Consolidate and deprecate ftime

ftime is an obsolete variation on gettimeofday, offering only
millisecond time resolution; it was probably a system call in ooold
versions of BSD Unix.  For historic reasons, we had three
implementations of it.  These are all consolidated into time/ftime.c,
and then the function is deprecated.

For some reason, the implementation of ftime in terms of gettimeofday
was rounding rather than truncating microseconds to milliseconds.  In
all the other places where we use a higher-resolution time function to
implement a lower-resolution one, we truncate.  ftime is changed to
match, just for tidiness' sake.

Like gettimeofday, ftime tries to report the time zone, and using that
information is always a bug.  This patch dummies out the reported
timezone information; the timezone and dstflag fields of the
returned "struct timeb" will always be zero.

Checked on x86_64-linux-gnu, i686-linux-gnu, powerpc64le-linux-gnu,
powerpc64-linux-gnu, and powerpc-linux-gnu.

Co-authored-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Reviewed-by: Lukasz Majewski <lukma@denx.de>

diff --git a/NEWS b/NEWS
index b066c75db36d0b68c2b20914fcbe07d258146c44..7e9d36e180c063a531390559d3856ed3768a882e 100644 (file)
--- a/NEWS
+++ b/NEWS
@@ -58,6 +58,9 @@ Deprecated and removed features, and other changes affecting compatibility:
   settimeofday available to newly linked binaries after there is a
   replacement for Linux's time-zone-like offset API.
 
+* The obsolete functions ftime has been deprecated and will be removed from
+  a future version of glibc.  Application should use clock_gettime instead.
+
 Changes to build and runtime requirements:
 
   [Add changes to build and runtime requirements here]

diff --git a/sysdeps/unix/bsd/ftime.c b/sysdeps/unix/bsd/ftime.c
deleted file mode 100644 (file)
index e1f20bc..0000000
--- a/sysdeps/unix/bsd/ftime.c
+++ /dev/null
@@ -1,40 +0,0 @@
-/* Copyright (C) 1994-2019 Free Software Foundation, Inc.
-   This file is part of the GNU C Library.
-
-   The GNU C Library is free software; you can redistribute it and/or
-   modify it under the terms of the GNU Lesser General Public
-   License as published by the Free Software Foundation; either
-   version 2.1 of the License, or (at your option) any later version.
-
-   The GNU C Library is distributed in the hope that it will be useful,
-   but WITHOUT ANY WARRANTY; without even the implied warranty of
-   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-   Lesser General Public License for more details.
-
-   You should have received a copy of the GNU Lesser General Public
-   License along with the GNU C Library; if not, see
-   <https://www.gnu.org/licenses/>.  */
-
-#include <sys/timeb.h>
-#include <sys/time.h>
-
-int
-ftime (struct timeb *timebuf)
-{
-  struct timeval tv;
-  struct timezone tz;
-
-  if (__gettimeofday (&tv, &tz) < 0)
-    return -1;
-
-  timebuf->time = tv.tv_sec;
-  timebuf->millitm = (tv.tv_usec + 500) / 1000;
-  if (timebuf->millitm == 1000)
-    {
-      ++timebuf->time;
-      timebuf->millitm = 0;
-    }
-  timebuf->timezone = tz.tz_minuteswest;
-  timebuf->dstflag = tz.tz_dsttime;
-  return 0;
-}

diff --git a/sysdeps/unix/sysv/linux/ftime.c b/sysdeps/unix/sysv/linux/ftime.c
deleted file mode 100644 (file)
index 5a5949f..0000000
--- a/sysdeps/unix/sysv/linux/ftime.c
+++ /dev/null
@@ -1,3 +0,0 @@
-/* Linux defines the ftime system call but doesn't actually implement
-   it.  Use the BSD implementation.  */
-#include <sysdeps/unix/bsd/ftime.c>

diff --git a/time/ftime.c b/time/ftime.c
index 8bedc0d91eac1e8cd4e876c2bab6b39ee8d74f50..b4bd58ecef1e641c39be72578417cf66c190965c 100644 (file)
--- a/time/ftime.c
+++ b/time/ftime.c
@@ -1,4 +1,5 @@
-/* Copyright (C) 1994-2019 Free Software Foundation, Inc.
+/* Deprecated return date and time.
+   Copyright (C) 1994-2019 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
 
    The GNU C Library is free software; you can redistribute it and/or
@@ -15,27 +16,18 @@
    License along with the GNU C Library; if not, see
    <https://www.gnu.org/licenses/>.  */
 
-#include <errno.h>
-#include <time.h>
 #include <sys/timeb.h>
+#include <time.h>
 
 int
 ftime (struct timeb *timebuf)
 {
-  int save = errno;
-  struct tm tp;
-
-  __set_errno (0);
-  if (time (&timebuf->time) == (time_t) -1 && errno != 0)
-    return -1;
-  timebuf->millitm = 0;
-
-  if (__localtime_r (&timebuf->time, &tp) == NULL)
-    return -1;
-
-  timebuf->timezone = tp.tm_gmtoff / 60;
-  timebuf->dstflag = tp.tm_isdst;
+  struct timespec ts;
+  __clock_gettime (CLOCK_REALTIME, &ts);
 
-  __set_errno (save);
+  timebuf->time = ts.tv_sec;
+  timebuf->millitm = ts.tv_nsec / 1000000;
+  timebuf->timezone = 0;
+  timebuf->dstflag = 0;
   return 0;
 }

diff --git a/time/sys/timeb.h b/time/sys/timeb.h
index b958dc3e4a9d340ba552822caa2516931f14348f..5c16f79da2d2ec1f901085436bf4cbe6bf1a34cb 100644 (file)
--- a/time/sys/timeb.h
+++ b/time/sys/timeb.h
@@ -36,7 +36,8 @@ struct timeb
 
 /* Fill in TIMEBUF with information about the current time.  */
 
-extern int ftime (struct timeb *__timebuf);
+extern int ftime (struct timeb *__timebuf)
+  __nonnull ((1)) __attribute_deprecated__;
 
 __END_DECLS
 

diff --git a/time/tst-ftime.c b/time/tst-ftime.c
index 4b7e90cc03ab3de571265c31c67ca33e8b7836a2..39d94a1b26872d5c291a27ac7ac69493ee3a0113 100644 (file)
--- a/time/tst-ftime.c
+++ b/time/tst-ftime.c
@@ -18,6 +18,7 @@
 
 #include <sys/timeb.h>
 #include <stdio.h>
+#include <libc-diag.h>
 
 static int
 do_test (void)
@@ -29,12 +30,18 @@ do_test (void)
     {
       prev = curr;
 
+      /* ftime was deprecated on 2.31.  */
+      DIAG_PUSH_NEEDS_COMMENT;
+      DIAG_IGNORE_NEEDS_COMMENT (4.9, "-Wdeprecated-declarations");
+
       if (ftime (&curr))
         {
           printf ("ftime returned an error\n");
           return 1;
         }
 
+      DIAG_POP_NEEDS_COMMENT;
+
       if (curr.time < prev.time)
         {
           printf ("ftime's time flowed backwards\n");