Re: [PATCH 0/3] perf tools: Enable strict JSON parsing

[Arnaldo Carvalho de Melo <acme@kernel.org>]

Em Fri, Oct 08, 2021 at 04:56:55PM +0530, kajoljain escreveu:
> 
> 
> On 10/8/21 3:32 PM, James Clark wrote:
> > 
> > 
> > On 08/10/2021 08:43, kajoljain wrote:
> >>
> >>
> >> On 10/7/21 4:35 PM, James Clark wrote:
> >>> After a discussion on "[PATCH 1/4] perf vendor events: Syntax corrections in Neoverse N1 json",
> >>> John Garry suggested that we can just modify the parser to make it more strict. Hopefully this will
> >>> remove the need to apply any future JSON comma fixup commits.
> >>>
> >>> Applies on top of "[PATCH v2 1/3] perf vendor events: Syntax corrections in Neoverse N1 json" on
> >>> perf/core.
> >>>
> >>> Also available at:
> >>>   git clone --branch james-json-parse-fix git@git.gitlab.arm.com:linux-arm/linux-jc.git
> >>
> >> Hi James,
> >>    Do we have any dependency patches on top of this patch series. I am
> >> reviewing and testing it, but in both powerpc and x86 system I am
> >> getting build issue. Not sure if I am missing something> 
> >> I am trying your changes on top of upstream perf.
> >>
> >> pmu-events/arch/test/test_soc/sys/uncore.json: json error Invalid
> >> character inside JSON string
> > 
> > Hi Kajol,
> > 
> > A trailing comma was fixed in this file 3 weeks ago at b8b350a. Can you
> > confirm if you have updated to get this commit on perf core?
> > 
> > Alternately you could pull from my branch above which is up to date enough
> > to include it.
> 
> Hi James,
>    Thanks for pointing it. Not getting build issue now.
> > 
> > The file is in pmu-events/arch/test/ so I would expect it to fail on all platforms.
> > 
> >> make[3]: *** [pmu-events/Build:18: pmu-events/pmu-events.c] Error 1
> >> make[3]: *** Deleting file 'pmu-events/pmu-events.c'
> >> make[2]: *** [Makefile.perf:667: pmu-events/pmu-events-in.o] Error 2
> >> make[2]: *** Waiting for unfinished jobs....
> >> make[1]: *** [Makefile.perf:238: sub-make] Error 2
> >> make: *** [Makefile:70: all] Error 2
> >>
> >> Also, Is it possible to add line number along with file name while
> >> showing this error `json error Invalid character inside JSON string`.
> >> It might make it easy to fix.
> > 
> > I can add a character number with the following fix if you think that would
> > be good enough? A line number might be a bigger change and involve keeping
> > track of newline characters.
> 
> Sure. I think then we can skip this change. Not sure if character
> number will be helpful.
> 
> Patch-set looks good to me.
> 
> Reviewed-by Kajol Jain<kjain@linux.ibm.com>

Applied ok as-is to my perf/core branch, applied and added your
Reviewed-by, thanks.

- Arnaldo
 
> Thanks,
> Kajol Jain
> 
> > 
> > diff --git a/tools/perf/pmu-events/json.c b/tools/perf/pmu-events/json.c
> > index 0544398d6e2d..41a14e1543bf 100644
> > --- a/tools/perf/pmu-events/json.c
> > +++ b/tools/perf/pmu-events/json.c
> > @@ -99,7 +99,7 @@ jsmntok_t *parse_json(const char *fn, char **map, size_t *size, int *len)
> >         res = jsmn_parse(&parser, *map, *size, tokens,
> >                          sz / sizeof(jsmntok_t));
> >         if (res != JSMN_SUCCESS) {
> > -               pr_err("%s: json error %s\n", fn, jsmn_strerror(res));
> > +               pr_err("%s: json error at character %u '%s'\n", fn, parser.pos, jsmn_strerror(res));
> >                 goto error_free;
> >         }
> >         if (len)
> > 
> > 
> > It prints this for the same error you have above>
> > pmu-events/arch/test/test_soc/sys/uncore.json: json error at character 213 'Invalid character inside JSON string'
> > 
> > Although funnily enough after re-introducing that extra comma it doesn't fail the build for me,
> > it just prints the error message. But I may have noticed some dependency tracking issues around
> > the json files.
> > 
> > James
> > 

-- 

- Arnaldo