Re: [PATCH v2 1/2] rust: support overriding crate_name

[Alice Ryhl <aliceryhl@google.com>]

On Tue, Mar 10, 2026 at 02:53:40PM +0000, Alice Ryhl wrote:
> Currently you cannot filter out the crate-name argument
> RUSTFLAGS_REMOVE_stem.o because the Rust filter-out invocation does not
> include that particular argument. Since --crate-name is an argument that
> can't be passed multiple times, this means that it's currently not
> possible to override the crate name. Thus, remove the --crate-name
> argument for drivers. This allows them to override the crate name using
> the #![crate_name] annotation.
> 
> The --crate-name argument is kept for the crates under rust/ for
> simplicity and to avoid changing many of them by adding #![crate_name].
> 
> The rust analyzer script is updated to use rustc to obtain the crate
> name of the driver crates, which picks up the right name when it is
> configured via #![crate_name] or not.
> 
> Note that the crate name in the python script is not actually that
> important - the only place where the name actually affects anything is
> in the 'deps' array which specifies an index and name for each
> dependency, and determines what that dependency is called in *this*
> crate. (The same crate may be called different things in each
> dependency.) Since driver crates are leaf crates, this doesn't apply and
> the rustc invocation only affects the 'display_name' parameter.
> 
> Signed-off-by: Alice Ryhl <aliceryhl@google.com>
> ---
>  scripts/Makefile.build            | 1 -
>  scripts/generate_rust_analyzer.py | 8 +++++++-
>  2 files changed, 7 insertions(+), 2 deletions(-)
> 
> diff --git a/scripts/Makefile.build b/scripts/Makefile.build
> index 32e209bc7985..adc3e2d1ac78 100644
> --- a/scripts/Makefile.build
> +++ b/scripts/Makefile.build
> @@ -332,7 +332,6 @@ rust_common_cmd = \
>  	-Zcrate-attr='feature($(rust_allowed_features))' \
>  	-Zunstable-options --extern pin_init --extern kernel \
>  	--crate-type rlib -L $(objtree)/rust/ \
> -	--crate-name $(basename $(notdir $@)) \
>  	--sysroot=/dev/null \
>  	--out-dir $(dir $@) --emit=dep-info=$(depfile)
>  
> diff --git a/scripts/generate_rust_analyzer.py b/scripts/generate_rust_analyzer.py
> index f9b545104f21..d25bc3d7e719 100755
> --- a/scripts/generate_rust_analyzer.py
> +++ b/scripts/generate_rust_analyzer.py
> @@ -194,6 +194,12 @@ def generate_crates(srctree, objtree, sysroot_src, external_src, cfgs, core_edit
>          except FileNotFoundError:
>              return False
>  
> +    def get_crate_name(path):
> +        return subprocess.check_output(
> +            [os.environ["RUSTC"], "--print", "crate-name", path],
> +            stdin=subprocess.DEVNULL,
> +        ).decode('utf-8').strip()
> +
>      # Then, the rest outside of `rust/`.
>      #
>      # We explicitly mention the top-level folders we want to cover.
> @@ -212,7 +218,7 @@ def generate_crates(srctree, objtree, sysroot_src, external_src, cfgs, core_edit
>  
>              logging.info("Adding %s", name)

Actually I guess we might want get_crate_name(path) here (or just path).
But the other uses of 'name' should stay as-is.

>              append_crate(
> -                name,
> +                get_crate_name(path),
>                  path,
>                  ["core", "kernel", "pin_init"],
>                  cfg=cfg,
> 
> -- 
> 2.53.0.473.g4a7958ca14-goog
>