1c92911e9e
This patch applies the lint rules described in the previous patch. There was also a significant amount of effort put into manually fixing things, since all of the templated functions, or structs defined in /spec, were not updated and had to be handled manually. Reviewed By: sivachandra, lntue Differential Revision: https://reviews.llvm.org/D114302
118 lines
4.4 KiB
C++
118 lines
4.4 KiB
C++
//===-- Implementation of mktime function ---------------------------------===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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#include "src/time/mktime.h"
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#include "src/__support/common.h"
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#include "src/time/time_utils.h"
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#include <limits.h>
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namespace __llvm_libc {
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using __llvm_libc::time_utils::TimeConstants;
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static constexpr int NON_LEAP_YEAR_DAYS_IN_MONTH[] = {31, 28, 31, 30, 31, 30,
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31, 31, 30, 31, 30, 31};
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// Returns number of years from (1, year).
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static constexpr int64_t get_num_of_leap_years_before(int64_t year) {
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return (year / 4) - (year / 100) + (year / 400);
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}
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// Returns True if year is a leap year.
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static constexpr bool is_leap_year(const int64_t year) {
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return (((year) % 4) == 0 && (((year) % 100) != 0 || ((year) % 400) == 0));
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}
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LLVM_LIBC_FUNCTION(time_t, mktime, (struct tm * tm_out)) {
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// Unlike most C Library functions, mktime doesn't just die on bad input.
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// TODO(rtenneti); Handle leap seconds.
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int64_t tm_year_from_base = tm_out->tm_year + TimeConstants::TIME_YEAR_BASE;
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// 32-bit end-of-the-world is 03:14:07 UTC on 19 January 2038.
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if (sizeof(time_t) == 4 &&
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tm_year_from_base >= TimeConstants::END_OF32_BIT_EPOCH_YEAR) {
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if (tm_year_from_base > TimeConstants::END_OF32_BIT_EPOCH_YEAR)
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return time_utils::out_of_range();
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if (tm_out->tm_mon > 0)
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return time_utils::out_of_range();
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if (tm_out->tm_mday > 19)
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return time_utils::out_of_range();
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if (tm_out->tm_hour > 3)
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return time_utils::out_of_range();
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if (tm_out->tm_min > 14)
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return time_utils::out_of_range();
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if (tm_out->tm_sec > 7)
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return time_utils::out_of_range();
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}
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// Years are ints. A 32-bit year will fit into a 64-bit time_t.
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// A 64-bit year will not.
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static_assert(sizeof(int) == 4,
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"ILP64 is unimplemented. This implementation requires "
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"32-bit integers.");
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// Calculate number of months and years from tm_mon.
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int64_t month = tm_out->tm_mon;
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if (month < 0 || month >= TimeConstants::MONTHS_PER_YEAR - 1) {
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int64_t years = month / 12;
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month %= 12;
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if (month < 0) {
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years--;
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month += 12;
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}
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tm_year_from_base += years;
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}
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bool tm_year_is_leap = is_leap_year(tm_year_from_base);
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// Calculate total number of days based on the month and the day (tm_mday).
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int64_t total_days = tm_out->tm_mday - 1;
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for (int64_t i = 0; i < month; ++i)
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total_days += NON_LEAP_YEAR_DAYS_IN_MONTH[i];
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// Add one day if it is a leap year and the month is after February.
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if (tm_year_is_leap && month > 1)
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total_days++;
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// Calculate total numbers of days based on the year.
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total_days += (tm_year_from_base - TimeConstants::EPOCH_YEAR) *
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TimeConstants::DAYS_PER_NON_LEAP_YEAR;
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if (tm_year_from_base >= TimeConstants::EPOCH_YEAR) {
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total_days += get_num_of_leap_years_before(tm_year_from_base - 1) -
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get_num_of_leap_years_before(TimeConstants::EPOCH_YEAR);
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} else if (tm_year_from_base >= 1) {
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total_days -= get_num_of_leap_years_before(TimeConstants::EPOCH_YEAR) -
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get_num_of_leap_years_before(tm_year_from_base - 1);
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} else {
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// Calculate number of leap years until 0th year.
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total_days -= get_num_of_leap_years_before(TimeConstants::EPOCH_YEAR) -
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get_num_of_leap_years_before(0);
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if (tm_year_from_base <= 0) {
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total_days -= 1; // Subtract 1 for 0th year.
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// Calculate number of leap years until -1 year
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if (tm_year_from_base < 0) {
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total_days -= get_num_of_leap_years_before(-tm_year_from_base) -
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get_num_of_leap_years_before(1);
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}
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}
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}
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// TODO(rtenneti): Need to handle timezone and update of tm_isdst.
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int64_t seconds = tm_out->tm_sec +
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tm_out->tm_min * TimeConstants::SECONDS_PER_MIN +
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tm_out->tm_hour * TimeConstants::SECONDS_PER_HOUR +
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total_days * TimeConstants::SECONDS_PER_DAY;
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// Update the tm structure's year, month, day, etc. from seconds.
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if (time_utils::update_from_seconds(seconds, tm_out) < 0)
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return time_utils::out_of_range();
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return static_cast<time_t>(seconds);
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}
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} // namespace __llvm_libc
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