Re: [PATCH 3/3] kbuild: Allow passing additional HOSTCFLAGS and HOSTLDFLAGS

From: Masahiro Yamada
Date: Thu Apr 05 2018 - 01:00:54 EST


2018-03-29 9:48 GMT+09:00 Laura Abbott <labbott@xxxxxxxxxx>:
>
> Similar to AFLAGS_KBUILD, there may be uses (e.g. hardening) for passing in
> additional flags to host programs. Allow these to be passed in from the
> environment.
>
> Signed-off-by: Laura Abbott <labbott@xxxxxxxxxx>
> ---
> Documentation/kbuild/kbuild.txt | 9 +++++++++
> Makefile | 3 +++
> 2 files changed, 12 insertions(+)
>
> diff --git a/Documentation/kbuild/kbuild.txt b/Documentation/kbuild/kbuild.txt
> index ac2363ea05c5..3751a4bc8596 100644
> --- a/Documentation/kbuild/kbuild.txt
> +++ b/Documentation/kbuild/kbuild.txt
> @@ -24,6 +24,15 @@ KAFLAGS
> --------------------------------------------------
> Additional options to the assembler (for built-in and modules).
>
> +AFLAGS_HOSTCFLAGS
> +--------------------------------------------------
> +Additional options passed to the compiler when building host programs.
> +
> +AFLAGS_HOSTLDFLAGS
> +--------------------------------------------------
> +Additional options passed to the linker (through the compiler) when buidling
> +host programs.
> +


I am afraid you misunderstood the meaning of 'AFLAGS'.

AFLAGS is not 'Additional flags', but 'Assembler flags'
that are used for compiling *.S files.

AFLAGS for host programs is weird.



I see similar proposals from different people.

I replied like follows:
https://lkml.org/lkml/2018/2/28/178

However, Robin seems busy lately.

I will wait a bit, then
if nobody does this, I may do it.




> AFLAGS_MODULE
> --------------------------------------------------
> Additional module specific options to use for $(AS).
> diff --git a/Makefile b/Makefile
> index 7ba478ab8c82..2cab3f8d489c 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -367,6 +367,9 @@ HOSTCXXFLAGS := -O2 $(HOST_LFS_CFLAGS)
> HOSTLDFLAGS := $(HOST_LFS_LDFLAGS)
> HOST_LOADLIBES := $(HOST_LFS_LIBS)
>
> +HOSTCFLAGS += $(AFLAGS_HOSTCFLAGS)
> +HOSTLDFLAGS += $(AFLAGS_HOSTLDFLAGS)
> +
> # Make variables (CC, etc...)
> AS = $(CROSS_COMPILE)as
> LD = $(CROSS_COMPILE)ld
> --
> 2.16.2
>
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--
Best Regards
Masahiro Yamada