[Bug c++/98103] [10 Regression] ICE tree check: expected tree that contains 'decl minimal' structure, have 'integer_cst' in cxx_eval_dynamic_cast_fn, at cp/constexpr.c:2003

[cvs-commit at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98103

--- Comment #5 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The releases/gcc-10 branch has been updated by Marek Polacek
<mpola...@gcc.gnu.org>:

https://gcc.gnu.org/g:a38b0c6d62d90a5a30cbd00d32e7b58ee1a21b78

commit r10-9205-ga38b0c6d62d90a5a30cbd00d32e7b58ee1a21b78
Author: Marek Polacek <pola...@redhat.com>
Date:   Wed Dec 2 14:33:13 2020 -0500

    c++: ICE with -fsanitize=vptr and constexpr dynamic_cast [PR98103]

    -fsanitize=vptr initializes all vtable pointers to null so that it can
    catch invalid calls; see cp_ubsan_maybe_initialize_vtbl_ptrs.  That
    means that evaluating a vtable reference can produce a null pointer
    in this mode, so cxx_eval_dynamic_cast_fn should check that and give
    and error.

    gcc/cp/ChangeLog:

            PR c++/98103
            * constexpr.c (cxx_eval_dynamic_cast_fn): If the evaluating of
vtable
            yields a null pointer, give an error and return.  Use objtype.

    gcc/testsuite/ChangeLog:

            PR c++/98103
            * g++.dg/ubsan/vptr-18.C: New test.

    (cherry picked from commit 0221c656bbe5b4ab54e784df3b109c60cb27e5b6)