I would like to know if there is macro
that stores list of all the existing variables.
My requirement is as follows. I have
a set of variables defined currently which starts with _BG%.
I need to change these variables to
begin with _SP% and also need to support _BG% for sometime.
I know that I can individually look
for variables and conditionally assign it as follows
_SPTMP ?= _BGTMP
Can I handle this using a foreach command
in make easily? without individual assignments.