[RFC v4 07/24] time: Deprecate struct timezone members

[Alistair Francis <alistair dot francis at wdc dot com>]

Append the struct timezone members with '_dep'. This indicates that
these members are deprecated and will cause build failures on code that
is currently using the members.

The struct timezone *tz variable contaions information on the current
timezone, in this structure:
    struct timezone {
        int tz_minuteswest;     /* minutes west of Greenwich */
        int tz_dsttime;         /* type of DST correction */
    };

The members are being renamed to create compilation failures for anyone
who is using them. This is being done for the following reasons.

On 32-bit systems with __ARCH_WANT_TIME32_SYSCALLS not defined there is
no way way to get the struct timezone via a syscall. AFAIK there are no
plans to add suppor to a future kernel.

The Linux documentation says that "The use of the timezone structure
is obsolete; the tz argument should normally be specified as NULL."

Most callers of gettimeofday() don't use the timezone data, see
example code from Debian below.

If __ASSUME_TIME64_SYSCALLS and __NR_clock_gettime64 are not defined
then struct timezone *tz will be set as usual.

Example code from Debian:
struct timeval my_gettime(void)
{
     struct timezone tz_ignored;
     struct timeval tv;
     gettimeofday(&tv, &tz_ignored);
     return tv;
}

Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
---
 sysdeps/unix/bsd/ftime.c | 4 ++--
 time/sys/time.h          | 4 ++--
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/sysdeps/unix/bsd/ftime.c b/sysdeps/unix/bsd/ftime.c
index 3a1c6e9b01c..bc4dfdab945 100644
--- a/sysdeps/unix/bsd/ftime.c
+++ b/sysdeps/unix/bsd/ftime.c
@@ -34,7 +34,7 @@ ftime (struct timeb *timebuf)
       ++timebuf->time;
       timebuf->millitm = 0;
     }
-  timebuf->timezone = tz.tz_minuteswest;
-  timebuf->dstflag = tz.tz_dsttime;
+  timebuf->timezone = tz.tz_minuteswest_dep;
+  timebuf->dstflag = tz.tz_dsttime_dep;
   return 0;
 }
diff --git a/time/sys/time.h b/time/sys/time.h
index 5dbc7fc627f..a35ccb7a58b 100644
--- a/time/sys/time.h
+++ b/time/sys/time.h
@@ -51,8 +51,8 @@ __BEGIN_DECLS
    This is obsolete and should never be used.  */
 struct timezone
   {
-    int tz_minuteswest;		/* Minutes west of GMT.  */
-    int tz_dsttime;		/* Nonzero if DST is ever in effect.  */
+    int tz_minuteswest_dep;		/* Minutes west of GMT.  */
+    int tz_dsttime_dep;		/* Nonzero if DST is ever in effect.  */
   };
 
 typedef struct timezone *__restrict __timezone_ptr_t;
-- 
2.22.0