wchar: Add __wcscpy_chk

CHANGELOG.rst

@@ -11,6 +11,11 @@
 1.0.0 (20??-??-??)
 ==================
 
+wchar
+-----
+
+* Add __wcscpy_chk.
+
 
 0.4.0 (2019-05-03)
 ==================

libgcompat/wchar.c

@@ -39,6 +39,27 @@ int __vswprintf_chk(wchar_t *s, size_t n, int flag, size_t slen,
 	return vswprintf(s, n, format, ap);
 }
 
+/**
+ * Copy a wide-character string, with buffer overflow checking
+ *
+ * LSB 5.0: LSB-Core-generic/baselib---wcscpy-chk-1.html
+ */
+wchar_t *__wcscpy_chk(wchar_t *dest, const wchar_t *src, size_t n)
+{
+	size_t srclen = wcslen(src) + 1;
+
+	assert(dest != NULL);
+	assert(src != NULL);
+	assert(n >= srclen);
+	if (dest < src) {
+		assert(dest + n <= src);
+	} else {
+		assert(src + n <= dest);
+	}
+
+	return wcscpy(dest, src);
+}
+
 /**
  * Representation of the glibc internals of wcstol(3).
  *