wcsrchr.c\string\src - musl - musl - an implementation of the standard library for Linux-based systems

#include <wchar.h>
wchar_t *wcsrchr(const wchar_t *s, wchar_t c)
{
	const wchar_t *p;
	for (p=s+wcslen(s); p>=s && *p!=c; p--);
	return p>=s ? (wchar_t *)p : 0;
}