snprintb.c revision 1.30
1 /* $NetBSD: snprintb.c,v 1.30 2024/02/16 18:17:10 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 1.30 2024/02/16 18:17:10 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 1.30 2024/02/16 18:17:10 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 *num_fmt, *cur_bitfmt, *sep_bitfmt = NULL; 68 int total_len, val_len, line_len, sep_line_len = 0; 69 char 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 int old_style = *bitfmt != '\177'; 81 if (!old_style) 82 bitfmt++; 83 switch (*bitfmt++) { 84 case 8: 85 num_fmt = "%#jo"; 86 break; 87 case 10: 88 num_fmt = "%ju"; 89 break; 90 case 16: 91 num_fmt = "%#jx"; 92 break; 93 default: 94 goto internal; 95 } 96 97 /* Reserve space for trailing blank line if needed */ 98 if (line_max > 0) 99 bufsize--; 100 101 total_len = snprintf(bp, bufsize, num_fmt, (uintmax_t)val); 102 if (total_len < 0) 103 goto internal; 104 105 val_len = line_len = total_len; 106 107 if ((size_t)total_len < bufsize) 108 bp += total_len; 109 else 110 bp += bufsize - 1; 111 112 #define STORE(c) do { \ 113 line_len++; \ 114 if ((size_t)(++total_len) < bufsize) \ 115 *bp++ = (c); \ 116 } while (0) 117 118 #define BACKUP() do { \ 119 if (sep_bp != NULL) { \ 120 bp = sep_bp; \ 121 sep_bp = NULL; \ 122 total_len -= line_len - sep_line_len; \ 123 restart = 1; \ 124 bitfmt = sep_bitfmt; \ 125 } \ 126 STORE('>'); \ 127 STORE('\0'); \ 128 if ((size_t)total_len < bufsize) \ 129 snprintf(bp, bufsize - total_len, num_fmt, \ 130 (uintmax_t)val); \ 131 total_len += val_len; \ 132 line_len = val_len; \ 133 bp += val_len; \ 134 } while (0) 135 136 #define PUTSEP() do { \ 137 if (line_max > 0 && (size_t)line_len >= line_max) { \ 138 BACKUP(); \ 139 STORE('<'); \ 140 } else { \ 141 /* Remember separator location */ \ 142 if (line_max > 0 && sep != '<') { \ 143 sep_line_len = line_len; \ 144 sep_bp = bp; \ 145 sep_bitfmt = cur_bitfmt; \ 146 } \ 147 STORE(sep); \ 148 restart = 0; \ 149 } \ 150 } while (0) 151 152 #define PUTCHR(c) do { \ 153 if (line_max > 0 && (size_t)line_len >= line_max - 1) { \ 154 BACKUP(); \ 155 if (restart == 0) \ 156 STORE(c); \ 157 else \ 158 sep = '<'; \ 159 } else { \ 160 STORE(c); \ 161 restart = 0; \ 162 } \ 163 } while (0) 164 165 #define PUTS(s) do { \ 166 while ((*(s)++) != 0) { \ 167 PUTCHR((s)[-1]); \ 168 if (restart) \ 169 break; \ 170 } \ 171 } while (0) 172 173 #define FMTSTR(sb, f) do { \ 174 int fmt_len = snprintf(bp, bufsize - total_len, sb, \ 175 (uintmax_t)f); \ 176 if (fmt_len < 0) \ 177 goto internal; \ 178 total_len += fmt_len; \ 179 line_len += fmt_len; \ 180 if ((size_t)total_len < bufsize) \ 181 bp += fmt_len; \ 182 } while (0) 183 184 sep = '<'; 185 if (old_style) { 186 /* old-style format, 32-bit, 1-origin. */ 187 for (uint8_t bit; (bit = *bitfmt) != 0;) { 188 cur_bitfmt = bitfmt++; 189 if (val & (1U << (bit - 1))) { 190 PUTSEP(); 191 if (restart) 192 continue; 193 sep = ','; 194 for (; *bitfmt > ' '; ++bitfmt) { 195 PUTCHR(*bitfmt); 196 if (restart) 197 break; 198 } 199 } else 200 for (; *bitfmt > ' '; ++bitfmt) 201 continue; 202 } 203 } else { 204 /* new-style format, 64-bit, 0-origin; also does fields. */ 205 uint64_t field = val; 206 int matched = 1; 207 while (*bitfmt != '\0') { 208 uint8_t kind = *bitfmt++; 209 uint8_t bit = *bitfmt++; 210 switch (kind) { 211 case 'b': 212 if (((val >> bit) & 1) == 0) 213 goto skip; 214 cur_bitfmt = bitfmt - 2; 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_bitfmt = bitfmt - 2; 226 uint8_t field_width = *bitfmt++; 227 field = (val >> bit) & 228 (((uint64_t)1 << field_width) - 1); 229 PUTSEP(); 230 if (restart == 0) 231 sep = ','; 232 if (kind == '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 (field != bit) 258 goto skip; 259 matched = 1; 260 if (kind == '=') 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 if (line_max > 0) { 282 bufsize++; 283 STORE('\0'); 284 if ((size_t)total_len >= bufsize && bufsize > 1) 285 buf[bufsize - 2] = '\0'; 286 } 287 STORE('\0'); 288 if ((size_t)total_len >= bufsize && bufsize > 0) 289 buf[bufsize - 1] = '\0'; 290 return total_len - 1; 291 internal: 292 #ifndef _KERNEL 293 errno = EINVAL; 294 #endif 295 return -1; 296 } 297 298 int 299 snprintb(char *buf, size_t bufsize, const char *bitfmt, uint64_t val) 300 { 301 return snprintb_m(buf, bufsize, bitfmt, val, 0); 302 } 303 # endif /* ! HAVE_SNPRINTB_M */ 304 #endif /* ! _STANDALONE */ 305
Indexes created Mon Sep 22 13:09:51 GMT 2025