[Bug target/111610] Cannot build cross compiler to darwin targets after r14-4108-g47346acb72b50d

["iains at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111610

--- Comment #3 from Iain Sandoe <iains at gcc dot gnu.org> ---
(In reply to Martin Jambor from comment #2)
> (In reply to Iain Sandoe from comment #1)
> > As a matter of record, we do not really support cross-compilers targeting an
> > unknown Darwin version (the idea of xxx-apple-darwin [without a specific
> > version] was to support building natively on macOS).  What will happen is
> > you will get the earliest supported OS version for the target arch (which
> > might not really be very representative)
> > 
> > It would likely be more representative/useful to choose some suitable OS
> > version:
> > 
> > e.g. powerpc-apple-darwin9 (latest) i686-apple-darwin17 (last 32b support)
> > x86_64-apple-darwin21 (up to date) .. and eventually aarch64-apple-darwin2x
> > ....
> > 
> > Of course, the build should not fail so we must fix it - but just pointing
> > out that the results from the current builds are from a configuration that
> > will be issuing warnings about choice of OS version.
> 
> IIUC, the test script takes all targets listed in contrib/config-list.mk and
> tries the above configuration and make all-host steps on all of those
> targets that are not explicitly excluded (currently only powerpc-freebsd13
> because of PR 108491). I don't really know how (or if) the list in that file
> is maintained, but it looks like if they should be removed, they should be
> removed from there?  Of course, we can exclude anything on our end too.

OK. Perhaps that list should be edited to reflect modern practice - but, if not
it's still better to have an old configuration tested than nothing (after all
it found this issue).  As it happens, we did already check for the
missing/unknown case for dsymutil but the enumeration clashes with another RTL
use of "UNKNOWN".  I'll land the fix shortly.