Re: [PATCH] Fix _GLIBCXX_DEBUG tests

[Jonathan Wakely <jwakely.gcc@gmail.com>]

On Mon, 14 Dec 2020, 06:51 François Dumont via Libstdc++, <
libstdc++@gcc.gnu.org> wrote:

> On 13/12/20 11:17 pm, Jonathan Wakely wrote:
> > On 13/12/20 15:52 +0100, François Dumont via Libstdc++ wrote:
> >> Some tests are XPASS because array assertions have been disabled for
> >> a good reason in C++11.
> >>
> >> I wonder if the respective non-constexpr _GLIBCXX_ASSERTION checks
> >> shouldn't target C++14 too. At the moment they are failing as
> >> expected but because of an Undefined Behavior no ?
> >
> > Hmm, maybe my "fix" for the bug was too hasty, and I should have done
> > this instead:
> >
> > --- a/libstdc++-v3/include/bits/c++config
> > +++ b/libstdc++-v3/include/bits/c++config
> > @@ -684,7 +684,7 @@ namespace std
> >
> >  #undef _GLIBCXX_HAS_BUILTIN
> >
> > -#if _GLIBCXX_HAVE_BUILTIN_IS_CONSTANT_EVALUATED
> > +#if _GLIBCXX_HAVE_BUILTIN_IS_CONSTANT_EVALUATED && __cplusplus >=
> > 201402L
> >  # define __glibcxx_assert_1(_Condition)                \
> >      if (__builtin_is_constant_evaluated())     \
> >       {                                         \
> >
> > That would allow us to keep the std::array runtime assertions for
> > C++11, and only disable them in constexpr contexts.
>
> I already tried to restore this check in C++11 runtime without success
> but I didn't try this approach.
>
> I'll have a try but C++11 forces constexpr to be just a return statement
> so I fear that it won't appreciate the additional assertion.
>


Ah yes, we'd need something like Daniel suggested, and it's not worth it
just for C++11.

Just limiting the tests to c++14 is fine.




> >
> >
> >> The other test is failing because of some cleanup in headers which
> >> makes <memory> include necessary.
> >>
> >> Â Â Â  libstdc++: Fix several _GLIBCXX_DEBUG tests
> >>
> >> Â Â Â  libstdc++-v3/ChangeLog:
> >>
> >> Â Â Â Â Â Â Â Â Â Â Â  *
> >> testsuite/23_containers/array/debug/back2_neg.cc: target c++14
> >> because assertion
> >> Â Â Â Â Â Â Â Â Â Â Â  for constexpr is disabled in C++11.
> >> Â Â Â Â Â Â Â Â Â Â Â  *
> >> testsuite/23_containers/array/debug/front2_neg.cc: Likewise.
> >> Â Â Â Â Â Â Â Â Â Â Â  *
> >> testsuite/23_containers/array/debug/square_brackets_operator2_neg.cc:
> >> Likewise.
> >> Â Â Â Â Â Â Â Â Â Â Â  *
> >> testsuite/23_containers/vector/debug/multithreaded_swap.cc: Include
> >> <memory>
> >> Â Â Â Â Â Â Â Â Â Â Â  for shared_ptr.
> >>
> >> Ok to commit ?
> >
> > Yes, thanks.
> >
> >
>
>