Re: [PATCH v2 3/3] build: rust: provide an option to inline C helpers into Rust

[Alice Ryhl]

On Tue, Feb 03, 2026 at 11:34:10AM +0000, Alice Ryhl wrote:
>  $(obj)/bindings/bindings_helpers_generated.rs: $(src)/helpers/helpers.c FORCE
>  	$(call if_changed_dep,bindgen)
>  
> +quiet_cmd_rust_helper = HELPER  $@
> +      cmd_rust_helper = \
> +	$(CC) $(filter-out $(CFLAGS_REMOVE_helpers/helpers.o), $(c_flags)) \
> +		-c -g0 $< $(if $(filter %_module.bc,$@),-DMODULE) -emit-llvm -o $@
> +
> +$(obj)/helpers/helpers.bc $(obj)/helpers/helpers_module.bc: $(src)/helpers/helpers.c FORCE
> +	+$(call if_changed_dep,rust_helper)

I think this needs:

$(obj)/helpers/helpers.bc: private part-of-builtin := y
$(obj)/helpers/helpers_module.bc: private part-of-module := y

at least it seems to make a difference for AutoFDO.

Alice