snprintb.c revision 1.34
1 /* $NetBSD: snprintb.c,v 1.34 2024/02/16 21:25:46 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 1.34 2024/02/16 21:25:46 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 1.34 2024/02/16 21:25:46 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 const char *num_fmt, *cur_bitfmt, *sep_bitfmt = NULL; 67 char sep; 68 int restart = 0; 69 70 #ifdef _KERNEL 71 /* 72 * For safety; no other *s*printf() do this, but in the kernel 73 * we don't usually check the return value 74 */ 75 (void)memset(buf, 0, bufsize); 76 #endif /* _KERNEL */ 77 78 int old_style = *bitfmt != '\177'; 79 if (!old_style) 80 bitfmt++; 81 switch (*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 int val_len = snprintf(buf, bufsize, num_fmt, (uintmax_t)val); 96 if (val_len < 0) 97 goto internal; 98 99 size_t total_len = val_len, line_len = val_len, sep_line_len = 0; 100 101 #define STORE(c) do { \ 102 if (total_len < bufsize) \ 103 buf[total_len] = (c); \ 104 total_len++; \ 105 line_len++; \ 106 } while (0) 107 108 #define BACKUP() do { \ 109 if (sep_line_len > 0) { \ 110 total_len -= line_len - sep_line_len; \ 111 sep_line_len = 0; \ 112 restart = 1; \ 113 bitfmt = sep_bitfmt; \ 114 } \ 115 STORE('>'); \ 116 STORE('\0'); \ 117 if (total_len < bufsize) \ 118 snprintf(buf + total_len, bufsize - total_len, \ 119 num_fmt, (uintmax_t)val); \ 120 total_len += val_len; \ 121 line_len = val_len; \ 122 } while (0) 123 124 #define PUTSEP() do { \ 125 if (line_max > 0 && line_len >= line_max) { \ 126 BACKUP(); \ 127 STORE('<'); \ 128 } else { \ 129 if (line_max > 0 && sep != '<') { \ 130 sep_line_len = line_len; \ 131 sep_bitfmt = cur_bitfmt; \ 132 } \ 133 STORE(sep); \ 134 restart = 0; \ 135 } \ 136 } while (0) 137 138 #define PUTCHR(c) do { \ 139 if (line_max > 0 && line_len >= line_max - 1) { \ 140 BACKUP(); \ 141 if (restart == 0) \ 142 STORE(c); \ 143 else \ 144 sep = '<'; \ 145 } else { \ 146 STORE(c); \ 147 restart = 0; \ 148 } \ 149 } while (0) 150 151 #define PUTS(s) do { \ 152 while ((*(s)++) != 0) { \ 153 PUTCHR((s)[-1]); \ 154 if (restart) \ 155 break; \ 156 } \ 157 } while (0) 158 159 #define FMTSTR(sb, f) do { \ 160 char *bp = total_len < bufsize ? buf + total_len : NULL; \ 161 size_t n = total_len < bufsize ? bufsize - total_len : 0; \ 162 int fmt_len = snprintf(bp, n, sb, (uintmax_t)f); \ 163 if (fmt_len < 0) \ 164 goto internal; \ 165 total_len += fmt_len; \ 166 line_len += fmt_len; \ 167 } while (0) 168 169 sep = '<'; 170 if (old_style) { 171 /* old-style format, 32-bit, 1-origin. */ 172 for (uint8_t bit; (bit = *bitfmt) != 0;) { 173 cur_bitfmt = bitfmt++; 174 if (val & (1U << (bit - 1))) { 175 PUTSEP(); 176 if (restart) 177 continue; 178 sep = ','; 179 for (; *bitfmt > ' '; ++bitfmt) { 180 PUTCHR(*bitfmt); 181 if (restart) 182 break; 183 } 184 } else 185 for (; *bitfmt > ' '; ++bitfmt) 186 continue; 187 } 188 } else { 189 /* new-style format, 64-bit, 0-origin; also does fields. */ 190 uint64_t field = val; 191 int matched = 1; 192 while (*bitfmt != '\0') { 193 uint8_t kind = *bitfmt++; 194 uint8_t bit = *bitfmt++; 195 switch (kind) { 196 case 'b': 197 if (((val >> bit) & 1) == 0) 198 goto skip; 199 cur_bitfmt = bitfmt - 2; 200 PUTSEP(); 201 if (restart) 202 break; 203 PUTS(bitfmt); 204 if (restart == 0) 205 sep = ','; 206 break; 207 case 'f': 208 case 'F': 209 matched = 0; 210 cur_bitfmt = bitfmt - 2; 211 uint8_t field_width = *bitfmt++; 212 field = (val >> bit) & 213 (((uint64_t)1 << field_width) - 1); 214 PUTSEP(); 215 if (restart == 0) 216 sep = ','; 217 if (kind == 'F') { /* just extract */ 218 /* duplicate PUTS() effect on bitfmt */ 219 while (*bitfmt++ != '\0') 220 continue; 221 break; 222 } 223 if (restart == 0) 224 PUTS(bitfmt); 225 if (restart == 0) 226 PUTCHR('='); 227 if (restart == 0) { 228 FMTSTR(num_fmt, field); 229 if (line_max > 0 230 && line_len > line_max) 231 PUTCHR('#'); 232 } 233 break; 234 case '=': 235 case ':': 236 /* 237 * Here "bit" is actually a value instead, 238 * to be compared against the last field. 239 * This only works for values in [0..255], 240 * of course. 241 */ 242 if (field != bit) 243 goto skip; 244 matched = 1; 245 if (kind == '=') 246 PUTCHR('='); 247 PUTS(bitfmt); 248 break; 249 case '*': 250 bitfmt--; 251 if (!matched) { 252 matched = 1; 253 FMTSTR(bitfmt, field); 254 } 255 /*FALLTHROUGH*/ 256 default: 257 skip: 258 while (*bitfmt++ != '\0') 259 continue; 260 break; 261 } 262 } 263 } 264 if (sep != '<') 265 STORE('>'); 266 if (line_max > 0) { 267 STORE('\0'); 268 if (bufsize >= 2 && total_len > bufsize - 2) 269 buf[bufsize - 2] = '\0'; 270 } 271 STORE('\0'); 272 if (bufsize >= 1 && total_len > bufsize - 1) 273 buf[bufsize - 1] = '\0'; 274 return (int)(total_len - 1); 275 internal: 276 #ifndef _KERNEL 277 errno = EINVAL; 278 #endif 279 return -1; 280 } 281 282 int 283 snprintb(char *buf, size_t bufsize, const char *bitfmt, uint64_t val) 284 { 285 return snprintb_m(buf, bufsize, bitfmt, val, 0); 286 } 287 # endif /* ! HAVE_SNPRINTB_M */ 288 #endif /* ! _STANDALONE */ 289
Indexes created Thu Oct 02 14:10:14 GMT 2025