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

[jjohnson]

On 2021-01-14 13:07, Nick Desaulniers wrote:
> > From: Mahesh Kumar Kalikot Veetil <mkalikot@xxxxxxxxxxxxxx>
> >
> > 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@xxxxxxxxxxxxxx>
> > Signed-off-by: Jeff Johnson <jjohnson@xxxxxxxxxxxxxx>
> > ---
> >  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)

blush

It was tested on a workspace that also contains the Clang LTO series
https://patchwork.kernel.org/project/linux-kbuild/patch/20201211184633.3213045-3-samitolvanen@xxxxxxxxxx/

I messed up when trimming, will update in v2