[Mesa-dev] [PATCH] texobj: add verbose api trace messages to several routines

[Jose Fonseca]

----- Original Message -----
> On Wed, Feb 27, 2013 at 1:21 AM, Jose Fonseca <jfonseca at vmware.com> wrote:
> > ----- Original Message -----
> >> Jordan Justen <jordan.l.justen at intel.com> writes:
> >>
> >> > Motivated by wanting to see if GenTextures was called by an
> >> > application while debugging another Steam overlay issue.
> >>
> >> Making a systematic MESA_DEBUG=api using dispatch tables and code
> >> generation seems like it would be nice instead of adding it ad-hoc.  Not
> >> something against this patch, just maybe a project for a janitor list if
> >> we have one.
> >>
> >> apitrace seems like it would be to replace it, but I've seen enough apps
> >> where it doesn't work (and in this case with the steam overlay it
> >> definitely doesn't) that we can't just rely on that.
> >
> > Could you elaborate on that? I'd like to understand how apitrace would miss
> > intercepting calls.
> 
> The Steam overlay uses LD_PRELOAD and there doesn't seem to be a way
> to both use the overlay and capture a trace.

I see.  But one can use apitrace through LD_LIBRARY_PATH instead of LD_PRELOAD. Steam is not the first app to have issues with LD_PRELOAD.

Currently there's no easy way to trace like through LD_LIBRARY_PATH -- one needs to follow the manual instructions in https://github.com/apitrace/apitrace/blob/master/README.markdown#linux but it this does indeed help, then we could add logic to the apitrace trace CLI command to setup LD_LIBRARY_PATH.

LD_PRELOAD tends to be more convenient but LD_LIBRARY_PATH should be indistinguishable for applications.

Jose