dtc: migrate parser to implicit rules

HOSTCFLAGS_dtc-parser.tab.o := $(HOSTCFLAGS_DTC)

# dependencies on generated files need to be listed explicitly

$(obj)/dtc-parser.tab.o: $(obj)/dtc-parser.tab.c $(obj)/dtc-parser.tab.h

$(obj)/dtc-lexer.lex.o:  $(obj)/dtc-lexer.lex.c $(obj)/dtc-parser.tab.h

$(obj)/dtc-lexer.lex.o: $(obj)/dtc-parser.tab.h

targets += dtc-parser.tab.c dtc-lexer.lex.c

clean-files += dtc-parser.tab.h

# GENERATE_PARSER := 1		# Uncomment to rebuild flex/bison output

ifdef GENERATE_PARSER

BISON = bison

FLEX = flex

quiet_cmd_bison = BISON   $@

      cmd_bison = $(BISON) -o$@ -d $<; cp $@ $@_shipped

quiet_cmd_flex = FLEX    $@

      cmd_flex = $(FLEX) -o$@ $<; cp $@ $@_shipped

$(obj)/dtc-parser.tab.c: $(src)/dtc-parser.y FORCE

        $(call if_changed,bison)

$(obj)/dtc-parser.tab.h: $(obj)/dtc-parser.tab.c

$(obj)/dtc-lexer.lex.c: $(src)/dtc-lexer.l FORCE

        $(call if_changed,flex)

endif