lib/printf.c

   1 /*
   2  * (C) Copyright 2004 Texas Instruments
   3  *
   4  * Based on the following file:
   5  *  linux/lib/vsprintf.c
   6  *
   7  *  Copyright (C) 1991, 1992  Linus Torvalds
   8  */
   9
  10 /* vsprintf.c -- Lars Wirzenius & Linus Torvalds. */
  11 /*
  12  * Wirzenius wrote this portably, Torvalds fucked it up :-)
  13  */
  14
  15 #include <stdarg.h>
  16 #include <common.h>
  17
  18 #ifdef CFG_PRINTF
  19
  20 /* we use this so that we can do without the ctype library */
  21 #define is_digit(c)     ((c) >= '0' && (c) <= '9')
  22
  23 size_t strnlen(const char * s, size_t count)
  24 {
  25         const char *sc;
  26
  27         for (sc = s; count-- && *sc != '\0'; ++sc)
  28                 /* nothing */;
  29         return sc - s;
  30 }
  31
  32 static int skip_atoi(const char **s)
  33 {
  34         int i=0;
  35
  36         while (is_digit(**s))
  37                 i = i*10 + *((*s)++) - '0';
  38         return i;
  39 }
  40
  41 #define ZEROPAD 1               /* pad with zero */
  42 #define SIGN    2               /* unsigned/signed long */
  43 #define PLUS    4               /* show plus */
  44 #define SPACE   8               /* space if plus */
  45 #define LEFT    16              /* left justified */
  46 #define SPECIAL 32              /* 0x */
  47 #define LARGE   64              /* use 'ABCDEF' instead of 'abcdef' */
  48
  49 #define do_div(n,base) ({ \
  50 int __res; \
  51 __res = ((unsigned long) n) % (unsigned) base; \
  52 n = ((unsigned long) n) / (unsigned) base; \
  53 __res; })
  54
  55 static char * number(char * str, long num, int base, int size, int precision
  56         ,int type)
  57 {
  58         char c,sign,tmp[66];
  59         const char *digits="0123456789abcdefghijklmnopqrstuvwxyz";
  60         int i;
  61
  62         if (type & LARGE)
  63                 digits = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";
  64         if (type & LEFT)
  65                 type &= ~ZEROPAD;
  66         if (base < 2 || base > 36)
  67                 return 0;
  68         c = (type & ZEROPAD) ? '0' : ' ';
  69         sign = 0;
  70         if (type & SIGN) {
  71                 if (num < 0) {
  72                         sign = '-';
  73                         num = -num;
  74                         size--;
  75                 } else if (type & PLUS) {
  76                         sign = '+';
  77                         size--;
  78                 } else if (type & SPACE) {
  79                         sign = ' ';
  80                         size--;
  81                 }
  82         }
  83         if (type & SPECIAL) {
  84                 if (base == 16)
  85                         size -= 2;
  86                 else if (base == 8)
  87                         size--;
  88         }
  89         i = 0;
  90         if (num == 0)
  91                 tmp[i++]='0';
  92         else while (num != 0)
  93                 tmp[i++] = digits[do_div(num,base)];
  94         if (i > precision)
  95                 precision = i;
  96         size -= precision;
  97         if (!(type&(ZEROPAD+LEFT)))
  98                 while(size-->0)
  99                         *str++ = ' ';
 100         if (sign)
 101                 *str++ = sign;
 102         if (type & SPECIAL) {
 103                 if (base==8)
 104                         *str++ = '0';
 105                 else if (base==16) {
 106                         *str++ = '0';
 107                         *str++ = digits[33];
 108                 }
 109         }
 110         if (!(type & LEFT))
 111                 while (size-- > 0)
 112                         *str++ = c;
 113         while (i < precision--)
 114                 *str++ = '0';
 115         while (i-- > 0)
 116                 *str++ = tmp[i];
 117         while (size-- > 0)
 118                 *str++ = ' ';
 119         return str;
 120 }
 121
 122
 123 static int vsprintf(char *buf, const char *fmt, va_list args)
 124 {
 125         int len;
 126         unsigned long num;
 127         int i, base;
 128         char * str;
 129         const char *s;
 130
 131         int flags;              /* flags to number() */
 132
 133         int field_width;        /* width of output field */
 134         int precision;          /* min. # of digits for integers; max
 135                                    number of chars for from string */
 136         int qualifier;          /* 'h', 'l', or 'L' for integer fields */
 137
 138         for (str=buf ; *fmt ; ++fmt) {
 139                 if (*fmt != '%') {
 140                         *str++ = *fmt;
 141                         continue;
 142                 }
 143
 144                 /* process flags */
 145                 flags = 0;
 146                 repeat:
 147                         ++fmt;          /* this also skips first '%' */
 148                         switch (*fmt) {
 149                                 case '-': flags |= LEFT; goto repeat;
 150                                 case '+': flags |= PLUS; goto repeat;
 151                                 case ' ': flags |= SPACE; goto repeat;
 152                                 case '#': flags |= SPECIAL; goto repeat;
 153                                 case '0': flags |= ZEROPAD; goto repeat;
 154                                 }
 155
 156                 /* get field width */
 157                 field_width = -1;
 158                 if (is_digit(*fmt))
 159                         field_width = skip_atoi(&fmt);
 160                 else if (*fmt == '*') {
 161                         ++fmt;
 162                         /* it's the next argument */
 163                         field_width = va_arg(args, int);
 164                         if (field_width < 0) {
 165                                 field_width = -field_width;
 166                                 flags |= LEFT;
 167                         }
 168                 }
 169
 170                 /* get the precision */
 171                 precision = -1;
 172                 if (*fmt == '.') {
 173                         ++fmt;
 174                         if (is_digit(*fmt))
 175                                 precision = skip_atoi(&fmt);
 176                         else if (*fmt == '*') {
 177                                 ++fmt;
 178                                 /* it's the next argument */
 179                                 precision = va_arg(args, int);
 180                         }
 181                         if (precision < 0)
 182                                 precision = 0;
 183                 }
 184
 185                 /* get the conversion qualifier */
 186                 qualifier = -1;
 187                 if (*fmt == 'h' || *fmt == 'l' || *fmt == 'L') {
 188                         qualifier = *fmt;
 189                         ++fmt;
 190                 }
 191
 192                 /* default base */
 193                 base = 10;
 194
 195                 switch (*fmt) {
 196                 case 'c':
 197                         if (!(flags & LEFT))
 198                                 while (--field_width > 0)
 199                                         *str++ = ' ';
 200                         *str++ = (unsigned char) va_arg(args, int);
 201                         while (--field_width > 0)
 202                                 *str++ = ' ';
 203                         continue;
 204
 205                 case 's':
 206                         s = va_arg(args, char *);
 207                         if (!s)
 208                                 s = "<NULL>";
 209
 210                         len = strnlen(s, precision);
 211
 212                         if (!(flags & LEFT))
 213                                 while (len < field_width--)
 214                                         *str++ = ' ';
 215                         for (i = 0; i < len; ++i)
 216                                 *str++ = *s++;
 217                         while (len < field_width--)
 218                                 *str++ = ' ';
 219                         continue;
 220
 221                 case 'p':
 222                         if (field_width == -1) {
 223                                 field_width = 2*sizeof(void *);
 224                                 flags |= ZEROPAD;
 225                         }
 226                         str = number(str,
 227                                 (unsigned long) va_arg(args, void *), 16,
 228                                 field_width, precision, flags);
 229                         continue;
 230
 231
 232                 case 'n':
 233                         if (qualifier == 'l') {
 234                                 long * ip = va_arg(args, long *);
 235                                 *ip = (str - buf);
 236                         } else {
 237                                 int * ip = va_arg(args, int *);
 238                                 *ip = (str - buf);
 239                         }
 240                         continue;
 241
 242                 case '%':
 243                         *str++ = '%';
 244                         continue;
 245
 246                 /* integer number formats - set up the flags and "break" */
 247                 case 'o':
 248                         base = 8;
 249                         break;
 250
 251                 case 'X':
 252                         flags |= LARGE;
 253                 case 'x':
 254                         base = 16;
 255                         break;
 256
 257                 case 'd':
 258                 case 'i':
 259                         flags |= SIGN;
 260                 case 'u':
 261                         break;
 262
 263                 default:
 264                         *str++ = '%';
 265                         if (*fmt)
 266                                 *str++ = *fmt;
 267                         else
 268                                 --fmt;
 269                         continue;
 270                 }
 271                 if (qualifier == 'l')
 272                         num = va_arg(args, unsigned long);
 273                 else if (qualifier == 'h') {
 274                         num = (unsigned short) va_arg(args, int);
 275                         if (flags & SIGN)
 276                                 num = (short) num;
 277                 } else if (flags & SIGN)
 278                         num = va_arg(args, int);
 279                 else
 280                         num = va_arg(args, unsigned int);
 281                 str = number(str, num, base, field_width, precision, flags);
 282         }
 283         *str = '\0';
 284         return str-buf;
 285 }
 286
 287 void serial_printf (const char *fmt, ...)
 288 {
 289         va_list args;
 290         uint i;
 291         char printbuffer[CFG_PBSIZE];
 292
 293         va_start (args, fmt);
 294
 295         /* For this to work, printbuffer must be larger than
 296          * anything we ever want to print.
 297          */
 298         i = vsprintf (printbuffer, fmt, args);
 299         va_end (args);
 300
 301         /* Print the string */
 302         serial_puts (printbuffer);
 303 }
 304 #endif