mirror of
https://github.com/reactos/reactos.git
synced 2024-11-19 21:48:10 +00:00
98 lines
2.5 KiB
C
98 lines
2.5 KiB
C
/*
|
|
* COPYRIGHT: See COPYING in the top level directory
|
|
* PROJECT: ReactOS system libraries
|
|
* FILE: lib/sdk/crt/string/wcstol.c
|
|
* PURPOSE: Unknown
|
|
* PROGRAMER: Unknown
|
|
* UPDATE HISTORY:
|
|
* 25/11/05: Added license header
|
|
*/
|
|
|
|
#include <precomp.h>
|
|
/*
|
|
* @implemented
|
|
*/
|
|
long
|
|
CDECL
|
|
wcstol(const wchar_t *nptr, wchar_t **endptr, int base)
|
|
{
|
|
const wchar_t *s = nptr;
|
|
long acc;
|
|
int c;
|
|
unsigned long cutoff;
|
|
int neg = 0, any, cutlim;
|
|
|
|
/*
|
|
* Skip white space and pick up leading +/- sign if any.
|
|
* If base is 0, allow 0x for hex and 0 for octal, else
|
|
* assume decimal; if base is already 16, allow 0x.
|
|
*/
|
|
do {
|
|
c = *s++;
|
|
} while (iswctype(c, _SPACE));
|
|
if (c == '-')
|
|
{
|
|
neg = 1;
|
|
c = *s++;
|
|
}
|
|
else if (c == L'+')
|
|
c = *s++;
|
|
if ((base == 0 || base == 16) &&
|
|
c == L'0' && (*s == L'x' || *s == L'X'))
|
|
{
|
|
c = s[1];
|
|
s += 2;
|
|
base = 16;
|
|
}
|
|
if (base == 0)
|
|
base = c == L'0' ? 8 : 10;
|
|
|
|
/*
|
|
* Compute the cutoff value between legal numbers and illegal
|
|
* numbers. That is the largest legal value, divided by the
|
|
* base. An input number that is greater than this value, if
|
|
* followed by a legal input character, is too big. One that
|
|
* is equal to this value may be valid or not; the limit
|
|
* between valid and invalid numbers is then based on the last
|
|
* digit. For instance, if the range for longs is
|
|
* [-2147483648..2147483647] and the input base is 10,
|
|
* cutoff will be set to 214748364 and cutlim to either
|
|
* 7 (neg==0) or 8 (neg==1), meaning that if we have accumulated
|
|
* a value > 214748364, or equal but the next digit is > 7 (or 8),
|
|
* the number is too big, and we will return a range error.
|
|
*
|
|
* Set any if any `digits' consumed; make it negative to indicate
|
|
* overflow.
|
|
*/
|
|
cutoff = neg ? ((unsigned long)LONG_MAX+1) : LONG_MAX;
|
|
cutlim = cutoff % (unsigned long)base;
|
|
cutoff /= (unsigned long)base;
|
|
for (acc = 0, any = 0;; c = *s++)
|
|
{
|
|
if (iswctype(c, _DIGIT))
|
|
c -= L'0';
|
|
else if (iswctype(c, _ALPHA))
|
|
c -= iswctype(c, _UPPER) ? L'A' - 10 : L'a' - 10;
|
|
else
|
|
break;
|
|
if (c >= base)
|
|
break;
|
|
if (any < 0 || (unsigned long)acc > cutoff || (acc == cutoff && c > cutlim))
|
|
any = -1;
|
|
else
|
|
{
|
|
any = 1;
|
|
acc *= base;
|
|
acc += c;
|
|
}
|
|
}
|
|
if (any < 0)
|
|
{
|
|
acc = neg ? LONG_MIN : LONG_MAX;
|
|
}
|
|
else if (neg)
|
|
acc = 0-acc;
|
|
if (endptr != 0)
|
|
*endptr = any ? (wchar_t *)((size_t)(s - 1)) : (wchar_t *)((size_t)nptr);
|
|
return acc;
|
|
}
|