1 // SPDX-License-Identifier: GPL-2.0-only 2 /* -*- linux-c -*- ------------------------------------------------------- * 3 * 4 * Copyright (C) 1991, 1992 Linus Torvalds 5 * Copyright 2007 rPath, Inc. - All Rights Reserved 6 * 7 * ----------------------------------------------------------------------- */ 8 9 /* 10 * Oh, it's a waste of space, but oh-so-yummy for debugging. This 11 * version of printf() does not include 64-bit support. "Live with 12 * it." 13 * 14 */ 15 16 #include <stdarg.h> 17 18 #include <linux/compiler.h> 19 #include <linux/ctype.h> 20 #include <linux/string.h> 21 22 static int skip_atoi(const char **s) 23 { 24 int i = 0; 25 26 while (isdigit(**s)) 27 i = i * 10 + *((*s)++) - '0'; 28 return i; 29 } 30 31 #define ZEROPAD 1 /* pad with zero */ 32 #define SIGN 2 /* unsigned/signed long */ 33 #define PLUS 4 /* show plus */ 34 #define SPACE 8 /* space if plus */ 35 #define LEFT 16 /* left justified */ 36 #define SMALL 32 /* Must be 32 == 0x20 */ 37 #define SPECIAL 64 /* 0x */ 38 39 #define __do_div(n, base) ({ \ 40 int __res; \ 41 __res = ((unsigned long) n) % (unsigned) base; \ 42 n = ((unsigned long) n) / (unsigned) base; \ 43 __res; }) 44 45 static char *number(char *str, long num, int base, int size, int precision, 46 int type) 47 { 48 /* we are called with base 8, 10 or 16, only, thus don't need "G..." */ 49 static const char digits[16] = "0123456789ABCDEF"; /* "GHIJKLMNOPQRSTUVWXYZ"; */ 50 51 char tmp[66]; 52 char c, sign, locase; 53 int i; 54 55 /* locase = 0 or 0x20. ORing digits or letters with 'locase' 56 * produces same digits or (maybe lowercased) letters */ 57 locase = (type & SMALL); 58 if (type & LEFT) 59 type &= ~ZEROPAD; 60 if (base < 2 || base > 16) 61 return NULL; 62 c = (type & ZEROPAD) ? '0' : ' '; 63 sign = 0; 64 if (type & SIGN) { 65 if (num < 0) { 66 sign = '-'; 67 num = -num; 68 size--; 69 } else if (type & PLUS) { 70 sign = '+'; 71 size--; 72 } else if (type & SPACE) { 73 sign = ' '; 74 size--; 75 } 76 } 77 if (type & SPECIAL) { 78 if (base == 16) 79 size -= 2; 80 else if (base == 8) 81 size--; 82 } 83 i = 0; 84 if (num == 0) 85 tmp[i++] = '0'; 86 else 87 while (num != 0) 88 tmp[i++] = (digits[__do_div(num, base)] | locase); 89 if (i > precision) 90 precision = i; 91 size -= precision; 92 if (!(type & (ZEROPAD + LEFT))) 93 while (size-- > 0) 94 *str++ = ' '; 95 if (sign) 96 *str++ = sign; 97 if (type & SPECIAL) { 98 if (base == 8) { 99 *str++ = '0'; 100 } else if (base == 16) { 101 *str++ = '0'; 102 *str++ = ('X' | locase); 103 } 104 } 105 if (!(type & LEFT)) 106 while (size-- > 0) 107 *str++ = c; 108 while (i < precision--) 109 *str++ = '0'; 110 while (i-- > 0) 111 *str++ = tmp[i]; 112 while (size-- > 0) 113 *str++ = ' '; 114 return str; 115 } 116 117 int vsprintf(char *buf, const char *fmt, va_list args) 118 { 119 int len; 120 unsigned long num; 121 int i, base; 122 char *str; 123 const char *s; 124 125 int flags; /* flags to number() */ 126 127 int field_width; /* width of output field */ 128 int precision; /* min. # of digits for integers; max 129 number of chars for from string */ 130 int qualifier; /* 'h' or 'l' for integer fields */ 131 132 for (str = buf; *fmt; ++fmt) { 133 if (*fmt != '%') { 134 *str++ = *fmt; 135 continue; 136 } 137 138 /* process flags */ 139 flags = 0; 140 repeat: 141 ++fmt; /* this also skips first '%' */ 142 switch (*fmt) { 143 case '-': 144 flags |= LEFT; 145 goto repeat; 146 case '+': 147 flags |= PLUS; 148 goto repeat; 149 case ' ': 150 flags |= SPACE; 151 goto repeat; 152 case '#': 153 flags |= SPECIAL; 154 goto repeat; 155 case '0': 156 flags |= ZEROPAD; 157 goto repeat; 158 } 159 160 /* get field width */ 161 field_width = -1; 162 if (isdigit(*fmt)) { 163 field_width = skip_atoi(&fmt); 164 } else if (*fmt == '*') { 165 ++fmt; 166 /* it's the next argument */ 167 field_width = va_arg(args, int); 168 if (field_width < 0) { 169 field_width = -field_width; 170 flags |= LEFT; 171 } 172 } 173 174 /* get the precision */ 175 precision = -1; 176 if (*fmt == '.') { 177 ++fmt; 178 if (isdigit(*fmt)) { 179 precision = skip_atoi(&fmt); 180 } else if (*fmt == '*') { 181 ++fmt; 182 /* it's the next argument */ 183 precision = va_arg(args, int); 184 } 185 if (precision < 0) 186 precision = 0; 187 } 188 189 /* get the conversion qualifier */ 190 qualifier = -1; 191 if (*fmt == 'h' || *fmt == 'l') { 192 qualifier = *fmt; 193 ++fmt; 194 } 195 196 /* default base */ 197 base = 10; 198 199 switch (*fmt) { 200 case 'c': 201 if (!(flags & LEFT)) 202 while (--field_width > 0) 203 *str++ = ' '; 204 *str++ = (unsigned char)va_arg(args, int); 205 while (--field_width > 0) 206 *str++ = ' '; 207 continue; 208 209 case 's': 210 s = va_arg(args, char *); 211 len = strnlen(s, precision); 212 213 if (!(flags & LEFT)) 214 while (len < field_width--) 215 *str++ = ' '; 216 for (i = 0; i < len; ++i) 217 *str++ = *s++; 218 while (len < field_width--) 219 *str++ = ' '; 220 continue; 221 222 case 'p': 223 if (field_width == -1) { 224 field_width = 2 * sizeof(void *); 225 flags |= ZEROPAD; 226 } 227 str = number(str, 228 (unsigned long)va_arg(args, void *), 16, 229 field_width, precision, flags); 230 continue; 231 232 case '%': 233 *str++ = '%'; 234 continue; 235 236 /* integer number formats - set up the flags and "break" */ 237 case 'o': 238 base = 8; 239 break; 240 241 case 'x': 242 flags |= SMALL; 243 fallthrough; 244 case 'X': 245 base = 16; 246 break; 247 248 case 'd': 249 case 'i': 250 flags |= SIGN; 251 fallthrough; 252 case 'u': 253 break; 254 255 default: 256 *str++ = '%'; 257 if (*fmt) 258 *str++ = *fmt; 259 else 260 --fmt; 261 continue; 262 } 263 if (qualifier == 'l') { 264 num = va_arg(args, unsigned long); 265 } else if (qualifier == 'h') { 266 num = (unsigned short)va_arg(args, int); 267 if (flags & SIGN) 268 num = (short)num; 269 } else if (flags & SIGN) { 270 num = va_arg(args, int); 271 } else { 272 num = va_arg(args, unsigned int); 273 } 274 str = number(str, num, base, field_width, precision, flags); 275 } 276 *str = '\0'; 277 return str - buf; 278 } 279 280 int sprintf(char *buf, const char *fmt, ...) 281 { 282 va_list args; 283 int i; 284 285 va_start(args, fmt); 286 i = vsprintf(buf, fmt, args); 287 va_end(args); 288 return i; 289 } 290