Re: [PATCH 2/2] kbuild: handle excessively long argument lists

Nick Desaulniers
2021-01-14T21:08:33Z

> From: Mahesh Kumar Kalikot Veetil <mkalikot@codeaurora.org>
>
> Modules with a large number of compilation units may be
> exceeding AR and LD command argument list. Handle this gracefully by
> writing the long argument list in a file. The command line options
> read from file are inserted in place of the original @file option.
>
> The usage is well documented at
> https://www.gnu.org/software/make/manual/html_node/File-Function.html
>
> Signed-off-by: Mahesh Kumar Kalikot Veetil <mkalikot@codeaurora.org>
> Signed-off-by: Jeff Johnson <jjohnson@codeaurora.org>
> ---
> scripts/Makefile.build | 6 +++++-
> 1 file changed, 5 insertions(+), 1 deletion(-)
>
> diff --git a/scripts/Makefile.build b/scripts/Makefile.build
> index 252b7d2..d5ef345 100644
> --- a/scripts/Makefile.build
> +++ b/scripts/Makefile.build
> @@ -425,7 +425,11 @@ $(obj)/lib.a: $(lib-y) FORCE
> # module is turned into a multi object module, $^ will contain header file
> # dependencies recorded in the .*.cmd file.
> quiet_cmd_link_multi-m = LD [M] $@
> - cmd_link_multi-m = $(LD) $(ld_flags) -r -o $@ $(filter %.o,$^)
> + cmd_link_multi-m = \
> + $(file >$@.in,$(filter %.o,$^)) \
> + $(LD) $(ld_flags) -r -o $@ @$@.in; \
> + rm -f $@.in
> +endif

Was this build tested?

$ make LLVM=1 LLVM_IAS=1 -j72 defconfig
scripts/Makefile.build:432: *** extraneous 'endif'. Stop.
make: *** [Makefile:535: scripts_basic] Error 2

(Please cc me on v2)

>
> $(multi-used-m): FORCE
> $(call if_changed,link_multi-m)
> --
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