Handling multiple, scoped, optional constraint files

[m-kru]

Hi,

I have the following core example.
My core consists of 3 files:

• core.vhd - core HDL source,
• constr-ref.xdc - constraints scoped to module (shall be used in synthesis and implementation),
• constr-cell.tcl - constraints scoped to cells (shall be used in implementation).

Moreover, I would like the users to have an option to opt out from the default constraints while declaring dependency on my core.
Let us assume, the target EDA tool is Vivado.
What is the idiomatic way in HAMMER to describe a core like this?