A project with it's own Makefiles

[blubee blubeeme]

I have a port that has a it's own Makefiles that you're suppose to call to
build for example the folder structure is like this:

project
--subfolderA
---subfolderA-src
---subfolderA-Makefile

--subfolderB
---subfolderB-src
---subfolderB-Makefile

--subfolderC
---subfolderC-src
---subfolderC-Makefile

you're suppose to choose which sets of examples you want to build.

To port this to FreeBSD do I have to write a cmake or makefile to
encapsulate these sub directories or is there tools already in place to
build this?