Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
MIME-Version: 1.0
References: <20210511044812.267965-1-aik@ozlabs.ru> <20210511112019.GK10366@gate.crashing.org>
 <1795b9efa40.27bb.1ca38dd7e845b990cd13d431eb58563d@ozlabs.ru>
 <20210511231635.GR10366@gate.crashing.org> <80ae1561-ed8d-cf3a-f3bb-d89cd07bfc24@ozlabs.ru>
 <20210512102640.GT10366@gate.crashing.org>
In-Reply-To: <20210512102640.GT10366@gate.crashing.org>
From:   Masahiro Yamada <masahiroy@kernel.org>
Date:   Fri, 14 May 2021 12:10:51 +0900
Message-ID: <CAK7LNAQkDDVigJbPKsPEcqQNz0z0Hc0r8h22MGB=8vMxMiMuDg@mail.gmail.com>
Subject: Re: [PATCH kernel v2] powerpc/makefile: Do not redefine $(CPP) for preprocessor
To:     Segher Boessenkool <segher@kernel.crashing.org>
Cc:     Alexey Kardashevskiy <aik@ozlabs.ru>,
        Michal Marek <michal.lkml@markovi.net>,
        Linux Kbuild mailing list <linux-kbuild@vger.kernel.org>,
        Nick Desaulniers <ndesaulniers@google.com>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Nicholas Piggin <npiggin@gmail.com>,
        Nathan Chancellor <nathan@kernel.org>,
        clang-built-linux <clang-built-linux@googlegroups.com>,
        linuxppc-dev <linuxppc-dev@lists.ozlabs.org>
Content-Type: text/plain; charset="UTF-8"
Precedence: bulk

On Wed, May 12, 2021 at 7:29 PM Segher Boessenkool
<segher@kernel.crashing.org> wrote:
>
> On Wed, May 12, 2021 at 01:48:53PM +1000, Alexey Kardashevskiy wrote:
> > >Oh!  I completely missed those few lines.  Sorry for that :-(
> >
> > Well, I probably should have made it a separate patch anyway, I'll
> > repost separately.
>
> Thanks.
>
> > >To compensate a bit:
> > >
> > >>It still puzzles me why we need -C
> > >>(preserve comments in the preprocessor output) flag here.
> > >
> > >It is so that a human can look at the output and read it.  Comments are
> > >very significant to human readers :-)
> >
> > I seriously doubt anyone ever read those :)
>
> I am pretty sure whoever wrote it did!


Keeping comments in the pre-processed linker scripts
is troublesome.

That is why -C was removed from scripts/Makefile.build


commit 5cb0512c02ecd7e6214e912e4c150f4219ac78e0
Author: Linus Torvalds <torvalds@linux-foundation.org>
Date:   Thu Nov 2 14:10:37 2017 -0700

    Kbuild: don't pass "-C" to preprocessor when processing linker scripts


You can entirely remove

 CPPFLAGS_vdso32.lds += -P -C -Upowerpc


-- 
Best Regards
Masahiro Yamada