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From: Ian Rogers <irogers@google.com>
Date: Sun, 19 May 2024 16:00:27 -0700
Message-ID: <CAP-5=fVYbewBtC0-GBKFUQq_gaGUMdZenCRyh3cyP4ff7yuqCA@mail.gmail.com>
Subject: Re: [PATCH v2 1/3] perf report: Support LLVM for addr2line()
To: "Steinar H. Gunderson" <sesse@google.com>
Cc: acme@kernel.org, linux-perf-users@vger.kernel.org, 
	linux-kernel@vger.kernel.org
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On Sun, May 19, 2024 at 2:01=E2=80=AFPM Steinar H. Gunderson <sesse@google.=
com> wrote:
>
> On Sun, May 19, 2024 at 11:23:26AM -0700, Ian Rogers wrote:
> > I think we might want to display this in the feature list during the bu=
ild:
> > https://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools-next.gi=
t/tree/tools/build/Makefile.feature?h=3Dperf-tools-next#n123
>
> Ack.
>
> > s/HAVE_LIBLLVM_SUPPORT/HAVE_LLVM_SUPPORT/
>
> Ack.
>
> >> +#pragma GCC diagnostic push
> >> +#pragma GCC diagnostic ignored "-Wunused-parameter"  /* Needed for LL=
VM 14. */
> > nit: pehaps disabling this should be conditional:
> > #if LLVM_VERSION_MAJOR =3D=3D 14
>
> It doesn't seem LLVM_VERSION_MAJOR is defined yet at this point, so I
> don't think that would work. (I just checked; 15 has the same issue.)
> In any case, I think it would be just more clutter for dubious gain.
>
> >> +       if (file) {
> >> +               if (line_info.FileName =3D=3D "<invalid>") {
> >> +                       /* Match the convention of libbfd. */
> >> +                       *file =3D nullptr;
> > Should "*file" be cleared if "!file" so the caller can reliably free it=
?
>
> I don't understand. If =E2=80=9C!file=E2=80=9D, then file =3D=3D NULL and=
 surely accessing
> *file would mean a crash?

You're right, sorry. Thanks,
Ian

> /* Steinar */