Make functions

Don't define new make functions in the product/board configuration, for two reasons:

  1. If the function is later used in an file, it will no longer be defined when the product configuration is converted to Starlark, and the file may not work as intended.
  2. The Makefile to Starlark converter only looks at one file at a time, and function definitions are often in different files than where they're invoked.

While a make function is really just a variable that's evaluated using the built-in $(call) function, the Make to Starlark converter will assume any variable defined with the define keyword is a function definition and reject it. So a function would look like:

define my-func
  Some text, arg1: $(1)
$(call my-func,foo)

We provide scripts to automatically replace some common functions with ones that are defined in the core build system Makefiles. They can be found at build/bazel/mk2rbc.