can I append more compile options to cflags or somewhere?

[han...@inka.co.kr]

Hello, I was build AOSP with 4.3.
it is work well, you guys doing great work.
but I want use more compile options for my work.

how can I do this?
I had googling.
and modified Android.mk for appending LOCAL_CFLAGS at each directory.
but it's not effective.

would anyone help me, please?