[libc] Add wcslen() function

Signed-off-by: Michael Brown <mcb30@ipxe.org>

src/core/wchar.c

@@ -0,0 +1,43 @@
+/*
+ * Copyright (C) 2012 Michael Brown <mbrown@fensystems.co.uk>.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER );
+
+/**
+ * @file
+ *
+ * Wide-character strings
+ *
+ */
+
+#include <wchar.h>
+
+/**
+ * Calculate length of wide-character string
+ *
+ * @v string		String
+ * @ret len		Length (excluding terminating NUL)
+ */
+size_t wcslen ( const wchar_t *string ) {
+	size_t len = 0;
+
+	while ( *(string++) )
+		len++;
+	return len;
+}

src/include/wchar.h

@@ -24,4 +24,6 @@ size_t wcrtomb ( char *buf, wchar_t wc, mbstate_t *ps __unused ) {
 	return 1;
 }
 
+extern size_t wcslen ( const wchar_t *string );
+
 #endif /* WCHAR_H */