https://gcc.gnu.org/bugzilla/show_bug.cgi?id=120013
--- Comment #10 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:b0de7297f2b5670386472229ab795a577c288ecf commit r16-752-gb0de7297f2b5670386472229ab795a577c288ecf Author: Nathaniel Shead <nathanielosh...@gmail.com> Date: Sat May 17 23:51:07 2025 +1000 c++/modules: Fix ICE on merge of instantiation with partial spec [PR120013] When we import a pending instantiation that matches an existing partial specialisation, we don't find the slot in the entity map because for partial specialisations we register the TEMPLATE_DECL but for normal implicit instantiations we instead register the inner TYPE_DECL. Because the DECL_MODULE_ENTITY_P flag is set we correctly realise that it is in the entity map, but ICE when attempting to use that slot in partition handling. This patch fixes the issue by detecting this case and instead looking for the slot for the TEMPLATE_DECL. It doesn't matter that we never add a slot for the inner decl because we're about to discard it anyway. PR c++/120013 gcc/cp/ChangeLog: * module.cc (trees_in::install_entity): Handle re-registering the inner TYPE_DECL of a partial specialisation. gcc/testsuite/ChangeLog: * g++.dg/modules/partial-8.h: New test. * g++.dg/modules/partial-8_a.C: New test. * g++.dg/modules/partial-8_b.C: New test. * g++.dg/modules/partial-8_c.C: New test. * g++.dg/modules/partial-8_d.C: New test. Signed-off-by: Nathaniel Shead <nathanielosh...@gmail.com> Reviewed-by: Jason Merrill <ja...@redhat.com>
