Re: [PATCH v9 23/27] Kbuild: add Rust support

[Masahiro Yamada <masahiroy@kernel.org>]

On Sat, Aug 6, 2022 at 12:44 AM Miguel Ojeda <ojeda@kernel.org> wrote:
>
> Having most of the new files in place, we now enable Rust support
> in the build system, including `Kconfig` entries related to Rust,
> the Rust configuration printer and a few other bits.
>
> Co-developed-by: Alex Gaynor <alex.gaynor@gmail.com>
> Signed-off-by: Alex Gaynor <alex.gaynor@gmail.com>
> Co-developed-by: Finn Behrens <me@kloenk.de>
> Signed-off-by: Finn Behrens <me@kloenk.de>
> Co-developed-by: Adam Bratschi-Kaye <ark.email@gmail.com>
> Signed-off-by: Adam Bratschi-Kaye <ark.email@gmail.com>
> Co-developed-by: Wedson Almeida Filho <wedsonaf@google.com>
> Signed-off-by: Wedson Almeida Filho <wedsonaf@google.com>
> Co-developed-by: Michael Ellerman <mpe@ellerman.id.au>
> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
> Co-developed-by: Sven Van Asbroeck <thesven73@gmail.com>
> Signed-off-by: Sven Van Asbroeck <thesven73@gmail.com>
> Co-developed-by: Gary Guo <gary@garyguo.net>
> Signed-off-by: Gary Guo <gary@garyguo.net>
> Co-developed-by: Boris-Chengbiao Zhou <bobo1239@web.de>
> Signed-off-by: Boris-Chengbiao Zhou <bobo1239@web.de>
> Co-developed-by: Boqun Feng <boqun.feng@gmail.com>
> Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
> Co-developed-by: Douglas Su <d0u9.su@outlook.com>
> Signed-off-by: Douglas Su <d0u9.su@outlook.com>
> Co-developed-by: Dariusz Sosnowski <dsosnowski@dsosnowski.pl>
> Signed-off-by: Dariusz Sosnowski <dsosnowski@dsosnowski.pl>
> Co-developed-by: Antonio Terceiro <antonio.terceiro@linaro.org>
> Signed-off-by: Antonio Terceiro <antonio.terceiro@linaro.org>
> Co-developed-by: Daniel Xu <dxu@dxuuu.xyz>
> Signed-off-by: Daniel Xu <dxu@dxuuu.xyz>
> Co-developed-by: Björn Roy Baron <bjorn3_gh@protonmail.com>
> Signed-off-by: Björn Roy Baron <bjorn3_gh@protonmail.com>
> Co-developed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com>
> Signed-off-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com>
> Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
> ---
>  .gitignore                     |   2 +
>  Makefile                       | 172 ++++++++++++++-
>  arch/Kconfig                   |   6 +
>  include/linux/compiler_types.h |   6 +-
>  init/Kconfig                   |  46 +++-
>  kernel/configs/rust.config     |   1 +
>  lib/Kconfig.debug              |  34 +++
>  rust/.gitignore                |   8 +
>  rust/Makefile                  | 381 +++++++++++++++++++++++++++++++++
>  rust/bindgen_parameters        |  21 ++
>  scripts/Kconfig.include        |   6 +-
>  scripts/Makefile               |   3 +
>  scripts/Makefile.build         |  60 ++++++
>  scripts/Makefile.debug         |  10 +
>  scripts/Makefile.host          |  34 ++-
>  scripts/Makefile.lib           |  12 ++
>  scripts/Makefile.modfinal      |   8 +-
>  scripts/cc-version.sh          |  12 +-
>  scripts/kconfig/confdata.c     |  75 +++++++
>  scripts/min-tool-version.sh    |   6 +
>  20 files changed, 877 insertions(+), 26 deletions(-)
>  create mode 100644 kernel/configs/rust.config
>  create mode 100644 rust/.gitignore
>  create mode 100644 rust/Makefile
>  create mode 100644 rust/bindgen_parameters
>
> diff --git a/.gitignore b/.gitignore
> index 97e085d613a2..5da004814678 100644
> --- a/.gitignore
> +++ b/.gitignore
> @@ -37,6 +37,8 @@
>  *.o
>  *.o.*
>  *.patch
> +*.rmeta
> +*.rsi
>  *.s
>  *.so
>  *.so.dbg
> diff --git a/Makefile b/Makefile
> index df92892325ae..a105cb893b4c 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -120,6 +120,15 @@ endif
>
>  export KBUILD_CHECKSRC
>
> +# Enable "clippy" (a linter) as part of the Rust compilation.
> +#
> +# Use 'make CLIPPY=1' to enable it.
> +ifeq ("$(origin CLIPPY)", "command line")
> +  KBUILD_CLIPPY := $(CLIPPY)
> +endif
> +
> +export KBUILD_CLIPPY
> +
>  # Use make M=dir or set the environment variable KBUILD_EXTMOD to specify the
>  # directory of external module to build. Setting M= takes precedence.
>  ifeq ("$(origin M)", "command line")
> @@ -267,14 +276,14 @@ no-dot-config-targets := $(clean-targets) \
>                          cscope gtags TAGS tags help% %docs check% coccicheck \
>                          $(version_h) headers headers_% archheaders archscripts \
>                          %asm-generic kernelversion %src-pkg dt_binding_check \
> -                        outputmakefile
> +                        outputmakefile rustavailable rustfmt rustfmtcheck
>  # Installation targets should not require compiler. Unfortunately, vdso_install
>  # is an exception where build artifacts may be updated. This must be fixed.
>  no-compiler-targets := $(no-dot-config-targets) install dtbs_install \
>                         headers_install modules_install kernelrelease image_name
>  no-sync-config-targets := $(no-dot-config-targets) %install kernelrelease \
>                           image_name
> -single-targets := %.a %.i %.ko %.lds %.ll %.lst %.mod %.o %.s %.symtypes %/
> +single-targets := %.a %.i %.rsi %.ko %.lds %.ll %.lst %.mod %.o %.s %.symtypes %/
>
>  config-build   :=
>  mixed-build    :=
> @@ -436,6 +445,7 @@ else
>  HOSTCC = gcc
>  HOSTCXX        = g++
>  endif
> +HOSTRUSTC = rustc
>  HOSTPKG_CONFIG = pkg-config
>
>  KBUILD_USERHOSTCFLAGS := -Wall -Wmissing-prototypes -Wstrict-prototypes \
> @@ -444,8 +454,26 @@ KBUILD_USERHOSTCFLAGS := -Wall -Wmissing-prototypes -Wstrict-prototypes \
>  KBUILD_USERCFLAGS  := $(KBUILD_USERHOSTCFLAGS) $(USERCFLAGS)
>  KBUILD_USERLDFLAGS := $(USERLDFLAGS)
>
> +# These flags apply to all Rust code in the tree, including the kernel and
> +# host programs.
> +export rust_common_flags := --edition=2021 \
> +                           -Zbinary_dep_depinfo=y \




Let me ask a question about the host_rust rule.



If I directly run the build command from the command line,
I get an error, like follows:


$ rustc --edition=2021 -Zbinary_dep_depinfo=y -Dunsafe_op_in_unsafe_fn
-Drust_2018_idioms -Dunreachable_pub -Dnon_ascii_idents -Wmissing_docs
-Drustdoc::missing_crate_level_docs -Dclippy::correctness
-Dclippy::style -Dclippy::suspicious -Dclippy::complexity
-Dclippy::perf -Dclippy::let_unit_value -Dclippy::mut_mut
-Dclippy::needless_bitwise_bool -Dclippy::needless_continue
-Wclippy::dbg_macro -O -Cstrip=debuginfo -Zallow-features=
--emit=dep-info,link --out-dir=scripts/
../scripts/generate_rust_target.rs
error: the option `Z` is only accepted on the nightly compiler



This is the same command recorded as in
scripts/.generate_rust_target.cmd



Why no error when it is invoked from Makefile?


I have not figured out where this difference comes from.








-- 
Best Regards
Masahiro Yamada