Re: [patch] [gdb/testsuite] include a use of the definition of a type to cause clang to emit debug info

[Joel Brobecker <brobecker at adacore dot com>]

> > The gdb11479.exp is obvious and can be pushed. The change to gdb11479.c,
> > on the other hand, changes the test, and I don't think we want that,
> > because I disagree with the outcome of Clang's optimization here.
> > If Clang doesn't want to fix the problem, best to just xfail the test
> > with Clang, and write a new one that provides the type definition as
> > Clang wants it.
> 
> Could you describe your objection here? In particular, as it relates
> to Dave's analysis of a similar gcc optimization. (Also a few people
> have been interested in implementing this same behavior in gcc).

The fact is, at the moment, that GCC generates the necessary debugging
information, without the need to create a typedef. If it stops working
thanks to a GCC "optimization", I would like to know about it (personally).
In this particular case, the type is used locally, albeit as a pointer,
and it would seem unfriendly to me that the user not be able to either
print the pointed object's size, or any of the enum's element, just
because it is only used via a pointer. I also seems strange to me
that an unused typedef is enough to trigger full debug info generation,
while a variable indirectly referencing a type is not.

That's why I suggested that we keep the current testcase as is,
with an xfail with clang, and create a new one if we want to, that
tests the behavior with the proposed work around.

That's only my opinion, however; it would be fine for the change
to go in if other maintainers disagree with me and approve the change.

-- 
Joel