[Bug c++/63194] New: [4.9/5 Regression] ICE in maybe_explain_implicit_delete, at cp/method.c:1552

["trippels at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63194

            Bug ID: 63194
           Summary: [4.9/5 Regression] ICE in
                    maybe_explain_implicit_delete, at cp/method.c:1552
           Product: gcc
           Version: 5.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: trippels at gcc dot gnu.org
                CC: jason at gcc dot gnu.org

Reduced from a huge boost testcase:

markus@x4 tmp % cat horzcollisionbar.ii
template <int>
class A {
 public:
  A() noexcept(noexcept(0)) = default;
};
class B {
  A<0> m_points;
};
void fn1(A<0>, A<0>) { B(); }

markus@x4 tmp % g++ -c -std=c++11 horzcollisionbar.ii
horzcollisionbar.ii: In function âvoid fn1(A<0>, A<0>)â:
horzcollisionbar.ii:9:26: error: use of deleted function âB::B()â
 void fn1(A<0>, A<0>) { B(); }
                          ^
horzcollisionbar.ii:6:7: note: âB::B()â is implicitly deleted because the
default definition would be ill-formed:
 class B {
       ^
horzcollisionbar.ii:6:7: error: use of deleted function âA<<anonymous> >::A()
[with int <anonymous> = 0]â
horzcollisionbar.ii:4:3: internal compiler error: in
maybe_explain_implicit_delete, at cp/method.c:1552
   A() noexcept(noexcept(0)) = default;
   ^
0x6ea0d8 maybe_explain_implicit_delete(tree_node*)
        ../../gcc/gcc/cp/method.c:1552
0x653df0 mark_used(tree_node*, int)
        ../../gcc/gcc/cp/decl2.c:4877
0x57233e build_over_call
        ../../gcc/gcc/cp/call.c:7019
0x57df65 build_new_method_call_1
        ../../gcc/gcc/cp/call.c:8098
0x57df65 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:8168
0x6e00ef locate_fn_flags
        ../../gcc/gcc/cp/method.c:906
0x6e2eca walk_field_subobs
        ../../gcc/gcc/cp/method.c:1193
0x6e3a34 synthesized_method_walk
        ../../gcc/gcc/cp/method.c:1435
0x6e9f7f maybe_explain_implicit_delete(tree_node*)
        ../../gcc/gcc/cp/method.c:1541
0x653df0 mark_used(tree_node*, int)
        ../../gcc/gcc/cp/decl2.c:4877
0x572cc2 build_over_call
        ../../gcc/gcc/cp/call.c:7381
0x57df65 build_new_method_call_1
        ../../gcc/gcc/cp/call.c:8098
0x57df65 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:8168
0x57eed9 build_special_member_call(tree_node*, tree_node*, vec<tree_node*,
va_gc, vl_embed>**, tree_node*, int, int)
        ../../gcc/gcc/cp/call.c:7712
0x6d83ab build_value_init(tree_node*, int)
        ../../gcc/gcc/cp/init.c:350
0x620e74 build_functional_cast(tree_node*, tree_node*, int)
        ../../gcc/gcc/cp/typeck2.c:1928
0x687643 cp_parser_functional_cast
        ../../gcc/gcc/cp/parser.c:23581
0x68118b cp_parser_postfix_expression
        ../../gcc/gcc/cp/parser.c:5936
0x683e73 cp_parser_unary_expression
        ../../gcc/gcc/cp/parser.c:7287
0x684c38 cp_parser_binary_expression
        ../../gcc/gcc/cp/parser.c:8030
Please submit a full bug report,
with preprocessed source if appropriate.
Please include the complete backtrace with any bug report.

Started with r203989.