[PATCH] meson: Add -finstrument-functions to debug builds

[Laurent Pinchart]

On Fri, Sep 13, 2024 at 01:00:35AM +0200, Paul Elder wrote:
> On Thu, Sep 12, 2024 at 05:58:54PM +0100, Kieran Bingham wrote:
> > Quoting Paul Elder (2024-09-12 17:49:09)
> > > Add -finstrument-functions to debug (and debugoptimized) build types.
> > > This will mainly be used for tracing functions with lttng by
> > > LD_PRELOADing liblttng-ust-cyg-profile.so (or
> > > liblttng-ust-cyg-profile-fast.so).
> > > 
> > > Signed-off-by: Paul Elder <paul.elder at ideasonboard.com>
> > > ---
> > >  meson.build | 6 ++++++
> > >  1 file changed, 6 insertions(+)
> > > 
> > > diff --git a/meson.build b/meson.build
> > > index 432ae1337..e8014e77f 100644
> > > --- a/meson.build
> > > +++ b/meson.build
> > > @@ -109,6 +109,12 @@ common_arguments = [
> > >      '-include', meson.current_build_dir() / 'config.h',
> > >  ]
> > >  
> > > +if get_option('buildtype').startswith('debug')
> > 
> > Why is this added to debug builds rather than any build with 'tracing
> > enabled' ?
> 
> On one hand, good point.
> 
> On the other hand, the function tracing *should* work without tracing
> enabled in libcamera. So technically they can be used separately. It's a
> matter of if we think there's an actual purpose for enabling it.

Do you envision function tracing to be used in production, or should
debugging issues in production rely on trace points only ?

> > meson_options has:
> > 
> > option('tracing',
> >         type : 'feature',
> >         value : 'auto',
> >         description : 'Enable tracing (based on lttng)')
> > 
> > so this could be 'if get_option('tracing') ?
> > 
> > 
> > > +    common_arguments += [
> > > +        '-finstrument-functions',
> > > +    ]
> > > +endif
> > > +
> > >  c_arguments = []
> > >  cpp_arguments = []
> > >  

-- 
Regards,

Laurent Pinchart