[PATCH v4 2/3] support: Provide xclock_settime test helper function

[Adhemerval Zanella]

On 17/02/2021 19:31, Lukasz Majewski wrote:
> The xclock_settime is a wrapper function on the clock_settime syscall
> to be used in the test code.
> 
> It checks if the GLIBC_TEST_ALLOW_TIME_SETTING env variable is defined
> in the environment in which test is executed. If it is not - the test
> ends as unsupported. Otherwise, the clock-settime is executed and return
> value is assessed.
> 
> ---
> Changes for v4:
> - Remove not needed #include <support/xthread.h>

LGTM with a small nit below.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>

> ---
>  support/Makefile         |  1 +
>  support/xclock_settime.c | 34 ++++++++++++++++++++++++++++++++++
>  support/xtime.h          |  5 +++++
>  3 files changed, 40 insertions(+)
>  create mode 100644 support/xclock_settime.c
> 
> diff --git a/support/Makefile b/support/Makefile
> index bb9889efb4..8d63fbd5da 100644
> --- a/support/Makefile
> +++ b/support/Makefile
> @@ -90,6 +90,7 @@ libsupport-routines = \
>    xchdir \
>    xchroot \
>    xclock_gettime \
> +  xclock_settime \
>    xclose \
>    xchmod \
>    xconnect \

Ok.

> diff --git a/support/xclock_settime.c b/support/xclock_settime.c
> new file mode 100644
> index 0000000000..183aba4876
> --- /dev/null
> +++ b/support/xclock_settime.c
> @@ -0,0 +1,34 @@
> +/* clock_settime with error checking.
> +   Copyright (C) 2021 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 <stdlib.h>
> +#include <support/check.h>
> +#include <support/xtime.h>
> +
> +void
> +xclock_settime (clockid_t clockid,
> +                const struct timespec *ts)
> +{
> +  if (getenv (SETTIME_ENV_NAME) == NULL)
> +    FAIL_UNSUPPORTED ("clock_settime is executed only when "\
> +                      SETTIME_ENV_NAME" is set\n");
> +
> +  const int ret = clock_settime (clockid, ts);

No need of 'const' here.

> +  if (ret < 0)
> +    FAIL_EXIT1 ("clock_settime (%d): %m", clockid);
> +}

Ok.

> diff --git a/support/xtime.h b/support/xtime.h
> index 2482837dee..b4ac3b59e2 100644
> --- a/support/xtime.h
> +++ b/support/xtime.h
> @@ -23,10 +23,15 @@
>  
>  __BEGIN_DECLS
>  
> +/* Name of the env variable, which indicates if it is possible to
> +   adjust time on target machine.  */
> +#define SETTIME_ENV_NAME "GLIBC_TEST_ALLOW_TIME_SETTING"
> +
>  /* The following functions call the corresponding libc functions and
>     terminate the process on error.  */
>  
>  void xclock_gettime (clockid_t clock, struct timespec *ts);
> +void xclock_settime (clockid_t clock, const struct timespec *ts);
>  
>  /* This helper can often simplify tests by avoiding an explicit
>     variable declaration or allowing that declaration to be const. */
> 

Ok.