[Bug c++/94186] [10 Regression] compiler incorrectly accepts a requires clause with predicate of non-bool type

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94186

--- Comment #5 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:fddfd3ce555965864b6116cf541f6355d2057d3d

commit r10-7361-gfddfd3ce555965864b6116cf541f6355d2057d3d
Author: Jason Merrill <jason@redhat.com>
Date:   Tue Mar 24 18:25:17 2020 -0400

    c++: Improve handling of ill-formed constraints [PR94186].

    It would have been trivial to make the error for non-bool constraint in
    satisfy_atom unconditional, but that didn't give context for the error or
    printing with the dependent form and template arguments.  So I changed a
    couple of places so that, when a hard error is encountered during quiet
    substitution/satisfaction, we go through again noisily; this builds up the
    necessary context.

    The similar change to tsubst_nested_requirement does not build up the
    necessary context; rather than try to fix that now I changed
    get_constraint_error_location to give up and use input_location if there's
    no CONSTR_CONTEXT.  In the case of concepts-pr67697.C, we still have a good
    source location because the NESTED_REQ has a correct EXPR_LOCATION, but
this
    patch doesn't improve context printing for this case as it does for the
    above.

    gcc/cp/ChangeLog
    2020-03-24  Jason Merrill  <jason@redhat.com>

            PR c++/94186
            * constraint.cc (constraint_satisfaction_value): Repeat noisily on
            error.
            (tsubst_nested_requirement): Likewise.
            (get_constraint_error_location): Allow missing context.
            (diagnose_atomic_constraint): Diagnose non-bool constraint here.
            (satisfy_atom): Not here.  Only diagnose non-constant when noisy.