[openssl-project] rule-based building attributes

[Andy Polyakov]

> appro> How about this. We have touched this when discussing windows-makefile. I
> appro> mean when I called it VC-specific, you disagreed, and I said that
> appro> embedding manifest effectively makes it VC-specific. In the context I
> appro> also suggested post-link stage, a command one could *add* to rule. Or
> appro> let's rephrase this and say that you can simply specify multiple
> appro> commands in an override rule. So with this in mind.
> appro> 
> appro> link => [ 'script-that-composes-list-of-objects $@.$$',
> appro>           'link -o $@ -list $@.$$' ]
> 
> So zooming in on this particular idea, I was concerned about how those
> object file names would be passed to the script...  but then you
> mention manifests, and it dawns on me that there's *nothing* stopping
> us from generating a file with the list of object files when building
> the Makefile.  That does make some kind of sense to me.
> 
> Or were you thinking something different?

Well, when I said "manifest embedding" I meant specifically $(MT) step
of the link rule. But if you want to call $@.$$ output from
'script-that-composes-list-of-objects' for manifest, sure you can do that.

> It would of course be
> possible to have the script you suggest pull data from configdata.pm,
> right?

Or from Makefile, whichever simplest.

> But considering we're talking about third parties building
> their own, that raises another concern, that we suddenly give the
> whole %unified_info structure public exposure that I'm not entirely
> sure were ready for.

You mean not ready to commit to not changing it as our discretion? Well,
then maybe grep-ing Makefile for libcrypto.a: would be more appropriate...