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LibC: Fix mktime argument updating

This commit is contained in:
Bananymous 2025-08-11 19:00:23 +03:00
parent 9b09d2b47a
commit 6ed0e84421
1 changed files with 29 additions and 23 deletions
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52
userspace/libraries/LibC/time.cpp
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@ -108,53 +108,59 @@ static constexpr bool is_leap_year(uint64_t year)
time_t mktime(struct tm* tm)
{
if (tm->tm_year < 70)
tzset();
struct tm modified = *tm;
if (modified.tm_year < 70)
{
errno = EOVERFLOW;
return -1;
}
tm->tm_min += tm->tm_sec / 60;
tm->tm_sec %= 60;
modified.tm_min += modified.tm_sec / 60;
modified.tm_sec %= 60;
tm->tm_hour += tm->tm_min / 60;
tm->tm_min %= 60;
modified.tm_hour += modified.tm_min / 60;
modified.tm_min %= 60;
tm->tm_mday += tm->tm_hour / 24;
tm->tm_hour %= 24;
modified.tm_mday += modified.tm_hour / 24;
modified.tm_hour %= 24;
static constexpr int month_days[] { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };
for (;;)
{
int days_in_month = month_days[tm->tm_mon];
if (tm->tm_mon == 1 && is_leap_year(tm->tm_year))
int days_in_month = month_days[modified.tm_mon];
if (modified.tm_mon == 1 && is_leap_year(modified.tm_year))
days_in_month++;
if (tm->tm_mday <= days_in_month)
if (modified.tm_mday <= days_in_month)
break;
tm->tm_mday -= days_in_month;
tm->tm_mon++;
modified.tm_mday -= days_in_month;
modified.tm_mon++;
}
tm->tm_year += tm->tm_mon / 12;
tm->tm_mon %= 12;
modified.tm_year += modified.tm_mon / 12;
modified.tm_mon %= 12;
tm->tm_yday = tm->tm_mday - 1;
for (int i = 0; i < tm->tm_mon; i++)
tm->tm_yday += month_days[i];
modified.tm_yday = modified.tm_mday - 1;
for (int i = 0; i < modified.tm_mon; i++)
modified.tm_yday += month_days[i];
const time_t num_febs = (tm->tm_mon > 1) ? tm->tm_year + 1 : tm->tm_year;
const time_t num_febs = (modified.tm_mon > 1) ? modified.tm_year + 1 : modified.tm_year;
const time_t leap_years = (num_febs - 69) / 4 - (num_febs - 1) / 100 + (num_febs + 299) / 400;
const time_t years = tm->tm_year - 70;
const time_t days = years * 365 + leap_years + tm->tm_yday;
const time_t hours = days * 24 + tm->tm_hour;
const time_t minutes = hours * 60 + tm->tm_min;
const time_t seconds = minutes * 60 + tm->tm_sec;
const time_t years = modified.tm_year - 70;
const time_t days = years * 365 + leap_years + modified.tm_yday;
const time_t hours = days * 24 + modified.tm_hour;
const time_t minutes = hours * 60 + modified.tm_min;
const time_t seconds = minutes * 60 + modified.tm_sec;
*tm = modified;
tm->tm_wday = (days + 4) % 7;
tm->tm_isdst = daylight;
return seconds;
}