FOO = foo
FOO_SPACE_BAR:=foo bar
FOO_COMMA_BAR:=foo,bar
$(FOO_SPACE_BAR):=foo
$(FOO_COMMA_BAR):=foo
FOOREF := FOO
test:
echo $(origin FOO)
echo $(origin FOO BAR)
echo $(origin FOO,BAR)
echo $(origin UNDEFINED)
echo $(origin PATH)
echo $(origin MAKEFILE_LIST)
echo $(origin CC)
echo $(origin $(FOOREF))
# TODO: support environment override, command line, and override.
# TODO: Also add more tests especially for += and ?=