https://gcc.gnu.org/bugzilla/show_bug.cgi?id=119154
--- Comment #11 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:4cd99e41ef687fd62d6908f4807de277c7dc9803 commit r15-8012-g4cd99e41ef687fd62d6908f4807de277c7dc9803 Author: Nathaniel Shead <nathanielosh...@gmail.com> Date: Mon Mar 10 23:35:40 2025 +1100 c++/modules: Handle gnu_inline attribute, cleanup linkage determination [PR119154] Currently, note_vague_linkage_fn is called on all definitions imported from modules. This is not correct, however; among other things, a gnu_inline function does not have vague linkage, and causes an ICE if its treated as such. There are other things that we seem to potentially miss (e.g. dllexport handling), so it seems sensible to stop trying to manage linkage in such an ad-hoc manner but to use the normal interfaces more often. While looking at this I also found that we seem to miss marking vague linkage variables as COMDAT, so this patch fixes that as well. The change to use expand_or_defer_fn exposes a checking-only ICE in trees_in::assert_definition, where we forget that we already installed a definition for a function. We work around this by instead of clearing DECL_SAVED_TREE entirely in expand_or_defer_fn_1, we instead set it to a dummy value. This way we can also avoid the check for !TREE_ASM_WRITTEN beforehand. PR c++/119154 gcc/cp/ChangeLog: * decl2.cc (vague_linkage_p): Don't treat gnu_inline functions as having vague linkage. * module.cc (trees_out::core_bools): Clear DECL_INTERFACE_KNOWN for vague-linkage entities. (read_var_def): Maybe set comdat linkage for imported var definitions. (module_state::read_cluster): Use expand_or_defer_fn instead of ad-hoc linkage management. (post_load_processing): Likewise. * semantics.cc (expand_or_defer_fn_1): Don't forget that we had a definition at all. gcc/testsuite/ChangeLog: * g++.dg/modules/linkage-3_a.C: New test. * g++.dg/modules/linkage-3_b.C: New test. * g++.dg/modules/pr119154_a.C: New test. * g++.dg/modules/pr119154_b.C: New test. Signed-off-by: Nathaniel Shead <nathanielosh...@gmail.com> Reviewed-by: Jason Merrill <ja...@redhat.com>
