[Bug c++/80562] [7/8 Regression] ICE using if constexpr with nonconstant expression in function template

["mpolacek at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80562

Marek Polacek <mpolacek at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2017-05-02
                 CC|                            |mpolacek at gcc dot gnu.org
   Target Milestone|---                         |7.2
            Summary|ICE using if constexpr with |[7/8 Regression] ICE using
                   |nonconstant expression in   |if constexpr with
                   |function template           |nonconstant expression in
                   |                            |function template
     Ever confirmed|0                           |1

--- Comment #1 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
commit df5390a9de5322cbaab3def921d3d517d4494144
Author: jason <jason@138bc75d-0d04-0410-961f-82ee72b054a4>
Date:   Wed Aug 10 21:58:23 2016 +0000

            Implement C++17 constexpr if.

            * cp-tree.h (IF_STMT_CONSTEXPR_P): New.
            * name-lookup.c (push_to_top_level, pop_from_top_level_1): Handle
it.
            * parser.h (struct cp_parser): Add in_discarded_stmt field.
            * parser.c (cp_parser_selection_statement): Handle 'if constexpr'.
            (cp_parser_jump_statement): Avoid deducing from a discarded return.
            * pt.c (tsubst_expr): Only instantiate taken branch of constexpr
if.
            * semantics.c (begin_if_stmt): Set the binding level this_entity.
            (finish_if_stmt_cond): Require the condition of a
            constexpr if to be constant.
            * decl.c (level_for_constexpr_if): New.
            (named_label_entry): Add in_constexpr_if field.
            (poplevel_named_label_1): Set it.
            (check_goto): Check it.
            (check_previous_goto_1): Check level_for_constexpr_if.

    git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@239338
138bc75d-0d04-0410-961f-82ee72b054a4