[snip]

quoted

Try running a current .dts through cpp today.  You will get errors  
like:

oftree.dts:15:3: error: invalid preprocessing directive #address

quoted

Because of props like:

       #cpus = <1>;
       #address-cells = <1>;
       #size-cells = <0>;

If these used some other symbol instead of '#' cpp will be happy and
we can use it to create macros for us.

Yeah, we're not going to be able to change those; they
are "By The Book".

By what book?  It would seem to me that BNF for dtc is completely  
under our control and if we want to change it we can.  I understand  
that there is some correspondence to Open Firmware, but it seems that  
if its people are ok with the dts format changing that's a lot easier  
than implementing tons of support in dtc for features that cpp gives us.

[I'm also guessing no one's really got time to go and implement these  
features in dtc]

Instead, we'll have to make the lexical analysis conscious
of something like a <newline> context sensitive token or so.
Or throw some flag to cpp to not emit location markers.

- kumar