From af20ae33e7dd949f2e770198e74ac8f058cb299d Mon Sep 17 00:00:00 2001 From: Miguel Ojeda Date: Thu, 15 Jan 2026 19:38:32 +0100 Subject: rust: kbuild: give `--config-path` to `rustfmt` in `.rsi` target `rustfmt` is configured via the `.rustfmt.toml` file in the source tree, and we apply `rustfmt` to the macro expanded sources generated by the `.rsi` target. However, under an `O=` pointing to an external folder (i.e. not just a subdir), `rustfmt` will not find the file when checking the parent folders. Since the edition is configured in this file, this can lead to errors when it encounters newer syntax, e.g. error: expected one of `!`, `.`, `::`, `;`, `?`, `where`, `{`, or an operator, found `"rust_minimal"` --> samples/rust/rust_minimal.rsi:29:49 | 28 | impl ::kernel::ModuleMetadata for RustMinimal { | - while parsing this item list starting here 29 | const NAME: &'static ::kernel::str::CStr = c"rust_minimal"; | ^^^^^^^^^^^^^^ expected one of 8 possible tokens 30 | } | - the item list ends here | = note: you may be trying to write a c-string literal = note: c-string literals require Rust 2021 or later = help: pass `--edition 2024` to `rustc` = note: for more on editions, read https://doc.rust-lang.org/edition-guide A workaround is to use `RUSTFMT=n`, which is documented in the `Makefile` help for cases where macro expanded source may happen to break `rustfmt` for other reasons, but this is not one of those cases. One solution would be to pass `--edition`, but we want `rustfmt` to use the entire configuration, even if currently we essentially use the default configuration. Thus explicitly give the path to the config file to `rustfmt` instead. Reported-by: Alice Ryhl Fixes: 2f7ab1267dc9 ("Kbuild: add Rust support") Cc: stable@vger.kernel.org Reviewed-by: Nathan Chancellor Reviewed-by: Gary Guo Link: https://patch.msgid.link/20260115183832.46595-1-ojeda@kernel.org Signed-off-by: Miguel Ojeda --- scripts/Makefile.build | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'scripts') diff --git a/scripts/Makefile.build b/scripts/Makefile.build index 5037f4715d74..0c838c467c76 100644 --- a/scripts/Makefile.build +++ b/scripts/Makefile.build @@ -356,7 +356,7 @@ $(obj)/%.o: $(obj)/%.rs FORCE quiet_cmd_rustc_rsi_rs = $(RUSTC_OR_CLIPPY_QUIET) $(quiet_modtag) $@ cmd_rustc_rsi_rs = \ $(rust_common_cmd) -Zunpretty=expanded $< >$@; \ - command -v $(RUSTFMT) >/dev/null && $(RUSTFMT) $@ + command -v $(RUSTFMT) >/dev/null && $(RUSTFMT) --config-path $(srctree)/.rustfmt.toml $@ $(obj)/%.rsi: $(obj)/%.rs FORCE +$(call if_changed_dep,rustc_rsi_rs) -- cgit v1.2.3