[Bug c++/68630] New: [concepts] internal compiler error: in add_expr, at tree.c:7828

["lucdanton at free dot fr" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68630

            Bug ID: 68630
           Summary: [concepts] internal compiler error: in add_expr, at
                    tree.c:7828
           Product: gcc
           Version: 6.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: lucdanton at free dot fr
  Target Milestone: ---

Created attachment 36877
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=36877&action=edit
Reduced testcase

Using 6.0.0 20151201 (experimental). The testcase was reduced mechanically,
must be compiled with any level of optimization above -O0 e.g.:

$ g++-trunk -std=c++1z -Og prepro.ii

The stack trace produced is noticeably similar to the one for PR 68116, but not
identical either:

prepro.ii:59:22: internal compiler error: in add_expr, at tree.c:7828
              &functor(l, &local::get)(), "", l.i, "");
                      ^

0xcb5d5d inchash::add_expr(tree_node const*, inchash::hash&)
        ../../gcc/gcc/tree.c:7828
0xcb5894 inchash::add_expr(tree_node const*, inchash::hash&)
        ../../gcc/gcc/tree.c:7801
0x8cf1de iterative_hash_expr
        ../../gcc/gcc/tree.h:4737
0x8cf1de gimplify_hasher::hash(gimple_temp_hash_elt const*)
        ../../gcc/gcc/gimplify.c:11535
0x8cf1de hash_table<gimplify_hasher,
xcallocator>::find_slot(gimple_temp_hash_elt* const&, insert_option)
        ../../gcc/gcc/hash-table.h:408
0x8cf1de lookup_tmp_var
        ../../gcc/gcc/gimplify.c:523
0x8cf1de internal_get_tmp_var
        ../../gcc/gcc/gimplify.c:558
0x8cabdc gimplify_expr(tree_node**, gimple**, gimple**, bool (*)(tree_node*),
int)
        ../../gcc/gcc/gimplify.c:10982
0x8d1e1a gimplify_modify_expr
        ../../gcc/gcc/gimplify.c:4687
0x8cb2da gimplify_expr(tree_node**, gimple**, gimple**, bool (*)(tree_node*),
int)
        ../../gcc/gcc/gimplify.c:10057
0x8cb379 gimplify_target_expr
        ../../gcc/gcc/gimplify.c:5525
0x8cb379 gimplify_expr(tree_node**, gimple**, gimple**, bool (*)(tree_node*),
int)
        ../../gcc/gcc/gimplify.c:10426
0x8cb685 gimplify_addr_expr
        ../../gcc/gcc/gimplify.c:5053
0x8cb685 gimplify_expr(tree_node**, gimple**, gimple**, bool (*)(tree_node*),
int)
        ../../gcc/gcc/gimplify.c:10103
0x8d05d8 gimplify_call_expr
        ../../gcc/gcc/gimplify.c:2506
0x8cb86d gimplify_expr(tree_node**, gimple**, gimple**, bool (*)(tree_node*),
int)
        ../../gcc/gcc/gimplify.c:10028
0x8d1e1a gimplify_modify_expr
        ../../gcc/gcc/gimplify.c:4687
0x8cb2da gimplify_expr(tree_node**, gimple**, gimple**, bool (*)(tree_node*),
int)
        ../../gcc/gcc/gimplify.c:10057
0x8cb379 gimplify_target_expr
        ../../gcc/gcc/gimplify.c:5525
0x8cb379 gimplify_expr(tree_node**, gimple**, gimple**, bool (*)(tree_node*),
int)
        ../../gcc/gcc/gimplify.c:10426