[v5] tst: time: Provide Y2038 tests for mktime (tst-mktime4.c)
Commit Message
This change adds new test to assess mktime's functionality.
To be more specific - following use cases are checked:
- Pass struct tm as epoch time
- Pass struct tm as value just before Y2038 threshold (returned
value shall be 0x7FFFFFFF)
- Pass struct tm as the first value after Y2038 threshold
(expected value - 0x80000000)
---
Changes for v2:
- Remove FAIL_UNSUPPORTED() when sizeof (time_t) <= 4
- Remove tzset () as it is already done in mktime ()
- Use TEST_COMPARE to check if correct result is received
- Use "TZ=:" glibc extension to guarantee UTC time zone
- Add two more checks - prepare struct tm in a way that mktime will
return 0xFFFFFFFF and 0x100000000
Changes for v3:
- Remove .tm_wday and .tm_yday as are irrelevant
- Add (time_t) -1 cast when checking mktime return value
- Replace "executed" with "compiled".
- Use long long int as the exp_val type to avoid overflow compilation error
- Rename tm1 to tm32bitmax
- Define tm0, tmY2038, tm32bitmax as const
- Pass the pointer to copy of aforementioned structs to test_mktime_helper
Changes for v4:
- Use __builtin_add_overflow instead of sizeof (time_t) > 4 to check
if time_t has overflowed.
Changes for v5:
- Fix indentation of the struct tm
- Add more verbose error message when expected value is different han result
- Add test prefix to commit message
---
time/Makefile | 2 +-
time/tst-mktime4.c | 107 +++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 108 insertions(+), 1 deletion(-)
create mode 100644 time/tst-mktime4.c
Comments
* Lukasz Majewski:
> + if ((long long int) result != exp_val)
> + FAIL_EXIT1 ("*** Result different than expected (%lld != %lld) in %d\n",
> + (long long int) result, exp_val, __LINE__);
See my previous comment about __LINE__L
<https://sourceware.org/pipermail/libc-alpha/2021-February/122422.html>
Thanks,
Florian
@@ -48,7 +48,7 @@ tests := test_time clocktest tst-posixtz tst-strptime tst_wcsftime \
tst-strptime3 bug-getdate1 tst-strptime-whitespace tst-ftime \
tst-tzname tst-y2039 bug-mktime4 tst-strftime2 tst-strftime3 \
tst-clock tst-clock2 tst-clock_nanosleep tst-cpuclock1 \
- tst-adjtime tst-ctime tst-difftime
+ tst-adjtime tst-ctime tst-difftime tst-mktime4
include ../Rules
new file mode 100644
@@ -0,0 +1,107 @@
+/* Test for mktime (4)
+ 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 <stdlib.h>
+#include <support/check.h>
+
+const struct tm tm0 =
+ {
+ .tm_year = 70,
+ .tm_mon = 0,
+ .tm_mday = 1,
+ .tm_hour = 0,
+ .tm_min = 0,
+ .tm_sec = 0,
+ .tm_wday = 4,
+ .tm_yday = 0,
+ };
+
+const struct tm tmY2038 =
+ {
+ .tm_year = 138,
+ .tm_mon = 0,
+ .tm_mday = 19,
+ .tm_hour = 3,
+ .tm_min = 14,
+ .tm_sec = 7,
+ };
+
+const struct tm tm32bitmax =
+ {
+ .tm_year = 206,
+ .tm_mon = 1,
+ .tm_mday = 7,
+ .tm_hour = 6,
+ .tm_min = 28,
+ .tm_sec = 15,
+ };
+
+static
+void test_mktime_helper (struct tm *tm, long long int exp_val)
+{
+ time_t result, t;
+
+ /* Check if we run on port with 32 bit time_t size */
+ if (__builtin_add_overflow (exp_val, 0, &t))
+ return;
+
+ result = mktime (tm);
+ if (result == (time_t) -1)
+ FAIL_EXIT1 ("*** mktime failed: %m");
+
+ if ((long long int) result != exp_val)
+ FAIL_EXIT1 ("*** Result different than expected (%lld != %lld) in %d\n",
+ (long long int) result, exp_val, __LINE__);
+}
+
+static int
+do_test (void)
+{
+ struct tm t;
+ /* Use glibc time zone extension "TZ=:" to to guarantee that UTC
+ without leap seconds is used for the test. */
+ TEST_VERIFY_EXIT (setenv ("TZ", ":", 1) == 0);
+
+ /* Check that mktime (1970-01-01 00:00:00) returns 0. */
+ t = tm0;
+ test_mktime_helper (&t, 0);
+
+ /* Check that mktime (2038-01-19 03:14:07) returns 0x7FFFFFFF. */
+ t = tmY2038;
+ test_mktime_helper (&t, 0x7fffffff);
+
+ /* Check that mktime (2038-01-19 03:14:08) returns 0x80000000
+ (time_t overflow). */
+ t = tmY2038;
+ t.tm_sec++;
+ test_mktime_helper (&t, 0x80000000);
+
+ /* Check that mktime (2106-02-07 06:28:15) returns 0xFFFFFFFF. */
+ t = tm32bitmax;
+ test_mktime_helper (&t, 0xFFFFFFFF);
+
+ /* Check that mktime (2106-02-07 06:28:16) returns 0x100000000. */
+ t = tm32bitmax;
+ t.tm_sec++;
+ test_mktime_helper (&t, 0x100000000);
+
+ return 0;
+}
+
+#include <support/test-driver.c>