xref: /netbsd-src/libexec/ld.elf_so/xprintf.c (revision e5548b402ae4c44fb816de42c7bba9581ce23ef5)
1 /*	$NetBSD: xprintf.c,v 1.18 2005/04/24 21:11:58 christos Exp $	 */
2 
3 /*
4  * Copyright 1996 Matt Thomas <matt@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 1.18 2005/04/24 21:11:58 christos 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 			case 'c':{
181 				int c = va_arg(ap, int);
182 				*bp++ = (char)c;
183 				fmt += 2;
184 				break;
185 			}
186 			default:
187 				*bp++ = *fmt;
188 				break;
189 			}
190 			break;
191 		}
192 		default:
193 			*bp++ = *fmt++;
194 			break;
195 		}
196 	}
197 
198 	*bp = '\0';
199 	return bp - buf;
200 }
201 
202 void
203 xvprintf(const char *fmt, va_list ap)
204 {
205 	char buf[256];
206 
207 	(void) write(2, buf, xvsnprintf(buf, sizeof(buf), fmt, ap));
208 }
209 
210 void
211 xprintf(const char *fmt, ...)
212 {
213 	va_list ap;
214 
215 	va_start(ap, fmt);
216 
217 	xvprintf(fmt, ap);
218 
219 	va_end(ap);
220 }
221 
222 void
223 xsnprintf(char *buf, size_t buflen, const char *fmt, ...)
224 {
225 	va_list ap;
226 
227 	va_start(ap, fmt);
228 
229 	xvsnprintf(buf, buflen, fmt, ap);
230 
231 	va_end(ap);
232 }
233 
234 const char *
235 xstrerror(int error)
236 {
237 
238 	if (error >= sys_nerr || error < 0) {
239 		static char buf[128];
240 		xsnprintf(buf, sizeof(buf), "Unknown error: %d", error);
241 		return buf;
242 	}
243 	return sys_errlist[error];
244 }
245 
246 void
247 xerrx(int eval, const char *fmt, ...)
248 {
249 	va_list ap;
250 
251 	va_start(ap, fmt);
252 	xvprintf(fmt, ap);
253 	va_end(ap);
254 	(void) write(2, "\n", 1);
255 
256 	exit(eval);
257 }
258 
259 void
260 xerr(int eval, const char *fmt, ...)
261 {
262 	int saved_errno = errno;
263 	va_list ap;
264 
265 	va_start(ap, fmt);
266 	xvprintf(fmt, ap);
267 	va_end(ap);
268 
269 	xprintf(": %s\n", xstrerror(saved_errno));
270 	exit(eval);
271 }
272 
273 void
274 xwarn(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 	errno = saved_errno;
285 }
286 
287 void
288 xwarnx(const char *fmt, ...)
289 {
290 	va_list ap;
291 
292 	va_start(ap, fmt);
293 	xvprintf(fmt, ap);
294 	va_end(ap);
295 	(void) write(2, "\n", 1);
296 }
297 
298 #ifdef DEBUG
299 void
300 xassert(const char *file, int line, const char *failedexpr)
301 {
302 
303 	xprintf("assertion \"%s\" failed: file \"%s\", line %d\n",
304 		failedexpr, file, line);
305 	abort();
306 	/* NOTREACHED */
307 }
308 #endif
309 #endif
310