Re: [PATCH 1/4] dt-bindings: fix error in 'make clean' after 'make dt_binding_check'

[Eugeniu Rosca <erosca@de.adit-jv.com>]

Dear Yamada-san,
Dear Kbuild experts,

On Fri, Jun 26, 2020 at 02:04:31AM +0900, Masahiro Yamada wrote:
> We are having more and more schema files.
> 
> Commit 8b6b80218b01 ("dt-bindings: Fix command line length limit
> calling dt-mk-schema") fixed the 'Argument list too long' error of
> the schema checks, but the same error happens while cleaning too.
> 
> 'make clean' after 'make dt_binding_check' fails as follows:
> 
>   $ make dt_binding_check
>     [ snip ]
>   $ make clean
>   make[2]: execvp: /bin/sh: Argument list too long
>   make[2]: *** [scripts/Makefile.clean:52: __clean] Error 127
>   make[1]: *** [scripts/Makefile.clean:66: Documentation/devicetree/bindings] Error 2
>   make: *** [Makefile:1763: _clean_Documentation] Error 2
> 
> 'make dt_binding_check' generates so many .example.dts, .dt.yaml files,
> which are passed to the 'rm' command when you run 'make clean'.
> 
> I added a small hack to use the 'find' command to clean up most of the
> build artifacts before they are processed by scripts/Makefile.clean
> 
> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
> ---
> 
>  Documentation/devicetree/bindings/Makefile | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/Makefile b/Documentation/devicetree/bindings/Makefile
> index a63898954068..f20d234aec46 100644
> --- a/Documentation/devicetree/bindings/Makefile
> +++ b/Documentation/devicetree/bindings/Makefile
> @@ -53,3 +53,8 @@ $(obj)/processed-schema.yaml: $(DT_SCHEMA_FILES) check_dtschema_version FORCE
>  	$(call if_changed,mk_schema)
>  
>  extra-y += processed-schema.yaml
> +
> +# Hack: avoid 'Argument list too long' error for 'make clean'. Remove most of
> +# build artifacts here before they are processed by scripts/Makefile.clean
> +clean-files = $(shell find $(obj) \( -name '*.example.dts' -o \
> +			-name '*.example.dt.yaml' \) -delete 2>/dev/null)

JFYI, we are running into the "Argument list too long" simply by trying to
clean an out-of-tree module (with lots of artifacts though), as below.
Seems to be happening on vanilla (v6.4-rc6-199-gb73056e9f82ebd) too.
Just in case there are any known hacks (or similar reports), please let us know.

$ make -C /data/linux-src M=my_module clean

make: Entering directory '/data/linux-src'
make -f ./scripts/Makefile.clean obj=my_module
set -e;  echo '  CLEAN   my_module';  rm -rf [~1k filenames / 200k char]
make[1]: /bin/sh: Argument list too long
make[1]: *** [scripts/Makefile.clean:45: __clean] Error 127

-- 
Best regards,
Eugeniu Rosca