tree c004a87a6ffda4fa32750fbbdc25a7678e1757d8
parent 2c503b6caf952882ea309ed056962769df0e6d3a
author Zi Wang <mrziwang@google.com> 1713392862 -0700
committer Cole Faust <colecfaust@gmail.com> 1714496332 -0700

Add func KATI_visibility_prefix

syntax: $(KATI_visibility_prefix var, prefix)

1, Add a func KATI_visibility_prefix that takes a variable
name and a list of strings, set this variable's visibility
to these strings. Each string represents the relative path
from the root, and is considered as prefix.

e.g. $(KATI_visibility_prefix VAR, vendor/ device/b baz.mk)
--> VAR is visible to "vendor/foo.mk", "device/bar.mk",
"device/baz.mk", "baz.mk", but not visible to "bar.mk",
"vendor.mk" or "vendor/baz.mk".

If variable visibility is set more than once, and with a
different list of strings, an error will occur.

2. When a variable is being referenced, if this variable has
visibility prefix set, check if the current referencing file
matches the visibility prefix. Throw an error if not.

3. In $(KATI_visibility_prefix FOO, prefix)
If FOO is not defined, create a variable FOO with empty value.
The prefix can also be reference to variable.
If so, this function will expand the reference and set the
visibility_prefix.