Add ARRAY_SIZE() macro

include/common/array-size.h

@@ -0,0 +1,19 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+#ifndef LABWC_ARRAY_SIZE_H
+#define LABWC_ARRAY_SIZE_H
+
+/**
+ * ARRAY_SIZE() - Get the number of elements in array.
+ * @arr: array to be sized
+ *
+ * This does not work on pointers.
+ *
+ * Recent versions of GCC and clang support -Werror=sizeof-pointer-div
+ * and thus avoids using constructs such as:
+ *
+ * #define same_type(a, b) (__builtin_types_compatible_p(typeof(a), typeof(b)) == 1)
+ * #define ARRAY_SIZE(a) ({ static_assert(!same_type(a, &(a)[0])); sizeof(a) / sizeof(a[0]); })
+ */
+#define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]))
+
+#endif /* LABWC_ARRAY_SIZE_H */