Re: [PATCH 05/18] rust: kbuild: define `procmacro-extension` variable

On Mon, Jun 08, 2026 at 05:40:02PM +0200, Miguel Ojeda wrote:
> On Mon, Jun 8, 2026 at 5:10 PM Nicolas Schier <[email protected]> wrote:
> >
> > Where does the 'libname.%' pattern come from?  Looking at the current
> > users of cmd_rustc_procmacro I'd expect a 'lib%' pattern instead.
> 
> Here, we want to extract the extension the operating system uses --
> this was originally added for macOS build support (Cc Tamir), and is
> `.so` in Linux but `.dylib` there (and if I recall correctly, we
> couldn't force `rustc` in macOS to use a file with `.so` as the
> extension, sadly).
> 
> In the commands, however, what we are trying to extract is the name of
> the crate instead. So that is why one is `lib%` and the other
> `libname.%` (a dummy library name).
> 
> Or do you mean something else?

Ah thanks!  If only that filename extension ('so' or 'dylib') is wanted, 
I'd rather expected the use of the '$(suffix)' function instead, as it 
may be easier to understand w/o knowing the name conversion rustc does:

  procmacro-extension := $(suffix $(call procmacro-name,dummy-crate-name))

but that's bike-shedding.

> Thanks a lot for the reviews! By the way, I sent a bit ago v2 (it
> doesn't change much, so I will pick your tags from here :)

Thanks.

Kind regards,
Nicolas