[Bug c++/95344] [9 Regression] Wparentheses (assignment used as truth value) on parenthesized ternary conditional E2

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95344

--- Comment #6 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The releases/gcc-9 branch has been updated by Marek Polacek
<mpolacek@gcc.gnu.org>:

https://gcc.gnu.org/g:74eb19c2499c1b9011629799e16d74f299f35b33

commit r9-8669-g74eb19c2499c1b9011629799e16d74f299f35b33
Author: Marek Polacek <polacek@redhat.com>
Date:   Thu Jun 11 18:38:00 2020 -0400

    c++: Fix bogus -Wparentheses warning [PR95344]

    Since r267272, which added location wrappers, cp_fold loses
    TREE_NO_WARNING on a MODIFY_EXPR that finish_parenthesized_expr set, and
    that results in a bogus -Wparentheses warning.

    I.e., previously we had "b = 1" but now we have "VIEW_CONVERT_EXPR<bool>(b)
= 1"
    and cp_fold_maybe_rvalue folds away the location wrapper and so we do
    2718             x = fold_build2_loc (loc, code, TREE_TYPE (x), op0, op1);
    in cp_fold and the flag is lost.

            PR c++/95344
            * cp-gimplify.c (cp_fold) <case MODIFY_EXPR>: Don't set
            TREE_THIS_VOLATILE here.
            (cp_fold): Set it here along with TREE_NO_WARNING.

            * c-c++-common/Wparentheses-2.c: New test.