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From:   Alice Ryhl <aliceryhl@google.com>
Date:   Mon, 2 Oct 2023 09:42:28 +0200
Message-ID: <CAH5fLgjUa+TRO_xOQp-uRo5wC8+iVgSh+MA573EjfFtiHbA4mg@mail.gmail.com>
Subject: Re: [PATCH v3] rust: Respect HOSTCC when linking for host
To:     Matthew Maurer <mmaurer@google.com>
Cc:     Miguel Ojeda <ojeda@kernel.org>,
        Alex Gaynor <alex.gaynor@gmail.com>,
        Wedson Almeida Filho <wedsonaf@gmail.com>,
        Masahiro Yamada <masahiroy@kernel.org>,
        Nathan Chancellor <nathan@kernel.org>,
        Nick Desaulniers <ndesaulniers@google.com>,
        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>,
        Andreas Hindborg <a.hindborg@samsung.com>,
        Nicolas Schier <nicolas@fjasle.eu>, Tom Rix <trix@redhat.com>,
        rust-for-linux@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-kbuild@vger.kernel.org, llvm@lists.linux.dev
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On Thu, Sep 28, 2023 at 9:48=E2=80=AFPM Matthew Maurer <mmaurer@google.com>=
 wrote:
>
> Currently, rustc defaults to invoking `cc`, even if `HOSTCC` is defined,
> resulting in build failures in hermetic environments where `cc` does not
> exist. This includes both hostprogs and proc-macros.
>
> Since we are setting the linker to `HOSTCC`, we set the linker flavor to
> `gcc` explicitly. The linker-flavor selects both which linker to search
> for if the linker is unset, and which kind of linker flags to pass.
> Without this flag, `rustc` would attempt to determine which flags to
> pass based on the name of the binary passed as `HOSTCC`. `gcc` is the
> name of the linker-flavor used by `rustc` for all C compilers, including
> both `gcc` and `clang`.
>
> Signed-off-by: Matthew Maurer <mmaurer@google.com>

Tested-by: Alice Ryhl <aliceryhl@google.com>