https://gcc.gnu.org/bugzilla/show_bug.cgi?id=120499
--- Comment #3 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:5b85364a6dd0bbfd3e26d3346b075a0819be7cd4 commit r16-3353-g5b85364a6dd0bbfd3e26d3346b075a0819be7cd4 Author: Nathaniel Shead <nathanielosh...@gmail.com> Date: Fri Aug 22 15:15:01 2025 +1000 c++/modules: Provide definitions of synthesized methods outside their defining module [PR120499] In the PR, we're getting a linker error from _Vector_impl's destructor never getting emitted. This is because of a combination of factors: 1. in imp-member-4_a, the destructor is not used and so there is no definition generated. 2. in imp-member-4_b, the destructor gets synthesized (as part of the synthesis for Coll's destructor) but is not ODR-used and so does not get emitted. Despite there being a definition provided in this TU, the destructor is still considered imported and so isn't streamed into the module body. 3. in imp-member-4_c, we need to ODR-use the destructor but we only got a forward declaration from imp-member-4_b, so we cannot emit a body. The point of failure here is step 2; this function has effectively been declared in the imp-member-4_b module, and so we shouldn't treat it as imported. This way we'll properly stream the body so that importers can emit it. PR c++/120499 gcc/cp/ChangeLog: * method.cc (synthesize_method): Set the instantiating module. gcc/testsuite/ChangeLog: * g++.dg/modules/imp-member-4_a.C: New test. * g++.dg/modules/imp-member-4_b.C: New test. * g++.dg/modules/imp-member-4_c.C: New test. Signed-off-by: Nathaniel Shead <nathanielosh...@gmail.com>
