-H_FILES := $(wildcard *.h)
-C_FILES := $(wildcard *.c)
-Y_FILES := $(wildcard *.y)
-L_FILES := $(wildcard *.l)
+H_FILES := $(call src-wildcard,*.h)
+C_FILES := $(call src-wildcard,*.c)
+Y_FILES := $(call src-wildcard,*.y)
+L_FILES := $(call src-wildcard,*.l)