[v4] tst: Provide test for difftime
Commit Message
This change adds new test to assess difftime's functionality by
adding some arbitrary offsets to current time_t value (read via
time).
If 64 bit time_t is supported, the same procedure is applied around
the threshold of Y2038 time overflow.
---
Changes for v2:
- Remove FAIL_UNSUPPORTED() when sizeof (time_t) <= 4
Changes for v3:
- Simplify the signature of test_difftime_helper (remove the start
argument)
- Use just some reproductible value of starting time_t instead of
calling time (NULL)
Changes for v4:
- Use __builtin_add_overflow instead of sizeof (time_t) > 4 to check
if time_t has overflowed.
---
time/Makefile | 2 +-
time/tst-difftime.c | 56 +++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 57 insertions(+), 1 deletion(-)
create mode 100644 time/tst-difftime.c
Comments
Dear Community,
> This change adds new test to assess difftime's functionality by
> adding some arbitrary offsets to current time_t value (read via
> time).
>
> If 64 bit time_t is supported, the same procedure is applied around
> the threshold of Y2038 time overflow.
>
> ---
> Changes for v2:
> - Remove FAIL_UNSUPPORTED() when sizeof (time_t) <= 4
>
> Changes for v3:
> - Simplify the signature of test_difftime_helper (remove the start
> argument)
> - Use just some reproductible value of starting time_t instead of
> calling time (NULL)
>
> Changes for v4:
> - Use __builtin_add_overflow instead of sizeof (time_t) > 4 to check
> if time_t has overflowed.
Are there any more comments regarding this test? Is it eligible for
pulling?
> ---
> time/Makefile | 2 +-
> time/tst-difftime.c | 56
> +++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 57
> insertions(+), 1 deletion(-) create mode 100644 time/tst-difftime.c
>
> diff --git a/time/Makefile b/time/Makefile
> index 486fb02ecb..7de2ce0196 100644
> --- a/time/Makefile
> +++ b/time/Makefile
> @@ -51,7 +51,7 @@ tests := test_time clocktest tst-posixtz
> tst-strptime tst_wcsftime \ tst-clock tst-clock2 tst-clock_nanosleep
> tst-cpuclock1 \ tst-adjtime tst-clock-y2038 tst-clock2-y2038 \
> tst-cpuclock1-y2038 tst-clock_nanosleep-y2038
> tst-clock_settime \
> - tst-clock_adjtime tst-ctime
> + tst-clock_adjtime tst-ctime tst-difftime
>
> include ../Rules
>
> diff --git a/time/tst-difftime.c b/time/tst-difftime.c
> new file mode 100644
> index 0000000000..262f3d1db7
> --- /dev/null
> +++ b/time/tst-difftime.c
> @@ -0,0 +1,56 @@
> +/* Test for difftime
> + 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 <time.h>
> +#include <support/check.h>
> +
> +static void
> +test_difftime_helper (time_t t1, time_t t0, double exp_val)
> +{
> + double sub = difftime (t1, t0);
> + if (sub != exp_val)
> + FAIL_EXIT1 ("*** Difftime returned %f (expected %f)\n", sub,
> exp_val); +}
> +
> +static int
> +do_test (void)
> +{
> + time_t t = 1383791700; /* Provide reproductible start value. */
> +
> + /* Check if difftime works with current time. */
> + test_difftime_helper (t + 1800, t - 1800, 3600.0);
> + test_difftime_helper (t - 1800, t + 1800, -3600.0);
> +
> + t = 0x7FFFFFFF;
> + /* Check if we run on port with 32 bit time_t size */
> + time_t tov;
> + if (__builtin_add_overflow (t, 1, &tov))
> + return 0;
> +
> + /* Check if the time is converted after 32 bit time_t overflow. */
> + test_difftime_helper (t + 1800, t - 1800, 3600.0);
> + test_difftime_helper (t - 1800, t + 1800, -3600.0);
> +
> + t = tov;
> + test_difftime_helper (t + 1800, t - 1800, 3600.0);
> + test_difftime_helper (t - 1800, t + 1800, -3600.0);
> +
> + return 0;
> +}
> +
> +#include <support/test-driver.c>
Best regards,
Lukasz Majewski
--
DENX Software Engineering GmbH, Managing Director: Wolfgang Denk
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-59 Fax: (+49)-8142-66989-80 Email: lukma@denx.de
On 05/02/2021 08:52, Lukasz Majewski wrote:
> This change adds new test to assess difftime's functionality by
> adding some arbitrary offsets to current time_t value (read via
> time).
>
> If 64 bit time_t is supported, the same procedure is applied around
> the threshold of Y2038 time overflow.
>
> ---
> Changes for v2:
> - Remove FAIL_UNSUPPORTED() when sizeof (time_t) <= 4
>
> Changes for v3:
> - Simplify the signature of test_difftime_helper (remove the start
> argument)
> - Use just some reproductible value of starting time_t instead of
> calling time (NULL)
>
> Changes for v4:
> - Use __builtin_add_overflow instead of sizeof (time_t) > 4 to check
> if time_t has overflowed.
LGTM, thanks.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
> ---
> time/Makefile | 2 +-
> time/tst-difftime.c | 56 +++++++++++++++++++++++++++++++++++++++++++++
> 2 files changed, 57 insertions(+), 1 deletion(-)
> create mode 100644 time/tst-difftime.c
>
> diff --git a/time/Makefile b/time/Makefile
> index 486fb02ecb..7de2ce0196 100644
> --- a/time/Makefile
> +++ b/time/Makefile
> @@ -51,7 +51,7 @@ tests := test_time clocktest tst-posixtz tst-strptime tst_wcsftime \
> tst-clock tst-clock2 tst-clock_nanosleep tst-cpuclock1 \
> tst-adjtime tst-clock-y2038 tst-clock2-y2038 \
> tst-cpuclock1-y2038 tst-clock_nanosleep-y2038 tst-clock_settime \
> - tst-clock_adjtime tst-ctime
> + tst-clock_adjtime tst-ctime tst-difftime
>
> include ../Rules
>
Ok.
> diff --git a/time/tst-difftime.c b/time/tst-difftime.c
> new file mode 100644
> index 0000000000..262f3d1db7
> --- /dev/null
> +++ b/time/tst-difftime.c
> @@ -0,0 +1,56 @@
> +/* Test for difftime
> + 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 <time.h>
> +#include <support/check.h>
> +
> +static void
> +test_difftime_helper (time_t t1, time_t t0, double exp_val)
> +{
> + double sub = difftime (t1, t0);
> + if (sub != exp_val)
> + FAIL_EXIT1 ("*** Difftime returned %f (expected %f)\n", sub, exp_val);
> +}
> +
> +static int
> +do_test (void)
> +{
> + time_t t = 1383791700; /* Provide reproductible start value. */
> +
> + /* Check if difftime works with current time. */
> + test_difftime_helper (t + 1800, t - 1800, 3600.0);
> + test_difftime_helper (t - 1800, t + 1800, -3600.0);
> +
> + t = 0x7FFFFFFF;
> + /* Check if we run on port with 32 bit time_t size */
> + time_t tov;
> + if (__builtin_add_overflow (t, 1, &tov))
> + return 0;
> +
> + /* Check if the time is converted after 32 bit time_t overflow. */
> + test_difftime_helper (t + 1800, t - 1800, 3600.0);
> + test_difftime_helper (t - 1800, t + 1800, -3600.0);
> +
> + t = tov;
> + test_difftime_helper (t + 1800, t - 1800, 3600.0);
> + test_difftime_helper (t - 1800, t + 1800, -3600.0);
> +
> + return 0;
> +}
> +
> +#include <support/test-driver.c>
>
Ok.
@@ -51,7 +51,7 @@ tests := test_time clocktest tst-posixtz tst-strptime tst_wcsftime \
tst-clock tst-clock2 tst-clock_nanosleep tst-cpuclock1 \
tst-adjtime tst-clock-y2038 tst-clock2-y2038 \
tst-cpuclock1-y2038 tst-clock_nanosleep-y2038 tst-clock_settime \
- tst-clock_adjtime tst-ctime
+ tst-clock_adjtime tst-ctime tst-difftime
include ../Rules
new file mode 100644
@@ -0,0 +1,56 @@
+/* Test for difftime
+ 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 <time.h>
+#include <support/check.h>
+
+static void
+test_difftime_helper (time_t t1, time_t t0, double exp_val)
+{
+ double sub = difftime (t1, t0);
+ if (sub != exp_val)
+ FAIL_EXIT1 ("*** Difftime returned %f (expected %f)\n", sub, exp_val);
+}
+
+static int
+do_test (void)
+{
+ time_t t = 1383791700; /* Provide reproductible start value. */
+
+ /* Check if difftime works with current time. */
+ test_difftime_helper (t + 1800, t - 1800, 3600.0);
+ test_difftime_helper (t - 1800, t + 1800, -3600.0);
+
+ t = 0x7FFFFFFF;
+ /* Check if we run on port with 32 bit time_t size */
+ time_t tov;
+ if (__builtin_add_overflow (t, 1, &tov))
+ return 0;
+
+ /* Check if the time is converted after 32 bit time_t overflow. */
+ test_difftime_helper (t + 1800, t - 1800, 3600.0);
+ test_difftime_helper (t - 1800, t + 1800, -3600.0);
+
+ t = tov;
+ test_difftime_helper (t + 1800, t - 1800, 3600.0);
+ test_difftime_helper (t - 1800, t + 1800, -3600.0);
+
+ return 0;
+}
+
+#include <support/test-driver.c>