https://gcc.gnu.org/g:bfe565d996d0c7f7f12891f533153b6be1b815a8
commit r14-12095-gbfe565d996d0c7f7f12891f533153b6be1b815a8 Author: Jason Merrill <[email protected]> Date: Tue Oct 14 23:27:57 2025 +0300 c++: pointer to auto member function [PR120757] Here r13-1210 correctly changed &A<int>::foo to not be considered type-dependent, but tsubst_expr of the OFFSET_REF got confused trying to tsubst a type that involved auto. Fixed by getting the type from the member rather than tsubst. PR c++/120757 gcc/cp/ChangeLog: * pt.cc (tsubst_expr) [OFFSET_REF]: Don't tsubst the type. gcc/testsuite/ChangeLog: * g++.dg/cpp1y/auto-fn66.C: New test. (cherry picked from commit ea6ef13d0fc4e020d8c405333153dad9eee1f18d) Diff: --- gcc/cp/pt.cc | 8 ++++++-- gcc/testsuite/g++.dg/cpp1y/auto-fn66.C | 20 ++++++++++++++++++++ 2 files changed, 26 insertions(+), 2 deletions(-) diff --git a/gcc/cp/pt.cc b/gcc/cp/pt.cc index 6ef4df3025df..4d05177379d1 100644 --- a/gcc/cp/pt.cc +++ b/gcc/cp/pt.cc @@ -21717,12 +21717,16 @@ tsubst_expr (tree t, tree args, tsubst_flags_t complain, tree in_decl) case OFFSET_REF: { - tree type = tsubst (TREE_TYPE (t), args, complain, in_decl); + /* We should only get here for an OFFSET_REF like A::m; a .* in a + template is represented as a DOTSTAR_EXPR. */ + gcc_checking_assert + (same_type_p (TREE_TYPE (t), TREE_TYPE (TREE_OPERAND (t, 1)))); tree op0 = RECUR (TREE_OPERAND (t, 0)); tree op1 = RECUR (TREE_OPERAND (t, 1)); + tree type = TREE_TYPE (op1); r = build2 (OFFSET_REF, type, op0, op1); PTRMEM_OK_P (r) = PTRMEM_OK_P (t); - if (!mark_used (TREE_OPERAND (r, 1), complain) + if (!mark_used (op1, complain) && !(complain & tf_error)) RETURN (error_mark_node); RETURN (r); diff --git a/gcc/testsuite/g++.dg/cpp1y/auto-fn66.C b/gcc/testsuite/g++.dg/cpp1y/auto-fn66.C new file mode 100644 index 000000000000..413154c2a7f8 --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp1y/auto-fn66.C @@ -0,0 +1,20 @@ +// PR c++/120757 +// { dg-do compile { target c++14 } } + +template <typename> struct A +{ + auto foo() {} +}; + +auto bar(void (A<int>::*)()) {} + +template <int> auto baz() +{ + bar(&A<int>::foo); +} + +int main() +{ + baz<0>(); + return 0; +}
