https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96242
--- Comment #3 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Patrick Palka <ppa...@gcc.gnu.org>: https://gcc.gnu.org/g:8eb329e963593342855b6072e5692659107337b7 commit r12-7076-g8eb329e963593342855b6072e5692659107337b7 Author: Patrick Palka <ppa...@redhat.com> Date: Sun Feb 6 10:47:48 2022 -0500 c++: dependent noexcept-spec on defaulted comparison op [PR96242] Here we're failing to instantiate the defaulted comparison op's explicit dependent noexcept-spec. The problem is ultimately that mark_used relies on maybe_instantiate_noexcept to synthesize a defaulted comparison op, but the relevant DECL_MAYBE_DELETED fn handling in m_i_n is intended for such functions whose noexcept-spec wasn't explicitly provided (and is therefore determined via synthesis), so m_i_n just exits early afterwards, without considering that the synthesized fn may have an explicit noexcept-spec that needs instantiating. This patch fixes this issue by making mark_used directly synthesize a DECL_MAYBE_DELETED fn before calling maybe_instantiate_noexcept. And in turn, we can properly restrict the DECL_MAYBE_DELETED fn synthesis in m_i_n to only those without an explicit noexcept-spec. PR c++/96242 gcc/cp/ChangeLog: * decl2.cc (mark_used): Directly synthesize a DECL_MAYBE_DELETED fn by calling maybe_synthesize_method instead of relying on maybe_instantiate_noexcept. Move call to m_i_n after the DECL_DELETED_FN handling. * pt.cc (maybe_instantiate_noexcept): Restrict DECL_MAYBE_DELETED fn synthesis to only those with an implicit noexcept-spec, and return !DECL_DELETED_FN instead of !DECL_MAYBE_DELETED afterwards. gcc/testsuite/ChangeLog: * g++.dg/cpp2a/spaceship-synth15.C: New test.
