On Wed, Oct 10, 2012 at 08:56:11AM -1000, Mitch Bradley wrote:

On 10/10/2012 8:45 AM, Stephen Warren wrote:

quoted

On 10/10/2012 12:23 PM, Mitch Bradley wrote:

quoted

On 10/10/2012 7:09 AM, Rob Herring wrote:

quoted

On 10/09/2012 04:16 PM, Stephen Warren wrote:

quoted

On 10/01/2012 12:39 PM, Jon Loeliger wrote:

[snip]

quoted

quoted

Instead of making a bunch of rules about how you can only use a small
subset of cpp, why not just add a "define name value" command to DTC?

I implemented a patch to do exactly that, and it was rejected because it
only solved part of the problem (named constants) and not the reset (a
completely generic macro language/... within dtc). The argument was that
defining just the named constant syntax on its own without knowing what
the unspecified future macro language will look like might result in the
named constant syntax not fitting into it.

That all said, I now think that using cpp is actually a much better
solution that adding yet more dtc-specific syntax. The *huge* benefit
here is that it allows you to share .h files between *.dts and C code,
so you don't have to write out the same set of #defines once in dtc
syntax and once in cpp syntax.

... and it imposes an equally *huge* restriction that you have to
restrict the .h file to avoid avoid C constructs.  That can be done, but
I've personally experienced a lot of headaches when trying to share .h
files between different languages.

Yes, but we already deal with that for asm files.  And the sorts of
defines we use in asm files are often the same ones we'd want in dts
files.


-- 
David Gibson			| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you.  NOT _the_ _other_
				| _way_ _around_!
http://www.ozlabs.org/~dgibson