[Bug c++/80259] New: [5/6/7 Regression] ICE deleting friend function

[reichelt at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80259

            Bug ID: 80259
           Summary: [5/6/7 Regression] ICE deleting friend function
           Product: gcc
           Version: 7.0
            Status: UNCONFIRMED
          Keywords: ice-on-invalid-code
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: reichelt at gcc dot gnu.org
  Target Milestone: ---

The following invalid code snippet triggers an ICE since GCC 5.1.0:

================================
void foo() {}

struct A
{
  friend void foo() = delete;
};
================================

bug.cc: In function 'void foo()':
bug.cc:1:6: internal compiler error: tree check: expected block, have
error_mark in lower_function_body, at gimple-low.c:98
 void foo() {}
      ^~~
0x100a3ec tree_check_failed(tree_node const*, char const*, int, char const*,
...)
        ../../gcc/gcc/tree.c:9817
0x146eb3a tree_check(tree_node*, char const*, int, char const*, tree_code)
        ../../gcc/gcc/tree.h:3064
0x146eb3a lower_function_body
        ../../gcc/gcc/gimple-low.c:98
0x146eb3a execute
        ../../gcc/gcc/gimple-low.c:181
Please submit a full bug report [etc.]