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Date:   Thu, 14 Jan 2021 17:07:46 -0800
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Subject: Re: [PATCH 1/2] kbuild: simplify cmd_mod
From:   Nick Desaulniers <ndesaulniers@google.com>
To:     jjohnson@codeaurora.org
Cc:     eberman@quicinc.com, linux-kbuild@vger.kernel.org,
        linux-kernel@vger.kernel.org, masahiroy@kernel.org,
        michal.lkml@markovi.net, mkalikot@codeaurora.org,
        psodagud@quicinc.com, Sami Tolvanen <samitolvanen@google.com>,
        Nick Desaulniers <ndesaulniers@google.com>
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> From: Mahesh Kumar Kalikot Veetil <mkalikot@codeaurora.org>
> 
> Modules with a large number of compilation units can exceed execv
> argument list resulting in E2BIG (Argument list too long) error.
> 
> Fix this by replacing shell 'echo > file' into a more native
> $(file op filename[,text]) option.
> 
> Signed-off-by: Mahesh Kumar Kalikot Veetil <mkalikot@codeaurora.org>
> Signed-off-by: Jeff Johnson <jjohnson@codeaurora.org>
> ---
>  scripts/Makefile.build | 9 +++++----
>  1 file changed, 5 insertions(+), 4 deletions(-)
> 
> diff --git a/scripts/Makefile.build b/scripts/Makefile.build
> index 4c058f1..252b7d2 100644
> --- a/scripts/Makefile.build
> +++ b/scripts/Makefile.build
> @@ -279,10 +279,11 @@ $(obj)/%.o: $(src)/%.c $(recordmcount_source) $(objtool_dep) FORCE
>  	$(call if_changed_rule,cc_o_c)
>  	$(call cmd,force_checksrc)
>  
> -cmd_mod = { \
> -	echo $(if $($*-objs)$($*-y)$($*-m), $(addprefix $(obj)/, $($*-objs) $($*-y) $($*-m)), $(@:.mod=.o)); \
> -	$(undefined_syms) echo; \
> -	} > $@
> +cmd_mod = $(file >$@,\
> +		$(if $($*-objs)$($*-y)$($*-m), \
> +			$(addprefix $(obj)/, $($*-objs) $($*-y) $($*-m)), \
> +			$(@:.mod=.o))) \
> +	$(undefined_syms) echo >> $@

I find the indendation to be a readability improvement. Thanks for the
patch.

Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>

>  
>  $(obj)/%.mod: $(obj)/%.o FORCE
>  	$(call if_changed,mod)
> -- 
> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
> a Linux Foundation Collaborative Project
> 
>