[Bug c++/92837] ICE on syntax error in requires clause, in cp_parser_constraint_primary_expression

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92837

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2019-12-06
                 CC|                            |asutton at gcc dot gnu.org,
                   |                            |jakub at gcc dot gnu.org
     Ever confirmed|0                           |1

--- Comment #1 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
This is an incorrect assumption in cp_parser_constraint_primary_expression.  It
assumes that when doing a tentative parse that the returned expr will always be
error_mark_node if there are any errors, but that is not the case, e.g. if
there is just missing closing ) it can simulate an error which later causes
cp_parse_definitely to fail, yet expr is still not error_mark_node and pce can
still be pce_ok.