Re: babeltrace | sink.ctf.fs escaping of struct member names

["MOESSBAUER, Felix via lttng-dev" <lttng-dev@lists.lttng.org>]

On Thu, 2025-12-04 at 11:01 -0500, Philippe Proulx wrote:
> On Thu, Dec 4, 2025 at 10:47 AM MOESSBAUER, Felix
> <felix.moessbauer@siemens.com> wrote:
> > 
> > Well... This is a more generic question if it is really the job of the
> > serializer to fix possible name clashes in the output. Anyways,
> > unfortunately LTTng uses this field and does not allow escaping.
> 
> Although I understand the question, I will not take the time to
> re-evaluate a design that involves CTF 1.8. I'm currently in a "quick
> fixes only" mode for this format, with the sole aim of keeping existing
> scenarios working.
> 
> > I would love to switch to CTF2, however we need support for it in
> > trace-compass, which AFAIK is not even implemented yet.
> 
> We're currently investigating the status of CTF 2 support in Trace
> Compass and what amount of work is remaining. We'll let you know.
> 
> > This is tricky, as we don't really know if the trace is an LTTng trace
> > or not. However, we can hide it behind the proposed create-lttng-index
> > flag, as it is anyways only needed in combination with an index (I
> > still don't know why, but ok...).
> 
> Yes we know. Have a look at make_lttng_trace_path_rel().

I already checked this function, but this is a bit too-strict, as
really only adding the index breaks the import. I also want to be able
to add the index to non lttng traces (which for instance lack some env
metadata) as otherwise the ftrace-to-ctf converter needs to fake the
metadata.

> 
> `create-lttng-index` would be another hint, but the trace environment
> has been good enough so far.

This is easy to implement and works perfectly fine. By that, traces
without an lttng index have "_cpu_id" and can be imported in trace-
compass. Traces with an lttng index get "cpu_id" and also now import
correctly.

I hope this solution is acceptable.

Anyways, thanks for the quick support.

Felix

> 
> Phil

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