[PATCH v2 03/11] Use clock_settime to implement stime; withdraw stime.

[Adhemerval Zanella <adhemerval dot zanella at linaro dot org>]

From: Zack Weinberg <zackw@panix.com>

Use clock_settime to implement stime; withdraw stime.

Changes from previous version:

  - Added a NEWS entry.

--

Unconditionally, on all ports, use clock_settime to implement stime,
not settimeofday or a direct syscall.  Then convert stime into a
compatibility symbol and remove its prototype from time.h.

Checked on x86_64-linux-gnu, i686-linux-gnu, powerpc64le-linux-gnu,
powerpc64-linux-gnu, powerpc-linux-gnu, and aarch64-linux-gnu.

Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
---
 NEWS                                  |  4 +++
 sysdeps/unix/stime.c                  | 39 ---------------------------
 sysdeps/unix/sysv/linux/syscalls.list |  1 -
 time/stime.c                          | 25 ++++++++---------
 time/time.h                           |  6 -----
 5 files changed, 17 insertions(+), 58 deletions(-)
 delete mode 100644 sysdeps/unix/stime.c

diff --git a/NEWS b/NEWS
index d7286841c9..8727b5e7f0 100644
--- a/NEWS
+++ b/NEWS
@@ -30,6 +30,10 @@ Deprecated and removed features, and other changes affecting compatibility:
   Request 25 to TS 18661-1, as applied for C2X.  Existing binaries that pass
   floating-point arguments directly will continue to work.
 
+* The obsolete function stime is no longer available to newly linked
+  binaries and it has been removed from <time.h> header.  This function
+  has been deprecated in favor of clock_settime.
+
 Changes to build and runtime requirements:
 
   [Add changes to build and runtime requirements here]
diff --git a/sysdeps/unix/stime.c b/sysdeps/unix/stime.c
deleted file mode 100644
index b40c33454a..0000000000
--- a/sysdeps/unix/stime.c
+++ /dev/null
@@ -1,39 +0,0 @@
-/* Copyright (C) 1992-2019 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 <errno.h>
-#include <stddef.h>		/* For NULL.  */
-#include <sys/time.h>
-#include <time.h>
-
-/* Set the system clock to *WHEN.  */
-
-int
-stime (const time_t *when)
-{
-  struct timeval tv;
-
-  if (when == NULL)
-    {
-      __set_errno (EINVAL);
-      return -1;
-    }
-
-  tv.tv_sec = *when;
-  tv.tv_usec = 0;
-  return __settimeofday (&tv, (struct timezone *) 0);
-}
diff --git a/sysdeps/unix/sysv/linux/syscalls.list b/sysdeps/unix/sysv/linux/syscalls.list
index cdcf6c127b..70b110979b 100644
--- a/sysdeps/unix/sysv/linux/syscalls.list
+++ b/sysdeps/unix/sysv/linux/syscalls.list
@@ -61,7 +61,6 @@ setfsgid	EXTRA	setfsgid	i:i	setfsgid
 setfsuid	EXTRA	setfsuid	i:i	setfsuid
 setpgid		-	setpgid		i:ii	__setpgid	setpgid
 sigaltstack	-	sigaltstack	i:PP	__sigaltstack	sigaltstack
-stime		-	stime		i:p	stime
 sysinfo		EXTRA	sysinfo		i:p	__sysinfo	sysinfo
 swapon		-	swapon		i:si	__swapon	swapon
 swapoff		-	swapoff		i:s	__swapoff	swapoff
diff --git a/time/stime.c b/time/stime.c
index a53c0e86ae..6ea3b6dcc1 100644
--- a/time/stime.c
+++ b/time/stime.c
@@ -15,23 +15,24 @@
    License along with the GNU C Library; if not, see
    <https://www.gnu.org/licenses/>.  */
 
-#include <errno.h>
+#include <shlib-compat.h>
+
+#if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_31)
+
 #include <time.h>
-#include <stddef.h>
 
 /* Set the system clock to *WHEN.  */
 
 int
-stime (const time_t *when)
+attribute_compat_text_section
+__stime (const time_t *when)
 {
-  if (when == NULL)
-    {
-      __set_errno (EINVAL);
-      return -1;
-    }
-
-  __set_errno (ENOSYS);
-  return -1;
+  struct timespec ts;
+  ts.tv_sec = *when;
+  ts.tv_nsec = 0;
+
+  return __clock_settime (CLOCK_REALTIME, &ts);
 }
 
-stub_warning (stime)
+compat_symbol (libc, __stime, stime, GLIBC_2_0);
+#endif
diff --git a/time/time.h b/time/time.h
index 72a1078d2c..7daaacce16 100644
--- a/time/time.h
+++ b/time/time.h
@@ -175,12 +175,6 @@ extern int daylight;
 extern long int timezone;
 #endif
 
-#ifdef __USE_MISC
-/* Set the system time to *WHEN.
-   This call is restricted to the superuser.  */
-extern int stime (const time_t *__when) __THROW;
-#endif
-
 
 /* Nonzero if YEAR is a leap year (every 4 years,
    except every 100th isn't, and every 400th is).  */
-- 
2.17.1