[Bug c++/94510] [9/10 Regression] nullptr_t implicitly cast to zero twice in std::array

["cvs-commit at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94510

--- Comment #11 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:587970215f4681def390e2a791aa3ba6adb65158

commit r10-7864-g587970215f4681def390e2a791aa3ba6adb65158
Author: Martin Sebor <msebor@gmail.com>
Date:   Wed Apr 22 02:27:54 2020 -0400

    c++: reject scalar array initialization with nullptr [PR94510]

    The change committed to GCC 9 to allow string literals as template
arguments
    caused the compiler to prune away, and thus miss diagnosing, conversion
from
    nullptr to int in an array initializer.  After looking at various
approaches
    to improving the pruning, we realized that the only place the pruning is
    necessary is in the mangler.

    gcc/cp/ChangeLog
    2020-04-22  Martin Sebor  <msebor@redhat.com>
                Jason Merrill  <jason@redhat.com>

            PR c++/94510
            * decl.c (reshape_init_array_1): Avoid stripping redundant trailing
            zero initializers...
            * mangle.c (write_expression): ...and handle them here even for
            pointers to members by calling zero_init_expr_p.
            * cp-tree.h (zero_init_expr_p): Declare.
            * tree.c (zero_init_expr_p): Define.
            (type_initializer_zero_p): Remove.
            * pt.c (tparm_obj_values): New hash_map.
            (get_template_parm_object): Store to it.
            (tparm_object_argument): New.

    gcc/testsuite/ChangeLog
    2020-04-22  Martin Sebor  <msebor@redhat.com>

            PR c++/94510
            * g++.dg/init/array58.C: New test.
            * g++.dg/init/array59.C: New test.
            * g++.dg/cpp2a/nontype-class34.C: New test.
            * g++.dg/cpp2a/nontype-class35.C: New test.