Re: [PATCH 2/2] perf parse-events: enable more flex/yacc warnings

[Arnaldo Carvalho de Melo]

Em Wed, Jun 10, 2020 at 11:05:26AM -0300, Arnaldo Carvalho de Melo escreveu:
> Em Tue, Jun 09, 2020 at 04:43:44PM -0700, Ian Rogers escreveu:
> > All C compiler warnings are disabled are disabled by -w. This change
> > removes the -w from flex and bison targets. To avoid implicit
> > declarations header files are declared as targets and included.

> > Tested with GCC 9.3.0 and clang 9.0.1.

> > Signed-off-by: Ian Rogers <irogers@xxxxxxxxxx>

> > +++ b/tools/perf/util/Build
<SNIP>
> > -$(OUTPUT)util/parse-events-flex.c: util/parse-events.l $(OUTPUT)util/parse-events-bison.c
> > +$(OUTPUT)util/parse-events-flex.c $(OUTPUT)util/parse-events-flex.h: util/parse-events.l $(OUTPUT)util/parse-events-bison.c
> >  	$(call rule_mkdir)
> > -	$(Q)$(call echo-cmd,flex)$(FLEX) -o $@ --header-file=$(OUTPUT)util/parse-events-flex.h $(PARSER_DEBUG_FLEX) util/parse-events.l
> > +	$(Q)$(call echo-cmd,flex)$(FLEX) -o $(OUTPUT)util/parse-events-flex.c \
> > +		--header-file=$(OUTPUT)util/parse-events-flex.h \
> > +		$(PARSER_DEBUG_FLEX) $<

<SNIP>
 
> And you took advantage of util/parse-events.l being
> the first dependency to replace it with $<

<SNIP>
 
> Damn, Makefiles are obtuse, we better do this more piecemeal, for
> instance, using $< where applicable first, etc.

I mean, first this, ok? Then you do the other bits, and please try to
keep the positioning as far as possible, so that visually we see what is
being replaced by what.

- Arnaldo

diff --git a/tools/perf/util/Build b/tools/perf/util/Build
index 8d18380ecd10..cc50fdfd0c2f 100644
--- a/tools/perf/util/Build
+++ b/tools/perf/util/Build
@@ -193,27 +193,27 @@ CFLAGS_genelf_debug.o  += -Wno-packed
 
 $(OUTPUT)util/parse-events-flex.c: util/parse-events.l $(OUTPUT)util/parse-events-bison.c
 	$(call rule_mkdir)
-	$(Q)$(call echo-cmd,flex)$(FLEX) -o $@ --header-file=$(OUTPUT)util/parse-events-flex.h $(PARSER_DEBUG_FLEX) util/parse-events.l
+	$(Q)$(call echo-cmd,flex)$(FLEX) -o $@ --header-file=$(OUTPUT)util/parse-events-flex.h $(PARSER_DEBUG_FLEX) %<
 
 $(OUTPUT)util/parse-events-bison.c: util/parse-events.y
 	$(call rule_mkdir)
-	$(Q)$(call echo-cmd,bison)$(BISON) -v util/parse-events.y -d $(PARSER_DEBUG_BISON) -o $@ -p parse_events_
+	$(Q)$(call echo-cmd,bison)$(BISON) -v %< -d $(PARSER_DEBUG_BISON) -o $@ -p parse_events_
 
 $(OUTPUT)util/expr-flex.c: util/expr.l $(OUTPUT)util/expr-bison.c
 	$(call rule_mkdir)
-	$(Q)$(call echo-cmd,flex)$(FLEX) -o $@ --header-file=$(OUTPUT)util/expr-flex.h $(PARSER_DEBUG_FLEX) util/expr.l
+	$(Q)$(call echo-cmd,flex)$(FLEX) -o $@ --header-file=$(OUTPUT)util/expr-flex.h $(PARSER_DEBUG_FLEX) %<
 
 $(OUTPUT)util/expr-bison.c: util/expr.y
 	$(call rule_mkdir)
-	$(Q)$(call echo-cmd,bison)$(BISON) -v util/expr.y -d $(PARSER_DEBUG_BISON) -o $@ -p expr_
+	$(Q)$(call echo-cmd,bison)$(BISON) -v %< -d $(PARSER_DEBUG_BISON) -o $@ -p expr_
 
 $(OUTPUT)util/pmu-flex.c: util/pmu.l $(OUTPUT)util/pmu-bison.c
 	$(call rule_mkdir)
-	$(Q)$(call echo-cmd,flex)$(FLEX) -o $@ --header-file=$(OUTPUT)util/pmu-flex.h util/pmu.l
+	$(Q)$(call echo-cmd,flex)$(FLEX) -o $@ --header-file=$(OUTPUT)util/pmu-flex.h %<
 
 $(OUTPUT)util/pmu-bison.c: util/pmu.y
 	$(call rule_mkdir)
-	$(Q)$(call echo-cmd,bison)$(BISON) -v util/pmu.y -d -o $@ -p perf_pmu_
+	$(Q)$(call echo-cmd,bison)$(BISON) -v %< -d -o $@ -p perf_pmu_
 
 CFLAGS_parse-events-flex.o  += -w
 CFLAGS_pmu-flex.o           += -w