_VOID);
1071 			break;
1072 		case 's':
1073 			ADDTYPE(TP_CHAR);
1074 			break;
1075 		case 'U':
1076 			flags |= LONGINT;
1077 			/*FALLTHROUGH*/
1078 		case 'u':
1079 			if (flags & QUADINT)
1080 				ADDTYPE(T_U_QUAD);
1081 			else
1082 				ADDUARG();
1083 			break;
1084 		case 'X':
1085 		case 'x':
1086 			if (flags & QUADINT)
1087 				ADDTYPE(T_U_QUAD);
1088 			else
1089 				ADDUARG();
1090 			break;
1091 		default:	/* "%?" prints ?, unless ? is NUL */
1092 			if (ch == '\0')
1093 				goto done;
1094 			break;
1095 		}
1096 	}
1097 done:
1098 	/*
1099 	 * Build the argument table.
1100 	 */
1101 	if (tablemax >= STATIC_ARG_TBL_SIZE) {
1102 		*argtable = (void **)
1103 		    malloc (sizeof (void *) * (tablemax + 1));
1104 	}
1105 
1106 	(*argtable) [0] = NULL;
1107 	for (n = 1; n <= tablemax; n++) {
1108 		switch (typetable [n]) {
1109 		    case T_UNUSED:
1110 			(*argtable) [n] = (void *) &va_arg (ap, int);
1111 			break;
1112 		    case T_SHORT:
1113 			(*argtable) [n] = (void *) &va_arg (ap, int);
1114 			break;
1115 		    case T_U_SHORT:
1116 			(*argtable) [n] = (void *) &va_arg (ap, int);
1117 			break;
1118 		    case TP_SHORT:
1119 			(*argtable) [n] = (void *) &va_arg (ap, short *);
1120 			break;
1121 		    case T_INT:
1122 			(*argtable) [n] = (void *) &va_arg (ap, int);
1123 			break;
1124 		    case T_U_INT:
1125 			(*argtable) [n] = (void *) &va_arg (ap, unsigned int);
1126 			break;
1127 		    case TP_INT:
1128 			(*argtable) [n] = (void *) &va_arg (ap, int *);
1129 			break;
1130 		    case T_LONG:
1131 			(*argtable) [n] = (void *) &va_arg (ap, long);
1132 			break;
1133 		    case T_U_LONG:
1134 			(*argtable) [n] = (void *) &va_arg (ap, unsigned long);
1135 			break;
1136 		    case TP_LONG:
1137 			(*argtable) [n] = (void *) &va_arg (ap, long *);
1138 			break;
1139 		    case T_QUAD:
1140 			(*argtable) [n] = (void *) &va_arg (ap, quad_t);
1141 			break;
1142 		    case T_U_QUAD:
1143 			(*argtable) [n] = (void *) &va_arg (ap, u_quad_t);
1144 			break;
1145 		    case TP_QUAD:
1146 			(*argtable) [n] = (void *) &va_arg (ap, quad_t *);
1147 			break;
1148 		    case T_DOUBLE:
1149 			(*argtable) [n] = (void *) &va_arg (ap, double);
1150 			break;
1151 		    case T_LONG_DOUBLE:
1152 			(*argtable) [n] = (void *) &va_arg (ap, long double);
1153 			break;
1154 		    case TP_CHAR:
1155 			(*argtable) [n] = (void *) &va_arg (ap, char *);
1156 			break;
1157 		    case TP_VOID:
1158 			(*argtable) [n] = (void *) &va_arg (ap, void *);
1159 			break;
1160 		}
1161 	}
1162 
1163 	if ((typetable != NULL) && (typetable != stattypetable))
1164 		free (typetable);
1165 }
1166 
1167 /*
1168  * Increase the size of the type table.
1169  */
1170 static void
1171 __grow_type_table (int nextarg, unsigned char **typetable, int *tablesize)
1172 {
1173 	unsigned char *const oldtable = *typetable;
1174 	const int oldsize = *tablesize;
1175 	unsigned char *newtable;
1176 	int newsize = oldsize * 2;
1177 
1178 	if (newsize < nextarg + 1)
1179 		newsize = nextarg + 1;
1180 	if (oldsize == STATIC_ARG_TBL_SIZE) {
1181 		if ((newtable = malloc(newsize)) == NULL)
1182 			abort();			/* XXX handle better */
1183 		bcopy(oldtable, newtable, oldsize);
1184 	} else {
1185 		if ((newtable = reallocf(oldtable, newsize)) == NULL)
1186 			abort();			/* XXX handle better */
1187 	}
1188 	memset(&newtable[oldsize], T_UNUSED, newsize - oldsize);
1189 
1190 	*typetable = newtable;
1191 	*tablesize = newsize;
1192 }
1193 
1194 
1195 #ifdef FLOATING_POINT
1196 
1197 extern char *__dtoa __P((double, int, int, int *, int *, char **, char **));
1198 
1199 static char *
1200 cvt(double value, int ndigits, int flags, char *sign, int *decpt,
1201     int ch, int *length, char **dtoaresultp)
1202 {
1203 	int mode, dsgn;
1204 	char *digits, *bp, *rve;
1205 
1206 	if (ch == 'f')
1207 		mode = 3;		/* ndigits after the decimal point */
1208 	else {
1209 		/*
1210 		 * To obtain ndigits after the decimal point for the 'e'
1211 		 * and 'E' formats, round to ndigits + 1 significant
1212 		 * figures.
1213 		 */
1214 		if (ch == 'e' || ch == 'E')
1215 			ndigits++;
1216 		mode = 2;		/* ndigits significant digits */
1217 	}
1218 	digits = __dtoa(value, mode, ndigits, decpt, &dsgn, &rve, dtoaresultp);
1219 	*sign = dsgn != 0;
1220 	if ((ch != 'g' && ch != 'G') || flags & ALT) {
1221 		/* print trailing zeros */
1222 		bp = digits + ndigits;
1223 		if (ch == 'f') {
1224 			if (*digits == '0' && value)
1225 				*decpt = -ndigits + 1;
1226 			bp += *decpt;
1227 		}
1228 		if (value == 0)	/* kludge for __dtoa irregularity */
1229 			rve = bp;
1230 		while (rve < bp)
1231 			*rve++ = '0';
1232 	}
1233 	*length = rve - digits;
1234 	return (digits);
1235 }
1236 
1237 static int
1238 exponent(char *p0, int exp, int fmtch)
1239 {
1240 	char *p, *t;
1241 	char expbuf[MAXEXP];
1242 
1243 	p = p0;
1244 	*p++ = fmtch;
1245 	if (exp < 0) {
1246 		exp = -exp;
1247 		*p++ = '-';
1248 	}
1249 	else
1250 		*p++ = '+';
1251 	t = expbuf + MAXEXP;
1252 	if (exp > 9) {
1253 		do {
1254 			*--t = to_char(exp % 10);
1255 		} while ((exp /= 10) > 9);
1256 		*--t = to_char(exp);
1257 		for (; t < expbuf + MAXEXP; *p++ = *t++);
1258 	}
1259 	else {
1260 		*p++ = '0';
1261 		*p++ = to_char(exp);
1262 	}
1263 	return (p - p0);
1264 }
1265 #endif /* FLOATING_POINT */
1266