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From:   Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>
Date:   Thu, 15 Apr 2021 02:47:51 +0200
Message-ID: <CANiq72kwge0-d-MYQ2vR9NBTe+0CKwzaVYtG3BEMjB-kLQ2e+g@mail.gmail.com>
Subject: Re: [PATCH 03/13] Makefile: Generate CLANG_FLAGS even in GCC builds
To:     Nick Desaulniers <ndesaulniers@google.com>
Cc:     Miguel Ojeda <ojeda@kernel.org>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        rust-for-linux@vger.kernel.org,
        Linux Kbuild mailing list <linux-kbuild@vger.kernel.org>,
        Linux Doc Mailing List <linux-doc@vger.kernel.org>,
        LKML <linux-kernel@vger.kernel.org>,
        Alex Gaynor <alex.gaynor@gmail.com>,
        Geoffrey Thomas <geofft@ldpreload.com>,
        Finn Behrens <me@kloenk.de>,
        Adam Bratschi-Kaye <ark.email@gmail.com>,
        Wedson Almeida Filho <wedsonaf@google.com>
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On Thu, Apr 15, 2021 at 1:47 AM Nick Desaulniers
<ndesaulniers@google.com> wrote:
>
> I'm ok with this approach, but I'm curious:
> If the user made a copy of the CLANG_FLAGS variable and modified its
> copy, would TENTATIVE_CLANG_FLAGS even be necessary? IIUC,
> TENTATIVE_CLANG_FLAGS is used to filter out certain flags before
> passing them to bindgen?
>
> Or, I'm curious whether you even need to rename this variable (or
> create a new variable) at all? Might make for a shorter diff if you
> just keep the existing identifier (CLANG_FLAGS), but create them
> unconditionally (at least not conditional on CC=clang).

This is only for the GCC builds -- and yeah, it is a hack. I still
need to think a bit more how to do this better; although ultimately
the proper solution is to have `bindgen` use GCC like it does with
`libclang` and avoid this altogether. That way we can ensure the
bindings are correct, support plugins, etc.

Cheers,
Miguel