| 1 | /* |
| 2 | * SPDX-License-Identifier: MIT |
| 3 | * |
| 4 | * Copyright (C) 2011-2013 Mathieu Desnoyers <mathieu.desnoyers@efficios.com> |
| 5 | */ |
| 6 | |
| 7 | #ifndef _BABELTRACE_UTC_H |
| 8 | #define _BABELTRACE_UTC_H |
| 9 | |
| 10 | #include <time.h> |
| 11 | |
| 12 | /* If set, use GNU or BSD timegm(3) */ |
| 13 | #if defined(_BSD_SOURCE) || defined(_SVID_SOURCE) |
| 14 | |
| 15 | static inline |
| 16 | time_t bt_timegm(struct tm *tm) |
| 17 | { |
| 18 | return timegm(tm); |
| 19 | } |
| 20 | |
| 21 | #elif defined(__MINGW32__) |
| 22 | |
| 23 | static inline |
| 24 | time_t bt_timegm(struct tm *tm) |
| 25 | { |
| 26 | return _mkgmtime(tm); |
| 27 | } |
| 28 | |
| 29 | #else |
| 30 | |
| 31 | #include <errno.h> |
| 32 | |
| 33 | /* |
| 34 | * This is a simple implementation of timegm() it just turns the "struct tm" into |
| 35 | * a GMT time_t. It does not normalize any of the fields of the "struct tm", nor |
| 36 | * does it set tm_wday or tm_yday. |
| 37 | */ |
| 38 | |
| 39 | static inline |
| 40 | int bt_leapyear(int year) |
| 41 | { |
| 42 | return ((year % 4) == 0 && ((year % 100) != 0 || (year % 400) == 0)); |
| 43 | } |
| 44 | |
| 45 | static inline |
| 46 | time_t bt_timegm(struct tm *tm) |
| 47 | { |
| 48 | int year, month, total_days; |
| 49 | |
| 50 | int monthlen[2][12] = { |
| 51 | /* Days per month for a regular year */ |
| 52 | { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 }, |
| 53 | /* Days per month for a leap year */ |
| 54 | { 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 }, |
| 55 | }; |
| 56 | |
| 57 | if ((tm->tm_mon >= 12) || |
| 58 | (tm->tm_mday >= 32) || |
| 59 | (tm->tm_hour >= 24) || |
| 60 | (tm->tm_min >= 60) || |
| 61 | (tm->tm_sec >= 61)) { |
| 62 | errno = EOVERFLOW; |
| 63 | return (time_t) -1; |
| 64 | } |
| 65 | |
| 66 | /* Add 365 days for each year since 1970 */ |
| 67 | total_days = 365 * (tm->tm_year - 70); |
| 68 | |
| 69 | /* Add one day for each leap year since 1970 */ |
| 70 | for (year = 70; year < tm->tm_year; year++) { |
| 71 | if (bt_leapyear(1900 + year)) { |
| 72 | total_days++; |
| 73 | } |
| 74 | } |
| 75 | |
| 76 | /* Add days for each remaining month */ |
| 77 | for (month = 0; month < tm->tm_mon; month++) { |
| 78 | total_days += monthlen[bt_leapyear(1900 + year)][month]; |
| 79 | } |
| 80 | |
| 81 | /* Add remaining days */ |
| 82 | total_days += tm->tm_mday - 1; |
| 83 | |
| 84 | return ((((total_days * 24) + tm->tm_hour) * 60 + tm->tm_min) * 60 + tm->tm_sec); |
| 85 | } |
| 86 | |
| 87 | #endif |
| 88 | |
| 89 | #endif /* _BABELTRACE_UTC_H */ |