From 13c0b30b24b1f7c6853cb8a3317568cb960efe99 Mon Sep 17 00:00:00 2001 From: Lukasz Majewski Date: Mon, 25 Jan 2021 12:51:41 +0100 Subject: [PATCH] tst: Provide test for difftime 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. Reviewed-by: Adhemerval Zanella --- 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 2dd70111b5..7caec2b271 100644 --- a/time/Makefile +++ b/time/Makefile @@ -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-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 + . */ + +#include +#include + +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