On 12/18/23 16:31, Jason Merrill wrote:
Tested x86_64-pc-linux-gnu. Does this make sense? Did you have another theory about how to merge these?
Why isn't push_abi_namespace doing the right setup here? (and I think get_global_binding might be similarly problematic?)
nathan
-- 8< -- Doing a dynamic_cast in both TUs broke because we were declaring a new __class_type_info in _b that conflicted with the one imported in the global module from _a. lookup_elaborated_type has a comment that we probably don't want to find such imports in general, but in this case it seems necessary to make the artificial lazy declarations of RTTI types work. gcc/cp/ChangeLog: * name-lookup.cc (lookup_elaborated_type): Look for bindings in the global namespace in the ABI namespace. gcc/testsuite/ChangeLog: * g++.dg/modules/pr106304_b.C: Add dynamic_cast. --- gcc/cp/name-lookup.cc | 10 ++++++++++ gcc/testsuite/g++.dg/modules/pr106304_b.C | 1 + 2 files changed, 11 insertions(+) diff --git a/gcc/cp/name-lookup.cc b/gcc/cp/name-lookup.cc index 09dc6ef3e5a..f15b338025d 100644 --- a/gcc/cp/name-lookup.cc +++ b/gcc/cp/name-lookup.cc @@ -8092,6 +8092,16 @@ lookup_elaborated_type (tree name, TAG_how how) // FIXME: This isn't quite right, if we find something // here, from the language PoV we're not supposed to // know it? + // We at least need to do this in __cxxabiv1 to unify lazy + // declarations of __class_type_info in build_dynamic_cast_1. + if (current_namespace == abi_node) + { + tree g = (BINDING_VECTOR_CLUSTER (*slot, 0) + .slots[BINDING_SLOT_GLOBAL]); + for (ovl_iterator iter (g); iter; ++iter) + if (qualify_lookup (*iter, LOOK_want::TYPE)) + return *iter; + } } } } diff --git a/gcc/testsuite/g++.dg/modules/pr106304_b.C b/gcc/testsuite/g++.dg/modules/pr106304_b.C index e8333909c8d..0d1da086176 100644 --- a/gcc/testsuite/g++.dg/modules/pr106304_b.C +++ b/gcc/testsuite/g++.dg/modules/pr106304_b.C @@ -5,4 +5,5 @@ module pr106304;void f(A& a) {as_b(a); + dynamic_cast<B*>(&a); } base-commit: 5347263b347d02e875879ca40ca6e289ac178919 prerequisite-patch-id: 66735c0c7beb22586ed4b632d10ec9094bb9920c
-- Nathan Sidwell
