| Message ID | 20220305092816.92114-1-masahiroy@kernel.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | kbuild: add --target to correctly cross-compile UAPI headers with Clang | expand |
diff --git a/usr/include/Makefile b/usr/include/Makefile index 703ee034033e..19ac4b63866d 100644 --- a/usr/include/Makefile +++ b/usr/include/Makefile @@ -12,7 +12,7 @@ UAPI_CFLAGS += $(CLANG_FLAGS) # 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)
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=. As a matter of fact, some exported headers include libc headers. For example, include/uapi/sound/asound.h includes <stdlib.h> and <time.h> after being exported. It is better to try to match the header search paths to the target we are compiling them for. Pick up the --target triple from KBUILD_CFLAGS in the same ways as commit 7f58b487e9ff ("kbuild: make Clang build userprogs for target architecture"). Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> --- As far as I tested on Debian, Clang falls back to /usr/include/ when libc dev package for the specified target is not installed. For example, --target=aarch64-linux-gnu tries to include /usr/aarch64-linux-gnu/include/stdlib.h , which is available when libc6-dev-arm64-cross is installed. Otherwise, includes /usr/include/stdlib.h usr/include/Makefile | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)