https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114950
--- Comment #1 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:c592310d5275e09977504c136419686bd2277af0 commit r15-2807-gc592310d5275e09977504c136419686bd2277af0 Author: Nathaniel Shead <nathanielosh...@gmail.com> Date: Mon Aug 5 22:37:57 2024 +1000 c++/modules: Fix merging of GM entities in partitions [PR114950] Currently name lookup generally seems to assume that all entities declared within a named module (partition) are attached to said module, which is not true for GM entities (e.g. via extern "C++"), and causes issues with deduplication. This patch fixes the issue by ensuring that module attachment of a declaration is consistently used to handling merging. Handling this exposes some issues with deduplicating temploid friends; to resolve this we always create the BINDING_SLOT_PARTITION slot so that we have somewhere to place attached names (from any module). This doesn't yet completely handle issues with allowing otherwise conflicting temploid friends from different modules to co-exist in the same module if neither are reachable from the other via name lookup. PR c++/114950 gcc/cp/ChangeLog: * module.cc (trees_out::decl_value): Stream bit indicating imported temploid friends early. (trees_in::decl_value): Use this bit with key_mergeable. (trees_in::key_mergeable): Allow merging attached declarations if they're imported temploid friends (which must be namespace scope). (module_state::read_cluster): Check for GM entities that may require merging even when importing from partitions. * name-lookup.cc (enum binding_slots): Adjust comment. (get_fixed_binding_slot): Always create partition slot. (name_lookup::search_namespace_only): Support binding vectors with both partition and GM entities to dedup. (walk_module_binding): Likewise. (name_lookup::adl_namespace_fns): Likewise. (set_module_binding): Likewise. (check_module_override): Use attachment of the decl when checking overrides rather than named_module_p. (lookup_imported_hidden_friend): Use partition slot for finding mergeable template bindings. * name-lookup.h (set_module_binding): Split mod_glob_flag parameter into separate global_p and partition_p params. gcc/testsuite/ChangeLog: * g++.dg/modules/tpl-friend-13_e.C: Adjust error message. * g++.dg/modules/ambig-2_a.C: New test. * g++.dg/modules/ambig-2_b.C: New test. * g++.dg/modules/part-9_a.C: New test. * g++.dg/modules/part-9_b.C: New test. * g++.dg/modules/part-9_c.C: New test. * g++.dg/modules/tpl-friend-15.h: New test. * g++.dg/modules/tpl-friend-15_a.C: New test. * g++.dg/modules/tpl-friend-15_b.C: New test. * g++.dg/modules/tpl-friend-15_c.C: New test. Signed-off-by: Nathaniel Shead <nathanielosh...@gmail.com> Reviewed-by: Jason Merrill <ja...@redhat.com>
