unsigned long long strtoull(const char *str, char **end, int base)
{
- long long ret = 0;
+ unsigned long long ret = 0;
if( !str || base < 0 || base > 36 || base == 1 ) {
if(end)
// Handle base detection for hex
if( base == 0 || base == 16 ) {
- if( *str == '0' && str[1] == 'x' ) {
+ if( *str == '0' && (str[1] == 'x' || str[1] == 'X') && isxdigit(str[2]) ) {
str += 2;
base = 16;
}
if( base == 0 )
base = 10;
+ // Value before getting within 1 digit of ULLONG_MAX
+ // - Used to avoid overflow in more accurate check
+ unsigned long long max_before_ullong_max = ULLONG_MAX / base;
+ unsigned int space_above = ULLONG_MAX - max_before_ullong_max * base;
while( *str )
{
int next = -1;
if( 'a' <= *str && *str <= 'a'+base-10-1 )
next = *str - 'a' + 10;
}
+ //_SysDebug("strtoull - ret=0x%llx,next=%i,str='%s'", ret, next, str);
if( next < 0 )
break;
+
+ // If we're already out of range, keep eating
+ if( ret == ULLONG_MAX ) {
+ errno = ERANGE;
+ str ++;
+ // Keep eating until first unrecognised character
+ continue;
+ }
+
+ // Rough then accurate check against max value
+ if( ret >= max_before_ullong_max )
+ {
+ //_SysDebug("strtoull - 0x%llx>0x%llx", ret, max_before_ullong_max);
+ if( (ret - max_before_ullong_max) * base + next > space_above ) {
+ //_SysDebug("strtoull - %u*%u+%u (%u) > %u",
+ // (unsigned int)(ret - max_before_ullong_max), base, next, space_above);
+ ret = ULLONG_MAX;
+ errno = ERANGE;
+ str ++;
+ continue;
+ }
+ }
ret *= base;
ret += next;
str ++;
long long strtoll(const char *str, char **end, int base)
{
int neg = 0;
- unsigned long long ret;
if( !str ) {
errno = EINVAL;
str++;
// Check for negative (or positive) sign
- if(*str == '-' || *str == '+') {
+ if(*str == '-' || *str == '+')
+ {
+ //_SysDebug("strtoll - str[0:1] = '%.2s'", str);
+ if( !isdigit(str[1]) ) {
+ // Non-digit, invalid string
+ if(end) *end = (char*)str;
+ return 0;
+ }
neg = (*str == '-');
str++;
}
- ret = strtoull(str, end, base);
+ unsigned long long ret = strtoull(str, end, base);
+ //_SysDebug("strtoll - neg=%i,ret=%llu", neg, ret);
- if( neg )
+ if( neg ) {
+ // Abuses unsigned integer overflow
+ if( ret + LLONG_MIN < ret ) {
+ errno = ERANGE;
+ return LLONG_MIN;
+ }
return -ret;
+ }
else
+ {
+ if( ret > LLONG_MAX ) {
+ errno = ERANGE;
+ return LLONG_MAX;
+ }
return ret;
+ }
}
long strtol(const char *str, char **end, int base)