Re: [PATCH] runqueue: Add output for -S option for listing the changepoints compared with an sstate cache

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

On Mon, 2014-01-27 at 14:39 +0100, Martin Jansa wrote:
> On Mon, Jan 27, 2014 at 01:23:25PM +0000, Richard Purdie wrote:
> > On Tue, 2014-01-21 at 22:37 +0000, Richard Purdie wrote:
> > > I appreciate its taken me a while to loop back around on this but I do
> > > now have an idea. What I'm proposing we do is add an optional parameter
> > > to -S. Without any parameter it would behave as it did classically.
> > > 
> > > With a parameter, it could trigger the current "debug sstate" behaviour
> > > to stdout and it also allows it to trigger an sstate siggen specific
> > > behaviour as appripriate. I have some prototype code with writes out a
> > > "locked-sigs.inc" file for example, triggered from this same code block.
> > > 
> > > I think this should let us do more creative things with sstate (even
> > > from the OE siggen class) yet also let it remain useful for different
> > > people.
> > 
> > So we have a small potential issue here. We use python's optparse which
> > doesn't allow optional arguments. This means we can make -S take options
> > but the options must always be specified.
> > 
> > It has good reason for this as its near impossible for optparse to tell
> > the difference between:
> > 
> > bitbake image -S tracesigs
> > and
> > bitbake image -S image2
> > 
> > So our options are:
> > 
> > a) Require a new parameter to -S always
> > b) Hack it to use the option after -S as a parameter (meaning -S should
> > always be last on the commandline). I do have a proof of concept but it
> > makes me uneasy
> > c) Add a new option with a different name
> > 
> > In the interests of not doing something which binds us into a problem in
> > future, I'm thinking -S should start to always take a parameter. The
> > only issue is I'd like that parameter to be metadata (siggen) definable
> > so we can't validate the option passed.
> > 
> > Any opinions?
> 
> What about using some existing parameter in combination with -S?
> 
> -S + -v shows tracesigs
> -S without -v old behavior

I have some use cases locally (such as locked sigs) which could really
benefit from a string parameter which gets passed into the siggen code.
I can see us needing more than two "behaviours" of -S...

I also think using something like -v will lead to more confusion and the
code won't be particularly nice either :/.

Cheers,

Richard