[v3] libstdc++/20534, debug mode vs. includes

[Benjamin Kosnik]

> Nice, thanks for fixing this. I tried, but failed: probably because
> wanted to accomplish to much: even avoiding assert while using debug
> mode itself. Doesn't seems feasible without major changes, I agree
> completely, and probably would not buy much anyway.

Yep.

> And...
> 
> >+ // { dg-do compile }
> >+ // { dg-options "-D__GLIBCXX__=99999999" }
> >+ // NB: This is done to force any generated and possibly included PCH
> >+ // to be invalid.
> >  
> >
> A cute trick ;) Any idea about a general solution for this problem? In
> the testsuite we have got quite a few testcases that, according to a
> comment on top, dating back to before PCHs, are supposed to be compiled
> including a given header *alone*. Maybe we can incapsulate your solution
> in a special "dg-do compile-no-pch" or something?!?

Ah hah! I'm glad you like this little hack. It seems like we need a
per-file solution for PCH and this seemed like the simplest and least
likely way to do it without getting us into trouble.

Yes, I think generalizing this is probably a good idea. However, I'm
hoping to not delay this patch for it.

Since you're now the dejagnu expert..... I leave it in your capable hands...

*ducks!*

-benjamin