[Bug c++/122786] [modules] section attribute in interface modules are silently dropped

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=122786

--- Comment #3 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:8e3c5ce5e802225a7416a32a9d9a3c2bb2380874

commit r16-8242-g8e3c5ce5e802225a7416a32a9d9a3c2bb2380874
Author: Nathaniel Shead <nathanieloshead@gmail.com>
Date:   Thu Mar 19 22:58:11 2026 +1100

    c++/modules: Support section attributes [PR122786]

    This is a minimal fix to not just silently drop the section attribute on
    stream-in.  Ideally we should be using cplus_decl_attributes for this,
    but it's not yet ready for modules (many attributes behave weirdly when
    applied not during parsing).  We should also be checking for
    incompatible sections on stream-in in is_matching_decl, but that would
    also be better handled more generally so I'm leaving that out of this
    patch.

    Instead this minimally fixes the issue by just re-applying the section
    name from the attributes we've streamed in.

            PR c++/122786

    gcc/cp/ChangeLog:

            * module.cc (trees_in::decl_value): Set section name from
            attribute.

    gcc/testsuite/ChangeLog:

            * g++.dg/modules/attrib-5_a.C: New test.
            * g++.dg/modules/attrib-5_b.C: New test.

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