[Bug c++/99033] New: [11 Regression] ICE in tree_to_poly_int64, at tree.c:3091

["gscfq@t-online.de" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99033

            Bug ID: 99033
           Summary: [11 Regression] ICE in tree_to_poly_int64, at
                    tree.c:3091
           Product: gcc
           Version: 11.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: gscfq@t-online.de
  Target Milestone: ---

Behavior of release versions changed between 20200517 and 20200524 :


$ cat z1.cc
struct S {
  char c;
  struct T {} T::*b[];
} a;

void f ()
{
  a.c = 1;
}


$ g++-11-20200517 -c z1.cc -fsanitize=undefined
$
$ g++-11-20210207 -c z1.cc -fsanitize=undefined
during GIMPLE pass: ubsan
z1.cc: In function 'void f()':
z1.cc:9:1: internal compiler error: in tree_to_poly_int64, at tree.c:3091
    9 | }
      | ^
0xf4bbe8 tree_to_poly_int64(tree_node const*)
        ../../gcc/tree.c:3091
0xf68db4 component_ref_size(tree_node*, special_array_member*)
        ../../gcc/tree.c:13909
0xd6eb12 decl_init_size(tree_node*, bool)
        ../../gcc/tree-object-size.c:196
0xd6f062 addr_object_size
        ../../gcc/tree-object-size.c:285
0xd70583 compute_builtin_object_size(tree_node*, int, unsigned long*,
tree_node**, tree_node**)
        ../../gcc/tree-object-size.c:570
0xcf945a instrument_object_size
        ../../gcc/ubsan.c:2150
0xcfe535 execute
        ../../gcc/ubsan.c:2405