diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog index cc950e8d74e6..1536c359fe8a 100644 --- a/gcc/cp/ChangeLog +++ b/gcc/cp/ChangeLog @@ -1,3 +1,9 @@ +2018-03-29 Jason Merrill + + PR c++/85093 - too many template args with pack expansion. + * pt.c (coerce_template_parms): Keep pack expansion args that will + need to be empty. + 2018-03-29 Jason Merrill * pt.c (build_non_dependent_expr): Propagate expr location. diff --git a/gcc/cp/pt.c b/gcc/cp/pt.c index 40ddf9ec989b..284eaf3cab66 100644 --- a/gcc/cp/pt.c +++ b/gcc/cp/pt.c @@ -8497,6 +8497,22 @@ coerce_template_parms (tree parms, goto bad_nargs; } + if (arg_idx < nargs) + { + /* We had some pack expansion arguments that will only work if the packs + are empty, but wait until instantiation time to complain. + See variadic-ttp3.C. */ + int len = nparms + (nargs - arg_idx); + tree args = make_tree_vec (len); + int i = 0; + for (; i < nparms; ++i) + TREE_VEC_ELT (args, i) = TREE_VEC_ELT (new_inner_args, i); + for (; i < len; ++i, ++arg_idx) + TREE_VEC_ELT (args, i) = TREE_VEC_ELT (inner_args, + arg_idx - pack_adjust); + new_inner_args = args; + } + if (lost) { gcc_assert (!(complain & tf_error) || seen_error ()); diff --git a/gcc/testsuite/g++.dg/cpp0x/variadic-empty1.C b/gcc/testsuite/g++.dg/cpp0x/variadic-empty1.C new file mode 100644 index 000000000000..42daeaa3dcb1 --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp0x/variadic-empty1.C @@ -0,0 +1,13 @@ +// PR c++/85093 +// { dg-do compile { target c++11 } } + +template class A {}; + +template class B { + typedef A AB; // { dg-error "arguments" } + AB ab; +}; + +int main() { + B b; +}