Re: [C++/Obj-C++ PATCH] Fix Objective-C++ breakage

["Richard Guenther" <richard dot guenther at gmail dot com>]

On Thu, Mar 27, 2008 at 11:56 PM, Mark Mitchell <mark@codesourcery.com> wrote:
> Richard Guenther wrote:
>
>  > Obj-C++ is certainly not a problem.  Java and Fortran are already part of all
>  > build/test cycles, libjava being a huge memory eater.
>
>  Is that a good thing?  I've done little middle-end work, so I don't have
>  much experience with this.  How often does a change to the optimizers
>  pass all of the C/C++ testsuites, but fail in the Java or Fortran
>  testsuites?
>
>  These aren't rhetorical questions; I have no idea.  I'm interested in
>  what actual experience is like here.  My guess would be that changes to
>  the build machinery are quite likely to break various languages, but
>  that changes to (say) the register allocator are unlikely to work
>  reliably in C/C++, but not in Fortran/Java.  And, that, in fact, Ada is
>  the language other than C/C++ most likely to show up problems.

Sadly it happens often enough that only libjava or java testing is affected
by a patch.  Likewise Fortran is often special in the kinds of IL produced.
Ada testing doesn't show failures most of the time, but it excercises parts
of the middle-end no other frontend does.

So they are all useful in that coverage of the C and C++ testsuite isn't
good enough to catch even obvious problems sometimes.

Richard.