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, 8 insertions, 0 deletions

diff --git a/posix/bits/types.h b/posix/bits/types.h
index 5e22ce41bf..cda0a70dd8 100644
--- a/posix/bits/types.h
+++ b/posix/bits/types.h
@@ -25,6 +25,7 @@
 
 #include <features.h>
 #include <bits/wordsize.h>
+#include <bits/timesize.h>
 
 /* Convenience types.  */
 typedef unsigned char __u_char;
@@ -138,6 +139,7 @@ __extension__ typedef unsigned long long int __uintmax_t;
 # error
 #endif
 #include <bits/typesizes.h>	/* Defines __*_T_TYPE macros.  */
+#include <bits/time64.h>	/* Defines __TIME*_T_TYPE macros.  */
 
 
 __STD_TYPE __DEV_T_TYPE __dev_t;	/* Type of device numbers.  */
@@ -211,6 +213,12 @@ __STD_TYPE __U32_TYPE __socklen_t;
    It is not currently necessary for this to be machine-specific.  */
 typedef int __sig_atomic_t;
 
+#if __TIMESIZE == 64
+# define __time64_t __time_t
+#else
+__STD_TYPE __TIME64_T_TYPE __time64_t;	/* Seconds since the Epoch.  */
+#endif
+
 #undef __STD_TYPE
 
 #endif /* bits/types.h */