Add routines to convert time_t to/from fixed-bit fields. These routines

serve two purposes: (1) so we can maintain backwards compatibility with
protocols (rwhod, dump, etc...) that either assume time_t is 32 bits or
assume sizeof(time_t) == sizeof(int), or make other similar assumptions.
(2) To tag such routines (by the presence of these calls) for future
cleanup/extension work.

The 32->64 routine, time32_to_time() (when time_t is 64 bits, that is),
is defined specifically to implement temporal locality to properly set the
msb bits of a 64 bit time_t quantity, using the 50 year rule.  The locality
code has not been implemented yet (and doesn't need to be for a while),
but that is the intent.   This will allow us to maintain backwards protocol
compatibility past 2038.

These routines are intended to be platform and time_t agnostic.

MFC after:	1 week

1 files changed, 7 insertions, 0 deletions

diff --git a/include/time.h b/include/time.h
index 1e38cb2..6cff713 100644
--- a/include/time.h
+++ b/include/time.h
@@ -136,6 +136,13 @@ size_t strftime __P((char *, size_t, const char *, const struct tm *));
 time_t time __P((time_t *));
 
 #ifndef _ANSI_SOURCE
+time_t time32_to_time __P((__int32_t t32));
+__int32_t time_to_time32 __P((time_t t));
+time_t time64_to_time __P((__int64_t t64));
+__int64_t time_to_time64 __P((time_t t));
+#endif /* not ANSI */
+
+#ifndef _ANSI_SOURCE
 void tzset __P((void));
 #endif /* not ANSI */