kbuild: add --target to correctly cross-compile UAPI headers with Clang

When you compile-test UAPI headers (CONFIG_UAPI_HEADER_TEST=y) with
Clang, they are currently compiled for the host target (likely x86_64)
regardless of the given ARCH=.

In fact, some exported headers include libc headers. For example,
include/uapi/linux/agpgart.h includes <stdlib.h> after being exported.
The header search paths should match to the target we are compiling
them for.

Pick up the --target triple from KBUILD_CFLAGS in the same ways as
commit 7f58b487e9 ("kbuild: make Clang build userprogs for target
architecture").

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
This commit is contained in:
Masahiro Yamada 2022-03-05 21:56:05 +09:00
parent 69304379ff
commit 9fbed27a7a

View File

@ -10,7 +10,7 @@ UAPI_CFLAGS := -std=c90 -Wall -Werror=implicit-function-declaration
# In theory, we do not care -m32 or -m64 for header compile tests.
# It is here just because CONFIG_CC_CAN_LINK is tested with -m32 or -m64.
UAPI_CFLAGS += $(filter -m32 -m64, $(KBUILD_CFLAGS))
UAPI_CFLAGS += $(filter -m32 -m64 --target=%, $(KBUILD_CFLAGS))
# USERCFLAGS might contain sysroot location for CC.
UAPI_CFLAGS += $(USERCFLAGS)