diff --git a/Makefile b/Makefile index d70ac9a3b8f..c8122e5765a 100644 --- a/Makefile +++ b/Makefile @@ -152,16 +152,55 @@ COMPARE_AND_REMOVE_FROM_RULE = $(eval $(call COMPARE_AND_REMOVE_FROM_RULE_HELPER # $1 The list to be checked # If a match is found, then RULE_FOUND is set to true # and MATCHED_ITEM to the item that was matched -define TRY_TO_MATCH_RULE_FROM_LIST_HELPER +define TRY_TO_MATCH_RULE_FROM_LIST_HELPER3 ifneq ($1,) ifeq ($$(call COMPARE_AND_REMOVE_FROM_RULE,$$(firstword $1)),true) MATCHED_ITEM := $$(firstword $1) else - $$(eval $$(call TRY_TO_MATCH_RULE_FROM_LIST_HELPER,$$(wordlist 2,9999,$1))) + $$(eval $$(call TRY_TO_MATCH_RULE_FROM_LIST_HELPER3,$$(wordlist 2,9999,$1))) endif endif endef +# A recursive helper function for finding the longest match +# $1 The list to be checed +# It works by always removing the currently matched item from the list +# and call itself recursively, until a match is found +define TRY_TO_MATCH_RULE_FROM_LIST_HELPER2 + # Stop the recursion when the list is empty + ifneq ($1,) + RULE_BEFORE := $$(RULE) + $$(eval $$(call TRY_TO_MATCH_RULE_FROM_LIST_HELPER3,$1)) + # If a match is found in the current list, otherwise just return what we had before + ifeq ($$(RULE_FOUND),true) + # Save the best match so far and call itself recursivel + BEST_MATCH := $$(MATCHED_ITEM) + BEST_MATCH_RULE := $$(RULE) + RULE_FOUND := false + RULE := $$(RULE_BEFORE) + $$(eval $$(call TRY_TO_MATCH_RULE_FROM_LIST_HELPER2,$$(filter-out $$(MATCHED_ITEM),$1))) + endif + endif +endef + + +# Recursively try to find the longest match for the start of the rule to be checked +# $1 The list to be checked +# If a match is found, then RULE_FOUND is set to true +# and MATCHED_ITEM to the item that was matched +define TRY_TO_MATCH_RULE_FROM_LIST_HELPER + BEST_MATCH := + $$(eval $$(call TRY_TO_MATCH_RULE_FROM_LIST_HELPER2,$1)) + ifneq ($$(BEST_MATCH),) + RULE_FOUND := true + RULE := $$(BEST_MATCH_RULE) + MATCHED_ITEM := $$(BEST_MATCH) + else + RULE_FOUND := false + MATCHED_ITEM := + endif +endef + # Make it easier to call TRY_TO_MATCH_RULE_FROM_LIST TRY_TO_MATCH_RULE_FROM_LIST = $(eval $(call TRY_TO_MATCH_RULE_FROM_LIST_HELPER,$1))$(RULE_FOUND)