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, 172 deletions

diff --git a/src/time/tzset.c b/src/time/tzset.c
deleted file mode 100644
index 7e836c2f..00000000
--- a/src/time/tzset.c
+++ /dev/null
@@ -1,172 +0,0 @@
-#include <time.h>
-#include <ctype.h>
-#include <limits.h>
-#include <stdlib.h>
-#include <string.h>
-#include "libc.h"
-
-#include "__time.h"
-
-long  __timezone = 0;
-int   __daylight = 0;
-char *__tzname[2] = { 0, 0 };
-int   __dst_offset = 0;
-
-weak_alias(__timezone, timezone);
-weak_alias(__daylight, daylight);
-weak_alias(__tzname, tzname);
-
-static char std_name[TZNAME_MAX+1];
-static char dst_name[TZNAME_MAX+1];
-
-/* all elements are zero-based */
-static struct rule {
-	signed char month;
-	signed char week;
-	short day;
-	int time;
-} __dst_start, __dst_end;
-
-static void zname(char *d, char **s)
-{
-	int i;
-	for (i=0; i<TZNAME_MAX && isalpha(d[i]=**s); i++, (*s)++);
-	d[i] = 0;
-}
-
-static int hhmmss(char **s)
-{
-	int ofs = strtol(*s, s, 10)*3600;
-	if (ofs >= 0) {
-		if (**s == ':') ofs += strtol(*s+1, s, 10)*60;
-		if (**s == ':') ofs += strtol(*s+1, s, 10);
-	} else {
-		if (**s == ':') ofs -= strtol(*s+1, s, 10)*60;
-		if (**s == ':') ofs -= strtol(*s+1, s, 10);
-	}
-	return ofs;
-}
-
-static int dstrule(struct rule *rule, char **s)
-{
-	if (**s != ',') return -1;
-	switch (*++*s) {
-	case 'J':
-		rule->month = 'J';
-		rule->day = strtol(*s+1, s, 10)-1;
-		break;
-	case 'M':
-		rule->month = strtol(*s+1, s, 10)-1;
-		if (**s != '.' || rule->month < 0 || rule->month > 11)
-			return -1;
-		rule->week = strtol(*s+1, s, 10)-1;
-		if (**s != '.' || rule->week < 0 || rule->week > 4)
-			return -1;
-		rule->day = strtol(*s+1, s, 10);
-		if (rule->day < 0 || rule->day > 6)
-			return -1;
-		break;
-	default:
-		rule->month = 'L';
-		rule->day = strtol(*s+1, s, 10);
-		break;
-	}
-	if (**s == '/') {
-		(*s)++;
-		rule->time = hhmmss(s);
-	} else rule->time = 7200;
-	return 0;
-}
-
-void tzset(void)
-{
-	char *z, *a;
-	
-	strcpy(std_name, "GMT");
-	strcpy(dst_name, "GMT");
-	__tzname[0] = std_name;
-	__tzname[1] = dst_name;
-	__timezone = 0;
-	__daylight = 0;
-	
-	if (!(z = getenv("TZ")) || !isalpha(*z)) return;
-
-	zname(std_name, &z);
-	__timezone = hhmmss(&z);
-
-	zname(dst_name, &z);
-	if (dst_name[0]) __daylight=1;
-	a = z;
-	__dst_offset = hhmmss(&z) - __timezone;
-	if (z==a) __dst_offset = -3600;
-
-	if (dstrule(&__dst_start, &z) || dstrule(&__dst_end, &z))
-		__daylight = 0;
-}
-
-void __tzset(void)
-{
-	static int lock[2], init;
-	if (init) return;
-	LOCK(lock);
-	if (!init) tzset();
-	init=1;
-	UNLOCK(lock);
-}
-
-static int is_leap(int year)
-{
-	year -= 100;
-	return !(year&3) && ((year%100) || !(year%400));
-}
-
-static int cutoff_yday(struct tm *tm, struct rule *rule)
-{
-	static const char days_in_month[] = {31,28,31,30,31,30,31,31,30,31,30,31};
-	static const int first_day[] = {0,31,59,90,120,151,181,212,243,273,304,335};
-	int yday, mday, leap;
-	
-	switch (rule->month) {
-	case 'J':
-		return rule->day + (tm->tm_mon > 1 && is_leap(tm->tm_year));
-	case 'L':
-		return rule->day;
-	default:
-		yday = first_day[rule->month];
-		leap = is_leap(tm->tm_year);
-		if (rule->month > 1 && leap) yday++;
-		mday = (rule->day - (yday + tm->tm_wday - tm->tm_yday) + 1400)%7 + 7*rule->week;
-		if (mday >= days_in_month[rule->month] + (leap && rule->month == 1))
-			mday -= 7;
-		return mday + yday;
-	}
-}
-
-struct tm *__dst_adjust(struct tm *tm)
-{
-	time_t t;
-	int start, end, secs;
-	int after_start, before_end;
-
-	if (tm->tm_isdst >= 0) return tm;
-	if (!__daylight) {
-		tm->tm_isdst = 0;
-		return tm;
-	}
-	
-	secs = tm->tm_hour*3600 + tm->tm_min*60 + tm->tm_sec;
-	start = cutoff_yday(tm, &__dst_start);
-	end = cutoff_yday(tm, &__dst_end);
-
-	after_start = (tm->tm_yday > start || (tm->tm_yday == start && secs >= __dst_start.time));
-	before_end = (tm->tm_yday < end || (tm->tm_yday == end && secs < __dst_end.time));
-
-	if ((after_start && before_end) || ((end < start) && (after_start || before_end))) {
-		tm->tm_sec -= __dst_offset;
-		tm->tm_isdst = 1;
-		t = __tm_to_time(tm);
-		return __time_to_tm(t, tm);
-	} else tm->tm_isdst = 0;
-
-	return tm;
-}