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xprintf.c revision 1.17 
      1 /*	$NetBSD: xprintf.c,v 1.17 2004/10/22 05:39:57 skrll Exp $	 */
      2 
      3 /*
      4  * Copyright 1996 Matt Thomas <matt (at) 3am-software.com>
      5  * All rights reserved.
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  * 1. Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in the
     14  *    documentation and/or other materials provided with the distribution.
     15  * 3. The name of the author may not be used to endorse or promote products
     16  *    derived from this software without specific prior written permission.
     17  *
     18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
     19  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     20  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     21  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     22  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
     23  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     24  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     25  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     26  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
     27  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     28  */
     29 
     30 #include <sys/cdefs.h>
     31 #ifndef lint
     32 __RCSID("$NetBSD: xprintf.c,v 1.17 2004/10/22 05:39:57 skrll Exp $");
     33 #endif /* not lint */
     34 
     35 #include <string.h>
     36 #include <stdlib.h>
     37 #include <unistd.h>
     38 #include <errno.h>
     39 #include <stdarg.h>
     40 
     41 #include "rtldenv.h"
     42 
     43 #ifdef RTLD_LOADER
     44 #define	SZ_LONG		0x01
     45 #define	SZ_UNSIGNED	0x02
     46 
     47 /*
     48  * Non-mallocing printf, for use by malloc and rtld itself.
     49  * This avoids putting in most of stdio.
     50  *
     51  * deals withs formats %x, %p, %s, and %d.
     52  */
     53 size_t
     54 xvsnprintf(char *buf, size_t buflen, const char *fmt, va_list ap)
     55 {
     56 	char *bp = buf;
     57 	char *const ep = buf + buflen - 4;
     58 	int size, prec;
     59 
     60 	while (*fmt != '\0' && bp < ep) {
     61 		switch (*fmt) {
     62 		case '\\':{
     63 			if (fmt[1] != '\0')
     64 				*bp++ = *++fmt;
     65 			continue;
     66 		}
     67 		case '%':{
     68 			size = 0;
     69 			prec = -1;
     70 	rflag:		switch (fmt[1]) {
     71 			case '*':
     72 				prec = va_arg(ap, int);
     73 				/* FALLTHROUGH */
     74 			case '.':
     75 				fmt++;
     76 				goto rflag;
     77 			case 'l':
     78 				size |= SZ_LONG;
     79 				fmt++;
     80 				goto rflag;
     81 			case 'u':
     82 				size |= SZ_UNSIGNED;
     83 				/* FALLTHROUGH */
     84 			case 'd':{
     85 				long sval;
     86 				unsigned long uval;
     87 				char digits[sizeof(int) * 3], *dp = digits;
     88 #define	SARG() \
     89 (size & SZ_LONG ? va_arg(ap, long) : \
     90 va_arg(ap, int))
     91 #define	UARG() \
     92 (size & SZ_LONG ? va_arg(ap, unsigned long) : \
     93 va_arg(ap, unsigned int))
     94 #define	ARG()	(size & SZ_UNSIGNED ? UARG() : SARG())
     95 
     96 				if (fmt[1] == 'd') {
     97 					sval = ARG();
     98 					if (sval < 0) {
     99 						if ((sval << 1) == 0) {
    100 							/*
    101 							 * We can't flip the
    102 							 * sign of this since
    103 							 * it can't be
    104 							 * represented as a
    105 							 * positive number in
    106 							 * two complement,
    107 							 * handle the first
    108 							 * digit. After that,
    109 							 * it can be flipped
    110 							 * since it is now not
    111 							 * 2^(n-1).
    112 							 */
    113 							*dp++ = '0'-(sval % 10);
    114 							sval /= 10;
    115 						}
    116 						*bp++ = '-';
    117 						uval = -sval;
    118 					} else {
    119 						uval = sval;
    120 					}
    121 				} else {
    122 					uval = ARG();
    123 				}
    124 				do {
    125 					*dp++ = '0' + (uval % 10);
    126 					uval /= 10;
    127 				} while (uval != 0);
    128 				do {
    129 					*bp++ = *--dp;
    130 				} while (dp != digits && bp < ep);
    131 				fmt += 2;
    132 				break;
    133 			}
    134 			case 'x':
    135 			case 'p':{
    136 				unsigned long val = va_arg(ap, unsigned long);
    137 				unsigned long mask = ~(~0UL >> 4);
    138 				int bits = sizeof(val) * 8 - 4;
    139 				const char hexdigits[] = "0123456789abcdef";
    140 				if (fmt[1] == 'p') {
    141 					*bp++ = '0';
    142 					*bp++ = 'x';
    143 				}
    144 				/* handle the border case */
    145 				if (val == 0) {
    146 					*bp++ = '0';
    147 					fmt += 2;
    148 					break;
    149 				}
    150 				/* suppress 0s */
    151 				while ((val & mask) == 0)
    152 					bits -= 4, mask >>= 4;
    153 
    154 				/* emit the hex digits */
    155 				while (bits >= 0 && bp < ep) {
    156 					*bp++ = hexdigits[(val & mask) >> bits];
    157 					bits -= 4, mask >>= 4;
    158 				}
    159 				fmt += 2;
    160 				break;
    161 			}
    162 			case 's':{
    163 				const char *str = va_arg(ap, const char *);
    164 				int len;
    165 
    166 				if (str == NULL)
    167 					str = "(null)";
    168 
    169 				if (prec < 0)
    170 					len = strlen(str);
    171 				else
    172 					len = prec;
    173 				if (ep - bp < len)
    174 					len = ep - bp;
    175 				memcpy(bp, str, len);
    176 				bp += len;
    177 				fmt += 2;
    178 				break;
    179 			}
    180 			default:
    181 				*bp++ = *fmt;
    182 				break;
    183 			}
    184 			break;
    185 		}
    186 		default:
    187 			*bp++ = *fmt++;
    188 			break;
    189 		}
    190 	}
    191 
    192 	*bp = '\0';
    193 	return bp - buf;
    194 }
    195 
    196 void
    197 xvprintf(const char *fmt, va_list ap)
    198 {
    199 	char buf[256];
    200 
    201 	(void) write(2, buf, xvsnprintf(buf, sizeof(buf), fmt, ap));
    202 }
    203 
    204 void
    205 xprintf(const char *fmt, ...)
    206 {
    207 	va_list ap;
    208 
    209 	va_start(ap, fmt);
    210 
    211 	xvprintf(fmt, ap);
    212 
    213 	va_end(ap);
    214 }
    215 
    216 void
    217 xsnprintf(char *buf, size_t buflen, const char *fmt, ...)
    218 {
    219 	va_list ap;
    220 
    221 	va_start(ap, fmt);
    222 
    223 	xvsnprintf(buf, buflen, fmt, ap);
    224 
    225 	va_end(ap);
    226 }
    227 
    228 const char *
    229 xstrerror(int error)
    230 {
    231 
    232 	if (error >= sys_nerr || error < 0) {
    233 		static char buf[128];
    234 		xsnprintf(buf, sizeof(buf), "Unknown error: %d", error);
    235 		return buf;
    236 	}
    237 	return sys_errlist[error];
    238 }
    239 
    240 void
    241 xerrx(int eval, const char *fmt, ...)
    242 {
    243 	va_list ap;
    244 
    245 	va_start(ap, fmt);
    246 	xvprintf(fmt, ap);
    247 	va_end(ap);
    248 	(void) write(2, "\n", 1);
    249 
    250 	exit(eval);
    251 }
    252 
    253 void
    254 xerr(int eval, const char *fmt, ...)
    255 {
    256 	int saved_errno = errno;
    257 	va_list ap;
    258 
    259 	va_start(ap, fmt);
    260 	xvprintf(fmt, ap);
    261 	va_end(ap);
    262 
    263 	xprintf(": %s\n", xstrerror(saved_errno));
    264 	exit(eval);
    265 }
    266 
    267 void
    268 xwarn(const char *fmt, ...)
    269 {
    270 	int saved_errno = errno;
    271 	va_list ap;
    272 
    273 	va_start(ap, fmt);
    274 	xvprintf(fmt, ap);
    275 	va_end(ap);
    276 
    277 	xprintf(": %s\n", xstrerror(saved_errno));
    278 	errno = saved_errno;
    279 }
    280 
    281 void
    282 xwarnx(const char *fmt, ...)
    283 {
    284 	va_list ap;
    285 
    286 	va_start(ap, fmt);
    287 	xvprintf(fmt, ap);
    288 	va_end(ap);
    289 	(void) write(2, "\n", 1);
    290 }
    291 
    292 #ifdef DEBUG
    293 void
    294 xassert(const char *file, int line, const char *failedexpr)
    295 {
    296 
    297 	xprintf("assertion \"%s\" failed: file \"%s\", line %d\n",
    298 		failedexpr, file, line);
    299 	abort();
    300 	/* NOTREACHED */
    301 }
    302 #endif
    303 #endif
    304