Key expansion and overrides?

[Richard Purdie <richard.purdie@linuxfoundation.org>]

Two interesting test cases:

OVERIDES = "myoverride"
TESTME = "myoverride"
FOO = "1"
FOO_${TESTME} = "2"

FOO = 1 or 2?

OVERIDES = "myoverride"
TESTME = "myoverride"
FOO = "1 2"
FOO_remove_${TESTME} = "2"

FOO = "1 2" or "1"?

Currently expansion in overrides doesn't work. I discovered this trying
to do:

X_remove_pn-gcc-cross-${TARGET_ARCH} = "Y"

which I do believe is a valid thing to attempt.

There are two ways of fixing this I guess. One is to call expandKeys()
before and after update_data() but I suspect we can still cases which
won't work. The other is to move to a model where overrides are applied
more dynamically and we lose the need for update_data(). There may be
some performance penalty for it.

I'm leaning towards trying to kill off update_data() right now...

Thoughts/comments welcome.

Cheers,

Richard