[libc] Introduces gmtime_r to LLVM libc, based on C99/C2X/Single Unix Sp.

gmtime and gmtime_r share the same common code. They call gmtime_internal
a static inline function. Thus added only validation tests for gmtime_r.

Reviewed By: sivachandra

Differential Revision: https://reviews.llvm.org/D99046

1 files changed, 20 insertions, 0 deletions

diff --git a/libc/src/time/gmtime_r.cpp b/libc/src/time/gmtime_r.cpp
new file mode 100644
index 000000000000..67bf12696e2e
--- /dev/null
+++ b/libc/src/time/gmtime_r.cpp
@@ -0,0 +1,20 @@
+//===-- Implementation of gmtime_r function -------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "src/time/gmtime_r.h"
+#include "src/__support/common.h"
+#include "src/time/time_utils.h"
+
+namespace __llvm_libc {
+
+LLVM_LIBC_FUNCTION(struct tm *, gmtime_r,
+                   (const time_t *timer, struct tm *result)) {
+  return time_utils::gmtime_internal(timer, result);
+}
+
+} // namespace __llvm_libc