Re: [PATCH 3/4] Makefile: lld: tell clang to use lld

[Nathan Chancellor <natechancellor@gmail.com>]

On Thu, Feb 07, 2019 at 02:01:51PM -0800, ndesaulniers@google.com wrote:
> This is needed because clang doesn't select which linker to use based on
> $LD but rather -fuse-ld=$(LD). This is problematic especially for
> cc-ldoption, which checks for linker flag support via invoking the
> compiler, rather than the linker.
> 
> Link: https://github.com/ClangBuiltLinux/linux/issues/342
> Suggested-by: Nathan Chancellor <natechancellor@gmail.com>
> Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
> ---
>  Makefile | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/Makefile b/Makefile
> index 0eae4277206e..6307c17259ea 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -502,6 +502,9 @@ endif
>  CLANG_FLAGS	+= -no-integrated-as
>  KBUILD_CFLAGS	+= $(CLANG_FLAGS)
>  KBUILD_AFLAGS	+= $(CLANG_FLAGS)
> +ifneq ($(shell $(LD) --version 2>&1 | head -n 1 | grep LLD),)
> +CLANG_FLAGS	+= -fuse-ld=lld
> +endif

This section needs to be moved up above KBUILD_CFLAGS otherwise it never
actually gets passed along.

With that change, please add:

Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
Tested-by: Nathan Chancellor <natechancellor@gmail.com>

>  export CLANG_FLAGS
>  endif
>  
> -- 
> 2.20.1.791.gb4d0f1c61a-goog
>