lib/string/strftime.[ch]: STRFTIME(): Add macro

This macro makes sure that the first argument is an array, and
calculates its size.

Reviewed-by: "Serge E. Hallyn" <serge@hallyn.com>
Signed-off-by: Alejandro Colomar <alx@kernel.org>

lib/string/strftime.c

@@ -0,0 +1,7 @@
+// SPDX-FileCopyrightText: 2024, Alejandro Colomar <alx@kernel.org>
+// SPDX-License-Identifier: BSD-3-Clause
+
+
+#include <config.h>
+
+#include "strftime.h"

lib/string/strftime.h

@@ -0,0 +1,19 @@
+// SPDX-FileCopyrightText: 2024, Alejandro Colomar <alx@kernel.org>
+// SPDX-License-Identifier: BSD-3-Clause
+
+
+#ifndef SHADOW_INCLUDE_LIB_STRFTIME_H_
+#define SHADOW_INCLUDE_LIB_STRFTIME_H_
+
+
+#include <config.h>
+
+#include <time.h>
+
+#include "sizeof.h"
+
+
+#define STRFTIME(dst, fmt, ...)  strftime(dst, NITEMS(dst), fmt, __VA_ARGS__)
+
+
+#endif  // include guard