using REQUIRES and PROVIDES in click elements

[Douglas S. J. De Couto]

How are people using ELEMENT_PROVIDES/ELEMENT_REQUIRES in click
elements?

I have a few elements that implement a C++ interface, say, a version
for userlevel (MyImpl), and a version for the kernel module (MyImpl2).

At the bottom of these elements I write:

ELEMENT_PROVIDES(MyInterface)

Another element, MyClient, requires an argument an element
implementing MyInterface, so I write at the bottom of MyClient:

ELEMENT_REQUIRES(MyInterface)

But MyClient doesn't get compiled into the linux module, because when
producing the element list for the linux module, click-buildtool sees
userlevel element MyImpl with ELEMENT_PROVIDES(MyInterface), and makes
MyInterface an anti-requirement...

That was not at all what I expected.  Can suggest a better way for me
to think about this?

d


-- 
Douglas S. J. De Couto    decouto at lcs.mit.edu