[Bug c++/105397] Cannot export module initializer symbols with `-fvisibility=hidden`

["redbeard0531 at gmail dot com" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105397

Mathias Stearn <redbeard0531 at gmail dot com> changed:

           What    |Removed                     |Added
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                 CC|                            |redbeard0531 at gmail dot com

--- Comment #1 from Mathias Stearn <redbeard0531 at gmail dot com> ---
Perhaps the best option is to default the visibility of the implicit functions
to the widest visibility of any function or object in module purview exposed by
the TU. The assumption being that if anything is visibile outside the library,
then it is expected to be imported from TUs outside the library and that should
Just Work. Conversely, if everything is defined as internal visibility, then it
is unlikely that this module was intended to be imported from outside of the
library, and so it may be desireable to allow different libs to have their own
module with the same name.

Unfortunately that doesn't give any good indication of what to do for
importable units that have an empty module purview (or where everything inside
it has TU-local internal linkage). While legal, maybe that isn't a case worth
optimizing the Just Works experience for?