On Tue, Aug 13, 2024 at 1:29 AM Matthew Maurer <mmaurer@xxxxxxxxxx> wrote: > > 1. `rustc` support will soon be a minimum rather than a pinned version. In the meantime, this happened, so we should update this sentence. > 2. We already support multiple LLVMs linked into `rustc`, and these are I guess you mean `rustc` is able to use multiple major versions of LLVM -- or what do you mean by "multiple LLVMs linked"? > +# $(rustc-option,<flag>) > +# Return y if the Rust compiler supports <flag>, n otherwise > +# Calls to this should be guarded so that they are not evaluated if > +# CONFIG_HAVE_RUST is not set. Hmm... why `HAVE_RUST`? Should that be `RUST_IS_AVAILABLE`? Or what is the intention? Perhaps a comment would help here -- e.g. something like the comment I used in the original approach [1]. Otherwise we will forget... :) Also, I guess you wanted to relax the precondition as much as possible, which is great, just to double check, do we expect a case outside `RUST=y`? > rustc-option = $(success,trap "rm -rf .tmp_$$" EXIT; mkdir .tmp_$$; $(RUSTC) $(1) --crate-type=rlib /dev/null -o .tmp_$$/tmp.rlib) I also had `out-dir` [1] since, if I remember correctly, `rustc` may create temporary files in a potentially read-only location even in this case. Also, should we do `-Dwarnings` here? > +# If you are testing for unstable features, consider `rustc-min-version` > +# instead, as features may have different completeness while available. `rustc-min-version` is not mainline yet -- we don't have a user yet, but I can send it if so. Thanks! [1] https://github.com/Rust-for-Linux/linux/pull/1087#issuecomment-2218445303 Cheers, Miguel
