[PATCH v2 REPOST] dtc: Add support for named integer constants

[Stephen Warren]

Jon Loeliger wrote at Wednesday, January 11, 2012 7:38 AM:
> > On Tue, Jan 10, 2012 at 01:54:30PM -0800, Stephen Warren wrote:
> > > John, David,
> > >
> > > What can we do to reach consensus on expanding dtc to handle named
> > > constants, or in general any future direction to extend the syntax with
> > > expressions etc.?
> >
> > Hrm, so, I'm not at all keen to add a named constant syntax without at
> > least having an outline of what a future macro/function syntax would
> > look like.
> 
> Which is where I thought it was left earlier...? :-)
> And it's not just what the macro/function syntax will look like,
> but also how these will play into a more generalized expression
> handling mechanism.  Defining something one-off now that doesn't
> fit well into a long term plan is less than ideal.
> 
> Yes, I know that is tantamount to requiring the whole, larger
> picture be solved first.  But Dave is right -- at least an outline
> of the direction.  Seriously, the lexical problems can form some
> of the nastiest gotchas if we're not careful from the onset.

So that all makes sense.

My question is: How can we get consensus on what we want that complete
future syntax to be? IIRC, Jon has a branch that implements a proposal,
and David at least posted a different proposal if not actual code that
implemented it. We're not missing proposals, but rather a mechanism to
decide between them?

For what it's worth, I'd tend towards a simple expression-based syntax
where property values can be calculated with C-style expressions. Basic
math stuff like ( ) + - * / & | ~ << >> and some basic string handling
operations (str(int) and concatenation). I think that'd cover the vast
majority of use-cases wouldn't it? For more advanced stuff like loops
to synthesize multiple nodes, it seems like writing a custom script to
generate the .dts file and then passing the result to dtc would be more
modular, and not require us to create a whole new Turing-complete
language in dtc?

-- 
nvpublic