Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.33 as permitted sender) client-ip=23.128.96.33;
MIME-Version: 1.0
References: <e2b943eca92abebbf035447b3569f09a7176c770.1702366951.git.viresh.kumar@linaro.org>
 <1c03eb18-a6ac-45c8-8fea-46097bb4e132@gmail.com>
In-Reply-To: <1c03eb18-a6ac-45c8-8fea-46097bb4e132@gmail.com>
From:   Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>
Date:   Thu, 14 Dec 2023 18:22:47 +0100
Message-ID: <CANiq72=mvca8PXoxwzSao+QFbAHDCecSKCDtV+ffd+YgZNFaww@mail.gmail.com>
Subject: Re: [PATCH V2] docs: rust: Clarify that 'rustup override' applies to
 build directory
To:     Tiago Lam <tiagolam@gmail.com>
Cc:     Viresh Kumar <viresh.kumar@linaro.org>,
        Miguel Ojeda <ojeda@kernel.org>,
        Alex Gaynor <alex.gaynor@gmail.com>,
        Wedson Almeida Filho <wedsonaf@gmail.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>,
        Alice Ryhl <aliceryhl@google.com>,
        Jonathan Corbet <corbet@lwn.net>,
        Vincent Guittot <vincent.guittot@linaro.org>,
        rust-for-linux@vger.kernel.org, linux-doc@vger.kernel.org,
        linux-kernel@vger.kernel.org
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
Precedence: bulk

On Thu, Dec 14, 2023 at 2:26=E2=80=AFPM Tiago Lam <tiagolam@gmail.com> wrot=
e:
>
> `scripts/min-tool-version.sh` won't exist within the build dir if the
> option the user takes is "enter the kernel build directory", right? It
> only works if they use the `--path` argument in the `rustup override
> set` option.

Yeah, the script is in the source tree, and the path is the build
tree. Giving a single one-liner with `--path <builddir>` and
`<srctree>/scripts...` would be simplest in the sense that it would
allow us to remove even the "enter ..." part too. But then the command
cannot be copy-pasted and it is likely harder for newcomers that may
not be using `O=3D`.

Something like v1 but a bit simpler, e.g. keeping things as they are,
but with just a sentence after the command like "If you are building
the kernel with `O=3D`, i.e. specifying an output directory, then you
should append `--path <builddir>`." could work.

Or we could just provide a `rustupoverride` Make target to do this for
us [1], since we have all the information needed and would be
copy-pasteable by everybody. I can send it as a non-mangled patch and
then Viresh can redo this one on top using it.

Cheers,
Miguel

[1]

diff --git a/Makefile b/Makefile
index 70fc4c11dfc0..7fe82dd4dc6f 100644
--- a/Makefile
+++ b/Makefile
@@ -276,7 +276,8 @@ no-dot-config-targets :=3D $(clean-targets) \
                         cscope gtags TAGS tags help% %docs check% cocciche=
ck \
                         $(version_h) headers headers_% archheaders
archscripts \
                         %asm-generic kernelversion %src-pkg dt_binding_che=
ck \
-                        outputmakefile rustavailable rustfmt rustfmtcheck
+                        outputmakefile rustavailable rustfmt rustfmtcheck =
\
+                        rustupoverride
 no-sync-config-targets :=3D $(no-dot-config-targets) %install
modules_sign kernelrelease \
                          image_name
 single-targets :=3D %.a %.i %.ko %.lds %.ll %.lst %.mod %.o %.rsi %.s
%.symtypes %/
@@ -1611,6 +1612,7 @@ help:
        @echo  '                    (requires kernel .config;
downloads external repos)'
        @echo  '  rust-analyzer   - Generate rust-project.json
rust-analyzer support file'
        @echo  '                    (requires kernel .config)'
+       @echo  '  rustupoverride  - Set up a rustup override for the
build directory'
        @echo  '  dir/file.[os]   - Build specified target only'
        @echo  '  dir/file.rsi    - Build macro expanded source,
similar to C preprocessing.'
        @echo  '                    Run with RUSTFMT=3Dn to skip
reformatting if needed.'
@@ -1735,6 +1737,11 @@ rustfmt:
 rustfmtcheck: rustfmt_flags =3D --check
 rustfmtcheck: rustfmt

+# `rustup override` setup target
+PHONY +=3D rustupoverride
+rustupoverride:
+       $(Q)rustup override set $(shell
$(srctree)/scripts/min-tool-version.sh rustc)
+
 # Misc
 # ------------------------------------------------------------------------=
---