diff --git a/gcc/cp/semantics.cc b/gcc/cp/semantics.cc index 3299e2704465b498001842f0904285be4b756e6f..57840176863bf9161c637ffdfb0a3d4f13ba7900 100644 --- a/gcc/cp/semantics.cc +++ b/gcc/cp/semantics.cc @@ -4650,20 +4650,19 @@ finish_type_pack_element (tree idx, tree types, tsubst_flags_t complain) error ("%<__type_pack_element%> index is not an integral constant"); return error_mark_node; } - HOST_WIDE_INT val = tree_to_shwi (idx); - if (val < 0) + if (tree_int_cst_sgn (idx) < 0) { if (complain & tf_error) error ("%<__type_pack_element%> index is negative"); return error_mark_node; } - if (val >= TREE_VEC_LENGTH (types)) + if (wi::to_widest (idx) >= TREE_VEC_LENGTH (types)) { if (complain & tf_error) error ("%<__type_pack_element%> index is out of range"); return error_mark_node; } - return TREE_VEC_ELT (types, val); + return TREE_VEC_ELT (types, tree_to_shwi (idx)); } /* Implement the __direct_bases keyword: Return the direct base classes diff --git a/gcc/testsuite/g++.dg/ext/type_pack_element4.C b/gcc/testsuite/g++.dg/ext/type_pack_element4.C new file mode 100644 index 0000000000000000000000000000000000000000..aa508c79090b9fadf41edf5e58e2588316d9e2f5 --- /dev/null +++ b/gcc/testsuite/g++.dg/ext/type_pack_element4.C @@ -0,0 +1,17 @@ +// PR c++/113834 +// { dg-do compile { target c++17 } } + +template <typename... _Elements> class tuple{}; +template <unsigned long __i, typename... _Elements> +__type_pack_element<__i, _Elements...> &get(tuple<_Elements...> &__t) noexcept; // { dg-error "index is out of range" } +tuple<int,int> data; +template <unsigned long Level> +unsigned take_impl(unsigned idx) { + if constexpr (Level != -1){ + return take_impl<Level - 1>(get<Level - 1>(data)); // { dg-error "" } + } + return 0; +} +int main() { + take_impl<2>(0); +}