snprintb.c revision 1.26
1 /* $NetBSD: snprintb.c,v 1.26 2024/02/16 01:57:50 rillig Exp $ */ 2 3 /*- 4 * Copyright (c) 2002 The NetBSD Foundation, Inc. 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 * 16 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 17 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 18 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 19 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 20 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 21 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 22 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 23 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 24 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 25 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 26 * POSSIBILITY OF SUCH DAMAGE. 27 */ 28 29 /* 30 * snprintb: print an interpreted bitmask to a buffer 31 * 32 * => returns the length of the buffer that would be required to print the 33 * string minus the terminating NUL. 34 */ 35 #ifndef _STANDALONE 36 # ifndef _KERNEL 37 38 # if HAVE_NBTOOL_CONFIG_H 39 # include "nbtool_config.h" 40 # endif 41 42 # include <sys/cdefs.h> 43 # if defined(LIBC_SCCS) && !defined(lint) 44 __RCSID("$NetBSD: snprintb.c,v 1.26 2024/02/16 01:57:50 rillig Exp $"); 45 # endif 46 47 # include <sys/types.h> 48 # include <inttypes.h> 49 # include <stdio.h> 50 # include <util.h> 51 # include <errno.h> 52 # else /* ! _KERNEL */ 53 # include <sys/cdefs.h> 54 __KERNEL_RCSID(0, "$NetBSD: snprintb.c,v 1.26 2024/02/16 01:57:50 rillig Exp $"); 55 # include <sys/param.h> 56 # include <sys/inttypes.h> 57 # include <sys/systm.h> 58 # include <lib/libkern/libkern.h> 59 # endif /* ! _KERNEL */ 60 61 # ifndef HAVE_SNPRINTB_M 62 int 63 snprintb_m(char *buf, size_t bufsize, const char *bitfmt, uint64_t val, 64 size_t l_max) 65 { 66 char *bp = buf, *s_bp = NULL; 67 const char *c_fmt, *s_fmt = NULL, *cur_fmt; 68 const char *sbase; 69 int bit, ch, t_len, s_len = 0, l_len, f_len, v_len, sep; 70 int restart = 0, matched = 1; 71 uint64_t field; 72 73 #ifdef _KERNEL 74 /* 75 * For safety; no other *s*printf() do this, but in the kernel 76 * we don't usually check the return value 77 */ 78 (void)memset(buf, 0, bufsize); 79 #endif /* _KERNEL */ 80 81 ch = *bitfmt++; 82 switch (ch != '\177' ? ch : *bitfmt++) { 83 case 8: 84 sbase = "%#jo"; 85 break; 86 case 10: 87 sbase = "%ju"; 88 break; 89 case 16: 90 sbase = "%#jx"; 91 break; 92 default: 93 goto internal; 94 } 95 96 /* Reserve space for trailing blank line if needed */ 97 if (l_max > 0) 98 bufsize--; 99 100 t_len = snprintf(bp, bufsize, sbase, (uintmax_t)val); 101 if (t_len < 0) 102 goto internal; 103 104 v_len = l_len = t_len; 105 106 if ((size_t)t_len < bufsize) 107 bp += t_len; 108 else 109 bp += bufsize - 1; 110 111 /* 112 * If the value we printed was 0 and we're using the old-style format, 113 * we're done. 114 */ 115 if (val == 0 && ch != '\177') 116 goto terminate; 117 118 #define STORE(c) do { \ 119 l_len++; \ 120 if ((size_t)(++t_len) < bufsize) \ 121 *bp++ = (c); \ 122 } while (0) 123 124 #define BACKUP() do { \ 125 if (s_bp != NULL) { \ 126 bp = s_bp; \ 127 s_bp = NULL; \ 128 t_len -= l_len - s_len; \ 129 restart = 1; \ 130 bitfmt = s_fmt; \ 131 } \ 132 STORE('>'); \ 133 STORE('\0'); \ 134 if ((size_t)t_len < bufsize) \ 135 snprintf(bp, bufsize - t_len, sbase, (uintmax_t)val);\ 136 t_len += v_len; \ 137 l_len = v_len; \ 138 bp += v_len; \ 139 } while (0) 140 141 #define PUTSEP() do { \ 142 if (l_max > 0 && (size_t)l_len >= l_max) { \ 143 BACKUP(); \ 144 STORE('<'); \ 145 } else { \ 146 /* Remember separator location */ \ 147 if (l_max > 0 && sep != '<') { \ 148 s_len = l_len; \ 149 s_bp = bp; \ 150 s_fmt = cur_fmt; \ 151 } \ 152 STORE(sep); \ 153 restart = 0; \ 154 } \ 155 } while (0) 156 157 #define PUTCHR(c) do { \ 158 if (l_max > 0 && (size_t)l_len >= l_max - 1) { \ 159 BACKUP(); \ 160 if (restart == 0) \ 161 STORE(c); \ 162 else \ 163 sep = '<'; \ 164 } else { \ 165 STORE(c); \ 166 restart = 0; \ 167 } \ 168 } while (0) 169 170 #define PUTS(s) do { \ 171 while ((ch = *(s)++) != 0) { \ 172 PUTCHR(ch); \ 173 if (restart) \ 174 break; \ 175 } \ 176 } while (0) 177 178 #define FMTSTR(sb, f) do { \ 179 f_len = snprintf(bp, bufsize - t_len, sb, (uintmax_t)f); \ 180 if (f_len < 0) \ 181 goto internal; \ 182 t_len += f_len; \ 183 l_len += f_len; \ 184 if ((size_t)t_len < bufsize) \ 185 bp += f_len; \ 186 } while (0) 187 188 /* 189 * Chris Torek's new bitmask format is identified by a leading \177 190 */ 191 sep = '<'; 192 if (ch != '\177') { 193 /* old (standard) format. */ 194 while ((bit = *bitfmt) != 0) { 195 cur_fmt = bitfmt++; 196 if (val & (1U << (bit - 1))) { 197 PUTSEP(); 198 if (restart) 199 continue; 200 sep = ','; 201 for (; (ch = *bitfmt) > ' '; ++bitfmt) { 202 PUTCHR(ch); 203 if (restart) 204 break; 205 } 206 } else 207 for (; *bitfmt > ' '; ++bitfmt) 208 continue; 209 } 210 } else { 211 /* new quad-capable format; also does fields. */ 212 field = val; 213 while (c_fmt = bitfmt, (ch = *bitfmt++) != '\0') { 214 bit = *bitfmt++; /* now 0-origin */ 215 switch (ch) { 216 case 'b': 217 if (((val >> bit) & 1) == 0) 218 goto skip; 219 cur_fmt = c_fmt; 220 PUTSEP(); 221 if (restart) 222 break; 223 PUTS(bitfmt); 224 if (restart == 0) 225 sep = ','; 226 break; 227 case 'f': 228 case 'F': 229 matched = 0; 230 cur_fmt = c_fmt; 231 f_len = *bitfmt++; /* field length */ 232 field = (val >> bit) & 233 (((uint64_t)1 << f_len) - 1); 234 PUTSEP(); 235 if (restart == 0) 236 sep = ','; 237 if (ch == 'F') { /* just extract */ 238 /* duplicate PUTS() effect on bitfmt */ 239 while (*bitfmt++ != '\0') 240 continue; 241 break; 242 } 243 if (restart == 0) 244 PUTS(bitfmt); 245 if (restart == 0) 246 PUTCHR('='); 247 if (restart == 0) { 248 FMTSTR(sbase, field); 249 if (l_max > 0 && (size_t)l_len > l_max) 250 PUTCHR('#'); 251 } 252 break; 253 case '=': 254 case ':': 255 /* 256 * Here "bit" is actually a value instead, 257 * to be compared against the last field. 258 * This only works for values in [0..255], 259 * of course. 260 */ 261 if ((int)field != bit) 262 goto skip; 263 matched = 1; 264 if (ch == '=') 265 PUTCHR('='); 266 PUTS(bitfmt); 267 break; 268 case '*': 269 bitfmt--; 270 if (!matched) { 271 matched = 1; 272 FMTSTR(bitfmt, field); 273 } 274 /*FALLTHROUGH*/ 275 default: 276 skip: 277 while (*bitfmt++ != '\0') 278 continue; 279 break; 280 } 281 } 282 } 283 if (sep != '<') 284 STORE('>'); 285 terminate: 286 if (l_max > 0) { 287 bufsize++; 288 STORE('\0'); 289 if ((size_t)t_len >= bufsize && bufsize > 1) 290 buf[bufsize - 2] = '\0'; 291 } 292 STORE('\0'); 293 if ((size_t)t_len >= bufsize && bufsize > 0) 294 buf[bufsize - 1] = '\0'; 295 return t_len - 1; 296 internal: 297 #ifndef _KERNEL 298 errno = EINVAL; 299 #endif 300 return -1; 301 } 302 303 int 304 snprintb(char *buf, size_t bufsize, const char *bitfmt, uint64_t val) 305 { 306 return snprintb_m(buf, bufsize, bitfmt, val, 0); 307 } 308 # endif /* ! HAVE_SNPRINTB_M */ 309 #endif /* ! _STANDALONE */ 310
Indexes created Tue Sep 23 22:09:46 GMT 2025