[Bug c++/90691] [9/10 regression] -Wsign-compare false-positive with constant

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90691

--- Comment #7 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Jason Merrill <jason@gcc.gnu.org>:

https://gcc.gnu.org/g:aaa26bf496a646778ac861aed124d960b5bf549f

commit r10-6527-gaaa26bf496a646778ac861aed124d960b5bf549f
Author: Jason Merrill <jason@redhat.com>
Date:   Sun Jan 26 22:58:32 2020 -0500

    c++: Use constexpr to avoid wrong -Wsign-compare (PR90691).

    We would like to do constexpr evaluation to avoid false positives on
    warnings, but constexpr evaluation can involve function body copying that
    changes DECL_UID, which breaks -fcompare-debug.  So let's remember
    that we need to avoid that.

        PR c++/90691
        * expr.c (fold_for_warn): Call maybe_constant_value.
        * constexpr.c (struct constexpr_ctx): Add uid_sensitive field.
        (maybe_constant_value): Add uid_sensitive parm.
        (get_fundef_copy): Don't copy if it's true.
        (cxx_eval_call_expression): Don't instantiate if it's true.
        (cxx_eval_outermost_constant_expr): Likewise.