snprintb.c revision 1.27
1 /* $NetBSD: snprintb.c,v 1.27 2024/02/16 17:42:49 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 1.27 2024/02/16 17:42:49 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 1.27 2024/02/16 17:42:49 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 line_max) 65 { 66 char *bp = buf, *sep_bp = NULL; 67 const char *c_fmt, *sep_fmt = NULL, *cur_fmt; 68 const char *num_fmt; 69 int ch, total_len, sep_line_len = 0, line_len, val_len, sep; 70 int restart = 0; 71 72 #ifdef _KERNEL 73 /* 74 * For safety; no other *s*printf() do this, but in the kernel 75 * we don't usually check the return value 76 */ 77 (void)memset(buf, 0, bufsize); 78 #endif /* _KERNEL */ 79 80 ch = *bitfmt++; 81 switch (ch != '\177' ? ch : *bitfmt++) { 82 case 8: 83 num_fmt = "%#jo"; 84 break; 85 case 10: 86 num_fmt = "%ju"; 87 break; 88 case 16: 89 num_fmt = "%#jx"; 90 break; 91 default: 92 goto internal; 93 } 94 95 /* Reserve space for trailing blank line if needed */ 96 if (line_max > 0) 97 bufsize--; 98 99 total_len = snprintf(bp, bufsize, num_fmt, (uintmax_t)val); 100 if (total_len < 0) 101 goto internal; 102 103 val_len = line_len = total_len; 104 105 if ((size_t)total_len < bufsize) 106 bp += total_len; 107 else 108 bp += bufsize - 1; 109 110 if (val == 0 && ch != '\177') 111 goto done; 112 113 #define STORE(c) do { \ 114 line_len++; \ 115 if ((size_t)(++total_len) < bufsize) \ 116 *bp++ = (c); \ 117 } while (0) 118 119 #define BACKUP() do { \ 120 if (sep_bp != NULL) { \ 121 bp = sep_bp; \ 122 sep_bp = NULL; \ 123 total_len -= line_len - sep_line_len; \ 124 restart = 1; \ 125 bitfmt = sep_fmt; \ 126 } \ 127 STORE('>'); \ 128 STORE('\0'); \ 129 if ((size_t)total_len < bufsize) \ 130 snprintf(bp, bufsize - total_len, num_fmt, \ 131 (uintmax_t)val); \ 132 total_len += val_len; \ 133 line_len = val_len; \ 134 bp += val_len; \ 135 } while (0) 136 137 #define PUTSEP() do { \ 138 if (line_max > 0 && (size_t)line_len >= line_max) { \ 139 BACKUP(); \ 140 STORE('<'); \ 141 } else { \ 142 /* Remember separator location */ \ 143 if (line_max > 0 && sep != '<') { \ 144 sep_line_len = line_len; \ 145 sep_bp = bp; \ 146 sep_fmt = cur_fmt; \ 147 } \ 148 STORE(sep); \ 149 restart = 0; \ 150 } \ 151 } while (0) 152 153 #define PUTCHR(c) do { \ 154 if (line_max > 0 && (size_t)line_len >= line_max - 1) { \ 155 BACKUP(); \ 156 if (restart == 0) \ 157 STORE(c); \ 158 else \ 159 sep = '<'; \ 160 } else { \ 161 STORE(c); \ 162 restart = 0; \ 163 } \ 164 } while (0) 165 166 #define PUTS(s) do { \ 167 while ((ch = *(s)++) != 0) { \ 168 PUTCHR(ch); \ 169 if (restart) \ 170 break; \ 171 } \ 172 } while (0) 173 174 #define FMTSTR(sb, f) do { \ 175 int fmt_len = snprintf(bp, bufsize - total_len, sb, \ 176 (uintmax_t)f); \ 177 if (fmt_len < 0) \ 178 goto internal; \ 179 total_len += fmt_len; \ 180 line_len += fmt_len; \ 181 if ((size_t)total_len < bufsize) \ 182 bp += fmt_len; \ 183 } while (0) 184 185 sep = '<'; 186 if (ch != '\177') { 187 /* old-style format, 32-bit, 1-origin. */ 188 for (int bit; (bit = *bitfmt) != 0;) { 189 cur_fmt = bitfmt++; 190 if (val & (1U << (bit - 1))) { 191 PUTSEP(); 192 if (restart) 193 continue; 194 sep = ','; 195 for (; (ch = *bitfmt) > ' '; ++bitfmt) { 196 PUTCHR(ch); 197 if (restart) 198 break; 199 } 200 } else 201 for (; *bitfmt > ' '; ++bitfmt) 202 continue; 203 } 204 } else { 205 /* new-style format, 64-bit, 0-origin; also does fields. */ 206 uint64_t field = val; 207 int matched = 1; 208 while (c_fmt = bitfmt, (ch = *bitfmt++) != '\0') { 209 int bit = *bitfmt++; 210 switch (ch) { 211 case 'b': 212 if (((val >> bit) & 1) == 0) 213 goto skip; 214 cur_fmt = c_fmt; 215 PUTSEP(); 216 if (restart) 217 break; 218 PUTS(bitfmt); 219 if (restart == 0) 220 sep = ','; 221 break; 222 case 'f': 223 case 'F': 224 matched = 0; 225 cur_fmt = c_fmt; 226 int field_width = *bitfmt++; 227 field = (val >> bit) & 228 (((uint64_t)1 << field_width) - 1); 229 PUTSEP(); 230 if (restart == 0) 231 sep = ','; 232 if (ch == 'F') { /* just extract */ 233 /* duplicate PUTS() effect on bitfmt */ 234 while (*bitfmt++ != '\0') 235 continue; 236 break; 237 } 238 if (restart == 0) 239 PUTS(bitfmt); 240 if (restart == 0) 241 PUTCHR('='); 242 if (restart == 0) { 243 FMTSTR(num_fmt, field); 244 if (line_max > 0 245 && (size_t)line_len > line_max) 246 PUTCHR('#'); 247 } 248 break; 249 case '=': 250 case ':': 251 /* 252 * Here "bit" is actually a value instead, 253 * to be compared against the last field. 254 * This only works for values in [0..255], 255 * of course. 256 */ 257 if ((int)field != bit) 258 goto skip; 259 matched = 1; 260 if (ch == '=') 261 PUTCHR('='); 262 PUTS(bitfmt); 263 break; 264 case '*': 265 bitfmt--; 266 if (!matched) { 267 matched = 1; 268 FMTSTR(bitfmt, field); 269 } 270 /*FALLTHROUGH*/ 271 default: 272 skip: 273 while (*bitfmt++ != '\0') 274 continue; 275 break; 276 } 277 } 278 } 279 if (sep != '<') 280 STORE('>'); 281 done: 282 if (line_max > 0) { 283 bufsize++; 284 STORE('\0'); 285 if ((size_t)total_len >= bufsize && bufsize > 1) 286 buf[bufsize - 2] = '\0'; 287 } 288 STORE('\0'); 289 if ((size_t)total_len >= bufsize && bufsize > 0) 290 buf[bufsize - 1] = '\0'; 291 return total_len - 1; 292 internal: 293 #ifndef _KERNEL 294 errno = EINVAL; 295 #endif 296 return -1; 297 } 298 299 int 300 snprintb(char *buf, size_t bufsize, const char *bitfmt, uint64_t val) 301 { 302 return snprintb_m(buf, bufsize, bitfmt, val, 0); 303 } 304 # endif /* ! HAVE_SNPRINTB_M */ 305 #endif /* ! _STANDALONE */ 306
Indexes created Mon Sep 22 13:09:51 GMT 2025