/cbits/HsTime.c

 1#include "HsTime.h"
 2#include <stdio.h>
 3
 4long int get_current_timezone_seconds (time_t t,int* pdst,char const* * pname)
 5{
 6#if HAVE_LOCALTIME_R
 7	struct tm tmd;
 8	struct tm* ptm = localtime_r(&t,&tmd);
 9#else
10	struct tm* ptm = localtime(&t);
11#endif
12	if (ptm)
13	{
14		int dst = ptm -> tm_isdst;
15		*pdst = dst;
16#if HAVE_TM_ZONE
17		*pname = ptm -> tm_zone;
18		return ptm -> tm_gmtoff;
19#elif defined(_MSC_VER) || defined(__MINGW32__) || defined(_WIN32)
20		// We don't have a better API to use on Windows, the logic to
21		// decide whether a given date/time falls within DST is
22		// implemented as part of localtime() in the CRT.  This is_dst
23		// flag is all we need here.
24		*pname = dst ? _tzname[1] : _tzname[0];
25		return - (dst ? _timezone - 3600 : _timezone);
26#else
27# if HAVE_TZNAME
28		*pname = *tzname;
29# else
30#  error "Don't know how to get timezone name on your OS"
31# endif
32# if HAVE_DECL_ALTZONE
33		return dst ? altzone : timezone;
34# else
35		return dst ? timezone - 3600 : timezone;
36# endif
37#endif // HAVE_TM_ZONE
38	}
39	else return 0x80000000;
40}