https://gcc.gnu.org/bugzilla/show_bug.cgi?id=116403
--- Comment #2 from GCC Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Nathaniel Shead <nsh...@gcc.gnu.org>: https://gcc.gnu.org/g:6f115a8eeea41d383dfb1bbb1af6ac9a97aee180 commit r15-3032-g6f115a8eeea41d383dfb1bbb1af6ac9a97aee180 Author: Nathaniel Shead <nathanielosh...@gmail.com> Date: Sun Aug 18 11:36:40 2024 +1000 c++/modules: Handle transitive reachability for deduction guides [PR116403] Currently we implement [temp.deduct.guide] p1 by forcing all deduction guides to be considered as exported. However this is not sufficient: for transitive non-exported imports we will still hide the deduction guide from name lookup, causing errors. This patch instead adjusts name lookup to have a new ANY_REACHABLE flag to allow for this case. Currently this is only used by deduction guides but there are some other circumstances where this may be useful in the future (e.g. finding existing temploid friends). PR c++/116403 gcc/cp/ChangeLog: * pt.cc (deduction_guides_for): Use ANY_REACHABLE for lookup of deduction guides. * module.cc (depset::hash::add_deduction_guides): Likewise. (module_state::write_cluster): No longer override deduction guides as exported. * name-lookup.cc (name_lookup::search_namespace_only): Ignore visibility when LOOK_want::ANY_REACHABLE is specified. (check_module_override): Ignore visibility when checking for ambiguating deduction guides. * name-lookup.h (LOOK_want): New flag 'ANY_REACHABLE'. gcc/testsuite/ChangeLog: * g++.dg/modules/dguide-4_a.C: New test. * g++.dg/modules/dguide-4_b.C: New test. * g++.dg/modules/dguide-4_c.C: New test. Signed-off-by: Nathaniel Shead <nathanielosh...@gmail.com> Reviewed-by: Jason Merrill <ja...@redhat.com>
