root/win32/strtoi64.c

DEFINITIONS

1. _strtoi64

#if _MSC_VERS <= 1300
#include "php_strtoi64.h"
/*
        From APR, apr_strings.c
        See http://www.apache.org/licenses/LICENSE-2.0
*/

PHPAPI int64_t _strtoi64(const char *nptr, char **endptr, int base)
{
        const char *s;
        int64_t acc;
        int64_t val;
        int neg, any;
        char c;

        /*
         * 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.
         */
        s = nptr;
        do {
                c = *s++;
        } while (isspace((unsigned char)c));
        if (c == '-') {
                neg = 1;
                c = *s++;
        } else {
                neg = 0;
                if (c == '+') {
                        c = *s++;
                }
        }

        if ((base == 0 || base == 16) && c == '0' && (*s == 'x' || *s == 'X')) {
                c = s[1];
                s += 2;
                base = 16;
        }
        if (base == 0) {
                base = c == '0' ? 8 : 10;
        }
        acc = any = 0;
        if (base < 2 || base > 36) {
                errno = EINVAL;
                if (endptr != NULL) {
                        *endptr = (char *)(any ? s - 1 : nptr);
                }
                return acc;
        }

        /* The classic bsd implementation requires div/mod operators
         * to compute a cutoff.  Benchmarking proves that iss very, very
         * evil to some 32 bit processors.  Instead, look for underflow
         * in both the mult and add/sub operation.  Unlike the bsd impl,
         * we also work strictly in a signed int64 word as we haven't
         * implemented the unsigned type in win32.
         *
         * Set 'any' if any `digits' consumed; make it negative to indicate
         * overflow.
         */
    val = 0;
        for ( ; ; c = *s++) {
                if (c >= '0' && c <= '9')
                        c -= '0';

#if (('Z' - 'A') == 25)
                else if (c >= 'A' && c <= 'Z')
                        c -= 'A' - 10;
                else if (c >= 'a' && c <= 'z')
                        c -= 'a' - 10;
#elif APR_CHARSET_EBCDIC
                else if (c >= 'A' && c <= 'I')
                        c -= 'A' - 10;
                else if (c >= 'J' && c <= 'R')
                        c -= 'J' - 19;
                else if (c >= 'S' && c <= 'Z')
                        c -= 'S' - 28;
                else if (c >= 'a' && c <= 'i')
                        c -= 'a' - 10;
                else if (c >= 'j' && c <= 'r')
                        c -= 'j' - 19;
                else if (c >= 's' && c <= 'z')
                        c -= 'z' - 28;
#else
# error "CANNOT COMPILE apr_strtoi64(), only ASCII and EBCDIC supported"
#endif
                else {
                        break;
                }

                if (c >= base) {
                        break;
                }

                val *= base;
                if ( (any < 0)  /* already noted an over/under flow - short circuit */
                                || (neg && (val > acc || (val -= c) > acc)) /* underflow */
                                || (val < acc || (val += c) < acc)) {       /* overflow */
                        any = -1;       /* once noted, over/underflows never go away */
#ifdef APR_STRTOI64_OVERFLOW_IS_BAD_CHAR
                        break;
#endif
                } else {
                        acc = val;
                        any = 1;
                }
        }

        if (any < 0) {
                acc = neg ? INT64_MIN : INT64_MAX;
                errno = ERANGE;
        } else if (!any) {
                errno = EINVAL;
        }

        if (endptr != NULL) {
                *endptr = (char *)(any ? s - 1 : nptr);
        }
        return (acc);
}
#endif