Re: [PATCH] build: check drivers class dependencies early

[David Marchand <david.marchand@redhat.com>]

On Tue, Aug 1, 2023 at 11:25 AM Bruce Richardson
<bruce.richardson@intel.com> wrote:
>
> On Tue, Aug 01, 2023 at 10:52:53AM +0200, David Marchand wrote:
> > Drivers implementing a class of devices (for example, drivers/event)
> > depend on the associated abstraction library (lib/eventdev).
> > This dependency is expressed in the top level meson.build for this class
> > (drivers/event/meson.build).
> >
> > As we are making more libraries optional, custom constructs referencing
> > the class dependencies in some drivers meson.build (event/dlb2) may break.
> >
> > It would be possible to add more checks in those drivers meson.build but
> > it is more straightforward to not even consider a driver meson.build when
> > the class dependencies are not met.
> >
> > Signed-off-by: David Marchand <david.marchand@redhat.com>
> > ---
> >  drivers/meson.build | 11 +++++++++++
> >  1 file changed, 11 insertions(+)
> >
> > diff --git a/drivers/meson.build b/drivers/meson.build
> > index 74ae8cb96b..c375352e77 100644
> > --- a/drivers/meson.build
> > +++ b/drivers/meson.build
> > @@ -70,6 +70,17 @@ foreach subpath:subdirs
> >      else
> >          class = subpath
> >          subdir(class)
> > +        skip_class = false
> > +        foreach d:std_deps
> > +            if not is_variable('shared_rte_' + d)
> > +                skip_class = true
> > +                message('Disabling all @1@ drivers: missing internal dependency "@0@"'
> > +                        .format(d, class))
> > +            endif
> > +        endforeach
> > +        if skip_class
> > +            continue
> > +        endif
> >      endif
> >
> >      # save class name on first occurrence
>
> I like this approach. However, we do need something in the summary at the
> end of the build too. Either:
>
> * Single message stating all drivers of a given class are skipped
> * (as now), message for each driver stating that it has been disabled
>
> The former is nice as it gives us a shorter summary. The latter is nice
> because it's consistent with what we have now.  Authors choice, which to go
> for! :-)

I like the shorter summary.
WDYT of:

diff --git a/drivers/meson.build b/drivers/meson.build
index c375352e77..02268918e4 100644
--- a/drivers/meson.build
+++ b/drivers/meson.build
@@ -74,11 +74,18 @@ foreach subpath:subdirs
         foreach d:std_deps
             if not is_variable('shared_rte_' + d)
                 skip_class = true
-                message('Disabling all @1@ drivers: missing internal
dependency "@0@"'
+                reason = 'missing internal dependency, "@0@"'.format(d)
+                if dpdk_libs_deprecated.contains(d)
+                    reason += ' (deprecated lib)'
+                endif
+                message('Disabling @1@/* drivers: missing internal
dependency "@0@"'
                         .format(d, class))
             endif
         endforeach
         if skip_class
+            drv_path = join_paths(class, '*')
+            dpdk_drvs_disabled += drv_path
+            set_variable(drv_path.underscorify() + '_disable_reason', reason)
             continue
         endif
     endif


This gives the following output (testing on top of your series
extending optional libs and a fix on the new reasm perf test).
https://github.com/david-marchand/dpdk/actions/runs/5725429526/job/15513923381#step:19:346

...
=================
Content Skipped
=================
...
drivers:
...
    mempool/dpaa2: not in enabled drivers build config
    mempool/octeontx: not in enabled drivers build config
    mempool/stack: not in enabled drivers build config
    dma/*: missing internal dependency, "dmadev"
    net/af_packet: not in enabled drivers build config
    net/af_xdp: not in enabled drivers build config
    net/ark: not in enabled drivers build config
...


-- 
David Marchand