src/console/vtxprintf.c

   1 /*  vtxprintf.c, from
   2  *    linux/lib/vsprintf.c
   3  *
   4  *  Copyright (C) 1991, 1992  Linus Torvalds
   5  */
   6
   7 #include <string.h>
   8 #include <div64.h>
   9 #include <console/vtxprintf.h>
  10
  11 /* haha, don't need ctype.c */
  12 #define isdigit(c)      ((c) >= '0' && (c) <= '9')
  13 #define is_digit isdigit
  14 #define isxdigit(c)     (((c) >= '0' && (c) <= '9') || ((c) >= 'a' && (c) <= 'f') || ((c) >= 'A' && (c) <= 'F'))
  15
  16 static int skip_atoi(const char **s)
  17 {
  18         int i=0;
  19
  20         while (is_digit(**s))
  21                 i = i*10 + *((*s)++) - '0';
  22         return i;
  23 }
  24
  25 #define ZEROPAD 1               /* pad with zero */
  26 #define SIGN    2               /* unsigned/signed long */
  27 #define PLUS    4               /* show plus */
  28 #define SPACE   8               /* space if plus */
  29 #define LEFT    16              /* left justified */
  30 #define SPECIAL 32              /* 0x */
  31 #define LARGE   64              /* use 'ABCDEF' instead of 'abcdef' */
  32
  33 static int number(void (*tx_byte)(unsigned char byte),
  34         unsigned long long num, int base, int size, int precision, int type)
  35 {
  36         char c,sign,tmp[66];
  37         const char *digits="0123456789abcdefghijklmnopqrstuvwxyz";
  38         int i;
  39         int count = 0;
  40
  41         if (type & LARGE)
  42                 digits = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";
  43         if (type & LEFT)
  44                 type &= ~ZEROPAD;
  45         if (base < 2 || base > 36)
  46                 return 0;
  47         c = (type & ZEROPAD) ? '0' : ' ';
  48         sign = 0;
  49         if (type & SIGN) {
  50                 if ((signed long long)num < 0) {
  51                         sign = '-';
  52                         num = -num;
  53                         size--;
  54                 } else if (type & PLUS) {
  55                         sign = '+';
  56                         size--;
  57                 } else if (type & SPACE) {
  58                         sign = ' ';
  59                         size--;
  60                 }
  61         }
  62         if (type & SPECIAL) {
  63                 if (base == 16)
  64                         size -= 2;
  65                 else if (base == 8)
  66                         size--;
  67         }
  68         i = 0;
  69         if (num == 0)
  70                 tmp[i++]='0';
  71         else while (num != 0)
  72                 tmp[i++] = digits[do_div(num,base)];
  73         if (i > precision)
  74                 precision = i;
  75         size -= precision;
  76         if (!(type&(ZEROPAD+LEFT)))
  77                 while(size-->0)
  78                         tx_byte(' '), count++;
  79         if (sign)
  80                 tx_byte(sign), count++;
  81         if (type & SPECIAL) {
  82                 if (base==8)
  83                         tx_byte('0'), count++;
  84                 else if (base==16) {
  85                         tx_byte('0'), count++;
  86                         tx_byte(digits[33]), count++;
  87                 }
  88         }
  89         if (!(type & LEFT))
  90                 while (size-- > 0)
  91                         tx_byte(c), count++;
  92         while (i < precision--)
  93                 tx_byte('0'), count++;
  94         while (i-- > 0)
  95                 tx_byte(tmp[i]), count++;
  96         while (size-- > 0)
  97                 tx_byte(' '), count++;
  98         return count;
  99 }
 100
 101
 102 int vtxprintf(void (*tx_byte)(unsigned char byte), const char *fmt, va_list args)
 103 {
 104         int len;
 105         unsigned long long num;
 106         int i, base;
 107         const char *s;
 108
 109         int flags;              /* flags to number() */
 110
 111         int field_width;        /* width of output field */
 112         int precision;          /* min. # of digits for integers; max
 113                                    number of chars for from string */
 114         int qualifier;          /* 'h', 'l', or 'L' for integer fields */
 115
 116         int count;
 117
 118         for (count=0; *fmt ; ++fmt) {
 119                 if (*fmt != '%') {
 120                         tx_byte(*fmt), count++;
 121                         continue;
 122                 }
 123
 124                 /* process flags */
 125                 flags = 0;
 126                 repeat:
 127                         ++fmt;          /* this also skips first '%' */
 128                         switch (*fmt) {
 129                                 case '-': flags |= LEFT; goto repeat;
 130                                 case '+': flags |= PLUS; goto repeat;
 131                                 case ' ': flags |= SPACE; goto repeat;
 132                                 case '#': flags |= SPECIAL; goto repeat;
 133                                 case '0': flags |= ZEROPAD; goto repeat;
 134                                 }
 135
 136                 /* get field width */
 137                 field_width = -1;
 138                 if (is_digit(*fmt))
 139                         field_width = skip_atoi(&fmt);
 140                 else if (*fmt == '*') {
 141                         ++fmt;
 142                         /* it's the next argument */
 143                         field_width = va_arg(args, int);
 144                         if (field_width < 0) {
 145                                 field_width = -field_width;
 146                                 flags |= LEFT;
 147                         }
 148                 }
 149
 150                 /* get the precision */
 151                 precision = -1;
 152                 if (*fmt == '.') {
 153                         ++fmt;
 154                         if (is_digit(*fmt))
 155                                 precision = skip_atoi(&fmt);
 156                         else if (*fmt == '*') {
 157                                 ++fmt;
 158                                 /* it's the next argument */
 159                                 precision = va_arg(args, int);
 160                         }
 161                         if (precision < 0)
 162                                 precision = 0;
 163                 }
 164
 165                 /* get the conversion qualifier */
 166                 qualifier = -1;
 167                 if (*fmt == 'h' || *fmt == 'l' || *fmt == 'L') {
 168                         qualifier = *fmt;
 169                         ++fmt;
 170                         if (*fmt == 'l') {
 171                                 qualifier = 'L';
 172                                 ++fmt;
 173                         }
 174                 }
 175
 176                 /* default base */
 177                 base = 10;
 178
 179                 switch (*fmt) {
 180                 case 'c':
 181                         if (!(flags & LEFT))
 182                                 while (--field_width > 0)
 183                                         tx_byte(' '), count++;
 184                         tx_byte((unsigned char) va_arg(args, int)), count++;
 185                         while (--field_width > 0)
 186                                 tx_byte(' '), count++;
 187                         continue;
 188
 189                 case 's':
 190                         s = va_arg(args, char *);
 191                         if (!s)
 192                                 s = "<NULL>";
 193
 194                         len = strnlen(s, precision);
 195
 196                         if (!(flags & LEFT))
 197                                 while (len < field_width--)
 198                                         tx_byte(' '), count++;
 199                         for (i = 0; i < len; ++i)
 200                                 tx_byte(*s++), count++;
 201                         while (len < field_width--)
 202                                 tx_byte(' '), count++;
 203                         continue;
 204
 205                 case 'p':
 206                         if (field_width == -1) {
 207                                 field_width = 2*sizeof(void *);
 208                                 flags |= ZEROPAD;
 209                         }
 210                         count += number(tx_byte,
 211                                 (unsigned long) va_arg(args, void *), 16,
 212                                 field_width, precision, flags);
 213                         continue;
 214
 215
 216                 case 'n':
 217                         if (qualifier == 'L') {
 218                                 long long *ip = va_arg(args, long long *);
 219                                 *ip = count;
 220                         } else if (qualifier == 'l') {
 221                                 long * ip = va_arg(args, long *);
 222                                 *ip = count;
 223                         } else {
 224                                 int * ip = va_arg(args, int *);
 225                                 *ip = count;
 226                         }
 227                         continue;
 228
 229                 case '%':
 230                         tx_byte('%'), count++;
 231                         continue;
 232
 233                 /* integer number formats - set up the flags and "break" */
 234                 case 'o':
 235                         base = 8;
 236                         break;
 237
 238                 case 'X':
 239                         flags |= LARGE;
 240                 case 'x':
 241                         base = 16;
 242                         break;
 243
 244                 case 'd':
 245                 case 'i':
 246                         flags |= SIGN;
 247                 case 'u':
 248                         break;
 249
 250                 default:
 251                         tx_byte('%'), count++;
 252                         if (*fmt)
 253                                 tx_byte(*fmt), count++;
 254                         else
 255                                 --fmt;
 256                         continue;
 257                 }
 258                 if (qualifier == 'L') {
 259                         num = va_arg(args, unsigned long long);
 260                 } else if (qualifier == 'l') {
 261                         num = va_arg(args, unsigned long);
 262                 } else if (qualifier == 'h') {
 263                         num = (unsigned short) va_arg(args, int);
 264                         if (flags & SIGN)
 265                                 num = (short) num;
 266                 } else if (flags & SIGN) {
 267                         num = va_arg(args, int);
 268                 } else {
 269                         num = va_arg(args, unsigned int);
 270                 }
 271                 count += number(tx_byte, num, base, field_width, precision, flags);
 272         }
 273         return count;
 274 }
 275