[PATCH 01/15] lib: wchar: add wide char string comparison functions

[Ahmad Fatoum]

From: Ahmad Fatoum <a.fat...@pengutronix.de>

For use by the EFI code, implement string comparison for wide character
strings.

Signed-off-by: Ahmad Fatoum <a.fat...@barebox.org>
---
 include/wchar.h |  3 +++
 lib/wchar.c     | 26 ++++++++++++++++++++++++++
 2 files changed, 29 insertions(+)

diff --git a/include/wchar.h b/include/wchar.h
index 392211039a61..02818815e183 100644
--- a/include/wchar.h
+++ b/include/wchar.h
@@ -24,4 +24,7 @@ size_t wcsnlen(const wchar_t *s, size_t maxlen);
 int mbtowc(wchar_t *pwc, const char *s, size_t n);
 int wctomb(char *s, wchar_t wc);
 
+int wcscmp (const wchar_t *s1, const wchar_t *s2);
+int wcsncmp (const wchar_t *s1, const wchar_t *s2, size_t n);
+
 #endif /* __WCHAR_H */
diff --git a/lib/wchar.c b/lib/wchar.c
index 49e946a09424..96db8116286a 100644
--- a/lib/wchar.c
+++ b/lib/wchar.c
@@ -124,3 +124,29 @@ char *strdup_wchar_to_char(const wchar_t *src)
 
        return dst;
 }
+
+int wcscmp(const wchar_t *s1, const wchar_t *s2)
+{
+       while (*s1 == *s2++) {
+               if (*s1++ == 0)
+                       return 0;
+       }
+
+       return *s1 - *--s2;
+}
+
+int wcsncmp (const wchar_t *s1, const wchar_t *s2, size_t n)
+{
+       if (n == 0)
+               return 0;
+
+       do {
+               if (*s1 != *s2++)
+                       return *s1 - *--s2;
+
+               if (*s1++ == 0)
+                       break;
+       } while (--n != 0);
+
+       return 0;
+}
-- 
2.39.5