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Date:   Mon, 19 Jun 2023 11:32:33 +0200
From:   Eugeniu Rosca <erosca@de.adit-jv.com>
To:     Masahiro Yamada <masahiroy@kernel.org>
CC:     Eugeniu Rosca <erosca@de.adit-jv.com>,
        <linux-kbuild@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
        Nathan Chancellor <nathan@kernel.org>,
        Nick Desaulniers <ndesaulniers@google.com>,
        Nicolas Schier <nicolas@fjasle.eu>,
        Eugeniu Rosca <roscaeugeniu@gmail.com>
Subject: Re: [PATCH] kbuild: make clean rule robust against too long argument
 error
Message-ID: <20230619093233.GB20014@lxhi-065>
References: <20230617153025.1653851-1-masahiroy@kernel.org>
 <20230617200700.GA31221@lxhi-065>
 <CAK7LNATbrP4Re+-9rY9d0=Dsk-O4DasZZtV0wM7SWg3Y5eLKmQ@mail.gmail.com>
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Hello Yamada-san,

On Mon, Jun 19, 2023 at 12:50:48AM +0900, Masahiro Yamada wrote:
> On Sun, Jun 18, 2023 at 5:07 AM Eugeniu Rosca <erosca@de.adit-jv.com> wrote:

[snip]

> > Please, correct me if I am wrong, but it looks like the magic/brilliance
> > is in the 'patsubst' function, since below version also fails for me:
> >
> > NOK: cmd_clean = printf '%s ' $(__clean-files) | xargs rm -rf
> 
> Right.
> Now, 'printf' (instead of 'rm') failed with the too long argument list.
> 
> GNU Make does not have the length limit, but shell does.
> So, the full-path list must be passed via stdout
> instead of the command line.
> 
> 
> The comment might be confusing.
> 
> I will repeat the same comment written in scripts/Makefile.build:
> 
>   # To make this rule robust against "Argument list too long" error,
>   # remove $(obj)/ prefix, and restore it by a shell command.

Sounds good to me. No open questions from my end :)

-- 
Best regards,
Eugeniu Rosca