the big time handling overhaul

this commit has two major user-visible parts: zoneinfo-format time
zones are now supported, and overflow handling is intended to be
complete in the sense that all functions return a correct result if
and only if the result fits in the destination type, and otherwise
return an error. also, some noticable bugs in the way DST detection
and normalization worked have been fixed, and performance may be
better than before, but it has not been tested.

1 files changed, 0 insertions, 83 deletions

diff --git a/src/time/__time_to_tm.c b/src/time/__time_to_tm.c
deleted file mode 100644
index e2d782be..00000000
--- a/src/time/__time_to_tm.c
+++ /dev/null
@@ -1,83 +0,0 @@
-#include <time.h>
-
-/* C defines the rounding for division in a nonsensical way */
-#define Q(a,b) ((a)>0 ? (a)/(b) : -(((b)-(a)-1)/(b)))
-
-#define DAYS_PER_400Y (365*400 + 97)
-#define DAYS_PER_100Y (365*100 + 24)
-#define DAYS_PER_4Y   (365*4   + 1)
-
-/* FIXME: use lldiv once it's fixed to compute quot,rem together */
-struct tm *__time_to_tm(time_t t, struct tm *tm)
-{
-	/* months are march-based */
-	static const int days_thru_month[] = {31,61,92,122,153,184,214,245,275,306,337,366};
-	long long bigday;
-	unsigned int day, year4, year100;
-	int year, year400;
-	int month;
-	int leap;
-	int hour, min, sec;
-	int wday, mday, yday;
-
-	/* start from 2000-03-01 (multiple of 400 years) */
-	t += -946684800 - 86400*(31+29);
-
-	bigday = Q(t, 86400);
-	sec = t-bigday*86400;
-
-	hour = sec/3600;
-	sec -= hour*3600;
-	min = sec/60;
-	sec -= min*60;
-
-	/* 2000-03-01 was a wednesday */
-	wday = (3+bigday)%7;
-	if (wday < 0) wday += 7;
-
-	t = -946684800LL - 86400*(31+29) + 9000000;
-	
-	year400 = Q(bigday, DAYS_PER_400Y);
-	day = bigday-year400*DAYS_PER_400Y;
-
-	year100 = day/DAYS_PER_100Y;
-	if (year100 == 4) year100--;
-	day -= year100*DAYS_PER_100Y;
-
-	year4 = day/DAYS_PER_4Y;
-	if (year4 == 25) year4--;
-	day -= year4*DAYS_PER_4Y;
-
-	year = day/365;
-	if (year == 4) year--;
-	day -= year*365;
-
-	leap = !year && (year4 || !year100);
-	yday = day + 31+28 + leap;
-	if (yday >= 365+leap) yday -= 365+leap;
-
-	year += 4*year4 + 100*year100 + 400*year400 + 2000-1900;
-
-	for (month=0; days_thru_month[month] <= day; month++);
-	if (month) day -= days_thru_month[month-1];
-	month += 2;
-	if (month >= 12) {
-		month -= 12;
-		year++;
-	}
-
-	mday = day+1;
-
-	tm->tm_sec = sec;
-	tm->tm_min = min;
-	tm->tm_hour= hour;
-	tm->tm_mday= mday;
-	tm->tm_mon = month;
-	tm->tm_year= year;
-	tm->tm_wday= wday;
-	tm->tm_yday= yday;
-	tm->__tm_zone = 0;
-	tm->__tm_gmtoff = 0;
-
-	return tm;
-}