1 // SPDX-License-Identifier: LGPL-2.1+ 2 3 #include <kunit/test.h> 4 #include <linux/time.h> 5 6 /* 7 * Traditional implementation of leap year evaluation. 8 */ 9 static bool is_leap(long year) 10 { 11 return year % 4 == 0 && (year % 100 != 0 || year % 400 == 0); 12 } 13 14 /* 15 * Gets the last day of a month. 16 */ 17 static int last_day_of_month(long year, int month) 18 { 19 if (month == 2) 20 return 28 + is_leap(year); 21 if (month == 4 || month == 6 || month == 9 || month == 11) 22 return 30; 23 return 31; 24 } 25 26 /* 27 * Advances a date by one day. 28 */ 29 static void advance_date(long *year, int *month, int *mday, int *yday) 30 { 31 if (*mday != last_day_of_month(*year, *month)) { 32 ++*mday; 33 ++*yday; 34 return; 35 } 36 37 *mday = 1; 38 if (*month != 12) { 39 ++*month; 40 ++*yday; 41 return; 42 } 43 44 *month = 1; 45 *yday = 0; 46 ++*year; 47 } 48 49 /* 50 * Checks every day in a 160000 years interval centered at 1970-01-01 51 * against the expected result. 52 */ 53 static void time64_to_tm_test_date_range(struct kunit *test) 54 { 55 /* 56 * 80000 years = (80000 / 400) * 400 years 57 * = (80000 / 400) * 146097 days 58 * = (80000 / 400) * 146097 * 86400 seconds 59 */ 60 time64_t total_secs = ((time64_t) 80000) / 400 * 146097 * 86400; 61 long year = 1970 - 80000; 62 int month = 1; 63 int mdday = 1; 64 int yday = 0; 65 66 struct tm result; 67 time64_t secs; 68 s64 days; 69 70 for (secs = -total_secs; secs <= total_secs; secs += 86400) { 71 72 time64_to_tm(secs, 0, &result); 73 74 days = div_s64(secs, 86400); 75 76 #define FAIL_MSG "%05ld/%02d/%02d (%2d) : %ld", \ 77 year, month, mdday, yday, days 78 79 KUNIT_ASSERT_EQ_MSG(test, year - 1900, result.tm_year, FAIL_MSG); 80 KUNIT_ASSERT_EQ_MSG(test, month - 1, result.tm_mon, FAIL_MSG); 81 KUNIT_ASSERT_EQ_MSG(test, mdday, result.tm_mday, FAIL_MSG); 82 KUNIT_ASSERT_EQ_MSG(test, yday, result.tm_yday, FAIL_MSG); 83 84 advance_date(&year, &month, &mdday, &yday); 85 } 86 } 87 88 static struct kunit_case time_test_cases[] = { 89 KUNIT_CASE(time64_to_tm_test_date_range), 90 {} 91 }; 92 93 static struct kunit_suite time_test_suite = { 94 .name = "time_test_cases", 95 .test_cases = time_test_cases, 96 }; 97 98 kunit_test_suite(time_test_suite); 99 MODULE_LICENSE("GPL"); 100