Try my just uploaded module, [metatools](https://github.com/jxy/metatools). There is a macro, `inlineProcs`. See one of the test examples: [https://github.com/jxy/metatools/blob/master/test/tinline000.nim](https://github.com/jxy/metatools/blob/master/test/tinline000.nim)
I'll put in documents later.