[Bug c++/60198] New: ICE with _Cilk_spawn in expression within template function

[reichelt at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60198

            Bug ID: 60198
           Summary: ICE with _Cilk_spawn in expression within template
                    function
           Product: gcc
           Version: 4.9.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: reichelt at gcc dot gnu.org

The following valid(?) code snippet (compiled with "-fcilkplus") triggers
an ICE on trunk:

===========================================
template<typename T> int foo()
{
  int i = (_Cilk_spawn foo<T>()) + 0;
  return i;
}

template int foo<int>();
===========================================

bug.cc: In instantiation of 'int foo() [with T = int]':
bug.cc:7:23:   required from here
bug.cc:3:31: internal compiler error: in tsubst_copy, at cp/pt.c:12887
   int i = (_Cilk_spawn foo<T>()) + 0;
                               ^
0x62a933 tsubst_copy
        ../../gcc/gcc/cp/pt.c:12887
0x607956 tsubst_copy_and_build(tree_node*, tree_node*, int, tree_node*, bool,
bool)
        ../../gcc/gcc/cp/pt.c:15110
0x608fda tsubst_copy_and_build(tree_node*, tree_node*, int, tree_node*, bool,
bool)
        ../../gcc/gcc/cp/pt.c:14188
0x6115c6 tsubst_expr
        ../../gcc/gcc/cp/pt.c:13812
0x61435d tsubst_expr
        ../../gcc/gcc/cp/pt.c:13327
0x611093 tsubst_expr
        ../../gcc/gcc/cp/pt.c:13219
0x61208c tsubst_expr
        ../../gcc/gcc/cp/pt.c:13424
0x60f2a9 instantiate_decl(tree_node*, int, bool)
        ../../gcc/gcc/cp/pt.c:19690
0x64d8c7 instantiate_pending_templates(int)
        ../../gcc/gcc/cp/pt.c:19806
0x688bed cp_write_global_declarations()
        ../../gcc/gcc/cp/decl2.c:4148
Please submit a full bug report, [etc.]