From 9736a42e1fb8df30d72cf28594d9046bf50200c1 Mon Sep 17 00:00:00 2001 From: Patrick Palka Date: Tue, 11 Oct 2022 15:02:23 -0400 Subject: c++ modules: ICE with templated friend and std namespace [PR100134] The function depset::hash::add_binding_entity has an assert verifying that if a namespace contains an exported entity, then the namespace must have been opened in the module purview: if (data->hash->add_namespace_entities (decl, data->partitions)) { /* It contains an exported thing, so it is exported. */ gcc_checking_assert (DECL_MODULE_PURVIEW_P (decl)); DECL_MODULE_EXPORT_P (decl) = true; } We're tripping over this assert in the below testcase because by instantiating and exporting std::A, we in turn define and export the hidden friend std::f(A) without ever having opened the enclosing namespace std within the module purview, and thus DECL_MODULE_PURVIEW_P for std is false. It's important that the enclosing namespace is std here: if we use a different namespace then the ICE disappears. This probably has something to do with us predefining std via push_namespace from cxx_init_decl_processing (which makes it look like we've opened it within the TU), whereas with another namespace we would instead lazily create its NAMESPACE_DECL from add_imported_namespace. Since templated friend functions are special in that they give us a way to introduce a namespace-scope function without having to explicitly open the namespace, this patch proposes to fix this ICE by propagating DECL_MODULE_PURVIEW_P from the introduced function to the enclosing namespace during tsubst_friend_function. PR c++/100134 gcc/cp/ChangeLog: * pt.cc (tsubst_friend_function): Propagate DECL_MODULE_PURVIEW_P from the introduced namespace-scope function to the namespace. gcc/testsuite/ChangeLog: * g++.dg/modules/tpl-friend-8_a.H: New test. * g++.dg/modules/tpl-friend-8_b.C: New test. --- gcc/cp/pt.cc | 8 ++++++++ gcc/testsuite/g++.dg/modules/tpl-friend-8_a.H | 9 +++++++++ gcc/testsuite/g++.dg/modules/tpl-friend-8_b.C | 8 ++++++++ 3 files changed, 25 insertions(+) create mode 100644 gcc/testsuite/g++.dg/modules/tpl-friend-8_a.H create mode 100644 gcc/testsuite/g++.dg/modules/tpl-friend-8_b.C diff --git a/gcc/cp/pt.cc b/gcc/cp/pt.cc index 5b9fc58..b80e7ff 100644 --- a/gcc/cp/pt.cc +++ b/gcc/cp/pt.cc @@ -11448,6 +11448,14 @@ tsubst_friend_function (tree decl, tree args) by duplicate_decls. */ new_friend = old_decl; } + + /* We've just introduced a namespace-scope function in the purview + without necessarily having opened the enclosing namespace, so + make sure the namespace is in the purview now too. */ + if (modules_p () + && DECL_MODULE_PURVIEW_P (STRIP_TEMPLATE (new_friend)) + && TREE_CODE (DECL_CONTEXT (new_friend)) == NAMESPACE_DECL) + DECL_MODULE_PURVIEW_P (DECL_CONTEXT (new_friend)) = true; } else { diff --git a/gcc/testsuite/g++.dg/modules/tpl-friend-8_a.H b/gcc/testsuite/g++.dg/modules/tpl-friend-8_a.H new file mode 100644 index 0000000..bd22904 --- /dev/null +++ b/gcc/testsuite/g++.dg/modules/tpl-friend-8_a.H @@ -0,0 +1,9 @@ +// PR c++/100134 +// { dg-additional-options -fmodule-header } +// { dg-module-cmi {} } + +namespace std { + template struct A { + friend void f(A) { } + }; +} diff --git a/gcc/testsuite/g++.dg/modules/tpl-friend-8_b.C b/gcc/testsuite/g++.dg/modules/tpl-friend-8_b.C new file mode 100644 index 0000000..76d7447 --- /dev/null +++ b/gcc/testsuite/g++.dg/modules/tpl-friend-8_b.C @@ -0,0 +1,8 @@ +// PR c++/100134 +// { dg-additional-options -fmodules-ts } +// { dg-module-cmi pr100134 } +export module pr100134; + +import "tpl-friend-8_a.H"; + +export std::A a; -- cgit v1.1