genksyms: migrate parser to implicit rules

Signed-off-by: Arnaud Lacombe <lacombar@gmail.com>
diff --git a/scripts/genksyms/Makefile b/scripts/genksyms/Makefile
index 5cdba24..a551090 100644
--- a/scripts/genksyms/Makefile
+++ b/scripts/genksyms/Makefile
@@ -2,52 +2,12 @@
 hostprogs-y	:= genksyms
 always		:= $(hostprogs-y)
 
-genksyms-objs	:= genksyms.o parse.o lex.o
+genksyms-objs	:= genksyms.o parse.tab.o lex.lex.o
 
 # -I needed for generated C source (shipped source)
 HOSTCFLAGS_parse.tab.o := -I$(src)
+HOSTCFLAGS_lex.lex.o := -I$(src)
 
 # dependencies on generated files need to be listed explicitly
-$(obj)/lex.o: $(obj)/parse.h $(obj)/keywords.c
+$(obj)/lex.lex.o: $(obj)/keywords.hash.c $(obj)/parse.tab.h
 
-# -I needed for generated C source (shipped source)
-HOSTCFLAGS_lex.o := -I$(src)
-
-ifdef GENERATE_PARSER
-
-# gperf
-
-quiet_cmd_keywords.c = GPERF   $@
-      cmd_keywords.c = gperf -L ANSI-C -a -C -E -g -H is_reserved_hash	\
-		       -k 1,3,$$ -N is_reserved_word -p -t $< > $@
-
-$(obj)/keywords.c: $(obj)/keywords.gperf FORCE
-	$(call if_changed,keywords.c)
-	cp $@ $@_shipped
-
-# flex
-
-quiet_cmd_lex.c = FLEX    $@
-      cmd_lex.c = flex -o$@ -d $<
-
-$(obj)/lex.c: $(obj)/lex.l $(obj)/keywords.c FORCE
-	$(call if_changed,lex.c)
-	cp $@ $@_shipped
-
-# bison
-
-quiet_cmd_parse.c = BISON   $@
-      cmd_parse.c = bison -o$@ -dtv $(filter-out FORCE,$^)
-
-$(obj)/parse.c: $(obj)/parse.y FORCE
-	$(call if_changed,parse.c)
-	cp $@ $@_shipped
-	cp $(@:.c=.h) $(@:.c=.h)_shipped
-
-$(obj)/parse.h: $(obj)/parse.c ;
-
-clean-files	+= parse.output
-
-endif
-
-targets += keywords.c lex.c parse.c parse.h