Re: [PATCH v4 25/30] xen/riscv: add minimal stuff to processor.h to build full Xen

[Oleksii <oleksii.kurochko@xxxxxxxxx>]

On Thu, 2024-02-15 at 17:43 +0100, Jan Beulich wrote:
> On 15.02.2024 17:38, Oleksii wrote:
> > On Tue, 2024-02-13 at 14:33 +0100, Jan Beulich wrote:
> > > On 05.02.2024 16:32, Oleksii Kurochko wrote:
> > > > +       depends on LLD_VERSION >= 150000 || LD_VERSION >=
> > > > 23600
> > > 
> > > What's the linker dependency here? Depending on the answer I
> > > might
> > > further
> > > ask why "TOOLCHAIN" when elsewhere we use CC_HAS_ or HAS_CC_ or
> > > HAS_AS_.
> > I missed to introduce {L}LLD_VERSION config. It should output from
> > the
> > command:
> >   riscv64-linux-gnu-ld --version
> 
> Doesn't answer my question though where the linker version matters
> here.
Then I misinterpreted your initial question.
Could you please provide further clarification or rephrase it for
better understanding?

Probably, your question was about why linker dependency is needed here,
then
it is not sufficient to check if a toolchain supports a particular  
extension without checking if the linker supports that extension   
too.
For example, Clang 15 supports Zihintpause but GNU bintutils
2.35.2 does not, leading build errors like so:
    
   riscv64-linux-gnu-ld: -march=rv64i_zihintpause2p0: Invalid or
   unknown z ISA extension: 'zihintpause'


~ Oleksii