snprintb.c revision 1.24
1 /* $NetBSD: snprintb.c,v 1.24 2024/02/15 22:48:58 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 1.24 2024/02/15 22:48:58 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 1.24 2024/02/15 22:48:58 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 { l_len++; \ 119 if ((size_t)(++t_len) < bufsize) \ 120 *bp++ = (c); \ 121 } while ( /* CONSTCOND */ 0) 122 123 #define BACKUP do { if (s_bp != NULL) { \ 124 bp = s_bp; s_bp = NULL; \ 125 t_len -= l_len - s_len; \ 126 restart = 1; \ 127 bitfmt = s_fmt; \ 128 } \ 129 STORE('>'); STORE('\0'); \ 130 if ((size_t)t_len < bufsize) \ 131 snprintf(bp, bufsize - t_len, sbase, (uintmax_t)val);\ 132 t_len += v_len; l_len = v_len; bp += v_len; \ 133 } while ( /* CONSTCOND */ 0) 134 135 #define PUTSEP do { \ 136 if (l_max > 0 && (size_t)l_len >= l_max) { \ 137 BACKUP; \ 138 STORE('<'); \ 139 } else { \ 140 /* Remember separator location */ \ 141 if (l_max > 0 && sep != '<') { \ 142 s_len = l_len; \ 143 s_bp = bp; \ 144 s_fmt = cur_fmt; \ 145 } \ 146 STORE(sep); \ 147 restart = 0; \ 148 } \ 149 } while ( /* CONSTCOND */ 0) 150 151 #define PUTCHR(c) do { \ 152 if (l_max > 0 && (size_t)l_len >= (l_max - 1)) {\ 153 BACKUP; \ 154 if (restart == 0) \ 155 STORE(c); \ 156 else \ 157 sep = '<'; \ 158 } else { \ 159 STORE(c); \ 160 restart = 0; \ 161 } \ 162 } while ( /* CONSTCOND */ 0) 163 164 #define PUTS(s) while ((ch = *(s)++) != 0) { \ 165 PUTCHR(ch); \ 166 if (restart) \ 167 break; \ 168 } 169 #define FMTSTR(sb, f) \ 170 do { \ 171 f_len = snprintf(bp, bufsize - t_len, sb, (uintmax_t)f); \ 172 if (f_len < 0) \ 173 goto internal; \ 174 t_len += f_len; \ 175 l_len += f_len; \ 176 if ((size_t)t_len < bufsize) \ 177 bp += f_len; \ 178 } while (/*CONSTCOND*/0) 179 180 /* 181 * Chris Torek's new bitmask format is identified by a leading \177 182 */ 183 sep = '<'; 184 if (ch != '\177') { 185 /* old (standard) format. */ 186 for (;(bit = *bitfmt) != 0;) { 187 cur_fmt = bitfmt++; 188 if (val & (1U << (bit - 1))) { 189 PUTSEP; 190 if (restart) 191 continue; 192 sep = ','; 193 for (; (ch = *bitfmt) > ' '; ++bitfmt) { 194 PUTCHR(ch); 195 if (restart) 196 break; 197 } 198 } else 199 for (; *bitfmt > ' '; ++bitfmt) 200 continue; 201 } 202 } else { 203 /* new quad-capable format; also does fields. */ 204 field = val; 205 while (c_fmt = bitfmt, (ch = *bitfmt++) != '\0') { 206 bit = *bitfmt++; /* now 0-origin */ 207 switch (ch) { 208 case 'b': 209 if (((unsigned int)(val >> bit) & 1) == 0) 210 goto skip; 211 cur_fmt = c_fmt; 212 PUTSEP; 213 if (restart) 214 break; 215 PUTS(bitfmt); 216 if (restart == 0) 217 sep = ','; 218 break; 219 case 'f': 220 case 'F': 221 matched = 0; 222 cur_fmt = c_fmt; 223 f_len = *bitfmt++; /* field length */ 224 field = (val >> bit) & 225 (((uint64_t)1 << f_len) - 1); 226 PUTSEP; 227 if (restart == 0) 228 sep = ','; 229 if (ch == 'F') { /* just extract */ 230 /* duplicate PUTS() effect on bitfmt */ 231 while (*bitfmt++ != '\0') 232 continue; 233 break; 234 } 235 if (restart == 0) 236 PUTS(bitfmt); 237 if (restart == 0) 238 PUTCHR('='); 239 if (restart == 0) { 240 FMTSTR(sbase, field); 241 if (l_max > 0 && (size_t)l_len > l_max) 242 PUTCHR('#'); 243 } 244 break; 245 case '=': 246 case ':': 247 /* 248 * Here "bit" is actually a value instead, 249 * to be compared against the last field. 250 * This only works for values in [0..255], 251 * of course. 252 */ 253 if ((int)field != bit) 254 goto skip; 255 matched = 1; 256 if (ch == '=') 257 PUTCHR('='); 258 PUTS(bitfmt); 259 break; 260 case '*': 261 bitfmt--; 262 if (!matched) { 263 matched = 1; 264 FMTSTR(bitfmt, field); 265 } 266 /*FALLTHROUGH*/ 267 default: 268 skip: 269 while (*bitfmt++ != '\0') 270 continue; 271 break; 272 } 273 } 274 } 275 if (sep != '<') 276 STORE('>'); 277 terminate: 278 STORE('\0'); 279 if (l_max != 0) { 280 STORE('\0'); 281 t_len--; 282 buf[bufsize] = '\0'; 283 } 284 return t_len; 285 internal: 286 #ifndef _KERNEL 287 errno = EINVAL; 288 #endif 289 return -1; 290 } 291 292 int 293 snprintb(char *buf, size_t bufsize, const char *bitfmt, uint64_t val) 294 { 295 return snprintb_m(buf, bufsize, bitfmt, val, 0); 296 } 297 # endif /* ! HAVE_SNPRINTB_M */ 298 #endif /* ! _STANDALONE */ 299
Indexes created Sun Sep 21 15:09:59 GMT 2025