[oe] bitbake dependency question

[Robert Cagle]

I'm trying to figure out a reasonable way to specify dependencies on an unknown/virtual set of other recipes.
For example,

Recipe A: Plugin #1 (installs a plugin spec somewhere in /usr/share)
Recipe B: Plugin #2 (same)
Recipe C: Plugin #3 (same).
Recipe D: Host Application (C based), which needs to be compiled last since it generates C code based on the spec files.

I'd rather not hard-code dependencies in Recipe D since the specific set of plugins may be different depending on the specified distribution layer or machine type. I can define a variable in local.conf and use it to define D's dependencies, but that means I'll have to define the set twice: in the distribution layer and in local.conf. Based on what I've read and experimented with, this seems be my only choice (other than restructuring the application).

I really just wanted to expand a variable in each of A,B,C 
   PLUGIN_RECIPES += "${PN}"

And have D declare
  DEPENDS = "${PLUGIN_RECIPES} other..."

But that doesn't seem possible. Am I missing another way? (Python datastore maybe?)

Thanks,
Bob