https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115361
--- Comment #3 from GCC Commits <cvs-commit at gcc dot gnu.org> --- The trunk branch has been updated by Jason Merrill <ja...@gcc.gnu.org>: https://gcc.gnu.org/g:8733d5d3873977d6ca82d71b28728650f988e9c8 commit r15-3684-g8733d5d3873977d6ca82d71b28728650f988e9c8 Author: Jason Merrill <ja...@redhat.com> Date: Sun Sep 15 13:50:04 2024 +0200 c++: -Wdangling-reference and empty class [PR115361] We can't have a dangling reference to an empty class unless it's specifically to that class or one of its bases. This was giving a false positive on the _ExtractKey pattern in libstdc++ hashtable.h. This also adjusts the order of arguments to reference_related_p, which is relevant for empty classes (unlike scalars). Several of the classes in the testsuite needed to gain data members to continue to warn. PR c++/115361 gcc/cp/ChangeLog: * call.cc (do_warn_dangling_reference): Check is_empty_class. gcc/testsuite/ChangeLog: * g++.dg/ext/attr-no-dangling6.C * g++.dg/ext/attr-no-dangling7.C * g++.dg/ext/attr-no-dangling8.C * g++.dg/ext/attr-no-dangling9.C * g++.dg/warn/Wdangling-reference1.C * g++.dg/warn/Wdangling-reference2.C * g++.dg/warn/Wdangling-reference3.C: Make classes non-empty. * g++.dg/warn/Wdangling-reference23.C: New test.