[Bug c++/106820] internal compiler error: in function_and_variable_visibility [for std::shared_ptr<data>{b,??} use via <memory> module]

["markmigm at gmail dot com" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106820

Mark Millard <markmigm at gmail dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
            Summary|internal compiler error: in |internal compiler error: in
                   |function_and_variable_visib |function_and_variable_visib
                   |ility [for                  |ility [for
                   |std::dynamic_pointer_cast   |std::shared_ptr<data>{b,??}
                   |use via <memory> module]    |use via <memory> module]

--- Comment #2 from Mark Millard <markmigm at gmail dot com> ---
I've produced a more reduced example source:

import <memory>;

struct data
{
        virtual ~data() = default;
};

auto test(std::shared_ptr<data> b)
{
        return std::shared_ptr<data>{b,nullptr};
}


nullptr is not special here: other alternative raw pointers also get
the "internal compiler error: in function_and_variable_visibility"
notice. nullptr is just the simplest example.

Using a #include instead also gets the error (as expected) --unless
the -fmodules-ts command line option is then omitted. -fmodules-ts
is important to getting the message in the FreeBSD lang/gcc12 context.