Re: [PATCH] kbuild: rust: avoid creating temporary files

From: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>
To: Masahiro Yamada <masahiroy@kernel.org>
Cc: "Miguel Ojeda" <ojeda@kernel.org>,
	"Wedson Almeida Filho" <wedsonaf@gmail.com>,
	"Alex Gaynor" <alex.gaynor@gmail.com>,
	"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>,
	"Björn Roy Baron" <bjorn3_gh@protonmail.com>,
	"Benno Lossin" <benno.lossin@proton.me>,
	"Alice Ryhl" <aliceryhl@google.com>,
	"Andreas Hindborg" <a.hindborg@samsung.com>,
	linux-kbuild@vger.kernel.org, rust-for-linux@vger.kernel.org,
	linux-kernel@vger.kernel.org, patches@lists.linux.dev,
	"Raphael Nestler" <raphael.nestler@gmail.com>,
	"Andrea Righi" <andrea.righi@canonical.com>,
	stable@vger.kernel.org
Subject: Re: [PATCH] kbuild: rust: avoid creating temporary files
Date: Sat, 22 Jul 2023 17:51:46 +0200	[thread overview]
Message-ID: <CANiq72kD2wxXy2ri8sBhVJ4y-JJiq+kYt_MRZwuwB9uGkX-_jQ@mail.gmail.com> (raw)
In-Reply-To: <CAK7LNASqumGb0xvSa8n4Heasz9BKxgk4mvzNXsfFhZE1G+Bxbg@mail.gmail.com>

On Thu, Jul 20, 2023 at 8:35 PM Masahiro Yamada <masahiroy@kernel.org> wrote:
>
> Maybe, the following was a breakage.
>
> commit 295d8398c67e314d99bb070f38883f83fe94a97a
> Author: Masahiro Yamada <masahiroy@kernel.org>
> Date:   Sat Jan 7 18:18:15 2023 +0900
>
>     kbuild: specify output names separately for each emission type from rustc
>
> Before that, rust_common_cmd had --out-dir.

That's right, good catch!

> BTW, do we also need to fix scripts/Makefile.host
> in case the external module Makefile creates host programs?

Indeed, we need it too. [1] would fix it (tested it with a trivial
out-of-tree Rust hostprog).

Do you want me to send it separately? i.e. to avoid losing the
`Tested-by`s etc. that we already got for this one, which is the
important one since that actually has users.

The hostprogs fix is not really critical for stable, since it is
unlikely there are users at all (we just got the first in-tree real
user in the Rust+KUnit integration coming into 6.6), but I guess it
does not hurt for the same reason.

Thanks!

Cheers,
Miguel

[1]

diff --git a/scripts/Makefile.host b/scripts/Makefile.host
index 7aea9005e497..54adf2e2ec51 100644
--- a/scripts/Makefile.host
+++ b/scripts/Makefile.host
@@ -86,7 +86,7 @@ hostc_flags    = -Wp,-MMD,$(depfile) \
 hostcxx_flags  = -Wp,-MMD,$(depfile) \
                  $(KBUILD_HOSTCXXFLAGS) $(HOST_EXTRACXXFLAGS) \
                  $(HOSTCXXFLAGS_$(target-stem).o)
-hostrust_flags = --emit=dep-info=$(depfile) \
+hostrust_flags = --out-dir $(dir $@) --emit=dep-info=$(depfile) \
                  $(KBUILD_HOSTRUSTFLAGS) $(HOST_EXTRARUSTFLAGS) \
                  $(HOSTRUSTFLAGS_$(target-stem))
