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xprintf.c revision 1.21.46.1 
      1 /*	$NetBSD: xprintf.c,v 1.21.46.1 2020/04/08 14:07:17 martin 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 1.21.46.1 2020/04/08 14:07:17 martin 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 #define SZ_SIZE_T	0x04
     47 
     48 /*
     49  * Non-mallocing printf, for use by malloc and rtld itself.
     50  * This avoids putting in most of stdio.
     51  *
     52  * deals with formats %x, %p, %s, and %d.
     53  */
     54 size_t
     55 xvsnprintf(char *buf, size_t buflen, const char *fmt, va_list ap)
     56 {
     57 	char *bp = buf;
     58 	char *const ep = buf + buflen - 4;
     59 	int size, prec;
     60 
     61 	while (*fmt != '\0' && bp < ep) {
     62 		switch (*fmt) {
     63 		case '\\':{
     64 			if (fmt[1] != '\0')
     65 				*bp++ = *++fmt;
     66 			continue;
     67 		}
     68 		case '%':{
     69 			size = 0;
     70 			prec = -1;
     71 	rflag:		switch (fmt[1]) {
     72 			case '*':
     73 				prec = va_arg(ap, int);
     74 				/* FALLTHROUGH */
     75 			case '.':
     76 				fmt++;
     77 				goto rflag;
     78 			case 'l':
     79 				size |= SZ_LONG;
     80 				fmt++;
     81 				goto rflag;
     82 			case 'z':
     83 				size |= SZ_SIZE_T;
     84 				fmt++;
     85 				goto rflag;
     86 			case 'u':
     87 				size |= SZ_UNSIGNED;
     88 				/* FALLTHROUGH */
     89 			case 'd':{
     90 				long sval;
     91 				unsigned long uval;
     92 				char digits[sizeof(int) * 3], *dp = digits;
     93 #define	SARG() \
     94 (size & SZ_LONG ? va_arg(ap, long) : \
     95 ((size & SZ_SIZE_T ? (long)va_arg(ap, size_t) : \
     96 va_arg(ap, int))))
     97 #define	UARG() \
     98 (size & SZ_LONG ? va_arg(ap, unsigned long) : \
     99 ((size & SZ_SIZE_T ? va_arg(ap, size_t) : \
    100 va_arg(ap, unsigned int))))
    101 
    102 				if (fmt[1] == 'd') {
    103 					if (size & SZ_UNSIGNED)
    104 						sval = UARG();
    105 					else
    106 						sval = SARG();
    107 					if (sval < 0) {
    108 						if ((sval << 1) == 0) {
    109 							/*
    110 							 * We can't flip the
    111 							 * sign of this since
    112 							 * it can't be
    113 							 * represented as a
    114 							 * positive number in
    115 							 * two complement,
    116 							 * handle the first
    117 							 * digit. After that,
    118 							 * it can be flipped
    119 							 * since it is now not
    120 							 * 2^(n-1).
    121 							 */
    122 							*dp++ = '0'-(sval % 10);
    123 							sval /= 10;
    124 						}
    125 						*bp++ = '-';
    126 						uval = -sval;
    127 					} else {
    128 						uval = sval;
    129 					}
    130 				} else {
    131 					if (size & SZ_UNSIGNED)
    132 						uval = UARG();
    133 					else
    134 						uval = SARG();
    135 				}
    136 				do {
    137 					*dp++ = '0' + (uval % 10);
    138 					uval /= 10;
    139 				} while (uval != 0);
    140 				do {
    141 					*bp++ = *--dp;
    142 				} while (dp != digits && bp < ep);
    143 				fmt += 2;
    144 				break;
    145 			}
    146 			case 'x':
    147 			case 'p':{
    148 				unsigned long val = va_arg(ap, unsigned long);
    149 				unsigned long mask = ~(~0UL >> 4);
    150 				int bits = sizeof(val) * 8 - 4;
    151 				const char hexdigits[] = "0123456789abcdef";
    152 				if (fmt[1] == 'p') {
    153 					*bp++ = '0';
    154 					*bp++ = 'x';
    155 				}
    156 				/* handle the border case */
    157 				if (val == 0) {
    158 					*bp++ = '0';
    159 					fmt += 2;
    160 					break;
    161 				}
    162 				/* suppress 0s */
    163 				while ((val & mask) == 0)
    164 					bits -= 4, mask >>= 4;
    165 
    166 				/* emit the hex digits */
    167 				while (bits >= 0 && bp < ep) {
    168 					*bp++ = hexdigits[(val & mask) >> bits];
    169 					bits -= 4, mask >>= 4;
    170 				}
    171 				fmt += 2;
    172 				break;
    173 			}
    174 			case 's':{
    175 				const char *str = va_arg(ap, const char *);
    176 				int len;
    177 
    178 				if (str == NULL)
    179 					str = "(null)";
    180 
    181 				if (prec < 0)
    182 					len = strlen(str);
    183 				else
    184 					len = prec;
    185 				if (ep - bp < len)
    186 					len = ep - bp;
    187 				memcpy(bp, str, len);
    188 				bp += len;
    189 				fmt += 2;
    190 				break;
    191 			}
    192 			case 'c':{
    193 				int c = va_arg(ap, int);
    194 				*bp++ = (char)c;
    195 				fmt += 2;
    196 				break;
    197 			}
    198 			default:
    199 				*bp++ = *fmt;
    200 				break;
    201 			}
    202 			break;
    203 		}
    204 		default:
    205 			*bp++ = *fmt++;
    206 			break;
    207 		}
    208 	}
    209 
    210 	*bp = '\0';
    211 	return bp - buf;
    212 }
    213 
    214 void
    215 xvprintf(const char *fmt, va_list ap)
    216 {
    217 	char buf[256];
    218 
    219 	(void) write(2, buf, xvsnprintf(buf, sizeof(buf), fmt, ap));
    220 }
    221 
    222 void
    223 xprintf(const char *fmt, ...)
    224 {
    225 	va_list ap;
    226 
    227 	va_start(ap, fmt);
    228 
    229 	xvprintf(fmt, ap);
    230 
    231 	va_end(ap);
    232 }
    233 
    234 void
    235 xsnprintf(char *buf, size_t buflen, const char *fmt, ...)
    236 {
    237 	va_list ap;
    238 
    239 	va_start(ap, fmt);
    240 
    241 	xvsnprintf(buf, buflen, fmt, ap);
    242 
    243 	va_end(ap);
    244 }
    245 
    246 #include "errlist_concat.h"
    247 
    248 const char *
    249 xstrerror(int error)
    250 {
    251 
    252 	if (error >= concat_nerr || error < 0) {
    253 		static char buf[128];
    254 		xsnprintf(buf, sizeof(buf), "Unknown error: %d", error);
    255 		return buf;
    256 	}
    257 	return concat_errlist + concat_offset[error];
    258 }
    259 
    260 void
    261 xerrx(int eval, const char *fmt, ...)
    262 {
    263 	va_list ap;
    264 
    265 	va_start(ap, fmt);
    266 	xvprintf(fmt, ap);
    267 	va_end(ap);
    268 	(void) write(2, "\n", 1);
    269 
    270 	exit(eval);
    271 }
    272 
    273 void
    274 xerr(int eval, const char *fmt, ...)
    275 {
    276 	int saved_errno = errno;
    277 	va_list ap;
    278 
    279 	va_start(ap, fmt);
    280 	xvprintf(fmt, ap);
    281 	va_end(ap);
    282 
    283 	xprintf(": %s\n", xstrerror(saved_errno));
    284 	exit(eval);
    285 }
    286 
    287 void
    288 xwarn(const char *fmt, ...)
    289 {
    290 	int saved_errno = errno;
    291 	va_list ap;
    292 
    293 	va_start(ap, fmt);
    294 	xvprintf(fmt, ap);
    295 	va_end(ap);
    296 
    297 	xprintf(": %s\n", xstrerror(saved_errno));
    298 	errno = saved_errno;
    299 }
    300 
    301 void
    302 xwarnx(const char *fmt, ...)
    303 {
    304 	va_list ap;
    305 
    306 	va_start(ap, fmt);
    307 	xvprintf(fmt, ap);
    308 	va_end(ap);
    309 	(void) write(2, "\n", 1);
    310 }
    311 
    312 #ifdef DEBUG
    313 void
    314 xassert(const char *file, int line, const char *failedexpr)
    315 {
    316 
    317 	xprintf("assertion \"%s\" failed: file \"%s\", line %d\n",
    318 		failedexpr, file, line);
    319 	abort();
    320 	/* NOTREACHED */
    321 }
    322 #endif
    323 #endif
    324