Simplify C/C++ compiler flags

[PATCH v1 4/6] perf build: Disable fewer flex warnings

Posted by Ian Rogers 2 years, 6 months ago

If flex is version 2.6.4, reduce the number of flex C warnings
disabled. Earlier flex versions have all C warnings disabled.

Signed-off-by: Ian Rogers <irogers@google.com>
---
 tools/perf/util/Build | 10 +++-------
 1 file changed, 3 insertions(+), 7 deletions(-)

diff --git a/tools/perf/util/Build b/tools/perf/util/Build
index 96f4ea1d45c5..32239c4b0393 100644
--- a/tools/perf/util/Build
+++ b/tools/perf/util/Build
@@ -279,13 +279,9 @@ $(OUTPUT)util/bpf-filter-bison.c $(OUTPUT)util/bpf-filter-bison.h: util/bpf-filt
 	$(Q)$(call echo-cmd,bison)$(BISON) -v $< -d $(PARSER_DEBUG_BISON) $(BISON_FILE_PREFIX_MAP) \
 		-o $(OUTPUT)util/bpf-filter-bison.c -p perf_bpf_filter_
 
-FLEX_GE_26 := $(shell expr $(shell $(FLEX) --version | sed -e  's/flex \([0-9]\+\).\([0-9]\+\)/\1\2/g') \>\= 26)
-ifeq ($(FLEX_GE_26),1)
-  flex_flags := -Wno-switch-enum -Wno-switch-default -Wno-unused-function -Wno-redundant-decls -Wno-sign-compare -Wno-unused-parameter -Wno-missing-prototypes -Wno-missing-declarations
-  CC_HASNT_MISLEADING_INDENTATION := $(shell echo "int main(void) { return 0 }" | $(CC) -Werror -Wno-misleading-indentation -o /dev/null -xc - 2>&1 | grep -q -- -Wno-misleading-indentation ; echo $$?)
-  ifeq ($(CC_HASNT_MISLEADING_INDENTATION), 1)
-    flex_flags += -Wno-misleading-indentation
-  endif
+FLEX_GE_264 := $(shell expr $(shell $(FLEX) --version | sed -e  's/flex \([0-9]\+\).\([0-9]\+\).\([0-9]\+\)/\1\2\3/g') \>\= 264)
+ifeq ($(FLEX_GE_264),1)
+  flex_flags := -Wno-redundant-decls -Wno-switch-default -Wno-unused-function
 else
   flex_flags := -w
 endif
-- 
2.41.0.487.g6d72f3e995-goog

Re: [PATCH v1 4/6] perf build: Disable fewer flex warnings

Posted by James Clark 2 years, 6 months ago


On 28/07/2023 07:49, Ian Rogers wrote:
> If flex is version 2.6.4, reduce the number of flex C warnings
> disabled. Earlier flex versions have all C warnings disabled.

Hi Ian,

I get a build error with either this one or the bison warning change:

  $ make LLVM=1 -C tools/perf NO_BPF_SKEL=1 DEBUG=1

  util/pmu-bison.c:855:9: error: variable 'perf_pmu_nerrs' set but not
used [-Werror,-Wunused-but-set-variable]
    int yynerrs = 0;

I tried a clean build which normally fixes these kind of bison errors.
Let me know if you need any version info.

James

> 
> Signed-off-by: Ian Rogers <irogers@google.com>
> ---
>  tools/perf/util/Build | 10 +++-------
>  1 file changed, 3 insertions(+), 7 deletions(-)
> 
> diff --git a/tools/perf/util/Build b/tools/perf/util/Build
> index 96f4ea1d45c5..32239c4b0393 100644
> --- a/tools/perf/util/Build
> +++ b/tools/perf/util/Build
> @@ -279,13 +279,9 @@ $(OUTPUT)util/bpf-filter-bison.c $(OUTPUT)util/bpf-filter-bison.h: util/bpf-filt
>  	$(Q)$(call echo-cmd,bison)$(BISON) -v $< -d $(PARSER_DEBUG_BISON) $(BISON_FILE_PREFIX_MAP) \
>  		-o $(OUTPUT)util/bpf-filter-bison.c -p perf_bpf_filter_
>  
> -FLEX_GE_26 := $(shell expr $(shell $(FLEX) --version | sed -e  's/flex \([0-9]\+\).\([0-9]\+\)/\1\2/g') \>\= 26)
> -ifeq ($(FLEX_GE_26),1)
> -  flex_flags := -Wno-switch-enum -Wno-switch-default -Wno-unused-function -Wno-redundant-decls -Wno-sign-compare -Wno-unused-parameter -Wno-missing-prototypes -Wno-missing-declarations
> -  CC_HASNT_MISLEADING_INDENTATION := $(shell echo "int main(void) { return 0 }" | $(CC) -Werror -Wno-misleading-indentation -o /dev/null -xc - 2>&1 | grep -q -- -Wno-misleading-indentation ; echo $$?)
> -  ifeq ($(CC_HASNT_MISLEADING_INDENTATION), 1)
> -    flex_flags += -Wno-misleading-indentation
> -  endif
> +FLEX_GE_264 := $(shell expr $(shell $(FLEX) --version | sed -e  's/flex \([0-9]\+\).\([0-9]\+\).\([0-9]\+\)/\1\2\3/g') \>\= 264)
> +ifeq ($(FLEX_GE_264),1)
> +  flex_flags := -Wno-redundant-decls -Wno-switch-default -Wno-unused-function
>  else
>    flex_flags := -w
>  endif

Re: [PATCH v1 4/6] perf build: Disable fewer flex warnings

Posted by Arnaldo Carvalho de Melo 2 years, 6 months ago

Em Fri, Jul 28, 2023 at 09:50:59AM +0100, James Clark escreveu:
> 
> 
> On 28/07/2023 07:49, Ian Rogers wrote:
> > If flex is version 2.6.4, reduce the number of flex C warnings
> > disabled. Earlier flex versions have all C warnings disabled.
> 
> Hi Ian,
> 
> I get a build error with either this one or the bison warning change:
> 
>   $ make LLVM=1 -C tools/perf NO_BPF_SKEL=1 DEBUG=1
> 
>   util/pmu-bison.c:855:9: error: variable 'perf_pmu_nerrs' set but not
> used [-Werror,-Wunused-but-set-variable]
>     int yynerrs = 0;
> 
> I tried a clean build which normally fixes these kind of bison errors.
> Let me know if you need any version info.

Trying to build it with the command line above I get:

  CC      util/expr.o
  CC      util/parse-events.o
  CC      util/parse-events-flex.o
util/parse-events-flex.c:7503:13: error: misleading indentation; statement is not part of the previous 'if' [-Werror,-Wmisleading-indentation]
            if ( ! yyg->yy_state_buf )
            ^
util/parse-events-flex.c:7501:9: note: previous statement is here
        if ( ! yyg->yy_state_buf )
        ^
1 error generated.
make[4]: *** [/var/home/acme/git/perf-tools-next/tools/build/Makefile.build:97: util/parse-events-flex.o] Error 1
make[4]: *** Waiting for unfinished jobs....
  LD      util/scripting-engines/perf-in.o
make[3]: *** [/var/home/acme/git/perf-tools-next/tools/build/Makefile.build:140: util] Error 2
make[2]: *** [Makefile.perf:682: perf-in.o] Error 2
make[2]: *** Waiting for unfinished jobs....
  CC      pmu-events/pmu-events.o
  LD      pmu-events/pmu-events-in.o
make[1]: *** [Makefile.perf:242: sub-make] Error 2
make: *** [Makefile:70: all] Error 2

⬢[acme@toolbox perf-tools-next]$ clang --version
clang version 14.0.5 (Fedora 14.0.5-2.fc36)
Target: x86_64-redhat-linux-gnu
Thread model: posix
InstalledDir: /usr/bin
⬢[acme@toolbox perf-tools-next]$

Re: [PATCH v1 4/6] perf build: Disable fewer flex warnings

Posted by Arnaldo Carvalho de Melo 2 years, 6 months ago

Em Fri, Jul 28, 2023 at 10:59:38AM -0300, Arnaldo Carvalho de Melo escreveu:
> Em Fri, Jul 28, 2023 at 09:50:59AM +0100, James Clark escreveu:
> > 
> > 
> > On 28/07/2023 07:49, Ian Rogers wrote:
> > > If flex is version 2.6.4, reduce the number of flex C warnings
> > > disabled. Earlier flex versions have all C warnings disabled.
> > 
> > Hi Ian,
> > 
> > I get a build error with either this one or the bison warning change:
> > 
> >   $ make LLVM=1 -C tools/perf NO_BPF_SKEL=1 DEBUG=1
> > 
> >   util/pmu-bison.c:855:9: error: variable 'perf_pmu_nerrs' set but not
> > used [-Werror,-Wunused-but-set-variable]
> >     int yynerrs = 0;
> > 
> > I tried a clean build which normally fixes these kind of bison errors.
> > Let me know if you need any version info.
> 
> Trying to build it with the command line above I get:
> 
>   CC      util/expr.o
>   CC      util/parse-events.o
>   CC      util/parse-events-flex.o
> util/parse-events-flex.c:7503:13: error: misleading indentation; statement is not part of the previous 'if' [-Werror,-Wmisleading-indentation]
>             if ( ! yyg->yy_state_buf )
>             ^
> util/parse-events-flex.c:7501:9: note: previous statement is here
>         if ( ! yyg->yy_state_buf )
>         ^

I added this to the patch to get it moving:

make: Leaving directory '/var/home/acme/git/perf-tools-next/tools/perf'
⬢[acme@toolbox perf-tools-next]$ git diff
diff --git a/tools/perf/util/Build b/tools/perf/util/Build
index 32239c4b0393c319..afa93eff495811cf 100644
--- a/tools/perf/util/Build
+++ b/tools/perf/util/Build
@@ -281,7 +281,7 @@ $(OUTPUT)util/bpf-filter-bison.c $(OUTPUT)util/bpf-filter-bison.h: util/bpf-filt

 FLEX_GE_264 := $(shell expr $(shell $(FLEX) --version | sed -e  's/flex \([0-9]\+\).\([0-9]\+\).\([0-9]\+\)/\1\2\3/g') \>\= 264)
 ifeq ($(FLEX_GE_264),1)
-  flex_flags := -Wno-redundant-decls -Wno-switch-default -Wno-unused-function
+  flex_flags := -Wno-redundant-decls -Wno-switch-default -Wno-unused-function -Wno-misleading-indentation
 else
   flex_flags := -w
 endif
⬢[acme@toolbox perf-tools-next]$


> 1 error generated.
> make[4]: *** [/var/home/acme/git/perf-tools-next/tools/build/Makefile.build:97: util/parse-events-flex.o] Error 1
> make[4]: *** Waiting for unfinished jobs....
>   LD      util/scripting-engines/perf-in.o
> make[3]: *** [/var/home/acme/git/perf-tools-next/tools/build/Makefile.build:140: util] Error 2
> make[2]: *** [Makefile.perf:682: perf-in.o] Error 2
> make[2]: *** Waiting for unfinished jobs....
>   CC      pmu-events/pmu-events.o
>   LD      pmu-events/pmu-events-in.o
> make[1]: *** [Makefile.perf:242: sub-make] Error 2
> make: *** [Makefile:70: all] Error 2
> 
> ⬢[acme@toolbox perf-tools-next]$ clang --version
> clang version 14.0.5 (Fedora 14.0.5-2.fc36)
> Target: x86_64-redhat-linux-gnu
> Thread model: posix
> InstalledDir: /usr/bin
> ⬢[acme@toolbox perf-tools-next]$

-- 

- Arnaldo

Re: [PATCH v1 4/6] perf build: Disable fewer flex warnings

Posted by Ian Rogers 2 years, 6 months ago

On Fri, Jul 28, 2023 at 7:02 AM Arnaldo Carvalho de Melo
<acme@kernel.org> wrote:
>
> Em Fri, Jul 28, 2023 at 10:59:38AM -0300, Arnaldo Carvalho de Melo escreveu:
> > Em Fri, Jul 28, 2023 at 09:50:59AM +0100, James Clark escreveu:
> > >
> > >
> > > On 28/07/2023 07:49, Ian Rogers wrote:
> > > > If flex is version 2.6.4, reduce the number of flex C warnings
> > > > disabled. Earlier flex versions have all C warnings disabled.
> > >
> > > Hi Ian,
> > >
> > > I get a build error with either this one or the bison warning change:
> > >
> > >   $ make LLVM=1 -C tools/perf NO_BPF_SKEL=1 DEBUG=1
> > >
> > >   util/pmu-bison.c:855:9: error: variable 'perf_pmu_nerrs' set but not
> > > used [-Werror,-Wunused-but-set-variable]
> > >     int yynerrs = 0;
> > >
> > > I tried a clean build which normally fixes these kind of bison errors.
> > > Let me know if you need any version info.
> >
> > Trying to build it with the command line above I get:
> >
> >   CC      util/expr.o
> >   CC      util/parse-events.o
> >   CC      util/parse-events-flex.o
> > util/parse-events-flex.c:7503:13: error: misleading indentation; statement is not part of the previous 'if' [-Werror,-Wmisleading-indentation]
> >             if ( ! yyg->yy_state_buf )
> >             ^
> > util/parse-events-flex.c:7501:9: note: previous statement is here
> >         if ( ! yyg->yy_state_buf )
> >         ^
>
> I added this to the patch to get it moving:
>
> make: Leaving directory '/var/home/acme/git/perf-tools-next/tools/perf'
> ⬢[acme@toolbox perf-tools-next]$ git diff
> diff --git a/tools/perf/util/Build b/tools/perf/util/Build
> index 32239c4b0393c319..afa93eff495811cf 100644
> --- a/tools/perf/util/Build
> +++ b/tools/perf/util/Build
> @@ -281,7 +281,7 @@ $(OUTPUT)util/bpf-filter-bison.c $(OUTPUT)util/bpf-filter-bison.h: util/bpf-filt
>
>  FLEX_GE_264 := $(shell expr $(shell $(FLEX) --version | sed -e  's/flex \([0-9]\+\).\([0-9]\+\).\([0-9]\+\)/\1\2\3/g') \>\= 264)
>  ifeq ($(FLEX_GE_264),1)
> -  flex_flags := -Wno-redundant-decls -Wno-switch-default -Wno-unused-function
> +  flex_flags := -Wno-redundant-decls -Wno-switch-default -Wno-unused-function -Wno-misleading-indentation
>  else
>    flex_flags := -w
>  endif
> ⬢[acme@toolbox perf-tools-next]$
>
>
> > 1 error generated.
> > make[4]: *** [/var/home/acme/git/perf-tools-next/tools/build/Makefile.build:97: util/parse-events-flex.o] Error 1
> > make[4]: *** Waiting for unfinished jobs....
> >   LD      util/scripting-engines/perf-in.o
> > make[3]: *** [/var/home/acme/git/perf-tools-next/tools/build/Makefile.build:140: util] Error 2
> > make[2]: *** [Makefile.perf:682: perf-in.o] Error 2
> > make[2]: *** Waiting for unfinished jobs....
> >   CC      pmu-events/pmu-events.o
> >   LD      pmu-events/pmu-events-in.o
> > make[1]: *** [Makefile.perf:242: sub-make] Error 2
> > make: *** [Makefile:70: all] Error 2
> >
> > ⬢[acme@toolbox perf-tools-next]$ clang --version
> > clang version 14.0.5 (Fedora 14.0.5-2.fc36)
> > Target: x86_64-redhat-linux-gnu
> > Thread model: posix
> > InstalledDir: /usr/bin
> > ⬢[acme@toolbox perf-tools-next]$

Thanks James/Arnaldo, I was trying to be aggressive in having more
flags, but it seems too aggressive. We should probably bring back the
logic to make this flag only added if it is supported:
  CC_HASNT_MISLEADING_INDENTATION := $(shell echo "int main(void) {
return 0 }" | $(CC) -Werror -Wno-misleading-indentation -o /dev/null
-xc - 2>&1 | grep -q -- -Wno-misleading-indentation ; echo $$?)
  ifeq ($(CC_HASNT_MISLEADING_INDENTATION), 1)
    flex_flags += -Wno-misleading-indentation
  endif
Arnaldo, is the misleading indentation in the bison generated code or
something copy-pasted from the parse-events.l ? If the latter we may
be able to fix the .l file to keep the warning.

Thanks,
Ian

> --
>
> - Arnaldo

Re: [PATCH v1 4/6] perf build: Disable fewer flex warnings

Posted by Arnaldo Carvalho de Melo 2 years, 6 months ago

Em Fri, Jul 28, 2023 at 08:26:54AM -0700, Ian Rogers escreveu:
> On Fri, Jul 28, 2023 at 7:02 AM Arnaldo Carvalho de Melo
> <acme@kernel.org> wrote:
> >
> > Em Fri, Jul 28, 2023 at 10:59:38AM -0300, Arnaldo Carvalho de Melo escreveu:
> > > Em Fri, Jul 28, 2023 at 09:50:59AM +0100, James Clark escreveu:
> > > >
> > > >
> > > > On 28/07/2023 07:49, Ian Rogers wrote:
> > > > > If flex is version 2.6.4, reduce the number of flex C warnings
> > > > > disabled. Earlier flex versions have all C warnings disabled.
> > > >
> > > > Hi Ian,
> > > >
> > > > I get a build error with either this one or the bison warning change:
> > > >
> > > >   $ make LLVM=1 -C tools/perf NO_BPF_SKEL=1 DEBUG=1
> > > >
> > > >   util/pmu-bison.c:855:9: error: variable 'perf_pmu_nerrs' set but not
> > > > used [-Werror,-Wunused-but-set-variable]
> > > >     int yynerrs = 0;
> > > >
> > > > I tried a clean build which normally fixes these kind of bison errors.
> > > > Let me know if you need any version info.
> > >
> > > Trying to build it with the command line above I get:
> > >
> > >   CC      util/expr.o
> > >   CC      util/parse-events.o
> > >   CC      util/parse-events-flex.o
> > > util/parse-events-flex.c:7503:13: error: misleading indentation; statement is not part of the previous 'if' [-Werror,-Wmisleading-indentation]
> > >             if ( ! yyg->yy_state_buf )
> > >             ^
> > > util/parse-events-flex.c:7501:9: note: previous statement is here
> > >         if ( ! yyg->yy_state_buf )
> > >         ^
> >
> > I added this to the patch to get it moving:
> >
> > make: Leaving directory '/var/home/acme/git/perf-tools-next/tools/perf'
> > ⬢[acme@toolbox perf-tools-next]$ git diff
> > diff --git a/tools/perf/util/Build b/tools/perf/util/Build
> > index 32239c4b0393c319..afa93eff495811cf 100644
> > --- a/tools/perf/util/Build
> > +++ b/tools/perf/util/Build
> > @@ -281,7 +281,7 @@ $(OUTPUT)util/bpf-filter-bison.c $(OUTPUT)util/bpf-filter-bison.h: util/bpf-filt
> >
> >  FLEX_GE_264 := $(shell expr $(shell $(FLEX) --version | sed -e  's/flex \([0-9]\+\).\([0-9]\+\).\([0-9]\+\)/\1\2\3/g') \>\= 264)
> >  ifeq ($(FLEX_GE_264),1)
> > -  flex_flags := -Wno-redundant-decls -Wno-switch-default -Wno-unused-function
> > +  flex_flags := -Wno-redundant-decls -Wno-switch-default -Wno-unused-function -Wno-misleading-indentation
> >  else
> >    flex_flags := -w
> >  endif
> > ⬢[acme@toolbox perf-tools-next]$
> >
> >
> > > 1 error generated.
> > > make[4]: *** [/var/home/acme/git/perf-tools-next/tools/build/Makefile.build:97: util/parse-events-flex.o] Error 1
> > > make[4]: *** Waiting for unfinished jobs....
> > >   LD      util/scripting-engines/perf-in.o
> > > make[3]: *** [/var/home/acme/git/perf-tools-next/tools/build/Makefile.build:140: util] Error 2
> > > make[2]: *** [Makefile.perf:682: perf-in.o] Error 2
> > > make[2]: *** Waiting for unfinished jobs....
> > >   CC      pmu-events/pmu-events.o
> > >   LD      pmu-events/pmu-events-in.o
> > > make[1]: *** [Makefile.perf:242: sub-make] Error 2
> > > make: *** [Makefile:70: all] Error 2
> > >
> > > ⬢[acme@toolbox perf-tools-next]$ clang --version
> > > clang version 14.0.5 (Fedora 14.0.5-2.fc36)
> > > Target: x86_64-redhat-linux-gnu
> > > Thread model: posix
> > > InstalledDir: /usr/bin
> > > ⬢[acme@toolbox perf-tools-next]$
> 
> Thanks James/Arnaldo, I was trying to be aggressive in having more
> flags, but it seems too aggressive. We should probably bring back the
> logic to make this flag only added if it is supported:
>   CC_HASNT_MISLEADING_INDENTATION := $(shell echo "int main(void) {
> return 0 }" | $(CC) -Werror -Wno-misleading-indentation -o /dev/null
> -xc - 2>&1 | grep -q -- -Wno-misleading-indentation ; echo $$?)
>   ifeq ($(CC_HASNT_MISLEADING_INDENTATION), 1)
>     flex_flags += -Wno-misleading-indentation
>   endif
> Arnaldo, is the misleading indentation in the bison generated code or
> something copy-pasted from the parse-events.l ? If the latter we may
> be able to fix the .l file to keep the warning.

I haven't checked, lemme do it now.

- Arnaldo

Re: [PATCH v1 4/6] perf build: Disable fewer flex warnings

Posted by Arnaldo Carvalho de Melo 2 years, 6 months ago

Em Fri, Jul 28, 2023 at 03:10:05PM -0300, Arnaldo Carvalho de Melo escreveu:
> Em Fri, Jul 28, 2023 at 08:26:54AM -0700, Ian Rogers escreveu:
> > On Fri, Jul 28, 2023 at 7:02 AM Arnaldo Carvalho de Melo
> > > I added this to the patch to get it moving:
> > >
> > > make: Leaving directory '/var/home/acme/git/perf-tools-next/tools/perf'
> > > ⬢[acme@toolbox perf-tools-next]$ git diff
> > > diff --git a/tools/perf/util/Build b/tools/perf/util/Build
> > > index 32239c4b0393c319..afa93eff495811cf 100644
> > > --- a/tools/perf/util/Build
> > > +++ b/tools/perf/util/Build
> > > @@ -281,7 +281,7 @@ $(OUTPUT)util/bpf-filter-bison.c $(OUTPUT)util/bpf-filter-bison.h: util/bpf-filt
> > >
> > >  FLEX_GE_264 := $(shell expr $(shell $(FLEX) --version | sed -e  's/flex \([0-9]\+\).\([0-9]\+\).\([0-9]\+\)/\1\2\3/g') \>\= 264)
> > >  ifeq ($(FLEX_GE_264),1)
> > > -  flex_flags := -Wno-redundant-decls -Wno-switch-default -Wno-unused-function
> > > +  flex_flags := -Wno-redundant-decls -Wno-switch-default -Wno-unused-function -Wno-misleading-indentation
> > >  else
> > >    flex_flags := -w
> > >  endif
> > > ⬢[acme@toolbox perf-tools-next]$
> > >
> > >
> > > > 1 error generated.
> > > > make[4]: *** [/var/home/acme/git/perf-tools-next/tools/build/Makefile.build:97: util/parse-events-flex.o] Error 1
> > > > make[4]: *** Waiting for unfinished jobs....
> > > >   LD      util/scripting-engines/perf-in.o
> > > > make[3]: *** [/var/home/acme/git/perf-tools-next/tools/build/Makefile.build:140: util] Error 2
> > > > make[2]: *** [Makefile.perf:682: perf-in.o] Error 2
> > > > make[2]: *** Waiting for unfinished jobs....
> > > >   CC      pmu-events/pmu-events.o
> > > >   LD      pmu-events/pmu-events-in.o
> > > > make[1]: *** [Makefile.perf:242: sub-make] Error 2
> > > > make: *** [Makefile:70: all] Error 2
> > > >
> > > > ⬢[acme@toolbox perf-tools-next]$ clang --version
> > > > clang version 14.0.5 (Fedora 14.0.5-2.fc36)
> > > > Target: x86_64-redhat-linux-gnu
> > > > Thread model: posix
> > > > InstalledDir: /usr/bin
> > > > ⬢[acme@toolbox perf-tools-next]$
> > 
> > Thanks James/Arnaldo, I was trying to be aggressive in having more
> > flags, but it seems too aggressive. We should probably bring back the
> > logic to make this flag only added if it is supported:
> >   CC_HASNT_MISLEADING_INDENTATION := $(shell echo "int main(void) {
> > return 0 }" | $(CC) -Werror -Wno-misleading-indentation -o /dev/null
> > -xc - 2>&1 | grep -q -- -Wno-misleading-indentation ; echo $$?)
> >   ifeq ($(CC_HASNT_MISLEADING_INDENTATION), 1)
> >     flex_flags += -Wno-misleading-indentation
> >   endif
> > Arnaldo, is the misleading indentation in the bison generated code or
> > something copy-pasted from the parse-events.l ? If the latter we may
> > be able to fix the .l file to keep the warning.
> 
> I haven't checked, lemme do it now.

It comes directly from flex's m4 files:

https://github.com/westes/flex/blob/master/src/c99-flex.skl#L2044

So I'll keep the -Wno-misleading-indentation, ok?

- Arnaldo