Re: [PATCH v2 1/7] kbuild: clear LDFLAGS in the top Makefile

[Nicolas Pitre]

On Fri, 16 Mar 2018, Masahiro Yamada wrote:

> Currently LDFLAGS is not cleared, so same flags are accumulated in
> LDFLAGS when the top Makefile is recursively invoked.
> 
> I found unneeded rebuild for ARCH=arm64 when CONFIG_TRIM_UNUSED_KSYMS
> is enabled.  If include/generated/autoksyms.h is updated, the top
> Makefile is recursively invoked, then arch/arm64/Makefile adds one
> more '-maarch64linux'.  Due to the command line change, modules are
> rebuilt needlessly.
> 
> Signed-off-by: Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx>

Acked-by: Nicolas Pitre <nico@xxxxxxxxxx>


> ---
> 
> Changes in v2: None
> 
>  Makefile | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/Makefile b/Makefile
> index d9bb6dd6..ac8755d 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -437,6 +437,7 @@ KBUILD_CFLAGS_KERNEL :=
>  KBUILD_AFLAGS_MODULE  := -DMODULE
>  KBUILD_CFLAGS_MODULE  := -DMODULE
>  KBUILD_LDFLAGS_MODULE := -T $(srctree)/scripts/module-common.lds
> +LDFLAGS :=
>  GCC_PLUGINS_CFLAGS :=
>  
>  export ARCH SRCARCH CONFIG_SHELL HOSTCC HOSTCFLAGS CROSS_COMPILE AS LD CC
> -- 
> 2.7.4
> 
>