[Bug c++/58701] New: [4.9 Regression] [c++11] ICE initializing member of static union

[reichelt at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58701

            Bug ID: 58701
           Summary: [4.9 Regression] [c++11] ICE initializing member of
                    static union
           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 "-std=c++11") triggers an ICE
on trunk (since at least 4.9.0 20130920):

===============
static union
{
  union
  {
    int i = 0;
  };
};
===============

bug.cc: In constructor 'constexpr<anonymous union>::<constructor>()':
bug.cc:2:1: internal compiler error: tree check: accessed operand 2 of
indirect_ref with 1 operands in build_anon_member_initialization, at
cp/semantics.c:7404
 {
 ^
0xd201a7 tree_operand_check_failed(int, tree_node const*, char const*, int,
char const*)
        ../../gcc/gcc/tree.c:9499
0x6d2677 tree_operand_check
        ../../gcc/gcc/tree.h:3109
0x6d2677 build_anon_member_initialization
        ../../gcc/gcc/cp/semantics.c:7404
0x6d2677 build_data_member_initialization
        ../../gcc/gcc/cp/semantics.c:7533
0x6d338d build_constexpr_constructor_member_initializers
        ../../gcc/gcc/cp/semantics.c:7652
0x6d338d massage_constexpr_body
        ../../gcc/gcc/cp/semantics.c:7752
0x6da9a3 register_constexpr_fundef(tree_node*, tree_node*)
        ../../gcc/gcc/cp/semantics.c:7856
0x56ea38 maybe_save_function_definition
        ../../gcc/gcc/cp/decl.c:13823
0x56ea38 finish_function(int)
        ../../gcc/gcc/cp/decl.c:13944
0x6acc19 synthesize_method(tree_node*)
        ../../gcc/gcc/cp/method.c:809
0x61e379 mark_used(tree_node*, int)
        ../../gcc/gcc/cp/decl2.c:4778
0x54d0b6 build_over_call
        ../../gcc/gcc/cp/call.c:7116
0x548eae build_new_method_call_1
        ../../gcc/gcc/cp/call.c:7813
0x548eae build_new_method_call(tree_node*, tree_node*, vec<tree_node*, va_gc,
vl_embed>**, tree_node*, int, tree_node**, int)
        ../../gcc/gcc/cp/call.c:7883
0x549e22 build_special_member_call(tree_node*, tree_node*, vec<tree_node*,
va_gc, vl_embed>**, tree_node*, int, int)
        ../../gcc/gcc/cp/call.c:7440
0x69eba7 expand_default_init
        ../../gcc/gcc/cp/init.c:1668
0x69eba7 expand_aggr_init_1
        ../../gcc/gcc/cp/init.c:1769
0x6a1779 build_aggr_init(tree_node*, tree_node*, int, int)
        ../../gcc/gcc/cp/init.c:1520
0x55e005 build_aggr_init_full_exprs
        ../../gcc/gcc/cp/decl.c:5552
0x55e005 check_initializer
        ../../gcc/gcc/cp/decl.c:5687
Please submit a full bug report, [etc.]