Here, DECL_DEPENDENT_P was false for the second using because Row<eT> is "the current instantiation", so lookup succeeds. But since Row itself has a dependent using-decl for operator(), the set of functions imported by the second using is dependent, so we should set the flag.
Tested x86_64-pc-linux-gnu, applying to trunk. PR c++/105006 gcc/cp/ChangeLog: * name-lookup.cc (lookup_using_decl): Set DECL_DEPENDENT_P if lookup finds a dependent using. gcc/testsuite/ChangeLog: * g++.dg/template/using30.C: New test. --- gcc/cp/name-lookup.cc | 15 +++++++++++++++ gcc/testsuite/g++.dg/template/using30.C | 13 +++++++++++++ 2 files changed, 28 insertions(+) create mode 100644 gcc/testsuite/g++.dg/template/using30.C diff --git a/gcc/cp/name-lookup.cc b/gcc/cp/name-lookup.cc index 323f96bcd24..ea947fabb7e 100644 --- a/gcc/cp/name-lookup.cc +++ b/gcc/cp/name-lookup.cc @@ -5665,6 +5665,21 @@ lookup_using_decl (tree scope, name_lookup &lookup) lookup.value = lookup_member (binfo, lookup.name, /*protect=*/2, /*want_type=*/false, tf_none); + /* If the lookup in the base contains a dependent using, this + using is also dependent. */ + if (!dependent_p && lookup.value) + { + tree val = lookup.value; + if (tree fns = maybe_get_fns (val)) + val = fns; + for (tree f: lkp_range (val)) + if (TREE_CODE (f) == USING_DECL && DECL_DEPENDENT_P (f)) + { + dependent_p = true; + break; + } + } + if (!depscope && b_kind < bk_proper_base) { if (cxx_dialect >= cxx20 && lookup.value diff --git a/gcc/testsuite/g++.dg/template/using30.C b/gcc/testsuite/g++.dg/template/using30.C new file mode 100644 index 00000000000..914252dd14c --- /dev/null +++ b/gcc/testsuite/g++.dg/template/using30.C @@ -0,0 +1,13 @@ +// PR c++/105006 + +template<class eT> +class Row { + using eT::operator(); + void operator()(); + class fixed; +}; + +template<class eT> +class Row<eT>::fixed : Row { + using Row::operator(); +}; base-commit: 4a9e92164a547afcf8cd3fc593c7660238ad2d59 -- 2.27.0