Re: dejagnu version update?

On Wed, 13 May 2020 at 18:19, Mike Stump via Gcc <[email protected]> wrote:
>
> I've changed the subject to match the 2015, 2017 and 2018 email threads.
>
> On May 13, 2020, at 3:26 AM, Thomas Schwinge <[email protected]> wrote:
> >
> > Comparing DejaGnu/GCC testsuite '*.sum' files between two systems ("old"
> > vs. "new") that ought to return identical results, I found that they
> > didn't:
>
> > I have not found any evidence in DejaGnu master branch that this not
> > working would've been a "recent" DejaGnu regression (and then fixed for
> > DejaGnu 1.6) -- so do we have to assume that this never worked as
> > intended back then?
>
> Likely not.
>
> > Per our "Prerequisites for GCC" installation documentation, we currently
> > require DejaGnu 1.4.4.  Advancing that to 1.6 is probably out of
> > question, given that it has "just" been released (four years ago).
>
> :-)  A user that wants full coverage should use 1.6, apparently.

As documented at
https://gcc.gnu.org/onlinedocs/libstdc++/manual/test.html#test.run.permutations
anything older than 1.5.3 causes problems for libstdc++ (and probably
the rest of GCC) because the options in --target_board get placed
after the options in dg-options. If the test depends on the options in
dg-options to work properly it might fail. For example, a test that
has { dg-options "-O2" } and fails without optimisation would FAIL if
you use --target_board=unix/-O0 with dejagnu 1.5.


> > As the failure mode with old DejaGnu is "benign" (only causes missing
> > execution testing), we could simply move on, and accept non-reproducible
> > results between different DejaGnu versions?  Kind of lame...  ;-|
>
> An ugly wart to be sure.
>
> So, now that ubuntu 20.04 is out and RHEL 8 is out, and they both contain 6, and SLES has 6 and since we've been sitting at 1.4.4 for so long, anyone want to not update dejagnu to require 1.6?

There are still lots of older systems in use for GCC dev, like all the
POWER servers in the compile farm (but I've put a recent dejagnu in
/opt/cfarm on some of them).

> I had previously approved the update to 1.5.3, but no one really wanted it as no one updated the requirement.  Let's have the 1.6 discussion.  I'm not only inclined to up to 1.6, but to actually edit it in this time.

Would the tests actually refuse to run with an older version?

> Anyone strongly against?  Why?

I'm in favour of requiring 1.5.3 or later, so 1.6 would be OK for me.