On 6/2/23 10:29, Patrick Palka wrote:
Bootstrapped and regtested on x86_64-pc-linux-gnu, does this look OK for trunk?
OK.
-- >8 -- The check for a non-template member function of a class template in is_specialization_of_friend is overbroad, and accidentally holds for a non-template hidden friend too, which causes the predicate to return true for decl = void non_templ_friend(A<int>, A<void>) friend_decl = void non_templ_friend(A<void>, A<void>) This patch refines the check appropriately. PR c++/109923 gcc/cp/ChangeLog: * pt.cc (is_specialization_of_friend): Fix overbroad check for a non-template member function of a class template. gcc/testsuite/ChangeLog: * g++.dg/template/friend79.C: New test. --- gcc/cp/pt.cc | 1 + gcc/testsuite/g++.dg/template/friend79.C | 20 ++++++++++++++++++++ 2 files changed, 21 insertions(+) create mode 100644 gcc/testsuite/g++.dg/template/friend79.C diff --git a/gcc/cp/pt.cc b/gcc/cp/pt.cc index 7c2a5647665..a15d1d062c6 100644 --- a/gcc/cp/pt.cc +++ b/gcc/cp/pt.cc @@ -1319,6 +1319,7 @@ is_specialization_of_friend (tree decl, tree friend_decl) of a template class, we want to check if DECL is a specialization if this. */ if (TREE_CODE (friend_decl) == FUNCTION_DECL + && DECL_CLASS_SCOPE_P (friend_decl) && DECL_TEMPLATE_INFO (friend_decl) && !DECL_USE_TEMPLATE (friend_decl)) { diff --git a/gcc/testsuite/g++.dg/template/friend79.C b/gcc/testsuite/g++.dg/template/friend79.C new file mode 100644 index 00000000000..cd2030df019 --- /dev/null +++ b/gcc/testsuite/g++.dg/template/friend79.C @@ -0,0 +1,20 @@ +// PR c++/109923 + +template<class T> +struct A { +private: + int x; + +public: + A() : x(0) { } + + friend void non_templ_friend(A val, A<void> weird) { + val.x++; // always works + weird.x++; // { dg-error "private" } should only work when T=void + } +}; + +int main() { + non_templ_friend(A<void>(), A<void>()); // { dg-bogus "" } + non_templ_friend(A<int>(), A<void>()); // { dg-message "required from here" } +}