See http://gcc.gnu.org/ml/gcc-patches/2007-09/msg01600.html
template<int M, int N> struct pair { int i, j; pair() : i(M), j(N) {} }; template<int... M> struct S { template<int... N> static int foo() throw (pair <M, N>...) { return 1; } }; int bar () { return S<0, 1, 2>::foo<0, 1> (); } ICEs in tsubst_exception_specification, tsubst_pack_expansion can return here either TREE_VEC (handled), error_mark_node (not handled and should be) or TYPE_PACK_EXPANSION (also needs handling). Additionally, tsubst_pack_expansion return value needs checking for error_mark_node rather than assuming it returns TREE_VEC in regenerate_decl_from_template and tsubst_initializer_list. -- Summary: [4.3 Regression] tsubst_pack_expansion assumed to return TREE_VEC Product: gcc Version: 4.3.0 Status: UNCONFIRMED Keywords: ice-on-invalid-code Severity: normal Priority: P3 Component: c++ AssignedTo: unassigned at gcc dot gnu dot org ReportedBy: jakub at gcc dot gnu dot org http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33509