makefile: don’t pick up autogenerated files

i3-config-wizard/Makefile

@@ -4,7 +4,8 @@ TOPDIR=..
 include $(TOPDIR)/common.mk
 
 # Depend on the object files of all source-files in src/*.c and on all header files
-FILES:=$(patsubst %.c,%.o,$(wildcard *.c))
+AUTOGENERATED:=cfgparse.tab.c cfgparse.yy.c
+FILES:=$(patsubst %.c,%.o,$(filter-out $(AUTOGENERATED),$(wildcard *.c)))
 HEADERS:=$(wildcard *.h)
 
 # Depend on the specific file (.c for each .o) and on all headers