[PATCH 2/2] kbuild: move -Wundef from KBUILD_CFLAGS to KBUILD_CPPFLAGS

[Masahiro Yamada <masahiroy@kernel.org>]

The use of an undefined macro in an #if directive is warned, but only
in *.c files. No warning from other files such as *.S, *.lds.S.

Since -Wundef is a preprocessor-related warning, it should be added to
KBUILD_CPPFLAGS instead of KBUILD_CFLAGS.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
---

 Makefile | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/Makefile b/Makefile
index 027d9163eff6..898a759e314e 100644
--- a/Makefile
+++ b/Makefile
@@ -523,12 +523,12 @@ LINUXINCLUDE    := \
 		$(USERINCLUDE)
 
 KBUILD_AFLAGS   := -D__ASSEMBLY__ -fno-PIE
-KBUILD_CFLAGS   := -Wall -Wundef -Werror=strict-prototypes -Wno-trigraphs \
+KBUILD_CFLAGS   := -Wall -Werror=strict-prototypes -Wno-trigraphs \
 		   -fno-strict-aliasing -fno-common -fshort-wchar -fno-PIE \
 		   -Werror=implicit-function-declaration -Werror=implicit-int \
 		   -Werror=return-type -Wno-format-security \
 		   -std=gnu11
-KBUILD_CPPFLAGS := -D__KERNEL__
+KBUILD_CPPFLAGS := -D__KERNEL__ -Wundef
 KBUILD_AFLAGS_KERNEL :=
 KBUILD_CFLAGS_KERNEL :=
 KBUILD_AFLAGS_MODULE  := -DMODULE
-- 
2.34.1