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Message-ID: <f278ea82-e949-f4d2-a48e-e615fa5491f6@gmail.com>
Date:   Fri, 16 Jun 2023 11:08:52 -0300
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Subject: Re: [PATCH v2 06/11] kbuild: rust_is_available: check that
 environment variables are set
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To:     Miguel Ojeda <ojeda@kernel.org>,
        Masahiro Yamada <masahiroy@kernel.org>,
        Wedson Almeida Filho <wedsonaf@gmail.com>,
        Alex Gaynor <alex.gaynor@gmail.com>
Cc:     Nathan Chancellor <nathan@kernel.org>,
        Nick Desaulniers <ndesaulniers@google.com>,
        Nicolas Schier <nicolas@fjasle.eu>,
        Boqun Feng <boqun.feng@gmail.com>, Gary Guo <gary@garyguo.net>,
        =?UTF-8?Q?Bj=c3=b6rn_Roy_Baron?= <bjorn3_gh@protonmail.com>,
        Benno Lossin <benno.lossin@proton.me>,
        Alice Ryhl <aliceryhl@google.com>,
        Andreas Hindborg <nmi@metaspace.dk>,
        linux-kbuild@vger.kernel.org, rust-for-linux@vger.kernel.org,
        linux-kernel@vger.kernel.org, patches@lists.linux.dev
References: <20230616001631.463536-1-ojeda@kernel.org>
 <20230616001631.463536-7-ojeda@kernel.org>
From:   Martin Rodriguez Reboredo <yakoyoku@gmail.com>
In-Reply-To: <20230616001631.463536-7-ojeda@kernel.org>
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On 6/15/23 21:16, Miguel Ojeda wrote:
> Sometimes [1] users may attempt to setup the Rust support by
> checking what Kbuild does and they end up finding out about
> `scripts/rust_is_available.sh`. Inevitably, they run the script
> directly, but unless they setup the required variables,
> the result of the script is not meaningful.
> 
> We could add some defaults to the variables, but that could be
> confusing for those that may override the defaults (compared
> to their kernel builds), and `$CC` would not be a simple default
> in any case.
> 
> Therefore, instead, explicitly check whether the expected variables
> are set (`$RUSTC`, `$BINDGEN` and `$CC`). If not, print an explanation
> about the fact that the script is meant to be called from Kbuild,
> since that is the most likely cause for the variables not being set.
> 
> Link: https://lore.kernel.org/oe-kbuild-all/Y6r4mXz5NS0+HVXo@zn.tnic/ [1]
> Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
> ---
> [...]

Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com>