Re: [PATCH 1/1] base.bbclass: fix COMPATIBLE_MACHINE

[Richard Purdie <richard.purdie@linuxfoundation.org>]

On Mon, 2016-04-11 at 10:11 +0800, Robert Yang wrote:
> 
> On 04/11/2016 09:56 AM, Christopher Larson wrote:
> > On Sun, Apr 10, 2016 at 6:17 PM Robert Yang <
> > liezhi.yang@windriver.com
> > <mailto:liezhi.yang@windriver.com>> wrote:
> > 
> > 
> > 
> >     On 04/11/2016 03:06 AM, Denys Dmytriyenko wrote:
> >      > On Sun, Apr 10, 2016 at 07:14:56AM -0700, Robert Yang wrote:
> >      >> It mismatched such as qemux86 and qemux86-64 which was
> > incorrect, for
> >      >> example:
> >      >> COMPATIBLE_MACHINE = "(qemux86)"
> >      >
> >      > That will match qemux86 and qemux86-64 and is by design!
> > It's a regular
> > 
> >     I'm afraid no, please see my last reply, for others such as
> >     MACHINE_OVERRIDES, they never design to work in such a way, so
> > I don't
> >     think that COMPATIBLE_MACHINE should work in this way. If you
> > really
> >     want to match more, I think that you can set it as
> > "(qemux86.*)" or
> >     something familiar.
> > 
> > 
> > That's an apples and oranges comparison. MACHINEOVERRIDES is part
> > of OVERRIDES,
> > which has *completely* different semantics than COMPATIBLE_*.
> > COMPATIBLE_MACHINE
> > is a regex variable more like BBMASK than anything else, and it's
> > been that way
> > since we introduced it. OVERRIDES has nothing to do with regular
> > expressions.
> 
> Since introduced ? I did a grep in oe-core and meta-openembedded, it
> seems
> that no ?
> 
> In oe-core:
> 
> $ grep 'COMPATIBLE_MACHINE.*qemux86' meta/recipes* -r
> linux-yocto_4.4.bb:COMPATIBLE_MACHINE = 
> "qemuarm|qemuarm64|qemux86|qemuppc|qemumips|qemumips64|qemux86-64"
> linux-yocto-tiny_4.4.bb:COMPATIBLE_MACHINE = "(qemux86)"
> linux-yocto-dev.bb:COMPATIBLE_MACHINE = 
> "(qemuarm|qemux86|qemuppc|qemumips|qemumips64|qemux86-64)"
> linux-yocto-tiny_4.1.bb:COMPATIBLE_MACHINE = "(qemux86)"
> linux-yocto-rt_4.1.bb:COMPATIBLE_MACHINE = 
> "(qemux86|qemux86-64|qemuarm|qemuppc|qemumips)"
> linux-yocto-rt_4.4.bb:COMPATIBLE_MACHINE = 
> "(qemux86|qemux86-64|qemuarm|qemuppc|qemumips)"
> linux-yocto_4.1.bb:COMPATIBLE_MACHINE = 
> "qemuarm|qemuarm64|qemux86|qemuppc|qemumips|qemumips64|qemux86-64"
> 
> In meta-openembedded:
> vboxguestdrivers_4.3.30.bb:COMPATIBLE_MACHINE = "(qemux86|qemux86
> -64)"
> 
> We can see that the only one sets qemux86 but no set qemux86-64 is
> linux-yocto-tiny:
> COMPATIBLE_MACHINE = "(qemux86)"
> 
> And it really doesn't work with qemux86-64.

The trouble is as others have mentioned, COMPATIBLE_MACHINE has always
worked this way. We can't really change that without a wider discussion
and at this point in the release in particular, I can't take such a
patch.

We do really need to think about the behaviour as it does do unexpected
things and catch people out.

I'd suggest you add a '$' to the end of the regex in linux-yocto-tiny
to resolve this. We could also add '$' to the end of the other usages
and make it clear it is a regex?

Cheers,

Richard