Re: [PATCH v2 2/9] configure: cross-compiling without cross_prefix

[Joelle van Dyne]

As the patch stands --cross-prefix="" works but I like having the
--enable-cross-compile option because it's more clear of the intention
(in logs and such). I've been struggling to come up with a concise
modification to the help text for --cross-prefix that explains that
empty PREFIX is allowed and why you would want to do that.

-j

On Tue, Oct 20, 2020 at 1:35 AM Paolo Bonzini <pbonzini@redhat.com> wrote:
>
> On 20/10/20 07:15, Thomas Huth wrote:
> >>>>>> +  ;;
> >>>>>> +  --enable-cross-compile) cross_compile="yes"
> >>>>>> +  ;;
> >>>>>> +  --disable-cross-compile) cross_compile="no"
> >>>>>
> >>>>> Can't you simply use --cros-prefix="" instead?
> >>>>
> >>>> I mean, still introduce the "cross_compile=yes" variable, just omit the 
> >>>> new
> >>>> options.
> >>>
> >>> That seems less intuitive for people trying to find this option. If --help
> >>> lists --enable-cross-compile I can guess what that means but there's no
> >>> way I could guess --cros-prefix="" unless I've been told or searched and
> >>> stumbled upon it. So unless it's a big problem I like the explicit options
> >>> better. Or is that a convention in other projects to use empty prefix to
> >>> enable cross compile that I don't know about?
> >
> > I don't think that --cross-prefix is a "standard" option... Most other
> > (GNU-tools related) projects use "--build" and "--host" instead... so I
> > guess we're free to chose here. Let's see whether other people here have an
> > opionion on this...
>
> Yeah, the way GNU tools do it is that you specify --build and --host,
> and --host triggers cross compilation.  I'm not sure how they'd handle
> the situation where the cross prefix is empty.
>
> For QEMU, I agree with Thomas that --cross-prefix="" is enough.
>
> Paolo
>