cpp vs. m4 for .s files

[Scott Schwartz]

gwyn at smoke.brl.mil (Doug Gwyn) writes:
   Don't use cpp for anything, please.  It need not even exist.

m4 is cute, but cpp does have one advantage over it: it understands
more than one flavor of quotes at a time.

define(x,100)
changequote(',')
foo[x] = 'x';
bar[x] = "x";