Y2038: Add 64-bit time for all architectures

glibc support for 64-bit time_t on 32-bit architectures
will involve:

- Using 64-bit times inside glibc, with conversions
  to and from 32-bit times taking place as necessary
  for interfaces using such times.

- Adding 64-bit-time support in the glibc public API.
  This support should be dynamic, i.e. glibc should
  provide both 32-bit and 64-bit implementations and
   let user code choose at compile time whether to use
   the 32-bit or 64-bit interfaces.

This requires a glibc-internal name for a type for times
that are always 64-bit.

Based on __TIMESIZE, a new macro is defined, __TIME64_T_TYPE,
 which is always the right __*_T_TYPE to hold a 64-bit-time.
__TIME64_T_TYPE equals __TIME_T_TYPE if __TIMESIZE equals 64
and equals __SQUAD_T_TYPE otherwise.

__time64_t can then replace uses of internal_time_t.

This patch was tested by running 'make check' on branch
master then applying this patch and its predecessor and
running 'make check' again, and checking that both 'make
check' yield identical results. This was done on
x86_64-linux-gnu and i686-linux-gnu.

	* bits/time64.h: New file.
	* include/time.h: Replace internal_time_t with __time64_t.
	* posix/bits/types (__time64_t): Add.
	* stdlib/Makefile: Add bits/time64.h to includes.
	* time/tzfile.c: Replace internal_time_t with __time64_t.

1 files changed, 9 insertions, 9 deletions

diff --git a/time/tzfile.c b/time/tzfile.c
index 72ef75f..844a68d 100644
--- a/time/tzfile.c
+++ b/time/tzfile.c
@@ -44,12 +44,12 @@ struct ttinfo
 
 struct leap
   {
-    internal_time_t transition;	/* Time the transition takes effect.  */
+    __time64_t transition;	/* Time the transition takes effect.  */
     long int change;		/* Seconds of correction to apply.  */
   };
 
 static size_t num_transitions;
-libc_freeres_ptr (static internal_time_t *transitions);
+libc_freeres_ptr (static __time64_t *transitions);
 static unsigned char *type_idxs;
 static size_t num_types;
 static struct ttinfo *types;
@@ -113,8 +113,8 @@ __tzfile_read (const char *file, size_t extra, char **extrap)
   size_t tzspec_len;
   char *new = NULL;
 
-  _Static_assert (sizeof (internal_time_t) == 8,
-		  "internal_time_t must be eight bytes");
+  _Static_assert (sizeof (__time64_t) == 8,
+		  "__time64_t must be eight bytes");
 
   __use_tzfile = 0;
 
@@ -217,9 +217,9 @@ __tzfile_read (const char *file, size_t extra, char **extrap)
 
   if (__builtin_expect (num_transitions
 			> ((SIZE_MAX - (__alignof__ (struct ttinfo) - 1))
-			   / (sizeof (internal_time_t) + 1)), 0))
+			   / (sizeof (__time64_t) + 1)), 0))
     goto lose;
-  total_size = num_transitions * (sizeof (internal_time_t) + 1);
+  total_size = num_transitions * (sizeof (__time64_t) + 1);
   total_size = ((total_size + __alignof__ (struct ttinfo) - 1)
 		& ~(__alignof__ (struct ttinfo) - 1));
   types_idx = total_size;
@@ -276,7 +276,7 @@ __tzfile_read (const char *file, size_t extra, char **extrap)
     goto lose;
 
   type_idxs = (unsigned char *) transitions + (num_transitions
-					       * sizeof (internal_time_t));
+					       * sizeof (__time64_t));
   types = (struct ttinfo *) ((char *) transitions + types_idx);
   zone_names = (char *) types + num_types * sizeof (struct ttinfo);
   leaps = (struct leap *) ((char *) transitions + leaps_idx);
@@ -578,7 +578,7 @@ __tzfile_default (const char *std, const char *dst,
 }
 
 void
-__tzfile_compute (internal_time_t timer, int use_localtime,
+__tzfile_compute (__time64_t timer, int use_localtime,
 		  long int *leap_correct, int *leap_hit,
 		  struct tm *tp)
 {
@@ -667,7 +667,7 @@ __tzfile_compute (internal_time_t timer, int use_localtime,
 	     initial search spot from it.  Half of a gregorian year
 	     has on average 365.2425 * 86400 / 2 = 15778476 seconds.
 	     The value i can be truncated if size_t is smaller than
-	     internal_time_t, but this is harmless because it is just
+	     __time64_t, but this is harmless because it is just
 	     a guess.  */
 	  i = (transitions[num_transitions - 1] - timer) / 15778476;
 	  if (i < num_transitions)