commit c285f533dca03ad24aee56b4d42e9a1a4a21d5df
parent 26b566cf17e2d11ad799bfc87a1053a0fbe250d7
Author: André Bargull <andre.bargull@gmail.com>
Date: Thu, 27 Nov 2025 10:03:35 +0000
Bug 1999315 - Part 6: Allow reference years after 1972 in calendars that need them. r=spidermonkey-reviewers,mgaudet
Implements the changes from <https://github.com/tc39/proposal-temporal/pull/3152>.
Differential Revision: https://phabricator.services.mozilla.com/D272026
Diffstat:
2 files changed, 232 insertions(+), 71 deletions(-)
diff --git a/js/src/builtin/temporal/Calendar.cpp b/js/src/builtin/temporal/Calendar.cpp
@@ -2208,6 +2208,115 @@ static bool CalendarDateToISO(JSContext* cx, CalendarId calendar,
}
/**
+ * CalendarMonthDayToISOReferenceDate ( calendar, fields, overflow )
+ */
+static bool NonISOMonthDayToISOReferenceDate(JSContext* cx, CalendarId calendar,
+ icu4x::capi::Calendar* cal,
+ ISODate startISODate,
+ ISODate endISODate,
+ MonthCode monthCode, int32_t day,
+ UniqueICU4XDate& resultDate) {
+ MOZ_ASSERT(startISODate != endISODate);
+
+ int32_t direction = startISODate > endISODate ? -1 : 1;
+
+ auto fromIsoDate = CreateICU4XDate(cx, startISODate, calendar, cal);
+ if (!fromIsoDate) {
+ return false;
+ }
+
+ auto toIsoDate = CreateICU4XDate(cx, endISODate, calendar, cal);
+ if (!toIsoDate) {
+ return false;
+ }
+
+ // Find the calendar year for the ISO start date.
+ int32_t calendarYear;
+ if (!CalendarDateYear(cx, calendar, fromIsoDate.get(), &calendarYear)) {
+ return false;
+ }
+
+ // Find the calendar year for the ISO end date.
+ int32_t toCalendarYear;
+ if (!CalendarDateYear(cx, calendar, toIsoDate.get(), &toCalendarYear)) {
+ return false;
+ }
+
+ while (direction < 0 ? calendarYear >= toCalendarYear
+ : calendarYear <= toCalendarYear) {
+ // This loop can run for a long time.
+ if (!CheckForInterrupt(cx)) {
+ return false;
+ }
+
+ auto candidateYear = CalendarEraYear(calendar, calendarYear);
+
+ auto result =
+ CreateDateFromCodes(calendar, cal, candidateYear, monthCode, day);
+ if (result.isOk()) {
+ auto isoDate = ToISODate(result.inspect().get());
+
+ // Make sure the resolved date is before |startISODate|.
+ if (direction < 0 ? isoDate > startISODate : isoDate < startISODate) {
+ calendarYear += direction;
+ continue;
+ }
+
+ // Stop searching if |endISODate| was reached.
+ if (direction < 0 ? isoDate < endISODate : isoDate > endISODate) {
+ resultDate = nullptr;
+ return true;
+ }
+
+ resultDate = result.unwrap();
+ return true;
+ }
+
+ switch (result.inspectErr()) {
+ case CalendarError::UnknownMonthCode: {
+ MOZ_ASSERT(CalendarHasLeapMonths(calendar));
+ MOZ_ASSERT(monthCode.isLeapMonth());
+
+ // Try the next candidate year if the requested leap month doesn't
+ // occur in the current year.
+ calendarYear += direction;
+ continue;
+ }
+
+ case CalendarError::OutOfRange: {
+ // ICU4X throws an out-of-range error when:
+ // 1. month > monthsInYear(year), or
+ // 2. days > daysInMonthOf(year, month).
+ //
+ // Case 1 can't happen for month-codes, so it doesn't apply here.
+ // Case 2 can only happen when |day| is larger than the minimum number
+ // of days in the month.
+ MOZ_ASSERT(day > CalendarDaysInMonth(calendar, monthCode).first);
+
+ // Try next candidate year to find an earlier year which can fulfill
+ // the input request.
+ calendarYear += direction;
+ continue;
+ }
+
+ case CalendarError::UnknownEra:
+ MOZ_ASSERT(false, "unexpected calendar error");
+ break;
+
+ case CalendarError::Generic:
+ break;
+ }
+
+ JS_ReportErrorNumberASCII(cx, GetErrorMessage, nullptr,
+ JSMSG_TEMPORAL_CALENDAR_INTERNAL_ERROR);
+ return false;
+ }
+
+ resultDate = nullptr;
+ return true;
+}
+
+/**
* NonISOMonthDayToISOReferenceDate ( calendar, fields, overflow )
*/
static bool NonISOMonthDayToISOReferenceDate(JSContext* cx, CalendarId calendar,
@@ -2287,85 +2396,34 @@ static bool NonISOMonthDayToISOReferenceDate(JSContext* cx, CalendarId calendar,
}
}
- // Try years starting from 31 December, 1972.
- constexpr auto isoReferenceDate = ISODate{1972, 12, 31};
+ constexpr ISODate candidates[][2] = {
+ // The reference date is the latest ISO 8601 date corresponding to the
+ // calendar date that is between January 1, 1900 and December 31, 1972
+ // inclusive.
+ {ISODate{1972, 12, 31}, ISODate{1900, 1, 1}},
- auto fromIsoDate = CreateICU4XDate(cx, isoReferenceDate, calendar, cal.get());
- if (!fromIsoDate) {
- return false;
- }
+ // If there is no such date, it is the earliest ISO 8601 date
+ // corresponding to the calendar date between January 1, 1973 and
+ // December 31, 2035.
+ {ISODate{1973, 1, 1}, ISODate{2035, 12, 31}},
- // Find the calendar year for the ISO reference date.
- int32_t calendarYear;
- if (!CalendarDateYear(cx, calendar, fromIsoDate.get(), &calendarYear)) {
- return false;
- }
-
- // 10'000 is sufficient to find all possible month-days, even for rare cases
- // like `{calendar: "chinese", monthCode: "M09L", day: 30}`.
- constexpr size_t maxIterations = 10'000;
+ // If there is still no such date, it is the latest ISO 8601 date
+ // corresponding to the calendar date on or before December 31, 1899.
+ //
+ // Year -8000 is sufficient to find all possible month-days, even for
+ // rare cases like `{calendar: "chinese", monthCode: "M09L", day: 30}`.
+ {ISODate{1899, 12, 31}, ISODate{-8000, 1, 1}},
+ };
UniqueICU4XDate date;
- for (size_t i = 0; i < maxIterations; i++) {
- // This loop can run for a long time.
- if (!CheckForInterrupt(cx)) {
+ for (auto& [start, end] : candidates) {
+ if (!NonISOMonthDayToISOReferenceDate(cx, calendar, cal.get(), start, end,
+ monthCode, day, date)) {
return false;
}
-
- auto candidateYear = CalendarEraYear(calendar, calendarYear);
-
- auto result =
- CreateDateFromCodes(calendar, cal.get(), candidateYear, monthCode, day);
- if (result.isOk()) {
- // Make sure the resolved date is before December 31, 1972.
- auto isoDate = ToISODate(result.inspect().get());
- if (isoDate.year > isoReferenceDate.year) {
- calendarYear -= 1;
- continue;
- }
-
- date = result.unwrap();
+ if (date) {
break;
}
-
- switch (result.inspectErr()) {
- case CalendarError::UnknownMonthCode: {
- MOZ_ASSERT(CalendarHasLeapMonths(calendar));
- MOZ_ASSERT(monthCode.isLeapMonth());
-
- // Try the next candidate year if the requested leap month doesn't
- // occur in the current year.
- calendarYear -= 1;
- continue;
- }
-
- case CalendarError::OutOfRange: {
- // ICU4X throws an out-of-range error when:
- // 1. month > monthsInYear(year), or
- // 2. days > daysInMonthOf(year, month).
- //
- // Case 1 can't happen for month-codes, so it doesn't apply here.
- // Case 2 can only happen when |day| is larger than the minimum number
- // of days in the month.
- MOZ_ASSERT(day > CalendarDaysInMonth(calendar, monthCode).first);
-
- // Try next candidate year to find an earlier year which can fulfill
- // the input request.
- calendarYear -= 1;
- continue;
- }
-
- case CalendarError::UnknownEra:
- MOZ_ASSERT(false, "unexpected calendar error");
- break;
-
- case CalendarError::Generic:
- break;
- }
-
- JS_ReportErrorNumberASCII(cx, GetErrorMessage, nullptr,
- JSMSG_TEMPORAL_CALENDAR_INTERNAL_ERROR);
- return false;
}
// We shouldn't end up here with |maxIterations == 10'000|, but just in case
diff --git a/js/src/tests/non262/Temporal/PlainMonthDay/reference-dates-chinese-calendar.js b/js/src/tests/non262/Temporal/PlainMonthDay/reference-dates-chinese-calendar.js
@@ -0,0 +1,103 @@
+// |reftest| skip-if(!this.hasOwnProperty("Temporal"))
+
+const calendar = "chinese";
+
+// The Chinese calendar has 29-30 days per month.
+const tests = [
+ {
+ day: 29,
+ leapMonth: false,
+ expected: [
+ "1972-03-14[u-ca=chinese]",
+ "1972-04-12[u-ca=chinese]",
+ "1972-05-12[u-ca=chinese]",
+ "1972-06-10[u-ca=chinese]",
+ "1972-07-09[u-ca=chinese]",
+ "1972-08-08[u-ca=chinese]",
+ "1972-09-06[u-ca=chinese]",
+ "1972-10-06[u-ca=chinese]",
+ "1972-11-04[u-ca=chinese]",
+ "1972-12-04[u-ca=chinese]",
+ "1972-01-15[u-ca=chinese]",
+ "1972-02-13[u-ca=chinese]",
+ ],
+ },
+ {
+ day: 29,
+ leapMonth: true,
+ expected: [
+ "1651-03-20[u-ca=chinese]",
+ "1947-04-20[u-ca=chinese]",
+ "1966-05-19[u-ca=chinese]",
+ "1963-06-20[u-ca=chinese]",
+ "1971-07-21[u-ca=chinese]",
+ "1960-08-21[u-ca=chinese]",
+ "1968-09-21[u-ca=chinese]",
+ "1957-10-22[u-ca=chinese]",
+ "2014-11-21[u-ca=chinese]",
+ "1984-12-21[u-ca=chinese]",
+ "2034-01-19[u-ca=chinese]",
+ "1404-02-19[u-ca=chinese]",
+ ],
+ },
+ {
+ day: 30,
+ leapMonth: false,
+ expected: [
+ "1970-03-07[u-ca=chinese]",
+ "1972-04-13[u-ca=chinese]",
+ "1966-04-20[u-ca=chinese]",
+ "1970-06-03[u-ca=chinese]",
+ "1972-07-10[u-ca=chinese]",
+ "1971-08-20[u-ca=chinese]",
+ "1972-09-07[u-ca=chinese]",
+ "1971-10-18[u-ca=chinese]",
+ "1972-11-05[u-ca=chinese]",
+ "1972-12-05[u-ca=chinese]",
+ "1970-01-07[u-ca=chinese]",
+ "1972-02-14[u-ca=chinese]",
+ ],
+ },
+ {
+ day: 30,
+ leapMonth: true,
+ expected: [
+ "1461-03-20[u-ca=chinese]",
+ "1765-04-19[u-ca=chinese]",
+ "1955-05-21[u-ca=chinese]",
+ "1944-06-20[u-ca=chinese]",
+ "1952-07-21[u-ca=chinese]",
+ "1941-08-22[u-ca=chinese]",
+ "1938-09-23[u-ca=chinese]",
+ "1718-10-23[u-ca=chinese]",
+ "-005738-11-17[u-ca=chinese]",
+ "-004098-12-19[u-ca=chinese]",
+ "-002172-01-19[u-ca=chinese]",
+ "-000179-02-18[u-ca=chinese]",
+ ],
+ },
+];
+
+for (let {day, leapMonth, expected} of tests) {
+ assertEq(expected.length, 12);
+
+ for (let i = 1; i <= 12; ++i) {
+ let expectedToString = expected[i - 1];
+
+ // Skip over dates which are too far into the past (and therefore are likely
+ // incorrect anyway). This avoids slowing down this test.
+ if (expectedToString.startsWith("-")) {
+ continue;
+ }
+
+ let monthCode = "M" + String(i).padStart(2, "0") + (leapMonth ? "L" : "");
+
+ let pmd = Temporal.PlainMonthDay.from({calendar, monthCode, day});
+ assertEq(pmd.monthCode, monthCode);
+ assertEq(pmd.day, day);
+ assertEq(pmd.toString(), expectedToString);
+ }
+}
+
+if (typeof reportCompare === "function")
+ reportCompare(true, true);
