/* Return a newly allocated time zone for NAME, or NULL on failure.
As a special case, return a nonzero constant for wall clock time, a
constant that survives freeing. */
timezone_t
tzalloc (char const *name)
{
size_t name_size = name ? strlen (name) + 1 : 0;
size_t abbr_size = name_size < ABBR_SIZE_MIN ? ABBR_SIZE_MIN : name_size + 1;
timezone_t tz = malloc (offsetof (struct tm_zone, abbrs) + abbr_size);
if (tz)
{
tz->next = NULL;
#if HAVE_TZNAME && !HAVE_TM_ZONE
tz->tzname_copy[0] = tz->tzname_copy[1] = NULL;
#endif
tz->tz_is_set = !!name;
extend_abbrs (tz->abbrs, name, name_size);
}
return tz;
}
/* Save into TZ any nontrivial time zone abbreviation used by TM, and
update *TM (if HAVE_TM_ZONE) or *TZ (if !HAVE_TM_ZONE &&
HAVE_TZNAME) if they use the abbreviation. Return true if
successful, false (setting errno) otherwise. */
static bool
save_abbr (timezone_t tz, struct tm *tm)
{
#if HAVE_TM_ZONE || HAVE_TZNAME
char const *zone = NULL;
char *zone_copy = (char *) "";
# if HAVE_TZNAME
int tzname_index = -1;
# endif
# if HAVE_TM_ZONE
zone = tm->tm_zone;
# endif
# if HAVE_TZNAME
if (! (zone && *zone) && 0 <= tm->tm_isdst)
{
tzname_index = tm->tm_isdst != 0;
zone = tzname[tzname_index];
}
# endif
/* No need to replace null zones, or zones within the struct tm. */
if (!zone || ((char *) tm <= zone && zone < (char *) (tm + 1)))
return true;
if (*zone)
{
zone_copy = tz->abbrs;
while (strcmp (zone_copy, zone) != 0)
{
if (! (*zone_copy || (zone_copy == tz->abbrs && tz->tz_is_set)))
{
size_t zone_size = strlen (zone) + 1;
if (zone_size < tz->abbrs + ABBR_SIZE_MIN - zone_copy)
extend_abbrs (zone_copy, zone, zone_size);
else
{
tz = tz->next = tzalloc (zone);
if (!tz)
return false;
tz->tz_is_set = 0;
zone_copy = tz->abbrs;
}
break;
}
zone_copy += strlen (zone_copy) + 1;
if (!*zone_copy && tz->next)
{
tz = tz->next;
zone_copy = tz->abbrs;
}
}
}
/* Replace the zone name so that its lifetime matches that of TZ. */
# if HAVE_TM_ZONE
tm->tm_zone = zone_copy;
# else
if (0 <= tzname_index)
tz->tzname_copy[tzname_index] = zone_copy;
# endif
#endif
return true;
}
