ACATS legal status cleared by FSF

[Richard Kenner]

    I'm 100% confident that there is value to having "make check" drive at
    least some set of Ada tests.  

I don't think *anybody* disagrees with that.  The question is what should
that subset be?  My experience with backend changes is that most of the
failures are in C3, CD, CXA, and CXG, with a smaller number in C4.  For
changes to other than the Ada front-end, the benefit of running additional
chapters is, in my opinion, small.  I can't remember a time when a backend
change caused an ACATS failure that didn't show up in one of those chapters.
That being said, I should also point out that the ACATS suite isn't a very
good test of the back-end at all, but perhaps running it with different
optimization levels will help.

    (with the implication that writing a C testcase is impossible or at
    least too much work).  

Usually impossible.  The issue is trees that can't be made in C, such as with
PLACEHOLDER_EXPR.

    It may make sense not to run the ACATS B tests by default, but they
    should at least be _present_ in the repository so that everyone is on
    an equal footing for changes that affect error messages.

I think everybody agrees with that too, but the question is what does
"present" mean with respect to the baselines, which is where the real
maintenance issue is.