Libraries: Create top level directory for libraries.

Things were getting a little crowded in the project root, so this patch
moves the Lib*/ directories into Libraries/.

Libraries/LibC/time.cpp

@@ -0,0 +1,120 @@
+#include <Kernel/Syscall.h>
+#include <assert.h>
+#include <errno.h>
+#include <sys/time.h>
+#include <sys/times.h>
+#include <time.h>
+
+extern "C" {
+
+time_t time(time_t* tloc)
+{
+    struct timeval tv;
+    struct timezone tz;
+    if (gettimeofday(&tv, &tz) < 0)
+        return (time_t)-1;
+    if (tloc)
+        *tloc = tv.tv_sec;
+    return tv.tv_sec;
+}
+
+int gettimeofday(struct timeval* __restrict__ tv, void* __restrict__)
+{
+    int rc = syscall(SC_gettimeofday, tv);
+    __RETURN_WITH_ERRNO(rc, rc, -1);
+}
+
+char* ctime(const time_t*)
+{
+    return const_cast<char*>("ctime() not implemented");
+}
+
+static inline bool __is_leap_year(int year)
+{
+    return ((year % 4 == 0) && ((year % 100 != 0) || (year % 400) == 0));
+}
+
+static const int __days_per_month[] = { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };
+static const int __seconds_per_day = 60 * 60 * 24;
+
+static void time_to_tm(struct tm* tm, time_t t)
+{
+    int days = t / __seconds_per_day;
+    int remaining = t % __seconds_per_day;
+    tm->tm_sec = remaining % 60;
+    remaining /= 60;
+    tm->tm_min = remaining % 60;
+    tm->tm_hour = remaining / 60;
+    tm->tm_wday = (4 + days) % 7;
+    int year;
+    for (year = 1970; days >= 365 + __is_leap_year(year); ++year)
+        days -= 365 + __is_leap_year(year);
+    tm->tm_year = year - 1900;
+    tm->tm_yday = days;
+    tm->tm_mday = 1;
+    if (__is_leap_year(year) && days == 59)
+        ++tm->tm_mday;
+    if (__is_leap_year(year) && days >= 59)
+        --days;
+    int month;
+    for (month = 0; month < 11 && days >= __days_per_month[month]; ++month)
+        days -= __days_per_month[month];
+    tm->tm_mon = month;
+    tm->tm_mday += days;
+}
+
+time_t mktime(struct tm* tm)
+{
+    int days = 0;
+    int seconds = tm->tm_hour * 3600 + tm->tm_min * 60 + tm->tm_sec;
+    for (int year = 70; year < tm->tm_year; ++year)
+        days += 365 + __is_leap_year(1900 + year);
+    tm->tm_yday = tm->tm_mday - 1;
+    for (int month = 0; month < tm->tm_mon; ++month)
+        tm->tm_yday += __days_per_month[month];
+    days += tm->tm_yday;
+    return days * __seconds_per_day + seconds;
+}
+
+struct tm* localtime(const time_t* t)
+{
+    if (!t)
+        return nullptr;
+    static struct tm tm_buf;
+    time_to_tm(&tm_buf, *t);
+    return &tm_buf;
+}
+
+struct tm* gmtime(const time_t* t)
+{
+    // FIXME: This is obviously not correct. What about timezones bro?
+    return localtime(t);
+}
+
+char* asctime(const struct tm*)
+{
+    ASSERT_NOT_REACHED();
+}
+
+size_t strftime(char*, size_t, const char*, const struct tm*)
+{
+    ASSERT_NOT_REACHED();
+}
+
+long timezone;
+long altzone;
+char* tzname[2];
+int daylight;
+
+void tzset()
+{
+    ASSERT_NOT_REACHED();
+}
+
+clock_t clock()
+{
+    struct tms tms;
+    times(&tms);
+    return tms.tms_utime + tms.tms_stime;
+}
+}