Re: [PATCH v2 1/3] perf report: Support LLVM for addr2line()

["Steinar H. Gunderson" <sesse@google.com>]

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 build:
> https://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools-next.git/tree/tools/build/Makefile.feature?h=perf-tools-next#n123

Ack.

> s/HAVE_LIBLLVM_SUPPORT/HAVE_LLVM_SUPPORT/

Ack.

>> +#pragma GCC diagnostic push
>> +#pragma GCC diagnostic ignored "-Wunused-parameter"  /* Needed for LLVM 14. */
> nit: pehaps disabling this should be conditional:
> #if LLVM_VERSION_MAJOR == 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 == "<invalid>") {
>> +                       /* Match the convention of libbfd. */
>> +                       *file = nullptr;
> Should "*file" be cleared if "!file" so the caller can reliably free it?

I don't understand. If “!file”, then file == NULL and surely accessing
*file would mean a crash?

/* Steinar */