RE: [OE-core] [PATCH] externalsrc.bbclass: Allow externalsrc to be extended with extra classes

[Peter Kjellerstedt <peter.kjellerstedt@axis.com>]

> -----Original Message-----
> From: Richard Purdie <richard.purdie@linuxfoundation.org>
> Sent: den 20 oktober 2021 11:59
> To: Peter Kjellerstedt <peter.kjellerstedt@axis.com>; Jose Quaresma
> <quaresma.jose@gmail.com>
> Cc: OE-core <openembedded-core@lists.openembedded.org>
> Subject: Re: [OE-core] [PATCH] externalsrc.bbclass: Allow externalsrc to
> be extended with extra classes
> 
> On Wed, 2021-10-20 at 09:09 +0000, Peter Kjellerstedt wrote:
> > I thought of another problem with the wrapper class solution: if we 
> > needto actually backport a newer version of the class from, e.g., 
> > Poky master, then there is now no natural place for it since it is 
> > occupied by the wrapper class. That means we would either have to 
> > rename the backported class, or put it somewhere else than in 
> > "classes". It also means backporting a class requires the wrapper 
> > class to be modified.
> >
> > Here is a question for Richard: what do you think of an idea I had to
> > add support in bitbake for extending classes? I do not mean to add 
> > something like bbclassappend, as I know that is troublesome. My idea 
> > instead is something like the prefuncs/postfuncs that we have for 
> > functions. I.e., before actually doing the inherit of a classfoo, 
> > bitbake would inherit anything specified in BBCLASS_PRE_INHERIT:foo, 
> > and after inheriting the class it would automatically inherit 
> > anything in BBCLASS_POST_INHERIT:foo.  That way one can simply extend 
> > a class through normal variable operations, making it easy to do, 
> > e.g., in the distro configuration.
> 
> That sounds very like a bbclassappend under a different name?
> 
> Cheers,
> 
> Richard

Well, I guess it is similar to what a bbclassappend file suffix would 
entail, but more flexible and controlled. Do you think something like 
this would work, or have I missed some technical problems that would 
prevent it? And if you think it is technically possible, would you be 
willing to accept a patch that implements it?

//Peter