[Bug c++/104040] linker: when exported template class from module is used in several .cpp with same tpl arg ~ undefined reference to not default non-inline destructor

["cvs-commit at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104040

--- Comment #1 from GCC Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Nathaniel Shead <nshead@gcc.gnu.org>:

https://gcc.gnu.org/g:0774240b4df9a9bc48ce33a9625788e402498f5a

commit r14-9883-g0774240b4df9a9bc48ce33a9625788e402498f5a
Author: Nathaniel Shead <nathanieloshead@gmail.com>
Date:   Fri Mar 29 13:53:54 2024 +1100

    c++: Keep DECL_SAVED_TREE of cdtor instantiations in modules [PR104040]

    A template instantiation still needs to have its DECL_SAVED_TREE so that
    its definition is emitted into the CMI. This way it can be emitted in
    the object file of any importers that use it, in case it doesn't end up
    getting emitted in this TU.

    This is true even for maybe-in-charge functions, because we don't
    currently stream the clones directly but instead regenerate them from
    this function.

            PR c++/104040

    gcc/cp/ChangeLog:

            * semantics.cc (expand_or_defer_fn_1): Keep DECL_SAVED_TREE for
            all vague linkage cdtors with modules.

    gcc/testsuite/ChangeLog:

            * g++.dg/modules/pr104040_a.C: New test.
            * g++.dg/modules/pr104040_b.C: New test.

    Signed-off-by: Nathaniel Shead <nathanieloshead@gmail.com>
    Reviewed-by: Jason Merrill <jason@redhat.com>