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Date:   Thu, 20 Jun 2019 13:54:06 -0700
From:   Matthias Kaehlcke <mka@chromium.org>
To:     Nick Desaulniers <ndesaulniers@google.com>
Cc:     Tom Roeder <tmroeder@google.com>,
        Masahiro Yamada <yamada.masahiro@socionext.com>,
        LKML <linux-kernel@vger.kernel.org>,
        Raul E Rangel <rrangel@chromium.org>,
        Tom Hughes <tomhughes@chromium.org>,
        Douglas Anderson <dianders@chromium.org>,
        Ryan Case <ryandcase@chromium.org>,
        Yu Liu <yudiliu@google.com>,
        Doug Anderson <dianders@google.com>
Subject: Re: [PATCH] gen_compile_command: Add support for separate
 KBUILD_OUTPUT directory
Message-ID: <20190620205406.GY137143@google.com>
References: <20190620184523.155756-1-mka@chromium.org>
 <CAKwvOdn-o9UszRW+MQ9Z0Ds9B2wSVBWUsPBPSF0S2DYxVFYpqA@mail.gmail.com>
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On Thu, Jun 20, 2019 at 12:53:22PM -0700, Nick Desaulniers wrote:
> On Thu, Jun 20, 2019 at 11:45 AM Matthias Kaehlcke <mka@chromium.org> wrote:
> >
> > gen_compile_command.py currently assumes that the .cmd files and the
> > source code live in the same directory, which is not the case when
> > a separate KBUILD_OUTPUT directory is used.
> 
> Great point; android builds the kernel outside of the source dir
> (`make O=/non-source/path ...`). Thanks for the patch! BTW if CrOS is
> doing cool stuff with compile_commands.json; I'd like to know!
> Particularly; I'm curious if it's possible to generate Ninja build
> files from compile_commands.json; I do miss Doug's Kbuild caching
> patches' speedup.
> Acked-by: Nick Desaulniers <ndesaulniers@google.com>

At this point Chrome OS doesn't do anything with compile_commands.json
for the kernel. I was just toying around a bit after a presentation
from Tom Hughes about IDE integration and encountered this limitation.