RFC: Monitoring old PRs, new dg directives

[Jeff Law]

On Tue, 2020-07-28 at 17:44 -0400, Marek Polacek via Gcc-patches wrote:
> In Bugzilla, for the c++ component, we currently have over 3200 open bugs.  In
> my experience, a good amount of them have already been fixed; my periodical
> sweeps always turn up a bunch of PRs that had already been fixed previously.
> Sometimes my sweeps are more or less random, but more often than not I'm just
> looking for duplicates of an existing PR.  Sometimes the reason the already
> fixed PRs are still open is because a PR that was fixed had duplicates that we
> didn't catch earlier when confirming the PR.  Sometimes a PR gets fixed as a
> side-effect of fixing another PR.  Manual sweeps are tedious and time-consuming
> because often you need to grab the test from the Bugzilla yet again (and
> sometimes there are multiple tests).  Even if you find a PR that was fixed, you
> still need to bisect the fix and perhaps add the test to our testsuite.  That's
> draining and since the number of bugs only increases, never decreases, it is not
> sustainable.
[ ... ]
Another approach is to add tests for unfixed bugs as XFAILs.  When we see the
test go from XFAIL to XPASS, then we know the bug got fixed.

Anyway, there's certainly room to do something here to make it easier to find
bugs we've already fixed.

jeff
>