[Bug c++/91110] [10 Regression] ICE: tree check: expected class 'type', have 'exceptional' (error_mark) in cp_omp_mappable_type_1, at cp/decl2.c:1421

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91110

--- Comment #2 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Created attachment 46579
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=46579&action=edit
gcc10-pr91110.patch

error_mark_node type doesn't have TYPE_MAIN_DECL, but more importantly,
error_mark_node on a type doesn't mean the type is incomplete, it means the
type is invalid, and some diagnostics should have been emitted already why it
is invalid.  So, IMNSHO we shouldn't emit any clarification messages in that
case.