diff options
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/vsprintf.c | 73 |
1 files changed, 45 insertions, 28 deletions
diff --git a/lib/vsprintf.c b/lib/vsprintf.c index 017290241261..e94b4bd25bc5 100644 --- a/lib/vsprintf.c +++ b/lib/vsprintf.c @@ -143,12 +143,14 @@ static int skip_atoi(const char **s) #define SPECIAL 32 /* 0x */ #define LARGE 64 /* use 'ABCDEF' instead of 'abcdef' */ -static char * number(char * buf, char * end, unsigned long long num, int base, int size, int precision, int type) +static char *number(char *buf, char *end, unsigned long long num, int base, int size, int precision, int type) { - char c,sign,tmp[66]; + char sign,tmp[66]; const char *digits; - static const char small_digits[] = "0123456789abcdefghijklmnopqrstuvwxyz"; - static const char large_digits[] = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ"; + /* we are called with base 8, 10 or 16, only, thus don't need "g..." */ + static const char small_digits[] = "0123456789abcdefx"; /* "ghijklmnopqrstuvwxyz"; */ + static const char large_digits[] = "0123456789ABCDEFX"; /* "GHIJKLMNOPQRSTUVWXYZ"; */ + int need_pfx = ((type & SPECIAL) && base != 10); int i; digits = (type & LARGE) ? large_digits : small_digits; @@ -156,7 +158,6 @@ static char * number(char * buf, char * end, unsigned long long num, int base, i type &= ~ZEROPAD; if (base < 2 || base > 36) return NULL; - c = (type & ZEROPAD) ? '0' : ' '; sign = 0; if (type & SIGN) { if ((signed long long) num < 0) { @@ -171,64 +172,80 @@ static char * number(char * buf, char * end, unsigned long long num, int base, i size--; } } - if (type & SPECIAL) { + if (need_pfx) { + size--; if (base == 16) - size -= 2; - else if (base == 8) size--; } + + /* generate full string in tmp[], in reverse order */ i = 0; if (num == 0) - tmp[i++]='0'; - else while (num != 0) - tmp[i++] = digits[do_div(num,base)]; + tmp[i++] = '0'; + else if (base != 10) { /* 8 or 16 */ + int mask = base - 1; + int shift = 3; + if (base == 16) shift = 4; + do { + tmp[i++] = digits[((unsigned char)num) & mask]; + num >>= shift; + } while (num); + } else do { /* generic code, works for any base */ + tmp[i++] = digits[do_div(num,10 /*base*/)]; + } while (num); + + /* printing 100 using %2d gives "100", not "00" */ if (i > precision) precision = i; + /* leading space padding */ size -= precision; - if (!(type&(ZEROPAD+LEFT))) { - while(size-->0) { + if (!(type & (ZEROPAD+LEFT))) { + while(--size >= 0) { if (buf < end) *buf = ' '; ++buf; } } + /* sign */ if (sign) { if (buf < end) *buf = sign; ++buf; } - if (type & SPECIAL) { - if (base==8) { - if (buf < end) - *buf = '0'; - ++buf; - } else if (base==16) { - if (buf < end) - *buf = '0'; - ++buf; + /* "0x" / "0" prefix */ + if (need_pfx) { + if (buf < end) + *buf = '0'; + ++buf; + if (base == 16) { if (buf < end) - *buf = digits[33]; + *buf = digits[16]; /* for arbitrary base: digits[33]; */ ++buf; } } + /* zero or space padding */ if (!(type & LEFT)) { - while (size-- > 0) { + char c = (type & ZEROPAD) ? '0' : ' '; + while (--size >= 0) { if (buf < end) *buf = c; ++buf; } } - while (i < precision--) { + /* hmm even more zero padding? */ + while (i <= --precision) { if (buf < end) *buf = '0'; ++buf; } - while (i-- > 0) { + /* actual digits of result */ + while (--i >= 0) { if (buf < end) *buf = tmp[i]; ++buf; } - while (size-- > 0) { + /* trailing space padding */ + while (--size >= 0) { if (buf < end) *buf = ' '; ++buf; @@ -276,7 +293,7 @@ int vsnprintf(char *buf, size_t size, const char *fmt, va_list args) used for unknown buffer sizes. */ if (unlikely((int) size < 0)) { /* There can be only one.. */ - static int warn = 1; + static char warn = 1; WARN_ON(warn); warn = 0; return 0; |