[PATCH RFC 4/5] kbuild: uapi: provide a C++ compatible dummy definition of NULL

From: Thomas Weißschuh

Date: Sun Mar 08 2026 - 17:24:39 EST


NULL works differently in C++ compared to C.

To allow testing the UAPI headers against C++ compilers, provide
a variant of NULL which works with those.

Signed-off-by: Thomas Weißschuh <linux@xxxxxxxxxxxxxx>
---
usr/dummy-include/stddef.h | 5 +++++
1 file changed, 5 insertions(+)

diff --git a/usr/dummy-include/stddef.h b/usr/dummy-include/stddef.h
index a61703d1c896..525489daffe2 100644
--- a/usr/dummy-include/stddef.h
+++ b/usr/dummy-include/stddef.h
@@ -3,6 +3,11 @@
#define _DUMMY_STDDEF_H

#define offsetof(TYPE, MEMBER) __builtin_offsetof(TYPE, MEMBER)
+
+#ifdef __cplusplus
+#define NULL 0
+#else
#define NULL ((void *)0)
+#endif

#endif /* _DUMMY_STDDEF_H */

--
2.53.0